Guo Yanyan, Lai Cui, Zeng Guangming, Gong Jilai, Su Chang, Yang Chunping, Xu Piao
College of Environmental Science and Engineering, Hunan University, Changsha, 410082, People's Republic of China.
Key Laboratory of Environmental Biology and Pollution Control, Hunan University, Ministry of Education, Changsha, 410082, People's Republic of China.
Environ Sci Pollut Res Int. 2017 Mar;24(8):7726-7739. doi: 10.1007/s11356-017-8468-9. Epub 2017 Jan 26.
Organochlorine pesticides (OCPs) in sediments could be released into water, posing great threats to human health and organisms. In this study, the treatment effectiveness of in situ sequestration of hexachlorocyclohexanes (HCHs) and dichlorodiphenyltrichloroethane (DDTs) in sediments was explored using multiwalled carbon nanotubes (MWCNTs) as adsorbents. Physicochemical tests (aqueous equilibrium concentrations, semipermeable membrane device (SPMD) uptake, and quiescent flux to overlying water) were conducted to evaluate the sequestration effectiveness of MWCNTs. Compared to the control, the MWCNT-treated sediments showed great reductions of HCHs and DDTs in aqueous equilibrium concentrations, SPMD uptake, and quiescent flux to overlying water. And the effects of dose of MWCNTs, diameter of MWCNTs, and contact time between MWCNTs and sediments on sequestration effectiveness were studied. Increased dose, decreased MWCNT diameter, and prolonged contact time resulted in a better sequestration effectiveness. The results indicated that the addition of MWCNTs to sediment could reduce the content of HCHs and DDTs released from sediments, reducing bioavailability of HCHs and DDTs and minimizing risks to ecosystem and human. MWCNTs have potential applications as adsorbents for in situ treatment of OCP-contaminated sediments.
沉积物中的有机氯农药（OCPs）可能会释放到水中，对人类健康和生物构成巨大威胁。在本研究中，以多壁碳纳米管（MWCNTs）为吸附剂，探索了沉积物中六氯环己烷（HCHs）和滴滴涕（DDTs）原位封存的处理效果。进行了物理化学测试（水相平衡浓度、半透膜装置（SPMD）摄取量以及向上覆水体的静态通量）以评估MWCNTs的封存效果。与对照组相比，经MWCNT处理的沉积物在水相平衡浓度、SPMD摄取量以及向上覆水体的静态通量方面，HCHs和DDTs的含量均大幅降低。并且研究了MWCNTs的剂量、MWCNTs的直径以及MWCNTs与沉积物之间的接触时间对封存效果的影响。剂量增加、MWCNT直径减小以及接触时间延长导致更好的封存效果。结果表明，向沉积物中添加MWCNTs可以降低沉积物中释放的HCHs和DDTs的含量，降低HCHs和DDTs的生物可利用性，并将对生态系统和人类的风险降至最低。MWCNTs作为原位处理受OCP污染沉积物的吸附剂具有潜在应用价值。
