Application of response surface methodology for ultrasound-assisted rapid ‎adsorption of meso-tetrakis(4-sulfonatophenyl) porphyrin by copper ‎nanowire-loaded in activated carbon: Characterization, equilibrium and ‎kinetic modeling

The combined ultrasonic assisted/nanoparticle based procedure was described for an economical and rapid removal of meso-tetrakis (4-sulfonatophenyl) porphyrin (TSPP) by copper nanowires loaded on activated carbon (Cu-NW-AC). The synthesized Cu-NW-AC was investigated by scanning electron microscopy (SEM) and X-ray diffraction (XRD). Response surface methodology (RSM) combined with central composite design (CCD) give useful information about the individual contribution and interaction amoung variables correspound to above adsorption. In CCD, the effects of variables in the following range, pH (X₁: 5.0-7.0), adsorbent dosage (X₂: 0.021-0.051 g), initial TSPP concentration (X₃: 3-15 mg l^-1) and ultrasound time (X₄: 2-10 min.) was investigated to obtain maximum adsorption effeciency. The experimental data were subsequently fitted to a second-order polynomial equation using multiple regression analysis by appropriate statistical methods. According to the results, the optimum adsorption conditions were found to be Cu-NW-AC = 0.04 g, TSPP = 6 mg l^-1, pH = 5.5 and ultrasound time = 8.0 min. The experimental extraction yield under optimal conditions was found to be 97.60% which confirmed by three replicate at optimum conditions leading to removal percentage of 98.16%. The adsorption equilibrium isotherm and kinetic models investigation revealed the suitability of Langmuir isotherm and pseudo-second-order model for best predication of experimental data. Maximum monolayer capacity (Q_m) calculated from Langmuir model was found to be 26.385 mg g^-1.