Bionic adsorbent for ultimate phosphorus removal of low-concentration sewage as well as preparation method and application of bionic adsorbent
By preparing a bionic adsorbent composed of M2+ metal salt, La3+lanthanum salt and amino acids, selective adsorption of phosphate is achieved using multiple interaction mechanisms, the existing adsorbents are solved in the low phosphorus removal efficiency and difficulty in regeneration in low concentration wastewater, and meets the strict emission standards in environmentally sensitive areas.
Patent Information
- Application Number
- CN202510209244.9
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-02-25
- Publication Date
- 2025-03-25
AI Technical Summary
The existing adsorbents have low phosphorus removal efficiency in low-concentration wastewater and are difficult to regenerate, making it difficult to meet the strict emission standards in environmentally sensitive areas.
M2+ metal salt and La3+lanthanum salt are used as laminates and amino acids are used as the backbone to prepare a bionic adsorbent through pH adjustment, co-precipitation, water bath crystallization and grinding screening processes, and selective adsorption of phosphate is achieved using multiple interaction mechanisms (such as surface complexation, ion exchange, electrostatic attraction, hydrogen bonding, and physical adsorption).
It has achieved efficient and selective removal of phosphate in low-concentration wastewater, met the emission standard of total phosphorus in the environmentally sensitive area below 0.02mg/L, and improved the regeneration and utilization capacity of adsorbents.
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Abstract
Description
Technical Field
[0001] The invention relates to the technical field of water treatment, in particular to a bionic adsorbent for extreme phosphorus removal in low-concentration sewage and a preparation method and application thereof, which is suitable for extreme phosphorus removal in low-concentration sewage. Background Art
[0002] Excessive inorganic phosphorus in water is a key factor causing eutrophication of water bodies. Studies have shown that eutrophication does not require nitrogen control, only phosphorus control, and the critical conditions for eutrophication in lakes are total nitrogen (TN)>0.2mg / L and total phosphorus (TP)>0.02mg / L. Especially for water bodies such as lakes and bays, formulating more stringent TP discharge limits is the most effective eutrophication prevention and control measure. Adsorption is currently one of the most attractive strategies for removing inorganic phosphorus from water / wastewater to ultra-low levels and then recycling it for reuse because it is simple and low-cost. However, traditional adsorbents have problems with slow adsorption rate and difficult regeneration. In particular, the high hydration energy of phosphate, the large number of coexisting competitive anions in water bodies, and the extremely low phosphate concentration pose great challenges to traditional adsorbents. It is urgent to develop an environmentally friendly adsorbent for extreme phosphorus removal in low-concentration sewage.
[0003] Under conditions where the phosphate concentration in water is low and there are a large number of other competing anions, an adsorbent with high selectivity for phosphate is required. From a thermodynamic point of view, it is generally believed that high selectivity means that the interaction energy between phosphate and the adsorbent material is high, which means that the binding force between them is strong, so the adsorbent is difficult to regenerate. To reuse the adsorbent material and recover the separated phosphate, regeneration is required. The regeneration capacity of saturated adsorbent materials is a key parameter for selecting adsorbent materials for phosphate removal, but how to strike a balance between the high selectivity and regeneration capacity of adsorbent materials? In nature, Escherichia coli transports essential nutrient phosphorus (mainly in the form of orthophosphate) to cells and organelles with high specificity. Studies have shown that it mainly relies on the high-affinity active transport system of phosphate-binding proteins to absorb phosphate, and this system cannot recognize other inorganic anions. "Nature" revealed that the phosphate-binding protein (PBP) in Escherichia coli can bind to a phosphate anion (HPO4 2- There are 11 hydrogen bonds between the four oxygen atoms of phosphate and the polar groups of proteins, and 1 hydrogen bond between the proton of phosphate and the carboxylic acid side chain. In addition, PBP in E. coli can also bind H2PO4 through 12 hydrogen bonds. -There are 10 hydrogen bonds between the four oxygen atoms of phosphate and the polar groups of