Cadmium-contaminated soil modifier and preparation method thereof and improvement method for cadmium-contaminated soil

Abstract

The invention discloses a cadmium-contaminated soil modifier and a preparation method thereof and an improvement method for the cadmium-contaminated soil. The cadmium-contaminated soil modifier is prepared from the following raw materials in percentage by weight: 1 to 7 percent of polyaluminum chloride, 3 to 28 percent of ferric sulfate, 7 to 28 percent of calcium hydrogen phosphate, 35 to 85 percent of citric acid, 2 to 15 percent of polyacrylamide and 0.5 to 8 percent of L-proline. The invention also discloses the preparation method of the cadmium-contaminated soil modifier and the improvement method for the cadmium-contaminated soil. According to the cadmium-contaminated soil modifier and the preparation method thereof and the improvement method for the cadmium-contaminated soil, disclosed by the invention, the prepared modifier has the characteristics of surface adsorption, surface complexation and the like; the migration and effectiveness of cadmium in heavy metal contaminated soil can be significantly reduced, the absorption of the cadmium by plants is reduced, the physiological resistance of crops is improved, structure and properties of the soil are improved and the uniformity of soil microbes is improved; the cadmium-contaminated soil modifier is especially suitable for calcareous soil. The modifier has the advantages of easiness in raw material obtaining, low cost andsimple preparation; the improvement method for the cadmium-contaminated soil is simple and stable in effect.

Description

Technical field [0001] The invention belongs to the technical field of soil remediation, and specifically relates to a cadmium contaminated soil amendment and a preparation method thereof and a cadmium contaminated soil improvement method. Background technique [0002] In recent years, my country's heavy metal pollution has shown an increasing trend, and soil heavy metal pollution poses a serious threat to the ecological environment, food safety and human health. Among them, cadmium (Cd) has non-degradable and long-lasting pollution to the environment, and it is difficult to reduce the amount naturally from the environment. my country is about 2.0×10 7 hm 2 Cultivated land has been polluted by heavy metals, of which the area of ​​farmland contaminated by cadmium amounts to 2.8×10 5 hm 2 . [0003] Common repair methods include engineering physical technology, chemical passivation technology and bioremediation technology. Among them, the physical remediation technology is only sui...

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Problems solved by technology

[0004] Now the method of chemical remediation is widely used in soil cadmium treatment. There is a chemical fixative for cadmium and lead contaminated soil remediation in the prior art. Not strong

In the prior art, there is a passivating agent for controlling the pollution of vegetable fields, which is mainly used for the chemical remediation of cadmium pollution in southern acidic soils, and is not suitable for calcareous soils

There is a cadmium-contaminated soil improver in the prior art, which is beneficial to reduce the absorption of heavy metals by crops. The effect of the improver is different under different soil textures, and the repair effect is unstable.

There is also a chemical remediation agent for cadmium pollution in farmland soil in the prior art, which is suitable for calcareous farmland soil. The remediation agent is applied into the soil along with the soil plowing, and is not suitable for drip irrigation of farmland.

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