Synthesis and characterization of a new natural saccharide polymer (n-LTP) for adsorption of Methylene Blue dye from an aqueous solution

Abstract

Abstract In this study, a new natural polysaccharide material, i.e., n-LTP, was synthesized by mixing Linum usitatissimum seed oil cake, Trigonella foenum-graecum and Plantago physilium husk in a 1:1:1 ratio for adsorption of Methylene Blue dye. BET, FTIR and SEM reveal the presence of various organic and inorganic functional groups besides heterogeneous surfaces of the adsorbent having a surface area of 384 m2/g. While optimizing the operational parameters, it is observed that at pH values of 12, contact time of 100 min, n-LTP dose of 1.5 mg, with dye concentration of 70 ppm at 50 °C, nearly 88% of adsorption take place. Experimental data show that the Freundlich isotherm (R2 = 0.96) and pseudo-first-order kinetic model (R2 = 0.9538) fit best to the process. A thermodynamic study showed that the process was spontaneous, endothermic and feasible. Electrostatic, π–π and hydrogen bonding interactions are involved in MB dye adsorption on n-LTP as confirmed by a surface complexation model (SCM). Overall, results of the study explored the potential f n-LTP for removal of MB dye from contaminated water. This study is novel as till now, to the best of our knowledge, no work has been reported on MB adsorption using n-LTP as an adsorbent specifically.