Chlorine history

The history of iaclusion compounds (1,2) dates back to 1823 when Michael Faraday reported the preparation of the clathrate hydrate of chlorine. Other early observations iaclude the preparation of graphite iatercalates ia 1841, the P-hydroquiaone H2S clathrate ia 1849, the choleic acids ia 1885, the cyclodexthn iaclusion compounds ia 1891, and the Hofmann s clathrate ia 1897. Later milestones of the development of iaclusion compounds refer to the tri-(9-thymotide benzene iaclusion compound ia 1914, pheaol clathrates ia 1935, and urea adducts ia 1940. 

The modem history of the military use of toxic chemical agents (1,3—5) dates from the first full-scale (chlorine) gas attack on April 22, 1915, near Ypres, Belgium in World War I. There were a few reports of the limited use of toxic chemicals since that time. The Italians employed mustard, a bUster agent, during the Ethiopian war in 1935 and 1936 the Japanese used toxic chemicals in a number of small-scale engagements in the early years of their war with China and Iraq purportedly employed both mustard and nerve gases in the 1980s. 

The use of mercury for extracting precious metals by amalgamation has a long history and was extensively used by Spain in the sixteenth century when her fleet carried mercury from Almaden to Mexico and returned with silver. However, environmental concerns have resulted in falling demand and excess production capacity. It is still used in the extraction of gold and in the Castner-Kellner process for manufacturing chlorine and NaOH (p. 72), and a further major use is in the manufacture of batteries. It is also used in street lamps and AC rectifiers, while its small-scale use in thermometers, barometers and gauges of different kinds, are familiar in many laboratories. 

On September 6, 1987, the European Economic Community and the United States signed a phase-out agreement for the manufacture and use of specific refrigerants containing chlorine and bromine in the hydrocarbon molecule because of the effects on the atmosphere s ozone layer. ° See Reference 20, p. 18.1, for a more detailed history of this... 

The performance of graphite in seawater, where chlorine is the principal gas evolved, is considerably better than in fresh water where oxygen is produced. Graphite is immune to chlorine and has a long history in the chemical industry in this and similar applications . 

MCA Case History No. 282 Erroneous addition of cone, sulfuric acid to sodium chlorate instead of sodium chloride caused an explosion owing to formation of chlorine dioxide [1]. Accidental contact of 93% acid on clothing previously splashed with sodium chlorate caused immediate ignition [2],... 

One case study was identified where a man who had been occupationally exposed to hexachloroethane was treated for a liver tumor (Selden et al. 1989). Exposure had occurred over a period of 6 years as a result of the presence of hexachloroethane in a degassing agent used during aluminum smelting. However, the hexachloroethane reacted at the 700 C use-temperature, releasing a gas that was 96% hexachlorobenzene with small amounts of other chlorinated compounds. Because there was occupational exposure to a mixture of chlorinated compounds rather than just hexachloroethane, it is highly unlikely that the tumor was the result of hexachloroethane exposure alone. Occupational exposure to mineral oil mists for 20 years was also part of the subject s employment history. 

GC is coupled with many detectors for the analysis of pesticides in wastewater. At the present time the most popular is GC-MS, which will be discussed in more detail later in this section. The flame ionization detector (FID) is another nonselective detector that identifies compounds containing carbon but does not give specific information on chemical structure (but is often used for quantification because of the linear response and sensitivity). Other detectors are specific and only detect certain species or groups of pesticides. They include electron capture,nitrogen-phosphorus, thermionic specific, and flame photometric detectors. The electron capture detector (ECD) is very sensitive to chlorinated organic pesticides, such as the organochlorine compounds (OCs, DDT, dieldrin, etc.). It has a long history of use in many environmental methods,... 

This book examines comprehensively the chlorine industry and its effects on the environment. It covers not only the history of chlorine production, but also looks at its products, their effects on the global environment and the international legislation which controls their use, release and disposal. Individual chapters are dedicated to subjects such as end use processes, water disinfection and metallurgy, environmental release of organic chlorine compounds, polychlorinated biphenyls, legal instruments and the future of the chlorine industry. 

From several price histories it is possible to establish caustic soda and chlorine values in different markets and hence calculate the ECU value and with it some measure of profitability. The chlorine value in export EDC can be calculated on the formula assuming the ethylene price is known. The chlorine value using hydrogen chloride is complicated by the extra costs of using HC1 rather than chlorine and the slightly lower yields with oxychlorination, though that too can be calculated to give a chlorine value. 

Pankow, J. F., Feenstra, S., Cherry, J. A., and Ryan, M. C., 1996, Dense Chlorinated Solvents in Groundwater Background and History of the Problem In Dense Chlorinated Solvents and Other DNAPLs in Groundwater (edited by J. F. Pankow and J. A. Cherry), Waterloo Press, Portland, OR, pp. 1-52. 

Durham RW, Oliver BG. 1983. History of Lake Ontario (Canada, USA) contamination from the Niagara river by sediment radiodating and chlorinated hydrocarbon analysis. Journal of Great Lakes Research 9(2) 160-168. 

If there is a suitable electron-withdrawing substituent, hydrate formation may be favoured. Such a situation exists with trichloroacetaldehyde (chloral). Three chlorine substituents set up a powerful negative inductive effect, thereby increasing the 8- - charge on the carbonyl carbon and favouring nucleophilic attack. Hydrate formation is favoured, to the extent that chloral hydrate is a stable solid, with a history of use as a sedative. 

Information about the history and technical importance of the electrochemistry of chlorine is available from earlier reviews [62] and data collections [14]. 

Alembic Reprint No. 13, The Early History of Chlorine, University of Chi-... 

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