CN111871361A

CN111871361A - Environment repairing material and preparation method and application thereof

Info

Publication number: CN111871361A
Application number: CN202010705246.4A
Authority: CN
Inventors: 罗琳; 彭逸喆; 杨�远; 罗双; 彭克俭
Original assignee: Hunan Agricultural University
Current assignee: Hunan Agricultural University
Priority date: 2020-07-21
Filing date: 2020-07-21
Publication date: 2020-11-03
Anticipated expiration: 2040-07-21
Also published as: CN111871361B

Abstract

The invention relates to the technical field of wastewater treatment, and discloses an environment restoration material, and a preparation method and application thereof. The method for preparing the environment repairing material comprises the following steps: (1) drying and crushing the red mud to obtain dry red mud powder; (2) mixing the dry red mud powder with water to obtain a red mud aqueous solution A, mixing the red mud aqueous solution A with an iron salt solution to obtain a mixed solution B, and mixing the mixed solution B with an alkali solution to obtain an environment repairing material III; wherein the iron salt solution contains iron ions and ferrous ions. The environment restoration material provided by the invention has the advantages of high stability, strong removal capability on target pollutants, simple preparation method, low cost, energy conservation and environmental protection.

Description

Environment repairing material and preparation method and application thereof

Technical Field

The invention relates to the technical field of wastewater treatment, and particularly relates to an environment restoration material and a preparation method and application thereof.

Background

Heavy metals are toxic substances causing environmental pollution, and once entering water or soil, the heavy metals are difficult to remove, and even cause permanent pollution. The diffusion and utilization of heavy metal polluted water sources seriously affect the health and safety of people, so the treatment of heavy metal pollution becomes an environmental and social problem which is urgently needed to be solved in China at present.

At present, the treatment method of the wastewater containing heavy metals mainly comprises a chemical precipitation method, an ion exchange method, a reverse osmosis method, an electrolysis method, a membrane separation method, an adsorption method, an electrochemical method and a microbiological method, and the adsorption method becomes one of the most promising treatment methods due to the advantages of high efficiency, economy, simple and convenient operation, easy regeneration and the like. The adsorbent is the core of the adsorption method, and the ideal adsorbent has the advantages of high adsorption capacity, strong surface reaction activity, high adsorption efficiency, simple and convenient operation, easy recovery, no secondary pollution, low cost and environmental protection. At present, various adsorbing materials for removing heavy metal ions in water bodies are researched and developed at home and abroad, and comprise a biological adsorbing material, a carbon adsorbing material, a metal synthetic material and the like, such as: activated carbon, biochar, activated alumina, bentonite, red mud, zeolite, furnace slag, resin silica gel, coconut shells and corn straws.

The biological adsorption material has limited adsorption capacity and low density, is not easy to settle and difficult to recover when used for water treatment, contains a large amount of organic matters, is easy to decompose by microorganisms in water, and causes secondary pollution such as over standard COD (chemical oxygen demand) of the water, black and odorous water and the like. Most biochar adsorbing materials are physically adsorbed by static adsorption and the like, the adsorption effect is not obvious, and the recovery is difficult, so that the adsorption efficiency of biochar is improved by a chemical or physical modification method through some researches, the biochar is magnetized, the recovery rate of the biochar can be improved through an external magnetic field, but the biochar material is always required to be roasted at high temperature, the roasting temperature of part of materials reaches 700-. Some metal-synthesized adsorbing materials, such as iron-manganese, iron-copper composite oxide materials, graphene oxide composite materials and the like, have obvious advantages in adsorption capacity, but have the defects of high production cost, complex preparation process, low yield and the like, and some metal materials have secondary pollution risks of metal precipitation in the use process, such as nano zero-valent iron and the like, and finally cannot be popularized in practical application.

Red mud is an insoluble solid residue produced during the production of alumina, and its composition and characteristics depend on the type and production process of bauxite. The red mud has strong alkalinity, contains a large amount of iron and aluminum compounds, is widely applied to environmental pollution treatment, and is also researched to improve the adsorption efficiency of the red mud through methods such as high-temperature modification, acid modification and the like. However, because of the strong hydrophilicity of the red mud, the modified red mud absorbent is difficult to recover in water, and has certain limitation in practical application.

Therefore, in the field of environmental remediation, the development of a wastewater treatment adsorbent having high adsorption capacity and easy recovery is urgently needed.

Disclosure of Invention

The invention aims to solve the problems of difficult red mud recovery and limited adsorption capacity in the prior art, and provides an environment restoration material, a preparation method and application thereof.

In order to achieve the above object, a first aspect of the present invention provides a method for preparing an environmental remediation material, the method comprising the steps of:

(1) drying and crushing the red mud to obtain dry red mud powder;

(2) mixing the dry red mud powder with water to obtain a red mud aqueous solution A, mixing the red mud aqueous solution A with an iron salt solution to obtain a mixed solution B, and finally mixing the mixed solution B with an alkali solution to obtain an environment repairing material III;

wherein the iron salt solution contains iron ions and ferrous ions.

