Preliminary evaluation of resorcinol-formaldehyde carbon gels for water pollutants removal

The present work was aimed to evaluate the suitability of resorcinol-formaldehyde carbon gels as adsorbent for water pollutants removal. The carbon gels were characterized using N₂ adsorption-desorption isotherm for specific surface area, and Fourier transform infrared (FTIR) for surface functional groups. Methylene blue and cesium were employed as model water pollutants. Results show that the un-oxidized carbon gel, despite its lower specific surface area (333 m²/g) displayed a 118 mg/g removal of methylene blue, that is higher than 35 mg/g by the oxidized carbon gel (418 m²/g). The evaluation of adsorption kinetics revealed a lower pseudo-first order rate constant of 0.088 h^-1 for 10 mg/L methylene blue adsorption. A positive effect of surface oxidation was demonstrated for cesium adsorption. On molar basis, however, the oxidized carbon gel exhibits a selective removal towards methylene blue compared to cesium. Carbon gel is a promising candidate for water pollutants removal, and further treatment needs to be sought to boost its performance.