Biomass adsorbent for heavy metal wastewater treatment and preparation method and treatment method thereof

Abstract

The invention provides a biomass adsorbent for heavy metal wastewater treatment as well as a preparation method and a treatment method thereof. The biomass adsorbent is prepared from the following raw materials in parts by weight: 50 to 70 parts of crop waste, 20 to 30 parts of microbial bacterium liquid, 18 to 24 parts of polyacrylamide, 20 to 28 parts of montmorillonite powder, 30 to 40 parts of magnetic Fe3O4 nanoparticles, 12 to 16 parts of beta-cyclodextrin, 15 to 20 parts of sodium alginate, 6 to 16 parts of gelatin and 10 to 18 parts of silane coupling agent. The stable biomass adsorbent with a good adsorption effect can be obtained through a reasonable raw material ratio and a specific preparation process, the crop wastes, polyacrylamide, montmorillonite powder and microbial flora are combined for cooperative treatment, heavy metals in wastewater can be effectively degraded, and the action effect is good.

Description

Technical Field

[0001] The present invention relates to the technical field of biomass adsorbents, and particularly relates to a biomass adsorbent for treating heavy metal wastewater, a preparation method thereof, and a treatment method thereof. Background Art

[0002] The main sources of heavy metal wastewater are cleaning wastewater, metallurgical wastewater, electroplating wastewater, mine wastewater, machinery manufacturing wastewater, and electronic semiconductor manufacturing wastewater, etc. Heavy metal ions are highly toxic and cannot be degraded. If directly discharged without treatment, they will cause serious environmental pollution and also affect human healthy life. The heavy metals are mainly lead, mercury, chromium, cadmium, arsenic, etc. Currently, the main treatment methods are: (1) physical methods such as flocculant flocculation, membrane separation technology, solvent extraction separation technology, etc.; (2) chemical methods such as chemical precipitation, electrolysis, etc.; (3) biological treatment methods such as biosorption, phytoremediation, and bioflocculation. Physical and chemical methods have problems of high treatment costs and energy consumption during the treatment process. At the same time, adding chemical reagents during the treatment process will generate other pollutions. The adsorption raw materials of the biomass adsorption method are relatively wide in source, the operation is relatively simple, and it is also conducive to recycling, etc., and the treatment efficiency is high. However, at present, there are still some problems with the biomass adsorption method, such as unreasonable biomass adsorbent formulations, unstable adsorption performance, limited heavy metal removal ability, and unsatisfactory treatment effects. Summary of the Invention

[0003] In view of this, the present invention provides a biomass adsorbent for treating heavy metal wastewater, a preparation method thereof, and a treatment method thereof.

[0004] The technical solution of the present invention is realized as follows:

[0005] A biomass adsorbent for treating heavy metal wastewater, comprising the following raw materials in parts by weight: 50 - 70 parts of crop waste, 20 - 30 parts of microbial bacterial liquid, 18 - 24 parts of polyacrylamide, 20 - 28 parts of montmorillonite powder, 30 - 40 parts of magnetic Fe3O4 nanoparticles, 12 - 16 parts of β-cyclodextrin, 15 - 20 parts of sodium alginate, 6 - 16 parts of gelatin, and 10 - 18 parts of silane coupling agent; the microbial bacterial liquid comprises Bacillus subtilis bacterial liquid, Saccharomyces cerevisiae bacterial liquid, and Lactobacillus bacterial liquid with a volume ratio of (6 - 9):(3 - 5):(1 - 2); the crop waste comprises corn straw, peanut shell, and corn cob with a mass ratio of (1 - 2):(2 - 4):(6 - 9).

[0006] Further, the effective viable count of the Bacillus subtilis is 2.5 - 5.0×10 8 cfu / ml, and the effective viable count of the Saccharomyces cerevisiae is 1.5 - 3.0×10 8cfu / ml. The effective viable count of lactic acid bacteria is 3.0 - 5.0×10 8 cfu / ml.

