A water treatment material for electrically enhanced adsorption filtration and its preparation method and application

Abstract

The present invention relates to the technical field of polymer materials, and specifically discloses a water treatment material for electrically enhanced adsorption filtration and a preparation method and application thereof. The present invention comprises the following steps: (1) ultrasonically cleaning the melamine sponge, drying it, placing it in a tube furnace, introducing a protective gas, and setting the heating rate to 4 to 6°C / min ‑1 , after preheating, continue to heat up to 900-1100°C, keep warm, cool to room temperature, and obtain ultra-light flexible carbon sponge; (2) dissolve tris(hydroxymethyl)aminomethane in a solvent to obtain a solution, adjust the pH to 8.4-8.6, then add dopamine and polyethyleneimine, mix, add ultra-light flexible carbon sponge, stir and react for 10-14h, and obtain a water treatment material for electrically enhanced adsorption and filtration. The present invention uses N-rich melamine sponge as a precursor, which has a larger specific surface area; the sponge has good conductivity after high-temperature carbonization of inert gas; dopamine and polyethyleneimine are modified to improve their adsorption potential.

Description

Technical Field

[0001] The invention relates to the technical field of polymer materials, and in particular to a water treatment material for electrically enhanced adsorption and filtration, and a preparation method and application thereof. Background Art

[0002] As the global population continues to grow, water issues are becoming more prominent. According to a United Nations report, about a quarter of the world's population lives in areas with water scarcity, and this number is expected to continue to grow in the coming decades. At the same time, factors such as overexploitation of water resources, pollution and climate change also pose a threat to the global water supply. In many regions, water resources face increasingly urgent challenges due to the rapid development of urbanization and industrialization. These challenges not only affect people's daily lives, but also have a profound impact on the environment, agriculture and industry.

[0003] In order to solve the problems of water scarcity and water pollution, researchers and engineers have been working tirelessly to find efficient and sustainable water treatment methods. Although traditional water treatment methods, such as chemical treatment and biological treatment, can purify water to a certain extent, there are also some problems that cannot be ignored. For example, chemical methods often consume huge amounts of energy and chemicals, while biological methods are limited by environmental conditions such as climate and water quality. Therefore, people are in urgent need of a new water treatment technology that can efficiently remove pollutants from water.

[0004] Among various water treatment technologies, adsorption technology has attracted much attention due to its high efficiency and universality. Adsorption is a method of removing pollutant particles from water by aggregating them on the surface or internal structure of the adsorbent. Compared with other treatment methods, adsorption technology has many advantages, such as easy operation, no restrictions on environmental factors, and high applicability to a variety of pollutants. Due to its flexibility and high efficiency, adsorption technology has been widely used in water treatment, wastewater treatment, drinking water purification and other fields. However, traditional adsorption materials such as activated carbon and lignin still have problems such as low adsorption efficiency and difficulty in regeneration. Therefore, it is necessary to provide a water treatment material for electrically enhanced adsorption filtration and its preparation method and application, so as to produce efficient and recyclable adsorption materials and further improve the removal efficiency of pollutants. Summary of the invention

[0005] The present invention aims to solve at least one of the technical problems existing in the above-mentioned prior art. To this end, the present invention proposes a water treatment material for electrically enhanced adsorption filtration and a preparation method and application thereof, so as to produce a highly efficient and recyclable adsorption material, further improve the removal efficiency of pollutants, and improve the regeneration efficiency of the adsorbent.

[0006] A first aspect of the present invention provides a method for preparing a water treatment material for electrically enhanced adsorption filtration.

[0007] Specifically, the following steps are included:

[0008] (1) Ultrasonic cleaning of melamine sponge, drying, placing in a tube furnace, introducing protective gas, and setting the heating rate to 4-6 °C min -1 After preheating, the temperature is continued to rise to 900-1100°C, kept warm, and cooled to room temperature to obtain an ultra-light and flexible carbon sponge;

[0009] (2) Dissolve tris(hydroxymethyl)aminomethane in a solvent to obtain a tris(hydroxymethyl)aminomethane solution, adjust the pH to 8.4-8.6, add dopamine and polyethyleneimine, mix, add ultralight flexible carbon sponge, stir and react for 10-14 hours, and obtain an electrically enhanced adsorption and filtration water treatment material.

