Modification of a Natural Zeolite with Fe(III)

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1737 18 , a,c 17 NaOH 1 − ) species; to − Most of these FeOH surface 2 4 20 > /HPO − 4 PO 2 and José Luis Cortina a The application of Fe(III) modified zeolites as and other anions, such as fluoride. 19 Under basic conditions, the formation of hydrated 18 16 , 15 Correspondence to: DianaTécnica Guaya, Particular de Departament Loja, Loja, Ecuador. of E-mail: [email protected] Chemistry, Universidad Department ofCatalunya-Barcelona Tech (UPC), Barcelona, Spain Chemical Engineering,Departament of Universitat Chemistry,Ecuador Universidad Técnica Politècnica Particular de de Loja,Water Technology Center Loja, CETaqua, Barcelona, Spain This study describes the modification of a natural zeolite (clinop- c a ∗ b iron oxides. iron hydroxide particles is the main modification mechanism. In general, the mineralmodified. properties However, of a the slight increase zeolite inassociated support the with are surface the not area formation haspying been of both hydrated the mineral surface oxideszeolitic and occu- material. channels of the porous structure of well as Al(III), Mn(II) or Zr(IV)has for been the primarily removal focused of on oxyanionic the removal species as of As(III)/As(V), toxic elements, such evaluate the sorption performance and the potential regeneration studies of modified zeolites have focusednism on with the little attention removal to mecha- their possible regeneration. tilolite) with Fe(III) togroups on promote the the zeolites structure formation toof favor of cationic the simultaneous (ammonium) uptake and anionic (H Adriana Farran + or a 13 , 12 due to their Fe-OH) in the iron zeolite (Z-Fe) enhances the phosphate uptake from Natural and 4 in Z-Fe. However, the ammonium sorption capacity slightly decreases from ≅ Therefore, the 3 , polymer 1 2 1 − 11 ) to the Fe(III) form , + In addition, zeolites 10 in Z-Fe. The equilibrium and kinetics sorption were well explained by the Langmuir 7 1 Na – − − 5 0.2 mg-P g ions are exchanged by Fe(III) + ± 2 mg-N g : 1737–1746 www.soci.org © 2015 Society of Chemical Industry ± César Valderrama, 14 91 2016; a,b* in Z-N to 3.4 1 solutions. When the modification process is car- in Z-N to 27 − 3 1 Surface-modified adsorbents have become more − 9 , 8 clinoptilolite; iron; phosphate; ammonium; sorption; kinetic

