Silver organic pollutants

Removability of Toxic Organic Pollutants from Wastewater in the Secondary Silver Subcategory... 

Organic pollutants Pesticides Metals Antimony Arsenic Asbestos Beryllium Cadmium Chromium Copper Cyanide Lead Mercury Nickel Selenium Silver Thallium Zinc... 

However, organic pollutants are often accompanied by heavy metal ion contaminants that can be reduced by photogenerated electrons into their less toxic, nonsoluble metallic form. Ti02-assisted photoreductive catalysis was found to be useful in the removal of certain heavy metals including mercury, silver, platinum, palladium, rhodium, and gold via their reduction followed by deposition at the catalyst surface [20-22] or photoreduction of nitroaromatic compounds [23-26]. The use of photogenerated electrons for deposition of metal layers on... 

Xu, Y., J. Zhang, K.W. Schramm and A. Kettrup. Endocrine effects of sublethal exposure to persistent organic pollutants (POPs) on silver carp (Hypophthalmicthys molitrix). Environ. Pollut. 120 683 —690, 2002. 

Otari, S.V., Patil, R.M., Nadaf, N.H., Ghosh, SJ., Pawar, S.H., 2014. Green synthesis of silver nanoparticles hy microorganism using organic pollutant its antimicrobial and catalytic apphcation. Environ. Sci. Pollut. Res. Int. 21 (2), 1503—1513. 

Hydrogen sulphide This is produced by the putrefaction of organic sulphur compounds or by the action of sulphate-reducing bacteria in anaerobic conditions (e.g. in polluted river estuaries). It is fairly rapidly oxidised to SOj and concentrations are considerably lower than those of (Table 2.6). Nevertheless it is responsible for the tarnishing of copper and silver at normal atmospheric concentrations. 

Thurberg, F.P., A. Calabrese, and M.A. Dawson. 1974. Effects of silver on oxygen consumption of bivalves at various salinities. Pages 67-78 in F.J. Vemberg and W.B. Vemberg (eds.). Pollution and Physiology of Marine Organisms. Academic Press, NY. 

Initially the owner tried to recycle or treat his wastes, because the process described in his registration was acceptable to the Massachusetts DEP. It appeared that the silver in the spent fixer had to be removed, and the remaining pollutants were mainly biodegradable organics. Four silver removal methods were considered by the owner [58]. 

Photoreactions on titanium dioxide have been the focus of considerable interest for some time. Titania offers the opportunity to oxidize organic compounds in polluted environments, and has also been exploited to generate titania-supported nanoparticles of metals (e.g., silver) via photoreduction reactions [85]. While there is not enough room here to thoroughly treat photocatalytic processes, a brief introduction to the subject is presented below. Readers seeking detailed treatments of this subject are referred to a recent review by Yates etal. on titania-facilitated photocatalysis [86]. 

Regarding the PTEFmax parameter, an evaluation can be perfomied using phenol as the organic model pollutant and silver (Ag+) as the inorganic model cation pollutant. The a pai-ameter is set to unity and the following enthalpies for silver reduction and for the formation of the OH group are considered ... 

This review considers the literature of the past years (up to 1979) that treats the preconcentration of the priority pollution metals antimony, arsenic, beryllium, cadmium, chromium, copper, lead, mercury, nickel, selenium, silver, thallium, and zinc. In some cases, a brief outline is given or some discussion of the method, but in most instances, the number of methods available precludes more than a mention of their specific application or special feature. For some elements such as mercury many methods of preconcentration are available, for others such as beryllium and thallium only a few are reported. Relatively few procedures actually detail the analysis of a sample containing several species both organic and inorganic, although this area is of major concern, because of large differences in the relative toxicity of the various species. 

Active carbons are unique and versatile adsorbents, and they are used extensively for the removal of undesirable odor, color, taste, and other organic and inorganic impurities from domestic and industrial waste water, solvent recovery, air purification in inhabited places, restaurants, food processing, and chemical industries in the removal of color from various syrups and pharmaceutical products in air pollution control from industrial and automobile exhausts in the purification of many chemical, pharmaceutical, and food products and in a variety of gas-phase applications. They are being increasingly used in the field of hydrometaUurgy for the recovery of gold, silver, and other metals, and as catalysts and catalyst supports. They are also well known for their applications in medicine for the removal of toxins and bacterial infections in certain ailments. Nearly 80% (-300,000 tons/yr) of the total active carbon is consumed for liquid-phase applications, and the gas-phase applications consume about 20% of the total production. 

---