ENHANCED REMOVAL OF PERSISTENT CONTAMINANTS AND TOXICITY REDUCTION THROUGH THE APPLICATION OF A TRIPLE-STAGE FENTON PROCESS TO SANITARY LANDFILL LEACHATES FROM YUCATAN, MEXICO

Sanitary landfill leachate (SLL) is a mixture of highly toxic and recalcitrant pollutants that threatens the water quality of the Yucatán Peninsula karst aquifer, one of the most extensive aquifers on the planet. To reduce the adverse environmental impacts of this wastewater, a triple-stage Fenton process (FP) was applied in an old SLL. Removal efficiencies were evaluated in terms of physicochemical variables, metal(oid)s concentrations, mass spectrometric identification of organic compounds and Daphnia magna acute toxicity test. The triple-stage FP achieved an 88% chemical oxygen demand (COD) removal, representing an improvement of 13% compared to FP performed in a single stage. Further, metal(oid)s such as aluminum, arsenic, chromium, nickel and zinc as well as organic compounds were substantially reduced. With respect to acute toxicity, the treatment produced a 64% reduction. Thus, this treatment system seems to be an effective option to reduce the dangerous level of SLL.