METHOD FOR FORMING AEROBIC GRANULES, DEVICE FOR FORMING AEROBIC GRANULES, METHOD FOR TREATING WASTEWATER, AND DEVICE FOR TREATING WASTEWATER

摘要

Provided is a method for forming aerobic granules in which a semibatch reactor for forming granules is used, the method involving repeatedly carrying out an inflowing step for causing organic-matter-containing wastewater that includes organic matter to flow in, a biological treatment step for biologically treating substances to be treated in the organic-matter-containing drainage water by using microbial sludge, a settling step for allowing the microbial sludge to settle out, and a discharge step for discharging biologically treated water which has been biologically treated, wherein the reaction time is adjusted such that the value obtained by dividing the total cycle time by the reaction time and multiplying the resulting quotient by the ratio of the MLSS concentration to the BOD load charged into the semibatch reactor is within a range of 0.05 to 0.25 kgBOD/kgMLSS/d, and the sludge is drawn such that the sludge retention period is 5 to 25 days.