Volume: 4, 2025
4th International PhD Student’s Conference at the University of Life Sciences in Lublin, Poland:
ENVIRONMENT – PLANT – ANIMAL – PRODUCT
Abstract number: E016
DOI: https://doi.org/10.24326/ICDSUPL4.E016
Published online: 9 April 2025
ICDSUPL, 4, E016 (2025)
Research on the sorption properties of bioadsorbents derived from plant materials
Dorota Paluch1*, Aleksandra Bazan-Woźniak1, Robert Pietrzak1
1 Department of Applied Chemistry, Faculty of Chemistry, Adam Mickiewicz University, Uniwersytetu Poznańskiego 8, 61-614 Poznań, Poland
* Corresponding author: dorpal1@amu.edu.pl
Abstract
The textile industry uses over 8,000 synthetic dyes, consuming 200 tons of water per ton of fabric and producing 800,000 tons of dyes annually. Adsorption, particularly with activated carbon, is a key method, with growing interest in producing activated carbon from agricultural and industrial waste. This study examines the effects of microwave-assisted and conventional activation with sodium carbonate and precursor selection on carbon sorbent production. Carbon adsorbents were synthesized from caraway and fennel seeds using Na₂CO₃ activation at 400 °C in a microwave furnace and 700 °C in a conventional furnace. The dried precursors were mixed with Na₂CO₃ at a mass ratio of 1 : 2 (precursor: activator) and divided into two parts. One part underwent activation at 400 °C with a heating rate of 10 °C/min in a nitrogen atmosphere (flow rate: 250 cm³/min) for 30 minutes. The other part was activated at 700 °C under the same conditions for 45 minutes. The textural characteristics of the obtained activated carbons were analyzed using nitrogen adsorption-desorption isotherms. In order to ascertain the acid-base properties the carbon materials, the content surface oxygen functional groups was evaluated using Bohem titration method. The study revealed specific surface areas ranging from 25 to 26 m²/g for microwave heating and from 269 to 345 m²/g for conventional heating, with predominantly acidic surface functional groups. Furthermore, sorption capacities for methylene blue ranged from 68 to 91 mg/g for microwave heating and from 37 to 77 mg/g for conventional heating. Utilising the experimental data, characteristic parameters for the Langmuir and Freundlich models were calculated. Based on the correlation coefficient values, methylene blue adsorption followed the Langmuir model, suggesting monolayer adsorption. Additionally, the results demonstrated that dye removal efficiency increased with process temperature. Thermodynamic analysis confirmed the process is spontaneous and endothermic, while adsorption kinetics followed a pseudo-second-order model. Studies indicate that fennel and caraway seeds can serve as effective precursors for bioadsorbents produced through direct activation for methylene blue removal from aqueous solutions. Furthermore, microwave-assisted activation has been shown to yield adsorbents with superior sorption capacities compared to conventional heating methods, despite having smaller total surface areas.
Keywords: adsorption, activated carbon, chemical activation
How to cite
D. Paluch, A. Bazan-Woźniak, R. Pietrzak, 2025. Research on the sorption properties of bioadsorbents derived from plant materials. In: 4th International PhD Student’s Conference at the University of Life Sciences in Lublin, Poland: Environment – Plant – Animal – Product. https://doi.org/10.24326/ICDSUPL4.E016