Environmental Exergy Analysis of Wastewater Treatment Plants

Abstract

This work evaluates the environmental impact of Wastewater Treatment Plants (WTP) based on data generated by the exergy analysis, calculating and applying environmental impact indexes for two WTP located in the Metropolitan Area of São Paulo. The environmental impact of the waste water treatment plants was done by means of evaluating two environmental impact exergy based indexes: the environmental exergy efficiency (ηenv,exerg) and the total pollution rate (Rpol,t). The environmental exergy efficiency is defined as the ratio of the exergy of the useful effect of the WTP to the total exergy consumed by human and natural resources, including all the exergy inputs. That relation is an indication of the theoretical potential of future improvements of the process. Besides the environmental exergy efficiency, it is also used the total pollution rate, based on the definition done by Makarytchev (1997), as the ratio of the destroyed exergy associated to the process wastes to the exergy of the useful effect of the process. The analysis of the results shows that this method can be used to quantify and also optimise the environmental performance of Wastewater Treatment Plants.

Sustainability analysis of a society based on exergy studies – a case study of the island of Samsø (Denmark)

“…That such a relatively big amount of resources are bound up in infrastructure and the inevitable dissipation of exergy which occurs as result of consumption only stresses the values of recycling (Amini et al, 2007) and the need to have more details about composition and elements in wastes and costs of cleaning processes in connection to wastes e such as solid waste Moberg et al, 2005;Kaysen and Petersen, 2010;Zhou et al, 2011) and waste water (Hellstr€ om, 1997; Mora and Oliver, 2006;Valderrama et al, 2013;Passarini et al, 2014). This in turn points at the importance of implementing Exergetic Life Cycle Assessment (ELCA) as suggested by Mester et al (2006).…”

Exergy as a guide to allocate environmental costs for implementing the Water Framework Directive in the Ebro River

“…The environmental exergy efficiency (g env.exerg ) of a process was also defined by other authors [5] as the ratio between the exergy of the products and the total exergy consumed in that process as shown in Eq. (3):…”

Exergy use review of wastewater study in Latin America

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