阅读说明：本技术 一种用于阻隔的瓜尔胶改性膨润土及其制备方法 (Guar gum modified bentonite for blocking and preparation method thereof ) 是由 李茹 张雨萌 于 2021-01-14 设计创作，主要内容包括：本发明公开的一种用于阻隔的瓜尔胶改性膨润土及其制备方法,该瓜尔胶改性膨润土包括钠基膨润土与瓜尔胶,其中瓜尔胶占膨润土质量的0.5-9％。制备方法包括以下步骤1)将去离子水加热至30-50℃,加入相应量的瓜尔胶搅拌溶解；2)膨润土加入聚合物溶液中,继续搅拌制得聚合物膨润土浆液；3)制得膨润土浆液静置3h,随后进行烘干,烘箱保持105℃,24h,制得用于阻隔的瓜尔胶改性膨润土及其制备方法。上述制备方法简单易操作,测定得到的聚合物膨润土的自由膨胀指数较原土有所提高,滤失量、渗透系数下降,极大提高了膨润土的防渗性能。(The invention discloses guar gum modified bentonite for barrier and a preparation method thereof, wherein the guar gum modified bentonite comprises sodium bentonite and guar gum, and the guar gum accounts for 0.5-9% of the mass of the bentonite. The preparation method comprises the following steps of 1) heating deionized water to 30-50 ℃, adding a corresponding amount of guar gum, stirring and dissolving; 2) adding bentonite into the polymer solution, and continuously stirring to obtain polymer bentonite slurry; 3) and standing the prepared bentonite slurry for 3 hours, then drying, keeping the temperature of an oven at 105 ℃ for 24 hours, and preparing the guar gum modified bentonite for obstruction and the preparation method thereof. The preparation method is simple and easy to operate, the free expansion index of the polymer bentonite obtained by determination is improved compared with that of the original soil, the filtration loss and the permeability coefficient are reduced, and the anti-seepage performance of the bentonite is greatly improved.)

1. The guar gum modified bentonite for barrier is characterized by comprising sodium bentonite and guar gum polymer, wherein the guar gum polymer accounts for 0.5-9% of the mass of the sodium bentonite, the sodium bentonite passes through a 200-mesh sieve, and the guar gum has a viscosity of 5000-5500cp and passes through the 200-mesh sieve.

2. The guar modified bentonite for barrier according to claim 1, wherein the guar polymer accounts for 0.5-5% of the mass of the sodium bentonite.

3. The guar gum modified bentonite for barrier according to claim 1, wherein the guar gum modified bentonite for barrier has a free swell index of 26.4-30.5mL/2g, a fluid loss of 15.8-18.6mL, and a permeability coefficient of 0.096-71.2 x 10 measured in deionized water^-12m/s。

4. The method of making guar modified bentonite for barrier of claim 1, characterized by comprising the steps of:

step 1) separating sodium bentonite and guar gum polymer, wherein the mass of the guar gum polymer is 0.5-9% of that of the sodium bentonite;

step 2) taking deionized water, heating to 30-50 ℃, adding the guar gum polymer into the deionized water, and stirring at 20-60 ℃ for 20-30min to completely dissolve the guar gum to obtain a polymer solution;

step 3) adding bentonite into the polymer solution, adjusting the temperature to 60-100 ℃, and continuing stirring for 5-8 hours to prepare polymer bentonite slurry;

and 4) standing the polymer bentonite slurry for 3 hours, drying by an oven, grinding and sieving to obtain the polymer modified bentonite for barrier.

5. The preparation method of the guar gum modified bentonite for barrier as claimed in claim 4, wherein in the step 2), the stirring speed is 150r/min to 350 r/min.

6. The preparation method of the guar gum modified bentonite for barrier according to claim 4, wherein in the step 4), the drying temperature of the oven is 105 ℃, the drying time is 24 hours, and the polymer modified bentonite for barrier is prepared by sieving the ground product through a 200-mesh sieve.

The technical field is as follows:

the invention belongs to the technical field of environmental engineering and environmental geotechnical engineering, and particularly relates to guar gum modified bentonite for blocking and a preparation method thereof.

