The report gives results of laboratory and pilot scale research to determine the effectiveness and economic feasibility of various physicochemical tertiary treatments in removing color, detergents, and other refractory pollutants from textile wastewater that has been previously treated biologically with activated sludge. Tertiary treatments included filtration on single and dual media filters, conventional and contact coagulation, adsorption on granular activated carbon, oxidation with ozone, ion exchange on anionic and cationic resins, and hyperfiltration. Each treatment was investigated individually and in combined systems. Results indicate that all tertiary treatments were effective in removing individual pollutants. However, feasibility of the processes (determined by economic factors, energy consumption, and technical availability) differed considerably. Hyperfiltration is more energy intensive than the other tertiary treatments. Ion-exchange resulted in poor COD removal and a large amount of post-generation wastewater. The most effective combined tertiary treatment consisted of contact coagulation on upflow filters, followed by dual media filtrations. The filtrations were preceded by chlorination with NaOCl and followed by adsorption on activated carbon as the final step.

Prepared for Environmental Protection Agency, Office of Research and Development. Public Law 480, SFC 055323, program element no. 1BB610. March 1978. Includes bibliographical references.