proteins, and 2 hydrogen bonds between the two protons of phosphate and the two carboxylic acid side chains. At the same time, the phosphate bound to PBP can be released, and the phosphate desorption efficiency is 90% at a pH of 12.5. There are multiple weak interactions between PBP and phosphate, and this process is highly selective and nearly reversible. The strength of hydrogen bonds is relatively weak, and the sum of 12 hydrogen bonds can produce significantly high interaction energy, resulting in high selectivity. However, each hydrogen bond is still reversible, and the 12 hydrogen bonds can be cleaved one by one in sequence. Therefore, the entire adsorption process is reversible. It can be seen that the ideal phosphate adsorption material should be able to produce multiple weak interactions with phosphate, so that the adsorption process is highly selective and reversible. Further studies have found that the interaction between the phosphate group and the phosphate-binding protein in Escherichia coli is closely related to the type and structure of the amino acid residues. The carboxylic acid side chain of aspartic acid (Asp) is a charged hydrogen bond receptor that can recognize HPO4 2- The carboxylic acid side chain can also prevent the ionized sulfate anion (SO4 2- ) binding, which plays a key role in the high phosphate selectivity of E. coli PBP. The guanidine group (-(NH2)3) and hydroxyl groups in serine (Ser), threonine (Thr), arginine (Arg) and glycine (Gly) can also be HPO4 2-The four oxygen atoms of PBPs form hydrogen bonds, of which the first two amino acids preferentially interact with the backbone amide and the side chain hydroxyl group (bifurcated effect), promoting the binding of short sequences. Copley and Barton also analyzed 38 proteins containing phosphate groups, indicating that in the helical binding site, the most common residue is Gly, followed by Arg, Thr, Ser and lysine (Lys); in the non-helical binding site, the most common residue is Arg, followed by Tyr, histidine (His), Lys and Ser. Therefore, the type and structure of amino acids play a crucial role in the high selectivity of phosphate-binding proteins. In addition, the study also found that phosphate binding occurs in the cavity of PBPs, which is completely matched with the size and shape of phosphate. In other words, shape complementarity is also the reason for the selective binding of PBPs to phosphate. Phosphate-binding proteins also give us a further inspiration that the selective removal of phosphate can be facilitated by constructing adsorbent materials with geometric shapes and sizes that match phosphates. Considering the effectiveness of the above-mentioned PBPs in selectively binding to phosphate, the phosphorus adsorption principle adopted by nature (i.e., the combination of different interaction mechanisms) has obvious inspiration for the preparation of phosphate selective adsorption materials. In view of the slow adsorption rate and difficult regeneration of existing adsorbents under the conditions of extreme phosphorus removal in low-concentration sewage, especially the high hydration energy of phosphate and the large number of coexisting competitive anions in the water body, a bionic adsorbent for extreme phosphorus removal in low-concentration sewage and its preparation method and application were invented based on nature's phosphorus adsorption principles (i.e. the combination of different interaction mechanisms), which are used to solve the above problems and thus achieve selective extreme phosphorus removal in low-concentration sewage. Summary of the invention
[0004] The purpose of the present invention is to overcome the shortcomings of the above-mentioned existing adsorbents in the extreme phosphorus removal of low-concentration sewage, and based on the phosphorus adsorption principle adopted by nature (i.e. the combination of different interaction mechanisms) for the selective adsorption of phosphate, a bionic adsorbent for the extreme phosphorus removal of low-concentration sewage and its preparation method and application are proposed, which can be suitable for the extreme phosphorus removal of low-concentration sewage.
[0005] In order to achieve the above object, one aspect of the present invention provides a method for preparing a bionic adsorbent for extreme phosphorus removal from low-concentration sewage, wherein the bionic adsorbent for extreme phosphorus removal from low-concentration sewage is prepared by M 2+ Metal salts and La 3+ Lanthanum salt is used as the layer plate, amino acid is used as the skeleton, and the process of pH adjustment, co-precipitation, water bath crystallization and grinding and screening is adopted to obtain a bionic adsorbent for extreme phosphorus removal in low-concentration wastewater.
