Kinetics and degradation mechanism of tris (1-chloro-2-propyl) phosphate in the UV/H2O2 reaction.
Kinetics and degradation mechanism of tris (1-chloro-2-propyl) phosphate in the UV/H2O2 reaction.
复制标题
DOI：
10.1016/j.chemosphere.2020.127461
复制
发表时间：
2020-07
期刊：
影响因子：
8.8
通讯作者：
Yeongjo Son;Young-Min Lee;K. Zoh
中科院分区：
文献类型：
--
作者：
Yeongjo Son;Young-Min Lee;K. Zoh
三(1-氯-2-丙基)磷酸(TCPP)是一种氯化有机磷酸盐，广泛用作阻燃剂和增塑剂。TCPP是一种已知的可疑致癌物质，传统的水处理方法如生物处理、氯化处理和紫外线照射无法有效地去除TCPP。在本研究中，采用UV/H_2O_2反应降解水中的TCPP。在UV/H_2O_2反应中，TCPP的降解符合准一级动力学规律。以硝基苯为参比化合物，用竞争动力学法测得三氯苯酚与羟基自由基反应的二级速率常数为4.35(±0.13)×10~8M−_1s−_1。HCO3-−、NO3-−和腐植酸等共存水组分对三氯苯酚的降解有一定的影响。在UV/H_2O_2反应中，总有机碳的矿化时间为12h，约占总有机碳的64.2%，而氯离子(Cl-−)和磷酸盐(PO43-−)离子被鉴定为离子副产物，氯(Cl)和磷(P)的回收率分别为96%和50%。用LC-QTOF/MS鉴定了TCPP的5种有机转化产物(TPS)，结合鉴定的TPS，发现TCPP在UV/H_2O_2反应中的主要降解途径是OH-自由基诱导的羟化反应。在UV/H_2O_2反应过程中，费氏弧菌的生物发光抑制率下降了70%，其时间-毒性曲线与TPS的时间-峰面积曲线相似。研究结果表明，UV/H_2O_2工艺能有效去除TCPP，并能显著降低矿化度和毒性。
Tris (1-chloro-2-propyl) phosphate (TCPP) is a chlorinated organic phosphate used in various applications as a flame retardant and plasticizer. TCPP is a known suspected carcinogen and is not effectively removed by traditional water treatments such as biological, chlorination, and UV irradiation. In this study, the UV/H2O2reaction was employed to degrade TCPP in water. TCPP was effectively degraded in the UV/H2O2reaction by pseudofirst-order kinetics. The second-order rate constant of the reaction between the TCPP and OH radical was determined to be 4.35 (±0.13) × 108M−1s−1using the competition kinetics with nitrobenzene as a reference compound. The degradation of TCPP was affected by the amount of H2O2, pH, and coexisting water components such as HCO3−, NO3−, and humic acid. Approximately 64.2% of total organic carbon (TOC) in TCPP was mineralized in 12 h during the UV/H2O2reaction, whereas chloride (Cl−) and phosphate (PO43−) ions were identified as ionic byproducts with the recoveries of 96% chlorine (Cl) and 50% phosphorus (P). Five organic transformation products (TPs) of TCPP were also identified using LC-qTOF/MS. Considering the identified TPs, the main degradation pathway of TCPP during the UV/H2O2reaction was found to be OH-radical-induced hydroxylation. Finally, a 70% decrease in bioluminescence inhibition in Vibrio fischeri was observed during the UV/H2O2reaction, and the time-toxicity profile was similar to the time-peak area profile of TPs. The result of this study implies that TCPP can be efficiently removed with significant mineralization and toxicity reduction by the UV/H2O2process.