[0007] Furthermore, the preparation method of the crop waste is as follows: Coarsely crush the crop waste to a particle size of 1 - 2 cm, add it to a hydrochloric acid solution and impregnate it by ultrasonic treatment to obtain a mixed material liquid, then add a potassium permanganate solution and impregnate it by ultrasonic treatment. Lower the temperature to room temperature and wash it with deionized water until it is neutral. Filter to obtain the filter residue, dry it, and then carbonize and crush it to obtain the crop waste.

[0008] Furthermore, the concentration of the hydrochloric acid solution is 20 - 30 wt%; the material - liquid ratio of the crop waste to the hydrochloric acid solution is 1:(5 - 6) g / mL; the concentration of the potassium permanganate solution is 3 - 5 wt%, and the mass ratio of the mixed material liquid to the potassium permanganate solution is (4 - 6):1 g / mL; the ultrasonic impregnation temperature is 50 - 70 °C, the ultrasonic power is 300 - 500 W, and the time is 20 - 30 min; the carbonization process is as follows: Heat it at a rate of 6 - 8 °C / min to 500 - 600 °C and carbonize for 4 - 6 h.

[0009] A preparation method of a biomass adsorbent for heavy metal wastewater treatment, comprising the following steps:

[0010] (1) Add the crop waste to water, let it stand for 30 - 60 min, then add Bacillus subtilis bacterial liquid, gelatin and stir to mix. Dry it at room temperature to obtain a mixed material A;

[0011] (2) Add montmorillonite powder to the beer yeast bacterial liquid and stir to mix. Dry it at room temperature to obtain a mixed material B;

[0012] (3) Dissolve sodium alginate in water to form a sodium alginate solution with a concentration of 2 - 4 wt%, then stir - mix it with the lactic acid bacteria liquid to obtain a mixed bacterial liquid. Drop the mixed bacterial liquid into a CaCl2 solution with a concentration of 2 - 5 wt% for immobilization for 7 - 8 h. Filter out the particles and wash them with physiological saline to obtain a mixed material C;

[0013] (4) Stir - mix the above - obtained mixed material A, mixed material B, and mixed material C evenly, then add polyacrylamide, magnetic Fe3O4 nanoparticles, β - cyclodextrin and a silane coupling agent and stir to mix evenly. Dry it at room temperature to obtain the target biomass adsorbent.

[0014] Furthermore, in step (1), the material - liquid ratio of the crop waste to water is 1:(1 - 3) g / mL, the stirring - mixing rotation speed is 80 - 120 r / min, and the time is 20 - 30 min; the added weight of polyvinyl alcohol is 1 - 5% of the weight of the crop waste.

[0015] Further, in step (2), the rotation speed of the stirring and mixing is 400 - 500 r / min, and the time is 15 - 20 min; in steps (3) and (4), the rotation speed of the stirring and mixing is 120 - 150 r / min, and the time is 15 - 20 min.

[0016] A treatment method for a biomass adsorbent for treating heavy metal wastewater, comprising the following steps: adjusting the pH value of the heavy metal wastewater, then adding the biomass adsorbent to the heavy metal wastewater, oscillating, filtering, and collecting the biomass adsorbent.

[0017] Further, the pH value is 2 - 7; the dosage of the biomass adsorbent is 0.2 - 0.5 g / L; the oscillation is carried out at a temperature of 25 - 30°C and a rotation speed of 200 - 300 r / min for 2 - 3 h, standing for 20 - 30 min, and then oscillating again for 2 - 3 h.

[0018] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0019] Through a reasonable raw material ratio, the present invention can obtain a stable biomass adsorbent with good adsorption effect. The present invention combines crop waste, polyacrylamide, montmorillonite powder and microbial bacteria, and the synergistic treatment can effectively degrade heavy metals in wastewater; and through a reasonable preparation process, the stability of the biomass adsorbent can be improved, while reducing the loss of microbial bacteria and ensuring the activity of microbial bacteria, so as to have a better adsorption function. In addition, after adding magnetic Fe3O4 nanoparticles to the present invention, the biomass adsorbent can be recovered, reducing the waste of raw materials. Using crop waste as raw materials, adsorbents with different pore sizes can be obtained through the combination of different crop raw materials, improving the utilization rate of waste while also improving the effect.

