Zbornik Prispevkov

Zaključna konferenca Life ReSoil – Demonstracija inovativne tehnologije pranja s toksičnimi kovinami močno onesnaženih vrtnih tal, 4. – 5. Oktober, Envit d.o.o., Ljubljana, Slovenija Closure conference of the project Life ReSoil-Demonstration of innovative soil washing technology for removal of toxic metals from highly contaminated garden soil, 4th – 5th October,Envit d.o.o., Ljubljana, Slovenia

Zaključna konferenca projekta LIFE ReSoil - Demonstracija inovativne tehnologije pranja s toksičnimi kovinami močno onesnaženih vrtnih tal Zbornik konference 4. – 5. oktober 2018 Envit d.o.o., Tržaška 330, Ljubljana, Slovenija

Closure conference of the project LIFE ReSoil - Demonstration of innovative soil washing technology for removal of toxic metals from highly contaminated garden soil Proceedings of the Conference 4th – 5th October 2018 Envit d.o.o., Tržaška 330, Ljubljana, Slovenia

Urednica / Editor: Neža Finžgar

Prispevki so recenzirani. Za jezikovno pravilnost odgovarjajo avtorji. Contributions have been reviewed. Proper use of language is the author`s responsibility.

Programski in recenzijski odbor / Programme and review Committee: dr. Neža Finžgar, prof. dr. Domen Leštan, dr. Maja Zupančič Justin, dr. Luka Teslić

Organizacijski odbor / The organizing Committee: Tinkara Rozina, dr. Neža Finžgar, Mateja Gorjup, dr. Maja Zupančič Justin

Založnik / Publisher: Envit d.o.o., Ljubljana 2018 Naslov urednika: Tržaška cesta 330 www.envit.si, [email protected]

Publikacija ni namenjena prodaji This publication is not intended for sale

Publikacija je dostopna na / Publication is available at: http://liferesoil.envit.si/?page_id=63605&lang=sl

Kataložni zapis o publikaciji (CIP) pripravili v Narodni in univerzitetni knjižnici v Ljubljani

COBISS.SI-ID=297172480

ISBN 978-961-288-861-9 (pdf)

Zaključna konference projekta LIFE ReSoil - Demonstracija inovativne tehnologije pranja s toksičnimi kovinami močno onesnaženih vrtnih tal Zbornik konference 4. – 5. oktober 2018 ENVIT d.o.o., Tržaška 330, Ljubljana, Slovenija

Organizatorji - Organizators

Finančna podpora – Financial support

Program konference – Conference Programme

Četrtek, 4. oktober 2018 / Thursday, 4. October 2018 G konferenčni center, velika dvorana, 1. nadstropje, Ljubljana G conference centre, Big hall, 1. Floor, Ljubljana

08 : 00 – 08 : 30 Registracija/registration 08 : 30 – 08 : 50 Dr. Neža Finžgar Pozdrav in uvod v konferenco. Predstavitev projekta LIFE ReSoil / Welcome, presentation of the project LIFE ReSoil Sekcija 1 : Tla in posledice onesnaženja s težkimi kovinami / Soil and the consequences of heavy metal contamination Vodja sekcije / Chairman: dr. Maja Zupančič Justin 08 : 50 – 9 : 20 Izr. prof. dr. Borut Uvodno predavanje/introductory lecture Vrščaj Onesnaženost tal - zavedanja in tveganja, poti in stranpoti (vabljeno predavanje/invited lecture) Soil contamination - awareness and threats, ways and strays Vrščaj B. Kmetijski inštitut Slovenije 9 : 20 – 9 : 35 doc. dr. Marko Zupan Onesnaženost tal v Sloveniji in prenos kovin v vrtnine (vabljeno predavanje/invited lecture) Soil contamination in Slovenia and transfer of metals to vegetables Zupan M. Univerza v Ljubljani, Biotehniška fakulteta, Slovenija 9 : 35 – 9 : 50 PhD Contin Marco Mercury contamination of soils form the Soča/Isonzo river basin (vabljeno predavanje/invited lecture) Kontaminacija tal z živim srebrom iz porečja Soče Contin M., Pellegrini E., De Nobili M. University of Udine, Department of Agricultural and Environmental Sciences 9 : 50 – 10 : 05 PhD Elisa Pellegrini Modelling Acid Volatile Sulfides (AVS) and Simultaneously Extractable Metals (SEM) in anoxic soils with a cutting-edge approach (vabljeno predavanje/invited lecture) Pellegrini E., Valdevit F., Balducci P., Contin M. and De Nobili M University of Udine, Department of Agricultural Food, Environmental and Animal Science 10 : 05 – 10 : 20 Dr. Stanislava Kirinčič Varnost lokalno pridelanih rastlinskih živil iz Zgornje Mežiške doline. (vabljeno predavanje/invited lecture) The safety of locally grown plant food from the Upper Meža valley Kirinčič S. Nacionalni inštitut za javno zdravje

10 : 20 – 10 : 40 Odmor za kavo, ogled posterjev

Sekcija 2 : Metode določevanje težkih kovin, tehnologije remediacije tal/ Methods for heavy metals determination and soil remediation technologies. Vodja sekcije / Chairman: dr. Neža Finžgar 10 : 40 – 11 : 00 prof. dr. Katarina Vogel Določanja vsebnosti in speciacije (vezavnih oblik) Mikuš kovin v tleh in rastlinah z metodami rentgenske fluorescenčne in absorpcijske spektrometrije (vabljeno predavanje/invited lecture) Metal concentration and speciation (ligand environment) in soil and plants by X-ray fluorescence and absorption spectrometry Vogel Mikuš K. Univerza v Ljubljani, Biotehniška fakulteta in Inštitut Jožef Stefan 11 : 00 – 11 : 15 mag. Bernarda Težave pri uvajanju sanacijskih tehnologij Podlipnik (vabljeno predavanje/invited lecture) Problems with the introduction of remediation technologies Podlipnik B. Ministrstvo za okolje in prostor 11 : 15 – 11 : 30 prof. dr. Helena Sanacije onesnaženih tal na otroških igriščih Grčman vrtcev (vabljeno predavanje/invited lecture) Remediation of contaminated soil in kindergarten playgrounds Grčman H. Univerza v Ljubljani, Biotehniška fakulteta, Slovenija 11 : 30 – 12 : 50 Razprava, kosilo, ogled in predstavitev posterjev Sekcija 3 : Čiščenje kontaminiranih tal z EDTA in lastnosti tal po remediaciji/ EDTA soil washing technology and soil properties after remediation Vodja sekcije / Chairman: prof. dr. Domen Leštan

12 : 50 – 13 : 05 prof. dr. Domen Leštan Predstavitev postopka čiščenja tal z EDTA (vabljeno predavanje/invited lecture) Presentation of the EDTA soil washing technology Leštan D. Univerza v Ljubljani, Biotehniška fakulteta 13 : 05 – 13 : 20 Erika Jež Ovrednotenje izvedljivosti remediacije s kelatnimi ligandi in ocena tveganj remediiranih tal (vabljeno predavanje/invited lecture) Fisibility evaluation of remediation with chelants and risk assessment of remediated soil Jež E. Univerza v Ljubljani, Biotehniška fakulteta 13 : 20 – 13 : 35 PhD Christoph Noller The influence of EDTA-soil washing and post treatment on the bioavailability of trace metals and plant growth (vabljeno predavanje/invited lecture) Vpliv remediacije z EDTA in nadaljnimi tretiranji na biodostopnost kovin v sledovih in rast rastlin

Noller S. C., Friesl-Hanl W., Hood-Nowotny R., Leštan D., Puschenreiter M., Watzinger A. University of Natural Resources and Life Sciences, Vienna

13 : 35 – 13 : 50 doc. dr. Vesna Zupanc Vpliv remediacije z EDTA na fizikalne lastnosti tal (vabljeno predavanje/invited lecture) Influence of EDTA washing on soil physical characteristics Zupanc V. Univerza v Ljubljani, Biotehniška fakulteta 13 : 50 – 14 : 00 Kratka pavza 14 : 00 – 14 : 15 dr. Anela Kaurin Biološke lastnosti in revitalizacija tal po remediaciji z EDTA (vabljeno predavanje/invited lecture) Biological properties and revitalization after EDTA remediation of metal contaminated soil. Kaurin A. Univerza v Ljubljani, Biotehniška fakulteta 14 : 15 – 14 : 30 doc. dr. Irena Maček Arbuskularna mikoriza v remediiranih tleh (vabljeno predavanje/invited lecture) Arbuscular mycorrhiza in remediated soil Maček I. Univerza v Ljubljani, Biotehniška fakulteta 14 : 30 – 14 : 45 prof. dr. Helena Prosen Razvoj analizne metode za spremljanje razkroja pesticidov v remediiranih tleh (vabljeno predavanje/invited lecture) Development of an analytical method for monitoring of pesticide degradation in remediated soil Prosen H. Univerza v Ljubljani, Fakulteta za kemijo in kemijsko tehnologijo

14 : 45 – 15 : 00 Simon Gluhar Odprava škodljivih emisij iz remediranih tal z dodajanjem nič valentnega Fe (vabljeno predavanje/invited lecture) Elimination of harmful emissions from remediated soil by adding zero valent Fe Gluhar S. Univerza v Ljubljani, Biotehniška fakulteta

Plakati/ posters Možnost adsorpcije kovin iz vod z uporabo biomase glive Ganoderma lucidum The possibility of metal adsorption from water medium on biomass of fungus Ganoderma lucidum U. Rozman, A. Žgajnar Gotvajn, G. Marolt, A. Gregori, G. Kalčikova Univerza v Ljubljani, Fakulteta za kemijo in kemijsko tehnologijo of Ljubljana

Changes of soil organic matter caused by EDTA soil washing treatment on PTM contaminated soil E. Jež1, D. Leštan2, M. De Nobili3,4, M. Contin3

1- Univerza v Ljubljani, Biotehnična fakulteta, Center za pedologijo in varstvo okolja 2-Univerity of Udine,Department of Agricultural and Environmental Sciences 3-University of Trieste, Department of Life Science

Petek, 5. oktober 2018 / Friday, 5th of October 2018

11:00-13:00 Otvoritev demonstracije inovativne tehnologije pranja s toksičnimi kovinami močno onesnaženih vrtnih tal in ogled demonstracijskega vrta

Opening of the demonstration plant for innovative soil washing technology for removal of toxic metals from highly contaminated garden soil Prevalje, Demonstration plant and visit the demonstration garden.

Uvodnik ...... 8

Editorial ...... 10

Soil pollution – awareness and threats, ways and strays / Onesnaženje tal - zavedanja in tveganja, poti in stranpoti Borut Vrščaj ...... 12

Onesnaženost tal v Sloveniji in prenos kovin v rastline/ Soil pollution in Slovenia and uptake of heavy metals into the plants Marko Zupan, Helena Grčman ...... 15

Kontaminacija tal z živim srebrom iz porečja Soče / Mercury contamination of soils form the Soča/Isonzo river basin Marco Contin1, Elisa Pellegrini1, Maria De Nobili1 ...... 18

Modelling Acid Volatile Sulfides (AVS) and Simultaneously Extractable Metals (SEM) in anoxic soils with a cutting-edge approach Elisa Pellegrini1, Filippo Valdevit1, Pietro Balducci1, Marco Contin1, Maria De Nobili1 ...... 19

Varnost lokalno pridelanih rastlinskih živil iz Zgornje Mežiške doline / The safety of locally grown plant food from the Upper Meža valley Stanislava Kirinčič, Matej Ivartnik, Helena Grčman, Marko Zupan, Agnes Šömen Joksić ...... 24

Določanja vsebnosti in speciacije kovin v tleh in rastlinah z metodami rentgenske fluorescenčne in absorpcijske spektrometrije / Metal concentration and speciation in soil and plants by X-ray fluorescence and absorption spectrometry Katarina Vogel-Mikuš, Iztok Arčon, Peter Kump, Alojz Kodre ...... 27

Remediacija na degradiranih industrijskih območij s hladno reciklažo / Remediation on degraded industrial site with cold recycling Nadja Romih, Uroš Apotekar, Roman Kugler, Cvetka Ribarič Lasnik...... 30

Sanacije onesnaženih tal na otroških igriščih vrtcev / Remediation of contaminated soil in kindergarten playgrounds Helena Grčman, Marko Zupan ...... 34

Predstavitev postopka čiščenja tal z EDTA / Presentation of the EDTA soil washing technology Domen Leštan...... 37

Ovrednotenje izvedljivosti remediacije s kelatnimi ligandi in ocena tveganj remediiranih tal / Fisibility evaluation of remediation with chelants and risk assesment of remediated soil Erika Jež, Domen Leštan ...... 39

The influence of EDTA-soil washing and post treatment on the bioavailability of trace metals and plant growth / Vpliv remediacije z EDTA in nadaljnimi tretiranji na biodostopnost kovin v sledovih in na rast rastlin Christoph S. Noller, Wolfgang Friesl-Hanl, Rebecca Hood-Nowotny, Domen Lestan, Markus Puschenreiter, Andrea Watzinger ...... 42

Vpliv remediacije z EDTA na fizikalne lastnosti tal / Influence of EDTA washing on soil physical properties Vesna Zupanc ...... 45

Biološke lastnosti in revitalizacija tal po remediaciji z EDTA / Biological properties and revitalization after EDTA remediation of metal contaminated soil Anela Kaurin, Domen Leštan ...... 48

Arbuskularna mikoriza v remediiranih tleh / Arbuscular Mycorrhiza in Remediated Soil Irena Maček, Nataša Šibanc, Sara Pintarič, Bojka Kump, Domen Leštan, Marjetka Suhadolc ...... 51

Razvoj analizne metode za spremljanje razkroja pesticidov v remediiranih tleh / Development of an analytical method for monitoring of pesticide degradation in remediated soil Tina Grubar, Domen Leštan, Simon Gluhar, Helena Prosen ...... 54

Možnost adsorpcije kovin iz vod z uporabo glive Ganoderma lucidum / The possibility of metal adsorption from water medium on biomass of fungus Ganoderma lucidum Ula Rozman, Andreja Žgajnar Gotvajn, Gregor Marolt, Andrej Gregori, Gabriela Kalčikova ...... 57

Odprava škodljivih emisij iz remediranih tal z dodajanjem nič valentnega Fe / Elimination of harmful emissions from remediated soil by adding zero valant Fe Simon Gluhar, Erika Jež, Domen Leštan ...... 60

Seznam avtorjev / Author Index ...... 63

Uvodnik

Evropski projekt LIFE ReSoil z naslovom Demonstracija inovativne tehnologije pranja s toksičnimi kovinami močno onesnaženih vrtnih tal se zaključuje. S projektom smo začeli julija 2013 in ga bomo po vseh uspešnih in dodatnih nepredvidenih aktivnostih zaključil z enoletnim podaljškom, v decembru 2018. Ob tej priložnosti smo organizirali Zaključno konferenco. Njen glavni namen je bil skupaj s strokovnjaki iz različnih področij orisati širino problematike obremenjevanja tal s toksičnimi elementi, predstaviti rezultate projekta in testiranja tehnologije v vseh njenih korakih.

V Evropi je verjetno več kot 340.000 območij tako močno onesnaženih, da potrebujejo sanacijo. Ravno tako ocenjujejo, da bo potrebno na Kitajskem v bližnji prihodnosti, zaradi izjemno intenzivnega kmetijstva, odstraniti prekomerne obremenitve na približno 20% kmetijskih zemljišč. Tudi v vseh večjih mestih na vzhodni obali in osrednjem delu ZDA so urbana tla onesnažena z ostanki barve na osnovi svinca ter ostanki emisij izgorevanja osvinčenega bencina. Tako kar 71% tal v vrtovih hiš New Yorka presega mejno vrednost svinca in potrebuje remediacijo. Svetovna zdravstvena organizacija je opredelila svinec kot eno od desetih kemikalij, ki imajo pomemben vpliv na javno zdravje. Dokazano je, da so prav urbana tla parkov, vrtov in igrišč vzrok zastrupitev s svincem pri otrocih. Posledično je večina držav postavila sanacijo onesnaženih zemljišč kot prednostno nalogo. Le-to pa ustvarja potrebo po čiščenju tal le s takimi tehnologijami, ki bodo sposobne ohraniti celovitost tal v vseh njihovih funkcijah. Danes se namreč končno zavedamo, da tudi tla predstavljajo neprecenljiv in neobnovljiv naravni vir. Opravljajo številne ekosistemske funkcije in so pomemben člen v verigi ohranjanja našega zdravja.

Za tla, ki so onesnažena predvsem s svincem, danes na trgu še vedno ni najti primerne tehnologije remediacije, ki bi bila izvedljiva in učinkovita na velikih in močno obremenjenih površinah in hkrati trajnostna z vidika ohranjanja rodovitnosti tal in preprečevanja generiranja novih odpadkov. Izkop in odlaganje onesnaženih tal je na žalost še vedno ena izmed rešitev, ki je največkrat v uporabi (v 82-84% primerih), kljub temu, da so nekatere države uvedle visoke takse na odlaganje izkopanih odpadnih zemljin. Hkrati pa izkop in odlaganje onesnaženih tal pomeni tudi trajno izgubo naravnega vira.

Tehnološki postopek, ki smo ga poimenovali ReSoil, je edini razpoložljiv remediacijski pristop, ki lahko učinkovito odstranjuje svinec in druge strupene kovine iz onesnaženih tal in hkrati ohranja tla rodovitna. Tehnologija ReSoil temelji na uporabi močnega vezavnega sredstva za kovine, EDTA, ki se v podobne namene uporablja tudi v prehrambni industriji. Dodatno prednost tehnologije, s stališča varovanja okolja in naravnih virov, je v inovativnemu načinu recikliranja EDTA in procesnih raztopin. Le-te recikliramo v zaprtem krogotoku, ki preprečuje nastajanje tekočih odpadnih raztopin. Po večletnih raziskavah in demonstraciji v okviru projekta, smo tehnologijo ReSoil privedli do stopnje pripravljene za komercializacijo. Rezultati, objavljeni v številnih publikacijah in prejeta vabila na konference, kažejo na njeno prodornost in trajnostno okoljsko inovacijo globalnega pomena. Za predstavitev tehnologije ReSoil smo podjetji Envit in Arhel na Prevaljah vzpostavili demonstracijski obrat s kapaciteto čiščenja 6 ton zemljine na dan in demonstracijski vrt v sodelovanju z Biotehniško fakulteto Univerze v Ljubljani, na katerem uspevajo vrtnine v očiščenih tleh.

Tehnologija lahko uporabimo za remediacijo močno obremenjenih tal s kovinami, kot so parkovne in vrtne površine urbanega okolja, zapuščena industrijska območja, kmetijska zemljišča in vojaška strelišča in druga vplivna območja teh površin, kot so brežine vodotokov.

Program zaključne konference smo razdelili v tri sekcije. V prvi sekciji so potekala predavanja o vlogi tal in posledicah onesnaženosti tal s potencialno toksičnimi elementi. V drugi sekciji so predavatelji predstavili metode določevanja onesnažil in tehnologije remediacije tal. V tretji sekciji pa so predavatelji z različnih znanstvenih disciplin predstavili rezultate raziskav, ki so bile izvedene z namenom ocene učinkovitosti ter okoljske sprejemljivosti tehnologije ReSoil. Predavalo je 17 vrhunskih strokovnjakov iz različnih slovenskih in tujih institucij. Zelo veseli smo bili tudi udeležbe s strani Ministrstva za okolje in prostor ter podjetij.

