BIOSORPTION AND DYNAMICS OF BACTERIAL-POPULATIONS IN ACTIVATED-SLUDGE

Nutritional relations are determining factors in the biological competition between filamentous and floc-forming microorganisms of activated sludge. Biosorption reflects the behaviour of microorganisms in relation to a given substrate. The results obtained from nearly 600 measurements of biosorption carried out in 11 wastewater treatment plants are presented. Biosorption of non-filamentous sludge is less than 30 mg COD/g SS for a 100 mg COD/g SS floc loading. Biosorption increases appreciably with the sludge volume index (SVI). These investigations provide a better understanding of the mechanisms involved in the contact zones. These techniques are successfully experimented in some cases of bulking where biosorption was at least equal to 40 mg COD/g SS.