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Effect of dissolved oxygen and chemical oxygen demand to nitrogen ratios on the partial nitrification/denitrification process in moving bed biofilm reactors

Zafarzadeh, A. and Bina, B. and Nikaeen, M. and Attar, H.M. and Khiadani, M.H. (2011) Effect of dissolved oxygen and chemical oxygen demand to nitrogen ratios on the partial nitrification/denitrification process in moving bed biofilm reactors. Iranian Journal of Biotechnology, 9 (3). pp. 197-205. ISSN 17283043 (ISSN)

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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).

Item Type: Article
Additional Information: Unmapped bibliographic data: LA - English [Field not mapped to EPrints] J2 - Iran. J. Biotechnol [Field not mapped to EPrints] AD - Department of Environmental Health Engineering, School of Paramidicine and Health, Golestan University of Medical Sciences and Health Services, P.O. Box 49165-513, Gorgan, Iran [Field not mapped to EPrints] AD - Department of Environmental Health Engineering, School of Public Health, Isfahan University of Medical Sciences, P.O. Box 82745-319, Isfahan, Iran [Field not mapped to EPrints] DB - Scopus [Field not mapped to EPrints]
Uncontrolled Keywords: COD/N, Dissolved Oxygen, Moving bed biofilm reactors (MBBRs), Partial nitrification, dissolved oxygen, nitrate, nitrite, nitrogen, nitrous oxide, organic carbon, aerobic reactor, article, biofilm reactor, biofiltration, biomass, chemical oxygen demand, concentration (parameters), controlled study, denitrification, effluent, moving bed biofilm reactor, nitrification, suspended particulate matter, waste component removal, waste water treatment plant
Subjects: مقالات نمایه شده محققین دانشگاه در سایت ,Web of Science ,Scopus
موارد کلی
Divisions: معاونت تحقیقات و فناوری
Depositing User: GOUMS
Date Deposited: 19 Apr 2015 04:25
Last Modified: 16 May 2015 16:16
URI: http://eprints.goums.ac.ir/id/eprint/2117

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