BACTERIAL MICROFLORA PARTICIPATING IN THE REMOVAL OF NITROGEN FROM INDUSTRIAL WASTEWATERS BY NITRIFICATION AND DENITRIFICATION

Google Scholar
  • 1 January 1984
    • journal article
    • research article
    • Vol. 33  (1) , 67-76
Abstract
Nitrification and denitrification were used to purify industrial nitrogenous-organic wastewaters containing 1,130 mg N/l (mainly in the form of ammonium and urea) and with mean COD 1,050 mg O2/1. The use of a five-step system consisting of two denitrifying beds and three nitrifying activated sludge reactors gave 99% removal of nitrogen and 54% reduction in COD during total retention time of the wastes of 81 hours. The participation of stage I nitrifying bacteria in the activated sludge was 4.4 to 5.8% and of stage II nitrifying bacteria 21.9 to 53.8%. Denitrifying bacteria in the denitrifying beds accounted for 90% of the isolated population, which was dominated by Alcaligenes faecalis and Paracoccus denitrificans.