非均相UV/Fenton氧化法降解水中六氯苯的研究
Degradation of hexachlorobenzene by heterogeneous UV/Fenton reaction
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摘要: 采用超声辐照促进浸渍法制备了非均相UV/Fenton催化剂Fe/Al2O3，并对其进行了表征。以制备的催化剂对水中六氯苯进行非均相UV/Fenton法氧化降解。考察了铁的负载量、初始pH、H2O2投加量、催化剂投加量和反应时间对六氯苯降解效果的影响，并探讨了六氯苯的降解动力学规律。结果表明，制备的催化剂表面活性组分分散均匀，对六氯苯具有较高的催化活性和重复利用性。非均相UV/Fenton法降解六氯苯的最佳实验条件为：铁的负载量为2%，废水初始pH为3，H2O2和Fe/Al2O3催化剂的投加量分别为34 mg/L和150 mg/L，反应时间为20 min。在此条件下，浓度为500 μg/L的六氯苯降解效率达94.5%。HCB的降解反应动力学规律可用Langmuir-Hinshwood方程很好地描述。六氯苯在催化剂表面的吸附常数为1.962 L/mg，表面反应速率常数为0.08 mg/（L·min）。Abstract: Heterogeneous UV/Fenton catalysts Fe/Al2O3 were prepared by ultrasonic-assisted impregnation and characterized by means of SEM and EDS. Hexachlorobenzene (HCB) in water was degraded by heterogeneous UV/Fenton reaction. Effects of iron-loaded amount, initial pH, H2O2 concentration, catalysts dosage and reaction time on degradation efficiency of HCB were investigated. Degradation kinetics of HCB was discussed, too. The results show that iron is dispersed on the surface of the catalysts uniformly. The catalyst has high activity for HCB and can be reused. The optimal conditions of operation were determined as follows: Iron-loaded amount 2%, initial pH 3, H2O2 dosage 34 mg/L, catalysts dosage 150 mg/L, reaction time 20 min. Under the optimal conditions, degradation efficiency of HCB can reach 94.5%. The degradation kinetics of HCB conformed to Langmuir-Hinshwood equation. The adsorption constant and the reaction rate constant are 1.962 L/mg and 0.08 mg/(L·min) respectively.
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Key words:
- catalyst /
- UV/Fenton /
- hexachlorobenzene /
- kinetics /
- heterogeneous reaction
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