Mushroom waste adsorbent modified by different forms of phosphoric acid anions, preparation method of mushroom waste adsorbent and application of mushroom waste adsorbent in extraction of radioactive uranium

Abstract

The invention discloses a mushroom waste adsorbent modified by phosphoric acid anions in different forms, a preparation method of the mushroom waste adsorbent and application of the mushroom waste adsorbent in radioactive uranium extraction. The method comprises the following steps: grinding the mushroom waste and potassium hydroxide, and chemically activating in a tubular furnace; and finally, modifying the mushroom waste adsorbent MS-P by using different forms of phosphoric acid anions, so that the mushroom waste adsorbent MS-P has certain adsorption capacity on uranyl ions, thereby synthesizing a series of mushroom waste adsorbents MS-P modified by different phosphoric acid anions. The prepared phosphoric acid anion modified mushroom waste adsorbent is wide in uranium adsorption range, and the uranium adsorption capacity can reach 661.73 mg / g when the pH value is equal to 4. The prepared MS-P adsorbent can efficiently extract uranium, and the uranium extraction rate can reach 99.05% under the concentration of 20 mg / L. According to the method, the mushroom waste is used as the raw material, the radioactive uranium element in the seawater is extracted and separated, the purposes of treating waste with waste and turning waste into wealth are achieved, and the method has very high application potential.

Description

Technical Field

[0001] The present invention relates to the technical field of the treatment of radioactive nuclide uranium and the preparation of green adsorbents, and particularly relates to a mushroom waste adsorbent modified by different forms of phosphoric acid anions, a preparation method thereof, and an application thereof in extracting radioactive uranium. Background Art

[0002] In the nuclear industry, uranium ( 235 U) is used as the main nuclear element for producing energy and is usually obtained through mineral mining. With the growth of the population, the social demand for energy has been increasing day by day, which ultimately leads to a doubling of the uranium ore mining volume year by year. However, uranium ore resources are limited, and long-term large-scale mining will cause uranium resource depletion. At the same time, uranium ( 235 U) is one of the most dangerous radioactive isotopes in nuclear wastewater, with a long half-life (t 1 / 2 = 1.0×10 5 ~4.5×10 9 years), non-biodegradable, and strong pollution characteristics. 235 The main form of 2+ U in nuclear wastewater is uranyl ion (UO2

[0003] ), and its radiation and chemical toxicity can cause permanent damage to the ecological environment and human health. Based on the above situation, it is crucial to quickly and effectively extract uranium from radioactive wastewater for the sustainable development of energy and the environment. Summary of the Invention

[0004] The present invention uses the biochar obtained after activating mushroom waste as the matrix, and modifies it with phosphoric acid anions to obtain mushroom waste adsorbents MS-P modified with different phosphoric acid anions. The uranium treatment ability of the adsorbents is studied, and by changing the experimental conditions, the stability and adsorption capacity of the adsorbents synthesized under different ratios are obtained. This is not only beneficial to solving the pollution problem of biomass waste represented by mushroom waste-based materials, but also conducive to treating uranium pollution, achieving waste treatment with waste and turning waste into treasure.

[0005] The present invention is realized through the following technical solutions: Mushroom waste adsorbents MS-P modified with different forms of phosphoric acid anions. The preparation method of the mushroom waste adsorbents modified with different forms of phosphoric acid anions includes the following steps:

[0006] 1) Grind the mushroom waste to obtain mushroom waste powder, mix the mushroom waste powder with potassium hydroxide and grind again. After grinding, put the mixed powder into a tube furnace for activation. After cooling, obtain an intermediate product. Wash the intermediate product with water and filter it until the pH = 7, and then dry it to obtain a black powder-like intermediate product;

[0007] 2) Prepare phosphorus solutions with different forms of phosphates. Add the black powder-like intermediate product obtained in step 1) into the phosphorus solution, disperse it ultrasonically to form a suspension, put the mixed system into an oscillation box for oscillation, centrifuge and then dry it to obtain mushroom waste adsorbents MS-P modified with different forms of phosphoric acid anions.

