CHARACTERIZATION AND TREATMENT OF KOHINOOR TEXTILE EFFLUENTS USING VARIOUS COAGULANTS

Abstract

Textile processing unit is one of the most important and largest industrial sectors of Pakistan with regard to production, source of foreign exchange and labor force employment. It alone contributes to 65% of the country's export, 46% of the industrial production, 38% of employed industrial manpower and 9% of Gross National Product (GNP). Textile industry could be termed as the back bone of Pakistan's economy. It holds 31% of the total investment in the country and pays Rupees 40 billion of salaries per year. Textile Wet Processing is the major source of water consumption and wastewater pollution. Field analyses were carried out for the characterization of effluent from Kohinoor Textile Mill for the evaluation of treatment options. There are various treatment techniques to remove textile wastewater pollution. Coagulation is one of these techniques to remove pollution due to these suspended particles. For the study, several composite samples, representing full cycle of wet processing, were collected and analyzed. Different Coagulants like alum, lime and ferrous sulphate and their combinations were applied to select the suitable ones with optimum removal efficiency. Settling characteristics of flocs formed in the coagulation process were studied in a laboratory scale settling unit. Alum in combination with lime gave the best result. It was found that chemical coagulation process is not only effective to remove the suspended solids and color pigments up to 90% to 98% but it would be also beneficial for the reduction of associated COD up to 20% to 55%. As wastewater from power house is within the NEQS limits, so it can be recycled. From cost analysis