Contamination consolidation

The pneumatic fracturing involves injection of highly pressurized air into the contaminated consolidated sediments, thus creating secondary fissures and channels and accelerating the removal of contaminants by vapor extraction, biodegradation, and thermal treatment. 

Solidification and stabilization processes. These immobilize the contaminants through physical or chemical processes. Solidification involves the entrapment of contaminants into a consolidated mass and stabilization is the conversion of contaminants to a chemical form that is less available. 

Rydell, CD. 1990. Written communication (March 27) to Barry L. Johnson. Agency for Toxic Substances and Disease Registry, regarding North Dakota Air Contaminant Limits. North Dakota State Department of Health and Consolidated Laboratories, Bismarck, ND. 

IPCS INCHEM is a means of rapid access to internationally peer reviewed information on chemicals commonly used throughout the world, which may also occur as contaminants in the environment and food. It consolidates information from a number of intergovernmental organizations whose goal it is to assist in the sound management of chemicals. 

Biovault is a commercially available, nonproprietary, ex situ treatment for soil and sediment contaminated with chlorinated and nonchlorinated volatile organic compounds (CVOCs and VOCs). The basic biovault process is to promote the degradation of the existing soil contaminants in consolidated piles by stimulation of the indigenous (or augmented) microbial population. The process typically includes low-intensity aeration, moisture control, and supplementation with nutrients. 

Limnofix In situ Sediment Treatment (LIST) technology is offered by Limnofix, Inc., a Colder Associates Company. The technology allows for the in situ treatment of contaminated sediment in surface waters. LIST enhances bioremediation of organic contaminants oxidizes sediments to control odor, nutrient release, or sulfide toxicity and produces stable marine sediment surfaces via consolidation and flocculation. 

To clean a mercury spill, consolidate the droplets with a piece of cardboard. Then suck the mercury into a filter flask with an aspirator. A disposable Pasteur pipet attached to a hose makes a good vacuum cleaner. To remove residual mercury, sprinkle elemental zinc powder on the surface and dampen the powder with 5% aqueous H2S04 to make a paste. Mercury dissolves in the zinc. After working the paste into contaminated areas with a sponge or brush, allow the paste to dry and sweep it up. Discard the powder as contaminated mercury waste. This procedure is better than sprinkling sulfur on the spill. Sulfur coats the mercury but does not react with the bulk of the droplet [D. N. Easton, Management and Control of Hg Exposure, Am. Lab., July 1988, p. 66],... 

Reduction. Hafnium oxide can be reduced using calcium metal to yield a fine, pyrophoric metal powder (see Calciumand calciumalloys). This powder contains considerable oxygen contamination because of oxygen s high solubility in hot hafnium, and cannot be consolidated into ductile metal. To obtain low oxygen ductile hafnium, the feed must be an oxygen-free halide compound such as hafnium tetrachloride or potassium hexafluorohafnate [16871-86-6]. 

Contamination limits the amount of handling and atmospheric exposure the powder can be subjected to before consolidation. The consolidation method most widely used is cold compaction and sintering. 

Because no process has been developed for selectively removing impurities in vanadium and vanadium alloys in the metallic state, it is essential that all starting materials, in aggregate, be pure enough to meet final product purity requirements. In addition, the consolidation method must be one that prevents contamination through reaction with air or with the mold or container material. 

The final tablet properties are also affected by the consolidation (i.e., bonding) mechanisms of the powder which is influenced by its chemical nature, the surface area of the contact points, contamination (including film coatings such as magnesium stearate), and interparticle distance. The predominant consolidation mechanisms are listed below ... 

Although platinum was introduced to Europe in the mid-18th century, it was first made commercially available in large quantities and in malleable form in 1805 by the English chemist William Hyde Wollaston. Previous attempts at consistently producing malleable metal were hindered by chemical purification techniques that gave platinum contaminated with deleterious metallic impurities. Richard KnighPs improved process of 1800 was carried out on a suitable sample of crude ore, and analysis of the purified platinum by spark source mass spectrometry (SSMS) indicates an impurity level of about 6%. Reconstruction of Wollaston s purification procedures, coupled with SSMS analysis, indicates that his product was over 98% pure. His superior chemical purification techniques, coupled with improvements in the powder consolidation method, explain Wollastons success. 

The principles for evaluations have been continuously reviewed and updated to take account of new scientific knowledge. FAO and WHO have recently initiated a project to update and consolidate principles for the assessment of food additives, contaminants, residues of veterinary drugs in food, and pesticide residues in food. 

Small Areas Consolidate as much material as possible and place into containers. In heavily contaminated areas, employ vacuum devices equipped with High Efficiency Particulate Air (HEPA) filters to remove as much agent as possible. Decontaminate the area with a fresh solution of HTH pool bleach in denatured alcohol (approximately 9 percent by weight) followed by decontamination with copious amounts of aqueous sodium hydroxide solution (a minimum of 10 percent by weight). Vigorous off-gassing may occur during this process. 

Small Areas Consolidate as much material as possible and place into containers. In heavily contaminated areas, employ vacuum devices equipped with High Efficiency Farticulate Air (HEFA) filters to remove as much agent as possible. Ventilate any enclosed or confined spaces. 

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