Nitrates contamination

There has been an increasing level of nitrate contamination of borehole supplies in the east of England, because of the use of agricultural fertilisers since the Second World War . Nitrates are known to exacerbate certain corrosion processes e.g. at soldered joints however the maximum value allowed for this ion by the EC drinking water directive (50 mg NO3 r ) should limit its significance. 

Istok JD, JM Senko, LR Krumholz, D Watson, MA Bogle, A Peacock, Y-J Chang, DC White (2004) In situ bioremediation of technetium and uranium in a nitrate-contaminated aquifer. Environ Sci Technol 38 468-475. 

Goss MJ, Goorahoo D (1995) Nitrate contamination of groundwater Measurement and prediction. Nutr Cycl Agroecosyst 42 331-338... 

The best H2-prodncer helper bacterinm strains convert the organic material found in dilute waste waters from the food processing industry (sugars and proteins). They are selected becanse in this way, a treatment of polluting waste waters can be linked to the elimination of polluting nitrate contamination. The ability to bring about denitrification... 

Van Maanen JM, Welle IJ, Hageman G, Dallinga JW, Mertens PL, Kleinjans JC (1996) Nitrate contamination of drinking water Relationship with HPRT variant frequency in lymphocyte DNA and urinary excretion of N-nitrosamines. Environ Health Perspec 104 522-528... 

Accuracy in the laboratory is obviously an important issue. If the analysis results reported by a laboratory are not accurate, everything a company or government agency strives for, the entire TQM system, may be in jeopardy. If the customer discovers the error, especially through painful means, the trust the public has placed in the entire enterprise is lost. For example, if a baby dies due to nitrate contamination in drinking water that a city s health department had determined to be safe, that department, indeed the entire city government, is liable. In this "worst-case scenario," some employees would likely lose their jobs and perhaps even be brought to justice in a court of law. 

The maximum efficiency is clearly at the point Pi, for the potassium efficiency decreases in passing towards P3. A mixture containing 295 grass, of sodium nitrate, 24 5 potassium carbonate, and 50 grms. of water, after agitation, furnishes a soln. corresponding with the point Pi, and there separates 24 1 grms. of potassium nitrate contaminated with 4 5 per cent. of carbonate—the theoretical yield is 23 6 of potassium nitrate. 

A small amount of hexanunine nitrate contaminates the product. 

Zero-valent iron can also be used for heavy-metal removal. Applications for cadmium and chromate removal have already been shown to be successful. When combined with chloride ions, iron has been shown to be a simple and inexpensive method to remove mercury from wastewater (Grau and Bisang, 1995). Nitrates also degrade in the presence of zero-valent iron, but the application of treating nitrate-contaminated water has not been extensively studied (Siantar et al., 1996). 

Siantar, D.P., Schreier, C.G., Chou, C., and Reinhard, M., Treatment of 1,2-dibromo-3-chloropropane and nitrate-contaminated water with zero-valent iron or hydrogen/palladium catalysts, Water Res., 30(10), 2315-2322, 1996. 

Nitrates and phosphates are two important nutrients that have been increasing markedly in natural waters since the mid-1960s. Sources of nitrate contamination include fertilizers, discharge from sewage treatment plants, and leachate from septic systems and manure. Nitrates from fertilizers leach readily from soils, and it has been estimated that up to 40% of applied nitrates enter water sources as runoff and leachate. Fertilizer phosphates, however, tend to be absorbed or bound to soil particles, so that only 20% to 25% of applied nitrates are leached into water. Phosphate detergents are another source of phosphate, one that has received much media attention in recent years. 

Tan, C.S., C.F. Drury, J.D. Gaynor, and T.W. Welacky (1993). Integrated soil, crop, and water management system to abate herbicide and nitrate contamination of the Great Lakes. Wat. Sci. Technol., 28 497-507. 

The complex may contain some (10-20%) [(en)2Co(NH2, N02)Co(en)2](N02)4 as an impurity unless contact with nitrate ions is avoided.17 To avoid nitrate contamination, chlorine gas can be used to oxidize the peroxo complex.17 The complex is difficult to purify by recrystallization. The p-amido-p-nitrito complex is extremely unreactive. 

Pickens et al. (1978) worked on nitrate contamination in wells drilled in a shallow sandy aquifer. An N03 plume was detected in carefully sampled depth profiles (section 7.3), as shown in Fig. 16.1. The contamination was attributed to extensive use of nitrate fertilizers. 

Groundwater Profiles and Their Bearing on Nitrate Contamination... 

Exercise 16.1 Read again the nitrate contamination case study (section 16.3.1) and suggest how to proceed. What should be done next ... 

Weil RR, Weismiller RA, Turner RS (1990). Nitrate contamination of groundwater under irrigated coastal plain soils, Journal of Environmental Quality, 19 441-448. 

High nitrate concentrations can cause methaemoglobinaemia (blue-baby syndrome) in bottle-fed infants. This condition is also associated with the simultaneous presence of bacterial contamination. The primary approach to managing nitrate contamination is prevention, particularly for rural wells, which are the major problem with regard to methaemoglobinaemia. In particular, protection of wells from runoff from fields and siting of manure stores, pit latrines and septic tanks will help to prevent contamination with nitrate and microbial pathogens. 

Bohlke, J. K., and Denver, J. M. (1995). Combined use of groundwater dating, chemical and isotopic analyses to resolve the history and fate of nitrate contamination in two agricultural watershed, Atlantic coastal plain, Maryland. Water Resour. Res. 31, 2319-2339. 

Portnoy,. W., Nowicki, B., Roman, C., andUrish, D. (1998). The discharge of nitrate-contaminated groundwater from developed shoreline to marsh-fringed estuary. Water Resour. Res. 34, 3095-3104. 

Staver, K. W., and Brinsfield, R. B. (1998). Use of cereal grain winter cover crops to reduce groundwater nitrate contamination in the Mid-Adantic coastal plain. J. Soil Water Conserv. 53, 230-240. 

Table 1 Comparison of the characteristics of technologies for water remediation by nitrate contamination. Elaborated from... 

Fogg G. E., Rolston D. E., Decker D. L., Louie D. T., and Grismer M. E. (1998) Spatial variation in nitrogen isotope values beneath nitrate contamination sources. Ground Water 36, 418-426. 

Kreitler C. W. and Jones D. C. (1975) Natural soil nitrate the cause of the nitrate contamination of groundwater in Runnels County, Texas. Ground Water 13, 53-61. 

Panno S. V., Hackley K. C., Hwang H. H., and Kelly W. R. (2001) Determination of the sources of nitrate contamination in karst springs using isotopic and chemical indicators. Chem. Geol. 179, 113-128. 

Puckett L. J., Cowdery T. K., Lorenz D. L., and Stoner J. D. (1999) Estimation of nitrate contamination of an agroecosystem outwash aquifer using a nitrogen mass-balance budget. J. Environ. Qual. 28, 2015-2025. 

Explosives factory workers exposed to a nitrate-contaminated environment lost it over a weekend and some chose to maintain their intake by using nitrate impregnated headbands (transdermal absorption) rather than have to accept the headaches and reacquire tolerance so frequently. 

Removal of nitrates from drinking water is an important area of research. Although technology in this area is developing, there is still a need to further optimize the current treatment. Physicochemical methods allow effective removal of nitrate ions from nitrate contaminated waters. Among these methods, the capital and operating costs are the lowest for the ion-exchange process (7,8,12,27). 

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