[0010] Preferably, in step (1), the step of placing in a tubular furnace further comprises first placing the dried melamine sponge in a corundum boat, and then placing the corundum boat in the tubular furnace.

[0011] Further preferably, the tube furnace is a quartz tube furnace.

[0012] Preferably, in step (1), the ultrasonic cleaning time is 8 to 12 minutes.

[0013] Further preferably, the ultrasonic cleaning time is 10 minutes.

[0014] Preferably, in step (1), the rate of introducing the protective gas is 80 to 120 mL / min.

[0015] Further preferably, in step (1), the rate of introducing the protective gas is 100 mL / min.

[0016] Preferably, in step (1), the melamine sponge is a cylinder with a bottom diameter of 0.5 to 1.5 cm and a height of 4 to 6 cm.

[0017] Further preferably, the melamine sponge is a cylinder with a bottom diameter of 1 cm and a height of 5 cm.

[0018] Preferably, in step (1), the drying temperature is 100-110° C. and the drying time is 8-16 hours.

[0019] Further preferably, in step (1), the drying temperature is 105° C. and the drying time is 8 to 16 hours.

[0020] Preferably, in step (1), the protective gas includes Ar, N 2 , H 2 At least one of .

[0021] Preferably, in step (1), the preheating temperature is 200-300° C. and the preheating time is 20-40 min.

[0022] More preferably, the preheating temperature is 250° C. and the preheating time is 30 min.

[0023] Preferably, in step (1), the insulation time is 100 to 150 minutes.

[0024] More preferably, the insulation time is 120 minutes.

[0025] Preferably, in step (1), the temperature is continued to be raised to 1000°C.

[0026] Preferably, in step (1), the heating rate is set to 5°C·min -1 .

[0027] Preferably, in step (2), the mass concentration of the tris(hydroxymethyl)aminomethane solution is 0.1-1%.

[0028] More preferably, the mass concentration of the tris(hydroxymethyl)aminomethane solution is 0.6%.

[0029] Preferably, in step (2), the mass ratio of dopamine to polyethyleneimine is 1:1-4.

[0030] Further preferably, the mass ratio of dopamine to polyethyleneimine is 1:2.

[0031] Preferably, in step (2), the solvent is ultrapure water.

[0032] Preferably, in step (2), the pH is adjusted to 8.5.

[0033] A second aspect of the present invention provides a water treatment material for electrically enhanced adsorption filtration.

[0034] Specifically, the water treatment material for electrically enhanced adsorption and filtration is prepared by the preparation method of the first aspect.

[0035] A third aspect of the present invention provides an application of an electrically enhanced adsorption and filtration water treatment material in the adsorption and removal of a broad spectrum of pollutants in water.

[0036] Preferably, the water treatment material for electrically enhanced adsorption filtration has at least one of the following functions (1) to (2):

[0037] (1) The adsorption capacity of water treatment materials for electrically enhanced adsorption filtration is enhanced under the action of the electric field, thereby improving the adsorption efficiency of organic matter and nutrients in water;

[0038] (2) The pore size of the water treatment material for electrically enhanced adsorption filtration is adjustable. Filtration is performed during compression, so that the sponge can adsorb pollutants in a compressed state. Backwashing is performed during decompression, so that the material can be efficiently adsorbed and regenerated.

[0039] Preferably, the broad-spectrum pollutants in water bodies include total suspended solids, total organic carbon, ammonia nitrogen, phosphates, and organic matter.

