Removal of Heavy Metal Ion Using Polymer-Functionalized Activated Carbon: Aspects of Environmental Economic and Chemistry Education

Table 3

Ionic properties of Ni, Cd, and Zn.

Characteristics	Ni	Cd	Zn
Stability constant of metal-humic acid complexes	3.2	2.78	2.74
Stability constant of metal-fulvic acid complexes	3.1/3.2	—	2.4/2.3
Electronic configuration	3d^84s^0	4d^105s^0	3d^104s^0
Pauling electronegativity	1.91	1.69	1.65
Atomic radii (pm)	69	95	—
Ionic potential	2.9	2.11	—

[18]; [19]; [20].