0.1 mg-P g 2 mg-N g

± ± The modification of zeolites with Fe(III) is typically performed in two stages as follows: (i) the conversion of the zeolite to the Na J Chem Technol Biotechnol form using NaCl, NaOH and NaOH/NaCl solutions;version of and the (ii) sodium the form con- of the zeolite (Z INTRODUCTION Eutrophication is awith serious phosphate environmental and problem ammoniumdue to overloading associated municipal effluents in and agricultural surface runoff. waters Abstract BACKGROUND: The incorporation ofammonium Fe(III) removal. was performed in a naturalRESULTS: clinoptilolite The (Z-N) for existence simultaneous of phosphate and hydroxyl groups ( removal from aqueous solutions Diana Guaya, simultaneous phosphate and ammonium (wileyonlinelibrary.com) DOI 10.1002/jctb.4763 Modification of a natural zeolite with Fe(III) for 0.6 Research Article Received: 23 April 2015 Revised: 15 June 2015 Accepted article published: 22 June 2015 Published online in Wiley Online Library: 20 July 2015 prominent in recent years. Ingranular addition to ferric granular hydroxides media, such (GFH)(GAC) as that and are granular used for activatedhave anions carbon adsorption, been other used iron to composites the confine support. iron A oxide convenientparticle particles method size in involves to the the control(e.g. preparation pores aggregation akaganeite) of of and in iron hydroxide a particles template, such as clay, ried out under acidic conditions, Na isotherm and the intraparticle diffusion model, respectively. CONCLUSIONS: Both the phosphate andphosphate ammonium sorption uptake capacity were slightly of affected iron by the zeolite coexistence was of decreased competing ions. in The the regeneration cycles. Desorption using a 1 mol L high abundance, availability and low cost. implementation of wastewater purification technologies forphosphate both and ammonium removal is required. synthetic zeolites arethat are crystalline widely used microporous in separationa promising and aluminosilicates material purification for processes environmental and applications 33 cationic species and, to a lesser extent, the formation of hydrated Fe-exchanged natural zeolite. using typical FeCl can be used as substrates for supportinglic and impregnating hydroxides metal- for oxyanionphosphate). uptake applications (i.e. arsenic and Keywords: Supporting information may be found in the online version of this article. solution under dynamic conditions provided higher© enrichment 2015 factors Society for of ammonium Chemical than Industry phosphate. ) 1 1 1 ), 1 Cl − − − 1 − 4 − and et al. 1 NH − )). The 1 1 with the − − ), sodium 1 1 − − : 1737–1746 (0.1 mol L , 25 mg-N L 91 ), bicarbonate 1 1 3 − − and 25 mg-N L Al)-P was deter- NaCl. Finally, the + (0.1 mol L 1 2016; − 1 3 − . The loaded sample 1 CO − ), NaHCO 2 1 ), magnesium (50 mg L − 1 C, and average values are − ), nitrate (30 mg L /Na C) in triplicate, and the aver- ∘ 1 3 C, and the average data are ∘ − ∘ 1 1 and 10–5000 mg-N L 1 ± ± 1 ± ). Finally, the Z-Fe sample (0.25 g) − 1 m) was added to 25 mL of a solution m) prior to analysis. The concentra- − μ μ and 25 mg-N L 200 1 − < J Chem Technol Biotechnol HCl. The residual phosphorus (R-P) was cal- ) and NaHCO 1 1 of the competing ion. The ion concentrations − − solution. The loaded sample was washed and 1 − . The tubes were withdrawn sequentially at spe- 1 ), sulfate (200 mg L ), calcium (160 mg L 1 − 1 1 − − − The Z-Fe sample (0.25 g) was equilibrated in 25 mL (0.1 mol L 23 3 Mg)-P was determined by two consecutive extractions in cific time intervals. All of theand tests were room performed temperature at 200 (21 rpm solutions (pH adjusted from 2 to 11). nium concentration in themixtures of presence common of competing individual ionseffluents: ions present by in addition and wastewater of the(without pH Z-Fe adjustment) containing sample 25 mg-P (0.1 L g)and to 25 solutions mg L were fixed at the averagefrom annual a composition tertiary of treatment the includingthe a stream reverse El osmosis Prat step wastewater at The treatment solution consisted plant of: (Barcelona chloride – (625 mg Spain). L (325 mg L mixed ion solutions. was equilibrated in a solution containing 20 mg-N L was equilibrated in a solution containing concentrations ranging from 1 to 2000 mg-P L and potassium (40 mg L age values are reported.10 min The and samples filtered were (45 centrifuged for tions of the phosphate and ammonium ionsin were determined the initial and remaining aqueousloaded solution. zeolite In samples addition, were the examined by fieldtron scanning elec- microscopy, and the mineralX-ray diffraction. phases were identified by (260 mg L (0.1 g) sample was added to 25 mg-P L 10 mg-P L CO + 2 (ii) Sorption capacity as a function of equilibrium pH: the Z-Fe culated based onadsorbed the and mass the extracted balanceat fractions. between The 200 rpm tests the were in phosphorus performed triplicate at 21 containing 25 mg-P L (iii) Sorption capacity as a function of phosphate and ammo- NaOH followed by extraction in 1 mol L dried prior to the extraction trials.fraction The loosely (LB-P) bound phosphorus was determinedof by the Z-Fe two loaded consecutive sample extractions (0.25 g) in 20 mL of 1 mol L 20 mL of 0.5 mol L Na of a 25 mg-P L (pH 7). The iron and aluminum fraction (Fe mined by two consecutive extractions in 20 mL of 0.1 mol L Phosphate speciation in the loaded Z-Feby samples fractionation assays The fractionation of phosphorus immobilizedperformed in based loaded on Z-Fe was a modifiedprotocol. three sequential step extraction reported. Phosphate and ammonium batch desorption studies The Z-Fe sample (0.5 g phosphorus linked to the(Ca calcium and magnesium compounds was washed and dried followedelution by equilibration solution: in (i.e. 25 mL of NaOH the (1 mol L tests wereat performed 200 rpmreported. in in triplicate two at 21 sorption–desorption cycles (iv) Batch kinetic sorption experiments: the Z-Fe (0.1 g) sample . . ) ) 3 1 1 1 1 21 − − − − et al. www.soci.org D Guaya (0.1 mol L 3 © 2015 Society of Chemical Industry m) and fixed-bed μ C for 24 h. The experi- 200 ∘ and 10–5000 mg-N L < 1 − Cfor24h. ∘ Weighed amounts of the dry samples (particle m) were shaken overnight in 25 mL of a solution con- μ 22 m) configurations. Z-N was modified to the iron form using μ 200 concentration: the Z-N and Z-Felibrated in samples solutions (0.25 without g) pH were adjustmenttions equi- using ranging concentra- from 1 to 2000 mg-P L Ranges of phosphate andselected ammonium considering the concentrations expected were biological values secondary of effluent a or conventional anaerobic digestion. concentrated A effluent ratio of from 2 to 5phate of concentration ammonium over was phos- usedage taking values as of reference the the compositionin aver- of Barcelona the – municipal Spain. wastewaters < 800 (i) Sorption capacity as a function of phosphate and ammonium < an adaptation of the method reported by Jiménez–Cedillo wileyonlinelibrary.com/jctb test followed by drying at 80 The Z-N sample (30 g) was treated in 250 mL of NaCl (0.1 mol L MATERIALS AND METHODS Incorporation of Fe(III) to the natural zeolite A natural zeolite (Z-N) obtainedvak from Republic) the was Zeocem washed Company and (Slo- dried at 80 Physicochemical characterization of the zeolites A powder X-rayused diffractometer for X-ray (D8 diffraction (XRD) Advanceand characterization Z-Fe A25 of the samples. Bruker) Z-N, Theof Z-Na was the chemical samples composition were determined andelectron using morphology a microscope field (JEOL emissiondispersive scanning JSM-7001 spectroscopy F) system (Oxford coupled Instrumentsinfrared to X-Max). absorption The spectra an were recorded energy onFTIR a 4100 Fourier transform (Jasco) spectrometer in the range 4000 to 550 cm ments were performed in batch (particles and re-use of the Z-Fe zeolite via sorption andtertiary desorption cycles wastewater for treatment applications. Thework objectives are of as this follows: (i) toto incorporate Fe(III) characterize into the natural modified zeolite; zeolite; (ii) pH (iii) and to concentration study on the the phosphate influence andonto of ammonium the sorption modified zeolite; (iv)kinetic to sorption determine parameters; the (v) to equilibriumtivityofcommonionsinwastewatereffluents;and(vi)toevalu- determine and the sorption selec- ate its performance in sorption and desorptionexperiments. cycles via dynamic ( size taining various phosphate (P) and ammoniumThe (N) following concentrations. types of experiments were performed: two consecutive times under refluxform of for the zeolite 4 (Z-Na). h Then, the to Z-Natwo sample obtain consecutive (30 the times g) was by sodium treated refluxing in 250for mL of 4 FeCl h to obtainples the were iron washed zeolite until (Z-Fe). no After chloride treatment, was detected the using sam- an AgNO Equilibrium and kinetic batch sorption studies The batchout equilibrium using a sorptionreported. standard experiments methodology that were has carried been previously The nitrogen gas adsorption methodspecific was surface area used of to the Z-N, determine Z-Namatic the and Z-Fe sorption samples on analyzer an (Micrometrics). auto- Theat tests least were four replicated timesreported. for each sample, and the average values are

