655 Monitoring of Nitrogen Compounds Contamination
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MONITORING OF NITROGEN COMPOUNDS CONTAMINATION OF PHEATIC WATERS IN THE WEST SIDE OF ROMANIA MONITORIZAREA CONTAMINĂRII CU COMPUŞI CU AZOT A APELOR FREATICE DIN PARTEA DE VEST A ROMÂNIEI LAZUREANU A., ALEXA Ersilia, CUC Liana, COZMA Antoanela, SAMBOTIN Dana, ALDA S., CARCIU GH., LAZUREANU D., CRACIUNESCU A., CHISALITA I. University of Agricultural Sciences and Veterinary Medicine Timisoara, Romania Abstract. The problem of depth and surface water contamination in the Banat region, is a topical issue, these days. During 1999-2007 the team of Agro-technique Discipline from Faculty of Horticulture and Forestry, USAMVB Timisoara, conducted detailed studies on nitrogen contamination (nitrates, nitrites and ammonium) of surface and deep groundwater in western Romania,. The test results of water samples taken from wells over 60 m depth, indicates the quality of drinking water located in deep groundwater. Instead surface groundwater in the Banat countryside, is leading a high content of nitrate, nitrite and ammonium. Key words: nitrates, nitrites, ammonium, groundwater. Rezumat. Problema contaminării apei de adâncime şi de suprafaţă cu contaminanţi în zona Banatului, prezintă o temă de actualitate în momentul de faţă. În perioada 1999-2007 colectivul Disciplinei de Agrotehică din cadrul Facultăţii de Horticultură şi Silvicultură, USAMVB Timişoara, a realizat studii aprofundate privind contaminarea cu compusi cu azot (nitrati, nitriti si amoniu) a apei freatice de suprafata si adancime din vestul României. Rezultatele analizelor probelor de apă prelevate din fântâni de peste 60 m adâncime, semnalează calitatea apei potabile din apa freatică situată la adâncime. În schimb apa freatică de suprafaţă, din spaţiul rural bănăţean, se remarcă printr- un nivel ridicat privind conţinutul de nitraţi, nitrţi şi amoniu. Cuvinte cheie: nitraţi, nitriţi, amoniu, ape freatice INTRODUCTION Worldwide previous research concluded that in many places over the world the underground water resources are severely polluted with chemicals that include nitrogen compounds (nitrates, nitrites, ammonium ion). Spill residue is abundant in highly populated areas (in urban areas), which presents a high risk with negative direct effect on most drinking water consumers. Among these sources, one in a continuous growing is the residue infiltration in agricultural land, which is mainly found where intensive agriculture is practiced. The waters are contaminated by agricultural activity, excessive and often inappropriate use of pesticides, and nitrates and phosphates fertilizers. Water pollution also comes from intensive farming practiced. 655 Nitrate pollution comes mainly from agriculture. Nitrogen is an essential element for life and in water undergoes many chemical and biochemical processes. Appears mainly as nitrate, nitrite, ammonia, nitrogen gas and fixed in organic compounds, groups that have continued processing or transit, forming "nitrogen cycle". Excess leads to eutrophication, contamination of aquifers, possible damage to human health: methemoglobinemia to children, gastric cancer etc. World Health Organization sets for a number of substances a limited range within different countries can adopt their own rules, expressed as maximum allowable concentrations. The technical quality of surface water and maximum limits for different chemical indicators are stipulated in STAS 4706/1988, and also, in section regulation which is gradually replacing the provisions of this standard. Chemical parameters of water quality are listed in Law 458/2002. European Directives considered as an acceptable maximum concentration of 50 mg/L for nitrate, 0.5 mg/L for nitrite and 0.5 mg/L for ammonia. MATERIAL AND METHOD For the risk factors evaluation on water pollution were taken samples from: - 9 private wells located in agricultural area of Sag-Part municipal waste deposition and adjacent area of deposition. Samples were collected quarterly in the period January 2004 - November 2006 (Cozma Antoanela, 2007) - 5-10 m deep wells, from the flood area of Timis County, Foeni, Cruceni, Uivar, Ionel, Otelec. Samples were taken quarterly in the period January 2005 - November 2007 (Vlaescu D., 2008) - private and public wells placed in Becicherecul Mic, Giarmata Vii and Gataia, localities representative regarding the accumulation of nitrogen compounds, pollution sources given by: intensive agriculture and livestock complex (Becicherecul Mic), amendments deposits (Gataia), salt ammonium usage to defrosting the runway- landing of Timisoara International Airport (Giarmata Vii). Sampling was done within May 1999 - May 2002 (Cuc, Liana, Lazureanu, A., 2001). Water sampling was done in accordance with SR ISO 5667-10, ISO SR 2852. Identification and determination of nitrogen compounds was done by Merck Spectrophotometer method. RESULTS AND DISCUSSIONS The experimental results on nitric content of water samples from municipal waste deposition area are given in figures 1-3. 