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Friday, February 25, 2005

Applied NanoWorks Announces Optically Transparent Pinnacle Zinc Oxide

Applied NanoWorks Announces Optically Transparent Pinnacle Zinc Oxide: "Pinnacle"

'Pinnacle Zinc Oxide's particles have a median size below 5nm with tight size distributions which enables its unique suspension. No coatings are applied to the zinc oxide nor are any surfactants used to aid in suspending the particles. Neutral pH and 10% solids content combine with particle purity...'

Everything You Wanted To Know About Water Softening

Ask Tom! Column
Guest article by Gary Schreiber, The Purolite Company about softening with ion exchange resins at waterandwastewater.com

AFS 2005 18th annual conference - Tracing the centrifugal separation of fine-particle slurries

2005 18th Annual Conference of the American Filtration and Separation Society
April 10-13, 2005 Atlanta, Georgia

presentation

Tracing the centrifugal separation of fine-particle slurries

Effect of centrifugal acceleration, particle interaction and concentration

T. Sobisch, D. Lerche, L.U.M. GmbH, Berlin, www.lum-gmbh.com, info@lum-gmbh.de

M. Beiser, A. Erk, Institut für Mechanische Verfahrenstechnik und Mechanik, Universität Karlsruhe (TH)

Unit processes using centrifugal fields are often applied for separation and classification of fine grained materials. Modeling of these processes requires information about the separation behaviour of the suspensions to be processed. To this end direct measurements in centrifuges are obligatory. Moreover, these measurements have to gather kinetic information as function of the processing conditions, particle interaction and particle concentration.

As a first step in this direction the separation behaviour of quartz (stable dispersions) and limestone suspensions (weakly and strongly flocculated) was investigated as function of solid concentration and centrifugal acceleration (11 – 1100 x g) using a multisample analytical centrifuge.

Particle interactions are characterized by determination of the packing density obtained under controlled conditions and by its variations under alternating centrifugal load.

Results of analytical centrifugation are compared with the separation behaviour under normal gravity and with the results traced by a centrifuge with manometric detection and by a disc centrifuge.

Centrifugation, solid-liquid separation, sedimentation, classification, physico-chemical aspects

Gelatin Precipitation - Water and Wastewater.com Help Forum

Water and Wastewater.com Help Forum - Gelatin Precipitation

Isoelectric point means that the protein is least soluble at this pH.
If removal at this pH proves inefficient, addition of clays or lime will surely remove it.

Interference of surfactants with coagulation - discussion at the Water and Wastewater.com Help Forum

Water and Wastewater.com Help Forum - Industrial Phosphating Rinse Electrocoagulation

It seems to me that the real problem is the interaction of the anionic surfactants with metal ions or their insoluble complexes.

Addition of a cationic polyelectrolyte should be very effective in avoiding interference from anionic surfactants and to some degree from nonionic too.

Thursday, February 17, 2005

Untersuchung der Trennung von Feinstpartikeldispersionen in Zentrifugen - GVC/DECHEMA Jahrestagungen 2005

Beitragsmeldung - Feststoffverfahrenstechnik

Untersuchung der Trennung von Feinstpartikeldispersionen in Zentrifugen

Einfluß von Zentrifugalbeschleunigung, Partikelwechselwirkungen und Konzentration