[0006] The method for preparing the bionic adsorbent for extreme phosphorus removal from low-concentration sewage comprises the following steps: (1.1) The M2+ Metal salts, La 3+ The salt and amino acid are in a molar ratio of M 2+ :La 3+ : Amino acid = (0.5~1.5): 1.0: (0.3~0.5) ratio is dissolved in ultrapure water to prepare a mixed solution; (1.2) In a water bath at 30-60°C, uniformly drip a 1 mol / L NaOH solution into the mixed solution obtained in step (1.1), stirring the mixture at a speed of 200-500 rpm with a magnetic stirrer, and monitoring the pH value in real time with a pH meter until the pH value of the system reaches 10, then stop dripping and collect the coprecipitate; (1.3) crystallizing the coprecipitate obtained in step (1.2) in a water bath at 50 to 120° C. for 12 to 24 hours to obtain a water bath crystallization product; (1.4) The water bath crystallization product obtained in step (1.3) is centrifuged and washed 2 to 6 times at a speed of 200 to 500 rpm for 1 to 3 min until the pH value is constant to obtain a muddy paste; (1.5) The sludge paste obtained in step (1.4) is dried at 50-150°C for 18-36 hours, then ground, and finally sieved through 100-400 meshes to obtain a bionic adsorbent for extreme phosphorus removal from low-concentration wastewater.
[0007] The technical solution further defined is as follows: a. In step (1.1), the M 2+ Metal salt is Mn 2+ , Ca 2 、Zn 2+ One of the metal salts, the amino acid is one of alanine, glycine, phenylalanine, glutamic acid, serine, and asparagine; b. In step (1.2), the uniform dripping is performed by a peristaltic pump with a flow rate of 2-10 ml / min.
[0008] In order to achieve the above-mentioned purpose, according to one aspect of the present invention, a bionic adsorbent for extreme phosphorus removal from low-concentration wastewater is provided. The bionic adsorbent for extreme phosphorus removal from low-concentration wastewater is prepared by the above-mentioned method for preparing the bionic adsorbent for extreme phosphorus removal from low-concentration wastewater.
[0009] In order to achieve the above-mentioned purpose, according to one aspect of the present invention, a bionic adsorbent for extreme phosphorus removal from low-concentration wastewater is provided, which is used for extreme phosphorus removal from low-concentration wastewater such as tail water from sewage treatment plants. The bionic adsorbent for extreme phosphorus removal from low-concentration wastewater is prepared by the above-mentioned method for preparing the bionic adsorbent for extreme phosphorus removal from low-concentration wastewater.
[0010] Furthermore, the total phosphorus content of low-concentration wastewater such as sewage treatment plant tailwater is 0.50~5.00 mg / L.
[0011] Furthermore, the extreme phosphorus removal effluent of low-concentration sewage meets the discharge standard of total phosphorus below 0.02 mg / L in environmentally sensitive areas.
[0012] The advantages of the present invention are: (1.1) The bionic adsorbent prepared by the present invention for extreme phosphorus removal from low-concentration sewage selectively adsorbs phosphates based on the phosphorus adsorption principle adopted by nature (i.e., a combination of different interaction mechanisms), involving multiple interaction mechanisms such as surface complexation, ion exchange, electrostatic attraction, hydrogen bonding, and physical adsorption, thereby achieving efficient selective adsorption and removal of phosphates under low-concentration sewage conditions and improving the regeneration capacity of the bionic adsorbent; (1.2) The bionic adsorbent prepared by the present invention for extreme phosphorus removal in low-concentration sewage can be used for selective adsorption and phosphorus removal in various sewage such as sewage plant tail water. It has the advantages of small dosage, large adsorption capacity, strong adsorption selectivity and strong regeneration ability. It is particularly suitable for extreme phosphorus removal in low-concentration sewage and meets the strict emission standard of total phosphorus below 0.02 mg / L in environmentally sensitive areas. DETAILED DESCRIPTION
[0013] It should be noted that, in the absence of conflict, the embodiments and features in the embodiments of the present application can be combined with each other. The present invention will be described in detail below in conjunction with the embodiments.
