A resource-based comprehensive utilization and treatment process for municipal sewage sludge

Abstract

The invention discloses a resource-based comprehensive utilization treatment process for municipal sludge. The process comprises the following steps: firstly, starch nano-microspheres are added into the municipal sludge, and ultrasonic oscillation treatment is performed under magnetic field conditions to obtain pre-treated sludge; then, oxygen is injected into the pre-treated sludge, high-pressure spraying is performed, and microwave activation is performed to obtain activated sludge; then, Chlorella is inoculated into the activated sludge, cultured, ultrasonic oscillation treated, and solid-liquid separation is performed to obtain a water phase and a solid phase, the water phase is reused as industrial water, and the solid phase is carbonized to prepare activated carbon, thereby realizing resource-based comprehensive utilization of the municipal sludge.

Description

Technical Field

[0001] The present invention relates to a sludge treatment method, in particular to a resource-based comprehensive utilization treatment process for urban sludge, and belongs to the technical field of waste pollutant treatment. Background Art

[0002] Municipal sludge refers to the sludge generated during the operation and maintenance of urban facilities related to urban life and urban life activities. With the development of urbanization, the amount of urban sludge generated is increasing. It contains a large number of bacteria, viruses, parasites, heavy metals, etc., and must be properly treated before discharge to avoid environmental pollution.

[0003] The theoretical method of urban sludge treatment is concentration, digestion, conditioning, dehydration, and transportation to reduce the organic content, reduce the water content of sludge, and reduce the volume of sludge. However, in practice, due to the lack of digestion equipment, urban sludge is generally treated by concentration, conditioning, dehydration, and transportation. The water content is high, the sludge volume is large, and the content of harmful substances such as bacteria and viruses is high, which increases the difficulty of subsequent disposal of the sludge. The difficult-to-degrade organic matter contained in urban sludge will rot and deteriorate, emit a foul odor, and cause secondary pollution. In addition, urban sludge often contains heavy metals to varying degrees. There are many types of heavy metals, and it is difficult to degrade naturally in the environment. This is also a major problem facing urban sludge treatment.

[0004] At present, the main treatment destinations for urban sewage sludge are landfill and incineration. Landfill will occupy a large amount of land resources, easily lead to deformation or landslide of the landfill body, blockage of the leachate collection pipeline, difficulty in mechanical compaction, and the stench will affect the surrounding environment; incineration will produce fly ash, which is dangerous, and the dioxins produced by incineration will cause secondary pollution. In order to better protect the environment, it is very meaningful to carry out comprehensive resource utilization of urban sewage sludge.

[0005] Patent application CN103588365A discloses a hydrothermal treatment method for municipal sludge, wherein a reagent is added to the sludge, and the reaction is carried out at 120-300°C for 1 minute to 5 hours, wherein the reagent is one or more of calcium hydroxide, calcium oxide and magnesium hydroxide, and further dehydration is performed. This patented technology cannot realize the comprehensive resource utilization of municipal sludge.

[0006] In the prior art, aerobic fermentation technology is also used to stabilize sludge and make use of it as a resource. However, traditional aerobic fermentation of sludge often requires the addition of additional carbon sources. The moisture content of unadjusted sludge is high, which is not conducive to biological fermentation and affects the fermentation effect. It is also difficult to reduce the heavy metal content in sludge by simple aerobic fermentation, which affects the sludge treatment effect.

[0007] There are three main methods for removing heavy metals from sludge: physical, chemical, and biological. The amount of sludge treated by physical methods is limited, and it is not easy to dispose of it on a large scale, and the treatment cost is high. Chemical methods usually require the addition of a large amount of reagents, which affects the resource utilization of sludge. The biological method is mainly based on microbial leaching, and it is necessary to add hydrophobic substances such as sulfur powder and pyrite powder as microbial energy substances. The treatment cycle is relatively long, and sulfur powder will also cause the "post-acidification effect" of the soil. Summary of the invention

[0008] The purpose of the present invention is to overcome the deficiencies of the above-mentioned prior art and provide a resource-based comprehensive utilization treatment process for urban sludge.

[0009] To achieve the above object, the present invention adopts the following technical solutions:

[0010] A resource-based comprehensive utilization treatment process for municipal sludge, the specific steps are as follows:

[0011] S1. First, starch nanospheres are added to municipal sludge, and ultrasonic oscillation treatment is performed under magnetic field conditions to obtain pretreated sludge;

[0012] S2. Then, oxygen is injected into the pretreated sludge, high pressure spraying is performed, and microwave activation is performed to obtain activated sludge;

[0013] S3. Chlorella is inoculated into the activated sludge, cultured, and subjected to ultrasonic oscillation. The solid-liquid separation is performed to obtain an aqueous phase and a solid phase. The aqueous phase is reused as industrial water, and the solid phase is carbonized to produce activated carbon.

[0014] Preferably, in step S1, the starch nanospheres are prepared by the following method:

[0015] (1) first esterifying starch with acetic anhydride to obtain starch acetate, then dissolving the starch acetate in acetone, adding deionized water dropwise, stirring and mixing, and waiting for the acetone to completely evaporate to obtain a starch acetate aqueous dispersion;

[0016] (2) Sodium hydroxide, urea and deionized water are then mixed and stirred until clear, and konjac glucomannan is added while stirring. Ultrasonic oscillation is applied at 300-400W for 3-4 hours, and 3-chloro-2-hydroxypropyltrimethylammonium chloride aqueous solution is added dropwise. The reaction is stirred at room temperature, the pH is adjusted to neutral, and dialyzed until the solution contains no Cl - , obtaining a modified konjac glucomannan solution;

[0017] (3) Finally, the modified konjac glucomannan solution is added to the starch acetate aqueous dispersion, ultrasonically vibrated evenly, and vacuum dried to obtain the product.

