A carbon-based composite material for remediation of arsenic and cadmium contaminated soil and its application

A technology for cadmium-contaminated soil and composite materials, applied in the field of carbon-based composite materials, to achieve stable performance, improve the effect of reducing soil total nitrogen or alkaline nitrogen content, and increase N element content

Active Publication Date: 2020-03-27
INST OF SOIL & FERTILIZER ANHUI ACAD OF AGRI SCI
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

The main technical problems to be solved by the present invention include: being able to effectively reduce the activity of anion As and cation Cd in heavy metal complex polluted soil at the same time, increase soil organic matter and available potassium and other nutrient content, without causing soil acidification or large total nitrogen and alkaline nitrogen content issues such as reduced

Method used

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  • A carbon-based composite material for remediation of arsenic and cadmium contaminated soil and its application
  • A carbon-based composite material for remediation of arsenic and cadmium contaminated soil and its application
  • A carbon-based composite material for remediation of arsenic and cadmium contaminated soil and its application

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0029] Prepare carbon-based composite material of the present invention

[0030] (1) Chop the wheat straw into small pieces of about 4 cm, wash and air-dry naturally, put it into a vacuum tube furnace for pyrolysis, the final temperature of pyrolysis is 400°C, keep it warm for 1.5h, take it out, and let it cool naturally to room temperature. The obtained straw biochar is passed through a 0.5mm sieve;

[0031] (2) Accurately weigh 16.16g of analytically pure Fe (NO 3 ) 3 9H 2 Add O reagent to a glass beaker, add 100mL deionized water to dissolve completely, stir evenly, and obtain a 0.4mol / L iron salt solution;

[0032] (3) Weigh 10g of sieved biochar, add it to the prepared iron salt solution, and place it on a magnetic stirrer to stir continuously. At this time, the pH value of the solution is about 1.7-1.9, and then add 5mol / L NaOH solution, so that the final pH value is stable at 7.00±0.02, and stand at room temperature for 24h;

[0033] (4) Use a vacuum filter bottle ...

Embodiment 2

[0036] Adsorption performance of carbon-based composites on As and Cd in water

[0037] Weigh 0.10 g of the carbon-based composite material prepared above into a 50 mL centrifuge tube, add 40 mL of As(III) or Cd simulated wastewater solution with an initial concentration of 1, 5, and 10 mg / L, respectively, and add 0.01 mol / L NaNO 3 The solution is used as a supporting electrolyte, and the pH of the solution is 0.01mol / L NaOH or HNO 3 The solution was adjusted to 5.8±0.2, shaken at room temperature for 24 hours, and after centrifugal filtration, the concentrations of arsenic and cadmium in the supernatant were measured. The results show that the carbon-based composite material prepared by the present invention has a good removal effect on As and Cd in water, and the removal efficiency is 92.1%-98.4% and 96.0%-97.1%, respectively, and the maximum adsorption capacity can be reached within 4 hours More than 95% of the adsorption reaction is relatively rapid. Through model fittin...

Embodiment 3

[0039] Remediation of Arsenic and Cadmium Contaminated Soil by Carbon-Based Composite Materials

[0040] As and Cd composite polluted soil was collected near the mining area, in which the Cd content of the soil was 31.3 times that of the national soil environmental quality secondary standard (GB 15618-2008), and the As content exceeded the standard by 1.3 times. Set the addition amount of carbon-based composite materials to 1% (w / w), which is approximately equivalent to 22.5t / hm of field application amount 2 . The soil and the carbon-based composite material were fully mixed and placed in plastic pots, sealed with plastic film, and a number of small holes were made to ensure the free circulation of air inside and outside the pot. Add deionized water regularly to keep the water content at 70% of the maximum field water holding capacity of the soil, and cultivate at room temperature for 30 days.

[0041] The results showed (Table 1) that after applying carbon-based composite m...

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Abstract

The invention discloses a carbon-based composite material for repairing arsenic and cadmium polluted soil and its application. The carbon-based composite material of the present invention uses crop straw as a raw material, prepares biochar by carbonization, and then mixes it with an iron salt solution at a certain solid-to-liquid ratio. composite material. The carbon-based composite material prepared by the present invention is applied on arsenic-cadmium complex polluted soil, combined with plowing, watering and other methods, can significantly reduce the content of effective arsenic and cadmium, and transform the arsenic and cadmium in the soil to a direction with less biological toxicity and mobility, It can also improve soil physical and chemical properties to a certain extent, and is suitable for application on various types of soil. The arsenic and cadmium ions in water can also be effectively removed, and the preparation process has simple operation steps, wide sources of materials, low production cost and environmental friendliness.

Description

technical field [0001] The invention relates to the field of remediation of soil polluted by heavy metals, in particular to a carbon-based composite material used for remediation of soil contaminated by arsenic and cadmium and an application thereof. Background technique [0002] Due to its high carcinogenicity and genotoxicity to humans, As is listed as a priority pollutant by WHO. In South and Southeast Asia, groundwater As pollution caused by geochemical effects has led to chronic As poisoning of millions of people, becoming the most serious environmental disaster in human history. Fertilizer and pesticide application, pesticide production, coal combustion and long-term mining and metallurgy activities will all cause As pollution. Long-term chronic arsenic poisoning in the human body can lead to serious diseases such as liver cancer and skin cancer, accompanied by teratogenic and mutagenic effects. Cd is also one of the most toxic heavy metals to humans. Cd entering th...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): B01J20/20B01J20/06B01J20/30C02F1/28B09C1/08C09K17/16C02F101/10C02F101/20
CPCB01J20/06B01J20/20B09C1/08C02F1/281C02F1/283C02F2101/103C02F2101/20C09K17/16
Inventor 吴萍萍李录久李敏
Owner INST OF SOIL & FERTILIZER ANHUI ACAD OF AGRI SCI
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