Mineralization of antibiotic sulfamethoxazole by photoelectro-Fenton treatment using activated carbon fiber cathode and under UVA irradiation
Mineralization of antibiotic sulfamethoxazole by photoelectro-Fenton treatment using activated carbon fiber cathode and under UVA irradiation
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使用活性碳纤维阴极和 UVA 照射下光电芬顿处理矿化抗生素磺胺甲恶唑
DOI：
10.1016/j.apcatb.2010.12.007
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发表时间：
2011-02-22
影响因子：
22.1
通讯作者：
Estrada, Adriana Ledezma
中科院分区：
文献类型：
--
作者：
Wang, Aimin;Li, Yu-You;Estrada, Adriana Ledezma
采用活性炭纤维（ACF）阴极，UVA（365 nm）照射，研究了浓度高达300 mg L-1的抗生素磺胺甲恶唑（SMX）的光电-Fenton（PEF）矿化作用。比较矿化研究了不同的方法：RuO 2/Ti阳极氧化（AO）。AO在电生H_2O_2存在下（AO-H_2 O_2），AO-H_2 O_2在UVA存在下（AO-H_2 O_2-UVA），以及电芬顿（EF）和PEF过程。在0.36 A的低施加电流下的PEF处理产生更快和更完全的去污染，在6小时的电解后去除80%的TOC。PEF工艺的较高氧化能力可归因于由光芬顿反应产生的额外羟基自由基（中心点OH）。在EF处理的情况下，63%的矿化是由于形成了短的中间体，如羧酸，这是难以氧化的中心点OH。在AO-H2 O2-UVA工艺中，约36%的TOC被去除后6小时，而在AO-H2 O2工艺中TOC被去除28%。通过AO工艺，SMX仅轻微矿化，仅去除25%的TOC。HPLC-MS分析允许在PEF工艺中SMX降解期间鉴别多达6种芳香族反应产物，主要由芳香环或/和异恶唑环的羟基化形成，伴随着中心点OH取代胺基（芳香环上）或甲基（异恶唑环上）。生成的羧酸，包括草酸，马来酸，草氨酸，甲酸和乙酸，通过离子排斥色谱检测。初始有机氮主要转化为NH 4+，沿着转化为NO3-。考虑到SMX在PEF过程中降解的所有氧化中间体和最终产物，提出了中心点OH和UVA的一般矿化机制。(C)2010年爱思唯尔BM。All rights reserved.
The mineralization of antibiotic sulfamethoxazole (SMX) of concentrations up to 300 mg L-1 was examined by photoelectro-Fenton (PEF) using an activated carbon fiber (ACF) cathode with UVA (365 nm) irradiation. Comparative mineralization has been studied by different methods: RuO2/Ti anodic oxidation (AO). AO in the presence of electrogenerated H2O2 (AO-H2O2), AO-H2O2 in the presence of UVA (AO-H2O2-UVA), and both the electro-Fenton (EF) and PEF processes. PEF treatment at a low applied current of 0.36 A yields a faster and more complete depollution with 80% of the TOC removed after 6 h of electrolysis. The higher oxidative ability of the PEF process can be attributed to the additional hydroxyl radicals (center dot OH) produced by the photo-Fenton reaction. The 63% mineralization in the case of EF treatment was due to the formation of short intermediates, such as carboxylic acids, which were difficult to oxidise with center dot OH. In the AO-H2O2-UVA process, about 36% of the TOC was removed after 6 h electrolysis, while 28% of the TOC was removed in the AO-H2O2 process. SMX is only slightly mineralized by the AO process, with only 25% of the TOC removed. HPLC-MS analysis allowed for up to six aromatic reaction products to be identified during the SMX degradation in the PEF process, mainly formed from the hydroxylation of the aromatic ring or/and isoxazole ring, accompanied by the substitution of the amine group (on aromatic cycle) or methyl group (on isoxazole ring) by center dot OH. The carboxylic acids generated, including oxalic, maleic, oxamic, formic and acetic acids, were detected by ion-exclusion chromatography. The initial organic nitrogen was mainly converted into NH4+ along with a very small proportion of NO3- ion. Considering all the oxidation intermediates and end products for SMX degradation in the PEF process, a general mineralization mechanism by center dot OH and UVA was proposed. (C) 2010 Elsevier BM. All rights reserved.