[0018] Further preferably, in step (1), starch is first added to acetic anhydride with stirring, stirred and dispersed evenly, esterification reaction is carried out at 50-60° C. for 3-4 hours, and the acetic anhydride is removed by washing with anhydrous ethanol for 3-4 times to obtain the starch acetate.

[0019] Further preferably, in step (1), the usage ratio of starch, acetic anhydride, acetone and deionized water is 1 g: 2-3 g: 2-3 mL: 2-3 mL.

[0020] Further preferably, in step (2), the dosage ratio of sodium hydroxide, urea, deionized water, konjac glucomannan, and 3-chloro-2-hydroxypropyltrimethylammonium chloride aqueous solution is 5g:5g:90-100mL:1g:0.3-0.4mL, and the mass concentration of 3-chloro-2-hydroxypropyltrimethylammonium chloride aqueous solution is 3-4%.

[0021] More preferably, in step (2), the reaction time is 5 to 6 hours under stirring at room temperature.

[0022] Further preferably, in step (2), the pH is adjusted using a 1 mol / L hydrochloric acid solution, and dialysis is performed using a dialysis bag with a molecular weight cutoff of 15 kD.

[0023] Further preferably, in step (3), the volume ratio of the modified konjac glucomannan solution to the starch acetate aqueous dispersion is 1:8-10.

[0024] Further preferably, in step (3), the process conditions of ultrasonic oscillation are: 300-400W ultrasonic oscillation for 40-50 minutes.

[0025] Preferably, in step S1, the mass ratio of municipal sludge to starch nanospheres is 100:2-3.

[0026] Preferably, in step S1, the magnetic field strength is 80-100 mT.

[0027] Preferably, in step S1, the process conditions of ultrasonic oscillation treatment are: 500-600W ultrasonic oscillation for 2-3 hours.

[0028] Preferably, in step S2, oxygen is injected into the pretreated sludge from the bottom, the injection amount is 0.2 to 0.3 L / min, and the injection time is 20 to 30 minutes.

[0029] Preferably, in step S2, the process conditions of high-pressure spraying are: the diameter of the spray port is 20 to 30 mm, the spray pressure is 0.8 to 1 MPa, and the spray time is 5 to 6 minutes.

[0030] Preferably, in step S2, the process conditions of microwave activation are: 400-500W microwave irradiation, irradiation for 2 minutes and rest for 1 minute, and the cumulative irradiation time is 40-50 minutes.

[0031] Preferably, in step S3, the Chlorella concentrate is added to the activated sludge, and the mass ratio of the activated sludge to the Chlorella concentrate is 100:0.01-0.02.

[0032] Preferably, in step S3, the culture conditions are: temperature 20-25° C., illumination 20,000-30,000 lux, stirring at 30-50 r / min for 50-60 minutes and then static culture for 3-5 days.

[0033] Preferably, in step S3, the process conditions of the ultrasonic oscillation treatment are: 800-900W ultrasonic oscillation for 2-3 hours.

[0034] Preferably, in step S3, the process conditions for carbonization treatment are: first increase the temperature to 450-470°C at 10-12°C / min, keep warm for 30-40 minutes, then increase the temperature to 500-510°C at 2-3°C / min, and keep warm for 50-60 minutes.

[0035] Beneficial effects of the present invention:

[0036] The invention first adds starch nano-microspheres into municipal sludge, performs ultrasonic oscillation treatment under magnetic field conditions, and obtains pre-treated sludge; then injects oxygen into the pre-treated sludge, sprays at high pressure, and activates with microwaves to obtain activated sludge; then inoculates Chlorella into the activated sludge, cultures it, performs ultrasonic oscillation treatment, separates the solid from the liquid to obtain a water phase and a solid phase, the water phase is reused as industrial water, and the solid phase is carbonized to produce activated carbon, thereby realizing the comprehensive resource utilization of municipal sludge.

[0037] The method comprises the following steps: firstly esterifying starch with acetic anhydride to obtain starch acetate, then dissolving the starch acetate in acetone, dripping deionized water dropwise, stirring and mixing, and waiting for the acetone to completely volatilize to obtain a starch acetate aqueous dispersion; then mixing sodium hydroxide, urea and deionized water until clarified, adding konjac glucomannan while stirring, 300-400W ultrasonic oscillation for 3-4 hours, dripping 3-chloro-2-hydroxypropyltrimethylammonium chloride aqueous solution dropwise, reacting by stirring at room temperature, adjusting the pH to neutral, and dialyzing until the solution does not contain Cl - , and obtain a modified konjac glucomannan solution; finally, add the modified konjac glucomannan solution to the starch acetate aqueous dispersion, oscillate evenly with ultrasonic waves, and dry under vacuum to obtain starch nanospheres. The starch nanospheres are added to the municipal sludge, which, on the one hand, adsorb and fix the pollutants, and on the other hand, under the coupling of the magnetic field and ultrasound, the movement of the nanospheres in the system disrupts the sludge flocs, so that the pollutants are fully released and then adsorbed and fixed.

