Method for repairing cadmium-contaminated soil through rice

Abstract

The invention discloses a method for repairing cadmium-contaminated soil through rice by means of water management and application. The method comprises the steps of 1, determining the time for the beginning of water management; 2, taking specific measures for water management. According to the method, the content of Cd at the overground parts of rice and rice grains is increased, and thus the effect of repairing the cadmium-contaminated soil is achieved. Due to water management, the redox potential of the soil changes, and thus the movability and bio-availability of Cd in the soil can be lowered. In the meanwhile, the water management cost is low, the operation is simple, batch treatment is easy to achieve, and large-scale application and popularization are facilitated.

Description

technical field [0001] The invention relates to the field of soil pollution control, in particular to a method for repairing cadmium-contaminated soil by using rice. Background technique [0002] With the continuous development of my country's industry and urbanization, the problem of soil heavy metal pollution caused by atmospheric deposition, sewage irrigation, use of agricultural materials, and solid waste stacking and disposal has become increasingly serious. In 2014, the "National Soil Pollution Survey Bulletin" jointly issued by the Ministry of Land and Resources and the Ministry of Environmental Protection showed that the quality of China's cultivated land soil environment is not optimistic, with a rate of 19.4% of points exceeding the standard, of which cadmium exceeded the rate of 7.0%. Heavy metal pollution will cause changes in the composition, structure and function of soil, and at the same time hinder the growth of crop roots and photosynthesis. The enrichment o...

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Problems solved by technology

[0007] The methods in the above reports have a certain effect on the remediation of cadmium-contaminated soil, but from the perspective of practical scope, implementation effect, secondary pollution risk and cost, there are still some defects in the above or similar reports: such as remediation Most of the biochars are industrial wastes with complex components, high processing costs, and the risk of secondary pollution. It is difficult to promote and apply them on a large scale. The field restoration and application of biochar consumes a lot, and the complex modification will undoubtedly increase the corresponding restoration costs.

In addition, alkaline substances can easily cause soil compaction and damage the physical and chemical properties of the soil.

Phytoremediation takes a long time

It is difficult to restore deep pollution, and the growth of plants is restricted due to climate and geological factors

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