Zhou Zeyu, Zhang Yaxin, Wang Hongtao, Chen Tan, Lu Wenjing
Department of Environmental Science and Engineering, Tsinghua University, Beijing, P.R. China.
College of Environmental Science and Engineering, Hunan University, Hunan, P.R. China.
PLoS One. 2014 Sep 25;9(9):e108765. doi: 10.1371/journal.pone.0108765. eCollection 2014.
Photochemical treatment is increasingly being applied to remedy environmental problems. TiO2-derived catalysts are efficiently and widely used in photodegradation applications. The efficiency of various photochemical treatments, namely, the use of UV irradiation without catalyst or with TiO2/graphene-TiO2 photodegradation methods was determined by comparing the photodegadation of two main types of hydrophobic chlorinated aromatic pollutants, namely, pentachlorophenol (PCP) and polychlorinated biphenyls (PCBs). Results show that photodegradation in methanol solution under pure UV irradiation was more efficient than that with either one of the catalysts tested, contrary to previous results in which photodegradation rates were enhanced using TiO2-derived catalysts. The effects of various factors, such as UV light illumination, addition of methanol to the solution, catalyst dosage, and the pH of the reaction mixture, were examined. The degradation pathway was deduced. The photochemical treatment in methanol soil washing solution did not benefit from the use of the catalysts tested. Pure UV irradiation was sufficient for the dechlorination and degradation of the PCP and PCBs.
光化学处理正越来越多地应用于解决环境问题。二氧化钛衍生的催化剂在光降解应用中得到了有效且广泛的使用。通过比较两种主要类型的疏水性氯化芳香污染物，即五氯苯酚（PCP）和多氯联苯（PCBs）的光降解情况，确定了各种光化学处理的效率，即无催化剂的紫外线照射或二氧化钛/石墨烯 - 二氧化钛光降解方法。结果表明，在纯紫外线照射下甲醇溶液中的光降解比所测试的任何一种催化剂都更有效，这与之前使用二氧化钛衍生催化剂提高光降解速率的结果相反。研究了各种因素的影响，如紫外线照射、向溶液中添加甲醇、催化剂用量以及反应混合物的pH值。推导了降解途径。甲醇土壤洗涤溶液中的光化学处理并未因所测试的催化剂而受益。纯紫外线照射足以使PCP和PCBs脱氯和降解。
