CN109759021B - A kind of preparation method of cyclodextrin-based Cu2O blend membrane for treating ppcps in regenerated water - Google Patents

Abstract

The invention discloses cyclodextrin-Cu for treating ppcps in reclaimed water₂A preparation method of an O blend membrane belongs to the field of environmental pollution treatment, and specifically comprises the following steps: 1) preparation of ultra-fine Cu₂O powder; 2) preparation of ultrafine Cyclodextrin-based-Cu by coupling agent₂An O composite material; 3) preparation of cyclodextrin-Cu by blending method₂O blend the film. The invention realizes the high-efficiency removal of PPCPs through the adsorption, photocatalytic degradation and membrane interception functions, and simultaneously realizes the excellent separation and recovery of the adsorbent through the membrane fixation function; meanwhile, the photocatalytic efficiency of the photocatalyst is greatly improved; and the life cycle of the membrane is increased, thereby reducing economic losses.

Description

Preparation of a cyclodextrin-based Cu2O blend membrane for treating ppcps in regenerated water method

technical field

The invention relates to a cyclodextrin-Cu ₂ O blended film used for treating ppcps and a preparation method thereof, and particularly belongs to the field of environmental pollution control.

Background technique

Pharmaceuticals and personal care products (PPCPs) are a new type of micro-pollutants with the characteristics of environmental stability, refractory degradation and bioaccumulation. Long-term exposure will cause irreversible potential harm to human health and the ecological environment. At present, such pollutants have been widely detected in surface water, groundwater, drinking water and reclaimed water (the concentration is generally at the level of 10ng/L-500mg/L). More than 80% of PPCPs pollution in urban water systems comes from reclaimed water. Therefore, it is of great theoretical and practical significance to carry out the removal technology of PPCPs in recycled water for the sustainable development of urban sewage reuse in my country.

Due to the limited effect of the traditional biological treatment technology in urban sewage treatment plants on the removal of PPCPs, related researches have been carried out on advanced oxidation, membrane filtration, activated carbon adsorption and combined process methods at home and abroad in recent years. Advanced oxidation technology (AOPs) achieves complete degradation of PPCPs or improves its biochemical properties through the strong oxidizing properties of free radicals (OH-based). Among them, photocatalyst technology has been widely used. This technology has a good effect on removing trace pollutants, but The agglomeration of ultrafine photocatalysts in solution is an important factor affecting the photocatalytic effect. Membrane filtration technology achieves the interception and removal of micro-pollutants through the molecular interception of membranes, and the removal rate can be as high as 99% or more, but the process energy consumption is very high. Adsorption is an efficient and feasible removal technology for PPCPs, with low cost, easy operation, no by-product formation and high removal efficiency, but the effective recovery of adsorbents is a problem that needs to be solved.

SUMMARY OF THE INVENTION

In order to solve the above problems, the purpose of the present invention is to provide a preparation method of cyclodextrin-Cu ₂ O blended membrane material which can not only efficiently treat ppcps in regenerated water, but also take into account the recovery of adsorbent and the inhibition of membrane fouling.

The preparation method of the cyclodextrin-Cu ₂ O blend membrane for treating ppcps in regenerated water provided by the present invention comprises the following steps:

1) Preparation of ultrafine Cu ₂ O powder;

2) Preparation of ultrafine cyclodextrin-Cu ₂ O composite material by coupling agent;

3) The cyclodextrin-Cu ₂ O blend film was prepared by blending method.

Step 1) is specifically as follows: add NaOH solution and CuSO ₄ solution into the reaction kettle, after magnetic stirring uniformly, add glucose solution, heat the reaction, cool the reaction kettle to room temperature, separate and purify the solid product to obtain ultrafine cuprous oxide powder. The molar ratio of CuSO ₄ , NaOH and glucose is 1:15:3. The concentration of the NaOH solution is 5 mol/L, the concentration of the CuSO ₄ solution is 1 mol/L, and the concentration of the glucose solution is 1.5 mol/L. In the heating reaction, the reaction temperature is 230-380° C., and the reaction time is 4-8 h. The separation and purification are specifically as follows: extracting the filter residue by suction filtration, washing with absolute ethanol for 3-5 times, and finally placing it in a vacuum drying box for vacuum drying. In the vacuum drying, the vacuum degree is 1200-4800pa, the drying temperature is 55-60°C, and the drying time is 2-20h.

