An effective method of measuring the activity of higher microorganisms in activated sludge
一种测定活性污泥中高等微生物活性的方法

A mechanical disruption method was experimentally applied to kill higher microorganisms in activated sludge; the activity of higher microorganisms could be indirectly calculated on the basis of the difference of oxygen uptake ratios (OURs) before and after disruption. The experiments indicated that a disperser could effectively break up and kill higher microorganisms and that they did not revive after enrichment for 138 h. As a control, yeasts were also disrupted by the disperser, to show that their numbers, morphology and activity were not mechanically affected, which implies that bacteria smaller than yeasts would not be mechanically affected either. To assure an almost identical morphology of flocs before and after disruption, the sludge after disruption was centrifuged to approach the same sludge volume index as before treatment. The activity of higher organisms could be calculated by measuring and comparing the OUR values of sludge samples before and after disruption, and was determined to be 12%~14% in this study.