Soil remediation refers to the use of physical, chemical and biological methods to transfer, absorb, and reduce the main technical principles
Dissolve and transform pollutants in the soil to reduce their concentration to an acceptable level, or convert toxic and harmful pollutants into harmless substances. Fundamentally speaking, the technical principles of remediation of contaminated soil may include: (1) Change the existing form of pollutants in the soil or the combination with the soil to reduce its mobility and bioavailability in the environment; ( 2) Reduce the concentration of harmful substances in the soil.
The United States invested nearly $100 billion in remediation of contaminated soil in the 1990s. The theory and technology of contaminated soil remediation has become the frontier of the entire environmental science and technology research. The process of soil remediation is quite long. The current solution to the problem of soil pollution requires scientists from different disciplines such as soil science, agronomy, ecology, biogeochemistry, marine science, and related production units and government decisions related to agriculture, forestry, and fishery. The joint efforts of the people.
China's soil pollution has posed a threat to the sustainable use of land resources and the ecological security of agricultural products. The farmland polluted by organic pollutants nationwide has reached 36 million hectares. The types of pollutants include petroleum, polycyclic aromatic hydrocarbons, pesticides, and organic chlorine. It also pollutes a large area of land; in the Shenfu Petroleum Sewage Irrigation Area, the surface and bottom soil polycyclic aromatic hydrocarbons content exceeds 600mg/kg, causing serious pollution of crops and groundwater. There are 20 million hectares of land contaminated with heavy metals nationwide, of which more than 700,000 hectares are seriously contaminated, and 130,000 hectares of land are forced to abandon cultivation because of excessive cadmium content. Because of this, China's contaminated soil remediation research is undergoing a transition from laboratory research to practical stage, and is about to enter a period of rapid and comprehensive governance.