High-efficiency adsorbent for refractory organic matters in wastewater and preparation method of high-efficiency adsorbent

Abstract

The invention discloses an efficient adsorbent for refractory organic matters in wastewater and a preparation method. The efficient adsorbent is prepared from the following raw material components: biomass, magnesium silicate clay minerals and MOFs (Metal-Organic Frameworks) in a mass ratio of 1: 1: (0.5-2), the MOFs in the raw materials have a high specific surface area and an adjustable pore structure, so that the adsorbent has excellent adsorption performance, the magnesium silicate clay mineral in the raw materials provides abundant electrostatic adsorption capacity, and the algae biomass in the raw materials can provide additional adsorption sites; functional groups on the surface of the algae biomass and a specific pore structure of MOFs can enable the composite material to have selective adsorption capacity on some refractory organics, the mass transfer capacity of the refractory organics on the surface of the composite material is enhanced through the outstanding surface point carrying performance of the magnesium silicate clay mineral, and the adsorption effect is good; meanwhile, the composite material has the advantages of sustainability and environmental protection.

Description

Technical Field

[0001] The invention relates to the technical field of adsorbents, and in particular to a high-efficiency adsorbent for refractory organic matter in wastewater and a preparation method thereof. Background Art

[0002] Refractory organic matter in wastewater usually has a complex chemical structure, such as long-chain alkanes, polycyclic aromatic hydrocarbons, chlorinated organic matter, synthetic polymers, etc. They are widely present in industrial production processes, such as dyes, pesticides, plastics, drugs and personal care products. Refractory organic matter is characterized by stability, persistence, potential toxicity and difficulty in treatment. The presence of refractory organic matter has caused serious pollution problems to water bodies and soil. Therefore, it is crucial to develop effective technologies for treating and removing these substances. At present, the methods for degrading these organic matter include biodegradation, chemical oxidation, photocatalytic degradation, adsorption and other technologies.

[0003] The adsorbents in the prior art have limited adsorption capacity and stability that needs to be improved when treating refractory organic matter in wastewater. In addition, for some refractory organic matter, the treatment effect of the adsorbents fails to meet the emission standards. Summary of the invention

[0004] In order to solve the above problems, the present invention provides a high-efficiency adsorbent for refractory organic matter in wastewater and a preparation method thereof. The use of algae biomass and metal organic frameworks (MOFs) aims to improve adsorption capacity, selectivity and regeneration while reducing costs and environmental impact.

[0005] A high-efficiency adsorbent for refractory organic matter in wastewater. The raw material components of the high-efficiency adsorbent include: biomass, magnesium silicate clay minerals and MOFs in a mass ratio of 1:1:0.5-2.

[0006] Description: The adsorbent has excellent adsorption performance due to the high specific surface area and adjustable pore structure of MOFs in the above raw materials. The magnesium silicate clay minerals in the raw materials provide rich electrostatic adsorption capacity, and the biomass in the raw materials can provide additional adsorption sites. The functional groups on the surface of algae biomass and the specific pore structure of MOFs can make the composite material have selective adsorption capacity for certain difficult-to-degrade organic matter; algae biomass is easy to obtain and process, making the production of composite materials more sustainable and environmentally friendly. At the same time, MOFs not only have excellent adsorption performance, but can also participate in chemical reactions as catalysts, such as catalytic degradation of organic pollutants, which increases the application range of composite materials. The fibrous structure of algae biomass can provide additional mechanical stability, and the outstanding surface point performance of magnesium silicate clay minerals enhances the mass transfer capacity of difficult-to-degrade organic matter on the surface of the composite material.

[0007] Furthermore, the preparation method of the algae biomass is:

[0008] S1-1. Pretreatment

[0009] Taking algae biomass with a water content of 15-20%, mixing the algae biomass with cellulase at a mass ratio of 1-2:1, standing at 40-50° C. and a pH value of 4.5-5.5 for 2-5 days to obtain pretreated algae biomass;

[0010] S1-2. Modification treatment

[0011] The pretreated algae biomass is dried to a moisture content of 10-12%; then, it is frozen at -30--20°C for 3-5 hours, taken out, and allowed to stand until the algae biomass reaches room temperature, and then dried at 60-80°C for 1-2 hours, and then the algae biomass is crushed with a crusher for 5-10 minutes, and then the crushed algae biomass is mixed with a hydrochloric acid solution with a mass concentration of 20% in a ratio of 2g:10-15ml, and allowed to stand at 20-30°C for 1-3 hours to obtain the modified algae biomass;

[0012] S1-3, Activation Treatment

[0013] The modified algae biomass is adjusted to pH=7 with NaOH solution; then, the modified algae biomass is activated and treated for 1-2 hours at 100-200° C. in a nitrogen atmosphere to obtain the biomass.

