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Alkalinity production

Miscellaneous. Hydrochloric acid is used for the recovery of semiprecious metals from used catalysts, as a catalyst in synthesis, for catalyst regeneration (see Catalysts, regeneration), and for pH control (see Hydrogen-ION activity), regeneration of ion-exchange (qv) resins used in wastewater treatment, electric utiUties, and for neutralization of alkaline products or waste materials. In addition, hydrochloric acid is also utilized in many production processes for organic and inorganic chemicals. [Pg.451]

Sodium bicarbonate is generally added to increase alkalinity and muriatic acid (HCl) or sodium bisulfate (NaHSO ) to reduce it. In general, with acidic sanitizers such as chlorine gas or trichloroisocyanuric acid, ideal total alkalinity should be in the 100—120 ppm range, whereas, with alkaline products such as calcium, lithium, or sodium hypochlorite, a lower ideal total alkalinity of 80—100 ppm is recommended (14). Alkalinity is deterrnined by titration with standard sulfuric acid using a mixed bromcresol green—methyl red indicator after dechlorination of the sample with thiosulfate. Dechlorination with thiosulfate causes higher readings due to formation of hydroxyl ion (32) ... [Pg.300]

Cesium perchlorate [13454-84-7], CsClO, mol wt 232.35 and theoretical cesium content hi.25/q, is a crystalline powder that decomposes at 250°C Cesium fluoride [13400-13-0], CsF, mol wt 151.90, theoretical cesium content 87.49%, has a melting point of 682—703°C and a boiling point of 1253°C. Cesium fluoride is an extremely hygroscopic, colorless, crystalline soUd it has a solubUity of 3.665 kg/L of water at 18°C. Cesium fluoride is made by exactly neutrali2ing cesium hydroxide with hydrofluoric acid and evaporating the resultant solution to dryness at 400°C. Excess HE results in a bifluoride salt that does not decompose at 400°C, and carbonate in the starting material gives an alkaline product. [Pg.376]

NOTE Strongly alkaline, closed loop LPHW system formulations, such as nitrite/borates, typically include an azole product at about 4 to 5% (50% solution). Lower alkalinity products (often the molybdates) have significantly less, perhaps only 0.5%. For comparison, open cooling water and chilled water system formulations typically contain about 2 to 3 % (50% solution) azole. [Pg.401]

The alkaline product from the wood ash was a crude solution of sodium and potassium carbonates called "lye". On boiling the vegetable oil with the lye, the soap (sodium and potassium salts of long chained fatty acids) separated from the lye due to the dispersive interactions between the of the fatty acid alkane chains and were thus, called "lyophobic". It follows that "lyophobic", from a physical chemical point of view, would be the same as "hydrophobic", and interactions between hydrophobic and lyophobic materials are dominantly dispersive. The other product of the soap making industry was glycerol which remained in the lye and was consequently, termed "lyophilic". Thus, glycerol mixes with water because of its many hydroxyl groups and is very polar and hence a "hydrophilic" or "lyophilic" substance. [Pg.53]

The behaviour with organic materials is generally good, except for alkaline products (amines, for example) and certain specific chemicals such as metacresol and hot nitrobenzene, which cause significant swelling (75-85%, for example). [Pg.595]

Indeed, in Antiquity, substances or waters with acid or alkaline properties such as vinegar, lime, or alkaline products (soda, alkaline ashes) were well known but there was no mention of hurts specifically due to these substances. It is mentioned that some waters, particularly these from alkaline springs are not drinkable, but nothing more. Actually, it will take more than a thousand years so that concentrated acids and bases could... [Pg.3]

This alkaline product is then to be weighed, and from the cover on the crucible, in order to keep in the vapor ... [Pg.538]

Four forms of the basic IAG model (27, 46) are described here to predict rates of recovery of LRL alkalinity. The models are described in order of increasing complexity and realism, reflecting the inclusion of IAG contributions from more biogeochemical processes (4,17). As previously discussed, chemical budgets from the first 3 years of acidification indicated that the main processes controlling IAG are sulfate reduction and cation production by ion exchange (in order of importance). Effects of nitrate and ammonium retention roughly cancel each other (in terms of net alkalinity production) (17). [Pg.157]

Aeolian arc (1 or 0.4 Ma to Present) Alicudi (0.06-0.03), Filicudi (1( )-0.04), Salma (0.4-0.013), Vulcano (0.12-1888 AD), Lipari (0.2-580 AD), Panarea (0.15-0.05), Strombo-li (0.2 — Present) - Stratovolcanoes with dominant calc-alkaline (basalt-andesite-rhyolite) and shoshonitic (basalt to rhyolite) compositions, with a few potassic alkaline products. [Pg.3]

