Humic acid particles dissolve and disintegrate

Humic acid particles are organic macromolecular aggregates bound by weak intermolecular forces. In water, they first undergo physical disintegration: water infiltration breaks large particles into fine micro-fractions. Subsequent chemical dissolution occurs mainly in neutral and alkaline water via functional group deprotonation and electrostatic repulsion. Acidic conditions, divalent cations and low temperature significantly slow their disintegration and dissolution.