ACTIVATED-SLUDGE POPULATION-DYNAMICS

The paper briefly surveys topics covered by the IAWQ Specialist Group on Activated Sludge Population Dynamics. The activated sludge populati on dynamics has been, formulated as a branch of water science and tech nology concerned with phenomena governing the relationships between ac tivated sludge microoganisms and their functions. The characterization of organic pollution fractions in wastewaters according to their rate of biodegradation has been discussed and the role of wastewater as an inoculum stressed. The characterization of activated sludge biomass h as been evaluated from two viewpoints: grouping according to metabolic abilities and identification and classification of activated sludge m icroorganisms. The basic selection mechanisms influencing the microbia l composition of activated sludge have been described. The problems wi th activated sludge settling and thickening properties have been menti oned as a typical example of applied population dynamics research.