Carbonization of Saccharide-based Materials for Wastewater Treatment Applications

Carbonized saccharide-based materials have potentials to be effectively used for the purification of wastewater. Saccharide-based materials are rich carbon-based materials, and herein banana peels and discarded chewing gum was exploited. Pyrochar/AgBr derived from discarded chewing gum was used for the decontamination of trichlorophenol (2,4,5-TCP) while biochar derived from banana peel waste was effectively used for the elimination of heavy metals ions. The surface, morphology, and magnetic properties of the prepared adsorbents were examined by Boehm titration; Fourier-transform infrared techniques and scanning electron microscope. The adsorption isotherm and kinetic behaviour of the pollutants were examined, and the results comprehensively explained. The pyrochar/AgBr possesses a pore volume and a SBET of 0.998 cm3 /g and 249.5 m2 /g respectively. 2,4,5-TCP removal efficiency at 10 mg/L was estimated to be ~96% and the Yoon–Nelson and Thomas models successfully described its dynamic behaviour. For the first time, commonly discarded chewing gum was employed as a prototype for the fabrication of high performing adsorbents engaged for the treatment of wastewater. Desorption and re-usability of pyrochar/AgBr were also assessed. The magnetic calcined biochar (MCB) possesses a high saturation magnetization value at 39.55 emu/g, porous structures, surface functional groups (COO− and–OH), and an SBET larger than the (CB). The optimum adsorption capacity of MCB at pH 6 are 72.8, 75.9, and 83.4 mg/g for Zn2+, Cu2+, and Hg2+, respectively for the single component adsorption and suitably fits in the Langmuir and Redlich-Peterson adsorption isotherms and the pseudo-second order for the adsorption kinetic models. MCB exhibited higher adsorption affinity toward Hg2+ than Cu2+ and Zn2+ for the multicomponent system as shown in the extended Langmuir isotherm (selectivity factor values). Keywords: Biochar; Discarded chewing gum; Banana peel; Magnetic biochar; trichlorophenol decontamination; heavy metals; Adsorption