ADSORPTION OF HEAVY METALS USING ACTIVATED CARBON DERIVED FROM CARICA PAPAYA SEED

Activated carbons were prepared from carica papaya seeds with particle sizes ranging from 355 - 835^m. 0.1M H3PO4 and ZnCl2 were each used for chemical activation at 3minutes residence time and at 7500C.This was after carbonizing the source material at 5000C and also residence time of 5 minutes. The adsorption of copper and lead from aqueous solution onto ZnCl2 and H3PO4 activated carbons was studied and assessed for the possibility of using the source materials for the removal of heavy metals from aqueous solution. The effect of varying the particle size of the activated carbons and the type of activating agents on the adsorption capacity were evaluated. The results indicate a difference in the uptake for the activated carbons as well as for the carbonized or raw materials. Little adsorption took place when raw material was used for the adsorption of the metals. The results indicated that the activity of 0.10M H3PO4 and 0.10M ZnCl2 activated carbons with particle size of less than 355 ^m gave the highest adsorption capacities; with ZnCl2 activated carbons exhibiting better adsorption capability than H3PO4 - activated carbons. This work has shown that carica papaya seed can be used to remove these two metals from aqueous solution.