Bizani E, Lambropoulou D, Fytianos K, Poulios I
Environmental Pollution Control Laboratory, Chemistry Department, Aristotle University of Thessaloniki, 541 24, Thessaloniki, Greece,
Environ Sci Pollut Res Int. 2014 Nov;21(21):12294-304. doi: 10.1007/s11356-014-3086-2. Epub 2014 Jun 15.
In this study, the degradation of molinate through heterogeneous photocatalysis, using two different types of the semiconductor TiO2 as photocatalyst, as well as through homogeneous treatment, applying the photo-Fenton reaction, has been investigated. As far as heterogeneous photocatalysis is concerned, the degradation of the pesticide follows apparent first-order kinetics, while the type of the catalyst and the pH value of the solution affect the degradation rate. The effect of the addition of electron scavengers (H2O2 and K2S2O8) was also studied. In the case of photo-Fenton-assisted system, the degradation also follows pseudo-first-order kinetics. Parameters such as iron's and electron scavenger's concentration and inorganic ions strongly affect the degradation rate. The extent of pesticide mineralization was investigated using dissolved organic carbon (DOC) measurements. The toxicity of the treated solution was evaluated using the Microtox test based on the luminescent bacteria Vibrio fischeri. The detoxification and mineralization efficiency was found to be dependent on the system studied, and although it did not follow the rate of pesticide disappearance, it took place in considerable extent. The study of the photodegradation treatment was completed by the determination of the intermediate by-products formed during the process, which was carried out using LC-MS/MS technique and led to similar compounds with both processes.
在本研究中，已对使用两种不同类型的半导体二氧化钛作为光催化剂通过多相光催化降解禾草丹以及通过光芬顿反应进行均相处理来降解禾草丹展开了研究。就多相光催化而言，农药的降解遵循表观一级动力学，而催化剂类型和溶液的pH值会影响降解速率。还研究了添加电子清除剂（过氧化氢和过硫酸钾）的影响。在光芬顿辅助体系的情况下，降解同样遵循准一级动力学。铁和电子清除剂的浓度以及无机离子等参数会强烈影响降解速率。使用溶解有机碳（DOC）测量来研究农药矿化程度。基于费氏弧菌发光细菌，采用Microtox测试评估处理后溶液的毒性。发现解毒和矿化效率取决于所研究的体系，并且尽管其不遵循农药消失的速率，但在相当程度上发生了。通过使用LC-MS/MS技术测定过程中形成的中间副产物完成了光降解处理的研究，该技术导致两个过程产生类似的化合物。
