Beschreibung:
A comparative study between an anaerobic side-stream reactor (ASSR) process and a sludge process reduction (SPR) activated sludge (SPRAS) process showed that the two-sludge SPRAS system greatly enhanced sludge reduction and accelerated the sludge decay rate. The highest rate coefficients of sludge decay, heterotroph lysis and particles hydrolysis were 0.106, 0.219 and 0.054 d-1 in the SPR module, followed by ASSR with coefficients of 0.060, 0.135 and 0.047 d-1. The SPR achieved an 81.9% higher sludge decay mass with a 32.8% smaller volume than the ASSR. The SPR preferentially enriched hydrolytic/fermentative and slow-growing bacteria. Metagenomics revealed that SPR strengthened the key hydrolases and L-lactate dehydrogenase in glycolysis pathways and weakened the citrate cycle, inducing metabolic uncoupling due to the reduced ATP biosynthesis. Inserting ASSR only altered the ATP biosynthesis pathway, but maintenance metabolism was dominant for sludge reduction, with a long sludge retention time prolonging the food chain for predation