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Background: Nowadays freshwater quality deterioration and quantity depletion are rapidly increasing across the globe. Especially fluoride polluted groundwater is causing a severe shortage of water supply and public health problem. Hence, this study was designed to investigate the performance of activated carbon produced from the Catha edulis stem for the removal of fluoride from aqueous solution. A C. edulis stem sample was collected from dumping sites of Addis Ababa City and its activation and carbonation processes were performed using H 2 SO 4 and a high temperature of 600 °C. The experimental study was designed to use a full factorial approach with a 3 3 which were the three factors with the three levels, namely pH (2, 7 and 9), contact times (60, 90 and 120 min) and adsorbent doses (0.5 g, 1.0 g and 1.5 g in 100 mL) at the initial fluoride concentration 30 mg/L which resulted in 81 experimental runs in triplicates. Results: The calculated maximum adsorption capacity of 18 mg/g was found under the Langmuir isotherm, whereas the Freundlich model (R 2 0.98) better fitted the experimental data, which indicated that the adsorption process was multilayer and cooperative. The maximum fluoride removal of 73% was observed at the optimum condition of adsorbent dose of 1.5 g in 100 mL contact time of 60 min and pH 2, whereas the predicted value of the fluoride removal of 69% was calculated under the same experimental condition. Fluoride removal was positive and strongly influenced by the adsorbent dose, whereas the adsorption pH was negatively and weakly impacted on removal. Conclusions: Generally, the performance of activated carbon for the removal of fluoride from aqueous solution is promising. The study also indicated that C. edulis activated carbon is a potential candidate for water treatment technology.

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