Abstract: A system in which human waste in toilet water is decomposed and the treated water is circulated as wash water includes a toilet bowl body portion, a soil water storage tank configured to store the soil water discharged from a toilet bowl temporarily, a pump configured to pump up and deliver the soil water in the soil water storage tank, a reaction treatment tower containing filter elements as a microorganism carrier and performing a biological treatment by dispersing the soil water fed from the pump from an upper portion of the tower to bring the same into contact with the filter element, a water storage tank under the reaction treatment tower and configured to receive and store water passed through the reaction treatment tower, and a pump configured to pump up the water in the water storage tank and deliver the same as the wash water.