Wang Qian, Kelly Barry C
Department of Civil and Environmental Engineering, National University of Singapore, Singapore.
Department of Civil and Environmental Engineering, National University of Singapore, Singapore.
Chemosphere. 2017 Sep;183:257-265. doi: 10.1016/j.chemosphere.2017.05.113. Epub 2017 May 20.
This study involved a field-based investigation to assess the occurrence, distribution and bioaccumulation behaviour of hydrophobic organic contaminants in a large-scale constructed wetland. Samples of raw leachate, water and wetland plants, Typha angustifolia, were collected for chemical analysis. Target contaminants included polychlorinated biphenyls (PCBs), organochlorine pesticides (OCP), as well as several halogenated flame retardants (HFRs) and personal care products (triclosan and synthetic musks). In addition to PCBs and OCPs, synthetic musks, triclosan (TCS) and dechlorane plus stereoisomers (syn- and anti-DPs) were frequently detected. Root concentration factors (log RCF L/kg wet weight) of the various contaminants ranged between 3.0 and 7.9. Leaf concentration factors (log LCF L/kg wet weight) ranged between 2.4 and 8.2. syn- and anti-DPs exhibited the greatest RCF and LCF values. A strong linear relationship was observed between log RCF and octanol-water partition coefficient (log K). Translocation factors (log TFs) were negatively correlated with log K. The results demonstrate that more hydrophobic compounds exhibit higher degrees of partitioning into plant roots and are less effectively transported from roots to plant leaves. Methyl triclosan (MTCS) and 2,8-dichlorodibenzo-p-dioxin (DCDD), TCS degradation products, exhibited relatively high concentrations in roots and leaves., highlighting the importance of degradation/biotransformation. The results further suggest that Typha angustifolia in this constructed wetland can aid the removal of hydrophobic organic contaminants present in this landfill leachate. The findings will aid future investigations regarding the fate and bioaccumulation of hydrophobic organic contaminants in constructed wetlands.
本研究进行了一项实地调查，以评估大型人工湿地中疏水性有机污染物的发生、分布和生物累积行为。采集了原渗滤液、水和湿地植物香蒲的样本进行化学分析。目标污染物包括多氯联苯（PCBs）、有机氯农药（OCP），以及几种卤代阻燃剂（HFRs）和个人护理产品（三氯生和合成麝香）。除了多氯联苯和有机氯农药外，还经常检测到合成麝香、三氯生（TCS）和十氯联苯立体异构体（syn-和anti-DPs）。各种污染物的根浓缩系数（log RCF L/kg湿重）在3.0至7.9之间。叶浓缩系数（log LCF L/kg湿重）在2.4至8.2之间。syn-和anti-DPs表现出最大的RCF和LCF值。观察到log RCF与正辛醇-水分配系数（log K）之间存在很强的线性关系。转运系数（log TFs）与log K呈负相关。结果表明，疏水性更强的化合物在植物根中的分配程度更高，从根向植物叶的转运效率更低。三氯生甲酯（MTCS）和2,8-二氯二苯并对二恶英（DCDD），即三氯生的降解产物，在根和叶中表现出相对较高的浓度，突出了降解/生物转化的重要性。结果进一步表明，该人工湿地中的香蒲有助于去除该垃圾渗滤液中存在的疏水性有机污染物。这些发现将有助于未来对人工湿地中疏水性有机污染物的归宿和生物累积进行研究。
