Alginate-based foam filled with nano-zeolite for effective adsorptive removal of methylene blue from water: performance and effect of operating conditions

摘要

One of the most toxic pollutants in the wastewater as a consequence of industrial activities is water-soluble dyes, which needed to be removed. In this study, a novel eco-friendly alginate-based foam adsorbent induced by ZSM-5 zeolite was prepared via simple freeze-drying and post-cross-linking method, characterized using different analyzes, and then used to remove methylene blue from aqueous solutions. Kinetics, isotherm, thermodynamics, mechanisms, contact angle and swelling investigation, regeneration, binary system experiments, and the parameters affecting the dye removal were investigated. The findings obtained from the batch adsorption process indicated that the adsorption of methylene blue using synthetic adsorbents has good conformity with conventional kinetic and isotherm models and the kinetics and isotherm are adjusted with the pseudo-second-order and the Temkin models, respectively. The adsorbent represented effective adsorptive removal of methylene blue with maximum efficiency of 97% and 4.57 mg/g adsorption capacity. With the increase in pH, concentration, and zeolite content in the foam, better adsorption performance was observed. Maximum dye adsorption was obtained in dye solution with 10 mg/L concentration, pH of 11, 25 & DEG;C, and adsorbent with 4 wt% zeolite content. The prepared adsorbents presented remarkable chemical stability and were readily recyclable with floatability in the aqueous solution.