CN111389243A - Lanthanum-carbon composite adsorbent doped polyvinylidene fluoride phosphorus removal film and preparation method and application thereof - Google Patents
Lanthanum-carbon composite adsorbent doped polyvinylidene fluoride phosphorus removal film and preparation method and application thereof Download PDFInfo
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Abstract
The invention discloses a lanthanum-carbon composite adsorbent doped polyvinylidene fluoride phosphorus removal film suitable for the field of water treatment, which comprises a lanthanum-carbon composite adsorbent and polyvinylidene fluoride, wherein the lanthanum-carbon composite adsorbent comprises X and Y, X is more than 0 and less than or equal to 30%, and Y is more than or equal to 70% and less than 100%. The preparation method of the polyvinylidene fluoride phosphorus removal film comprises the following steps: (a) adding polyvinylidene fluoride and lanthanum-carbon composite adsorbent into N-methyl pyrrolidone, and fully stirring to obtain uniform membrane casting solution; (b) and standing the casting solution, removing bubbles in vacuum, coating the casting solution on a glass plate in a scraping manner, standing the glass plate in the air for 25-35 s, immersing the glass plate in an ethanol solution, curing to form a film, and dropping the film from the glass plate.
Description
Technical Field
The invention relates to the technical field of water treatment, in particular to a polyvinylidene fluoride phosphorus removal film doped with a lanthanum-carbon composite adsorbent, and a preparation method and application thereof.
Background
The eutrophication of the water body can be caused by the over-high concentration of nitrogen and phosphorus nutrient substances in the water body, and the mass propagation of harmful algae can be promoted to form algal blooms. The occurrence of algal blooms poses a serious threat to the supply of drinking water and the conservation of aquatic ecosystems. The reduction of the input of nutrient elements, especially phosphorus elements, is an important component of eutrophication management, wherein the control of the total phosphorus concentration in sewage is an effective practice.
At present, the sewage biological phosphorus removal technology is sensitive to changes of organic loads, toxic substances, reactor operating parameters and the like, and the phosphorus removal effect is not stable. The chemical phosphorus removal method can realize stable phosphorus removal effect, but the phosphorus removal process needs to invest a large amount of chemical agents, so that the cost is higher. In contrast, adsorptive phosphorus removal is an efficient and economical method for phosphate removal and recovery.
The lanthanum element has excellent adsorption performance on phosphate, is widely applied to removal of phosphate in water and shows good effect. However, in practical applications, these lanthanum-containing adsorbents have some problems: firstly, the nano-scale lanthanum-containing adsorbent has good adsorption performance, but aggregates are easily formed in the using process, so that the removal efficiency is influenced; secondly, lanthanum ion can be dissolved and released from the lanthanum-containing adsorbent in the using process, and the risk of secondary pollution exists. Therefore, the preparation of a safe and efficient water phosphate adsorbent is imperative.
Tannic acid is a porous polymer commonly found in plant bodies, having a high porosity and a highly cross-linked porous network structure. In addition, the membrane technology is simple to operate, does not need to add chemical agents, has good and stable effluent quality and is widely applied to the field of water treatment. Polyvinylidene fluoride films are receiving attention because of their advantages such as high mechanical strength, good thermal stability, resistance to chemical agents, and the like.
Patent specification No. CN101579620A discloses a porous molded body with high adsorption performance, which contains an organic polymer resin, which may be polyvinylidene fluoride, and an inorganic ion adsorbent, which may be selected from lanthanum-containing metal oxides. The porous forming body is suitable for adsorbing and removing low-concentration phosphorus in wastewater, and has large adsorption capacity. However, the material obtained by the above patent technology has no filtering capability, and cannot be combined with the membrane technology, and the phosphorus adsorption performance needs to be further improved.
Disclosure of Invention
Aiming at the defects in the field, the invention provides the lanthanum-carbon composite adsorbent doped polyvinylidene fluoride phosphorus removal membrane, the lanthanum-carbon composite adsorbent is uniformly dispersed and fixed in the polyvinylidene fluoride membrane, and the lanthanum-carbon composite adsorbent is immobilized by using a polymer as a supporting material, so that the problems of easy agglomeration and difficult recovery of lanthanum are solved. The lanthanum-carbon composite adsorbent is doped in the polyvinylidene fluoride membrane, so that the problem of lanthanum leakage of the lanthanum-carbon composite adsorbent can be solved, and phosphorus, suspended matters (SS) and the like in sewage can be removed on the premise of ensuring high pure water flux.
