Field Survey and Advanced Oxidation Treatment of Waste Landfill Leachate in Hanoi, Vietnam

Abstract

The quality of leachate collected from waste landfills which received industrial and municipal waste in Hanoi was analyzed in order to obtain information on the current situation of pollutants in these sites. The leachate collected from Tay Mo landfill and Nam Son landfill showed the high concentration of iron and mercury. It was also recognized that the high strength of COD and color of leachate are the primary problems to be resolved at both sites. The application of several advanced oxidation processes (AOPs) to Tay Mo landfill leachate revealed that Fenton reaction and photo-Fenton reaction under pH adjustment effectively removed COD and color from the leachate and degraded the humic substance in it. Mutagenicity of the leachate was increased by UV-TiO₂-H₂O₂, Fenton (pH 3) and UV-Fenton (pH 3) treatments. This indicates that degradation of organic matters in the leachate resulted in the generation of toxic intermediates. Further investigation of the operating conditions of AOPs is necessary to minimize the environmental impact of waste landfill leachate.