WO2022166187A1

WO2022166187A1 - Attapulgite surface modification method

Info

Publication number: WO2022166187A1
Application number: PCT/CN2021/115776
Authority: WO
Inventors: 董良飞; 孙俊杰; 叶天宝
Original assignee: 南京公诚节能新材料研究院有限公司
Priority date: 2021-02-02
Filing date: 2021-08-31
Publication date: 2022-08-11
Also published as: CN112794337A

Abstract

Provided is an attapulgite surface modification method, comprising: S3: putting attapulgite into a sodium hydroxide solution, and performing hot alkali modification on natural attapulgite to obtain alkali-modified attapulgite, optionally, performing heat modification on the attapulgite before alkali modification; and S4: adding aluminum chloride to the alkali-modified attapulgite for reaction and polymerization. The attapulgite surface modification method further comprises: S1: replacing magnesium in an attapulgite crystal with aluminum ions to improve the treatment performance of the attapulgite crystal on algae; and S2: polymerizing the aluminum ions on the surface of the attapulgite, so that the surface of the attapulgite is rich in positive charges, and the coagulation effect of the attapulgite is enhanced. According to the attapulgite surface modification method, the attapulgite is first subjected to the heat and alkali modification and then subjected to the aluminum chloride modification, so that the spatial structure of the attapulgite is improved, the adsorption performance of the algae is enhanced, the effect of the attapulgite in the algae treatment is further improved, both economy and environmental protection are achieved, and the modified attapulgite has obvious advantages in the field of water treatment.

Description

A kind of surface modification method of attapulgite

technical field

The invention relates to the technical field of water treatment, in particular to a method for modifying the surface of attapulgite.

Background technique

With the acceleration of social development and industrialization, the pressure on the environment such as rivers and lakes is increasing day by day. The eutrophication problem of many lakes and rivers is intensified, and even serious pollution has caused the imbalance of the water ecological environment. The microbial population represented by algae exploded and proliferated. The sensory impact of algal toxins and the release of algal toxins not only seriously affect the water environment and landscape, but also pose a serious threat to the safety of rivers, lakes, aquatic organisms and human life and production.

In recent years, many scholars at home and abroad have developed a large number of technical means to reduce or remove algae in water bodies of rivers and lakes, thereby controlling algal blooms. At present, the prevention and control of algal blooms in rivers and lakes are mainly prevention and direct control. The direct treatment methods include physical method, chemical method, microbial method and the combined application of these methods. Physical methods include mechanical salvage algae removal, direct filtration algae removal, microfiltration algae removal, air flotation algae removal, ultrasonic algae removal and other methods. The algae in the water body can be directly eliminated by using sterilization or filtration equipment. The principle is simple and can be used. Directly reduce algal biomass in water without secondary pollution, but this method requires a lot of manpower and material resources, and has a narrow application range for a large range of water bodies. The chemical method uses chemical fungicides to kill algae. The fungicides usually used in algae treatment include copper sulfate, chlorine dioxide, hydrogen peroxide, glutaraldehyde, etc. It is also dangerous and easy to cause secondary pollution. These compounds diffuse in the water body and have a direct toxic effect on aquatic organisms, and the algal toxins released after the death of algae are the main causes of liver cancer. Microbial method mainly uses photosynthetic bacteria, Bacillus and other microorganisms as algaecide, and through its life metabolism, it transforms, degrades and transfers pollutants in water, so as to purify water body. This method has high cost and long cycle. It is difficult to apply on a large scale, and it will also bring problems such as alien biological invasion. Attapulgite clay (hereinafter referred to as attapulgite) due to its special fibrous rod crystal structure and hollow space structure, algae adsorb, enrich and precipitate on the surface of attapulgite, so that algae can be removed. However, the unmodified attapulgite itself has poor sol property, low flocculation and sedimentation rates, which makes the algae treatment efficiency low, and it is difficult to achieve a good removal effect when the amount is small. . Therefore, the present invention utilizes the algae removal properties of attapulgite, uses aluminum chloride as the main modifier to modify the surface of the attapulgite, enhances the algae removal performance of the attapulgite, and prepares the algae removal agent.