A lanthanum-carbon composite adsorbent doped polyvinylidene fluoride phosphorus removal film comprises a lanthanum-carbon composite adsorbent and polyvinylidene fluoride (PVDF), wherein the lanthanum-carbon composite adsorbent is X in mass percent, the polyvinylidene fluoride (PVDF) is Y in mass percent, X is more than 0 and less than or equal to 30 percent, and Y is more than or equal to 70 percent and less than 100 percent;
the preparation method of the lanthanum-carbon composite adsorbent comprises the following steps:
(1) adding 4, 4' -diaminobiphenyl into hydrochloric acid at the temperature of 3-10 ℃, uniformly mixing, adding nitrous acid, performing diazotization reaction, adding a mixed solution of tannic acid and sodium carbonate after the reaction is finished, stirring for reaction for 10-12 h, and collecting a solid product;
(2) and (2) dispersing the solid product obtained in the step (1) in a soluble lanthanum salt solution, adjusting the pH value to 10-12, and carbonizing the obtained precipitate at 500-700 ℃ under inert gas to obtain the lanthanum-carbon composite adsorbent.
The invention takes the tannic acid as the lanthanum substrate, which is beneficial to dispersing the lanthanum adsorbent.
Preferably, the mass ratio of the lanthanum-carbon composite adsorbent to the polyvinylidene fluoride is 1: 3.5-10, and under the preferable ratio, the pure water flux of the polyvinylidene fluoride phosphorus removal film doped with the lanthanum-carbon composite adsorbent reaches 110L/(m) under the pressure condition of 0.25MPa2H) above.
Preferably, in the step (1), the ratio of 4, 4' -diaminobiphenyl to HCl to nitrous acid to tannic acid to sodium carbonate is 0.8 to 1g, 25 to 36mmol, 0.6 to 0.8g, 0.7 to 0.9g, and 0.9 to 1.8 g. The solid product obtained by the reaction in the preferred proportion has a larger specific surface area after carbonization.
In order to achieve the best phosphorus adsorption capacity by taking the specific surface area and the L a dispersibility into consideration, in the step (2), the ratio of the solid product obtained in the step (1) to L a in the soluble lanthanum salt is preferably 1g: 0.1-0.2 mol.
Preferably, in the step (2), the carbonization time is 1-2 h, so that the carbonization is completed.
The thickness of the polyvinylidene fluoride phosphorous removal film doped with the lanthanum-carbon composite adsorbent is controllable, and the preferable thickness is 150-250 mu m. The film thickness is too thin, the mechanical property is poor, and the film is easy to damage; excessive film thickness can result in reduced film porosity.
The invention also provides a preparation method of the polyvinylidene fluoride phosphorus removal film doped with the lanthanum-carbon composite adsorbent, which comprises the following steps:
(a) adding polyvinylidene fluoride and lanthanum-carbon composite adsorbent into N-methyl pyrrolidone, and fully stirring to obtain uniform membrane casting solution;
(b) and standing the casting solution, removing bubbles in vacuum, blade-coating the casting solution on a glass plate, placing the glass plate in the air for 25-35 s, immersing the glass plate in an ethanol solution, curing to form a film, and falling off the film from the glass plate to obtain the polyvinylidene fluoride phosphorus removal film doped with the lanthanum-carbon composite adsorbent.
In order to fully dissolve polyvinylidene fluoride and improve the dispersion degree of the lanthanum-carbon composite adsorbent and polyvinylidene fluoride, in the step (a), the mass of the N-methyl pyrrolidone accounts for 80-90% of the sum of the mass of the polyvinylidene fluoride, the mass of the lanthanum-carbon composite adsorbent and the mass of the N-methyl pyrrolidone.
In the step (b), after blade coating, placing in the air for 25-35 s for pore forming.
Experiments show that the ethanol content in the ethanol solution influences the smoothness of the membrane surface, preferably, in the step (b), the volume fraction of ethanol in the ethanol solution is 10-20%, which is beneficial to the smoothness of the membrane surface.
The invention also provides application of the polyvinylidene fluoride phosphorus removal film doped with the lanthanum-carbon composite adsorbent in water treatment.
The polyvinylidene fluoride phosphorus removal film doped with the lanthanum-carbon composite adsorbent has high pure water flux, can be recycled, and is particularly suitable for advanced treatment of phosphorus and suspended particles (SS) in the effluent of a secondary sedimentation tank.
