Binding characteristics of Cd2+, Zn2+, Cu2+, and Li+ with humic substances: Implication to trace element enrichment in low-rank coals

摘要

Binding characteristics of metal ions (Li+, Cd2+, Zn2+, Cu2+) with humic substances (HSs) are investigated by first principle calculation at BP86/SDD level. In the present work, HSs are well represented by singly deprotonated alkyl/aryl carboxylic acid. The results reveal that the bidentate is the strongest complexation form. Moreover, with the increase of ionic potential, the binding energies of HSs to chelate metal ions increase in order, Li+