A kind of heavy metal polluted soil remediation method

A technology of polluted soil and remediation method, applied in the field of heavy metal contaminated soil remediation, can solve the problems of complicated operation steps, large energy consumption, etc., and achieve the effects of large specific surface area, increased soil organic carbon content, and strong adsorption capacity

Inactive Publication Date: 2021-03-09
山东省鲁南地质工程勘察院(山东省地质矿产勘查开发局第二地质大队)
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  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

This method also has the effect of reducing heavy metals in the soil, but there are some problems in it. Taking out the soil for ex-situ treatment, high-pressure washing and screening is accompanied by huge energy consumption. At the same time, the separation system is multi-gradient sorting, and the operation steps are cumbersome.

Method used

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  • A kind of heavy metal polluted soil remediation method
  • A kind of heavy metal polluted soil remediation method
  • A kind of heavy metal polluted soil remediation method

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0047] A preparation method of modified magnetic biochar, comprising the steps of:

[0048] (1) After crushing 50g of peanut shell biochar raw material to a particle size of 2-5mm, soak it in 1L 50mM FeSO 4 . 7H 2 O solution, shake at room temperature for 12h and filter to obtain solid raw material;

[0049] (2) drying the solid raw material obtained in step (1) at 60°C, and then pyrolyzing it at 600°C for 1.5 hours to obtain magnetic biochar;

[0050] (3) Prepare magnetic biochar-supported Ca-Al hydrotalcite adsorbent by hydrothermal method: 0.03mol Ca(NO 3 ) 2 , 0.01mol Al(NO 3 ) 3 9H 2 O was dissolved in 50mL of water, and 5g of the magnetic biochar prepared in step (2) was added, mixed well and set aside; then, under stirring conditions, a mixture containing 0.01mol NaOH and 0.02mol NaOH was added to the above mixed solution 2 CO 3 20mL mixed aqueous solution, and hydrothermally reacted at 140°C for 4h, after the reaction was completed, filtered, washed, and dried...

Embodiment 2

[0055] In order to investigate the effect of different reaction times, weigh 200g of soil that has passed through a 2mm mesh sieve, and pour it into a 1L beaker. Add 400mL of deionized water at a water-to-soil ratio of 2:1. After standing still for 1 h, 6 g of the modified magnetic biochar prepared in Example 1 was added at 1% of the soil mass, stirred for 30 min, and two parallel experiments were set up. After standing for 12h, 24h, 36h and 48h respectively, the magnetic biochar with adsorbed Cd was reclaimed with a magnet, and the removal rate of total cadmium in the measurement and calculation soil was as follows: image 3 shown.

[0056] The effect of different dosages, weigh 3 parts of 200g soil that has passed through a 2mm mesh sieve, and pour it into a 1L beaker. Add 400mL of deionized water at a water-to-soil ratio of 2:1. After standing still for 1h, add 1g, 2g and 4g of modified magnetic biochar (prepared in Example 1) respectively in the beaker with 0.5%, 1% and...

Embodiment 3

[0058] The air-dried soil passed through a 2mm sieve was subjected to particle size classification, the content of Cd in different particle sizes was measured, and the distribution of Cd content in different particle sizes was calculated. Clay particle size <0.002mm, powder particle size 0.002-0.02mm, sand particle size 0.02-2mm.

[0059] like Figure 5 As shown, the content of Cd in clay, silt and sand is 1.83, 1.42, 0.69mg / kg respectively, and it can be seen that the Cd concentration in clay is the highest. Therefore, removing a small part of clay can make the total amount of soil Cd reach reduction effect.

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Abstract

The invention discloses a method for remediating heavy metal polluted soil, which comprises the following steps: water is poured into the soil, and then 0.5-2% of modified magnetic biochar is put into the soil according to the mass of the soil, and the modified magnetic biochar is fully stirred evenly to make the modified magnetic biochar and soil It is in a mixed state of mud and water. After standing still, add water and stir to make the modified magnetic biochar float out of the water, and then recover the magnetic biochar enriched in free Cd and soil clay particles, so as to achieve the purpose of reducing the total Cd in the soil. With the help of the magnetic and floating properties of the modified magnetic biochar, the invention enriches free Cd and soil particles with high Cd concentration, reduces the amount of Cd in the soil, and at the same time, the application of the modified magnetic biochar can also improve the soil . The modified magnetic biochar prepared by the invention has the ability to float, can be recovered by magnetic force, has simple restoration process, strong operability, and is green and environment-friendly, and is an environment-friendly restoration technology.

Description

technical field [0001] The invention relates to the technical field of soil pollution remediation for environmental protection, in particular to a method for remediating heavy metal polluted soil. Background technique [0002] In heavy metal pollution, cadmium (Cd) is one of the most potentially harmful metal pollutants to human health. In 2014, the Ministry of Environmental Protection and the Ministry of Land and Resources published the "Soil Pollution Investigation Bulletin". Point exceeding the standard rate as high as 7%. Therefore, it is urgent to remediate Cd-contaminated soil and reduce soil Cd. [0003] At present, there are many remediation methods for soil Cd reduction, such as phytoremediation technology and chemical leaching technology, and each method has its own advantages and disadvantages. Phytoremediation technology is environmentally safe and has economic advantages. However, most hyperaccumulator plants are small in size, slow in growth, and difficult to...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): B09C1/00
CPCB09C1/00B09C2101/00
Inventor 宋炳忠卢国宏薄怀志李传夏赵付平
Owner 山东省鲁南地质工程勘察院(山东省地质矿产勘查开发局第二地质大队)
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