Preparation of cationic cellulose modified magnesium aluminum silicate and method for treating wastewater

Abstract

The application discloses a kind of cation cellulose modified magnesium aluminum silicate preparation and wastewater treatment method, specifically related to wastewater treatment technical field, including the following steps: step one: take cation cellulose and dissolve in clean water, stirring is dissolved uniformly;Step two: add dry, crushed and sieved magnesium aluminum silicate, reaction is carried out, and cation cellulose modified magnesium aluminum silicate is obtained;Step three: product is filtered, washed, and then placed in 110 DEG C constant temperature baking 2h;Step four: after drying, the product is crushed, and passes through 100 mesh screen, and cation cellulose modified magnesium aluminum silicate that can simultaneously treat anion and cation wastewater ≤100 mesh is obtained.The application uses cation cellulose to intercalate modification for magnesium aluminum silicate for wastewater treatment, and the magnesium aluminum silicate modified by cation cellulose, in addition to having the performance of general organic modified bentonite, also has the advantages of cheap price, higher efficiency, and can simultaneously adsorb anion and cation in wastewater, is convenient for use.

Description

Technical Field

[0001] This invention relates to the field of wastewater treatment technology, and more specifically, to a method for preparing cationic cellulose-modified magnesium aluminum silicate and treating wastewater thereon. Background Technology

[0002] Bentonite is a clay mineral widely distributed in nature and belongs to non-metallic minerals. Due to its electrical charge and large specific surface area, bentonite has good ion exchange capacity and adsorption performance, and can be used to remove a variety of pollutants. However, due to the strong hydrophilicity of the surface silicon-oxygen structure and the hydrolysis of a large number of exchangeable cations in the interlayer, a thin water film usually exists on the surface of natural bentonite, which limits its application in aqueous solutions.

[0003] Organically modified bentonite can solve the above problems. Currently, commonly used organically modified bentonite is generally obtained by intercalation modification through cation exchange between organic cationic quaternary ammonium salts and bentonite layers. For example, CN104028212A describes a method for preparing organically modified bentonite for adsorbing thiocyanate ions, which uses hexadecyltrimethylammonium bromide (CTAB) to organically modify bentonite. Another example is CN103240051A, a method for treating wastewater with composite cationic modified bentonite, which uses octadecyltrimethylammonium bromide (OTMAB) to organically modify bentonite. Organically modified bentonite increases the interlayer spacing and specific surface area, increasing the effective adsorption sites and improving its adsorption of substances that are poorly soluble in water, have large molecular weights, and complex structures. However, this modified bentonite mainly adsorbs polymers and inorganic anions in solution, and has difficulty adsorbing heavy metal cations. In addition, commonly used organic cationic quaternary ammonium salts, such as CTAB and OTMAB, are expensive and difficult to promote.

[0004] Magnesium aluminum silicate is also a clay mineral similar to kaolinite, widely found in nature. It has a 2:1 layered silicate structure similar to bentonite. Magnesium aluminum silicate can also be prepared by modifying natural bentonite. The principle is to remove high-valence cations between layers through chemical modification, allowing Li+, K+, Na+ and water molecules to be adsorbed between the layers. At the same time, it causes the crystal to expand along the c-axis, leading to the initial dissociation of the layered structure, thus preparing magnesium aluminum silicate. Magnesium aluminum silicate has better temperature stability and acid resistance than bentonite. It is a material with a very large specific surface area and a very developed microporous system, thus having better dispersibility and adsorption properties than bentonite.

[0005] In nature, cellulose is the most widely distributed and abundant polymer material. It has the characteristics of wide availability, low price, recyclability, easy biodegradability and chemical modification, and has great application potential. Cellulose is a macromolecular polysaccharide composed of D glucose linked by β-1,4 glycosidic bonds. Due to the large number of hydroxyl groups, it can coordinate with metal cations to form metal coordination compounds and is also often used as an adsorbent material.

