NOVELTY - The system comprises a digestion tank including a cover for covering an upper portion of the digestion tank, where the cover includes a vent to eject the desulfurized biogas. An outlet port guides the biogas generated in the digestion tank to the outside. An anaerobic digester mixes the hydrogen sulfide generated in the digestive fluid with the oxygen. A gas vehicle is arranged in an upper portion of the cover to collect the biogas. An air supply nozzle is installed in the outlet port of the cover, and sprays the air to a space between the gas vehicle and the cover.    USE - The desulfurization system is useful for performing an anaerobic digestion process (claimed) of organic wastewater such as food waste.    ADVANTAGE - The system can easily remove the ammonium sulfate from the anaerobic digester, and effectively removes the hydrogen sulfide remaining within the biogas without requiring a separate microorganism or chemicals as a desulfurization liquid.    DETAILED DESCRIPTION - The system comprises a digestion tank including a cover for covering an upper portion of the digestion tank, where the cover includes a vent to eject the desulfurized biogas. An outlet port guides the biogas generated in the digestion tank to the outside. An anaerobic digester mixes the hydrogen sulfide generated in the digestive fluid with the oxygen. A gas vehicle is arranged in an upper portion of the cover to collect the biogas. An air supply nozzle is installed in the outlet port of the cover, and sprays the air to a space between the gas vehicle and the cover. A blower is connected with the air supply nozzle to transfer the external air to the air supply nozzle, and is installed in an outer side of the digestion tank. The biogas coming out from the vent is supplied to a digestive fluid through a gas nozzle of a gas blower. The digestive fluid desulfurized by the external air is transferred to an aeration basin. The air flowing into a top-end part of the air supply nozzle is biogas. A drawer is opened and closed in a side of the cover, and the air and the biogas in the upper portion of the cover are reacted with the crystal and dropped down.