He Shichong, Zhu Lizhong
Department of Environmental Science, Zhejiang University, Hangzhou, Zhejiang, 310058, China.
Zhejiang Provincial Key Laboratory of Organic Pollution Process and Control, Hangzhou, Zhejiang, 310058, China.
Sci Rep. 2017 Oct 26;7(1):14140. doi: 10.1038/s41598-017-14562-y.
Sorptive landfill liners can prevent the migration of the leachate pollutants. However, their sorption ability will decrease over time. A method should be developed to maintain the sorption ability of landfill liners. In this study, we combined cetyltrimethylammonium bromide-bentonite (CTMAB-bentonite) and zero-valent iron (ZVI) to develop a self-cleaning liner that can retain its sorption ability for a long period. Batch experiments and calculation simulations were employed to analyse the sorption ability of this liner material and the ecological risk of halogenated hydrocarbons. The results showed that CTMAB-bentonite could sorb halogenated hydrocarbons well, with saturated sorption capacities (Q ) of 10.2, 14.5, 6.69, 18.5, 29.4, and 49.7 mg·g for dichloroethane (DCA), trichloroethane (TCA), dichloroethene (DCE), trichloroethylene (TCE), tetrachloroethylene (PCE), and 1,3- dichloropropene (1,3-DCP), respectively. Using the mixture of 0.5 g iron and 0.5 g CTMAB-bentonite could dramatically increase the removal efficiency of DCE, TCE, and PCE. The reaction with ZVI did not change the structure of CTMAB-bentonite and its sorption ability remained consistent. Calculation results suggested that the self-cleaning landfill liner would dramatically decrease the hazard index (HI) of the eluate. However, the humic acid and salt in leachate would cause a reduction in the removal of halogenated hydrocarbons.
吸附性垃圾填埋场衬垫可以防止渗滤液污染物的迁移。然而，它们的吸附能力会随着时间的推移而下降。应该开发一种方法来维持垃圾填埋场衬垫的吸附能力。在本研究中，我们将十六烷基三甲基溴化铵-膨润土（CTMAB-膨润土）和零价铁（ZVI）结合起来，开发出一种能够长期保持其吸附能力的自清洁衬垫。采用批量实验和计算模拟来分析这种衬垫材料的吸附能力以及卤代烃的生态风险。结果表明，CTMAB-膨润土对卤代烃具有良好的吸附性能，对二氯乙烷（DCA）、三氯乙烷（TCA）、二氯乙烯（DCE）、三氯乙烯（TCE）、四氯乙烯（PCE）和1,3-二氯丙烯（1,3-DCP）的饱和吸附容量（Q）分别为10.2、14.5、6.69、18.5、29.4和49.7 mg·g。使用0.5 g铁和0.5 g CTMAB-膨润土的混合物可以显著提高DCE、TCE和PCE的去除效率。与ZVI的反应没有改变CTMAB-膨润土的结构，其吸附能力保持一致。计算结果表明，自清洁垃圾填埋场衬垫将显著降低洗脱液的危害指数（HI）。然而，渗滤液中的腐殖酸和盐分将导致卤代烃去除率的降低。
