Abstract: The leachate treatment system of domestic waste incineration plants generally adopts the “anaerobic+biochemical+membrane+concentrated liquid re-concentration” process. There were some problems for this process such as long treatment process， complicated equipment operations， high equipment investment， and high operating costs. A new process of “softening +ultrafiltration（UF） +reverse osmosis（RO）” membrane treatment was used to replace the conventional “membrane + concentrated liquid re-concentration” process， and a pilot test of MBR effluent from a leachate treatment system in a incineration plant was carried out. The results showed that the new process was simple and easy to operate. When the overall recovery rate was 80%， the total hardness （calculated as CaCO3）， COD and Cl- removal rate of the MBR effluent reached 99.4%， 98.3% and 95.5%， respectively， achieved the treatment effect of the conventional process. And economic analysis showed that the new process saved about 46.7% in operating power consumption and equipment depreciation compared with the original process.

Key words: leachate, membrane treatment, chemical softening, ultrafiltration, reverse osmosis