Detection of benzene in landfill leachate from Gohagoda dumpsite and its removal using municipal solid waste derived biochar

Abstract

Numerous landfill associated volatile organic compounds (VOCs) are emerging concern due to their potential risk of health. Benzene is one of the most common VOCs in landfill leachate. Biochar has bulged as a universal sorbent for the removal of contaminants from water and soil. Hence, this study examines the potential of biochar derived from municipal solid waste (MSW-BC) on adsorption of benzene so that MSW can be recycled to treat its own pollutants. Landfill leachate was collected from five sampling points at Gohagoda MSW dumpsite and analyzed for benzene. In order to evaluate the potential of MSW-BC for removal of benzene from water, the equilibrium adsorption was procured by using headspace GCMS. The effects of pH, contact time and sorbent (1-10 g/L), sorbate (30-300 μg/L) concentration were investigated using a batch sorption technique. Benzene was detected in landfill leachate, approximately 20 μg/L. The batch experiments indicated that benzene adsorption was dependent solution pH and percentage removal became higher above pH 7 and highest adsorption 42.7 μg/g was observed within 24 hours at pH 9. Maximum saturated sorption capacity of MSW-BC for benzene was 87.0 μg/g. Preliminary experiment data suggest a potential of MSW-BC to be utilized as a material for VOC remediation from MSW dumpsites.