Background art:

aiming at the characteristics of long heavy metal-organic composite pollution period, complex occurrence state and great difficulty in soil cooperative treatment in northeast regions, a barrier technology is adopted to avoid migration and diffusion of pollutants in a polluted site. The barrier technology is a technology for blocking the way of pollutant migration and diffusion in a soil medium by laying a barrier layer, so that the polluted medium is isolated from the surrounding environment, and the pollutants are prevented from contacting with a human body and being migrated along with precipitation or underground water to further cause harm to the human body and the surrounding environment.

The bentonite is used as a seepage-proofing material, and has excellent moisture absorption expansibility, high adsorbability, low permeability and good self-sealing property, so that the bentonite is widely used for various seepage-proofing projects. The cheap characteristic of bentonite makes the bentonite widely noticed by people. In order to achieve a better anti-seepage effect, the bentonite is modified to reduce the permeability of the bentonite, so that a better barrier property is achieved.

The invention content is as follows:

the invention aims to overcome the defects in the prior art and provides the guar gum modified bentonite for barrier and the preparation method thereof.

In order to achieve the purpose, the invention adopts the following technical scheme:

the guar gum modified bentonite for barrier comprises sodium bentonite and guar gum polymer, wherein the guar gum polymer accounts for 0.5-9% of the mass of the sodium bentonite.

The sodium bentonite is sieved by a 200-mesh sieve.

The guar gum has the viscosity of 5000-5500cp, and is sieved by a 200-mesh sieve.

The guar gum polymer accounts for 0.5-5% of the mass of the sodium bentonite.

Compared with the original soil, the microstructure of the guar gum modified bentonite for blocking has rough surface and forms a plurality of small holes.

The guar gum modified bentonite for barrier has a free expansion index of 26.4-30.5mL/2g, a filtration loss of 15.8-18.6mL and a permeability coefficient of 0.096-71.2 x 10 measured in deionized water^-12m/s。

The preparation method of the guar gum modified bentonite for barrier comprises the following steps:

step 1) separating sodium bentonite and guar gum polymer, wherein the mass of the guar gum polymer is 0.5-9% of that of the sodium bentonite;

step 2) taking deionized water, heating to 30-50 ℃, adding the guar gum polymer into the deionized water, and stirring at 20-60 ℃ for 20-30min to completely dissolve the guar gum to obtain a polymer solution;

step 3) adding bentonite into the polymer solution, adjusting the temperature to 60-100 ℃, and continuing stirring for 5-8 hours to prepare polymer bentonite slurry;

and 4) standing the polymer bentonite slurry for 3 hours, drying by an oven, grinding and sieving to obtain the polymer modified bentonite for barrier.

In the step 1), a water bath constant-temperature magnetic stirring box is used, the addition amount of deionized water is 500mL, and the initial water level in the water bath box is positioned at the scale mark of a 500mL beaker.

In the step 2), the addition amount of the guar gum respectively accounts for 0.5%, 0.8%, 1%, 3%, 5%, 7% and 9% of the mass of the bentonite.

In the step 2), the stirring speed is 150 r/min-350 r/min.

In the step 4), the drying temperature of the oven is 105 ℃, the drying time is 24 hours, and the bentonite polymer is prepared by sieving the bentonite polymer with a 200-mesh sieve after grinding.

The invention has the beneficial effects that:

(1) compared with the original soil, the guar gum modified bentonite provided by the invention has the advantages that the swelling index is improved, the filtration loss is reduced, and the permeability coefficient is reduced;

(2) through a scanning electron microscope image, the surface of the modified bentonite becomes rough, a plurality of small cavities are formed, a barrier is added in the process of transporting the pollutants, and the permeability coefficient is reduced.

Description of the drawings:

figure 1 is an SEM image of guar modified bentonite for barrier prepared in example 3 of the present invention;

figure 2 is an SEM image of guar modified bentonite for barrier prepared in example 2 of the present invention.

The specific implementation mode is as follows:

the present invention will be described in further detail with reference to examples.

Experiments are carried out by controlling a variable method, and under the condition that the amount of the added deionized water is determined to be certain, the researched variables comprise the bentonite mixing amount, the guar gum mixing amount, the temperature and the rotating speed.

