Optimization of synthesis variables and characterization of devilfish bone chars for the removal of cadmium(II) from water

The optimization of the synthesis variables of bone chars prepared from devilfish bones was studied in this work. The prepared materials were characterized by thermogravimetric analysis, X-ray diffraction, and scanning electron microscopy. Textural properties and amount of active sites were also determined. The adsorbents were used for the removal of Cd2%2b from aqueous solution. Based on a D-Optimal experimental design, the synthesis of 13 materials was established, which were calcined in a tube furnace at a temperature range of 600 to 800 °C and synthesis time of 1 to 3 h with a heating ramp of 10 °C min−1. The adsorption capacity of the adsorbents to remove Cd2%2b in batch adsorbers at pH 7.0 and T = 25 °C was evaluated. The bone char that exhibited the highest adsorption capacity of 124.6 mg g−1 was synthesized at 600 °C and 3 h. Analysis of variance (ANOVA) on the bone char synthesis model revealed that calcination temperature is significant on Cd2%2b adsorption capacity and independent of time. The optimum values of the calcination variables for a maximum adsorption capacity of 117.4 mg g−1 were 600 °C and 1 h. The textural and physicochemical properties of the bone adsorbent confirmed the presence of Cd2%2b on its surface. Graphical abstract: [Figure not available: see fulltext.] © 2022, The Author(s), under exclusive licence to The Materials Research Society.

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