Wastewater treatment tank, wastewater treatment system, wastewater treatment method, and wastewater treatment method

摘要

PPROBLEM TO BE SOLVED: To provide a technique which can rationally reduce the volume of a solid material contained in wastewater while simplifying the structure of a wastewater treatment tank. PSOLUTION: This wastewater treatment tank 103 has a plurality of treatment tanks including at least two aerobic treatment tanks 115 and 121 in a housing 110 and treats a water to be treated by sequentially transferring inflow water to be treated to each of the treatment tanks 115 and 121. The tank 103, is characterized by being constituted so that at least one of the aerobic treatment tanks 115 and 121 reduces the volume of the solid material contained in the water to be treated by circulating the water from a treatment tank 117 which is positioned on the downstream side from the aerobic treatment tank 115 and positioned on the upstream side from the other aerobic treatment tank 121, to the aerobic treatment tank 115. PCOPYRIGHT: (C)2004,JPO