Journal article

The influence of ionic strength and osmotic pressure on the dewatering behaviour of sewage sludge

Daan Curvers, Shane P Usher, Adam R Kilcullen, Peter J Scales, Hans Saveyn, Paul Van der Meeren

CHEMICAL ENGINEERING SCIENCE | PERGAMON-ELSEVIER SCIENCE LTD | Published : 2009

Abstract

In this work, we investigated the importance of osmotic pressure in the overall dewaterability behaviour of a biotic sludge. Biotic sludges, such as activated or digested sludge from waste water treatment, are known to be difficult to dewater, due to their high compressibility and their gel-like water retention capacity. These properties are partly attributed to the presence of surface charges, which are due to the biological nature and the presence of weakly charged extra-cellular polymeric substances. Both in filtration and centrifugation experiments, charge related effects were partly neutralised through a controlled increase in the bulk ionic strength by the addition of NaCl. It was obse..

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