ABSTRACT:
Nitrogen occurs naturally under oxidation of nitric anhydride, N2O5 and nitrates, NO3- and also from ammonia, and ammonium ions, NH4+. Because of increase in human activities environmental nitrate concentrations also increased which leads to introduction of large quantities of nitrates into ground and surface waters. Agriculture is the major source of nitrate pollution because of using of nitrogen-containing fertilizers, concentrated livestock and poultry farming. Nitrates are also released from the industrial production of glass, explosives, as well as from various chemical production and separation processes. Highest reduction in nitrate content was found in benzene extract of U.lactuca 91% and very minimal reduction of 12 % was found in aqueous extract of E.intestinalis. Among all, the extracts of Ulva lactuca, Enteromorpha flexuosa fell under Category A (Good reduction), and benzene was found to be the best solvent system. Maximum reduction by powdered algae was found in C.antenina collected from Covelong and Puduchery (375 mg/l).