Chlorine clarifier

The clarified and acidified brine is treated with gaseous chlorine which is injected into the solution in a small excess over the theoretical stoichometric relation by weight of 0.28 1 chlorine to iodide. The oxidation occurs according to... 

Part of the continuously recirculated solution is bled off and sent to the iodine finishing process. Iodine finishing consists of contacting this bleed of concentrated acidic iodide solution with gaseous chlorine, through which iodine is formed by oxidation and precipitated. After iodine precipitation, the resulting acidic mother Hquor, saturated with free iodine, is pumped back to acidify the clarified brine and to recover the remaining iodine. 

Manufacture. Phosphoms pentachloride is manufactured by either batch or continuous processing. In the former, the phosphoms trichloride usually dissolves in carbon tetrachloride before being treated with chlorine. A mixture of ca one part of phosphoms trichloride to one part of carbon tetrachloride is introduced to a water-jacketed vessel that contains an efficient stirrer and a tight cover with a redux condenser. The chlorine is passed into the vessel below the Hquid level, and crystals of phosphoms pentachloride form in the Hquid. When the reaction is completed, the suspension of crystals of phosphoms pentachloride in the carbon tetrachloride is drawn out of the vessel and the crystals are filtered and then dried by circulating hot water through the jacket of the filter. The clarified carbon tetrachloride is returned to the reaction vessel. 

Mixing of the electrode products causes hydrolytic precipitation of the nickel and, after separation of the nickel hydroxide, the filtrate was returned to the cells. The sequence of the electrolytic purification steps is outlined in Figure 6.28. Nickel hydroxide slurry is first added to the anolyte for the purpose of raising the pH to 3.7 (2 H+ + Ni(OH) = Ni2+ + 2 H20), and iron(II) is oxidized by introducing chlorine. This causes hydrolytic precipitation of the iron(III) and corrects the nickel ion deficiency by the low anodic current efficiency. The iron(III) hydroxide is removed by filteration. The clarified solution is then treated with nickel carbonate and further chlorine to oxidize the cobalt(II) and allow its separation as cobalt(I II) hydroxide. 

Some synonyms in the Alphabetical index are followed by bracketed notations. These notations provide additional clarifying information about the entry such as composition, modifications to the agents (e.g., thickened, dusty, binary), or a note for historical context. For example, "White Star" was a gas blend that was employed by the British in World War I consisting of 50% phosgene and 50% chlorine. The entry appears as ... 

Water Treatment. The source of water for this experiment was a pilot plant located on the Seine River upstream from Paris, France (Figure 1). The pilot plant uses an upflow solids contact clarifier (Pulsator, Degremont, Rueil Malmaison, France) followed by rapid sand filtration (RSF). The filtered water is then distributed over four treatment lines to evaluate the efficiency of various ozone-GAC combinations (ozonation rates of 1 or 5 ppm O3 and 10-30 min of contact time). The GAC used in this study was Calgon F-400 (Calgon Corp.). Disinfection by chlorine or chlorine dioxide completed the process. In this chapter, line 3 treatment was not considered a complete treatment for the water supply. This line was studied to evaluate the efficiency of a high ozonation rate. 

The mode of action of ZnCL has not been clarified Nevertheless. it is thought to interact with complex 16, because its presence increases the rate of reaction. Moreover it seems to be involved in cleavage of tine of the two diastereotopic chlorine atoms, because the diastereoseleetivity of the reaction increases simultaneously. 

Mizushima, Shimanouchi, Nakamura, Hayashi, and Tsuchiya (7.39)], have furnished a significant basis for our understanding of the types of isomeric chain configurations which can exist in chlorine-containing high polymers. Studies of this type are dictated by the particular polymer under investigation. Sometimes the necessary information will be found in the literature in other cases a careful study of such model compounds may have to be initiated in order to clarify certain aspects of the polymer spectrum. 

Numerous cases of electrochemical halogenation (chlorination, bromination, iodination) are known and have been discussed in some detail by Allen 6 Generally, these reactions appear to be indirect electrolytic processes, since in most cases the substrates are oxidized at higher potentials than chloride, bromide, and iodide ion. More work is needed, however, to clarify anodic halogenation mechanism. 

Chemical addition is typically used with clarification to improve both the utility and performance of the unit operation. Coagulants and flocculants are generally used to improve the ability to settle particles in the clarifier. Jar tests are used to determine the proper dosage of chemicals and streaming current detectors or turbidity monitors are used to monitor performance and control chemical dosage. Chlorine is often used to improve the removal of organics and color in the clarifier. Chlorine also provides disinfection of the make-up water to prevent the clarifiers from going septic. 

Chlorine is usually added upstream of a clarifier to oxidize organics, to improve the removal of color in the clarifier, and to control... 

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