Patent ID: 11878926
Assignee: VEOLIA WATER SOLUTIONS & TECHNOLOGIES SUPPORT
Field: Environmental technology (Chemistry)
Classification: CPC C  Y | IPC C

Claim 9:
10. A mainstream deammonification process for removing ammonium and phosphorus from a stream of wastewater while reducing a tendency of sludge produced in the process to bulk, the process comprising:
clarifying the wastewater stream in a primary clarifier and producing a primary effluent;
directing a first portion of the primary effluent to a biological treatment reactor and removing carbon from the primary effluent to produce treated wastewater;
after treating the first portion of the primary effluent in the biological treatment reactor, directing the treated wastewater into an integrated fixed film activated sludge (IFAS) deammonification reactor that is provided with intermittent aeration, including periods of air on and periods of air off;
directing a second portion of the primary effluent to an anaerobic or anoxic selector located upstream of the IFAS deammonification reactor and in the anaerobic or anoxic selector, selecting biological phosphorus removing microorganisms and non-filamentous microorganisms;
directing an effluent from the anaerobic or anoxic selector into the IFAS deammonification reactor and in the process bypassing the biological treatment reactor;
injecting the effluent from the anaerobic or anoxic selector into the IFAS deammonification reactor wherein the effluent from the anaerobic or anoxic selector is mixed with the treated wastewater in the IFAS deammonification reactor to form a wastewater mixture;
in the IFAS deammonification reactor, removing ammonium from the wastewater mixture by a nitritation and an anammox process and removing phosphorus from the wastewater mixture; and
directing the wastewater mixture from the IFAS deammonification reactor to a secondary clarifier and producing a secondary effluent and a clarifier underflow and recycling a portion of the clarifier underflow to the anaerobic or anoxic selector.