Civil and Environmental Engineering Department, University of South Florida, 4202 E. Fowler Ave., Tampa, FL 33620, USA.
J Environ Manage. 2013 Dec 15;131:7-15. doi: 10.1016/j.jenvman.2013.09.043. Epub 2013 Oct 17.
Despite concerns of sanitation provision, water scarcity, climate change, and resource depletion, limited research has been conducted to assess the environmental impact of wastewater treatment and resource recovery strategies to improve access to sanitation and resource utilization in developing world settings. Accordingly, the goal of this study is to evaluate the potential benefits of mitigating the environmental impact of two small community-managed wastewater treatment systems in rural Bolivia using resource recovery (i.e., water reuse and energy recovery). Life Cycle Assessment (LCA) is used to estimate the embodied energy, carbon footprint, and eutrophication potential of these systems under existing and resource recovery conditions. Two distinct technologies are analyzed: (1) an upflow anaerobic sludge blanket reactor (UASB) followed by two maturation ponds in series (UASB-Pond system) and (2) a facultative pond followed by two maturation ponds in series (3-Pond system). For the existing systems, bathroom and collection infrastructure had a higher energy intensity than the treatment processes, whereas direct methane emissions from treatment were the primary contributors to the carbon footprint. Taking advantage of reclaimed water was found to greatly reduce the eutrophication potential for both systems, in which the reduction increases proportionally to the percentage of water that is reclaimed. Energy recovery from the UASB-Pond system provided a 19% reduction in embodied energy and a 57% reduction in carbon footprint. Combining water reuse and energy recovery for the UASB-Pond system reduced the eutrophication potential, embodied energy and carbon footprint simultaneously. This highlights the benefits of integrated resource recovery.
尽管存在卫生设施供应、水资源短缺、气候变化和资源枯竭等问题，但对于评估废水处理和资源回收策略对改善发展中国家环境卫生和资源利用的环境影响的研究还很有限。因此，本研究的目的是评估通过资源回收（即水再利用和能源回收）来减轻玻利维亚两个小型社区管理的废水处理系统的环境影响的潜在益处。生命周期评估（LCA）用于估算这些系统在现有和资源回收条件下的隐含能源、碳足迹和富营养化潜力。分析了两种截然不同的技术：（1）上流式厌氧污泥床反应器（UASB）后接两个串联的成熟塘（UASB-塘系统）和（2）兼性塘后接两个串联的成熟塘（3-塘系统）。对于现有系统，浴室和收集基础设施的能源强度高于处理过程，而处理过程中的直接甲烷排放是碳足迹的主要贡献者。利用再生水可大大降低两个系统的富营养化潜力，其中减少量与回收水的百分比成正比。UASB-塘系统的能源回收可使隐含能源减少 19%，碳足迹减少 57%。UASB-塘系统的水再利用和能源回收的结合可同时降低富营养化潜力、隐含能源和碳足迹。这突显了综合资源回收的好处。
