Assessment of water conservation efficiency in Wastewater Treatment Plants of Kitakyushu City
学生名：李 欣潔
研究テーマ：Assessment of water conservation efficiency in Wastewater Treatment Plants of Kitakyushu City
入学年月:2018.04
修了年月:2020.03
取得学位:修士（工学）
論文概要:The water footprint is a key indicator for assessing water resource usage, including the gray water footprint, which measures the water volume required to dilute pollutants to meet specific quality standards. Applying water footprint theory to wastewater treatment plant evaluation introduces a novel methodology. This study calculates the gray water footprint and evaluates the economic and environmental benefits of five wastewater treatment plants in Kitakyushu, Japan, focusing on water quantity, water quality, and watershed sustainability.
The research calculates the total water footprint and analyzes how reducing and managing the gray water footprint can enhance the sustainability of wastewater treatment operations. Among the plants, Shinmachi demonstrates the highest efficiency in treating COD pollutants, while Hiagari is most effective in handling TN and TP pollutants.
A sustainable evaluation model is developed by comparing the annual gray water footprint of each plant with the annual runoff in the basin. The analysis reveals that the Shinmachi, Hiagari, Kitato, and Kogasaki treatment plants operate sustainably, contributing to watershed protection. However, the Sone plant is identified as unsustainable in treating TP pollutants, requiring improvement.
To address these shortcomings, the study proposes measures such as technical upgrades to improve pollutant removal rates and equipment modernization to enhance treatment capacity. These strategies aim to make unsustainable plants more effective in managing pollutant loads.
The findings highlight the practicality and scientific validity of the evaluation model, providing valuable insights for decision-makers in optimizing wastewater treatment plant operations. The study offers a comprehensive approach for assessing environmental and economic impacts, contributing to the sustainable management of urban water resources.