ClO_2-CuO@蒙脱土催化氧化降解土壤中的蒽

Degradation of anthracene-contaminated soil by ClO_2-CuO@montmorillonite catalytic oxidation process

采用尿素水解法制备了CuO-蒙脱土复合材料,XRD和IR表明制备的CuO-蒙脱土复合材料同时存在CuO和蒙脱土两种物质。TEM表明对CuO-蒙脱土复合材料中CuO纳米颗粒的直径为4~5 nm,均匀分散在蒙脱土片层上。使用CuO-蒙脱土作为二氧化氯（ClO_2）氧化的催化剂,研究了ClO_2-CuO@蒙脱土催化氧化降解土壤中蒽的效果。结果表明,土壤中蒽污染物浓度为89.8 mg·kg-1时,最佳条件为25℃、水土比为3、污染土壤初始pH 7、ClO_2用量为1.0 mol·kg-1、CuO-蒙脱土用量为1 g·kg-1、反应时间30 min,此时,土壤中蒽的降解率可达到90%以上。ClO_2-CuO@蒙脱土催化氧化降解土壤中蒽的反应动力学对ClO_2浓度符合一级反应动力学,反应过程中产生活性·OH,提高了蒽降解的效率。

CuO-montmorillonite was prepared using urea hydrolysis. X-ray diffraction（ XRD） and Infrared Spectroscopy（ IR） showed the presence of CuO and montmorillonite in CuO-montmorillonite,while TEM indicated that 4-5 nm CuO nanoparticles were dispersed uniformly on the lamella of montmorillonite. CuO-montmorillonite was used as the catalyst for ClO_2 oxidative degradation of anthracene-contaminated soil. The optimum operating parameters for ClO_2-CuO@ montmorillonite catalytic oxidation degradation of anthracene-contaminated soil were as follows： anthracene concentration 89. 9 mg·kg-1,25 ℃,water to soil ratio 1 ∶ 3,initial pH 7,ClO_2 concentration 1 mol·kg-1,CuO-montmorillonite dosage 1 g·kg-1,and reaction time 30 min. Anthracene degradation efficiency reached over 90%. Kinetic studies revealed that ClO_2 catalytic oxidation degradation of anthracene-contaminated soil with CuO-montmorillonite as a catalyst followed pseudo-first-order kinetics with respect to ClO_2 concentration. In addition,strongly oxidizing hydroxyl radicals was produced during ClO_2-CuO @montmorillonite catalytic oxidation,which improved the efficiency of anthracene degradation in contaminated soil.