Production of activated carbon from HNO₃-treated sawdust for methylene blue adsorption in solution

https://doi.org/10.62239/jca.2025.015

Abstract

The report presents the process of preparing activated carbon (AC) from sawdust treated with HNO₃ and evaluating the adsorption capacity of methylene blue (MB) of the material in solution. AC was synthesized under suitable conditions: carbonization at 600^oC, then activated with  HNO₃ 2M for 3 hours and further treated with NaOH. The structure and properties of the material were determined by modern methods such as XRD, SEM and FTIR. Analysis of the nitrogen adsorption – desorption process gave the specific surface area (BET) of  440.5433 m²/g. Investigation of the adsorption of activated carbon in the methylene blue concentration range from 5 - 35 ppm showed that 0.02g AC gave high adsorption efficiency when the MB concentration was below 20 ppm (H > 90%). Langmuir and Freundlich models were used to investigate the adsorption capacity, in which MB adsorption according to Langmuir isotherm model is more suitable than Frendlich model.