Breaking the silence - Israeli veteran soldiers experience

Very impressive introduction given by a veteran Israeli solder about experience in occupied territories. Introduction to the exhibition given in English.

Watch introduction

LUM at World Filtration Congress WFC 11

11th World Filtration Congress in GRAZ, AUSTRIA, APRIL 16-20, 2012

LUM will present at the exhibition

Booth G5

and give 4 presentations on different topics

Accelerated screening by multisample analytical centrifugation for selection of flocculants and demulsifiers

T. Sobisch*, D. Lerche

LUM GmbH, Berlin / Germany info@lum-gmbh.de, www.lum-gmbh.com

Selection of flocculants and demulsifiers is a frequent challenge. It relates to remedy of settling issues and to the optimization of separation processes in fields like wastewater treatment and crude oil processing.

Multisample analytical centrifugation based on STEP-Technology offers a unique option for screening for the optimal product, additive concentration and separation conditions. Not only the degree of separation but also separation kinetics and the residual turbidity can be determined with high throughput by comparison of 12 samples under identical conditions in 1 run.

The potential of this approach is demonstrated by case studies for the selection of flocculants for centrifugal dewatering of wastewater sludges and for selection of optimum demulsifier selection for crude oil dewatering.

Keywords: additive screening, flocculant selection, demulsifier selection, dewatering efficiency, separation velocity, analytical centrifugation

Measurement of x ray profiles – a new method for the evaluation of separation behaviour of concentrated nontransparent dispersions

A. Zierau*, A. Fedur, T. Sobisch, D. Lerche

LUM GmbH, Berlin / Germany i

Detailed evaluation of the separation behaviour of dispersion is problematic for concentrated nontransparent dispersions. It is difficult to define a separation level or to trace differences in solids concentration along the liquid column.

Measurement of space and time resolved x ray transmission profiles offers a unique solution to this problem. This approach can even be used to determine concentration gradients in sediments, which is of great importance for separation unit processes like filtration, settling and centrifugation. Even more information about the structure of sediments can be used to deduce the nature of particle interactions and to determine the degree of flocculation.

The method can be applied to determine the kinetics of separation processes or to determine the concentration distribution obtained after separation, i.e. after settling, centrifugation, filtration.

The measurement technique and its application for different systems like mineral suspensions and emulsions is introduced.

Keywords: x-ray, dispersion structure, suspensions, emulsions, separation analysis, sediment profiles

Separation and consolidation behaviour of flocculated versus non-flocculated dispersions: A reliable laboratory classification test

T.Sobisch, A. Zierau, D.Lerche*

LUM GmbH, Berlin/Germany

Flocculation behaviour is important in many technical applications and especially in solid-liquid separation. While for some applications sedimentation and consolidation have to be avoided or minimized, for solid-liquid separation these are essential. Often the value of Zeta-potential is employed to judge the state in the sense of flocculated versus non-flocculated dispersions. But this approach is often not applicable especially in case of sterically or rheologically stabilized dispersion. There is a need for fast reliable methods for comprehensive characterization of flocculation processes.

Analytical centrifugation based on Space and Time resolved detection of Extinction Profiles of electromagnetic waves (STEP-Technology) over the entire sample height was used to characterize the nature of particle interactions and the degree of flocculation in dispersions at original concentration. Photometric and x-ray measurements were carried out.

Investigations on sedimentation and consolidation behaviour of flocculated polydisperse suspensions of different suspensions made from quartz, lime stone, titanium oxide, magnetic therapeutic carrier particles and enzyme coated nanoparticles are presented to demonstrate the procedure. Colloidal stable dispersions (stable against flocculation, agglutination) show typical polydisperse sedimentation behaviour, whereas flocculated dispersions exhibit zone sedimentation and gradual consolidation. While the packing density for colloidal stable dispersions does depend only slightly on the excess pressure acting on the sediment it strongly depends on pressure for flocculated dispersions and it takes much longer to reach corresponding equilibrium packing density. Instead of carrying out measurements at different accelerations it is also possible to evaluate the compressibility of sediments (or cream layers) by increasing the acceleration step-wise and recording the kinetics of the sediment (cream layer) height or packing sediment concentration. It was shown that in all investigated suspensions the state of flocculation was correctly classified even at very high concentration but e.g. in case of polymer stabilized magnetic micro- and nano-particles high Zeta-potential (40 - 60 mV) would lead to false “non-flocculated” classification.

Keywords: flocculation state, analytical centrifugation, Zeta-potential, coated nanoparticles, compressibility, sediment density, emulsions, suspensions, sedimentation, creaming

Is it possible to reduce costs for pilot centrifuge testing by lab scale tests?