[0020] The biomass adsorbent of the present invention has good adsorption effects on heavy metals such as lead, copper, and chromium in heavy metal wastewater, and has wide applicability. Specific Embodiments

[0021] In order to better understand the technical content of the present invention, specific embodiments are provided below to further illustrate the present invention.

[0022] The experimental methods used in the embodiments of the present invention are all conventional methods unless otherwise specified.

[0023] The materials, reagents, etc. used in the embodiments of the present invention can be obtained from commercial channels unless otherwise specified.

[0024] The Bacillus subtilis used in the present invention, numbered CICC10732, was purchased from the China Center of Industrial Culture Collection of Microorganisms.

[0025] The Saccharomyces cerevisiae of the present invention was cultured according to the following steps: The dried waste brewer's yeast from Yanjing Brewery was purchased and inoculated into the sterilized solid medium. The solid medium was obtained by dissolving 0.5 g of yeast extract, 1.0 g of peptone, 2.0 g of glucose, and 2.5 g of agar in deionized water to make up 100 mL, heating and melting, and then placed in a constant temperature incubator and cultured at 25 °C for 24 h. Then the cultured yeast was inoculated into the sterile liquid medium and cultured in a shaking incubator at 25 °C for 72 h. The composition of the liquid medium was: 5 g of yeast extract, 10 g of peptone, 20 g of glucose, and 1 L of deionized water.

[0026] The lactic acid bacterium used in the present invention is Lactiplantibacillus plantarum, numbered CICC21790, and was purchased from the China Center of Industrial Culture Collection of Microorganisms.

[0027] Example 1

[0028] The biomass adsorbent for heavy metal wastewater treatment in this example comprises the following raw materials in parts by weight: 60 parts of crop waste, 25 parts of microbial bacterial liquid, 20 parts of polyacrylamide, 26 parts of montmorillonite powder, 35 parts of magnetic Fe3O4 nanoparticles, 12 parts of β-cyclodextrin, 18 parts of sodium alginate, 12 parts of gelatin, and 15 parts of silane coupling agent; the microbial bacterial liquid comprises Bacillus subtilis bacterial liquid, Saccharomyces cerevisiae bacterial liquid, and lactic acid bacterium bacterial liquid with a volume ratio of 8:4:1; the effective viable count of Bacillus subtilis is 4.0×10 8 cfu / ml, the effective viable count of Saccharomyces cerevisiae is 2.0×10 8 cfu / ml, and the effective viable count of lactic acid bacterium is 4.0×10 8 cfu / ml; the crop waste comprises corn straw, peanut shell, and corn cob with a mass ratio of 1:3:7;

[0029] The preparation method of the crop waste is as follows: Coarsely crush the crop waste to a particle size of 2 cm, add a hydrochloric acid solution with a concentration of 24 wt%, and the material-liquid ratio of the crop waste to the hydrochloric acid solution is 1:6 g / mL. Perform ultrasonic impregnation at a temperature of 60 °C and an ultrasonic power of 400 W for 20 min to obtain a mixed material-liquid. Then add a potassium permanganate solution with a concentration of 4 wt%, and the mass ratio of the mixed material-liquid to the potassium permanganate solution is 5:1 g / mL. Perform ultrasonic impregnation at a temperature of 60 °C and an ultrasonic power of 400 W for 30 min. Lower the temperature to room temperature and wash with deionized water until neutral. Filter to obtain the filter residue, dry it, and then carbonize it at a heating rate of 8 °C / min to 600 °C for 5 h and crush it to obtain the crop waste;

[0030] A preparation method of a biomass adsorbent for treating heavy metal wastewater includes the following steps:

[0031] (1) Add the crop waste to water and let it stand for 50 min. The material-liquid ratio of the crop waste to water is 1:3 g / mL. Then add Bacillus subtilis bacterial liquid, gelatin, and 5% by weight of polyvinyl alcohol of the crop waste and stir and mix at a rotation speed of 100 r / min for 25 min. Dry at room temperature to obtain a mixed material A;