The removal rate of Total Phosphorus (TP) in effluent treated by the polyvinylidene fluoride phosphorus removal film doped with the lanthanum-carbon composite adsorbent is less than 0.05 mg/L and can reach more than 98%.
Compared with the prior art, the invention has the main advantages that:
1. the problem of recycling the traditional lanthanum adsorbent is solved, and the dissolution loss of lanthanum in the use process is effectively reduced; the agglomeration of lanthanum is avoided, the dispersity of lanthanum in the lanthanum-carbon composite adsorbent is improved, and the lanthanum-carbon composite adsorbent has large specific surface area and high phosphorus adsorption capacity.
2. The doping of the lanthanum-carbon composite adsorbent can well improve the surface characteristics of the polyvinylidene fluoride membrane and improve the pure water flux of the membrane.
3. The lanthanum-carbon composite adsorbent doped polyvinylidene fluoride phosphorus removal film can synchronously realize the adsorption removal of phosphate while filtering sewage.
Drawings
Fig. 1 is a graph showing the results of a test of adsorption capacity of a lanthanum-carbon composite adsorbent prepared in example 1 and a pure lanthanum adsorbent prepared in comparative example 1;
FIG. 2 is a diagram showing the results of pure water flux tests of polyvinylidene fluoride phosphorus removal films doped with lanthanum-carbon composite adsorbents and doped with pure lanthanum adsorbents at different doping ratios;
FIG. 3 is a graph showing the phosphorus removal results of polyvinylidene fluoride phosphorus removal films doped with lanthanum-carbon composite adsorbents and doped with pure lanthanum adsorbents at different doping ratios;
FIG. 4 is a graph showing the result of phosphorus removal in the effluent of the secondary sedimentation tank after the phosphorus removal membrane of example 6 is recycled for 4 times of advanced treatment;
FIG. 5 is a graph showing the results of removing Suspended Substances (SS) from the effluent of the secondary sedimentation tank after 4 cycles of the dephosphorization membrane of example 6.
Detailed Description
The invention is further described with reference to the following drawings and specific examples. It should be understood that these examples are for illustrative purposes only and are not intended to limit the scope of the present invention. The following examples are conducted under conditions not specified, usually according to conventional conditions, or according to conditions recommended by the manufacturer.
The preferable preparation scheme of the polyvinylidene fluoride phosphorus removal film doped with the lanthanum-carbon composite adsorbent is as follows:
adding 0.81g of 4, 4' -diaminobiphenyl into 300m of L hydrochloric acid diluent containing 0.7-1 vol% of concentrated hydrochloric acid (containing 36-37 wt% of HCl) at the temperature of 4 ℃ to facilitate dissolution, adding 90m of L nitrous acid solution containing 0.7-0.8 wt% of nitrous acid after 15-20 min to react for 20-30 min to completely convert amino into diazonium salt, wherein the solution turns from dark yellow to bright yellow, then adding 90m of L mixed solution containing 0.8-1 wt% of tannic acid and 1-2 wt% of sodium carbonate, magnetically stirring for 10-12 h to obtain a tan solid product, filtering, freeze-drying the obtained product for 24h, drying, grinding the product, and mixing the obtained product with L aCl3Dispersed in L aCl at a mass ratio of 1:383·6H2In the O solution, adjusting the pH value to 10-12 with NaOH solution, and passing throughFiltering, drying at 60-80 ℃ overnight, and carbonizing in a tube furnace at 500-700 ℃ for 1-2 h in an inert atmosphere, wherein the carbonized material is the lanthanum-carbon composite adsorbent. The inert atmosphere may be a noble gas or nitrogen.
Dissolving 10.5-16 parts by mass of polyvinylidene fluoride powder in 81-85 parts by mass of N-methyl pyrrolidone solvent, stirring for 1-2 hours on a magnetic stirrer, adding 0-4.5 parts by mass of lanthanum-carbon composite adsorbent (the total mass of polyvinylidene fluoride, N-methyl pyrrolidone and lanthanum-carbon composite adsorbent is 100 parts), stirring until all the components are dissolved until a uniform casting film liquid is obtained, and then placing the obtained casting film liquid in a vacuum box for defoaming for 8-12 hours. And (3) coating the defoamed casting film liquid on a glass plate in a scraping mode, controlling the height of a scraping knife to be 200 mu m, placing the glass plate in air for 30s for pore forming, immediately immersing the glass plate into a 10-20 vol% ethanol water solution coagulating bath, solidifying and forming after 2-3 min, obtaining a lanthanum-carbon composite adsorbent doped polyvinylidene fluoride phosphorus removal film after the film falls off from the glass plate, and finally placing the film in 4 ℃ water for preservation.
