INVESTIGATION INTO THE USE OF CONSTRUCTED REEDBEDS FOR MUNICIPAL WASTE DUMP LEACHATE TREATMENT

The Institute of Biology, University of Ljubljana, has established a pilot-scale constructed reedbed system to investigate the potential of this low-technology approach to the treatment of contaminated municipal waste dump leachate which is recognised to be a serious problem in Slovenia. The 600 m2 gravel media reedbed, planted with Phragmites australis has been in operation since October 1990, receiving a mean daily leachate flow of 26 m3. Although the removal percentages for BOD5, COD and SS were only 32%, 36%, and 73%, respectively, this was adequate to achieve an acceptable effluent quality in terms of discharge requirements, despite widely fluctuating influent characteristics, the presence of organic toxins in the leachate, and operational and environmental problems including poor hydraulics of the gravel media and poor establishment of reeds in the first year.