Salt enrichment

A second potential application is pressure-driven desalination. When a pressure difference is applied across the membrane, the concentrated ionic groups in the ion exchange domains are swept through the membrane, producing a salt-enriched permeate on the low-pressure side. This process, usually called piezodialysis, has a number of conceptual advantages over the alternative, conventional reverse osmosis, because the minor component (salt), not the major component (water), permeates the membrane. 

Electrodialysis — Figure. The electro dialysis cell (a) [i] (a = anion-permeable membrane c = cation-permeable membrane o = positive ion = negative ion ion migration under action of electrical current (b), causes salt depletion in alternate compartments and salt enrichment in adjacent ones (c))... 

Vovk I. F. (1987) Radiolytic salt enrichment and brines in the crystalline basement of the East European Platform. In Saline Water and Gases in Crystalline Rocks, Special Paper 33 (eds. P. Fritz and S. K. Frape). Geological Association of Canada, Memorial University, Newfoundland, pp. 197-210. 

The predominant landscapes are dry steppe, semi-desert and desert, mainly calcium-sodium, gypsum and salt-enriched types. The well expressed forms ofmeso-and micro-relief, such as saucer-like and outstretched depressions, temporary water channels, and micro-hills, as typical plain relief and the shallow ground water level are accompanied with the contrast moisture redistribution, distinguish differentiation of soil and vegetation types. This is finally accompanied with an extensive accumulation of boron in salty depressions due to the transpiration biogeochemical barrier. 

Addition of salts (e.g. potassium phosphate dibasic ) partitions an aqueous system containing 202 w/v polyethylene glycol < PEG) into two liquid phases a PEG enriched phase and a salt enriched phase. Proteins and polymers (e.g. DNA, albumin, immunoglobulins, alpha-1 antitrypsin, and PEG) distribute unevenly between the two phases. Partition coefficients (concentration in PEG phase / concentration in salt phase = K) are influenced by physical parameters, such as salt composition and concentration, pH (ion ratios) and temperature. Specific proteins (e.g. alpha-1 antitrypsin) exhibit low K values in a wide range of conditions. 

Figure 6.36 Piezodialysis of a potassium chloride solution using a mosaic ion exchange membrane (membrane thickness about 200 A, ion exchange capacity of cation and anion exchange parts are almost the same). Salt enrichment Es = [(CujCi) — 1] X 100 (C, concentration of feed solution Cu concentration of permeate). ( ) Membrane prepared by casting dioxane solution of the polymer. ( ) Membrane prepared by casting benzene solution of the polymer. (A) Membrane prepared by casting cyclohexane solution of the polymer.

Problem 10.56. One of the products of radiation fallout from atmospheric bomb testing or nuclear accidents as at Chernobyl is iodine-131. People living in a region where iodine-131 was known to have been deposited were encouraged to use salt enriched with nonradioactive iodine-127. What was the basis of this treatment ... 

These tests are set up with the test fuel over a simulated water bottom. The ratio of fuel to the water bottom, mentioned in the literature, ranges anywhere from 1 1 to 1,000 1. The industry standard for the simulated water bottom is Bushnell Haas Mineral Salts Enrichment Medium (Bushnell and Haas, 1941). 

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