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From Water and Wastewater.com Industry News
Scope of Oral Presentation The operation of high performance dewatering machines such as high pressure filter presses and decanters relies heavily on the use of flocculants for sludge conditioning. Due to the varying composition of wastewater sludges pre-selection of promising flocculants before field tests is a frequent task. To this end, a lot of different laboratory methods have been developed, which are in part very sophisticated. More common are methods very simple, but strongly based on individual judgement and experience. They often lack automatic recording, need substantial sample volume and are generally time consuming. Measurement of the capillary suction time (CST), of electrokinetic and rheological properties, jar-, filtration and centrifugation experiments were often used, sometimes with good correlation to the performance under practical conditions, sometimes with misleading results. The efficiency of sludge dewatering by decanter centrifuges is governed by two critical parameters – on the one hand the separation rate of the sludge flocs, on the other hand by the compressibility of the sludge cake. Therefore, a laboratory procedure, able to measure these parameters simultaneously, was developed. Further, the action of high shear stresses during mechanical processing had to be encountered for. The key to the development of the new method was the application of multisample analytical centrifuges – the Stability Analyser LUMiFuge® and the Dispersion Analyser LUMiSizer®. This devices offer a wide potential for applied research, product control and optimization related to separation stability of dispersions and separation processes. It is also very capable for characterization of sludges regarding their settling behaviour and shear stability. Information on Instruments for characterization and optimization of separation processes and dispersion stability at the conference: -Lecture: session 414, Thursday April 22nd, 2004; T. Sobisch, D. Lerche, L.U.M. GmbH, Germany "Use of Analytical Centrifugation for Evaluation of Solid-Liquid Separation in Decanter Centrifuges: Application for Selection of Flocculants for Sludge Dewatering" -Poster session: 146, Monday April 19th, 2004; D. Lerche, T. Sobisch, L.U.M. GmbH, Germany "Characterization of Sedimentation and Consolidation Behaviour of Concentrated Dispersions by Analytical Centrifugation" About LUM GmbH L.U.M. GmbH is an independent, technology orientated German company working in the fields of measuring techniques and biotechnology. Founded 1994 by the scientist Prof. Dr. Dietmar Lerche as a development and service company, L.U.M. GmbH has under his leadership positively acquired it’s position on the global market. The inter-disciplinary team develops, produces and markets costumer orientated new products that solve many common problems in the fields of separation, and analysis of nano- and micro scaled fluid/fluid as well as fluid/solid dispersions. For more information contact: L.U.M. GmbH Rudower Chaussee 29 (OWZ) 12489 Berlin Germany Email: info@lum-gmbh.de Web site: http://www.lum-gmbh.com/ © Copyright 1998 - 2008 Water and Wastewater.com |
