Exergy analysis in the assessment of the sustainability of waste gas treatment systems

This study focuses on the sustainability of different technological options for the treatment of waste gases from a waste water treatment plant loaded with volatile organic compounds. The options considered an biofiltration, active carbon adsorption and catalytic and thermal oxidation. The amount of resources and utilities to construct and operate each system have been inv estigated from the point of view of the Second Law of thermodynamics. The u nit in which all resources are treated is Joules of exergy. It was conclude d that biofiltration was the most exergetically efficient system. The cumul ative exergy consumption of the resources and utilities for construction an d operation have been quantified in exergy terms. Further on, the requireme nts for the abatement of emissions generated by operating the waste gas tre atment systems and the amount of renewables have been taken into account in the assessment of the sustainability of the waste gas treatment technologi es. Finally, a comparison between exergy analysis and life cycle analysis i n assessing the sustainability of the waste gas treatment options, is prese nted. (C) 2001 Elsevier Science B.V. All rights reserved.