title: Treatment of high-ammonium anaerobic digester supernatant by aerobic granular sludge and ultrafiltration processes.
abstract: Anaerobic sludge digester supernatant characterized by 569 mg TKN L(-1), high color and a COD/N ratio of 1.4 was treated in granular sequencing batch reactors (GSBRs) followed by post-denitrification (P-D) and ultrafiltration (UF) steps. The use of granular sludge allowed for the oxidation of ammonium in anaerobic digester supernatant at all investigated GSBR cycle lengths of 6, 8 and 12 h. The highest ammonium removal rate (15 mg N g(-1) VSS h(-1)) with removal efficiency of 99% was noted at 8 h. Since the GSBR effluent was characterized by a high concentration of nitrites, slowly-degradable substances and biomass, additional purification steps were applied. In P-D stage, the microbial activity of granular biomass in the GSBR effluent was implemented. The P-D was supported by external carbon source addition and the most advantageous variant comprised dosing of half of the theoretical acetate dose for nitrite reduction in the 3-h intervals. The use of the system consisting of the GSBR with 8 h, an optimal P-D variant and a UF for the treatment of anaerobic digester supernatant allowed for the 99%, 71% and 97% reductions of TKN, COD and color, respectively.
authors.affiliation: Department of Environmental Biotechnology, University of Warmia and Mazury in Olsztyn, Słoneczna 45 G, 10-709 Olsztyn, Poland. agnieszka.cydzik@uwm.edu.pl
authors.forename: Agnieszka
authors.initials: A
authors.lastname: Cydzik-Kwiatkowska
authors.forename: Magdalena
authors.initials: M
authors.lastname: Zielińska
authors.forename: Katarzyna
authors.initials: K
authors.lastname: Bernat
authors.forename: Irena
authors.initials: I
authors.lastname: Wojnowska-Baryła
authors.forename: Tomasz
authors.initials: T
authors.lastname: Truchan
mesh_terms: D000693:Anaerobiosis; D019149:Bioreactors; D058440:Denitrification; D000644:Quaternary Ammonium Compounds / Q000032:analysis / Q000737:chemistry*; D012722:Sewage / Q000737:chemistry*; D014462:Ultrafiltration; D014865:Waste Disposal, Fluid / Q000379:methods*; D014874:Water Pollutants, Chemical / Q000032:analysis / Q000737:chemistry*
chemical_list: D000644:Quaternary Ammonium Compounds; D012722:Sewage; D014874:Water Pollutants, Chemical