[0008] For the above-mentioned mushroom waste adsorbents modified with different forms of phosphoric acid anions, in step 1), grind the mushroom waste into powder, pass through a 80-mesh sieve, and take the material under the sieve.

[0009] For the above-mentioned mushroom waste adsorbents modified with different forms of phosphoric acid anions, in step 1), by mass ratio, the mass ratio of mushroom waste: potassium hydroxide = 1:0 - 2.

[0010] For the above-mentioned mushroom waste adsorbents modified with different forms of phosphoric acid anions, in step 1), the activation temperature of the tube furnace is 400 - 800 °C, and the activation time is 2 h.

[0011] For the above-mentioned mushroom waste adsorbents modified with different forms of phosphoric acid anions, in step 2), by mass concentration, the phosphorus concentration in the phosphorus solution is 0 - 200 mg / L, and the mass ratio of the black powder-like intermediate product: phosphorus solution = 1 mg:1 mL.

[0012] For the above-mentioned mushroom waste adsorbents modified with different forms of phosphoric acid anions, in step 2), the different forms of phosphoric acid anions include monohydrogen phosphate, pyrophosphate, tripolyphosphate, and hexametaphosphate.

[0013] For the above mushroom waste adsorbent modified by different forms of phosphate anions, in step 2), the oscillation is carried out at 30 °C and 180 r / min for 12 h.

[0014] Application of the above mushroom waste adsorbent modified by different forms of phosphate anions in adsorbing radioactive uranium.

[0015] For the above application, the method is as follows: Take a solution containing uranyl ions, adjust the pH of the solution to 2 - 8, add the above mushroom waste adsorbent modified by different forms of phosphate anions, and carry out oscillatory adsorption at 30 °C and 180 r / min for 24 h, then filter and dry.

[0016] The present invention uses the biochar obtained by activating mushroom waste as the matrix, and through phosphate anion modification, different mushroom waste adsorbents MS-P modified by phosphate anions are obtained.

[0017] The beneficial effects of the present invention are as follows:

[0018] 1) The mushroom waste adsorbent modified by different phosphate anions in the present invention contains a large number of phosphorus-containing groups that have an affinity for uranyl ions.

[0019] 2) The different mushroom waste adsorbents modified by phosphate anions prepared in the present invention have a green and environmentally friendly synthesis route, a large adsorption capacity for uranium elements, and practical applicability.

[0020] 3) The raw materials of the present invention have a wide source, the reaction is rapid and efficient, the reaction conditions are mild, and no expensive catalyst is required. The prepared adsorbent can be used for the treatment of uranium elements in water pollution.

[0021] 4) The present invention not only helps to solve the pollution problem of biomass waste represented by waste mushroom waste-based materials, but also helps the recovery and utilization of radioactive uranium, realizing the transformation of waste into treasure.

[0022] 5) The different mushroom waste adsorbents modified by phosphate anions prepared in the present invention all have a high adsorption efficiency in a uranium solution with a concentration of 20 mg / L and a pH of 3 - 8; and in a uranium solution with a concentration of 200 mg / L and a pH of 4, the maximum adsorption capacity is 661.73 mg / g.

[0023] In summary, the different mushroom waste adsorbents modified by phosphate anions prepared in the present invention can effectively adsorb uranyl ions, and the preparation process is simple, green, with a high adsorption rate and a large adsorption capacity, having strong practical application potential. Description of the Drawings

[0024] Figure 1 It is a schematic diagram of the synthesis of the mushroom waste adsorbent modified by different forms of phosphate anions.

[0025] Figure 2It is the infrared spectrum of the mushroom waste adsorbent modified by phosphate anions.

[0026] Figure 3 It is the scanning electron microscope images of mushroom waste (A) and the mushroom waste adsorbent modified by phosphate anions (700-2KOH-MS-100P) (B).

