The degradation of sulfamethoxazole (SMX) by a synthesized ZnO catalyst and under UVA irradiation was examined. ZnO nanostructures were developed by a facile hydrothermal-assisted method. The effect of ZnO heating time and synthesis reaction, pH, catalyst loading, and SMX initial concentration on process efficiency was studied. Water matrices, such as humic acid (HA) solution and surface water (SW), were also used to resemble real environmental water samples. It was observed that when ZnO is synthesized at pH 7.5, nanorods grow on its surface, while nanoplatelets are formed when synthesis takes place at pH 12.5. SMX removal reached 84% after 60 min of treatment in the presence of 200 mg/L ZnO catalyst (8 h-heated at pH 7.5; C₀ = 10 mg/L). The pseudo-first-order kinetic constants of SMX photodegradation were calculated at 0.039, 0.030 and 0.016 min⁻¹ for 5, 10, and 20 mg/L SMX, respectively. This decreased efficiency was attributed to the excessive coverage of catalyst surface by SMX molecules, evidenced by SEM micrographs produced after treatment. SMX degradation in SW (12.5%) was considerably lower than in UPW (47.4%) due to the presence of natural organic matter in the first. Interestingly, SMX removal was greatly enhanced in HA matrix (99%) and this can be attributed to the ability of HA to sensitize colloidal ZnO. In all cases, morphological changes of ZnO nanostructures were observed after photocatalytic treatment. It was confirmed that SMX degradation takes place through HO by adding HO quenchers, such as tert-butyl alcohol and methanol, in the reactant mixture.

研究了合成的ZnO催化剂在UVA照射下对磺胺甲恶唑（SMX）的降解。ZnO纳米结构是通过简便的水热辅助方法开发的。研究了ZnO加热时间和合成反应，pH，催化剂负载量和SMX初始浓度对工艺效率的影响。诸如腐植酸（HA）溶液和地表水（SW）之类的水基质也被用来模拟真实的环境水样。观察到当在pH 7.5合成ZnO时，纳米棒在其表面生长，而当在pH 12.5合成时形成纳米片。在200 mg / L ZnO催化剂存在下处理60分钟后，SMX去除率达到84％（在pH 7.5加热8 h； C ₀= 10 mg / L）。对于5、10和20 mg / L SMX，SMX光降解的拟一级动力学常数分别为0.039、0.030和0.016 min ^-1。该降低的效率归因于SMX分子对催化剂表面的过度覆盖，这由处理后产生的SEM显微照片证明。由于首先存在天然有机物，SW中的SMX降解（12.5％）大大低于UPW（47.4％）。有趣的是，在HA基质（99％）中SMX的去除得到了极大的增强，这可以归因于HA敏化胶体ZnO的能力。在所有情况下，光催化处理后均观察到ZnO纳米结构的形态变化。通过添加HO可以确定SMX降解是通过HO发生的反应混合物中的淬灭剂，例如叔丁醇和甲醇。