The emerging pollutant octocrylene is not efficiently removed from effluents by conventional treatment and is recurrently found in rivers. This study evaluated the adsorption of octocrylene using commercial carbon and biochar from spent coffee grounds activated with ZnCl2. The two adsorbents had an efficiency of approximately 100% in pollutant removal throughout the experimental design. The kinetics and equilibrium isotherms showed a good correlation with the experimental data. The kinetics showed adsorption of the contaminant in 40 min for both adsorbents. The model equilibrium isotherms with the best fit and adsorption capacity was Langmuir for biochar, with a capacity of 37.822 ± 0.005 µg∙mg−1 compared to 33.602 ± 0.202 µg∙mg−1 for commercial carbon. Furthermore, a toxicity analysis of a 600 µg∙L−1 octocrylene solution was carried out before and after adsorption with the two charcoals separately, using Allium cepa roots. Before adsorption, the solution was phytotoxic and cytogenotoxic. After adsorption, the solution obtained for each charcoal no longer caused toxicity to the roots. The charcoals tested had high removal efficiency and adsorption capacity, a condition reiterated by the toxicity results. However, biochar better represented the Langmuir model in the adsorption process when removing octocrylene from the aqueous medium.