[0027] Figure 4 It is the influence of different activation temperatures on the adsorption effect.

[0028] Figure 5 It is the influence of different amounts of potassium hydroxide added on the adsorption effect.

[0029] Figure 6 It is the influence of different phosphate anion concentrations on the adsorption effect.

[0030] Figure 7 It is the influence of different phosphate anion forms on the adsorption effect.

[0031] Figure 8 It is the comparison diagram of the adsorption performance of 700-2KOH-MS-100P for uranium at pH = 2-8.

[0032] Figure 9 It is the fitting diagram of the adsorption isotherm of 700-2KOH-MS-100P for uranium at pH = 4. Detailed implementation manners

[0033] The present invention will be further described below through specific examples, but the present invention is not limited thereby.

[0034] Example 1 Different mushroom waste adsorbents modified by phosphate anions obtained by activation under different temperature conditions

[0035] 1. Different mushroom waste adsorbents modified by phosphate anions (400-2KOH-MS-100P)

[0036] The mushroom waste is taken from the culture medium for mushroom growth, and its main components are sawdust, wheat bran, gypsum and shiitake mushroom strains.

[0037] 1) Grind the mushroom waste into powder with a pulverizer, sieve it with an 80-mesh sieve, and take the material under the sieve as the mushroom waste powder, marked as MS-80. Take 2 g of the mushroom waste powder and grind it with 2 g of potassium hydroxide for 30 min, place it in a tubular furnace at 400 °C for activation for 2 h, cool it, and then filter and wash the obtained intermediate product until it is neutral, and dry it at 80 °C to obtain a black powdery intermediate product, marked as 400-2KOH-MS.

[0038] 2) Grind the dried 400 - 2KOH - MS into powder. Take 0.1 g of 400 - 2KOH - MS powder and add it to 100 mL of monohydrogen phosphate solution with a phosphorus concentration of 100 mg / L. Obtain a suspension by ultrasonic dispersion. At 30 °C and 180 r / min, shake and adsorb for 24 h, then filter and dry to obtain mushroom waste adsorbents modified with different phosphate anions, named 400 - 2KOH - MS - 100P.

[0039] 2. Mushroom waste adsorbents modified with different phosphate anions (500 - 2KOH - MS - 100P)

[0040] Prepared according to the method in 1, the difference is that the activation temperature of 500 °C is used instead of 400 °C to obtain mushroom waste adsorbents modified with different phosphate anions, named 500 - 2KOH - MS - 100P.

[0041] 3. Mushroom waste adsorbents modified with different phosphate anions (600 - 2KOH - MS - 100P)

[0042] Prepared according to the method in 1, the difference is that the activation temperature of 600 °C is used instead of 400 °C to obtain mushroom waste adsorbents modified with different phosphate anions, named 600 - 2KOH - MS - 100P.

[0043] 4. Mushroom waste adsorbents modified with different phosphate anions (700 - 2KOH - MS - 100P)

[0044] Prepared according to the method in 1, the difference is that the activation temperature of 700 °C is used instead of 400 °C to obtain mushroom waste adsorbents modified with different phosphate anions, named 700 - 2KOH - MS - 100P.

[0045] 5. Mushroom waste adsorbents modified with different phosphate anions (800 - 2KOH - MS - 100P)

[0046] Prepared according to the method in 1, the difference is that the activation temperature of 800 °C is used instead of 400 °C to obtain mushroom waste adsorbents modified with different phosphate anions, named 800 - 2KOH - MS - 100P.

[0047] Example 2: Mushroom waste adsorbents modified with different phosphate anions under different potassium hydroxide addition amounts

[0048] 1. Mushroom waste adsorbents modified with different phosphate anions (700 - 0KOH - MS - 100P)

[0049] The mushroom waste is taken from the mushroom growth medium, and its main components are sawdust, wheat bran, gypsum, and Lentinula edodes strains.

