Polyhydroxyalkanoate production during wastewater treatment

摘要

A wastewater treatment process elicits microorganisms to convert a waste stream/organic resource to intracellular biopolymer polyhydroxyalkanoate (PHA). The process includes (i) waste stream/organic resource composition feed criteria, (ii) configuration coupled with operational parameters, and (iii) PHA-laden biomass separation and stabilization. A waste stream/organic resource capable of producing enhanced levels of PHA may be selected based on a combination of criteria, which may include short chain fatty acid concentration, protein concentration, polysaccharides concentration, and total suspended solids concentration. The waste stream is introduced into an aeration basin upon a specific configuration and operated under various parameter combinations for selecting/enriching microorganisms capable of producing PHA. The PHA-laden biomass is separated and stabilized for downstream PHA related product beneficial uses. The present process achieves concurrent wastewater treatment and PHA production, where PHA level (of more than 10% on a cell-weight basis) otherwise could not be obtained.

主权项

1. A process for polyhydroxyalkanoate (PHA) production during wastewater treatment, the process comprising:
introducing a return activated sludge (RAS) into an aeration basin at a first location; introducing a waste stream suitable for increased PHA production into the aeration basin at a second location along the length of the aeration basin that is a distance downstream from the first location to provide a first zone upstream from the second location at which the waste stream is introduced followed by a second zone downstream from the second location at which the waste stream is introduced, the first zone selecting microorganisms capable of accumulating PHA, the second zone promoting the production of PHA by the microorganisms in the aeration basin; operating the aeration basin under operational parameters in which the first zone selects microorganisms capable of accumulating PHA followed by the second zone that promotes the production of PHA by the microorganisms in the aeration basin; processing a treated waste stream from the aeration basin to separate activated sludge (AS) from an effluent, wherein a first portion of the AS is returned to the aeration basin as the RAS; and processing a second portion of the AS to produce a stabilized PHA-laden biomass.