Influence of retention time on ABR anaerobic sludge hydrolysis acidification process

The primary sludge is operated by ABR anaerobic hydrolysis acidification process to generate carbon resource. The reactor provides stabile acidogenic performance under the conditions of 35°C, HRT=28 h, and SRT=3 d during 30 days. ρ(SCOD) and ρ(VFAs) of effluents reach the peak values at 1182 mg/L and 602.8 mg/L during the operating time. Result shows that the sludge hydrolytic acidification system can successfully achieve the accumulation of VFAs. Retention time has significant impacts on the carbon accumulation system. Under the same conditions, the increase of HRT can improve the accumulation of carbon, however, when HRT is more than 32 h, the carbon resource accumulation slows down. When SRT is 5 d, ρ(SCOD) and ρ(VFA) are up to 1498 mg/L and 895.3 mg/L; When the SRT increases to 7 d, the acidogenic performance decreases.