Example 1
Adding 0.81g of 4, 4' -diaminobiphenyl into 300m L hydrochloric acid diluent containing 0.73 volume percent of concentrated hydrochloric acid (containing 36-37 weight percent of HCl) at the temperature of 4 ℃ to facilitate the dissolution, adding 90m L nitrous acid solution containing 0.76 mass percent after 15min to react for 20min to completely convert amino into diazonium salt, wherein the solution turns from dark yellow to bright yellow, adding 90m L mixed solution containing 0.87 mass percent of tannic acid and 1.67 mass percent of sodium carbonate, magnetically stirring for 10h to obtain a tan solid product, filtering, freeze-drying the obtained product for 24h, drying, grinding the product, and mixing the obtained product with L aCl3Dispersed in L aCl at a mass ratio of 1:383·6H2In the O solution, the pH value is adjusted to 10 by NaOH solution, the solution is filtered and dried at 60 ℃ overnight, and then the product is carbonized for 1h in a tube furnace at 700 ℃ under inert atmosphere, and the carbonized material is lanthanum carbon composite adsorbent (L aH/CM).
21g N-methyl pyrrolidone is added into a 50m L beaker, then 3.75g of the weighed polyvinylidene fluoride powder is added into the beaker, the mixture is stirred on a magnetic stirrer until the powder is dissolved and the solution is uniform to obtain casting solution, the casting solution is sealed and placed in a vacuum box for deaeration for 12h, a film is formed on a glass plate by blade coating, the height of a scraper is controlled to be 200 mu m, the glass plate is placed in air for 30s and then immediately placed in a 20 vol% ethanol solution condensation bath, after 2min, the film falls off from the glass plate to obtain a phosphorus removal film of the polyvinylidene fluoride, and the phosphorus removal film is transferred into cold water at 4 ℃ for storage for later use.
Comparative example 1
LaCl3·6H2Adjusting the pH value of the O solution to 10 by using NaOH solution, filtering, drying at 60 ℃ overnight, and carbonizing at 700 ℃ in a tube furnace under inert atmosphere for 1h to obtain the pure lanthanum adsorbent.
The BET specific surface area test result shows that the specific surface area of the lanthanum-carbon composite adsorbent prepared in example 1 is as high as 61.7m2In g, the specific surface area of the pure lanthanum adsorbent prepared in comparative example 1 was only 7.7m2The carbon group has a higher specific surface area because it has a good dispersibility of the lanthanum-adsorbing material.
The results of the adsorption capacity test of the lanthanum carbon composite adsorbent prepared in example 1 and the pure lanthanum adsorbent prepared in comparative example 1 are shown in fig. 1, and according to the fitting of two adsorption film types (Freundlich model and L angmuir model), it is found that the phosphorus adsorption capacity of the lanthanum carbon composite adsorbent is 48mg/g, while the phosphorus adsorption capacity of the pure lanthanum adsorbent is 30 mg/g.
Example 2
The difference from the example 1 is that 0.1875g of the lanthanum-carbon composite adsorbent prepared in the example 1 is also added into the casting solution, and the rest conditions are the same, so as to obtain the polyvinylidene fluoride phosphorus removal film doped with the lanthanum-carbon composite adsorbent. The mass ratio of the polyvinylidene fluoride to the lanthanum-carbon composite adsorbent is 20: 1.
Example 3
The difference from the example 1 is that 0.25g of the lanthanum-carbon composite adsorbent prepared in the example 1 is added into the casting solution, and the rest conditions are the same, so that the polyvinylidene fluoride phosphorus removal film doped with the lanthanum-carbon composite adsorbent is obtained. The mass ratio of the polyvinylidene fluoride to the lanthanum-carbon composite adsorbent is 15: 1.
Example 4
The difference from the example 1 is that 0.375g of the lanthanum-carbon composite adsorbent prepared in the example 1 is also added into the casting solution, and the rest conditions are the same, so that the polyvinylidene fluoride phosphorus removal film doped with the lanthanum-carbon composite adsorbent is obtained. The mass ratio of the polyvinylidene fluoride to the lanthanum-carbon composite adsorbent is 10: 1.
