Polymer-enhanced ultrafiltration: counterion distribution and its relation with the divalent metal-ion retention properties by sulfonic acid polyelectrolytes

Liquid-Phase Polymer-Based Retention: Theory, Modeling, and Application for the Removal of Pollutant Inorganic Ions

“…Geckeler et al (1986) carried out the first experimental advances and analytical applications related to this technique [6,21,22]. Later, many research groups have worked on the evaluation and description of retention properties of different water-soluble polymers (WSPs) for environmental and analytical applications [5,[21][22][23][24][25][26][27][28][29][30]; it is important to highlight the works done by Rivas et al related to the modeling and development of new experimental configurations and novel applications of this technique [3,31,32]. separate low molecular weight species dissolved in aqueous solution [5].…”

“…On the other hand, during LPR technique by enrichment method, PIIs are added to the external zone and transported to internal zone as PII concentration in the external zone is continuously increased. In this case, concentration of PIIs in the permeate depends on their distribution between the external and internal zones [31].…”

“…As modeling strategy, LPR system can be described as a group of four independent regions contacted with a fifth "passive" region [31]. The regions considered are (1) reservoir (which is a passive component in the washing method, but in other operation modes, such as the enrichment method, it should be considered), (2) solution bulk (which is the fraction of the solution where metal ions are not affected by the interaction with some retainer component of the cell which can be, for example, WSP or membrane), (3) permeate (this is the fraction of solution which can pass through the membrane and corresponds only to solvent and solutes distributed in the solution bulk), (4) membrane surface (which is based in the adsorption process on polymeric surfaces and retention properties of polymer in solid phase when an aqueous stream is passed through it), and (5) polymer domain (which is the region where the strongly interacting counterions with the polymer are distributed) [31].…”

“…As modeling strategy, LPR system can be described as a group of four independent regions contacted with a fifth "passive" region [31]. The regions considered are (1) reservoir (which is a passive component in the washing method, but in other operation modes, such as the enrichment method, it should be considered), (2) solution bulk (which is the fraction of the solution where metal ions are not affected by the interaction with some retainer component of the cell which can be, for example, WSP or membrane), (3) permeate (this is the fraction of solution which can pass through the membrane and corresponds only to solvent and solutes distributed in the solution bulk), (4) membrane surface (which is based in the adsorption process on polymeric surfaces and retention properties of polymer in solid phase when an aqueous stream is passed through it), and (5) polymer domain (which is the region where the strongly interacting counterions with the polymer are distributed) [31]. If the membrane is considered to be an inert component and the polymer is not present in the cell (blank experiment) then regions 1, 2, 3, and 4 can be considered under a hydrodynamic control and system can be described from filtration theories; when the polymer is present and membrane is not inert, regions 2, 4, and 5 are assumed to be controlled by two factors: a hydrodynamic control resulting from its interaction with regions 1, 3, and 4 and a physicochemical control related to the WSP-PII and membrane-PII interactions.…”

“…(1) modeling of inert system, (2) membrane-PII interaction parameter (modeling of blank experiment), (3) WSP-PII interaction parameter (modeling of LPR in presence of WSP considering the membrane as an inert component), and (4) WSP-membrane-PII interaction parameters [31].…”