Chitosan-boehmite desiccant composite as a promising adsorbent towards heavy metal removal

Owing to the widespread occurrence and potential health effects, many treatment strategies have been developed across the world to remove the heavy metal contaminants in water. Developing affordable and sustainable nanoscale materials are the prime factors for the success of such treatment systems in the field. The present study explores the use of desiccant waste, exhausted after several cycles of dehumidification processes. The granulated composite desiccant is composed of boehmite nanoparticles reinforced with chitosan fibrils. The composite was synthesized via a simple and scalable one-pot sol-gel route at atmospheric pressure and room temperature. The desiccant was employed for dehumidification/regeneration cycles. The reuse potential of exhausted desiccant towards enhanced removal of metal ions was analyzed and demonstrated. After adsorption the nanocomposite was characterized to establish its chemical composition and structure. Batch and fixed-bed column adsorption experiments were performed to evaluate the removal efficiency of the nanocomposite and to assess the parameters that influence the adsorption process. The experimental evidences confirm the fast kinetics of adsorption/ desorption and effective regeneration of the composite. The enhanced removal capacity, excellent reuse potential, high stable granules, eco-friendly synthesis approach makes the adsorbent an excellent candidate for the removal of wide range of heavy metals in water.