Theory and mathematical models of ion retention by watersoluble polymers during membrane filtration

Abstract

SUMMARYTheoretical approaches to the description of ion retention in aqueous solution by soluble polymers during membrane filtration are proposed. Examination of the chemisms responsible for inorganic ion complexation and retention by membrane-based separations helps to select appropriate hydrophilic polymers and optimum chemical conditions for the process. The ion separation and enrichment data may be formally explained by using mathematical models based on the theory of kinetics of the reactions in partially open systems.

Arsenite retention properties of water‐soluble metal–polymers

“…In the FTIR spectra of poly(AA)-Sn, prepared with different tin contents, the most important absorption bands (in cm 21 ) appear at: 3437 m(OH); 2928-2861 m(CÀ ÀH) of CH 2 and CH groups; 1720 m(C¼ ¼O) of carboxylic acid groups; 1567 m assym (COO 2 ) groups; 1407 m sym (COO 2 ), and so on. For pure poly(AA), the doublet at 1451-1400 cm 21 is observed with the maximum intensity at 1451 cm 21 , differing from poly(AA)-Sn where the intensity is inverted. This result suggests that the band at 1407 cm 21 for poly(AA)-Sn would be a symmetric carboxylate, m sym (COO 2 ), produced by the interaction with tin salt, which is enhanced.…”

“…For pure poly(AA), the doublet at 1451-1400 cm 21 is observed with the maximum intensity at 1451 cm 21 , differing from poly(AA)-Sn where the intensity is inverted. This result suggests that the band at 1407 cm 21 for poly(AA)-Sn would be a symmetric carboxylate, m sym (COO 2 ), produced by the interaction with tin salt, which is enhanced. This result is corroborated by the enhancement of band intensity at 1612-1567 cm 21 attributed to m asymm (COO 2 ).…”

“…This result suggests that the band at 1407 cm 21 for poly(AA)-Sn would be a symmetric carboxylate, m sym (COO 2 ), produced by the interaction with tin salt, which is enhanced. This result is corroborated by the enhancement of band intensity at 1612-1567 cm 21 attributed to m asymm (COO 2 ). The presence of asymmetric and symmetric bands corresponding to COO 2 groups on the poly (AA)-Sn samples can be used to identify the binding metal-ligand.…”

“…The presence of asymmetric and symmetric bands corresponding to COO 2 groups on the poly (AA)-Sn samples can be used to identify the binding metal-ligand. It is remarkable that as tin content increases from 3 to 20 wt %, there is an increase of intensity of the carboxylate group band and also a displacement towards lower frequencies in this region from 1612 to 1567 cm 21 , respectively. It is assumed that a positive resonance effect by the carboxylate anion in the presence of tin will decrease the binding order, thus decreasing the vibrational frequency.…”

“…By washing method, x mmol (where x 5 0.2, 1, 2, 4, and 6) of the poly(AA)-Sn, with weight molecular over 100,000 g mol 21 , are dissolved in twice-distilled water, and the solution containing 0.01 mmol of As(III) is added to the cell solution. The solutions are brought to 20 mL of total volume and the pH is adjusted by adding 0.1M NaOH or 0.1M HNO 3 .…”