Treatment of organic chlorine in pulping effluents by activated sludge

Demirbas, G.
Gokcay, C.F.
Dilek, Filiz Bengü
A model activated sludge (AS) plant was fed by pulping effluents from a straw and reed processing paper works. The model was initially operated to simulate a dedicated treatment plant by continuously receiving chlorinated effluents from the pulp bleachery. In this simulation cycle the model activated:sludge was seeded only once during start-up and did not receive any domestic sewage after that. A carbon source was added in some of the experiments to bring up the organic content. In the second simulation cycle the pulping effluent was co-treated with municipal sewage. In this case the activated sludge unit:was being continuously dosed by microorganisms and the organics present in the sewage. A higher organic chlorine (AOX) removal was obtained at shorter SRTs in the co-treatment AS. High AOX removal was achieved at longer SRTs in the dedicated, once-seeded AS. The AOX removal mechanism was mineralization in both cycles. (C) 1999 Published by Elsevier Science Ltd on behalf of the IAWQ. All rights reserved.