[0032] (2) Add montmorillonite powder to the beer yeast bacterial liquid and stir and mix at a rotation speed of 400 r / min for 15 min. Dry at room temperature to obtain a mixed material B;

[0033] (3) Dissolve sodium alginate in water to form a sodium alginate solution with a concentration of 3 wt%. Then stir and mix it with the lactic acid bacteria liquid at a rotation speed of 120 r / min for 20 min to obtain a mixed bacterial liquid. Drop the mixed bacterial liquid into a CaCl2 solution with a concentration of 4 wt% for immobilization for 7 h. Filter out the particles and wash them with normal saline to obtain a mixed material C;

[0034] (4) Stir and mix the obtained mixed material A, mixed material B, and mixed material C at a rotation speed of 130 r / min for 20 min. Then add polyacrylamide, magnetic Fe3O4 nanoparticles, β-cyclodextrin, and a silane coupling agent and stir and mix at a rotation speed of 140 r / min for 18 min. Dry at room temperature to obtain the target biomass adsorbent;

[0035] The method for treating heavy metal wastewater with the target biomass adsorbent includes the following steps: Adjust the pH value of the heavy metal wastewater to 5. Then add the biomass adsorbent to the heavy metal wastewater. The dosage of the biomass adsorbent is 0.3 g / L. Perform oscillation at a temperature of 28 °C and a rotation speed of 200 r / min for 3 h, let it stand for 26 min, perform oscillation again for 2 h, filter, and collect the biomass adsorbent.

[0036] Example 2

[0037] The biomass adsorbent for heavy metal wastewater treatment in this embodiment comprises raw materials in the following parts by weight: 50 parts of crop waste, 20 parts of microbial bacterial liquid, 18 parts of polyacrylamide, 20 parts of montmorillonite powder, 30 parts of magnetic Fe3O4 nanoparticles, 12 parts of β-cyclodextrin, 15 parts of sodium alginate, 6 parts of gelatin, and 10 parts of silane coupling agent; the microbial bacterial liquid comprises Bacillus subtilis bacterial liquid, Saccharomyces cerevisiae bacterial liquid, and Lactobacillus bacterial liquid with a volume ratio of 6:3:1; the effective viable count of Bacillus subtilis is 2.5×10 8 cfu / ml, the effective viable count of Saccharomyces cerevisiae is 1.5×10 8 cfu / ml, and the effective viable count of Lactobacillus is 3.0×10 8 cfu / ml; the crop waste comprises corn straw, peanut shell, and corn cob with a mass ratio of 1:2:6;

[0038] The preparation method of the crop waste is as follows: coarsely crush the crop waste to a particle size of 1 cm, add a hydrochloric acid solution with a concentration of 20 wt%, and the material-liquid ratio of the crop waste to the hydrochloric acid solution is 1:5 g / mL. Perform ultrasonic impregnation at a temperature of 50°C and an ultrasonic power of 300 W for 20 min to obtain a mixed material liquid. Then add a potassium permanganate solution with a concentration of 3 wt%, and the mass ratio of the mixed material liquid to the potassium permanganate solution is 4:1 g / mL. Perform ultrasonic impregnation at a temperature of 50°C and an ultrasonic power of 300 W for 20 min. Lower the temperature to room temperature and wash with deionized water until neutral. Filter to obtain the filter residue, dry it, and then carbonize it at a heating rate of 6°C / min to 500°C for 4 h and crush it to obtain the crop waste;

[0039] The preparation method of the biomass adsorbent for heavy metal wastewater treatment comprises the following steps:

[0040] (1) Add the crop waste to water and let it stand for 60 min. The material-liquid ratio of the crop waste to water is 1:3 g / mL. Then add Bacillus subtilis bacterial liquid, gelatin, and 1% by weight of polyvinyl alcohol based on the weight of the crop waste and stir and mix at a rotation speed of 80 r / min for 20 min. Dry it at room temperature to obtain a mixed material A;

[0041] (2) Add montmorillonite powder to the Saccharomyces cerevisiae bacterial liquid and stir and mix at a rotation speed of 400 r / min for 15 min. Dry it at room temperature to obtain a mixed material B;