[0040] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0041] (1) The present invention uses N-rich melamine sponge as a precursor, which has a larger specific surface area;

[0042] (2) After being carbonized by inert gas at high temperature, the sponge has good electrical conductivity;

[0043] (3) Dopamine and polyethyleneimine were modified to prepare water treatment materials with electrically enhanced adsorption and filtration, further improving the capacitance performance and hydrophilicity of carbon sponge and increasing its adsorption potential;

[0044] (4) Using the electric field to significantly improve the adsorption efficiency of organic matter and nutrients in water;

[0045] (5) By utilizing the compressibility of water treatment materials for electrically enhanced adsorption filtration, the sponge can adsorb pollutants in a compressed state and backwash the sponge in a decompressed state, thereby achieving efficient adsorption and regeneration of the material. BRIEF DESCRIPTION OF THE DRAWINGS

[0046] Figure 1 is a schematic diagram of the reaction system structure;

[0047] Figure 2 This is a diagram showing the effect of the water treatment material for electrically enhanced adsorption filtration on TOC and SS removal in Example 1;

[0048] Figure 3 This is a diagram showing the effect of the water treatment material for electrically enhanced adsorption filtration in Example 1 on the removal of ammonia nitrogen and phosphate;

[0049] Figure 4 Decompression of the water treatment material for electrical enhanced adsorption filtration in Example 1 / backwashing and desorption of NH under compression 4 + Efficiency graph;

[0050] Figure 5 Decompression of the water treatment material for electrical enhanced adsorption filtration in Example 1 / backwashing and desorption of PO under compression 4 3- Efficiency graph;

[0051] Figure 6 This is a cyclic stability diagram of the phosphorus removal performance of the water treatment material for electrically enhanced adsorption filtration in Example 1;

[0052] Figure 7 This is a diagram showing the effect of the water treatment material for electrically enhanced adsorption and filtration on the removal of organic pollutants in Example 1;

[0053] Figure 8 This is a diagram showing the removal effect of TOC and SS by ultra-light flexible carbon sponge in comparative example 1;

[0054] Fig. 9 This is a diagram showing the removal effect of ammonia nitrogen and phosphate by the ultra-light flexible carbon sponge in comparative example 1. DETAILED DESCRIPTION

[0055] In order to make the technical scheme of the present invention more clearly understood by those skilled in the art, the following embodiments are listed for illustration. It should be pointed out that the following embodiments do not limit the protection scope of the present invention.

[0056] Unless otherwise specified, the raw materials, reagents or devices used in the following examples can be obtained from conventional commercial sources or by existing known methods.

[0057] Example 1

[0058] Water treatment material for electrically enhanced adsorption filtration and preparation method thereof.

[0059] The specific steps include:

[0060] (1) Commercial melamine sponge was cut into cylinders with a bottom diameter of 1 cm and a height of 5 cm. Ultrasonic cleaning was performed with ultrapure water in an ultrasonic cleaner for 10 min. The sponge was placed in a 105°C oven for 16 h to remove the water adsorbed by the sponge during the cleaning process. The cleaned sponge was placed in a corundum boat to make the heat transfer more uniform. The boat was placed in a quartz tube furnace and an Ar / H 2 As protective gas, the ventilation rate was set to 100 mL / min. The heating rate of the tube furnace was set to 5 °C min -1 , preheated at 250°C for 30 minutes to remove part of the bound water of the sponge, then continued to heat up to 1000°C, kept heated at this temperature for 120 minutes, and then naturally cooled slowly to room temperature to obtain an ultra-light and flexible carbon sponge.

[0061] (2) 0.6 g of Tris(hydroxymethyl)aminoethane (Tris) was dissolved in 100 mL of ultrapure water. The pH value of the Tris(hydroxymethyl)aminoethane solution was about 10.5. The pH was adjusted to 8.5 using dilute hydrochloric acid. Then 0.2 g of dopamine (DA) and 0.4 g of polyethyleneimine (PEI) were added and mixed. An ultralight flexible carbon sponge was placed in the mixture and stirred on a shaker for 12 h to obtain an electrically enhanced adsorption and filtration water treatment material.

[0062] Comparative Example 1

[0063] Ultralight flexible carbon sponge and preparation method thereof.