Attapulgite is a natural silicate mineral rich in magnesium and aluminum, which is not harmful to the environment, and has a unique nano-scale chain layered molecular structure, and the crystals are rod-shaped or fibrous. The large specific surface area and fine pore structure make it have good adsorption, many nano-sized pores have a large number of active centers, coupled with strong mechanical properties and thermal stability, it is an excellent carrier. The invention uses aluminum chloride to make the surface of attapulgite carry a large number of positively charged ions, neutralize the negatively charged ions on the surface of algae, destabilize the algae, and finally realize the removal of algae, purify the water body, and achieve the purpose of improving and improving water quality. Therefore, we improved this and proposed a method for surface modification of attapulgite.

Practical Invention Content

In order to solve the above-mentioned technical problems, the present invention provides the following technical solutions:

A kind of attapulgite surface modification method of the present invention comprises the following steps:

S1: Substitute magnesium in attapulgite crystals with aluminum ions to improve its treatment performance against algae;

S2: The aggregation of aluminum ions on the surface of attapulgite makes the surface of attapulgite rich in positive charges and enhances its coagulation effect;

S3: put the attapulgite into the sodium hydroxide solution, and perform thermal alkali modification on the natural attapulgite to obtain the alkali-modified attapulgite;

S4: adding aluminum chloride to the alkali-modified attapulgite for reaction and polymerization, and using aluminum chloride to perform inorganic modification on the surface of the attapulgite to obtain modified attapulgite;

In the above technical solution, the step sequence of the thermal alkali modification of attapulgite and the modification of aluminum chloride is limited. In the implementation, it is necessary to first perform thermal and alkali modification on the attapulgite, and then further perform the aluminum chloride inorganic modification on the attapulgite. modified.

As a preferred technical solution of the present invention, the specific steps of thermal modification are as follows: according to step S4, the mined attapulgite is baked at 0°C-500°C for 1-3 hours to obtain thermally modified Attapulgite.

As a preferred technical solution of the present invention, the specific step of the alkali modification is, according to step S4, the mixed reaction system of the thermally modified attapulgite, sodium hydroxide and solvent is reacted at room temperature for 1-3 hours, the mixed reaction system should be carried out under stirring conditions.

As a preferred technical solution of the present invention, the rotational speed of the stirring condition should be 200-500 r/min, the solvent is deionized water, and the mass ratio of the thermally modified attapulgite to sodium hydroxide is (5- 10): 1.

As a preferred technical solution of the present invention, the specific steps of the aluminum chloride modification are: according to step S3, the mixed reaction system of attapulgite, aluminum chloride and solvent after thermal alkali modification is heated at 60℃-90℃ The reaction is carried out under the condition of ℃ for 6-10 hours.

As a preferred technical solution of the present invention, the mixed reaction system should be carried out under stirring conditions, and the rotating speed of the stirring conditions should be 200-500 r/min, and the solvent is deionized water.

As a preferred technical solution of the present invention, the mass ratio of the aluminum chloride to the solvent is (10-30): 100, and the mass ratio of the alkali-modified attapulgite to the aluminum chloride is (1-3): 1.

The beneficial effects of the present invention are:

1. Thermal modification can remove excess bound water inside attapulgite, open the internal structure, and increase the specific surface area of attapulgite; alkali modification can activate the internal groups of attapulgite, so that many hydroxyl structures are attached to the surface of attapulgite, increasing the chemical activity of attapulgite ; Positively charged aluminum ions have a certain coagulation effect in water, and attapulgite can enhance the flocculation effect of algae;

2. The surface modification of attapulgite by heat, alkali and aluminum chloride improves the spatial structure of attapulgite, enhances the adsorption performance of algae, and further improves the effect of attapulgite in algae treatment;

Compared with other algaecides in the field of water treatment, attapulgite has low price and low applicable cost, and for the environment, attapulgite itself is not harmful to the environment, and the added aluminum chloride and other modified substances have no impact on the environment. Very little, from the perspective of economy and environmental protection, modified attapulgite has obvious advantages in the field of water treatment.

Description of drawings

The accompanying drawings are used to provide a further understanding of the present invention, and constitute a part of the specification, and are used to explain the present invention together with the embodiments of the present invention, and do not constitute a limitation to the present invention. In the attached image:

Fig. 1 is a flow chart of a method for modifying the surface of attapulgite according to the present invention.

Detailed ways

The preferred embodiments of the present invention will be described below with reference to the accompanying drawings. It should be understood that the preferred embodiments described herein are only used to illustrate and explain the present invention, but not to limit the present invention.

