Evaluation of inorganic adsorbents for the removal of problematic textile dyes and pesticides

This paper evaluates three inorganic adsorbents (activated bauxite, fullers earth and a synthetic clay), relative to activated carbon, for the removal of several representative contaminants of major concern and frequent occurrence in UK textile industry effluents; reactive dyes, pentachlorophenol and Propetamphos. The results indicate that, for the removal of reactive dyes, the synthetic clay was the most effective adsorbent over the pH range from pH 5.5 to pH 8.5 and temperature range from 20 to 40 degrees C, although comparable dye removals were exhibited by activated carbon under neutral and alkaline conditions. Under acidic conditions activated bauxite was as effective as activated carbon. Fullers; Earth was largely ineffective. With regard to the removal of pesticides activated carbon was highly effective, whereas the three inorganic adsorbents showed negligible removals. (C) 1997 IAWQ. Published by Elsevier Science Ltd.