[0014] Description: Through the above method, various properties of biomass such as specific surface area, structure and stability can be improved. Cellulase can degrade cellulose in algae biomass, form more pores, adsorption sites and increase its specific surface area, improve the adsorption capacity of the adsorbent and facilitate the adsorption of difficult-to-degrade organic matter by the adsorbent. At the same time, it can reduce the content of harmful substances that may exist in algae biomass and improve the biological safety of the adsorbent; through modification and activation treatment, the physical properties of algae biomass can be changed, the microstructure of algae biomass can be optimized, and its structural stability and durability in the water treatment process can be improved.

[0015] Furthermore, the algae biomass includes one or more of Chlorella, Spirulina, and diatom.

[0016] Note: The above are all common algae raw materials.

[0017] Furthermore, in S1-1, the algae biomass with a water content of 15-20% is obtained by the following method: soaking the algae biomass in a treatment liquid, stirring, the soaking temperature is 30-35°C, the soaking time is 20-30 minutes, the stirring time is 15-20 minutes, and then taking it out and low-temperature drying it at 40-45°C until the water content of the algae biomass is 15-20%.

[0018] Note: By obtaining the above-mentioned specific water content, the activity of algae substances can be improved in advance, avoiding the formation of ice crystals during direct processing that would destroy the structural state of the algae.

[0019] Furthermore, the treatment liquid is an aqueous solution containing 5-8 wt % disodium hydrogen phosphate and 1-2 wt % vitamin B12.

[0020] Note: The above-mentioned treatment solution can also ensure that the algae are in a suitable growth environment, making its surface less susceptible to damage by subsequent treatments, thereby affecting its structure and properties.

[0021] The present invention also provides a method for preparing a high-efficiency adsorbent for refractory organic matter in wastewater, comprising the following steps:

[0022] S1. Biomass, 3-aminopropyltriethoxysilane and anhydrous ethanol are mixed in a ratio of 1-2 g: 1 ml: 100 ml, and magnetically stirred at room temperature for 1-3 h; then centrifuged at 500-800 rpm for 10-15 min, the supernatant is removed, and the biomass is washed with anhydrous ethanol;

[0023] S2. According to the ratio of 1g:1g:0.5-2g:10ml, the biomass, magnesium silicate clay mineral and MOFs treated by S1 are placed in deionized water, and treated for 20-30min by an ultrasonic cell disruptor at a power of 400-500W, and then 4-5wt% glutaraldehyde is added, and magnetic stirring is performed at room temperature for 12-20h; and centrifuged at 900-1000rpm for 10-15min, the supernatant is removed to obtain a solid, and then the solid is dried and heat-treated to obtain a high-efficiency adsorbent.

[0024] Description: Through the above method, 3-aminopropyltriethoxysilane is used to react with the hydroxyl groups on the surface of biomass to introduce amino functional groups, thereby enhancing the binding force between biomass and MOFs. At the same time, glutaraldehyde can react with the amino groups introduced by 3-aminopropyltriethoxysilane to form a stable cross-linked network, thereby improving the chemical and thermal stability of the composite material. Through the above method, algae biomass is combined with MOFs to form a porous composite material with a hierarchical structure, thereby improving the adsorption capacity.

[0025] Furthermore, the rotation speed of the magnetic stirring is 500-600 rpm.

[0026] Note: The above stirring parameters are more preferred. Beyond this range, the reaction between biomass and 3-aminopropyltriethoxysilane has no promoting effect.

[0027] Furthermore, the drying treatment is: standing at a temperature of -40 to -45°C for 30 to 60 minutes, then heating to 20 to 30°C at a heating rate of 8 to 10°C / min, and then standing at a pressure of 0.2MPa and a temperature of 50 to 70°C for 1 to 3 hours.

