Woo O T, Chung W K, Wong K H, Chow Alex T, Wong P K
Department of Biology, The Chinese University of Hong Kong, Shatin, NT Hong Kong SAR, China.
J Hazard Mater. 2009 Sep 15;168(2-3):1192-9. doi: 10.1016/j.jhazmat.2009.02.170. Epub 2009 Mar 18.
Polycyclic aromatic hydrocarbons (PAHs) are hydrophobic pollutants and their low water solubility limits their degradation in aqueous solution. The presence of water-miscible solvent such as acetone can increase the water solubility of PAHs, however acetone will also affect the degradation of PAH. In this study the effects of acetone on the photocatalytic degradation efficiency and pathways of 5 selected PAHs, namely naphthalene (2 rings), acenaphthylene (3 rings), phenanthrene (3 rings), anthracene (3 rings) and benzo[a]anthracene (4 rings) were investigated. The Microtox toxicity test was used to determine whether the PCO system can completely detoxify the parental PAHs and its intermediates. The addition of 16% acetone can greatly alter the degradation pathway of naphthalene and anthracene. Based on intermediates identified from degradation of the 5 PAHs, the location of parental PAHs attacked by reactive free radicals can be correlated with the localization energies of different positions of the compound. For toxicity analysis, irradiation by UV light was found to induce acute toxicity by generating intermediates/degradation products from PAHs and possibly acetone. Lastly, all PAHs (10 mg l(-1)) can be completely detoxified by titanium dioxide (100 mg l(-1)) within 24h under UVA irradiation (3.9 mW cm(-2)).
多环芳烃（PAHs）是疏水性污染物，其低水溶性限制了它们在水溶液中的降解。与水混溶的溶剂（如丙酮）的存在可以增加PAHs的水溶性，然而丙酮也会影响PAH的降解。在本研究中，研究了丙酮对5种选定PAHs（即萘（2环）、苊烯（3环）、菲（3环）、蒽（3环）和苯并[a]蒽（4环））的光催化降解效率和途径的影响。使用Microtox毒性测试来确定光催化氧化（PCO）系统是否能使母体PAHs及其中间体完全解毒。添加16%的丙酮会极大地改变萘和蒽的降解途径。基于从5种PAHs降解中鉴定出的中间体，反应性自由基攻击母体PAHs的位置可以与化合物不同位置的定位能相关联。对于毒性分析，发现紫外线照射会通过产生PAHs以及可能的丙酮的中间体/降解产物而诱导急性毒性。最后，在UVA照射（3.9 mW cm(-2)）下，所有PAHs（10 mg l(-1)）在24小时内可被二氧化钛（100 mg l(-1)）完全解毒。
