Method for restoring heavy metal pollution of vegetable field soil with in-situ passivation method

Abstract

The invention provides a method for restoring heavy metal pollution of vegetable field soil with an in-situ passivation method. The method comprises the step of applying sepiolite and monocalcium phosphate in the vegetable field soil to be restored according to the proportions of 3-9 percent and 0.25 percent of the dry soil according to the specific pollution condition and mixing evenly the sepiolite and monocalcium. The invention reasonably uses passivation materials of sepiolite and monocalcium, remarkably reduces the bioavailability and transferability of the soil heavy metal by reactions of absorption, complexation and precipitation, and the like between the sepiolite and monocalcium and the heavy metal element, simultaneously improves the self-cleaning capacity of the soil, improves the soil fertility condition so as to produce high-quality and high-yield vegetables and restore the ecological function and industrial function of the vegetable field soil. The invention has the advantages of wide material source, simple use method, low cost, favorable restoring effect, wide application range, no secondary pollution and favorable ecological benefits and economical benefits.

Description

Technical field [0001] The invention relates to a treatment technology for soil heavy metal pollution, in particular to a method for in-situ passivation and restoration of vegetable soil heavy metal pollution. Background technique [0002] my country is a major vegetable producer and consumer in the world, with a vegetable planting area of ​​more than 17 million hectares and a total output of more than 500 million tons, making it the world's third largest vegetable exporter. However, due to the high multiple cropping index, the large input of pesticides and fertilizers, and most of them are distributed in the suburbs, which are greatly affected by urban industrialization pollution, the heavy metal pollution of my country's vegetable fields is becoming more and more serious. Investigations have shown that Cd pollution in vegetable soils in my country is relatively serious, with a Cd content exceeding the standard rate of 24.1%. More than 10,000 hectares of vegetable plots in the ...

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Problems solved by technology

The restoration ability of natural clay minerals is limited, and to achieve a better restoration effect, the amount of application is often large, resulting in high treatment costs, and the practicability is affected to a certain extent; although modification measures such as acid treatment, heat treatment, and ion exchange can improve its restoration. Efficiency, but these measures often lead to higher costs and are difficult to promote and apply on a large scale

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