Sewer ventilation and odor transport model for sanitary sewers

我们现有的卫生下水道系统的设计是为了有效地输送污水，而不考虑下水道顶部空间的空气流动。因此，许多城市都面临着从下水道释放的恶臭（污浊的空气）的困扰。恶臭主要是硫化氢（H2S），由污水中的硫或硫酸盐在厌氧条件下由细菌产生。H2S将从污水中释放到污水顶空空气中，然后通过污水系统内的气流输送。当下水道中的空气被加压时，H2S将通过下水道系统中的人孔扒孔或集水池等开口泄漏到大气中。硫化氢的气味对公众是一种滋扰，并严重影响了排放点附近社区的生活质量。高浓度时，它也可能是有毒的，并导致下水道管道腐蚀。市政当局一直在努力控制下水道异味，但由于问题的复杂性，成效有限。来自阿尔伯塔大学的四名研究人员将与埃德蒙顿市密切合作，开发下水道通风（空气运动）和气味运输模型。将进行室内实验、数值模拟和现场监测，研究下水道系统中恶臭（H2S）的产生和释放，以及考虑空气幕和空气跳线的水滴结构和污水流的夹带空气的水力研究。计算机模型将开发下水道通风和气味运输，无论是作为一个独立的软件或嵌入作为模块的商业软件，如Mike Urban。它将培养总共8名研究生（2名博士，2名硕士和40万名学生），以及两名博士后，从事与我们基础设施更新相关的重要课题。拟议的研究将为市政当局设计下水道通风和气味控制策略，以及改造现有下水道系统及其未来设计提供有用的工具。

Our existing sanitary sewer systems have been designed to efficiently carry sewage flow without the consideration for air movement in sewer headspace. As a result, many municipalities are facing the nuisance of odor (foul air) releases from sewers. The odor, mainly hydrogen sulfide (H2S), is generated from sulfur or sulfate in sewage by bacteria in anaerobic condition. The H2S will release from sewage to sewer headspace air, and then be transported by the air flow inside the sewer systems. When the air in sewers is pressurized, H2S will leak into the atmosphere via openings such as manhole pickholes or catch basins in combined sewer systems. The odor of H2S is a nuisance to the public and substantially impacts the living quality of the communities close to release points. At a high concentration, it can also be toxic and responsible for sewer pipe corrosions. Municipalities have been working hard on sewer odor control but with limited successes due to the complexity of the issue. Four researchers from the University of Alberta will work closely with the City of Edmonton to develop sewer ventilation (air movement) and odor transport model. Laboratory experiments, numerical modeling and field monitoring will be carried out to study odor (H2S) generation and release in sewer systems, and hydraulic study on air entrainment in drop structures and by sewage flow with the consideration of air curtains and air jumpers. Computer model will be developed on sewer ventilation and odor transport, either as a stand-alone software or embedded as module in a commercial software such as Mike Urban. It will train a total of eight graduate students (2 PhD, 2 M.Sc. and 4 MEng students), as well as two post-doctoral fellows, to work on the important topic related to our infrastructural renewal. The proposed study will provide a useful tool for municipalities on designing sewer ventilation and odor control strategies, as well as retrofitting existing sewer systems and their future design.