[0028] Furthermore, the heat treatment is to heat treat the mixture in a nitrogen atmosphere at 150-200° C. for 30-60 min.

[0029] Note: The above-mentioned drying treatment and heat treatment can further activate the cross-linked biomass and MOFs composite material, optimize its structural morphology, and make it more suitable for difficult-to-degrade materials.

[0030] Furthermore, the MOFs are prepared by a solvothermal method; the preparation method of MOFs includes:

[0031] Cu(NO3)2·3H2O, 2-methylimidazole and N,N-dimethylformamide are selected in a molar ratio of 1:2:10-15, and then stirred until dissolved to obtain a solution. The solution is then heated to 120-150°C at a heating rate of 5°C / min, and then allowed to stand for 15-20 hours, and then naturally cooled to room temperature and dried at 50-70°C to obtain MOFs.

[0032] Note: The above method can be used to prepare MOFs materials suitable for wastewater treatment.

[0033] The beneficial effects of the present invention are:

[0034] The present invention makes the adsorbent have excellent adsorption performance by using the high specific surface area and adjustable pore structure of MOFs in the raw material, provides rich electrostatic adsorption capacity through the magnesium silicate clay mineral in the raw material, and provides additional adsorption sites through the algae biomass in the raw material. The functional groups on the surface of the algae biomass and the specific pore structure of MOFs can make the composite material have selective adsorption capacity for certain difficult-to-degrade organic matter; the algae biomass is easy to obtain and process, making the production of the composite material more sustainable and environmentally friendly. At the same time, MOFs not only have excellent adsorption performance, but can also participate in chemical reactions as catalysts, and the fibrous structure of the algae biomass can provide additional mechanical stability. The preparation method of the present invention utilizes 3-aminopropyltriethoxysilane to react with hydroxyl groups on the surface of algae biomass to introduce amino functional groups, thereby enhancing the binding force between the algae biomass and MOFs; at the same time, glutaraldehyde can react with the amino groups introduced by 3-aminopropyltriethoxysilane to form a stable cross-linked network, thereby improving the chemical and thermal stability of the composite material; the outstanding surface charged point performance of the magnesium silicate clay mineral enhances the mass transfer capacity of the refractory organic matter on the surface of the composite material; through the above method, the algae biomass is combined with MOFs to form a porous composite material with a hierarchical structure, thereby improving the adsorption capacity. DETAILED DESCRIPTION

[0035] In order to further illustrate the method adopted by the present invention and the effect achieved, the technical solution of the present invention will be clearly and completely described in combination with experiments below.

[0036] Example 1: A highly efficient adsorbent for refractory organic matter in wastewater, wherein the raw material components of the highly efficient adsorbent include: biomass, magnesium silicate clay minerals and MOFs in a mass ratio of 1:1:0.6; the algae biomass includes Chlorella, Spirulina and diatoms in a mass ratio of 1:1:1;

[0037] The preparation method of the algae biomass is:

[0038] S1-1. Pretreatment

[0039] Taking algae biomass with a water content of 18%, mixing the algae biomass with cellulase at a mass ratio of 1.5:1, and standing at 45° C. and a pH value of 5 for 3 days to obtain pretreated algae biomass;

[0040] S1-2, Modification treatment

[0041] The pretreated algae biomass is dried to a water content of 11%; then, it is frozen at -25°C for 4 hours, taken out, and allowed to stand until the algae biomass reaches room temperature, and then dried at 70°C for 1.5 hours, and then the algae biomass is crushed with a crusher for 8 minutes, and then the crushed algae biomass is mixed with a hydrochloric acid solution with a mass concentration of 20% in a ratio of 2g:12ml, and allowed to stand at 25°C for 2 hours to obtain modified algae biomass;

[0042] S1-3, Activation Treatment

[0043] The modified algae biomass was adjusted to pH=7 with 30 wt % NaOH solution; and then activated in a nitrogen atmosphere at 150° C. for 1.5 h to obtain biomass.

