腐殖酸与Cu^(2+)、Zn^(2+)、Fe^(3+)的络合作用

Complexation of Cu^(2+),Zn^(2+)and Fe^(3+) Metal Ions with Humic

用电位滴定法研究了腐殖酸与Cu2+、Zn2+、Fe3+的络合作用,它们的络合形成常数可通过作图法获得.随着溶液中金属离子浓度的增大,络合形成常数减小.同时发现络合形成常数FA大于HA;Cu2+和Fe3+大于Zn2+.

The humic substances-fulvic acid(FA)and humic acid(HA) and their complexations with metal ions Cu^(2+),Zn^(2+)and Fe^(3+) were investigated by using potentiometric titration. The formation constants of the metal ion complexes with HA and FA were obtained by graphical approaches. It was found that formation constants decrease with the increasing concentration of metal in the solution.The formation constants of FA are larger than those of HA and the formation constants of Cu^(2+) and Fe^(3+) are larger than those of Zn^(2+).