[0006] Cationic cellulose, also known as cationic hydroxyethyl cellulose, is obtained by reacting hydroxyethyl cellulose with a cationic etherifying agent. It is relatively inexpensive. In addition to the properties of cellulose, the quaternary ammonium salt cations in cationic cellulose can also exchange with the cations in the layered silicate structure, intercalating and modifying the layered silicate material to make the modified material positively charged and capable of binding with negatively charged anions. In addition, the large number of hydroxyl groups in cellulose can complex with heavy metal cations, thus enabling the material to remove both anions and cations from the solution.

[0007] In the existing technology, most of the techniques for modifying bentonite are organic cationic quaternary ammonium salts. This method is expensive, inefficient, and cannot simultaneously adsorb anions and cations in wastewater.

[0008] Therefore, there is an urgent need for a method for preparing cationic cellulose-modified magnesium aluminum silicate and for wastewater treatment. Summary of the Invention

[0009] To overcome the aforementioned deficiencies of the prior art, embodiments of the present invention provide a method for preparing cationic cellulose-modified magnesium aluminum silicate and for wastewater treatment. The present invention uses cationic cellulose to intercalate and modify magnesium aluminum silicate for wastewater treatment. In addition to possessing the properties of general organic-modified bentonite, the cationic cellulose-modified magnesium aluminum silicate is cheaper, more efficient, and can simultaneously adsorb anions and cations in wastewater. It has good practical performance and is easy to promote and use, thereby solving the problems mentioned in the background art.

[0010] To achieve the above objectives, the present invention provides the following technical solution: a method for preparing cationic cellulose-modified magnesium aluminum silicate, comprising the following steps:

[0011] Step 1: Dissolve cationic cellulose in clean water and stir until dissolved.

[0012] Step 2: Add dried, pulverized and sieved magnesium aluminum silicate, and react to obtain cationic cellulose-modified magnesium aluminum silicate;

[0013] Step 3: The product is filtered, washed, and then baked at a constant temperature of 110℃ for 2 hours;

[0014] Step 4: The dried product is pulverized and passed through a 100-mesh sieve to obtain cationic cellulose-modified magnesium aluminum silicate with a mesh size of ≤100, which can simultaneously treat anionic and cationic wastewater.

[0015] In a preferred embodiment, the cationic cellulose in step one and the magnesium aluminum silicate in step two have weight compositions of 60-40% and 40-60%, respectively.

[0016] In a preferred embodiment, the cationic cellulose in step one is JR-400.

[0017] In a preferred embodiment, the reaction temperature in step two is 20–100°C, and the reaction time is 1–4 hours.

[0018] A wastewater treatment method using cationic cellulose-modified magnesium aluminum silicate, comprising the preparation method of cationic cellulose-modified magnesium aluminum silicate as described in any one of the above-mentioned methods and the following steps:

[0019] Step 1: When treating mixed cation and anion wastewater, adjust the pH value of the wastewater to the appropriate level according to the type of ions to be treated.

[0020] Step 2: Add cationic cellulose-modified magnesium aluminum silicate for wastewater treatment.

[0021] In a preferred embodiment, the cationic cellulose-modified magnesium aluminum silicate for Cr2O7 2− During treatment, the maximum adsorption capacity is achieved at pH=2.

[0022] In a preferred embodiment, the cationic cellulose-modified magnesium aluminum silicate-MnO4 − Cd 2+ Cu 2+ During treatment, the maximum adsorption capacity is achieved at pH=3.

[0023] In a preferred embodiment, the cationic cellulose-modified magnesium aluminum silicate for Co 2+ During treatment, the maximum adsorption capacity is achieved at pH=4.

[0024] In a preferred embodiment, in MnO4 − Cr2O7 2− Cd 2+ Co 2+ and Cu 2+ In the mixed wastewater solution, within the pH range of 1 to 6, the cationic cellulose-modified magnesium aluminum silicate exhibits varying degrees of adsorption for all five ions.

