Phytoremediation of long-term PCB-contaminated soil: A greenhouse feasibility study.

Abstract: Polychlorinated biphenyls (PCBs) are persistent organic pollutants, which were banned several decades ago but still exist in the environment, posing a threat to human health. Previously, joint sealants containing PCBs were used in construction. In this study, the long-term PCB-contaminated soils were from a residential area in Västerås Municipality, where the PCBs have been leaching from buildings to the soil for several years. The objective of this thesis is to investigate the feasibility of using plants to remove PCBs from the contaminated soil at a greenhouse scale, and to use a site-specific guideline model for the risk assessment of this contaminated site. After a literature review, four plant species were selected for the greenhouse cultivation including alfalfa (Medicago sativa L.), white clover (Trifolium repens L.), horseradish (Armoracia rusticana L.) and tobacco (Nicotiana tobacum L.). The plants cultivated in the greenhouse were maintained for 92 days and then the concentrations of PCBs in the initial and remediated soils were analyzed by GC-MS. The results indicate that the selected plant species can enhance the removal of high chlorinated PCBs from soils. In the risk assessment, the contents of PCBs in soils were higher than the calculated site-specific guideline, which means it is urgent to implement measures for protecting residents’ health.