Charged characteristics and aggregation properties of humic acid in water environment

By studying the changing rules of the Zeta potential and particle size, the effect of chemical conditions on the states of the charge and aggregation of the humic acids (HAs) was discussed. It was found that the HAs had the property of self-flocculation. With the lower pH and the relatively higher ionic strength, the absolute values of Zeta potential for the HA colloidal particles decreased with polymerization degree increasing, thereby forming micelle aggregation and coagulation. Moreover, with the increasing of the HA concentration and subsequently the increasing of the absolute values of Zeta potential, the condensation degree of the HA colloidal particles decreased, which resulting in the state with the smaller particle sizes.