Competitive-adsorption-based in-situ quick restoration method for cadmium-polluted paddy field

A technology of competitive adsorption and repair methods, applied in the field of in-situ repair of heavy metal-contaminated soil in environmental protection, can solve problems such as difficult treatment, high repair costs, follow-up risks, and large repair engineering, so as to improve soil quality and reduce soil repair costs , the effect of short repair cycle

Inactive Publication Date: 2015-09-02
TIANJIN POLYTECHNIC UNIV
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0006] The present invention aims at the problems of serious cadmium pollution in existing paddy fields, difficult treatment, large amount of restoration work, high restoration cost and subsequent risks, etc., and proposes that heavy metal cadmium ions in cadmium-polluted paddy fields are in-situ comple

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0018] Apply 0.01mol / L citric acid solution in cadmium-contaminated paddy fields (total cadmium content in soil is 3.1mg / kg), make the depth of tillage plate to water surface be 10cm, the amount of complexing agent added is 1000 mass of soil cadmium content times; use a tractor equipped with a rotary tiller to stir the soil and aqueous solution for 2 minutes to dissolve the heavy metals in the soil; 2 Put in the chelating nonwoven fabric with hydroxyl and carboxyl groups and move it continuously for 3 minutes to make it fully adsorbed, then take out the nonwoven fabric; carry out the next cycle, after 4 cycles, the cadmium content in the soil is 0.21mg / kg, reaching the soil Environmental quality standards, complete soil remediation.

Embodiment 2

[0020] Apply 0.05mol / L tartaric acid solution in cadmium-contaminated paddy fields (total cadmium content in soil is 1.4mg / kg), make the depth of the tillage plate to the water surface be 30cm, and add complexing agent for 800 mass times of soil cadmium content ;Use a tractor equipped with a rotary tiller to stir the soil and aqueous solution for 10 minutes to dissolve the heavy metals in the soil; 2 Put in the chelating functional non-woven fabric with amino and amide groups and move it continuously for 5 minutes to make it fully adsorbed, then take out the non-woven fabric; carry out the next cycle, after 3 cycles, the soil cadmium content is 0.25 mg / kg, reaching Soil environmental quality standards, complete soil remediation.

Embodiment 3

[0022] Apply 0.10mol / L malic acid solution in cadmium-contaminated paddy fields (total cadmium content in soil is 0.8mg / kg), make the depth of tillage plate to water surface be 25cm, the amount of adding complexing agent is 500 mass of soil cadmium content use a tractor equipped with a rotary tiller to stir the soil and aqueous solution for 30 minutes to dissolve the heavy metals in the soil; 2 Put in the chelating functional nonwoven fabric with thiourea group and move it continuously for 2 minutes to make it fully adsorbed, then take out the nonwoven fabric; carry out the next cycle, after 2 cycles, the cadmium content in the soil is 0.22 mg / kg, reaching the soil Environmental quality standards, complete soil remediation.

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Abstract

The invention relates to an in-situ quick restoration method for a cadmium-polluted paddy field. A complexing agent aqueous solution is sprayed into water in the cadmium-polluted paddy field; the rotary-tillage mixing is carried out; cadmium ions are dissolved out in the water in the paddy field in an in-situ complexing manner from polluted soil; chelate functional non-woven fabric with a stronger chelation action is quickly put into the paddy field and is constantly moved so that the chelate functional non-woven fabric is enabled to carry out competitive adsorption sufficiently; heavy-metal cadmium is transferred onto the non-woven fabric from a liquid-phase aqueous solution; afterwards, the non-woven fabric is taken out; a complexing agent is released and regenerated at the same time. The complexing agent which is environment-friendly and high-efficiency and is further economical and practical is selected and used for the in-situ quick restoration method for the cadmium-polluted paddy field, and cannot cause secondary pollution after being used. By using the in-situ quick restoration method for the cadmium-polluted paddy field, the heavy-metal cadmium in soil can be thoroughly removed, and the in-situ quick restoration method for the cadmium-polluted paddy field has the characteristics of simpleness in operation, low cost, high restoration effect, short restoration period and the like when being applied to the cadmium-polluted paddy field. The paddy field which is treated for one day by applying a technique provided by the invention can be carried out with agricultural planting. The invention provides an energy-saving, quick and environment-friendly in-situ restoration method for the soil in the paddy field which is polluted by the heavy-metal cadmium.

Description

technical field [0001] The invention relates to an in-situ rapid restoration of cadmium pollution in paddy fields, a method for thoroughly removing heavy metal cadmium in soil by using the principle of competitive adsorption, and realizing recycling and reuse of complexing agents, belonging to the technical field of in-situ restoration of heavy metal-contaminated soil in environmental protection . Background technique [0002] In recent years, with China's rapid industrialization and urbanization, a large amount of heavy metals have been discharged into the environment through various channels, which has increased the burden of heavy metals on the environment and caused serious soil heavy metal pollution problems. The "National Soil Pollution Survey Bulletin" shows that my country's soil is seriously polluted by heavy metals, with an exceeding rate of 13.3%, and the moderately and severely polluted cultivated land reaches about 50 million mu, and it is showing a growing tren...

Claims

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Application Information

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IPC IPC(8): B09C1/08
Inventor 魏俊富崔莉孔志云王会才赵孔银
Owner TIANJIN POLYTECHNIC UNIV
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