Zahvaljujemo se vsem avtorjem in udeležencem, ki so prispevali k uspešni izvedbi Zaključne konference. V zborniku so objavljeni razširjeni povzetki predavanj. dr. Neža Finžgar, vodja projekta LIFE ReSoil

Editorial

The European project LIFE ReSoil, Demonstration of innovative soil washing technology for removal of toxic metals from highly contaminated garden soil, is in its final stages. We started the project in July 2013 and will complete it with a one-year extension in December 2018 after all additional and unforeseen although successful activities. On this occasion, we organised the Closure conference. Its primary purpose was to outline, together with experts from various fields, the extent of the problem of soil pollution with toxic elements, present the results of the project and testing of the technology in all its stages.

In Europe, more than 340 000 sites are likely to be highly contaminated and in need of remediation measure. About 20% of farmland soil in China require urgent remediation action. Urban soils are contaminated by Pb-based paint and emissions from the combustion of leaded gasoline in all major cities in the east coast and US-heartland; i.e. 71% of the home garden soils in New York exceed Soil Clean-up objective limits for Pb. The World Health Organization has identified lead as one of ten chemicals that have a significant impact on public health. It has been proven that urban surfaces of parks, gardens and playgrounds are the cause of lead poisoning in children. As a result, most countries have set up the restoration and remediation of contaminated land as a priority. Consequently, this creates the need to clean soil only with such technologies that can preserve the integrity of the soil in all their functions. Today, we are finally aware that the soil also represents an invaluable and non- renewable natural resource. They perform numerous ecosystem functions and are an essential link in the chain of maintaining our health.

For soil contaminated mainly with lead, there is still no suitable remediation technology available on the market today, which would be viable and efficient on large and heavily polluted areas and at the same time sustainable regarding preserving soil fertility and preventing the generation of new waste. Unfortunately, the excavation and disposal of contaminated soils are still one of the most commonly used solutions (in 82-84% of cases), although some countries have introduced high taxes on the disposal of excavated waste soils. At the same time, the excavation and disposal of contaminated soils also mean a permanent loss of natural resource.

The technological process, called ReSoil, is the only available remediation option that can effectively remove lead and other toxic metals from contaminated soil and preserves soil as a natural resource. ReSoil is EDTA-based soil-washing technology with innovative technology for recycling of EDTA and process waters in closed-loop and thus ensuring generation of no liquid wastes. ReSoil is a breakthrough, globally important green environmental innovation in the verge of commercialization. The results published in numerous publications and received invitations to conferences show that its profoundness and sustainable environmental innovation are of global importance. To demonstrate the ReSoil technology, the cooperating companies Envit and Arhel set up a demonstration plant in Prevalje with a capacity for remediating six tons of soil a day and a demonstration garden in cooperation with the Biotechnical Faculty University of Ljubljana, on which the plants grow in remediated soil.

Technology can be used for remediation of highly metal polluted soils, such as park and garden surfaces of the urban areas, abandoned industrial areas, agricultural land and military ranges and other affected areas by these surfaces, such as streams of watercourses.

The final conference program was divided into three sections. In the first section, lectures were held on the role of soil and the consequences of soil contamination with potentially toxic elements. In the second section, lecturers presented methods for the determination of pollutants and soil remediation technologies. In the third section, lecturers from different scientific disciplines presented the results of research that were carried out in order to assess the effectiveness and environmental acceptability of ReSoil technology. Top 17 experts from various Slovenian and foreign institutions presented their lectures. We were also delighted with the participation of the Ministry of the Environment and Spatial Planning and companies.

We sincerely thank all authors and participants who contributed to the successful implementation of the Closure conference. Extended summaries of presented lectures are published in this conference proceedings.

Neža Finžgar PhD, LIFE ReSoil project manager

Soil pollution – awareness and threats, ways and strays Onesnaženje tal - zavedanja in tveganja, poti in stranpoti

Borut Vrščaj Kmetijski inštitut Slovenije / Agricultural Institute of Slovenia

Izvleček: Prispevek obravnava uvodne vsebin o onesnaženosti tal, definicije, vire, tokova in razpršena onesnaževanja, ekosistemske storitve tal v povezavi z onesnaženjem tal, ter ključna vprašanja, ki si jih moramo v Sloveniji zastavita da bi uspešno pristopili k sanacijam in remediacijam onesnaženih zemljišč. Ključne besede: tla, onesnaženje, sanacije Abstract The article deals with the introductory contents on soil contamination, definitions, sources, hot-spot and diffuse pollution, soil ecosystem services in relation to soil pollution, and key issues that we need to set in Slovenia in order to approach to remediation of contaminated land successfully. Keywords: soil, pollution, remediation Onesnaženje tal Izraz 'onesnaženje' tal se nanaša na prisotnost kemikalije ali snovi v tleh izven kraja in/ali prisotnost pri koncentraciji, ki je višja od običajne in ki ima hkrati škodljive učinke na kateri koli neciljni organizem. Onesnaženje tal največkrat ni mogoče neposredno oceniti ali vizualno zaznati, zaradi česar jo označujemo kot skrito tveganje, Onesnaženje tal ni naravno povišana koncentracija onesnaževala v tleh in ne vsebnost onesnaževala, ki nima škodljivih učinkov na neciljne organizme. FAO definicija je korektna, a kljub temu obstajajo težave, povezane z njo. Namreč, v praksi se pojavljajo vprašanja kot kaj je naravno?, ali Kako razlikovati onesnaženje od naravnega ozadja, kako so visoka naravna ozadja?; in, če nadaljujemo, Kaj je normalno? Kaj je torej običajno, kaj tvegano, in kaj sprejemljivo v tleh različnih vrst rab; npr. v kmetijskih tleh, mestnih zelenicah, otroških in športnih igriščih, parkih, gozdovih, industrijskih in prometnih površinah. Ravno tako imamo težave ločiti tveganja povezana z onesnaženimi tlemi od tveganj in izpostavljenosti, ki izvirajo iz osebnega in širšega okolja (npr. bivališče, delovni prostor), prostora, načina življenja, in ne nazadnje, našega osebnega genoma. Na pomembna vprašanja kateri in kakšni so škodljivi učinki, kako jih meriti; kako ločiti od drugih okoljskih vplivov in tveganj imamo odgovore, a še zdaleč ne tako celovite, kot bi jih potrebovali. Kljub tem vprašanjem, pa velja, da onesnažena tla predstavljajo tveganje za okolje in človekovo zdravje, ki je pogosto visoko in nesprejemljivo, tako, da ga je treba odstraniti ali vsaj zmanjšati na sprejemljivo raven. Onesnaževala v tleh in viri onesnaževal Seznam onesnaževal v tleh je dolg in zajema tako organske in anorganske snovi kot škodljive organizme. Najbolj so poznane težke kovine in metaloidi, nato policiklični aromatski ogljikovodiki, obstojna organska onesnaževala, pesticidi, dušik in fosfor v previsokih koncentracijah, radionuklidi, patogeni mikroorganizmi in drugi. Raznolikost onesnaževal in kompleksna zgradba tal, kemijski in fizikalni procesi v tleh, so izziv za prepoznavanje, odkrivanje, spremljanje in vrednotenje onesnaženj. Glede na vire in prostorsko razporeditev onesnaženj tal poznamo lokalno/točkovno in razpršeno onesnaženje oz. onesnaževanje tal. Lokalna/točkovna onesnaženja so največkrat območja majhnega obsega, neredko

nekaj deset m2 metrov ali ha. Viri in načini onesnaženja so pri točkovnih onesnaževanjih običajno poznani in posledice so pogosto tudi vidne. Najpogosteje gre za lokalizirane antropogene dejavnosti v okviru sedanjih in bivših industrijski objektov, odlagališč odpadkov, različna razlitja, rudarstvo, železarstvo, kovinska in elektro industrija, uporaba kmetijskih, industrijskih in vojnih kemikalij, vojne, itd. Razpršeno onesnaženje pokriva (zelo) široka območja, neredko desetine/stotine km2. Nakopičena onesnažila v tleh pogosto ne izvirajo samo iz enega zlahka identificiranega vira. Najpogosteje gre za prepleteno onesnaženje iz različnih virov, ki prispejo v tla preko zračnega transporta ali poplavnih voda. Razpršeno onesnaževanje močno vpliva na okolje in zdravje ljudi, ga je težko prostorsko ovrednotiti in je izziv za spremljanje. Prisotno je dlje časa, učinki so pa so skriti/zabrisani in dolgoročni. Glavni viri razpršenega onesnaženja so izpusti industrije, prometa in poselitve; onesnažene odpadne vode, uporaba blata iz čistilnih naprav, FFS, onesnaženih gnojil, erozije tal onesnaženih lokacij, poplave, preizkusi jedrskega orožja, itd. Razpršeno onesnaževanje je doseglo 'skrite kotičke' našega planeta in za še tako idiličen naravni ekosistem je težko trditi, da gre za neokrnjeno naravo. Zdravje tal in ekosistemske storitve. Tla smo v preteklosti povezovali predvsem s kmetijstvom in gozdarstvo. Saj naj bi bila glavna funkcija tal pridelav hrane in vse druge biomase. Vendar opravljajo tla vitalne ekosistemske storitve, ki omogočajo življenje in njegovo pestrost kopenskih ekosistemov; so umeščena v središče okoljskih procesov, določajo biotsko pestrost nad tlemi, so vir surovin, energije, in veljajo za 'skladišče' koristnih genov. Tu se v povezavi z onesnaženjem tal osredotočamo na primarno ekosistemske storitev, to je pridelava hrane. V letu 2015 je Slika 1: Vpliv onesnaženosti tal na funkcije / ekosistemske 95% proizvodnje hrane odvisno storitve tal ( povzeto po FAO) od tal. Samo zdrava, neonesnažena tla lahko in zagotovijo več zdrave hrane. Reševanje problematike onesnaženosti tal v Sloveniji Onesnaženje tal zaradi lokalnih specifičnosti zahteva prilagojene pristope. Preučiti je treba dobre prakse v tujini (F, UK, D ...) in jih dopolniti za naše potrebe. Ravno tako je treba razvijati nove tehnike sanacije tal. O onesnaženju tal je treba jasneje in pogosteje spregovoriti v javnosti in to ne kot o slovenski posebnosti, temveč kot na "črno dediščino" razvitih držav, zlasti Evrope. Onesnaženje postaja v Sloveniji velik, včasih tudi lokalno predimenzioniran problem. Javna, umirjena in strokovna diskusija je nujna za odpravo t.i. NIMBY reakcij, ki v Sloveniji pogosto ovirajo ali celo onemogočajo smiselne ukrepe sanacije/blaženja onesnaženosti tal. Tu vidimo potrebo po večji aktivnosti stroke in države. Iskanje krivcev za onesnaženje tal je nepotrebno tratenje energije; saj, tudi ko so znani, jih največkrat ni možno pripraviti v sanacijo tal. Strategija 'onesnaževalec plača' največkrat ni ali je le zelo težko

izvedljiva. Podpirati je treba razvoj čistilne industrije; nova, na znanju temelječa mala in srednja podjetja. Njihove aktivnosti pa je treba zasnovati na kakovosti in pazljivem spremljanju rezultatov/uspešnosti sanacij. Ključna vprašanja za zmanjšanje onesnaženosti tal v SI so Kje, kako, koliko je zemlja onesnažena? Koliko ha tal moramo sanirati? Kje in kako zmanjšati / ublažiti grožnje onesnaževanju? Katere so smiselne in katere ustrezne tehnologije? Kakšni so postopki sanacije? Kako se boriti proti učinku NIMBY? Kako naslavljati javnost, prizadete državljane, NGO, medije? Ta in druga pomembna vprašanja, je treba odgovoriti in ustrezno zastaviti programe sanacij.

Viri Adriano C.D. 2001. Trace Elements in Terrestrial Environments; Biogeochemistry, Bio availability and Risks of Metals. New York, Springer-Verlag: FAO (Ur). 2018. Be the solution to Soil Pollution - Outcome. Rome, Italy, FAO: 977 p.

FAO 2018. SOIL POLLUTION: a hidden reality. S.l., FOOD & AGRICULTURE ORG

FAO (Ur). 2018. Be the solution to Soil Pollution - Proceedings. Rome, Italy, FAO: 977 p.

Reimann C., et all,. 2017. GEMAS: Establishing geochemical background and threshold for 53 chemical elements in European agricultural soil. Applied Geochemistry

Onesnaženost tal v Sloveniji in prenos kovin v rastline

Soil pollution in Slovenia and uptake of heavy metals into the plants

Marko Zupan1, Helena Grčman1 1 University of Ljubljana, Biotechnical Faculty, Jamnikarjeva 101, Ljubljana, Slovenija

Abstract Increased concentrations of metals in the environment can endanger human health. The concentrations are not acute, so intake of these substances through the food chain is an invisible threat. Soil pollution assessment/monitoring in Slovenia is under the jurisdiction of the Slovenian Environment Agency, where reports and data are available via two web applications (ATLAS OKOLJA, GEOPORTAL ARSO). Areas where soils are polluted are mostly at and around former mining and smelting facilities (Upper Meža valley, Celje, Idrija, Jesenice, Zasavje, etc.). Contaminated soils with (heavy) metals and metalloids represent a potential threat to human health via dusting or via uptake and excessive accumulation in agricultural plants. The bioavailability of metals is the most important factor that influences uptake from soil to plants, in addition to total soil metal concentration and plant species.

Ključne besede: onesnaženost tal, nevidna grožnja, dostopnost kovin rastlinam

Keywords: soil pollution, invisible threat, availability of metals to plants

Onesnaženost tal – nevidna grožnja Onesnaženost tal je grožnja tlom, ki je za razliko od nekaterih fizičnih degradacij okolja (na primer erozija tal, zemeljski plazovi) neposredno manj opazna oziroma nevidna. Povečana vsebnost onesnažil v tleh običajno ne vpliva fitotoksično na vegetacijo, vendar lahko nekatere potencialno nevarne snovi prehajajo v rastline in najprej v prehranjevano verigo živali in človeka. Kemijsko stanje tal in odstopanje od naravnega stanja lahko ugotovimo le z odvzemom vzorcev in analizo. V grobem lahko potencialno nevarne snovi (onesnažila) delimo v dve skupini: 1) organska onesnažila so praviloma sintetičnega izvora, ki jih v naravnih tleh ni, izjema je na primer skupina policikličnih aromatskih ogljikovodikov (PAO); 2) anorganske potencialno nevarne snovi, katere v največji meri predstavljajo elementi v različnih oblikah in spojinah (kovine in polkovine As, Cd, Cu, Cr, Hg, Ni, Pb, Zn, …). Zaradi procesov preperevanja kamnin tekom nastanka tal se kovine v tleh akumulirajo in so v določeni količini že prisotne (naravno ozadje), dodatno pa se akumulacija in vsebnost v tleh poveča s človekovo dejavnostjo. Zaradi vezave na talne delce ostajajo koncentracije povečane tudi po prenehanju onesnaževanja.

Onesnaženost tal v Sloveniji Onesnaženost tal v Sloveniji je povezana predvsem s preteklo rudniško in topilniško dejavnostjo ter drugo težko industrijo (Zgornja Mežiška dolina, Idrija in porečje Idrijce, Celjska kotlina, Zasavje, Litija, Jesenice z okolico, Podljubelj, itd.), mestoma intenzivnim kmetijstvom v nekaterih ruralnih območjih in ob večjih urbanih naseljih zaradi vpliva prometa in kurišč (npr. Ljubljana). Raziskave in meritve onesnaženosti tal lahko razdelimo v dve skupini: 1) državni monitoring stanja tal (ROTS – Raziskave onesnaženosti tal Slovenije, meritve stanja tal in monitoring uspešnosti sanacijskih ukrepov v okviru Programa izboljšanja stanja okolja v Zgornji Mežiški dolini (ZMD; Ur. l. RS, 119/07), monitoring gozdnih tal, reševanje problematike starih bremen; 2) lokalne meritve stanja tal (različne raziskovalne naloge, geokemične raziskave, izvajanje okoljskih programov v občinah, okoljske nesreče, itd.). Projekt ROTS se izvaja na osnovi Nacionalnega programa varstva okolja (NPVO; Ur. l. RS 83/99) in Resolucije Nacionalnega programa varstva okolja (ReNPVO; Ur. l. RS 2/06) na celotnem območju R. Slovenije, vzorčenje tal poteka na v naprej določenih lokacijah v mreži različne resolucije glede na rabo tal in

nadmorsko višino, izvajajo se meritve pedoloških lastnosti in vseh potencialno nevarnih snovi glede na Uredbo o mejnih, opozorilnih in kritičnih vrednostih nevarnih snovi v tleh (Ur. l. RS, 68/96). Metodologija vzorčenja, analiz in poročanja je opisana v publikaciji Raziskave onesnaženosti tal Slovenije (Zupan in sod., 2008), ki je tako kot podatki državnega monitoringa stanja tal dostopna na spletni strani Agencije RS za okolje. Podatki ROTS predstavljajo objektivno stanje o onesnaženosti tal Slovenije in so osnova za poročanje o stanju tal Evropski agenciji za okolje (EEA). Podatki ROTS in delno tudi za Zgornjo Mežiško dolino so na voljo tudi grafično v obliki tematskih kart in standardiziranih izpisov za vsako lokacijo preko aplikacij ATLAS OKOLJA in GEOPORTAL ARSO (povezave so navedene v virih).

Vnos kovin v rastline Onesnažena tla zaradi akumulacije kovin lahko tudi več desetletij po prenehanju onesnaževanja predstavljajo vir kovin za rastline, živali in človeka. Glavni poti vnosa kovin iz tal v človeka sta (1) prašenje tal in (2) vnos preko rastlin oziroma živil rastlinskega in živalskega izvora. Vsebnost nekega elementa v tleh, ki je razpoložljiva rastlinam, je odvisna od abiotičnih dejavnikov kot so celotna vsebnost tega elementa v tleh, njegove kemijske lastnosti (speciacija), prisotnosti drugih elementov v tleh in lastnosti tal, ki vplivajo na dinamiko procesov v talni raztopini: pH, redoks potencial, delež organske snovi, gline, karbonatov, fosfatov in oksidov Fe in Mn (Adriano, 2001). Rastline večino kovin sprejemajo preko korenin, zato je koncentracija kovine v rastlini za nekatere dobro dostopne elemente v dobri odvisnosti od koncentracije v tleh. Elementi Cd, B, Br, Cs in Rb imajo za večino rastlin dobro dostopnost, medtem ko so Pb, Ba, Ti, Zn, Sc, Bi, Ga in delno tudi Fe in Se težje sprejemljivi za rastline oziroma se slabo premeščajo od korenin v nadzemne dele (Adriano, 2001; Kabata-Pendias in Pendias, 1984). Na koncentracijo kovin v rastlinah v največji meri vpliva biodostopnost kovine v tleh, in biotični dejavniki: vrsta in včasih tudi sorta rastline, starost rastline oziroma užitnega dela, habitus, razvejanost in aktivnost koreninskega sistema ter prisotnost mikoriznih gliv. Rastline lahko vsebujejo tudi prašne delce onesnaženih tal na svoji površini, kar ni nezanemarljivo pri nadaljnjem vnosu kovin v prehranjevalno verigo preko živali (prašna krma) ali kadar uživamo neoprane pridelke neposredno na vrtu - na primer jagode. Z vidika vnosa kovin v prehranjevalno verigo je pomembna predvsem vsebnost v užitnem delu rastline, pri čemer je v pomoč splošno pravilo, da največ kovin pride v rastlino preko korenin in se tam tudi zadrži; le del se transportira v nadzemne dele, najmanj kovin se premešča v tkiva semen oziroma plodov, saj ima veliko kovin slabo mobilnost v floemu (Bergmann, 1992; Zupan in sod., 1996; Marschner, 2012; Page in Feller, 2015). V skupini z veliko in srednjo sposobnostjo za sprejem in vnos kovin v užitne dele spadajo predvsem rastline, pri katerih uživamo zeleni nadzemni del (špinača, solata, blitva, endivija) in/ali podzemni del (pesa, redkvica, repa, krompir); večina kapusnic ima majhno translokacijo v liste, najmanj kovin se premešča v plod (Tabela 1).