Preferably, the drying and crushing process in the step (1) comprises a crushing process I, a drying process and a crushing process II;

preferably, the process of the crushing treatment I comprises: air-drying the red mud, removing impurities, and then crushing to obtain red mud coarse powder which can pass through a 60-80-mesh sieve;

preferably, the drying process comprises: drying the red mud subjected to the crushing treatment I to constant weight at the temperature of 85-105 ℃;

preferably, the process of the crushing treatment II comprises: and (3) crushing and grinding the dried red mud to obtain dried red mud powder which can pass through a sieve of 80-100 meshes.

Preferably, the process of mixing I in step (2) comprises: mixing the dry red mud powder with water under an oxygen-free condition and stirring for 30-60min to obtain the red mud aqueous solution A;

preferably, the process of mixing II comprises: under the oxygen-free condition, the red mud aqueous solution A and the ferric salt solution are mixed and heated to 50-80 ℃ to obtain the mixed solution B;

preferably, the process of mixing III comprises: dropwise adding the alkali solution into the mixed solution B under the oxygen-free condition until the pH value of the mixed solution B is 10-12, and stirring for 1-6h under the closed condition at the temperature of 50-80 ℃.

Preferably, in the step (2), the ferric ion is at least one of ferric chloride, ferric sulfate and ferric nitrate, the ferrous ion is at least one of ferrous chloride, ferrous sulfate and ferrous nitrate, and the alkali of the alkali solution is selected from sodium hydroxide and/or potassium hydroxide;

preferably, the molar mass ratio of the iron ions to the ferrous ions in the iron salt solution is 1.5-3: 1.

preferably, in the step (2), the content of the iron element in the iron salt solution is 35-145g relative to 100g of the dry red mud powder.

Preferably, the solvents of the iron salt solution and the alkali solution and the water are oxygen-free ultrapure water, and the oxygen-free ultrapure water is prepared by passing ultrapure water through nitrogen to remove dissolved oxygen.

Preferably, the method further comprises: and filtering the mixed liquid C obtained by mixing the mixture III to obtain a filter cake, cleaning, drying and grinding the filter cake, and then sieving the filter cake with a 100-mesh sieve to obtain the environment repairing material with the particle size of less than 0.15 mm.

In a second aspect, the invention provides an environmental remediation material produced by a method according to the invention.

In a third aspect, the invention provides the use of an environmental remediation material according to the invention in wastewater treatment.

Preferably, the heavy metal ions in the wastewater contain at least one of antimony, arsenic and lead.

Through the technical scheme, the invention has the beneficial effects that:

(1) the environment-repairing material prepared by the invention adopts red mud loaded nano ferroferric oxide, and has the advantages of good magnetism, high stability, rich surface crystal structure, multiple surface adsorption functional groups, strong target pollutant removal capacity and the like;

(2) the environment restoration material provided by the invention has obvious treatment effect on various heavy metal ions, can reach adsorption balance in a short time, has large adsorption capacity which is obviously higher than that of red mud, has the highest removal rate of 98.57% on Sb (III) solution with the initial solution concentration of 10mg/L, and has the removal rates of 98.86% and 97.77% on As (V) solution with the initial solution concentration of 100 mu/L and Pb (II) solution with the initial solution concentration of 8.55mg/L when the addition amount of the environment restoration material is 0.2 g/L;

(3) the preparation method of the environment restoration material provided by the invention is simple, low in cost, high in production efficiency, energy-saving and environment-friendly, does not need high-temperature treatment, and can realize large-scale production;

(4) according to the preparation method of the environment restoration material, provided by the invention, the red mud is effectively used as a carrier of the nano ferroferric oxide to form the magnetic environment restoration material for treating the heavy metals in the wastewater, so that a way is provided for red mud recycling, waste treatment by waste is realized, a large amount of land resources occupied by the red mud are avoided, and serious pollution to the environment such as the ambient atmosphere, water, soil, microorganisms and the like is avoided.

Drawings

FIG. 1 is a graph showing the relationship between the red mud and the "adsorption time-adsorption capacity" of the environmental remediation materials prepared in examples 1 to 3 with respect to Sb (III);

FIG. 2 is a graph showing the relationship between the amount of addition and the removal rate of Sb (III) in the environmental remediation material prepared in example 1;

FIG. 3 is a graph of "initial concentration-adsorption capacity" of the environmental remediation material produced in example 1 versus Sb (III) at various temperatures;

FIG. 4 is an EDAX diagram of Red Mud (RM);

FIG. 5 shows an environmental remediation material (RM: nFe) made in accordance with example 1₃O₄EDAX plot of 1: 1);

FIG. 6 shows an environmental remediation material (RM: nFe) made in accordance with example 1₃O₄TEM images of 1:1) and Red Mud (RM);

FIG. 7 shows an environmental remediation material (RM: nFe) made in accordance with example 1₃O₄BET specific surface area test chart 1: 1);

FIG. 8 shows an environmental remediation material (RM: nFe) produced in example 1₃O₄1:1) pore size distribution test chart.

