乔宇 吴明伟 石玉青 梁杰

摘  要： 根据催化氧化原理，利用4A分子筛为载体，次氯酸钠（NaClO）为氧化剂，通过硫酸锰（MnSO4）在其表面的原位氧化来制备对环境无害的锰氧化物（MnOx）改性的分子筛（MnOx@MS）材料.通过场发射扫描电镜（FE-SEM）和X射线衍射（XRD）对材料进行了表征.XRD分析表明：Mn元素是以MnOx形式存在，在pH为7.2时，反应得到的MnOx中Mn离子的价态最高.测试表明：Mn离子的价态越高对含酚废水的处理效果就越好.采用在最优条件下得到的MnOx@MS材料作为催化剂，对过氧化氢（H2O2）氧化降解含酚废水进行研究，考察了不同体系、温度、pH值和H2O2用量对苯酚降解的影响.结果表明：在优化的降解条件下，120 min内，未改性分子筛对苯酚的去除率仅为35%，而MnOx@MS改性材料对苯酚的去除率达到82%，说明通过MnOx改性后的分子筛，对苯酚的氧化降解能力大大提高.

关键词： 分子筛; 原位氧化; 锰氧化物（MnOx）; 降解; 含酚废水

中图分类号： O 69    文献标志码： A    文章编号： 1000-5137（2021）06-0706-08

Abstract： An environmentally safe manganese oxide （MnOx） modified molecular sieve （MnOx@MS） for the effective treatment of phenol containing wastewater was prepared via an in situ oxidation of manganese sulfate（MnSO4）on the surface of 4A molecular sieve with sodium hypochlorite （NaClO） as the oxidant. The materials were characterized by field emission scanning electron microscopy （FE-SEM） and X-ray diffraction （XRD）. XRD analysis showed that manganese was present in the form of manganese oxides. The manganese oxide had the highest valence state when the reaction pH was 7.2. The results showed that the higher the valence of manganese ion in manganese oxides， the better the treatment effect of phenolic wastewater was. The oxidative degradation of phenol-containing wastewater by hydrogen peroxide was studied using manganese oxide modified molecular sieve as the catalyst under the optimum preparation conditions. The effects of different systems， wastewater temperature， pH value of wastewater， and the amount of hydrogen peroxide on the degradation of phenol were investigated. The results showed that under the optimum degradation conditions of wastewater， within 120 min the removal rate of phenol by the unmodified molecular sieve was only 35%， while that of phenol by manganese oxide modified molecular sieve was 82%， indicating that the oxidative degradation performance of phenol by manganese oxide modified molecular sieve was greatly improved.

Key words： molecular sieve; in situ oxidation; manganese oxide（MnOx）; degradation; phenolic wastewater

0  引 言

隨着国家工业化的发展，生产化学试剂的同时排放了大量的有机废水，从而引发了一系列环境问题，含酚废水尤其突出，这类废水主要含有苯酚及其衍生物，对微生物具有较强的毒害作用[1-3].如果不经处理直接排放，则会对环境造成严重的污染[4].更重要的是，酚类物质一旦被人体皮肤吸收，会引起头疼、昏睡，甚至呼吸困难等症状[5].因此，关于含酚废水的污染和治理技术得到了广泛的关注.分子筛吸附是一种常用于处理含酚废水的方法.

由于4A分子筛具有多孔结构、较大的比表面积……