[0038] Injecting oxygen into the pre-treated sludge, high-pressure spraying, and microwave activation improves the uniformity and fluidity of the sludge, making the sludge fully activated. Through the subsequent chlorella cultivation, the pollutants in the sludge are fully adsorbed and fixed. Finally, the water phase obtained by solid-liquid separation can be directly reused as industrial water, and the solid phase is carbonized to produce activated carbon, realizing efficient resource comprehensive utilization of urban sludge. DETAILED DESCRIPTION

[0039] The present invention is further described below in conjunction with embodiments. It should be noted that the following description is only for explaining the present invention and does not limit its contents.

[0040] Embodiment 1:

[0041] A resource-based comprehensive utilization treatment process for municipal sludge, the specific steps are as follows:

[0042] S1. First, starch nanospheres are added to municipal sludge, and ultrasonic oscillation treatment is performed under magnetic field conditions to obtain pretreated sludge;

[0043] The mass ratio of municipal sludge to starch nanospheres was 100:2; the magnetic field intensity was 80 mT; the process conditions of ultrasonic oscillation treatment were: 500 W ultrasonic oscillation for 2 hours;

[0044] S2. Then, oxygen is injected into the pretreated sludge, high pressure spraying is performed, and microwave activation is performed to obtain activated sludge;

[0045] Oxygen was injected into the pretreated sludge from the bottom at a rate of 0.2 L / min for 20 minutes;

[0046] The process conditions of high-pressure injection are as follows: injection port diameter is 20 mm, injection pressure is 0.8 MPa, and injection time is 5 min;

[0047] The process conditions of microwave activation were as follows: 400 W microwave irradiation, 2 min on and 1 min off, with a cumulative irradiation time of 40 min;

[0048] S3. Chlorella is then inoculated into the activated sludge, cultured, ultrasonically treated, and solid-liquid separated into an aqueous phase and a solid phase, the aqueous phase is reused as industrial water, and the solid phase is carbonized to produce activated carbon;

[0049] Chlorella concentrate (purchased from Wudi Lvqi Bioengineering Co., Ltd.) was added to the activated sludge, and the mass ratio of activated sludge to Chlorella concentrate was 100:0.01;

[0050] The culture conditions were: temperature 20°C, light 20,000 lux, stirring at 30 rpm for 50 minutes and then static culture for 3 days;

[0051] The process conditions of ultrasonic oscillation treatment were: 800W ultrasonic oscillation for 2 hours;

[0052] The process conditions of carbonization treatment are: first increase the temperature to 450°C at 10°C / min, keep it warm for 30 minutes, then increase the temperature to 500°C at 2°C / min, and keep it warm for 50 minutes.

[0053] In step S1, the starch nanospheres are prepared by the following method:

[0054] (1) First, 1 kg of corn starch was stirred and added to 2 kg of acetic anhydride, and the mixture was stirred and dispersed uniformly. The mixture was subjected to esterification reaction at 50° C. for 3 hours, and the acetic anhydride was removed by washing with anhydrous ethanol for 3 times to obtain starch acetate. The starch acetate was then dissolved in 2 L of acetone, and 2 L of deionized water was added dropwise, and the mixture was stirred and mixed. After the acetone was completely volatilized, a starch acetate aqueous dispersion was obtained.

[0055] (2) 0.05 kg of sodium hydroxide, 0.05 kg of urea and 0.9 L of deionized water were mixed and stirred until clear, 0.01 kg of konjac glucomannan was added while stirring, ultrasonic oscillation was performed at 300 W for 3 hours, 3 mL of 3% 3-chloro-2-hydroxypropyltrimethylammonium chloride aqueous solution was added dropwise, and the mixture was stirred at room temperature for 5 hours. The pH was adjusted to neutral with 1 mol / L hydrochloric acid solution, and dialyzed with a dialysis bag with a molecular weight cutoff of 15 kD until the solution contained no Cl - , obtaining a modified konjac glucomannan solution;

[0056] (3) Finally, the modified konjac glucomannan solution was added to the starch acetate aqueous dispersion, ultrasonically vibrated at 300W for 40 minutes, and vacuum dried to obtain the product.

[0057] In step (3), the volume ratio of the modified konjac glucomannan solution to the starch acetate aqueous dispersion is 1:8.

[0058] Embodiment 2:

[0059] A resource-based comprehensive utilization treatment process for municipal sludge, the specific steps are as follows:

[0060] S1. First, starch nanospheres are added to municipal sludge, and ultrasonic oscillation treatment is performed under magnetic field conditions to obtain pretreated sludge;

[0061] The mass ratio of municipal sludge to starch nanospheres was 100:3; the magnetic field intensity was 100 mT; the process conditions of ultrasonic oscillation treatment were: 600 W ultrasonic oscillation for 3 hours;

[0062] S2. Then, oxygen is injected into the pretreated sludge, high pressure spraying is performed, and microwave activation is performed to obtain activated sludge;

[0063] Inject oxygen into the pretreated sludge from the bottom at a rate of 0.3 L / min for 30 minutes;

[0064] The process conditions of high-pressure injection are: injection port diameter 30 mm, injection pressure 1 MPa, injection time 6 min;

