Particulate silver

It is clear that in natural waters, ionic silver and some silver complexes were readily adsorbed on to particles with less than 25% as dissolved ions, complexes or colloids. It was also considered that the exposure route for particulate silver had not been fully explored [33]. 

Van den Pol AN (1986) Tyrosine hydroxylase immunoreactive neurons throughout the hypothalamus receive glutamate decarboxylase immunoreactive synapses a double pre-embed-ding immunocytochemical study with particulate silver and HRP. J Neurosci 6 877-891... 

I. In reality, Sennert s most influential experiment involved the precipitation of silver carbonate out of a silver-nitric acid solution by means of added potassium carbonate. But upon heating, silver carbonate decomposes into pure silver, carbon dioxide, and oxygen. When Sennert heated the precipitate, he apparently (and understandabfy) thought that he was merely fusing particulate silver. At any rate, his major point, that the silver atoms are not decomposed by the nitric acid, still stands. 

The gases from the several furnaces treating the slimes carry bismuth, silver, gold, and other values as particulates, which are recovered via Cottrell precipitators, baghouses, or scmbbers. 

This method is used for the determination of total chromium (Cr), cadmium (Cd), arsenic (As), nickel (Ni), manganese (Mn), beiylhum (Be), copper (Cu), zinc (Zn), lead (Pb), selenium (Se), phosphorus (P), thalhum (Tl), silver (Ag), antimony (Sb), barium (Ba), and mer-cuiy (Hg) stack emissions from stationaiy sources. This method may also be used for the determination of particulate emissions fohowing the procedures and precautions described. However, modifications to the sample recoveiy and analysis procedures described in the method for the purpose of determining particulate emissions may potentially impacl the front-half mercury determination. 

Air (particulate PbS) Collection of particles onto filter, suspension in THF, recollection onto silver filter XRD 60 pg/m3 102.6 NIOSH 1994... 

Most measurements of silver concentrations in natural waters prior to the use of clean techniques are considered inaccurate. Until analytical capabilities that exceed the dissolved-particulate classification are developed, it will be necessary to rely on laboratory and theoretical modeling studies to fully understand chemical speciation of silver in natural waters (Andren et al. 1995). 

Techniques for controlling particulate matter to prevent plugging of SILVER II electrolytic cell channels must be developed and demonstrated. 

Porous metals have long been commercially available for particulate filtration. They have been used in some cases as microfiltration membranes that can withstand harsh environments, or as porous supports for dynamic membranes. Stainless steel is by far the most widely used porous metal membrane. Other materials include silver, nickel. Monel, Hastelloy and Inconel. Their recommended maximum operating temperatures range from 200 to 650°C. Elepending on the pore diameter which varies from 0.2 to 5 microns, the water permeability of these symmetric membranes can exceed 3000 L/h-m -bar and is similar to that obtained with asymmetric ceramic microfiltration membranes. Due to the relatively high costs of these membranes, their use for microfiltration has not been widespread. 

Filters collect liquid and solid particles by mechanisms including diffusion, impaction, interception, electrostatic attraction, and sedimentation onto the filter while allowing the gas to pass through. The types commonly used in atmospheric particulate collection are membranes, fibrous mats, or porous sheets. Different filter materials are used depending on the particular type of measurement being carried out, including Teflon, quartz fiber, nylon, silver, cellulose filters, glass fibers, and polycarbonate. The characteristics of each are summarized by Chow (1995). 

Fig. 6.5 Typical negative-going LSV recorded on the upper black squares) and bottom (open circles) face of a sterling silver coupon exposed in cultural institutions. The larger peak intensity measuring at — 1.6 on upper face indicates a selective attack of this face that is probably due to the deposition of particulate matter...

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