LARGE FULL-SCALE APPLICATION OF MEMBRANE TECHNOLOGY FOR WATER RECLAMATION IN WUXI, CHINA-CASE STUDY

Membrane technology like membrane bioreactor (MBR) and ultrafiltration-reverse osmosis process has been developed and applied for decades. In China, it has been increasingly widely applied in wastewater treatment and reclamation plants. This paper presented experience with several years of full-scale operation at the Wuxi New District, which has successfully adopted the large-scale application of membrane technology for water reclamation. The design and results of long-term operation of three MBRs in local wastewater treatment plant and a ultrafiltration-reverse osmosis plant in industry were introduced and discussed. Since 2009, the application of MBRs in three wastewater treatment plant with capacity ranging from 20,000 m(3)/d to 80,000 m3/d in Wuxi New District has allowed the 1A standard discharge of sewage that initially contained 360 similar to 510 mg/L CODcr, 250 similar to 300 mg/L SS, 43 similar to 55 mg/L total nitrogen and 3.1 similar to 5.0 mg/L total phosphate. With a product capacity of 10,000 m(3)/d, the high-purity reclamation of fluoride wastewater from a semiconductor manufacture which was recycled for industrial use and landscape irrigation was achieved by the adoption of a dual-membrane ultrafiltration-reverse osmosis plant. The dual membrane process yielded permeate with fluoride content below 1.0 mg/L and the product water quality meet the custom requirements. In the reverse osmosis operation, a positive correlation between feed temperature and permeate fluoride was observed.