[0065] The process conditions of microwave activation were as follows: 500 W microwave irradiation, 2 min on and 1 min off, with a cumulative irradiation time of 50 min;

[0066] S3. Chlorella is then inoculated into the activated sludge, cultured, ultrasonically treated, and solid-liquid separated into an aqueous phase and a solid phase, the aqueous phase is reused as industrial water, and the solid phase is carbonized to produce activated carbon;

[0067] Chlorella concentrate (purchased from Wudi Lvqi Bioengineering Co., Ltd.) was added to the activated sludge, and the mass ratio of activated sludge to Chlorella concentrate was 100:0.02;

[0068] The culture conditions were: temperature 25°C, light 30,000 lux, stirring at 50 rpm for 60 minutes and then static culture for 5 days;

[0069] The process conditions of ultrasonic oscillation treatment were: 900W ultrasonic oscillation for 3 hours;

[0070] The process conditions of carbonization treatment are: first increase the temperature to 470°C at 12°C / min, keep it warm for 40 minutes, then increase the temperature to 510°C at 3°C / min, and keep it warm for 60 minutes.

[0071] In step S1, the starch nanospheres are prepared by the following method:

[0072] (1) First, 1 kg of corn starch was stirred and added to 3 kg of acetic anhydride, and the mixture was stirred and dispersed uniformly. The mixture was subjected to esterification reaction at 60° C. for 4 hours, and the acetic anhydride was removed by washing with anhydrous ethanol for 4 times to obtain starch acetate. The starch acetate was then dissolved in 3 L of acetone, and 3 L of deionized water was added dropwise, and the mixture was stirred and mixed. After the acetone was completely volatilized, a starch acetate aqueous dispersion was obtained.

[0073] (2) 0.05 kg of sodium hydroxide, 0.05 kg of urea and 1 L of deionized water were mixed and stirred until clear, 0.01 kg of konjac glucomannan was added while stirring, ultrasonic oscillation was performed at 400 W for 4 hours, 4 mL of 4% 3-chloro-2-hydroxypropyltrimethylammonium chloride aqueous solution was added dropwise, and the mixture was stirred at room temperature for 6 hours. The pH was adjusted to neutral with 1 mol / L hydrochloric acid solution, and dialyzed with a dialysis bag with a molecular weight cutoff of 15 kD until the solution contained no Cl. - , obtaining a modified konjac glucomannan solution;

[0074] (3) Finally, the modified konjac glucomannan solution is added to the starch acetate aqueous dispersion, ultrasonically vibrated at 300-400W for 40-50 minutes, and vacuum dried to obtain the product.

[0075] In step (3), the volume ratio of the modified konjac glucomannan solution to the starch acetate aqueous dispersion is 1:10.

[0076] Embodiment 3:

[0077] A resource-based comprehensive utilization treatment process for municipal sludge, the specific steps are as follows:

[0078] S1. First, starch nanospheres are added to municipal sludge, and ultrasonic oscillation treatment is performed under magnetic field conditions to obtain pretreated sludge;

[0079] The mass ratio of municipal sludge to starch nanospheres was 100:2; the magnetic field intensity was 100 mT; the process conditions of ultrasonic oscillation treatment were: 500W ultrasonic oscillation for 3 hours;

[0080] S2. Then, oxygen is injected into the pretreated sludge, high pressure spraying is performed, and microwave activation is performed to obtain activated sludge;

[0081] Inject oxygen into the pretreated sludge from the bottom at a rate of 0.2 L / min for 30 minutes;

[0082] The process conditions of high-pressure injection are as follows: injection port diameter is 20 mm, injection pressure is 1 MPa, and injection time is 5 min;

[0083] The process conditions of microwave activation were as follows: 500 W microwave irradiation, 2 min on and 1 min off, with a cumulative irradiation time of 40 min;

[0084] S3. Chlorella is then inoculated into the activated sludge, cultured, ultrasonically treated, and solid-liquid separated into an aqueous phase and a solid phase, the aqueous phase is reused as industrial water, and the solid phase is carbonized to produce activated carbon;

[0085] Chlorella concentrate (purchased from Wudi Lvqi Bioengineering Co., Ltd.) was added to the activated sludge, and the mass ratio of activated sludge to Chlorella concentrate was 100:0.02;

[0086] The culture conditions were: temperature 20°C, light 30,000 lux, stirring at 30 rpm for 60 minutes and then static culture for 3 days;

[0087] The process conditions of ultrasonic oscillation treatment were: 900W ultrasonic oscillation for 2 hours;

[0088] The process conditions of carbonization treatment are: first increase the temperature to 450°C at 12°C / min, keep it warm for 40 minutes, then increase the temperature to 510°C at 2°C / min, and keep it warm for 50 minutes.

[0089] In step S1, the starch nanospheres are prepared by the following method:

[0090] (1) First, 1 kg of corn starch was stirred and added to 3 kg of acetic anhydride, and the mixture was stirred and dispersed uniformly. The mixture was subjected to esterification reaction at 50° C. for 4 hours, and the acetic anhydride was removed by washing with anhydrous ethanol for 3 times to obtain starch acetate. The starch acetate was then dissolved in 3 L of acetone, and 2 L of deionized water was added dropwise, and the mixture was stirred and mixed. After the acetone was completely volatilized, a starch acetate aqueous dispersion was obtained.

