A proposed methodology for in-situ treatment of MSW leachate

Abstract

Municipal solid waste (MSW) leachate consists of different constituents (contaminants) having the potential for undergoing chemical, physical and/or biological processes. The normal leachate handling procedure includes collection and off-site treatment, although the concept of landfill bioreactor was recently introduced in which leachate recycling is the main component. The barrier systems which separate the waste from the underlying soil and groundwater, and which minimize the migration of contaminants from the landfill, frequently consist of natural clayey deposits or recompacted clay. There seems to be a tendency towards using active barriers which are capable of removing certain contaminants within MSW leachate, although they are usually designed on a contaminant specific basis. The main objective of this paper is to propose a methodology for the removal of contaminants within MSW leachate, while it passes through different stages each having a certain effect on a single (or a group of) contaminant(s). The mentioned stages can be categorized into three main groups; adsorbant filters (natural and/or natural modified materials and also some type of waste materials), electrokinetic, processes and a media for biological growth. However using the proposed systems, may not necessarily result in elimination of leachate collection facilities, but it can have a beneficial effect compared to the treatment methods, also reducing the risk of groundwater contamination.