With the development of industry, the pollution of toxic organic pollutants to soil has become more and more serious, and even threatens human health. Faced with this severe situation, humic acid has played a full role in repairing the pollution of toxic organic matter to soil. So how does humic acid repair the pollution of toxic organic matter to soil?
Humic acid has an adsorption and precipitation effect on organic pollutants in soil
Humic acid mainly combines with organic pollutants through physical adsorption, distribution, hydrogen bonds, covalent bonds and other pathways to reduce the biological effectiveness of toxic organic pollutants in soil.
Humic acid has a surfactant solubilizing effect, which allows organic matter to be eluted from the soil, and then the eluent is pumped to the surface for further treatment to reduce the content of organic matter in the soil.
The organic-non-polar composite colloid formed by humic acid and soil colloids further enhances the adsorption of organic matter.
The adsorption performance of humic acid on ions can make the cations of organic matter tightly adsorbed around the humic acid molecules, reducing the migration of organic pollutants in the soil.
The molecular weight of humic acid directly affects the adsorption effect on organic pollutants. As the molecular weight of humic acid increases, the adsorption of hydrophobic organic matter is enhanced: in the structure of humic acid, the increase of fat structure promotes the adsorption of humic acid on hydrophobic substances, and the increase of aromatic structure weakens the adsorption of humic acid on hydrophobic substances. Its polarity may be an important parameter for controlling the adsorption of hydrophobic organic matter. Studies have shown that divalent cations (Ca2+, etc.) can enhance the adsorption of hydrophobic organic pollutants (such as certain pesticides) by promoting the exposure of hydrophobic sites of humic acid.
The above is the entire content of this article. In terms of repairing the pollution of toxic organic matter to the soil, humic acid also has a redox effect on organic pollutants in the soil, and it can also promote the degradation of organic matter by soil microorganisms. The next article will explain these two principles of humic acid.