title: Uncoupling the solids retention times of flocs and granules in mainstream deammonification: A screen as effective out-selection tool for nitrite oxidizing bacteria.
abstract: This study focused on a physical separator in the form of a screen to out-select nitrite oxidizing bacteria (NOB) for mainstream sewage treatment. This separation relied on the principle that the NOB prefer to grow in flocs, while anammox bacteria (AnAOB) reside in granules. Two types of screens (vacuum and vibrating) were tested for separating these fractions. The vibrating screen was preferred due to more moderate normal forces and additional tangential forces, better balancing retention efficiency of AnAOB granules (41% of the AnAOB activity) and washout of NOB (92% activity washout). This operation resulted in increased NOB out-selection (AerAOB/NOB ratio of 2.3) and a total nitrogen removal efficiency of 70% at influent COD/N ratio of 1.4. An effluent total nitrogen concentration <10mgN/L was achieved using this novel approach combining biological selection with physical separation, opening up the path towards energy positive sewage treatment.
authors.affiliation: Center for Microbial Ecology and Technology (CMET), Ghent University, Gent, Belgium; DC Water, DC, USA; Department of Civil & Environmental Engineering, Bucknell University, Lewisburg, PA, USA.
authors.forename: M
authors.initials: M
authors.lastname: Han
authors.affiliation: Center for Microbial Ecology and Technology (CMET), Ghent University, Gent, Belgium; Research Group of Sustainable Energy, Air and Water Technology, Department of Bioscience Engineering, University of Antwerp, Antwerpen, Belgium. Electronic address: Siegfried.Vlaeminck@UAntwerpen.be.
authors.forename: S E
authors.initials: SE
authors.lastname: Vlaeminck
authors.affiliation: DC Water, DC, USA.
authors.forename: A
authors.initials: A
authors.lastname: Al-Omari
authors.affiliation: ARAconsult, Innsbruck, Austria.
authors.forename: B
authors.initials: B
authors.lastname: Wett
authors.affiliation: Hampton Roads Sanitation District, Virginia Beach, USA.
authors.forename: C
authors.initials: C
authors.lastname: Bott
authors.affiliation: DC Water, DC, USA.
authors.forename: S
authors.initials: S
authors.lastname: Murthy
authors.affiliation: DC Water, DC, USA.
authors.forename: H
authors.initials: H
authors.lastname: De Clippeleir
mesh_terms: D000641:Ammonia / Q000378:metabolism; D001419:Bacteria / Q000378:metabolism*; D057919:Biological Oxygen Demand Analysis; D019149:Bioreactors / Q000382:microbiology*; D004867:Equipment Design; D005427:Flocculation; D009573:Nitrites / Q000378:metabolism*; D009584:Nitrogen / Q000378:metabolism; D010084:Oxidation-Reduction; D012722:Sewage; D014865:Waste Disposal, Fluid / Q000295:instrumentation* / Q000379:methods*
chemical_list: D009573:Nitrites; D012722:Sewage; D000641:Ammonia; D009584:Nitrogen
keywords: Biological nutrient removal; Nitrification; Nitritation/denitritation; Partial nitritation/anammox; Shortcut nitrogen removal