title: Bacterial microflora participating in the removal of nitrogen from industrial wastewaters by nitrification and denitrifaction.
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/l. 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.
mesh_terms: D000421:Alcaligenes / Q000378:metabolism; D001407:Bacillus / Q000378:metabolism; D001419:Bacteria / Q000378:metabolism*; D041841:Bradyrhizobiaceae / Q000378:metabolism; D006868:Hydrolysis; D007220:Industrial Waste; D009584:Nitrogen / Q000378:metabolism*; D010231:Paracoccus denitrificans / Q000378:metabolism; D011549:Pseudomonas / Q000378:metabolism; D013045:Species Specificity; D014508:Urea / Q000378:metabolism; D014871:Water Microbiology
chemical_list: D007220:Industrial Waste; D014508:Urea; D009584:Nitrogen