催化臭氧技术降解污水中抗生素类污染物的效能和原理研究

发布时间：2018-10-29 15:53

【摘要】：污水再生利用的研究可以有效的缓解我国水资源短缺的问题,催化臭氧氧化技术是一种高效的高级氧化技术,对污水中的大部分有机物有较好的降解效果,铁基催化剂因其分布广泛、催化效率高而备受重视。为了研究污水再生利用的深度处理新技术,自制了四种催化剂:负载铁的纳米二氧化硅小球(Fe-KCC-1)、Ce_(0.1)Fe_(0.9)OOH、纳米Fe_3O_4/MWCNTs、纳米Fe_3O_4-CeO_2/MWCNTs,并对其物化性质进行了表征。选取了磺胺二甲嘧啶(SMT)、邻苯二甲酸二甲酯(DMP)、卡马西平(CBZ)、对羟基苯甲酸(p-HBA)四种污染物和某生活污水厂的二级出水为研究对象,考察了各体系对污染物的降解率、矿化率及影响因素,并探讨了污染物的降解途径和催化剂的催化机理;另外本文耦合了催化臭氧和BAF技术,研究其对二级出水中有机物的降解效果。文中得到如下主要结论:1、利用同晶替代法制备了Ce_(0.1)Fe_(0.9)OOH,掺入金属铈不影响针铁矿原本的晶体结构;利用水热法制备了纳米Fe-KCC-1,具有较高的比表面积(464.56 m~2/g);采用共沉淀法制备了纳米Fe_3O_4/MWCNTs复合物,拥有超顺磁性;利用共沉淀法制备了纳米Fe_3O_4-CeO_2/MWCNTs复合物,长度粗细均匀,金属氧化物均匀分散在碳纳米管的表面。2、Fe-KCC-1-O_3体系对SMT矿化率是单独臭氧氧化的1.6倍,Ce_(0.1)Fe_(0.9)OOH-O_3体系对SMT矿化率是单独臭氧氧化的1.74倍;纳米Fe_3O_4/MWCNTs O_3体系对DMP和p-HBA的降解率也要高于单独臭氧氧化体系。3、催化臭氧氧化体系在一个广泛的pH范围内均表现出良好的催化氧化效果。臭氧用量、催化剂用量和污染物的初始浓度对抗生素的降解都有一定的影响。4、通过检测降解反应中间产物,提出了SMT、DMP、p-HBA在催化臭氧氧化体系中可能的降解途径;并通过考察自由基消除剂的影响以及对催化剂反应前后的表征分析,探讨了Fe-KCC-1-O_3体系、Ce_(0.1)Fe_(0.9)OOH-O_3体系和Fe_3O_4/MWCNTs O_3体系中自由基的产生机理,并根据相关分析提出了各种催化剂可能的催化机制。5、Fe_3O_4-CeO_2/MWCNTs O_3体系对城市二级出水中微量有机污染物有较好的去除效率,二级出水对SMT和CBZ在该体系下的降解影响不大;催化臭氧氧化耦合生物曝气滤池技术(BAF)组合工艺对污水的COD降解率达到60%以上。
[Abstract]:The study of wastewater recycling can effectively alleviate the shortage of water resources in China. Catalytic ozonation is an efficient advanced oxidation technology, which has a good degradation effect on most of the organic matter in sewage. Iron-based catalysts have attracted much attention because of their wide distribution and high catalytic efficiency. In order to study the new advanced treatment technology for wastewater reuse, four kinds of catalysts were prepared: iron loaded nano-silica pellet (Fe-KCC-1) and Ce_ _ (0.1) Fe_ _ (0.9) OOH, nanocrystalline Fe_3O_4/MWCNTs,. The physicochemical properties of nano Fe_3O_4-CeO_2/MWCNTs, were characterized. Four pollutants of sulfadimethazine (SMT), dimethyl phthalate (DMP), carbamazepine (CBZ), p-hydroxybenzoic acid (p-HBA), and secondary effluent from a domestic wastewater plant were selected as the research object. The degradation rate, mineralization rate and influencing factors of each system were investigated, and the degradation pathway of pollutants and the catalytic mechanism of catalyst were discussed. In addition, the catalytic ozone and BAF techniques were coupled to study the degradation of organic matter in secondary effluent. The main conclusions are as follows: 1. Ce_ _ (0.1) Fe_ _ (0.9) OOH, doped with cerium has no effect on the crystal structure of goethite. Nanocrystalline Fe-KCC-1, was prepared by hydrothermal method with high specific surface area (464.56 mm2 / g), and nanosized Fe_3O_4/MWCNTs composite with superparamagnetic property was prepared by coprecipitation method. Nanocrystalline Fe_3O_4-CeO_2/MWCNTs composites were prepared by coprecipitation method with uniform length and uniform metal oxides dispersed on the surface of carbon nanotubes. The mineralization rate of SMT in Fe-KCC-1-O_3 system was 1.6 times higher than that in ozonation alone, and that of SMT in Ce_ (0.1) Fe_ (0.9) OOH-O_3 system was 1.74 times higher than that in ozonation alone. The degradation rate of DMP and p-HBA in nano-sized Fe_3O_4/MWCNTs / O _ 3 system was also higher than that in the single ozonation system. 3. The catalytic ozonation system showed good catalytic oxidation effect in a wide range of pH. The amount of ozone, the amount of catalyst and the initial concentration of pollutants have certain influence on the degradation of antibiotics. 4. By detecting the intermediate products of degradation reaction, the possible degradation pathway of SMT,DMP,p-HBA in catalytic ozonation system is proposed. The influence of free radical scavenger and the characterization of the catalyst before and after the reaction were investigated, and the Fe-KCC-1-O_3 system was discussed. The mechanism of free radical production in Ce_ (0.1) Fe_ (0.9) OOH-O_3 system and Fe_3O_4/MWCNTs O _ 2O _ 3 system was studied. According to the correlation analysis, the possible catalytic mechanism of various catalysts was proposed. The Fe_3O_4-CeO_2/MWCNTs / C _ 2O _ 3 system has better removal efficiency for trace organic pollutants in the secondary outlet water, and the secondary effluent has little effect on the degradation of SMT and CBZ in this system. Catalytic Ozone Oxidation coupled Biological aeration filter (BFAF) the COD degradation rate of wastewater by (BAF) process is over 60%.
【学位授予单位】：中国地质大学(北京)
【学位级别】：博士
【学位授予年份】：2017
【分类号】：X703

【相似文献】