CN102974603A - Method for improving heavy metal contaminated soil by adopting combination of red mud and liquid film - Google Patents

Abstract

The invention relates to a method for improving heavy metal contaminated soil by adopting combination of red mud and a liquid film. The method is characterized by comprising the concrete steps of mixing the red mud with the liquid film, applying the mixture into the heavy metal contaminated soil, wherein the mass ratio of the red mud to the liquid film is 5-10% for repairing the heavy metal contaminated soil; simultaneously keeping the moisture content of the soil at 4-5% during the period of crop growth, and keeping the pH of the soil at 6.7-6.9. The concentration of chromium ions is obviously reduced after repairing by adopting the method disclosed by the invention, and the heavy metal contaminated soil is effectively processed.

Description

Method for the improvement of heavy metal polluted soil by combined use of red mud and liquid mulch

technical field

The invention relates to the combined use of red mud and liquid plastic film to improve heavy metal-polluted soil. Specifically, solid waste red mud and liquid plastic film are used in combination according to a certain ratio to achieve the removal of heavy metal chromium in soil.

Background technique

With the acceleration of urbanization, the physical and chemical properties of the soil have deteriorated. At the same time, a large amount of solid waste generated by urbanization is mostly disposed of in general landfills, causing serious pollution to the soil. Improper mining of mineral resources has exposed a large number of abandoned mining sites, polluted farmland through water flow and other channels, and also caused the heavy metal content in the soil to seriously exceed the standard. Red mud is a kind of solid waste generated during the production process of alumina plant. It not only occupies land, pollutes the environment, but also causes groundwater pollution and waste of resources. The comprehensive utilization of red mud is a very important and urgent problem to be solved. Liquid mulch film is a degradable black liquid mulch film. The liquid mulch film not only has the effects of plastic mulch film on increasing temperature, preserving moisture, and preserving seedlings, but also has strong adhesion ability, which can connect soil particles into ideal aggregates. Combining red mud with existing liquid mulch can be used for early mulching of crops in arid and cold hilly areas. Another use is for saline-alkali remediation of sandy land, wasteland, tidal flats, etc. It can also be used for road construction On the slope protection, we are committed to studying whether the combination of red mud and the existing liquid plastic film can not only maintain the functions of the original plastic plastic film to increase temperature, keep moisture, and protect seedlings, but also integrate the advantages of liquid plastic plastic film to increase the temperature difference between day and night and be degradable. The polluted land enables the use of a large area of land that cannot grow crops due to heavy metal pollution, increasing the area of crop operations.

Contents of the invention

Purpose of the invention:

The invention relates to a method for compounding red mud and liquid plastic film to improve heavy metal-polluted soil. The purpose is to use red mud and liquid plastic film in combination to degrade heavy metal chromium in the soil. By changing the composite ratio of red mud and liquid plastic film , thereby improving its degradation of pollutants.

Technical solutions:

A method for compounding red mud and liquid mulch to improve heavy metal-contaminated soil, characterized in that: the specific steps are as follows:

Mix red mud with liquid mulch and apply it to heavy metal-contaminated soil. The mass ratio of red mud to liquid mulch is 5% to 10%, which is used to remediate heavy metal-contaminated soil; at the same time, keep the water content of the soil at 4-5%, the pH of the soil is maintained at 6.7-6.9.

The mass ratio of the red mud applied to the soil to the liquid plastic film is 8%.

Advantages and effects:

The present invention proposes a method for compounding red mud and liquid mulch to improve heavy metal polluted soil, which has the following advantages:

1. Waste utilization of red mud: Red mud is a kind of solid waste generated during the production process of alumina plants. It not only occupies land, pollutes the environment, but also causes groundwater pollution and waste of resources. The comprehensive utilization of red mud is a very important and urgent problem to be solved.

2. The use of liquid plastic film: Liquid plastic film not only maintains the functions of the original plastic film to increase temperature, preserve moisture, and protect seedlings, but also has the advantages of increasing the temperature difference between day and night and being degradable.

3. The mixed use of red mud and liquid mulch can effectively treat the land polluted by heavy metals, make use of a large area of land that cannot be planted with crops due to heavy metal pollution, and increase the area of crop operations.

Detailed ways:

The present invention will be further described below in conjunction with specific examples, but the protection scope of the present invention is not limited by the examples.

