Velásquez Marizú, Santander I Paola, Contreras David R, Yáñez Jorge, Zaror Claudio, Salazar Ricardo A, Pérez-Moya Montserrat, Mansilla Héctor D
a Facultad de Ciencias Químicas , Universidad de Concepción , Casilla , Concepción , Chile.
J Environ Sci Health A Tox Hazard Subst Environ Eng. 2014;49(6):661-70. doi: 10.1080/10934529.2014.865447.
This article presents experimental results on 47 μmol L(-1) sulfathiazole (STZ) degradation by Fenton and photo-Fenton reactions using multivariate analysis. The optimal experimental conditions for reactions were obtained by Response Surface Methodology (RSM). In the case of the Fenton reactions there were 192 μmol L(-1) ferrous ions (Fe(II)) and 1856 μmol L(-1) hydrogen peroxide (H2O2), as compared with 157 μmol L(-1) (Fe(II)) and 1219 μmol L(-1) (H2O2) for photo-Fenton reactions. Under these conditions, around 90% of STZ degradation were achieved after 8 minutes treatment by Fenton and photo-Fenton reactions, respectively. Moreover, a marked difference was observed in the total organic carbon (TOC) removal after 60-min treatment, achieving 30% and 75% for the Fenton and photo-Fenton reactions, respectively. Acetic, maleic, succinic and oxamic acids could be identified as main Fenton oxidation intermediates. A similar pattern was found in the case of photo-Fenton reaction, including the presence of oxalic acid and ammonia at short periods of irradiation with UV-A. The calculated values of Average Oxidation State (AOS) corroborate the formation of oxidized products from the initial steps of the reaction.
本文采用多变量分析方法，展示了通过芬顿反应和光芬顿反应降解47μmol L⁻¹磺胺噻唑（STZ）的实验结果。反应的最佳实验条件通过响应面法（RSM）获得。在芬顿反应中，亚铁离子（Fe(II)）浓度为192μmol L⁻¹，过氧化氢（H₂O₂）浓度为1856μmol L⁻¹；相比之下，光芬顿反应中Fe(II)浓度为157μmol L⁻¹，H₂O₂浓度为1219μmol L⁻¹。在这些条件下，芬顿反应和光芬顿反应分别处理8分钟后，STZ的降解率均达到约90%。此外，在60分钟处理后，观察到总有机碳（TOC）去除率存在显著差异，芬顿反应和光芬顿反应分别达到30%和75%。乙酸、马来酸、琥珀酸和草氨酸可被鉴定为主要的芬顿氧化中间体。在光芬顿反应中也发现了类似的模式，包括在UV-A短时间照射下存在草酸和氨。平均氧化态（AOS）的计算值证实了反应初始步骤中氧化产物的形成。
