【作者】 胡晓芳；

【导师】 孔海南；

【作者基本信息】 上海交通大学 ， 环境工程， 2009， 硕士

【摘要】 内分泌干扰物(EDCs)在环境中的广泛存在对人类和其他生物的健康构成了潜在威胁,而污水中的内分泌干扰物在经过城市污水处理厂处理后随污水和污泥的排放是影响其最终去向的重要途径之一。本论文选取了来自工业生产过程中的内分泌干扰物壬基酚、辛基酚、4-t-辛基酚和双酚A四种疏水性较强的烷基酚类的内分泌干扰物,以及17-α-乙炔基雌二醇和雌三醇两种类固醇类内分泌干扰物进行污水处理工艺中主要内分泌干扰物的迁移转化分析。主要研究内容包括:污水和污泥中EDCs的分析方法的优化,实际污水处理厂中EDCs在不同处理单元的浓度变化分析以及通过实验室小试分析在生物处理中活性污泥对EDCs的吸附和降解特性。对EDCs分析过程优化的研究表明通过衍生化方法能够有效提高EDCs尤其是类固醇类物质的分析精度和回收率,衍生化后样品通过气相色谱-质谱联用技术进行分析,所测6种EDCs的污水加标回收率为73.3%-124%,污泥加标回收率为84.8%-122.5%,精密度在1.34%-10.5%之间,最低检出限均低于1.87ng/L。同时也证明了极性较强的Plexa小柱作为活性污泥样品的固相萃取柱更为理想。在对闵行污水处理厂各个单元污水进行分析研究过程中,发现EDCs的去除主要通过与悬浮固体吸附共沉淀去除和在生化池中生物污泥的吸附降解去除,而在生化池的缺氧段EDCs中NP和OP存在明显的水相浓度升高的现象,这主要是由于回流的生物污泥在溶解氧缺少的情况下重新释放所造成以及其前体物的降解所致,这也说明了在二次沉淀池中存在着EDCs重新释放到处理水中,引起EDCs随水排放到环境中的风险。在实验室小试条件下,通过小型生物反应装置分别进行了活性抑制状态、缺氧状态和有氧状态下活性污泥对EDCs的吸附降解分析试验。试验结果表明,活性污泥对于所测物质在近0.5小时内快速吸附的过程,水相呈相应地快速下降趋势,然后缓慢趋于平衡状态,各种EDCs的泥相-水相的分配系数logKd与辛醇-水分配系数logKow的相关性为R> 0.8813。溶解氧水平不仅对污泥的吸附特性产生明显影响,同时也对活性污泥对EDCs的降解过程有重要的作用。溶解氧的提高明显强化了活性污泥对EDCs的吸附性能,在有氧状态下,活性污泥中4-t-辛基酚、辛基酚、壬基酚、双酚A、17-α-乙炔基雌二醇、雌三醇Kd值分别为57953L/kg,87983 L/kg,378349 L/kg,2193.3 L/kg,1769.5L/kg,30.84 L/kg,在缺氧状态下,Kd值分别为1586.3L/kg,23678.5 L/kg,24831.4 L/kg,16.54 L/kg,68.73 L/kg,1.88 L/kg。同时也提高了微生物对烷基酚类EDCs去除效率,有氧状态下,6小时去除率均超过89.7%;缺氧状态下,除雌三醇外,去除率都在77.6%以下。而17-α-乙炔基雌二醇的去除则主要依靠污泥的吸附作用来去除,雌三醇的去除依靠快速转化作用。更多还原

【Abstract】 Endocrine disrupting chemicals (EDCs) which widely existed in the environment potentially threat to humans and other animals. The translocation and transformation of endocrine disrupting chemicals in wastewater treatment plant is an important pathway which affects their final fate.This study was conducted to investigate the fate and removal of dominant endocrine disrupting chemicals in wastewater treatment plant. The alkylphenols (4-tert-octylphenol, octylphenol, 4-nonylphenol, bisphenol A) and steroids (17α-ethynylestradiol and estriol) were studiedThe main research included the optimization of the analytical methods of EDCs in water and sludge, the analysis of the concentration of selected EDCs in different units of wastewater treatment plant, and the adsorption and biodegradation characteristics of EDCs in sludge during biological treatment.In the optimization of analytical method, a derivatisation step was introduced to increase the recovery and precision. After derivatisation, gas chromatography (GC) coupled with mass spectra (MS) analysis was applied to detect the concentration of EDCs. The optimized method was further verified by performing spiking experiments in liquid and solid phase in activated sludge matrices respectively, and the recovery is between 73.3%-124% and 84.8%-122.5%. The intra-day relative standard deviations of the peak area were 1.34%-10.5%, and the detection limits were below 1.87ng/L. The extraction efficiency of 3 SPE cartridge was compared, it is found that the Bond Elut-Plexa with the gradient of polarity on the polymer surface is more suitable for the 6 selected EDCs.In the research of the concentration of EDCs in different units of wastewater treatment plant, the main removal pathway of EDCs was adsorption by suspended solids and biodegradation in biological sludge. The concentration of EDCs in water significantly increased in anoxic stage, this was mainly because the release of EDCs from sludge on the condition of low DO, or because NP and OP were two important intermediates in the decomposition of NPEOs and OPEOs. And it also explained that the EDCs would be released to water in the secondary settling tank, which may cause the entry of EDCs to the environment from discharge.In the lab experiment, the absorption and biodegradation of EDCs in actived sludge were studied in inactivation, anoxic condition and aerobic condition. For 6 EDCs, which were strongly hydrophobic, a fast adsorption happened in the first 30 mins,correspondingly their concentrations in water quickly declined. The quantitative structure-activity relationship analysis relationship analysis was performed to study the corelations between sludge-water distribution coefficients logKd and logKow, and the result showed the relative coefficient was above 0.8813. Dissolved oxygen concentration not only affected the absorption characteristics strongly, but also took an important part in the degradation of alkylphenols. The increase of dissolved oxygen concentration strengthened the adsorption characteristics. Under aerobic condition, sludge-water distribution coefficients (Kd) of 4-tert-octylphenol, octylphenol, 4-nonylphenol, bisphenol A, 17α-ethynylestradiol and estriol were 57953L/kg, 87983 L/kg, 378349 L/kg, 2193.3 L/kg, 1769.5L/kg, 30.84 L/kg, respectively, while under aerobic condition, Kd were 1586.3L/kg, 23678.5 L/kg, 24831.4 L/kg, 16.54 L/kg, 68.73 L/kg, 1.88 L/kg, respectively. Increase of dissolved oxygen concentration enhanced the biodegradation effect. Under aerobic condition, the removal rates of all the selected EDCs in 6 hours were above 89.7%, while under anoxic condition, the removal rates were all below 77.6% except estriol. For the steroids, the removal of 17α-ethynylestradiol was mainly caused by absorption of sludge and the removal of estriol was mainly caused by fast transformation.更多还原