Enhanced biological phosphorus removal from wastewater in the tropics
Cokro, Angel Anisa
Date of Issue2018
School of Civil and Environmental Engineering
Enhanced Biological Phosphorus Removal (EBPR) is a phosphors (P) removal method that utilizes the capacity of Polyphosphate Accumulating Organisms (PAOs) to store P more than what is needed for growth. Conventionally, warm temperatures are thought to adversely affect EBPR, while presence of anaerobic stage with distinct separation of carbon and electron acceptors is considered fundamental for successful EBPR. However, recent findings have challenged these paradigms. This dissertation investigated EBPR at warm temperatures when carbon like volatile fatty acids (VFAs) and electron acceptors (e.g. nitrate and/or nitrite) were concomitantly present. Additionally, this thesis also explored a potential strategy to resuscitate failing EBPR systems at warm temperature via addition of wasted activated sludge (WAS). This dissertation showed that non-denitrifying PAOs (non-DPAOs), a group of PAOs that cannot use nitrate and/or nitrite as electron acceptors could carry out EBPR despite the simultaneous presence of carbon and nitrate/nitrite, potentially eliminated the needs for anaerobic stage. However, long term stability of anoxic/aerobic EBPR at warm temperature was influenced by proliferation of non-PAO organisms like certain types of Glycogen Accumulating Organisms (GAOs) or heterotrophic denitrifiers that could compete for carbon. Additionally, WAS addition showed promising potential to be developed as cheap alternative to resuscitate deteriorating EBPR systems.
DRNTU::Engineering::Environmental engineering::Water treatment