Analysis of Wastewater Loaded with Paint Before and After Treatment of Coagulation-Flocculation

The analysis of wastewater from a factory of painted steel tiles showed a high pollution degree. The pollution load (organic and mineral) of these waters generates degradation or even an eutrophication of the receiving environment (river and sea). The objective of this study was to reduce this pollution by applying an appropriate pretreatment that takes into account the industrial effluent standards, opportunities and interests of the company. The pretreatment of clarification chosen was the coagulation-flocculation where we have used two coagulants such as aluminum sulphate and ferric chloride and two types of flocculant: anionic and cationic. Clarification tests by jar-test showed that the mixture of aluminum sulphate/cationic flocculant gives the best results. However, the sludge volume remains high despite its decline to 290 cm(3) after 24 h of settling. By comparing the results of analysis of wastewater before and after treatment, we can deduce that the method used is satisfactory.