1. Apply chemical amendments and take biological improvement measures to increase soil environmental capacity and enhance soil purification capabilities.
2. Strengthen environmental management and comprehensive prevention and control of contaminated soil, and vigorously develop cleaner production.
3. Regulate soil redox conditions: Regulate soil redox potential to convert some heavy metal pollutants into insoluble precipitates, control their migration and transformation, and reduce the harm of pollutants. Adjusting soil redox potential is mainly achieved by adjusting soil moisture management and farming practices.
4. Change the farming system and implement soil plowing and soil replacement: Changing the farming system will cause changes in soil environmental conditions and eliminate the hazards of certain pollutants. For severely polluted soil, remove the topsoil and replace it with soil; for lightly polluted soil, dig deep or replace it with non-polluted soil.
5. Adopt agro-ecological engineering measures: propagate non-edible seeds and grow cash crops on contaminated soil to reduce the way pollutants enter the food chain, or use certain animals, plants and microorganisms to quickly It absorbs or degrades pollutants in the soil to achieve the purpose of purifying the soil.
Because the same metal has different forms in the soil, its migration and transformation characteristics and pollution properties are also different. Therefore, when studying the hazards of heavy metals in the soil, not only their total content must be paid attention to, but also their total content must be paid attention to. Pay attention to the content of various forms.
Extended information:
Soil is made from weathered rocks. Different rocks contain various heavy metal elements. The chemical elements of the parent rock determine the initial chemical content in the soil. Affects the environmental background value of heavy metal elements in soil.
At the same time, the influencing factors of the parent rock in the formation of soil also affect the content of heavy metals in the soil. For example, quartz rocks with strong wind resistance control the content of heavy metals in the soil developed on them. However, carbonate rocks with weak wind resistance do not have a strong effect on controlling the content of heavy metals in the soil developed on them.
In soil, it is generally small and easily leached with water, and cannot be decomposed by soil microorganisms; on the contrary, organisms can enrich heavy metals, often causing heavy metals to gradually accumulate in the soil environment, and even some heavy metal elements in the soil It can also be converted into more toxic methyl compounds, and some can accumulate in the human body at harmful concentrations through the food chain, seriously endangering human health.
Compared with the pollution of water environment, the pollution of soil environment by heavy metals is more difficult to control. Pollution is more harmful.
Soil has a certain natural purification function. This feature should be fully utilized when regulating and preventing soil pollution, and effective measures should be taken to increase and improve the type and quantity of soil colloids and increase the adsorption of harmful substances by the soil. capacity and adsorption capacity, thereby reducing the activity of pollutants in the soil, enhancing the self-purification ability of the soil environment, and improving the capacity of the soil environment.
When the amount and speed of heavy metal pollutants input into the soil environment is not large or the soil is lightly polluted, taking corresponding measures to increase the capacity of the soil environment is important for preventing the occurrence of soil pollution or mitigating the impact of heavy metals on crops. Pollution hazards are effective.
Baidu Encyclopedia - Heavy metal pollution in soil