[0025] The technical effects and advantages of this invention are as follows:

[0026] This invention uses cationic cellulose to intercalate and modify magnesium aluminum silicate for wastewater treatment. Magnesium aluminum silicate modified with cationic cellulose has the properties of general organic-modified bentonite, but it is cheaper, more efficient, and can simultaneously adsorb anions and cations in wastewater. It has good practical effects and is easy to promote and use. Attached Figure Description

[0027] Figure 1 The XRD diffraction patterns of magnesium aluminum silicate before and after JR400 modification according to the present invention are shown.

[0028] Figure 2 The image shows the Zeta potential of the JR400 modified magnesium aluminum silicate of the present invention at different pH values.

[0029] The attached figures are labeled as follows: a) Unmodified; b) Modified. Detailed Implementation

[0030] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0031] As attached Figure 1 and attached Figure 2 As shown, this invention provides a method for preparing cationic cellulose-modified magnesium aluminum silicate, comprising the following steps:

[0032] Step 1: Dissolve cationic cellulose in clean water and stir until dissolved.

[0033] Step 2: Add dried, pulverized and sieved magnesium aluminum silicate, and react to obtain cationic cellulose-modified magnesium aluminum silicate;

[0034] Step 3: The product is filtered, washed, and then baked at a constant temperature of 110℃ for 2 hours;

[0035] Step 4: The dried product is pulverized and passed through a 100-mesh sieve to obtain cationic cellulose-modified magnesium aluminum silicate with a mesh size of ≤100, which can simultaneously treat anionic and cationic wastewater.

[0036] Compared to the cationic cellulose in step one, the magnesium aluminum silicate in step two has a weight composition of 60-40% and 40-60%, respectively.

[0037] The cationic cellulose used in step one is JR-400.

[0038] In step two, the reaction temperature is 20–100°C and the reaction time is 1–4 hours.

[0039] A wastewater treatment method using cationic cellulose-modified magnesium aluminum silicate, comprising the preparation method of cationic cellulose-modified magnesium aluminum silicate as described in any one of the above-mentioned methods and the following steps:

[0040] Step 1: When treating mixed cation and anion wastewater, adjust the pH value of the wastewater to the appropriate level according to the type of ions to be treated.

[0041] Step 2: Add cationic cellulose-modified magnesium aluminum silicate for wastewater treatment.

[0042] The cationic cellulose-modified magnesium aluminum silicate for Cr2O7 2− During treatment, the maximum adsorption capacity is achieved at pH=2.

[0043] The cationic cellulose-modified magnesium aluminum silicate to MnO4 − Cd 2+ Cu 2+ During treatment, the maximum adsorption capacity is achieved at pH=3.

[0044] The cationic cellulose-modified magnesium aluminum silicate for Co 2+ During treatment, the maximum adsorption capacity is achieved at pH=4.

[0045] In MnO4 − Cr2O7 2− Cd 2+ Co 2+ and Cu 2+ In the mixed wastewater solution, within the pH range of 1 to 6, the cationic cellulose-modified magnesium aluminum silicate exhibits varying degrees of adsorption for all five ions. Example

[0046] At a reaction temperature of 80℃, a JR400 concentration of 1.5%, and a reaction time of 2 hours, 1.00 g of magnesium aluminum silicate was taken, and JR400 was added at a mass ratio of magnesium aluminum silicate to JR400 of 1:0.8. The required amount of JR400 for the reaction was 0.26 g. Example

[0047] At a reaction temperature of 40℃, a JR400 concentration of 1%, and a reaction time of 2 hours, 1.00 g of magnesium aluminum silicate was taken, and JR400 was added at a mass ratio of magnesium aluminum silicate to JR400 of 1:1. The required amount of JR400 for the reaction was 0.53 g. Example

[0048] At a reaction temperature of 60℃, a JR400 concentration of 1.5%, and a reaction time of 2 hours, 1.00 g of magnesium aluminum silicate was taken, and JR400 was added at a mass ratio of magnesium aluminum silicate to JR400 of 1:1. The required amount of JR400 for the reaction was 0.55 g.

