Life Cycle Assessment on a Decentralized Domestic Wastewater Treatment System Case of a Community-Based Reclaimed Water Facility in Tianjin, China

• Published in: Journal of Human and Environmental Symbiosis Vol. 38; no. 1; pp. 25 - 35
• Main Authors: LIANG, Zhiyi, YU, Han, FAN, Xuezhou, ZHANG, Jiawen, LI, Yong, XU, Zhenguo, YU, Hongbing, MATSUMOTO, Toru
• Format: Journal Article
• Language: English
• Published: Japan Association for Human and Environmental Symbiosis 31.03.2022
• Subjects: Critical distance; Decentralized reclaimed water reuse facility; Domestic wastewater treatment; Greenhouse gas emissions; Life cycle assessment
• ISSN: 1346-3489; 2434-902X
• DOI: 10.32313/jahes.38.1_25

The centralized wastewater treatment system (CWWT) resulted by economies of scale plays an essential role in improving urban environment and saving water resources, but it needs the support of a complicated pipeline system due to usually location far from the city center. The decentralized wastewater treatment system (DWWT) is another option for treating wastewater and reusing effluent on site, with an advantage of not requiring a pipeline system. This study evaluated a large community-based wastewater treatment system comparing operating in DWWT or CWWT. The results show that: 1) CWWT consumes only 20% of the electricity of DWWT in its operation phase, but consumes 14 times more chemicals and 158 times more fresh water than DWWT; 2) pipeline system supporting CWWT contributes 65% of total GHG emissions during the construction phase; and 3) the critical distance is 56 km when applying 300 mm internal diameter reinforced concrete pipes (RCP), and is shortened in scenarios where thicker RCPs are used and replaced with prestressed concrete cylinder pipes.