Plant extraction-agronomic regulation and control combined remediation method for alkalescent heavy metal contaminated farmland soil

Abstract

The invention relates to a plant extraction-agronomic regulation and control combined remediation method for alkalescent heavy metal contaminated farmland soil. According to the method, soil in a to-be-remediated area is pretreated; hyperaccumulation plants are planted once or multiple times until the soil heavy metal content in the to-be-remediated area meets a remediation target value; after thesoil is retreated, low-accumulation crops of target heavy metals are planted; edible parts are harvested after maturation, the content of heavy metals is detected, the crops can be edible or sold inthe market if meeting a standard, otherwise, harmless treatment is performed; and a plurality of low-accumulation crops are planted by adopting different agronomy regulation and control, and the low-accumulation crops with the edible parts meeting the standard are screened out for long-term planting in different seasons. According to the invention, the method has the advantages of synchronous achieving of restoration, production and earning, simplicity, high efficiency, high soil utilization rate, thorough restoration, long maintenance time, no potential risk, no influence on the structure andphysicochemical properties of soil, and realization of long-term planting of heavy metal low-accumulation crops meeting standards according to actual conditions in a time-sharing manner, so the quality and the yield of the crops are guaranteed.

Description

technical field [0001] The invention relates to the technical field of regeneration of polluted soil, in particular to a plant extraction-agronomic regulation combined restoration method for partial alkaline heavy metal polluted farmland soil. Background technique [0002] The environmental quality of farmland soil is related to the safe production of agricultural products and the safety, stability and productivity of farmland ecosystem. [0003] In the existing technology, from the perspective of technical approaches, the remediation of heavy metal pollution in farmland is generally divided into three remediation ideas, which are ways to remove the total amount of heavy metals, reduce the activity of heavy metals, and reduce the risk of heavy metals in the food chain. [0004] Commonly used farmland soil remediation technologies include passivation technology, agronomic regulation, phytoremediation, chemical leaching, etc. Among them, passivation technology is widely used ...

AI Technical Summary

Problems solved by technology

Among them, passivation technology is widely used because of its advantages of simple engineering operation, low cost, in-situ and ex-situ implementation, quick effect, and large-scale promotion. However, it cannot remove heavy metals in soil and only reduces its effective As time goes by, heavy metals after passivation may be reactivated, so there is a potential risk, and frequent addition of chemical passivators will affect the soil structure and physical and chemical properties, and affect the quality of crops and output

Chemical leaching technology is easy to destroy the physical structure and physical and chemical properties of soil, reduce soil fertility, and is not conducive to the growth of crops. The implementation is also relatively complicated. In some cases, there is a risk of secondary pollution by organic solvents.

Phytoremediation alone can completely remove heavy metals in the soil, but it is greatly affected by the environment, the restoration period is long, and land use is affected during the treatment period

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