Hydrochar from Spent Coffee Grounds: Characterization and Application for Phenol Removal from Aqueous Solutions Under Static and Dynamic Conditions.
5 affiliations
- 1Laboratory of Process Engineering and Industrial Systems (LRGPSI), National School of Engineers of Gabes, University of Gabes, Gabès 6029, Tunisia.
- 2Applied Physics Department, Industrial Engineering School, University of Extremadura, Avda. Elvas, s/n, 06006 Badajoz, Spain.
- 3Centre for Environmental Studies and Research, Sultan Qaboos University, Al-Khoud, Muscat 123, Oman.
- 4The Institute of Materials Science of Mulhouse (IS2M), University of Haute Alsace, CNRS, UMR 7361, F-68100 Mulhouse, France.
- 5University of Strasbourg, F-67081 Strasbourg, France.
Abstract
In this work, spent coffee grounds (SCGs) waste is converted into an activated hydrochar (AHC) through hydrothermal carbonization (HTC) at 180 °C followed by steam activation at 850 °C for 1 h. The AHC was firstly characterized and then tested for phenol removal from synthetic aqueous solutions in both batch and column modes. Characterization results show that the AHC is an amorphous material rich in numerous functional groups and has interesting textural properties, with a surface area and a total pore volume of 219.2 m² g⁻¹ and 0.156 cm³ g⁻¹, respectively. These promising properties permit the AHC to successfully remove phenol from aqueous solutions under wide-batch experimental conditions with an adsorption capacity of 226.4 mg g⁻¹. Moreover, this process was found to be spontaneous, endothermic, and favorable, involving physical and chemical mechanisms. Furthermore, even in column mode, the AHC retains a strong ability to remove phenol, with an adsorbed amount of 42.3 mg g⁻¹ observed for the lowest flow rate (14 mL min⁻¹). The phenol breakthrough curves (BTCs) from the column were best fitted with a Thomas model, indicating that limitations of external and intraparticle mass-transfer of phenol are relatively small. Finally, the phenol-loaded AHC can be efficiently regenerated with hot water for at least two cycles. Indeed, the average adsorption efficiencies in the second cycle were evaluated to be 97.7% and 72.7% of those measured in the first cycle, in batch and column modes, respectively. These promising technical results should be consolidated with a detailed life-cycle assessment study in the future.
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BibTeX
@article{dadi2026hydrochar,
title = {{Hydrochar from Spent Coffee Grounds: Characterization and Application for Phenol Removal from Aqueous Solutions Under Static and Dynamic Conditions.}},
author = {Sihem Dadi and Hanen Nouri and Beatriz Ledesma and Silvia Román and Salah Jellali and Mejdi Jeguirim and Monia Guiza},
journal = {Toxics},
year = {2026},
month = oct,
doi = {10.3390/toxics14100926},
url = {https://europepmc.org/article/MED/42931713},
note = {CC BY},
}
RIS
TY - JOUR
TI - Hydrochar from Spent Coffee Grounds: Characterization and Application for Phenol Removal from Aqueous Solutions Under Static and Dynamic Conditions.
AU - Sihem Dadi
AU - Hanen Nouri
AU - Beatriz Ledesma
AU - Silvia Román
AU - Salah Jellali
AU - Mejdi Jeguirim
AU - Monia Guiza
PY - 2026
DA - 2026/10/19
JO - Toxics
DO - 10.3390/toxics14100926
UR - https://europepmc.org/article/MED/42931713
AB - In this work, spent coffee grounds (SCGs) waste is converted into an activated hydrochar (AHC) through hydrothermal carbonization (HTC) at 180 °C followed by steam activation at 850 °C for 1 h. The AHC was firstly characterized and then tested for phenol removal from synthetic aqueous solutions in both batch and column modes. Characterization results show that the AHC is an amorphous material rich in numerous functional groups and has interesting textural properties, with a surface area and a total pore volume of 219.2 m² g⁻¹ and 0.156 cm³ g⁻¹, respectively. These promising properties permit the AHC to successfully remove phenol from aqueous solutions under wide-batch experimental conditions with an adsorption capacity of 226.4 mg g⁻¹. Moreover, this process was found to be spontaneous, endothermic, and favorable, involving physical and chemical mechanisms. Furthermore, even in column mode, the AHC retains a strong ability to remove phenol, with an adsorbed amount of 42.3 mg g⁻¹ observed for the lowest flow rate (14 mL min⁻¹). The phenol breakthrough curves (BTCs) from the column were best fitted with a Thomas model, indicating that limitations of external and intraparticle mass-transfer of phenol are relatively small. Finally, the phenol-loaded AHC can be efficiently regenerated with hot water for at least two cycles. Indeed, the average adsorption efficiencies in the second cycle were evaluated to be 97.7% and 72.7% of those measured in the first cycle, in batch and column modes, respectively. These promising technical results should be consolidated with a detailed life-cycle assessment study in the future.
SN - 2305-6304
ER -