Behaviour and Distribution Pattern of Nutrients in River-Estuarine Waters of Mahanadi, Orissa, India

Abstract

Seasonal and spatial distributions of nutrients (NO $_2$ -N, NO $_3$ -N, NH $_4$ -N, PO $_4$ -P, SiO $_4$ -Si, total nitrogen and total phosphorous) in relation to some physico-chemical features (DO, BOD, TSS, TDS, SO $_4^{2-}$ and Cl $^{-}$ ) were studied for 31 different stations of Mahanadi river-estuarine system. Results of nutrient concentrations exhibit pronounced seasonal variations and distribution pattern indicating large inputs possibly from two major fertilizer plants, municipal sewage from three major towns as well as agricultural runoff. The seasonal nutrients variation (except SiO $_4$ -Si) exhibits higher values during monsoon season in unpolluted stations and the reverse trend for polluted stations, which are related to agricultural runoff and regional anthropogenic activities respectively. Silicate shows a well-defined pattern of distribution with higher concentration during monsoon, which is slightly removed from the estuarine water of Mahanadi during pre-monsoon season. High organic contribution of nitrogen and phosphorus are well marked at Atharbanki creek into the Mahanadi river estuarine system.