Complete and simultaneous removal of ammonium and m-cresol in a nitrifying sequencing batch reactor

• Published in: Biodegradation (Dordrecht) Vol. 24; no. 3; pp. 377 - 385
• Main Authors: Zepeda, Alejandro, Ben-Youssef, Chérif, Rincón, Susana, Cuervo-López, Flor, Gómez, Jorge
• Format: Journal Article
• Language: English
• Published: Dordrecht Springer Netherlands 01.06.2013; Springer; Springer Nature B.V
• Subjects: Ammonia; Aquatic Pollution; Aromatic compounds; Biodegradation; Biodegradation of pollutants; Biodegradation, Environmental; Biological and medical sciences; Biomedical and Life Sciences; Bioreactors; Biotechnology; Cresols - isolation & purification; Environment and pollution; Fundamental and applied biological sciences. Psychology; Geochemistry; Industrial applications and implications. Economical aspects; Kinetics; Life Sciences; Microbiology; Nitrification; Original Paper; Oxidation; Oxidation-Reduction; Quaternary Ammonium Compounds - isolation & purification; Sewage; Soil Science & Conservation; Terrestrial Pollution; Waste Management/Waste Technology; Waste Water Technology; Water Management; Water Pollution Control; Cresol; Oxidation; Inhibition; Sequencing batch reactor; Nitrification; Biodegradation; Ammonium; m-Cresol
• ISSN: 0923-9820; 1572-9729
• DOI: 10.1007/s10532-012-9595-0

The kinetic behavior, oxidizing ability and tolerance to m -cresol of a nitrifying sludge exposed to different initial concentrations of m -cresol (0–150 mg C L −1 ) were evaluated in a sequencing batch reactor fed with 50 mg NH 4 + -N L −1 and operated during 4 months. Complete removal of ammonium and m -cresol was achieved independently of the initial concentration of aromatic compound in all the assays. Up to 25 mg  m -cresol-C L −1 (C/N ratio of 0.5), the nitrifying yield (Y-NO 3 − ) was 0.86 ± 0.05, indicating that the nitrate was the main product of the process; no biomass growth was detected. From 50 to 150 mg  m -cresol-C L −1 (1.0 ≤ C/N ≤ 3.0), simultaneous microbial growth and partial ammonium-to-nitrate conversion were obtained, reaching a maximum microbial total protein concentration of 0.763 g L −1 (247 % of its initial value) and the lowest Y-NO 3 − 0.53 ± 0.01 at 150 mg  m -cresol-C L −1 . m -Cresol induced a significant decrease in the values of both specific rates of ammonium and nitrite oxidation, being the ammonium oxidation pathway the mainly inhibited. The nitrifying sludge was able to completely oxidize up to 150 mg  m -cresol-C L −1 by SBR cycle, reaching a maximum specific removal rate of 6.45 g  m -cresol g −1 microbial protein-N h −1 . The number of SBR cycles allowed a metabolic adaptation of the nitrifying consortium since nitrification inhibition decreased and faster oxidation of m -cresol took place throughout the cycles.