Treatment of mature landfill leachate by biofilters and Fenton oxidation.
A series of processes by biofilter and Fenton oxidation to treat mature landfill leachate has been devised. At a hydraulic loading rate of 20 l m(-3)d(-1), a biofilter packed with aged refuse is found to remove 80% of chemical oxygen demand (COD), 89% of ammonia nitrogen and 96% of total phosphorus (TP). Particularly, TP levels dropped below 1 mg l(-1). The optimal condition for Fenton oxidation was selected to be an initial pH of 5, a dosage of 0.01 and 0.02 mol l(-1) of FeSO(4) and H(2)O(2), respectively, and a duration of 3h, where COD removal efficiency reaches 58.6%, and BOD(5)/COD ratio is raised from 0.05 to 0.20. Subsequent treatment by a biofilter packed with slag reduces COD, ammonia nitrogen levels to less than 100, 25 mg l(-1), respectively. A pilot scale experiment conducted in situ demonstrates that this series of processes exhibits a high efficiency in removing pollutants from mature landfill leachate and it is viable for application.
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Department of Environmental Science & Technology, Shanghai Key Laboratory on Urbanization Ecological Process and Ecorestoration, Shanghai 200062, East China Normal University, PR China. bxie@des.ecnu.edu.cn
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D000641:Ammonia / Q000737:chemistry; D019149:Bioreactors; D002681:China; D004784:Environmental Monitoring; D005374:Filtration; D006861:Hydrogen Peroxide / Q000737:chemistry; D006863:Hydrogen-Ion Concentration; D017665:Hydroxyl Radical; D009584:Nitrogen / Q000737:chemistry; D010100:Oxygen / Q000737:chemistry*; D012037:Refuse Disposal / Q000379:methods*; D013997:Time Factors; D014867:Water / Q000737:chemistry; D014872:Water Movements; D014874:Water Pollutants, Chemical / Q000032:analysis
D014874:Water Pollutants, Chemical; D014867:Water; D017665:Hydroxyl Radical; D000641:Ammonia; D006861:Hydrogen Peroxide; D009584:Nitrogen; D010100:Oxygen