Wang Chunying, Zeng Ting, Gu Chuantao, Zhu Sipin, Zhang Qingqing, Luo Xianping
College of Resource and Environmental Engineering, Jiangxi University of Science and Technology, Ganzhou, China.
School of Chemistry and Chemical Engineering, Xiamen University, Xiamen, China.
Front Chem. 2019 Dec 13;7:852. doi: 10.3389/fchem.2019.00852. eCollection 2019.
Photolysis and photocatalysis of typical phthalic acid esters (dimethyl phthalate, DMP; diethyl phthalate, DEP; dibutyl phthalate, DBP) were carried out in UV, UV/TiO, and UV-Vis/BiWO systems. All of the selected phthalic acid esters and their decomposition byproducts were subjected to qualitative and quantitative analysis through HPLC and GC-MS. The results of 300 min of photolysis and photodegradation reaction were that each system demonstrated different abilities to remove DMP, DEP, and DBP. The UV/TiO system showed the strongest degradation ability on selected PAEs, with removal efficiencies of up to 93.03, 92.64, and 92.50% for DMP, DEP, and DBP in 90 min, respectively. UV-Vis/BiWO had almost no ability to remove DMP and DEP. However, all of the systems had strong ability to degrade DBP. On the other hand, the different systems resulted in various byproducts and PAE degradation pathways. The UV system mainly attacked the carbon branch and produced o-hydroxybenzoates. No ring-opening byproducts were detected in the UV system. In the photocatalytic process, the hydroxyl radicals produced not only attacked the carbon branch but also the benzene ring. Therefore, hydroxylated compounds and ring-opening byproducts were detected by GC-MS in both the UV/TiO and UV-Vis/BiWO photocatalytic systems. However, there were fewer products due to direct hole oxidation in the UV-Vis/BiWO system compared with the UV/TiO system, which mainly reacted with the pollutants via hydroxyl radicals.
在紫外线、紫外线/二氧化钛和紫外-可见/钨酸铋体系中对典型邻苯二甲酸酯（邻苯二甲酸二甲酯，DMP；邻苯二甲酸二乙酯，DEP；邻苯二甲酸二丁酯，DBP）进行了光解和光催化实验。通过高效液相色谱（HPLC）和气相色谱-质谱联用仪（GC-MS）对所有选定的邻苯二甲酸酯及其分解副产物进行了定性和定量分析。300分钟光解和光降解反应的结果表明，每个体系对DMP、DEP和DBP的去除能力不同。紫外线/二氧化钛体系对选定的邻苯二甲酸酯显示出最强的降解能力，在90分钟内，DMP、DEP和DBP的去除效率分别高达93.03%、92.64%和92.50%。紫外-可见/钨酸铋体系几乎没有去除DMP和DEP的能力。然而，所有体系对DBP都有很强的降解能力。另一方面，不同体系产生了各种副产物和邻苯二甲酸酯降解途径。紫外线体系主要攻击碳支链并生成邻羟基苯甲酸酯。在紫外线体系中未检测到开环副产物。在光催化过程中，产生的羟基自由基不仅攻击碳支链，还攻击苯环。因此，在紫外线/二氧化钛和紫外-可见/钨酸铋光催化体系中，通过GC-MS检测到了羟基化化合物和开环副产物。然而，与主要通过羟基自由基与污染物反应的紫外线/二氧化钛体系相比，紫外-可见/钨酸铋体系中由于直接空穴氧化产生的产物较少。
