Landfill Leachate Treatment by Reverse Osmosis System

Abstract

Landfill leachate contains highly concentrated inorganic salts and relatively low level of organics measured as BOD or COD, which are reported to have recalcitrant chlorinated carbon such as dioxins. Those feature of leachate are induced from waste dumped mostly composed of incinerated ashes. Conventional leachate treatment system with calcium removal, biological treatment, sedimentation with coagulation, filtration and carbon adsorption cannot remove inorganic salt and persistent organic matters. A landfill leachate treatment test system with reverse osmosis system using DT-Module has been tested and operated at a landfill site in Japan and showed an excellent performance removing highly concentrated salts by 99.4% and chlorinated carbon such as dioxins by 99.6% or more. Recovery rates of reverse osmosis system were 90-95%. By those experiments, it became to be possible to adopt reverse osmosis system for leachate treatment in Japan in combination with proper concentrate treatment.