Effect of Chemical Activation on the Adsorption of Heavy Metals Using Activated Carbons from Waste Materials

Abstract

The effect of chemical activation on the adsorption of metals ions (Cr2+, Cu2+, Ni2+, Pb2+, Fe2+, and Zn2+) using waste Nigerian based bamboo, coconut shell, and palm kernel shell was investigated. The bamboo, coconut, and palm kernel shell were carbonized at 400°C–500°C and activated at 800°C using six activating agents. Chemical activation had significant effect on the iodine number and invariably increased the micropores and macropores of the activated carbons produced from bamboo, coconut, and palm kernel shell. It also affected the adsorption of metal ions and the type of carboneous material used for activation. The highest metal ions adsorbed were obtained from bamboo activated with HNO3. The cellulose nitrite formed during the activation of bamboo with HNO3combined with high pore volume and low ash content of bamboo effectively create more reaction sites for adsorption of different metal ions. This shows that waste bamboo activated with HNO3can effectively be used to remove metal ions from waste streams and in different metal recovery processes than activated carbon from coconut shell and palm kernel shell.

Effect of Self‐Doped Heteroatoms in Biomass‐Derived Activated Carbon for Supercapacitor Applications

“…After physical or chemical activation, biomass activated carbon can greatly increases its specific surface area and porosity, which could facilitate the transfer of charge in the double‐layer structure. Chemical activation usually involves in mixing amorphous carbon with acids, bases or chlorides, to form porous structure, while physical activation is done in a high‐temperature oxidation environment with CO, CO 2 , and so on . In comparison, chemical activation, and especially KOH activation, is more economical, more efficient and greener than physical activation.…”

Activated coconut shell charcoal carbon using chemical-physical activation

“…It was reported that the use of activator agent NaOH did not produce surface area as high as KOH due to KOH dehydrate and oxidize stronger than NaOH for activating biomass. While the activation with HCl acid increased the porosity of activated carbon thus created more reactive sites for metal ion adsoption [22]. During activation, reaction between C and HCl make the devolatilization process occurs and develop the rudimentary pore structure in the charcoal [23].…”

Effect of pretreatment process on the characteristics of activated carbons produced from chemical activation of scrap tire

“…The iodine number is one of the most useful parameters for characterization of ACs. This number can express the activity level and the micropore content of the ACs [23]. increased the iodine number and higher numbers are achieved in higher pyrolysis temperatures.…”