Fabrication of Composites of Sodium Alginate with Guar Gum and Iron Coated Activated Alumina for the Purification of Water from Direct Blue 86

Abstract

This study aims to purify water from hazardous dyes and for this purpose, a novel adsorbent is developed that was synthesized by using sodium alginate, guar gum and iron coated activated alumina (SA@GG@ICAA Composites) with the Ion Gelation Method. The novel composites were characterized by using SEM, XRD, DSC, FTIR, BET, EDX, zeta potential and zeta sizer. These novel composites were used for the removal of Direct Blue 86 (DB86). The surface area of the adsorbent was found to be 5.606 m2/g. Zeta size and zeta potential was found to be 169.9 nm and −47.7 mV, respectively. Optimized parameters were achieved for best adsorption of the selected dye. For DB86, the removal efficiency was found to be 97% at 40 ppm (dye concentration), 150 min (contact time), 3 (pH) and 150 mg (adsorbent concentration) at λmax of 620 nm. Linear and non-linear forms of adsorption isotherms are applied on the experimental data to check the adsorption methodology and its chemistry. The non-linear form of the Freundlich isotherm was found to be best fitted for the current work (0.942) as compared with the linear form (0.76). The first order kinetics model and second order kinetics model are applied in both linear and non-linear forms, and results with a high R2 value were obtained for the non-linear form of pseudo-first order kinetics. The adsorption mechanism was found to be electrostatic based on the interaction of the adsorbent and dye. Synthesized adsorbent can be successfully applied for the removal of DB86 dye from waste water.