[0014] Example 1 In order to achieve the above object, one aspect of the present invention provides a method for preparing a bionic adsorbent for extreme phosphorus removal from low-concentration sewage, wherein the bionic adsorbent for extreme phosphorus removal from low-concentration sewage is prepared by M 2+ Metal salts and La 3+ Lanthanum salt is used as the layer plate, amino acid is used as the skeleton, and the process of pH adjustment, co-precipitation, water bath crystallization and grinding and screening is adopted to obtain a bionic adsorbent for extreme phosphorus removal in low-concentration wastewater. The method for preparing the bionic adsorbent for extreme phosphorus removal from low-concentration sewage comprises the following steps: (1.1) The M 2+ Metal salts, La 3+ The salt and amino acid are in a molar ratio of M 2+ :La 3+ : amino acids are dissolved in ultrapure water at a ratio of 1.0:1.0:0.3 to prepare a mixed solution; (1.2) In a 35°C water bath, add 1 mol / L NaOH solution to the mixed solution obtained in step (1.1) at a uniform rate, stir at 300 rpm with a magnetic stirrer, and monitor the pH value in real time with a pH meter until the pH value of the system reaches 10, then stop adding and collect the coprecipitate; (1.3) crystallizing the coprecipitate obtained in step (1.2) in a water bath at 80° C. for 18 hours to obtain a water bath crystallization product; (1.4) The water bath crystallization product obtained in step (1.3) was centrifuged and washed 4 times at a speed of 500 rpm for 1 min until the pH value was constant to obtain a muddy paste; (1.5) The sludge obtained in step (1.4) is dried at 105°C for 24 hours, then ground, and finally sieved through 200 meshes to obtain a bionic adsorbent for extreme phosphorus removal from low-concentration wastewater.
[0015] The technical solution further defined is as follows: a. In step (1.1), the M 2+ Metal salt is Mn 2+ , the amino acid is alanine; b. In step (1.2), the uniform dripping is performed by a peristaltic pump with a flow rate of 5 ml / min.
[0016] Example 2 In order to achieve the above object, one aspect of the present invention provides a method for preparing a bionic adsorbent for extreme phosphorus removal from low-concentration sewage, wherein the bionic adsorbent for extreme phosphorus removal from low-concentration sewage is prepared by M 2+ Metal salts and La 3+ Lanthanum salt is used as the layer plate, amino acid is used as the skeleton, and the process of pH adjustment, co-precipitation, water bath crystallization and grinding and screening is adopted to obtain a bionic adsorbent for extreme phosphorus removal in low-concentration wastewater. The method for preparing the bionic adsorbent for extreme phosphorus removal from low-concentration sewage comprises the following steps: (1.1) The M 2+ Metal salts, La 3+ The salt and amino acid are in a molar ratio of M 2+ :La 3+ : amino acids are dissolved in ultrapure water at a ratio of 0.5:1.0:0.5 to prepare a mixed solution; (1.2) In a 60°C water bath, add 1 mol / L NaOH solution to the mixed solution obtained in step (1.1) at a uniform rate, stir at 500 rpm with a magnetic stirrer, and monitor the pH value in real time with a pH meter until the pH value of the system reaches 10, then stop adding and collect the coprecipitate; (1.3) crystallizing the coprecipitate obtained in step (1.2) in a water bath at 120° C. for 12 hours to obtain a water bath crystallization product; (1.4) The water bath crystallization product obtained in step (1.3) was centrifuged and washed three times at a speed of 500 rpm for 1 min until the pH value was constant to obtain a muddy paste; (1.5) The sludge obtained in step (1.4) is dried at 50°C for 36 hours, then ground, and finally sieved through 100 meshes to obtain a bionic adsorbent for extreme phosphorus removal from low-concentration wastewater.
