Peng Jianbiao, Zhang Yaozong, Zhang Chaonan, Miao Dong, Li Jianhua, Liu Haijin, Wang Lianhong, Gao Shixiang
School of Environment, Henan Normal University, Key Laboratory for Yellow River and Huai River Water Environmental and Pollution Control, Ministry of Education, Henan Key Laboratory for Environmental Pollution Control, Xinxiang 453007, PR China.
State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210023, PR China.
Sci Total Environ. 2019 Jul 10;673:726-733. doi: 10.1016/j.scitotenv.2019.03.354. Epub 2019 Mar 25.
As a typical nanomaterial, graphene oxide (GO) can be easily dispersed in water and may affect the aqueous environment. In this paper, the degradation of triclosan (TCS) in a Fenton-like system Fe/HO in GO aqueous solution was investigated. Interestingly, it was observed that GO at low concentration (2.0 mg/L) could exhibit significant catalytic effect on TCS removal. Meanwhile, results of XPS, Raman and TEM spectroscopy suggested the structure and chemical composition of GO did not exhibit significant change after the oxidation process within 30 min. As per the radical quenching experiments and ESR tests, hydroxyl radical (·OH) was mainly responsible for the decomposition of TCS. Further mechanism study indicated that the reaction activation energy (E) could be lowered and the production of ·OH be promoted in the presence of GO, respectively. A total of nine intermediates of TCS degradation were detected by TOF-LC-MS after SPE procedure. Finally, ecotoxicity assessment revealed that degradation of TCS by Fe/HO system in GO aqueous solution could yield by-products of smaller toxicity compared with parent compounds.
作为一种典型的纳米材料，氧化石墨烯（GO）能够轻易地分散于水中，并可能对水环境产生影响。本文研究了在GO水溶液中，类芬顿体系Fe/HO对三氯生（TCS）的降解情况。有趣的是，研究发现低浓度（2.0 mg/L）的GO对TCS的去除具有显著的催化作用。同时，XPS、拉曼光谱和透射电子显微镜光谱的结果表明，在30分钟的氧化过程后，GO的结构和化学成分并未发生显著变化。根据自由基猝灭实验和电子顺磁共振测试，羟基自由基（·OH）是TCS分解的主要原因。进一步的机理研究表明，在GO存在的情况下，反应活化能（E）会降低，·OH的生成会得到促进。经过固相萃取程序后，通过飞行时间液相色谱-质谱联用仪共检测到TCS降解的9种中间产物。最后，生态毒性评估表明，与母体化合物相比，Fe/HO体系在GO水溶液中对TCS的降解会产生毒性较小的副产物。
