Physical remediation technology refers to the use of physical characteristics of pollutants and soil itself to fix pollutants in the soil and prevent them from migrating and spreading in the soil. By this method, the damage of heavy metals to the ecological environment can be reduced. Physical remediation technology also includes a series of methods such as microwave heating, desorption and steam leaching. However, the cost of ex-situ repair or in-situ repair is extremely high, which can not directly eliminate the pollution source, and simply deal with non-point source pollution can not achieve the real restoration purpose.

2. Chemical remediation technology

Chemical remediation technology includes curing, passivation, leaching and other methods. Compared with physical remediation technology, it has higher efficiency and faster remediation speed, but a lot of chemicals and substances need to be put into the remediation process, which will cause serious damage to the soil structure, and the use of chemicals also greatly increases the remediation cost. At the same time, the excessive use of a large number of chemicals restricts soil remediation, and microorganisms in the soil cannot be metabolized, which will destroy the growth of crops and may also cause secondary pollution of the soil.

3. Bioremediation technology

Bioremediation technology, natural attenuation and phytoremediation technology will not destroy the organic matter in the soil, with low cost and little change in soil structure. However, bioremediation technology has great limitations in the application process. Deep soil remediation is difficult and easily affected by climate factors, which will make the remediation cycle of crops in soil longer, and it is more suitable for soils with low heavy metal pollution and large pollution range and area.

4. Joint repair technology

China has always attached great importance to the remediation of heavy metals in farmland, and all departments will work together to increase the intensity of remediation. Remediation of soil heavy metal pollution is a long-term work, but there are many problems in theoretical research and practice, which should be combined with other disciplines to learn from each other's strengths.