【作者】 赵永富；

【导师】 郑正；

【作者基本信息】 南京大学 ， 环境工程， 2012， 博士

【摘要】 邻苯二甲酸酯(Phthalic Acid Esters、PAEs)是一类水溶性低、生物富集性高,具有严重生殖毒性的环境内分泌干扰物。PAEs类物质有20多种,广泛存在于土壤、底泥、水体、生物、空气及大气沉降物等环境样品中,被美、日、欧及我国列为环境优先控制污染物之一。本文以DMP、DEP和DBP为对象,系统地研究了高能辐射法去除水中PAEs的降解效率、影响因素、辐射去除机理及其产物的生物毒性。主要实验结果如下：DMP、DEP和DBP均能被辐照有效降解。辐照功效GD与PAEs浓度有正相关关系,但随吸收剂量的增加呈指数下降；γ辐照比EB辐照能量利用率更高；不同气氛条件下辐照降解效率比较,充O2>饱和空气>充N2；降解反应常数在中等pH值(5-8)时最高,高pH(8-10)时有下降趋势,而低pH(2-4)时则迅速降低；不同类型PAEs辐照去除效率依次为DMP>DEP>DBP>DOP;DMP辐照降解反应皆遵循一级动力学关系(1n[C0/C]=kD,0-375mg/L, r>0.99);辐射降解反应主要以OH·氧化反应为主,eaq次之,H·作用最小。采用UV、HLCP、自由基清除法、LC-MS和标准物质再辐照降解方法都证实：DMP降解产物主要是DMP-(OH)n、苯酚和羟基苯甲酸类等。由此推测辐射降解反应可分为低剂量加成和高剂量开环两个阶段,即：羟基自由基作为主要活性粒子首先加成到DMP苯环上形成DMP羟基化产物,该羟基化产物继续被羟基衍生化,再经水解反应、开环分解成小分子,最终被完全矿化。三种生物毒性试验(生物发光菌、藻类和斑马鱼急性毒性)皆表明：辐照降低了DMP溶液的生物毒性。实验发现DMP辐照溶液毒性在低剂量时反而增强,原因是DMP-(OH) n生物毒性大于DMP。总之,高能辐射法去除水中PAEs是可行的。本研究对饮用水PAEs微污染和高浓度废水的处理具有重要的指导意义。更多还原

【Abstract】 Phthalic Acid Esters (PAEs) is one of environmental endocrine disruptors, with low water solubility, high bioaccumulation and sever reproductive toxicity. There are more than20PAEs substances, which are ubiquitous in the soil, sediment, water, plants, animals, air and atmospheric deposition. They are chosen as one of the environmental pollutants to be firstly controlled by the United States, Japan, Europe and China. This research used the DMP, DEP and DBP as research objects to remove PAEs in water by high-energy radiation method. It contains four aspects:the removal efficiency, the influencing factor, the degradation mechanism of PAEs, and the change of bio-toxicity for PAEs solution. The experimental results are shown as follows:DMP, DEP and DBP can be efficiently degraded by high energy irradiation. The removal efficacy of irradiation (GD) were positively correlated with the concentration of PAEs, but dropped exponentially with the increase of dose; the energy utilization rate of gamma irradiation was higher than that of EB irradiation; the efficiency of irradiation degradation in DMP solution aerated with different atmosphere, were O2> saturated air> N2; the degradation reaction constants in the middle value of pH (5-8) was the highest, there was a downward trend in higher pH (8-10), while decreased rapidly in the lower pH (2-4); the irradiation removal efficiency of different types of PAEs were DMP>DEP> DBP> DOP>; DMP degradation reaction was followed a first-order kinetic relationship (In[Co/C]= kD,0-375mg/L, r>0.99); the OH· radical oxidation reaction was the major radiation degradation reaction, eaq-radical was the second one and H·radical was the last one.Using UV, HLCP, radical-scavenging, LC-MS and the method of radiation degradation standard substance, the results were confirmed: the degradation products of DMP were mainly DMP-(OH) n, phenols and p-hydroxybenzoic acids etc. It was suggested that the radiation degradation reaction can be divided into two stages: low dose addition reaction and high dose ring-opening reaction. Hydroxyl radicals as main active species was first added to a DMP phenyl ring and formed the DMP hydroxylated products, the hydroxylated products continue to be derivatisation, followed by hydrolysis reaction, ring opening broken down into small molecules, the products were finally completed mineralization.Three kinds of biological toxicity tests (bioluminescent bacteria, algae and zebra fish acute toxicity) had shown that: irradiation reduced bio-toxicity in DMP solution. Experiments showed that the toxicity of DMP solution irradiated on low doses was enhanced. The reason is that the bio-toxicity of DMP-(OH) n was greater than DMP.In short, removal of PAEs in water by high energy radiation was feasible. This research has important guiding significance in the disposal of micro-polluted drinking water and high PAEs concentration wastewater.更多还原