Notice of Retraction: Micro-Aerobic Granulation of Digestion Sludge in an EGSB Reactor for the Treatment of Actual Coking Wastewater

Abstract

To accomplish rapidly the micro-aerobic granulation process of digestion sludge for the treatment of actual coking wastewater and meanwhile achieve high COD, phenol SCN and CN removal, the EGSB reactor was employed with two operation stages. Stage I : Granular sludge was formed from digestion sludge using brewery wastewater as substrate in the anaerobic way (meanwhile adding little granules, which were 1/7 of the total biomass). Stage II : Granular sludge was acclimatized with the actual coking wastewater through continuous micro-oxygenation way. The experimental results showed that the granular sludge could quickly form in lOd in the EGSB reactor seeded with digestion sludge and little loose granules. It took only about 6 months for the successful micro-aerobic acclimating of the granular sludge by the actual coking wastewater. The removal efficiencies of COD, phenol, SCN and CN were 72.9, 99.5, 95.7 and 97.5%, respectively, at 12.1h hydraulic retention time (HRT) and for 631-922, 12.8-37.7, 0.3-57.8 and 66.7-232.7mg.L-1 influent COD, phenol, SCN and CN concentration.