Extraction acid concentration, effect

The distribution of highly extractable solutes such as and Pu between the aqueous and organic phases is strongly dependent upon the nitrate anion concentration in the aqueous phase. This salting effect permits extraction or reextraction (stripping) of the solute by controlling the nitric acid concentration in the aqueous phase. The distribution coefficient, D, of the solute is expressed as... 

The main differences between these processes are the acid concentration and the extraction temperature to effect selective removal of isobutylene. The acid concentration range is 45—65%. Figure 4 shows a simplified flow diagram of the CFR process. 

Tests are made on the extraction of acetic acid from a dilute aqueous solution by means of a ketone in a small spray tower of diameter 46 mm and effective height of 1090 mm with the aqueous phase run into the top of the tower. The ketone enters free from acid at the rate of 0.0014 m3/sm2, and leaves with an acid concentration of 0.38 kmol/m3. The concentration in the aqueous phase falls from 1.19 to 0.82 kmol/m3. 

Establishing control methods between the solvent extraction and electrowinning circuits, for flow rates, acid concentrations, and effect of recycle liquors on copper purity... 

CSSX that hydrogen-bond donor modifiers were most effective for Cs extraction, TBP being a poor modifier by comparison (413). The results of preliminary tests showed that the process is effective at selectively extracting Cs and Sr from solutions of nitric acid concentration between 0.5 and 2.5 M. Cesium and Sr can be stripped from the solvent with 0.01 M HN03 solution. 

By increasing the ionic strength, that is, the acid or metallic salt concentration, in the aqueous phase, the concentration of the extracted acid or salt in the organic phase increases and induces an increase in the attractions between reverse micelles (see below). Numerically, all the terms can be evaluated (7, 37, 83). It can then clearly be concluded that this effect is the origin of the third-phase formation. 

Asai et al. (1999) determined that phospholipid hydroperoxides (PLOOH) are key products for oxidative injury in membranous phospholipid layers in the plasma, red blood cells (RBC), and liver of mice. The formation and accumulation of PLOOH have been confirmed in several cellular disorders, various diseases, and in aging. A lower PLOOH level was found in RBC of the spice-extract-fed mice (65 to 74% of the nonsupplemented control mice). The liver lipid peroxidizability induced with Fe2+/ascorbic acid was effectively suppressed in mice by dietary supplementation with the turmeric and capsicum extracts. Although no difference in the plasma lipids was observed, the liver triacylglycerol concentration of the turmeric-extract-fed mice was markedly reduced to half of the level in the control mice. These findings suggest that these spice extracts could act antioxidatively in vivo by food supplementation, and that the turmeric extract has the ability to prevent the deposition of triacylglycerols in the liver. 

The extraction rate increased with an increase in the lactic acid concentration (Fig. 4) and a decrease in the solution pH (Fig. 5). It is well known that Alamine 336 can only extract the undissociated acid (26). The observed effects of pH and lactic acid were mainly attributed to the undissociated lactic acid concentration in the solution, as illustrated in Fig. 6 with combined data from Figs. 4 and 5. At low acid concentrations, the extraction rate was proportional to the lactic acid concentration, indicating that the reaction was first order with lactic acid concentration. However, at higher acid... 

Fig. 6. Effect of undissociated lactic acid concentration on extraction rate with Alamine 336 (30% [v/v] in 2-octanol) at pH 4.5 and 80 mL/min flow rate. The curve is from the model simulation.

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