|Title||Activation of Cassava Stem Biochar by Physico-Chemical Method for Stimulating Cadmium Removal Efficiency from Aqueous Solution|
|Publication Type||Journal Article|
|Year of Publication||2014|
|Authors||Prapagdee, Songkrit, Piyatiratitivorakul Somkiat, and Petsom Amorn|
Removal of Cadmium (Cd) from aqueous solution using biochar was considered a cost effective sorbent. Biochar quality and specification depend on its carbonization process. In this study, the cassava stem biochars were produced at temperature of 300, 400 and 500◦C with slow pyrolysis technique. The biochar in each carbonization temprature was activated with physio-chemical treatments, pre-activated by 1.63M KOH solution then activated with second pyrolysis as same as first pyrolysis conditions. Adsorption study by using biochar adsorb Cd ion from Cd(NO¬3)2 solution by batch static method. The results indicated that the removal efficiency of acivated biochar produced at pyrolysis temperature 300◦C can be increased from 10.46 to 24.88 mg/g and was selected for adsorption characteristics and biochar properties. Adsorption isotherm of non-activated and activated biochar were fitted both Languimer and Freundlich isotherm (r^2 >0.95). The BET surface area of activated biochar was increased from 6.8818 to 9.4964 m2/g, while, pore size and chemical properties could be preserved. In summary, our results suggest that KOH pre-activated and second pyrolysis could increase Cd removal efficiency from aqueous solution.