Tabela 1: Razvrstitev kmetijskih rastlin glede na sposobnost vnosa kovin v užitne dele VELIKA SREDNJA MAJHNA ZELO MAJHNA solata ohrovt zelje fižol špinača pesa – koren sladka koruza grah blitva repa – koren brokoli melone endivija redkvica cvetača paradižnik kreša gorčica brstični ohrovt paprika repa – zeleni del krompir zelena jajčevec pesa - zeleni del čebula jagodičje sadje korenje

Literatura Adriano D. C. 2001. Trace elements in the terrestrial environments. 2nd ed. New York, Berlin, Heidelberg, Tokyo, Springer-Verlag: 867 str.

ATLAS OKOLJA: http://gis.arso.gov.si/atlasokolja/profile.aspx?id=Atlas_Okolja_AXL@Arso

Bergmann W. 1992. Nutritional disorders of plants-development, visual and analytical diagnosis. Jena, Gustav Fischer Verlag: 741 str.

GEOPORTAL ARSO: https://gis.arso.gov.si/geoportal/catalog/main/home.page

Kabata-Pendias A., Pendias, H. 1984. Trace elements in soils and plants. Boca Raton Florida, CRC Press: 315 str. Marschner P. 2012. Marschner's mineral utrition of higher plants. Third edition. London, Academic Press: 651 str.

Nacionalni program varstva okolja (NPVO) – Program ukrepov na področju varstva tal. (1999). Ur. L. RS št.83/99

Odlok o območjih največje obremenjenosti in o programu ukrepov za izboljšanje kakovosti okolja v zgornji mežiški dolini. (2007). Ur. l. RS št.119/07

Page V., Feller U. (2015). Heavy metals in Crop Plants: Transport and Redistribution -Processes on the Whole Plant Level. Agronomy, 5: 447-463

Resolucija o nacionalnem programu varstva okolja 2005 – 2012. (2006). Ur. L. RS št. 02/06

Uredba o mejnih, opozorilnih in kritičnih imisijskih vrednostih nevarnih snovi v tleh. (1996). Ur. l. RS št.68/96

Zupan M., Grčman H., Lobnik F. 2008. Raziskave onesnaženosti tal Slovenije. Ljubljana, Agencija RS za okolje: 63 str.

Zupan M., Hudnik V., Lobnik F., Grčman H. (1996). Akumulacija kadmija, svinca in cinka v nekaterih kmetijskih rastlinah. V: 1. slovenski kongres o hrani in prehrani, Bled: 1-9

Mercury contamination of soils form the Soča/Isonzo river basin

Kontaminacija tal z živim srebrom iz porečja Soče

Marco Contin1, Elisa Pellegrini1, Maria De Nobili1 1University of Udine, Department of Agricultural, Food, Environmental and Animal Sciences

Keywords: Mercury contamination, speciation, sequential extraction procedures, thermal desorption.

The existence of mining activity in Idrija (Slovenia) has been demonstrated to be the primary source of mercury (Hg) in the Gulf of Trieste (northern Adriatic Sea) through the trans-boundary Soča/Isonzo river inputs. Due to erosion of the mining region, particulate material strongly enriched in Hg was transported for centuries downstream and deposited on the riverside soils by the flooding of the Soča/Isonzo river. As a consequence, these soils are characterized by a diffuse Hg contamination with concentrations reaching up 80 μg g-1, many times the threshold limit for contaminated soils. Several “hot spots” of Hg contamination were identified along the river basin, probably linked to the most frequent flooding areas and corresponding to paleo-riverbeds. Soils of the river basin were characterized along their profile, to highlight the different depositional processes and eventual leaching processes. High values of Hg were found up to 2m depth. Mercury mobility, bioavailability and toxicity depends on its physical and chemical form, thus, the improvement of Hg fractionation protocols is strongly required. A major problem of fractionation protocols is the lack of selectivity (it is only possible to distinguish operationally defined groups of compounds) and the production of artefacts during the analytical procedure itself. In order to separately identify Hg species within the group of “matrix-bound” Hg, thermo-desorption measurements were performed after each step of a leaching test. The leaching test separates seven Hg binding forms namely soluble plus exchangeable, Mn oxides, organic matter, amorphous Fe oxides, crystalline Fe oxides, non-cinnabar Hg and cinnabar Hg. Thermal desorption (TD) was applied linearly heating from room temperature to 800 °C. Elemental Hg was detected by atomic absorption spectrometer, based on Zeeman correction. Two soils with Hg contamination of different source and time were analyzed: 1) an agricultural soil contaminated by the Idrjia past mining activity, 2) a sediment recently contaminated due to emissions from a chlor-alkali plant. Coupling TD measurements with leaching procedure allowed the identification of two Hg fractions in the agricultural soil, the main fraction is Hg sulfide, followed by organically bound Hg. On the contrary, in chlor-alkali contaminated sediment only the organically bound Hg has been clearly identified. This work posed the evidence that TD can not be a stand-alone tool for Hg fractionation mainly due to peaks overlapping, but it requires other “wet-chemistry” techniques. The prevalence of sulfur-Hg (cinnabar) and abundance of carbonates is an index of extremely low metal availability in these soils, nevertheless changes in salinity, due to see intrusion, and redox potential, may induce a gradual release of more soluble/bioavailable forms of mercury.

Modelling Acid Volatile Sulfides (AVS) and Simultaneously Extractable Metals (SEM) in anoxic soils with a cutting-edge approach

Elisa Pellegrini1, Filippo Valdevit1, Pietro Balducci1, Marco Contin1, Maria De Nobili1 1University of Udine, Department of Agricultural, Food, Environmental and Animal Sciences

Keywords: metal bioavailability, SEM/AVS ratio, Structural Equation Modelling, chemical bindings, ligands

Introduction Toxic metal bioavailability in benthic and aquatic organisms is commonly assessed using the ∑SEM/AVS molar ratio (Di Toro et al. 1990). Acid Volatile Sulfides (AVS) are the reactive fraction of soil sulfides determined operationally with a cold 6M HCl treatment while Simultaneously Extractable Metals (SEM) are the metal aliquot solubilized during this treatment. Concretely, the AVS fraction includes dissolved sulfur species and metastable iron sulfide minerals (Rickard and Morse 2005) whereas SEM are typically divalent metals, most of them harmful for organisms (Cd, Cu, Ni, Pb and Zn). Because of the higher metal affinity to sulfides compared to other ligands, AVS binds divalent cationic metals forming iron mineral precipitates, highly insoluble and unavailable for organisms (Di Toro et al. 1990). If ∑SEM  AVS (or ∑SEM/AVS  1) in molar terms, no excess of metals is bioavailable to cause toxicity (McGrath et al. 2002). Despite this apparently simple framework, SEM can include non-sulfides metals (Di Toro et al. 1992) because other soil chemical ligands can bind SEM (Yu et al. 2001) such as soil organic matter, Fe/Mn-oxides and carbonates (Kunito et al. 2017, McGrath et al. 2002, Yu et al. 2001). These ligands can diminish the efficacy of the ∑SEM/AVS ratio to predict metal bioavailability and soil toxicity. Therefore, the aim of the present study was to define the factors affecting AVS production in anoxic soils and the key chemical bindings of SEM, using a cutting-edge modelling technique called Structural Equation Modelling.

Methods Soils subject to flooding were collected in six saltmarshes of the Marano and Grado Lagoon (northern Adriatic Sea). Saltmarshes are key environments for studying AVS and SEM dynamics, being frequently flooded by salty tides that carries high amount of sulfate. The AVS content was determined using the SPS field method (Pellegrini et al. in press) that imply the HCl treatment of a known volume of soil and the trap of the evolved H2S in a paper strip (treated with PbNO3). The developed colour (due to PbS formation on the paper surface) is compared with reference charts, previously prepared in the laboratory, and returns the concentration of AVS per soil volume. The SEM of Cd, Ni, Cu, Pb and Zn were determined in the HCl solution, used for the AVS measurement, by ICP-OES. The dataset includes 81 soil samples. A summary of collected data is reported in Table 1.

Table 1: Summary of the chemico-physical properties of soil dataset.

hydroperiod AVS Eh pH carbonates ∑SEM total metals total Fe labile C -1 -3 -1 -3 -1 -1 -1 (hsubmergence day ) mmol dm mV g kg mmol dm mg kg mg kg mg kg

min 2.3 0 -570 6.9 3 0 16 2032 42 1st quantile 6.6 0.25 -290 7.3 151 0.34 132 12585 102 median 9.9 0.63 -49 7.5 228 0.63 186 17020 173 mean 10.2 4.36 -95 7.5 291 0.98 183 16561 201 3rd quantile 13.9 3.25 88 7.7 378 1.62 246 23115 250 max 22.8 40.0 233 8.9 849 4.09 388 32900 817

N.A.* - 1 2 2 14 - 10 10 7 * N.A. Not available data. The Structural Equation Modelling technique is a powerful analysis that allows to combine multiple linear models in a single causal network (Vile et al. 2006). This analysis was recently implemented by Lefcheck (2016) in R software for Environmental and Ecological studies (piecewiseSEM package). Represented as a graphical path model (Vile et al. 2006), this statistic method resolves complex relationships, defined in a priori hypothesised model, attributing a weight to each tested relationship. In the present study, the Structural Equation Modelling allowed to figure out direct and indirect relationships among variables linked to AVS and SEM and to rank chemical bindings of SEM on a weight basis, as returned from the model.

Two models were selected with an increasing degree of complexity. The first model aimed to define factors affecting AVS and SEM, without the presence of additional chemical SEM ligands. The considered variables were: hydroperiod (index of flooding), pH, soil redox potential (Eh), AVS, ∑SEM and total content of the divalent metals Cd, Ni, Cu, Pb and Zn (total metals). The second model includes possible ligands of SEM in addition to AVS i.e., carbonates, total Fe (index of Fe-oxides) and labile organic C. The two tested models are shown in Figure 1.

Figure 1: The hypothesised structural equation models without (1st model) and with (2nd model) possible chemical bindings of Simultaneously Extractable Metals (SEM)

Main achievements The structural equation modelling returned high significant models, which fit was tested with the Fisher’s C statistic. Only significant relationships of the two models are reported in Figure 2.

Figure 2: Simplified results from the Structural Equation Modelling analysis. Black arrows refer to statistical significant linear relationships (p ≤ 0.05). Line width of arrows is proportional to the size of the effect. The + and – symbols refer to the positive or negative relationship between the variables.

In the first model (Fisher’s C = 1.7, df = 2, p = 0.44), the hydroperiod influenced positively the pH and negatively the soil redox potential (Eh). In fact, during flooding, pH converges to neutrality due to the - buffer effect of CO2 via the H2CO3-HCO3 reaction and redox reactions. The O2 availability in soil, instead, decreases due to the reduction of air spaces within soil particles that are filled with water (McBride 1994). Being 7.5 the median value of pH, high amounts of sulfides are expected due to the pH-dependency of sulfate reduction in soil (Connell and Patrick 1968). AVS resulted directly and positively influenced by the pH. Most of reduction reactions in soil consume H+ resulting in pH increase (Narteh and Sahrawat 1999), the including the sulfate reduction process (Miao et al. 2012). On the contrary, AVS were only indirectly related to the hydroperiod, which effect is mediated by pH. Total metal content in soil was determined directly by the Eh and only indirectly by the hydroperiod. High flooding, thus lowering Eh, reduce metal availability due to the higher adsorption of metals on Fe/Mn-oxides that drives the formation of insoluble sulfide compounds (Van et al. 1998, Elliot et al. 1986). However, in the present model, Eh was negatively correlated to total metals. The soil redox status (Eh) seemed to mitigate the negative effect of the hydroperiod on metal content in anoxic soils. Surprisingly, total metal content did not correlate with SEM. Moreover, pH positively influenced SEM amount. In fact, bioavailability of metals is reported to be strongly driven by pH (Sun et al. 2007, Burton et al. 2006). AVS were negatively correlated to SEM, confirming the AVS binding role for metals in anoxic sediments and the use of the ∑SEM/AVS ratio to predict metal toxicity (McGrath et al. 2002).

Including in the model additional possible ligands for SEM (Model 2), the relationship between AVS and SEM was no more statistically significant. The second model (Fisher’s C = 8.8, df = 10, p = 0.5) highlighted the key function of labile C and carbonates as most important chemical bindings of SEM. Yu at al. (2001) found that organic matter and carbonates are the principal binding phases of SEM in extremely anoxic sediments, in addition to AVS. Here, SEM are bound to soil organic matter (labile C) due to metal-organic complexes (Gambrell and Patrick 1988). High amount of organic matter and carbonates in soil could therefore decrease metal bioavailability for organisms. Besides, organic matter is also the substrate for the microbial activity. High amount of labile C in soil fuels the microbial activity of sulfate-reducing microorganisms with the consequent increase of sulfides. The organic C is oxidised while sulfate is reduced (Canfield 2001), therefore high C availability means high AVS produced. Upon anoxic conditions, carbonates promote AVS production, which process leads to the formation of stable metal sulfides and to the increase of pH (Kunito et al. 2017), explaining the positive relationships between carbonates, AVS and pH. None relationship arose between SEM and total Fe, probably due to

the wide Eh range of our soil dataset. In fact, the suggested role of Fe-oxides as bindings agent was defined only for slightly anoxic sediments (Yu et al. 2001). On the contrary, total Fe seemed to be a good index for total metal content in soil.

Final remarks The lack of significant relationship between AVS and SEM in the model including chemical ligands of SEM could be attributed to the greater role of soil organic matter and carbonates as bindings, regardless to the ∑SEM/AVS ratio. For a total of 81 records analysed, 36 of them showed a ∑SEM/AVS ratio > 1. When SEM are in excess and soils show high amount of organic matter or carbonates, the SEM and AVS approach could be not more trustworthy. If this is the case, the prediction of soil toxicity could be strongly altered when chemical bindings in addition to AVS are not considered. In conclusion, in the light of present achievements, pH and total metal content could have only a minor impact on toxic metals bioavailability, at least for calcareous coastal flooded soils.

References Burton, E.D., Bush, R.T., Sullivan, L. A. (2006) Acid-volatile sulfide oxidation in coastal flood plain drains: iron− sulfur cycling and effects on water quality. Environ. Sci. Technol. 40(4), 1217-1222. Canfield, D.E. (2001) Isotope fractionation by natural populations of sulfate-reducing bacteria. Geochim. Cosmochim. Ac. 65(7), 1117-1124. Connell, W.E., Patrick, W.H. (1968)Sulfate reduction in soil: effects of redox potential and pH. Science. 159(3810), 86-87. Di Toro, D.M., Mahony, J.D., Hansen, D.J., Scott, K.J., Carlson, A.R., Ankley, G.T. (1992) Acid volatile sulfide predicts the acute toxicity of cadmium and nickel in sediments. Environ. Sci. Technol. 26(1), 96- 101. Di Toro, D.M., Mahony, J.D., Hansen, D.J., Scott, K.J., Hicks, M.B., Mayr, S.M., Redmond, M.S. (1990) Toxicity of cadmium in sediments: the role of acid volatile sulfide. Environ. Toxicol. Chem. 9(12), 1487-1502. Elliott, H.A., Liberati, M.R., Huang, C.P. (1986) Competitive Adsorption of Heavy Metals by Soils 1. J. Environ. Quality. 15(3), 214-219. Gambrell, R.P., Patrick, W.H. (1988) The influence of redox potential on the environmental chemistry of contaminants in soils and sediments. In: The ecology and management of wetlands. Springer, Boston, MA. 319-333. Kunito, T., Toya, H., Sumi, H., Ishikawa, Y., Toda, H., Nagaoka, K., Kazutoshi, S., Aikawa, Y., Matsumoto, S. (2017) Evaluating the effects of metals on microorganisms in flooded paddy soils using the SEM/AVS-based approach and measurements of exchangeable metal concentrations. Arch. Environ. Con. Tox. 72(3), 402-417. Lefcheck, J.S. (2016) piecewiseSEM: Piecewise structural equation modelling in R for ecology, evolution, and systematics. Methods Ecol. Evol. 7(5), 573-579. McBride, M.B. (1994) Environmental chemistry of soils. Oxford Univ. Press, New York. McGrath, J.A., Paquin, P.R., Di Toro, D.M. (2002) Use of the SEM and AVS approach in predicting metal toxicity in sediments. Fact sheet on environmental risk assessment. 10, 1-7. Miao, Z., Brusseau, M.L., Carroll, K.C., Carreón-Diazconti, C., Johnson, B. (2012) Sulfate reduction in groundwater: characterization and applications for remediation. Environ. Geochem. Hlth. 34(4), 539- 550. Narteh, L.T., Sahrawat, K.L. (1999) Influence of flooding on electrochemical and chemical properties of West African soils. Geoderma. 87(3-4), 179-207.

Pellegrini, E., Contin, M., Vittori Antisari, L., Vianello, G., Ferronato, C., De Nobili, M. in press. A new paper sensor method for field analysis of Acid Volatile Sulfides (AVS) in soils. Environ. Toxicol. Chem. Rickard, D., Morse, J.W. (2005) Acid volatile sulfides (AVS). Mar. Chem. 97, 141-197. Sun, L., Chen, S., Chao, L., Sun, T. (2007) Effects of flooding on changes in Eh, pH and speciation of cadmium and lead in contaminated soil. Bulletin Environ. Contam. Toxicol. 79(5), 514-518. Van den Berg, G.A., Loch, J.P.G., Winkels, H.J. (1998) Effect of fluctuating hydrological conditions on the mobility of heavy metals in soils of a freshwater estuary in the Netherlands. Water Air Soil Poll. 102(3-4), 377-388. Vile, D., Shipley, B., Garnier, E. (2006) A structural equation model to integrate changes in functional strategies during oldfield succession. Ecology. 87 (2), 504–517. Yu, K.C., Tsai, L.J., Chen, S.H., Ho, S.T. (2001) Chemical binding of heavy metals in anoxic river sediments. Water Res. 35(17), 4086-4094.

