Liquid wastes hypochlorite

The main waste materials from destroying chemical munitions are solids soot, charcoal, gravel, inorganic dust, and metal fragments from the weapons. The only liquid waste from the DBG is spent hypochlorite solution from decontamination of the system prior to maintenance operations. ... 

The chlorine liquefaction plant comprises a bromine-removal column, a compression-condensation unit and a Tetra absorption/distillation unit (Fig. 14.2). Waste streams of chlorine are absorbed in diluted cell-liquor in the chlorine destruction area. As a result, the destruction liquid contains sodium chloride and less sodium hydroxide than is usual. Bromine from the bromine-removal column is also added to the chlorine destruction unit. The hypochlorite solution that is formed contains a reasonable amount of bromine and salts. However, it is a hypochlorite of non-marketable quality. 

In the electrolysis plant of Akzo Nobel in Rotterdam a hypochlorite production unit is in operation. This unit has two functions handling chlorine-containing waste gases from the plant and production of hypochlorite. The reaction is carried out in a two-step apparatus in which a liquid jet-loop reactor and a packed column are in series. In this way chlorine is converted to hypochlorite and emissions of chlorine to the atmosphere are avoided. 

Tribromomethane [75-25-2] (bromoform), CHBr3, is usually sold mixed with up to 3—4% ethanol as a stabilizer. The pure liquid has mp, 7.7°C bp, 149.5°C cP A, 2.8912 g/mL 19D 1.5980 (87). Water solubility is about 0.3 g/100 g at 25°C. Bromoform is prepared from chloroform by the replacement procedures indicated (88). The classical method of preparation involves reaction of acetone and sodium hypobromite the latter may be generated from sodium hypochlorite and a bromide (89). Uses have been found in syntheses, in pharmacy as a sedative and antitussive, in gauge fluids, and as a dense liquid for separating minerals. Traces of bromoform and bromochloroforms are likely to be present in municipal waters and wastes as a result of chlorination in the presence of naturally occurring bromide ions and humic substances (90). Removal can be accomplished by adsorption on activated charcoal. 

Solutions. Wear goggles and protective gloves and clothing. Cover spill with a 1 1 1 mixture by weight of soda ash, clay cat litter (bentonite), and sand. Scoop the mixture into a container and transport to the fume hood. Estimate the weight of fluorouracil in the spilled liquid and add 10% calcium hypochlorite solution (see waste disposal for preparation), allowing 100 mL for each 500 mg of fluorouracil. Allow to stand overnight,... 

To a plastic bucket (10 L), add sodium hypochlorite solution (500 mL) and liquid soap (10 mL) and make up to two-thirds full with hot water. This solution will be used at the end of the procedure to dispose of the waste and decontaminate used equipment. 

Due to its high vapor pressure at the operating temperature of the electrolysis, mercury, whose circulating tonnage represents 700 to 2400 kg/t per day of chlorine production capacity, pollutes the different gaseous streams produced (chlorine, hydrogen). Similarly, it contaminates the different liquids produced by the operation (spent brine, caustic soda, etc.). This results in substantial losses, which must be limited for economic as well as environmental reasons. Whereas small. amounts of mercury in the chlorine (0.1 to 0.2 g/t) are not detrimental to its subsequent uses, the same cannot be said of caustic soda, especially for food applications, in which it is removed by filtration (up to 15 ppb), for hydrogen, from which it is removed (up to 3 to 5 ppb) by absorption in sodium hypochlorite, adsorption on activated charcoal etc, and aqueous wastes, from which it is removed (up to 5 to 10 ppb) by precipitation, adsorption, reduction or extraction. The spent brine, which normally contains 1 to 10 ppm mercury and occasionally 1000 ppm, is usually recycled and therefore does not require treatment... 

Waste solutions containing cyanides treated with sodium hypochlorite are converted to harmless cyanate, which can be further processed to ammonia and carbon dioxide by addition of diluted sulfuric acid to pH 7. Surplus HCN gas can be neutralized by aqueous sodium hydroxide and then oxidized. Caution has to be advised with liquid hydrogen cyanide because bases including sodium hydroxide and sodium cyanide may initiate a violent polymerization11331. 

Z lost can be removed from the casings (spray canisters) after the lids have been cut off only by manual work, an extremely hazardous activity. Decontamination of the disassembled parts and of the tools used, like spoons and spatulas, is possible only by using the very effective German emulsion, which contains tetrachloroethylene as solvent and calcium hypochlorite as oxidant. The used decontaminant solutions constitute a further disposal problem, because they cannot be released into the waste water channel but must be burned, like liquid CW agents, in the incineration plant in Munster. 

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