[0064] The difference from Example 1 is that Comparative Example 1 does not contain the step of amino modification, and specifically comprises the following steps:

[0065] (1) Commercial melamine sponge was cut into cylinders with a bottom diameter of 1 cm and a height of 5 cm, and ultrasonically cleaned with ultrapure water in an ultrasonic cleaner for 10 min. It was placed in a 105°C oven for 16 h to remove the moisture adsorbed by the sponge during the cleaning process. The cleaned sponge was placed in a corundum boat to make the heat transfer more uniform. The boat was placed in a quartz tube furnace, and Ar / H2 was introduced as a protective gas with a ventilation rate of 100 mL / min. The heating rate of the tube furnace was set to 5°C·min-1, and it was preheated at 250°C for 30 min to remove some of the bound water in the sponge, and then the temperature was continued to rise to 1000°C, and it was kept heated at this temperature for 120 min, and then naturally cooled slowly to room temperature to obtain an ultralight and flexible carbon sponge.

[0066] Comparative Example 2

[0067] Amino modified sponge and preparation method thereof.

[0068] The difference from Example 1 is that Comparative Example 2 does not contain the step of carbonizing the melamine sponge, and specifically comprises the following steps:

[0069] (1) 0.6 g of Tris(hydroxymethyl)aminoethane (Tris) was dissolved in 100 mL of ultrapure water. The pH value of the Tris(hydroxymethyl)aminoethane solution was about 10.5. The pH was adjusted to 8.5 using dilute hydrochloric acid. 0.2 g of dopamine (DA) and 0.4 g of polyethyleneimine (PEI) were added and mixed. A commercial melamine sponge was placed in the mixture and stirred on a shaker for 12 h to obtain an amino-modified sponge.

[0070] Adsorption removal performance test:

[0071] 1. Adsorption and removal of total suspended solids (SS) and total organic carbon (TOC) in water without electric field enhancement.

[0072] use Figure 1 The reaction system shown in the figure is used for auxiliary testing. The reaction system consists of a reactor, a peristaltic pump, a water storage tank, and a DC power supply. Domestic sewage is taken as the water sample to be purified, and three pieces of water treatment materials for electrically enhanced adsorption and filtration prepared in Example 1 are placed at the anode and cathode, respectively. Figure 2 As shown, after 150 min of filtration time, 63% removal of TOC and 78% removal of SS can be achieved.

[0073] 2. Adsorption and removal of nitrogen and phosphorus in water under electric field enhancement.

[0074] use Figure 1 The reaction system shown in the figure is used for auxiliary testing. The simulated wastewater is prepared with ammonium chloride and sodium dihydrogen phosphate for the experiment. The ammonia nitrogen concentration is 20 mg / L and the phosphate concentration is 2 mg / L. Three pieces of water treatment materials for electrically enhanced adsorption and filtration prepared in Example 1 are placed at the anode and cathode, respectively. Figure 3 As shown, 95% removal of ammonia nitrogen and phosphate can be achieved under a 2 V electric field within a treatment time of 150 min.

[0075] 3. Cyclic stability test.

[0076] After adsorption saturation, decompression backwashing can achieve faster desorption of nitrogen and phosphorus ions (NH 4 + :7vs.11min;PO4 3- :6vs.11min)(such as Figure 4 and Figure 5 Using the decompression backwashing method for desorption, the water treatment material for electrically enhanced adsorption filtration prepared in Example 1 can achieve a removal efficiency of about 95% after 10 cycles (as shown in FIG. Figure 6 shown).

[0077] 4. Adsorb and remove organic pollutants in water.

[0078] use Figure 1 The reaction system shown in the figure is used for auxiliary testing, using carbamazepine and acid orange 7 as cations and anions to represent organic pollutants. Three pieces of water treatment materials prepared by the electrical enhanced adsorption and filtration in Example 1 are placed at the anode and cathode, respectively. The initial concentrations of carbamazepine and acid orange 7 are 50 mg / L. Figure 7 It can be seen that under the action of the electric field, the removal rates of carbamazepine and acid orange 7 were significantly improved.

[0079] 5. Adsorption and removal of total suspended solids (SS) and total organic carbon (TOC) in water without electric field enhancement.

