Phytoremediation of Polychlorobiphenyls PCBs in Landfill E-Waste Leachate with Water Hyacinth E.Crassipes

Abstract The presence of e-waste in a landfill can release persistent organic pollutants POPs including polychlorinated biphenyls PCBs into the environment. PCBs are a family of more than 200 chemical compounds congeners each of which consists of two benzene rings and one to ten chlorine atoms. This study investigated use of water hyacinth Eichhornia crassipes for phytoremediation of landfill leachate waste containing PCB. Landfill leachate was simulated in the laboratory by spiking water samples with PCB to obtain concentrations of 5 10 and 15 amp956gL which were in one to two orders of magnitude above the US Environmental Protection Agency EPA limit of 0.5 amp956gL or 0.5 ppb. Water hyacinth plants were grown in 2 L samples of the PCB spiked water for 15 days and evaluated for tolerance and bioaccumulation of PCB. Phytoremediation of PCB spiked water by the plants was evaluated by measuring the change in concentration of PCB. The plants tolerated PCB concentrations in the range of 5 to 15 amp956gL without depicting any serious adverse effect except for change in root color and an initial wilting of peripheral leaves. Water hyacinth reduced the concentration of PCBs in the leachate over 15 days from 15 to 0.42 amp956gL for the 15 amp956gL initial concentration sample and to below the GCMS detection limit of 0.142 amp956gL for the 10 and 5 ugL initial concentration samples. Bioaccumulation of PCB in the plant tissue was evaluated through solid phase extraction and testing of samples for PCB with GCMS. Bioaccumulation of PCBs at a concentration of 0.179 amp956gg was observed in the water hyacinth roots for the 15 amp956gL sample but none was detected for the lower initial PCB concentration and shoots. The study demonstrated potential of water hyacinth plants in phytoremediation of PCBs in e-waste leachate