Water Footprint Assessment for Wastewater Treatment: Method, Indicator, and Application

Abstract

The water footprint in terms of the sum of both direct and indirect water cost of wastewater treatment is for the first time accounted in this work. On the basis of the hybrid method as a combination of process analysis and input-output analysis, a detailed water footprint accounting procedure is provided to cover the supply chain of a wastewater treatment plant. A set of indices intending to reveal the efficiency as well as renewability of wastewater treatment systems are devised as parallels of corresponding indicators in net energy analysis for energy supply systems. A case study is carried out for the Beijing Space City wastewater treatment plant as a landmark project. The high WROI (water return on investment) and low WIWP (water investment in water purified) indicate a high efficiency and renewability of the case system, illustrating the fundamental function of wastewater treatment for water reuse. The increasing of the wastewater and sludge treatment rates are revealed in an urgent need to reduce the water footprint of China and to improve the performance of wastewater treatment.

Taiwan’s Ecological Footprint (1994–2011)

“…The ecological footprint is a powerful indicator of the sustainability of development, as it considers the dynamics that are associated with the pressure that is exerted on the environment by the use of (renewable and non-renewable) resources as inputs and various outputs (such as waste or CO 2 ) [15]. The ecological footprint was modified to deal with assessing several applications such as the exergy based ecological footprint [16][17][18], water footprint [19], pig-biogas-fish system [20], fruit production systems [21], etc. Therefore, the ecological footprint can be utilized to measure the dependency of both consumers and producers on the global ecosystem [22].…”

Embodiment of virtual water of power generation in the electric power system in China

“…All these analyses showed that virtual water accounting can bring comprehensive and accurate insights into water management issues. Recently, virtual water was also used to investigate the water issues within the specific engineering and technological systems or sectors, such as wastewater treatment system [26], building's engineering system [27] and service sector [28].…”

Water footprint assessment in wastewater treatment plants

“…To the best of our knowledge, the application of the WF assessment methodology to WWTPs 95 is limited to the work of Liu et al, (2012) and Shao and Chen (2013). The first study only 96 estimated the grey water footprint of anthropogenic emissions to major rivers, not specifically 97 from WWTPs, and the second study only accounted for the blue water footprint (the study 98 also did not account for sludge treatment, which is extremely important in LCA).…”