掺杂型纳米MnO_2/Al_2O_3催化剂的制备及催化臭氧化处理驱油污水二级出水

Preparation of Doped Nano-MnO_2/Al_2O_3 Catalyst and Catalytic Ozonation of Secondary Effluent of Oil Extraction Wastewater for Advanced Treatment

以Al2O3为载体,制备了掺杂型纳米Mn O2/Al2O3催化剂,考查了最佳制备条件;研究了臭氧催化氧化法处理驱油废水二级生化处理出水的效果及其影响因素。结果表明,制备的纳米Mn O2催化剂的XRD谱图中可以明显看到α-Mn O2的衍射峰;动态光散射仪（DLS）分析表明纳米Mn O2的粒度主要分布在80~180 nm之间,从XRD、扫描电镜（SEM）和透射电镜（TEM）表征可知。α-Mn O2主要呈球形,其直径在25~50 nm之间;催化剂的比表面积达到157.48 m2·g-1。催化剂的最佳焙烧温度和焙烧时间分别为550℃和4 h;活性组分含量为6%时,Mn O2/Al2O3催化剂的催化活性最强.当进水COD为100~120 mg·L-1、Mn O2/Al2O3催化剂的投量为70 mg·L-1、臭氧投量为240 mg·h-1,催化臭氧氧化30 min时,有机物的去除率达到55%以上,出水COD指标满足《污水综合排放标准》一级A标准。·OH氧化在臭氧催化氧化降解有机污染物体系中起主导作用,其平均产生速率为30.84μmmol·L-1·min-1。制备的掺杂型纳米Mn O2/Al2O3催化剂具有制备方法简单、催化效率高、使用寿命长、二次污染小等优点。

A doped nano-MnO2/Al2O3 catalyst was prepared by using Al2O3 as cartier and the preparation conditions were optimized. Catalytic ozonation of secondary effluent in oil extraction wastewater plant was investigated by using the nano-MnO2/Al2O3 catalyst. The crystal structure of nano-MnO2 indicates that diffraction peak of a-MnO2 is found obviously according to XRD analysis. The nanoparticles size mainly ranges from 80 to 180 nm according to dynamic light scattering （DLS） analysis. According to the analysis of X-ray diffraction （ XRD）, scanning electron microscopy （SEM） and transmission electron microscopy （TEM）, Nano-sized a-MnO2 is mainly composed of spherical particles with a diameter of 80-180 nm. The specific surface area of the catalyst reaches 157.48 m2·g-1 and the optimal calcination temperature and time is 550℃and 4 h, respectively. The catalytic activity of the catalyst is highest when the nanoMnO2 content is 6%. The removal rate of COD is higher than 55% within 30 min under the condition of catalyst dose of 70 mg · L-1 and ozone dose of 240 mg· h-1 when the influent COD was 100-120 mg ·L-1. The effluent can meet demand of the Integrated Wastewater Discharge Standard, China. · OH plays a leading role in the degradation of organic pollutants with an average ·OH production rate of 30. 84 μmmol/（ L · min）. The prepared MnO2/ methods, long work life, high catalytic effici Al2O3 catalyst possesses the advantages of simple preparation ency and low secondary pollution.