【作者】 李建忠；

【导师】 刘翔；

【作者基本信息】 清华大学 ， 环境科学与工程， 2013， 博士

【摘要】 内分泌干扰物（Endocrine disrupting chemicals，EDCs）在极低浓度下即具有危害性，城市污水及再生水是其重要来源。再生水用于农业灌溉、河湖补水和地下水补给，导致EDCs进入土壤和含水层，引发环境生态和人体健康风险。本研究的目的是通过建立快速灵敏的EDCs检测方法，调查EDCs在再生水与地下水回灌区的时空分布特征，筛选典型EDCs，研究土壤吸附、土壤微生物降解和回灌条件对其迁移转化过程的影响，进而模拟和预测其在地下水回灌场地的迁移转化规律，从而为再生水回用的风险评价提供理论指导和技术支撑。通过优化固相萃取、超高效液相色谱和质谱条件，建立了同时测定再生水和地下水中雌酮（Estrone，E1）、雌二醇（17β-estradiol，E2）、17α-乙炔基雌二醇（17α-ethinylestradiol，EE2）、雌三醇（Estriol，E3）、双酚A（BisphenolA，BPA）、壬基酚和辛基酚等7种EDCs的检测方法，定量限为0.01-0.06ng/L。对北京市潮白河再生水回灌地下水的场地调查表明，64个再生水样品中E1、E2、EE2、E3和BPA检出率为100%。51个地下水样品中（埋深为30-80m）EDCs检出率为80.4%，BPA浓度最高。45.1%的地下水样品中EE2超过其预测无影响浓度，其生态风险最大。BPA和EE2被筛选为再生水回灌场地的典型内分泌干扰物。通过分析土壤和土壤有机质对EDCs的吸附特性与其结构特征的相关性发现，土壤有机质含量、比表面积以及吸附质的临界分子直径都能够影响EDCs饱和吸附量，EDCs在微孔中的扩散是产生慢吸附的原因，解吸滞后性与黑碳的含量和位置相关。特异性吸附作用使BPA与EE2强烈竞争土壤中吸附位，从而增强其迁移性。EDCs的降解过程可以用伪一级动力学方程描述。双溶质体系EDCs的半衰期比单溶质体系延长1.4-2.9倍。甾体雌激素的转化路径为E2/EE2→E1→E3。长时间吸附与解吸滞后性，对EDCs生物降解过程有抑制作用。通过土柱模拟试验发现，连续回灌土柱中土壤添加0.5%黑碳使EE2和BPA的迁移速率降低45%左右。相同回灌量（约1-10倍柱体积）条件下，间歇回灌土柱EDCs出水浓度为连续回灌土柱的0-44.5%。基于潮白河砂柱实验建立的EDCs对流-弥散模型，能够模拟预测潮白河地下水回灌区均质性较好的潜水层中EDCs的变化，EE2和BPA的迁移速率分别为21.4m/年和28.5m/年，半衰期分别为21.7d和20.4d。回灌10年后，EE2和BPA的影响范围分别达到距岸边337m和734m处。更多还原

【Abstract】 Endocrine disrupting chemicals (EDCs) are harmful to wildlife even atconcentrations as low as1ng/L. The effluent of wastewater treatment plants, as well asthe reclaimed water originated from it, is considered as a major source of EDCs.The reclaimed water can transfer EDCs into soil and groundwater when it is usedfor irrigation and groundwater recharge. The purpose of this study was to investigate thespatial and seasonal variation of concentrations of EDCs in aquifers recharged byreclaimed water, meanwhile, select the typical EDCs, and then investigate the influenceof adsorption, biodegradation and recharge conditions on the fate of the typical EDCs,thus simulating and predicting the migration and transformation processes in aquifersrecharged by reclaimed water, so as to provide a technical support for risk assessment ofreusing the reclaimed water.An analytical method of separating and determining seven selected EDCs inwastewater and reclaimed water was developed. The method was based on solid-phaseextraction and ultra-performance liquid chromatography tandem mass spectrometry.The limit of detections for selected EDCs, namely, estrone (E1),17β-estradiol (E2),17α-ethinyl estradiol (EE2), estriol (E3), bisphenol A (BPA),4-n-nonylphenol, and4-t-octylphenol, ranged from0.01ng/L to0.06ng/L for reclaimed water andgroundwater.The detection rate of E1, E2, EE2, E3and BPA was100%among the64reclaimedwater samples in the Chaobai River, Beijing, where reclaimed water is used to rechargegroundwater through the permeable bed. The detection rate of EDCs was80.4%amongthe51groundwater samples. The highest detection frequency of BPA indicated thatBPA can be used as a sewage tracer in groundwater. The concentrations of EE2in23groundwater samples exceeded its predicted no-effect concentrations which indicatedthat EE2is the major compound causing the estrogenic activity of groundwater. Thus,BPA and EE2are selected as two typical EDCs in the studied aquifers recharged byreclaimed water.The saturated sorption capacity of EDCs in soil was influenced by the total organiccarbon and specific surface area of soil and molecular diameters of EDCs. The rate-limiting step of EDCs sorption was the diffusion in micropores. Sorptionnonlinearity was influenced by hard carbon content. The content and locationdifferences of hard carbon could explain various degrees of desorption hysteresis. BPAsignificantly suppressed the sorption of EE2, which could be attributed to the specificsorption on the hard carbon. The strong competitive sorption of BPA can enhance themobility of EE2.The aerobic biodegradation rates of EDCs in the soil-water system could bedescribed by a pseudo-first-order kinetic equation. The half-lives of EDCs in allcombinations were1.4-2.9times prolonged in the binary-chemical system than in thesingle chemical system. The following biotransformation pathway of estrogen wasproposed: E2/EE2→E1→E3. The desorption hysteresis suppressed the biodegradationrates of EDCs.In soil column under continual recharging, the migration rates of EE2and BPAdecreased45%after mixing0.5%black carbon with the packing soil. Theconcentrations of EE2and BPA in the effluent of soil column under intermittentrecharging were only0-44.5%of that under continual recharging. The parameters ofconvection-dispersion model were calculated by measuring the breakthrough curves ofEE2and BPA in the lab-scale column packed with the river sand obtained from theChaobai River. The convection-dispersion model fitted well with the measuredconcentrations of EE2and BPA in the unconfined aquifer with good uniformity. In thisaquifer, the migration rates of EE2and BPA were21.4m/a and28.5m/a, respectively.The half-lives were21.7d for EE2and20.4d for BPA. After ten years of continualrecharging, EE2and BPA will be detected in the groundwater with the distance of337mand734m to the bank of the Chaobai River.更多还原