PROBLEM TO BE SOLVED: To contrive effective utilization and an environmental countermeasure by preventing offensive odor such as putrefactive odor generated from a wet dust-removing facility used in agricultural facilities or the like at present and cleaning sewage and composting refuse and sludge or the like. SOLUTION: Anaerobic microorganisms are charged to a water tank in a wet dust removing facility and only stirring is performed. Operational running is performed by charging an effective anaerobic microorganism group, which inhibits putrefactive decomposition of organic substance and promotes fermentable decomposition, to the water tank in the wet dust removing facility. Offensive odor such as putrefaction odor is not generated from water in the water tank and discharged refuse and sludge even after an operating season without mentioning duration of operational running. Water in the water tank is made clean together with the elapse of time and can be used for operational running of the next year as it is. When refuse and sludge discharged from the water tank are buried in soil of a field or the like, these are decomposed for about three weeks and become compost and a natural cycle is established. Water in the water tank is used as a soil amendment because the effective anaerobic microorganism group is gradually propagated. Garbage and organic substance such as rice hull are fermented and decomposed and composted.
