Water contamination is a serious environmental issue, with dyes being one of the most prevalent contaminants in freshwater. These dyes are released by various industries, including textiles, paint, leather, cosmetics, paper, and pulp. Even in small concentrations, dyes can harm aquatic life and ecosystems.  In a study published in Scientific Reports, Eleryan et al., investigated a new approach to removing hazardous dyes like Direct Blue 86 (DB86) and Acid Yellow 36 (AY36) from aqueous environments. The researchers used biochar-sulphur (DRB-S) made from Delonix regia seed pods (DPSPs) as an inexpensive and environmentally friendly adsorbent.  

The study found that the optimal pHpH is a measure of how acidic or alkaline a substance is. A pH of 7 is neutral, while lower pH values indicate acidity and higher values indicate alkalinity. Biochars are normally alkaline and can influence soil pH, often increasing it, which can be beneficial More for AY36 and DB86 adsorption to the DRB-S was at pH 1.5. Equilibrium was attained at 30 and 90 minutes of reaction time interaction for AY36 and DB86, respectively. The Langmuir model and pseudo-second-order-model best described the biosorption of both dye molecules to the biosorbent. The determined biosorption capacities for AY36 and DB86 were 270.27 mg/g and 36.23 mg/g, respectively.   The researchers concluded that the DRB-S adsorbent exhibited an impressive sorption capacity and successfully removed AY36 and DB86 dyes. The biosorbent has potential applications in wastewater treatment and can be recycled without affecting its adsorption effectiveness.  

This study highlights the potential of biocharBiochar is a carbon-rich material created from biomass decomposition in low-oxygen conditions. It has important applications in environmental remediation, soil improvement, agriculture, carbon sequestration, energy storage, and sustainable materials, promoting efficiency and reducing waste in various contexts while addressing climate change challenges. More derived from Delonix regia seed pods as a sustainable and effective adsorbent for removing hazardous dyes from wastewater. This approach could contribute to reducing water pollution and protecting aquatic ecosystems.  

SOURCE : Eleryan, A., Aigbe, U. O., Ukhurebor, K. E., Hassaan, M. A., Ragab, S., Osibote, O. A., Hossain, I., & Nemr, A. E. (2025). Adsorption of Acid Yellow 36 and direct blue 86 dyes to Delonix regia biochar-sulphur. Scientific Reports, 15(1), 3448. https://doi.org/10.1038/s41598-025-85405-4