TECHNOLOGY FOCUS - INSTRUMENTATION AND TESTING - Preferred Components: The anaerobic digestion tank provided with the desulfurization unit includes a cover located on the upper part of the tank and provided with a vent ejecting desulfurized biogas and an outlet port for flowing biogas generated in the digestion tank. The upper portion of the cover is provided with a gas vehicle for collecting biogas at the top part of the cover and an air supply nozzle on the outlet side of the cover for injecting air into a space between the cover and the gas vesicle. A blower transfers the power to external air within the air supply nozzle, and installed in the outside of the digestion tank and connected to the air supply nozzle. The external air supplied by the blower and the biogas generated in the digestion tank react in the space between the gas vesicle and the cover. The outlet port of the digestion tank cover to the upper side sprays air and air flows from the top-end part of the air supply nozzle with the biogas within the digestion tank by forming space between the gas vesicle and the digestion tank cover. A drawer for opening and closing one side of the digestion tank cover, and embedded with crystals, which are dropped down to react with air and biogas in the upper portion of the digestion tank cover. The degassing vessel comprises an degassing vessel cover located on the upper side opening part of the degassing vessel; an air inlet and an outlet are provided on either sides of the cover, where the blower is connected to the air inlet of the degassing vessel cover and the external air transferred by the blower with power flows into the degassing vessel inner portion and discharges ammonia through the outlet of the degassing vessel cover. The anaerobic vessel is provided with an outlet located at the lower side of an anaerobic vessel cover, which contacts the processing water surface. The wall of the anaerobic vessel is installed with a warm water pipe at its bottom surface and heats the processing water of the anaerobic vessel inner portion with the warm water. The second solid-liquid separator is provided with a scum reservoir for separating the scum from the processing water treated at the biological treatment water tank; and injects the scum of the first solid-liquid separator.