Humic acid is one of the major components of humic substances. Chemically, it is a super-molecular aromatic acid composed by various functional groups, taking on effects of sorption, complexation, chelation, flocculation, which dissolves loads of hydrophobic matters. They can also be found in peat, coal, many upland streams and ocean water.

Major applications
Humic acid is mainly employed in industry in forms of additive, its effects are: to improve product quality, to retrench raw material and to reduce energy expenditure; for instance, it may be applied as boiler water soften agent and as petroleum drilling fluid decreasing and filtering agent. By chelating the ions, humic acids facilitate the uptake of these ions by several mechanisms, one of which is preventing their precipitation, another seems to be a direct and positive influence on their bioavailability. They also dissolve loads of hydrophobic matters and along with the above characteristic they take care of harmful matters, preventing waters from contamination.
Since their pH values are below 7, namely acidic, humic acids alleviate the world-challenging issue of soil salinisation.