In biological treatment, some of the pollutants in the wastewater are removed by adhering to the sludge or discharged as excess sludge without being decomposed. In addition, even if it is decomposed, it may be stored as nutrients in the fungus body.

GENKI increases the degradability and reduces both of these (undegraded substances and nutrients in the fungus body), resulting in a decrease in the amount of excess sludge.