Method for reducing effective cadmium content of soil

Abstract

The invention discloses a method for reducing effective cadmium content of soil. The method provided by the invention is characterized in that a passivator of meerschaum powder of 60 meshes is applied to farmland polluted by cadmium; a utilization amount equation of the passivator of the meerschaum powder of 60 meshes is determined according to effective cadmium content of soil; and a utilizationmethod of the passivator of the meerschaum powder comprises 1, removing crop straws of the farmland or crushing the crop straws, 2, uniformly scattering the passivator of the meerschaum powder of 60 meshes on the surface of soil of the farmland by an artificial method or a mechanical method, 3, mechanically turning the soil at least twice for uniform mixing, wherein a soil turning depth is in a range of 15 to 20 centimeters, and in application, it is guaranteed that wind power is below a level of 2 to 3 or the meerschaum powder do not be blown away, and 4, sowing crops and then carrying out irrigation 2 to 3 times under the condition that a normal demand amount of agricultural production water is satisfied, wherein quality of the agricultural production water for the irrigation satisfies a farmland irrigation water quality standard and an irrigation method is aopted. The method for reducing effective cadmium content of soil has the advantages of wide application scope, low cost, simple operation, no influence on agricultural production and environmental benefits, can be utilized for effective treatment on farmland which has a large area of a cadmium-polluted part, can reduce the content of cadmium which can be absorbed by crops, and can prevent penetration of effective cadmium of the soil into agricultural products.

Description

technical field [0001] The invention relates to the technical field of repairing and controlling soil heavy metal pollution, in particular to a method for reducing the content of available cadmium in soil. Background technique [0002] At present, there are two main ways to remediate and control soil heavy metal pollution at home and abroad: one is to change the form of heavy metals in the soil to fix them, reducing their mobility and bioavailability in the environment; the other is to remove heavy metals from the soil. . Around these two approaches, various treatment methods such as physical restoration, chemical restoration, biological restoration and ecological restoration have been proposed. Such as: alien soil method, electrochemical method, leaching method, phytoremediation, microbial remediation and ecological utilization measures, etc. In fact, according to the characteristics of heavy metal pollution in different soils, in the process of selecting appropriate reme...

AI Technical Summary

Problems solved by technology

Since the principle of passivation technology is to use passivating agents to fix soil active cadmium to reduce its activity, and there are certain differences in soil available cadmium content, the method of determining the dosage according to the percentage of soil weight is subject to certain restrictions in technology promotion. constraints

[0004] Second, there is no detailed and complete elaboration on the dosing method of the passivator, later operation and maintenance, and the number of dosing, and there is no systematic investigation of the effect of the passivator on the physical and chemical properties of the soil.

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