An Effect of pH on Radiation Assisted Modification of Oxygen-Rich Activated Carbon by Urea

Abstract:

Activated carbons (ACs) are a versatile group of adsorbents for water pollution control, especially organic dyes. Harsh chemicals and high temperatures are required for the activation process of ACs, which becomes a significant concern due to their toxicity and harmful effects on human health and the environment. Gamma irradiation, an alternative green technique, is a promising strategy for pretreatment and escalates the nitrogen or oxygen functional group of ACs. The current study provides the modification of ACs by the gamma irradiation in the various pH (5-11) of urea solution. The modified ACs were characterized by scanning electron microscopy (SEM), nitrogen gas adsorption-desorption analysts (BET), temperature program desorption (TPD), Fourier-transform infrared spectroscopy (FTIR), Raman spectroscopy, and X-ray diffraction spectroscopy (XRD). The point of zero charges and dye adsorption capacities were determined. This finding demonstrates that the ACs can be modified by gamma irradiation at 25 kGy in the urea solution media. The degree of graphitization enhanced significantly at pH 11(AC-pH11). The oxygen-rich functional groups created by radiation assists could enhance the electrostatic attraction between acid gases or cationic dyes. AC-pH11 also was able to adsorb methylene blue (160.73 ± 1.70 mg/g) greater than methyl orange (127.57 ± 2.22 mg/g).

• Periodical: Key Engineering Materials (Volume 904)
• Pages: 407-412
• DOI: https://doi.org/10.4028/www.scientific.net/KEM.904.407
• Online since: November 2021
• Authors: Threeraphat Chutimasakul, Tinutda Phonlam, Varistha Chobpattana, Pattra Lertsarawut, Wilasinee Kingkam, Sakchai Laksee, Tanagorn Kwamman*
• Keywords: Activated Carbons, Dye Absorption, Gamma Irradiation, Oxygen-Rich

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