METHOD FOR RECOVERING VALUABLE MATERIAL FROM ORGANIC WASTE LIQUID

摘要

PURPOSE:To recover efficiently the valuable materials by regulating the retention time in the second bioreactor of the organic waste liquid which is acid-fermented in the first bioreactor so that the acetic acid may be converted into gaseous methane, and recovering the organic acid by membrane separation. CONSTITUTION:The organic waste liquid which is acid-fermented in the first bioreactor 2 is supplied into the second immobilized bioreactor 3 wherein the retention time of the organic waste liquid is regulated so that the acetic acid may be mostly converted into gaseous methane by the methane fermentation due to the bacteria immobilized on a carrier. The generated gaseous methane is sent to a recovery passage 4. The organic waste liquid after methane fermentation is supplied into a membrane separator 5 wherein the organic acid having >=3 C and consisting essentially of propionic acid is recovered by the selective organic acid permeating action of a separation membrane 5a such as a reverse osmosis membrane and an ion exchange membrane. The organic acid is sent to a recovery passage 6, and the organic waste liquid is sent to the waste liquid treating equipment 7.