1738 1739 (4) (1) (2) (3) that (e.g. 3.4 0.8 - 1.4 3.7 0.2 0.2 1.0 2.4 )was 1 + FeOH) e ± ± ± ± ± ± ± ± ± loq* 2 + − ≅ The Z-Fe < 29 2Na + + Notably, some as well as the ) + 2 3Na 1 27 + − and Fe(OH) + Na and 547 cm 3 + + + 1 2 FeCl − + 2 ( 1.4 57.4 0.1 0.4 0.0 - 0.0 3.3 1.5 23.3 0,2 1.0 0,1 0.6 0,0 12.8 Fe 2 v ± ± ± ± ± ± ± ± 3 w (s)). ) loq* 1.1 loq* ) 3 − − FeCl < < × The formation of ( − wileyonlinelibrary.com/jctb ) ZO ZO e 31 . The hydroxyl groups of the , and 1541 cm ZO C 1 ) represent the initial and equi- ). In addition, a fraction of Fe(III) > > 30 ( 1 − + 1 ( − − > 2 − o ↔ ↔ ↔ The Z-N (Fig. S4(a)) and Z-Na (Fig. C , and the deformation vibration of 2 3 ( 1 + 2 + + − 28 FeOH). (mg L , FeOH = 4 − . ≅ e Fe 1630 cm 2.6 60.3 0.0 1.5 0.1 0.4 0.2 5.3 1.7 29.1 0.5 1.8 0.3 1.1 0.2 0.4 0.5 e 1 FeCl ∼ − ± ± ± ± ± ± ± ± ± FeCl q + loq* ZO , 1455 cm + ) 1 + < are related to the presence of the surface > − + + ) 1100 cm 1 + )andC − Na Na ∼ 1 )or − − − Fe-OH form (e.g. (Fe(OH) + Na 2 − represents the zeolitic structure. ≅ ZO ZO − to 3100 cm Chemical composition (wt%) of the zeolitic materials: natu- ZO > > (mg L ions cannot be disregarded. 1 ( ZO > − 3 o (FeOH 3 ( + 2 > ) 2 − loq: limit of quantification ZO A network of crystal clusters with a homogeneous size distribu- The FTIR spectra of Z-N, Z-Na and Z-Fe (supporting information Table 1. ral zeolite (Z-N), sodium zeolite (Z-Na) and iron zeolite (Z-Fe) ElementO Z-N 57.8 Z-Na* Z-Fe Na 0.3 Mg 0.4 Al 5.3 Si 29.7 Cl K2.9 Ca 1.9 Ti 0.2 Fe 1.6 > water was located at tion was identified in the FSEM imageing information of Fig. the S3a). The Z-N crystals sample of (support- clinoptilolite displayedcharacteristic the plate-like morphology with large cavities and entries in to the channels inside the zeolite framework. zeolitic structure are associated with3700 the cm peaks in the range from with Fe calculated using Equation (4). lamellar crystals and smalland particles Z-Fe covered (supporting the information surface Figssodium S3(b), of and (c)), iron Z-Na confirming modification was that achieved in clinoptilolite. Fig. S4) displayed peaks between 798 cm where C spectra exhibit some changesion in exchange with comparison the to trivalentlocated Z-N Fe(III) due (Fig. at S4(c)). to 1396 The cm the new bands correspond with the stretching bridgesgroups. of The the stretching Al-O-Si vibration and of Si-O-Si to the Si–O the groups band corresponds at where shift at 3396 cm iron hydroxide groups ( is caused by thethe modification Fe(III) species step even due atFig. to low S2), pH the promoting values strong the (supporting formation acidity information of of Fe(OH) ( librium concentrations, respectively, v (L) is the aqueous solution Phosphate and ammonium equilibrium isotherms The equilibrium uptake for phosphate and ammonium (q S4(b)) spectra exhibited minimalion differences, exchange which between is cations typical with for a similar valence. will be in the ), ), + 26 2 1 1 , − − The 21 , 8 25 ), which ∘ and Ca ), chloride treatment. 1 + ) of Z-N and − 3 1 − ,K g + )). The sorption 2 1 2 − . In addition, it is and 32.08 NaOH solution at a + content was due to ∘ 2 1 + − 0.3 m ), sulfate (10 mg L solution is provided in 1 ), calcium (80 mg L ± 3 − 1 − , 22.52 ∘ ,andCa + Unfortunately, no discussion ), which are the predominant 2 + 2 22 , 17.36 , : 1737–1746 © 2015 Society of Chemical Industry ), ammonium (25 mg L ∘ 1 15 ,Mg − 91 + m) were packed in a glass column -FeOOH) as the crystalline iron phase μ 𝛽 , 11.23 . ∘ 2016; and FeCl 1 ) and potassium (20 mg L − 800 The vanadomolybdophosphoric acid col- 1 + solutions used to modify the zeolites. The 2 − < 3 24 ), sodium (130 mg L 1 at 9.92 − 𝜃 . Then, Z-Fe was saturated in the absence of com- ), bicarbonate (162.5 mg L 1 1 − − 100 mm). The expected values of the effluent streams × The FSEM-EDX analysis indicated that the chemical composition In the Z-Na sample, the increase in the Na wasobservedinZ-Fe,whichisincontrasttothereportsofamor- phous iron oxide species forming on natural zeolite surfaces. species distribution diagram for the FeCl J Chem Technol Biotechnol ions. The iron content in Z-Fe exhibitedto an eight-fold ion increase exchange due between K The Z-Na andreflections Z-Fe (i.e. 2 spectra exhibited the zeolite characteristic did not change. The smalltions changes observed in in the the intensity Z-Feof of spectra cation the exchange resulted reflec- sites from by the iron occupation ions due to the FeCl RESULTS AND DISCUSSION Characterization of modified Fe(III) zeolite The XRD patterns of Z-N,Fig. Z-Na S1) and indicated Z-Fe that (supporting clinoptilolitewhich as information coexisted the main with crystalline quartz phase, andintermediate stage albite. in The the zeolite Z-Na modification sample to theto was iron the an form due easy sodium removal in ion exchange applications. Modification of a natural zeolite with Fe(III)Phosphate and ammonium sorption and desorptionstudies column The Z-Fe samples ( www.soci.org species in the FeCl Fig. S2 in theof supporting the information. zeolite The can modification beFe-Cl process described complexes by (Equations exchange (1)–(3)) reactions involving even though the exchange peting ions and regenerated using a 1 mol L flow rate of 0.5 mL min Analytical methods Standard methods were used for(N) phosphate determination. (P) and ammonium has been providedchloride in in these the previous samplecomplexes studies. is (e.g. The associated FeCl presence with the of presence of Fe-Cl orimetric method (4500-Pthe C) allowed ammonia-selective for electrodeemployed P for quantification, method N determination. and (4500-NH3 Thea ions Thermo D) were Scientific determined Ionic was using ICS-1000). Chromatograph (Dionex ICS-1100 and nitrate (15 mg L magnesium (25 mg L under dynamic conditionsabsence was of evaluated competing in1.85 ions the mL min with presence a and countercurrent flow rate of important to note the existence ofzeolite, chloride (1.1%) which in the is modified consistentnatural with or previously reported synthetic results zeolites. for In addition, the specific surface area (19.8 (312.5 mg L the cationic exchange reaction between the Mg existence of akaganeite ( Z-Fe was the same. of clinoptilolite consisted of O, Na, Mg,main Al, elements Si, (Table K, 1). Ca, Ti and Fe as the from secondary treatment atplant (Barcelona the – El Spain) were Prattion (i.e. considered phosphate wastewater (12.5 for mg treatment the L feed composi- (15 mm 4 + 20 (9) (7) (8) (10) ions et al. /PO even (1%), close 4 + et al. 5 4 + 2 PCZ : 1737–1746 91 + 4 2016; However, Liu NH 39 (3 %) and Ca − + Z (4%), which is in agree- − 4 − 2 4 + + Binuclear Na Bidentate 2 Bidentate PO Monodentate + > 2 Mononuclear HPO H Mg Na due to a complexation reaction > . − − … … ↔ m 3 (5 %) ) + + 4 + 3 − OH OH 2 2 + . The cation mixture decreases by 16% 2 K + (10%) NH + OH OH OH 2 (NH + However, no mineralogical phase was > n + + + − − 38 , + and ion-exchange resins impregnated with 40 J Chem Technol Biotechnol Na O 37 Fe OH Fe 2 36 Na > sorption pH dependence exhibited an unex- (6 %) FeOH O H − − − OH and Mg − + O + ≅ OH Z Z 4 + + 2 Z 2 ≤ − (16%) | minerals. P || ≤ O P O OH /Ca + P 4 + 2 > − > Ca Fe − /Na O O → − + > 2 4 − O O O − − , and then, the removal values could not be explained by the Z ions. The NH − 3 HPO ∕ The reduction of the P sorption capacity above a pH of 8, The electrostatic interactions of the surface groups of Z-Fe < Fe Fe + − 4 Fe pected increase evenNH above a pH 9.3 when it is converted to indicates the acid-baseformed properties during of the the impregnation hydrated processes iron with oxides a pH (Equations (7) and (9)) aresorption responsible at for acidic the pH lowest values ammonium H (near pH 2) due to competition with and Ca/PO (18%) reported Fe(III) removal of NH hydrated iron oxides. exchange reaction defined by Equation (10). identified by XRDtheir analysis content of the beingtant loaded below decrease iron in the samples the limit ammonium due of removal to was detection. promoted An by K impor- Effect of competing ions on phosphatesorption and ammonium The phosphate sorption exhibitedpresence a of slight Mg improvement in the to 8. This behaviorakaganeite is minerals in agreement with published data for the and 38% for the phosphate and ammonium uptakes, respectively. which has been reported forof a a precipitation synthetic reaction zeolite involving the due formation to of Mg/NH the effect with Fe atoms as though the ion-exchange coefficients are favored for NH over K ment with the behavior reported for a synthetic zeolite − − PO Fe 2 − PZC attraction Z Z → H −−−−−−−−− − Electrostatic Z − L pH Z (5) (6) ≫ + FeOH 2 www.soci.org D Guaya Hydroxilation in Z-N −−−−−−−− ≅ − pH 0.2 mg-P OH 1 − 0.99) com- ± − → PZC ≥ Fe OH 2 © 2015 Society of Chemical Industry pH − − ). In contrast, a ≥ Z 1 Fe 2 mg-N g − Complexation −−−−−−−− e − − ± pH C PZC → Z pH e m log C q < or by means of coulombic 1 n Protonation −−−−−−− + − ) is associated with the forma- pH 34 − 4 − + 0.1 mg-P g 2 4 − m – 3 F q ± 4 PO 32 K 1 . 2 L (non-specific adsorption), as shown OH HPO H K log -PO − pzc = − = 2 Fe e e 4 e ) is the Freundlich equilibrium sorption + q C 35 − q 1/n Z ) ) is the maximum sorption capacity, K 1 OH log 1 in Z-Fe was observed. − -HPO − − 1 − − 4 Fe PO − (mg g 2 )/(mg L Z 1 − m ) is the Langmuir sorption equilibrium constant and 2 mg-N g 1 − ± ) compared with Z-N (0.6 ((mg g 1 The phosphate removal was not dependent on the pH in the The Langmuir isotherm provided a better description of the − F K range of 2 to 11 (Fig. 2).oxyanion The sorption (H mechanism of the phosphate wileyonlinelibrary.com/jctb (L mg volume and w (g) isammonium equilibrium the sorption mass was of evaluated theLangmuir according (Equation zeolite. to (5)) The the and Freundlich phosphate (Equation and (6)) isotherms: decrease in ammonium capacity from 33 in Equations (8) and (9). to 27 where q pared with theonly Freundlich describes the isotherm experimental data (Table at 2 lowThese concentrations and levels. results Fig. suggest 1), that which affinity the sites on availability the of zeolite fortion specific monolayer and or/and and homogenous equal sorp- ioncapacity exchange. exhibited The phosphate ag maximum six-fold sorption increase in Z-Fe (3.4 tion of monodentate and bidentatesurface complexes with groups the of hydroxyl both ofcation exchange the positions exchanged or iron on the complexes hydrated on iron the oxides ( constant. phosphate and ammonium equilibrium sorption (R forces depending on the pH groups) inside the zeolite micropores (specificis adsorption), represented which by Equation (7);

