Improving agent of soil polluted by Si/Fe composite cadmium and preparation and application method of improving agent

Abstract

The invention discloses an improving agent of soil polluted by Si / Fe composite cadmium and a preparation and application method of the improving agent. The method comprises the following specific steps: (1) mixing Fe(NO3)3 and NaOH solution to prepare a modifier; (2) taking purified diatomite and a modifier solution, uniformly mixing, and stirring to form a muddy state; (3) baking a mixture to obtain the improving agent of the soil polluted by the Si / Fe composite cadmium. The improving agent disclosed by the invention has the beneficial effects that after the improving agent is applied into the soil polluted by cadmium according to applying amount, the content of exchangeable cadmium in the soil can be reduced by 37.5%, the water content is increased by 58.2%, and organic matters and a pHvalue are not greatly changed; the cadmium pollution to the soil can be effectively controlled, meanwhile the stability of basic physicochemical properties such as the pH value and organic matters ofthe soil can be maintained, the raw materials are low-cost and easy to obtain, the process is simple, the cost is lower, and no secondary pollution is caused.

Description

technical field [0001] The invention relates to the field of cadmium-contaminated soil improver and its preparation, in particular to a Si / Fe composite cadmium-contaminated soil improver and its preparation and application method. Background technique [0002] Soil is one of the important resources for human survival, but with the advancement of industrialization, soil cadmium pollution is becoming more and more serious. According to relevant research in recent years, there are different degrees of cadmium pollution problems in all parts of my country. At present, my country's soil cadmium pollution involves 25 regions in 11 provinces and cities. For example, the average content of cadmium in polluted soil in Antbang area of ​​Shanghai is 21.48 mg / kg, and the content of cadmium in soil in old sewage irrigation areas in the suburbs of Guangzhou is as high as 228.0 mg / kg. Most of the cadmium pollution in farmland soil in my country is caused by the sewage irrigation of indus...

AI Technical Summary

Problems solved by technology

The present invention is to study the restoration of cadmium-contaminated soil with diatomite loaded with hydroxyl iron. Diatomite is a clay mineral with a huge specific surface area and numerous pores, but the natural diatomite has no effect on the control of soil heavy metal pollution. Obviously, the modification of diatomite is an inevitable trend to deal with heavy metal pollution

Hydroxyl iron and diatomaceous earth can control heavy metal-contaminated soil to a certain extent when used alone, but the physical and chemical structure of diatomite has defects, and hydroxyl iron has the disadvantages of being easily oxidized and agglomerated when used alone

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