纳米铁氧化物催化类Fenton反应降解抗生素磺胺

采用纳米铁矿物(赤铁矿α-Fe₂O₃、磁赤铁矿γ-Fe₂O₃、磁铁矿Fe₃O₄、水铁矿Fe₅HO₈·4H₂O)为催化剂与H₂O₂构成类Fenton反应,进行抗生素磺胺的氧化降解研究,并考察磺胺初始浓度、铁氧化物投加量、H₂O₂浓度、溶液pH等对磺胺氧化降解过程的影响。结果表明,磺胺初始浓度2 mg·L^-1、赤铁矿投加量1 g·L^-1、H₂O₂浓度30 mL·L^-1、溶液pH 3.6和温度25 ℃条件下,反应72 h后磺胺的降解率为99.27%。利用LC-MS进行产物分析,表明铁氧化物催化类Fenton反应降解磺胺主要是催化氧化反应,磺胺分子结构中的对位氨基被氧化成硝基。

Degradation of Antibiotic Sulfanilamide in Aqueous Solution via a Heterogeneous Fenton-like Reaction Catalyzed by Nano-Iron Oxides

Degradation of antibiotic sulfanilamide by a heterogeneous Fenton-like reaction was investigated using different nano- iron oxides(hematite, maghemite, magnetite, and ferrihydrite) as catalyst and hydrogen peroxide as oxidizing agent. The influences of initial sulfanilamide concentration, catalyst amount, H₂O₂ dose, and initial pH value on Fenton-like reaction were assessed. The optimal reaction conditions were 2 mg·L^-1 of initial sulfanilamide concentration, 1 g·L^-1 of catalyst, 30 mL·L^-1 of H₂O₂, and 3.6 of initial pH, and the degradation rate of sulfanilamide could reach 99.27% within 72 h. The degradation process of sulfanilamide by the Fenton-like reaction was mainly oxidation of -NH2 group to the -NO₂ via catalytic oxidation reaction.