Removal of Heavy Metals from Industrial Wastewaters Using Local Alum and Other Conventional Coagulants-A Comparative Study

The present study aimed at effective management and purification of industrial wastewaters using cheaper and locally available local alum for removal of heavy metals as a substitute to convectional coagulants. The effect of local alum, aluminum sulphate and ferric chloride on the metal contents of industrial wastewaters was investigated in the pH range of 5.9-7.5. Wastewater samples from battery, paint and textile industries were treated with different doses of locally available alum, aluminum sulphate and ferric chloride in order to determine and compare their effectiveness in removing heavy metal contents of the wastewaters. The percentage removal of the metals from the industrial wastewaters increased with mg L super(-1) dosage of the coagulants used with optimal performance generally at a slightly alkaline pH. Local alum proved to be equally effective in removing heavy metals from the industrial wastewater samples compared with the conventional aluminum sulphate and ferric chloride.