[0042] (3) Sodium alginate was added to water to prepare a sodium alginate solution with a concentration of 2 wt%, and then it was stirred and mixed with lactic acid bacteria liquid at a rotation speed of 120 r / min for 15 min to obtain a mixed bacteria liquid. The mixed bacteria liquid was dropped into a CaCl2 solution with a concentration of 2 wt% for immobilization for 7 h, the particles were filtered out and washed with physiological saline to obtain a mixed material C;

[0043] (4) The obtained mixed material A, mixed material B, and mixed material C were stirred and mixed at a rotation speed of 120 r / min for 15 min, and then polyacrylamide, magnetic Fe3O4 nanoparticles, β-cyclodextrin, and silane coupling agent were added and stirred and mixed at a rotation speed of 120 r / min for 15 min, and then dried at room temperature to obtain the target biomass adsorbent;

[0044] The method for treating heavy metal wastewater with the target biomass adsorbent includes the following steps: adjusting the pH value of the heavy metal wastewater to 2, then adding the biomass adsorbent to the heavy metal wastewater, the dosage of the biomass adsorbent is 0.2 g / L, oscillating at a temperature of 25 °C and a rotation speed of 200 r / min for 2 h, standing for 20 min, oscillating again for 2 h, filtering, and collecting the biomass adsorbent.

[0045] Example 3

[0046] The biomass adsorbent for treating heavy metal wastewater in this example includes the following raw materials in parts by weight: 70 parts of crop waste, 30 parts of microbial bacteria liquid, 24 parts of polyacrylamide, 28 parts of montmorillonite powder, 40 parts of magnetic Fe3O4 nanoparticles, 16 parts of β-cyclodextrin, 20 parts of sodium alginate, 16 parts of gelatin, and 18 parts of silane coupling agent; the microbial bacteria liquid includes Bacillus subtilis liquid, Saccharomyces cerevisiae liquid, and lactic acid bacteria liquid with a volume ratio of 9:5:2; the effective viable count of Bacillus subtilis is 5.0×10 8 cfu / ml, the effective viable count of Saccharomyces cerevisiae is 3.0×10 8 cfu / ml, and the effective viable count of lactic acid bacteria is 5.0×10 8 cfu / ml; the crop waste includes corn straw, peanut shell, and corn cob with a mass ratio of 2:4:9;

[0047] The preparation method of the crop waste is as follows: Coarsely crush the crop waste to a particle size of 2 cm, add a hydrochloric acid solution with a concentration of 30 wt%, and the material-liquid ratio of the crop waste to the hydrochloric acid solution is 1:6 g / mL. Perform ultrasonic impregnation for 30 min at a temperature of 70 °C and an ultrasonic power of 500 W to obtain a mixed material-liquid. Then add a potassium permanganate solution with a concentration of 5 wt%, and the mass ratio of the mixed material-liquid to the potassium permanganate solution is 6:1 g / mL. Perform ultrasonic impregnation for 30 min at a temperature of 70 °C and an ultrasonic power of 500 W. Lower the temperature to room temperature and wash with deionized water until neutral. Filter to obtain the filter residue, dry it, and then carbonize it at a heating rate of 8 °C / min to 600 °C for 6 h, and crush it to obtain the crop waste;

[0048] A preparation method of a biomass adsorbent for treating heavy metal wastewater includes the following steps:

[0049] (1) Add the crop waste to water and let it stand for 60 min. The material-liquid ratio of the crop waste to water is 1:3 g / mL. Then add Bacillus subtilis bacterial liquid, gelatin, and 3% by weight of polyvinyl alcohol of the crop waste, and stir and mix at a rotation speed of 120 r / min for 30 min, and dry at room temperature to obtain a mixed material A;

[0050] (2) Add montmorillonite powder to the beer yeast bacterial liquid and stir and mix at a rotation speed of 500 r / min for 20 min, and dry at room temperature to obtain a mixed material B;

