PHYSICO-CHEMICAL TREATMENT OF STEEL STRIPS ROLLING MILL WASTEWATER

Abstract

Making the industrial effluent match the quality standards set by pollution control bodies is the foremost requirement to save our water, land and atmosphere from environmental degradation. Steel processing industry is ever expanding industry which causes considerable pollution. Water requirement for pickling is of the order of 300-600 litres/ton of steel processed. About 80-85% water consumed in the pickling process is discharged as wastewater. The volume and nature of wastewater depends upon the raw material technology and environmental conditions. Various methods are available for the treatment and disposal of pickling effluents. All methods have their own limitations. Therefore even with efficient methods required quality of effluents is not achieved. For this purpose research and development work at various places is going on to evolve an economically viable solution to the problem. This study is an attempt in this direction. For chemical treatment lime and caustic soda neutralization was employed. Iron, manganese, SS and TDS removals at different pH values have been studied to ascertain optimum pH for each of the above wastewater components. Jar test apparatus was employed for neutralization experiments.