Researchers at São Paulo State University (UNESP) in Brazil have come up with an innovative strategy to eliminate glyphosate, a popular herbicide, from water. The technique, inspired by the concept of the circular economy, involves utilizing sugarcane bagasse, a waste material produced by sugar and ethanol plants. By isolating and chemically functionalizing sugarcane bagasse fibers, they create an adsorbent material that effectively removes glyphosate from water through filtration, decantation, or centrifugation.
Glyphosate is widely used around the world as an effective herbicide for controlling unwanted plant growth, including weeds, invasive species, and agricultural pests. Despite its low cost and ability to enhance crop yields, scientific studies have raised concerns about glyphosate’s potential human health risks, including its possible link to cancer. Consequently, several countries have restricted or banned the use of glyphosate-containing products due to these safety concerns. However, in Brazil alone, an average of 173,150.75 metric tons of glyphosate products are used annually, with a significant portion ending up in water sources through rainfall.
To address the issue of glyphosate contamination in water, scientists at UNESP’s School of Sciences and Technology (FCT) in Presidente Prudente developed a method to remove glyphosate using sugarcane bagasse. The team, led by postdoctoral fellow Guilherme Dognani and Professor Aldo Eloizo Job, obtained cellulose fibers from bagasse by isolating them from hemicellulose and lignin. The fibers were then functionalized with quaternary ammonia groups, giving them a positive charge. These modified cellulose microfibers easily bind to glyphosate molecules, facilitating their removal from water.
The researchers conducted experiments to determine the optimal conditions for glyphosate adsorption using the functionalized cellulose microfibers. They found that pH variation played a crucial role in the process. At different pH levels, both the cellulose microfibers and glyphosate adopted different molecular configurations. The researchers discovered that the most effective pH level for interaction between the adsorbent material and glyphosate was pH 14, resulting in optimal adsorption and removal.
To evaluate the adsorption capacity of the functionalized cellulose microfibers, the researchers prepared different fractions of a glyphosate solution with pH levels of 2, 6, 10, and 14. Each fraction was then mixed with identical amounts of cellulose microfibers and agitated for 24 hours. After the reaction occurred, the solutions were analyzed using visible light spectrophotometry to measure the levels of glyphosate. The researchers calculated the removal efficiency by comparing the initial and final glyphosate levels in each sample and determined the adsorption capacity based on the pH level.
The development of a glyphosate removal method using sugarcane bagasse opens up possibilities for a more sustainable approach to water treatment. By repurposing a waste material and transforming it into an effective adsorbent, this technique provides an environmentally friendly solution for removing glyphosate from water sources. Further research and refinement of this method could contribute to reducing the negative impact of glyphosate on human health and the environment.
The researchers at São Paulo State University have successfully developed an innovative method for removing glyphosate from water using sugarcane bagasse. By utilizing the concept of the circular economy and repurposing waste material, this technique offers a sustainable solution to the problem of glyphosate contamination. With further exploration and optimization, this method has the potential to mitigate the health and environmental risks associated with glyphosate use, contributing to a safer and greener future.