title: A novel rotation generator of hydrodynamic cavitation for waste-activated sludge disintegration.
abstract: The disintegration of raw sludge is very important for enhancement of the biogas production in anaerobic digestion process as it provides easily degradable substrate for microorganisms to perform maximum sludge treatment efficiency and stable digestion of sludge at lower costs. In the present study the disintegration was studied by using a novel rotation generator of hydrodynamic cavitation (RGHC). At the first stage the analysis of hydrodynamics of the RGHC were made with tap water, where the cavitation extent and aggressiveness was evaluated. At the second stage RGHC was used as a tool for pretreatment of a waste-activated sludge (WAS), collected from wastewater treatment plant (WWTP). In case of WAS the disintegration rate was measured, where the soluble chemical oxygen demand (SCOD) and soluble Kjeldahl nitrogen were monitored and microbiological pictures were taken. The SCOD increased from initial 45 mg/L up to 602 mg/L and 12.7% more biogas has been produced by 20 passes through RGHC. The results were obtained on a pilot bioreactor plant, volume of 400 L.
authors.affiliation: Laboratory for Water and Turbine Machines, Faculty of Mechanical Engineering, University of Ljubljana, Aškerčeva 6, SI-1000 Ljubljana, Slovenia. Electronic address: martin.petkovsek@fs.uni-lj.si.
authors.forename: Martin
authors.initials: M
authors.lastname: Petkovšek
authors.affiliation: Javno podjetje centralna čistilna naprava Domžale-Kamnik d.o.o. (Domžale-Kamnik Wastewater Treatment Plant), Študljanska 91, 1230 Domžale, Slovenia.
authors.forename: Matej
authors.initials: M
authors.lastname: Mlakar
authors.affiliation: Javno podjetje centralna čistilna naprava Domžale-Kamnik d.o.o. (Domžale-Kamnik Wastewater Treatment Plant), Študljanska 91, 1230 Domžale, Slovenia.
authors.forename: Marjetka
authors.initials: M
authors.lastname: Levstek
authors.affiliation: Javno podjetje centralna čistilna naprava Domžale-Kamnik d.o.o. (Domžale-Kamnik Wastewater Treatment Plant), Študljanska 91, 1230 Domžale, Slovenia.
authors.forename: Marjeta
authors.initials: M
authors.lastname: Stražar
authors.affiliation: Laboratory for Water and Turbine Machines, Faculty of Mechanical Engineering, University of Ljubljana, Aškerčeva 6, SI-1000 Ljubljana, Slovenia.
authors.forename: Brane
authors.initials: B
authors.lastname: Širok
authors.affiliation: Laboratory for Water and Turbine Machines, Faculty of Mechanical Engineering, University of Ljubljana, Aškerčeva 6, SI-1000 Ljubljana, Slovenia.
authors.forename: Matevž
authors.initials: M
authors.lastname: Dular
mesh_terms: D005240:Feasibility Studies; D057446:Hydrodynamics; D012399:Rotation; D012722:Sewage / Q000737:chemistry*; D014865:Waste Disposal, Fluid / Q000191:economics / Q000295:instrumentation / Q000379:methods*
chemical_list: D012722:Sewage
keywords: Biogas production; Disintegration; Hydrodynamic cavitation; Waste-activated sludge