Technology for restoring heavy-metal polluted seedling-throwing planting rice field by using root system micro geochemical barrier technology

Abstract

The invention discloses a technology for restoring a heavy-metal polluted seedling-throwing planting rice field by using a root system micro geochemical barrier technology. The method comprises the following steps: (1) mixing rice field seedling raising soil with a heavy-metal repairing material, carrying out rest seedling growing processes according to a local cultivation system; and (2) adding the heavy-metal repairing material into farmland in processes of base fertilizer application and later-period topdressing, and carrying out cultivation in other farming processes according to local habits. In the technology, according to the characteristic that a root system absorbs substances in soil in a growth process of rice, a proper mineral material is selected to form chemical barriers on the periphery, so that the absorption effect of the root system is protected, and absorption of the root system to the pollutants is reduced or blocked. When the method is used to repair and treat a rice field polluted by cadmium and lead, the effective state of cadmium in the farmland can be reduced by 40%, and the repaired rice can reach a standard.

Description

technical field [0001] The invention relates to the field of remediation of heavy metal pollution, in particular to a process for repairing heavy metal pollution by throwing seedlings and planting paddy fields with root system micro-geochemical barrier technology. Background technique [0002] During the migration of elements, if the physical and chemical conditions of the environment change drastically, resulting in the decline of the migration ability of the elements that originally migrated stably in the medium, and the elements precipitate due to the formation of a large number of compounds, these conditions or factors that cause element precipitation are called for geochemical barriers. According to the principle of geochemical barrier, using the adsorption and absorption characteristics of mineral materials, heavy metal pollution in water and soil in environmental media can be treated, which is the application of geochemical barrier technology. [0003] Heavy metals s...

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Problems solved by technology

CN1058851002A discloses that a lead and cadmium barrier agent is sprayed on the leaves of rice at the tillering stage, heading stage, and filling stage respectively. The order of the enrichment and distribution of heavy metals in rice is root, stem, seed, and leaf. Ineffective in reducing lead and cadmium content in rice

[0005] In the past, heavy metal restoration projects in farmland were mostly broadcast directly in the field, which has four disadvantages: (1) The amount of materials used is large, and a lot of materials are broadcast into the soil layer far away from the rice root system. Although it can also repair the farmland, it is inevitable. Some waste; (2) increasing the labor of farmers, sowing in large fields is more labor-intensive, and the common people may not accept it; (3) The materials scattered in the field may be turned to the deep soil far away from the plowing layer with repeated plowing of the field (4) The amount of materials used is large, and the cost of repair is high. The common people cannot afford the cost, and the technology cannot be promoted smoothly.

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