Abstract The effect of chemical activation on the adsorption of metals ions (Al2+, Cu2+, Ni2+, Mg2+and Fe2+) using waste Nigerian based coconut shell was investigated. Coconut shell was carbonized at 400 ˚C and activated at 400, 500, 600 and 650 ˚C using four activating agents. The produced activated carbon was characterized which revealed that increase in carbonization temperature leads to a decrease in both the ash content and char yield while the moisture content decreases with increase in carbonization temperature and pore volume are in a rise and fall pattern and increase in volatile content. The iodine value increased progressively with activation temperature, and then decreased when the temperature exceeded 600 ˚C, the optimum temperature for the production of activated carbons from coconut shell is approximately 600 ˚C The adsorption of metal ions using coconut activated with H2SO4 and HCl was significantly higher than carbons activated with NaOH and Ca(OH)2. This shows that waste coconut activated with H2SO4 and HCl can effectively be used to remove metal ions from waste waters and in different metal recovery processes than coconut shell activated with NaOH and Ca(OH)2.
Keywords Coconut shell, adsorption, heavy metals, activated carbon.