Removal of UV Quenching Substances in Landfill Leachate with Open Channel Reverse Osmosis Membrane Technologies

D. Lei, D.P. Xu, F. Li



Sequencing batch reactor (SBR) is one of the widely applied biological approaches for landfill leachate treatment. The SBR process is most effective in treating young leachate, which mainly consists of volatile fatty acids. However, the SBR process has limitations in treating methanogenic phase leachate (Li et al., 2009). Humic substances, derived from cellulose and lignin with high molecular weight and fulvic acid-like materials with medium to high molecular weight are the predominant organic substances in methanogenic leachate (Cossu, 2007). Humic substances are not readily biodegradable (Poblete et al., 2011), and pass through the biological treatment processes, appearing in the SBR effluent. The SBR effluent is often discharged or transported to the publically owned treatment works (POTWs). To avoid of the formation of disinfection by-products (DBPs) caused by chlorine disinfection, ultra-violet (UV) disinfection has recently been adopted for the disinfection of the effluent of POTWs. Humic substances and fulvic acid-like materials were found to contribute to the majority of UV light quenching fractions which consequently interfere the disinfection process at POTWs where UV light is applied (Zhao et al. 2013). This study reports the findings of a full-scale one-stage open channel reverse osmosis plant treating landfill leachate SBR effluent in east coast of USA to reduce the UV quenching substances. The results presented in this study indicate that open channel reverse osmosis membrane is able to significantly reduce the UV quenching substances in the landfill leachate SBR effluent. The open channel RO membrane has achieved satisfactory water quality, process stability and membrane flux results. Open channel RO polishing after biological treatment has been demonstrated as an effective technology for landfill leachate treatment.