Impounding of ortho-Chlorophenol by Zeolitic Materials Adapted from Bagasse Fly Ash: Four Factor Three Level Box-Behnken Design Modelling and Optimization

Abstract

The present study enlightens the impounding of ortho-chlorophenol (OCP) onto zeolitic composites derived from agricultural waste Bagasse Fly Ash (BFA). The OCP impounding was enhanced by modifying native BFA by electrolyte supported microwave hydrothermal treatment (MZBFA) and magnetic modification (MMZBFA). The synthesized sorbents were characterized by instrumental techniques (XRF, PXRD, SEM and FTIR). The adsorption process was optimized under four different process variables like: pH (4–7), agitation time (30–120 min), initial sorbate concentration (\({50-150\,{\rm mg}\,{\rm L}^{-1}}\)), sorbent dosage (\({1-4\,{\rm g}\,{\rm L}^{-1}}\)) based on Box-Behnken design with response surface methodology. The highest predicted adsorption capacities at pH 7 with \({1\,{\rm g}\,{\rm L}^{-1}}\) sorbent dose for MZBFA and MMZBFA were found to be 29.95 and \({31.94\,{\rm mg}\,{\rm g}^{-1}}\) for agitation time of 75 and 120 min and initial sorbate concentration 150 and \({100\,{\rm mg}\,{\rm g}^{-1}}\) , respectively, which were approximated with laboratory results. The isotherm data and kinetic data were best described by Langmuir model and pseudo-second-order model, respectively. The sorbents are stable after three cyclic runs when regenerated with 0.5M NaOH solution.