title: Anammox sludge immobilized in polyvinyl alcohol (PVA) cryogel carriers.
abstract: This study evaluated the use of PVA cryogels to encapsulate slow-growing anammox bacteria for deammonification treatment of wastewater. The cryogel pellets were prepared by freezing-thawing at -8 °C. On average, pellets contained 11.8 mg-TSS/g-pellet of enriched anammox sludge NRRL B-50286 (Candidatus Brocadia caroliniensis) in 4-mm cubes. They were tested with synthetic and partially nitrified swine wastewater using continuous stirred-tank reactors packed at 20% (w/v). The immobilized gel was retained inside the reactor by a screen that eliminated the need of sludge recycling. The stoichiometry of anammox reaction was maintained for more than 5 months under non-sterile conditions. The process was not limited by substrates availability unless quite low N concentration (<5 mg/L) achieving >93% removal efficiency. In mass balances, >80% of the potential N conversion activity was achieved (2920 mg-N/kg-pellet/d). In addition, the immobilized bacteria were resilient to inhibition at high nitrite concentrations (244-270 mg-N/L).
authors.affiliation: USDA-ARS Coastal Plains Soil, Water and Plant Research Center. 2611 W. Lucas St., Florence, SC 29501, USA. albert.magri@gmail.com
authors.forename: Albert
authors.initials: A
authors.lastname: Magrí
authors.forename: Matias B
authors.initials: MB
authors.lastname: Vanotti
authors.forename: Ariel A
authors.initials: AA
authors.lastname: Szögi
mesh_terms: D000641:Ammonia / Q000302:isolation & purification / Q000378:metabolism*; D001421:Bacteria, Anaerobic / Q000378:metabolism*; D018914:Cells, Immobilized / Q000502:physiology; D059985:Cryogels / Q000737:chemistry*; D011142:Polyvinyl Alcohol; D012722:Sewage / Q000382:microbiology*; D014874:Water Pollutants, Chemical / Q000302:isolation & purification / Q000378:metabolism*; D018508:Water Purification / Q000379:methods*
chemical_list: D059985:Cryogels; D012722:Sewage; D014874:Water Pollutants, Chemical; D000641:Ammonia; D011142:Polyvinyl Alcohol