A Study on Application of Gravel Contact Oxidation Treatment to an Urban Drainage – Take Liuchuan River in Taichung as an Example

• Main Authors: Tien-Yu Tai, 戴天佑
• Other Authors: Yung-Hsu Hsieh
• Format: Others
• Language: zh-TW
• Published: 2017
• Online Access: http://ndltd.ncl.edu.tw/handle/76368635150399072611

碩士 === 國立中興大學 === 環境工程學系所 === 105 === Liuchuan canal is an urban water course in Taichung City that has been contaminated by domestic and commercial wastewater over the years. Several attempted to revive Liuchan canal were unsuccessful until the Environmental Protection Agency funded Taichung City for a river and environmental improvement project in 2012. The 4-year project consists of a Gravel Contact Oxidation Treatment system (GCOT)-Chonghua Water Purification Station and Low Impact Development Demonstrative Work. The project has turned the canal into a popular recreational area, and further inspired the central government to allocate 28 billion dollars budget to promote the same method for future projects. With many polluted urban river affecting the environment of the cities, improvement work have become necessary. However, further study is required to understand what Chonghua system contributes to water quality improvement of Liuchan and whether the system is suitable for other urban rivers. Therefore, Literature reviews, method development, water quality and specification analysis were conducted to further understand the core of the project. Water quality analysis indicates DO and BOD were improved slightly after Chonghua system commenced operation. However, ammonia and phosphorus had inclination trend shown from the data. Combined with site visit results, this indicates potential eutrophication downstream of the Chonghua system. By the effluent discharge, many bubbles were observed. Therefore, this research have also concluded potential contamination due to surfactants from domestic and commercial use. Furthermore the design specifications indicated Chonghua system has higher depths and retention time compare to other systems in Japan and Taiwan, which may cause operational problems within the system. In conclusion, the research recommends continuous monitoring of ammonia, phosphorus, algae growth and surfactants. If the situation persist, then mitigation measure must be taken. Meanwhile continuous monitoring of the GCOT chamber is also suggested to make sure the long retention time and depth would cause problem to the system. Finally, GCOT method is recommended to act as a temporary, instead of permanent, solution to the sewer network due to its short construction time, less cost, and lower pollutant removal rate.