The adopted sodium bentonite is provided by Liaoning Guangdong mining industry and is sieved by a 200-mesh sieve.

The guar gum used was supplied by Michelin as G810488, viscosity 5000-.

Example 1

Step 1) a 500ml beaker is selected, deionized water is added, and a constant temperature magnetic stirrer is used for heating to 40 ℃.

And 2) mixing guar gum polymer with deionized water, wherein the adding amount of the guar gum polymer accounts for 3% of the mass of the bentonite, stirring and heating by using a constant-temperature magnetic stirrer, adjusting the temperature to 60 ℃, controlling the rotating speed of a rotor to be 150r/min, and stirring for 30 minutes to prepare a polymer solution.

And 3) sieving bentonite by using a 200-mesh sieve, adding the bentonite into the polymer solution, wherein the mass ratio of the added bentonite to water is 0.05: 1, stirring and heating by using a constant-temperature magnetic stirrer, adjusting the temperature to 60 ℃, controlling the rotating speed of a rotor to be 150r/min, and stirring for 8 hours to form mixed slurry of bentonite and polymer.

And 4) standing the prepared bentonite slurry for 3 hours, then drying at 105 ℃ in an oven for 24 hours, then grinding, and sieving with a 200-mesh sieve to obtain the guar gum modified bentonite for obstruction.

Example 2

Step 1) a 500ml beaker is selected, deionized water is added, and a constant temperature magnetic stirrer is used for heating to 40 ℃.

And 2) mixing guar gum polymer with deionized water, wherein the adding amount of the guar gum polymer accounts for 5% of the mass of the bentonite, stirring and heating by using a constant-temperature magnetic stirrer, adjusting the temperature to 60 ℃, controlling the rotating speed of a rotor to be 200r/min, and stirring for 30 minutes to prepare a polymer solution.

And 3) sieving bentonite by using a 200-mesh sieve, adding the bentonite into the polymer solution, wherein the mass ratio of the added bentonite to water is 0.15: 1, stirring and heating by using a constant-temperature magnetic stirrer, adjusting the temperature to 70 ℃, controlling the rotating speed of a rotor to be 200r/min, and stirring for 8 hours to form mixed slurry of bentonite and polymer.

And 4) standing the prepared bentonite slurry for 3 hours, then drying at 105 ℃ in an oven for 24 hours, then grinding, and sieving with a 200-mesh sieve to obtain the guar gum modified bentonite for obstruction, wherein an SEM image of the bentonite is shown in figure 2.

Example 3

Step 1) a 500ml beaker is selected, deionized water is added, and a constant temperature magnetic stirrer is used for heating to 40 ℃.

And 2) mixing guar gum polymer with deionized water, wherein the adding amount of the guar gum polymer accounts for 1% of the mass of the bentonite, stirring and heating by using a constant-temperature magnetic stirrer, adjusting the temperature to 60 ℃, controlling the rotating speed of a rotor to be 300r/min, and stirring for 30 minutes to prepare a polymer solution.

And 3) sieving bentonite by using a 200-mesh sieve, adding the bentonite into the polymer solution, wherein the mass ratio of the added bentonite to water is 0.1: 1, stirring and heating by using a constant-temperature magnetic stirrer, adjusting the temperature to 80 ℃, controlling the rotating speed of a rotor to be 300r/min, and stirring for 8 hours to form mixed slurry of bentonite and polymer.

And 4) standing the prepared bentonite slurry for 3 hours, then drying at 105 ℃ in an oven for 24 hours, then grinding, and sieving with a 200-mesh sieve to obtain the guar gum modified bentonite for obstruction, wherein an SEM image of the bentonite is shown in figure 1.

Example 4

Step 1) a 500ml beaker is selected, deionized water is added, and a constant temperature magnetic stirrer is used for heating to 40 ℃.

And 2) mixing guar gum polymer with deionized water, wherein the adding amount of the guar gum polymer accounts for 7% of the mass of the bentonite, stirring and heating by using a constant-temperature magnetic stirrer, adjusting the temperature to 60 ℃, controlling the rotating speed of a rotor to be 250r/min, and stirring for 30 minutes to prepare a polymer solution.

