(12f) A Multi-Dimensional Strategy for Treatment of Raw Landfill Leachate Wastewater Using Electroperoxone

Population explosion and rapid urbanization have led to rampant increase in waste generation and environmental pollution. Solid waste generated by cities across the globe is expected to become 2.2 billion tons per year by 2025. Landfilling has become the preferred strategy for disposal of solid wastes. However, mismanaged landfill leachate is capable of polluting the surrounding surface and ground water, resulting in potential health hazards. Moreover, the presence of dissolved organics in ground water causes ineffective chlorination and carcinogenic disinfection by-products. Hence, landfill leachate needs appropriate and sufficient treatment before its discharge into water bodies. Unfortunately, conventional treatment technologies are unable to treat raw (i.e., not pre-treated) leachate to a satisfactory level. Electroperoxone, being a promising advanced oxidation process, is herein investigated in the treatment of raw leachate wastewater from Buck Run landfill, Mississippi. We critically compare the performance of electroperoxone with electrolysis and ozonation, for the removal of humic acid, a model persistent organic pollutant and a major component of leachate. Secondly, a comprehensive treatment of the leachate was carried out using relatively inexpensive Reticulated Vitreous Carbon (RVC) cathode and Platinum-coated Titanium anode. Optimization of H₂O₂ generation under varying aeration rates, applied current, electrode surface area and solution pH was performed. ^.OH radical estimation in all three processes showed that the maximum radical generation was in electroperoxone. This experimental system offers a multi-pronged attack and tackles (i) Total Organic Carbon (TOC), (ii) Color, (iii) Disinfection, (iv) Organic suspended solids, (v) Turbidity and (vi) Toxicity. We obtained a TOC degradation of 72%, 81.9% turbidity removal, and 84% suspended solids removal within 480 min, 99.72% decolorization within 240 min, and 99.93% disinfection within 180 min. Mechanisms responsible for the above efficient performances were also investigated. Electroperoxone thus proves to be a highly promising technology for the effective removal of such persistent contaminants in complex real wastewater systems.