[0044] The method for preparing a highly efficient adsorbent for refractory organic matter in wastewater comprises the following steps:

[0045] S1. Biomass, 3-aminopropyltriethoxysilane and anhydrous ethanol were mixed in a ratio of 1.5 g: 1 ml: 100 ml, and magnetically stirred at room temperature for 2 h; the speed of the magnetic stirring was 550 rpm;

[0046] Then centrifuge at 700 rpm for 13 min, remove the supernatant, and then wash the biomass with anhydrous ethanol;

[0047] S2. The biomass, magnesium silicate clay mineral and MOFs treated by S1 were placed in deionized water at a ratio of 1g:1g:0.6g:10ml, and treated for 25 minutes using an ultrasonic cell disruptor at a power of 450W, and then 4.5wt% glutaraldehyde was added, and magnetic stirring was performed for 15 hours at room temperature; and centrifuged at 950rpm for 12 minutes, and the supernatant was removed to obtain a solid, and then the solid was dried and heat-treated to obtain a high-efficiency adsorbent;

[0048] The drying treatment is as follows: standing at -42°C for 40 minutes, then heating to 25°C at a heating rate of 9°C / min, and then standing at a pressure of 0.2MPa and a temperature of 60°C for 2 hours;

[0049] The heat treatment is to heat the mixture in a nitrogen atmosphere at 180° C. for 40 minutes;

[0050] The MOFs are prepared by a solvothermal method, which specifically adopts the preparation method in the document "Preparation and Application Research of Metal Organic Framework Porous Materials (MOFs)".

[0051] Example 2: This example is different from Example 1 in that the raw material components are different. The raw material components of the high-efficiency adsorbent include: biomass, magnesium silicate clay mineral and MOFs in a mass ratio of 1:1:0.5.

[0052] Example 3: This example is different from Example 1 in that the raw material components are different. The raw material components of the high-efficiency adsorbent include: biomass, magnesium silicate clay mineral and MOFs in a mass ratio of 1:1:0.2.

[0053] Example 4: This example is different from Example 1 in that the temperature parameters of the algae biomass are different, S1-1, standing at 40°C to obtain the pretreated algae biomass;

[0054] S1-2, freezing at -30°C, taking out, and standing until the algae biomass reaches room temperature, then drying at 60°C, and then crushing the algae biomass with a crusher, mixing the crushed algae biomass with a hydrochloric acid solution with a mass concentration of 20%, and standing at 20°C to obtain the modified algae biomass;

[0055] S1-3. Activate the biomass at 100° C. in a nitrogen atmosphere.

[0056] Example 5: This example is different from Example 1 in that the temperature parameters of the algae biomass are different.

[0057] S1-1, standing at 50° C. to obtain pretreated algae biomass;

[0058] S1-2, freezing at -20°C, taking out, and standing until the algae biomass reaches room temperature, then drying at 80°C, and then crushing the algae biomass with a crusher, mixing the crushed algae biomass with a hydrochloric acid solution with a mass concentration of 20%, and standing at 30°C to obtain the modified algae biomass;

[0059] S1-3. Activate the biomass at 200° C. in a nitrogen atmosphere.

[0060] Example 6: This example is different from Example 1 in that the raw material ratio parameters of the algae biomass are different.

[0061] S1-1, taking algae biomass with a water content of 20%, mixing the algae biomass with cellulase in a mass ratio of 1:1, and letting the mixture stand at a pH of 5.5 to obtain pretreated algae biomass;

[0062] S1-2, drying the pretreated algae biomass to a water content of 10%; freezing, drying, and crushing, and then mixing the crushed algae biomass with a hydrochloric acid solution with a mass concentration of 20% in a ratio of 2g:10ml.

[0063] Example 7: This example is different from Example 1 in that the raw material ratio parameters of the algae biomass are different.

[0064] S1-1, taking algae biomass with a water content of 15%, mixing the algae biomass with cellulase at a mass ratio of 2:1, and letting it stand at a pH of 4.5 to obtain pretreated algae biomass;

[0065] S1-2, drying the pretreated algae biomass to a water content of 12%; freezing, drying, and crushing, and then mixing the crushed algae biomass with a hydrochloric acid solution with a mass concentration of 20% in a ratio of 2g:15ml.

[0066] Example 8: This example is different from Example 1 in that the time parameters of the algae biomass are different, S1-1, standing for 2 days;

[0067] S1-2, taking out after freezing for 3 hours, drying for 2 hours, crushing for 10 minutes, and standing for 3 hours to obtain modified algae biomass;

[0068] S1-3, activation treatment for 1 hour to obtain biomass.