[0049] As attached Figure 1 As shown, the diffraction peak of unmodified magnesium aluminum silicate at 7.19° decreased to 6.37° after modification with JR400, indicating that JR400 was successfully intercalated into the layered structure of magnesium aluminum silicate.

[0050] As attached Figure 2 As shown, an appropriate amount of JR400 modified magnesium aluminum silicate was prepared into a suspension with deionized water, and the pH was adjusted to different values ​​with dilute HCl or NaOH. The zeta was measured. In the acidic range, JR400 modified magnesium aluminum silicate is positively charged and can electrostatically attract anions.

[0051] Optimization of single anion and cation treatments using modified magnesium aluminum silicate:

[0052] In five 100mL Erlenmeyer flasks, 50mL solutions of KMnO4, K2Cr2O7, CdSO4, CoSO4•7H2O, and CuSO4•5H2O were prepared, with concentrations (w / v) of 0.032%, 0.020%, 0.046%, 0.238%, and 0.014%, respectively. 0.050g of JR00 modified magnesium aluminum silicate was added to each flask. The solutions were adjusted to different pH values, stirred at room temperature for 3 hours under sealed conditions, and the adsorption capacity of the modified magnesium aluminum silicate for various anions and cations was measured to optimize the pH.

[0053] pH=3, JR00 modified magnesium aluminum silicate against MnO4 − The maximum adsorption capacity is 52.8 mg / g;

[0054] pH=2, JR00 modified magnesium aluminum silicate against Cr2O7 2− The maximum adsorption capacity is 88.5 mg / g;

[0055] pH=3, JR00 modified magnesium aluminum silicate for Cd 2+ The maximum adsorption capacity is 44.8 mg / g;

[0056] pH=4, JR00 modified magnesium aluminum silicate for Co 2+ The maximum adsorption capacity is 19.3 mg / g;

[0057] pH=3, JR00 modified magnesium aluminum silicate for Cu 2+ The maximum adsorption capacity is 27.2 mg / g. Example

[0058] In a 100 mL Erlenmeyer flask, measured amounts of KMnO4, K2Cr2O7, CdSO4, CoSO4•7H2O, and CuSO4•5H2O were added to prepare a 50 mL mixture with concentrations of 0.032%, 0.020%, 0.046%, 0.238%, and 0.014%, respectively. Then, 1.250 g of JR00 modified magnesium aluminum silicate was added, and the pH of the solution was adjusted to 2. The mixture was stirred at room temperature for 3 hours under sealed conditions. The removal rates of various anions and cations by the modified magnesium aluminum silicate were measured.

[0059] MnO4 − 99.5%;

[0060] Cr2O7 2− 99.8%;

[0061] Cd 2+ 77.7%;

[0062] Co 2+ 13.3%;

[0063] Cu 2+ 99.6%. Example

[0064] In a 100 mL Erlenmeyer flask, measured amounts of KMnO4, K2Cr2O7, CdSO4, CoSO4•7H2O, and CuSO4•5H2O were added to prepare a 50 mL mixture with concentrations of 0.032%, 0.020%, 0.046%, 0.238%, and 0.014%, respectively. Then, 1.250 g of JR00 modified magnesium aluminum silicate was added, and the pH of the solution was adjusted to 3. The mixture was stirred at room temperature for 3 hours under sealed conditions. The removal rates of various anions and cations by the modified magnesium aluminum silicate were measured.

