Variability in carbon isotope fractionation of trichloroethene during degradation by persulfate activated with zero-valent iron: Effects of inorganic anions
Variability in carbon isotope fractionation of trichloroethene during degradation by persulfate activated with zero-valent iron: Effects of inorganic anions
复制标题
零价铁活化过硫酸盐降解过程中三氯乙烯碳同位素分馏的变化：无机阴离子的影响
DOI：
10.1016/j.scitotenv.2016.01.011
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发表时间：
2016
影响因子：
9.8
通讯作者：
Li Xiaoqian
中科院分区：
文献类型：
--
作者：
Liu Yunde;Zhou Aiguo;Gan Yiqun;Li Xiaoqian
稳定碳同位素分析具有用于评价有机污染物原位修复效果的潜力。这种同位素技术的成功应用需要了解与所考虑的反应相关的碳同位素分馏的幅度和可变性。研究了无机阴离子（硫酸根、碳酸氢根和氯离子）对三氯乙烯（TCE）在零价铁活化过硫酸盐降解过程中碳同位素分馏的影响。结果表明，显著的碳同位素分馏（富集因子ε范围为− 3.4 ± 0.3至− 4.3 ± 0.3 ‰）与零铁剂量、硫酸盐浓度和碳酸氢盐浓度无关。然而，ε值（范围为− 7.0 ± 0.4至− 13.6 ± 1.2 ‰）取决于氯化物浓度，表明氯化物可以显著影响零价铁活化过硫酸盐降解TCE过程中的碳同位素分馏。ε值对氯离子浓度的依赖性表明，TCE的降解机制可能不同于硫酸根（SO4自由基点−）引起的降解机制。在定量评价原位化学氧化（ISCO）反应性能时，忽略氯离子对ε值的影响会带来许多不确定性。
Stable carbon isotope analysis has the potential to be used for assessing the performance ofin situremediation of organic contaminants. Successful application of this isotope technique requires understanding the magnitude and variability in carbon isotope fractionation associated with the reactions under consideration. This study investigated the influence of inorganic anions (sulfate, bicarbonate, and chloride) on carbon isotope fractionation of trichloroethene (TCE) during its degradation by persulfate activated with zero-valent iron. The results demonstrated that the significant carbon isotope fractionation (enrichment factors ε ranging from − 3.4 ± 0.3 to − 4.3 ± 0.3 ‰) was independent on the zero-iron dosage, sulfate concentration, and bicarbonate concentration. However, the ε values (ranging from − 7.0 ± 0.4 to − 13.6 ± 1.2 ‰) were dependent on the chloride concentration, indicating that chloride could significantly affect carbon isotope fractionation during TCE degradation by persulfate activated with zero-valent iron. The dependence of ε values on chloride concentration, indicated that TCE degradation mechanisms may be different from the degradation mechanism caused by sulfate radical (SO4radical dot−). Ignoring the effect of chloride on ε value may cause numerous uncertainties in quantitative assessment of the performance of thein situchemical oxidation (ISCO).