[0050] 1) Grind the mushroom waste into powder with a grinder, sieve it through an 80-mesh sieve, and take the material under the sieve as the mushroom waste powder, marked as MS-80. Take 2 g of the mushroom waste powder and grind it with 0 g of potassium hydroxide for 30 min, place it in a tube furnace for activation at 700 °C for 2 h. After cooling, filter and wash the obtained intermediate product until it is neutral, and dry it at 80 °C to obtain the intermediate product in black powder form, marked as 700-2KOH-MS.

[0051] 2) Grind the dried 700-2KOH-MS into powder. Take 0.1 g of the 700-2KOH-MS powder, add 100 mL of monohydrogen phosphate solution with a phosphorus concentration of 100 mg / L, and disperse it ultrasonically to obtain a suspension. Shake and adsorb at 30 °C and 180 r / min for 24 h, filter, and dry to obtain the mushroom waste adsorbent modified with different phosphate anions, named 700-0KOH-MS-100P.

[0052] 2. Mushroom waste adsorbent modified with different phosphate anions (700-1KOH-MS-100P)

[0053] Prepared according to the method in 1, the difference is that 1 g of potassium hydroxide is used instead of 0 g of potassium hydroxide to obtain the mushroom waste adsorbent modified with different phosphate anions, named 700-1KOH-MS-100P.

[0054] 3. Mushroom waste adsorbent modified with different phosphate anions (700-2KOH-MS-100P)

[0055] Prepared according to the method in 1, the difference is that 2 g of potassium hydroxide is used instead of 0 g of potassium hydroxide to obtain the mushroom waste adsorbent modified with different phosphate anions, named 700-2KOH-MS-100P.

[0056] 4. Mushroom waste adsorbent modified with different phosphate anions (700-4KOH-MS-100P)

[0057] Prepared according to the method in 1, the difference is that 4 g of potassium hydroxide is used instead of 0 g of potassium hydroxide to obtain the mushroom waste adsorbent modified with different phosphate anions, named 700-4KOH-MS-100P.

[0058] Example 3. Mushroom waste adsorbents modified with different phosphate anions obtained by adsorption at different phosphorus concentrations

[0059] 1. Mushroom waste adsorbent modified with different phosphate anions (700-2KOH-MS-50P)

[0060] The mushroom waste is taken from the culture medium for mushroom growth, and its main components are sawdust, wheat bran, gypsum, and Lentinula edodes strains.

[0061] 1) Grind the mushroom waste into powder with a grinder, sieve it through an 80-mesh sieve, and take the material passing through the sieve as the mushroom waste powder, marked as MS-80. Take 2 g of the mushroom waste powder and grind it with 2 g of potassium hydroxide for 30 min, place it in a tubular furnace for activation at 700 °C for 2 h. After cooling, filter and wash the obtained intermediate product until it is neutral, and dry it at 80 °C to obtain a black powder intermediate product, marked as 700-2KOH-MS.

[0062] 2) Grind the dried 700-2KOH-MS into powder. Take 0.1 g of the 700-2KOH-MS powder and add it to 100 mL of a monohydrogen phosphate solution with a phosphorus concentration of 50 mg / L, and disperse it ultrasonically to obtain a suspension. Shake and adsorb at 30 °C and 180 r / min for 24 h, filter, and dry to obtain a mushroom waste adsorbent modified with different phosphate anions, named 700-0KOH-MS-50P.

[0063] 2. Mushroom waste adsorbent modified with different phosphate anions (700-2KOH-MS-100P)

[0064] Prepared according to the method in 1, the difference is that a monohydrogen phosphate solution with a phosphorus concentration of 100 mg / L is used instead of the phosphorus solution with a concentration of 50 mg / L to obtain a mushroom waste adsorbent modified with different phosphate anions, named 700-2KOH-MS-100P.