A method for compounding red mud and liquid mulch to improve heavy metal-contaminated soil, characterized in that: the specific steps are as follows:

Mix red mud with liquid mulch and apply it to heavy metal-contaminated soil. The mass ratio of red mud to liquid mulch is 5% to 10%, which is used to remediate heavy metal-contaminated soil; at the same time, keep the water content of the soil at 4-5%, the pH of the soil is maintained at 6.7-6.9.

The mass ratio of the red mud applied to the soil to the liquid plastic film is 8%.

Put red mud and liquid mulch into the soil polluted by heavy metals in proportion and plant crops, measure the heavy metal content in the soil before planting and one month or two months after planting, observe the growth of crops, and judge the relationship between red mud and liquid mulch based on the results obtained from the experiment Remediation effect of mixed use of mulch film on heavy metal polluted soil. The concentration of chromium ion is 100mg/kg~150mg/kg, and the mass ratio of red mud and liquid plastic film is 5%~10%.

1 1.5kg soil + 210mg potassium dichromate + 10g red mud + 100ml liquid film + cabbage 2 1.5kg soil + 150mg potassium dichromate + 10g red mud + 100ml liquid film + cabbage 3 1.5kg soil + 210mg potassium dichromate + 20g red mud + 100ml liquid mulch + cabbage 4 1.5kg soil + 150mg potassium dichromate + 20g red mud + 100ml liquid mulch + cabbage

The above table is the addition of various qualities in the potted soil, while keeping the water content of the soil at 4-5% and the pH of the soil at about 6.7-6.9 during the crop growth period.

Example 1:

Mix red mud with liquid mulch and apply it to heavy metal-contaminated soil. The mass ratio of red mud to liquid mulch is 5% and 10%, which is used to remediate heavy metal-contaminated soil; at the same time, keep the water content of the soil at 4%, the pH of the soil was kept at 6.7.

The combined addition of red mud and liquid plastic film had an obvious beneficial effect on reducing the content of chromium ions in the soil. In the potted crop of Chinese cabbage, the concentration of heavy metals is 150 mg/kg, and the ratios of red mud and liquid plastic film are 5% and 10%, respectively. Adding a ratio of 10% is better than adding a ratio of 5%.

Example 2:

Mix red mud with liquid mulch and apply it to heavy metal-contaminated soil. The mass ratio of red mud to liquid mulch is 5% and 10%, which is used to remediate heavy metal-contaminated soil; at the same time, keep the water content of the soil at 5%, the pH of the soil was kept at 6.9.

The combined addition of red mud and liquid plastic film had an obvious beneficial effect on reducing the content of chromium ions in the soil. In the potted plant of Chinese cabbage, the concentration of heavy metals is 100 mg/kg, and the ratios of red mud and liquid plastic film are 5% and 10%, respectively. Adding a ratio of 5% is better than adding a ratio of 10%.

Example 3:

Mix red mud with liquid mulch and apply it to heavy metal-contaminated soil. The mass ratio of red mud to liquid mulch is 8%, which is used to repair heavy metal-contaminated soil; at the same time, keep the soil moisture at 5% during crop growth. The pH of the soil was maintained at 6.9.

The combined addition of red mud and liquid plastic film had an obvious beneficial effect on reducing the content of chromium ions in the soil. In the potted crop of Chinese cabbage, the concentration of heavy metals is 100 mg/kg, and the ratio of red mud to liquid plastic film is 8%, the decrease of chromium ion concentration is better than 5% and 10%.

Conclusion: By adopting the method of improving heavy metal-contaminated soil by using red mud and liquid mulch in combination with the present invention, the concentration of chromium ions decreases significantly, and the land polluted by heavy metals is effectively treated, so that a large area of land that cannot be planted with crops due to heavy metal pollution It can be used to increase the crop operation area.

Claims (2)

1. a red mud and liquid-state mulch film compound use are to the method for heavy metal pollution soil improvement, and it is characterized in that: concrete steps are as follows:

Red mud is mixed with liquid-state mulch film, impose in the heavy-metal contaminated soil, the mass ratio of red mud and liquid-state mulch film is 5% ~ 10%, is used for making the heavy-metal contaminated soil reparation; During plant growth, keep simultaneously soil water content at 4-5%, the pH of soil remains on 6.7-6.9.

2. press red mud claimed in claim 1 and liquid-state mulch film compound use to the method for heavy metal pollution soil improvement, it is characterized in that: imposing on the red mud of soil and the mass ratio of liquid-state mulch film is 8%.