无机阴离子对 UV/过硫酸盐转化三（2-氯乙基）磷酸酯（TCEP）过程中降解动力学和同位素分馏的影响。
The effects of inorganic anions on degradation kinetics and isotope fractionation during the transformation of tris(2-chloroethyl) phosphate (TCEP) by UV/persulfate.
机构信息
Key Laboratory of Pollution Control Chemistry and Environmental Functional Materials for Qinghai-Tibet Plateau of the National Ethnic Affairs Commission, School of Chemistry and Environment, Southwest Minzu University, Chengdu 610041, China; Key Laboratory of General Chemistry of the National Ethnic Affairs Commission, School of Chemistry and Environment, Southwest Minzu University, Chengdu 610041, China.
Key Laboratory of Pollution Control Chemistry and Environmental Functional Materials for Qinghai-Tibet Plateau of the National Ethnic Affairs Commission, School of Chemistry and Environment, Southwest Minzu University, Chengdu 610041, China; Key Laboratory of General Chemistry of the National Ethnic Affairs Commission, School of Chemistry and Environment, Southwest Minzu University, Chengdu 610041, China.
出版信息
Sci Total Environ. 2022 Nov 10;846:157462. doi: 10.1016/j.scitotenv.2022.157462. Epub 2022 Jul 19.
Tris(2-chloroethyl) phosphate (TCEP), as a typical chlorinated flame retardant, is attracting more attention as a carcinogen. Although persulfate-based oxidation exhibits good performance in removing refractory organic pollutants, the kinetics of persulfate-based remediation are affected by inorganic anions, which causes inaccurate remediation efficiency. This study combines steady-state radical concentration modelling with isotope fractionation to investigate the effects of inorganic anions on TCEP degradation by UV/persulfate (UV/PS). In the absence of anions during UV/PS system, the observed degradation rate was (9.7 ± 0.1) × 10 s, which was approximately 93 % attributed to sulfate radical (SO•) oxidation based on radical modelling. Carbon isotope fractionation, coupled with the identification of transformation products by mass spectrometry, suggests a carbon bond split during TCEP degradation with a carbon isotopic fractionation value (ε) of -1.6 ± 0.2 ‰ (± 95 % confidence intervals). With respect to co-existing anions in UV/PS system, the addition of chloride (Cl) had a negligible effect on degradation rates, while the addition of hydrogencarbonate (HCO) caused them to decrease, and the addition of hydrogenphosphate (HPO) caused them to increase. Radical modelling suggested that SO• was transformed to chlorine radicals (Cl•/Cl•), phosphate radicals (HPO•), and carbonate radicals (CO•). Furthermore, the overlapping 95 % confidence intervals (C.I.) and the statistical tests (p > 0.05) both agree that Cl and HPO gain identical ε values. Nevertheless, when HCO coexisted in the UV/PS system, the ε values were distinct. The addition of HCO would result in ε variation of TCEP in the UV activated PS process, which should receive more attention when applying remediation.
三（2-氯乙基）磷酸酯（TCEP）作为一种典型的含氯阻燃剂，因其致癌性而受到越来越多的关注。尽管过硫酸盐氧化在去除难处理有机污染物方面表现出良好的性能，但过硫酸盐修复的动力学受到无机阴离子的影响，导致修复效率不准确。本研究结合稳态自由基浓度模型和同位素分馏，研究了无机阴离子对 UV/过硫酸盐（UV/PS）体系中 TCEP 降解的影响。在 UV/PS 体系中不存在阴离子的情况下，观察到的降解速率为（9.7 ± 0.1）×10-2 s-1，根据自由基模型，这大约 93%归因于硫酸根自由基（SO•）氧化。碳同位素分馏，结合质谱鉴定的转化产物，表明 TCEP 降解过程中存在碳键断裂，碳同位素分馏值（ε）为-1.6 ± 0.2 ‰（±95%置信区间）。对于 UV/PS 体系中共存的阴离子，氯离子（Cl）的添加对降解速率几乎没有影响，而碳酸氢根（HCO）的添加导致降解速率降低，而磷酸氢根（HPO）的添加导致降解速率升高。自由基模型表明 SO•转化为氯自由基（Cl•/Cl•）、磷酸根自由基（HPO•）和碳酸根自由基（CO•）。此外，重叠的 95%置信区间（C.I.）和统计检验（p>0.05）都表明 Cl 和 HPO 获得相同的 ε 值。然而，当 HCO 共存于 UV/PS 体系中时，ε 值是不同的。HCO 的添加会导致 UV 激活 PS 过程中 TCEP 的 ε 值发生变化，在应用修复时应更加注意这一点。
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