Introduction
Wastewater often contains mixed pollutants like dyes and pharmaceuticals, making treatment more difficult than single-pollutant removal. In this study, Griffin Loebsack and co-authors investigated how biochar removes methyl orange (MO), methylene blue (MB), and acetaminophen (ACT) from wastewater. The main focus was understanding how these pollutants compete or support each other during adsorption, which is important for real wastewater treatment systems .
Materials and Methods
Biochar was produced from Douglas fir and Miscanthus at 500°C and 800°C, with some samples further treated using KOH and H₂O₂ to improve surface functional groups. Adsorption tests were performed for single pollutants and mixed solutions. FTIR, BET, and UV–Vis analysis were used to study biochar properties and pollutant removal performance .
Results and Discussion
Biochars containing both hydroxyl and carbonyl groups showed better adsorption because they allowed multiple mechanisms like electrostatic attraction and π–π interactions. Methyl orange and methylene blue often improved each other’s adsorption due to strong intermolecular interactions. However, biochars with mainly hydroxyl groups showed stronger competition for adsorption sites, reducing efficiency. Surface functional groups were found to be more important than surface area alone .
Conclusion
The study shows that biochar performance depends strongly on surface chemistry, especially in mixed-pollutant systems. Biochars with balanced oxygen-containing groups performed best and improved pollutant removal from complex wastewater. This helps design better low-cost biochar adsorbents for sustainable water treatment .
Reference
Loebsack, G., Yeung, K. K.-C., Berruti, F., & Klinghoffer, N. B. (2025). Adsorption of Organic Pollutants From Wastewater Using Biochar: A Mechanistic Study on Competitive Adsorption Behavior. Water Environment Research, 97, e70164. https://doi.org/10.1002/wer.70164