Detailed Description

The endpoints of the ranges and any values disclosed herein are not limited to the precise range or value, and such ranges or values should be understood to encompass values close to those ranges or values. For ranges of values, between the endpoints of each of the ranges and the individual points, and between the individual points may be combined with each other to give one or more new ranges of values, and these ranges of values should be considered as specifically disclosed herein.

In a first aspect, the present invention provides a method of preparing an environmental remediation material comprising the steps of:

(1) drying and crushing the red mud to obtain dry red mud powder;

wherein the iron salt solution contains iron ions and ferrous ions.

According to the invention, ferric salt and alkali are utilized to form nano ferroferric oxide, red mud is used as a carrier, nano ferroferric oxide is used as an active ingredient, and the active ingredient is loaded on the carrier through a coprecipitation method, so that the red mud-loaded nano ferroferric oxide magnetic environment restoration material is formed. The ferric salt solution is prepared by mixing ferric salt containing ferric ions and ferrous ions with a solvent and then carrying out ultrasonic treatment for 5-10min, so that the distribution of the ferric ions and the ferrous ions in the ferric salt solution is more uniform.

Preferably, the drying and pulverizing process in the step (1) includes a pulverizing process I, a drying process and a pulverizing process II.

Preferably, the process of the crushing treatment I comprises: and (3) drying the red mud, removing impurities, and then crushing to obtain red mud coarse powder which can pass through a 60-80-mesh sieve. Wherein the 60-80 mesh sieve can be 60 mesh sieve, 65 mesh sieve, 70 mesh sieve or 80 mesh sieve; the impurity removal is mainly to provide larger impurity particles after the red mud raw material is naturally air-dried and then to crush the red mud raw material. The inventor finds that, in the preferred embodiment, the drying and pulverizing process II is easier to perform, which is beneficial to improving the adsorption capacity of the environmental remediation material.

preferably, the process of the crushing treatment II comprises: and (3) crushing and grinding the dried red mud to obtain dried red mud powder which can pass through a sieve of 80-100 meshes. The screening by 80-100 meshes can be specifically 80 meshes, 90 meshes or 100 meshes, and the inventor finds that the loading effect of the dry red mud powder on the nano ferroferric oxide is better in the preferred specific embodiment.

Preferably, the process of mixing I in step (2) comprises: mixing the dry red mud powder with water under the oxygen-free conditionMixing and stirring for 30-60min to obtain the red mud aqueous solution A. In the present invention, the oxygen-free condition may be obtained by introducing N into the mixed solution₂In this preferred embodiment, the inventors have found that red mud can be more uniformly dispersed in an aqueous system, and that ferroferric oxide synthesized by a coprecipitation method can be more uniformly supported, so that the adsorption capacity of the environment restoration material is more excellent.

Preferably, the process of mixing II comprises: and under the oxygen-free condition, mixing the red mud aqueous solution A with the ferric salt solution, and heating to 50-80 ℃ to obtain the mixed solution B. The inventor finds that under the preferred embodiment, the iron salt and the alkali solution are more beneficial to carry out the coprecipitation reaction to form the nano ferroferric oxide.

Preferably, the process of mixing III comprises: dropwise adding the alkali solution into the mixed solution B under the oxygen-free condition until the pH value of the mixed solution B is 10-12, and stirring for 1-6h under the closed condition at the temperature of 50-80 ℃. The inventor finds that in the preferred embodiment, the coprecipitation effect of the iron salt and the alkali solution is better, and the reaction is more complete, so that the red mud has a better loading effect on the nano ferroferric oxide.

Preferably, in the step (2), the ferric ion is at least one of ferric chloride, ferric sulfate and ferric nitrate, the ferrous ion is at least one of ferrous chloride, ferrous sulfate and ferrous nitrate, and the alkali of the alkali solution is selected from sodium hydroxide and/or potassium hydroxide.

Preferably, the molar mass ratio of the iron ions to the ferrous ions in the iron salt solution is 1.5-3: 1. the inventor finds that under the preferred embodiment, the conversion rate of ferric ions and ferrous ions in the ferric salt solution into nano ferroferric oxide is improved.

Preferably, in the step (2), the content of the iron element in the iron salt solution is 35-145g, specifically 35g, 55g, 75g, 95g, 115g, 135g, 145g, and any value in a range formed by any two of these values, relative to 100g of the dry red mud powder. The inventor finds that in the preferred embodiment, the red mud completely supports the nano ferroferric oxide formed by the iron element precipitation in the iron salt solution, and the adsorption capacity of the environment repairing material is better.

Preferably, the solvents of the iron salt solution and the alkali solution and the water are oxygen-free ultrapure water, and the oxygen-free ultrapure water is prepared by passing ultrapure water through nitrogen to remove dissolved oxygen. The ultrapure water in the present invention means water having a resistivity of 18 M.OMEGA.. cm (25 ℃ C.), and oxygen-free ultrapure water is introduced into the ultrapure water by introducing N₂30min-60min, and removing dissolved oxygen in ultrapure water. The inventor finds that in the preferred embodiment, the preparation process of the environment repairing material is in an oxygen-free state, which is more beneficial to forming a nano ferroferric oxide form, so that the red mud has a better loading effect and higher stability on the ferroferric oxide.

