Synthesis and characterization of a new guar gum 4-hydroxybenzoic acid resin and its use for the separation of heavy metal ions in industrial effluents

Hydroxybenzoic acid group has been incorporated onto guar gum by modified Porath's method of functionalization of polysaccharides. The newly synthesized guar gum 4‐hydroxybenzoic acid (GHBA) resin was characterized by Fourier‐transform infrared spectroscopy, elemental analysis, ion‐exchange capacity, column reusability, and physicochemical properties. The distribution coefficient (Kd) values and effect of pH on chelation of these metal ions using batch method were studied. The separations of mixture of Fe2+, Zn2+, Cu2+, Cd2+, and Pb2+ metal ions on GHBA resin on the basis of their distribution coefficient at various pH were also achieved using column chromatography. The effect of experimental parameters such as pH, treatment time, agitation speed, temperature, adsorbent dose, initial metal ion concentration, and flow rate on the removal of metal ions has been also studied. GHBA resin is effective adsorbents for the removal of different toxic metal ions from aqueous solutions and follows the order: Fe2+ > Zn2+ > Cu2+ > Cd2+ > Pb2+. POLYM. ENG. SCI. 2013. © 2012 Society of Plastics Engineers