Method for restoration of heavy metal-polluted soil in rice farmland

Abstract

The invention discloses a method for restoration of heavy metal-polluted soil in rice farmland, and belongs to the field of heavy metal treatment technologies of farmlands. The method includes the following steps: (1) preparing a reagent; (2) packing the reagent prepared in the step (1) into adsorption balls, and packing the adsorption balls into a chemical bag so as to obtain a heavy metal adsorption device; (3) burying the heavy metal adsorption device obtained in the step (2) into mud until being just buried when rice seedlings are planted; (4) recovering the reagent, and taking the heavy metal adsorption device out of the soil when rice is harvested; and (5) drying the adsorption reagent particles obtained in the step (4) in the sun until complete dryness so as to realize recycling ofwaste resources. A diatomaceous earth component is added to the reagent so that the reagent has a good adsorption effect, an in-situ restoration method is adopted, heavy metal can be separated from the farmland soil through the adsorption reagent particles, and the adsorption reagent particles along with crops can be taken out of the farmland soil in the crop harvest season, so that the problem ofhard treatment of heavy metal-polluted farmland soil is solved, and the original organic structure of the soil is not damaged.

Description

technical field [0001] The invention belongs to the technical field of heavy metal treatment in farmland, and in particular relates to a method for repairing heavy metal pollution in rice farmland. Background technique [0002] Existing chemical remediation technologies mainly include 1. Ex-situ chemical leaching method - for soil heavily polluted by heavy metals in farmland, the soil is dug out first, and then the heavy metals are removed by large-scale spray chemical washing methods, and then the soil is backfilled in situ , this method involves high cost due to transportation and other methods, and the original organic matter structure of the soil will be destroyed after the soil is chemically washed, which will greatly change the properties of the farmland soil. 2. In-situ solidification / passivation method - the use of solidification passivation materials for heavy metal pollutants in farmland can reduce the activity of heavy metals in the soil, without affecting the gro...

AI Technical Summary

Problems solved by technology

[0002] Existing chemical remediation technologies mainly include 1. Ex-situ chemical leaching method - for soil heavily polluted by heavy metals in farmland, the soil is dug out first, and then the heavy metals are removed by large-scale spray chemical washing methods, and then the soil is backfilled in situ , this method involves high cost due to transportation and other methods, and the original organic matter structure of the soil will be destroyed after the soil is chemically washed, which will greatly change the properties of the farmland soil

2. In-situ solidification / passivation method - the use of solidification passivation materials for heavy metal pollutants in farmland can reduce the activity of heavy metals in the soil, without affecting the growth of crops or making the heavy metal residues in the fruits of agricultural products lower than the national standards. This method does not reduce the heavy metal content in the soil, and changes with time, climate, and geographical conditions, and may re-change the form of heavy metal ions and affect the growth of subsequent crops and food security.

Images