Abstract
A hollow fiber microfiltration (HMF) membrane featured a unique air-backwashing and a high filtration rate under a low pressure and a low cross flow rate was successfully incorporated with aerobic submerged biofilters for the advanced treatment of domestic wastewater. The average filtrate flux around 1.3×10-5 m s-1 with organic removal of 70-85% was obtained for direct filtration of domestic wastewater under the working pressure of 50-100 kPa and the cross flow rate of 0.2-0.3 m s-1 with the periodical chemical cleaning at every 3-4 weeks. The filtrate was successfully treated by using a packed bed biofilter (PBF) at low SS discharge rate in the effluent.
The biological wastewater treatment system consists of a moving bed aerobic biofilter followed by HMF was found to be extremely effective to treat the domestic wastewater for the reuse of treated water. The filtrate flux in this system was over 2.5×10-5 m s-1 with the effluent BOD of 1-5 mg·l-1. The power consumption to treat 1 m3 of domestic wastewater in this system was estimated to be 0.3-0.4 kWh, which is comparable to that in municipal treatment plants.
