Humic acid is also known as humus acid. A complex mixture of natural organic polymer compounds. Black or black brown amorphous powder, slightly soluble in water and acid, soluble in hot concentrated nitric acid with dark red. Soluble humic acid can be formed by reacting with alkali solution. It can be also used as dispersion and emulsification agents. It has weak acidity, hydrophilicity, complexation, redox, ion-exchange and physiological activity because it contains elements such as carbon, hydrogen, oxygen, nitrogen, and active groups such as hydroxyl, carbonyl, carboxyl, quinone, methoxy and aromatic nuclei. According to the process of its formation, it is divided into primary humic acid and regenerative humic acid. According to the solubility and color difference, it is divided into humic acid or humus acid (soluble in alkali solution), brown humic acid or melilotic acid (soluble in acetone, ethanol), fulvic acid (soluble in water). It exists in soil humics and lean coal, which is formed by partial decomposition of plant residues in the presence of air and water. Thus, it can be extracted from peat, lignite, or some soil and used as soil modifier, plant growth stimulant, insecticide, fertilizer, herbicide, medicine, mud stabilizer for oil drilling, ion exchanger and also battery plate, etc. Its sodium or ammonium salt can be used to prepared the humic acid coalball as a binder.
Humic acid is the effective component of the coal alkali solution for the fluid loss additive of slurry. It is not a single compound, but a mixture of a variety of compounds with different molecular sizes and inconsistencies in the structure. These compounds contain nitrogen, hydrogen, oxygen, carbon and other elements. From the analysis of functional groups and structural, it is proved that they are the multifunctional chain polymers containing aromatic rings and alkene bonds. These functional groups contain carboxyl, alcohol hydroxyl, phenolic hydroxyl, methoxy, quinoxy, nitrogen-containing group and so on. Carboxyl, phenolic hydroxyl and methoxy play the leading role in mud treatment agents. Molecular weight from 1900~4900, such as:
It is mainly formed by the ancient plants, which accumulated in marshland after death. Through the complex biochemical and physicochemical changes, the decarboxylation and dehydration reaction had occurred in the plant wreckage, releasing gaseous products such as carbon dioxide, water, and methane. Finally, a new brown gelatinous substance - peat was produced. The peat contains a large amount of humic acid, bitumen and a large amount of water.
- Used as a filtrate reducer with resistance to high temperature for fresh water drilling fluid with the effect of reducing viscosity. But the salt resistance is poor.
- Used as fertilizer and soil acid regulating agent
- The raw material for the production of humic acid compound fertilizer, the raw material for the production of drilling additive and pesticides.
- Biochemical research
- Plant growth stimulating hormone. Humic acid macromolecule is connected with carboxyl, hydroxyl, carbonyl, benzoquinonyl, methoxy and other functional groups. Exchange with metal ions, adsorption, complexation, chelation and so on. In a dispersive system, as the polyelectrolytes, it has the effects on condensation, peptisation and dispersion, etc.
The reaction of lignite and caustic soda [lignite: caustic soda = 100: (10~20) (mass ratio)]. The product can be obtained after the reaction liquid is filtered, concentrated and dried.
Drilling fluids, printing inks, plant growth.
Metal chelator; pigments.Humic acid is used as a soil supplement in agriculture and human nutritional supplement. It is used to improve the growth and cultivation of crops, citrus, turf, flowers. It is also used to improve the strength of organically-deficient soils. It is utilized to stimulate the immune system and treating the influenza, avian flu, swine flu and other viral infections.
A brown, polymeric constituent of soils, lignite, and peat; it contains the brownishblack pigment melanin. It is soluble in bases, but insoluble in mineral acids and alcohols. It is not a well-defined compound but a mixture of polymers containing aromatic
Humic acid (HA) is a heterogeneous macromolecule mainly found in soil and water.
Humic acid is a partially decomposed aromatic, organic matter that originates from terrestrial vegetation. It is made up of dark colored amorphous materials and is the end-product of the action of bacteria and certain enzymes. Most of the humic acid has a large fraction of carboxylic functional group which enables the humic acid molecule to chelate with positively charged multivalent ions (Mg++, Fe++ etc). The action of chelation helps plants to absorb the nutrients effectively. This function is one of the most important roles of humic acid. Humic acid also contains the phenolic functional group.
;Humic acids are derived from peptide, lipid and carbohydrate precursors. Peat, lignite coal, leonardite,decomposing driftwood and fish excreta are rich in humic acids. Leonardite is a highly oxidized form of organic matter and is technically known as a low rank coal which is between peat and sub-bituminous coal. Most of the humic acid found in rivers, lakes and even oceans has flowed from land over long periods of time. In the aquatic media, humic acid molecules develop unique characteristics.
Humic acid can be broken down into two groups, based on the size and polarity of the individual components. The smaller, more polar fraction is called fulvic acid and the larger, non-polar fraction is the humic acid. The acids are soluble in sodium hydroxide.
Humic acids are soluble in alkaline solutions. But on acidification of the alkaline extracts, they precipitate (Fulvic acid, on the other hand, remains soluble on acidification of the extract). Their molecular weight is in the range of tens of thousands to a million. They are believed to be polymerization products of fulvic acids and their decay products.
The three main components of humus are humin, humic acid and fulvic acid.
Humification is the process in which organic matter decomposes into humus.