[0080] use Figure 1 The reaction system shown in the figure is used for auxiliary testing, and no voltage is applied. Domestic sewage is taken as the water sample to be purified, and three amino-modified sponges prepared in Comparative Example 2 are placed at the anode and cathode, respectively. Figure 8 As shown, after 150 min of filtration time, 43% removal of TOC and 40% removal of SS can be achieved.

[0081] 6. Adsorption and removal of nitrogen and phosphorus from water under electric field enhancement.

[0082] use Figure 1 The reaction system shown in the figure is used to assist in the test. Ammonium chloride and sodium dihydrogen phosphate are used to prepare simulated wastewater for the experiment. The ammonia nitrogen concentration is 20 mg / L and the phosphate concentration is 2 mg / L. Three pieces of ultra-light flexible carbon sponges prepared in Comparative Example 1 are placed on the cathode and anode respectively. Fig. 9 As shown, 36% ammonia nitrogen and 45% phosphate removal can be achieved under a 2 V electric field within a treatment time of 150 min.

[0083] The preferred specific embodiments of the present invention are described in detail above. It should be understood that a person skilled in the art can make many modifications and changes based on the concept of the present invention without creative work. Therefore, any technical solution obtained by any modification, equivalent replacement, improvement, etc. made by a person skilled in the art based on the concept of the present invention through logical analysis, reasoning or limited experiments on the basis of the prior art shall be within the scope of protection determined by the claims.

Claims

1. A method for preparing a water treatment material for electrically enhanced adsorption filtration, characterized in that: The following steps are involved: (1) Ultrasonic cleaning of melamine sponge, drying, placing in a tube furnace, introducing protective gas, and setting the heating rate to 4-6 °C min -1 After preheating, the temperature is continued to rise to 900-1100°C, kept warm, and cooled to room temperature to obtain an ultra-light and flexible carbon sponge; (2) Dissolve tris(hydroxymethyl)aminomethane in a solvent to obtain a tris(hydroxymethyl)aminomethane solution, adjust the pH to 8.4-8.6, add dopamine and polyethyleneimine, mix, add ultralight flexible carbon sponge, stir and react for 10-14 hours, and obtain an electrically enhanced adsorption and filtration water treatment material.

2. The preparation method according to claim 1, characterized in that: In step (1), the step of placing in a tubular furnace further comprises first placing the dried melamine sponge in a corundum boat, and then placing the corundum boat in the tubular furnace.

3. The preparation method according to claim 1, characterized in that: In step (1), the rate of introducing the protective gas is 80 to 120 mL / min.

4. The preparation method according to claim 1, characterized in that: In step (1), the protective gas includes at least one of Ar, N2, and H2.

5. The preparation method according to claim 1, characterized in that: In step (1), the preheating temperature is 200-300° C. and the preheating time is 20-40 min.

6. The preparation method according to claim 1, characterized in that: In step (2), the mass concentration of the tris(hydroxymethyl)aminomethane solution is 0.1-1%.

7. The preparation method according to claim 1, characterized in that: In step (2), the mass ratio of dopamine to polyethyleneimine is 1:1-4.

8. A water treatment material for electrically enhanced adsorption filtration, characterized in that: The water treatment material for electrically enhanced adsorption filtration is prepared by the preparation method described in any one of claims 1 to 7.

9. Use of the electrically enhanced adsorption and filtration water treatment material of claim 8 in the adsorption and removal of a wide spectrum of pollutants in water.

10. The use according to claim 9, characterized in that: The water treatment material for electrically enhanced adsorption filtration has at least one of the following functions (1) to (2): (1) The adsorption capacity of water treatment materials for electrically enhanced adsorption filtration is enhanced under the action of the electric field, thereby improving the adsorption efficiency of organic matter and nutrients in water; (2) The pore size of the water treatment material for electrically enhanced adsorption filtration is adjustable. Filtration is performed during compression, so that the sponge can adsorb pollutants in a compressed state. Backwashing is performed during decompression, so that the material can be efficiently adsorbed and regenerated.

Images