Catchment-Scale Water Management of Wastewater Treatment in an Urban Sewerage System with CO2 Emission Assessment

Abstract

In this study, a dynamic numerical model was developed to examine catchment-scale wastewater management, including urban household wastewater treatment. The model allowed both water quality and energy consumption to be evaluated. This system was applied to an actual sewerage system, and the effects of management strategies on water quality and energy consumption were assessed in a numerical simulation. The entire water resource system of a basin, including a forest catchment and an urban area, was evaluated synthetically from a spatial distribution perspective with respect to water quantity and quality. The life-cycle assessment technique was applied to optimize wastewater treatment management with the aim of improving water quality and reducing CO2 emissions. A numerical model was developed to predict the water cycle and contamination in the catchment and the city; the effect of a wastewater treatment system on the urban region was evaluated; pollution loads were quantitatively assessed; and the effect of excluding rainwater from the treatment system during flooding and the effect of urban rainwater control on water quality were examined. Analysis indicated that controlling the amount of rainwater inflow into a wastewater treatment plant in an urban area with a combined sewerage system has a large impact on reducing CO2 emissions because of the load reduction on the urban sewerage system.