Effect of metal ions loaded onto activated carbons on desorption activation energy of dichloromethane
This work involves the investigation of the effects of different metal ions loaded on activated carbon(AC)on the activation energy for desorption of dichloromethane.Texture parameters of the modified activated carbons were measured with Micromeritics ASAP 2010M.TPD experiment was conducted to measure the activation energy for dichloromethane desorption.The variation of the desorption activation energy of dichloromethane on activated carbons was discussed with the help of the hard soft acid base(HSAB) principle.The results showed that the desorption activation energy of dichloromethane on Al(Ⅲ)/SY-6AC,Li(Ⅰ)/SY-6AC,Mg(Ⅱ)/SY-6AC,Fe(Ⅲ)/SY-6AC and Ca(Ⅱ)/SY-6AC was larger than that on the original AC,however,the activation energy for dichloromethane desorption from Ag(Ⅰ)/SY-6AC was lower than that on the original AC.In comparison with the original activated carbon,the loading of Al3+,Li+,Mg2+,Fe3+ or Ca2+enhanced the interaction between dichloromethane and the surfaces of modification activated carbons because Al3+,Li+,Mg2+,Fe3+ or Ca2+ are hard acid and dichloromethane is a hard base,and the loading of Ag+ weakened the interaction between dichloromethane and the Ag(I)/AC surfaces because Ag+ is a soft acid.