[0069] Example 9: This example is different from Example 1 in that the time parameters of the algae biomass are different, S1-1, standing for 5 days;

[0070] S1-2, taking out after freezing for 5 hours, drying for 1 hour, crushing for 5 minutes, and standing for 1 hour to obtain modified algae biomass;

[0071] S1-3, activation treatment for 2 hours to obtain biomass.

[0072] Example 10: The difference between this example and Example 1 is that the raw material ratio in the preparation method of the high-efficiency adsorbent is different. S1, biomass, 3-aminopropyltriethoxysilane and anhydrous ethanol are mixed in a ratio of 1g:1ml:100ml; S2, biomass and MOFs treated by S1 are placed in deionized water in a ratio of 1g:0.5g:10ml, and then 4wt% glutaraldehyde is added.

[0073] Example 11: The difference between this example and Example 1 is that the raw material ratio in the preparation method of the high-efficiency adsorbent is different. S1, biomass, 3-aminopropyltriethoxysilane and anhydrous ethanol are mixed in a ratio of 2g:1ml:100ml; S2, biomass treated with S1 and MOFs are placed in deionized water in a ratio of 1g:2g:10ml, and then 5wt% glutaraldehyde is added.

[0074] Example 12: This example is different from Example 1 in that the preparation parameters in the preparation method of the high-efficiency adsorbent are different.

[0075] S1, magnetic stirring at room temperature for 3 hours; the speed of the magnetic stirring is 500 rpm; then centrifuging at 500 rpm for 10 minutes, removing the supernatant, and then washing the biomass with anhydrous ethanol;

[0076] S2, using an ultrasonic cell disruptor at 400 W power for 30 min, then adding glutaraldehyde, and magnetically stirring at room temperature for 12 h; and centrifuging at 900 rpm for 10 min, removing the supernatant to obtain a solid, and then drying and heat treating the solid to obtain a high-efficiency adsorbent;

[0077] The drying treatment is as follows: standing at -40°C for 30 minutes, then heating to 20°C at a heating rate of 8°C / min, and then standing at a pressure of 0.2MPa and a temperature of 50°C for 3 hours;

[0078] The heat treatment is to heat the mixture in a nitrogen atmosphere at 200° C. for 60 minutes.

[0079] Example 13: This example is different from Example 1 in that the preparation parameters in the preparation method of the high-efficiency adsorbent are different.

[0080] S1, magnetic stirring at room temperature for 1 hour; the speed of the magnetic stirring is 600 rpm; then centrifuging at 800 rpm for 15 minutes, removing the supernatant, and then washing the biomass with anhydrous ethanol;

[0081] S2, using an ultrasonic cell disruptor at 500W power for 20 minutes, then adding glutaraldehyde, and magnetically stirring at room temperature for 20 hours; and centrifuging at 1000rpm for 15 minutes, removing the supernatant to obtain a solid, and then drying and heat treating the solid to obtain a high-efficiency adsorbent;

[0082] The drying treatment is as follows: standing at -45°C for 60 minutes, then heating to 30°C at a heating rate of 10°C / min, and then standing at a pressure of 0.2MPa and a temperature of 70°C for 1 hour;

[0083] The heat treatment is to heat the mixture in a nitrogen atmosphere at 150° C. for 30 minutes.

[0084] Example 14: This example is different from Example 1 in that, in S1-1, the algae biomass with a water content of 18% is obtained by the following method: the algae biomass is soaked in a treatment liquid with stirring at a soaking temperature of 33°C for 25 min and a stirring time of 18 min, then taken out and low-temperature dried at 42°C until the water content of the algae biomass is 18%; the treatment liquid is an aqueous solution containing 7wt% disodium hydrogen phosphate and 1.5wt% vitamin B12.

[0085] Example 15: This example differs from Example 14 in that the treatment parameters are different. The algae biomass is immersed in the treatment liquid and stirred. The immersion temperature is 30°C, the immersion time is 20 min, the stirring time is 15 min, and then the algae biomass is taken out and low-temperature dried at 40°C until the water content of the algae biomass is 15%. The treatment liquid is an aqueous solution containing 5wt% disodium hydrogen phosphate and 1wt% vitamin B12.

