title: Sedimentation behaviour of sludge particles in a biogas tower reactor and the function of a hydrostatically pressurized sedimenter.
abstract: It was found that anaerobic sludge particles contain gas bubbles. Due to the compressibility of the bubbles, which are entrapped in the sludge agglomerates, a pressure-dependent sedimentation characteristic of the sludge particles was found and mathematically described. Enhanced hydrostatic pressure results in a considerable increase of the settling velocity of sludge particles. On this basis the concept of a hydrostatically pressurized sedimenter is presented and its performance analyzed. Due to the hydrostatical pressurization of the sedimenter the produced gas is kept in the liquid phase until the liquid phase is saturated. To avoid a degassing of the liquid which results in the undesired release of gas bubbles a maximum liquid dwell time in the sedimenter must not be exceeded.
authors.affiliation: Deutsche Hefewerke GmbH & Co. oHG, 22041 Hamburg, Germany.
authors.forename: Torsten
authors.initials: T
authors.lastname: Pietsch
authors.forename: Ralf
authors.initials: R
authors.lastname: Mehrwald
authors.forename: Ralf
authors.initials: R
authors.lastname: Grajetzki
authors.forename: Jan
authors.initials: J
authors.lastname: Sens
authors.forename: Herbert
authors.initials: H
authors.lastname: Märkl
mesh_terms: D001421:Bacteria, Anaerobic; D019149:Bioreactors; D005740:Gases; D011312:Pressure; D012722:Sewage / Q000737:chemistry*; D014872:Water Movements
chemical_list: D005740:Gases; D012722:Sewage