Surface coated Guar gum biocomposite (Zeolite imidazolate framework (ZIF-8) - Guar gum – Polyvinylpyrrolidone) as an environmentally friendly adsorbent: Preparation, isotherm and kinetics of pollutant removal

Abstract

With the growing population and industrial activities, water pollution by several chemicals such as dyes has become a significant and worrying challenge. Herein, surface-coated Guar gum biopolymer (Zeolite imidazolate framework (ZIF-8)-Guar gum (GG)-Polyvinylpyrrolidone (PVP)) was prepared. The ZIF-8 with Guar gum and Polyvinylpyrrolidone polymer was used to prepare binary (GG/ZIF-8 (GZ) and PVP/ZIF-8 (PZ)) and ternary (GG/PVP/ZIF-8 (GPZ)) biocomposites and used to remove the cationic dye (Basic Blue 41 (BB41)). The structure and morphology of the materials were investigated using XRD, FTIR, Raman, BET, and SEM. The removal efficiencies obtained under optimal conditions, including pollutant concentration of 50 mg/L, pH = 4.5, contact time of 120 min, and adsorbent dose of 0.004 g, were obtained for PZ, GZ, and GPZ adsorbents, 67.7 %, 66.6 %, and 86.6 %, respectively. Also, the experimental adsorption capacity for 0.001 g of adsorbent was 1166.07 mg/g for GZ, 1064.01 mg/g for PZ, and 1634.01 mg/g for GPZ. The obtained data from the Langmuir isotherm and pseudo-second-order kinetic showed high coefficient values. Also, GG/PVP/ZIF-8 had high reusability after three cycles (79 %). It could be concluded that GPZ is an efficient adsorbent for BB41 adsorption from water due to its easy synthesis, high adsorption capacity, remarkable efficiency, biocompatibility, and biodegradability.