Synthesis and Characterization of Activated Carbon/Maghemite/Starch Magnetic Bionanocomposite and Its Application for Permanganate Removal from Aqueous Solution

Magnetic bionanocomposite of Activated Carbon/Maghemite/Starch was synthesized via coprecipitation method and used for permanganate removal from aqueous solution. Physical and structural features and magnetic properties of bionanocomposite were assessed using different techniques including X-ray diffraction, scanning electron microscopy, Fourier transform infrared spectrometer and vibrating sample magnetometer. Different isotherms, kinetic and thermodynamic models of adsorption process were investigated. The adsorption process showed more consistency with the pseudo-second-order kinetic model. Adsorption isotherm data indicated a better compatibility with Langmuir model. Thermodynamic findings revealed that adsorption process is spontaneous and endothermic. The maximum adsorption capacity of permanganate obtained by response surface methodology under optimal conditions of pH 2, an adsorbent dose of 0.5 g L−1 and initial concentration of permanganate ion of 50 mg L−1 was 48.25 mg g−1. Given the biocompatibility, nontoxicity, and availability of starch and magnetic property of composite adsorbent contributing to the acceleration of final separation of a pollutant from solution, this bionanocomposite can be regarded as a suitable and effective adsorbent for water pollutants removal at low concentrations.