Swimming-pools

Acryhcs and modacryhcs are also useflil industrial fibers. Fibers low in comonomer content, such as Dolan 10 and Du Font s PAN Type A, have exceptional resistance to chemicals and very good dimensional stabihty under hot—wet conditions. These fibers are useflil in industrial filters, battery separators, asbestos fiber replacement, hospital cubical curtains, office room dividers, uniform fabrics, and carbon fiber precursors. The exceUent resistance of acryhc fibers to sunlight also makes them highly suitable for outdoor use. Typical apphcations include modacryhcs, awnings, sandbags, tents, tarpauhns, covers for boats and swimming pools, cabanas, and duck for outdoor furniture (59). 

The key markets for quaternaries are as swimming pool algaecides and in cooling water appHcations (see Water, treatment of swimming pools, spas, AND HOTTUBs), which further explains their importance as process biocides rather than preservatives. Some uses in latex films and plastics have been claimed (14,15). Primary quaternary ammonium industrial antimicrobial agents and their producers are presented in Table 4. 

The organo chlorine compounds are more expensive than inorganic chlorine compounds, but offer improved stabiUty against photolytic breakdown ia swimming pools (21). Swimming pool sanitation is generally accompHshed with 1—3 ppm free chlorine residual (see CHLORAMINES AND BROMAMINES Water, treati nt of swifting pools, spas, and hot tubs). ... 

Lithium Hypochlorite. Lithium hypochlorite [13840-33-0], LiOCl, is obtained from reaction of chlorine and an aqueous solution of lithium hydroxide. The soHd is usually obtained as a dry stable product containing other alkaH haHdes and sulfates (64). A product containing 35% available chlorine is used for sanitizing appHcations in swimming pools and in food preparation areas where its rapid and complete dissolution is important. The salt can also be obtained in higher purity by reaction of lithium hydroxide and hypochlorous acid (65). 

A number of pool, also called swimming pool, reactors have been built at educational institutions and research laboratories. The core in these reactors is located at the bottom of a large pool of water, 6 m deep, suspended from a bridge. The water serves as moderator, coolant, and shield. An example is the Lord nuclear reactor at the University of Michigan, started in 1957. The core is composed of fuel elements, each having 18 aluminum-clad plates of 20% enriched uranium. It operates at 2 MW, giving a thermal flux of 3 x 10 (cm -s). The reactor operates almost continuously, using a variety of beam tubes, for research purposes. 

Water Purification reservoirs, swimming pools, cooling towers... 

Chlorinated rubberis often used in combination with medium od drying type alkyds. The alkyd gives better toughness, flexibdity, adhesion, and durabdity, and the chlorinated mbber contributes to faster drying and better resistance to water and chemicals. The principal appHcations are highway traffic paint, concrete floor, and swimming pool paints. 

Light-Duty Recreational Surfaces. Artificial surfaces intended for incidental recreational use, eg, swimming pool decks, patios, and landscaping, are designed primarily to provide a practical, durable, and attractive surface. Minimum cost is a prime consideration and has driven the quaUty of some such products to a low level. Most surfaces in this category utilize polypropylene ribbon and a tufted fabric constmction (see Olefin polymers, polypropylene). ... 

Tetrasilver tetroxide is a powerful oxidizer for sanitizing swimming pools, hot tubs, and industrial cooling system waters (see Water, treatment of SWIMMINGPOOLS, SPAS, AND HOT tubs). This oxide is slightly soluble and its dissociation into silver ions is enhanced by the addition of the oxidizer KgSgOg. Bivalent and trivalent silver disinfectants have been shown to be from 50 to 200 times more effective as sanitizers than monovalent silver compounds. 

Sodium bisulfate, NaHSO, is a convenient mild acid and is safe for uses as a household toilet-bowl cleaner, automobile-radiator cleaner, and for swimming pool pH adjustment. It is used for metal pickling, as a dye-reducing agent, for soil disinfecting, and as a promoter in hardening certain types of cement. 

Treatment of swimming pools, spas, and hot tubs. Waterproofing and water/oil repellency. 

Table 1. Chlorine Sanitizers Used in Swimming Pools...

NaOH for stabiUty which has only a small effect on pool pH. It is a commonly used sanitizer for swimming pools. In pool water, it produces hypochlorite ion and hypochlorous acid ... 

Calcium Hypochlorite. This chemical, marketed since 1928, is one of the most widely used swimming-pool water sanitizers. Calcium hypochlorite, a crystalline sofld, is a convenient source of available chlorine and is sold in granular or tablet form for use in home, semiprivate, and commercial pools. When dissolved in water, Ca(OCl)2 forms hypochlorous acid and hypochlorite ion similar to NaOCl. It contains small amounts of stabilizing Ca(OH)2, which has a very small effect on pool pH (7). Calcium hypochlorite has superior storage stabiUty and much higher available CI2 concentration than Hquid bleach, which reduces storage requirements and purchasing frequency. 

Other Sanitizers and Treatment Systems. Other sanitizers and swimming pool treatment systems used to a limited extent are bromine, quats, ozone, ionizers, electrolyzers, uv, UV/H2O2, and Ag/H202. 

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