Adsorption Effectiveness of Coffee Grounds Activated Carbon in Reducing Iron (Fe) Control in Water

Abstract

High iron (Fe) content in water can be harmful to human health. A viable approach to diminish iron levels involves the utilization of an adsorbent, specifically activated carbon produced from coffee grounds. This study explores using activated carbon made from coffee grounds, treated with Nitric Acid (HNO₃), to reduce Fe levels in water. The experiment used a pretest-posttest controlled group design with 31 samples of 500 ml Fe solution. Adsorption was done using the batch method, with different adsorbent doses (0.5 and 1.5, g) and stirring times (30, 60, 120, 180, and 360 minutes) at 150 rpm and 80 mesh particle size. Data were analyzed using Two Way ANOVA. The study successfully produced activated carbon from coffee grounds, with water content at 1.46%, ash content at 8.58%, and iodine absorption of 1038 mg/g. The highest Fe reduction occurred at a 0.5 g dose and 120-minute contact time, resulting in 0.014 mg/l of Fe. Two Way ANOVA results showed a p-value above 0.05, indicating no significant difference. The adsorption followed the Freundlich isotherm model (R² = 0.9879), while the kinetics followed a zero-order model (R² = 0.2476). The findings suggest that coffee grounds are an effective adsorbent for reducing iron levels in water, though further research is needed to address water turbidity without compromising adsorption efficiency.