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EFFECTIVE DESIGN OF GAS‐MIXING SYSTEMS FOR THICK SLUDGE DIGESTION: TWO CASE STUDIES
Author(s) -
Cumiskey A.,
Harrison D.,
Dawson M.,
Jolly M.
Publication year - 2003
Publication title -
water and environment journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.437
H-Index - 37
eISSN - 1747-6593
pISSN - 1747-6585
DOI - 10.1111/j.1747-6593.2003.tb00427.x
Subject(s) - anaerobic digestion , mixing (physics) , waste management , digestion (alchemy) , hydrolysis , mesophile , thermal hydrolysis , environmental science , pulp and paper industry , sewage sludge treatment , process engineering , chemistry , engineering , methane , sewage treatment , chromatography , biology , physics , organic chemistry , quantum mechanics , bacteria , genetics , biochemistry
In the UK and elsewhere, advances in the design of anaerobic mesophilic digesters have resulted in a trend towards the digestion of thicker sludges. This includes a number of new facilities using ‘bolt‐on’ technologies such as thermal hydrolysis, pre‐pasteurisation and enzymic hydrolysis. Thermal hydrolysis utilises thickened sludge, and the digester is fed with a high dry‐solids content (typically 12%), thereby intensifying the digestion process and reducing reactor volumes. However, there is limited experience in the design of digester mixing systems for such applications. As the trend continues towards advanced digestion technology, more emphasis will be placed on the basic unit process operation of mixing. This paper describes the design of a gas‐mixing system for thick feed sludges for two full‐scale plants at Mogden and Aberdeen. Mogden is a refurbishment project and Aberdeen is a newly constructed plant.