Synthesis and efficiency comparison of reed straw-based biochar as a mesoporous adsorbent for ionic dyes removal

Oleksii Tomin; Riku Vahala; Maryam R Yazdani

doi:10.1016/j.heliyon.2024.e24722

Synthesis and efficiency comparison of reed straw-based biochar as a mesoporous adsorbent for ionic dyes removal

Heliyon. 2024 Jan 15;10(2):e24722. doi: 10.1016/j.heliyon.2024.e24722. eCollection 2024 Jan 30.

Authors

Oleksii Tomin¹, Riku Vahala¹, Maryam R Yazdani²

Affiliations

¹ Department of Built Environment, School of Engineering, Aalto University, P.O. Box 15200, FI-00076, Aalto, Finland.
² Department of Mechanical Engineering, School of Engineering, Aalto University, P.O. Box 14400, FI-00076, Aalto, Finland.

Abstract

The reed straw is assessed as a potential source of widely available renewable biomass for biochar production and compared with two other waste-based biomasses, namely fruit stones blend, and brewery spent grains. The biochars were activated via steam and CO₂. While steam activation yielded 12 % carbon from reed biomass, CO₂ activation resulted in biomass degradation. The characterization of reed biochar showed a mesoporous structure and a high surface area of 514 m²/g. The adsorption tests displayed a decent adsorption capacity of biochar, with values of 92.6 mg/g for methylene violet dye and 35.7 mg/g for acid green dye. Only 1 g/L dosage of reed biochar was able to remove 99 % of the 50 mg/L methylene violet solution in 15 min and 60 % of the 50 mg/L acid green solution in 10 min. The obtained results demonstrate reed biomass as a suitable source for biochar production as well as reed-based biochar as a promising dye adsorbent.

Keywords: Biochar; CO2 activation; Dyes adsorption; Mesoporous adsorbent; Reed straw biomass; Steam activation; Waste biomass; Water treatment.