PRODUCTION METHOD OF METHANE GAS FROM OLIVE MILL WASTE

Disclosed herein is a method for producing methane gas from olive mill wastewater. The method comprises the steps of (a) obtaining secondary sludge containing nitrogen sources from a municipal sewage treatment plant and selectively culturing the secondary sludge under anaerobic conditions to produce concentrated anaerobic microbial sludge, (b) feeding another secondary sludge containing nitrogen sources obtained from the municipal sewage treatment plant and olive mill wastewater to the concentrated anaerobic microbial sludge, followed by mixing, and (c) anaerobically digesting the mixture to produce methane gas and effluent. According to the method, olive mill wastewater can be anaerobically digested without pretreatment, methane gas can be produced in high yield, and olive mill wastewater and secondary sludge can be simultaneously treated. In addition, anaerobic digestion can be performed in one reaction tank, which is advantageous in terms of space reduction.