Kigelia africana Fruit Carbon as a Low Cost Adsorbent for Removal of Copper(II) Ions from Aqueous Solution

Fruit of Kigelia africana tree is cylindrical and weigh approximately 2.5 kg. A mature tree produces hundreds of fruits every year but not used for any purpose, and hence a waste material in this region. Heating dried fruit powder with 1:1 sulphuric acid at 110°C for 24 h has resulted in carbonaceous material which showed marked adsorption properties. Copper(II) adsorption capacity of this Kigelia africana fruit powder carbon material (KAFP) was found to be 21.74 mg/L and almost 90% removal was achieved by treating 100 mg of adsorbent material in 100 mL (10 mg/L) of Cu(II) solution. Adsorption data fitted well into Langmuir adsorption isotherm equation. Metal uptake was maximum at pH 7 and almost negligible at much lower pH values.