Dries Jan, Bastiaens Leen, Springael Dirk, Agathos Spiros N, Diels Ludo
Department of Environmental Technology, Flemish Institute for Technological Research, Boeretang 200, 2400 Mol, Belgium.
Environ Sci Technol. 2004 May 15;38(10):2879-84. doi: 10.1021/es034933h.
The sorption and degradation of the chlorinated ethenes tetrachloroethene (PCE, 5 mg L(-1)) and trichloroethene (TCE, 10 mg L(-1)) were investigated in zero-valent iron systems (ZVI, 100 g L(-1)) in the presence of compounds common to contaminated groundwater with varying physicochemical properties. The potential competitors were chlorinated ethenes, monocyclic aromatic hydrocarbons, and humic acids. The effect of a complex matrix was tested with landfill contaminated groundwater. Nonlinear Freundlich isotherms adequately described chloroethene sorption to ZVI. In the presence of the more hydrophobic PCE (5 mg L(-1)), TCE sorption and degradation decreased by 33% and 30%, respectively, while TCE (10 mg L(-1)) decreased PCE degradation by 30%. In the presence of nonreactive hydrophobic hydrocarbons (i.e., benzene, toluene, and m-xylene at 100 mg L(-1)), TCE and PCE sorption decreased by 73% and 55%, respectively. The presence of the hydrocarbons had no effect on TCE degradation and increased PCE reduction rates by 50%, suggesting that the displacement of the chloroethenes from the sorption sites by the aromatic hydrocarbons enhanced the degradation rates. Humic acids did not interfere significantly with chloroethene sorption or with TCE degradation but lowered PCE degradation kinetics by 36% when present at high concentrations (100 mg L(-1)). The landfill groundwater with an organic carbon content of 109 mg L(-1) C had no effect on chloroethene sorption but inhibited TCE and PCE degradation by 60% and 70%, respectively.
在零价铁体系（ZVI，100 g L(-1)）中，研究了四氯乙烯（PCE，5 mg L(-1)）和三氯乙烯（TCE，10 mg L(-1)）这两种氯化乙烯的吸附和降解情况，体系中存在具有不同物理化学性质的受污染地下水中常见的化合物。潜在的竞争物包括氯化乙烯、单环芳烃和腐殖酸。用垃圾填埋场受污染的地下水测试了复杂基质的影响。非线性Freundlich等温线能充分描述氯乙烯在ZVI上的吸附。在疏水性更强的PCE（5 mg L(-1)）存在时，TCE的吸附和降解分别降低了33%和30%，而TCE（10 mg L(-1)）使PCE的降解降低了30%。在存在非反应性疏水性烃类（即100 mg L(-1)的苯、甲苯和间二甲苯）时，TCE和PCE的吸附分别降低了73%和55%。烃类的存在对TCE降解没有影响，且使PCE的还原速率提高了50%，这表明芳烃将氯乙烯从吸附位点上置换出来，从而提高了降解速率。腐殖酸对氯乙烯吸附或TCE降解没有显著干扰，但在高浓度（100 mg L(-1)）存在时，会使PCE降解动力学降低36%。有机碳含量为109 mg L(-1) C的垃圾填埋场地下水对氯乙烯吸附没有影响，但分别抑制了TCE和PCE降解60%和70%。
