Integrated waste water management of a sewer system and a waste water treatment focused on the hydraulic plant load

Abstract

Consulta en la Biblioteca ETSI Industriales (Riunet)

[EN] The municipality of Solbjerg is a suburb in the south of Aarhus. In the past years the population of Solbjerg has increased and new residential areas were implemented. A detailed analysis and evaluation of the sewer system and waste water treatment plant of Solbjerg will show how much more water can be discharged by the existing sewer system and treated at the existing plant. The sewer system is analyzed in a variety of situations, depending on the characteristics of the system as such rain events, which can lead to overflow problems. A sensitivity test is performed in order to measure the response of the sewer system due to changes of those characteristics. Along the analysis, MOUSE Mike Urban is used as the main tool for simulations of the performance of the system. A model is developed representing the sewer system of Solbjerg. Regarding an increase in precipitation in the next years, the system will be overloaded in several nodes. Therefore, various solutions were simulated and evaluated. At the end, the best solution to improve the capacity of the system included a combination of increasing pipe diameters and building two basins in the two nodes with the highest impervious areas. An increasing population can affect the waste water treatment plant likewise the sewer system. The analysis of the 2011 data showed that all processes are performing well under dry weather conditions. In most cases, there are large vacant capacity which means that the plant can process more water and a higher pollution load. When it comes to large storm events plant reaches its limits. The hydraulic retention time for grit removal just meets the requirements, but there is no vacant capacity. However, this part is not very essential for the whole treatment plant. Even more severe overflow situations occur at the clarifier. The overflow rate exceeded the requirements three times in 2011 and the hydraulic retention time is just large enough to meet the requirements. For this reason the third part of the report focuses on the hydraulic plant load. This can be solved by designing a new secondary clarifier based on ATV procedure. Also, using MBR technology will be taken into consideration.