Xn:Harmful;
75-27-4Relevant articles and documents
REACTIONS OF CARBENES WITH ANIONS
Suelzle, Detlev
, p. 2769 - 2770 (1987)
CHBrCl2, CHCl2I and CHBr2I are prepared by a simple method based on the reaction of dichloro or dibromocarbene with the corresponding alkali metal halogenides under phase transfer conditions.
PROCESS FOR PREPARING BROMOTRICHLOROMETHANE
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Page/Page column 6-7, (2018/10/19)
The present invention relates to a process for preparing bromotrichloromethane comprising a) providing bromine in chloroform; and b) radiation of the resulting solution with light in the range of 350 to 550 nm, wherein said solution of bromine in chloroform is not radiated with radiation of a wavelength below 350nm.
Transient puffs of trace organic emissions from a batch-fed waste propellant incinerator
Hart, John R.
, p. 559 - 569 (2007/10/03)
Emissions data have been obtained from a waste propellant incinerator. The incinerator is a dual fixed hearth, controlled air incinerator equipped with acid gas and particulate scrubbing. Puffing has been evident in this waste propellant incinerator by spikes in the CO concentration. Transient puffs of organics may travel down the combustion chambers and lead to stack emissions. The major conclusions from this study are that (1) transient puffs are formed due to the semi-batch feed nature of the combustion process (causing a local oxygen deficiency) and high water content of the desensitized propellant; (2) in batch-fed combustors, puffs can contribute to most of the organic emissions (which are relatively low) measured with US EPA sampling and analytical methods; (3) it is estimated that batch-fed combustion contributes up to 7-18 times more emissions than steady-state combustion will generate; (4) by applying dispersion analyses to determine the amount of oxygen deficiency in the flame zone, the combustion zone concentration of CO during batch-fed operation could be as high as 160,000 ppm, compared to a measured peak stack concentration of 1200 ppm CO; and (5) an organic sample is collected and averaged over at least a 2-h period that smooths out the transient peaks of organics emissions during batch-fed operation. For emissions that are associated with long-term potential health impacts, this is an appropriate sampling method. However, if a compound has a short-term potential health impact, it may be important to measure the time-resolved emissions of the compound.
Modelling the formation of brominated trihalomethanes in chlorinated drinking waters
Nokes,Fenton,Randall
, p. 3557 - 3568 (2007/10/03)
The chlorination of water containing bromide and natural organic matter (NOM) leads to the formation of brominated trihalomethanes (THMs). The extent of brominated THM formation depends, inter alia, on the bromide:chlorine concentration ratio ([Br-]:[chlorine]). A reaction scheme is proposed from which a simple kinetic model is developed that mathematically relates the extent of bromination, and the relative abundances of the four THMs, to the [Br-]:[chlorine] ratio. In the scheme, the trihalogenated precursors to THMs are formed by three steps each of which substitutes either bromine or chlorine into an activated carbon site in the NOM. This leads to six pairs of competing bromination:chlorination reactions, whose rate constant ratios (k(b):k(c)) have been estimated by using the model to fit THM data obtained from the chlorination of 17 waters from New Zealand. The individual k(b):k(c) ratios range from 4 to 15. From a plot of the ratio of total bromine to total chlorine present in the THMs as a function of the [Br-]:[chlorine] ratio, an apparent overall k(b):k(c) ratio of 9.1 is obtained. Using USEPA cancer potency factors, the model is used to predict the relative cancer risk associated with THMs as a function of the [Br-]:[chlorine] ratio. This risk increases steeply to a peak at a [Br-]:[chlorine] ratio of approximately 0.15, then gradually decreases to the value associated with bromoform alone. The risk associated with THMs may vary considerably through changes in the [Br-]:[chlorine] ratio as the result of natural variation in the [Br-], or through poor control of chlorine dosing.
