Absorbance study on the adsorptive removal of Fe(III) ions using activated carbon from coconut shells

Turning Coconut-Shell Waste into Clean-Water Solution: Fast Fe(III) Removal with Microporous Activated Carbon (SDG 6 & SDG 12)
A Universitas Padjadjaran team synthesized activated carbon from coconut shells (carbonized 700 °C/1 h, chemically activated with ZnCl₂ 10%, then re-activated at 700 °C under N₂) and demonstrated efficient removal of Fe(III) from water. Materials showed microporous texture with BET surface area ~490.29 m²/g and amorphous aromatic carbon features (XRD), validated by SEM–EDS.
In batch tests (Fe(III) nitrate 100–200 ppm; contact time 5–30 min; adsorbent 0.005–0.5 g), the maximum adsorption capacity reached 60.95 mg/g (0.005 g; 200 ppm; 15 min), while the highest removal efficiency was 83.81% (0.5 g; 100 ppm; 15 min).
The work supports low-cost, circular solutions for clean water (SDG 6) using agri-waste valorization (SDG 12).

Open access DOI: https://doi.org/10.1016/j.crgsc.2025.100458
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