Denitrification of high concentrations of nitrites and nitrates in synthetic medium with different sources of organic carbon. III. Methanol
Błaszczyk, M.; Gałka, E.; Sakowicz, E.; Mycielski, R.
Acta Microbiologica Polonica 34(2): 195-205
1985
ISSN/ISBN: 0137-1320 PMID: 2412408 Document Number: 267233
The denitrification of nitrites and nitrates (1000 mg N/l) in medium containing methanol as a source of organic carbon was studied. Continuous cultures of mixed population of autochtonic microflora from bottom sludge of nitrogenous wastewater reservoir were set up in a chemostat-type column and packed bed reactor. The efficiency of denitrification of nitrates in packed bed reactor was 506.7 N/l/h whereas denitrification of nitrites was from 8.7 to 16.0 mg N/l/h depending on the granulation of the filling material. In the latter case 83% nitrogen was removed from the medium. One of the factors causing low efficiency of denitrification of nitrites is excessive alkalinization of the medium in the bed. The use of a three-step bed with adjusted pH resulted in complete denitrification of nitrites with efficiency 60 mg N/l/h. The bacteria inside the bed were dominated by Paracoccus denitrificans and by Pseudomonas aeruginosa when nitrates were present. The sensitivity of P. denitrificans to high concentrations of nitrates seems to be the second factor contributing to low efficiency of denitrification with methanol as organic substrate.