Influences of operation parameters on performance of MBR treating digested piggery wastewater

To optimize operation parameters of MBRs for anaerobic digested piggery wastewater, three different HRTs, intermittent aeration run/off and effluent suction run/off were adopted. Nine tests were arranged according to orthogonal table. The results showed that when influent COD was 1240～1830 mg/L and BOD5 was 154～420 mg/L, effluent COD was 208～811 mg/L and BOD5 was 7～13 mg/L, COD and BOD5 removal rates were 51.7%～83.2% and 93.0%～97.1%, respectively. HRT had a remarkable effect on COD removal during experiments. COD removal with HRT=24 h was different evidently between that with HRT=15 h or 20 h. The increments were 7.3% and 13.4% respectively. When Water temperature was 24～28℃, NH4+-N removal rate improved evidently with water temperature, but water temperature was 28～35.8℃, NH4+-N removal rate changed little with water temperature.