Abstract

Assessment of water quality in Noyyal River from 20/12/2010 to 27/12/2011 was carried out in this study. Water samples were collected from the Noyyal River at a stretch of 3800 m. The sampling locations have been fixed at every 50 m. The parameters were estimated such as dissolved oxygen (DO), pH, Temperature, chemical oxygen demand (COD), total dissolved solids (TDS), Sulphate, Chloride, total hardness etc. This study had two phases. In the first phase, the estimation of water quality parameters was carried out and in the second phase water quality index have been determined based on the existing standards. The effects of municipal sewage on river water quality have also been investigated. The depletion of DO concentration due to the simultaneous effect of water pollution, thus leads to more uncertainty about the survival of DO dependent aquatic species. From the study, it revealed that TDS, sulphate, chloride, and hardness were estimated to be high concentration at sampling location 10 (S₁₀). Among the sample locations, in most of the places, high concentration of TDS, Hardness, sulphate and chloride and low level of DO were observed. Our findings highlighted the deterioration of water quality in the river and are due to human activities. This analysis reveals that the surface water needs some degree of treatment before consumption.

Key words: Noyyal River, dissolved oxygen (DO), water quality index, water quality parameters.