Microbial restoration method for heavy metal polluted soil

Abstract

The invention relates to the technical field of soil pollution treatment and especially provides a microbial restoration method for heavy metal polluted soil. In the method, the planting mode for plants for restoration of the heavy metal polluted soil is completely changed, wherein the plants for restoration are not pre-cultured in a greenhouse and can be directly planted into the heavy metal polluted soil; the method is free of requirement on concentration of heavy metal ions in the soil and greatly reduces planting difficulty. Heavy metal ions in the lower layer are effectively isolated by covering an asbestos fiber fabric to form an isolation layer; microorganisms are added to soil to reduce the content of metal ions in soil; the soil is watered and then is covered with a film to complex and settle the metal ions; finally, an absorption layer of attapulgite powder can absorb the metal ions for preventing secondary pollution.

Description

technical field [0001] The invention relates to the technical field of soil pollution control, in particular to a method for microbial remediation of heavy metal polluted soil. Background technique [0002] With the continuous development of the global economy, soil heavy metal pollution has become a major problem facing the global environmental quality. Human activities (mineral mining, metal smelting, domestic wastewater discharge, use of chemical fertilizers and pesticides, etc.) have greatly accelerated the production of heavy metals on the earth. The chemical cycle makes the heavy metals in the environment continuously increase, which increases the harm of heavy metals to human health. When heavy metals entering the environment exceed their capacity in the environment, heavy metal pollution can occur. Heavy metal pollutants are persistent pollutants, and the harm to the environment and human body is difficult to eliminate. Heavy metals have the characteristics of stro...

AI Technical Summary

Problems solved by technology

[0004] The above heavy metal repair techniques all have a certain effect on heavy metal repair, but they also have their own shortcomings in practical applications.

Phytoremediation technology has limited types of plants for remediation, and its repair speed is slow, and the retreatment of plants that accumulate a large amount of heavy metals is also the main factor that limits the large-scale promotion of phytoremediation technology; microbial remediation technology generally only adsorbs a single heavy metal. The effect is good, and because the microbial organisms are small, the amount of heavy metals repaired is also small, so this also limits the application of using microorganisms for large-scale on-site repair; the electrodynamic repair technology is still in the experimental research stage, and due to different soil Different physical and chemical properties also have a series of limiting factors in practical application; soil leaching technology is complex and expensive;

[0005] Taking phytoremediation as an example, the existing methods mostly use greenhouses to pre-cultivate the repaired plants. After the seeds grow and develop into seedlings, they are then transplanted to heavy metal-contaminated plots for soil remediation. The cost of transplanting has increased significantly, and it is difficult to achieve mass production. Phytoremediation is currently in the state of experimentation or small-scale trial planting, which is far from idealized restoration

If the seeds are directly sown in heavy metal-contaminated soil, the seeds are difficult to germinate and the germination rate is extremely low. Even if some seeds germinate, the plants are difficult to grow. Because the seeds do not really grow up in the environment of heavy metal ions, it is difficult to exert the heavy metal absorption effect.