Varnost lokalno pridelanih rastlinskih živil iz Zgornje Mežiške doline

The safety of locally grown plant food from the Upper Meža valley

Stanislava Kirinčič1, Matej Ivartnik2, Helena Grčman3, Marko Zupan3, Agnes Šömen Joksić4,5 1 National Institue of Public Health, Trubarjeva 2, Ljubljana, Slovenija 2 National Institue of Public Health, OE Ravne na Koroškem, Ob Suhi 5b, Ravne na Koroškem, Sl. 3 University of Ljubljana, Biotechnical Faculty, Jamnikarjeva 101, Ljubljana, Slovenija 4 National Institue of Public Health, OE Koper, Vojkovo nabrežje 4a, Koper,Slovenija 5 University of Primorska, Faculty of Health Sciences, Polje 42, Izola, Slovenija

Abstrakt Povprečna koncentracija svinca (Pb) v listnati in korenasti zelenjavi, lokalno pridelani v Zgornji Mežiški dolini, ZMD, je od 6 do 30 krat večja od povprečne koncentracije za isti skupini zelenjave s slovenskega trga, medtem ko je povprečna koncentracija kadmija (Cd) od 2 do 7 krat večja. Povprečna koncentracija Pb je bila večja v zelenjavi, pridelani v ZMD na tleh z vsebnostjo Pb nad kritično imisijsko vrednostjo (bolj onesnažena tla) v primerjavi s tlemi z vsebnostjo Pb med opozorilno in kritično imisijsko vrednostjo (onesnažena tla). Povprečna koncentracija Pb v korenasti zelenjavi, pridelani na onesnaženih in bolj onesnaženih tleh, je presegala zakonodajne mejne vrednosti, ki veljajo za zelenjavo na trgu. Ocenjena izpostavljenost Pb je zaradi uživanja listnate in korenaste zelenjave pridelane v ZMD za povprečnega uživalca, v odvisnosti od starostne skupine, od 6 do 29 krat večja od ocenjene izpostavljenosti potrošnika, ki uživa tovrstna živila s slovenskega trga. Pri otrocih ocenjena izpostavljenost Pb samo zaradi uživanja listnate in korenaste zelenjave pridelane v ZMD na bolj onesnaženih tleh, brez ostalih prehranskih virov, presega v EU postavljeno na zdravju temelječo smerno vrednost za razvojno nevrotoksičnost. Potrebno je nadaljnje zmanjševanje izpostavljenosti svincu prebivalcev ZMD, zlasti najobčutljivejših skupin, kot so otroci in nosečnice. Najnovejše raziskave o koncentraciji svinca v krvi otrok namreč kažejo, da se slednja v zadnjih letih v Zgornji Mežiški dolini ne zmanjšuje več, kljub temu, da še ni dosegla zadovoljive ravni.

Ključne besede: svinec, kadmij, zelenjava, varnost, Zgornja Mežiška dolina.

Keywords: lead, cadmium, vegetables, safety, Upper Meža valley.

Introduction Due to mining and melting of lead ore in the past, the Upper Meža valley (UMV) became a degraded area, with increased concentrations of lead and cadmium in the environment and consequently also in the locally grown foods. The article deals with comparison of average concentrations of lead in leafy and root vegetables, grown and sampled in the UMV in the period 2008-2016 (Kirinčič et al., 2017) with the average concentrations of leaf and root vegetables from the Slovenian market. The latter were sampled in the period 2011-2016. The comparison of the estimated Pb exposure from consumption of vegetables grown in the UMV (Kirinčič et al., 2017) with estimated Pb exposure from consumption of vegetables from the Slovenian market was also made.

Results

Figure 1: Average concentrations of Pb in vegetables (mg/kg wet weight) grown in the Upper Meža valley (Kirinčič et al., 2017) and from the Slovenian market.

Figure 2: Chronic exposure to Pb through average consumption of leaf and root vegetables grown in the Upper Meža valley (UMV) (μg/kg bw/day) (Kirinčič et al., 2017) and through consumption of foods from the Slovenian market.

Acknowledgments The authors would like to acknowledge the Administration of the Republic of Slovenia for Food Safety, Veterinary and Plant Protection for providing data on concentrations of metals in foods from the Slovenian market.

References

Decree on limit values, alert thresholds and critical levels of dangerous substances into the soil (Official Journal RS, No. 68/96 in 41/04 – ZVO-1).

EC (European Commission). (2006). Commission Regulation (EC) No 1881/2006 of 19 December 2006 setting maximum levels for certain contaminants in foodstuffs. Official Journal of the European Union, L 364, 5—24.

Kirinčič, S., Ivartnik, M., Grčman, H., Zupan, M., Šömen Joksić, A., & Golja, V. (2017). Izpostavljenost prebivalcev Zgornje Mežiške doline strupenim kovinam iz lokalno pridelane zelenjave in tal. Exposure of inhabitants of Zgornja Mežiska dolina to toxic metals in locally grown vegetables and soil. Zbornik referatov in povzetkov, Slovenski kemijski dnevi 2017, 1-7.

EFSA. (2012a). Lead dietary exposure in the European population. EFSA Journal, 10(7), 2831.

EFSA. (2012b). Cadmium dietary exposure in the European population. EFSA Journal, 10(1), 2551.

Določanja vsebnosti in speciacije kovin v tleh in rastlinah z metodami rentgenske fluorescenčne in absorpcijske spektrometrije

Metal concentration and speciation in soil and plants by X-ray fluorescence and absorption spectrometry

Katarina Vogel-Mikuš1,2, Iztok Arčon3,2, Peter Kump2, Alojz Kodre4,2 1Biotechnical faculty, University of Ljubljana, Jamnikarjeva 101, 1000 Ljubljana 2Jozef Stefan Institute, Jamnikarjeva 39, 1000. Ljubljana 3University of Nova Gorica, Vipavska 13, 5000 Nova Gorica 4Faculty of Mathematics and Physics, University of Ljubljana, Jadranska 19, SI-1000 Ljubljana

Abstract Activities associated with industry, agriculture and traffic have resulted in global pollution of ecosystems with metals posing threats to animal and human health. Hence, there is a growing need to develop powerful analytical tools for monitoring metal concentrations and speciation in the biosphere and its abiotic environment, with the common goals to assess metal bioavailability, toxicity and associated risks, and to develop environmentally friendly technologies for cleaning and remediation of metal-polluted and degraded ecosystems. Use of advanced X-ray based techniques applied in two case studies investigating Cd and Hg uptake and metabolism in plants will be presented.

Povzetek Dejavnosti povezane z industrijo, kmetijstvom in prometom so vzrok za globalno onesnaženje ekosistemov s kovinami, kar ogroža zdravje živali in ljudi. Zato se poraja vedno večja potreba po razvoju naprednih analiznih tehnik za spremljanje koncentracije in speciacije kovin v živem in neživem okolju, s skupnima ciljema oceniti biodostopnost, strupenost in tveganja zaradi prisotnosti kovin v okolju ter razviti okolju prijazne tehnologije za čiščenje in sanacijo s kovinami onesnaženih in degradiranih ekosistemov. Predstavljena bo uporaba naprednih tehnik na osnovi rentgenskih žarkov pri študijah privzema in presnove Cd in Hg v rastlinah.

Ključne besede: rastline, fitoremediacja, strupenost, biodostopnost, rentgenska fluorescenčna spektrometrija, rentgenska absorpcijska spektrometrija, EXAFS, XANES, sinhrotronske tehnike

Keywords: plants, phytoremediation, toxicity, bioavailability X-ray fluorescence spectrometry, X-ray absorption spectrometry, EXAFS, XANES

Metals in increased concentrations in the environment pose threats to living organisms, because they interfere with vital biological processes, including photosynthesis and respiration. By replacement of essential minerals in structural and functional molecules, especially enzymes, binding to thiol and amino groups of proteins, or direct/indirect induction of free radicals, they cause malfunctioning of important biological molecules and increase oxidative stress. In order to get deeper insight into metal uptake, transport, localization and speciation in plants, a holistic approach using complementary analytical techniques is needed. The techniques span the range from “bulk” analyses of metal concentrations in soil and plant organs to imaging of metal distribution in plant tissues and cells, and techniques for determination of metal speciation and local ligand environment at organ, tissue and cellular levels. The techniques addressed in this talk include: energy dispersive X-ray fluorescence spectrometry (EDXRF), synchrotron micro-X-ray fluorescence spectroscopy (SR-micro-XRF) and synchrotron X-ray absorption

spectroscopy (extended X-ray absorption fine structure [EXAFS], and X-ray absorption near-edge structure [XANES]).

Methodology Two case studies will be presented, including Cd uptake, distribution and speciation in metal- hyperaccumulating pennycress, and Hg uptake and speciation in mycorrhizal roots of maize. Metal concentrations in soil and plants were analysed by EDXRF, using radioisotope sources Am-241 (for analysis of Cd) and Cd-109 (for analysis of Hg) (Nečemer et al., 2008). Metal localization studies were performed by micro-proton induced X-ray emission (micro-PIXE)(Vogel-Mikuš, Pongrac, & Pelicon, 2014) and micro X-ray fluorescence spectroscopy (micro-XRF) performed at ID21 beamline of European synchrotron radiation facility (ESRF) in France (Koren, Arčon, Kump, Nečemer, & Vogel- Mikuš, 2013). Metal speciation was analysed by X-ray absorption spectroscopy at BM23 beamline, ESRF. In the case of Cd plant exposure, the Cd- hyperaccumulating pennycress (Noccaea praecox (Wulfen) F.K.Mey) was grown in hydroponic experiments (Koren et al., 2013). The plants were exposed to CdCl2 or CdSO4. Physiological parameters and Cd uptake were monitored. Cd localization and speciation was performed in leaves by micro-XRF at ID21 beamline, ESRF (Koren et al., 2013). Cadmium speciation and ligand environment was studied at BM23 and ID21 beamlines, ESRF (Koren et al., 2013). Mercury experiments were performed in soil collected in Idrija and soil artificially contaminated by HgCl2 while maize (Zea mays L.) was used as a test organism. Maize was inoculated with arbuscular mycorrhizal fungi isolated from soil collected in Idrija (Debeljak et al., 2018). Mercury speciation studies were performed at BM23 beamline, ESRF (Kodre et al., 2017).

Results & Discussion In the leaves of N. praecox Cd is predominately stored in large vacuolated epidermal cells (Figure 1), mainly bound to carboxylic acids as shown by Cd-L3 XANES. Cd is traced also in photosynthetically active mesophyll, but mainly accumulated in intercellular space (the apoplast) bound to strong sulphur ligands (Koren et al., 2013). In Idrija soil Hg is mainly occurring as cinnabar (HgS). Mycorrhizal fungi enhance Hg uptake into maize roots and bind it mainly to metallothioneins as shown by Hg-L3 edge EXAFS (Figure 2), where Hg is coordinated to four sulphur atoms. In plants, however, Hg is coordinated to two sulphur atoms involving simple sulphur ligands such as cystein.

Figure 1. Micro-XRF Cd (red) localization in Figure 2. Hg coordination in maize mycorrhizal leaves of N. praecox. A) epidermis, B) mesophyll. roots. As proved by EXAFS, Hg is bound to four The grey image is taken in X-ray absorption sulphur ligands as in metallothioneins, while in mode to visualize the leaf tissue morphology. plants generally simple two-sulphur ligands as cysteine are involved.

Acknowledgements

Studies were financed by the Slovenian Research Agency programmes (P1-0212 and P1-0112). We acknowledge ESRF for the beamtime at ID21 (projects EC 719, EC 968) and BM23 (projects LS-2209 and LS- 2275).

References Debeljak, M., van Elteren, J. T., Špruk, A., Izmer, A., Vanhaecke, F., & Vogel-Mikuš, K. 2018. The role of arbuscular mycorrhiza in mercury and mineral nutrient uptake in maize. Chemosphere, 212: 1076–1084.

Kodre, A., Arčon, I., Debeljak, M., Potisek, M., Likar, M., & Vogel-Mikuš, K. 2017. Arbuscular mycorrhizal fungi alter Hg root uptake and ligand environment as studied by X-ray absorption fine structure. Environmental and Experimental Botany, 133: 12–23.

Koren, Š., Arčon, I., Kump, P., Nečemer, M., & Vogel-Mikuš, K. 2013. Influence of CdCl2 and CdSO4 supplementation on Cd distribution and ligand environment in leaves of the Cd hyperaccumulator Noccaea (Thlaspi) praecox. Plant and Soil, 370(1–2): 125–148.

Nečemer, M., Kump, P., Ščančar, J., Jaćimović, R., Simčič, J., Pelicon, P., Budnar, M., Jeran, Z., Pongrac, P., Regvar, M., & Vogel-Mikuš, K. 2008. Application of X-ray fluorescence analytical techniques in phytoremediation and plant biology studies. Spectrochimica Acta Part B: Atomic Spectroscopy, 63(11): 1240–1247.

Vogel-Mikuš, K., Pongrac, P., & Pelicon, P. 2014. Micro-PIXE elemental mapping for ionome studies of crop plants. International Journal of PIXE, 24(3–4): 217–233.

Remediacija na degradiranih industrijskih območij s hladno reciklažo

Remediation on degraded industrial site with cold recycling

Nadja Romih1, Uroš Apotekar2, Roman Kugler2, Cvetka Ribarič Lasnik1 1Inštitut za okolje in prostor, Slovenija, [email protected] VOC Komunala, d. o. o., Slovenija, uroš[email protected]

Abstract In accordance to the list of degraded areas it is time for remediating areas into useful areas for different purposes. The abandoned industrial areas are presenting a large area, that there is no known technology, that would restore surface in primary condition. Common technical opinion is that polluted soil should not be transferred and should be remediated in-situ. Degraded areas should establish to such condition, where surface is not presenting contamination in air, due to dusting of soil, and leaching through the soil profile into underground waters any more. Use of cold recycling is one of possible technologies of remediation, where composite achieves uniaxial compressive strength of ≥ 100 MPa, which will be allowing final use of a remediating area also for the putting up of more demanding buildings. Ključne besede: degradirana območja, gradbeni odpadki, remediacija, hladna reciklaža Key words: degraded areas, construction wastes, remediation, cold recycling Degradirana območja V EU je po podatkih Evropske okoljske agencije evidentiranih okrog 250.000 degradiranih območij zaradi opuščene dejavnosti, podobnih območju Stare Cinkarne v Celju. Samo v Sloveniji je bilo leta 2011 evidentiranih 194 tovrstnih območij v skupni površini 979 ha. Gre za območja, kjer je degradacijo povzročila industrija, vojaška dejavnost, transport in infrastrukturne dejavnosti ter rudarska dejavnost.

Sanacija degradiranih območij Sanacije degradiranih območij in s tem okoljskih bremen potekajo v svetu različno, v splošnem pa lahko opazimo trend, da se v okoljsko visoko ozaveščenih državah opušča odvažanje onesnažene zemljine na odlagališča nevarnih odpadkov ali njihova enkapsulacija, saj je takšno ravnanje z odpadki le začasna rešitev, ki v resnici postane breme prihodnjih rodov. Nove pristope pri ravnanju z odpadki predpisuje panevropski dokument Waste Fremework Directive (2008/98/ES), ki ga je v svoj pravni red vključila tudi Slovenija. Ta odlaganje odpadkov obravnava kot skrajno nesprejemljivo ter prednostno zahteva njihovo snovno predelavo in obravnavo kot potencialen vir surovin. Vir surovin je torej lahko gradbeni odpadek kot tudi nevaren odpadek, če ga znamo spremeniti v okoljsko sprejemljivega. Tako se zapirajo snovne krožne zanke brez potreb po naravnih surovinah. Po svetu je v uporabi več različnih pristopov za remediacijo onesnaženih zemljin. Ameriška okoljska agencija (EPA) jih klasificira in razvršča na izolacijo, ekstrakcijo ‐ fizično separacijo, metode za zmanjšanje strupenosti in imobilizacijo. Najpogostejša je uporaba imobilizacije, pri kateri se onesnažena zemljina zmeša z različnimi aditivi. To zagotavlja trajno fizikalno in kemijsko imobilizacijo onesnažil. Kot aditivi se pogosto uporabljajo portlandski cement, apno, gline in razni reciklirani materiali (leteči pepeli, jeklarske žlindre, humusni pripravki in podobno). Metode imobilizacije so bile uporabljene tudi pri enem največjih projektov

remediacije onesnažene zemljine v Evropi – gradnji olimpijskega parka za olimpijske igre v Londonu leta 2012.

Hladna reciklaža Hladna reciklaža se že skoraj 20 let uporablja kot reciklaža asfalta za primer obnovitve cest. Postopek hladne reciklaže omogoča ohranjanje naravnih virov in manj izpustov zaradi prevoza materiala. Stroški obnove cest so z uporabo hladnega reciklatorja lahko nižji v povprečju tudi za 10 €/m3. Napredna nepropustna zadrževalna pregrada predstavlja inovativni in celoviti pristop izvajanja postopka remediacije na industrijsko degradiranih območjih, kjer se s postopkom hladne reciklaže ne posega v kritično onesnaženo zemljino in kjer je potrebna relativno nizka vgradnja kompozita za samo izvedbo pregrade (30‐35 cm). Vir surovin za kompozit: različne vrste gradbenih odpadkov, dosegljivih v gradbeništvu pri obnovi cest in objektov, ki danes ostajajo kot neizkoriščen vir materialov. Potencialni vir za izdelavo ustreznega kompozita za izdelavo nepropustne zadrževalne pregrade predstavljajo različne vrste gradbenih odpadkov dosegljivi v gradbeništvu pri obnovi cest, objektov in v današnjem času ostajajo kot neizkoriščen odpadek kot so na primer: ‐ 17 05 07 Tolčenec izpod železniških tirov in pragov, ki ni naveden pod 17 05 07. ‐ 17 09 04 Mešani gradbeni odpadki in odpadki iz rušenja objektov, ‐ 17 01 01 Beton, ‐ 17 01 02 Opeke, ‐ 17 03 02 Bitumenske mešanice, ki niso navedene pod 17 03 01 – asfaltni drobljenec, ki ostaja pri obnovi cest kot odpadek. Lastnost asfalta je samo z uporabo cementa in vode pri velikih temperaturnih razlikah in zunanjih vplivov negativna zaradi pokanja. Reciklator pa v svojo tehnologijo lahko uvaja tudi penjeni bitumen in tako se lastnost preplastenja zaradi uporabe bitumenske mešanice izboljša oziroma bitumen zaradi svoje lastnosti prožnosti, elastičnosti in povrnitve v prvotno stanje ob obremenitvah izniči negativne lastnosti preplastitve ob zunanjih vplivih. Zelo pomembna pozitivna lastnost uporabe takšnega reciklatorja je ne- ustvarjanje odpadkov zemljine, saj je ne dviguje, zaradi kontinuiranega dovajanja vode v času preplastitve bitumenske mešanice ne povzroča prašenja v okolico. Za ustrezno izdelavo recepture je potrebno določiti sestavo zrnavosti, stabilizacijske mešanice, optimalno vrsto ter količino stabilizacijskega veziva (bitumen). Pomembne so laboratorijske raziskave in notranja kontrola izvedbe del na gradbišču in v laboratoriju. Zadrževalne pregrade so mišljene tudi kot pregrade za hidrološko izolacijo območja s permanentnimi pregradami proti vtoku in iztoku podtalnice in meteorne vode.

