Pollution indicators and impact assessment of pollutants discharged into the river Ganga

The water of the river Ganga was monitored for DO, BOD, Eh, rH2 and sulfate‐reducing bacterial population (SRB) in order to test the comparative efficiency of these parameters as pollution indicators, to assess the pollutional states of the river and to evaluate the impact of pollutants on the river water. This study revealed that rH2 was an efficient pollution indicator. The SRB density might also be used as a pollution indicator, provided sulfate ions existed in such water bodies. All the indicators showed that the river stretch receiving rayon factory effluents and untreated sewage was in a highly polluted state, and the river was found to be more polluted in its deeper layers. The ANOVA tests with the indicators, BOD and SRB, revealed that the different pollutants discharged into the river had different pollution impacts.