 Biochar has been shown to be effective at removing both tetracycline and hexavalent chromium, CR-6, two contaminants that pose serious threats to human health. Cassava stock, rubberwood, and sugarcane bagasse have all been found to be effective materials for making biochar, which can then be modified with potassium hydroxide, KOH, to increase its efficiency. The modified biocars exhibited increased porosity and redux capacity, allowing them to more effectively absorb tetracycline and CR-6 through electrostatic attraction, reduction reactions, pi-pi stacking interactions, hydrogen bonding, porfilling effects, and surface complexation. This research provides valuable insight into the mechanisms behind the simultaneous removal of these two contaminants from wastewater and could lead to the development of more efficient and cost-effective methods for treating water polluted with these substances. This article was authored by Qingxiang Wang, Yan Yu, Wenfei Lu, and others.