1740 1741 2 R N N P P ate All mAll n um Potassium d Experimental Langmuir Freundlich wileyonlinelibrary.com/jctb )1/ ng anion 1/n m Magnesiu ng cation aad ) 1 (mg/L) − e C F Competin Competin K )/(mg L e Sulph te Chlori e Bicarbon m Calcium 1 − Nitrat Sodium ((mg g P-N P-N and the phosphate sorption rates were lower compared Individual eﬀect of (a) cations and (b) anions for phosphate (P) 43 0 1000 2000 3000 4000 .8 .8 2 0

3 2 1 0 0

3.6 2.7 0.9 0.0 3.6 3 2.7 2 1 0.9 0 00.0

40 30 20 10

e e

(mg/g) q (mg/g) q

e (mg/g) q (a) (b) Figure 3. and ammonium (N) removal by iron zeolite (Z-Fe). Phosphate and ammonium sorption kinetics The sorption kineticsions of for both Z-Fe thematerials are (Fig. phosphate 5). comparable Equilibrium and was withis ammonium reached those in within agreement 200 reported min withzeolite, which for the zeolitic behavior of a Fe (III) natural modiﬁed (b) , − 3 . )R 1 1 − − L K with coex- 1 − Langmuir Freundlich Experimental Langmuir Freundlich )(Lmg 1 − m q (mg/L) e and at 25 mg-N g (mg g pH C 1 − Notably, a reduction in the phos- : 1737–1746 © 2015 Society of Chemical Industry Therefore, there is no competi- 0.99) provided a better description Ammonium 41 , 91 ≥ 39 40 , 2 5 2016; and in the presence of cations at 3.3 mg-P g AmmoniumAmmonium 33 27 0.006 0.004 0.99 0.99 1.84 0.80 0.36 0.46 0.94 0.96 Phosphate 0 500 1000 1500 2000 2500 1

−

5 4 3 2 1 0

Isotherm parameters for phosphate and ammonium sorption on natural zeolite (Z-N) and iron zeolite (Z-Fe) e (mg/g) q Eﬀect of pH on phosphate and ammonium removal by iron The combination of anions decreases the phosphate and Experimental and theoretical equilibrium isotherms for (a) phosphate and (b) ammonium removal by iron zeolite (Z-Fe) at constant equilibrium (a) 0.2. 01234567891011 42

