Continuous Treatment of Textile Water by Ozonation and Coagulation

Abstract
A continuous process of combined ozonation and chemical coagulation was employed for treatment of textile wastewaters from several dyeing and finishing plants. Ozonation was found to be highly effective in color removal with complete discolorization of textile wastewater being achieved in less than 10 min in the continuous reactor. Chemical coagulation was observed to be mainly responsible for removing dissolved and suspended solids with a COD removal efficiency of up to 66%. The treatment efficiency of the combined process can be further enhanced when used in conjunction with the activated sludge process. Preliminary economic analysis of the process shows that ozonation for decolorization is highly competitive in terms of its total cost compared with use of decoloring agent. The cost saving is further complemented by a considerable improvement in the overall quality of the treated wastewater.