Hits:

Indexed by:期刊论文

Date of Publication:2008-07-01

Journal:JOURNAL OF ENVIRONMENTAL SCIENCES

Included Journals:SCIE、PubMed、ISTIC、CSCD

Volume:20

Issue:8

Page Number:933-939

ISSN No.:1001-0742

Key Words:simultaneous nitrification and denitrification (SND); chemical oxygen demand and nitrogen (COD/N) ratio; dissolved oxygen (DO) concentration

Abstract:The effects of chemical oxygen demand and nitrogen (COD/N) ratio and dissolved oxygen concentration (DO) on simultaneous nitrification and denitrification (SND) were investigated using an airlift internal circulation membrane bioreactor (AIC-MBR) with synthetic wastewater. The results showed that the COD efficiencies were consistently greater than 90% regardless of changes in the COD/N ratio. At the COD/N ratio of 4.77 and 10.04, the system nitrogen removal efficiency became higher than 70%. However, the nitrogen removal efficiency decreased to less than 50%, as the COD/N ratio shifted to 15.11. When the operating DO concentration was maintained at 1.0 mg/L in AIC-MBR, a satisfying SND was achieved. Either low or high DO concentration could restrain SND.