Method for restoring soil polluted by heavy metal cadmium by using mesquite

Abstract

The invention discloses a method for restoring soil polluted by heavy metal cadmium by using mesquite, comprising the following steps: 1) planting cassia alata plants on the soil polluted by the heavy metal cadmium; and 2) adding ethylenediamine tetraacetic acid into the soil as a fortifier while planting the cassia alata plants. The test results show that: the cassia alata has higher anti-cadmium ability and is suitable to be planted at cadmium polluted areas; while ethylenediamine tetraacetic acid can intensify the restoring function of the cassia alata, the more the amount of the ethylenediamine tetraacetic acid is added in the soil, the more cadmium is enriched within the cassia alata.

Description

technical field [0001] The invention relates to the field of soil pollution control, and more specifically, the invention relates to a method for repairing soil polluted by heavy metal cadmium by using leguminous shrubs. Background technique [0002] Soil is an important natural resource for the survival and development of human society. However, with the rapid development of industry and agriculture and the intensification of urbanization, the pollution of soil environment in my country is becoming more and more serious. Among them, soil heavy metal pollution is a hot issue of global concern. At present, the area of ​​cultivated land polluted by heavy metals in my country is nearly 2×10 7 m 2 , accounting for about 1 / 5 of the total arable land area, resulting in an annual grain production reduction of 1×10 7 Many tons, the food polluted by heavy metals reaches 1.2×10 every year 7 tons, the annual economic loss is at least 2×10 7 Yuan. Heavy metal elements are generally...

AI Technical Summary

Problems solved by technology

However, chelating agents such as EDTA are not easy to degrade in the environment, and their presence in the soil will seriously affect the growth and development of non-remediation plants; in addition, their solubilization and flow-enhancing effects on substances in the soil will lead to the degradation of target heavy metals and other non-target metals. After activation, it transfers to deep soil or groundwater, causing secondary pollution of soil or water environment and increasing the difficulty of restoration; moreover, since most chelating agents are non-specific in binding to metal elements, they activate heavy metals at the same time It also activates other trace elements in the soil, such as Fe, Mn, Ca, Mg, etc., which increases the leaching loss of these elements, which may lead to plant nutrient deficiency, which is very unfavorable to plant growth

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