Method for extracting sludge protein

Abstract

The invention discloses an extraction method for extracting sludge protein, which comprises the following steps: taking water-containing sludge, adding alkali, uniformly stirring to obtain a premix, sealing and heating the premix, and immediately releasing pressure to obtain a reactant; taking out reactants and carrying out filter pressing to obtain filtrate S1; taking D-201 resin for modification; taking the filtrate S1, pumping the filtrate S1 into an ion resin column, and discharging filtrate S2; and pumping methanol into the ion resin column for elution, discharging the eluent after elution, and blow-drying the eluent to obtain the protein. According to the method, the ion resin is modified, so that the adsorption capacity and the adsorption rate are improved, and engineering application of the ion resin to protein separation of the sludge thermal hydrolysate is realized.

Description

Technical Field

[0001] The invention relates to the field of sludge protein extraction, in particular to a method for extracting sludge protein. Background Art

[0002] With the continuous improvement of my country's urbanization level, the amount of sludge generated by municipal sewage treatment plants currently ranks first in the world. The current disposal methods for municipal sludge include incineration and landfill, but they have disadvantages such as low resource utilization and large land occupation. Sludge contains a large amount of protein, and the protein content in the extracellular polymers secreted by microorganisms is also relatively high, so it has a high resource utilization value. Sludge thermal hydrolysis technology is a new type of sludge disposal technology. Organic acids, proteins, ammonia nitrogen and other substances are mixed in the thermal hydrolysis liquid, which cannot be used as resources in a targeted manner, so they must be separated or purified. Ionic resin is a commonly used adsorption material for separating proteins and organic matter, but it also has defects such as low adsorption capacity and low adsorption rate. Summary of the invention

[0003] The purpose of the present invention is to provide a method for extracting sludge protein.

[0004] The innovation of the present invention is that the present invention modifies the ion resin, thereby improving the adsorption capacity and adsorption rate, and realizing the engineering application of the ion resin in protein separation of sludge thermal hydrolyzate.

[0005] In order to achieve the above-mentioned object of the invention, the technical solution of the present invention is:

[0006] A method for extracting sludge protein comprises the following steps

[0007] (1) Take water-containing sludge with a water content of 80-98%, add alkali and stir evenly to obtain a premix, the amount of alkali added is 5‰-6% of the mass of the absolute dry sludge in the tax-containing sludge;

[0008] (2) sealing the premix, heating it to 170° C., and then immediately releasing the pressure to obtain a reactant;

[0009] (3) taking out the reactants and filtering them to obtain filtrate S1;

[0010] (4) Take D-201 resin and soak it in a 3-5% by mass sodium hydroxide solution for 6 hours to obtain a premixed solution;

[0011] (5) stirring the premixed solution under ultrasonic conditions for 1 h to obtain a mixed solution No. 1;

[0012] (6) washing the No. 1 mixed solution with clean water until the washing solution is neutral to obtain a No. 1 washing resin;

[0013] (7) soaking the No. 1 washing resin in 5% by volume hydrochloric acid for 6 hours to obtain an soaked resin;

[0014] (8) washing the soaked resin with clean water until the washing liquid is neutral to obtain a second washing resin;

[0015] (9) Repeat steps (3) to (8) three times to obtain a preliminary resin, and dry the preliminary resin at a drying temperature of 30 to 50° C. to obtain a dried resin;

[0016] (10) mixing ZnO and a drying resin to obtain a mixture, wherein the weight ratio of ZnO to the drying resin is 1 to 1.5:1;

[0017] (11) adding 0.04 mol / L copper nitrate solution dropwise to the mixture and reacting for 60 to 80 min to obtain a second mixed solution;

[0018] (12) adjusting the pH of the mixed solution No. 2 to 7 to obtain a mixed solution No. 3;

[0019] (13) The mixed solution No. 3 is placed in an oven at 60° C. and aged for 10 to 14 h to obtain a solid substance No. 1;

[0020] (14) washing the solid material No. 1 with anhydrous ethanol and distilled water for more than one time to obtain a washed material;

[0021] (15) drying the rinsed product at 40° C. to obtain a dried product;

[0022] (16) Load the dried product into an ion resin column and rinse it with distilled water;

[0023] (17) Take the filtrate S1 in step (3) and pump it into the ion resin column. The mass ratio of the filtrate S1 to the dried product is 100 to 1000:1. Pump and discharge until it is completely discharged. The discharged product is the filtrate S2.

