CN-121972132-A - Iron modified activated carbon composite material for promoting heavy metal repair and preparation method thereof

Abstract

The invention relates to the technical field of preparation of active carbon composite materials, and discloses an iron modified active carbon composite material for promoting heavy metal repair and a preparation method thereof. The method comprises the following steps of (1) preprocessing raw materials to obtain preprocessed materials, (2) adding the preprocessed materials into ferric chloride solution, stirring for 2h at 150rpm, performing ultrasonic oscillation and dispersion for 30min to obtain suspension, transferring the suspension into an oven, drying to constant weight at 60 ℃ to obtain an intermediate, and (3) grinding, sieving, transferring the intermediate into a muffle furnace for pyrolysis treatment and naturally cooling. The biochar obtained by the invention has a complex internal pore structure and is sufficient for providing sites for the adsorption or combination of pollutants. Wherein, the iron modification reduces the specific surface area and pore volume of the biochar material, improves the average pore diameter, and adds iron element to improve the pH value of the modified biochar, thereby enhancing the adsorption capacity to metal cations (such as cadmium and lead).

Inventors

• FANG PING
• LIU JIAZHEN
• ZHU ZIYU
• JI XIONGHUI
• Xie yunhe
• WU JIAMEI
• LU YAOXIONG

Assignees

• 湖南省耕地与农业环境生态研究所
• 同济大学

Dates

Publication Date

20260505

Application Date

20260123

Claims (5)

1. 1. The preparation method of the iron modified activated carbon composite material for promoting heavy metal repair is characterized by comprising the following steps of: (1) Pretreating the raw materials to obtain pretreated materials; (2) Adding the pretreated material into ferric chloride solution, stirring for 2 hours at 150rpm, performing ultrasonic oscillation and dispersion for 30 minutes to obtain suspension, transferring into an oven, and drying to constant weight at 60 ℃ to obtain an intermediate; (3) Grinding, sieving, transferring to a muffle furnace for pyrolysis treatment, and naturally cooling.
2. 2. The method of claim 1, wherein in step (1), the pretreatment is cleaning, drying, crushing, grinding and sieving of the raw material.
3. 3. A method according to claim 1 or 2, wherein in step (2) the mass fraction of elemental iron in the ferric chloride solution is 5%.
4. 4. The method according to claim 1 or 2, wherein in the step (3), the condition of the pyrolysis treatment is satisfied that the temperature rise rate is 5-10 ℃ per minute, the temperature is uniformly raised to 550 ℃ within 150min, and the temperature is kept for 240min.
5. 5. An iron-modified activated carbon composite material for promoting heavy metal repair, prepared by the method of any one of claims 1 to 4.

Description

Iron modified activated carbon composite material for promoting heavy metal repair and preparation method thereof Technical Field The invention relates to the technical field of preparation of active carbon composite materials, in particular to an iron modified active carbon composite material for promoting heavy metal repair and a preparation method thereof. Background The soil area polluted by the heavy metals in China is wider, the pollution problem is serious, wherein the pollution of cadmium is particularly prominent, and the first national soil pollution condition investigation (2005-2013) shows that the total exceeding rate of the heavy metal pollutants in the soil reaches 16.1 percent, and the primary inorganic pollutant is cadmium. Cadmium and cadmium compounds are classified as a class of carcinogens, cadmium exposure being associated with osteoporosis, nephrotoxicity, neurotoxicity, carcinogenicity, genotoxicity, teratogenicity, endocrine, and reproductive negative effects. Ecological risks associated with the deleterious effects of cadmium on organisms include inhibition of plant and soil animal growth, degradation of soil microflora, irreversible adverse effects on land ecosystems, and the like. Therefore, it is urgent to develop an effective soil remediation technology. Currently, common soil remediation methods include chemical precipitation, physical removal, bioremediation, and the like. However, these methods have some limitations such as high cost, unstable treatment effect, and risk of secondary pollution to the soil environment. Soil amendments are commonly used to reduce metal concentrations in plants, improve crop production safety, and may also have positive effects in soil remediation processes contaminated with heavy metals such as cadmium. In contrast, activated carbon shows great potential in heavy metal removal due to its superior adsorption performance and good stability. Disclosure of Invention The invention aims to solve the problem that common biochar has few adsorption or binding sites for heavy metal pollutants. In order to achieve the above object, a first aspect of the present invention provides a method for preparing an iron-modified activated carbon composite material for promoting heavy metal repair, the method comprising the steps of: (1) Pretreating the raw materials to obtain pretreated materials; (2) Adding the pretreated material into ferric chloride solution, stirring for 2 hours at 150rpm, performing ultrasonic oscillation and dispersion for 30 minutes to obtain suspension, transferring into an oven, and drying to constant weight at 60 ℃ to obtain an intermediate; (3) Grinding, sieving, transferring to a muffle furnace for pyrolysis treatment, and naturally cooling. Preferably, in the step (1), the pretreatment is to clean, dry, crush, grind and screen the raw materials. Further preferably, in the step (2), the mass fraction of the iron element in the ferric chloride solution is 5%. Preferably, in the step (3), the pyrolysis treatment condition is satisfied that the heating rate is 5-10 ℃ per min, the temperature is uniformly increased to 550 ℃ within 150min, and the temperature is kept for 240min. In a second aspect, the invention provides an iron modified activated carbon composite material for promoting heavy metal repair, which is prepared by the method in the first aspect. The iron modified activated carbon composite material for promoting heavy metal repair and the preparation method thereof have the following beneficial effects: (1) The method provided by the invention overcomes the defects of the existing method for preparing the activated carbon by taking the straw and the biogas residue as raw materials, the used biogas residue and straw are environment-friendly raw materials, the cost is lower, and the collection and pretreatment methods are simple and convenient to apply. (2) The biochar obtained by the method provided by the invention has a complex internal pore structure and is sufficient for providing sites for the adsorption or combination of pollutants. Wherein, the iron modification reduces the specific surface area and pore volume of the biochar material, improves the average pore diameter, and adds iron element to improve the pH value of the modified biochar, thereby enhancing the adsorption capacity to metal cations (such as cadmium and lead). Therefore, the method provided by the invention can be applied to the field of absorption and removal of heavy metal cadmium in soil, and has better application potential. Additional features and advantages of the invention will be set forth in the detailed description which follows. Drawings FIG. 1 is a scanning electron microscope test chart of activated carbon obtained in examples of the present invention and comparative examples; FIG. 2 is a chart showing Fourier IR spectrum test of activated carbon obtained in examples and comparative examples of the present invention. Detailed Description The en