Monolithic PolyHIPE Polymer (PHP), being a highly porous, low density, open cellular material was produced by polymerization of a high internal phase emulsion (HIPE) in which the polymerizable continuous phase consisted of monomers, styrene (STY), and divinyl benzene (DVB). The inner dispersed phase (90 vol %) was an aqueous solution containing 0.4 wt % potassium persulphate as initiator. The resulting porous structure had 12% crosslinking density. Surface chemistry of the monoliths was modified by chloromethylation and amination to impart anionic functionality. Surface modified monoliths had ion exchange capacity of 3.01 meq/g, and had the ability to uptake water about 10 times of its mass. It was used Cr (VI) ion removal from aqueous solution. The experimental results investigated for both the Langmuir and the Dubinin–Radushkevich adsorption models. The maximum Cr (VI) adsorptions are 126.6 mg Cr (VI)/g and 129.3 mg Cr (VI)/g, respectively. The mean free energy E of adsorption is 11.18 kJ/mol according to the Dubinin–Radushkevich adsorption model, indicating that the adsorption occurs through a chemical ion‐exchange process and it is not diffusion limited. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 42286.

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The porous foam is made by the polymerisation of a high internal phase emulsion and it is a highly porous, low density, open cellular material. Surface properties of the foam were chemically modified via a sulfonation process. Sulfonation added ‒SO3(‒)H(+) groups to the polymer matrix. The ion adsorption behavior of copper ions on sulfonated polymer beads, depending on inlet concentration (10-60 mg/L), pH of inlet solution (2.00-5.20) and flow velocity (1.7-11.4 m/h) was studied. It was shown that the amount of copper adsorbed was not affected with increasing concentration of feed solutions and flow velocity. Also the process was highly pH dependent. The maximum removal was 117.96 mg Cu/g dry adsorbent at flow velocity 11.4 m/h. Column experimental tests were conducted to provide data for theoretical modeling and to verify the system performance of the process. A theoretical column model adopted in this work was found to describe well the ion adsorption breakthrough characteristics.

Anionic functionalized monolithic macro-porous polymers were used for the removal of hexavalent chromium(VI) anions from aqueous solution in column experiments. At a flux of 1.0 cm min and 30 mg Cr(VI) L(-1) feed concentration, breakthrough capacity and apparent capacity were 0.066 g Cr(VI) g(-1) anionic monolith and 0.144 g Cr(VI) g(-1) anionic monolith, respectively. The degree of column utilization was found to lie in the range 41-46%. Two kinetic models, theoretical and Thomas models, were applied to experimental data to predict the breakthrough curves and to determine the characteristic parameters of the column useful for process design. The simulation of the whole breakthrough curve was effective with the models. At a flux of 1.0 cm min and 30 mg Cr(VI) L(-1) feed concentration, the dispersion coefficient and adsorption equilibrium constant (K) were 3.14 × 10(-7) m s(-1) and 3,840, respectively. Also, Thomas model parameters k1 (rate constant of adsorption) and qm (equilibrium solid-phase concentration of sorbed solute) were 1.08 × 10(-3) L mg(-1) min(-1) and 0.124 g g(-1), respectively. After reaching equilibrium adsorption capacity, the monoliths were regenerated using 1 N HCl and were subsequently re-tested. It was found that the regeneration efficiency reduced from 98% after second usage to 97% after the third usage.