Pilot Scale Treatment of Textile and Paint Effluents by Physicochemical and Advanced Filtration Processes

Abstract

The results of investigation on application of ferrous and modified diatomaceous earth materials in physicochemical treatment of textile and paint effluents using locally designed pollution abatement process is presented. The optimum conditions and efficiency of the process was determined using the following optimized parameters: coagulant concentration of 300mg/L, coagulation pH of 6, stirring speed of 80rpm and adsorbent height of 60cm. The locally designed pollution abatement process was utilized to treat paint and textile effluents consecutively for six months. It employed three basic concepts of wastewater treatment. Primary and intermediate stages were based on neutralization and coagulation principles while tertiary stage was based on filtration and adsorption using sand and modified diatomaceous earth packing materials. The main wastewater pollution indicators chemical oxygen demand and biological oxygen demand recorded approximately 70% and 60% reductions for textile and paint effluents after clarification respectively. Tertiary treatment with modified diatomaceous earth materials further im- proved the effluents quality by approximately 20%. It was found that both the textile and paint effluents showed high suscepti- bility to treatment using combined actions of ferrous-sulphate and modified earth materials (referred to as Clay-mix). Results based on type of adsorbent material used recorded about 85% - 90% pollutants reductions for both effluents. Furthermore, the modified clay-mix was at best when acidic, it yielded quality effluent when the pH of solubilization was at 4 and 5 for both effluents. Overall effect of treatment yielded quality effluent that conformed to guidelines for effluent discharge set by national environmental standards and regulations enforcement agency.