In recent years, the rapidly growing essential oil industry has generated residues that, if improperly managed, can harm ecosystems by contaminating soil and water. This study proposes a sustainable solution by converting these residues into biochar through pyrolysis. We specifically examine the potential of oregano and citronella biochars to remove methylene orange dye and evaluate their safety for use in water treatment and soil enhancement.
This research assessed the impact of oregano and citronella biochars, produced at various temperatures, on radish seed germination and root development. The control group showed strong results with 90–100% germination and an average root length of 3.54 cm. Oregano biochar at 300 °C was toxic to seed growth, while oregano biochar at 400 °C improved germination but did not match the control group. Citronella biochar at both 300 °C and 400 °C resulted in better germination rates but still fell short of the control group. Additionally, our findings reveal that citronella biochar (BCR) at 400 °C successfully removed 88.8% of the methyl orange dye. However, the combination of oregano biochar (BOR) and citronella biochar (BCR) at 300 °C did not significantly affect dye concentration reduction. In conclusion, while applying BOR and BCR produced at 400 °C to soil is environmentally safe, it does not markedly enhance plant growth. These results highlight the critical considerations for using these biochars in agricultural practices.
Author Contributions
Conceptualization, A.H; data curation, M.R. and L.Y. formal analysis, M.R., G.K. and C.H. funding acquisition, A.H.; investigation, M.H.E.-D. and C.H.; Methodology, L.Y. and M.H.E.-D.; project administration, M.H.E.-D.; resources, M.R. and A.H.; supervision, K.H and M.H.E.-D.; validation, M.R., K.H., A.H., C.H. and M.H.E.-D.; visualization, A.H. and G.K.; writing—original draft, M.R.; writing—review and editing, C.H., K.H. and M.H.E.-D. All authors have read and agreed to the published version of the manuscript.
Funding
This research received no external funding.
Institutional Review Board Statement
Not applicable.
Informed Consent Statement
Not applicable.
Data Availability Statement
The original contributions presented in the study are included in the article, further inquiries can be directed to the corresponding author.
Conflicts of Interest
The authors declare no conflicts of interest.
Disclaimer/Publisher’s Note: The statements, opinions and data contained in all publications are solely those of the individual author(s) and contributor(s) and not of MDPI and/or the editor(s). MDPI and/or the editor(s) disclaim responsibility for any injury to people or property resulting from any ideas, methods, instructions or products referred to in the content. |
© 2024 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https://creativecommons.org/licenses/by/4.0/).