Water Quality Assessment of River Ganga in West Bengal based on Physico-Chemical and Bacteriological Parameters

The present study reveals the seasonal and spatial changes in physico-chemical as well as bacteriological parameters in the lower stretch of river Ganga at West Bengal. Water samples were collected from five different sampling stations viz., Serampore, Palta, Tribeni, Nabadwip and Berhampore on monthly basis for two consecutive years 2019–2020 and 2020–2021. Sixteen physico-chemical parameters- water temperature, total suspended solids, turbidity, total dissolved solids, electrical conductivity, pH, dissolved oxygen, biochemical oxygen demand, chemical oxygen demand, nitrate, nitrite, phosphate-phosphorous, total hardness, total alkalinity, sodium and potassium, and two bacteriological parameters - total coliform and fecal coliform were measured to assess the water quality of river Ganga at selected stations on a seasonal basis. Correlation analysis on these parameters displayed significant positive and negative correlations among themselves. Physico-chemical parameters didn't vary significantly at different sites, however seasonal variations were significant. The two bacteriological parameters were significantly different at different sampling sites but only total coliform significantly differed seasonally. DO, BOD, TH, TC and FC are critical parameters in this study. Among the five sampling stations, Berhampore and Serampore were more polluted in respect of bacteriological parameters. Human religious activities and mass bathing near Berhampore sampling station were responsible for high bacteriological pollution.