[0086] Example 16: This example is different from Example 14 in that the treatment parameters are different. The algae biomass is immersed in the treatment liquid and stirred. The soaking temperature is 35°C, the soaking time is 30 minutes, the stirring time is 120 minutes, and then the algae biomass is taken out and low-temperature dried at 45°C until the water content of the algae biomass is 20%; the treatment liquid is an aqueous solution containing 8wt% disodium hydrogen phosphate and 2wt% vitamin B12.

[0087] Example 17: This example is different from Example 1 in that the preparation method of MOFs includes:

[0088] Cu(NO3)2·3H2O, 2-methylimidazole, and N,N-dimethylformamide were selected in a molar ratio of 1:2:12, and then stirred until dissolved to obtain a solution. The solution was then heated to 130°C at a heating rate of 5°C / min, then allowed to stand for 18 hours, naturally cooled to room temperature, and dried at 60°C to obtain MOFs.

[0089] Example 18: This example is different from Example 17 in that the preparation method of MOFs includes:

[0090] Cu(NO3)2·3H2O, 2-methylimidazole, and N,N-dimethylformamide were selected in a molar ratio of 1:2:10, and then stirred until dissolved to obtain a solution. The solution was then heated to 120°C at a heating rate of 5°C / min, then allowed to stand for 15 hours, naturally cooled to room temperature, and dried at 50°C to obtain MOFs.

[0091] Example 19: This example is different from Example 17 in that the preparation method of MOFs includes:

[0092] Cu(NO3)2·3H2O, 2-methylimidazole, and N,N-dimethylformamide were selected in a molar ratio of 1:2:15, and then stirred until dissolved to obtain a solution. The solution was then heated to 150°C at a heating rate of 5°C / min, then allowed to stand for 20 hours, naturally cooled to room temperature, and dried at 70°C to obtain MOFs.

[0093] Experimental Example: The description of this experimental example is based on the scheme described in Example 1, and is intended to illustrate the practical application effect of the present invention.

[0094] Experimental Example: 1. Degradation tests were performed on the high-efficiency adsorbents obtained in Examples 1 to 19 respectively;

[0095] Specifically, 1L of organic wastewater with a COD value of 10500mg / L is taken, and the concentration of polychlorinated biphenyls in the organic wastewater is 500mg / L; the organic wastewater is separated from the oil to remove floating objects and impurities in the wastewater, and then 100g of the high-efficiency adsorbent in the embodiment is added for adsorption treatment for 4 days; the removal rate of total organic matter (COD value change percentage %) and the removal rate of polychlorinated biphenyls (polychlorinated biphenyl concentration change percentage %) are obtained.

[0096] The test results of Examples 1 to 19 are as follows:

[0097] 1. Explore the effects of different treatment methods on adsorption effect;

[0098] Comparative Example 1: Only 100 g of MOFs were used for degradation.

[0099] Comparative Example 2: Only 100 g of the algae biomass in Example 1 was used for degradation.

[0100] Comparative Example 3: The difference from Example 1 is that the algae biomass is not subjected to the treatments of S1-1 to S1-3, and Chlorella, Spirulina and diatoms in a mass ratio of 1:1:1 are directly used as the algae biomass to prepare steps S1-S2.

[0101] Example 1, Example 14, Example 17, and Comparative Examples 1 to 3 were compared, as shown in Table 1;

[0102] Table 1 Experimental results of wastewater adsorption by adsorbents obtained under different treatment methods

[0103] parameter Removal rate of organic matter% Removal rate of PCBs (%) Example 1 90 92 Embodiment 14 92 93 Embodiment 17 96 93 Comparative Example 1 46 61 Comparative Example 2 65 40 Comparative Example 3 77 55

[0104] As can be seen from Table 1, by comparing Example 1 with Comparative Example 1, it can be seen that the raw material components and the preparation method in Example 1 have relatively significant effects. In Comparative Example 1, only MOFs are used for adsorption, which may be limited by the poor stability of MOFs themselves in water and susceptibility to degradation or structural damage caused by environmental factors. The problem that large molecular weight and difficult-to-degrade organic matter is not easy to be adsorbed can be solved by the preparation method in Example 1, thereby significantly improving the removal rate of organic matter and polychlorinated biphenyls.