[0091] (2) 0.05 kg of sodium hydroxide, 0.05 kg of urea and 1 L of deionized water were mixed and stirred until clear, 0.01 kg of konjac glucomannan was added while stirring, ultrasonic oscillation was performed at 300 W for 4 hours, 3 mL of 4% 3-chloro-2-hydroxypropyltrimethylammonium chloride aqueous solution was added dropwise, and the mixture was stirred at room temperature for 5 hours. The pH was adjusted to neutral with 1 mol / L hydrochloric acid solution, and dialyzed with a dialysis bag with a molecular weight cutoff of 15 kD until the solution contained no Cl. - , obtaining a modified konjac glucomannan solution;

[0092] (3) Finally, the modified konjac glucomannan solution is added to the starch acetate aqueous dispersion, ultrasonically vibrated at 400W for 40 minutes, and vacuum dried to obtain the product.

[0093] In step (3), the volume ratio of the modified konjac glucomannan solution to the starch acetate aqueous dispersion is 1:10.

[0094] Embodiment 4:

[0095] A resource-based comprehensive utilization treatment process for municipal sludge, the specific steps are as follows:

[0096] S1. First, starch nanospheres are added to municipal sludge, and ultrasonic oscillation treatment is performed under magnetic field conditions to obtain pretreated sludge;

[0097] The mass ratio of municipal sludge to starch nanospheres was 100:2.5; the magnetic field intensity was 90 mT; the process conditions of ultrasonic oscillation treatment were: 600 W ultrasonic oscillation for 2.5 hours;

[0098] S2. Then, oxygen is injected into the pretreated sludge, high pressure spraying is performed, and microwave activation is performed to obtain activated sludge;

[0099] Oxygen was injected into the pretreated sludge from the bottom at a rate of 0.25 L / min for 25 minutes;

[0100] The process conditions of high-pressure injection are as follows: injection port diameter 25 mm, injection pressure 0.9 MPa, injection time 5 min;

[0101] The process conditions of microwave activation were: 450 W microwave irradiation, 2 min on and 1 min off, with a cumulative irradiation time of 45 min;

[0102] S3. Chlorella is then inoculated into the activated sludge, cultured, ultrasonically treated, and solid-liquid separated into an aqueous phase and a solid phase, the aqueous phase is reused as industrial water, and the solid phase is carbonized to produce activated carbon;

[0103] Chlorella concentrate (purchased from Wudi Lvqi Bioengineering Co., Ltd.) was added to the activated sludge, and the mass ratio of activated sludge to Chlorella concentrate was 100:0.015;

[0104] The culture conditions were: temperature 22°C, light 25000 lux, stirring at 40 r / min for 55 minutes and then static culture for 4 days;

[0105] The process conditions of ultrasonic oscillation treatment were: 900W ultrasonic oscillation for 2.5 hours;

[0106] The process conditions of carbonization treatment are: first increase the temperature to 460°C at 11°C / min, keep it warm for 35 minutes, then increase the temperature to 505°C at 2.5°C / min, and keep it warm for 55 minutes.

[0107] In step S1, the starch nanospheres are prepared by the following method:

[0108] (1) First, 1 kg of corn starch was stirred and added to 2.5 kg of acetic anhydride, and the mixture was stirred and dispersed evenly. The mixture was subjected to esterification reaction at 55° C. for 3.5 hours, and the acetic anhydride was removed by washing with anhydrous ethanol three times to obtain starch acetate. The starch acetate was then dissolved in 2 L of acetone, and 2.5 L of deionized water was added dropwise, and the mixture was stirred and mixed until the acetone was completely volatilized to obtain a starch acetate aqueous dispersion;

[0109] (2) 0.05 kg of sodium hydroxide, 0.05 kg of urea and 0.9 L of deionized water were mixed and stirred until clear, and 0.01 kg of konjac glucomannan was added while stirring. Ultrasonic oscillation was performed at 350 W for 3.5 hours, and 3.5 mL of 3.5% 3-chloro-2-hydroxypropyltrimethylammonium chloride aqueous solution was added dropwise. The mixture was stirred at room temperature for 5 hours, and the pH was adjusted to neutral with 1 mol / L hydrochloric acid solution. The solution was dialyzed with a dialysis bag with a molecular weight cutoff of 15 kD until the solution contained no Cl. - , obtaining a modified konjac glucomannan solution;

[0110] (3) Finally, the modified konjac glucomannan solution was added to the starch acetate aqueous dispersion, ultrasonically vibrated at 350W for 45 minutes, and vacuum dried to obtain the product.

[0111] In step (3), the volume ratio of the modified konjac glucomannan solution to the starch acetate aqueous dispersion is 1:9.

