Farmland heavy metal contaminated soil passivator as well as preparation method and application thereof

Abstract

The invention provides a soil passivator, a preparation method thereof and application of the soil passivator in farmland heavy metal pollution remediation, and relates to farmland heavy metal pollution soil remediation. The passivator is prepared from the following raw materials: natural zeolite, ferrous sulfate and brucite, the use amount of the ferrous sulfate is 10%-50% of the mass of the natural zeolite, the use amount of the brucite is 10%-40% of the mass of the natural zeolite, and the passivator can be obtained by uniformly mixing all the components. The passivator nt is simple in preparation method, natural in raw material source, free of secondary pollution to soil and convenient to construct, farmland fallow is not needed during application, the passivator is applied in leisureseasons, and normal agricultural planting is not affected; the passivator provided by the invention is low in price and obvious in remediation effect, can effectively reduce the content of heavy metals in crops and the content of available heavy metals in soil, and has a good application prospect in the aspect of remediation of large-scale heavy metal contaminated farmlands.

Description

technical field [0001] The invention belongs to the technical field of contaminated soil remediation, and in particular relates to a passivator for farmland heavy metal polluted soil, a preparation method and application thereof. Background technique [0002] With the accelerated development of industrialization and urbanization, the pollution of heavy metals in cultivated soil in my country is becoming more and more serious. At present, heavy metal pollution in my country's farmland soil presents a trend of spreading from point to surface, from the periphery of large and medium-sized cities to rural areas in the outer suburbs, and the quality and safety of agricultural products are seriously threatened by heavy metal pollution. In southern acid rice regions, such as Hunan, Jiangxi, Hubei, Sichuan, Guangxi, Yunnan, Guangdong and other regions, heavy metal cadmium pollution in farmland soil is more common, especially in rice. The 2014 "National Soil Pollution Survey Bulletin...

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Problems solved by technology

Among these technologies, engineering measures are only suitable for small-area and heavily polluted soil remediation due to the large amount of engineering involved and high cost; for large-area farmland heavy metal pollution remediation not only requires a lot of manpower, material resources, high cost, but also easy Causes the weakening of farmland fertility and the destruction of the plow layer; although the agronomic control measures have the characteristics of simple operation, low cost and relatively mature technology, etc.

However, in the agronomic control measures, the adjustment of planting structure may make it difficult for farmers to accept; water management technology requires long-term flooding, which will have an adverse effect on crop rotation in dry season; currently, lime is mainly used to adjust the pH value of acidic soil. A series of negative effects, and the effect is generally low, and the operation is extremely inconvenient; phytoremediation technology is generally suitable for heavily polluted farmland with heavy metals, the repair effect is stable, the cost is low, and there is no secondary pollution, but the repair time is long, and the normal operation of crops is affected during the repair process. The government will not be able to afford a large amount of restoration compensation funds, and it will be difficult to promote the application in a large area and dispose of the restored plants; the passivation restoration technology has the advantages of fast restoration speed, good effect, strong stability, moderate price, and simple operation. It does not affect agricultural production, and can realize production while repairing, especially suitable for repairing large-scale medium-to-light heavy metal polluted farmland soil

At present, the situation of heavy metal pollution in farmland soil in my country is severe. Facing the status quo of heavy metal pollution in farmland with a wide range and large amount, and immature large-scale restoration and treatment technologies, in order to effectively solve the problems of soil pollution and food safety, it is urgent to develop high-efficiency solutions for heavy metal pollution in farmland. Economical, green and sustainable restoration and safe utilization technology

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