V mesecu aprilu 2018 je VOC Celje d.d. v konzorciju s podjetjem VOC Komunala d.o.o. poskusno izvedel tehnologijo hladne reciklaže na območju Stare Cinkarne v Celju (slika 2).

Slika 2: Postroj hladne reciklaže Slika 3: Poskusna izvedba hladne reciklaže na območju Stare Cinkarne v Celju

Cilj je ponuditi kompozit z enoosno tlačno trdostjo ≥ 100 MPa, kar bo omogočalo končno uporabo remediiranega območja tudi za postavitev zahtevnejših objektov kot so stavbe in bloki.

Ključna je konceptualna zasnova izgradnje same zadrževalne pregrade, ki preprečuje infiltracijo padavin, izpiranje, raznašanje snovi z erozijo vetra in vode ter nekontrolirane posege ljudi in živali v kontaminirano onesnaženo zemljino oziroma nasutje. Ključno je to, da bo takšna rešitev omogočala tudi možnost vzpostavitve vegetacije in ureditev krajine ter tako vplivala na izboljšanje razmer tako v nasutju kot v podzemni vodi.

Slika 4:Ureditev degradiranega območja v uporabno zemljišče za različne namene

Literatura Martin N. Sara, Priročnik: Site Assessment and Remediation Handbook, 2nd Edition.

G. Dermont, M. Bergeron, G. Mercier, and M. Richer‐Laflèche. Soil washing for metal removal: A review of physical/chemical technologies and field applications. Journal of Hazardous Materials. 2008, 152(1): 1‐31.

Reddy K.R., Adams J.F., Richardson C. (1999). Potential technologies for remediation of brownfield. Practice Periodical of Hazardous, Toxic, and Radioactive Waste Management 3(2), pp. 61– 68.

Burlakovs Juris. Contamination remediation with soil amendments by immobilization of heavy metals. Doctoral thesis. Riga, 2015. University of Latvia, Faculty of geography and earth sciences, Department of environmental science. 147 p.

WIRTGEN, Cold recycling technology, 1st edition, 2012. Priročnik. Wirtgen GmbH.

Jurjavčič P., Cotič Z. Priročnik za trajnostno obnovo voziščnih konstrukcij po postopku hladne in-situ reciklaže, 2014. Life projekt ReBirth.

B. Hrast, Hladna reciklaža obstoječih cest ‐ stabiliziranje z različnimi vezivi. Diplomska naloga. Ljubljana 2012. Univerza v Ljubljani, Fakulteta za gradbeništvo in geodezijo.

Lampič B., Cigale D., Kušar S., Potočnik Slavič I., Foški M., Zavodnik Lamovšek A., Barborič B., Meža S., Radovan D. Celovita metodologija za popis in analizo degradiranih območij, izvedba pilotnega popisa in vzpostavitev ažurnega registra : Končno poročilo. Ljubljana: [Filozofska fakulteta, Univerza v Ljubljani], 2017. 192 str., graf. prikazi, zvd., fotogr. [COBISS.SI-ID 65700194]

Leben J., Mladenovič A., Mauko Pranjić A., Leban J., Cotič Z., Jurjavčič P., Šprinzer M. About the project ReBirth : how to increase the use of recycled industrial and construction waste. V: Athens 2014 Sustainable Solid Waste Management : proceedings, 2nd International Conference on Sustainable Solid Waste Management, 12th - 14th June 2014. Athens: National Technical University of Athens [etc.]. 2014. http://athens2014.biowaste.gr/pdf/jure_pr.pdf. [COBISS.SI-ID 2092903]

Mladenovič A., Oprčkal P. Remediacija onesnaženih zemljin : Okoljski dan gospodarstva - Po sledeh nevarnih snovi, Ljubljana, 1. junij 2017. [COBISS.SI-ID 2305639]

Sanacije onesnaženih tal na otroških igriščih vrtcev

Remediation of contaminated soil in kindergarten playgrounds

Helena Grčman1, Marko Zupan1 1 University of Ljubljana, Biotechnical Faculty, Jamnikarjeva 101, Ljubljana, Slovenija

Abstract Playgrounds are particularly sensitive land use due to high risk regarding transfer of possible potentially toxic substances (PTS) from soil to human organism. Children spend long time outside, play with the soil and consequently could inhale and consume soil particles. Due to their smaller body mass, permissible daily intake could be quickly reached or exceeded. This article presents preventive measures for minimizing transfer of PTS from soil to children and remediation strategy in the case of critically polluted soil on children playgounds. Experiences were obtained by remediation of four playgrounds with critically polluted soil in Ljubljana and Celje municipality. In the case of slightly polluted soils, the contact of children with bare soil surface should be avoided as far as possible. This can be achieved with the regular maintenance of grass cover (mowing, watering, fertilizing). Permanent eroded surfaces in the shadow or under the swings could be efficiently cover with different material (artificial covers, wooden chocks, bark, paving stones). In the case of highly polluted soils, soil excavation and replacement with unpolluted soils was proved as an appropriate measure. However, special attention to the quality of the new soil material was needed (texture, pH, elemental composition). Field measurement of elemental composition with portable XRF analyser was proven as appropriate tool for testing the variability and suitability of soil and other used material (gravel, grass carpet). We recommend also soil monitoring immediately after the remediation and regularly in the five-year intervals.

Ključne besede: onesnaženost tal, otroška igrišča, sanacije

Keywords: soil pollution, playgrounds, remediation

Uvod Zelene površine otroških igrišč so primerno okolje za igro otrok in element zdravega razvoja. Vendar tla, še posebej v mestih, lahko vsebujejo potencialno nevarne snovi za zdravje (onesnažila). Te so lahko posledica onesnaževanja preko zraka (industrija, promet,...) ali navoza onesnažene zemljine ob gradbenih delih. Vnos potencialno nevarnih snovi iz tal v otroški organizem je z vdihovanjem onesnaženega prahu v zraku ali z uživanjem onesnaženih tal. Čeprav se zdi slednji način manj verjeten, je to najpogostejša pot vnosa onesnažil iz tal v otroški organizem. Otroci se s tlemi igrajo in tla preko umazanih rok vnesejo v usta. V želodcu se zaradi nizkega pH dostopnost potencialno nevarnih snovi iz tal poveča. Zaradi velike izpostavljenosti zdravja otrok, je potrebno v primerih, da so tla na otroških igriščih onesnažena, izvajati preventivne ali sanacijske ukrepe.

Preventivni ukrepi za zmanjševanje vnosa onesnažil iz tal v otroški organizem Če je le mogoče, je potrebno zagotoviti, da tla na otroških igriščih ne vsebujejo potencialno nevarnih snovi v koncentracijah, ki presegajo opozorilne vrednosti, ki jih predpisuje Uredba o mejnih, opozorilnih in kritičnih imisijskih vrednostih nevarnih snovi v tleh (Uradni list RS, št. 68/96). V kolikor to ni mogoče, je potrebno v največji možni meri preprečiti stik otrok z golimi površinami. To lahko na večjih površinah in sončnih legah dosežemo z rednim vzdrževanjem travne ruše, kar pomeni redno košnjo, zalivanje v poletnih mesecih in gnojenje. Pod igrali in v senci dreves, kjer travna ruša zelo slabo uspeva in večinoma nastanejo trajne erodirane površine, je bolje tla prekriti s primernimi materiali, kot so tartan,

različne perforirane umetne mase, leseni čoki, lubje, tlakovci, asfalt. Pri tem je potrebno za vsako lokacijo poiskati ustrezno rešitev glede na naravne danosti, velikost igrišča in arhitekturno zasnovo.

Slike 1-2: Prekrivanje golih površin in skrb za travno rušo sta ključna preventivna ukrepa.

Sanacije kritično onesnaženih tal na otroških igriščih Če vrednosti katerekoli merjene potencialno nevarne snovi presežejo kritično vrednost, so potrebni temeljitejši ukrepi, ki najprej zahtevajo podrobnejšo raziskavo razsežnosti onesnaženja ter izdelavo ocene tveganja za zdravje otrok. V kolikor ocena tveganja pokaže nevarnost za zdravje, je potrebno izvesti sanacijo igrišča. V dosedanjih primerih kritične onesnaženosti (Ljubljana, Celje), je bil izveden izkop (do globine 50 cm) in zamenjava z neonesnaženimi tlemi. Najprimernejša so naravna neonesnažena tla (Ur. l. RS, št. 34/08, 61/11) s primernimi fizikalnimi in kemijskimi lastnostmi (ilovnata tekstura, nevtralna pH vrednost). Zaradi velike naravne variabilnosti tal svetujemo tudi sprotne meritve elementne sestave tal s prenosnim rentgenskim fluorescentnim spektrometrom – XRF (Sliki 3 in 4), s čimer lahko preverjamo tudi ustreznost drugih uporabljenih materialov (gramoza za tampon, travnih tepihov). Med izvedbo sanacije je potrebno upoštevati varnostne ukrepe za preprečevanje širjenja onesnaženja. Prašenje preprečimo, če odstranitev in odvoz zemljine potekata pri primerni vlažnosti tal, to je od 80 do 100 % poljske kapacitete tal za vodo, ali v praksi 48 ur po intenzivnih padavinah. Če sanacija poteka v obdobju daljšega suhega vremena je potrebno dan pred izkopom tla primerno navlažiti. Odsvetujemo delo v premokrem stanju tal, ko se tla blatijo in se lahko onesnaženo blato pri transportu cedi iz vozil. V mokrem stanju so tla pri uporabi težke gradbene mehanizacije tudi zelo ranljiva za poslabšanje fizikalnih lastnosti tal. Izvajalci gradbenih del morajo biti ustrezno zaščiteni z delovno opremo. Igrišče mora biti med izvedbo sanacije zaprto in ograjeno z zaščitno ograjo. Po odstranitvi onesnažene zemljine je potrebno oprati vse izpostavljene površine, ki bodo na igrišču ostale po prenovi, kar lahko zajema tudi pranje fasade, če je bila ta dalj časa izpostavljena nalaganju prahu zaradi prašenja onesnaženih tal. Po izvedeni sanaciji je potrebno izvesti kontrolni monitoring tal. Svetujemo, da se stanje tal spremlja z rednim monitoringom v petletnih intervalih.

Slike 1-2: Preverjanje materialov s prenosnim rentgenskih fluorescentnim spektrometrom.

Literatura Uredba o mejnih, opozorilnih in kritičnih imisijskih vrednostih nevarnih snovi v tleh (Ur. l. RS, št. 68/96)

Uredba o obremenjevanju tal z vnašanjem odpadkov (Ur. l. RS, št. 34/08 in 61/11).

Predstavitev postopka čiščenja tal z EDTA

Presentation of the EDTA soil washing technology

Domen Leštan1,2 1Centre for Soil and Environmental Sciences, University of Ljubljana, Ljubljana, Slovenia 2Envit Ltd., Trzaska cesta 330, 1000 Ljubljana, Slovenia

Abstrakt Število ljudi in pritisk na talni fond stalno rasteta. S tem se povečuje verjetnost za pridelavo hrane na s kovinami onesnaženih območjih in s tem povezana zdravstvena tveganja. Rešitev sta čiščenje (remediacija) in ponovna uporaba tal za kar do sedaj ni bilo primernih metod. Nova patentirana tehnologija omogoča ekonomično, učinkovito, trajnostno in za okolje varno odstranjevanje svinca in drugih nevarnih kovin iz onesnaženih tal pri čemer se osnovni reagent in procesne vode reciklirajo v zaprti procesni zanki, ni škodljivih emisij v okolje, tla pa po čiščenju ostanejo rodovitna. V sodelovanju in inženirsko podporo podjetja Arhel d.o.o. in s EU sredstvi Life+ (ReSoil) je bila patentirana tehnologija z remediacijsko napravo v Prevaljah v Mežiški dolini povečana v demonstracijsko merilo.

Ključne besede: Strupene kovine, pranje tal z EDTA, funkcionalna remediirana tla

Keywords: Toxic metals, EDTA soil-washing, functional remediated soils

Fertile soil is a valuable, limited resource, but often contaminated with a number of toxic metals, with Pb representing the most pervasive and persistent risk to human health. Any exposure to Pb is considered to be potentially harmful to human health; no threshold for adverse effects has been identified. Only a fraction of Pb contaminated soils is treated due to the lack of efficient and environmentally sustainable technologies. We recently developed an unique soil washing technology, which efficiently removes Pb and other toxic metals from soil by complexation with a strong chelant, EDTA. The patented technology features a novel reaction of alkaline substitution, precipitation and adsorption of toxic metals on polysaccharides and chelant acidic precipitation for process waters and EDTA recycling in a closed loop (Figure 1). No wastewaters and minimum (<1%) solid wastes are generated (US Patent 9108233 B2; EP Patent 3153246 B1). The post-remedial toxic emissions from soil are mitigated to the levels close or bellow limits of quantification by effective soil rinsing and addition of zero-valent Fe (Fe0) into the soil slurry (GB Patent Appl. 1720126.0) which enables for fast and permanent adsorption of small residual quantities of EDTA and toxic metals chelates. The process is abiotic; poor EDTA biodegradability is not an issue even if exceedingly high chelant concentrations are used in soil washing. Furthermore, Fe0 slurry addition simultaneously immobilize As which is a common soil co-contaminant. Technology is cost-efficient (136-186 $ ton-1 without profit, economy of scale) by reagent recycling, using inexpensive/ waste materials (lime, H2SO4, waste paper, scrap iron) and common machinery. Realistically tended vegetable gardens with EDTA-remediated soil have supported the growth of vegetables, grasses and horticultural plants. Pb uptake by plants was prevented or significantly reduced. Remediation with high EDTA doses to some extend affected the soil C and N cycles, soil enzyme activities and the structure and abundance of soil microbial populations, especially arbuscular mycorrhizae. However, using simple and inexpensive revitalisation measures, e.g., addition of compost, healthy un-polluted soil and commercial or indigenous microbial AM inoculum, completely restored microbial life. Supported by s EU Life+ (ReSoil) funds and in cooperation with engineering firm Arhel Ltd. was the novel technology recently scaled-up into demonstrational remediation plant in city of Prevalje, Slovenia, with the capacity

of up to 6 ton of soil per day (https://www.youtube.com/watch?v=r50LNFog-Hc&feature=youtu.be). Further detailed studies on ecosystem services provided by remediated soils are underway (Figure 1).

Figure 1: Development of novel remediation technology and remediated soil testing.

Acknowledgement The work was supported by EU project LIFE12 ENV/SI/000969, Arhel Ltd., Slovenia, and the Slovenian Research Agency, Grant J4-6808.

Literature LEŠTAN, Domen. Washing of contaminated soils : US 9108233 B2), United States Patent Office, 2015. LEŠTAN, Domen, FINŽGAR, Neža, GERL, Marko, GLUHAR, Simon, LAKOVIČ, Gorazd, HAMITI, Branko. Method for soil and sediment remediation : EP 3153246 B1, Munchen: EPO, 2018. LEŠTAN, Domen. Curbing toxic emissions from remediated substrate : application no. GB1720126.0, Newport: Intellectual Property Office, 2017.

Ovrednotenje izvedljivosti remediacije s kelatnimi ligandi in ocena tveganj remediiranih tal

Fisibility evaluation of remediation with chelants and risk assesment of remediated soil

Erika Jež1, Domen Leštan2 1, Biotehniška fakulteta, Univerza v Ljubljani, Slovenija, [email protected] 2 Biotehniška fakulteta, Univerza v Ljubljani, Slovenija, [email protected]

Abstract From soil samples from 268 locations in the Meza Valley, Slovenia on average 63 % of Pb were removed with washing solution containing 60 mM Na2H2EDTA per kg of soil. Geostatistical simulations showed that the contaminated area covers 19.4 km2 and that soil remediation has the potential to reduce the area with Pb above the critical regulatory threshold limit by 91 %. Additional 20 soil samples from Pb contaminated areas were extracted. EDTA soil retention and potential secondary emissions of EDTA were examined. On average, 1% and up to 64% of applied EDTA was after remediation retained in soils The secondary emissions of EDTA increased with the acidity of the media. Exposing soil to model abiotic and biotic ageing factors did not induce additional secondary emissions of EDTA retained in remediated soil.

Povzetek Iz 268 onesnaženih vzorcev tal v Mežiški dolini smo z ekstrakcijo uspeli odstraniti 63 % svinca ob uporabi 60 mM Na2H2EDTA na kg tal. Prostorska interpolacija podatkov nakazuje, da v Mežiški dolini onesnaženje tal s svincem pokriva 19,4 km2. Po ekstrakciji vzorcev z EDTA se je onesnaženo območje zmanjšalo za 91 %. Dodatnih 20 onesnaženih vzorcev tal smo ter določali delež ostankov EDTA v remediiranih tleh ter potencialne sekundarne emisije EDTA iz remediiranih tal. Po ekstrakciji v tleh ostaja od 1do 64 % EDTA. Do sekundarnih emisij pride le ob spiranju s kislo raztopino. Prav tako ni bilo povišanja sekundarnih emisij po izpostavitvi tal biotskim in abiotskim dejavnikom.

Ključne besede: Pranje tal, EDTA, svinec, nevarne emisije Keywords: Soil remediation, EDTA, lead, toxic emissions

Introduction There is land contamination in most industrialized countries and it is a growing problem in the emerging economies. One of the most affected locations in Slovenia is the Meza Valley that is historically contaminated from Pb mining and smelting. Effective soil remediation is there urgently needed (Ivartnik and Erzen, 2010). Soil washing using the chelating agent ethylenediamine tetraacetate (EDTA) has been found to be effective way to remove potential toxic metals out of the poluted soils (Finzgar and Leštan, 2007). The application of geostatistical techniques to describe the spatial distribution and variability of soil contaminants as a component of risk assessment has already been demonstrated in many papers (Dao et al., 2013; Wu and Zhang, 2010). However, there are very few reports on using geostatistics to provide an estimate of remediation outcomeand as a tool for planning activities and managing uncertainty in site remediation (McKenna, 1998). EDTA-based remediation is reaching maturity but also little information is available on the state of chelant in remediated soil. EDTA complexes with toxic metals (chelates) are a potential health risk; they are poorly biodegradable (Tiedje, 1975) and persist in the soil environment (Meers et al., 2005). Wen et al. (2009) reported that only 14% of EDTA was

decomposed in 20 days. Sub-soil transportation of complexed toxic metals and the spread of pollution could therefore pose a long-term environmental hazard (Rahman et al., 2010).

Materials and methods Soil samples from 268 locations in the Meza Valley were extracted with the chelating agent 60 mM Na2H2EDTA per kg of soil. Pb concentration in soli were measured before and after extraction. Data were interpolated - Empirical Bayesian kriging method (EBK) to produce classification map. 20 soil -1 samples were extracted with 120 mM kg Na2H2EDTA, CaNa2EDTA, H4EDTA and EDTA in extraction solution was measured (Wang et al., 2013).

Results and discussion Soil samples from 268 locations in the Meza Valley, Slovenia with Pb concentrations up to 8955 mg kg−1 were extracted with the chelating agent ethylenediamine tetraacetate (EDTA). On average 63 % of Pb were removed with washing solution containing 60 mM Na2H2EDTA per kg of soil. Geostatistical simulations showed that the contaminated area covers 19.4 km2 and that soil remediation has the potential to reduce the area with Pb above the critical regulatory threshold limit by 91 % (Fig 1).

