In a significant stride toward sustainable environmental solutions, new research published in Case Studies in Chemical and Environmental Engineering showcases an innovative approach to combat Bisphenol A (BPA) contamination in water. Led by a team of researchers including Hashinika Matharage, Mahesh Jayaweera, Nilanthi Bandara, Jagath Manatunge, Daham Jayawardana, and Janith Dissanayake, this study transforms king coconut shells, a common agricultural waste product, into a highly effective adsorbent for removing this pervasive endocrine-disrupting chemical. This groundbreaking work not only addresses a critical environmental issue but also offers a dual benefit by valorizing waste, aligning perfectly with circular economy principles for a healthier aquatic ecosystem.

The widespread presence of BPA in our water systems is a growing concern, stemming from its extensive use in plastics and resins for everyday products like food containers and pipes. Its persistence and potential to disrupt hormones pose serious health risks to both wildlife and humans, impacting reproductive systems, development, and even contributing to conditions like cardiovascular disease and cancer. Current BPA removal methods often fall short, either introducing new chemical hazards, demanding excessive energy, or lacking cost-effectiveness. This pressing need for efficient, sustainable, and affordable solutions is precisely where this research shines, by championing adsorption, a technique noted for its operational robustness and effectiveness.

This study meticulously explored the potential of king coconut shell 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 as a green adsorbent. Initially, researchers investigated various pyrolysisPyrolysis is a thermochemical process that converts waste biomass into bio-char, bio-oil, and pyro-gas. It offers significant advantages in waste valorization, turning low-value materials into economically valuable resources. Its versatility allows for tailored products based on operational conditions, presenting itself as a cost-effective and efficient More temperatures, finding that biochar produced at an elevated temperature of 800°C demonstrated the highest BPA removal efficiency, achieving 70.1 ± 0.9%. This improvement is linked to the increased carbon content, enhanced porous structures, and larger surface area developed at higher temperatures, creating more available sites for BPA adsorption. This foundational step confirmed 800°C as the optimal pyrolysis temperature for this particular biochar, setting the stage for further enhancements.

Building on this, the team focused on chemical activation and particle size optimization to unlock the biochar’s full potential. Among various activators, hydrochloric acid (HCl) proved most effective, boosting the BPA removal efficiency of the 800°C pyrolyzed biochar (KBC800) from 70.1 ± 0.9% to a remarkable 80.1 ± 0.9%. This enhancement is attributed to the acid’s ability to remove impurities, increase porosityPorosity of biochar is a key factor in its effectiveness as a soil amendment and its ability to retain water and nutrients. Biochar’s porosity is influenced by feedstock type and pyrolysis temperature, and it plays a crucial role in microbial activity and overall soil health. Biochar More, and enhance the surface area and fixed carbon content, which are crucial for effective adsorption. However, the most significant breakthrough came with particle size reduction: by grinding the HCl-activated biochar from 1.0–4.0 mm down to a fine powder of 75–105 µm, the BPA removal efficiency soared to a complete 100%. This dramatic improvement highlights the critical role of increased surface area at a microscopic level. The material exhibited a robust maximum adsorption capacity of 39.53 mg/g, aligning well with the Langmuir isotherm model, which suggests a uniform, monolayer adsorption process. Optimal conditions for this impressive removal were identified at a 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 range of 3–7, with a biochar dosage of 5.0 g/L and an initial BPA concentration of 100.0 ppm.

Beyond its exceptional removal capabilities, the reusability of the adsorbent is paramount for practical, long-term applications. The study demonstrated that the KBC800-HCl biochar could be effectively regenerated using ethanol, maintaining an impressive removal efficiency of over 79.6% even after five consecutive cycles. This reusability confirms the material’s long-term feasibility and economic viability for real-world water treatment. The underlying mechanisms driving this high adsorption performance are complex but primarily involve π–π electron donor/acceptor interactions, where the aromatic structure of the biochar strongly attracts BPA molecules. Additionally, pore-filling effects, where BPA molecules physically occupy the numerous pores within the biochar, and hydrophobic interactions also play significant roles.

This research successfully demonstrates that king coconut biochar, optimized through pyrolysis and chemical activation, offers a sustainable, highly efficient, and reusable solution for removing BPA from water. This innovative approach not only tackles a pressing environmental contaminant but also transforms agricultural waste into a valuable resource, offering a practical and eco-friendly solution for water purification, particularly beneficial for resource-constrained regions. The findings underscore the immense potential of biochar-based technologies to contribute to a cleaner, healthier future.

Source: Matharage, H., Jayaweera, M., Bandara, N., Manatunge, J., Jayawardana, D., & Dissanayake, J. (2025). From Waste to Resource: King Coconut Biochar as a Green Adsorbent for Bisphenol A Removal. Case Studies in Chemical and Environmental Engineering.