Influence Factor and Membrane Fouling in SMBR for Food Wastewater Treatment

Based on the practical engineering and aimed at the food wastewater, a series experiments were conducted to investigate parameter on the effluents qualities by submerged membrane bioreactor (SMBR). A better removal performance in a SMBR could be achieved to treat food wastewater. The removal efficiencies in MBR were obtained worked with HRT at 10 h, DO at 2.5 mg/L and pH at 7.8, respectively. During the whole experimental period, the SMBR effluent COD and color varied in the range 35-50 mg/L and 20-30 degrees, respectively. In this way, the effluent met the national first grade discharge standard steadily and avoided the nonsynchronous degradation of COD and color. The membrane fouling was investigated by analysis of the images and the SEM. The chemical cleaning of the membrane with a 5% solution of HCl can removal most of the fouling pollutants. When the membrane was regenerated with a 1% solution of NaOH, membrane fouling was diminished. After treatment with both two cleaning agents, the membrane maintained its flux within a range of 0.08 to 0.09 m³/(m²/d).