Process for restoring heavy metal contaminated soil/sludge through combining nanometer zero-valent iron with electromagnetic rake

A technology of nano-zero-valent iron and polluted soil, which is applied in the restoration of polluted soil, etc., to achieve the effect of simple structure, low cost and low energy consumption

Inactive Publication Date: 2012-06-20
TONGJI UNIV
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0007] The purpose of the present invention is to provide a nano-zero-valent iron-electromagnetic rake joint repair process for heavy metal-

Method used

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  • Process for restoring heavy metal contaminated soil/sludge through combining nanometer zero-valent iron with electromagnetic rake
  • Process for restoring heavy metal contaminated soil/sludge through combining nanometer zero-valent iron with electromagnetic rake
  • Process for restoring heavy metal contaminated soil/sludge through combining nanometer zero-valent iron with electromagnetic rake

Examples

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Embodiment 1

[0034] The soil was collected at a depth of 5-80cm in a certain place. The content of heavy metals (zinc, chromium, cadmium, lead, cobalt, nickel, copper) in the soil was between 5-150 mg / Kg, and the pH value was between 6.5-7.3. In this study, several soil samples with the same heavy metal content were designed. For several samples with the same conditions, the amount of nZVI was increased sequentially (1-20 kg), and the effect of nZVI on the removal rate of heavy metals in soil was investigated as the amount of nZVI increased. Variety. In order to make the experimental effect more obvious, heavy metal soil was spiked with a heavy metal concentration of 300-1800 mg / Kg, where the soil volume was 50-80 kg, the water volume was 100-400 L, and the nZVI volume was 1-20 kg. According to the technological process of this study, the water and the spiked soil were mixed for 10 h in the mixing reaction device, and the contents of heavy metals in the mixed liquid water and soil were res...

Embodiment 2

[0036] The soil is collected at a depth of 10-100cm in a certain place. The local content of heavy metals (zinc, lead, cobalt, nickel, copper) in the soil is between 3-100mg / Kg, and the pH value is between 6.8-7.5. This study is designed as a soil sample with a specific heavy metal content (500-1500mg / Kg), and the same amount of nZVI (2-20kg) is added to the sample in batches. Each time nZVI is added, after the reaction is sufficient, the heavy metals will be adsorbed. The separation of nZVI was used to determine the removal rate of heavy metals in soil. In order to make the experimental effect more obvious, the method of adding heavy metals to the soil was adopted, and the concentration of heavy metals was 500-1500 mg / Kg. Here, the amount of soil was 10-70 kg, and the volume of water was 100-500 L. According to the technological process of this study, the water and the spiked soil were mixed for 15 hours through the mixing reaction device, and the contents of heavy metals in ...

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Abstract

The invention relates to a process for restoring heavy metal contaminated soil/sludge through combining nanometer zero-valent iron (nZVI) with an electromagnetic rake. The specific procedures are as follows: soil/sludge to be treated and nanometer zero-valent iron are mixed intensively; a part of heavy metal in the soil/sludge is reduced by nZVI and the other part is adsorbed to the surface of the nZVI; after reaction, clean soil/sludge and the nZVI are separated through an electromagnetic rake device; and the electromagnetic rake adsorbs the nZVI through the acting force of a generated magnetic field, so that the nZVI can be fixed on a column of the electromagnetic rake to be separated effectively. Through the physical separation, changes to the physical chemical property of the soil/sludge are reduced during or after the process of removal. The process is simple to operate and obvious in effect; copper, nickel, zinc, cobalt, chromium, cadmium, lead and the like in soil can be removed at one time, and then heavy metal adsorbed on nZVI is reclaimed and separated through the electromagnetic rake. The process of restoring heavy metal contaminated soil/ sludge through the nZVI technology has the characteristics of low cost, high restoring efficiency and the like; and resources are reclaimed through the electromagnetic rake, so that secondary pollution is not caused.

Description

technical field [0001] The invention relates to the purification technology of soil / sludge polluted by heavy metals, in particular to a nanometer zero-valent iron-electromagnetic rake joint restoration process of heavy metal-contaminated soil / sludge. Background technique [0002] With the development of industry and the modernization of agricultural production, the problem of environmental pollution is becoming more and more serious, among which the problem of soil heavy metal pollution is very prominent. Since Wagner KH and Siddiqi I first published literature on soil heavy metal pollution in 1973, it has been more than 30 years of research. Soil is one of the main natural resources that human beings rely on for survival, and it is also an important part of the human ecological environment. However, as an open system, soil is exchanging material and energy with other elements in the environment every moment, and heavy metals enter the soil through atmospheric deposition, s...

Claims

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Application Information

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IPC IPC(8): B09C1/08
Inventor 张伟贤张亚雷
Owner TONGJI UNIV
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