LIFE CYCLE AND ECONOMIC EVALUATION OF EFFLUENT TREATMENT AND REUSE SYSTEM INTEGRATING ANAEROBIC REACTORS, CONSTRUCTED WETLANDS AND OZONIZATION

Abstract

The evaluation of the environmental sustainability and economic costs of a combined system for wastewater treatment and reuse composed by anaerobic reactors (ARs), hybrid constructed wetlands (CWs) and ozonation were investigated in this study. The Life Cycle Assessment (LCA) software SimaPro 8.04 was applied on the data from the system construction and monitoring, which was treating wastewater from an university campus. Economic assessment was conducted considering construction, equipment acquisition and operation costs. In relation to system construction, ARs and CW2 presented most potential impacts due to high-density polyethylene and fiberglass, respectively. Regarding the system operation, Ozonation accounted for 95% of total impacts through network analysis, due to its high energy consumption, and the environmental impacts categories Global warming, Non-renewable energy, Respiratory effects, Non-carcinogenic and eutrophication were the most significant. Concerning the economic assessment, the treatment cost considering only the ARs was estimated in 6.5 US$/m³, considering the integration with the hybrid CWs it nearly doubled (13.5 US$/m³), with the combined system it increased to 28.6 US$/m³. Most expenses were related to energy demand and sludge removal and treatment. Therefore, although the system achieved local standards for wastewater reuse, future studies should investigate local generation of renewable energy and alternative construction materials to reduce impacts and costs.