Ecological blanket for fixing heavy metal and method of removing heavy metal in soil through combination of ecological blanket and phytoremediation

Abstract

The invention relates to the technical field of regeneration of contaminated soil, in particular to an ecological blanket for fixing heavy metal and a method of removing heavy metal in soil through the combination of the ecological blanket and phytoremediation, and provides the ecological blanket for fixing heavy metal and the method of removing heavy metal in soil through the combination of the ecological blanket and phytoremediation. The ecological blanket comprises a modified zeolite middle layer, an inner permeable geotextile layer and an outer permeable geotextile layer, wherein the innerpermeable geotextile layer and the outer permeable geotextile layer wrap the zeolite middle layer. The ecological blanket is buried below the surface soil of farmland contaminated by heavy metal, hyperaccumulators are planted on the surface soil, heavy soil ions are promoted to downwards transfer along with solutions in the irrigation process, and finally remediation of the soil contaminated by heavy metal is achieved through removal of the ecological blanket and harvesting of the hyperaccumulators. The ecological blanket and the method achieve the effective combination effect of a chemical fixation method-phytoremediation technology, and are high in efficiency of removing lead, zinc and cadmium in soil.

Description

technical field [0001] The invention relates to the technical field of regeneration of polluted soil, in particular to an ecological blanket for immobilizing heavy metals and a method for removing soil heavy metals in combination with phytoremediation. Background technique [0002] Soil heavy metal pollution has the characteristics of long-term, hysteresis, and accumulation. It can enter the food chain through various channels to accumulate and amplify, and then threaten human health. The heavy metal pollution of farmland soil in my country is complex and the scope of pollution is wide. It is urgent to develop a repair method with simple operation, fast effect and low cost. [0003] At present, the common methods of treating heavy metal-contaminated soil include: engineering treatment methods, such as foreign soil, soil replacement, etc.; physical restoration methods, such as electrothermal restoration method, vitrification technology, electric restoration technology, etc.; ...

AI Technical Summary

Problems solved by technology

[0004] However, chemical fixation and phytoremediation still have some disadvantages

The chemical fixation method can only passivate heavy metals, but cannot remove them from the soil. The fixation effect of the modifier on heavy metals will be affected by soil environmental factors, such as soil moisture, pH, soil type, heavy metal type, etc. When these factors change When, the solidified heavy metals may be reactivated or transformed, resulting in secondary pollution

Phytoremediation has the disadvantages of long repair time and low biomass, and the repair period for heavy metal-contaminated soil is too long, so it has not been widely used

However, the chemical fixation method can passivate the heavy metals in the rhizosphere soil of plants, and inhibit the absorption of heavy metals by hyperaccumulative plants to a certain extent. Therefore, the combination of chemical fixation and phytoremediation often fails to achieve the combined effect.

At present, there are no literature reports on the combination of the two to achieve the desired effect

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