title: Biological removal of selenate and ammonium by activated sludge in a sequencing batch reactor.
abstract: Wastewaters contaminated by both selenium and ammonium need to be treated prior to discharge into natural water bodies, but there are no studies on the simultaneous removal of selenium and ammonium. A sequencing batch reactor (SBR) was inoculated with activated sludge and operated for 90days. The highest ammonium removal efficiency achieved was 98%, while the total nitrogen removal was 75%. Nearly a complete chemical oxygen demand removal efficiency was attained after 16days of operation, whereas complete selenate removal was achieved only after 66days. The highest total Se removal efficiency was 97%. Batch experiments showed that the total Se in the aqueous phase decreased by 21% with increasing initial ammonium concentration from 50 to 100mgL-1. This study showed that SBR can remove both selenate and ammonium via, respectively, bioreduction and partial nitrification-denitrification and thus offer possibilities for treating selenium and ammonium contaminated effluents.
authors.affiliation: UNESCO-IHE, Westvest 7, 2611 AX Delft, The Netherlands; Université Paris-Est, Laboratoire Géomatériaux et Environnement (LGE), EA 4508, UPEM, 77454 Marne-la-Vallée, France. Electronic address: joyabrata2006@gmail.com.
authors.forename: J
authors.initials: J
authors.lastname: Mal
authors.affiliation: Biofouling and Biofilm Process Section, Water and Steam Chemistry Division, Bhabha Atomic Research Centre, Kalpakkam 603102, Tamil Nadu, India; Homi Bhabha National Institute, Anushaktinagar, Mumbai 400 094, India.
authors.forename: Y V
authors.initials: YV
authors.lastname: Nancharaiah
authors.affiliation: UNESCO-IHE, Westvest 7, 2611 AX Delft, The Netherlands; Université Paris-Est, Laboratoire Géomatériaux et Environnement (LGE), EA 4508, UPEM, 77454 Marne-la-Vallée, France.
authors.forename: E D
authors.initials: ED
authors.lastname: van Hullebusch
authors.affiliation: UNESCO-IHE, Westvest 7, 2611 AX Delft, The Netherlands; Department of Chemistry and Bioengineering, Tampere University of Technology, P.O. Box 541, Tampere, Finland.
authors.forename: P N L
authors.initials: PN
authors.lastname: Lens
mesh_terms: D064751:Ammonium Compounds / Q000302:isolation & purification*; D061249:Batch Cell Culture Techniques / Q000379:methods*; D001673:Biodegradation, Environmental; D057919:Biological Oxygen Demand Analysis; D019149:Bioreactors / Q000382:microbiology*; D009566:Nitrates / Q000302:isolation & purification; D009573:Nitrites / Q000302:isolation & purification; D009584:Nitrogen / Q000302:isolation & purification; D064586:Selenic Acid / Q000302:isolation & purification*; D012643:Selenium / Q000302:isolation & purification; D012722:Sewage / Q000382:microbiology*; D013997:Time Factors
chemical_list: D064751:Ammonium Compounds; D009566:Nitrates; D009573:Nitrites; D012722:Sewage; D012643:Selenium; D064586:Selenic Acid; D009584:Nitrogen
keywords: Activated sludge; Elemental selenium; Selenate bioreduction; Sequencing batch reactor; Simultaneous nitrification and denitrification