Pilot Scale Study on Combined Ultra Filtration and Other Technique to Treat Rural Domestic Sewage

Abstract

The rural domestic sewage was treated by using combined ultra filtration with reverse osmosis (RO), constructed wetlands and biofilter respectively. The results showed that the average concentrations of COD, TP, NH4-N and TN in the effluent were 118.1, 5.4, 75.5 and 85.0 mg/L, and the average removal rates were 77.0%, 58.1%, -2.7%, and 15.1% by ultra filtration respectively. And then the effluent treated by RO process, the above water quality indicators had reached the I A level of the discharge standard of pollutants for urban wastewater (GB18918-2002). The average removal rates of COD were 35.6% and 35.1%, TP were 11.9% and 9.8%, NH4-N were 5.4% and 23.7%, TN were 6.1% and 7.6% by constructed wetlands and biofilter respectively. The overall removal rates of pollutants were not high and the effluent quality was not stable through the above two techniques. Therefore, further improvement is needed in design and operation of constructed wetlands and biofilter. Ultra filtration-reverse osmosis integrated equipment can be designed to treat dispersed domestic sewage in rural areas.