【作者】 樊慧菊；

【导师】 张立秋；

【作者基本信息】 北京林业大学 ， 生态环境工程， 2014， 博士

【摘要】 随着仪器分析技术的不断发展,环境中的药物污染物逐渐被检出,某些药物的危害具有潜在性和长期性的特点,因此受到广泛关注。本论文主要考察模拟市政污水中药物污染物在膜生物反应器(MBR)工艺中的去除情况,研究pH, SRT等操作条件对药物去除效果的影响,通过静态实验确定污泥吸附和生物降解对药物去除贡献；重点研究PAC强化MBR工艺对难生物降解药物污染物的去除情况,对比考察两工艺对药物去除过程中污泥特性以及微生物群落结构的变化,探讨PAC-MBR工艺对药物类污染物的强化去除机制。研究结果表明,MBR工艺对初始浓度为5μg/L的酰胺咪嗪,双氯芬酸钠,萘普生,17β-雌二醇以及扑热息痛的去除率分别为3.2%,38.5%,55.4%,90%和92.2%,MBR工艺对目标药物的去除率产别较大。进水pH值会影响药物在水中的存在形态,影响药物与污泥之间的静电作用,进而影响药物的去除率,较长的污泥龄(SRT)有利于提高药物的去除率。通过污泥的静态吸附试验得到,灭活污泥对上述五种目标药物的去除率分别为71.5%,40.1%,60.1%,68.2%和7.9%,研究发现污泥对药物的吸附去除率与药物的辛醇水分配系数成正比。污泥的吸附生物降解规律表明,扑热息痛、雌二醇和萘普生的去除主要由生物降解完成的,双氯芬酸钠的去除主要是依赖生物吸附,而两种去除作用都不能有效的将酰胺咪嗪去除,药物的理化性质,特别是表面官能团(如吸电子基团/给电子基团)对其生物降解具有较大影响。PAC强化MBR去除药物污染物的试验结果表明,PAC-MBR工艺对初始浓度为200μg/L的酰胺咪嗪、萘普生、新诺明和双氯芬酸的去除率较MBR分别提高22%,12%,19%和14%。PAC强化MBR反应器内污泥耗氧速率提高了近20%,有利于药物的生物降解去除；污泥的粒径较MBR小,比表面积较大,有利于对药物的吸附去除。在两种处理工艺中,溶解性微生物副产物、腐殖酸类物质和芳香族类蛋白质是污泥胞外聚合物(EPS)的主要组成成分,但是其含量不同,蛋白质与多糖的比例不同。通过对两处理工艺中微生物群落结构的变化分析得到,在开始阶段两反应器内微生物种类单一,并且差异较小,运行八个月时,微生物的种类增加并且两工艺中微生物种类差异变得明显,在PAC-MBR工艺出现了药物降解菌,说明PAC的加入不仅起到吸附药物的作用,还能够改变污泥的性质,使微生物多样性增加,从而进一步提高对药物的去除效果。通过对目标药物生物降解产物的结构分析,发现给电子基团易于被氧化,形成含氧官能团；吸电子基团由于与其周围的原子或原子团产生共轭作用,与吸电子基团相连但又不产生共轭作用的化学键易于断裂。更多还原

【Abstract】 With the development of instrumental analysis techniques, pharmaceutical pollutants were gradually detected and drew attention due to its potential, long-term, harmful characteristics.The aim of this study are to investigate the removal efficiencies of five Pharmaceuticals from synthetic domestic wastewater under different influent pH and SRT condition in the membrane bioreactor (MBR).Batch experiments were conducted to explore the contributions of sludge adsorption and biodegradation for pharmaceuticals removal.PAC enhanced MBR was used to investigate the persistent pharmaceuticals removal efficiencies. In this process, sludge characteristics and microbial communitywerecompared with the MBR process. And the mechanism of pharmaceuticals removal in the PAC enhanced MBR were demonstrate.Notable difference of those pharmaceuticals removal efficiencies was observed, at about92.2,90.0,55.4,38.5and3.2%for acetaminophen,17β-Estradiol, naproxen, diclofenac sodium and carbamazepine, respectively. The form of pharmaceuticals exit and the electronic attraction between pharmaceuticals and sludge were influenced by influent pH. And it influented the pharmaceuticals removal. Higher removal efficiencies were obtained at the extened SRTcondition. Results of batch adsorption experiments via sterilized sludge showed that the removal efficiencies of five pharmaceuticals by sludge adsorption were7.9,68.2,60.1,40.1and71.5%, respectively, which were positively correlated with their octanol-water partition coefficients. Results of batch experiments via activated sludge showed that acetaminophen,17β-Estradiol and naproxenwere mainly achieved by biodegradation, diclofenac sodium was mainly achieved by sludge adsorption and neither sludge adsorption nor biodegradation is effective for its removal. Pharmaceuticals properties taken effect on its removal, especially, functional groups (electronic donating group/electronic withdrawing group) mainly affect their biodegradation removals.Powdered activated carbon (PAC) enhancedMBR on pharmaceuticals removal exhibited higher average removal efficiencies for carbamazepine, diclofenac sodium, naproxen and sulfamethoxazole about22%,12%,19%and14%than the one without PAC.In the PAC enhanced MBR, specific oxygen uptake rate was20%higher than the MBR, which benefit the pharmaceuticals removal.Particle size distribution was lower than the MBR which exhibit larger specific surface area and favored for pharmaceuticals removal.Soluble microbial byproducts, humic substances and aromatic protein were the main components of sludge extracellular polymeric substances (EPS). But the content and proportions of protein and polysaccharide were differentbetween the two processes. Microbial communities of the two processwere analyzed. At the beginning, the microbial species of the two systems were similar. After eight months of the operation, microbial species in both two processed increased and more pharmaceuticals biodegradation bacterium such as sulfamethoxazole biodegradation bacterium were found in the PAC-MBR process. Therefore the pharmaceuticals removal efficiencies were improved.The products of pharmaceuticals in contact with activated sludge were investigated, and results showed that the electronic donating groups are readily oxidizable functional groups. The electronic withdrawing groups break weak bonds.更多还原