In-situ Reduction of Leachate Organic Loading - Case study: Kahrizak Landfill

Leachate treatment as a major environmental problem has rarely been studied in Iran. To avoid using the conventional treatment methods and technologies currently employed in other countries, a bench scale study was conducted to achieve a practically applicable meanwhile cost effective leachate treatment method in an in-situ Condition. The objective of in-situ leachate treatment is to provide appropriate conditions within the landfill structure to allow the required chemical, physical and biological reactions to occur, resulting in reduction in organic loading of the leachate. The proposed method which was based on using construction and demolition wastes as the anaerobic growth medium at the bottom of the landfill, demonstrated acceptable results in reducing the organic loading of leachate sampled from Kahrizak landfill site. The method is therefore recommended as a cost effective leachate treatment system applicable to several landfills in Iran, provided the site specific tests are carried out. The results of the experiments where mixed construction and demolition wastes generated in Tehran were employed indicated about 80% reduction of organic loading in terms of total organic carbon and chemical oxygen demand. Among other advantages of the proposed system is the fact that the leachate volume is subject to a severe reduction, due to evaporation, So there is no need for effluent discharge to the environment.