MEASURING THE GROWTH RATE OF FILAMENTOUS BACTERIA AND INFLUENCE OF THE BACTERIA ON SETTLEABILITY, THICKENING PROPERTY AND FLOC CONFIGURATION OF ACTIVATED SLUDGE
1988; Elsevier BV; Linguagem: Inglês
10.1016/b978-0-08-036884-9.50050-8
AutoresRyoko Yamamoto, Saburo Matsui,
Tópico(s)Wastewater Treatment and Nitrogen Removal
ResumoThe growth rate of filamentous bacteria in activated sludge was measured using a simple method to measure the length of filamentous microbes. In the activated sludge cultivated continuously with glucose and pepton, filamentous bacteria, Sphaerotilus natans grew logarithmically at the rate of 1.0/day which was greater than whole sludge growth rate of 0.2/day estimated from SRT and they rapidly created filamentous bulking. Furthermore, influence of the growth of filamentous bacteria on settleability, thickening property and floc configuration was examined. The sludge settleability evaluated in terms of SVI at Phase I correlated with total length of filamentous bacteria. When the total length increased over 103 cm/mg MLSS, sludge settleability became poor. The activated sludge which contained large amount of filamentous bacteria showed not only poor settleability but also poor compression by centrifigation. However, coagulation of those activated sludge was good. The floc size of activated sludges which contained filamentous bacteria between 102 and 103 cm/mg MLSS was on the average about 100 um. The degrees of sphericity and circularity as the indexes of irregularity of the floe configuration were about 0.8 and 0.7 respectively. The greater the filamentous bacteria amount, the greater the floc size and the greater irregularity of the floc configuration were observed.
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