Dewatering of Brewery Sludge Produced from a Dedicated Aerobic Effluent Treatment Plant

Abstract

This paper details the characterisation of sludge produced from a trickling filter effluent treatment plant dedicated to the treatment of brewery effluent and reports on centrifuge trials for thickening and dewatering it. Characterisation of the sludge revealed that the total solids content was low and variable, at 2-2.5% wlw dried solids (DS), and that the sludge exhibited very poor settling characteristics. A study of the rheological properties of the sludge indicated that at around 2.5% wlw DS.the sludge could best be modelled by the Hershel-Bulkley equation.The variation in rheological properties with solids concentration was measured on samples thickened in the laboratory. Large scale dewatering of polyelectrolyte conditioned sludge was carried out using an Alfa Laval decanter centrifuge in order to obtain cake suitable for further processing or disposal. Operational and dosing conditions were varied and a cake with up to 25% wlw DS was produced using cationic polyelectrolytes Zetag-87 & CT85.

The Composting of Brewery Sludge

“…This was achieved by cationic polyelectrolyte flocculation with around 10 kg t -1 DS Zetag-87 (Allied Colloids, Bradford, UK) and the solids separated with an Alfa Laval pilot plant centrifuge 6 .…”

“…6 The potential market for the final compost product has encouraged the investigation into large-scale composting regimes dedicated to the treatment of organic wastes generated in the brewing industry. 8 However, with increasing interest and government backing for the composting of other waste streams, such as Municipal Solid Waste (MSW), there may be a potential use for nutrient rich brewery sludge cake as an adjunct in these systems.…”