[0065] 3. Mushroom waste adsorbent modified with different phosphate anions (700-2KOH-MS-150P)

[0066] Prepared according to the method in 1, the difference is that a monohydrogen phosphate solution with a phosphorus concentration of 150 mg / L is used instead of the phosphorus solution with a concentration of 50 mg / L to obtain a mushroom waste adsorbent modified with different phosphate anions, named 700-2KOH-MS-150P.

[0067] 4. Mushroom waste adsorbent modified with different phosphate anions (700-2KOH-MS-200P)

[0068] Prepared according to the method in 1, the difference is that a monohydrogen phosphate solution with a phosphorus concentration of 200 mg / L is used instead of the phosphorus solution with a concentration of 50 mg / L to obtain a mushroom waste adsorbent modified with different phosphate anions, named 700-2KOH-MS-200P.

[0069] Example 4: Mushroom waste adsorbents modified with different phosphate anions obtained by adsorption under different morphological phosphate anions 1. Mushroom waste adsorbent modified with different phosphate anions (700-2KOH-MS-100P)

[0070] The mushroom waste is taken from the culture medium for mushroom growth, and its main components are wood chips, wheat bran, gypsum and Lentinula edodes strains.

[0071] 1) Grind the mushroom waste into powder with a pulverizer, sieve it through an 80-mesh sieve, and take the material under the sieve as the mushroom waste powder, marked as MS-80. Take 2 g of the mushroom waste powder and grind it with 2 g of potassium hydroxide for 30 min, place it in a tubular furnace for activation at 700 °C for 2 h, after cooling, filter and wash the obtained intermediate product until it is neutral, and dry it at 80 °C to obtain a black powder intermediate product, marked as 700-2KOH-MS.

[0072] 2) Grind the dried 700-2KOH-MS into powder, take 0.1 g of the 700-2KOH-MS powder, add 100 mL of monohydrogen phosphate solution with a phosphorus concentration of 100 mg / L, and disperse it ultrasonically to obtain a suspension. At 30 °C and 180 r / min, shake and adsorb for 24 h, filter, and dry to obtain a mushroom waste adsorbent modified with different phosphate anions, named 700-2KOH-MS-100P. 2. Mushroom waste adsorbent modified with different phosphate anions (700-2KOH-MS-100P2)

[0073] Prepared according to the method in 1, the difference is that a pyrophosphate solution with a phosphorus concentration of 100 mg / L is used instead of the phosphorus solution with a concentration of 100 mg / L to obtain a mushroom waste adsorbent modified with different phosphate anions, named 700-2KOH-MS-100P2.

[0074] 3. Mushroom waste adsorbent modified with different phosphate anions (700-2KOH-MS-100P3)

[0075] Prepared according to the method in 1, the difference is that a tripolyphosphate solution with a phosphorus concentration of 100 mg / L is used instead of the phosphorus solution with a concentration of 100 mg / L to obtain a mushroom waste adsorbent modified with different phosphate anions, named 700-2KOH-MS-100P3.

[0076] 4. Mushroom waste adsorbent modified with different phosphate anions (700-2KOH-MS-100P6)

[0077] Prepared according to the method in 1, the difference is that a tripolyphosphate solution with a phosphorus concentration of 100 mg / L is used instead of the phosphorus solution with a concentration of 100 mg / L to obtain a mushroom waste adsorbent modified with different phosphate anions, named 700-2KOH-MS-100P6.

[0078] Characterization

[0079] 1. Figure 2are the infrared spectra of mushroom waste adsorbents modified by different phosphate anions. Among them, MS-80, 700-2KOH-MS, and 700-2KOH-MS-100P respectively represent the powder of mushroom waste after grinding and sieving through 80 meshes, the mushroom waste after adding the optimal amount of potassium hydroxide and activating at the optimal temperature, and the adsorbent with the optimal ratio. From Figure 2 it can be seen that broad and scattered peaks of different intensities appear near 3300 cm -1 for all three materials, which is caused by the O-H stretching vibration in cellulose.