140 nitrate 2004 121 120 88 mg/l 86 91 100 77 71 70 6765 80 64,5 69,367,8 51 56,4 60 48 55 47,3 42,2 40 34,3 23 8,9 3,6 5,3 6,5 4,5 20 2,3 6,7 3,2 2 1,4 4,77,3 3,9 1,8 4,3 1,8 0 1 2 3 4 5 6 7 8 9 jan. apr. jul. oct. Fig. 1. Nitrate content in water samples taken deposition area in 2004 656 100 96 nitrate 2005 91.4 80 78 mg/l 73 65.1 60.32 67 67 67.14 59.2 60.1 58.7 56 61 60.31 60 56.4 53.2 52.4 49.5 44.2 44 47.8 40 32.7 20 6.7 11 9.43 6.45.7 4 4.5 6.5 5.4 2.8 2.7 1.3 0 1.9 1 2 3 4 5 6 7 8 9 jan. apr. jul. oct. Fig. 2. Nitrate content in water samples taken deposition area in 2005 250 nitrate 2006 230.7 195 200 mg/l 150 125 116 100 90.4 81.2 81.7 78.2 65.1 63.6 55.156.6 43 59.8 50 52.4 36.7 50.448.6 25.4 28.6 5 6.3 4.22.3 5.7 4.2 2.7 4.8 1.5 11.3 2.72.4 7.1 3.9 1.3 0 2.4 1 2 3 4 5 6 7 8 9 jan. apr. jul. oct. Fig. 3. Nitrate content in water samples taken deposition area in 2006 The experimental results indicated that maximum admitted limit of 50 mg/l nitrate was exceed, in 41.66% of the analyzed samples in 2004, 44.22% to 41.66% in 2005 respectively in 2006, these excesses registering for wells near land agricultural cultivation (sites 1-3 and 8) or in rural households in which livestock is develop. Water samples taken from wells deep drilled more than 20 m or from the public water supply network, did not exceed the maximum admitted levels. Explanation regarding high levels of nitrate content in low depth drilled wells villages is given by non- compliance of water sources protection norms namely: the prohibition of animal waste dropped on land and cultivated field on which is applying fertilizer near and are water sources (Cuc, Liana, Lazureanu, A., 2001). Also, excessive use of nitrogen fertilizers and non-compliance nitrogen demands of plant uptake leads to a low assimilation of these compounds in plants protein genesis and shift the excess nitrates in groundwater. Evolution of the nitrate content according to the seasons show a decrease of nitrate content in summer, and then during the autumn-winter period nitrate content in water sample registered an upward trend. This sinusoidal evolution related to months of the year is explained by the growing stage of crops (Cozma Antoanela şi colab., 2006). Ammonium content exceeds the maximum admitted limit only to one well (Location 6). Nitrite content does not exceed the maximum allowable limit which according with STAS is 0.5 mg/L in no one of the analyzed samples. Nitrite is formed because of nitrate decomposition processes. Water samples taken from the public distribution of drinking water network are within normal limits. 657 In water samples taken from surface water from the flooded area of Timis County (table 1) was found following: In 2005 in the localities Cruceni and Otelec where sampling depth was low, 5 and 6 m, the nitrates concentration in February, April, June and September was very high varying between 160.0 mg/L and 201.6 mg/L, exceeding 3-4 times the maximum admitted limit. In 2006 in Cruceni (6 m) and Otelec (5 m) following the nitrate analysis made the values decreased compared to 2005, registering exceeded values over limit of 3 times in these areas. In Otelec nitrate concentration decreased from 201.6 mg/L (value found in September 2005) to 159.6 mg/L (September 2006), representing the place with highest nitrates level. Table 1 - Results of nitrates (NO3 ) content analysis in the flooded area in Timis county Sample/locality/depth 2005 Month, mg/l february april june september Blank variant 0,00 0,00 0,00 0,00 1- Foeni - 10 m 17,0 20,1 27,6 23,2 2- Cruceni - 6 m 160,0 170,9 196,3 191,0 3 - Uivar – 9 m 13,2 21,1 29,9 28,8 4 - Ionel - 10 m 27,6 28,1 28,9 29,6 3 - Otelec - 5 m 170,0 173,0 194,4 201,6 Sample/locality/depth 2006 Month, mg/l february april june september Blank variant 0,00 0,00 0,00 0,00 1 - Foeni - 10 m 19,7 24,2 24,9 25,6 2 - Cruceni - 6 m 196,4 191,5 199,7 193,0 3 - Uivar – 9 m 24,1 26,6 30,7 30,9 4 - Ionel - 10 m 28,5 33,0 38,1 34,7 3 - Otelec - 5 m 149,9 157,7 150,5 159,6 Sample/locality/depth 2007 Month, mg/l february april june september Blank variant 0,00 0,00 0,00 0,00 1 - Foeni - 10 m 23,40 27,10 23,60 26,70 2 - Cruceni - 6 m 205,40 187,90 195,40 201,20 3 - Uivar – 9 m 35,70 32,10 41,15 36,30 4 - Ionel - 10 m 32,10 29,70 36,80 39,70 3 - Otelec - 5 m 156,70 171,60 167,80 169,70 In 2007, as in previous years, in areas Foeni (10 m) Uivar (9 m) and Ionel (10 m) nitrates values did not exceeded the maximum limit, the highest value was recorded in June – 41.15 mg/L.