Step 2) is specifically: taking the ultrafine Cu ₂ O powder prepared in step 1) and stirring it with toluene into a paste, adding a coupling agent dropwise, heating and refluxing for reaction, cooling to room temperature, adding a cyclodextrin-based material, and under nitrogen protection The reaction is heated and stirred, cooled to room temperature and then left to stand, and the solid product is separated and purified to obtain a cyclodextrin-Cu ₂ O composite material. The concentration of the Cu ₂ O powder in toluene is 1 g/mL, and the mass/volume ratio of the Cu ₂ O powder to the coupling agent is (5-10):(14-18) g/mL. The mass ratio of the Cu ₂ O powder to the cyclodextrin-based material is (5-10):(8-16). In the reflux reaction, the temperature is 130°C-140°C, and the reflux time is 4h. For the heating and stirring reaction, the reaction temperature was 128° C. and the reaction time was 2 h. The said standing, the standing time is 18-30h, and the separation and purification are as follows: filtering and collecting the filter residue, washing with acetone, ether, methanol and distilled water for 3-5 times respectively, and vacuum drying. In the vacuum drying, the vacuum degree is 1200-4800pa, the temperature is 55-60°C, and the drying time is 2-20h. The cyclodextrin-based material is one of α-cyclodextrin, β-cyclodextrin and γ-cyclodextrin cross-linked polymer. The coupling agent is a silane coupling agent, including aminopropyltriethoxysilane (KH550), vinyltriethoxysilane (A151), vinyltriethoxysilane (A171), mercaptopropyl One or more of trimethyl(eth)oxysilane (KH580, KH590).

Step 3) is specifically as follows: adding PVDF powder and organic solvent into a round-bottomed flask, stirring to obtain a uniform and transparent membrane material solution, adding PVP powder and the cyclodextrin-Cu ₂ O composite prepared in step 2) under stirring The materials are fully mixed and ultrasonically dispersed to obtain a suspension casting liquid. The casting liquid is left to stand for natural defoaming, poured onto a glass plate for gel setting, scraped, and dried to obtain a cyclodextrin-Cu ₂ O co-polymer. mixed film. The concentration of the PVDF powder in the organic solvent is 0.25g/mL, the concentration of the PVP powder in the organic solvent is 1:10-1:15g/mL, and the cyclodextrin-Cu ₂ The mass ratio of O composite to PVDF powder is 1:5-1:12. The organic solvent is one of N,N-dimethylacetamide, N,N-dimethylformamide, N-methylpyrrolidone and dimethyl sulfoxide. For the drying, the temperature is 55-60° C., and the drying time is 2-20h.

The particle size of the ultrafine Cu ₂ O powder obtained in step 1) is 50-500 nm.

The mass ratio of cuprous oxide, cyclodextrin and membrane in the cyclodextrin-Cu ₂ O blend membrane obtained by the method is 1:1.6:20-25, and the membrane pore size is less than 0.01 micron.

beneficial effect

In the present invention, cyclodextrin is bonded to the surface of nanometer Cu ₂ O through a coupling agent, and a film material modified by a cyclodextrin-Cu ₂ O composite material is prepared by a blending method. The photocatalysis-adsorption-membrane combination system The high _- efficiency removal of PPCPs is achieved through adsorption, photocatalytic degradation and membrane retention, and the membrane immobilization effect achieves excellent separation and recovery of the adsorbent. Improve the photocatalytic efficiency of the photocatalyst; the photocatalytic degradation of organic matter by the photocatalyst and the modification of the hydrophilic and hydrophobic properties of the membrane by cyclodextrin simultaneously suppress the membrane fouling, so that the service life of the membrane can be increased, thereby reducing economic losses.

Specifically:

1) The cyclodextrin base-Cu ₂ O blend film prepared by the present invention realizes an effective combination of photocatalysis-adsorption-membrane removal of trace organics. The combined system uses cyclodextrin adsorption, cuprous oxide photocatalytic oxidation The PPCPs can be efficiently removed by the action and membrane entrapment, and the PPCPs can be degraded or converted into small molecules with higher biodegradability.