T. Sobisch, D. Lerche, L.U.M. GmbH, Berlin,

www.lum-gmbh.com, info@lum-gmbh.de

M. Beiser, A. Erk, Institut für Mechanische Verfahrenstechnik und Mechanik, Universität Karlsruhe (TH)


Zentrifugalfelder werden in technischen Verfahrensoperationen häufig zur Abscheidung und Klassierung von Feinstpartikeln genutzt. Für die Auslegung der entsprechenden Trennprozesse ist die Modellierung des Bewegungsverhaltens von feinsten Teilchen in Suspensionen erforderlich. Da bisher zuverlässige Methoden zur Vorausberechnung der Abtrenngeschwindigkeit bzw. deren Verteilung in realen Systemen fehlen, ist dies beim gegenwärtigen Stand der Technik mit einem hohen Maß an Empirie verbunden. Dies führt zu einem hohen Aufwand bei der Einrichtung der Trennaggregate (umfangreiches Programm an Betriebsversuchen) und beim Betrieb der Anlagen unter nicht optimalen Bedingungen. Da das Trennverhalten in sehr komplexer Weise von Betriebsparametern und Eigenschaften bzw. Wechselwirkungen (zwischenpartikuläre Kräfte, Partikelkonzentration) im jeweiligen Stoffsystem abhängig ist, ist die Problemstellung nur über direkte Messungen in Zentrifugen lösbar, wobei die Datenbasis für die Modellierung geschaffen wird. Eine Übertragbarkeit von Ergebnissen aus Untersuchungen ohne Einfluß des Zentrifugalfeldes ist, insbesondere bei destabilisierten Suspensionen, nicht gegeben.

Als erster Schritt in diese Richtung wurde das Trennverhalten von Quarzsuspensionen (stabile Dispersionen) und Kalksteinsuspensionen (schwach und stark geflockt) als Funktion der Feststoffkonzentration und der Zentrifugalbeschleunigung (11 – 1100 x g) mittels einer photometrischen analytischen Zentrifuge untersucht.

Die Partikelwechselwirkungen wurden über die Packungsdichte und deren Änderungen im alternierenden Zentrifugalfeld charakterisiert.

Die Ergebnisse mittels photometrischer Zentrifugation wurden mit dem Trennverhalten ohne Einfluß eines Zentrifugalfeldes und mit Untersuchungen in einer Manometerzentrifuge und in einer Scheibenzentrifuge verglichen.

"Contaminated Sediments in European River Basins" SedNet booklet

SedNet - News

Sednet:
"The booklet gives a short, state-of-the-art overview of the main scientific, policy and regulatory issues on contaminated sediments, based on the results of the SedNet network activities. In particular, this booklet describes the main sources, transport processes and impacts of contaminated sediment and describes the main methods used to evaluate (including chemical analysis, bioassays and impact assessment) and manage (such as treatment, disposal and beneficial uses) contaminated sediment in river basins. The booklet also presents the main policies and regulations that relate to contaminated sediment (including the EU Water Framework Directive) and describes recent developments in sediment management, such as the move towards the basin-scale approach, the use of risk-based management and the need for stakeholder participation in the decision-making process."

Monday, February 14, 2005

Surfactant Combinations for Enhanced Removal of Contaminants

read the article

One of the main restricting factors in the remediation of soils is the low aqueous solubility of several organic compounds, which leads to resistance to mobilization by conventional pump and treat measures and to low bioavailability. The application of surfactants to resolve these problems has been a focus of research in recent years. However, usefulness of surfactant addition has been conversely discussed in literature. Promising results obtained with model contaminations in the laboratory often failed under real world conditions.

Surface-active additives have the potential to improve the efficiency of soil clean-up by physico-chemical and biological processes if their functional properties are adjusted to the special demands of the remediation technology and the soil/contaminant system. However, how to find tailor-made solutions by applying the different utilizable wetting, dispersing, emulsifying and solubilizing properties, is not understood properly so far.

The paper gives an overview of results obtained in recent years working on selection of surface-active additive combinations for different purposes. This included surfactant combinations for the hydraulic in-situ remediation of soils, for the stimulation of biodegradation, several surfactant formulations with high extraction efficiency for different contaminants, special additives for the enhanced washing of tar contaminated soils as well as the development of a two-step bioreactor process for removal of contaminants with low bioavailability. The article is intended to provide a basis for discussion of problems associated with surfactant application and possibly for future cooperation.

(Originally presented at the FZK/TNO International Conference on Contaminated Land - "Contaminated Soil '2000", 18 - 22 September 2000, Leipzig)

The author welcomes related discussions and comments and is very interested in providing confidential information for research or commercialisation purposes.