And 3) sieving bentonite by using a 200-mesh sieve, adding the bentonite into the polymer solution, wherein the mass ratio of the added bentonite to water is 0.2: 1, stirring and heating by using a constant-temperature magnetic stirrer, adjusting the temperature to 100 ℃, controlling the rotating speed of a rotor to be 250r/min, and stirring for 8 hours to form mixed slurry of bentonite and polymer.

And 4) standing the prepared bentonite slurry for 3 hours, then drying at 105 ℃ in an oven for 24 hours, then grinding, and sieving with a 200-mesh sieve to obtain the guar gum modified bentonite for obstruction.

Example 5

Step 1) a 500ml beaker is selected, deionized water is added, and a constant temperature magnetic stirrer is used for heating to 40 ℃.

And 2) mixing guar gum polymer with deionized water, wherein the adding amount of the guar gum polymer accounts for 9% of the mass of the bentonite, stirring and heating by using a constant-temperature magnetic stirrer, adjusting the temperature to 60 ℃, regulating the rotating speed of a rotor to 350r/min, and stirring for 30 minutes to prepare a polymer solution.

And 3) sieving bentonite by using a 200-mesh sieve, adding the bentonite into the polymer solution, wherein the mass ratio of the added bentonite to water is 0.25: 1, stirring and heating by using a constant-temperature magnetic stirrer, adjusting the temperature to 90 ℃, regulating the rotating speed of a rotor to 350r/min, and stirring for 8 hours to form mixed slurry of bentonite and polymer.

And 4) standing the prepared bentonite slurry for 3 hours, then drying at 105 ℃ in an oven for 24 hours, then grinding, and sieving with a 200-mesh sieve to obtain the guar gum modified bentonite for obstruction.

Example 6

Step 1) a 500ml beaker is selected, deionized water is added, and a constant temperature magnetic stirrer is used for heating to 40 ℃.

And 2) mixing guar gum polymer with deionized water, wherein the adding amount of the guar gum polymer accounts for 0.5 percent of the mass of the bentonite, stirring and heating by using a constant-temperature magnetic stirrer, adjusting the temperature to 60 ℃, controlling the rotating speed of a rotor to be 280r/min, and stirring for 30 minutes to prepare a polymer solution.

And 3) sieving bentonite by using a 200-mesh sieve, adding the bentonite into the polymer solution, wherein the mass ratio of the added bentonite to water is 0.15: 1, stirring and heating by using a constant-temperature magnetic stirrer, adjusting the temperature to 90 ℃, controlling the rotating speed of a rotor to be 280r/min, and stirring for 8 hours to form mixed slurry of bentonite and polymer.

And 4) standing the prepared bentonite slurry for 3 hours, then drying at 105 ℃ in an oven for 24 hours, then grinding, and sieving with a 200-mesh sieve to obtain the guar gum modified bentonite for obstruction.

Example 7

Step 1) a 500ml beaker is selected, deionized water is added, and a constant temperature magnetic stirrer is used for heating to 40 ℃.

And 2) mixing guar gum polymer with deionized water, wherein the adding amount of the guar gum polymer accounts for 0.8 percent of the mass of the bentonite, stirring and heating by using a constant-temperature magnetic stirrer, adjusting the temperature to 60 ℃, regulating the rotating speed of a rotor to 260r/min, and stirring for 30 minutes to prepare a polymer solution.

And 3) sieving bentonite by using a 200-mesh sieve, adding the bentonite into the polymer solution, wherein the mass ratio of the added bentonite to water is 0.20: 1, stirring and heating by using a constant-temperature magnetic stirrer, adjusting the temperature to 90 ℃, controlling the rotating speed of a rotor to be 260r/min, and stirring for 8 hours to form mixed slurry of bentonite and polymer.

And 4) standing the prepared bentonite slurry for 3 hours, then drying at 105 ℃ in an oven for 24 hours, then grinding, and sieving with a 200-mesh sieve to obtain the guar gum modified bentonite for obstruction.

The materials prepared in examples 1-7 were subjected to the free swell index test, the fluid loss test, and the permeability coefficient test, respectively, and the specific data are shown in tables 1-3 below, and SEM characterization was performed.

TABLE 1

TABLE 2

TABLE 3