| Abstrakt: |
In current work, using powdered activated carbon, potassium humate, and polyaluminium chloride as raw materials, we have generated the new powdered activated carbon-based composite (PACMC). Scanning electron microscopy-energy-dispersive X-ray spectrometry, Fourier-transform infrared spectrometer, laser particle size analyzer and zero point charge analyses were used to characterize the PACMC. The prepared PACMC were tested for the removal of Cr(VI) at different pH, initial metal ions concentration, adsorbent dosage, time, and temperature. The results demonstrated that PACMC led to the removal efficiency of Cr(VI) being 95.67% at pH 2.0, with the equilibrium adsorption capacity of 23.92 mg/g (dosage = 2 g/L, C0 = 50 mg/L). The kinetic studies indicated that pseudo-second-order and Elovich models fit the experimental data well. The Temkin model gives the best fit for the adsorption of Cr(VI). Moreover, thermodynamic parameters revealed that the adsorption of Cr(VI) on PACMC was an endothermic and spontaneous process. Importantly, the binding mechanism of Cr(VI) is primarily controlled by the electrostatic attraction between Cr(VI) and the protonated functional groups of PACMC. Reducing functional groups (such as carboxyl, hydroxyl, carbonyl) in PACMC can be used as electron donors, and Cr(VI) has strong oxidation, so Cr(VI) can be reduced to Cr(III). Overall, PACMC served as a potential adsorbent to remove harmful Cr(VI) from aqueous solution. [ABSTRACT FROM AUTHOR] |
