TY - JOUR
T1 - Engineered tea-waste biochar for the removal of caffeine, a model compound in pharmaceuticals and personal care products (PPCPs), from aqueous media
AU - Keerthanan, S.
AU - Bhatnagar, Amit
AU - Mahatantila, Kushani
AU - Jayasinghe, Chamila
AU - Ok, Yong Sik
AU - Vithanage, Meththika
N1 - Funding Information:
Authors acknowledge research funding ( ASP/01/RE/SCI/2018-65 ) provided by the Research Council, and analytical facilities of Instrument Center, Faculty of Applied Sciences, University of Sri Jayewardenepura .
Publisher Copyright:
© 2020
Copyright:
Copyright 2020 Elsevier B.V., All rights reserved.
PY - 2020/8
Y1 - 2020/8
N2 - This study aimed to synthesize engineered tea-waste biochar, pyrolyzed at 700 °C using steam activation (TWBC-SA) for caffeine (CFN) removal from aqueous media. The morphological features and available functional groups on the surface of biochar were characterized using scanning electron microscopy (SEM), Fourier-transform infrared spectroscopy (FTIR), and X-ray photoelectron spectroscopy (XPS). Adsorption batch experiments were carried out at various pH values (3–10), contact time (up to 24 h), and initial concentration of CFN (10–300 mg L−1) using 1 g L−1 of TWBC-SA at 25 °C. SEM images showed the distribution of well-developed pores on the surface of biochar. FTIR spectra revealed that the surface of TWBC-SA provided extra aromatic character, which was further confirmed by XPS analysis. pH-adsorption edge data showed a maximum adsorption capacity of 15.4 mg g−1at pH 3.5. The experimental data were best-fitted to the non-linear Elovich kinetic model, demonstrating the contribution of chemical forces for adsorption of CFN onto the heterogeneous surface of TWBC-SA (initial rate of adsorption = 55.6 mg g−1min−1). Non-linear forms of Freundlich and Temkin isotherm models were fitted with the experimental data, describing favorability of chemical interactions between CFN and TWBC-SA. Finally, it is demonstrated that the adsorption of CFN by TWBC-SA is mainly governed by the chemisorption mechanism via electrostatic interactions and nucleophilic attraction. Thus, the engineered steam-activated tea-waste biochar has a high potential for adsorbing CFN from water.
AB - This study aimed to synthesize engineered tea-waste biochar, pyrolyzed at 700 °C using steam activation (TWBC-SA) for caffeine (CFN) removal from aqueous media. The morphological features and available functional groups on the surface of biochar were characterized using scanning electron microscopy (SEM), Fourier-transform infrared spectroscopy (FTIR), and X-ray photoelectron spectroscopy (XPS). Adsorption batch experiments were carried out at various pH values (3–10), contact time (up to 24 h), and initial concentration of CFN (10–300 mg L−1) using 1 g L−1 of TWBC-SA at 25 °C. SEM images showed the distribution of well-developed pores on the surface of biochar. FTIR spectra revealed that the surface of TWBC-SA provided extra aromatic character, which was further confirmed by XPS analysis. pH-adsorption edge data showed a maximum adsorption capacity of 15.4 mg g−1at pH 3.5. The experimental data were best-fitted to the non-linear Elovich kinetic model, demonstrating the contribution of chemical forces for adsorption of CFN onto the heterogeneous surface of TWBC-SA (initial rate of adsorption = 55.6 mg g−1min−1). Non-linear forms of Freundlich and Temkin isotherm models were fitted with the experimental data, describing favorability of chemical interactions between CFN and TWBC-SA. Finally, it is demonstrated that the adsorption of CFN by TWBC-SA is mainly governed by the chemisorption mechanism via electrostatic interactions and nucleophilic attraction. Thus, the engineered steam-activated tea-waste biochar has a high potential for adsorbing CFN from water.
KW - Caffeine
KW - Engineered biochar
KW - Micropollutant
KW - Stimulant drug
KW - Tea waste
KW - Water treatment
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U2 - 10.1016/j.eti.2020.100847
DO - 10.1016/j.eti.2020.100847
M3 - Article
AN - SCOPUS:85083883299
SN - 2352-1864
VL - 19
JO - Environmental Technology and Innovation
JF - Environmental Technology and Innovation
M1 - 100847
ER -