Evaluation of the performance of packed bed column for heavy metal ion removal using rice husk powder coated with iron oxide nanoparticles

The packed bed column study investigated the removal of toxic metal ions (Cr, Pb & Zn) using rice husk coated with iron oxide nanoparticles as an adsorbent material. The chemical fusion process prepared the nanomaterial adsorbent, and iron oxide capping provides stability to the prepared nano adsorbent. The characteristics of prepared nano adsorbents and their stability were examined by SEM/EDX, VSM, XRD, Zeta Potential, TGA & DTA methods. Breakthrough curves confirm the ability to obtain the maximum adsorption under operating conditions of 5, 7.5 & 10 -cm bed heights, 100, 200 & 300 - mg/L of metal ion concentrations and 5, 7.5 & 10 - mL/min of inflow rate of the solutions into the column. The ANOVA & CCD analysis confirms the linearity of actual and predicted values of the amount of adsorption process. Thomas and BDST model studies show the best fit to the regression values for obtaining earlier breakthroughs in the fixed bed column. At the pH of 2.0, the maximum amount of heavy metals adsorption was observed. The maximum desorption rate of the column and adsorbent material was obtained by adding 0.3 N of H2SO4 at 40 minutes average time for all the three metal ions.