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Theoretical aspects of bulking in activated sludge
Author(s) -
Hermanowicz Slawomir W.
Publication year - 1993
Publication title -
water environment research
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.356
H-Index - 73
eISSN - 1554-7531
pISSN - 1061-4303
DOI - 10.2175/wer.65.3.8
Subject(s) - settling , activated sludge , dimensionless quantity , protein filament , sewage sludge , percolation theory , volume (thermodynamics) , biosolids , elasticity (physics) , chemistry , pulp and paper industry , sewage treatment , materials science , environmental engineering , environmental science , composite material , thermodynamics , physics , engineering , biochemistry , conductivity
Percolation theory was applied in a theoretical analysis of bulking of activated sludge caused by filamentous microorganisms. Dimensionless filament concentration was defined as L = TEFLv · d 2 (where TEFLv = total extended filament length per unit volume, d = length of an individual filament). For L less than a critical value L * , sludge settling is not affected. For L > L * sludge settling is impaired. The critical value L * was theoretically estimated at 0.90 and compared with experimental data reported in the literature. Settling and compression of sludge in a sludge volume index test was analyzed. Elasticity modulus of compressed sludge was related to solids concentration.