± 5 4 3 2 1 0

e (mg/g) (mg/g) q The phosphate and ammonium sorption capacity has a varia- The Langmuir isotherm (R Z-Fe Phosphate 3.4 0.02 0.99 0.59 0.25 0.71 Z-N Phosphate 0.6 0.01 0.99 0.02 0.47 0.97 Table 2. of the phosphate and ammonium equilibrium sorption inence the pres- of competing ions compared(Table 3, with Fig. the 4). Freundlich The isotherm the presence ammonium of ions sorption at 23 capacity mg-N g decreased in tion of less 5% in thefor presence of other chloride and sulfate zeolites as reported (Fig. 3). J Chem Technol Biotechnol Figure 2. zeolite (Z-Fe). pH 3.1 Figure 1. Modification of a natural zeolite with Fe(III) www.soci.org tion between theseouter-sphere species complexation. for the same binding sites due to ammonium uptake by 8% and 14%, respectively. isting anions and cations.uptake capacity Similarly, was observed decrease in inat the 3.1 presence the mg-P of g ions phosphate and anions phate removal was promoted by the coexistence of HCO which is consistent withzeolite. the selectivity reported for a modified 2 (12) (13) R et al. )and )and f 1 D − : 1737–1746 (mg L The effective 91 s C 47 , N-Anions N-Cations N-Ions P-N 46 t n 2016; t p z D s 2 2 C yields a straight line. In r f 𝜋 D hrC 2 1/2 t = = ) ), respectively, 2 1 )) − t ) e )1/ t e q q q q (mg/L) 1/n ( ) e ( 1 − − C − 1 In addition, the phosphate and ammo- 1 ( ) as a function of F J Chem Technol Biotechnol t ) is the intraparticle diffusion rate constant ( 45 K q ln ) mechanisms corresponding to the homoge- )/(mg L p ln -1/2 1 − D − h − are the solute loadings on the adsorbent phase 1 e − ) describes the thickness of the boundary layer (i.e. q 1 − ((mg g ) are the ion concentrations in solution and in the 1 − and equilibrium (mg g and (mg g t t t q 0 900 1800 2700 3600 4500 6 0

30 24 18 12

(mg kg

e (mg/g) q When the rate of sorption is controlled by liquid film diffusion, The fitting of the kinetic data to the intraparticle diffusion model z where k nous particle diffusion model (HPDM) (Fig. 6). and A (mg g this rate can be expressed as shown in Equation (13): particle diffusivity calculates the sorption on the spherical particlesusing Equation (12): nium sorption were evaluated based on the film diffusion ( the higher the value ofThe A, sorption the process is greater controlled the bythe boundary sorption intraparticle layer uptake diffusion ( effect). when contrast, when two or morethe steps data influence result the in sorption multi-linear process, plots. revealed two linear steps.particle Therefore, diffusion film may diffusionammonium be followed used sorption. by to describe the phosphate and at time C where particle diffusion ( (b) 2 (11) 2400 www.soci.org D Guaya ns ations nions P-N P-An P-Ca P-Ion )R C. 1 © 2015 Society of Chemical Industry ∘ − 1 L K 1800 ± Langmuir Freundlich A FeOH). ≅ + 200 mg/L) 2 (m ∕ e 1 t C )(Lmg t 1 k − = m q t ions being faster than phosphate ion q 012 (mg g + 600 and Na + 4 Isotherm parameters for phosphate and ammonium sorption by iron zeolite (Z-Fe) in the presence of competing ions 0

(Equation (11)) was employed to describe the sorption

4 3 2 1 0 Evolution of phosphate and ammonium sorption uptake versus Equilibrium capacity for (a) phosphate and (b) ammonium recovery by the iron zeolite (Z-Fe) in the presence of competing ions.

e (mg/g) q 44 (a) The intraparticle diffusion model reported by Weber and PhosphateP-AnionsP-CationsP-IonsAmmoniumN-Anions 3.4N-CationsN-Ions 3.1 3.3 27 3.1 25 0.02 25 0.01 0.02 23 0.004 0.02 0.99 0.003 0.002 0.99 0.99 0.002 0.99 0.99 0.99 0.98 0.59 0.99 0.35 0.54 0.80 0.53 0.69 0.45 0.25 0.46 0.31 0.26 0.46 0.71 0.24 0.45 0.81 0.49 0.80 0.96 0.47 0.98 0.97 0.99 0.99 Table 3. wileyonlinelibrary.com/jctb time for iron zeolite (Z-Fe) in batch experiments at 21 with those of the ammoniumbetween ions, which NH is due to ion exchange Figure 5. Figure 4. mechanisms of the zeolitesion assuming in it the was sphericaladsorbate promoted solution. adsorbent by and diffu- convective diffusion in the complexation on the zeolite surface ( Morris

1742 1743 53 2 and ± 4 6 4 6 3 ± ± ± ± CO 2 Mg)-P com- ,Na + 3 60.033 ± 6% of phosphorus ± Desorption (%) Mg)-P (mg/g) R-P 452 591 566 492 Experimental Particle difussion Film difussion + ± ± ± ± wileyonlinelibrary.com/jctb 49 74 73 80.3939 ± in the ﬁrst sorption–desorption cycle Al)-P (Ca 3 time (min) In addition, 39 + CO 54 2 3 /Na 20.5354 CO 3 Mg)-P; R-P 2 ± + 3 3 CO Speciation of phosphate immobilized on the 2 LB-P (Fe Simultaneous phosphate and ammonium desorp- /0.1 MNa NaHCO Na 3 1 1 NaOH 64 8 % phosphorus was associated with the iron and alu- − − 0 100 200 300 400 500 1 C − ± Al)-P; (Ca ∘ + ±