2) In the cyclodextrin-based Cu ₂ O blend membrane prepared by the present invention, the immobilization of the membrane realizes the excellent separation and recovery of the cyclodextrin adsorbent, and avoids the difficulty of recovery and reuse of the adsorbent in the solution, resulting in secondary pollution problem.

3) In the cyclodextrin-Cu ₂ O blend film prepared by the present invention, the surface modification of the photocatalyst Cu ₂ O by cyclodextrin changes the surface properties of cuprous oxide, effectively inhibits the agglomeration of cuprous oxide, and greatly improves the photocatalytic performance. The efficiency of the catalyst to oxidize ppcps while avoiding the secondary pollution of the photocatalyst.

4) The cyclodextrin base-Cu ₂ O blend film prepared by the present invention has the photocatalytic degradation effect of photocatalyst cuprous oxide on organic matter in the film, the bacteriostatic effect of photocatalyst cuprous oxide, and the hydrophilic and hydrophobic effect of cyclodextrin on the film. The modification of performance also inhibits membrane fouling, which increases the service life of the membrane, thereby reducing economic losses.

5) The cyclodextrin-Cu ₂ O blend film prepared by the present invention has a simple preparation process, easy control of the reaction, and is economically feasible. By adjusting the ratio of each component of the cyclodextrin-Cu ₂ O, the maximum The realization of the enrichment and degradation of various types of ppcps.

Detailed ways

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

Example 1

A preparation method of a cyclodextrin-based Cu ₂ O blend film for treating ppcps in regenerated water: 1) add 30 mL of 5 mol/L NaOH solution and 10 mL of 1 mol/L CuSO ₄ solution into the reactor, stir magnetically After homogeneous, add 20 mL of 1.5 mol/L glucose solution to the above mixed solution, place the reaction kettle in a thermostat for high temperature reaction, control the temperature of the thermostat to be 330 ° C, cool the reaction kettle to room temperature after 6 hours of reaction, suction filtration, It was washed with absolute ethanol for 5 times, and finally dried in a vacuum drying oven (the vacuum degree was 4800pa, the drying temperature was 60°C, and the drying time was 5h) to obtain the cuprous oxide powder with a particle size of 200nm-300nm. 2) Take 5 g of cuprous oxide powder into a three-necked flask, add 5 mL of toluene and stir at low temperature until the solution becomes a paste, then dropwise add 14 mL of vinyltriethoxysilane, and heat up to 130 ° C, reflux for 4 hours, and then cool to a At room temperature, 8.0g of β-cyclodextrin cross-linked polymer was added, mixed uniformly, under nitrogen protection, stirred at a constant temperature of 128 °C for 2 hours, then cooled to room temperature, and stood for 18 hours. Acetone, ether, methanol, and distilled water were thoroughly washed three times, and the filter residue was dried in an electric heating vacuum drying oven to obtain a β-cyclodextrin-Cu ₂ O composite material (the vacuum drying conditions were the same as in step 1). 3) Add a certain amount of PVDF powder and organic solvent N,N-dimethylacetamide into the round-bottomed flask, stir to obtain a uniform and transparent membrane material liquid, add a certain amount of PVP powder under stirring and step 2 ) prepared β-cyclodextrin-Cu ₂ O composite material (the concentration of PVDF powder in the organic solvent is 0.25 g/mL, the concentration of PVP powder in the organic solvent is 1:15 g/mL, and the The mass ratio of dextrin-based-Cu ₂ O composite material and PVDF powder is 1:12), and after thorough mixing, ultrasonic dispersion is obtained to obtain a suspension casting liquid. After setting, the film is scraped and dried in an oven (temperature is 55-60° C., drying time is 2-20h) to obtain a β-cyclodextrin-Cu ₂ O blended film.