Two-Step Bioreactor Process for Removal of Contaminants with Low Bioavailability

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This paper reports on attempts to develop an economically feasible bioremediation technique for contaminants with low bioavailability. To this end, different options for a combined physicochemical and biological treatment process were evaluated for soils contaminated with polycyclic aromatic hydrocarbons (PAH). Options evaluated for enhanced bioremediation included pre-extraction with surfactant solutions, a washing pretreatment, which consisted of attrition in the presence of different additives and fractionation by size as well as biodegradation in presence of different additives. Pre-extraction with surfactant solutions will not be feasible because of associated surfactant costs. Washing pretreatment resulted in a seriously enhanced bioavailability, even when performed without additives. Special designed surfactant combinations, which stimulate biodegradation without preferential degradation of surfactants, exhibited substantial enhancement of biodegradation rates if their composition and concentration is adapted to the actual contaminated soil. However, even under improved conditions biodegradation rates were too slow to obtain low enough residual values in reasonable times. Therefore, a new two-stage bioreactor system was developed, which enhances removal rates drastically (> 90% in 3 days). Progress achieved was illustrated in relation to published results of other bioreactor approaches.

(originally presented at ACHEMA 2000 - International Meeting on Chemical Engineering, Environmental Protection and Biotechnology, 22. – 27. 5. 2000 Frankfurt am Main)

Keywords:
bioavailability, bioreactors, soil remediation, surfactant combinations, PAH, pyrene,
biodegradation, soil washing, soil fines

The Author welcomes related discussions, comments and is very interested in passing so far confidential information for research or commercialisation purposes.

Investigations on Sludge Dewatering with the Separation Analyser LUMiFuge 114

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Practical application studies of the sludge dewatering process and its control by flocculant addition require adequate laboratory methods. At present numerous methods are used on laboratory scale, however, they are generally time-consuming and often lack practical relevance. A newly developed separation analyser has been applied for rapid evaluation of sludge properties (sedimentation and packing behaviour, shear sensitivity) and of the efficiency of polymeric flocculants for sludge dewatering in decanter centrifuges (in relation to flocculant concentration and mechanical conditioning, development of an appropriate laboratory procedure). Experiments were carried out with sewage sludges of different origin and characteristics and a number of commercial flocculants without dilution of sludges. It was revealed that the development of appropriate methods for sample pretreatment is essential for getting relevant results for sludge dewatering under practical conditions.
(Originally presented at the 3rd International Conference of the Kolloidgesellschaft e.V.
Adsorption and Nanostructures – From Theory to Application
Budapest 25 – 28 September 2000)

The Author welcomes related discussions and comments.
Additional information (reference list of publications, different applications of the separation analyser) is available and up-dated at www.AppliedColloidsSurfactants.info and at www.lum-gmbh.de.
Further developments have been achieved in relation to the flocculant selection procedure, which are summarized in the paper ‘Pre-selection of Flocculants by the Separation Analyser Lumifuge 114’ available here at InfoClearinghouse.com and on the Preprint Archive http://www.sciencedirect.com/preprintarchive Chemistry Preprint Archive, Volume 2002, Issue 4, April 2002, Pages 265 - 274 and at Filtech2003/wfc9

Pre-Selection of Flocculants by the Separation Analyser Lumifuge 114 - Article at InfoClearinghouse

read the article


This paper (originally presented at the IWA World Water Congress in Berlin, 2001) reports on lab-scale investigations in relation to pre-selection of flocculants for sludge dewatering with decanter centrifuges using the separation analyser Lumifuge 114. Experiments were carried out with sludge samples of different origin and a number of commercial flocculants.
Kinetics of sedimentation and clarification were measured as well as the compression behaviour and shear sensitivity of sludge sediments. Results obtained were compared with CST-measurements and discussed in relation to findings under field conditions. The separation analyser is an efficient tool for the characterization of sludge samples and flocculant optimisation. The development of appropriate methods for sample pre-treatment is essential for getting relevant results for sludge dewatering under practical conditions. Flocculant performance could be estimated by evaluation of stability against intensive shearing, total solids obtained and initial dewaterability of the sludge cake. Results were in good agreement with field results. The beneficial or negative influence of mechanical pre-conditioning of sludges before flocculant addition could only be deduced by experiment. The separation analyser can be used to this end for model investigations. A screening procedure has been developed. Efficient flocculants should produce high residual total solids and good initial compressibility as well. Lab-scale investigations deliver more reliable results if the dynamic behaviour of the sludge under centrifugal acceleration is also investigated. The separation analyser Lumifuge 114 can provide results about the compression behaviour of sludges in the range between 10 and 100 s. So far no other method or device is known which can deliver such results.
The author welcomes related discussion and comments.
Additional information (reference list of publications, different applications of the separation analyser) is available and up-dated at www.AppliedColloidsSurfactants.info and at www.lum-gmbh.de.
A previous paper on the Preprint Archive “Investigations on sludge dewatering with the separation analyser LUMiFuge 114” contains more details on the principle and is related also to sludge characterization, available on the Preprint Archive http://www.sciencedirect.com/preprintarchive Chemistry Preprint Archive, Volume 2002, Issue 10, October 2002, Pages 1-11. For recent results see Filtech2003/wfc9

