Can Phosphorus Accumulating Organisms (PAOs) Control Non- Bulking High Effluent TSS Upsets in Activated Sludge Wastewater Treatment Plants? An East Bay Municipal Utility District Case Study

摘要

The competition between phosphorus accumulating organisms (PAOs) and glycogen accumulating organisms (GAOs) is well known in biological nutrient removal (BNR) activated sludge plants because of the loss of phosphorus removal that takes place when GAOs dominate a BNR activated sludge process. Anaerobic selectors, designed to control filamentous bulking in activated sludge, should be able to function just as well whether GAOs or PAOs dominate the activated sludge, since both take up and remove soluble organics in an anaerobic zone and thereby prevent filamentous growth. Nonetheless, a very large GAO that dominates anaerobic selectors at very low MCRTs (< 1.0 days) can rapidly grow large numbers of cells that cause high effluent total suspended solids (TSS) upsets. Keeping the MCRT between 1.2 and 2.0 days might be the answer to stop TSS upsets caused by rapid GAO growth.