Example 1:

s1: Grind the attapulgite raw ore into fine powder and pass through a 200-mesh sieve to obtain attapulgite powder; obtain attapulgite powder.

s2: put attapulgite powder and sodium hydroxide in a small amount of deionized water in a mass ratio of 5:1, and stir for 1 hour at normal temperature to obtain alkali-modified attapulgite.

s3: Under the condition that the pH is about 5, put the alkali-modified attapulgite and aluminum chloride into a small amount of deionized water according to the mass ratio of 1:1, and stir them for 6 hours at 60 ° C and 200 r/min to disperse them. Dried, crushed to get the finished product.

Embodiment 2:

s1: Grind the attapulgite raw ore into fine powder and pass through a 200-mesh sieve to obtain attapulgite powder; bake the attapulgite powder at a temperature of 200° C. for 1 hour to obtain heat-modified attapulgite.

s2: Put the heat-modified attapulgite and sodium hydroxide into a small amount of deionized water at a mass ratio of 5:1, and stir at room temperature for 1 hour to obtain alkali-modified attapulgite.

s3: Under the condition that the pH is about 5, the hot alkali modified attapulgite and aluminum chloride are put into a small amount of deionized water according to the mass ratio of 1:1, and stirred for 6 hours at 60 ° C and 200 r/min to disperse them. Dry, pulverize, and get the finished product.

Embodiment three:

s1: Grind the attapulgite raw ore into fine powder and pass through a 200-mesh sieve to obtain attapulgite powder; bake the attapulgite powder at a temperature of 500° C. for 1 hour to obtain heat-modified attapulgite.

s3: Under the condition of pH of about 5, put the hot alkali modified attapulgite and aluminum chloride into a small amount of deionized water according to the mass ratio of 1:1, and stir for 6 hours at 60 ° C and 200 r/min to disperse them. Dry, pulverize, and get the finished product.

Embodiment 4:

s2: put the attapulgite powder and sodium hydroxide in a small amount of deionized water in a mass ratio of 10:1, and stir for 1 hour at normal temperature to obtain alkali-modified attapulgite.

s3: Under the condition that the pH is about 6, put the alkali-modified attapulgite and aluminum chloride into a small amount of deionized water according to the mass ratio of 1:1, stir for 6 hours at 80 ° C and 200 r/min to disperse them, and dry them. Dried, crushed to get the finished product.

Embodiment 5:

s2: Put the heat-modified attapulgite and sodium hydroxide into a small amount of deionized water in a mass ratio of 10:1, and stir at room temperature for 1 hour to obtain alkali-modified attapulgite.

s3: Under the condition of pH of about 6, put the hot alkali modified attapulgite and aluminum chloride into a small amount of deionized water according to the mass ratio of 1:1, and stir for 6 hours at 80 ° C and 200 r/min to disperse them. Dry, pulverize, and get the finished product.

Embodiment 6:

s3: Under the condition of pH of about 6, put the hot alkali modified attapulgite and aluminum chloride into a small amount of deionized water according to the mass ratio of 1:1, and stir for 6 hours at 80 ° C and 200 r/min to disperse them. Dry, pulverize, get the finished product

Comparative Example 1:

The natural attapulgite without any modification was used alone as an algaecide for algae control.

Comparative Example 2:

Put thermally modified attapulgite and sodium hydroxide in a small amount of deionized water in a mass ratio of 5:1, and stir at room temperature for 1 hour to obtain alkali-modified attapulgite, which is used in algae treatment (heat-alkaline modification is performed on attapulgite alone. sex).

Comparative Example 3:

The thermally modified attapulgite and aluminum chloride were put into a small amount of deionized water at a mass ratio of 1:1, and stirred at 80 ° C and 200 r/min for 6 hours to obtain aluminum chloride-modified attapulgite, which was used in algae treatment (for algae treatment). Attapulgite is modified with aluminum chloride alone).

Take the simulated water body with cyanobacterial chlorophyll content of 100-110 μg/, pH controlled at 7.0±1.0, and put the materials obtained in Examples 1-6 and Comparative Examples 1-3 into the simulated test water body of the same weight, and the dosage is 1g/L , 30 minutes later, the test is carried out. The following table shows the test results.

After analysis, in Comparative Example 1 to Comparative Example 3, unmodified, single thermal alkali modification, and single aluminum chloride modification were respectively used, and the obtained products were used in algae treatment, and the algae removal rate was compared with that of Examples 1-6. , the value is obviously low, and the effect on algae treatment is far less than the effect of the product in this application on algae treatment, so it can be concluded that the modified attapulgite prepared by the method of this application is comparable in algae treatment. It has a relatively better application effect than the prior art.

