| 摘要 |
<p>When conducting a chemical cleaning of a submerged membrane element used when subjecting an organic wastewater containing high concentration of manganese to membrane bioreactor treatment, in a bioreactor treatment tank, organic matter decomposition and manganese removal are simultaneously and efficiently conducted, and high recovery effect is achieved without adversely affecting microorganisms in activated sludge by a cleaning method for a submerged membrane element used in a membrane bioreactor treatment in which organic wastewater containing 1 mg/L or more of manganese is subjected a biological treatment in a bioreactor treatment tank and then subjected to solid-liquid separation by a membrane filtration device provided in the bioreactor treatment tank, in which after a first liquid containing an oxidizing agent is injected from a secondary side of the submerged membrane element to a primary side thereof and maintained for a certain period of time, the first liquid containing an oxidizing agent is suction-discharged from the secondary side to the outside of the system, and then a second liquid containing an acid is injected from the secondary side of the submerged membrane element to the primary side thereof and maintained for a certain period of time, followed by conducting suction filtration operation.</p> |