[0065] MnO4 − 99.7%;

[0066] Cr2O7 2− 99.7%;

[0067] Cd 2+ 90.5%;

[0068] Co 2+ 16.5%;

[0069] Cu 2+ 99.8%. Example

[0070] In a 100 mL Erlenmeyer flask, measured amounts of KMnO4, K2Cr2O7, CdSO4, CoSO4•7H2O, and CuSO4•5H2O were added to prepare a 50 mL mixture with concentrations of 0.032%, 0.020%, 0.046%, 0.238%, and 0.014%, respectively. Then, 1.250 g of JR00 modified magnesium aluminum silicate was added, and the pH of the solution was adjusted to 4. The mixture was stirred at room temperature for 3 hours under sealed conditions. The removal rates of various anions and cations by the modified magnesium aluminum silicate were measured.

[0071] MnO4 − 90.6%;

[0072] Cr2O7 2− 99.4%;

[0073] Cd 2+ 86.8%;

[0074] Co 2+ 19.3%;

[0075] Cu 2+ : 99.3%.

[0076] This invention uses cationic cellulose to intercalate and modify magnesium aluminum silicate for wastewater treatment. Magnesium aluminum silicate modified with cationic cellulose has the properties of general organic-modified bentonite, but it is cheaper, more efficient, and can simultaneously adsorb anions and cations in wastewater. It has good practical effects and is easy to promote and use.

[0077] In conclusion, the above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for preparing cationic cellulose-modified magnesium aluminum silicate, characterized in that, Includes the following steps: Step 1: Dissolve cationic cellulose in clean water and stir until dissolved. Step 2: Add dried, pulverized and sieved magnesium aluminum silicate, and react to obtain cationic cellulose-modified magnesium aluminum silicate; Step 3: The product is filtered, washed, and then baked at a constant temperature of 110℃ for 2 hours; Step 4: The dried product is pulverized and passed through a 100-mesh sieve to obtain cationic cellulose-modified magnesium aluminum silicate with a mesh size of ≤100, which can simultaneously treat anionic and cationic wastewater.

2. The method for preparing cationic cellulose-modified magnesium aluminum silicate according to claim 1, characterized in that: Compared to the cationic cellulose in step one, the magnesium aluminum silicate in step two has a weight composition of 60-40% and 40-60%, respectively.

3. The method for preparing cationic cellulose-modified magnesium aluminum silicate according to claim 1, characterized in that: The cationic cellulose used in step one is JR-400.

4. The method for preparing cationic cellulose-modified magnesium aluminum silicate according to claim 1, characterized in that: In step two, the reaction temperature is 20–100°C and the reaction time is 1–4 hours.

5. A wastewater treatment method using cationic cellulose-modified magnesium aluminum silicate, characterized in that, The method for preparing cationic cellulose-modified magnesium aluminum silicate according to any one of claims 1-4, and the following steps: Step 1: When treating mixed cation and anion wastewater, adjust the pH value of the wastewater to the appropriate level according to the type of ions to be treated. Step 2: Add cationic cellulose-modified magnesium aluminum silicate for wastewater treatment.

6. A wastewater treatment method using cationic cellulose-modified magnesium aluminum silicate according to claim 5, characterized in that: The cationic cellulose-modified magnesium aluminum silicate for Cr2O7 2− During treatment, the maximum adsorption capacity is achieved at pH=2.

7. A wastewater treatment method using cationic cellulose-modified magnesium aluminum silicate according to claim 5, characterized in that: The cationic cellulose-modified magnesium aluminum silicate to MnO4 − Cd 2+ Cu 2+ During treatment, the maximum adsorption capacity is achieved at pH=3.

8. A wastewater treatment method using cationic cellulose-modified magnesium aluminum silicate according to claim 5, characterized in that: The cationic cellulose-modified magnesium aluminum silicate for Co 2+ During treatment, the maximum adsorption capacity is achieved at pH=4.

9. A wastewater treatment method using cationic cellulose-modified magnesium aluminum silicate according to claim 5, characterized in that: In MnO4 − Cr2O7 2− Cd 2+ Co 2+ and Cu 2+ In the mixed wastewater solution, within the pH range of 1 to 6, the cationic cellulose-modified magnesium aluminum silicate exhibits varying degrees of adsorption for all five ions.

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