Cyanides in wastes

Kuban V. 1992. Gas permeation and preconcentration in the flow-injection determination of acid-available cyanide in waste water. Anal Chim Acta 259(1 ) 45-52. 

Zhu Z, Fang Z. 1987. Spectrophotometric determination of total cyanide in waste waters in a flow-injection system with gas-diffusion separation and pre-concentration. Anal Chim Acta 198 25-36. 

Tecator Ltd. (1987) Cyanides in Waste Waters, Soils and Sludges using the 1026 Distilling Unit. Application Note AN 89/87 and AN 86/87, Tecator Ltd, Hoganes, Sweden. 

Funazo et al. [794] have also described a more sensitive gas chromatographic procedure capable of determining down to 3gg L 1 total cyanide in waste waters. The method is based on the derivatisation of cyanide to benzonitrile, which is extracted with benzene and determined by flame thermionic gas chromatography. In the derivatisation reaction, aqueous cyanide reacts with aniline and sodium nitrite in the presence of copper(II) sulphate and forms benzonitrile. 

Ozonation has also been found to be effective for the neutralization of cyanide in waste waters [27]. 

Z. Zhu and Z. Fang, Gas Diffusion Separation Flow Injection Analysis of Cyanide in Waste Waters [in Chinese]. Kexue Tongbao, 31 (1986) 800. 

Wet Air Oxidation. With wet air oxidation, increased temperature and pressure are used to oxidize dilute concentrations of organics and some inorganics, such as cyanide, in aqueous wastes that contain too much water to be incinerated, but are too toxic to be treated biologically. In general, wet air oxidation provides primary treatment for wastewaters that are subsequendy treated by conventional methods. This technology can be used with wastes that are pumpable (slurries andUquids). 

Corrective Action Application At a hazardous waste treatment storage and disposal facility in Washington State, a cyanide-bearing waste required treatment. The influent waste stream contained 15 percent cyanide. Electrolytic oxidation was used to reduce the cyanide concentration to less than 5 percent. Alkaline chlorination was used to further reduce the cyanide concentration to 50 mg/1 (the cleanup objective). The electrolytic process was used as a first stage treatment because the heat of reaction, using alkaline chlorination to treat the concentrated cyanide waste, would be so great that it would melt the reactor tank. 

Situation and Criteria A method was to be developed to determine trace amounts of cyanide (CN ) in waste water. The nature of the task means precision is not so much of an issue as are the limits of detection and quantitation (LOD, LOQ), and flexibility and ease of use. The responsible chemist expected cyanide levels below 2 ppm. 

Fuller, W.H., Movement of Selected Metals, Asbestos and Cyanide in Soils Applications to Waste Disposal Problems, EPA 600/2-77-020, NTIS PB 266 905, U.S. EPA, 1977. 

Lagas, P., J.P.G. Loch, and K. Harmsen. 1982. The behaviour of cyanide in a landfill and the soil beneath it. Pages 169-178 in R. Perry (ed.). Effects of Waste Disposal on Groundwater and Surface Water Intern. Assoc. Hydrolog. Sci., Publ. No. 139. 

Several studies document the biodegradation of mixtures of cyanides and thiocyanate in waste waters (e g., Boucabeille et al. 1994b Mudder and Whitlock 1984 Paruchuri et al. 1990 Shivaraman et al. 

The CSIRO Division of Mineral Products, Port Melbourne, Victoria, Australia, is conducting research to develop a process to recover fluoride and aluminum from spent pot lining ash with concurrent production of an environmentally safe residue that is suitable for disposal. The proposed method involves initial calcination which thermally decomposes the cyanide in the spent pot lining. Successful completion of this research would reduce the amount of hazardous wastes that contain potentially harmful leachable cyanides that can enter the groundwater during open air storage. 

The U.S. Bureau of Mines-Spokane Research Center is conducting research on the environmental impacts of placing mine wastes underground as backfill. This work includes a review of residual cyanide in placed landfill, water quality monitorings at two mines and laboratory tests of cyanide fate in underground environments and permeability/leachate effects through cemented tailings. 

Chattaraj S, Das A. 1991. Indirect determination of free cyanide in industrial waste effluent by atomic absorption spectrometry. Analyst (London) 116(7) 739-741. 

The CHEM-STA process can be limited by the presence of oxiders, such as chlorine, peroxide, permanganate, or persulfate. The presence of cyanide or chromium in waste can also create treatment limitations. All of the information provided in this summary is based on vendor literature and has not been independently verified. 

The vendor claims that this technology can break down groundwater contaminants including the following toluene, ethylbenzene, xylene volatile organic compounds (VOCs) fuel hydrocarbons and cyanides in industrial wastes. It can also destroy pathogenic organisms. 

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