Density of Pollution Indicator Bacteria in Relation to Physicochemical Factors During Diel Cycle of River Ganga at Ichapore, West Bengal, India

A diurnal study was undertaken in April 2014 to record the bacterial density and some of the physicochemical factors of the river Ganga near Ichapore, West Bengal, India. The pollution indicating bacteria (total coliform, faecal coliform and faecal streptococci) were found in maximum numbers at 14.00 hrs and minimum at 20.00 hrs. All the bacterial populations were abundant and showed diel rhythm. The physicochemical parameters (temperature, pH, dissolved oxygen (DO), bicarbonate, total hardness, calcium hardness and electrical conductivity) also showed diurnal fluctuation pattern. The total coliform showed significant positive correlation with temperature, pH and electrical conductivity whereas the faecal coliform showed significant inverse correlation with DO. On the other hand, faecal streptococci showed significant positive correlation with temperature, pH and electrical conductivity and significant inverse correlation with DO. The river water in this areas needs a substantial degree of purification treatment before use.