A method for repairing heavy metal polluted soil by pressure filtration and leaching

A technology for polluted soil and heavy metals, applied in the field of environmental remediation, can solve the problems of excessive heavy metal indexes and excessive heavy metal indexes of soil leaching toxicity, and achieve the effects of increasing the reaction concentration and reducing the amount of eluent

Inactive Publication Date: 2017-11-10
HUNAN MUKUN ENVIRONMENTAL PROTECTION
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0006] Aiming at the defects existing in the existing soil leaching repair technology, the present invention aims to provide a method for pressure filtration leaching and repairing of heavy metal contaminated soil, which can effectively solve the problem that the leaching liquid remains in the prior art leaching process. In the soil, the soil leaching toxicity heavy metal index exceeds the standard. Further, the present invention can solve the problem that when the free heavy metal in the residual soil is converted into a solid phase with a stabilizer after leaching, the tiny particles produced enter into the leaching toxicity detection. The liquid phase leads to the problem that the heavy metal index exceeds the standard

Method used

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  • A method for repairing heavy metal polluted soil by pressure filtration and leaching
  • A method for repairing heavy metal polluted soil by pressure filtration and leaching
  • A method for repairing heavy metal polluted soil by pressure filtration and leaching

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Embodiment 1

[0029] A method for repairing heavy metal-contaminated soil by pressure filtration and leaching, comprising the following steps:

[0030] (1) Crushing and screening: Based on the soil of a Pb-contaminated waste site, the total Pb concentration is 3.075 mg / g, the contaminated soil is sent to the crusher for crushing, and then enters the screening system for two-stage screening. Separation of impurities and large-grained stones in the soil to obtain 300kg of sieved soil;

[0031] (2) Slurry reaction: Slurry the sieved soil at a solid-to-liquid ratio of 1:4, and stir and react with 0.7mol / L hydrochloric acid for 30 minutes to fully react the acid-soluble heavy metals in the soil;

[0032] (3) Press filter leaching: put the fully reacted slurry into the filter press reactor for filtration, then pump 350L of clear water into the filter press reactor, and let the clear water wash away the remaining residue in the capillary pores of the soil filter cake. The acid solution is replace...

Embodiment 2

[0036] A method for repairing heavy metal-contaminated soil by pressure filtration and leaching, comprising the following steps:

[0037] (1) Crushing and screening: Based on the soil of a Pb-contaminated waste site, the total Pb concentration is 3.075 mg / g, the contaminated soil is sent to the crusher for crushing, and then enters the screening system for two-stage screening. Separating the impurities and large-grained stones in the soil to obtain 250kg of sieved soil;

[0038](2) Slurry reaction: Slurry the sieved soil at a solid-to-liquid ratio of 1:3, and stir and react with 1mol / L hydrochloric acid for 30 minutes to fully react the acid-soluble heavy metals in the soil;

[0039] (3) Press filter leaching: put the fully reacted slurry into the filter press reactor for filtration, then pump 750L of clear water into the filter press reactor, and let the clear water wash away the remaining residue in the capillary pores of the soil filter cake. The acid solution is replaced ...

Embodiment 3

[0043] A method for repairing heavy metal-contaminated soil by pressure filtration and leaching, comprising the following steps:

[0044] (1) Crushing and screening: Based on the soil of a Pb-contaminated waste site, the total Pb concentration is 3.075 mg / g, the contaminated soil is sent to the crusher for crushing, and then enters the screening system for two-stage screening. Separation of impurities and large-grained stones in the soil to obtain 400kg of sieved soil;

[0045] (2) Slurry reaction: Slurry the sieved soil at a solid-to-liquid ratio of 1:5, and stir and react with 0.1mol / L hydrochloric acid for 30 minutes to fully react the acid-soluble heavy metals in the soil;

[0046] (3) Press filter leaching: put the fully reacted slurry into the filter press reactor for filtration, then pump 400L of clear water into the filter press reactor, and let the clear water wash away the remaining residue in the capillary pores of the soil filter cake. The acid solution is replace...

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Abstract

The invention discloses a method for repairing heavy metal polluted soil by pressure filtration and leaching. The restoration method includes the following steps: S1, crushing and screening the heavy metal-contaminated soil; S2, pulping the crushed and screened soil, and adding acid to fully react with acid-soluble heavy metals in the soil; S3 The above-mentioned fully reacted slurry is subjected to pressure filtration, and the residual acid solution in the capillary pores of the soil filter cake is replaced and diluted by clear water; Heavy metals are fully reacted; S5 puts synergists into the filter press reactor to stabilize the free heavy metals remaining in the soil, and at the same time migrates the tiny heavy metal particles formed during the stabilization process out of the soil, and the filter cake is passed through clean water Rinse, so that the heavy metal ions or compounds or complexes remaining in the filter cake can be further fully washed out with the water flow, and the repaired soil can be obtained. The invention solves the problem in the prior art that the leaching solution remains in the soil during the leaching process and the index of toxic heavy metals leached from the soil exceeds the standard.

Description

technical field [0001] The invention relates to a method for repairing heavy metal polluted soil by pressure filtration and leaching, and belongs to the field of environmental restoration. Background technique [0002] With the rapid development of my country's economy, resource-based minerals have been exploited rapidly, and mining, metallurgy, and chemical companies have launched one after another. Due to relatively backward environmental protection measures and inadequate supervision, the pollution of industrial sites and surrounding soil and groundwater has become increasingly serious. A series of environmental pollution incidents; at the same time, with the acceleration of urbanization and people's increasing sensitivity to environmental pollution, the restoration and reuse of heavy metal-contaminated soil has become one of the most urgent environmental issues. Due to the characteristics of long-term, concealment and irreversibility of heavy metal pollution, it will dire...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): B09C1/02
Inventor 刘闺华张光文罗波盛国军江幸马雪林
Owner HUNAN MUKUN ENVIRONMENTAL PROTECTION
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