Busitema researchers test new approach to textile pollution using farm waste

Researchers at Busitema University have developed a novel method to address textile wastewater pollution using carbon-based materials derived from agricultural waste. Ivan Ssebagala and Samson Rwahwire converted passion fruit waste, tamarind coatings, mulondo kernels, and bean waste into carbon dots, which effectively removed methylene blue dye from wastewater. Their findings were published in Elsevier’s Next Materials.

The study demonstrated that carbon dots from these agricultural sources removed over 95% of methylene blue. Tamarind-derived carbon dots showed the highest efficiency at 99.2%, followed by mulondo at 98.5%, passion fruit at 95.8%, and bean waste at 95.4%. The researchers utilized a hydrothermal process to transform the plant waste into carbon-rich materials and tested their dye-capturing capabilities under various conditions.

Optimal removal conditions were identified at an adsorbent dose of 0.8 grams per liter, an initial dye concentration of 6 milligrams per liter, and a treatment time of 19 minutes. The carbon dots' varied surfaces facilitated the bonding and removal of dye molecules from the wastewater.

This research addresses the environmental challenge posed by synthetic dyes in textile industry wastewater. Methylene blue, a common dye, was chosen for its prevalence and associated environmental and health risks. The study highlights the potential of using agricultural residues instead of commercial treatment materials, offering a sustainable and cost-effective alternative.

The researchers suggest that carbon dots could serve as efficient biosorbents, potentially replacing commercial activated carbon in some applications. This approach links agriculture, materials engineering, and environmental protection, particularly in agricultural countries like Uganda, where waste can be repurposed into valuable resources.

While promising, further research is necessary to transition from laboratory experiments to large-scale applications. Challenges such as production scalability, repeated use, cost, and performance in diverse industrial conditions require additional investigation. Nonetheless, the study underscores the potential of reimagining local materials, turning agricultural by-products into valuable tools for environmental remediation.

The study, titled “Synthesis of green carbon dots from selected agricultural waste (peels/coatings) for removal of methylene blue from textile wastewater,” was published in Next Materials by Elsevier in 2025.