[0112] Comparative Example 1

[0113] A resource-based comprehensive utilization treatment process for municipal sludge, the specific steps are as follows:

[0114] S1. First, starch nanospheres are added to municipal sludge, and ultrasonic oscillation treatment is performed under magnetic field conditions to obtain pretreated sludge;

[0115] The mass ratio of municipal sludge to starch nanospheres was 100:2; the magnetic field intensity was 80 mT; the process conditions of ultrasonic oscillation treatment were: 500 W ultrasonic oscillation for 2 hours;

[0116] S2. Then, oxygen is injected into the pretreated sludge, high pressure spraying is performed, and microwave activation is performed to obtain activated sludge;

[0117] Oxygen was injected into the pretreated sludge from the bottom at a rate of 0.2 L / min for 20 minutes;

[0118] The process conditions of high-pressure injection are as follows: injection port diameter is 20 mm, injection pressure is 0.8 MPa, and injection time is 5 min;

[0119] The process conditions of microwave activation were as follows: 400 W microwave irradiation, 2 min on and 1 min off, with a cumulative irradiation time of 40 min;

[0120] S3. Chlorella is then inoculated into the activated sludge, cultured, ultrasonically treated, and solid-liquid separated into an aqueous phase and a solid phase, the aqueous phase is reused as industrial water, and the solid phase is carbonized to produce activated carbon;

[0121] Chlorella concentrate (purchased from Wudi Lvqi Bioengineering Co., Ltd.) was added to the activated sludge, and the mass ratio of activated sludge to Chlorella concentrate was 100:0.01;

[0122] The culture conditions were: temperature 20°C, light 20,000 lux, stirring at 30 rpm for 50 minutes and then static culture for 3 days;

[0123] The process conditions of ultrasonic oscillation treatment were: 800W ultrasonic oscillation for 2 hours;

[0124] The process conditions of carbonization treatment are: first increase the temperature to 450°C at 10°C / min, keep it warm for 30 minutes, then increase the temperature to 500°C at 2°C / min, and keep it warm for 50 minutes.

[0125] In step S1, the starch nanospheres are prepared by the following method: first, 1 kg of corn starch is stirred and added into 2 kg of acetic anhydride, the mixture is stirred and dispersed evenly, an esterification reaction is carried out at 50° C. for 3 hours, the acetic anhydride is removed by washing with anhydrous ethanol for 3 times to obtain starch acetate, and then the starch acetate is dissolved in 2 L of acetone, 2 L of deionized water is added dropwise, the mixture is stirred and mixed, and the acetone is completely volatilized to obtain a starch acetate aqueous dispersion, which is then dried in vacuo.

[0126] Comparative Example 2

[0127] A resource-based comprehensive utilization treatment process for municipal sludge, the specific steps are as follows:

[0128] S1. First, starch nanospheres are added to municipal sludge and subjected to ultrasonic oscillation treatment to obtain pretreated sludge;

[0129] The mass ratio of municipal sludge to starch nanospheres was 100:2; the process conditions of ultrasonic oscillation treatment were: 500W ultrasonic oscillation for 2 hours;

[0130] S2. Then, oxygen is injected into the pretreated sludge, high pressure spraying is performed, and microwave activation is performed to obtain activated sludge;

[0131] Oxygen was injected into the pretreated sludge from the bottom at a rate of 0.2 L / min for 20 minutes;

[0132] The process conditions of high-pressure injection are as follows: injection port diameter is 20 mm, injection pressure is 0.8 MPa, and injection time is 5 min;

[0133] The process conditions of microwave activation were as follows: 400 W microwave irradiation, 2 min on and 1 min off, with a cumulative irradiation time of 40 min;

[0134] S3. Chlorella is then inoculated into the activated sludge, cultured, ultrasonically treated, and solid-liquid separated into an aqueous phase and a solid phase, the aqueous phase is reused as industrial water, and the solid phase is carbonized to produce activated carbon;

[0135] Chlorella concentrate (purchased from Wudi Lvqi Bioengineering Co., Ltd.) was added to the activated sludge, and the mass ratio of activated sludge to Chlorella concentrate was 100:0.01;

[0136] The culture conditions were: temperature 20°C, light 20,000 lux, stirring at 30 rpm for 50 minutes and then static culture for 3 days;

[0137] The process conditions of ultrasonic oscillation treatment were: 800W ultrasonic oscillation for 2 hours;

[0138] The process conditions of carbonization treatment are: first increase the temperature to 450°C at 10°C / min, keep it warm for 30 minutes, then increase the temperature to 500°C at 2°C / min, and keep it warm for 50 minutes.

[0139] In step S1, the starch nanospheres are prepared by the following method:

[0140] (1) First, 1 kg of corn starch was stirred and added to 2 kg of acetic anhydride, and the mixture was stirred and dispersed uniformly. The mixture was subjected to esterification reaction at 50° C. for 3 hours, and the acetic anhydride was removed by washing with anhydrous ethanol for 3 times to obtain starch acetate. The starch acetate was then dissolved in 2 L of acetone, and 2 L of deionized water was added dropwise, and the mixture was stirred and mixed. After the acetone was completely volatilized, a starch acetate aqueous dispersion was obtained.

[0141] (2) 0.05 kg of sodium hydroxide, 0.05 kg of urea and 0.9 L of deionized water were mixed and stirred until clear, 0.01 kg of konjac glucomannan was added while stirring, ultrasonic oscillation was performed at 300 W for 3 hours, 3 mL of 3% 3-chloro-2-hydroxypropyltrimethylammonium chloride aqueous solution was added dropwise, and the mixture was stirred at room temperature for 5 hours. The pH was adjusted to neutral with 1 mol / L hydrochloric acid solution, and dialyzed with a dialysis bag with a molecular weight cutoff of 15 kD until the solution contained no Cl - , obtaining a modified konjac glucomannan solution;

[0142] (3) Finally, the modified konjac glucomannan solution was added to the starch acetate aqueous dispersion, ultrasonically vibrated at 300W for 40 minutes, and vacuum dried to obtain the product.

