Isfahan University of Medical Sciences

Science Communicator Platform

Stay connected! Follow us on X network (Twitter):
Share this content! On (X network) By
Effect of Dissolved Oxygen and Chemical Oxygen Demand to Nitrogen Ratios on the Partial Nitrification/Denitrification Process in Moving Bed Biofilm Reactors



Zafarzadeh A1 ; Bina B2 ; Nikaeen M2 ; Attar HM2 ; Khiadani MH2
Authors
Show Affiliations
Authors Affiliations
  1. 1. Department of Environmental Health Engineering, School of Paramidicine and Health, Golestan University of Medical Sciences and Health Services, Gorgan, P.O. Box 49165-513, Iran
  2. 2. Department of Environmental Health Engineering, School of Public Health, Isfahan University of Medical Sciences, Isfahan, P.O. Box 82745-319, Iran

Source: Iranian Journal of Biotechnology Published:2011

Abstract

Partial nitrification was reported to be technically feasible and economically favorable, especially for wastewater with high ammonium concentration or low C/N ratio. In this study, the effect of dissolved oxygen (DO) and influent ratio of chemical oxygen demand to nitrogen (COD/N) ratio on biological nitrogen removal from synthetic wastewater was investigated. Experiments were conducted in moving bed biofilm reactors (MBBRs) on partial nitrification process in pilot-plant configuration for 300 days. DO levels were changed from 0.04 to 0.12 and 0.42 to 3.4 mg/l in the anoxic (R1) and aerobic (R2) reactors, respectively. The optimum DO for partial nitrification was between 1-1.5 mg/l in the aerobic reactor (R2). Influent COD/N ratios between 20 and 2 g COD/g-N were tested by changing the nitrogen loading rate (NLR) supplied to the pilot plant. During operational conditions when the DO concentration in aerobic reactor was above 1 mg/l, near complete organic carbon removal occurred in the total MBBRs system. The effluent total nitrogen concentration in the operational conditions (1.7-2.1 mg O2/l and NH+ 4-N=35.7 mg N/l) was obtained in the range of 0.85-2 mg/l. The highest nitrite accumulation (50%- 52%) took place at the DO concentration of 1-1.5 mg/l and increased with decreasing COD/N ratio in aerobic reactor (R2). This study showed that the average nitrification rate at various COD/N ratios is about 0.96 gN/m2 per day while the maximum nitrification rate is about 2 gN/m2 per day at COD/N ratios lower than 6. The experimental COD/N ratio for denitrification was close to complete sum of NO2 - and NO3 - (NOx) removal efficiency (about 99%) at COD/N ratio equal 14 in the operational conditions in the anoxic reactor (R1).
Other Related Docs
17. Advanced Oxidation Treatment of Composting Leachate of Municipal Solid Waste by Ozone-Hydrogen Peroxide, International Journal of Environmental Health Engineering (2014)
27. Evaluation of Stability Parameters in In-Vessel Composting of Municipal Solid Waste, Iranian Journal of Environmental Health Science and Engineering (2011)
28. Evaluation of Flat Sheet Membrane Bioreactor Efficiency for Municipal Wastewater Treatment, International Journal of Environmental Health Engineering (2012)
33. Biological Excess Sludge Reduction in Adsorption/Bio-Oxidation Process by Enhancing Predators' Growth, International Journal of Environmental Health Engineering (2020)
34. Performance Evaluation of an Anaerobic Baffled Reactor Treating Wheat Flour Starch Industry Wastewater, Iranian Journal of Environmental Health Science and Engineering (2007)
40. Anaerobic Biodegradation of Ethylene Dichloride in an Anaerobic Sequential Batch Reactor, International Journal of Environmental Health Engineering (2012)
41. The Study of Leachate Treatment by Using Three Advanced Oxidation Process Based Wet Air Oxidation, Iranian Journal of Environmental Health Science and Engineering (2013)
44. Composting Leachate Treatment by an Anaerobic Migrating Blanket Reactor, Ecology, Environment and Conservation (2015)
45. Determination of Design Parameters of Urban Wastewater Treatment Plants in the Cold Regions of Iran, International Journal of Environmental Health Engineering (2012)
47. Nickel (Ii) Removal From Industrial Plating Effluent by Fenton Process, Environmental Engineering and Management Journal (2015)
50. Use of a Uv/H2o2 Process for Posttreatment of a Biologically Treated Composting Leachate, Turkish Journal of Engineering and Environmental Sciences (2014)