[Extreme thermophilic (70 degrees C), combining two-phase anaerobic/activated sludge/bio-activated charcoal for treating food wastewater].

This study was conducted to investigate the performance of combining two-phase anaerobic(TPA)/activated sludge(AS)/bio-activated charcoal(BAC), seeded with mesophilic sludge, for treating food wastewater at extreme temperature (70 degrees C) to allow treated water to be reused for closed heat water circuits. The system had a total hydraulic retention time of 42h. Reactor performance was characterized by COD, VFA, pH, amino-acid. An overall COD treatment efficiency of 99.62%, VFA and amino-acide of 100% and pH between 6.6 - 7.5 were observed for the system. COD removal of acidification phase, methane phase, activated sludge and BAC was 49.7%, 33.7%, 14.5%, and 1.1%, respectively. VFA removal of methane phase, activated sludge and BAC was 56%, 21.2% and 21.8%, respectively. Amino-acid removal of methane phase, activated sludge and BAC was 34.8%, 62% and 3%, respectively. COD concentration of effluent in the system was lower than 50 mg/L. An additional experiments show that activated sludge and bio-activated charcoal at 70 degrees C may allow COD concentration of influent up to 3500 mg/L and COD removal was up to 95.8% at high organic loading 4.5 kg/(m3 x d) with aerobic condition.