The Application of Humic Acid in Environmental Protection
The composition and properties of humic acid determine its broad application prospect in environmental protection.
Because the humic acid material molecular structure contains chinone semiquinone group and other functional groups, it can react with hydrogen sulfide as a desulfurized for waste gas. Humic acid and humates can be used as adsorbents for atomic fission products, coagulants for radioactive wastewater treatment, and adsorbents for isotopes and rare elements in radioactive wastes and wastewater. Humic acid has a large internal surface area and contains carboxyl and phenolic hydroxyl groups, which can exchange, complex, and chelate with heavy metal ions. Therefore, humic acid can be used to treat industrial wastewater containing heavy metals, oily wastewater, printing and dyeing wastewater, and waste gas.
As early as the 1970s, the Shanghai Institute of chemical technology, the Institute of Geosciences, and the Institute of soil science of the Chinese Academy of Sciences used humic acid substances to adsorb heavy metal ions in industrial wastewater. The adsorption rate was several times higher than that of activated carbon, and the adsorption capacity of mercury, lead, copper, cadmium, zinc, and other heavy metal ions could reach 90% ~ 98%. Humic acid has a good adsorption effect on wastewater containing Cr6+.