Researchers from the Laboratory of Study and Research in Applied Chemistry at the University of Abomey-Calavi in Benin have developed a sustainable method to convert agricultural waste into valuable activated carbon. This innovative approach addresses both environmental concerns and the growing demand for effective water treatment solutions. The study, led by Elie Sogbochi, focuses on the stems of Hibiscus sabdariffa, a plant widely used in Africa to produce a popular fruit juice known as bissap. Traditionally, the leftover stems have posed an environmental challenge due to their lack of use.
The researchers found that these stems possess a high content of lignin and cellulose, making them suitable for conversion into activated carbon when treated with orthophosphoric acid at moderate temperatures. The resulting porous carbons exhibited impressive specific surface areas, reaching up to 1066 m²/g. This high porosity is essential for applications in wastewater treatment, as it enhances the material’s ability to adsorb pollutants.
Sogbochi noted, “These activated carbons are good candidates for the development of bio-sourced filters for the treatment of industrial wastewater.” This statement highlights the potential for these materials to be used in commercial water filtration systems, particularly in industries that produce significant amounts of wastewater.
The research also delved into the adsorption capabilities of the activated carbons, specifically regarding methylene blue, a common dye pollutant. The study demonstrated that the adsorption process is predominantly driven by chemisorption, indicating a strong interaction between the carbon and the dye molecules. The findings revealed that the Langmuir model best describes the adsorption behavior, suggesting that these activated carbons can effectively remove pollutants from water at capacities of 588 mg/g and 526 mg/g, depending on the preparation ratios.
This development opens up opportunities for various sectors, including environmental services, agriculture, and waste management. Companies focused on sustainable practices may find value in utilizing these bio-sourced materials to enhance their filtration systems. Furthermore, as industries face increasing regulatory pressures to manage wastewater more effectively, the demand for innovative solutions like those developed by Sogbochi and his team will likely rise.
Published in ‘Scientific African’, this research underscores the potential of agricultural by-products to contribute to environmental sustainability while addressing pressing industrial challenges. The study not only provides a practical solution to waste management but also paves the way for the creation of eco-friendly materials in the field of water treatment.