Preferably, the method further comprises: and filtering the mixed liquid C obtained by mixing the mixture III to obtain a filter cake, cleaning, drying and grinding the filter cake, and then sieving the filter cake with a 100-mesh sieve to obtain the environment repairing material with the particle size of less than 0.15 mm. The inventors found that in the preferred embodiment, the purity of the environmental remediation material is higher and the adsorption effect is better.

Specifically, the treatment process of the mixed liquor C comprises the following detailed steps: and (3) cooling the mixed solution C to room temperature, filtering to obtain a filter cake, cleaning the filter cake to be neutral by using oxygen-free ultrapure water, placing the filter cake in a vacuum drying oven, performing vacuum drying for 24 hours at the temperature of 85-105 ℃, taking out the filter cake from the vacuum drying oven, and grinding the filter cake by using an agate mortar and sieving the filter cake with a 100-mesh sieve to obtain the environment repairing material with the particle size of less than 0.15 mm.

In a second aspect, the present invention provides an environmental remediation material produced by the method of the present invention.

The present invention will be described in detail below by way of examples. In the following examples, arsenic and antimony were measured by a liquid chromatography-atomic fluorescence spectrometer (Beijing Hai LC-AFS-9530) using hydride atomic fluorescence in GB/T5750.6-2006, lead was measured by a flame atomic absorption spectrophotometer (Shimadzu AA6880, Japan) using flame atomic absorption spectrophotometry in GB/T5750.6-2006, SEM-EDAX characterization was measured by a scanning electron microscope (Zeiss merlin compe), TEM characterization was measured by a transmission electron microscope (FEI Tecnai G2F 3), BET characterization was measured by a physical adsorption apparatus (Mike 2460); the red mud raw material is collected from an aluminum smelting plant in the city of coke manufacture in Henan province, ultrapure water is prepared by adopting an ultrapure water instrument (excellent ZYUPT-5T), and other raw materials are commercially available products of chemical purity.

The preparation method of the oxygen-free ultrapure water in the embodiment comprises the following steps: introducing N into ultrapure water₂30min-60min, and removing dissolved oxygen in ultrapure water.

Example 1

(1) Naturally drying collected red mud, taking out larger impurity particles, crushing, sieving with a 70-mesh sieve to obtain red mud coarse powder capable of sieving with the 70-mesh sieve, drying the red mud coarse powder in a constant temperature blast drying oven at 95 ℃ to constant weight, crushing, grinding, and sieving with a 90-mesh sieve to obtain dry red mud powder;

5.56g of FeSO are weighed₄·7H₂O and 10.8g FeCl₃·6H₂Adding O (the molar mass ratio is 1:2) into a beaker, adding 150mL of oxygen-free ultrapure water, and performing ultrasonic treatment for 8min to obtain an iron salt solution;

(2) in continuous on N₂Under the condition of keeping an oxygen-free environment, placing a conical flask filled with 200mL of oxygen-free ultrapure water on a magnetic stirrer, stirring at room temperature, adding 4.63g of the dry red mud powder obtained in the step (1), and fully stirring for 45min to obtain a red mud aqueous solution A;

(3) in continuous on N₂Under the condition of keeping an oxygen-free environment, mixing the red mud water solution A obtained in the step (2) with the ferric salt solution obtained in the step (1), and heating to 65 ℃ to obtain a mixed solution B;

(4) in continuous on N₂Under the condition of keeping an oxygen-free environment, dropwise adding NaOH solution with the molar concentration of 3mol/L into the mixed solution B obtained in the step (3) at the speed of 4mL/min until the pH value of the mixed solution B is 11, and sealing the mixed solution B into a strip at the temperature of 65 DEG CMagnetically stirring for 4 hours under the condition of stirring to obtain a mixed solution C;

(5) and (4) cooling the mixed liquid C obtained in the step (4) to room temperature, filtering to obtain a filter cake, cleaning the filter cake to be neutral by using oxygen-free ultrapure water, placing the filter cake in a vacuum drying oven, performing vacuum drying for 24 hours at the temperature of 95 ℃, taking out the filter cake from the vacuum drying oven, grinding the filter cake by using an agate mortar, and sieving the filter cake with a 100-mesh sieve to obtain the environment repairing material with the particle size of less than 0.15 mm.

