[Characteristics of sludge in treatment of high concentrated organic wastewater by swim-bed technology].

Based on the technology of conditional activated sludge process, swim-bed technology involving the novel biomass attachment material biofringe (BF) is one of the new and efficient advanced municipal wastewater treatments process. The process demonstrated effective treatment of high concentrated organic wastewater. When VLRs were from 1.7 kg/(m3 x d) to 4.5 kg/(m3 x d), 96% of average COD removal efficiencies and 80.7% of nitrification rate were achieved, respectively. The BF material allowed for attachment of large amounts of biomass. The mixed liquor suspended solid (MLSS) concentrations in the reactor reached 23 g/L at the highest during operation period, with holding 20-50 mL/g of SVI. An exponential law was found to be suitable to describe the variation of the viscosity as a function of MLSS. The granulation phenomenon of sludge was observed during the experiment. Protozoan and metazoans on the bio-film and suspended sludge were proved existing in the system by microscopic observation and DNA experiment. Observed sludge yields from 0.1046 to 0.1723 (MLSS/BOD) were obtained in swim-bed system.