Decontamination oxidation

Rapid Nucleophilic/Oxidative Decontamination of Chemical Warfare Agents." Industrial ... 

Both hydrolysis and oxidation can be speeded up by catalysts. Wagner-Jauregg et al. (1955) and Gustafson and co-workers (1959,1962,1963) have investigated the use of copper as a catalyst for the hydrolysis of nerve agents and sulphur mustard. Iron has been studied as a catalyst of oxidative decontamination the reader is referred to Yang et al (1992) for detailed comments. 

Raber E and McGuire R (2002). Oxidative decontamination of chemical and biological warfare agents using L-Gel. J Hazard Mater, B93, 339-352. 

The oxidative decontamination process for mustard, a CWA threat of major concern, targeted by us and others, is selective sulfoxidation, eq 1, because the sulfoxide has been known for decades to be far less toxic than mustard itself (2, 3). 

In contrast, the corresponding sulfone, a product of over-oxidation, has substantial toxicity (fairly potent vesicant). Thus, viable oxidative decontamination systems must exhibit high selectivity for sulfoxide as well as high rates. 

Other examples of sonoelectrochemical breakdown of pollutants include enhanced removal of phenol from industrial effluents by electrooxidation.49 Thus, >80% oxidation of PhOH to maleic acid was achieved when ultrasound (25 kHz, 104 W m 2) was applied to a solution containing phenol (100 g L i) and NaCl (2 g L i) in an electrolyzer, instead of only 50% without ultrasound. Recent German and French patents describe respectively the oxidative decontamination of pollutants in watei o and an electrochemical cell for the treatment of swimming-pool waters. i... 

Gonzaga, R, Perez, E., Rico-Lattes, L, and Lattes, A. 2001. New microemulsions for oxidative decontamination of mustard gas analogues and polymer-thickened half-mustard. New J Chem, 25, 151-155. 

The cobalt deposition rate on new, replacement, or decontaminated recirculation piping surface has been reduced by pretreating the piping using an atmosphere of oxygenated wet steam to form an oxide film (25). Studies have been conducted for both PWRs and BWRs to reduce the cobalt content of materials used in the nuclear parts of the plants, particularly in hardened and wear surfaces where cobalt-base alloys ( 50% Co) are used (26). Some low cobalt materials have been developed however, the use of the materials is limited to replacement parts or new plants. 

If decontamination caimot be left to natural processes, chemical neutralizers or means of physical removal must be employed. In general, the neutralizers are of two types chlorine-based oxidants or strong bases. Some neutralizers have been especially developed for the decontamination of chemical agents. 

One such decontaminant is supertropical bleach (STB). STB is a mixture of chlorinated lime and calcium oxide containing about 30% available chlorine. It can be used either as a dry mix or as a slurry to decontaminate some equipment surfaces and terrain. The dry mix is prepared with two parts bleach to three parts earth by volume. A slurry typically consists of 40 parts STB to 60 parts by weight of water. This material is then sprayed or swabbed on the contaminated surface (see Bleaching agents). STB is an effective decontaminant for mustard, lewisite, and VX. It is less effective against nerve agents other than VX. 

Halazone, W,A/-dichloro-7 -carboxybenzenesulfonamide [80-13-7] is suitable for the decontamination of water, as is also succinchlorimide, /V-ch1orosuccinimide [128-09-6] which is a white crystalline compound having a chlorine odor. Succinchlorimide is strongly bactericidal when compared to hypochlorites, and is less affected by organic matter than halazone. However, it is inferior to hypochlorites as a cysticide (29). Chloroazodin, also known as azochloramide and W,A/-dichloro-azodicarbonamidine [502-98-7] is claimed to be relatively nontoxic to tissue. AppHed to a wound it acts as a mild and slow oxidant (30). 

Intensive technologies are derived from the processes used for the treatment of potable water. Chemical methods include chlorination, peracetic acid, ozonation. Ultra-violet irradiation is becoming a popular photo-biochemical process. Membrane filtration processes, particularly the combination microfiltration/ultrafiltra-tion are rapidly developing (Fig. 3). Membrane bioreactors, a relatively new technology, look very promising as they combine the oxidation of the organic matter with microbial decontamination. Each intensive technique is used alone or in combination with another intensive technique or an extensive one. Extensive... 

It hydrolyses in acidic medium to form HC1 and nonvolatile (solid) chlorovinylarsenious oxide, which is a less potent vesicant than ED. Hydrolysis in alkaline medium, as in decontamination with alcoholic caustic or carbonate solution, produces acetylene and trisodium arsenate (Na3AS04). 

Oxidation is a means of decontamination. There are several methods that can facilitate oxidation to treat contaminated groundwater. In the following we describe two examples of such technologies. 

DAF is used to remove suspended solids by decreasing their apparent density they then rise and float on the water surface. DAF is also used to remove soluble iron, VOCs, oils, and surface active agents by oxidation, air stripping, and surface adsorption. The flotation technology is becoming one of the most important technologies for groundwater decontamination, industrial effluent treatment, and water purification.58-6170... 

The development of catalysts for the oxidation of organic compounds by air under ambient conditions is of both academic and practical importance (1). Formaldehyde is an important intermediate in synthetic chemistry as well as one of the major pollutants in the human environment (2). While high temperature (> 120 °C) catalytic oxidations are well known (3), low temperature aerobic oxidations under mild conditions have yet to be reported. Polyoxometalates (POMs) are attractive oxidation catalysts because these extensively modifiable metal oxide-like structures have high thermal and hydrolytic stability, tunable acid and redox properties, solubility in various media, etc. (4). Moreover, they can be deposited on fabrics and porous materials to render these materials catalytically decontaminating (5). Here we report the aerobic oxidation of formaldehyde in water under mild conditions (20-40 °C, 1 atm of air or 02) in the presence of Ce-substituted POMs (Ce-POMs). 

S02 and NOx in flue gas from coal combustion contribute to smog and acid rain. Methods to remove these pollutants include alkaline wet scrubber systems that fix S02 to solid CaS04, and selective catalytic reduction by metal/metal oxide systems of NO/NOz to N2 and steam in the presence of ammonia. Particulate active carbons have also been used in flue gas decontamination, especially as they avoid costly scrubber processes and can operate at lower temperatures. The potential of active carbon fibers in this application has been explored by a... 

Standard burials are acceptable when contamination levels are low enough to allow bodies to be handled without wearing additional protective equipment. Cremation may be required if remains cannot be completely decontaminated. Although arsenic vesicant agents are destroyed at the operating temperature of a commercial crematorium (i.e., above 1000°F), the initial heating phase may volatilize some of the agents and allow vapors to escape. Additionally, combustion will produce toxic and potentially volatile arsenic oxides. 

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