RELATIONSHIPS BETWEEN ORGANIC LOADING AND SOME PROPERTIES OF ACTIVATED-SLUDGE

Investigations into changes in dehydrogenase activity, sludge volume i ndex, and flee size were carried out in the conditions of dynamic subs trate overload. An analysis of the changes of particular parameters in the load function is especially useful in these conditions. The analy sis takes into account chronological succession of the obtained result s. Interrelationships between the considered parameters were observed. Although dehydrogenase activity showed the greatest precision in refl ecting changes in organic loading and substrate removal rate, it was i mpossible on this basis to predict negative changes in the structure o f flocs. However, measurements of flee size made this possible. It has been shown that the average size of flocs and their size distribution are important parameters for the proper control of the activated slud ge process. It has also been stated that only an assessment of both bi ochemical and physical properties gives the correct picture of changes taking place in activated sludge.