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COMBINED ORGANIC CARBON AND COMPLETE NITROGEN REMOVAL USING ANAEROBIC AND AEROBIC UPFLOW FILTERS.
- Source :
- Water Science & Technology; 1994, Vol. 30 Issue 12, p297-306, 10p
- Publication Year :
- 1994
-
Abstract
- Two laboratory upflow aerobic and anaerobic tilters fed with synthetic wastewaters were used to study firstly the effects of aeration rate on the nitrification of anaerobically pre-treated effluents and secondly the effects of recycle-to-influent ratios on methane production rate, denitrification and nitrification performances of a combined aerobic and anaerobic wastewater treatment process. Nitrification of anaerobically pre-treated effluent was accompanied by aerobic post-treatment for residual COD removal. A comparison of nitrification performances using autotrophic medium and anaerobically pre-treated effluents (containing 1203 mg COD 1 <superscript>-1</superscript>) with the same ammonia nitrogen concentration of about 300 mg NH<subscript>4</subscript>-N 1<superscript>-1</superscript> showed that 3% of added ammonia nitrogen was assimilated by autotrophic nitrifiers during nitrification of the autotrophic medium while up to 30% was assimilated by both nitrifiers and heterotrophs during organic carbon removal and nitrification of anaerobically pre-treated effluent. Furthermore, it was suspected that significant nitrogen loss through denitrification occurred in the aerobic filter especially at low aeration rates. In the study of the combined aerobic-anaerobic system, maximum ammonia nitrogen removal of 70% through denitrification was obtained at recycle-to-influent ratios of 4 and 5. COD removal efficiency in the anaerobic filter decreased from 77 to 60% for recycle-to-influent ratios of zero to 5. Overall COD removal efficiency of the entire system was constant at about 99% due to heterotrophic COD removal in the aerobic filter. [ABSTRACT FROM AUTHOR]
Details
- Language :
- English
- ISSN :
- 02731223
- Volume :
- 30
- Issue :
- 12
- Database :
- Complementary Index
- Journal :
- Water Science & Technology
- Publication Type :
- Academic Journal
- Accession number :
- 26962680
- Full Text :
- https://doi.org/10.2166/wst.1994.0629