Example 2

(1) Naturally drying collected red mud, taking out larger impurity particles, crushing, sieving with a 60-mesh sieve to obtain red mud coarse powder capable of sieving with the 60-mesh sieve, drying the red mud coarse powder in a constant temperature blast drying oven at 85 ℃ to constant weight, crushing, grinding, and sieving with a 80-mesh sieve to obtain dry red mud powder;

4.77g of FeCl were weighed₂·4H₂O and 14.4g Fe₂(SO₄)₃(the molar mass ratio is 1:1.5) adding 150mL of oxygen-free ultrapure water into a beaker, and carrying out ultrasonic treatment for 5min to obtain an iron salt solution;

(2) in continuous on N₂Under the condition of keeping an oxygen-free environment, placing a conical flask filled with 200mL of oxygen-free ultrapure water on a magnetic stirrer, stirring at room temperature, adding 2.32g of the dry red mud powder obtained in the step (1), and fully stirring for 30min to obtain a red mud aqueous solution A;

(3) in continuous on N₂Under the condition of keeping an oxygen-free environment, mixing the red mud water solution A obtained in the step (2) with the ferric salt solution obtained in the step (1), and heating to 50 ℃ to obtain a mixed solution B;

(4) in continuous on N₂Dropwise adding a KOH solution with the molar concentration of 1mol/L into the mixed solution B obtained in the step (3) at the speed of 2mL/min under the condition of keeping an anaerobic environment until the pH value of the mixed solution B is 10, and magnetically stirring for 1h under the conditions of 50 ℃ and sealing to obtain a mixed solution C;

(5) and (4) cooling the mixed liquid C obtained in the step (4) to room temperature, filtering to obtain a filter cake, cleaning the filter cake to be neutral by using oxygen-free ultrapure water, placing the filter cake in a vacuum drying oven, performing vacuum drying for 24 hours at the temperature of 85 ℃, taking out the filter cake from the vacuum drying oven, grinding the filter cake by using an agate mortar, and sieving the filter cake with a 100-mesh sieve to obtain the environment repairing material with the particle size of less than 0.15 mm.

Example 3

(1) Naturally drying collected red mud, taking out larger impurity particles, crushing, sieving with a 80-mesh sieve to obtain red mud coarse powder capable of sieving with the 80-mesh sieve, drying the red mud coarse powder in a constant temperature blast drying oven at 105 ℃ to constant weight, crushing, grinding, and sieving with a 100-mesh sieve to obtain dry red mud powder;

2.98g of FeCl were weighed₂·4H₂O and 12.2g FeCl₃·6H₂Adding O (the molar mass ratio is 1:3) into a beaker, adding 150mL of oxygen-free ultrapure water, and carrying out ultrasonic treatment for 10min to obtain an iron salt solution;

(2) in continuous on N₂Under the condition of keeping an oxygen-free environment, placing a conical flask filled with 200mL of oxygen-free ultrapure water on a magnetic stirrer, stirring at room temperature, adding 9.26g of the dry red mud powder obtained in the step (1), and fully stirring for 60min to obtain a red mud aqueous solution A;

(3) in continuous on N₂Under the condition of keeping an oxygen-free environment, mixing the red mud water solution A obtained in the step (2) with the ferric salt solution obtained in the step (1), and heating to 80 ℃ to obtain a mixed solution B;

(4) in continuous on N₂Dropwise adding a NaOH solution with the molar concentration of 5mol/L into the mixed solution B obtained in the step (3) at the speed of 5mL/min under the condition of keeping an anaerobic environment until the pH value of the mixed solution B is 12, and magnetically stirring for 6 hours under the conditions of 80 ℃ and sealing to obtain a mixed solution C;

(5) and (4) cooling the mixed liquid C obtained in the step (4) to room temperature, filtering to obtain a filter cake, cleaning the filter cake to be neutral by using oxygen-free ultrapure water, placing the filter cake in a vacuum drying oven, performing vacuum drying for 24 hours at the temperature of 105 ℃, taking out the filter cake from the vacuum drying oven, grinding the filter cake by using an agate mortar, and sieving the filter cake with a 100-mesh sieve to obtain the environment repairing material with the particle size of less than 0.15 mm.

Example 4

5.56g of FeSO are weighed₄·7H₂O and 10.8g FeCl₃·6H₂Adding O (the molar mass ratio is 1:2) into a beaker, adding 150mL of ultrapure water, and carrying out ultrasonic treatment for 8min to obtain an iron salt solution;

(2) placing a conical flask filled with 200mL of ultrapure water on a magnetic stirrer, stirring at room temperature, adding 6g of the dry red mud powder obtained in the step (1), and fully stirring for 45min to obtain a red mud aqueous solution A;

(3) mixing the red mud water solution A obtained in the step (2) with the ferric salt solution obtained in the step (1), and heating to 65 ℃ to obtain a mixed solution B;

(4) dropwise adding NaOH solution with the molar concentration of 3mol/L into the mixed solution B obtained in the step (3) at the speed of 4mL/min until the pH value of the mixed solution B is 11, and magnetically stirring for 4 hours at the temperature of 65 ℃ under the closed condition to obtain mixed solution C;

Test example

The environmental remediation materials prepared in the above examples 1-3 were prepared by completely generating Fe from Fe in the solution of ferric salt₃O₄Based on the above, the dry red mud powder and Fe in examples 1 to 3 were calculated₃O₄The mass ratio theoretical values of (A) are respectively 1:1. 1: 2. 2: nFe in the following test example₃O₄1:1 denotes the environmental remediation material prepared in example 1 as RM: nFe₃O₄The environmental remediation material prepared in example 2 is represented by 1:2 as RM: nFe₃O₄The environmental remediation material prepared in example 3 was represented by 2: 1.