[0080] After activation, the intensity of this peak is greatly weakened, indicating that after activation, due to the cleavage of hydroxyl groups, the cellulose content is greatly reduced. At the same time, the intensities of the infrared absorption peaks of the activated material 700-2KOH-MS all show a certain degree of decrease, proving that activation causes a certain degree of collapse of the cellulose skeleton. It can be seen from the locally enlarged infrared spectrum that the modified material 700-2KOH-MS-100P shows characteristic absorption peaks of calcium pyrophosphate (P-O-P stretching vibration absorption peaks) at 1153 cm -1 and 723 cm -1 , thus proving that the monohydrogen phosphate reacts with calcium sulfate in 700-2KOH-MS and the modification is successful. At the same time, due to the synergistic effect after modification with monohydrogen phosphate, the intensities of the infrared absorption peaks of 700-2KOH-MS-100P all increase to a certain extent.

[0081] 2. Figure 3 are the scanning electron micrographs of mushroom waste (A) and the mushroom waste adsorbent modified by phosphate anions (700-2KOH-MS-100P) (B). From Figure 3 it can be seen that although the components in mushroom waste are relatively complex, it is still not difficult to see that it has an aggregated structure of short fibers. After activation and modification, the surface of the material changes from smooth to rough, and pore structures appear, increasing the specific surface area and facilitating the adsorption reaction. This also shows that the mushroom waste adsorbent modified by phosphate anions has been successfully prepared.

[0082] Example 5 Application of mushroom waste adsorbents modified by different phosphate anions in the adsorption of radioactive uranium (I) Adsorption effect of the synthesized MS-P adsorbent on uranium under different activation temperature conditions

[0083] Method: Weigh 5 mg of MS-80, 400-2KOH-MS-100P, 500-2KOH-MS-100P, 600-2KOH-MS-100P, 700-2KOH-MS-100P, and 800-2KOH-MS-100P prepared in Examples 1 to 4 respectively, add them to 5 mL of a U(VI) solution with a concentration of 20 mg / L and a pH of 4, and shake in an oscillation box at 30 °C and 180 r / min for 24 h. The results are as Figure 4 .

[0084] It can be seen from Figure 4 that untreated MS-80 also has a certain adsorption capacity for uranium. This may be because untreated mushroom waste contains cellulose, and cellulose acts as an adsorbent. After activation, the cellulose content is greatly reduced, and calcium sulfate in the material is exposed, becoming the main site for reaction with monohydrogen phosphate. As the temperature rises from 400 °C to 700 °C, the adsorption capacity of the material for uranium gradually increases, reaching a maximum of 97.68%. This is caused by the synergistic effect of the collapse of the activated cellulose skeleton and the exposure of calcium sulfate. When the activation temperature reaches 800 °C, the adsorption capacity of the material for uranium decreases. This may be because the excessive temperature leads to deep carbonization of the material, and the cellulose skeleton collapses severely, which is not conducive to the adsorption of uranium by the material. (2) Adsorption effect of MS-P adsorbent synthesized under different potassium hydroxide addition conditions on uranium

[0085] Method: Weigh 5 mg of 700-0KOH-MS-100P, 700-1KOH-MS-100P, 700-2KOH-MS-100P, and 700-4KOH-MS-100P prepared in Examples 1 to 4 respectively, add them to 5 mL of a U(VI) solution with a concentration of 20 mg / L and a pH of 4, and shake in an oscillation box at 30 °C and 180 r / min for 24 h. The results are as Figure 5 .

[0086] It can be seen from Figure 5 that as the potassium hydroxide addition increases, the adsorption capacity of the material for uranium shows a trend of increasing first and then decreasing. This may be because as the potassium hydroxide addition increases, when it reaches 2 g, the adsorbent has a rough surface and a large specific surface area, which is conducive to the occurrence of the adsorption reaction, and the maximum adsorption capacity for uranium reaches 97.68%. However, further increasing the KOH addition seriously damages the cellulose skeleton structure and is not conducive to the adsorption of uranium.