Fig 5: Prediction map of Pb concentrations in soils of the Meza Valley before and after soil samples extraction with EDTA. A broken line indicates areas of critical Pb soil concentrations.

Soil samples from Pb contaminated areas in Slovenia, Austria, Czech Republic and USA were extracted with 120 mM kg-1 Na2H2EDTA, CaNa2EDTA and H4EDTA. EDTA soil retention and potential secondary emissions of EDTA were examined. On average, 15% and up to 64% of applied EDTA was after remediation retained in acidic soils. Much less; in average 1% and up to the 22% of EDTA was retained in calcareous soils. The secondary emissions of EDTA retained in selected remediated soil

increased with the acidity of the media (average pH end point 3.6) released up to 36% of EDTA applied in the soil (28.1 mmol kg-1). Extraction with deionised water (pH > 6.0) did not produce measurable EDTA emissions. Exposing soil to model abiotic (thawing/freezing cycles) and biotic (ingestion by earthworms Lumbricus rubellus) ageing factors did not induce additional secondary emissions of EDTA retained in remediated soil.

References Dao, L., Morrison, L., Kiely, G., Zhang, C., 2013. Spatial distribution of potentially bioavailable metals in surface soils of a contaminated sports ground in Galway, Ireland. Environ. Geochem. Health 35, 227– 238.

Finzgar, N., Lestan, D., 2007. Multi-step leaching of Pb and Zn contaminated soils with EDTA. Chemosphere 66, 824–832.

Ivartnik, M., Erzen, I., 2010. The IEUBK model for lead blood burden prediction in children used in the exploration and remediation of the UpperMeža valley environment. Slov. J. Public Health 49, 76–85.

McKenna, S.A., 1998. Geostatistical approach for managing uncertainty in environmental remediation of contaminated soils; case study. Environ. Eng. Geosci. 4, 175–184.

Meers, E., Ruttens, A., Hopgood, M.J., Samson, D., Tack, F.M.G., 2005. Comparison of EDTA and EDDS as potential soil amendments for enhanced phytoextraction of heavy metals. Chemosphere 58, 1011-1022.

Rahman, I.M.M., Hossain, M.M., Begum, Z.A., Rahman, M.A., Hasegawa, H., 2010. Environmental consequences associated with chelant-assisted phytoremediation of metal-contaminated soil. In: Golubev, I. (Ed.), Handbook of Phytoremediation. Nova Science Publishers, New York, pp. 709-722.

Tiedje, J.M., 1975. Microbial Degradation of Ethylenediaminetetraacetate in Soils and Sediments Microbial Degradation of Ethylenediaminetetraacetate in Soils, 30, 2-5.

Wang, J., Yu, J., Kong, X.Z., Hou, L., 2013. Spectrophotometric determination of EDTA in aqueous solution through ferroin formation using sodium sulfite as the reducer. Chemosphere 91, 351-357.

Wen, J., Stacey, S.P., McLaughlin, M.J., Kirby, J.K., 2009. Biodegradation of rhamnolipid, EDTA and citric acid in cadmium and zinc contaminated soils. Soil Biol. Biochem. 41, 2214-2221.

Wu, C., Zhang, L., 2010. Heavy metal concentrations and their possible sources in paddy soils of amodern agricultural zone, southeastern China. Environ. Earth Sci. 60, 45–56.

The influence of EDTA-soil washing and post treatment on the bioavailability of trace metals and plant growth

Vpliv remediacije z EDTA in nadaljnimi tretiranji na biodostopnost kovin v sledovih in na rast rastlin

Christoph S. Noller1, Wolfgang Friesl-Hanl1,2, Rebecca Hood-Nowotny1, Domen Lestan3, Markus Puschenreiter1, Andrea Watzinger1 1Institute of Soil Research, University of Natural Resources and Life Sciences, Vienna, Austria 2Environmental Recourses and Technologies, AIT Austrian Institute of Technology GmbH, Austria 3Agronomy Department, Biotechnical Faculty, University of Ljubljana, Slovenia

Keywords: soil washing, contaminated sites, bioavailability, trace metals, soil amendments

Introduction The “Garden Soil” project seeks to investigate different aspects of a recently developed soil washing procedure, able to extract up to 80, 40 and 70 % of Pb, Cd and Zn respectively, while working in a closed circuit without appreciable losses of both, process water and the chelating agent in use (EDTA) (Voglar and Lestan, 2012). The applicability of the remediated soil for re-use will be tested in an outdoor experiment in raised beds containing two trace metal (TM) contaminated soils from Austria and Slovenia. The TM bioavailability and plant uptake will be monitored over a 2-year period to determine possible trace metal remobilization processes e.g. due to a shift in the concentration equilibrium between the soluble and mineral phase or due to the incomplete complexation of the remaining EDTA (Udovic and Lestan, 2010). Finally, the processed soil will be treated with soil additives to immobilize TMs and to support soil revitalization (Kaurin et al., 2018). The success of the procedure will be evaluated using microbiological- and molecular techniques and an in-depth investigation of the nutrient cycle using plant material labeled with stable isotopes (13C, 15N). This pre-trial was set up using EDTA-washed and natural Cambisol from Arnoldstein in 300 ml pots. The present experiment aimed to select appropriate soil amendments among several compost (5 and 10 % (w/w)) and biochar variants (3 % (w/w)), as well as iron and manganese-rich mineral amendments (1 % (w/w)); tested in combined and single treatments.

Results & Discussion

Fig. 1 TM concentrations in the aerial tissue of “Topsi” radish plants (n = 5) were investigated on different soil treatments. U = unwashed; W = washed; Co = control; NPK= fertilized; Brfk = F. Breakfast cultivar; WTS = water treatment sludge; V = vermicompost; V10 = 10 % (w/w) V;

K = compost; CS = straw-biochar 600 °C; C550 = miscanthus-biochar 550 °C; C700 = miscanthus-biochar 700 °C; Mix/M1 = V + CS; M2 = V + CS + WTS; M3 = V + WTS; M4 = V + FeO + MnO. The bars over the Boxplots indicate significantly different subsets (p < 0.05). The measured TM concentrations in plants grown on substrate using unwashed soil (U), ranged between 100 - 600 mg kg-1 Zn, 3.5 - 25 mg kg-1 Cd and 0.5 - 15 mg kg-1 Pb (Figure 1). While Pb and Cd are toxic for plants in small concentrations, Zn is essential for human and plant nutrition, however, it can exert toxic effects on spinach at concentrations over 100 mg kg-1 DM in the aerial tissue and should not exceed 75 mg kg-1 DM in leaf vegetables if meant for human consumption (Adriano, 2001). The concentration of Cd and Pb in leaf vegetables should not exceed 2 mg kg-1 and 3 mg kg-1 respectively (European Commission, 2006). In almost all replicates of the U-variants these values were exceeded, and the toxic effects most likely contributed to the significant reduction in plant DM (p < 0.05) (Figure 2). The EDTA- washing procedure significantly reduced the TM availability to the radish plants in the washed control (W-Co) by 269 mg kg-1 Zn and 9.6 mg kg-1 Cd compared to unwashed control (U-Co). Among the washed soil variants, the use of amendments showed no significant effect on the Zn/Cd plant uptake. The bioavailability of Pb was not significantly altered by the soil washing procedure and for some variants, exceed the values in the U-treatments. The U-Mix variant showed the lowest bioavailable Pb overall. Possible causes of the enhanced TM availability after soil washing are part of upcoming investigations.

Fig. 2 (left) The DM of the harvested radish plants are presented as boxplots of the single variants. For abbreviations see figure 2. The lines over the boxplots indicate homogeneous subsets and are significantly different (p < 0.05). Fig. 2(right) Resulting from the post treatment of the washing procedure, the soil gains the structure of small pellets up to 3 cm long. The use of washed soil for the substrate mixtures lead to a significant increase in plant DM (p < 0.05), even though plants showed a high variance. Within the two soil treatments (U and W), no significant difference was found (p ≥ 0.05). However, plants growing on the vermicompost variant (W-V) showed a significantly higher plant DM (p < 0.05) compared to most of the unwashed treatments (except U- Mix) and tended to have the highest yield among all W-variants. The favorable properties of the soil amendments could have been compounded by the structural changes caused by the post treatment after the washing procedure, were the soil sludge is pressed through a sieve and cut into small pellet-like pieces (Figure 2). This positive property was already observed during the germination stage, were radish plants grown in the variants including washed soil showed faster development and will be further investigated. The positive effect of the physical properties and/or lower trace metal concentrations apparently exceeded the expected loss of plant nutrients due to the EDTA washing (Jelusic et al., 2014).

References Adriano, D.C., 2001. Trace elements in terrestrial environments: Biogeochemistry, bioaccessibility and the risk of metals, 2nd ed. Springer, New York, US.

European Commission, 2006. Commission Regulation (EC) No 1881/2006 of 19 December 2006 setting maximum levels for certain contaminants in foodstuffs. Off J Eur Union 364, 5–24.

Jelusic, M., Vodnik, D., Lestan, D., 2014. Revitalization of EDTA-remediated soil by fertilization and soil amendments. Ecological engineering 73, 429–438.

Kaurin, A., Cernilogar, Z., Lestan, D., 2018. Revitalisation of metal-contaminated, EDTA-washed soil by addition of unpolluted soil, compost and biochar: Effects on soil enzyme activity, microbial community composition and abundance. Chemosphere 193, 726–736.

Udovic, M., Lestan, D., 2010. Redistribution of residual Pb, Zn, and Cd in soil remediated with EDTA leaching and exposed to earthworms (Eisenia fetida). Environmental technology 31, 655–669.

Voglar, D., Lestan, D., 2012. Pilot-scale washing of metal contaminated garden soil using EDTA. Journal of hazardous materials 215, 32–39.

Vpliv remediacije z EDTA na fizikalne lastnosti tal Influence of EDTA washing on soil physical properties

Vesna Zupanc1 1Biotechnical Faculty, University of Ljubljana, Slovenia, [email protected]

Abstract Soil washing as a metal pollution remediation process, especially intensive mixing of the soil slurry and soil compression after de-watering, significantly deteriorates physical properties of soil compared to non-remediated soil. Physical properties of porous media, such as soil, describe its structure (e.g. aggregate stability, bulk density and porosity), determine water balance processes, such as water retention, water flow (hydraulic conductivity under saturated, unsaturated conditions), solute transport and energy transfer. Differences in selected physical properties between original and remediated soil and repacked and consolidated soil samples were evaluated. Remediated soils show significant differences to non-remediated soils in water retention properties.

Keywords: soil remediation, soil washing, soil physical properties

Povzetek Pranje tal je postopek remediacije za tla onesnažena s težkimi kovinami. Pri tem postopku so tla v obliki blata podvržena intenzivnemu mešanju, stiskanju, kar bistveno spremeni fizikalne lastnosti tal v primerjavi z izvornimi tlemi. Fizikalne lastnosti poroznih medijev, kot so tla, opišejo strukturo (stabilnost agregatov, gostota tal in poroznost), lastnosti, ki vplivajo na procese vodne bilance tal (hidravlična prevodnost nasičenih in nenasičenih tal) ter prenos energije in snovi v tleh. Obravnavamo razlike v izbranih fizikalnih lastnostih med izvornimi in remediiranimi tlemi ter zapakiranimi porušenimi in konsolidiranimi vzorci. Remediirana tla kažejo na spremenjene vodnozadrževalne lastnosti.

Ključne besede: remediacija tal, pranje tal, fizikalne lastnosti tal

Introduction Soils are dynamic and diverse natural systems that lie at the interface between earth, air, water, and life. They are critical ecosystem service providers for the sustenance of humanity (Needleman, 2013). Soils are non-renewable resource that is subjected to several forms of degradation, heavy metal pollution among them. Soil washing with EDTA is a metal pollution remediation process. However, intensive mixing of the soil slurry and soil compression after de-watering, significantly deteriorates physical properties of soil compared to non-remediated soil (e.g. Voglar and Leštan, 2012). Chemical treatment combined with physical treatment, such as exposure to high pressure for removal of heavy metals, produces at the end, essentially, amorphous mass, that, without any further treatment, is absent of structure and any functionality (Zupanc et al., 2014). Changed physical properties of remediated soil influence interaction of plant roots with soil system and affect soil water regime

Physical properties of porous media, such as soil, describe its structure (e.g. aggregate stability, bulk density and porosity), determine water balance processes, such as water retention, water flow (hydraulic conductivity under saturated, unsaturated conditions), solute transport and energy transfer. Particularly soil hydraulic characteristics are crucial as they control water and solute movement and, hence, the behavior of soluble chemical remnants in remediated soils. Usually, soil physical properties are evaluated after soil samples have been taken from a soil profile for laboratory analyses or analyses and tests are conducted in the field. Evaluation of properties of remediated soil deals with severely disturbed

soil, after soil washing treatment. Here, we summarize differences in selected physical properties between original and remediated soil and repacked and consolidated soil samples.

Materials and method Soil from Arnoldstein, Austria, was evaluated. Soil texture was determined by the pipette method (ISO 11277, 2009). For laboratory measurements of hydraulic properties, disturbed soil samples were repacked in cylinders at a dry bulk density of 1.3 g·cm−3 (cylinder volume 250 cm3 for evaporation method, Schindler et al., 2010; device: HYPROP, Meter/UMS GmbH, Germany). At the end of the measurements, the samples were oven dried at 105 °C for 24 h to derive total porosity and bulk density (assumed particle density of 2.65 g·cm−3). The HYPROP-FIT software (Meter/UMS GmbH, Germany) was used to fit the parameters of soil water retention and hydraulic conductivity models to evaporation measurements.

Results EDTA washing changes textural composition of the soil (sand/silt/clay ratio 42.5/45.9/11.6 for original soil vs 31.5/52.1/16.4 for remediated soil) which has been previously established (e.g. Zupanc et. al 2014, Guo et. al, 2018). In our study, original soil samples have field capacity (1 − 2.5 pF) between 50 and 33 %, independent of nature of the sample. Remediated soils have field capacity between 48 and 28 % for repacked soil and around 40 % for consolidated (Figure 1). Results show that measuring hydraulic properties with evaporation method depends if soils are repacked or consolidated.

Figure 1: Water retention curve for original and remediated soil.

Conclusions Reasons for changes in soil functionality after soil washing process are alterations in chemical and physical characteristics such as soil aggregate fractionation and stability, hydraulic conductivity or water retention properties (Zupanc et al., 2014). Furthermore, changed physical characteristics of remediated soil influence interaction of plant roots with soil system and affect soil water regime. Methods and timeframe for evaluation of physical properties remediated soils must be carefully considered. Remediated, consolidated soil has lower water retention compared to original soil.

Acknowledgements This research has been supported by ARRS research project J4-8219 Urban Gardens.

Literatura Needelman, B. A. (2013) What Are Soils? Nature Education Knowledge 4(3):2 Schindler, U., Durner, W., von Unold, G., Mueller, L., and Wieland, R. The evaporation method: Extending the measurement range of soil hydraulic properties using the air-entry pressure of the ceramic cup. Journal of plant nutrition and soil science. 563-572 (2010) 173

Voglar, D., Lestan, D., Pilot-scale washing of metal contaminated garden soil using EDTA, Journal of Hazardous Materials 215–216 (2012) 32–39

Guo X., Zhao G., Zhang G., He Q., Wei Z., Zheng W., Qian T., Wu Q. 2018. Effect of mixed chelators of EDTA, GLDA, and citric acid on bioavailability of residual heavy metals in soils and soil properties. Chemosphere 209 (2018) 776e782

Zupanc V, Kastelec D, Lestan D, Grcman H. Soil physical properties after EDTA washing and amendment with inorganic and organic additives. Environmental Pollution. 56–62(2014)186

Biološke lastnosti in revitalizacija tal po remediaciji z EDTA Biological properties and revitalization after EDTA remediation of metal contaminated soil

Anela Kaurin1, Domen Leštan1 1Univerza v Ljubljani, Biotehniška fakulteta, Oddelek za agronomijo, Katedra za pedologijo in varstvo okolja, Slovenija, [email protected]

Povzetek Remediacija tal zmanjšuje nevarnost onesnaženja, vendar lahko hkrati negativno vpliva na biotske lastnosti tal. Zgodovinsko onesnažena kisla tla iz Arnoldsteina (Avstrija) in karbonatna tla iz Mežice (Slovenija) smo oprali in tako odstranili 78 in 60 % Pb kot glavnega onesnaževalca. Remediacija je v kislih tleh povzročila manjše spremembe v encimski aktivnosti, medtem ko je uporaba večjega odmerka EDTA (30 vs 100 mmol kg-1) pri pranju karbonatnih tal izrazito zmanjšala encimsko aktivnost. Remediacija je v obojih tleh spremenila sestavo mikrobne združbe. Dodatek komposta je v kislih remediranih tleh iz Arnoldsteina povečal dehidrogenazno aktivnost in spremenil sestavo mikrobne združbe. V remediranih Mežiških tleh so dodatki povrnili encimsko aktivnost na izhodiščno vrednost originalnih tal in obnovili sestavo mikrobne združbe. V drugem delu poskusa smo preučili sposobnost mikroorganizmov v EDTA-opranih tleh za privzem hranil in proizvodnjo encimov po dodatku substratov z različno stopnjo razgradljivostjo (glukoza, mikroceluloza, škrob in zmleti kalčki lucerne). Remediacija je imela zanemarljiv učinek na mikrobno dihanje v kislih tleh. Nasprotno, je remediacija v karbonatnih tleh zmanjšala nastanek celokupnega CO2 po dodatku glukoze (enostavni) in lucerne (kompleksni substrat). Remediacija je zmanjšala stopnjo nitrifikacije v kisih tleh in prepolovila nitrifikacijo v karbonatnih tleh. Remediacija je v obojih tleh rahlo pozitivno vplivala na dehidrogenazno in β-glukozidazno aktivnost in zmanjšala ureazo aktivnost.

Ključne besede: remediacija, revitalizacija, talni encimi, talni mikroorganizmi

Keywords: soil remediation, revitalization, soil enzymes, soil microorganisms

Introduction Contamination of soil with potentially toxic metals such as Pb, Zn and Cd is of great environmental concern due to their long-term persistence, hazards to humans and toxicity to soil biota (Bolan et al., 2014). Soil washing and PTM removal with the chelating agent ethylenediamine tetraacetate (EDTA) is a solution to efficiently manage the risks and potentially preserve soil functionality and services (Jelusic et al., 2014). However, the stringent physical conditions during soil washing reduce soil microbial activity and diversity (Jelusic et al., 2013). This necessitates effective post-remedial revitalisation measures.

Material and methods Soils were remediated as described by Lestan (2017). The enzyme activities were measured spectrophotometrically according to Eivazi and Tabatabai (1988), Thalmann (1968), and Hoffmann and Teicher (1961). The microbial community composition was assessed using a TRFLP fingerprinting method (Lane, 1991; White et al., 1990; Liu et al., 1997). Substrate induced respiration was determined using commercial equipment OxiTop Control (WTW, Wilheim, Germany) and nitrification according to Broos et al. (2007).

