Performance and Kinectics Aspects of Nitrogen Removal in a Biofilm Sequencing Batch Reactor

• Published in: International Journal of Environmental Research Vol. 7; no. 2; pp. 515 - 522
• Main Authors: Costa, RHR, Wolff, D B, Souto, V S
• Format: Journal Article
• Language: English
• Published: 01.01.2013
• Subjects: Freshwater
• ISSN: 1735-6865

A biofilm sequencing batch reactor with a volume of 1.42 m super(3), nylon nets providing a 4,140 m super(2)/m super(3) support area for biofilms and an automated operation with 8 hour cycles was studied. The duration of the experiment was 135 days. Removal efficiencies e greater than or equal to 80% were obtained for carbonaceous matter, producing an effluent with 31 plus or minus 26.8 mg/L of filtered COD, 7 plus or minus 3.6 mg/L of BOD sub(5) and 12 plus or minus 3.2 mg/L of TOC. The average removal efficiency of ammonium was 77 plus or minus 16.6%, with a mean concentration in the effluent of 14 plus or minus 10.2 mg NH sub(4)-N/L. The denitrification efficiency was 80 plus or minus 14.7%. The effluent characteristics met the requirements of Brazilian environmental standard for discharge to receiving water bodies. A kinetic study of nitrification and denitrification showed that during the aerobic phase the specific rate of ammonium consumption was 0.057 g NH sub(4)-N/g VSS.d and the production of NOx-N was 0.074 g NOx-N/g VSS.d, while the specific rate of NOx-N consumption was 0.05 g NOx-N/g VSS.d during the anoxic phase. The suspended and fixed biomass was composed of 50% ammonium-oxidizing bacteria (AOB).