活性污泥吸附降解邻苯二甲酸酯类物质的试验研究

发布时间：2018-11-28 11:22

【摘要】：邻苯二甲酸酯类物质(PAEs)是一类人工合成有机化合物,广泛应用于增塑剂和添加剂。PAEs能通过食物链在生物体内逐渐富集,具有致癌、致畸、破坏免疫和生殖功能等毒性。近年来,由于塑料制品的大量使用以及生活污水、工农业废水的大量排放,在诸多水体中都检测到PAEs的残留。以活性污泥法为主要工艺的污水厂的排放水是PAEs进入水体的主要途径。因此,研究活性污泥吸附降解PAEs的特性具有重要意义。本论文选取邻苯二甲酸丁基苄基酯(BBP)邻苯二甲酸二辛酯(DOP)、邻苯二甲酸二(2-乙基己基)酯(DEHP)、邻苯二甲酸二丁酯(DBP)、邻苯二甲酸二甲酯(DMP)和邻苯二甲酸二乙酯(DEP)6种典型邻苯二甲酸酯类物质作为研究对象,进行了活性污泥的吸附降解实验研究,主要研究内容及结果如下：探究了活性污泥降解PAEs的动力学特征分析以及活性污泥吸附PAEs机理的初步分析。试验研究主要内容及结论如下：(1)建立了6种PAEs色谱及质谱分析条件。根据质谱特征碎片离子及相对保留时间进行双重定性,以峰面积-外标法定量,得到PAEs的标准曲线,6种PAEs的线性范围在1.0mg/L-8.0mg/L之间,相关系数均大于0.90,线性相关性较好,最低检出限介于0.003-0.008μg/L。(2)进行了吸附时间、初始浓度、温度、pH值等环境条件对活性污泥吸附PAEs的影响研究。研究结果表明,活性污泥吸附PAEs开始15min时浓度迅速降低,在2h时基本达到吸附平衡；初始PAEs的浓度越高,活性污泥的吸附作用越强,但吸附平衡时间基本不变。活性污泥对6种PAEs的吸附量不同,DOP最大,DMP最小,初始PAEs的浓度值越大时,吸附结果越明显,PAEs正辛醇-水分配系数(Kow)高时,更容易被活性污泥的吸附。活性污泥吸附PAEs是一个放热过程,低温有利于吸附,高温有利于脱附,吸附的最适温度为25℃左右,且DMP、DEP的吸附过程受温度的影响较大。活性污泥对PAEs的吸附作性能：DOPDEHPDBPDEPDMP,分子量小、烷基支链少的PAEs更易溶于水中,不易被活性污泥吸附。偏酸性条件下活性抑制的活性污泥对PAEs的吸附效果较差,偏碱性时吸附效果好,pH值大于9.0后活性污泥对PAEs的吸附没有明显变化。(3)进行了多种环境条件对活性污泥吸附PAEs的交互影响试验研究。研究结果表明,中性条件下盐度使活性污泥吸附PAEs的能力降低,酸性条件下盐度使活性污泥的吸附能力提高；细胞壁是否破碎对活性污泥在酸碱及盐度的条件下吸附效果影响不显著。(4)活性污泥对DMP、DEP、DEHP、DBP、BBP的生物降解过程符合一级动力学特征,但活性污泥对这5种PAEs的吸附降解的程度不同,降解速率常数存在差异。活性污泥对DMP、DEP、DOP、DEHP的等温吸附过程符合Freundlich等温方程,25℃时吸附常数KF值：DOPDEHPDEPDMP。
[Abstract]:Phthalate ester (PAEs) is a kind of synthetic organic compound, which is widely used in plasticizer and additive. PAEs can be enriched gradually through the food chain and has carcinogenic, teratogenic, immune and reproductive toxicity. In recent years, due to the large use of plastic products and domestic sewage, industrial and agricultural wastewater discharge, PAEs residues are detected in many water bodies. The main way for PAEs to enter the water body is to discharge water from wastewater treatment plant with activated sludge process as the main process. Therefore, it is of great significance to study the characteristics of activated sludge adsorption and degradation of PAEs. In this thesis, Ding Ji benzyl phthalate (BBP) dioctyl phthalate (DOP),) di (2-ethylhexyl) phthalate (DEHP), dibutyl phthalate (DBP),) was selected. The adsorption and degradation of activated sludge by dimethyl phthalate (DMP) and diethyl phthalate (DEP) were studied. The main contents and results are as follows: the kinetic characteristics of PAEs degradation by activated sludge and the mechanism of PAEs adsorption by activated sludge were analyzed. The main contents and conclusions are as follows: (1) six PAEs chromatographic and mass spectrometry conditions were established. According to the characteristic fragment ion and the relative retention time of mass spectrometry, the standard curve of PAEs was obtained by using peak area and external standard method. The linear range of six PAEs was between 1.0mg/L-8.0mg/L. The linear correlation coefficient was higher than 0.90, and the lowest detection limit was 0.003-0.008 渭 g / L. (2) the effects of adsorption time, initial concentration, temperature and pH value on the adsorption of PAEs by activated sludge were studied. The results showed that the concentration of PAEs decreased rapidly at the beginning of 15min adsorption by activated sludge and reached the adsorption equilibrium at 2 h. The higher the initial concentration of PAEs was, the stronger the adsorption of activated sludge was, but the adsorption equilibrium time was almost unchanged. The adsorption capacity of six kinds of PAEs in activated sludge was different, DOP was the largest and DMP was the smallest. The higher the initial concentration of PAEs was, the more obvious the adsorption result was, and the higher the PAEs n-octanol-water partition coefficient (Kow) was, the easier it was to be adsorbed by activated sludge. Activated sludge adsorption of PAEs is an exothermic process, low temperature is favorable to adsorption, high temperature is conducive to desorption, the optimum adsorption temperature is about 25 鈩，

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