CHEMICAL REDUCTION OF NITRATE IN SYNTHETIC WASTEWATER BY ZERO VALENT IRON

Abstract

Nitrate is chemically occurring compound in nature. It is appreciably found in the regions where the use of nitrogenous fertilizer is in excess amount. The permissible limit of nitrate in ground water is 50mg/I. High nitrate may cause methemoglobinemia, blue baby syndrome and cancer. Chemical reduction by using Zero Valent Iron (ZVI) is simple, economical and essential technique for reducing the nitrate contaminant in ground water. ZVI same as iron powder but it is zero valence iron. Typically it is synthesised in bio chemical lab. The property and characteristics of ZVI is considered by scientific techniques e.g. Scanning Electron Microscopy (SEM), Brunauer, Emmett and Teller (BET), Particle Size analyser and Zeta Potential. The particles traced in the range of 40 - 100nm offering surface area 6.61m2/g. The initial concentration sample were prepared and treated with ZVI. Reduction is carried out at elevated temperature (55 - 60°C) and atmospheric pressure. Suitable reduction conditions are Fe° dose (I - 3mg/I), p1-1 of the nitrate solution (>11) and mixing intensity 120 - 150 rpm. The Average percentage reduction is estimated around 70% within an hour. Chemical reduction reaction order becomes pseudo first order reaction