Improved biological treatment of nitrogen-deficient wastewater by incorporation of N-2-fixing bacteria

Kargi F., Ozmihci S.

BIOTECHNOLOGY LETTERS, vol.24, no.15, pp.1281-1284, 2002 (SCI-Expanded) identifier identifier

  • Publication Type: Article / Article
  • Volume: 24 Issue: 15
  • Publication Date: 2002
  • Doi Number: 10.1023/a:1016262026321
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Page Numbers: pp.1281-1284
  • Keywords: Azotobacter, biological treatment, nitrogen deficient wastewaters, OLIVE-MILL WASTE, AZOTOBACTER-VINELANDII
  • Dokuz Eylül University Affiliated: Yes


The N-2-fixing bacterium, Azotobacter vinelandii, was used both in single culture and in combination with activated sludge culture for the treatment of nitrogen-deficient wastewaters as an alternative to external nitrogen supplementation. Azotobacter-supplemented activated sludge culture removed more total organic carbon (TOC), especially at low initial TN/COD (total nitrogen/chemical oxygen demand) ratios, than the Azotobacter-free culture. Up to 95% TOC removal efficiencies were obtained with synthetic media of TN/COD <4 when Azotobacter was used singly or with activated sludge. The results indicated clear advantage of using Azotobacter in the activated sludge to improve TOC removal from nitrogen-deficient wastewaters.