Application of wetland plants in the remediation of polychlorinated biphenyls in contaminated soils

Electric and electronic waste termed as e-waste which is significant contributor of environmental pollution. Polychlorinated biphenyls (PCBs) are emitted from e-waste activities and affect the human health and soil quality, so PCBs removal from the soil has become a global concern. Phytoremediation provides sustainable solution to treat PCBs contaminated soils. Current study was conducted to investigate the abilities of several promising wetland plants for their PCBs removal efficiency. The soils samples were collected from PCB-contaminated sites at Layyari, Karachi Pakistan. Alternanthera sessilis ( L. ), Bacopa moneiri ( L. ) Pennell , Centella asiatica ( L. ) Urban , Juncus articulatus L. , and Cyperus arenarius Retz were grown under floody conditions. Further, two conditions floody and dry systems without plants were also simultaneously studied. The results indicated that Bacopa moneiri ( L .) Pennell showed more degradation of total PCBs; Cyperus arenarius Retz was effective for high chlorinated PCBs and Uncus articulates for the low chlorinated PCBs. The highest removal efficiency of total PCBs, high chlorinated PCBs, and low chlorinated PCBs was in range 30–34%. Floody condition facilitated higher degradation of high chlorinated PCBs and dry soil condition facilitated the degradation of low chlorinated PCBs. This is the first study using these plants for PCBs removal. The results suggest that these wetland plants could be used in future for the removal of PCBs contaminated soils.