1. Determination of adsorption effect of environment repairing material on Sb (III) and adsorption time

Red Mud (RM) was used as comparative example 1, and nano-sized ferroferric oxide (nFe) was purchased from the market₃O₄) As comparative example 2, 0.02g of red mud and nFe g of red mud were weighed out separately₃O₄And the environment repairing materials prepared in the examples 1 to 3 are used as test samples, the test samples are respectively added into polyethylene plastic bottles filled with 100mL of Sb (III) solution, the concentration of Sb (III) in the Sb (III) solution is 10mg/L, pH to be 4.6 +/-0.2, and then the polyethylene plastic bottles are put into a water bath shaker for adsorption experiment, the rotating speed is set to be 150r/min, and the temperature is set to be 25 ℃; taking supernatant liquid at 0min, 10min, 20min, 30min, 40min, 50min, 60min, 90min, 120min, 180min, 240min and 300min respectively, measuring the concentration of the residual Sb (III) in the solution by atomic fluorescence, and calculating the adsorption capacity of the red mud and the environment repairing material prepared in the embodiment 1-the embodiment 3 to the Sb (III), wherein the result is shown in figure 1.

As is apparent from fig. 1, the environmental remediation materials prepared in examples 1 to 3 provided by the present invention have a significantly higher sb (iii) adsorption effect than Red Mud (RM) and nano-sized ferroferric oxide (nFe)₃O₄) In addition, the magnetic environment restoration material prepared in example 1 had the best adsorption effect and the largest adsorption capacity.

2. Determination of removal rate of Sb (III) in water body by environment repairing material

Respectively weighing 0.01g, 0.02g, 0.05g, 0.08g, 0.1g, 0.12g, 0.15g and 0.18g of the environment restoration material prepared in the embodiment 1 into a polyethylene plastic bottle, adding 100mL of Sb (III) solution with the concentration of 10mg/L, pH of 4.6 +/-0.2, namely the adding amount of the environment restoration material is 0.1g/L, 0.2g/L, 0.5g/L, 0.8g/L, 1g/L, 1.2g/L, 1.5g/L and 1.8g/L, and then putting the polyethylene plastic bottle into a constant-temperature water bath shaking table for oscillation at the rotation speed of 150r/min and the temperature of 25 ℃; after 24h of reaction, the supernatant liquid is respectively taken, the concentration of the residual Sb (III) in the solution is measured by atomic fluorescence, and the removal rate is calculated, and the result is shown in figure 2. As can be seen from FIG. 2, under the treatment conditions, the removal rate of Sb (III) is increased along with the increase of the dosage of the environmental remediation material, and after the dosage is increased to 0.8g/L, the adsorption effect on Sb (III) is basically stable, the removal rate is not obviously changed, and the removal rate of Sb (III) can reach 98.57% at most.

Weighing 0.02g of the environment restoration material prepared in the example 1, adding the environment restoration material into a polyethylene plastic bottle filled with 100mL of Sb (III) solution with the Sb (III) concentration of 16.18mg/L, pH of 4.6 +/-0.2, and then putting the polyethylene plastic bottle into a water bath shaking table for adsorption experiment, wherein the rotating speed is set to be 150r/min and the temperature is 25 ℃; after 24 hours, the supernatant was sampled, and the concentration of the remaining Sb (III) in the solution was measured by atomic fluorescence, and the removal rate of Sb (III) was calculated to be 37.94% and the adsorption capacity was calculated to be 30.69 mg/g.

3. Determination of Sb (III) adsorption capacity of environment restoration material in water body

Setting seven test groups, wherein each test group is provided with 3 polyethylene plastic bottles, each polyethylene plastic bottle is filled with 100mL of Sb (III) solution, and 0.02g of the environment repairing material prepared in the embodiment 1 is added, wherein the concentrations of Sb (III) in the Sb (III) solutions of the seven test groups are respectively 5mg/L, 10mg/L, 15mg/L, 20mg/L, 25mg/L, 35mg/L and 50mg/L, and the pH value is 4.6 +/-0.2, then placing the polyethylene plastic bottles into a constant-temperature shaking box for adsorption test, and the rotating speed of each test group is 150r/min, the temperature is respectively 15 ℃, 25 ℃ and 35 ℃; after 24h of reaction, the supernatant was taken, the concentration of the remaining Sb (III) in the solution was measured by atomic fluorescence, and the removal rate was calculated, the result is shown in FIG. 3. As can be seen from FIG. 3, the adsorption capacity of the environmental remediation material to Sb (III) increases with increasing temperature, and the maximum adsorption capacity can reach 103.58 mg/g.