[0024] (18) Pump methanol into the ion resin column in step (17) for elution. Methanol and

[0025] The mass ratio of the dried material is 10 to 20:1, and the eluent is discharged after elution;

[0026] (19) The eluate was blown dry with a nitrogen blower to obtain the protein.

[0027] Furthermore, the taxable sludge in step (1) is municipal sludge with a moisture content of 80%.

[0028] Furthermore, in the step (12), when adjusting the second mixed solution, the acid adjusted is 0.1 mol / L nitric acid, and the base adjusted is 0.1 mol / L sodium hydroxide.

[0029] The beneficial effects of the present invention are:

[0030] 1. The present invention modifies the ion resin to improve the adsorption capacity and adsorption rate, thereby realizing the engineering application of the ion resin in the separation of protein from sludge thermal hydrolyzate. DETAILED DESCRIPTION

[0031] The technical solutions in the embodiments of the present invention will be described clearly and completely below.

[0032] Example 1: A method for extracting sludge protein, comprising the following steps:

[0033] (1) Take water-containing sludge with a water content of 80%, add alkali and stir evenly to obtain a premix, the alkali is KOH, and the amount of alkali added is 5‰ of the absolute dry sludge mass in the tax-containing sludge;

[0034] (2) sealing the premix, heating it to 170° C., and then immediately releasing the pressure to obtain a reactant;

[0035] (3) taking out the reactants and filtering them to obtain filtrate S1;

[0036] (4) Take D-201 resin and soak it in 3% sodium hydroxide solution for 6 hours to obtain a premixed solution;

[0037] (5) stirring the premixed solution under ultrasonic conditions for 1 h to obtain a mixed solution No. 1;

[0038] (6) washing the No. 1 mixed solution with clean water until the washing solution is neutral to obtain a No. 1 washing resin;

[0039] (7) soaking the No. 1 washing resin in 5% by volume hydrochloric acid for 6 hours to obtain an soaked resin;

[0040] (8) washing the soaked resin with clean water until the washing liquid is neutral to obtain a second washing resin;

[0041] (9) Repeat steps (3) to (8) three times to obtain a preliminary resin, and dry the preliminary resin at a drying temperature of 30° C. to obtain a dried resin;

[0042] (10) mixing ZnO and a drying resin to obtain a mixture, wherein the weight ratio of ZnO to the drying resin is 1:1;

[0043] (11) adding 0.04 mol / L copper nitrate solution dropwise to the mixture and reacting for 60 min to obtain a mixed solution No. 2;

[0044] (12) adjusting the pH of the mixed solution No. 2 to 7 to obtain a mixed solution No. 3; when adjusting the mixed solution No. 2, the acid adjusted is 0.1 mol / L nitric acid, and the base adjusted is 0.1 mol / L sodium hydroxide;

[0045] (13) The mixed solution No. 3 was placed in an oven at 60°C for aging for 10 h to obtain a solid substance No. 1;

[0046] (14) washing the solid material No. 1 once with anhydrous ethanol and distilled water to obtain a washed material;

[0047] (15) drying the rinsed product at 40° C. to obtain a dried product;

[0048] (16) Load the dried product into an ion resin column and rinse it with distilled water;

[0049] (17) Take the filtrate S1 in step (3) and pump it into the ion resin column. The mass ratio of the filtrate S1 to the dried product is 100:1. Pump and discharge until it is completely discharged. The discharged product is the filtrate S2.

[0050] (18) pumping methanol into the ion resin column in step (17) for elution, wherein the mass ratio of methanol to the dried product is 10:1, and discharging the eluate after elution;

[0051] (19) The eluate was blown dry with a nitrogen blower to obtain the protein.