The prepared β-cyclodextrin-Cu ₂ O blended membrane material was used in a membrane reactor. The reactor was continuously passed through a 0.02 mg/L diclofenac solution and placed in a natural light at a temperature of 25 °C for the reaction. After 12 h The measured concentration of diclofenac became 0.0032 mg/L, and the removal rate was 84%. For comparison, a single PVDF membrane material was used, and 1 mg/L diclofenac solution was continuously passed through the reactor. Under the same conditions, the removal rate of diclofenac after 12 h was 48.6%. The photocatalytic performance of the β-cyclodextrin-Cu ₂ O blend film was tested. Before the experiment, the β-cyclodextrin-Cu 2 O blend film reached the adsorption equilibrium under dark conditions, and then subjected to light treatment under the same conditions. The film sample size was 3.5 cm × 4 cm, and it was found that the photocatalyst cuprous oxide increased the removal rate of diclofenac by 1.23 times. At the same time, the membrane flux test of β-cyclodextrin-Cu ₂ O blend membrane material and single membrane material was carried out by terminal filtration test, and it was found that the membrane fouling critical in β-cyclodextrin-Cu ₂ O blend membrane The time is about 1.53 times the original time. This example shows that the material has the functions of efficiently enriching diclofenac and photocatalytically degrading diclofenac; meanwhile, the membrane fouling phenomenon of the β-cyclodextrin-Cu ₂ O blend film is suppressed.

Example 2

A cyclodextrin-based Cu ₂ O blend film for treating ppcps in regenerated water, the preparation method is as follows: 1) 30 mL of 5 mol/L NaOH solution and 10 mL of 1 mol/L CuSO ₄ solution are added into a reaction kettle, and the magnetic After stirring evenly, add 20 mL of 1.5 mol/L glucose solution to the above mixed solution, place the reaction kettle in a thermostat for high temperature reaction, control the temperature of the thermostat to be 480°C, cool the reaction kettle to room temperature after 6 hours of reaction, and filter with suction. , the filter residue was washed 3 times with anhydrous ethanol, and finally placed in a vacuum drying oven for drying (conditions were the same as in Example 1) to obtain a cuprous oxide powder with a particle size of about 50 nm. 2) Take 5 g of cuprous oxide powder into a three-necked flask, add 5 mL of toluene and stir at low temperature until the solution becomes a paste, then dropwise add 18 mL of vinyltriethoxysilane, and heat up to 140 ° C, reflux for 4 hours, and then cool to a At room temperature, 8.0g of β-cyclodextrin cross-linked polymer was added, mixed uniformly, under nitrogen protection, stirred at a constant temperature of 128 ° C for 2 hours, then cooled to room temperature, left standing for 30 hours, and filtered after the solid was fully settled. Acetone, ether, methanol and distilled water were fully washed for 5 times, and the filter residue was dried in an electric heating vacuum drying oven to obtain β-cyclodextrin-Cu ₂ O composite material (drying conditions were the same as in step 1). 3) Add a certain amount of PVDF powder and organic solvent N,N-dimethylacetamide into the round-bottomed flask, stir to obtain a uniform and transparent membrane material liquid, add a certain amount of PVP powder and β- Cyclodextrin-Cu ₂ O composite material (the concentration of PVDF powder in the organic solvent is 0.25 g/mL, the concentration of PVP powder in the organic solvent is 1:10 g/mL, and the concentration of cyclodextrin-Cu The mass ratio of ₂ O composite material and PVDF powder is 1:5), and after fully mixing, ultrasonic dispersion is performed to obtain a suspension casting liquid. After drying in an oven, a β-cyclodextrin-Cu ₂ O blend film was obtained (drying conditions were the same as in step 3 of Example 1).

The prepared β-cyclodextrin-Cu ₂ O blended membrane material was used in a membrane reactor. The reactor was continuously passed through 5 μg/L ibuprofen solution and placed in natural light at a temperature of 25 °C for 12 h. The concentration of ibuprofen was measured to be 0.42 μg/L, and the removal rate was 91.6%.