[0017] The technical solution further defined is as follows: a. In step (1.1), the M 2+ The metal salt is Zn 2+ , the amino acid is glutamic acid; b. In step (1.2), the uniform dripping is performed by a peristaltic pump with a flow rate of 10 ml / min.
[0018] Example 3 In order to achieve the above object, one aspect of the present invention provides a method for preparing a bionic adsorbent for extreme phosphorus removal from low-concentration sewage, wherein the bionic adsorbent for extreme phosphorus removal from low-concentration sewage is prepared by M 2+ Metal salts and La 3+ Lanthanum salt is used as the layer plate, amino acid is used as the skeleton, and the process of pH adjustment, co-precipitation, water bath crystallization and grinding and screening is adopted to obtain a bionic adsorbent for extreme phosphorus removal in low-concentration wastewater. The method for preparing the bionic adsorbent for extreme phosphorus removal from low-concentration sewage comprises the following steps: (1.1) The M 2+ Metal salts, La 3+ The salt and amino acid are in a molar ratio of M 2+ :La 3+ : amino acids are dissolved in ultrapure water at a ratio of 1.5:1.0:0.3 to prepare a mixed solution; (1.2) In a 30°C water bath, add 1 mol / L NaOH solution to the mixed solution obtained in step (1.1) at a uniform rate, stir at 200 rpm with a magnetic stirrer, and monitor the pH value in real time with a pH meter until the pH value of the system reaches 10, then stop adding and collect the coprecipitate; (1.3) crystallizing the coprecipitate obtained in step (1.2) in a water bath at 120° C. for 12 hours to obtain a water bath crystallization product; (1.4) The water bath crystallization product obtained in step (1.3) was centrifuged and washed 6 times at a speed of 200 rpm for 3 min until the pH value was constant to obtain a muddy paste; (1.5) The sludge obtained in step (1.4) is dried at 150° C. for 18 h, then ground, and finally sieved through 400 meshes to obtain a bionic adsorbent for extreme phosphorus removal from low-concentration wastewater.
[0019] The technical solution further defined is as follows: a. In step (1.1), the M 2+ The metal salt is Ca 2+ , the amino acid is glycine; b. In step (1.2), the uniform dripping is performed by a peristaltic pump with a flow rate of 2 ml / min.
[0020] Example 4 In order to achieve the above object, one aspect of the present invention provides a method for preparing a bionic adsorbent for extreme phosphorus removal from low-concentration sewage, wherein the bionic adsorbent for extreme phosphorus removal from low-concentration sewage is prepared by M 2+ Metal salts and La 3+ Lanthanum salt is used as the layer plate, amino acid is used as the skeleton, and the process of pH adjustment, co-precipitation, water bath crystallization and grinding and screening is adopted to obtain a bionic adsorbent for extreme phosphorus removal in low-concentration wastewater. The method for preparing the bionic adsorbent for extreme phosphorus removal from low-concentration sewage comprises the following steps: (1.1) The M 2+ Metal salts, La 3+ The salt and amino acid are in a molar ratio of M 2+ :La 3+ : amino acids are dissolved in ultrapure water at a ratio of 1.1:1.0:0.3 to prepare a mixed solution; (1.2) In a 50°C water bath, add 1 mol / L NaOH solution to the mixed solution obtained in step (1.1) at a uniform rate, stir at 400 rpm with a magnetic stirrer, and monitor the pH value in real time with a pH meter until the pH value of the system reaches 10, then stop adding and collect the coprecipitate; (1.3) crystallizing the coprecipitate obtained in step (1.2) in a water bath at 100° C. for 15 hours to obtain a water bath crystallization product; (1.4) The water bath crystallization product obtained in step (1.3) was centrifuged and washed 4 times at a speed of 400 rpm for 2.5 min until the pH value was constant to obtain a muddy paste; (1.5) The sludge obtained in step (1.4) is dried at 80°C for 30 hours, then ground, and finally sieved through 200 meshes to obtain a bionic adsorbent for extreme phosphorus removal from low-concentration wastewater.