[0143] In step (3), the volume ratio of the modified konjac glucomannan solution to the starch acetate aqueous dispersion is 1:8.

[0144] Comparative Example 3

[0145] A resource-based comprehensive utilization treatment process for municipal sludge, the specific steps are as follows:

[0146] S1. First, starch nanospheres are added to municipal sludge, and ultrasonic oscillation treatment is performed under magnetic field conditions to obtain pretreated sludge;

[0147] The mass ratio of municipal sludge to starch nanospheres was 100:2; the magnetic field intensity was 80 mT; the process conditions of ultrasonic oscillation treatment were: 500 W ultrasonic oscillation for 2 hours;

[0148] S2. Then, oxygen is injected into the pretreated sludge and high-pressure spray is performed to obtain activated sludge;

[0149] Oxygen was injected into the pretreated sludge from the bottom at a rate of 0.2 L / min for 20 minutes;

[0150] The process conditions of high-pressure injection are as follows: injection port diameter is 20 mm, injection pressure is 0.8 MPa, and injection time is 5 min;

[0151] S3. Chlorella is then inoculated into the activated sludge, cultured, ultrasonically treated, and solid-liquid separated into an aqueous phase and a solid phase, the aqueous phase is reused as industrial water, and the solid phase is carbonized to produce activated carbon;

[0152] Chlorella concentrate (purchased from Wudi Lvqi Bioengineering Co., Ltd.) was added to the activated sludge, and the mass ratio of activated sludge to Chlorella concentrate was 100:0.01;

[0153] The culture conditions were: temperature 20°C, light 20,000 lux, stirring at 30 rpm for 50 minutes and then static culture for 3 days;

[0154] The process conditions of ultrasonic oscillation treatment were: 800W ultrasonic oscillation for 2 hours;

[0155] The process conditions of carbonization treatment are: first increase the temperature to 450°C at 10°C / min, keep it warm for 30 minutes, then increase the temperature to 500°C at 2°C / min, and keep it warm for 50 minutes.

[0156] In step S1, the starch nanospheres are prepared by the following method:

[0157] (1) First, 1 kg of corn starch was stirred and added to 2 kg of acetic anhydride, and the mixture was stirred and dispersed uniformly. The mixture was subjected to esterification reaction at 50° C. for 3 hours, and the acetic anhydride was removed by washing with anhydrous ethanol for 3 times to obtain starch acetate. The starch acetate was then dissolved in 2 L of acetone, and 2 L of deionized water was added dropwise, and the mixture was stirred and mixed. After the acetone was completely volatilized, a starch acetate aqueous dispersion was obtained.

[0158] (2) 0.05 kg of sodium hydroxide, 0.05 kg of urea and 0.9 L of deionized water were mixed and stirred until clear, 0.01 kg of konjac glucomannan was added while stirring, ultrasonic oscillation was performed at 300 W for 3 hours, 3 mL of 3% 3-chloro-2-hydroxypropyltrimethylammonium chloride aqueous solution was added dropwise, and the mixture was stirred at room temperature for 5 hours. The pH was adjusted to neutral with 1 mol / L hydrochloric acid solution, and dialyzed with a dialysis bag with a molecular weight cutoff of 15 kD until the solution contained no Cl - , obtaining a modified konjac glucomannan solution;

[0159] (3) Finally, the modified konjac glucomannan solution was added to the starch acetate aqueous dispersion, ultrasonically vibrated at 300W for 40 minutes, and vacuum dried to obtain the product.

[0160] In step (3), the volume ratio of the modified konjac glucomannan solution to the starch acetate aqueous dispersion is 1:8.

[0161] Test example

[0162] The aqueous phases and activated carbon obtained in Examples 1 to 4 and Comparative Examples 1 to 3 were subjected to relevant tests, as follows:

[0163] 1. Water quality testing of water phase:

[0164] COD, measured using a COD detector;

[0165] Ammonia nitrogen concentration is determined by referring to HJ 536-2009 "Determination of ammonia nitrogen in water quality - salicylic acid spectrophotometry";

[0166] The suspended matter content is determined by referring to GB 11901-89 “Determination of suspended matter in water by gravimetric method”;

[0167] The test results are shown in Table 1.

[0168] Table 1. Water quality test of water phase

[0169] COD(mg / L) Ammonia nitrogen (mg / L) Suspended matter (mg / L) Example 1 15 0.3 33 Example 2 15 0.3 31 Example 3 13 0.2 30 Example 4 12 0.2 28 Comparative Example 1 32 1.4 67 Comparative Example 2 35 1.5 75 Comparative Example 3 34 1.5 73

[0170] It can be seen from Table 1 that the water phases obtained in Examples 1 to 4 can meet the demand for industrial water.

[0171] In Comparative Example 1, the addition of modified konjac glucomannan solution was omitted when preparing starch nanospheres, the magnetic field condition was omitted in Comparative Example 2, and microwave activation was omitted in Comparative Example 3, and the water quality was obviously deteriorated, indicating that the specially prepared starch nanospheres of the present invention work synergistically with treatment methods such as magnetic field conditions and microwave activation, and have a more sufficient treatment effect on municipal sludge.

