NSF-BSF: Collaborative Research: Solids and reactive transport processes in sewer systems of the future: modeling and experimental investigation

在美国，大约有16,000个卫生下水道系统，通过超过740,000英里的公共下水道为1.9亿多人服务。卫生下水道是一种地下管道，旨在将住宅、商业和工业建筑的污水输送到城市污水处理厂。这些废水含有固体废物，如人类排泄物、来自水槽、淋浴和厕所的污染水以及其他废物。卫生下水道对它们所服务的社区以安全的方式管理和处理废水至关重要。影响这些卫生下水道系统的两个主要问题是堵塞和硫化氢的形成，硫化氢是一种剧毒和腐蚀性气体。下水道堵塞可能导致未经处理的受污染废水溢出到个人物业、当地社区和环境中。下水道堵塞还会导致异味和有害气体的释放，如硫化氢，这对人类健康是危险的。NSF-BSF项目的目标是调查进入下水道的固体废物的特性，影响其移动和积累的因素，以及下水道系统中硫化氢和其他有害物质的形成。为了推进这一目标，首席调查员将结合实验室和现场实验以及计算机模拟来预测固体废物和有害物质在下水道中的流动方式。考虑到不同的不确定性来源，绩效指标还建议开发软件工具，以帮助跟踪和模拟这些过程。该项目的成功完成将使社会受益，因为它将产生新的数据和模型，以改善对固体如何在下水道中移动的基本了解，并确定未来废水特性变化可能产生的脆弱性和潜在问题。学生教育和培训将为社会带来更多好处，包括指导德克萨斯大学奥斯汀分校的一名本科生和一名研究生，以及伊利诺伊大学芝加哥分校的一名研究生。下水道堵塞和硫化氢的形成是危害卫生下水道完整性的两个关键问题，并对经济、环境和公共健康产生严重影响。预计更多地采用可持续水技术将显著改变排放到下水道系统的废水的数量和质量，导致意想不到的负面影响。用水量的减少预计会增加固体的沉积，改变下水道系统内的固液生化过程，加剧下水道堵塞和硫化氢的形成。NSF-BSF项目的总体目标是调查排入下水道的生活固体的动态特征，影响这些固体的运输、沉积和积累的因素，以及下水道系统中硫化氢和其他关键生化物种的形成和转化。这项研究的具体目标是：1)进行实验室和现场实验，以确定下水道中总固体迁移、沉积和转化的物理方面；2)开发开源软件工具，以模拟固液生化相互作用，能够跟踪下水道系统中关键生化物种的去向和迁移，并量化和传播不同的不确定性来源；以及3)创建一个计算框架，以确定由于各种分散供水技术下废水排放特征的未来变化、人口迁移以及由于气候变化而导致的渗透/流入模式的变化。该项目的成功完成将弥合下水道系统中固体运输和固液生化过程方面的基本知识空白，并将能够识别未来废水特性不确定的长期和短期变化下的脆弱性。该奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。

In the United States, there are approximately 16,000 sanitary sewer systems serving more than 190 million people through over 740,000 miles of public sewers. Sanitary sewers are underground pipes designed to deliver sewage water from residential, commercial, and industrial buildings to the city sewage treatment plants. This wastewater contains solid waste such as human excreta, soiled water from sinks, showers, and toilets, and other waste. Sanitary sewers are critical to the communities that they serve for managing and disposing of wastewater in a safe manner. Two major problems affecting these sanitary sewer systems are blockages and the formation of hydrogen sulfide, a highly toxic and corrosive gas. Sewer blockages can result in overflow of untreated contaminated wastewater into individual properties, local communities, and the environment. Sewer blockages can also lead to bad smells and the release of harmful gases, such as hydrogen sulfide, which is dangerous to human health. The goal of this NSF-BSF project is to investigate the characteristics of the solid waste that enters sewers, the factors that affect how it moves and accumulates, and the formation of hydrogen sulfide and other harmful substances in sewer systems. To advance this goal, the Principal Investigators (PIs) will use a combination of laboratory and field experiments, as well as computer modeling, to predict how solid waste and harmful substances travel in sewers. The PIs also propose to develop software tools to help track and model these processes, considering different sources of uncertainty. The successful completion of this project will benefit society through the generation of new data and models to improve the fundamental understanding of how solids move in sewers and identify vulnerabilities and potential problems that may arise from future changes in wastewater characteristics. Additional benefits to society will be achieved through student education and training including the mentoring of one undergraduate and one graduate student at the university of Texas, Austin and one graduate student at the University of Illinois at Chicago.Sewer blockages and the formation of hydrogen sulfide, a highly toxic and corrosive gas, are two critical issues that compromise the integrity of sanitary sewers and have severe economic, environmental, and public health impacts. The increased adoption of sustainable water technologies is forecasted to significantly alter the quantity and quality of the wastewater discharged into sewer systems, leading to unintended negative implications. Water demand reductions are expected to increase the deposition of solids and alter the solid-liquid biochemical processes within the sewer system, exacerbating sewer blockages and hydrogen sulfide formation. The overarching goal of this NSF-BSF project is to investigate the dynamic characteristics of domestic solids discharged to sewers, the factors that affect the transport, deposition, and accumulation of these solids, and the formation and transformation of hydrogen sulfide and other key biochemical species in sewer systems. The specific objectives of the research are to 1) conduct lab and field experiments to characterize the physical aspects of gross solids transport, deposition, and transformation in sewers; 2) develop open-source software tools to model solid-liquid biochemical interactions, enable tracking the fate and transport of key biochemical species in sewer systems, and quantify and propagate different sources of uncertainty; and 3) create a computational framework for identifying potential breakpoints due to future changes in the characteristics of wastewater discharges under various decentralized water technologies, population shifts, and changes in infiltration/inflow patterns due to climate change. The successful completion of this project will bridge the fundamental knowledge gaps in solids transport and solid-liquid biochemical processes in sewer systems and will enable identifying vulnerabilities under future uncertain long- and short-term shifts in wastewater characteristics.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.