Malachite Green Adsorption Onto Date Stems Activated Carbon

Hadoun Hocine*¹, Belgacem Ahmed²

¹Nuclear Research Center of Algiers. 02, Bd Frantz Fanon, B.P. 399, Algiers, (ALGERIA)

²University of Science and Technology Houari Boumediene, FGMGP, B.P. 32 EL-Alia Bab-Ezzouar, Algiers, (ALGERIA)

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ABSTRACT – DOI: https://dx.doi.org/10.47204/EMSR.5.1.2023.012-029

In this study, Malachite Green was used as model to assess the performance of a new porous carbon to remove bulky pollutants from aqueous solution. The adsorbent was prepared from date stems by chemical activation and systemically characterized for the physicochemical properties by means of nitrogen adsorption, Fourier transform infrared, X-ray diffraction and microscopy analysis. The porous carbon is predominantly mesoporous having high surface area (1455m²/g); high pore volume (1.045cm³/g) and rich in oxygen groups. Adsorption experiments were carried out in batch method under varying conditions of the process such as pH, initial concentration, adsorbent dosage, contact time and temperature. The equilibrium time was reached in 100min and maximum removal was obtained at pH between 6 and 8, for an adsorbent dosage of 5 g/L and an initial concentration of 100 mg/L. In order to determine the best fit isotherm, experimental data were analyzed using two and three parameters model represented by Langmuir, Freundlich, Temkin, Dubinin-Radushkevich, Redlich-Peterson, koble-Corrigan, Toth, and Fritz-Schluender isotherms. Adsorption isotherms is consistent with Redlich-Peterson and Fritz-Schluender equations and maximum adsorption capacity calculated from the Langmuir isotherm was 142.86mg/g. The kinetics of the adsorption followed the pseudo-second-order equation and thermodynamic analysis revealed that the adsorption of malachite green dye is spontaneous, exothermic and physical in nature. Hence, the developed carbon could be successfully used as alternative to the commercially available adsorbents since date stems are largely available which guarantee its continued utilization in the future.