Abstract

Widely used as wood preservatives for the last century, Pentachlorophenol (PCP) and chromated copper arsenate (CCA) have been shown to leach from treated surfaces and contaminate soil of wood storage sites. We performed a four-year field phytoremediation trial in southern Quebec (Canada) on a site contaminated with PCP and CCA with the following objectives: (1) assess the potential of willow, fescue, alfalfa and Indian mustard to tolerate and translocate CCA and PCP residues in their aerial tissues, (2) investigate the possibility of phytoextraction of dioxins and furans, and (3) test the effect of nitrogen fertilizer on phytoremediation performance. We showed that while nitrogen fertilization increased the chlorophyll content of plants, it did not result in a significantly greater plant biomass. We also showed that plants grown in the presence of PCP/CCA residues were able to translocate and concentrate trace elements in their aerial tissues, but also dioxins and furans (PCDD/F). This suggests that plants grown on sites polluted by PCP might contain dioxins and furans and should be treated as contaminated by these toxic chemicals. Finally, the reduction of soil contaminants at the end of the trial suggests that phytoremediation is a promising approach for decontaminating such sites.

摘要

五氯苯酚（PCP）和铬酸砷酸铜（CCA）在上个世纪广泛用作木材防腐剂，已被证明会从经过处理的表面浸出并污染木材储存场所的土壤。我们在魁北克南部（加拿大）对受PCP和CCA污染的地点进行了为期四年的现场植物修复试验，其目标如下：（1）评估柳树，羊茅，苜蓿和印度芥菜对CCA和PCP的耐受和转运潜力其气管组织中的残留物，（2）研究二恶英和呋喃植物提取的可能性，（3）测试氮肥对植物修复性能的影响。我们表明，尽管施氮增加了植物的叶绿素含量，但并未导致植物生物量显着增加。我们还表明，在存在PCP / CCA残留物的情况下生长的植物能够转运和集中微量元素，使其空气中的组织以及二恶英和呋喃（PCDD / F）集中。这表明在被五氯苯酚污染的地点生长的植物可能含有二恶英和呋喃，应将其视为被这些有毒化学物质污染了。最后，在试验结束时减少土壤污染物表明，植物修复是对此类场所进行净化的有前途的方法。