Passivating agent and repairing method for in situ repairing of heavy metal cadmium in soil

Abstract

The invention discloses a passivating agent and a repairing method for in situ repairing of heavy metal cadmium in soil. The raw materials of the passivating agent comprise biochar, treated bacterium residues and modified sepiolite. The raw materials of the passivating agent have sufficient sources, and the process flow meets production requirements of enterprises, so preparation of a large amount of the passivating agent can be ensured. The passivating agent can significantly inhibit the activity of heavy metal cadmium in farmland soil and reduce the content of heavy metal cadmium in the edible parts of agricultural products, can be applied to the in situ passivation repairing of medium-light cadmium polluted farmlands at a large scale, and has a broad application prospect in the field of improvement of the safety productivity of medium-light cadmium polluted farmlands s.

Description

technical field [0001] The invention relates to the field of agricultural environmental pollution prevention and control and repair, in particular to a passivator and a repair method for in-situ repair of heavy metal cadmium in soil. Background technique [0002] According to the "National Soil Pollution Survey Bulletin" published in 2014, the total exceeding rate of soil pollutants in mainland China is as high as 16.1%, and the rate of exceeding the standard in cultivated land soil points is as high as 19.4%, and the pollutant types are mainly heavy metals. Crops can absorb heavy metals in the soil and transport them to edible parts, and then accumulate in the human body through the food chain. When the accumulation exceeds the safety threshold, it will cause harm to human health. It can be seen that soil heavy metal pollution has become a major obstacle restricting agricultural production safety. [0003] The seriousness of heavy metal pollution in farmland soil has also ...

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Problems solved by technology

However, the current research on soil heavy metal passivation materials still has the following obstacles: First, the current research mostly focuses on the passivation effect of the original material itself, although some modified materials have been developed and their passivation effect on heavy metals has been verified. Higher than the original material, but the preparation process applied is still in the small-scale development of the laboratory, not suitable for factory production

The second is that the passivation effect of a single passivation method on heavy metal ions is limited, and the current research focuses on a single passivation material, and there are few studies on the passivation effect of heavy metals on composite passivation materials with complementary functions.

The third is that the current research is mostly focused on potted plants and simulation experiments, and the results of field experiments are still relatively lacking. However, the original intention of the research and development of heavy metal passivators is the remediation of heavy metal soil in the field, and even field experiments should be used as the most important indicator for testing the passivation effect.

[0005] Therefore, the existing farmland heavy metal pollution remediation technology has problems such as complex preparation process, environmental pollution during production process, unsuitable for factory production, and limited passivation effect on heavy metal ions.

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