METHOD AND SYSTEM FOR METHANE FERMENTATION TREATMENT OF WASTEWATER CONTAINING SULFUR COMPOUND

摘要

A method for the anaerobic methane fermentation treatment of a waste water containing a sulfur compound, which comprises adding an oxidizing agent to an organic wastewater, to thereby oxidize the sulfur compound in the wastewater to a molecular sulfur, subsequently introducing the resultant wastewater to an aerobic treatment step to subject it to methane fermentation treatment, and controlling the amount of the oxidizing agent to be added to the wastewater by using, as an indicator, the concentration of the residual oxidizing agent in the water flowing into the aerobic treatment step and/or the concentration of hydrogen sulfide in a biogas generated; and a system for practicing the method. The above oxidizing agent can be ozone, hydrogen peroxide, sodium hypochlorite or a bromine based oxidizing agent. When use is made of the concentration of hydrogen sulfide in a biogas generated in the above aerobic treatment step as the indicator, the oxidizing agent is preferably added so as for said concentration to be 3 % or less.