Bionic remediation method for heavy metal contaminated soil

A technology of polluted soil and remediation method, which is applied in the restoration of polluted soil, etc., can solve the problems of heavy burden, low efficiency, and long time consumption of waste biological disposal, and achieve the goal of less waste residue generation, less reagent consumption, and less damage Effect

Inactive Publication Date: 2018-11-06
TIANJIN UNIVERSITY OF TECHNOLOGY
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0007] However, the problem with the bioremediation method is that since heavy metals are not biological components ((so far, no living organisms have been found to use heavy metals as their main nutritional components, mostly foreign matter!), this limits the amount that the organisms per unit mass can fix. The amount of heavy metals, so "direct" bioremediation is not only time-consuming and inefficient, but also the disposal burden of waste biomass containing heavy metals is too heavy

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0025] Weigh 1g of copper-contaminated soil, wherein the copper content is 34.6mg. Under stirring at 20°C, first add 25 mL of an aqueous solution containing 2% citric acid. Afterwards, adjust the pH of the mixed system to 3-4, wash and soak for 24 hours under stirring. Then, let it stand, and filter and separate the soil and the copper-containing supernatant washing solution. After that, 25 mL of aqueous solution containing 2% citric acid was added for secondary soaking and extraction. Then, let it stand, and filter and separate the soil and the copper-containing supernatant washing solution again. After testing, the residual copper content in the soil after treatment is less than 30mg / kg. After treatment, the soil was adjusted to pH 6-7 with dipotassium hydrogen phosphate solution, and returned to the field.

[0026] At 5-10°C, add 0.13g of ferric nitrate and 0.8g of potassium dihydrogen phosphate to the copper-containing upper washing solution, and adjust the pH to 6-7 w...

Embodiment 2

[0028] Weigh 1g of nickel-contaminated soil, which contains 22.9mg of nickel. Add 30 mL of an aqueous solution containing 1% tartaric acid at 50°C under stirring, then adjust the pH of the system to 4-5, wash and soak for 24 hours while stirring. Then, let it stand, and filter and separate the soil and the nickel-containing supernatant washing solution. After testing, the residual nickel content in the soil after treatment is less than 20mg / kg. The soil was adjusted to pH 6-7 with potassium bicarbonate solution.

[0029] At ~15°C, add 3.9g of ferric sulfate and 0.05g of calcium phosphate to the nickel-containing upper washing liquid, and adjust the pH to 8~9 with sodium carbonate. After standing still, after filtering and separating the nickel-containing precipitate and the upper water phase, the residual nickel content in the water phase was detected to be 0.1mg / L. After the water phase is supplemented with a small amount of nitric acid to pH 4-5, it is recycled for washin...

Embodiment 3

[0031] Weigh 1g of copper-contaminated soil, wherein the copper content is 34.6mg. Under stirring at 40°C, 20 mL of an aqueous solution containing 2.5% potassium sodium tartrate was added. Afterwards, adjust the pH of the mixed system to 5-6, wash and soak for 24 hours under stirring. Then, let it stand, filter and separate the soil and the upper copper-containing washing solution. After testing, the residual copper content in the soil after treatment is less than 30mg / kg. The soil was adjusted to pH 6-7 with ammonium carbonate solution.

[0032]At ~40°C, add 0.2g of ferrous sulfate heptahydrate and 0.5g of phosphoric acid to the copper-containing washing solution on the upper layer, and adjust the pH to 7~8 with calcium oxide. After standing still, the copper-containing precipitate and the upper water phase were separated by filtration, and the residual copper content in the water phase was detected to be 0.05 mg / L. After the aqueous phase is supplemented with a small amo...

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Abstract

The invention discloses a bionic remediation method for heavy metal contaminated soil. The bionic remediation method for the heavy metal contaminated soil comprises the following steps: adequately washing the heavy metal contaminated soil by virtue of an aqueous solution containing a natural coordination agent at a certain temperature and under a certain pH condition; after the content of heavy metals in the soil reaches the standard or the content of the heavy metals in the washing solution does not continue to be increased any more, separating the soil from an upper-layer washing solution containing the heavy metals; then adding an iron-containing reagent, a calcium-containing reagent, a phosphorus-containing reagent and / or carbonate into the upper-layer washing solution containing the heavy metals at a certain temperature and under a certain pH condition, standing and precipitating, and then separating precipitates containing the heavy metals to be removed, from an upper-layer waterphase; and carrying out pH value conditioning and supplementing an appropriate amount of the coordination agent for the upper-layer water phase, and then cyclically using the upper-layer water phasefor washing for the soil. The method for carrying out bionic remediation on the heavy metal contaminated soil under an approximately natural condition reserves the advantage of environment friendliness of biological remediation, and reduces the time needed for the soil remediation. Moreover, compared with plant remediation, a waste amount after the soil remediation can be greatly reduced.

Description

【Technical field】 [0001] The invention belongs to the field of remediation of soil polluted by heavy metals or treatment of other solid wastes containing heavy metals in the environmental protection / treatment technology. In particular, a biomimetic restoration technology for heavy metal-contaminated soil is an environmentally friendly restoration method. 【Background technique】 [0002] Soil is an important natural resource for human survival and development. With the rapid development of metal processing industry, electroplating industry, machinery manufacturing industry, leather industry and textile industry and other industrial fields, more and more heavy metal pollutants enter the soil, causing heavy metal pollution in the soil. Non-degradable heavy metals seriously inhibit the normal growth of crops and endanger human health through the food chain. [0003] The remediation ideas of heavy metal-contaminated soil can be summarized into two categories: one is to change th...

Claims

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Application Information

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Patent Type & AuthorityApplications(China)
IPC IPC(8): B09C1/08
CPCB09C1/08
Inventor孙波裴晓芳万钧吴新世张春雪
OwnerTIANJIN UNIVERSITY OF TECHNOLOGY