Example 3

A cyclodextrin-based Cu ₂ O blend membrane for treating ppcps in regenerated water, the preparation method is as follows: 1) 30 mL of 5mol/L NaOH solution and 10 mL of 1 mol/L CuSO ₄ solution are added into a reaction kettle, and the magnetic After stirring evenly, add 20 mL of 1.5 mol/L glucose solution to the above mixed solution, place the reaction kettle in a thermostat for high temperature reaction, control the temperature of the thermostat to be 280°C, cool the reaction kettle to room temperature after 6 hours of reaction, and filter with suction. , the filter residue was washed 4 times with absolute ethanol, and finally dried in a vacuum drying oven (conditions were the same as in step 1 of Example 1) to obtain a cuprous oxide powder with a particle size of about 100 nm. 2) Add 10 g of cuprous oxide powder into a three-necked flask, add 10 mL of toluene and stir at low temperature until the solution becomes a paste, then dropwise add 15 mL of aminopropyltriethoxysilane (KH550), and heat up to 135 ° C, reflux After 4 hours, it was cooled to room temperature, and then 16.0 g of β-cyclodextrin polymer was added, mixed uniformly, and stirred at a constant temperature of 128 °C for 6 hours under nitrogen protection, then cooled to room temperature, and allowed to stand for 24 hours. Fully wash with acetone, ether, methanol, and distilled water for 4 times respectively, and dry the filter residue in an electric heating vacuum drying oven to obtain a β-cyclodextrin-Cu ₂ O composite material (drying conditions are the same as in Example 1, Step 2)) . 2) Add a certain amount of PVDF powder and organic solvent N,N-dimethylacetamide into the round-bottomed flask, stir to obtain a uniform and transparent membrane material liquid, add a certain amount of PVP powder and β- Cyclodextrin-Cu ₂ O composite material (the concentration of PVDF powder in the organic solvent was 0.25 g/mL, the concentration of PVP powder in the organic solvent was 1:12 g/mL, and the concentration of cyclodextrin-Cu The mass ratio of ₂ O composite material and PVDF powder is 1:8), after fully mixing, ultrasonic dispersion is obtained to obtain a suspension casting liquid, the casting liquid is left to stand for natural defoaming, poured on a glass plate for gel setting, and then scraped. After drying in an oven, a β-cyclodextrin-Cu ₂ O blend film was obtained (the drying conditions were the same as those in step 3 of Example 1).

The prepared β-cyclodextrin-Cu ₂ O blend membrane material was used in a membrane reactor. The reactor was continuously passed through a 0.2 μg/L salicylic acid solution and placed in a natural light with a temperature of 25 °C for the reaction. After 8 hours, the salicylic acid concentration was measured to become 0.0298 μg/L, and the removal rate was 85.1%.

Claims (18)

