Ultrasonic Assisted Adsorption of Basic Dyes from Binary Component Systems onto ZnO Nanoparticles Loaded on Activated Carbon Derived from Almond Shell: Optimization by Central Composite Design

In this study, ZnO nanoparticles were loaded on activated carbon prepared from almond shell (ZnO-NP-AC). Then, this novel material applied as an efficient adsorbent for the ultrasonic assisted simultaneous removal of Basic Blue 41(BB41) and Basic Red 46 (BR46) in binary solution.  The efficiency of proposed activated carbon was enhanced by acid treatment and subsequent modification by physical mixing with ZnO- NP. The identification by different techniques such as FT-IR, SEM and XRD confirm its porous structure and appearance of various functional groups on AC. In batch process mode, the effect of variables such as adsorbent dosage, initial dyes concentration and sonication time on the removal of dyes were studied by central composite design (CCD) combined with response surface methodology (RSM) and desirability function (DF). The optimum values of input variables were found to be 0.03 g of adsorbent, 19 min of sonication time, 14 mg/L of BR46, 9 mg/L of BB41in pH 6 to high removal percentage (85% and 91% for BR 46, BB41, respectively). Among of the conventional isotherm and Kinetic models, p-factor and second-order models showed reasonable fit to the adsorption equilibrium data, respectively.