T. Detloff*, S. Küchler, T. Sobisch, D. Lerche

LUM GmbH, Berlin / Germany

Unit processes using centrifugal fields are often applied for separation and classification of diverse materials. Modelling of these processes requires information about the separation behaviour of the suspensions to be processed. To this end direct measurements in centrifuges are obligatory for the dimensioning of the separation units to obtain the desired cut-off size and residual effluent turbidity. Moreover, these measurements have to gather kinetic information as function of the processing conditions, viscosity behaviour, particle interaction and particle concentration of the product. Results of measurements at earth gravity cannot be scaled up to reflect the situation in a centrifugal field.

A multisample analytical centrifugation technique with photometric detection is presented which allows a comprehensive characterization of separation processes in the centrifugal field at lab scale with high sample throughput. In particular the type of sedimentation behaviour (free sedimentation of individual particles, hindered settling, zone settling) can be deduced from the progression of the transmission profiles. Even more it can determine the critical residence time as function of feed concentration for a desired effluent clarity and allows measuring the velocity distribution of particles inside the centrate in-situ.

Approaches for dimensioning the centrifugation at larger scale based on these in-situ at labscale available data are discussed.

Keywords: process optimization, solid-liquid separation, liquid-liquid separation, process design, decanter centrifuges, analytical centrifugation

Was gesagt werden muss - Günther Grass - an den Reaktionen sollt Ihr sie erkennen.

Was gesagt werden muss - Kultur - sueddeutsche.de

Kernsätze

'Es ist das behauptete Recht auf den Erstschlag,
der das von einem Maulhelden unterjochte
und zum organisierten Jubel gelenkte
iranische Volk auslöschen könnte, ...'

'Warum aber schwieg ich bislang?
Weil ich meinte, meine Herkunft,
die von nie zu tilgendem Makel behaftet ist,
verbiete, diese Tatsache als ausgesprochene Wahrheit
dem Land Israel, dem ich verbunden bin
und bleiben will, zuzumuten....'

'....zudem ist zu hoffen,
es mögen sich viele vom Schweigen befreien,
den Verursacher der erkennbaren Gefahr
zum Verzicht auf Gewalt auffordern und
gleichfalls darauf bestehen,
daß eine unbehinderte und permanente Kontrolle
des israelischen atomaren Potentials
und der iranischen Atomanlagen
durch eine internationale Instanz
von den Regierungen beider Länder zugelassen wird.
Nur so ist allen, den Israelis und Palästinensern,
mehr noch, allen Menschen, die in dieser
vom Wahn okkupierten Region
dicht bei dicht verfeindet leben
und letztlich auch uns zu helfen.'

Allgemeine Reaktion der politischen Klasse
'Antisemitismus', 'Hasspamphlet', 'Verirrung'

Erinnert mich an frühere Anforderungen an die sozialistische Persönlichkeit
Parteilichkeit, 'wem nützt es', klar Stellung beziehen, zu den Siegern der Geschichte gehören ...

Dogmen kann man auch nicht mit den besten Argumenten beikommen.

Insektenvernichtungsmittel künftig ein zunehmendes Problem für Gewässer in Europa - Helmholtz-Zentrum für Umweltforschung UFZ - Forschen für die Umwelt

Insektenvernichtungsmittel künftig ein zunehmendes Problem für Gewässer in Europa - Helmholtz-Zentrum für Umweltforschung UFZ - Forschen für die Umwelt

Zitate:
Europas Gewässer werden in Zukunft stärker mit Insektenvernichtungsmitteln belastet sein als bisher. Das ist das Ergebnis einer Studie des Helmholtz-Zentrums für Umweltforschung (UFZ)...

Die Wissenschaftler empfehlen deshalb, den Eintrag von Pflanzenschutzmitteln drastisch zu minimieren. Neben einer Verminderung des Pestizideinsatzes kann dies durch die Einrichtung von Pufferzonen am Gewässer erfolgen.


Lediglich für 12 Küstenstaaten der USA gibt es Schätzungen, die einen generellen Anstieg des Insektizideinsatzes im Zeitraum 2000 bis 2100 von bis zu 28 Prozent erwarten. Die europäische Studie dagegen rechnet mit einem wesentlichen höheren Anstieg von bis zum 23fachen des momentanen Insektizideinsatzes in einzelnen Ländern je nach Stärke des Temperaturanstiegs und der zugrunde gelegten Landnutzungsänderung.
 

Außer Begrenzung der Auswirkungen durch Pufferzonen werden keine Alternativen gefordert/diskutiert.

Eine Alternative wäre Stärkung der natürlichen Feinde der Schadinsekten.