Sodium water quality indicator

The field studies indicated that all of the dechlorination chemicals were effective in neutralizing free and combined chlorine to below 0.1 mg/L. In most cases the stoichiometric amount of dechlorination chemicals removed more than 90% of the chlorine. However, the reaction rates and the water quality impacts varied with the type, amount, and form of the chemicals used. In general, the rates of dechlorination using sodium/calcium thiosulfate were slower than those using the other chemicals. However, studies by others indicated that dechlorination of wastewater samples using sodium thiosulfate was more rapid that using ascorbic acid (24). 

When used in powder or crystal form, dechlorination chemicals (ascorbic acid and sodium thiosulfate) dissolved rapidly causing water-quality concerns, although physical methods (tablets) have been developed since to slow down dissolution rates. Sodium sulfite, when used in tablet form, was very effective in dose control. One tablet was sufficient to dechlorinate 2 mg/L of chloraminated water to below 0.1 mg/L for 45 min when water was released at 100 gpm. Finally, these field tests also indicated that the flow rates of chlorinated waters can significantly impact the efficiency of dechlorination operations. 

Unfortunately, the same authorities also do not provide any recommendations for FW silica content, sodium content, or electrical resis-tivity/conductivity, all of which are important constituents of high-quality water and are used as indicators of purity. (Silica and conductivity recommendations are, however, provided for BW quality.)... 

Concentration measurements of aqueous solutions of salt, sugar, antifreeze etc. Quality control of a number of industrial processes requires checking the concentration stability of different solutions and water soluble fluids. The off-line use of Abbe refractometers is sometimes an obstacle to real-time process control. Several researchers have tested different types of LPGs for the measurement of concentrations of aqueous solutions of sugar, salts, and antifreeze. Falciai et al. [16] used a UV written LPG (X = 1,530 nm, A - 400 pm) to measure concentrations of aqueous solutions of sodium chloride (NaCl) and calcium chloride (CaCl2) having refractive indices in the 1.32-1.42 range. In a later paper, Falciai et al. [17] also measured... 

Uses pH indicator useful in the pH range 5.2 (yel.) to 6.8 (purple) commonly used as the water-sol. sodium salt, as a solution in dil. sodium hydroxide, or as a solution in ethanol Manuf./Distrib. AMRESCO http //www.amresco-inc.com, Aldrich http //www.sigma-aidrich.com, Alfa Aesar http //www.aifa.com, Charkit http //www.charkit.com-, Curtiss Labs Dudley http //www.dudiey-chem.com-. Eastern Chem. http //www.u-g.com. Sigma Spectrum Quality Prods. 

The acidity of halogenated solvents can be determined by titration with 0.01N sodium hydroxide in the presence of a 0.1 % solution of bromophenyl blue indicator. Similar to the determination of alkalinity, acidity is determined in water extract. The determination can also be done directly in solvent but the solution of sodium hydroxide should be prepared in methanol. A third option is to determine acidity by a pH-metric titration of a water extract. Prior to determination, the pH of solvent is measured. If the pH is above 7, then an alkalinity measurement is done by the above method. If the pH is below 7, acidity is determined by this method. The method is used to establish purchasing and manufacturing specifications and control the quality of solvents. 

The acidity of benzene, toluene, xylenes, naphthas, and other aromatic hydrocarbons is determined by the titration of a water extract with 0.01 N sodium hydroxide in the presence of 0.5% phenolphthalein indicator solution. The method is suitable for setting specifications, internal quality control, and development of solvents. The result indicates the potential corrosivity of solvent. 

Procedure. Dissolve 0-5 g (or 0 5 ml) of the amine in a mixture of 3 ml of concentrated hydrochloric add and 2 ml of water. Cool the solution to 5 in an ice-bath. Prepare an ice-cold solution of 0 4 g of good quality sodium nitrite in 4 ml of water and add it slowly in small portions, stirring continuously, to the amine solution. Keep the solution below 10 during this operation. Leave the solution in the ice-bath for 5-10 minutes and then place a drop of the solution on starch-iodide paper. It should show an immediate blue colour, indicating the presence of an excess of nitrous acid. If this is not so, add a further small volume of sodium nitrite... 

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