[0052] Example 2: A method for extracting sludge protein, comprising the following steps:

[0053] (1) Take water-containing sludge with a water content of 90%, add alkali and stir evenly to obtain a premix, the alkali is KOH, and the amount of alkali added is 1% of the mass of the absolute dry sludge in the tax-containing sludge;

[0054] (2) sealing the premix, heating it to 170° C., and then immediately releasing the pressure to obtain a reactant;

[0055] (3) taking out the reactants and filtering them to obtain filtrate S1;

[0056] (4) Take D-201 resin and soak it in 4% sodium hydroxide solution for 6 hours to obtain a premixed solution;

[0057] (5) stirring the premixed solution under ultrasonic conditions for 1 h to obtain a mixed solution No. 1;

[0058] (6) washing the No. 1 mixed solution with clean water until the washing solution is neutral to obtain a No. 1 washing resin;

[0059] (7) soaking the No. 1 washing resin in 5.5% by volume hydrochloric acid for 6 hours to obtain an soaked resin;

[0060] (8) washing the soaked resin with clean water until the washing liquid is neutral to obtain a second washing resin;

[0061] (9) Repeat steps (3) to (8) three times to obtain a preliminary resin, and dry the preliminary resin at a drying temperature of 40° C. to obtain a dried resin;

[0062] (10) mixing ZnO and a drying resin to obtain a mixture, wherein the weight ratio of ZnO to the drying resin is 1.2:1;

[0063] (11) adding 0.04 mol / L copper nitrate solution dropwise to the mixture and reacting for 70 min to obtain a mixed solution No. 2;

[0064] (12) adjusting the pH of the mixed solution No. 2 to 7 to obtain a mixed solution No. 3; when adjusting the mixed solution No. 2, the acid adjusted is 0.1 mol / L nitric acid, and the base adjusted is 0.1 mol / L sodium hydroxide;

[0065] (13) The mixed solution No. 3 was placed in an oven at 60°C for aging for 12 h to obtain a solid substance No. 1;

[0066] (14) washing the solid material No. 1 twice with anhydrous ethanol and distilled water to obtain a washed material;

[0067] (15) drying the rinsed product at 40° C. to obtain a dried product;

[0068] (16) Load the dried product into an ion resin column and rinse it with distilled water;

[0069] (17) Take the filtrate S1 in step (3) and pump it into the ion resin column. The mass ratio of the filtrate S1 to the dried product is 500:1. Pump and discharge until it is completely discharged. The discharged product is the filtrate S2.

[0070] (18) pumping methanol into the ion resin column in step (17) for elution, wherein the mass ratio of methanol to the dried product is 15:1, and discharging the eluate after elution;

[0071] (19) The eluate was blown dry with a nitrogen blower to obtain the protein.

[0072] Example 3: A method for extracting sludge protein, comprising the following steps:

[0073] (1) taking water-containing sludge with a water content of 98%, adding alkali and stirring uniformly to obtain a premix, wherein the alkali is KOH, and the amount of alkali added is 6% of the mass of the absolute dry sludge in the tax-containing sludge;

[0074] (2) sealing the premix, heating it to 170° C., and then immediately releasing the pressure to obtain a reactant;

[0075] (3) taking out the reactants and filtering them to obtain filtrate S1;

[0076] (4) Take D-201 resin and soak it in 5% by mass sodium hydroxide solution for 6 hours to obtain a premixed solution;

[0077] (5) stirring the premixed solution under ultrasonic conditions for 1 h to obtain a mixed solution No. 1;

[0078] (6) washing the No. 1 mixed solution with clean water until the washing solution is neutral to obtain a No. 1 washing resin;

[0079] (7) soaking the No. 1 washing resin in 6% by volume hydrochloric acid for 6 hours to obtain an soaked resin;

[0080] (8) washing the soaked resin with clean water until the washing liquid is neutral to obtain a second washing resin;

[0081] (9) Repeat steps (3) to (8) three times to obtain a preliminary resin, and dry the preliminary resin at a drying temperature of 50° C. to obtain a dried resin;

[0082] (10) mixing ZnO and a drying resin to obtain a mixture, wherein the weight ratio of ZnO to the drying resin is 1.5:1;

[0083] (11) adding 0.04 mol / L copper nitrate solution dropwise to the mixture and reacting for 80 min to obtain a second mixed solution;

[0084] (12) adjusting the pH of the mixed solution No. 2 to 7 to obtain a mixed solution No. 3; when adjusting the mixed solution No. 2, the acid adjusted is 0.1 mol / L nitric acid, and the base adjusted is 0.1 mol / L sodium hydroxide;