[0087] (3) Adsorption effect of MS-P adsorbent synthesized under different monohydrogen phosphate concentrations on uranium

[0088] Method: Weigh 5 mg of 700-2KOH-MS, 700-2KOH-MS-50P, 700-2KOH-MS-100P, 700-2KOH-MS-150P, and 700-2KOH-MS-200P prepared in Examples 1 to 4 respectively, and add them to 5 mL of a U(VI) solution with a concentration of 20 mg / L and a pH of 4. Oscillate in an oscillation box at 30 °C and 180 r / min for 24 h. The results are as Figure 6 。

[0089] It can be seen from Figure 6 that the material without monohydrogen phosphate modification also has a certain adsorption effect on uranium. This is because after the material is activated by KOH, the surface changes from rough to smooth, and the emergence of the pore structure increases the specific surface area, which is beneficial to the adsorption of uranium. Monohydrogen phosphate reacts with a small amount of calcium sulfate in the mushroom waste to form new active sites with stronger affinity for uranyl ions. As the concentration of monohydrogen phosphate increases, the number of new active sites increases. However, when the phosphorus concentration in monohydrogen phosphate reaches 100 mg / L, limited by the calcium sulfate content in the mushroom waste, the number of active sites cannot be further increased. Therefore, further increasing the phosphorus concentration has little effect on the adsorption effect.

[0090] (4) Adsorption effect of MS-P adsorbent synthesized under different phosphoric acid anion morphology conditions on uranium

[0091] Method: Weigh 5 mg of 700-0KOH-MS-100P, 700-2KOH-MS-100P2, 700-2KOH-MS-100P3, and 700-2KOH-MS-100P6 prepared in Examples 1 to 4 respectively, and add them to 5 mL of a U(VI) solution with a concentration of 20 mg / L and a pH of 4. Oscillate in an oscillation box at 30 °C and 180 r / min for 24 h. The results are as Figure 7 。

[0092] It can be seen from Figure 7 that monohydrogen phosphate is the best phosphoric acid form, and the adsorption rate of the modified material reaches 99.05%. Due to the V-shaped structure of pyrophosphate and the unique cyclic structure of hexametaphosphate, the steric hindrance is increased, which is not conducive to its binding with calcium sulfate sites, resulting in a decrease in the adsorption efficiency. The linear structure of tripolyphosphate has little effect on its adsorption effect.

[0093] (5) Adsorption effect of mushroom waste adsorbents modified with different phosphoric acid anions on uranium under different acidities

[0094] Method: Weigh 5 mg of 700-2KOH-MS-100P prepared in Examples 1 to 4, add 5 mL of a U(VI) solution with a concentration of 20 mg / L, and the pH values of the solutions are 2, 3, 4, 5, 6, 7, and 8 respectively. Oscillate in an oscillation box at 30 °C and 180 r / min for 24 h. The results are as Figure 8 .

[0095] It can be seen from Figure 8 that as the pH increases, the adsorption effect of the material on uranium shows a trend of first increasing and then decreasing. When pH = 4, 5, 6, the adsorption effects are almost the same at 99.99%. Therefore, pH = 4 is selected as the optimal adsorption condition; when pH = 7, the adsorption rate decreases slightly, probably because uranyl ions with negative charges appear at this time, resulting in a decrease in the adsorption effect; when pH = 8, the adsorption effect increases slightly, probably due to the synergistic effect of the spontaneous formation of uranyl hydroxide precipitate by uranyl ions and the adsorption of the material at this time.