Results and discussion Remediation of the Arnoldstein soil decreased urease activity, increased ß-glucosidase activity, and had no impact on dehydrogenase activity measured in a 15-week pot experiment. Conversely, the use of a

high dose of EDTA in the Meza soil, resulted in pronouncedly decreased enzyme activities. Remediation shifted the microbial community composition in both soils. For revitalisation, the remediated soils were amended with compost and inocula of un-contaminated soil. In the Arnoldstein soil compost increased the dehydrogenase activity and altered the microbial community composition. In the remediated Meza soil amendments returned the enzyme activities back to the baseline in the original soil and restored the microbial community composition. In the second part of the experiment we studied the capacity of microbes in EDTA-remediated soils to acquire nutrients and produce enzymes through utilisation of four substrates with decreasing decomposability. Remediation had an insignificant effect on microbial respiration in Arnoldstein soil induced by sequential additions of glucose, micro-cellulose, starch, and alfa-alfa sprout powder. In contrast, remediation of calcareous Meza soil reduced cumulative CO2 production after glucose (simple) and alfalfa (complex substrate) addition. Remediation reduced the nitrification rate in Arnoldstein soil and halved nitrification in Meza soil. Remediation in both soils slightly or positively affected dehydrogenase and β-glucosidase activity, and decreased urease activity.

4 Soil 2.5 % Soil 5 % 4 A Soil 10 % Compost 2.5 % Compost 5 % Compost 10 % 3 Remediated Original 3

2 2

original soil original 1 1 TPF conc., ratio to ratio conc., TPF

0 0 3 6 9 12 15 3 6 9 12 15 Time (Weeks) Time (Weeks) Figure 1: The dynamics of dehydrogenase (TPF production) activity in amended (addition of 2.5%, 5% and 10% of unpolluted soil and compost) and non-amended remediated (A) Arnoldstein and (B) Meza soil. Data are presented as a ratio of measurements in remediated and original soil (Kaurin in sod., 2018).

Acknowledgements This work was supported by the Slovenian Research Agency under Grants J4-8219 and J4-6808.

Literatura Bolan, N., Kunhikrishnan, A., Thangarajan, R., Kumpiene, J., Park, J., Makino, T., Kirkham, M.B., Scheckel, K., Remediation of heavy metal(loid)s contaminated soils - to mobilize or to immobilize? J. Hazard. Mater. 266 (2014), 141-166.

Broos, K., Warne, M.S.J., Heemsbergen, D.A., Stevens, D., Barnes, M.B., Correll, R.L., Mclaughlin, M.J., Soil factors controlling the toxicity of copper and zinc to microbial processes in australian soils. Environ. Toxicol. Chem. 4 (2007), 583-590.

Eivazi, F., Tabatabai, M., Glucosidases and galactosidases in soils. Soil. Biol. Biochem. 20 (1988), 601- 606.

Hoffmann, E., Teicher, K., Ein kolorimetrisches verfahren zur bestimmung der ureaseaktivitat in boden. Pflanzenernaehr Dung Bodenkd 95 (1961), 55-63.

Jelusic, M., Grcman, H., Vodnik, D., Suhadolc, M., Lestan, D., Functioning of metal contaminated garden soil after remediation. Environ. Pollut. 174 (2013), 63-70.

Jelusic, M., Vodnik, D., Macek, I., Lestan, D., Effect of EDTA washing of metal polluted garden soils. Part II: can remediated soil be used as a plant substrate? Sci. Total. Environ. 475 (2014), 142-152.

Kaurin, A., Cernilogar, Z., Lestan, D., Revitalisation of metal-contaminated, EDTA-washed soil by addition of unpolluted soil, compost and biochar: effects on soil enzyme activity, microbial community composition and abundance. Chemosphere 193 (2018), 726-736.

Kaurin, A., Lestan, D., Multi-substrate induced microbial respiration, nitrification potential and enzyme activities in metal-polluted, EDTA-washed soils. Environ. Pollut. 243 (2018) 238-245.

Lane, D.J., 16S/23S rRNA sequencing. In: Stackebrandt, E., Goodfellow, M. (Eds.), Nucleic Acid Techniques in Bacterial Systematics. John Wiley and Sons, New York, NY, 1991, pp. 115-175.

Lestan, D., Novel chelant-based washing method for soil contaminated with Pb and other metals - a pilot-scale study. Land Degrad. Dev. 28 (2017), 2585-2595.

Liu, W., Marsh, T., Cheng, H., Forney, L., Characterization of microbial diversity by determining terminal restriction fragment length polymorphisms of genes encoding 16S rRNA. Appl. Environ. Microbiol. 63 (1997), 4516-4522.

Thalmann, A., Zur methodik der bestimmung der dehydrogenaseaktivit€at im bodenmittels triphenyltetrazoliumchlorid (TTC). Landwirtsch. Forsch 21 (1968), 249-259.

White, T.J., Bruns, S., Lee, S., Taylor, J., Amplification and direct sequencing of fungal ribosomal RNA genes for phylogenetics. In: Innis, M., Gelfand, D., Sninsky, J., White, T. (Eds.), PCR Protocols: a Guide to Methods and Applications. Academic Press, Florida, 1990, pp. 315-322.

Arbuskularna mikoriza v remediiranih tleh

Arbuscular Mycorrhiza in Remediated Soil

Irena Maček1, 2,*, Nataša Šibanc1, 2, Sara Pintarič1, Bojka Kump1, Domen Leštan1, Marjetka Suhadolc1 1Department of Agronomy, Biotechnical Faculty, University of Ljubljana, Jamnikarjeva 101, SI-1000 Ljubljana, Slovenia, *corresponding author: [email protected] (I. Maček)

2Faculty of Mathematics, Natural Sciences and Information Technologies (FAMNIT), University of Primorska, Glagoljaška 8, SI-6000 Koper

Abstract Soil is a limited resource often contaminated with heavy metals. Recently, several soil remediation processes have been developed, including an EDTA (ethylenediaminetetraacetic acid) chelating agent extraction that results in high removal efficiency of the contaminants. There is a limited knowledge on how this procedure affects soil microorganisms, including plant root endosymbiotic arbuscular mycorrhizal (AM) fungi. Mycorrhizal potential of soil after the remediation procedure is very limited and molecular characterisation of AM fungal diversity before and after soil remediation show that in roots of plants growing in remediated soil practically no arbuscular mycorrhiza forms. However, with time functional mycorrhiza is established either by spontaneous dispersal of mycorrhizal propagules from the surrounding environment (e.g. by wind) or by additional inoculation with AM fungal inoculum (e.g. by adding roots and rhizosphere soil to the remediated substrate). The use of the local grassland inoculum resulted in a higher AM fungal diversity in the roots of plants growing in the remediated soil compared to the ones revitalized with the commercial inoculum. Moreover, continuous growth of plants (Lolium perenne) in remediated soil has been shown as an important factor not only for development of mycorrhiza, but is also highly correlated with overall microbial biomass and abundance of gene markers for specific microbial groups (archaea, bacteria and fungi).

Izvleček Tla so omejen naravni vir, ki je pogosto onesnažen s težkimi kovinami. V zadnjem času je bilo razvith več tehnologij za remediacijo tal, med drugimi tudi tehnologija pranja tal in ekstrakcije kovin z EDTA (ethilendiamintetraocetna kislina), rezultat katere je visoka stopnja učinkovitosti odstanjevana kontaminantov iz tal. O tem, kako ta postopek vpliva na talne microbe, še ni veliko znanega, vključno z vplivom na arbuskularne mikorizne (AM) glive, ki so pomembni koreninski endosimbionti velike večine kopenskih rastlin. Mikorizni potencial tal je po njihovi remediaciji zelo omejen in molekularna karakterizacija diverzitete AM gliv pred in po remediaciji je pokazala, da v koreninah rastlin, ki rastejo v tleh takoj po remediaciji, praktično ni arbuskularne mikorize. S časom pa se tudi v remediiranih tleh razvije funkcionalna simbioza, ki nastane s spontanim razširjanjem mikoriznih gliv iz okolice (npr. z vetrom) ali z načrtovano inokulacijo tal z inokulumom (npr. z dodatkom korenin in rizosfernih tal remediiranemu substratu). Uporaba inokuluma iz lokalnega travnika je rezultirala v večji diverziteti AM gliv v koreninah rastlin, ki so rasle v remediiranih tleh, kot je bilo to v primeru uporabe komercialnega inokuluma. Pomembno vlogo pri sami revitalizaciji remediiranih tal je imela tudi stalna prisotnost vitalnih rastlin (npr. Lolium perenne). Slednja se je izkazala kot pomemben dejavnik ne le pri razvoju mikorize, ampak je prisotnost rastline tudi močno pozitivno povezana z razvojem mikrobne biomase v remediiranih tleh ter z abundanco molekularnih markerjev za specifične skupine mikrobov (arheje, bakterije in glive).

Ključne besede: arbuskularne mikorizne glive, AM glive, biodiverziteta, rastlinske korenine, remediacija

Keywords: arbuscular mycorrhizal fungi, AM fungi, biodiversity, plant roots, remediation

Introduction

Soil remediation with washing with an aqueous solution of EDTA has been proven as good option for cleaning heavy metal contaminated soil (e.g. Finzgar & Lestan, 2007; Voglar & Lestan, 2013), and it has been shown that this soil can be used as a plant growth media (e.g. Jelusic et al., 2014). But the remediated substrate still needs some improvement to be considered as a functional and living soil. The harsh remediation conditions presumably destroy the majority of life in the remediated soil, though only limited direct measurements of biodiversity have been done (e.g. for plant symbiotic arbuscular mycorrhizal (AM) fungi) (Maček et al., 2016).

In terrestrial ecosystems, symbiotic associations between plant roots and AM fungi are near ubiquitous, with 90% of all plant species forming mycorrhiza. The majority of land plants receive inorganic nutrients via an indirect uptake through the symbiotic AM fungi, in addition AM fungi positively affect plant defence to biotic and abiotic stress, and soil structure. AM fungi and other plant-growth-promoting microorganisms have been used as inocula for biofertilisation and phytostimulation or different soil types. In addition to using indigenous inocula a growing number of inocula are being marketed which may help to restore functionality of remediated soil. The commercial inocula, however, typically include only a limited taxa richness which is usually also not very well defined (typically no molecular data on the taxa identity is available on the product specification).

Methods and Results

In our preliminary experiment the first attempt was made to revitalize the remediated soil with AM fungi, and to evaluate the newly established diversity using molecular tools (Maček et al., 2016). Our tests show that functional symbiosis can be established in the remediated soil by the use of indigenous inoculum (rhizosphere soil) as a good source of diverse fungal propagules for revitalisation of remediated soil. In 2016 a soil mesocosm experiment has been set where succession of the microbial communities (archaea, bacteria and fungi) and their function (N-cycle marker) has been followed in regular time-intervals (min. 3-times per year) for two years. Two different soil types – calcareous soil from Meža Valley (SI), and acidic soil from Stossau, Arnoldstein (AT) – were used, both polluted (original soil) and after remediation (washing with EDTA), and Lolium perenne was used as a plant host for AM fungi. Plant growth and biomass and plant root colonisation with AM fungi has been followed in regular intervals. In addition, soil and plant root samples have been taken and processed for sequencing (Illumina, MiSeq) to quantify the development of AM fungal diversity and communities in the mesocosms. Preliminary results from this study will be presented and discussed.

Acknowledgement The authors acknowledge the financial support from the Slovenian Research Agency (project J4-7052, and research core funding No. P4-008).

References

Finzgar, N. & Lestan, D. Multistep leaching of Pb and Zn contaminated soils with EDTA. Chemosphere 824-832 (2007)66.

Jelusic, M., Vodnik, D., Maček, I., Lestan, D. Effect of EDTA washing of metal polluted garden soils. Part II: Can remediated soil be used as a plant substrate? Sci. Tot. Environ. 142-152(2014)475. Maček, I., Šibanc, N., Kavšček, M., Lestan, D. Diversity of arbuscular mycorrhizal fungi in metal polluted and EDTA washed garden soils before and after soil revitalization with commercial and indigenous fungal inoculum. Ecol. Engineer. 330-339(2016)95. Voglar, D. & Lestan, D. Pilot scale washing of Pb, Zn and Cd contaminated soil using EDTA and process water recycling. Chemosphere 76-82(2013)91.

Razvoj analizne metode za spremljanje razkroja pesticidov v remediiranih tleh

Development of an analytical method for monitoring of pesticide degradation in remediated soil

Tina Grubar1, Domen Leštan2, Simon Gluhar2, Helena Prosen1* 1 Fakulteta za kemijo in kemijsko tehnologijo, Univerza v Ljubljani, Ljubljana, Slovenija 2 Biotehniška fakulteta, Univerza v Ljubljani, Ljubljana, Slovenija *kontaktni avtor: [email protected]

Abstract Heavy metals are a very important group of soil pollutants because of their high toxicity. Agriculture on polluted soil is not recommended because of uptake of metals into the crops. An acceptable remediation technology for heavy metal-polluted soil should be effective, economically acceptable, and it should lead to normal functioning of the soil. Soil washing with EDTA solution, followed by revitalization, is a viable option. In this study, a reliable extraction and analytical method was developed for the determination of four selected pesticides in heavy-metal contaminated soil before and after the remediation and revitalization in order to indirectly monitor their biotic degradation, which gives a reliable measure of functioning of the soil microorganisms. For the extraction of pesticides from the soil, ultrasonic extraction was used, followed by SPE clean-up, while analysis was performed by HPLC- DAD. Method has shown satisfactory recoveries (75–89 %), precision (RSD 5–22 %), and LODs 5– 10 μg/kg for all analytes. The results of monitoring have shown that there was no difference in pesticide concentration after either two or three weeks in treated and untreated soils from two contaminated sites. This is a further confirmation of the efficacy of the applied soil remediation technology.

Keywords: heavy metals, EDTA, soil remediation, pesticide degradation, monitoring. Ključne besede: težke kovine, EDTA, remediacija tal, razkroj pesticidov, spremljanje koncentracij.

Uvod Količina rodovitnih tal se povsod po svetu hitro zmanjšuje iz različnih vzrokov: erozija, urbanizacija, gradnja prometne infrastrukture, industrializacija ipd. Preostala rodovitna tla so pogosto onesnažena in težke kovine predstavljajo zelo pomembno skupino onesnaževal. Njihova povišana koncentracija v tleh je zelo pogosto posledica onesnaževanja iz preteklih stoletij na področjih rudnikov in kovinsko- predelovalne industrije. Posebej problematične težke kovine so Pb, Cr, Cd, Cu, Hg, Zn, Ni ter polkovina As, ki so srednje do visoko strupeni za rastline in živali, vključno s človekom. Slednji z njimi pride v stik predvsem preko zaužitja pridelkov, ki so zrasli na onesnaženih tleh, pa tudi preko pitne vode. Tako onesnažena tla je možno čistiti na različne načine, vendar mora biti remediacijska tehnologija učinkovita in ekonomsko upravičena za široko uporabo. Med in po procesu odpadni materiali ne smejo predstavljati večjega tveganja. Končni cilj je, da bi remediirana tla normalno funkcionirala [1]. Leštan in sodelavci so razvili in patentirali učinkovit postopek pranja tal [2] z raztopino EDTA, ki kompleksira večino kovinskih ionov. Po končni separaciji raztopine od tal se EDTA reciklira in torej ne predstavlja odpadka. Očiščena tla je potrebno še pognojiti in revitalizirati z različnimi dodatki [3]. V tej raziskavi smo želeli preveriti, ali se remediirana in revitalizirana tla razlikujejo od neočiščenih glede svoje zmožnosti razkroja pesticidov. Razvili smo zanesljivo analizno metodo za določanje štirih izbranih pesticidov (bentazon BTZ, izoproturon IPR, mekoprop MCPP, metolaklor MCL) v tleh. S to

metodo smo nato spremljali koncentracijo pesticidov v tleh, onesnaženih s težkimi kovinami, pred in po pranju z EDTA in revitalizaciji. Koncentracijo smo spremljali do tri mesece po nanosu pesticidov.

Rezultati z razpravo Izbrana analizna tehnika za določanje koncentracije pesticidov je bila HPLC-DAD. Uporabili smo gradientno elucijo z zmesjo acetonitrila (ACN) in 0,1 % HCOOH v prečiščeni vodi. Absorbanco smo merili pri 225, 240 in 310 nm. Večji del razvoja metode je bil posvečen optimizaciji ekstrakcijske metode za pesticide iz tal. Uporabili smo ultrazvočno ekstrakcijo in preizkusili učinkovitost različnih kombinacij topil: aceton, ACN, prečiščena voda, 0,1 % mravljična kislina. Kot najboljša se je izkazala kombinacija ACN in 0,1 % mravljične kisline. Ekstrakti so vsebovali veliko motečih spojin, zato smo v nadaljnjem koraku optimizirali postopek čiščenja ekstraktov z ekstrakcijo na trdno fazo (SPE). Uporabili smo ekstrakcijske kolone z reverzno fazo (C18). Acetonitril, uporabljen za ultrazvočno ekstrakcijo iz tal, bi motil vezavo analitov na sorbent (Slika 1), zato smo ga predhodno odstranili z uparevanjem. Pri SPE postopku smo optimizirali ionsko moč raztopine za ekstrakcijo in topilo za elucijo analitov. Optimalne pogoje smo dosegli pri dodatku 1 % NaCl v ekstrakt in elucijo analitov s sorbenta s 5 mL ACN. Končno metodo ultrazvočne ekstrakcije tal s SPE čiščenjem, ki ji je sledila analiza končnega ekstrakta s HPLC-DAD, smo tudi delno validirali. Metoda je imela zadovoljive izkoristke (75–89 %) in ponovljivost (RSD 5–22 %). Meje zaznave so bile 5–10 μg/kg tal za vse štiri pesticide.

120 100 80 60 40

Izkoristek [%] 20 0 0 % ACN 1 % ACN 5 % ACN 10 % ACN

BTZ IPR MCPP MCL

Slika 1: Vpliv deleža acetonitrila v ekstraktih tal na izkoristek SPE ekstrakcije. Metodo smo uporabili za spremljanje koncentracij pesticidov v tleh v rastnem poskusu. Za rastni poskus so bile uporabljene štiri vrste tal: tla iz Mežiške doline, pred in po remediaciji; tla iz Arnoldsteina, Avstrija, pred in po remediaciji. Tla so bila v koritih na odprtem, po sejanju žita smo nanesli komercialni pripravek posameznega pesticida po navodilih proizvajalca. Koncentracijo pesticidov smo spremljali 30-90 dni, dokler ni koncentracija padla pod mejo zaznave. Primer je na Sliki 2. Rezultati so pokazali, da po 2-3 tednih med koncentracijo pesticidov v obojih tleh pred in po remediaciji ni razlike. To dodatno potrjuje učinkovitost in uporabnost aplicirane remediacijske tehnologije.

3500 3000 2500 2000

[ng/g] 1500 c 1000 500 0 0 10 20 30 40 t [dnevi]

originalna tla remediirana tla

Slika 2: Spremljanje koncentracije bentazona v tleh iz Arnoldsteina. Zahvala H. Prosen bi se zahvalila za finančno podporo ARRS (raziskovalni program P1-0153).

Literatura [1] A. B. Cundy, R. P. Bardos, A. Church, M. Puschenreiter, W. Friesl-Hanl, I. Muller, S. Neu, M. Mench, N. Witters, J. Vangronsveld. J. Environ. Manag. 129(2013)283.