[0051] (3) Dissolve sodium alginate in water to form a sodium alginate solution with a concentration of 4 wt%, and then stir and mix it with the lactic acid bacteria liquid at a rotation speed of 150 r / min for 20 min to obtain a mixed bacterial liquid. Drop the mixed bacterial liquid into a CaCl2 solution with a concentration of 5 wt% for immobilization for 8 h, filter out the particles, and wash them with physiological saline to obtain a mixed material C;

[0052] (4) Stir and mix the obtained mixed material A, mixed material B, and mixed material C at a rotation speed of 150 r / min for 20 min, and then add polyacrylamide, magnetic Fe3O4 nanoparticles, β-cyclodextrin, and silane coupling agent and stir and mix at a rotation speed of 150 r / min for 20 min, and dry at room temperature to obtain the target biomass adsorbent;

[0053] A method for treating heavy metal wastewater with the target biomass adsorbent includes the following steps: Adjust the pH value of the heavy metal wastewater to 7, then add the biomass adsorbent to the heavy metal wastewater. The dosage of the biomass adsorbent is 0.5 g / L. Perform oscillation at a temperature of 30 °C and a rotation speed of 300 r / min for 3 h, let it stand for 30 min, perform oscillation again for 3 h, filter, and collect the biomass adsorbent. That's it.

[0054] Comparative Example 1

[0055] The difference between this comparative example and Example 1 lies in that the raw material ratio of the biomass adsorbent for heavy metal wastewater treatment is different.

[0056] The biomass adsorbent for heavy metal wastewater treatment in this comparative example comprises the following raw materials in parts by weight: 30 parts of crop waste, 15 parts of microbial bacterial liquid, 40 parts of polyacrylamide, 10 parts of montmorillonite powder, 20 parts of magnetic Fe3O4 nanoparticles, 35 parts of β-cyclodextrin, 35 parts of sodium alginate, 26 parts of gelatin, and 5 parts of silane coupling agent.

[0057] Comparative Example 2

[0058] The difference between this comparative example and Example 1 lies in that it does not contain crop waste.

[0059] The biomass adsorbent for heavy metal wastewater treatment in this example comprises the following raw materials in parts by weight: 25 parts of microbial bacterial liquid, 20 parts of polyacrylamide, 26 parts of montmorillonite powder, 35 parts of magnetic Fe3O4 nanoparticles, 12 parts of β-cyclodextrin, 18 parts of sodium alginate, 12 parts of gelatin, and 15 parts of silane coupling agent; the microbial bacterial liquid comprises Bacillus subtilis bacterial liquid, Saccharomyces cerevisiae bacterial liquid, and Lactobacillus bacterial liquid with a volume ratio of 8:4:1; the effective viable count of Bacillus subtilis is 4.0×10 8 cfu / ml, the effective viable count of Saccharomyces cerevisiae is 2.0×10 8 cfu / ml, and the effective viable count of Lactobacillus is 4.0×10 8 cfu / ml;

[0060] The preparation method of the biomass adsorbent for heavy metal wastewater treatment comprises the following steps:

[0061] (1) Add montmorillonite powder and gelatin to the Saccharomyces cerevisiae bacterial liquid and Bacillus subtilis bacterial liquid, stir and mix at a rotation speed of 400 r / min for 15 min, and dry at room temperature to obtain a mixed material B;

[0062] (2) Add sodium alginate to water to prepare a sodium alginate solution with a concentration of 3 wt%, then stir and mix it with the Lactobacillus bacterial liquid at a rotation speed of 120 r / min for 20 min to obtain a mixed bacterial liquid, drop the mixed bacterial liquid into a CaCl2 solution with a concentration of 4 wt% for immobilization for 7 h, filter out the particles, and wash them with physiological saline to obtain a mixed material C;

[0063] (3) Stir and mix the obtained mixed materials A, B, and C at a rotation speed of 130 r / min for 20 min, then add polyacrylamide, magnetic Fe3O4 nanoparticles, β-cyclodextrin, and silane coupling agent and stir and mix at a rotation speed of 140 r / min for 18 min, and dry at room temperature to obtain the target biomass adsorbent;

[0064] The method for treating heavy metal wastewater with the target biomass adsorbent includes the following steps: adjust the pH value of the heavy metal wastewater to 5, then add the biomass adsorbent to the heavy metal wastewater, the dosage of the biomass adsorbent is 0.3 g / L, oscillate at a temperature of 28 °C and a rotation speed of 200 r / min for 3 h, stand for 26 min, oscillate again for 2 h, filter, and collect the biomass adsorbent.

