91 / 2023-07-13 15:35:48

Undervalued Humin Components in Humus: Composition, Properties, and Prospects

Humin,Heavy metals,Functional groups,Adsorption properties,Biological stability

As a kind of recognized polymer organic compound mixture, humus substance widely exists in soil, water, sludge, and agricultural solid waste, and plays an important role in environmental protection and sustainable development of agriculture. According to the extraction ability of humus substance in alkaline solution, it can be divided into humic acid, fulvic acid and humin components. However, humin is often neglected as an insoluble component. It is a great waste of resources. Some studies show that humin accounts for about 50-70% of the world's total humus substance. In addition, the surface of humin is rich in carboxyl, hydroxyl, carbonyl, nitro and other active functional groups that can be complexed pollutants, which has great potential in environmental remediation and resource reuse. However, the structure and properties of humin vary greatly depending on the source and extraction method. This has resulted in controversy surrounding the preparation and analysis. In this paper, the relationship between humin sources, extraction methods and structure, as well as its effects on environmental remediation, and even microbial activity are reviewed. Due to the high degree of polymerization of humin and the limitation of technical conditions, it is still difficult to get a full view. Therefore, humin is expected to become a new generation of environmental remediation materials, and it still has potential value worth exploring.