Coconut charcoal: powerful water decontaminant
Coconut water, an iconic symbol of beach culture, is a refreshing beverage that helps beat the heat, particularly during the summer. However, consuming just 250 milliliters of this liquid results in approximately 1 kilo of waste in the form of coconut shells, which are not utilized and take 10 to 15 years to decompose.
To address this issue and prevent the wasteful disposal of coconut shells in landfills or the environment, researchers at the Fluminense Federal University (UFF) have sought a solution that not only repurposes this residue but also contributes to purifying the water consumed by the population.
In his PhD thesis, researcher Bruno Salarini Peixoto, under the guidance of Professor Marcela de Moraes from the UFF Institute of Chemistry, has developed a cost-effective and efficient technique to convert green coconuts into magnetic charcoal, which can be used as a powerful decontaminant.
Moraes explains that the process begins by transforming the coconut into biochar through controlled combustion. Subsequently, an activation process is employed, and magnetic nanoparticles are added to the product. This resulting magnetic biochar possesses the ability to adsorb and attract contaminants from water, effectively removing them. Moreover, due to its magnetization, the charcoal can be easily separated from the water by using magnets once it has adsorbed the pollutants.
According to her, the magnetic removal of charcoal from water is a more economical alternative to traditional filtration methods.
Medicine residues
The significance of magnetic biochar becomes even more apparent when considering its potential role in water treatment plants for eliminating drug residues, including antibiotics.
"With the increasing consumption of medication worldwide, a significant amount of these drugs is excreted through various means, including urine. Additionally, improper drug disposal practices contribute to the problem," notes Moraes.
She points out that the conventional methods employed in water treatment plants are unable to eliminate these "emerging contaminants," which are pollutants that have gained recent recognition.
"The current water and wastewater treatment facilities are not designed to eliminate these substances. As a result, these pollutants circulate through the treatment process and eventually return to our water supply. Without intervention, the concentration of these substances will continue to rise, resulting in an increased dosage of antibiotics in the water we consume," explains the professor.
The researcher suggests that charcoal can be introduced directly into water treatment tanks or installed in pipes through which the treated water flows after leaving the treatment plant.
"We are currently evaluating the possibility of trapping the charcoal and allowing the water to pass through it. We are also considering patenting the production process of this biochar. The next step involves collaborating with the water treatment plant here in Niterói [a municipality in Rio de Janeiro where UFF is located] to initiate the implementation of this material," Marcela de Moraes stated.
Funding for the research was provided by the Research Support Fund of the State of Rio de Janeiro (Faperj), the National Council for Scientific and Technological Development (CNPq), and the Coordination for the Improvement of Higher Education Personnel (Capes).
