The Effect of Energy Saving in Wastewater Treatment Plant on the Environmental Sustainability of the Plant

Abstract

Wastewater treatment plants (WWTPs) have significant function for the urban water management. However, they can consume large amount of energy for reducing the pollutant concentration in aquatic environments. In this work, the effect of energy saving in the selected wastewater treatment plant (before and after the energy saving revisions) on the environmental sustainability of the plant was investigated by life cycle assessment (LCA). Two situations were assessed comparatively: WWTP-1 (before energy saving) and WWTP-2 (after energy saving). Life cycle impacts were evaluated in terms of both mid-point and end-point impact categories by ReCiPe 2016 methodology. The results showed that contribution of electricity consumption in WWTP-2 significantly decreased in almost all mid-point impact categories compared with WWTP-1. Considering damage assessment, overall environmental burden of WWTP-2 was determined to be 36% lower than WWTP-1. It was also noted that in addition to electricity saving, the method chosen for sludge disposal was decisive in the environmental performance of the wastewater treatment plant.