[0096] (VI) Adsorption Isotherm of the Optimal Synthetic Ratio Adsorbent (700-2KOH-MS-100P) for Adsorbing U(VI)

[0097] Method: Take 5 mL, 10 mL, 15 mL, 20 mL, 25 mL, and 30 mL of U(VI) solutions with a concentration of 200 mg / L of uranium solution respectively, and adjust the pH to 4. Add 5 mg of 700-2KOH-MS-100P respectively, and oscillate in an oscillation box at 30 °C and 180 r / min for 24 h. The results are as Figure 9 .

[0098] It was found from the acidity experiment that at pH = 4, the adsorption effect of 700-2KOH-MS-100P is the best. Therefore, at pH = 4 and a uranium concentration of 200 mg / L, the saturated adsorption capacity of the adsorbent was measured, and the experimental data were fitted with Langmuir, Freundlich, Temkin, and Dubinin-Re adsorption isotherm models. The fitting results are as Figure 9 shown. The fitting values R 2 of the four models are 0.965, 0.890, 0.918, and 0.908 respectively. This shows that the adsorption isotherm of MS-P for U(VI) is more in line with the Langmuir model, and the maximum adsorption capacity for U(VI) is 661.73 mg / g, indicating that the adsorption of U(VI) by the adsorbent is a monolayer adsorption process, and the adsorption sites of the adsorbent are evenly dispersed on the surface of the adsorbent.

Claims

1. Mushroom waste adsorbent MS-P modified with different forms of phosphate anions, characterized in that: The preparation method of the mushroom waste adsorbent modified with phosphate anions in different forms comprises the following steps: 1) Grinding the mushroom waste to obtain mushroom waste powder, mixing the mushroom waste powder with potassium hydroxide and grinding again, After grinding, the mixed powder is placed in a tube furnace for activation, and an intermediate product is obtained after cooling. The intermediate product is washed with water and filtered to pH = 7, and then dried to obtain a black powder intermediate product; 2) preparing a phosphorus solution with phosphates in different forms, adding the intermediate product in black powder form obtained in step 1) into the phosphorus solution, and dispersing the mixture by ultrasonication to prepare a suspension, placing the mixture in an oscillating box for oscillation, centrifuging and drying the mixture to obtain mushroom waste adsorbent MS-P modified with phosphate anions in different forms.

2. The mushroom waste adsorbent modified with different forms of phosphate anions according to claim 1, characterized in that: In step 1), the mushroom waste is ground into powder, passed through an 80-mesh sieve, and the sieve residue is taken.

3. The mushroom waste adsorbent modified with different forms of phosphate anions according to claim 1, characterized in that: In step 1), the mass ratio of mushroom waste to potassium hydroxide is 1:0-2.

4. The mushroom waste adsorbent modified with different forms of phosphate anions according to claim 1, characterized in that: In step 1), the activation temperature of the tubular furnace is 400-800° C., and the activation time is 2 h.

5. The mushroom waste adsorbent modified with different forms of phosphate anions according to claim 1, characterized in that: Step 2), according to mass concentration, the phosphorus concentration in the phosphorus solution is 0-200 mg / L, and the intermediate product in black powder form: phosphorus solution = 1 mg: 1 mL.

6. The mushroom waste adsorbent modified with phosphate anions in different forms according to claim 1, characterized in that: Step 2), different forms of phosphate anions include monohydrogen phosphate, pyrophosphate, tripolyphosphate, and hexametaphosphate.

7. The mushroom waste adsorbent modified with phosphate anions in different forms according to claim 1, characterized in that: Step 2), the shaking is carried out at 30° C. and 180 r / min for 12 h.

8. Use of the mushroom waste adsorbent modified with phosphate anions in different forms as described in any one of claims 1 to 7 in the adsorption of radioactive uranium.

9. The use according to claim 8, characterized in that: The method is as follows: take a solution containing uranyl ions, adjust the pH of the solution to 2-8, add the mushroom waste adsorbent modified with phosphate anions in different forms as described in any one of claims 1-7, shake and adsorb at 30°C and 180r / min for 24h, filter and dry.

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