By comparing Examples 1-6, it can be seen that although the material ratio and temperature of the modified attapulgite are slightly different, the effects obtained when applied to algae treatment are very similar.

To sum up, the attapulgite modification method of the present application is used to modify the attapulgite, so that the modified attapulgite has a better application effect in the field of algae treatment than the prior art. In addition, the attapulgite has low price and low applicable cost; the modification reagent in this method does not cause pollution to the environment, and has obvious advantages in the field of algae treatment.

It will be apparent to those skilled in the art that the present invention is not limited to the details of the above-described exemplary embodiments, but that the present invention may be embodied in other specific forms without departing from the spirit or essential characteristics of the invention. Therefore, the embodiments are to be regarded in all respects as illustrative and not restrictive, and the scope of the invention is to be defined by the appended claims rather than the foregoing description, which are therefore intended to fall within the scope of the claims. All changes within the meaning and range of the equivalents of , are included in the present invention. Any reference signs in the claims shall not be construed as limiting the involved claim.

In addition, it should be understood that although this specification is described in terms of embodiments, not every embodiment only includes an independent technical solution, and this description in the specification is only for the sake of clarity, and those skilled in the art should take the specification as a whole , the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art

Finally, it should be noted that: in the description of the present invention, it should be noted that the orientations or positional relationships indicated by the terms "vertical", "upper", "lower", "horizontal", etc. are based on the orientations shown in the accompanying drawings Or the positional relationship is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the indicated device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the present invention.

In the description of the present invention, it should also be noted that, unless otherwise expressly specified and limited, the terms "arranged", "installed", "connected" and "connected" should be understood in a broad sense, for example, it may be a fixed connection, It can also be a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or an indirect connection through an intermediate medium, or the internal communication between the two components. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific situations.

The above descriptions are only preferred embodiments of the present invention, and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still understand the foregoing embodiments. The technical solutions described are modified, or some technical features thereof are equivalently replaced. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

A method for modifying the surface of attapulgite, comprising the following steps:

S1: Substitute magnesium in attapulgite crystals with aluminum ions to improve its treatment performance against algae;

S2: The aggregation of aluminum ions on the surface of attapulgite makes the surface of attapulgite rich in positive charges and enhances its coagulation effect;

S3: put the attapulgite into the sodium hydroxide solution, and perform thermal alkali modification on the natural attapulgite to obtain the alkali-modified attapulgite;

S4: adding aluminum chloride to the alkali-modified attapulgite for reaction and polymerization, and using aluminum chloride to perform inorganic modification on the surface of the attapulgite to obtain modified attapulgite;

In the above technical solution, the step sequence of the thermal alkali modification of attapulgite and the modification of aluminum chloride is limited. In the implementation, it is necessary to first perform thermal and alkali modification on the attapulgite, and then further perform the aluminum chloride inorganic modification on the attapulgite. modified.
A kind of attapulgite surface modification method according to claim 1, is characterized in that:

The specific steps of the thermal modification are: according to step S4, the mined raw ore attapulgite is baked at 0°C-500°C for 1-3 hours to prepare thermally modified attapulgite.
A kind of attapulgite surface modification method according to claim 1, is characterized in that:

The specific steps of the alkali modification are, according to step S4, the mixed reaction system of the thermally modified attapulgite, sodium hydroxide and solvent is reacted under normal temperature conditions for 1-3 hours, and the mixed reaction system should be stirred under the condition of stirring. conduct.
A kind of attapulgite surface modification method according to claim 3, is characterized in that:

The rotational speed of the stirring conditions should be 200-500 r/min, the solvent is deionized water, and the mass ratio of the thermally modified attapulgite to sodium hydroxide is (5-10):1.
A kind of attapulgite surface modification method according to claim 1, is characterized in that:

The specific steps of the aluminum chloride modification are: according to step S3, the mixed reaction system of attapulgite, aluminum chloride and solvent after thermal alkali modification is reacted at 60°C-90°C for 6-10 hours.
A kind of attapulgite surface modification method according to claim 5, is characterized in that:

The mixed reaction system should be carried out under stirring conditions, the rotational speed of the stirring conditions should be 200-500 r/min, and the solvent is deionized water.
A kind of attapulgite surface modification method according to claim 5, is characterized in that:

The mass ratio of the aluminum chloride to the solvent is (10-30):100, and the mass ratio of the alkali-modified attapulgite to the aluminum chloride is (1-3):1.