Simultaneous oxidation of ammonium and p-cresol linked to nitrite reduction by denitrifying sludge.
The metabolic capability of denitrifying sludge to oxidize ammonium and p-cresol was evaluated in batch cultures. Ammonium oxidation was studied in presence of nitrite and/or p-cresol by 55 h. At 50 mg/L NH4+-N and 76 mg/L NO2--N, the substrates were consumed at 100% and 95%, respectively, being N2 the product. At 50 mg/L NH4+-N and 133 mg/L NO2--N, the consumption efficiencies decreased to 96% and 70%, respectively. The increase in nitrite concentration affected the ammonium oxidation rate. Nonetheless, the N2 production rate did not change. In organotrophic denitrification, the p-cresol oxidation rate was slower than ammonium oxidation. In litho-organotrophic cultures, the p-cresol and ammonium oxidation rates were affected at 133 mg/L NO2--N. Nonetheless, at 76 mg/L NO2--N the denitrifying sludge oxidized ammonium and p-cresol, but at different rate. Finally, this is the first work reporting the simultaneous oxidation of ammonium and p-cresol with the production of N2 from denitrifying sludge.
Departamento de Biotecnología, Universidad Autónoma Metropolitana-Iztapalapa, DF, Mexico.
G
G
González-Blanco
R
R
Beristain-Cardoso
F
F
Cuervo-López
F J
FJ
Cervantes
J
J
Gómez
D052818:Autotrophic Processes; D001419:Bacteria / Q000378:metabolism; D061249:Batch Cell Culture Techniques; D001673:Biodegradation, Environmental; D003408:Cresols / Q000378:metabolism*; D058440:Denitrification; D009573:Nitrites / Q000378:metabolism*; D009584:Nitrogen / Q000378:metabolism; D058458:Nitrogen Cycle; D010084:Oxidation-Reduction; D000644:Quaternary Ammonium Compounds / Q000378:metabolism*; D012722:Sewage / Q000382:microbiology*; D013997:Time Factors
D003408:Cresols; D009573:Nitrites; D000644:Quaternary Ammonium Compounds; D012722:Sewage; C032538:4-cresol; D009584:Nitrogen