Method for increasing the rate of anaerobic bioremediation in a bioreactor

摘要

A process is disclosed to increase the anaerobic bioremediation rate in a bioreactor by recirculating to the bioreactor that portion of a pollution stream that has flowed through a passageway containing material on whose surface anaerobic microorganisms can attach or become immobilized at a flow rate that would slough from the surface and return to the stream at least a portion of the microorganisms from the surface. A preferred flow rate would be one which, after the surface of the material has been substantially covered with immobilized microorganisms, sloughs from the surface and returns to the stream a portion of the immobilized microorganisms at a rate of at least 105 cfu for each milliliter of the stream flowing through the passageway, more preferably 106-108 cfu. Another preferred flow rate would be one in which the total BOD consumed in the passageway per unit of time is maximized. Still another preferred flow rate would be 0.1-12.0 times the volume of the passageway per hour. In another embodiment a microorganism incubation apparatus for bioremediation of a liquid pollution stream is provided which comprises: a column having a passageway extending through the column, charged, porous material positioned in the passageway and having a surface about which microorganisms can become immobilized, means for retaining the material in the passageway and structured to allow the stream to pass through the passageway, and a pump sized to flow the stream through the passageway at a flow rate sufficient to slough from the surface and return to the stream at least a portion of any microorganisms attached or immobilized on the surface of the material.