3.50 3.00 2.50 2.00 1.50 1.00 0.50 0.00

e t (mg/g) q The partial phosphate desorption was due to complexation 0.1 mol L 0.1 NaHCO 0.1 mol L 0.98 0.03 4 Table 6. tion efficiency from21 loaded Z-Fe in batch experiments at Elution solution1molL Phosphate Ammonium Table 5. iron zeolite (Z-Fe)(Fe associated to the chemical forms: LB-P; q (mg/g) (mg/g) % (mg/g) % (mg/g) % (mg/g) % is in agreement with previousThe results 54 using a syntheticminum zeolite. hydroxides. This resultof suggests the that hydrated thefor Fe-OH iron phosphate groups oxides removal, which inof is Z-Fe a in are accordance synthetic with primarily the zeolite. responsible report was immobilized by calciumpounds. and Chemical magnesium precipitation (Ca but encouraged no phosphate mineral phase uptake wasconcentrations determine being below by the XRD limit analysis of quantification. due to the Phosphate and ammonium batch desorption Higher recovery ratios were obtainedphate for from ammonium the loaded than zeolite phos- using NaOH, NaHCO (Table 6). between hydrated iron oxide groupsmation and of phosphate Ca-Mg phosphate and mineral the phases. All for- ofZ-Fe the regenerated samples exhibited acompared with larger ammonium decrease removal in capacity phosphate in the uptake subsequent mixtures of NaHCO (b) There- 09 12 − − 51 10 10 , × × 50 1.9 0.5 , 0.95 0.98 0.97 0.96 9 1.2 2.1 In addition, the is the thickness 49 , h 48 Experimental Particle diffusion Film difussion , 11 13 45 − − m for a poorly stirred 5 10 10 − × × 0.1 0.1 0.92 0.98 0.99 0.89 10 due to the hydroxyl groups 4.6 1.6 × 1 . Therefore, particle diffusion p − D 2%, respectively (Table 5), which ) ) time (min) : 1737–1746 © 2015 Society of Chemical Industry ± -1/2 -1/2 ) ) 91 h h 1 1 − 1 1 − s − − s 2 2 2 2 2 2 (m 2016; R R R R (m f p and 1040 cm (mg g (mg g is the average radius of the zeolite particles 1 t1 t2 r 2% and 3 k k − ± 52 is the contact time (min) and t 0 100 200 300 400 500 than those found for Kinetic parameters for phosphate and ammonium f , 1455 cm D 1 48 m),

Experimental and theoretical sorption kinetics of (a) phosphate and (b) ammonium ions for Z-Fe.

−

0.20 0.15 0.10 0.05 0.00 4

t (mg/g) q − (a) 10 diffusion × Both the phosphate and ammonium sorption exhibited higher Based on FSEM–EDAX analysis, the loaded Z-Fe possessed a sur- Particle diffusion D Film diffusion D ModelIntraparticle Kinetic parameters Phosphate Ammonium Table 4. removal by iron zeolite (Z-Fe) of film around the zeolite particle (1 was the rate-limitingoccurred step, on and the surface monolayerwith of the molecular results zeolite reported sorption (Table for 4), ammoniumlites at which sorption low on initial is ammonium natural concentrations. consistent zeo- values of J Chem Technol Biotechnol Phosphorus speciation in the loaded Z-Fe samples The L-B andphosphorous R-P at were 4 the minor fractions of the immobilized zeolite, respectively, (1 Figure 6. Modification of a natural zeolite with Fe(III) www.soci.org evaluation of the sorption kinetics wasmodels performed (supporting information via Equations convention S1–S2 and Table S1). face covered by several lamellar particlesFig. (supporting S3(d)), information and the existence ofobserved, phosphorus which but may not be nitrogen due was toof the content quantification. being below After the sorption, limit compact the crystalline zeolite framework. The surfaceporting loaded exhibited zeolite information a spectra Fig. (sup- S5)3392 cm exhibited changes in the bands at solution). fore, the increase in phosphate removalreduction at in the expense ammonium of sorption a occurredto slight binding on site Z-N competition, as and reported Z-Fe foraluminum due a form. natural zeolite in the (Fe(OH)) of the zeolite surfacereactions participating with in the the phosphate complexation and ammonium ions.

et al. Eluted ammonium (%) ammonium Eluted NaOH 1 − : 1737–1746 Fe-OH func- 100 80 60 40 20 0 N-Ions 91 ≅ . 1 − 2016; N . 1 − ) groups of the zeolitic struc- − NaOH at 0.5 mL min 1 − Bed Volume Bed volume J Chem Technol Biotechnol 012345678 0 40 80 120 160 200 240 280 0

1.0 0.8 0.6 0.4 0.2 0.0

4000 3000 2000 1000

0 C/C Concentration (mg/L) Concentration

The enhancement ofthe the ammonium phosphateThe exchange uptake ammonium capacity slightly sorptionand of affected primarily complexation occurred the with by the modified ion (ZO zeolite. exchange This researchence was financially and(CPQ2011-26799) supported Innovation and by through2009SGR905, Ministry the 2014SGR050). the The authors of gratefully Catalan ZERODISCHARGE thank R.(Aigues Estany Sci- government project de (project Barcelona),Tecnologíco M. ref. del Gullom Agualites (EMMA), (CETaqua)), supply. Finally, I. Zeocem thanksMicroscopy, Sancho (Slovakia) to Universitat I. (Centro for Politècnica Lopez zeo- de (Laboratoryanalysis and Catalunya) of to Electronic for N. the MorenoDiana Guaya (IDAEA-CSIC) FSEM acknowledges for the XRD financial determinations. support of Secretaría de ACKNOWLEDGEMENTS provided enrichment factorsammonium, of 39 respectively. andoperation However, 80 revealed for the phosphate auptake and sorption–desorption capacity. reduction Therefore, in re-impregnationafter steps reuse the are cycles, anionicloaded required or zeolites have based and the potential on forsoil cationic use quality. the as additives reusability to improve limitations, the ture and aprecipitation combination and inner of sphere electrostatictional complexation with interactions, groups acting chemical asuptake. the The sorption coexistence of mechanismphosphate competing for ions and phosphate slightly ammonium affecteddynamic sorption the uptake experiments, onto the Z-Fe. desorption In the using 1 mol L (b)

(b) Eluted phosphate (%) phosphate Eluted and 1 www.soci.org D Guaya 100 80 60 40 20 0 − P-Ions at 306 BV, 1 ) and phos- − 1 P − © 2015 Society of Chemical Industry 3% of the eluted ± at 257 BV. In addition, 1 − 0.95) was 26 mg-N g at 122 BV in the presence of coex- Bed volume = 1 Bed Volume 0 − 2% of the eluted ammonium at 4 BV. The ± ) sorption by Z-Fe with and without competing 1 − . Under these conditions, enrichment factors of 40 012345678 1 − 0 0 25 50 75 100 125 150 175 75 50 25 150 125 100

Desorption proﬁles of (a) phosphate and (b) ammonium from loaded iron zeolite (Z-Fe) using 1 mol L Breakthrough curves of (a) phosphate and (b) ammonium uptake by iron zeolite (Z-Fe) at ﬂow rate of 1.8 mL min 1.0 0.8 0.6 0.4 0.2 0.0 Concentration (mg/L) Concentration