[0172] 2. Activated carbon performance test

[0173] The activated carbon obtained in Examples 1 to 4 and Comparative Examples 1 to 3 was used to adsorb toluene-containing flue gas (temperature 200° C.), and the flue gas flowed through the purification chamber containing the activated carbon at a flow rate of 1 m / s. The concentration of the flue gas before and after treatment was detected by a toluene detector, and the removal rate was calculated. Removal rate (%) = (concentration before treatment - concentration after treatment) / concentration before treatment × 100. The test results are shown in Table 2.

[0174] Table 2. Toluene removal rate

[0175] Toluene removal rate (%) Example 1 99.85 Example 2 99.86 Example 3 99.90 Example 4 99.92 Comparative Example 1 95.03 Comparative Example 2 94.11 Comparative Example 3 94.58

[0176] It can be seen from Table 2 that the activated carbon obtained in Examples 1 to 4 has a good treatment effect on toluene-containing flue gas.

[0177] In comparative example 1, the addition of modified konjac glucomannan solution was omitted when preparing starch nanospheres, the magnetic field condition was omitted in comparative example 2, and microwave activation was omitted in comparative example 3. The flue gas treatment effect was significantly deteriorated, indicating that the specially prepared starch nanospheres of the present invention synergistically act with treatment methods such as magnetic field conditions and microwave activation, and have a more sufficient treatment effect on municipal sludge.

[0178] Although the above describes the specific implementation methods of the present invention, it does not limit the scope of protection of the present invention. Based on the technical solution of the present invention, various modifications or variations that can be made by those skilled in the art without creative work are still within the scope of protection of the present invention.

Claims

1. A process for comprehensive resource utilization of municipal sludge, characterized in that: The specific steps are as follows: S1. First, starch nanospheres are added to municipal sludge, and ultrasonic oscillation treatment is performed under magnetic field conditions to obtain pretreated sludge; S2. Then, oxygen is injected into the pretreated sludge, high pressure spraying is performed, and microwave activation is performed to obtain activated sludge; S3. Chlorella is then inoculated into the activated sludge, cultured, ultrasonically treated, and solid-liquid separated into an aqueous phase and a solid phase, the aqueous phase is reused as industrial water, and the solid phase is carbonized to produce activated carbon; In step S1, the starch nanospheres are prepared by the following method: (1) first esterifying starch with acetic anhydride to obtain starch acetate, then dissolving the starch acetate in acetone, adding deionized water dropwise, stirring and mixing, and waiting for the acetone to completely evaporate to obtain a starch acetate aqueous dispersion; (2) Sodium hydroxide, urea and deionized water are then mixed and stirred until clear, and konjac glucomannan is added while stirring. Ultrasonic oscillation is applied at 300-400W for 3-4 hours, and 3-chloro-2-hydroxypropyltrimethylammonium chloride aqueous solution is added dropwise. The reaction is stirred at room temperature, the pH is adjusted to neutral, and dialyzed until the solution contains no Cl - , obtaining a modified konjac glucomannan solution; (3) Finally, the modified konjac glucomannan solution is added to the starch acetate aqueous dispersion, ultrasonically vibrated evenly, and vacuum dried to obtain the product.

2. The process for comprehensive resource utilization of municipal sludge according to claim 1, characterized in that: In step S1, the mass ratio of municipal sludge to starch nanospheres is 100:2-3.

3. The process for comprehensive resource utilization of municipal sludge according to claim 1, characterized in that: In step S1, the magnetic field strength is 80-100 mT.

4. The process for comprehensive resource utilization of municipal sludge according to claim 1, characterized in that: In step S1, the process conditions of ultrasonic oscillation treatment are: 500-600W ultrasonic oscillation for 2-3 hours.

5. The process for comprehensive resource utilization of municipal sludge according to claim 1, characterized in that: In step S2, oxygen is injected into the pretreated sludge from the bottom, the injection amount is 0.2 to 0.3 L / min, and the injection time is 20 to 30 minutes.

6. The process for comprehensive resource utilization of municipal sludge according to claim 1, characterized in that: In step S2, the process conditions of high-pressure injection are: the injection port diameter is 20-30 mm, the injection pressure is 0.8-1 MPa, and the injection time is 5-6 minutes.

7. The process for comprehensive resource utilization of municipal sludge according to claim 1, characterized in that: In step S2, the process conditions of microwave activation are: 400-500W microwave irradiation, irradiation for 2 minutes and rest for 1 minute, and the cumulative irradiation time is 40-50 minutes.

8. The process for comprehensive resource utilization of municipal sludge according to claim 1, characterized in that: In step S3, the chlorella concentrate is added to the activated sludge, and the mass ratio of the activated sludge to the chlorella concentrate is 100:0.01-0.02; The culture conditions are: temperature 20-25°C, light 20000-30000 lux, stirring at 30-50 r / min for 50-60 minutes and then static culture for 3-5 days.

9. The process for comprehensive resource utilization of municipal sludge according to claim 1, characterized in that: In step S3, the process conditions of ultrasonic oscillation treatment are: 800-900W ultrasonic oscillation for 2-3 hours; The process conditions of carbonization treatment are: first increase the temperature to 450-470°C at 10-12°C / min, keep warm for 30-40 minutes, then increase the temperature to 500-510°C at 2-3°C / min, and keep warm for 50-60 minutes.