Potential of reduction in the emission of methane and nitrous oxide from swine wastewater after treated by two different systems

Abstract

Swine wastewater have high pollution load, requiring treatment before its disposal into the environment. Methane (CH4) potentially emitted for such waste is considered 21 times more polluting than Carbon dioxide (CO2), and the nitrous oxide (N2O) is considered 310 times. In this way, projects of the Clean Development Mechanism (CDM) and energy use related to the CH4are worldwide diffused. It was evaluated the potential greenhouse gas emissions in the influent and effluent from digesters and stabilization ponds used to treat the swine wastewaters in two commercial farms operating in full cycle, located in the municipality of Oratorios-MG, Brazil. Using the methodology "AM0006" to estimate the average potential of greenhouse gases, it was identified 55% and 23% of reduction in emissions from digesters and stabilization ponds, respectively. Thus, when comparing the two systems, in the conditions that they were operated, it can be concluded that the digestion treatment system was more suitable for the treatment of swine wastewater, when taking into account only the emission of the mentioned gases, subjects of this study.