4. Determination of adsorption capacity of environment remediation material on Sb (V) in water body

Weighing 0.02g of the environment repairing material prepared in the embodiment 1 into a polyethylene plastic bottle, adding 100mL of Sb (V) solution with the concentration of 10mg/L, pH of 2.6 +/-0.2, then putting the polyethylene plastic bottle into a constant-temperature shaking box for adsorption experiment, rotating at the speed of 150r/min and at the temperature of 25 ℃, taking supernatant after reacting for 24 hours, measuring the concentration of the residual Sb (V) in the solution through atomic fluorescence, and calculating the adsorption capacity to be 44.2 mg/g.

5. Determination of Pb (II) removal rate of environmental remediation material in water body

Weighing 0.02g of the environment repairing material prepared in the example 1 into a polyethylene plastic bottle, adding 100mL of Pb (II) solution with Pb (II) concentration of 8.55mg/L, pH of 5.3 +/-0.2, then putting the polyethylene plastic bottle into a constant-temperature shaking box for adsorption experiment, wherein the rotating speed is 150r/min, the temperature is 25 ℃, taking supernatant after reacting for 5h and 24h, measuring the concentration of the residual Pb (II) in the solution through atomic absorption, calculating the removal rate of Pb (II) when reacting for 5h to be 70.14%, and the removal rate of Pb (II) when reacting for 24h to be 97.77%.

6. Determination of removal rate of As (V) in water body by environment remediation material

Setting two polyethylene plastic bottles, respectively weighing 0.02g of the environment repairing material prepared in the embodiment 1 into the polyethylene plastic bottles, adding 100mL of As (V) solution with the pH value of 7.0 +/-0.2, wherein the concentrations of As (V) in the As (V) solution are respectively 100 mu/L and 800 mu/L, then putting the polyethylene plastic bottles into a constant-temperature shaking box for adsorption experiment at the rotation speed of 150r/min and the temperature of 25 ℃, respectively taking supernatant after reacting for 4h and 24h, measuring the concentration of the residual As (V) in the solution through atomic fluorescence, and calculating the removal rate of As (V) of the As (V) solution with the initial concentration of 100 mu/L at 4h to be 95.58% and the removal rate of As (V) at 24h to be 98.86%; the removal rate of As (V) in the solution with the initial concentration of 800 mu/L at 24h can reach 83.72%.

Setting three polyethylene plastic bottles, respectively weighing 0.02g, 0.04g and 0.08g of the environment repairing material prepared in the embodiment 1 into the polyethylene plastic bottles (namely the adding amount of the environment repairing material is respectively 0.2g/L, 0.4g/L and 0.8g/L), adding 100mL of As (V) solution with the As (V) concentration of 50 mu/L, pH of 2.0 +/-0.2, then putting the polyethylene plastic bottles into a constant-temperature shaking box for adsorption experiment at the rotating speed of 220r/min and the temperature of 25 ℃, taking supernatant after reacting for 45min, measuring the concentration of the residual As (V) in the solution through atomic fluorescence, and calculating the removal rate of the As (V) when the adding amount is 0.2g/L to be 92.96%; the As (V) removal rate was 95.71% when the amount of addition was 0.4 g/L; the As (V) removal rate was 96.93% when the amount of addition was 0.8 g/L.

7. Determination of removal rate of As (III) in water body by environment remediation material

Weighing 0.02g of the environment repairing material prepared in the example 1 into a polyethylene plastic bottle, adding 100mL of As (III) solution with the As (III) concentration of 100 mu/L, pH of 7.0 +/-0.2, then putting the polyethylene plastic bottle into a constant-temperature shaking box for adsorption experiment, taking supernatant after reacting for 4h and 24h at the rotating speed of 150r/min and the temperature of 25 ℃, measuring the concentration of the residual As (III) in the solution through atomic fluorescence, and calculating the removal rate of the As (III) at the reaction time of 4h to be 80.69% and the removal rate of the As (III) at the reaction time of 24h to be 90.90%.

8. Determination of removal rate of arsenic and antimony in arsenic and antimony composite polluted industrial wastewater by environment remediation material

Industrial wastewater A, B, C was obtained from antimony smelting works in the city of cold water, Jiangxi, Hunan province, and the total arsenic (As) and total antimony (Sb) contents were determined As shown in Table 1 by filtering the wastewater with a 0.45 μm aqueous membrane to remove impurities and digesting with atomic fluorescence.

TABLE 1

Wastewater numbering	Total arsenic (mg/L)	Total antimony (mg/L)	pH
				A	21.24±0.10	8.13±0.21	9.46±0.2
B	0.89±0.02	5.33±0.04	8.18±0.2
				C	0.0266±0.00	4.01±0.00	7.69

100mL of the filtered wastewater A, B, C was respectively put into a polyethylene plastic bottle, 0.1g of the environment restoration material prepared in example 1 was added (i.e., the amount of the environment restoration material added was 1g/L), the solution was shaken for 3 hours at a temperature of 25 ℃ and a rotation speed of 150r/min and then filtered with a 0.45 μm water system filter, the concentrations of the remaining As and Sb in the solution were measured by atomic fluorescence, and the removal rates of As and Sb in the wastewater A, B, C were calculated As 27.69%, 85.90% and 93.48%, and the removal rates of Sb were calculated As 7.26%, 20.53% and 19.02%, respectively.

