A pilot study of sewage treatment lagoons near Melbourne indicated that the best way to enhance nitrogen removal in such lagoons was to promote nitrification. Combined algal/bacterial biofilms grown on surfaces immersed in the lagoons showed potential for greatly increasing the extent of nitrification. A laboratory study was undertaken to determine the effect of pH, dissolved oxygen concentration, temperature and other factors on the nitrifying capabilities of such biofilms; effective nitrification was observed at temperatures down to 10°C, at pH's down to 5.5 and at dissolved oxygen levels down to 2.5 mg/L. Tanks containing biofilm-coated plates nitrified much more effectively than tanks containing only suspended microbial growths. At dissolved oxygen levels of 2-3 mg/L, up to 30% of the ammonia-nitrogen fed to tanks containing biofilm-coated plates was removed by denitrification. Photosynthetic activity in the biofilm greatly enhanced nitrification efficiencies at low dissolved oxygen levels.
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Research Article| October 01 1992
Biofilms as an Aid to Nitrogen Removal in Sewage Treatment Lagoons
P. H. Scott;
Water Sci Technol (1992) 26 (7-8): 1707–1716.
K. Baskaran, P. H. Scott, M. A. Connor; Biofilms as an Aid to Nitrogen Removal in Sewage Treatment Lagoons. Water Sci Technol 1 October 1992; 26 (7-8): 1707–1716. doi: https://doi.org/10.2166/wst.1992.0614
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