0 C/C at 167 BV to 1.1 mg-P g (a) (a) 1 − The profiles of the ammonium and phosphate desorption in a phosphate and 92 highest concentrations were determined to be 131 mg-P L wileyonlinelibrary.com/jctb CONCLUSIONS In this study,(Fe(III)) a resulted simple in modification simultaneous process cationic of and an anionic iron sorption. zeolite isting ions. NaOH solution (Fig. 8) indicated a recovery of 88 Simultaneous phosphate and ammonium uptake inassays dynamic The breakthrough curves of ammonium (25 mg L Figure 8. sorption cycles. Therefore,capacity in obtained operational instudies the terms, of impregnation Fe-loaded the zeolites step do not sorption cycles was discuss and general reuse, lost. regeneration and Previous loadingviously capacity reported. losses Therefore, have the not reuse beenrequire of pre- re-impregnation the after modified cycling, or zeolite the will loadedbe zeolites potentially could used for improvement of soil quality. Figure 7. and 80 were achieved for phosphate and ammonium, respectively. and in the presence of competing ions,sorption the capacity ammonium decreased maximum to 15 mg-N g ions are shown in Fig. 7. The ammonium maximumity sorption capac- at column saturation (C/C phate (12.5 mg L the phosphate maximum sorption capacity decreased from 2.7 mg Pg 3834 mg-P L