REE patterns are fractionated for all the rocks, but tholeiites show lower La/Yb ratios than alkaline products (Fig. 8.5a). Incompatible element patterns normalised to primordial mantle compositions for mafic rocks are very different from the Aeolian arc and central-southern Italian peninsula. Both tholeiitic and alkaline basalts show a marked upward convexity, with negative spikes of K (Fig. 8.5b). Note, however, that there are also negative anomalies for Hf and Ti, which are uncommon in most Na-alkaline basalts from intraplate settings (e.g. Wilson 1989). Overall, the Etna magmas have been found to be more enriched in volatile components than common intraplate magmas, and water contents up to 3-4 wt % have been found by melt inclusion studies (Corsaro and Pompilio 2004 Pompilio, personal communication). [Pg.222]

Electromembrane processes such as electrolysis and electrodialysis have experienced a steady growth since they made their first appearance in industrial-scale applications about 50 years ago [1-3], Currently desalination of brackish water and chlorine-alkaline electrolysis are still the dominant applications of these processes. But a number of new applications in the chemical and biochemical industry, in the production of high-quality industrial process water and in the treatment of industrial effluents, have been identified more recently [4]. The development of processes such as continuous electrodeionization and the use of bipolar membranes have further extended the range of application of electromembrane processes far beyond their traditional use in water desalination and chlorine-alkaline production. [Pg.83]

In addition to the monopolar membrane described above a large number of special property membranes are used in various applications such as low-fouling anion-exchange membranes used in certain wastewater treatment applications or composite membranes with a thin layer of weakly dissociated carboxylic acid groups on the surface used in the chlorine-alkaline production, and bipolar membranes composed of a laminate of an anion- and a cation-exchange layer used in the production of protons and hydroxide ions to convert a salt in the corresponding acids and bases. The preparation techniques are described in detail in numerous publications [13-15]. [Pg.88]

Similar events also seem to have occurred with the boiler C and D fly ashes. Both fly ashes also generate alkaline leachates (see Table II). A comparison of the boiler temperatures that produced the boiler C and boiler D fly ashes and their ash fusion temperatures suggest that the boiler temperatures were high enough to cause fusion of their respective fly ashes within the boilers. Temperatures of 2600 and 2700°F were measured above the flame basket in the boiler C and boiler D, respectively. This is some 200° above the softening temperatures of the fly ashes. Apparently, the high temperatures encountered by the fly ash in the B boilers, boiler C and boiler D, have resulted in fusion reactions that have led to alkaline products that can be dissolved upon contact with water to form alkaline leachates. [Pg.342]

Other work has shown alkalinity production associated with Mn(IV), Fe(III), and SO42-in an anoxic fjord (Yao and Millero, 1995). [Pg.401]

Schiff S. L. and Anderson R. F. (1986) Alkalinity production in epilimnetic sediments acidic and non-acidic lakes. Water Air Soil Pollut. 31, 941-948. [Pg.4944]

More that 5300 test samples have been studied in the Skintex system, including petrochemicals, agrochemicals, household products, and cosmetics. The reproducibility with standard deviations of 5-8% is excellent. New protocols applicable to very low irritation test samples and alkaline products have increased the applicability of this method. Skintex validation studies resulting in an 80-90% correlation to the Draize scoring have been reported by S.C. Johnson Son and the Eood and Drug and Safety Center. [Pg.2650]

Several prespotter formulations are disclosed in the patent literature. Acidic compositions that contain a mixture of nonionic surfactants and hydrotropes [163], thickened alkaline products with hypohalite bleaches [164,165], and enzyme-containing formulas [ 166] have all been developed for use as prespotters. Although... [Pg.361]

These cleaners should not only be tested for their stain-removing ability, but also for their soap scum cleaning. Although such alkaline products generally show poor soap scum cleaning compared to the acid bathroom cleaners, many consumers use them for general bathroom/tile cleaning. [Pg.613]

Schematic diagram illustrating the chlorine/alkaline production process... Schematic diagram illustrating the chlorine/alkaline production process...
Both quicklime and hydrated lime are dusty, alkaline products. Not surprisingly, a common injury associated with them is grit or dust in the eye. The use of adequate eye protection in all lime production and handling areas is essential. Indeed, some firms have made the use of some form of eye protection compulsory throughout the lime area and have, as a consequence, dramatically reduced the number of eye injuries. [Pg.400]

CORROSION, CATHODIC - Corrosion resulting resulting from a cathodic condition of a structure usually caused by the reaction of an amphoteric metal with the alkaline products of electrolysis. [Pg.48]


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See also in sourсe #XX -- [ Pg.419 ]




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