[0105] By comparing Example 1 with Comparative Example 2, it can be seen that compared with the problem that the adsorption capacity is not as good as that of MOFs in the adsorption process using only algae biomass in Comparative Example 2, the combination of the two in Example 1 can solve these problems, thereby significantly improving the removal rate of organic matter and polychlorinated biphenyls.

[0106] By comparing Example 1 with Comparative Example 3, it can be found that in Comparative Example 3, the algae biomass is not prepared and modified, and the raw material is directly used. Therefore, the specific surface area, structure and stability of the algae biomass are not high, and the regeneration ability is poor. The algae biomass in Example 1 can form more pores, adsorption sites and increase its specific surface area through cellulase and modification, activation and other treatment steps, thereby improving the adsorption capacity of the adsorbent and the selectivity, structural stability and durability for difficult-to-degrade organic matter.

[0107] By comparing Example 1 with Example 14, it can be found that in Example 14, the algae biomass is pretreated. Through this pretreatment step, the activity of the algae material can be improved in advance, and the freezing and formation of ice crystals that destroy the structural state of the algae during the direct treatment process can be avoided; this operation is not performed in Example 1, so compared with Example 14, the treatment of Example 1 is slightly insufficient.

[0108] By comparing Example 1 with Example 17, it can be found that Example 17 provides a method for preparing MOFs. In the modified method, by optimizing and selecting relevant raw materials and parameters, the obtained MOFs can avoid the shortcomings of low stability and poor macromolecular adsorption effect compared with the MOFs in the prior art used in Example 1, and are suitable for removing organic matter in the wastewater in this example and have good adsorption effect.

[0109] 2. Explore the influence of different preparation parameters on the experimental results of wastewater adsorption by the obtained adsorbent;

[0110] Examples 1-19 were compared, as shown in Table 2;

[0111] Table 2 Experimental results of wastewater adsorption on the adsorbents obtained with different preparation parameters

[0112]

[0113]

[0114] As can be seen from Table 2, by comparing Example 1, Example 2 and Example 3, it can be found that the raw material components in Example 1 are more preferred. The reason is that the combination ratio of the biomass, magnesium silicate clay mineral and MOFs in Example 1 is in accordance with the structural state of the obtained material, and the adsorption capacity for some organic matter is better;

[0115] By comparing Example 1, Example 4 and Example 5, it can be found that the temperature parameter of Example 1 is more preferred. The temperature can affect the growth state of algae biomass and the composition of biomass. For example, the temperature has an effect on the cell wall structure. Temperature changes can affect the structure and chemical properties of the algae cell wall. High temperature may cause the cell wall to soften and degrade, while low temperature may make the cell wall harder and difficult to degrade.

[0116] By comparing Example 1, Example 6 and Example 7, it can be found that the raw material ratio parameters of the algae biomass in Example 1 are more preferred, and the ratio of the algae biomass and the cellulase in Example 1 is better, so that the cellulase can fully exert its degradation effect, forming a more optimized morphology, more pores and adsorption sites to improve the adsorption effect;

[0117] By comparing Example 1, Example 8 and Example 9, it can be found that the time parameter in Example 1 is more preferred. The time parameter affects the treatment effect of each step on the algae biomass. Too long or decisive treatment time may cause differences in the surface properties of the algae biomass. Overall, the preparation method of Example 1 is more preferred.

[0118] By comparing Example 1, Example 10 and Example 11, it can be found that the raw material ratio of the algae biomass and the MOFs composite material in Example 1 is more preferred; compared with Example 2 and Example 3, these raw materials include auxiliary agents such as 3-aminopropyltriethoxysilane and glutaraldehyde, and it can be found that the ratio of all these raw materials in Example 1 is better;

[0119] By comparing Example 1, Example 12 and Example 13, it can be found that the preparation parameters in Example 1 are more preferred. The preparation parameters in Example 1 include temperature parameters and stirring parameters. The setting of these parameters may affect the reaction rate of the composite process and the crystallinity of MOFs, thereby affecting the pore structure of the composite material. On the whole, the preparation parameters in Example 1 are more preferred.

[0120] By comparing Example 14, Example 15 and Example 16, it can be found that the pretreatment parameters for algae biomass in Example 14 are better, which may be because these parameters are suitable for surface activation of algae biomass;

[0121] By comparing Example 17, Example 18 and Example 19, it can be found that the preparation parameters of the MOFs in Example 17 are more preferred. It may be that under this parameter, the structure and active adsorption sites of the obtained MOFs are better.

