Use of Isotope Techniques to Determine The Source of Nitrogen Compounds in Grounwater

Abstract

Rapidly growing population and the accompanying urbanization, industrialization, increase in agricultural activities, to the decrease in available water resources and pollution is caused.

Nowadays, nitrogen compounds significantly pollute water sources and nitrogen sources in determining pollutants has increased the use of isotope techniques. Determine the source of pollutants, water pollution prevention, controlling and plays an important role in water management.

Nitrogen has long been unregarded by isotope geologists perhaps because most of its compounds are solube in water. Stable isotope abundances of ¹⁵N have been used extensively to provide information on the origins and transformations of inorganic N in surface and groundwaters. The isotopic composition of inorganic N in soils and groundwater influenced by microbial or physical processes such as denitrification, nitrification, and ion exchange.

Nitrate (NO₃^-) is found naturally at moderate concentrations in many aquatic environments,

but is often enriched to high levels by anthropogenic activities involving nitrogenous compounds such as mineral fertilizer and by-products of organic compounds from agriculture, septic systems, and poultry, hog or cattle manure.

The nitrogen isotopes (¹⁵N and ¹⁴N) are useful anthropogenic tracers. The biogenic isotopic fractionations are complex, but often allow to determine the source of organic pollution in groundwater .

Combined isotope analyses of nitrogen and oxygen in NO₃^- leaves fingerprints on natural and anthropogenic sources of nitrate, on the microbial denitrification, nitrification and biological fixation processes and the nitrogen budget in the groundwater.