Department of Chemical Engineering, McGill University, Montreal, Quebec, Canada.
J Hazard Mater. 2011 Feb 15;186(1):67-75. doi: 10.1016/j.jhazmat.2010.10.080. Epub 2010 Oct 27.
In this study, photolytic and photocatalytic removal of the antibiotic sulfamethoxazole (SMX) under UVC radiation (λ=254 nm) was investigated. The light intensity distribution inside the batch photoreactor was characterized by azoxybenzene actinometry. The intensity of incident radiation was found to be a strong function of position inside the reactor. 12 mg L(-1) of SMX was completely removed within 10 min of irradiation under UVC photolysis, compared to 30 min under TiO(2) photocatalysis. COD measurement was used as an indication of the mineralization efficiency of both processes and higher COD removal with photocatalysis was shown. After 6h of reaction with photolysis and photocatalysis, 24% and 87% removal of COD was observed, respectively. Two of the intermediate photo-products were identified as sulfanilic acid and 3-amino-5-methylisoxazole by direct comparison of the HPLC chromatograms of standards to those of treated solutions. Ecotoxicity of treated and untreated solutions of SMX towards Daphnia magna was also investigated. It was found that a 3:1 ratio of sample to standard freshwater and a high initial concentration of 60 mg L(-1) of SMX were used to obtain reliable and reproducible results. The photo-products formed during photocatalytic and photolytic processes were shown to be generally more toxic than the parent compound.
在这项研究中，研究了在 UVC 辐射（λ=254nm）下光解和光催化去除抗生素磺胺甲恶唑（SMX）的情况。通过偶氮苯动力学法对间歇式光反应器内的光强分布进行了表征。结果发现，入射辐射的强度是反应器内部位置的强函数。在 UVC 光解下，12mg/L 的 SMX 在 10 分钟内即可完全去除，而在 TiO2 光催化下则需要 30 分钟。COD 测量被用作两种工艺的矿化效率的指示，并且显示出光催化具有更高的 COD 去除率。在光解和光催化反应 6 小时后，分别观察到 24%和 87%的 COD 去除率。通过将标准的 HPLC 色谱图与处理后的溶液的 HPLC 色谱图进行直接比较，鉴定出两种中间光产物为磺胺和 3-氨基-5-甲基异恶唑。还研究了处理和未处理的 SMX 溶液对大型蚤的生态毒性。结果发现，使用 3:1 的样品与标准淡水比和 60mg/L 的初始高浓度可以获得可靠和可重复的结果。光催化和光解过程中形成的光产物通常比母体化合物毒性更大。
