Department of Chemical Engineering, University of Alcalá, 28871 Alcalá de Henares, Madrid, Spain.
Water Res. 2013 Oct 1;47(15):5546-56. doi: 10.1016/j.watres.2013.06.030. Epub 2013 Jun 25.
This study aims to assess the removal of a set of non-polar pollutants in biologically treated wastewater using ozonation, ultraviolet (UV 254 nm low pressure mercury lamp) and visible light (Xe-arc lamp) irradiation as well as visible light photocatalysis using Ce-doped TiO2. The compounds tracked include UV filters, synthetic musks, herbicides, insecticides, antiseptics and polyaromatic hydrocarbons. Raw wastewater and treated samples were analyzed using stir-bar sorptive extraction coupled with comprehensive two-dimensional gas chromatography (SBSE-CG × GC-TOF-MS). Ozone treatment could remove most pollutants with a global efficiency of over 95% for 209 μM ozone dosage. UV irradiation reduced the total concentration of the sixteen pollutants tested by an average of 63% with high removal of the sunscreen 2-ethylhexyl trans-4-methoxycinnamate (EHMC), the synthetic musk 7-acetyl-1,1,3,4,4,6-hexamethyltetrahydronaphthalene (tonalide, AHTN) and several herbicides. Visible light Ce-TiO2 photocatalysis reached ~70% overall removal with particularly high efficiency for synthetic musks. In terms of power usage efficiency expressed as nmol kJ(-1), the results showed that ozonation was by far the most efficient process, ten-fold over Xe/Ce-TiO2 visible light photocatalysis, the latter being in turn considerably more efficient than UV irradiation. In all cases the efficiency decreased along the treatments due to the lower reaction rate at lower pollutant concentration. The use of photocatalysis greatly improved the efficiency of visible light irradiation. The collector area per order decreased from 9.14 ± 5.11 m(2) m(-3) order(-1) for visible light irradiation to 0.16 ± 0.03 m(2) m(-3) order(-1) for Ce-TiO2 photocatalysis. The toxicity of treated wastewater was assessed using the green alga Pseudokirchneriella subcapitata. Ozonation reduced the toxicity of treated wastewater, while UV irradiation and visible light photocatalysis limited by 20-25% the algal growth due to the accumulation of reaction by-products. Three transformation products were identified and tracked along the treatments.
本研究旨在评估臭氧化、紫外线（UV254nm 低压汞灯）和可见光（氙弧灯）辐照以及使用 Ce 掺杂 TiO2 的可见光光催化对经生物处理废水的一组非极性污染物的去除效果。跟踪的化合物包括紫外线滤光剂、合成麝香、除草剂、杀虫剂、防腐剂和多环芳烃。使用搅拌棒吸附萃取结合全二维气相色谱（SBSE-CG×GC-TOF-MS）对原水和处理水样进行分析。臭氧处理可去除 209μM 臭氧剂量下的大多数污染物，总去除率超过 95%。紫外线照射使 16 种受测试污染物的总浓度平均降低了 63%，其中防晒剂 2-乙基己基反-4-甲氧基肉桂酸酯（EHMC）、合成麝香 7-乙酰基-1,1,3,4,4,6-六甲基四氢化萘（tonalide，AHTN）和几种除草剂的去除率较高。可见光 Ce-TiO2 光催化的总去除率达到~70%，对合成麝香的去除效率特别高。就以 nmol kJ(-1) 表示的功率使用效率而言，结果表明臭氧处理是迄今为止最有效的工艺，比 Xe/Ce-TiO2 可见光光催化效率高 10 倍，而后者又比紫外线照射效率高得多。在所有情况下，由于污染物浓度较低时反应速率较低，处理过程中的效率均降低。光催化的使用大大提高了可见光照射的效率。对于可见光照射，每阶的集光面积从 9.14±5.11 m(2) m(-3) 阶(-1) 降低到 Ce-TiO2 光催化的 0.16±0.03 m(2) m(-3) 阶(-1)。使用绿藻斜生栅藻评估处理后废水的毒性。臭氧处理降低了处理后废水的毒性，而紫外线照射和可见光光催化由于反应副产物的积累，限制了藻类生长 20-25%。在处理过程中鉴定并跟踪了三种转化产物。
