Si-FeOOH/H2O2类芬顿降解盐酸四环素废水的效能及其机理

摘要

采用碱沉法制备的Si-FeOOH作为非均相类芬顿催化剂，研究其催化降解盐酸四环素废水的效能，考察了催化剂投量、pH、过氧化氢加入量对盐酸四环素降解效能和反应速率的影响。实验结果表明：在催化剂投加量3.0 g·L−1、H2O2投加量9.9 mmol·L−1、pH为3、室温[(25±1)℃]的条件下，盐酸四环素降解率为90%，一级反应速率常数为0.0504 min-1。与催化剂FeOOH相比，类芬顿催化剂Si-FeOOH性能更卓越。同时采用探针化合物正丁醇、苯醌，证明了Si-FeOOH /H2O2催化体系中的氧化活性种主要为羟基自由基（·OH）和超氧自由基（HO2·），并推测了其催化反应机理。%The performance of Si-FeOOH, as a type of Fenton-like heterogeneous catalyst made by alkaline precipitation methods, was evaluated with degrading tetracycline hydrochloride (TH) in wastewater and reaction condition including catalyst loading, pH and hydrogen peroxide dosage examined. The results show that the degradation rate of tetracycline hydrochloride can reach up to 90% and the reaction rate 0.0504 min−1 at catalyst loading 3.0 g·L−1, H2O2 dosage 9.9 mmol·L−1, pH 3 and temperature (25±1)℃. A comparison with FeOOH catalyst indicates that Fenton-like Si-FeOOH is better than FeOOH. Various contaminants and probe compounds (n-butanol, benzoquinone) were used to identify the active species involved in the catalytic system. The results revealed that the hydroxyl radicals (·OH) and superoxide radical (HO2·) may be responsible for the degradation of tetracycline hydrochloride (TH). The possible catalytic oxidation mechanism was also discussed. The use of Si-FeOOH /H2O2 system may be a feasible approach for the elimination of widely existing pollutants.