1744 1745 , J J Fuel et al. ,edby :542–546 :235–240 Water Res 79 J Chem Tech- 183 JEnvironSci J Hazard Mater Sep Purif Technol :699–706 (2011). 186 :292–297 (2012). Micropor Mesopor Mater Natural Zeolites in Water :405–407 (1980). :749–754 (2009). 9 J Solid State Chem 130 :402–411 (2013). wileyonlinelibrary.com/jctb 229–230 220 FTIR spectroscopic investigation of J Hazard Mater :731–740 (2007). Micropor Mesopor Mater 67 :602–608 (2006). J Environ Qual In situ ˇ SurfaceComplexationModeling:HydrousFerric L, Bastl Z, Nagyová S, Dolinská S, Jorík V 298 :894–900 (2007). :146–154 (2013). Chem Eng J J Fluorine Chem J Hazard Mater :267–276 (2013). :247–252 (2010). 46 :31–59 (1963). :101–107 (2009). 233 18 Chemosphere 175 : n/a-n/a (2015). EDITOR: Latest info required (this jour- 89 145 . John Wiley & Sons, Inc., New York (1990). :939–945 (2009). :359–366 (2008). :365–378 (2000). :1603–1613 (2007). :1643–1649 (2009). :670–674 (2008). J, Liu H, Liu R, Zhao X, Sun L and Qu J, Adsorptive removal of phosphate by aPowder nanostructured Technol Fe–Al–Mn trimetal oxide adsorbent. Oxide bimetallic oxides: promisingaqueous adsorbents solutions. for removal of As(V) in (2010). of arsenatesiron–manganese-modified as clinoptilolite-rich tuffs. 163 water pollutant on iron, manganese and in the presence ofand the trace coordination ions Fe(II): of the Fe(III). effect of the ammonia, amine adsorption capacities of amorphousaqueous Fe/Al solutions. mixed hydroxides from removal of ammoniumEnviron and Eng Res phosphate from aqueous solutions. calcareous sediments1. wastewater. American Public HealthWorks Association, Association, and American Water Environment Water Federation (2000). using microwave-treated natural Chinese zeolite. 58 tion capacity. Treatment – How EffectiveElshorbagy is W and Their Chowdhury Use, RK. InTech, Rijeka, in 81–112 Water (2013). Treatment (2005). of acid sites onCatal ZSM-5 Today zeolite with pyridine as a probe molecule. Removal of pyridine from liquidnatural and and gas synthetic phase zeolites. by copper forms of Phosphate adsorptionJ on Colloid Interface Sci synthetic goethite and akaganeite. Sanit Eng Div cation, structure, adsorption and catalysis. 37 active sites and adsorbateicate interactions SBA-15 in molecular sieves. mesoporous aluminosil- removal from aqueous solution usingmeric sorbent a containing hybrid hydrated ferric impregnated oxide poly- nolBiotechnol (HFO). nal) trace phosphate removal41 from water and wastewater. solutions by using natural Chinese (Chende) zeolite as adsorbent. Hazard Mater in marine electrolytes by zeolite88 synthesized from coal fly ash. of phosphate ions fromInd aqueous Eng Chem solution Res using synthetic zeolite. wastewater by20 model-La(III) zeolite adsorbents. and phosphates sorption from simulated reclaimed watersified by clinoptilolite. mod- 33 Dzombak D and Morel F, 34 Simsek EB, Özdemir E and Beker U, Zeolite supported mono- and 21 Jiménez-Cedillo MJ, Olguín MT and Fall C, Adsorption kinetic 20 Liu H, Yang L, Ma M, Li P and Wei Y, The transformation of ferrihydrite 35 Sujana MG, Soma G, Vasumathi N and Anand S, Studies on fluoride 22 Kim KS, Park JO and Nam SC, Synthesis23 of Hieltjes Iron-loaded AHM and zeolites Lijklema L, for Fractionation of inorganic phosphates in 24 APHA A, WEF., Standard methods for the examination of25 water and Lei L, Li X and Zhang X, Ammonium removal from aqueous solutions 26 Doula MK, Synthesis of a clinoptilolite–Fe27 system with Margeta high Cu K, sorp- Logar NZ, Šiljeg M and Farkaš A, 28 Reháková M, Fortunová 31 Jin F and Li Y, A FTIR and TPD examination of the distributive properties 32 L 36ChitrakarR,TezukaS,SonodaA,SakaneK,OoiKandHirotsuT, 29 Li J, Qiu J, Sun Y and Long Y,30 Studies on Luan natural Z STI and zeolite: modifi- Fournier JA, 37 You X, Guaya D, Farran A, Valderrama C and Cortina JL, Phosphate 38 Blaney LM, Cinar S and SenGupta AK,39 Hybrid anion Huang H, exchanger Xiao X, for Yan B and Yang L, Ammonium removal from aqueous 40 Guan Q, Hu X, Wu D, Shang X, Ye C and41 Kong H, Onyango MS, Phosphate Kuchar removal D, Kubota M and Matsuda H, Adsorptive removal 42 Ning P, Bart H-J, Li B, Lu X43 and Huo Zhang H, Lin Y, H, Dong Phosphate Y, Cheng removal H, Wang from H and Cao L, Ammonia-nitrogen 44 Weber WJ and Morris JC, Kinetics of adsorption on carbon solution. Chem ,Struc- J Hazard :323–329 :128–137 :804–808 :203–207 Chem Eng J et al. study of the 51 ,Removalof 351 163 280 ˇ cJ Surf Coat Technol et al. ex situ :396–403 (2011). :408–415 (2009). J Colloid Interface Sci Pseudomonas aerugi- :7–13 (2008). :111–121 (2011). 281 and 118 88 ˇ con I, Kova :4327–4333 (2008). Appl Clay Sci 271 Desalination 42 Desalination :206–216 (2011). J Hazard Mater In situ :181–188 (2012). , 54 :20–31 (2014). 156 et al. Desalination Microchem J :49–55 (2010). 258 Water Res :167–180 (2003). : 1737–1746 © 2015 Society of Chemical Industry Desalination bski W and Barczyk K, Application of ¸ 54 91 e 349 Appl Clay Sci 2016; Micropor Mesopor Mater ´ c ŠC, Mazaj M, Tušar NN, Ar Powder Technol :318–323 (2011). :43–51 (2013). React Funct Polym Micropor Mesopor Mater 187 225 in sol-gel derivatized aluminum alloy plates. J Colloid Interface Sci :527–536 (2008). :145–150 (2014). :431–438 (2014). IR spectra in thegroups. studies of zeolites from D4R and D6R structural ammonium from aqueous solutions using zeolitefly synthesized ash from by a fusion method. enhanced modification with ironfor of arsenic clinoptilolite-rich sorption zeolitic from322 aqueous tuff solutions. Pérez-Cruz MA, Reyes-Ortega Y I, A novel bentonite-humicremoval of phosphate acid and ammonium composite from eutrophic waters. materialEng J Bephos™ for (2011). of iron- or iron–manganese-modified zeolite-rich tuffs forAs(V) As(III) and water pollutants. investigation into the ammonium removalnatural performance of zeolite: Yemeni modification, ionmodynamics. exchange mechanism, and ther- (2014). as a factornosa to control biofilm254 formation of phosphate fromattapulgite-based eutrophic versatile adsorbent. waters using natural calcium-rich of nutrients frommodified simulated zeolite combined swine with struvite wastewater crystallization. 256 by adsorption of KC and Afyuni M,and release Ion-exchange using process natural Iranian for zeolite. ammonium removal Iron-modified light expanded clayarsenic(V) aggregates from groundwater. for the removal of tructured in montmorillonite clays:tion. preparation and characteriza- (2009). hydrous iron oxide precipitationarsenic with zeolite from filtration to contaminated remove water. inorganic/organic polymer typeprocess material from drinking in water. the Arsenic removal inorganic nanoparticles: characterization and environmental applications. istics of As(V) on iron-coated zeolite. (2011). using modified natural zeolite. of arsenic from water usingMater Fe-exchanged natural zeolite. ture investigation of As(III)- and As(V)-species boundclinoptilolite to Fe-modified tuffs. 5 Zhang M, Zhang H, Xu D, Han L, Niu D, Tian B 1 Zamparas M, Drosos M, Georgiou Y, Deligiannakis Y and Zacharias 8 Jiménez-Cedillo MJ, Olguín MT, Fall C and Colín A, Adsorption capacity 6 Alshameri A, Ibrahim A, Assabri AM, Lei X, Wang H and Yan C, The 3 Villanueva ME, Salinas A, Copello GJ and Díaz LE, Point of zero charge 2 Yin H and Kong M, Simultaneous removal of ammonium and 9 Huang H, Xiao D, Pang R, Han C and Ding L, Simultaneous removal 7 Malekian R, Abedi-Koupai J, Eslamian SS, Mousavi SF, Abbaspour 4 Król M, Mozgawa W, Jastrz 19 Dávila-Jiménez MM, Elizalde-González MP, Mattusch J, Morgenstern P, 10 Haque N, Morrison G, Cano-Aguilera I and Gardea-Torresdey JL, 11 Villalba JC, Constantino VRL and Anaissi FJ, Iron oxyhydroxide nanos- 15 Li Z, Jiang W-T, Jean J-S, Hong H, Liao L and Lv G, Combination of 12 Iesan CM, Capat C, Ruta F and Udrea I,13 Evaluation of Cumbal a L, novel Greenleaf hybrid J, Leun D and SenGupta AK, Polymer supported 14 Jeon C-S, Baek K, Park J-K, Oh Y-K and Lee S-D, Adsorption character- 16 Bilici Baskan M and Pala A, Removal of arsenic from drinking water 17 Li Z, Jean J-S, Jiang W-T, Chang P-H, Chen C-J and Liao L, Removal 18 Šiljeg M, Stefanovi J Chem Technol Biotechnol REFERENCES Supporting Information Supporting information may be found inarticle. the online version of this Modification of a natural zeolite with Fe(III)Educación Superior, Ciencia, Tecnología- e Ecuador) Innovación and (Senescyt Universidad(Project Técnica - 2014: Particular PROY_QUI_826). de Loja - Ecuador www.soci.org et al. :101–109 :300–306 Chem Eng J : 1737–1746 304 91 241–242 2016; J Colloid Interface Sci J Hazard Mater :71–76 (2014). J Chem Technol Biotechnol 116 Fuel :204–213 (2015). ammonium retention processesFTIR, onto EDX Cactus and leaves(2012). fibers SEM using analysis. neous phosphate and ammonium removalby from a aqueous hydrated aluminum solution oxide modified271 natural zeolite. lite/hydrated iron oxideadsorbent composite to from simultaneously retain coal cationicfrom and fly water. anionic ash pollutants as efficient of ammonium and phosphateas by influenced zeolite by synthesized salt treatment. from(2006). fly ash 51 Wahab MA, Boubakri H, Jellali S and Jedidi N, Characterization52 of Guaya D, Valderrama C, Farran A, Armijos C and Cortina JL, Simulta- 53 Xie J, Wang Z, Wu D and Kong H, Synthesis and properties of zeo- 54 Wu D, Zhang B, Li C, Zhang Z and Kong H, Simultaneous removal www.soci.org D Guaya ´ :1159–1169 snik J and 171 © 2015 Society of Chemical Industry ,Adsorptionmecha- et al. :155–160 (2005). Chem Eng J :142–150 (2010). 46 70 :15–20 (2013). 103 . McGraw-Hill, New York (1962). :289–297 (2013). 143 Sep Purif Technol React Funct Polym Ion Exchange Sep Purif Technol nisms of high-levels of ammonium ontozeolites. natural and NaCl-modified (2011). evaluation of phenol/anilinesolutions mixtures onto adsorption activated fromresin carbon (MN200). aqueous and hypercrosslinked polymeric of mechanism, kinetic andco-adsorption isotherm onto of ammonia natural and zeolite. humic acid Buszewski B,natural Ammonium zeolite, removal Transcarpathianand from mordenite, column tests. kinetics, aqueous equilibrium solution by ically modified zeoliteBioresource Technol and bioflocculant from activated sludge. 45 Lin L, Lei Z, Wang L, Liu X, Zhang Y, Wan C 49 Sprynskyy M, Lebedynets M, Zbytniewski R, Namie 47 Valderrama C, Barios JI, Caetano M, Farran A and Cortina JL, Kinetic 46 Helfferich FG, 48 Moussavi G, Talebi S, Farrokhi M and Sabouti RM, The investigation 50 Guo J, Yang C and Zeng G, Treatment of swine wastewater using chem- wileyonlinelibrary.com/jctb

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