Example 5
The difference from the example 1 is that 0.75g of the lanthanum-carbon composite adsorbent prepared in the example 1 is added into the casting solution, and the rest conditions are the same, so that the polyvinylidene fluoride phosphorus removal film doped with the lanthanum-carbon composite adsorbent is obtained. The mass ratio of the polyvinylidene fluoride to the lanthanum-carbon composite adsorbent is 5: 1.
Example 6
The difference from the example 1 is that 1.07g of the lanthanum-carbon composite adsorbent prepared in the example 1 is added into the casting solution, and the rest conditions are the same, so that the polyvinylidene fluoride phosphorus removal membrane doped with the lanthanum-carbon composite adsorbent is obtained. The mass ratio of the polyvinylidene fluoride to the lanthanum-carbon composite adsorbent is 3.5: 1.
Comparative example 2
The difference from the example 6 is that the pure lanthanum adsorbent prepared in the comparative example 1 with equal mass is adopted to replace the lanthanum-carbon composite adsorbent prepared in the example 1, and the rest conditions are the same, so that the polyvinylidene fluoride phosphorus removal film doped with the pure lanthanum adsorbent is obtained. The mass ratio of the polyvinylidene fluoride to the pure lanthanum adsorbent is 3.5: 1.
Placing the polyvinylidene fluoride phosphorus removal membranes prepared in the embodiments 1-6 and the comparative example 2 at the bottom in an ultrafiltration cup of 500m L, pouring pure water or effluent of a secondary sedimentation tank with the phosphorus concentration to be treated being 0.2 mg/L into the ultrafiltration cup, introducing 0.25MPa of inert gas, and filtering the liquid to be treated through the phosphorus removal membrane under constant pressure.
As shown in FIG. 2, the pure water flux results show that the pure water flux of the membrane can be increased even further after doping with a certain proportion of the lanthanum-carbon composite adsorbent, particularly, the highest pure water flux is obtained when 0.75g of the lanthanum-carbon composite adsorbent is added, and the pure water flux of the polyvinylidene fluoride phosphorus removal membrane added with 1.07g of the lanthanum-carbon composite adsorbent of example 6 is 112.8L/(m) at a pressure of 0.25MPa2H). While 1.07g of pure lanthanum sorbent-doped polyvinylidene fluoride was also usedThe pure water flux of the ethylene phosphorus removal film is obviously lower than that of the pure polyvinylidene fluoride phosphorus removal film.
The phosphorus removal result is shown in fig. 3, and for a higher phosphorus concentration (0.2 mg/L), the phosphorus removal film of polyvinylidene fluoride doped with 1.07g of lanthanum-carbon composite adsorbent of example 6 has the best phosphorus removal effect, and can reach the environmental quality standard of class II water area of surface water of china (TP <0.1 mg/L).
When the secondary sedimentation tank effluent with the phosphorus concentration of 0.2 mg/L is deeply treated by using the lanthanum-carbon composite adsorbent doped polyvinylidene fluoride phosphorus removal film in the embodiment 6, the removal conditions of phosphorus and Suspended Solids (SS) in the 4-time recycling process are shown in figures 4 and 5, wherein the phosphorus concentration in the effluent can still reach the environmental quality standard of the II-type water area of the surface water in China (TP <0.1 mg/L), and the removal rate of the SS can reach more than 98%.
Furthermore, it should be understood that various changes and modifications can be made by one skilled in the art after reading the above description of the present invention, and equivalents also fall within the scope of the invention as defined by the appended claims.
Claims (10)
1. A lanthanum-carbon composite adsorbent doped polyvinylidene fluoride phosphorus removal film is characterized by comprising a lanthanum-carbon composite adsorbent and polyvinylidene fluoride, wherein the lanthanum-carbon composite adsorbent comprises X and Y, X is more than 0 and less than or equal to 30%, and Y is more than or equal to 70% and less than 100%;
the preparation method of the lanthanum-carbon composite adsorbent comprises the following steps:
(1) adding 4, 4' -diaminobiphenyl into hydrochloric acid at the temperature of 3-10 ℃, uniformly mixing, adding nitrous acid, performing diazotization reaction, adding a mixed solution of tannic acid and sodium carbonate after the reaction is finished, stirring for reaction for 10-12 h, and collecting a solid product;
(2) and (2) dispersing the solid product obtained in the step (1) in a soluble lanthanum salt solution, adjusting the pH value to 10-12, and carbonizing the obtained precipitate at 500-700 ℃ under inert gas to obtain the lanthanum-carbon composite adsorbent.
