State Key Laboratory of Pollution Control and Resources Reuse, School of the Environment, Nanjing University, Nanjing, Jiangsu 210023, PR China.
State Key Laboratory of Pollution Control and Resources Reuse, School of the Environment, Nanjing University, Nanjing, Jiangsu 210023, PR China; School of the Environment, Nanjing Normal University, Nanjing, Jiangsu 210046, PR China.
J Hazard Mater. 2017 Sep 5;337:34-46. doi: 10.1016/j.jhazmat.2017.05.005. Epub 2017 May 5.
In this study, an electromagnetic induction electrodeless lamp (EIEL) was first introduced into UV advanced oxidation processes (AOPs) for photodegradation of Diatrizoate (DTZ), which was the most persistent iodinated X-ray contrast medium (ICM), and traditional Hg lamps were taken as references. Direct photolysis rate of DTZ under EIEL irradiation was 1.34 times as that under Hg irradiation, but the electric energy consumption was 0.87 times. In this sense, the combination of EIEL and oxidants (O, HO and SO(PS)) was further investigated. The remarkably increased photodegradation rates were observed in UV/PS system due to primary contribution rate of SO (62.5%) based on the results of radical concentrations and second-order rate constants of DTZ with SO and OH. Inorganic ions influencing the photodegradation process were investigated. The effect of natural organic materials (NOMs) in UV/PS system was studied based on contribution ratios of light screening effect and quenching. Transformation mechanisms of DTZ in UV/PS system included deiodination, intramolecular cyclization, decarboxylation, deacetylation and deamination, which were further confirmed by frontier electron density calculations. The study indicated that UV/PS with EIEL irradiation has the potential to remove pharmaceuticals in contaminated aquatic environments.
在这项研究中，首次将电磁感应无电极灯（EIEL）引入到用于二碘酞酸盐（DTZ）光降解的 UV 高级氧化工艺（AOP）中，DTZ 是最持久的碘代 X 射线造影剂（ICM），并以传统的汞灯作为参考。在 EIEL 辐照下，DTZ 的直接光解速率是 Hg 辐照下的 1.34 倍，而电能消耗仅为 0.87 倍。从这个意义上说，进一步研究了 EIEL 与氧化剂（O、HO 和 SO(PS)）的组合。由于 SO 的主要贡献率（基于自由基浓度和 DTZ 与 SO 和 OH 的二级速率常数的结果为 62.5%），在 UV/PS 体系中观察到了明显增加的光降解速率。研究了影响光降解过程的无机离子。根据光屏蔽效应和淬灭的贡献比，研究了天然有机物质（NOMs）在 UV/PS 体系中的影响。在 UV/PS 体系中，DTZ 的转化机制包括脱碘、分子内环化、脱羧、脱乙酰基和脱氨，这通过前沿电子密度计算得到了进一步证实。该研究表明，EIEL 辐照下的 UV/PS 有可能去除受污染水环境中的药物。
