Effects of seasonal variation on the water quality of the Kadalundi river, India: evaluation of water quality indices, physicochemical and biological parameters

The quality of the water depends on a variety of factors as it can contain both natural and manmade impurities. In this work, the water quality of the Kadalundi river, Kerala, India has been assessed with a special focus on the impact of seasonal variations . The quality of water for the entire year was analysed thoroughly collecting sixty water samples. The physicochemical parameters, such as turbidity, pH, total dissolved solids, total hardness, chlorides, iron, nitrate, dissolved oxygen, biochemical oxygen demand, and chemical oxygen demand, as well as bacteriological parameters (total coliforms and Escherichia coli), were evaluated as per the Indian standard methods, IS 3025. Each parameter was compared with the standard desirable limit prescribed by the Bureau of Indian Standards. The results were further examined with the weighted arithmetic water quality index and the Nemerow's pollution index (NPI) methods. The study reveals that the overall water quality is very poor and hence proper treatment before use is recommended. According to the NPI, turbidity and iron are the most contributing parameters to the pollution of the river.