Claims

1. A highly efficient adsorbent for refractory organic matter in wastewater, characterized in that: The raw material components of the high-efficiency adsorbent include: biomass, magnesium silicate clay mineral and MOFs in a mass ratio of 1:1:0.5-2.

2. The highly efficient adsorbent for refractory organic matter in wastewater according to claim 1, characterized in that: The preparation method of the biomass is: S1-1. Pretreatment Taking algae biomass with a water content of 15-20%, mixing the algae biomass with cellulase at a mass ratio of 1-2:1, standing at 40-50° C. and a pH value of 4.5-5.5 for 2-5 days to obtain pretreated algae biomass; S1-2. Modification treatment The pretreated algae biomass is dried to a moisture content of 10-12%; then, it is frozen at -30--20°C for 3-5 hours, taken out, and allowed to stand until the algae biomass reaches room temperature, and then dried at 60-80°C for 1-2 hours, and then the algae biomass is crushed with a crusher for 5-10 minutes, and then the crushed algae biomass is mixed with a hydrochloric acid solution with a mass concentration of 20% in a ratio of 2g:10-15ml, and allowed to stand at 20-30°C for 1-3 hours to obtain the modified algae biomass; S1-3, Activation Treatment The modified algae biomass is adjusted to pH=7; and then activated in a nitrogen atmosphere at 100-200° C. for 1-2 hours to obtain the biomass.

3. A highly efficient adsorbent for refractory organic matter in wastewater as claimed in claim 2, characterized in that: The algae biomass includes one or more of chlorella, spirulina, and diatom.

4. The high-efficiency adsorbent for refractory organic matter in wastewater according to claim 2, characterized in that: In S1-1, the algae biomass with a water content of 15-20% is obtained by the following method: soaking the algae biomass in a treatment liquid, stirring, the soaking temperature is 30-35°C, the soaking time is 20-30 minutes, the stirring time is 15-20 minutes, and then taking it out and low-temperature drying it at 40-45°C until the water content of the algae biomass is 15-20%.

5. The high-efficiency adsorbent for refractory organic matter in wastewater according to claim 4, characterized in that: The treatment liquid is an aqueous solution containing 5-8 wt % disodium hydrogen phosphate and 1-2 wt % vitamin B12.

6. The method for preparing a highly efficient adsorbent for refractory organic matter in wastewater according to claim 1, characterized in that: The steps include: S1. Biomass, 3-aminopropyltriethoxysilane and anhydrous ethanol are mixed in a ratio of 1-2 g: 1 ml: 100 ml, and magnetically stirred at room temperature for 1-3 h; then centrifuged at 500-800 rpm for 10-15 min, the supernatant is removed, and the biomass is washed with anhydrous ethanol; S2. According to the ratio of 1g:1g:0.5-2g:10ml, the biomass, magnesium silicate clay mineral and MOFs treated by S1 are placed in deionized water, and treated for 20-30min by an ultrasonic cell disruptor at a power of 400-500W, and then 4-5wt% glutaraldehyde is added, and magnetic stirring is performed at room temperature for 12-20h; and centrifuged at 900-1000rpm for 10-15min, the supernatant is removed to obtain a solid, and then the solid is dried and heat-treated to obtain a high-efficiency adsorbent.

7. The method for preparing a highly efficient adsorbent for refractory organic matter in wastewater according to claim 6, characterized in that: The rotation speed of the magnetic stirring is 500-600 rpm.

8. The method for preparing a highly efficient adsorbent for refractory organic matter in wastewater according to claim 6, characterized in that: The drying treatment is as follows: standing at a temperature of -40 to -45°C for 30 to 60 minutes, then heating to 20 to 30°C at a heating rate of 8 to 10°C / min, and then standing at a pressure of 0.2 MPa and a temperature of 50 to 70°C for 1 to 3 hours.

9. The method for preparing a highly efficient adsorbent for refractory organic matter in wastewater according to claim 6, characterized in that: The heat treatment is to heat the mixture in a nitrogen atmosphere at 150-200° C. for 30-60 minutes.

10. The method for preparing a highly efficient adsorbent for refractory organic matter in wastewater according to claim 1, characterized in that: The MOFs are prepared by a solvothermal method.

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