[2] D. Leštan, N. Finžgar, M. Gerl, S. Gluhar, G. Lakovič, B. Hamiti. Patent application no. GB1517757.9 (2015).

[3] M. Jelušič, D. Vodnik, D. Leštan. Ecol. Engin. 73(2014)429.

Možnost adsorpcije kovin iz vod z uporabo glive Ganoderma lucidum

The possibility of metal adsorption from water medium on biomass of fungus Ganoderma lucidum

Ula Rozman1, Andreja Žgajnar Gotvajn2, Gregor Marolt3, Andrej Gregori4, Gabriela Kalčikova5 1Fakulteta za kemijo in kemijsko tehnologijo, Univerza v Ljubljani, [email protected] 2Fakulteta za kemijo in kemijsko tehnologijo Univerza v Ljubljani, [email protected] 3Fakulteta za kemijo in kemijsko tehnologijo, Univerza v Ljubljani, [email protected] 4MycoMedica d.o.o., Slovenija, [email protected] 5Fakulteta za kemijo in kemijsko tehnologijo, Univerza v Ljubljani, [email protected]

Abstract In the last decades, heavy metal pollution has become serious environmental problem. Biosorption, using biomaterials is regarded as a cost-effective treatment of heavy metals from the contaminated water. In this study, we investigate the possibility of using dried biomass of fungus Ganoderma lucidum as biosorbent for removal of lead, copper, cadmium and chromium. The dried biomass was pre-treated with four different techniques and results showed that the percentage of removal metal using untreated biomass and pre-treated biomass was very comparable (above 84% in all cases). The kinetic mechanism of the adsorption process was determined by pseudo-second-order Lagergren model.

Ključne besede: adsorpcija, biosorpcija, Ganoderma lucidum, gliva, težke kovine

Keywords: adsorption, biosorption, fungi, Ganoderma lucidum, heavy metals

Uvod Težke kovine uvrščamo med nevarna onesnaževala, ki se v tleh kopičijo zaradi industrijskih dejavnosti kot so galvanizacija, metalurgija, rudarstvo in proizvodnja kemikalij. Iz tal pa s spiranjem zlahka vstopajo tudi v vodni ekosistem.1 Za odstranjevanje težkih kovin iz vod se običajno uporabljajo fizikalno-kemijske metode kot so ekstrakcija, ionska izmenjava, kemijska precipitacija in membranska separacija. Te metode pa imajo skupnih kar nekaj slabosti, kot so visoki stroški, slaba selektivnost in proizvodnja velikih količin odpadkov. Dostikrat pa njihovo odstranjevanje s temi metodami sploh ni možno, saj so koncentracije kovin prenizke, a kljub temu za vodno okolje že problematične.2

Adsorpcija velja za eno izmed pogosteje uporabljenih metod za odstranjevanje težkih kovin. Učinkovitost procesa je odvisna od kinetičnih parametrov in kapacitete adsorbenta. V zadnjem času se preiskuje predvsem možnosti uporabe različnih bioloških materialov, med katerimi je še posebno zanimiva uporaba nežive biomase, posebej gliv. Neživa glivna biomasa ima veliko sposobnost odstranjevanja težkih kovin, strupenost kovin ne vpliva na adsorpcijsko kapaciteto sistema in uporabljeno biomaso lahko enostavno regeneriramo. Neživi biomasi lahko z različnimi aktivacijskimi metodami še izboljšamo učinkovitost.3

Eksperimentalni del Za ovrednotenje učinkovitosti adsorpcije izbranih težkih kovin na neživo biomaso smo uporabili trosnjake glive Ganoderma lucidum. Trosnjaki so bili zmleti in posušeni, nato smo material presejali

preko sita, da smo dobili delce velikosti od 125 µm do 355 µm. Kovine, ki smo jih izbrali za poskus so bile baker (II) (CuSO4 · 5H2O), krom (VI) (K2Cr2O7), svinec (II) (Pb(NO3)2) in kadmij (II) (Cd(NO3)2 · 4H2O).

V preliminarnem poskusu smo določili obseg adsorpcije vseh štirih kovin na neobdelano in obdelano biomaso (Tabela 1). Izbrali smo štiri različne načine obdelave biomase (0,5 M NaOH, 10 vol% H2O2, 0,5 M NaCl in 3 g/L raztopina pralnega praška), vsakič smo biomaso izpostavili za 60 min. Po obdelavi smo biomaso sprali do nevtralnega pH. Neobdelano in obdelano biomaso smo nato sušili 24 h na 60 °C. Pripravili smo raztopine kovin s koncentracijo 1 mg/L in dodali glivno biomaso, da je bila njena masna koncentracija v poskusu 10 g/L. Poskus je trajal 2 uri, pri temperaturi 24 ± 1 °C in konstantnih obratih mešanja 125 rpm. Za izračun količine odstranjene kovine smo vzorčili pred in po koncu poskusa, vsak vzorec smo pred nadaljnjo analizo prefiltrirali. Koncentracijo kovin v raztopini smo določili z metodo ICP-MS (masni spektrometer z induktivno sklopljeno plazmo).

Tabela 1: Delež odstranjenih kovin z različno obdelano glivno biomaso. Obdelava biomase/kovina Cu (II) [%] Cr (VI) [%] Pb (II) [%] Cd (II) [%] Brez predobdelave 98,2 84,1 89,6 88,3 NaOH 87,4 16,9 83,4 96,9 H2O2 / 92,5 95,9 89,1 NaCl 98,2 47,8 98,6 99,3 Pralni prašek 95,7 19,3 98,5 99,3 / - poskus ni bil izveden

Ker je imela neobdelana biomasa izredno dobre adsorpcijske sposobnosti, smo se odločili, da bomo karakterizirali učinkovitost adsorpcije v odvisnosti od časa samo z neobdelano glivno biomaso, saj so v tem primeru stroški procesa in njegov vpliv na okolje najmanjši. Poskus smo ponovili pod enakimi pogoji in z enakimi koncentracijami kovin in glivne biomase. Za razlago mehanizma procesa smo uporabili Lagergrenov model adsorpcije. Po modelni enačbi psevdo drugega reda smo izračunali 4 konstanto hitrosti (K) in adsorbirano količino adsorbata na enoto mase adsorbenta (qe) (Tabela 2) . Ugotovili smo, da se hitrost odstranjevanja med kovinami precej razlikuje, medtem ko je adsorbirana količina kovine na maso glive pri vseh štirih kovinah približno enaka.

Tabela 2: Konstante hitrosti, adsorbirane količine kovin na maso glive in korelacijski koeficient Cu (II) Cr (VI) Pb (II) Cd (II) K [g mg-1 min-1] 10,46 (R2 =1,0000) 2,82 (R2 =0,9987) 11,44 (R2 =0,9999) 13,14 (R2 =0,9996) -1 qe [mg g ] 0,079 0,091 0,069 0,059

Zaključek Rezultati so nam pokazali, da imajo posušeni trosnjaki glive Ganoderma lucidum izredno dobro adsorpcijsko kapaciteto za vezavo izbranih težkih kovin. V prvem delu poskusa smo ugotovili, da se delež odstranjenih kovin pri adsorpciji z neobdelano biomaso oziroma obdelano biomaso bistveno ne razlikuje, kar pomeni, da obdelava biomase ni potrebna, s tem pa lahko zmanjšamo stroške procesa in porabo kemikalij. Pri razlagi mehanizma adsorpcije smo uporabili Lagergrenov model adsorpcije psevdo drugega reda, kjer je bilo ugotovljeno, da se hitrost adsorpcije med izbranimi kovinami razlikuje, medtem ko je adsorbirana količina adsorbata na glivno biomaso pri izbranih kovinah približno enaka.

Zahvala Raziskava je bila delno financirana iz sredstev programske skupine P2-191 (Kemijsko inženirstvo) in programske skupine P1-0153 (Raziskave in razvoj analiznih metod in postopkov).

Literatura

1Lesmana, S.O., Febriana, N., Soetaredjo, F.E., Sunarso, J., Ismadji, S.: Studies on potential applications of biomass fort he separation of heavy metals from water and wastewater. Biochemical Engineering Journal. 2009, 44, 19-41.

2Krowiak Witek, A., Szafran, R.G., Modelski, S.: Biosorption of heavy metals from aqueous solutions onto peanut shell as a low-cost biosorbent. Desalination. 2011, 265, 126-134.

3Rangabhashiyam, S., Balasubramanian, P.: Characteristics, performances, equlibrium and kinetic modeling aspects of heavy metal removal using algae. Bioresource Technology Reports. 2018.

4Kowanga, K.D., Gatebe, E., Mauti, G.O.,, Mauti, E.M.: Kinetic, sorption isotherms, pseudo-first-order model and pseudo-second-order model studies of Cu(II) and Pb(II) using defatted Moringa oleifera seed powder. The Journal of Phytopharmacology. 2016, 5(2), 71-78.

Odprava škodljivih emisij iz remediranih tal z dodajanjem nič valentnega Fe

Elimination of harmful emissions from remediated soil by adding zero valant Fe

Simon Gluhar1, Erika Jež1, Domen Leštan1 1Biotehniška fakulteta, Univerza v Ljubljani, Slovenija, [email protected]

Povzetek Pranje onesnaženih tal s EDTA (recikliranim pretežno v obliki Ca soli) omogoča učinkovito odstranjevanje nevarnih kovin in hkrati ne vodi v obsežne spremembe fizikalno-kemijskih in bioloških lastnosti tal. V preteklosti je bila uporaba EDTA pri remediaciji problematizirana zaradi post- remediacijskih emisij toksičnih kelatov v podtalje in njihove okoljske obstojnosti. Karbonatna tla iz Mežiške doline v Sloveniji in kisla tla iz Arnoldsteina v Avstriji s 940 in 862 mg Pb kg-1, ki so bila onesnažena še s Zn in Cd, smo sprali s 100 in 60 mM EDTA v pilotni remediacijski napravi (50 kg na šaržo) in odstranili 60 in 78% Pb. Obdelana tla smo trikrat izpirali v filtrni stiskalnici dokler nismo v zadnji raztopini izmerili 5.5 in 5.8 mM EDTA. EDTA in raztopine za pranje in izpiranje smo reciklirali/očistili v zaprti procesni zanki – pri tem nismo generirali nobene odpadne vode. Ugotovili smo, da vmešavanje 0,5-1,5% nič valentnega Fe v mešanico tal in procesne raztopine tik pred črpanjem tal v filtrno stiskalnico, zmanjša emisije toksičnih kelatov iz remediiranih tal. Glavni mehanizem je verjetno adsorpcija EDTA-kelatov na nič valentno Fe. Po 6 dneh skladiščenja smo remedirana tla izpostavili močnim simuliranim padavinam. Iz kislih remediranih tal z dodatkom Fe smo izprali 0.1, 0.6, 0.026 mg kg-1 Pb, Zn in Cd glede na 0.1, 0.2, 0.002 mg kg-1 Pb, Zn in Cd iz originalnih (neremediranih tal). Pri karbonatnih tleh nismo zaznali koncentracije Pb in Cd v izpirkih. Smo pa zaznali 0.6 mg kg-1 Zn v izpirkih iz remediranih tleh z dodatkom železa, glede na 0.1 mg kg-1 Zn iz originalnih tal. V izcednih vodah iz remediranih tal z dodatkom Fe in originalnih tal (kislih in karbonatnih) nismo zaznali koncentracije EDTA. Kot so pokazali naši poskusi, je učinkovito preprečevanje toksičnih izpustov po remediaciji izrednega pomena za priznanje pranja tal z EDTA ligandom, kot okoljsko varni remediaciji.

Ključne besede: Pranje tal z EDTA, po-remediacijske emisije, EDTA, remedirana tla

Keywords: EDTA-based soil washing, post-remedial emissions, EDTA, remediated soil

Introduction Efficient, cost-effective, sustainable and environmentally safe soil remediation is a solution for Pb contaminated areas. We recently developed an unique soil washing technology, which efficiently removes Pb and other toxic metals from soil by complexation with a strong chelant, ethylenediaminetetraacetate (EDTA) (Leštan, 2017). Currently, the major argument against using EDTA in soil remediation is the risk of uncontrolled post-remedial leaching. The objective of our current work was to achieve an efficient, simple, fast and reliable means of preventing emissions of residual EDTA chelates.

Material and methods

EDTA and metals determination

For EDTA determination a spectrophotometric method (Wang et al., 2013). Metals in solutions were measured directly using flame atomic absorption spectrometry (AAS, Varian AA240FS). Soils were digested in aqua regia in a microwave oven and then measured by AAS.

Pilot-Scale Soil Remediation Soil remediation, the reagent recycling and process solutions cleaning and recycling are described by Lestan (2017).

Fe Amendments Zero-valent Fe (Fe0) was applied (0.5 – 1.5% w/ w, dry soil weight) in the slurry phase of remediated soil, immediately before separation of soil solid and liquid phases in a chamber filter press and soil rinsing.

Determination of toxic chelates from Soils The extractability of EDTA, Pb, Zn and Cd from soil into water was used to assess the potential of toxic emissions from contaminated and remediated soils. We used water extractability test (30g of wet soil and 30 mL of dH2O) and the EPA Method 1313 equilibrium leaching test.

Results and Discussion

Emissions Curbing by Fe0 Amendment Into the Soil Slurry Phase Addition of Fe0 into the soli slurry shifted the desorption/adsorption equilibrium towards adsorption of chelates. Amendment rapidly reduced toxic metals and EDTA concentrations to levels measured in the extract from original soils (Fig. 1). A reduction of metals extractability was also measured in sterilised remediated and Fe0 amended acidic soil. This result excludes biotic mechanisms. (Fig. 1).

40 Rem 16 12 A Rem 35 B A B Rem+Fe(0,5%) 35 Rem+Fe(0,5%) 14 30

) 10

)

) 1

Rem+Fe(1%) 1 -

Rem+Fe(1%) - 1 - 30 12 25 Rem+Fe(1,5%) 8 Rem+Fe(1,5%) 25 10 20 20 8 6 15

15 6 4

Conc. Pb (mg kg(mg Pb Conc. Conc. Zn (mg kg (mg Zn Conc. Conc. Zn (mg kg (mg Zn Conc. 10 Conc. Pb (mg kg(mg Pb Conc. 10 4 Orig 2 Orig 5 5 Orig 2 Orig 0 0 0 0 0 7 14 21 28 35 42 49 56 63 70 0 7 14 21 28 35 42 49 56 63 70 0 7 14 21 28 35 42 0 7 14 21 28 35 42 Time (days) Time (days) Time(days) Time (days) 0.7 25 0.7 140 C D

C D 0.6 Orig

) )

0.6 1

) 120 20

- -

1) 0.5 - 0.5 100 kg g 15

m 0.4 0.4 80 (

Cd 0.3 . 10 0.3 60

onc 0.2

Conc. Fe (mg kg (mg Fe Conc. C 0.2 kg (mg Fe Conc. 40 5 Conc. Cd (mg kg (mg Cd Conc. 0.1 0.1 20 Orig.< LOQ Orig < LOQ Orig 0.0 0 0.0 0 0 7 14 21 28 35 42 0 7 14 21 28 35 42 0 7 14 21 28 35 42 49 56 63 70 0 7 14 21 28 35 42 49 56 63 70 Time (days) Time (days) Time (days) Time (days) 3.0 1.2

E E

) )

1 1.0

1 -

2.5 -

0.8 2.0 0.6 1.5 0.4 1.0 LOQ

0.2 Conc. EDTA (mmol kg (mmol EDTA Conc. 0.5 kg (mmol EDTA Conc. LOQ 0.0 0.0 0 7 14 21 28 35 42 0 7 14 21 28 35 42 49 56 63 70 Time(days) Time (days)

Figure 1: Concentrations of toxic metals (A-C), Fe (D) and EDTA (E) in extracts from Meza (right) and Arnoldstein (left) remediated and remediated Fe0 amended soil during ageing.

Robustness of Fe0 Amendment to Curb Toxic Emissions Ten kg of soil was placed in a perforated plastic container a week after remediation and exposed to excessive simulated rainfall. The cumulative concentrations of EDTA and chelated metals in leachates from the container were measured. Even under these conditions, Fe0 amendment to both remediated soils reduced cumulative emissions to very low levels, or below the LOQ. The leachability of toxic elements and other soil pollutants reflects the sum of many different components, of which the effect of pH dominates. To check the pH factor, we assessed emissions by means of the multi-point pH

equilibrium soil leaching method (EPA, 2009). Calcareous and acidic soils 86 and 100 days after remediation were used. Leachability of Pb and Cd from all calcareous soils at this endpoint was below the LOQ Zn leachability from remediated calcareous soils was quite low but higher than from the original soil, presumably due to Zn complexation with fulvic and humic acids.

Conclusion The adsorption of EDTA-chelates on Fe0 is abiotic; obtained results show that after efficient soil washing/rinsing the slow EDTA biodegradability may not be an issue in curbing hazardous toxic emissions.

Literature

J.W., J.Y., X.Z.K., L.H., Spectrophotometric determination of EDTA in aqueous solution through ferroin formation using sodium sulfite as the reducer, Chemosphere 351–357 (2013)91.

D.L., Novel chelant-based washing method for soil contaminated with Pb and other metals: A pilot- scale study, L. Degrad. Dev. 2585–2595 (2017)28.

Preliminary EPA Method 1313, Leaching Test (Liquid–Solid Partitioning as a Function of Extract pH) of Inorganic Species in Solid Materials Using a Parallel Batch Extraction Test. US Environmental Protection Agency, 2009.

Seznam avtorjev / Author Index

Agnes Šömen Joksić ….….…24 Marco Contin …………………18, 19

Alojz Kodre ……………...…27 Maria De Nobili………………18, 19

Andrea Watzinger …………..42 Marjetka Suhadolc………….……51

Andrej Gregori………………57 Marko Zupan …….…..…15, 24, 34

Andreja Žgajnar Gotvajn …...57 Markus Puschenreiter……..……42

Anela Kaurin …………...... 48 Matej Ivartnik ………….…………..24

Bojka Kump ………………...51 Nadja Romih ………………..………30

Borut Vrščaj……………....…12 Nataša Šibanc …………….……..…51

Christoph S. Noller……….....42 Peter Kump …………………..….….27

Cvetka Ribarič Lasnik……....30 Pietro Balducci …………..……..…19

Domen Leštan 37, 39, 42, 48, 51, 54, 60 Rebecca Hood-Nowotny…….…42

Elisa Pellegrini ……...…. 18, 19 Roman Kugler……………………....30

Erika Jež ………………. 39, 60 Sara Pintarič …………….……….….51

Filippo Valdevit ………...…..19 Simon Gluhar ……...... 54, 60

Gabriela Kalčikova …………57 Stanislava Kirinčič ………………..24

Gregor Marolt …………...... 57 Tina Grubar…………………………..54

Helena Grčman …..…15, 24, 34 Ula Rozman………………..…………57

Helena Prosen ……………....54 Uroš Apotekar……………………...30

Irena Maček………………....51 Vesna Zupanc ……………………….45

Iztok Arčon ………………………….27 Wolfgang Friesl Hanl……….…...42

Katarina Vogel Mikuš ………….27