2. The lanthanum-carbon composite adsorbent-doped polyvinylidene fluoride phosphorus removal film according to claim 1, wherein the mass ratio of the lanthanum-carbon composite adsorbent to the polyvinylidene fluoride is 1: 3.5-10.
3. The lanthanum-carbon composite adsorbent-doped polyvinylidene fluoride phosphorus removal film according to claim 1, wherein in the step (1), the ratio of 4, 4' -diaminobiphenyl, HCl, nitrous acid, tannic acid and sodium carbonate is 0.8-1 g, 25-36 mmol, 0.6-0.8 g, 0.7-0.9 g and 0.9-1.8 g.
4. The lanthanum-carbon composite adsorbent doped polyvinylidene fluoride phosphorus removal film according to claim 1, wherein in the step (2), the ratio of the solid product obtained in the step (1) to L a in the soluble lanthanum salt is 1g: 0.1-0.2 mol.
5. The lanthanum-carbon composite adsorbent doped polyvinylidene fluoride phosphorus removal film according to claim 1, wherein in the step (2), the carbonization time is 1-2 h.
6. The lanthanum-carbon composite adsorbent doped polyvinylidene fluoride phosphorus removal film according to any one of claims 1 to 5, wherein the thickness is 150 to 250 μm.
7. The preparation method of the lanthanum-carbon composite adsorbent doped polyvinylidene fluoride phosphorus removal film according to any one of claims 1 to 6, characterized by comprising the following steps:
(a) adding polyvinylidene fluoride and lanthanum-carbon composite adsorbent into N-methyl pyrrolidone, and fully stirring to obtain uniform membrane casting solution;
(b) and standing the casting solution, removing bubbles in vacuum, blade-coating the casting solution on a glass plate, placing the glass plate in the air for 25-35 s, immersing the glass plate in an ethanol solution, curing to form a film, and falling off the film from the glass plate to obtain the polyvinylidene fluoride phosphorus removal film doped with the lanthanum-carbon composite adsorbent.
8. The preparation method according to claim 7, wherein in the step (a), the mass of the N-methyl pyrrolidone accounts for 80-90% of the mass of the polyvinylidene fluoride, the lanthanum-carbon composite adsorbent and the N-methyl pyrrolidone.
9. The method according to claim 7, wherein the volume fraction of ethanol in the ethanol solution in step (b) is 10-20%.
10. The use of the lanthanum-carbon composite adsorbent doped polyvinylidene fluoride phosphorus removal film according to any one of claims 1 to 6 in water treatment.
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| CN103721677A (en) * | 2014-01-13 | 2014-04-16 | 农业部沼气科学研究所 | Preparation method of biomass carbon composite material for removing phosphorus in wastewater |
| US20150190784A1 (en) * | 2012-07-26 | 2015-07-09 | Commonwealth Scientific And Industrial Research Organisation | Gas separation processes |
| CN105817148A (en) * | 2016-05-11 | 2016-08-03 | 北京大学 | Ultrafiltration membrane with simultaneous phosphorus and nitrogen removal function and preparation method thereof |
| CN108706566A (en) * | 2018-05-18 | 2018-10-26 | 辽宁大学 | Porous polymer and its derivative Carbon Materials of the template-free method synthesis based on tannic acid under temperate condition |
| CN110170295A (en) * | 2019-06-13 | 2019-08-27 | 昆明理工大学 | A kind of dephosphorization adsorbent and preparation method thereof |
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| Publication number | Priority date | Publication date | Assignee | Title |
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| US20150190784A1 (en) * | 2012-07-26 | 2015-07-09 | Commonwealth Scientific And Industrial Research Organisation | Gas separation processes |
| CN103721677A (en) * | 2014-01-13 | 2014-04-16 | 农业部沼气科学研究所 | Preparation method of biomass carbon composite material for removing phosphorus in wastewater |
| CN105817148A (en) * | 2016-05-11 | 2016-08-03 | 北京大学 | Ultrafiltration membrane with simultaneous phosphorus and nitrogen removal function and preparation method thereof |
| CN108706566A (en) * | 2018-05-18 | 2018-10-26 | 辽宁大学 | Porous polymer and its derivative Carbon Materials of the template-free method synthesis based on tannic acid under temperate condition |
| CN110170295A (en) * | 2019-06-13 | 2019-08-27 | 昆明理工大学 | A kind of dephosphorization adsorbent and preparation method thereof |
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