Abstract:Two-stage complete mixing ferment process was used for developing carbon source. Influence of HRT and SRT on the ferment system were studied. Effective HRT of the process was between 32 to 36 h, when SRT was 4 d and sludge recycle rate was 1, average SCOD of effluents was in the range of 1090~1180 mg/L, while separation effect of the sludge thickener was very well, and MLSS of supernatant was in the range of 50~80 mg/L; In the condition of HRT was 32 h and sludge recycle rate was 1, effective SRT of the process was in the range of 4~7d, and average SCOD of effluents was between 980~1179 mg/L, acidogenic bacteria and methanogenic bacteria could be separated effectively. Alkalinity was an important parameter of the primary sludge ferment system. In the process of primary sludge hydrolysis and acidification, ammonia nitrogen and phosphorus would be released. In the conditions of HRT was 32 h and SRT was 4 d, the release rate of ammonia nitrogen and phosphorus were 3.88 mgN/gVSS and 0.27 mgP/gVSS.