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The effect of shear on the dewatering of water treatment residuals
Author(s) -
Novak John T.,
Bandak Nazih
Publication year - 1994
Publication title -
journal ‐ american water works association
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.466
H-Index - 74
eISSN - 1551-8833
pISSN - 0003-150X
DOI - 10.1002/j.1551-8833.1994.tb06276.x
Subject(s) - dewatering , alum , shear (geology) , lime , softening , flocculation , mixing (physics) , materials science , pulp and paper industry , geotechnical engineering , composite material , environmental science , environmental engineering , geology , metallurgy , engineering , physics , quantum mechanics
Conditioning with an appropriate polymer at the optimum dosage reduces the tendency of alum sludge to deteriorate under shear and, thus, leads to better dewatering. These researchers investigated, at bench scale, the dewatering performance of drinking‐water treatment plant sludges under varying shear conditions and the effect of conditioning with polymers. It was found that unconditioned alum sludges fracture during mixing and are more sensitive to the intensity of shear than to the mixing time. Polymers reduce this tendency to deteriorate, with the dosage required for the best dewatering depending on both the mixing time and the intensity of shear. Lime‐softening sludges do not deteriorate when subjected to shear