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Abstract
Landfill sites, that are the ultimate depository of solid waste stream in most societies, have the potential to generate leachate containing a complex mixture of contaminants of emerging concern (CECs) such as pharmaceutical compounds, plasticizers, and endocrine disrupting compounds, which can have negative effects on human and ecosystem health. More than 60% of the landfills in the U.S. discharge leachate to publicly owned treatment works (POTW), i.e. municipal wastewater treatment plants, because of its convenience and low cost. Apart from CECs, UV absorbing substances (UVAS) can cause major disruption to the effectiveness of wastewater treatment processes and often require pretreatment of leachate prior to discharge to POTW. Literature suggests that white-rot fungi are able to degrade both types of contaminants.This work investigated the removal of a selection of CECs and UVAS in real landfill leachate with non-sterile aerobic bench scale reactors utilizing Phanerochaete chrysosporium in pellet form. Batch and column plug flow reactor were used in this study, and finally treated LL was evaluated for biotoxicity with activated sludge respiration inhibition test. Meanwhile, the leachate from four landfills with various closure status was tested for occurrence of CECs.
The study found that phenol, a regulated compound in LL, was consistently removed in both batch and plug flow reactors. Acetaminophen was removed significantly as well. Fungal reactors were not efficient in reducing UV absorbance while they were effective in removal of carbon content up to about 40%. Landfill leachate characteristics in water quality parameters and CECs occurrence were variable among landfills of different closure status. While differences in some instances were statistically significant, they were not sufficient to justify different treatment approach to leachate based on closure status.