・Activated Sludge Method and Contact Oxidation Method are kinds of solid-liquid separation, therefore, a treatment and a disposition of sludge are necessary.

・However, Jarikko Purification System does not need a treatment and a disposition of sludge.

・Activated Sludge Method is designed by the BOD concentration or the BOD load. However, in Jarikko Purification System, BOD quickly decreases and SS slowly decreases. Therefore, the specifications of wastewater should be measured by the SS concentration or the SS load.

・Necessary retention time is determined by the SS concentration.

・Aeration quantity is also determined by the SS concentration.