The Life-Cycle Assessment of Urban Sewage Sludge Disposal Systems of Ekbatan Tehran Wastewater Treatment Plant

The present study has assessed the life-cycle as an efficient method for environmental analysis, four disposal systems, and the management of urban sewage sludge in Ekbatan Tehran wastewater treatment plant. In order to assess the effects of the life-cycle Eco Indicator 99 method was used by OPENLCA software, and system boundary has been considered since the arrival of swage to wastewater treatment until its exit and the disposal of sludge. According to the results, using sludge in agricultural lands has positively influenced the group effect of fossil fuels due to economizing the production of phosphor and nitrogen fertilizers. On the other hand, using sludge in agriculture has negatively influenced the carcinogenetic group effects, Inorganics Respiratory, ecotoxicity, acidification, and fertilization, which is mainly due to the heavy metals in sludge. However, industrial fertilizers have some heavy metals. Therefore, comparing the effects of life cycle from two processes of using sludge and industrial fertilizer may be considered in decision making to select the optimal process.