Collaborative research: impact of wastewater derived organic nitrogen on eutrophication

合作研究：废水中有机氮对富营养化的影响

• 批准号: 0932632
• 负责人: Hans Paerl
• 金额: $ 10.43万
• 依托单位: University of North Carolina at Chapel Hill
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2009
• 资助国家: 美国
• 起止时间: 2009-08-15 至 2012-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0932632&HistoricalAwards=false
• 关键词: Collaborative; research; impact; wastewater; derived

0932665/0932632 Gu/Paerl Many municipal wastewater treatment facilities are facing increasingly stringent effluent N limits that are near or beyond the current limits of technology. Removal of dissolved organic nitrogen (DON) becomes necessary if the permitted N level is below the limit of conventional N removal technology. The capital cost required to research and install advanced treatment technologies for further removal of the residual DON is substantial. Current regulations use total nitrogen for setting limits without consideration of the possibility that DON and inorganic N may differ in their bioavailability to phytoplankton and therefore their potential harmful impact on receiving aquatic systems. The question arises on whether further reduction of DON will bring substantial environmental benefits relative to the significant cost incurred, given the uncertainty over the bioavailability of wastewater derived DON (wwDON). Currently, there is little information on the wwDON bioavailability to phytoplankton in receiving waters and there is no accepted method for quantitatively assessing the wwDON bioavailability. This study proposes to addresses this issue and fill in the knowledge gap for understanding the impact of wastewater derived organic nitrogen on receiving aquatic ecosystems. The proposed research aims at investigating the characteristics of wwDON from municipal treatment facilities and assessing the bioavailability of wwDON to phytoplankton and its impact on eutrophication. Although N is usually limiting for saline waters, both saline waters and freshwaters are of concern here because most municipalities discharge to freshwaters, and recent studies indicated that the fate and lability (labile) of N in upstream freshwater systems will eventually affect the transport of N and nutrient condition in down-stream N-sensitive estuary and coastal systems. The specific objectives are: 1. Assess the bioavailability of wwDON to two phytoplankton species known to play roles in eutrophication. 2. Investigate the bioavailability of wwDON to both saline and freshwater phytoplankton and the role of bacteria in labilization of wwDON to algae. 3. Examine the relationship between the composition of wwDON and its bioavailability, and identify the fractions of wwDON that are bioavailable versus recalcitrant. 4. Further evaluate the fate and bioavailability of wwDON to natural biota (including both algae and bacteria) using 15N-labeled wwDON produced in situ. The project will demonstrate the benefits of interdisciplinary and integrated approach for solving environmental challenges. The multidisciplinary research covers expertise in at least three disciplines that will apply unique, comprehensive, and state-of-the-art assessment of the bioavailability of wwDON to freshwater aquatic systems. The proposed research addresses a pressing issue with significant social and economical impacts that have not previously been investigated. The results will provide essential information and framework for developing a standard wwDON bioavailability assessment method that are urgently needed by utilities and regulators in order to target their treatment design and investments at eliminating the N components that are truly harmful to receiving aquatic ecosystems and therefore maximizing the environmental benefits. The project will enhance both existing and new education outreach programs at the two institutions. At NU, there is BEST (Biotechnology for the Environment, Showcase and Training), a center recently initiated by Gu; CONNECTIONS and RET, two NSF funded education programs; and CO-OP, a distinguished experiential learning program for NU. At UNC, there are NSF-supported (Ecosystems, EID and Ocean Sciences Programs) summer internships at UNC-IMS and NSF-supported Summer Pre-graduate Research Experience Program (SPGRE). All these programs intend to attract and involve students from diverse backgrounds. The PI started ITRI (Industrial Translational Research Initiative) and will work with WEF/WERF (Water Environment Federation) for information dissemination to professionals and practitioners via web-based tools and databases

0932665/0932632 Gu/Paerl许多城市污水处理设施正面临日益严格的污水氮限值，这些限值已接近或超过当前的技术极限。如果允许的氮水平低于常规脱氮技术的限制，则必须去除溶解有机氮（DON）。研究和安装用于进一步去除残留DON的先进处理技术所需的资本成本是巨大的。目前的法规使用总氮来设定限制，而没有考虑DON和无机氮对浮游植物的生物利用度可能不同的可能性，因此它们对接收水生系统的潜在有害影响。问题在于，鉴于废水衍生DON（wwDON）的生物利用度的不确定性，进一步减少DON是否会带来相对于所产生的显著成本的实质性环境效益。目前，有很少的信息，在接收沃茨的浮游植物的wwDON生物利用度，并没有被接受的方法定量评估的wwDON生物利用度。本研究旨在解决这一问题，并填补知识空白，了解废水来源的有机氮对接收水生生态系统的影响。拟议的研究旨在调查市政处理设施的wwDON的特性，并评估wwDON对浮游植物的生物利用度及其对富营养化的影响。虽然N通常是限制盐水沃茨，盐水沃茨和淡水沃茨的关注，因为大多数城市排放到淡水沃茨，最近的研究表明，上游淡水系统中的命运和不稳定性（不稳定）的N最终会影响下游N敏感的河口和沿海系统的N和营养条件的传输。具体目标是：1.评估wwDON对两种已知在富营养化中发挥作用的浮游植物物种的生物利用度。2.调查wwDON对盐水和淡水浮游植物的生物利用度以及细菌在wwDON向藻类转化中的作用。3.检查wwDON的组成与其生物利用度之间的关系，并确定与枸橼酸相比具有生物利用度的wwDON组分。4.使用原位产生的15 N标记的wwDON进一步评估wwDON对天然生物群（包括藻类和细菌）的命运和生物利用度。该项目将展示跨学科和综合方法解决环境挑战的好处。多学科研究涵盖了至少三个学科的专业知识，这些学科将对wwDON的生物利用度进行独特，全面和最先进的评估。拟议的研究解决了一个紧迫的问题，具有重大的社会和经济影响，以前没有被调查。研究结果将为开发标准的wwDON生物利用度评估方法提供必要的信息和框架，这些方法是公用事业和监管机构迫切需要的，以便将其处理设计和投资目标定位于消除对接收水生生态系统真正有害的N组分，从而最大限度地提高环境效益。该项目将加强这两个机构现有的和新的教育外联方案。在NU，有最好的（生物技术为环境，展示和培训），一个中心最近发起的顾;连接和RET，两个NSF资助的教育计划;和合作，一个杰出的经验学习计划NU。在北卡罗来纳大学，有NSF支持的（生态系统，EID和海洋科学计划）夏季实习在UNC-IMS和NSF支持的夏季研究生前研究体验计划（SPGRE）。所有这些项目都旨在吸引和吸引来自不同背景的学生。PI启动了伊特里（工业转化研究计划），并将与WEF/WERF（水环境联合会）合作，通过基于网络的工具和数据库向专业人员和从业人员传播信息