Friday, February 11, 2005

High Gloss Emulsion waste varnish - Discussion at the Water and Wastewater.com Help Forum

Water and Wastewater.com Help Forum - High Gloss Emulsion waste varnish

I hope you are aware that the solvent 2-(2-Butoxy)Ethanol is a very hazardous chemical (causing blood cancer and other nasty things).
MSDS
Therefore, the workers should be protected against uptake over the skin and air tract. Ideally the varnish should be replaced by another less harmful product.

I would guess cationic flocculants or clay will be effective in removing the varnish residues and the anionic surfactant Sodium Dioctyl Sulphosuccinate. The solvents might be treatable biologically. You should check the solvents content in the wastewater by gas chromatography.

Kind regards
T. Sobisch

DAF for food wastewater - Coverage at the Water and Wastewater.com Help Forum

Water and Wastewater.com Help Forum - DAF for food wastewater

Thursday, February 10, 2005

InfoClearinghouse.com- for distribution of technical information and publishing on the web

InfoClearinghouse.com-technical information and publishing

"Several years ago, we started a small website for technical information
distribution called InfoClearinghouse.com. We have not actively promoted the
site, but it has been used by thousands of users to download over 17,000
documents over the past few years.

We are currently seeking authors of technical information to contribute to the
site. If you have information that would be useful to others, or know of
documents in the public domain that may not be readily available in a digital
format, we would like to hear from you. You can choose to use the site to
distribute information for free or you can charge a download fee for your
original work. We also provide free scanning of your paper documents (e.g.,
dissertations, theses or reports that were never published and may not be
available anywhere else, or government documents that you have found useful.)

Our current environmental documents that may be of interest .....

include:

-Subsurface Contamination Reference Guide

-Evaluation of Soil Vapor Extraction and Treatment Using Internal Combustion
Engine Technology

-Bound Residue Formation and Chemical Binding in Soil: a Literature Survey

-Field Methods for Ferrous Iron (and Dissolved Manganese) Analysis in
Monitoring Wells

-Schematic Diagram for a Passive Bioventing / Barometric Pumping Valve

-How to use a Level I Fugacity Model to Estimate Contaminant Partitioning in
the Subsurface

-Monitoring and Assessment of In-Situ Biocontainment of Petroleum Contaminated
Ground-Water Plumes

They are all FREE to download

Friday, February 04, 2005

Mother Earth News: Natural Housecleaning -Replacement of thousand different cleaners

Mother Earth News: Natural Housecleaning

A sound article
Also reach to the conclusion that it is difficult to replace sophisticated products like washing powder, dish washing compositions.

Also when creating your own compositions and using the recommended agents - all require safety measures!

Thursday, February 03, 2005

Synthetic musk could pose toxicity risk

Synthetic musk could pose toxicity risk

A scientific study has shown that artificial musk fragrance can increase sensitivity to toxins in mussels, indicating possible implications for human health. Simon Pitman reports on the findings.

'Headed by professor David Epel from Stanford University, the study shows that mussels have a defense system that normally prevents toxins from entering cells. However, the research found that synthetic musks intensify the toxicity of other pollutants by interfering with proteins in the cell membranes.'

'these results have further implications for human life, as human cells use the same transporter mechanisms as mussels. This leads to the conclusion that exposure to musks in people might impair defense systems, which in turn increases the risk of exposure to normally excluded toxins.'