REGIONAL GEOCHEMICAL EVALUATION OF ARSENIC, IRON, PHOSPHATE AND NITROGENOUS CONTAMINATIONS IN GROUNDWATER OF THE AQUIFERS OF EASTERN BIHAR AND NORTH-EASTERN JHARKHAND

摘要

Ground water and surface water are extensively used for drinking and other domestic as well as industrial purposes. Since the dawn of the human civilization, the quality of water is being depleted and degraded due to various regions. The present study was conducted in the Bhagalpur, Katihar, Purnea, Araria districts of eastern Bihar and Sahibganj district of Jharkhand state, India. The present study proposed to determine the existence and intensity of arsenic contamination in aquifers along the Mid Ganga Plain. The quality of underground and surface water in the study area have been assessed considering five parameters viz. Arsenic, Iron, Phosphate, Ammonia and Nitrate. Altogether 60 water samples, including private and government hand pumps, deep tube wells, river water and natural spring were tested. It was observed that the underground water of the study area is highly contaminated with arsenic (BDL to 417.1 ppb) as well as of iron (0.1 to 20ppm). Arsenic in 50 water samples was above the drinking water specifications as prescribed by WHO (1999) and ISI (2003), whereas, Phosphate, Ammonia and Nitrate were well within the permissible limit, but exceeds in some places. Some commonly observed symptoms of chronic arsenic poisoning like melanosis, hyperkeratosis and skin diseases were also observed during study. This might be due to the excessive consumption of arsenic contaminated water. The correlation in between arsenic and other water parameters was examined and an inverse relationship was established in between Arsenic and Nitrate.