[0021] The technical solution further defined is as follows; In step (1.1), the M2+ Metal salt is Mn 2+ , the amino acid is serine; In step (1.2), the uniform dripping is performed by a peristaltic pump with a flow rate of 8 ml / min.
[0022] Performance characterization: 0.18g of each of the bionic adsorbents for extreme phosphorus removal from low-concentration sewage prepared in Example 1, Example 2, Example 3, and Example 4 were added to low-concentration sewage such as tail water from a sewage treatment plant, wherein the total phosphorus was 0.50 and 5.00 mg / L, respectively, for extreme phosphorus removal. The residual phosphorus concentration was measured at 10 min and 30 min, respectively, and the experiment was repeated. The evaluation results are shown in Appendix 1.
[0023] Table 1
[0024] It can be seen from the above experimental data that the removal effects of TP in the four embodiments within 30 minutes meet the emission standard of total phosphorus below 0.02 mg / L in environmentally sensitive areas, and the removal efficiency is basically unchanged after 10 repetitions of the experiment.
[0025] The above are only preferred embodiments of the present invention and are not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.
Claims
1. A bionic adsorbent for extreme phosphorus removal in low-concentration sewage and its preparation method and application, characterized in that: The bionic adsorbent for extreme phosphorus removal of low-concentration sewage is M 2+ Metal salts and La 3+ Lanthanum salt is used as the layer plate, amino acid is used as the skeleton, and the process of pH adjustment, co-precipitation, water bath crystallization and grinding and screening is adopted to obtain a bionic adsorbent for extreme phosphorus removal in low-concentration wastewater. The method for preparing the bionic adsorbent for extreme phosphorus removal from low-concentration sewage comprises the following steps: (1.1) The M 2+ Metal salts, La 3+ The salt and amino acid are in a molar ratio of M 2+ :La 3+ : Amino acid = (0.5~1.5): 1.0: (0.3~0.5) ratio is dissolved in ultrapure water to prepare a mixed solution; (1.2) In a water bath at 30-60°C, add 1 mol / L NaOH solution to the mixed solution obtained in step (1.1) at a uniform rate, stir at a speed of 200-500 rpm with a magnetic stirrer, and monitor the pH value in real time with a pH meter until the pH value of the system reaches 10, then stop adding and collect the coprecipitate; (1.3) crystallizing the coprecipitate obtained in step (1.2) in a water bath at 50 to 120° C. for 12 to 24 hours to obtain a water bath crystallization product; (1.4) The water bath crystallization product obtained in step (1.3) is centrifuged and washed 2 to 6 times at a speed of 200 to 500 rpm for 1 to 3 min until the pH value is constant to obtain a muddy paste; (1.5) The sludge paste obtained in step (1.4) is dried at 50-150°C for 18-36 hours, then ground, and finally sieved through 100-400 meshes to obtain a bionic adsorbent for extreme phosphorus removal from low-concentration wastewater.
2. A bionic adsorbent for extreme phosphorus removal in low-concentration sewage according to claim 1, and its preparation method and application, characterized in that: The M 2+ Metal salt is Mn 2+ , Ca 2 、Zn 2+ One of the metal salts, the amino acid is one of alanine, glycine, phenylalanine, glutamic acid, serine, and asparagine.
3. A bionic adsorbent for extreme phosphorus removal from low-concentration sewage according to claim 1, and its preparation method and application, characterized in that: The uniform dripping is dripping by a peristaltic pump with a flow rate of 2-10 ml / min.
4. The bionic adsorbent for extreme phosphorus removal from low-concentration sewage according to claim 1, and its preparation method and application, characterized in that: The total phosphorus content of low-concentration sewage such as tail water from a sewage treatment plant is 0.50-5.00 mg / L.
5. The bionic adsorbent for extreme phosphorus removal from low-concentration sewage according to claim 1, and its preparation method and application, characterized in that: The extreme phosphorus removal effluent of the low-concentration sewage meets the discharge standard of total phosphorus below 0.02 mg / L in environmentally sensitive areas.