[0065] Comparative Example 3

[0066] The difference between this comparative example and Example 1 is that the preparation method of the crop waste is different.

[0067] The preparation method of the crop waste is as follows: coarsely crush the crop waste to a particle size of 2 cm, carbonize at a rate of 8 °C / min to 600 °C for 5 h, and then crush to obtain the crop waste.

[0068] Comparative Example 4

[0069] The difference between this comparative example and Example 1 is that the preparation method of the biomass adsorbent for treating heavy metal wastewater is different.

[0070] The preparation method of the biomass adsorbent for treating heavy metal wastewater includes the following steps:

[0071] Mix the crop waste, montmorillonite powder, and sodium alginate evenly to obtain a mixed material, then add it to water and stir evenly. The liquid-solid ratio of water to the mixed material is 1:5 g / mL. Then add Bacillus subtilis bacterial liquid, Saccharomyces cerevisiae bacterial liquid, gelatin, and 5% of the weight of the crop waste of polyvinyl alcohol and stir and mix at a rotation speed of 130 r / min for 20 min. Then add polyacrylamide, magnetic Fe3O4 nanoparticles, β-cyclodextrin, and silane coupling agent and stir and mix at a rotation speed of 140 r / min for 18 min, and dry at room temperature to obtain the target biomass adsorbent.

[0072] The heavy metals were adsorbed and treated by using the biomass adsorbents of Examples 1-3 and Comparative Examples 1-4 of the present invention and the corresponding treatment methods. An artificial simulated heavy metal wastewater containing heavy metal ions of lead, copper, and chromium with an initial concentration of 200 mg / L for each heavy metal was used. The mass concentration of the metal ions after adsorption was measured by atomic absorption spectrophotometry, and the adsorption rate (%) of the heavy metals was statistically analyzed. Each example and comparative example was tested 3 times, and the results were averaged. The results are shown in Table 1 below.

[0073] Adsorption rate (%) = (Initial mass concentration of heavy metal ions - Mass concentration of heavy metal ions after adsorption) / Initial mass concentration of heavy metal ions × 100%

[0074] Table 1 Experimental results of heavy metal removal

[0075]

[0076]

[0077] The above results show that the biomass adsorbents prepared in Examples 1-3 of the present invention have good adsorption and removal effects under the synergistic action of various raw materials during the adsorption treatment of heavy metal ions. In Comparative Example 1, the raw material ratio of the biomass adsorbent is different; in Comparative Example 2, no crop waste is contained; in Comparative Example 3, the preparation method of the crop waste is different; and in Comparative Example 4, the preparation method of the biomass adsorbent is different, resulting in a decrease in the adsorption and removal ability.

[0078] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent replacements, improvements, 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 biomass adsorbent for heavy metal wastewater treatment, characterized in that, It includes the following raw materials in parts by weight: 50 - 70 parts of crop waste, 20 - 30 parts of microbial bacterial liquid, 18 - 24 parts of polyacrylamide, 20 - 28 parts of montmorillonite powder, 30 - 40 parts of magnetic Fe3O4 nanoparticles, 12 - 16 parts of β-cyclodextrin, 15 - 20 parts of sodium alginate, 6 - 16 parts of gelatin, and 10 - 18 parts of silane coupling agent; the microbial bacterial liquid includes Bacillus subtilis bacterial liquid, Saccharomyces cerevisiae bacterial liquid, and Lactobacillus bacterial liquid with a volume ratio of (6 - 9):(3 - 5):(1 - 2); the crop waste includes corn straw, peanut shell, and corn cob with a mass ratio of (1 - 2):(2 - 4):(6 - 9).

