Drinking water nitrates

In the case of clarified feeds and low current densities, membrane lifetime can be as long as seven or 10 years for brackish water desalination or drinking water nitrate removal, respectively. However, if the feed solution is fouling or scaling or the ED separation plant has not been well designed or is not properly conducted, membrane lifetime is no longer than a year. 

Methemoglobinemia induced by the acute nitrates/nitrites exposure of infants through drinking water enhances the oxidative reactions and a significant perturbation of enzyme antioxidant systems. Further assessments taking into account the relation between drinking water nitrates and other systems involved in the antioxidant protection are hence much necessary. 

Ward, M.H., de Kok, T.M., Levallois, P., Brender, J., Gulis, G., Nolan, B.T., and Van Dershce, J. 2005. Workgroup report Drinking-water nitrate and health—Recent findings and research needs. Environmental Health Perspectives, 113(11) 1607-14. 

Weyer, P. et al.. Municipal drinking water nitrate level and cancer risk in older women The Iowa Women s Health Study, Epidemiology, 12, 327, 2001. 

Nitrate (NO.D in natural waters is derived from sources such as fertilizers and undertreated animal and human waste. U.S. environmental regulations set a maximum of 10 ppm NO3 nitrogen in drinking water. Nitrate is commonly analyzed by reduction to nitrite (NO2), followed by a colorimetric assay of NO2. Metallic Cd has been the most common reducing agent for NO3. However, the use of toxic Cd should be curtailed to protect the environment. 

Using the luminol photochemiluminescence it is possible to determine not only the nitrates (as reported by us earlier), but also the nitrites. The urotropin is added to the water sample, and the solution obtained is illuminated by the Hg lamp. The chemiluminescence is measured after the addition of basic luminol solution to the illuminated solution. The detection limit is 2-10 M. The nitrates contained in the drinking water do not interfere at tenfold excess. 

S. Deak, quoted in Health Hazards from Nitrates in Drinking Water, Report on a WHO meeting, Copenhagen, 5-9 Mareh 1984, WHO, Geneva, 1985. 

SI 1996/2971 Control of Pollution (Applications, Appeals and Registers) Regulations SI 1996/3001 Surface Waters (Abstraction for Drinking Water) (Classification) Regulations SI 1996/3105 The Nitrate Sensitive Areas (Amendment) Regulations... 

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. 

Increases in nitrate + nitrite have been well documented in the Great Lakes (19). Relative increases over the past twenty years have been between 30 and 200% with the highest increases in the most populated and agriculturally productive basins of Lakes Ontario and Erie (29). Currently no adverse impacts due to this increase have been observed and concentrations are well below the 10 mg.L maximum acceptable drinking water concentration for the protection of human health. Changing N P ratios, however, can impact phytoplankton community structure (30). 

Cyanides can be fatal to fish at <1 ppm. Because of concern over the possible in vivo conversion of nitrate into carcinogenic nitrosamines, the nitrate content of drinking water must be strictly controlled. Nitrate and phosphate pollution can also cause eutrophication in still or slow-moving warm waters by stimulation of algae growth in the presence of... 

Papadoyannis, I. N., Samanidou, V. F., and Nitsos, C. C., Simultaneous determination of nitrate and nitrite in drinking water and human serum by anion-exchange chromatography and UV detection, /. Liquid Chromatogr. Related Technol., 22, 2023, 1999. 

Twenty-three teratogenicity studies in which lead compounds (acetate or nitrate) were administered in the drinking water or feed or by gavage to rats and mice have shown no evidence that lead causes... 

Laboratory colony given drinking water containing 200 mg Pb/L as lead nitrate for 30 days experimentals vs. controls... 

Change in water quality Critical values for drinking water (e.g. nitrate, pesticides)... 

Nitrogen species, such as nitrate and nitrite, are known to be confirmed procarcinogens. The excessive input of these nitrogen compounds with food and drinking water in the presence of tertiary amines, for instance, from medicines, can lead to the formation of carcinogenic N-nitrosoamines. 

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