Applicability of sustainability indicators to wastewater treatment processes

Abstract

Wastewater treatment is an important process of considerable significance for environmental, economic and social aspects of sustainability. Although wastewater treatment helps reduce environmental pollution, thus limiting negative societal effects, it may have negative impacts on sustainability; for instance, waste discharged during the treatment. Determination of the impact of a particular process generally involves application of a set of sustainability indicators that evaluate environmental, economic and societal issues. However, indicators are usually presented without a description that is sufficiently detailed to enable repetition of the calculations. For example, sustainability indicators for evaluation of wastewater treatment processes are commonly presented in tabular form. The objective of this work is to assess a set of sustainability indicators for evaluation of environmental, economic and societal aspects of wastewater treatment processes. Some of the presented indicators have not previously been used in the context of wastewater treatment. Usually environmental sustainability is assessed through calculation of greenhouse gas release, waste discharge and energy use. Economic sustainability is determined by estimating capital and wastewater operating costs. Social sustainability is evaluated based on working conditions, e. g., worker stress, work satisfaction and attitudes to achieving sustainability. The applicability of the approach and indicators chosen is evaluated with case studies of wastewater treatment for which the presented sustainability indicators are calculated. The results show that environmental and economic indicators can easily be determined quantitatively, but social indicators require a qualitative approach. The usability of the indicators and their limitations are critically analyzed. © 2013 Elsevier B.V.