Concentration of salt solutions

Conductivity cell Concentration of salt solution. Measured conductivity that represents concentration is within +X% of final concentration. 

FIGURE 31.3 Zeta potentials of a glass surface as functions of the concentrations of salt solutions with the cations (from bottom to top) K, Ca +, Al, Th ". ... 

Kb = dissociation constant of weak base and c = concentration of salt solution. 

In the unit considered in Example 14.2A, the weak liquor is fed to effect 0 and flows on to 0 and then to . The steam is also fed to 0, and the process is known as forward-feed since the feed is to the same unit as the steam and travels down the unit in the same direction as the steam or vapour. It is possible, however, to introduce the weak liquor to effect and cause it to travel from to to , whilst the steam and vapour still travel in the direction of 0 to to . This system, shown in Figure 14.6, is known as backward-feed. A further arrangement for the feed is known as parallel-feed, which is shown in Figure 14.7. In this case, the liquor is fed to each of the three effects in parallel although the steam is fed only to the first effect. This arrangement is commonly used in the concentration of salt solutions, where the deposition of crystals makes it difficult to use... 

The concentrates of salt solutions made by electrodialysis of seawater are suited as feed to the evaporators of salt manufacturing plants with considerable savings in overall energy requirements. Other applications also are based on the concentrating effects of electrodialysis, for instance, tenfold increases of concentrations of depleted streams from nickel and copper plating plants are made routinely. 

Some of the proteins can be removed from membranes by agents that disrupt ionic and polar bonding (e.g., urea or high concentrations of salt solution). These are known as extrinsic or peripheral proteins. Other proteins, called intrinsic or integral proteins, can be removed only by treating the membranes with detergents or with organic solvents. 

From the result of IR spectra, it should be expected that the amount of binding metals relates to the number of introduced side chains. When the concentration of salt solution is sufficient for the treatment, the quantity of binding metals levels off, i.e., binding sites are saturated [33]. Figure 14 shows relationships between the amount of introduced side chains and that of binding Zn for... 

Afonso, M.D., Hagmeyer, G., and Gimbel, R., Streaming potential measurements to assess the variation of nanofiltration membrane surface charge with the concentration of salt solutions, Separ. Purl Tech., 22, 529, 2001. 

Figure 21 Dry weight distribution ratios for pertechnetate versus the moIal concentration of salt solution contacted with ABEC-5000.

The reviews made by F. L. LaQue on this subject indicate that the salt spray test cannot realistically be used, for example, for parts with complicated shapes. This deficiency is principally due to the fact that the salt spray particles fall in vertical patterns, creating a strong orientation dependency. Another major inadequacy of the test is the variable sensitivity of different metallic materials to the ions present in various service environments. Since different metals also are affected differently by changes in the concentrations of salt solutions, the salt spray test is not really appropriate for ranking different materials in an order of relative resistance to salt water or salt air. The variability of the environments, even for seagoing equipment, is another factor that is extremely difficult to reproduce in a laboratory. Before attempting to simulate such natural environments, it is thus recommended that the chemistry of the environment and all other parameters controlling the corrosion mechanisms be monitored over time, in a serious attempt to characterize the worst exposure conditions. 

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