US 11,999,641 B2
Method and apparatus for multi-deselection in wastewater treatment
Maureen O'Shaughnessy, Herndon, VA (US); Christine deBarbadillo, Washington, DC (US); Charles Bott, Virginia Beach, VA (US); Haydee De Clippeleir, Washington, DC (US); Bernhard Wett, Innsbruck (AT); and Sudhir Murthy, Herndon, VA (US)
Assigned to HAMPTON ROADS SANITATION DISTRICT, Virginia Beach, VA (US); and D.C. WATER AND SEWER AUTHORITY, Washington, DC (US)
Filed by Hampton Roads Sanitation District, Virginia Beach, VA (US); D.C. Water and Sewer Authority, Washington, DC (US); Bernhard Wett, Innsbruck (AT); Sudhir Murthy, Herndon, VA (US); and Maureen O'Shaughnessy, Herndon, VA (US)
Filed on Mar. 14, 2022, as Appl. No. 17/654,790.
Claims priority of provisional application 63/160,497, filed on Mar. 12, 2021.
Prior Publication US 2022/0289603 A1, Sep. 15, 2022
Int. Cl. C02F 3/12 (2023.01); C02F 3/02 (2023.01)
CPC C02F 3/1236 (2013.01) [C02F 3/025 (2013.01); C02F 3/1263 (2013.01); C02F 3/1268 (2013.01); C02F 2301/046 (2013.01)] 8 Claims
OG exemplary drawing
 
1. A water or wastewater treatment system, comprising:
an influent containing contaminated water;
a reactor comprising (i) an inlet, (ii) a bioreactor, (iii) an internal deselector, and (iv) an outlet, wherein:
(i) the inlet is configured to receive the influent and supply the contaminated water to the bioreactor;
(ii) the bioreactor is configured to disperse the contaminated water in a solid-liquid mixture, treat the solid-liquid mixture and form biological solids;
(iii) the internal deselector is configured to retain, or retard, a first portion of the biological solids from the solid-liquid mixture and output a deselected solid-liquid mixture comprising a second portion of the biological solids; and
(iv) the outlet is configured to receive the deselected solid-liquid mixture and output the deselected solid-liquid mixture, including the second portion of the biological solids, from the reactor; and
a particle deselector configured to receive the deselected solid-liquid mixture and deselect part of the second portion of the biological solids in the deselected solid-liquid mixture to output the deselected part of the second portion of the biological solids; and
a return line configured to supply a remaining part of the second portion of the biological solids to the reactor, wherein the bioreactor comprises a feed zone that receives the influent using a differential influent cascade approach or differential feast famine approach;
wherein the biological solids include particles having an average solids residence time (avSRT) for selecting fast and slow growing organisms with different treatment functions, hereby improving an efficiency of the deselection, wherein: particles in the deselected part of the second portion of the biological solids have a solids residence time (IoSRT) that is lower than the average solids residence time (avSRT); and particles in the retained or the retarded part of the second portion of the biological solids have a solids residence time (hiSRT) that is higher than the average solids residence time (avSRT); wherein the particle deselector comprises at least one of a density-based (DB) deselector or a particle size-compressibility (PSC) deselector or a particle shear and
wherein the internal deselector is configured to perform an internal deselection step to deselect the second portion of biological solids using:
a mixing source;
a visible, ultraviolet or infrared photo source;
a heat source;
a gas source;
a pressure source;
an electromagnetic source; or
a flow source.