Chlorine shocking

This has been observed both at FilmTec and by Glater and co-workers (53). Because of the low rate of oxidation of FT-30 membrane by chlorine it can tolerate an accidental exposure to chlorine. Shock chlorinations, if used with care, are possible, but not generally recommended. 

Lithium Hypochlorite Pool Shock 1.0-3.0 ppm as HOCl Completely water soluble Shelf-life stable Easy to handle Highest cost chlorine shock... 

Actually, I was just ignorant, which is a curable deficiency. Next time, I first eliminated hydrocarbon leaks into the cooling water system and chlorine shocked the cells, using bottled chlorine. 

Dichlorine h ptoxide, CljO, is the most stable of the chlorine oxides. It is a yellow oil at room temperature, b.p. 353 K, which will explode on heating or when subjected to shock. It is the anhydride of chloric(VlI) acid (perchloric acid) from which it is prepared by dehydration using phosphorus(V) oxide, the acid being slowly reformed when water is added. 

Chlorine heptoxide is more stable than either chlorine monoxide or chlorine dioxide however, the CX C) detonates when heated or subjected to shock. It melts at —91.5°C, bods at 80°C, has a molecular weight of 182.914, a heat of vapori2ation of 34.7 kj/mol (8.29 kcal/mol), and, at 0°C, a vapor pressure of 3.2 kPa (23.7 mm Hg) and a density of 1.86 g/mL (14,15). The infrared spectmm is consistent with the stmcture O CIOCIO (16). Cl O decomposes to chlorine and oxygen at low (0.2—10.7 kPa (1.5—80 mm Hg)) pressures and in a temperature range of 100—120°C (17). It is soluble in ben2ene, slowly attacking the solvent with water to form perchloric acid it also reacts with iodine to form iodine pentoxide and explodes on contact with a flame or by percussion. Reaction with olefins yields the impact-sensitive alkyl perchlorates (18). 

SuperchlorinationShock Treatment. Superchlorination or shock treatment of pool water is necessary since accumulation of organic matter, nitrogen compounds, and algae consumes free available chlorine and impedes disinfection. Reaction of chlorine with constituents of urine or perspiration (primarily NH" 4, amino acids, creatinine, uric acid, etc) produces chloramines (N—Cl compounds) which are poor disinfectants because they do not hydrolyze significantly to HOCl (19). For example, monochloramine (NH2CI) is only 1/280 as effective as HOCl against E. coli (20). 

During superchlorination or shock treatment, ammonium ion is oxidized to nitrogen by breakpoint chlorination which is represented by the simplified reaction sequence... 

Urea (24), amino acids (25), and creatinine (26) are also decomposed during superchlorination or shock treatment, with formation of N2 and other oxidation products. However, the process is slower than with ammonium ion (see Chloramines and BROMAMINEs). Urea is the principal nitrogen-containing compound in swimming pools. Since it is an amide, it reacts slowly with chlorine, yielding N2, NCl, and NO/ (27). 

Superchlorination typically refers to a dding FAC equal to 10 x ppm CAC, whereas shock treatment generally involves addition of 10 ppm FAC. The frequency of superchlorination or shock treatment depends on bather load and temperature. Calcium hypochlorite, because of its convenience, is widely used for superchlorination and shock treatment. Sodium hypochlorite, LiOCl, or chlorine gas are also used. Chloroisocyanurates are not recommended since their use would result in excessive cyanuric acid concentrations. 

The concentration of inorganic and organic chloramines in pool water is controlled by superchlorination or shock treatment. Because chloramines are decomposed by sunlight, their effects are more noticeable in indoor pools or spas. Nitrogen trichloride, the primary volatile chloramine, is a strong irritant similar to chlorine. Its effect is noticeable at >0.5 mg/m (>0.1 ppm) (73). The concentration of NCl depends on the extent of ventilation and typically varies from 0.2 to 0.5 mg /m (0.04 to 0.1 ppm) (74). 

Lithium hypochlorite is used in I I laundry detergents and I I dry laundry bleaches. Like sodium hypochlorite, it does not precipitate soaps and other anionic detergents. However, lithium hypochlorite is an expensive source of available chlorine and not much is used for bleaching. Its principal use is as a shocking agent for swimming pool disinfection. 

The resistance of graphite to thermal shock, its stabiUty at high temperatures, and its resistance to corrosion permit its use as self-supporting vessels to contain reactions at elevated temperatures (800—1700°C), eg, self-supporting reaction vessels for the direct chlorination of metal and alkaline-earth oxides. The vulnerabiUty of cemented joints in these appHcations requires close tolerance ( 0.10 mm) machining, a feat easily accompHshed on graphite with conventional metal machining equipment. 

The process of post-chlorinating PVC was carried out during World War II in order to obtain polymers soluble in low-cost solvents and which could therefore be used for fibres and lacquers. The derivate was generally prepared by passing chlorine through a solution of PVC in tetrachloroethane at between 50°C and 100°C. Solvents for the product included methylene dichloride, butyl acetate and acetone. These materials were of limited value because of their poor colour, poor light stability, shock brittleness and comparatively low softening point. 

Combined Chlorine-Aldehyde Treatment A combined chlorine-aldehyde treatment that has two stages, that is, chlorination and subsequent biocide application, has been suggested. Short-residence-time shock doses of glutaraldehyde have been applied after chlorination [1180]. It has been established that a primary chlorination in overall bacterial control is useful. 

Shock-sensitive [1], it explodes on heating in a (sealed ) capillary, like its lower homologue. The crude product prepared by chlorine oxidation of the corresponding... 

Several nitro compounds are soluble in chlorine trifluoride, but the solutions are extremely shock-sensitive. These include trinitrotoluene, hexanitrobiphenyl, hexanitrodiphenyl-amine, -sulfide or -ether. Highly chlorinated compounds behave similarly. 

During the preparation of this explosive liquid by interaction of sulfuryl chloride fluoride and sodium azide, traces of chlorine must be eliminated from the former to avoid detonation. The product is nearly as shock-sensitive as glyceryl nitrate and may explode on rapid heating. Solutions (25 wt%) in solvents may be handled safely. The corresponding fluoride is believed to behave similarly. 

Potassium ignites in fluorine and in dry chlorine (unlike sodium). In bromine vapour it incandesces, and explodes violently in liquid bromine. Mixtures with iodine incandesce on heating, and explode weakly on impact. Potassium reacts explosively with molten iodine bromide and iodine, and a mixture with the former is shock-sensitive and explodes strongly. Molten potassium reacts explosively with iodine pentafluoride [1], Contact with iodine trichloride causes ignition [2],... 

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