Key Laboratory of Marine Environment and Ecology, Ministry of Education, Qingdao, Shandong Province, PR China.
Key Laboratory of Marine Environment and Ecology, Ministry of Education, Qingdao, Shandong Province, PR China; College of Environmental Science and Engineering, Ocean University of China, Shandong Province, PR China.
Ecotoxicol Environ Saf. 2019 Jan 30;168:443-449. doi: 10.1016/j.ecoenv.2018.10.103. Epub 2018 Nov 5.
Microcosm experiments were conducted to examine the attenuation of selected chemicals, i.e. m-xylene (MX), o-xylene (OX) and p-xylene (PX), under simulated marine conditions. Natural attenuation and the contribution of oxidation, photodegradation, biodegradation and volatilization to total attenuation were evaluated. The development of attenuation was in agreement with pseudo-first-order kinetics for all xylenes. The half-lives of MX, OX, and PX under optimal conditions were 0.76, 0.74 and 0.88 days, respectively. Attenuation kinetics were proposed to analyze the natural attenuation of xylenes. The leading attenuation type of MX, OX, and PX was volatilization, and the attenuation rate constants (K) were 0.5587, 0.6733, and 0.4821 d, respectively. Biodegradation of OX (K: 0.0003 d) was extremely inhibited. The attenuation kinetics presented the attenuation of xylenes in microcosm. The reaction kinetics could be applied to analyze the natural attenuation of chemicals. MX and OX can be converted to one another under certain conditions. Toluene and ethylbenzene were detected for OX in the OP (oxidation and photodegradation) experiment under simulated marine conditions. 4-Methylbenzyl alcohol, p-methyl benzaldehyde and p-toluic acid, as the major intermediates, were identified during the natural attenuation of PX using GC/MS.
进行了微观实验，以检验在模拟海洋条件下选定化学物质（即间二甲苯（MX）、邻二甲苯（OX）和对二甲苯（PX））的衰减情况。评估了自然衰减以及氧化、光降解、生物降解和挥发对总衰减的贡献。所有二甲苯的衰减均符合准一级动力学。在最佳条件下，MX、OX 和 PX 的半衰期分别为 0.76、0.74 和 0.88 天。衰减动力学被用来分析二甲苯的自然衰减。MX、OX 和 PX 的主要衰减类型是挥发，衰减速率常数（K）分别为 0.5587、0.6733 和 0.4821 d。OX 的生物降解（K：0.0003 d）受到极大抑制。衰减动力学呈现了微宇宙中二甲苯的衰减情况。反应动力学可用于分析化学物质的自然衰减。在一定条件下，MX 和 OX 可以相互转化。在模拟海洋条件下的 OP（氧化和光降解）实验中，检测到 OX 中有甲苯和乙苯。使用 GC/MS 鉴定了 PX 自然衰减过程中的主要中间产物：4-甲基苄醇、对甲基苯甲醛和对甲苯酸。
