Induced effects of gamma irradiation on activated carbon derived from Hyphaene Thebaica husks as a potential adsorbent for chlorpyrifos pesticide-air purification

Document Type : Original Article

Authors

1 Chemistry department, Faculty of Science, Al-Azhar university

2 National Research Centre

3 Chemistry department, Faculty of Sci., Al-Azhar university

4 Professor of Physical Chemistry Department, Faculty of Science, Al-Azhar University.

5 Lecturer of physical Chemistry department, Faculty of Science, Al-Azhar University, Cairo, Egypt

Abstract

In the current study, Doum palm husk of Hyphaene Thebaica (HT), a local agro-waste, was utilized as a new source to produce activated carbon (HT-AC). The thermally prepared adsorber was chemically activated by phosphoric acid aqueous solution and exposed to γ-ray at doses of 2.5-10 Grays (Gy) for capacity enhancement. Characterization of the obtained products were tested using FT-IR, SEM-EDX, XRD, BET and Raman spectroscopy. The carbon species were then utilized in the ambient air purification from the chlorpyrifos (trade name, Ictafos) pesticide air pollutant. Results showed the development of very high surface area of 1439, 1702 and 1561 m2/g for the parent HT-AC and its HT-AC2.5Gy and HT-AC5Gy irradiated forms, respectively. The experimental and theoretical results clarified the best fitting of pseudo-first-order model in describing the Chlorpyrifos sorption reaction. Thermodynamic analysis revealed physical sorption of the hazardous material onto the surfaces of the activated carbons with exothermic process of non-spontaneous nature. Experimental kinetics presented that, HT-AC2.5Gy had excellent fitting to the Langmuir isotherm model, wherein the adsorption was proceeded in a monolayer manner with a uniform surface energy. Conversely, Freundlich isotherm was perfectly fitted to the original HT-AC and HT-AC5Gy, where the multilayer and heterogeneous adsorption mechanism was exhibited.

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  • Receive Date: 27 September 2021
  • Revise Date: 19 October 2021
  • Accept Date: 24 October 2021
  • First Publish Date: 24 October 2021