【作者】 王梓松；

【导师】 曾光明； 余健；

【作者基本信息】 湖南大学 ， 环境工程， 2008， 硕士

【摘要】 双酚A(BPA)是典型的内分泌干扰物,诸多研究表明BPA在试管试验与活体试验中均表现出对动物体急性毒性和对生殖、胚胎、神经系统发育的内分泌干扰影响,由于其在现代工业中的广泛应用,可以经由各种途径污染地表水体和地下水体,而地表水又是目前饮用水的重要水源之一,因而可能通过饮用水途径使人类遭受直接或潜在的暴露风险。更有研究表明,即使采用了氯氧化甚至臭氧氧化工艺,一些水厂的出厂水中仍有双酚A检出,由此对现有的饮用水常规和深度处理技术提出了新的挑战。本论文分别探讨了BPA在饮用水常规处理及常用工艺过程中的行为与归趋,具体为以下三个方面:在饮用水混凝过程中的行为特征、在活性炭处理工艺中的吸附行为、在臭氧消毒过程中的氧化降解规律,以期为客观评价BPA在饮用水净化工艺过程中的转化、归趋以及有效控制饮用水体中这类有机物的污染提供理论依据。以聚合氯化铝(PAC)作为混凝剂,探讨了双酚A(BPA)在模拟水体混凝过程中的去除效果和混凝特征。结果表明,在较低TOC浓度和浊度条件下,随着PAC投加量的增加,BPA的去除效果呈先上升后下降的趋势,本实验条件下最优的混凝剂投量约为BPA/PAC=1:2.6(质量比)。值pH值6.0~8.0时,混凝对BPA有相对较好的去除率,此时水体中铝盐多核络合物的电中和是混凝的主要作用机理。原水中的腐殖酸类有机物和浊度物质对BPA的混凝过程有较大的影响,较高浓度的腐殖酸类物质会削弱PAC对BPA的混凝效果,而随着浊度的提高,BPA的去除率呈先上升后下降的趋势。通过模拟实验,考察活性炭吸附BPA的速度,BPA活性炭吸附等温线的测定与绘制,并就溶液pH、吸附温度、溶液离子强度以及吸附质粒径等对吸附过程中BPA行为机制有较大影响的控制条件进行了逐个深入探讨。并就活性炭对BPA的吸附动力学及模型做了初步归纳。发现二级模型可以很好地描述整个吸附过程,说明活性炭对BPA的吸附以化学吸附为主。本文还考察了在饮用水臭氧消毒环境下BPA在臭氧直接作用下的氧化降解过程及机理,运用现代波谱分析手段对降解产物及途径进行了初步分析。并对影响BPA臭氧降解的主要影响条件做了探讨。研究论证了臭氧无法完全降解BPA,只能是将其氧化为某些混合副产物,而这些降解产物浓度是随反应时间逐渐积累而增大的。更多还原

【Abstract】 It has been reported that BPA has estrogenic activity and acute toxicity toward aquatic organisms and human cultured cells (Nakagawa and Tayama, 2000). It has also been detected that the pollution of BPA can be created when using BPA to manufacture other compounds and products including releases from many current commodities. Because of BPA was widely used in the world,BPA can pollute the surface water and the groundwater through lots of ways.While the surface water is the most important water source of drinking water, the human race face the risk to be direct or indirect exposed under BPA. And as some report,even employed the chlorination and ozonization during the drinking water treatment,BPA can still be detected in the outlet.Thereout the drinking water conventional treatment confront the new challenge.In this study, three typical behaviors of BPA in drinking water conventional treatment was investigated including: behavior in PAC coagulation, adsorption behavior on active carbon, degradation in aqueous medium by ozone.The goal of this study is to objective assessment the transformation and fate of BPA during the drinking water conventional treatment.So that to provide the theoretical base for effective controlling the EDCs in drinking water.Jar tests were performed to test the removel efficiency of BPA and the coagulating properties in water coagulation process with polyaluminum chloride (PAC) as coagulant. When the concentration of organic matter and turbidity was low in the solution, the experimental results showed that the removal of BPA increased firstly and subsequently decreased with the PAC dosage increasing. That means we can find the optimal PAC dosage theoretically, and the optimal PAC dosage is found at BPA/PAC=1:2.6(M/M) at our experiment conditions. It is found that BPA could be removed by PAC coagulation fairly efficiently at pH 6.0~8.0, attributed to the charge-neutralizing mechanism by polynuclear aluminous salts in the solution. The humic matters and the turbidity matters in the solution have significant effect on BPA removal by PAC coagulation. The BPA removal will be weakened at high humic matters .And the removal rate of BPA increased firstly and subsequently decreased with the turbidity increasing.The adsorption capacity , adsorption kinetics and impact factors of endocrine disrupting chemicals ( EDCs) bisphenol A (BPA) in water on granular activated carbon (GAC) were investigated in this study. The results showed that high BPA adsorption capacity could be achieved by GAC. Moreover, the experiment results of adsorption isotherm fitted Freundlich model.The variation of adsorption capacity was influenced by particle diameter of GAC. By the comparison between different adsorption kinetics, it could be drawn that pseudo second order model could be used to simulate the adsorption process effectively.This study investigated the process and the mechanism of BPA degradation in aqueous medium by ozone.The modern spectroscopy was employed to analysis the degradation product and degradation pathway.The influence factor include ozone dosage, initial concentration, ozonation time and ozone adding time was investigated. Result of experiment shows ozonation can not make BPA total degradated but only some mixture of byproduct .And the concentration of this byproduct is cumulated during the reaction time.更多还原