2. The biomass adsorbent for heavy metal wastewater treatment according to claim 1, characterized in that, The viable count of the Bacillus subtilis is 2.5 to 5.0×10 8 cfu / ml, the viable count of the Saccharomyces cerevisiae is 1.5 to 3.0×10 8 cfu / ml, and the viable count of the lactic acid bacteria is 3.0 to 5.0×10 8 cfu / ml.

3. The biomass adsorbent for treating heavy metal wastewater according to claim 1, characterized in that, The preparation method of the crop waste is as follows: The crop waste is roughly crushed to a particle size of 1 - 2 cm, added with hydrochloric acid solution and ultrasonically impregnated to obtain a mixed material liquid, then added with potassium permanganate solution and ultrasonically impregnated, the temperature is lowered to room temperature and washed with deionized water until neutral, the filter residue is filtered out, dried, and then carbonized and pulverized to obtain the crop waste.

4. The biomass adsorbent for heavy metal wastewater treatment according to claim 3, wherein The concentration of the hydrochloric acid solution is 20 - 30 wt%; the material - liquid ratio of the crop waste to the hydrochloric acid solution is 1:(5 - 6) g / mL; the concentration of the potassium permanganate solution is 3 - 5 wt%, and the mass ratio of the mixed material liquid to the potassium permanganate solution is (4 - 6):1 g / mL; the temperature of the ultrasonic impregnation is 50 - 70 °C, the ultrasonic power is 300 - 500 W, and the time is 20 - 30 min; the carbonization process is: heating to 500 - 600 °C at a rate of 6 - 8 °C / min for carbonization for 4 - 6 h.

5. The preparation method of the biomass adsorbent for heavy metal wastewater treatment according to any one of claims 1-4, characterized in that, It includes the following steps: (1) Add the crop waste to water and let it stand for 30 - 60 min, then add Bacillus subtilis bacterial liquid, gelatin, and polyvinyl alcohol and stir - mix, and dry at room temperature to obtain mixed material A; (2) Add montmorillonite powder to the Saccharomyces cerevisiae bacterial liquid and stir - mix, and dry at room temperature to obtain mixed material B; (3) Dissolve sodium alginate in water to form a sodium alginate solution with a concentration of 2 - 4 wt%, then stir - mix it with Lactobacillus bacterial liquid to obtain a mixed bacterial liquid, drop the mixed bacterial liquid into a CaCl2 solution with a concentration of 2 - 5 wt% for immobilization for 7 - 8 h, filter out the particles, and wash them with normal saline to obtain mixed material C; (4) Stir - mix the above - obtained mixed material A, mixed material B, and mixed material C evenly, then add polyacrylamide, magnetic Fe3O4 nanoparticles, β - cyclodextrin, and silane coupling agent and stir - mix evenly, and dry at room temperature to obtain the target biomass adsorbent.

6. The preparation method of the biomass adsorbent for heavy metal wastewater treatment according to claim 5, characterized in that In step (1), the material - liquid ratio of the crop waste to water is 1:(1 - 3) g / mL, the stirring - mixing speed is 80 - 120 r / min, and the time is 20 - 30 min; the added weight of polyvinyl alcohol is 1 - 5% of the weight of the crop waste.

7. The preparation method of the biomass adsorbent for heavy metal wastewater treatment according to claim 5, characterized in that, In step (2), the stirring - mixing speed is 400 - 500 r / min, and the time is 15 - 20 min; in steps (3) and (4), the stirring - mixing speed is 120 - 150 r / min, and the time is 15 - 20 min.

8. The treatment method of the biomass adsorbent for heavy metal wastewater treatment according to any one of claims 1-4, characterized in that, It includes the following steps: Adjust the pH value of the heavy metal wastewater, then add the biomass adsorbent to the heavy metal wastewater, oscillate, filter, and collect the biomass adsorbent, and that's it.

9. The processing method according to claim 8, wherein The pH value is 2-7; the dosage of the biomass adsorbent is 0.2-0.5 g / L; the oscillation is carried out at a temperature of 25-30 °C and a rotation speed of 200-300 r / min for 2-3 h, stand still for 20-30 min, and then oscillate again for 2-3 h.

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