Researchers at the University of Waterloo discovered that biochar charcoal separation can soak up toxic chromium from water while transforming it into a less dangerous state. The paper discusses how researchers at the University of Waterloo demonstrate biochar’s ability to oxidise harmful chromium from water:
Budimir, F., Ptacek, C. J., Amos, R. T., & Blowes, D. W. (2024). Chromium isotope fractionation during the removal of hexavalent chromium by oak-based biochar. Chemosphere, 369, 143880. https://doi.org/10.1016/j.chemosphere.2024.143880
The main two forms of the heavy metallic chromium are Chromium(III), which serves as an important trace element in the human body yet it differs from chromium(VI), the other form, because the latter is classified as a carcinogenic agent responsible for lung, ovarian and liver cancer disease. The production of leather goods textile and steel metal creates Chromium(VI) as an industrial waste product.
Biochar, which is charcoal produced by heating agricultural waste in the absence of oxygen. The manufacturing technique yields a porous material containing carbon which demonstrates strong adsorptive properties. The study team under the direction of Ph.D. candidate Filip Budimir examined how biochar functioned to both extract chromium(VI) from polluted water while converting the substance into chromium(III) which demonstrates lower toxicity.
Research teams from the University of Saskatchewan conducted their analysis using the Canadian Light Source facility to study how oak-based biochar treatment affects chromium-contaminated water. Laboratory experiments showed that biochar substances effectively made a transformation of 85% of chromium(VI) into chromium(III) after maintaining the solution for 120 hrs. The results indicate that biochar serves a dual role as a philtre and an active player in water decontamination.
“We were happy to see that the majority of what we were finding on the biochar grains was chromium-3 and not chromium-6,”
In addition to chromium reduction, the study observed that chromium isotopes fractionated during the removal process. Lighter chromium isotopes were preferentially removed and converted more efficiently than heavier ones. This fractionation effect could be used monitor biochar-based cleanup in groundwater contamination.
The ability of biochar to both absorb and transform chromium(VI) into a safer form offers a viable option for treating contaminated water sources, particularly at industrial sites where conventional remediation methods can be costly and complex.
