Treatment of landfill leachate by hybrid precipitation/microfiltration/nanofiltration process

Abstract

This paper describes a promising method to treat stabilized landfill leachate. Such method consists of a combination of chemical precipitation processes, a cost-effective technique with high potential to remove contaminants with foulant nature, microfiltration aimed at removing the produced precipitate and nanofiltration (NF) for final polishing. This study was carried out on a bench unit comprising a precipitation reactor associated with a submerged hollow-fiber microfiltration membrane module and a flat NF membrane cell operated in batch and continuous mode with a treating capacity of 0.1 L h(-1). Combining these processes yielded a clear and colorless permeate and proved to be very efficient at removing organic and inorganic matter. The results showed the importance of membrane processes to ensure treated landfill leachate quality. Also the precipitation associated with microfiltration as a pretreatment process is able to guarantee low membrane fouling due to the significant retention of humic substances which are known for their high potential to cause NF membrane fouling.