Department of Environmental Engineering, Faculty of Engineering, Kasetsart University, Bangkok, 10900, Thailand.
Sci Rep. 2022 Aug 25;12(1):14540. doi: 10.1038/s41598-022-18852-y.
This research investigates the cost-effectiveness of four sludge treatment scenarios for centralized (C) and decentralized (D) wastewater treatment plants (WWTP) using life cycle cost assessment (LCCA). The environmental impacts and costs are quantified by Stepwise2006. The most environmentally and financially viable WWTP construction option for Bangkok, Thailand (2022-2031) is determined in terms of LCCA and net present value (NPV). The environmental costs of D-treatment scenarios are lower than those of C-treatment scenarios. The total environmental costs of C- and D-fertilizer scenarios are lower than those of C- and D-dewatering scenarios. The net cash flow per functional unit of C-WWTPs is higher than that of D-WWTPs. The C-fertilizer scenario is the most environmentally and economically viable treatment scenario due to the lowest LCCA deficit (-5.58 THB per m treated effluent). Composting should thus be adopted for treating sludge. The most environmentally and financially viable WWTP construction option is option I (building four C-WWTPs within 10 years) due to the lowest LCCA deficit (-19925 million THB) and smallest financial loss (NPV = -6309.96 million THB). Essentially, the local administration of the capital should adopt option I as a guideline in formulating the wastewater treatment management policy of 2022-2031.
本研究采用生命周期成本评估（LCCA）方法，考察了集中式（C）和分散式（D）污水处理厂（WWTP）四种污泥处理方案的成本效益。通过 Stepwise2006 对环境影响和成本进行量化。以 LCCA 和净现值（NPV）为指标，确定了泰国曼谷 2022-2031 年最具环境和财务可行性的 WWTP 建设方案。D 处理方案的环境成本低于 C 处理方案。C 和 D 施肥方案的总环境成本低于 C 和 D 脱水方案。每单位功能单元的 C-WWTP 净现金流量高于 D-WWTP。由于 LCCA 赤字最低（每处理 1 立方米污水为-5.58 泰铢），C-施肥方案是最具环境和经济效益的处理方案。因此，应采用堆肥处理污泥。由于 LCCA 赤字最低（-199.25 亿泰铢）和财务损失最小（NPV=-63.0996 亿泰铢），因此，最具环境和财务可行性的 WWTP 建设方案是方案 I（在 10 年内建造四座 C-WWTP）。实质上，首都地方政府应将方案 I 作为制定 2022-2031 年污水处理管理政策的指导方针。