1. a preparation method for the cyclodextrin base-Cu ₂ O blend film for treating ppcps in regenerated water, it is characterized in that: comprising the following steps: 1) Preparation of ultrafine Cu ₂ O powder; 2) Preparation of ultra-fine cyclodextrin-Cu ₂ O composite material by coupling agent, specifically: taking the ultra-fine Cu ₂ O powder prepared in step 1) and stirring it with toluene into a paste, adding coupling agent dropwise, and heating to reflux reaction, after cooling to room temperature, adding cyclodextrin-based material, heating and stirring the reaction under nitrogen protection, cooling to room temperature and standing, separating and purifying the solid product to obtain cyclodextrin-based-Cu ₂ O composite material; 3) Preparation of cyclodextrin-Cu ₂ O blend membrane by blending method, specifically: adding PVDF powder and organic solvent into a round-bottomed flask, stirring to obtain a uniform and transparent membrane material liquid, adding PVP powder under stirring and the cyclodextrin-Cu ₂ O composite material prepared in step 2), fully mixed and ultrasonically dispersed to obtain a suspension casting liquid, the casting liquid is left to stand for natural defoaming, poured onto a glass plate for gel setting, and then scraped off the film , and the cyclodextrin-Cu ₂ O blend film was obtained after drying. 2. The method for preparing a cyclodextrin-based Cu ₂ O blended film for treating ppcps in regenerated water according to claim 1, characterized in that: step 1) is specifically: taking NaOH solution and CuSO ₄ solution and adding reaction In the kettle, after magnetic stirring is uniform, add glucose solution, heat the reaction, cool the reaction kettle to room temperature, separate and purify the solid product to obtain ultrafine cuprous oxide powder. 3. The method for preparing a cyclodextrin-Cu ₂ O blended membrane for treating ppcps in regenerated water according to claim 2, wherein the molar ratio of the CuSO ₄ , NaOH and glucose is 1:15 :3. 4. The preparation method of the cyclodextrin-Cu ₂ O blended film for treating ppcps in regenerated water according to claim 2, characterized in that: the concentration of the NaOH solution is 5 mol/L, and the CuSO solution is ₅ mol/L. The concentration of glucose solution is 1 mol/L, and the concentration of glucose solution is 1.5 mol/L. 5 . The method for preparing a cyclodextrin-Cu ₂ O blended film for treating ppcps in regenerated water according to claim 2 , wherein the heating reaction is performed at a reaction temperature of 230-380° C. and a reaction time of 230-380° C. 6 . 4-8h. 6. The preparation method of the cyclodextrin-Cu ₂ O blended membrane for treating ppcps in regenerated water according to claim 2, characterized in that: the separation and purification is specifically: extracting the filter residue by suction filtration, Washed with water ethanol for 3-5 times, and finally placed in a vacuum drying box for vacuum drying. 7. The method for preparing a cyclodextrin-Cu ₂ O blended film for treating ppcps in regenerated water according to claim 6, characterized in that: the vacuum drying has a vacuum degree of 1200-4800pa, and drying The temperature is 55-60℃, and the drying time is 2-20h. 8. The preparation method of the cyclodextrin-Cu ₂ O blended film for treating ppcps in regenerated water according to claim 1, wherein the concentration of the Cu ₂ O powder in toluene is 1 g/ mL, the mass/volume ratio of the Cu ₂ O powder and the coupling agent is (5-10): (14-18) g/mL. 9 . The method for preparing a cyclodextrin-Cu ₂ O blended film for treating ppcps in regenerated water according to claim 1 , wherein the mass ratio of the Cu ₂ O powder to the cyclodextrin-based material is: 10 . as (5-10):(8-16). 10 . The method for preparing a cyclodextrin-Cu ₂ O blend film for treating ppcps in reclaimed water according to claim 1 , wherein the reflux reaction is performed at a temperature of 130° C.-140° C. and a reflux time. 11 . for 4h. 11 . The method for preparing a cyclodextrin-Cu ₂ O blended film for treating ppcps in regenerated water according to claim 1 , wherein the heating and stirring reaction is performed at a reaction temperature of 128° C. and a reaction time of 128° C. 12 . 2h. 12. The method for preparing a cyclodextrin-Cu ₂ O blended membrane for treating ppcps in regenerated water according to claim 1, characterized in that: the standing time is 18-30 h, and the separation and purification Specifically, the filter residue is collected by filtration, washed with acetone, ether, methanol, and distilled water for 3-5 times respectively, and vacuum-dried. 13. The method for preparing a cyclodextrin-Cu ₂ O blend film for treating ppcps in regenerated water according to claim 12, characterized in that: the vacuum drying has a vacuum degree of 1200-4800pa and a temperature of 55 -60℃, drying time is 2-20h. 14. The method for preparing a cyclodextrin-Cu ₂ O blended film for treating ppcps in reclaimed water according to claim 1, wherein the cyclodextrin-based material is β-cyclodextrin cross-linked polymer. 15. The method for preparing a cyclodextrin-Cu ₂ O blend film for treating ppcps in regenerated water according to claim 1, wherein the coupling agent is a silane coupling agent selected from ammonia propyltriethoxysilane (KH550), vinyltriethoxysilane (A151), vinyltrimethoxysilane (A171), mercaptopropyltrimethoxysilane (KH580), mercaptopropyltriethoxy One or more of silanes (KH590). 16. The method for preparing a cyclodextrin-Cu ₂ O blend film for treating ppcps in regenerated water according to claim 1, wherein the concentration of the PVDF powder in the organic solvent is 0.25g /mL, the concentration of the PVP powder in the organic solvent is 1:10-1:15g/mL, and the mass ratio of the cyclodextrin-Cu ₂ O composite material to the PVDF powder is 1:5-1 :12. 17. The method for preparing a cyclodextrin-Cu ₂ O blend film for treating ppcps in regenerated water according to claim 1, wherein the organic solvent is N,N-dimethylacetamide, One of N,N-dimethylformamide, N-methylpyrrolidone and dimethylsulfoxide. 18. The method for preparing a cyclodextrin-Cu ₂ O blend film for treating ppcps in regenerated water according to claim 1, wherein the drying is performed at a temperature of 55-60° C. The time is 2-20h.