Industrial waste pollution in the Kano river basin

Abstract

Kano River basin, which serves as the main source of water supply to metropolitan Kano, is also used as receiving body for industrial wastes from Sharada and Challawa industrial estates. Of the three major rivers in this basin, the Salanta river was found to receive the highest pollution from the industrial discharges with COD of 8,557.4mg/l, total solids of 16,934.6mg/l, hardness of 1,349.6mg/l CaCO3, and ammonia nitrogen of 5,150.0mg/l. The Challawa river had COD of 598.7mg/l, total solids of 1,609.9mg/l, hardness of 1,332.0mg/l CaCO3 and ammonia‐nitrogen 400mg/l. Both empty into the Kano river where the COD was 1,166.9mg/l, total solids 1,458.0mg/l, hardness 2,506.8mg/l and ammonia‐nitrogen 530mg/l. Although these rivers are being used extensively for water supply, irrigation, and fishing, the quality of the water was found to be unsuitable for these purposes. The paper suggests that waste water pre‐treatment by all industries, imposition of direct charges on industrial effluents by the regulating agency, as well as continuous monitoring and surveillance are required to ensure the protection of the water resources in the basin.