Determination of treatment method of leachate by using eluate

Abstract

The purpose of the research was to investigate if the treatment method for the leachate generated at the landfills can be determined by using the eluate obtained from the same solid waste to be dumped at the landfill area. The eluate was generated by using the Standard Leaching Test (SLT-3) and was analyzed for pH, Biochemical Oxygen Demand (BOD), Chemical Oxygen Demand (COD), eleven metals and inorganics. Also leachate was sampled from a sanitary landfill and analyzed for the same parameters. The composition of the eluate and the leachate was compared and it was observed that the generated eluate resembles the leachate. Then coagulation and flocculation tests using 8M aluminium sulphate (Al₂ (SO₄)₃) and 1M FeCl₃ at acidic and basic media were applied and some of the treated eluate was filtered through activated carbon. The results indicated that although the applied coagulation and flocculation processes in the acidic media were effective in the removal of COD from the eluate, it was not effective in the removal of metal and inorganic elements while the opposite was true at the basic media. High removal efficiency of the metal and inorganic elements was obtained by using 15 mL 1M iron chloride at basic media (pH 9) and then filtering through activated carbon. By the application of the filtration through activated carbon approximately 80 percent removal efficiency for both BOD and COD of the eluate and leachate were obtained. The results of the research indicated that eluate resembling the leachate, which can be obtained by the SLT-3 method using the solid waste to be disposed at the sanitary landfill, can be used for the determination of the treatment method for the treatment of the leachate to be generated later.

Keywords:

• Eluate
• leachate
• SLT-3 test
• coagulation-flocculation
• coagulant

Acknowledgments

The author extends her gratitude to the Commission of the Scientific Research Projects of Boğaziçi University (Project No. 95Y0046) and TUBITAK for their support for the realization of the research. She also acknowledges the effort that Mr.Albert Levi has put in the preparation of the manuscript.