Monitoring of Ganga water and sediments vis-à-vis tannery pollution at Kanpur (India): a case study.

The leather industry, besides being a major contributor to the Indian national economy, is unfortunately also one of the major polluters. The present article discusses the influence of the wastes on the physicochemical characteristics of the Ganga water and sediments. Two sampling sites have been chosen at Kanpur, the first before and the second after the point where tanneries are located. The same physicochemical parameters which have been determined in the wastes have been monitored at these two sites for two seasons. The results reveal that most parameters increase as the river traverses between these two points. The increase in values of parameters such as BOD, COD, Cl-, and total solids could be due to the domestic wastes just as much as to the tannery wastes. Phenols and sulfides, can also come from other sources, but their probability of coming from tanneries is higher. However, chromium is one parameter which can primarily be identified to originate from the tanneries. The speciation of the sediments for chromium reveals that the leakage of chromium into the Ganga is taking place at the second site. There is almost a ten fold increase in chromium at the second site as compared to the first. At the first site the surface chromium is primarily in the residual fraction while at the second site it is in the Fe-Mn oxide fractions.