Investigating the effectiveness of rice husk-derived low-cost activated carbon in removing environmental pollutants: a study of its characterization

• Published in: International journal of phytoremediation 2024-02, Vol.26 (3), p.427-447
• Main Authors: Kaya, Nihan, Carus Özkeser, Esma, Yıldız Uzun, Zeynep
• Format: Article
• Language: English
• Subjects: Activated carbon; Adsorbents; Adsorption; Aqueous solutions; biochar; Biodegradation, Environmental; capture; Carbon dioxide; Charcoal; Charcoal - chemistry; Chemical analysis; Cost analysis; cost effectiveness; dyes; Environmental Pollutants; heat production; Hydrogen-Ion Concentration; Infrared analysis; Kinetics; KOH-activated biochar; methyl red; Oryza; phytoremediation; Pollutant removal; Pollutants; Porosity; Pyrolysis; Rice; rice hulls; rice husk; Spectroscopy, Fourier Transform Infrared; surface area; temperature; Water Pollutants, Chemical - chemistry; Water Purification
• ISSN: 1522-6514; 1549-7879; 1549-7879
• DOI: 10.1080/15226514.2023.2246584

The chemically activated biochar was produced through the pyrolysis of rice husk. Thermal gravimetric and elemental analysis were conducted to characterize the raw rice husk. The activated biochar product underwent evaluation through SEM, BET and, FT-IR analysis. This cost-effective activated carbon was utilized as an adsorbent for the elimination of environmental pollutants. At a temperature of 25 °C, the activated biochar product exhibited an impressive maximum CO 2 adsorption capacity of 152 mg/g. This exceptional performance can be attributed to its notable surface area and porosity, measuring at 2,298 m 2 /g and 0.812 cm 3 /g, respectively. This product was also utilized to remove methyl red (MR) dye from an aqueous solution. The optimal parameters for the removal of MR were determined as follows: a pH of 6.0, a temperature of 25 °C, an initial MR concentration of 50 mg/L, and an adsorbent dosage of 0.4 g/L. At a duration of 140 min, the system attained its maximum equilibrium adsorption capacity, reaching a value of 62.06 mg/g. Furthermore, the calculated maximum MR removal efficiency stood at an impressive 99.31%. The thermodynamic studies demonstrated that the MR removal process was spontaneous, exothermic, and increased randomness. Kinetic studies suggested that the pseudo-second-order model can fit well. Rice is the staple food for a significant portion of the world's population. Rice husk, which is released during the production and processing of rice, is one of the most important agricultural wastes worldwide. In this study, low cost activated carbon was produced by converting renewable resource such as rice husk biomass into a product with high added value. The resulting product, with its high surface area, can offer a more sustainable, cost-effective, and versatile alternative for a range of industrial, environmental, and medical applications. Carbon-based activated biochar was produced from rice husk, which is one of the lignocellulosic agricultural wastes, by performing pyrolysis and activation processes together. The structural properties of the biochar product were improved using KOH-activation technique. The usability of activated biochar in CO 2 capture and removal of MR dye were investigated. The potential of the product obtained by the pyrolysis of rice husk wastes to be a raw material source for the production of chemical that can be used as an alternative to commercial activated carbon in the removal of environmental pollutants was