9. Characterization and analysis of environmental remediation materials and red mud

Appropriate amounts of the environmental remediation material prepared in example 1 and Red Mud (RM) were weighed and subjected to SEM-EDAX analysis, TEM analysis, BET analysis, and BJH analysis, and the results are shown in fig. 4 to 8, respectively. FIGS. 4 and 5 are SEM-EDAX analysis diagrams of Red Mud (RM) and the environmental remediation material made according to example 1 of the present invention, respectively. As can be seen from fig. 4, the red mud has a certain iron content, but after loading, as shown in fig. 5, the material has changed not only in morphology but also in surface chemical properties, after loading nano ferroferric oxide, the contents of Si and Al elements are relatively reduced, the characteristic peak is reduced, and the content of Fe element is greatly increased, which indicates that the nano ferroferric oxide is successfully loaded on the red mud surface, and the Fe content on the surface of the environmental remediation material prepared in example 1 is about 3.7 times that of the Red Mud (RM).

Fig. 6 is a TEM analysis view of the environmental remediation material and Red Mud (RM) prepared according to example 1 of the present invention. As can be seen from FIG. 6, the Red Mud (RM) is in the form of a block, and the environmental remediation material (RM: nFe) prepared in example 1₃O₄1:1) the surface is piled with nanometer level irregular fine spherical particles, the diameter of the particles is very small, the particle size range of the aggregate is 50-200nm, the surface is loose and porous, the particles are in an irregular crystal structure, and the nano ferroferric oxide is formedWork is loaded on the surface of the red mud, and the environment restoration material prepared in the example 1 has a large specific surface area and a large pore volume.

FIGS. 7 and 8 are a BET specific surface area test chart and a BJH pore size distribution test chart of the environmental remediation material prepared in example 1, and it can be seen from FIG. 7 that N of the environmental remediation material prepared in example 1 is₂The adsorption and desorption isotherms belong to type IV in IUPAC classification, and an H3 type hysteresis loop is arranged, which indicates that the environment repairing material has slit holes formed by particle accumulation; as can be seen from FIG. 8, the environmental remediation material is in P/P₀The highest phase did not reach equilibrium, which also indicates that the environmental remediation material prepared in example 1 is built up of spherical particles, which is consistent with the TEM characterization in fig. 6. The environmental remediation material prepared in example 1 has a large specific surface area (171.63 m) calculated by using BET multipoint²In terms of a/g) and a relatively large pore volume (0.31 cm)³/g), the average pore diameter of the environment-remediating material prepared in example 1 was calculated to be 7.62nm from the BJH adsorption method. Therefore, the environment restoration material prepared in example 1 is a typical mesoporous structure, and becomes an ideal material for adsorbing heavy metals in water purification.

The preferred embodiments of the present invention have been described above in detail, but the present invention is not limited thereto. Within the scope of the technical idea of the invention, many simple modifications can be made to the technical solution of the invention, including combinations of various technical features in any other suitable way, and these simple modifications and combinations should also be regarded as the disclosure of the invention, and all fall within the scope of the invention.

Claims

1. A method of preparing an environmental remediation material comprising the steps of:

(1) drying and crushing the red mud to obtain dry red mud powder;

wherein the iron salt solution contains iron ions and ferrous ions.

2. The method according to claim 1, wherein the drying-pulverizing process in step (1) includes a pulverizing process I, a drying process and a pulverizing process II;

3. The method of claim 1, wherein the process of mixing I in step (2) comprises: mixing the dry red mud powder with water under an oxygen-free condition and stirring for 30-60min to obtain the red mud aqueous solution A;

4. The method of claim 1, wherein the ferric ions in step (2) are derived from at least one of ferric chloride, ferric sulfate and ferric nitrate, the ferrous ions are derived from at least one of ferrous chloride, ferrous sulfate and ferrous nitrate, and the alkali of the alkali solution is selected from sodium hydroxide and/or potassium hydroxide;

5. the method according to claim 1, wherein in step (2), the content of iron element in the ferric salt solution is 35-145g relative to 100g of the dry red mud powder.

6. The method according to any one of claims 1 to 5, wherein the solvents of the iron salt solution and the alkali solution and the water are oxygen-free ultrapure water, which is obtained by removing dissolved oxygen from ultrapure water by passing nitrogen gas therethrough.

7. The method according to any one of claims 1-5, further comprising: and filtering the mixed liquid C obtained by mixing the mixture III to obtain a filter cake, cleaning, drying and grinding the filter cake, and then sieving the filter cake with a 100-mesh sieve to obtain the environment repairing material with the particle size of less than 0.15 mm.

8. An environmental remediation material made by the method of any one of claims 1 to 7.

9. Use of the environmental remediation material of claim 8 in wastewater treatment.

10. Use according to claim 9, wherein the heavy metal ions in the wastewater contain at least one of antimony, arsenic and lead.