Contamination Of Water By Nitrate: A General Discussion Problems Associated, Causes, Prevention And Effects

This paper illustrates the source and significance of nitrogen for groundwater and presents a general study and discussion of nitrogen contamination with reference to its causes and prevention Nitrogen is a major constituent of the earth's atmosphere and occurs in many different gaseous forms such as elemental nitrogen, nitrate and ammonia. Natural reactions of atmospheric forms of nitrogen with rainwater result in the formation of nitrate and ammonium ions. While nitrate is a common nitrogenous compound due to natural processes of the nitrogen cycle, anthropogenic sources have greatly increased the nitrate concentration, particularly in groundwater. The largest anthropogenic sources are septic tanks, application of nitrogen-rich fertilizers to turfgrass, and agricultural processes. Levels of nitrates in groundwater in some instances are above the safe levels proposed by the EPA and thus pose a threat to human health. Particularly in rural, private wells, incidence of methemoglobinemia appears to be the result of high nitrate levels. Methemoglobinemia, or blue baby syndrome, robs the blood cells of their ability to carry oxygen. Due to the detrimental biological effects, treatment and prevention methods must be considered to protect groundwater aquifers from nitrate leaching and high concentrations. Treatment through ion-exchange and other processes can rehabilitate already contaminated water, while prevention, such as reduced dependence on nitrogen-rich fertilizers can lower the influx of nitrates.Major sources of nitrogen in rural aquifers are related to wastewater disposal (onsite systems and leaky sewers), solid waste disposal (landfills and waste tips). The most significant health effect associated with nitrate ingestion is Methemoglobinaemia (Blue baby Syndrome) in infants under six months of age. Another concern about nitrate ingestion is the possibility that nitrites in the stomach and intestines may contribute to the development of some cancers. The major source of nitrogen in the many districts of India  are due to unplanned septic tanks.