Chromium (VI) separation from aqueous solution using anion exchange membrane

Abstract

), which is further reduced to an amine group using hydrazine hydrate to form an anion-exchange membrane (AEM). The membrane thus formed is characterized for its properties such as ionexchange capacity, membrane swelling, contact angle measurements, and membrane morphologies. The results show that the membrane becomes highly hydrophilic on the introduction of a charge and the separation experiments on the chromium (VI) salt solution show that the permeate flux (keeping the same rejection level of 90%) is considerably increased (by 100-fold). The analysis of separation of Cr(VI) from its aqueous solution has been done by solving a two-dimensional (in cylindrical coordinates) space-charge model (SCM). A series solution of the nonlinear Poisson-Boltzmann equation has been generated, which leads to a considerable reduction in the computational

Removal of Hexavalent Chromium from Water by Polyurethane–Keratin Hybrid Membranes

“…The development of an effective treatment that can reduce heavy metal concentrations is very important in order to guarantee acceptable levels at affordable costs. Nowadays, conventional methods to remove Cr(VI) include chemical precipitation, ion exchange, filtration, electrochemical treatment, evaporative recovery (Aksu et al 2002), flocculation (Brostow et al 2009), adsorption, solvent extraction and membrane-based separation (Wang and Chung 2006;Pugazhenthi and Kumar 2005). Nevertheless, these high-technology processes have significant disadvantages including incomplete metal removal, expensive process, high reagent or energy requirements, and generation of waste products that require disposal (Aksu et al 2002).…”

Electrodialysis‐based separation technologies: A critical review

“…Electrodialysis (ED) is a type of technology which arranges ion‐exchange membranes alternately in a direct current field 1–23. As shown in Figure 1a, there are at least five elements complementary for ED applications4: (1) direct current supply, which proves effective to reinforce ion migration; (2) electrodes, where the oxidation/reduction reactions occur to realize the transformation from ionic conduction to electron conduction and thus provide the original driving force for ion migration; (3) ion exchange membranes, the key components which permit the transport of counter ions and block the passage of co‐ions; (4) solvents, which make a continuum for ion transport by filling the space between electrodes and membranes; (5) electrolytes, the current carriers between cathode and anode.…”

Fabrication of asymmetric poly (m-phenylene isophthalamide) nanofiltration membrane for chromium(VI) removal

“…A wide range of technologies have been investigated for the removal of Cr(VI) from water such as ion-exchange (Galán B et al, 2005), adsorption (Basha et al, 2008;Basha and Murthy, 2007;Ghiaci et al, 2004), precipitation (Visvanathan et al, 1989) and membrane-based separation (Kishore et al, 2003;Pugazhenthi and Kumar, 2005;Chiha et al, 2006). Based on the interaction between chromate anions and the charged membranes, nanofiltration (NF) may likely become an attractive and suitable tool to separate chromate from aqueous solution (Neelakandan et al, 2003;Hafiarle et al, 2000).…”