title: Effects of different quinoid redox mediators on the removal of sulphide and nitrate via denitrification.
abstract: The impact of different quinoid redox mediators on the simultaneous conversion of sulphide and nitrate in a denitrifying culture was evaluated. All quinones evaluated, including anthraquinone-2,6-disulphonate (AQDS), 2-hydroxy-1,4-naphthoquinone and 1,2-naphthoquinone-4-sulphonate (NQS) were reduced by sulphide under abiotic conditions. NQS showed the highest reduction rate by sulphide (132 micromol h(-1)) and promoted the maximum rate of sulphide oxidation (87 micromol h(-1)) by denitrifying sludge, which represents an increase of 44% compared to the control lacking quinones. The reduced form of AQDS (AH(2)QDS) served as an electron donor for the microbial reduction of nitrite and N(2)O, which represents the first demonstration of hydroquinones supporting the microbial reduction of denitrifying intermediates. The results taken as a whole suggest that some quinones may significantly increase the rate of removal of S and N under denitrifying conditions.
authors.affiliation: Departamento de Ciencias del Agua y del Medio Ambiente, Instituto Tecnológico de Sonora, Avenida 5 de Febrero 818 Sur, Cd. Obregón, Sonora 85000, Mexico.
authors.forename: Clicerio
authors.initials: C
authors.lastname: Aranda-Tamaura
authors.forename: María Isabel
authors.initials: MI
authors.lastname: Estrada-Alvarado
authors.forename: Anne-Claire
authors.initials: AC
authors.lastname: Texier
authors.forename: Flor
authors.initials: F
authors.lastname: Cuervo
authors.forename: Jorge
authors.initials: J
authors.lastname: Gómez
authors.forename: Francisco J
authors.initials: FJ
authors.lastname: Cervantes
mesh_terms: D000693:Anaerobiosis; D006873:Hydroquinones / Q000737:chemistry*; D009566:Nitrates / Q000032:analysis / Q000737:chemistry*; D010084:Oxidation-Reduction; D012722:Sewage / Q000382:microbiology*; D013440:Sulfides / Q000032:analysis / Q000737:chemistry*; D014874:Water Pollutants, Chemical / Q000032:analysis / Q000737:chemistry*; D018508:Water Purification / Q000379:methods*
chemical_list: D006873:Hydroquinones; D009566:Nitrates; D012722:Sewage; D013440:Sulfides; D014874:Water Pollutants, Chemical