Contaminated soil passivator and preparation method and application thereof

Abstract

The invention relates to a contaminated soil passivator and a preparation method and application thereof. The passivator is formed by mixing the following raw materials in percentage by weight: 30-60 percent of a natural clay mineral material, 30-60 percent of industrial harmless wastes and 10-20 percent of a cation-exchanger, wherein the cation-exchanger refers to an X-type molecular sieve or a molecular sieve with the particle size of more than 4A. Compared with the prior art, the passivator disclosed by the invention is completely prepared from the natural clay mineral material and a mineral-like material, the cost is low, secondary pollution is avoided, the environment friendliness idea is completely achieved, the pulverized fuel ash and other industrial wastes are introduced, the problems such as waste storage and treatment are solved, and the passivator has good passivation effect and high long-term stability on the contaminated soil, particularly heavy metal contaminated soil, and is suitable for large-scale popularization and application.

Description

technical field [0001] The invention belongs to the technical field of environmental protection and relates to the passivation or harmless treatment of polluted soil, in particular to a polluted soil passivator and its preparation method and application. Background technique [0002] In recent years, due to the frequent occurrence of major environmental events such as cadmium rice, blood lead, and cancer villages, the problem of heavy metal pollution in soil and groundwater has attracted more and more attention. From the perspective of the formation process and mechanism of heavy metal-contaminated soil, the process of eradicating pollution must be long-term and gradual. Therefore, it is urgent to develop a treatment method that is efficient, environmentally friendly, and cost-effective. [0003] The solidification / stabilization repair technology has been widely used in Europe and the United States because of its advantages such as wide application range, short processing ti...

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Problems solved by technology

[0005] In the past five years, plant methods and biological methods have gradually been sought after by researchers, but research on soil heavy metal pollution stabilization or passivation technology has gradually decreased, and there are not many related patents. The Chinese patent with publication number CN101805617A discloses a The heavy metal passivator for facility vegetable field soil and the preparation method thereof are as follows: 10%-30% of medical stone powder, 10%-30% of diatomite powder, 10%-20% of zeolite powder, and 20%-20% of lignite powder. 30% and 25% to 35% fly ash passivation agent can achieve the passivation of heavy metals in the soil of vegetable fields and reduce the content of heavy metals available in soil crops, but the passivation agent has poor adsorption and exchange performance for heavy metals , the processing effect is poor

Chinese Patent Publication No. CN101045599A has invented a method of using lime-modified fly ash adsorbent to passivate the high content of zinc and copper in dewatered municipal sludge, and the passivation rate of heavy metal copper and zinc in sludge can be achieved. Up to 85% and 70%, but the preparation process of the above-mentioned adsorbent is complicated, and the temperature of 30-80 ° C is required for the treatment at the same time, and the requirements for the use environment are relatively high

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