Toward new benchmark adsorbents : preparation and characterization of activated carbon from argan nut shell for bisphenol A removal

Abstract

<div lang="en" class="abs"><p class="abs_header">Abstract</p><p>The use of argan nut shell as a precursor for producing activated carbon was investigated in this work. Two activated carbons AC-HP and AC-Na were prepared from argan nut shell by chemical activation method using phosphoric acid (H₃PO₄) and sodium hydroxide (NaOH), respectively. Textural, morphological, and surface chemistry characteristics were studied by nitrogen physisorption, TGA, SEM, TXRF, FTIR, XRD, and by determining the pH_PZC of the AC-HP. The adsorption experiments revealed that AC-HP was more efficient in adsorption of BPA due to high specific surface area (1372 m²/g) compared to AC-Na (798 m²/g). The obtained adsorption data of BPA on AC-HP correlated well with the pseudo-second-order model and the Langmuir isotherm (Qmax = 1250 mg/g at 293 K). The thermodynamic parameters (Δ<em>G°</em> < 0, Δ<em>H°</em> < 0, and Δ<em>S°</em> < 0) indicate that adsorption of BPA on AC-HP was spontaneous and exothermic in nature. The regeneration of AC-HP showed excellent results after 5 cycles (95–93%). This work does not only provide a potential way to use argan nut shell but also represents a sustainable approach to synthesize AC-HP, which might be an ideal material for various applications (energy storage, catalysis, and environmental remediation).</p></div>