Development of an Integrated Environmental Impact Assessment Model for Assessing Nitrogen Emissions from Wastewater Treatment Plants

Environmental impact of the WWTP is assessed using LIME2, Japanese Life cycle impact assessment model. Environmental loads shown in Fig. 1 is assessed in this study. Pollutants and substances cause environmental problem (Midpoint) and damage human, ecosystem, and social assets (Endpoint). We newly developed. This study impacts to the endpoints are converted economic value to enable compare total impact on environment. To estimate damage factor (DFNH4-N in equation(2)) data of environmental water in Saitama Pref., Japan is obtained. The WWTP is operated by the conventional activated sludge process with continuous aeration under two operating conditions (case 1 and case 2) . The wastewater was treated with less aeration in case 1, to save electricity consumption, without nitrification. In case 2 nitrification was accelerated with a large rate of aeration.