Treatment of bleaching effluent in sequential activated sludge and nitrification systems

Abstract

Dechlorination and degradation mechanisms of bleaching effluent were studied in a sequential activated sludge and nitrification reactor. Effect of bleaching effluent on dechlorination performances was examined at various organic loading rates in the system. Released inorganic chlorine (ICl) was increased from 4.5 to 8.5 mg/l in the first stage activated sludge reactor while it was decreased from 10 to 2.5 mg/l in the subsequent nitrification reactor. Removal efficiencies of AOX were found as 15-33% and 5-25% in the activated sludge and the nitrification reactor respectively. TOC removal efficiencies achieved were 67-85% in the activated sludge reactor. The removal efficiency of NH₄ achieved 94-98% in the nitrification reactor.