Effect of Activated Sludge Bioselector Designs on Estrogen-Degradation Kinetics

活性污泥生物选择器设计对雌激素降解动力学的影响

• 批准号: 1067744
• 负责人: H.David Stensel
• 金额: $ 33.53万
• 依托单位: University of Washington
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2011
• 资助国家: 美国
• 起止时间: 2011-09-15 至 2014-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1067744&HistoricalAwards=false
• 关键词: Effect; Activated; Sludge; Bioselector; Designs

PI: H. David StenselProposal Number: CBET-106744Institution: University of WashingtonTitle: Effect of Activated Sludge Bioselector Designs on Estrogen-Degradation KineticsEstrogens are known endocrine disruptor compounds (EDC) that can affect aquatic life at concentrations as low as 0.35 ng/L. A main source of aquatic estrogen contamination is wastewater treatment plant (WWTPs) effluents. Estrogens enter the WWTP through normal human water use. In order of their EDC potency these estrogens are 17á-ethynyl estradiol (EE2, a synthetic estrogen), 17â- estradiol (E2), estrone (E1) and estriol (E3). Biological degradation is a primary estrogen removal mechanism at WWTPs and EE2 is degraded much slower than E1 and E2. Prior work by the research team found that heterotrophic bacteria play a major role in estrogen biodegradation even when grown on a wide range of organic substrates. Laboratory experiments with three bioreactors fed synthetic feed showed that EE2, E1 and E2 degradation kinetics varied among reactors configured for anaerobic/aerobic sequenced treatment, which selects for phosphorus accumulation organism; anoxic/aerobic sequenced treatment, which selects for facultative organisms; and aerobic treatment. The anaerobic and anoxic selector designs are also important for biological nutrient removal (BNR) systems, commonly used today. Critical questions for this research are: (1) will similar relative degradation kinetics for the different microbial populations (anaerobicaerobicanoxic) occur when treating actual municipal wastewater versus synthetic, (2) how will microbial populations compare within the selector designs, and (3) can EE2-degrading bacteria be identified for study in pure culture. Parallel bench scale reactors similar to those described above for the three configurations treating municipal primary effluent will be integrated with mechanistic modeling and advanced molecular and microbial techniques to address biodegradation kinetics of estrogens at relevant ng/L concentrations. Specific research goals include: (1) Evaluate the effect of selector/BNR process designs on estrogen removal performance; (2) compare the EE2, E1, and E2 degradation kinetics in the different reactor configurations; (3) characterize the microbial populations for the different selector designs through terminal restriction fragment length polymorphism (T-RFLP), (4) determine if the fraction of estrogen-degrading biomass is higher for the bioreactors with higher specific estrogen degradation rates, and (5) evaluate estrogen degradation ability of microbial isolates obtained from the study bioreactors (including anaerobic and anoxic selectors). The results will be incorporated into a comprehensive estrogen/activated sludge model based on the International Water Association ASM1 and ASM2d models. The estrogen/ASM1 model has been completed by us by applying the industry GPS-X software. Similar work will be done with the ASM2d model, which includes enhanced biological phosphorus removal. The models include free and conjugated forms of E1, E2 and EE2, deconjugation and biodegradation kinetics, possible production of E1 from E2 degradation, and liquid-solids partitioning of estrogens.The intellectual merit of the project is its transformational approach, which integrates modeling the fate of a micropollutant in a biological process with a fundamental co-substrate mechanism, bioselector design effects, and microbial composition based on molecular methods. A second potential far reaching benefit will be the development of pure cultures capable of EE2 degradation under condition similar to WWTP for future kinetic and genetic studies, and development of qPCR primer sets for monitoring select EE2-degrading heterotrophs in WWTP facilities.The broader impacts of the project are benefits to society by providing a basis to optimize WWTP biotreatment design to minimize estrogen release to the environment. Direct educational benefits include the training of graduate students, and participation of undergraduate researchers. Increased participation by underrepresented groups will be realized through established University of Washington programs and continued partnership with the UW, College of Engineering Office of Diversity.

PI: H. David stensel提案号：cbet - 106444机构：华盛顿大学标题：活性污泥生物选择器设计对雌激素降解动力学的影响雌激素是已知的内分泌干扰化合物（EDC），浓度低至0.35 ng/L时可影响水生生物。水生雌激素污染的主要来源是污水处理厂的出水。雌激素通过人类正常用水进入污水处理厂。根据它们的EDC效力，这些雌激素依次是17á-ethynyl雌二醇（EE2，一种合成雌激素），17<e:2> -雌二醇（E2），雌酮（E1）和雌三醇（E3）。生物降解是WWTPs去除雌激素的主要机制，EE2的降解速度远慢于E1和E2。研究小组先前的工作发现，即使在广泛的有机基质上生长，异养细菌在雌激素的生物降解中也起着重要作用。实验结果表明，厌氧/好氧顺序处理反应器中EE2、E1和E2的降解动力学存在差异，厌氧/好氧顺序处理选择了积累磷的生物；缺氧/好氧序列处理，选择兼性生物；有氧治疗。厌氧和缺氧选择器的设计对于目前常用的生物营养物去除（BNR）系统也很重要。本研究的关键问题是：(1)不同微生物种群（厌氧-好氧-厌氧）在处理实际城市废水和合成废水时是否会出现相似的相对降解动力学，(2)在选择器设计中如何比较微生物种群，以及(3)能否在纯培养中鉴定出降解ee2的细菌进行研究。类似于上述用于处理城市初级污水的三种配置的平行实验规模反应器将与机制建模和先进的分子和微生物技术相结合，以解决相关ng/L浓度下雌激素的生物降解动力学问题。具体研究目标包括：(1)评价选择器/BNR工艺设计对雌激素去除性能的影响；(2)比较不同反应器配置下EE2、E1和E2的降解动力学；(3)通过末端限制性片段长度多态性（T-RFLP）表征不同选择器设计下的微生物种群特征；(4)确定雌激素特异性降解率较高的生物反应器中雌激素降解生物量的比例是否更高；(5)评估从研究生物反应器（包括厌氧和缺氧选择器）中获得的微生物分离物的雌激素降解能力。研究结果将被纳入基于国际水协会ASM1和ASM2d模型的综合雌激素/活性污泥模型。雌激素/ASM1模型由我们应用行业GPS-X软件完成。类似的工作将在ASM2d模型上进行，其中包括增强的生物除磷。这些模型包括E1， E2和EE2的自由和共轭形式，解偶联和生物降解动力学，E2降解可能产生的E1，以及雌激素的液固分配。该项目的智力优势在于它的转型方法，它将微污染物在生物过程中的命运建模与基本的共底物机制、生物选择器设计效应和基于分子方法的微生物组成结合起来。第二个潜在的长远利益将是开发出能够在类似污水处理厂的条件下降解EE2的纯培养物，用于未来的动力学和遗传学研究，以及开发qPCR引物集，用于监测污水处理厂设施中筛选出的降解EE2的异养生物。该项目的更广泛影响是社会效益，为优化污水处理厂生物处理设计提供依据，以最大限度地减少雌激素对环境的释放。直接的教育效益包括研究生的培养和本科生研究人员的参与。通过华盛顿大学已建立的项目，以及与西澳大学工程学院多样性办公室的持续合作，将增加代表性不足群体的参与。