[0085] (13) The mixed solution No. 3 was placed in an oven at 60°C for aging for 14 h to obtain a solid substance No. 1;

[0086] (14) washing the solid material No. 1 twice with anhydrous ethanol and distilled water to obtain a washed material;

[0087] (15) drying the rinsed product at 50° C. to obtain a dried product;

[0088] (16) Load the dried product into an ion resin column and rinse it with distilled water;

[0089] (17) Take the filtrate S1 in step (3) and pump it into the ion resin column. The mass ratio of the filtrate S1 to the dried product is 1000:1. Pump and discharge until it is completely discharged. The discharged product is the filtrate S2.

[0090] (18) Pump methanol into the ion resin column in step (17) for elution. Methanol and

[0091] The mass ratio of the dried material is 20:1, and the eluent is discharged after elution;

[0092] (19) The eluate was blown dry with a nitrogen blower to obtain the protein.

[0093] Comparative Example 1:

[0094] (1) Take water-containing sludge with a water content of 80%, add alkali and stir evenly to obtain a premix, the alkali is KOH, and the amount of alkali added is 5‰ of the absolute dry sludge mass in the tax-containing sludge;

[0095] (2) sealing the premix, heating it to 170° C., and then immediately releasing the pressure to obtain a reactant;

[0096] (3) taking out the reactants and filtering them to obtain filtrate S1;

[0097] (4) Load D-201 resin into an ion resin column and rinse with distilled water;

[0098] (5) Take the filtrate S1 in step (3) and pump it into the ion resin column in step (4). The mass ratio of filtrate S1 to D-201 resin is 100:1. Pump and discharge until it is completely discharged. The discharged filtrate is S2.

[0099] (6) Pumping methanol into the ion resin column in step (5) for elution, methanol and

[0100] The mass ratio of D-201 resin is 10:1, and the eluate is discharged after elution.

[0101] The eluents of Examples 1 to 3 and Comparative Example 1 were blown dry with a nitrogen blower to obtain proteins. The extracted protein content and purity are shown in the following table:

[0102] Example 1 Example 2 Example 3 Comparative Example 1 Protein purity / % 67.5 69.4 66.1 48 Protein content / mg 589 530 570 420

[0103] The described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

Claims

1. A method for extracting sludge protein, characterized in that: The following steps are included Take water-containing sludge with a moisture content of 80-98%, add alkali and stir evenly to obtain a premix. The amount of alkali added is 5‰-6% of the absolute dry sludge mass in the tax-containing sludge; The premix is ​​sealed and heated to 170° C. and then the pressure is immediately released to obtain a reactant; The reactant is taken out and filtered to obtain filtrate S1; Take D-201 resin and soak it in 3-5% sodium hydroxide solution for 6 hours to obtain a premixed solution; The premixed solution was stirred under ultrasonic conditions for 1 h to obtain a mixed solution No. 1; The mixed solution No. 1 is washed with clean water until the washing solution is neutral to obtain a washing resin No. 1; The No. 1 washing resin is soaked in 5% by volume hydrochloric acid for 6 hours to obtain an soaked resin; The soaked resin is rinsed with clean water until the washing liquid is neutral to obtain a No. 2 washing resin; Repeat steps (3) to (8) three times to obtain a preliminary resin, and dry the preliminary resin at a drying temperature of 30 to 50° C. to obtain a dried resin; Mixing ZnO and drying resin to obtain a mixture, wherein the weight ratio of ZnO to the drying resin is 1-1.5:1; Add 0.04 mol / L copper nitrate solution dropwise to the mixture and react for 60-80 min to obtain mixed solution No. 2; Adjusting the pH of the No. 2 mixed solution to 7 to obtain a No. 3 mixed solution; The mixed solution No. 3 was placed in a 60°C oven for aging for 10-14 hours to obtain a solid substance No. 1; The solid material No. 1 is washed with anhydrous ethanol and distilled water more than once to obtain a washed material; The rinsed product is dried at 40° C. to obtain a dried product; Load the dried material into an ion resin column and add distilled water to rinse; Take the filtrate S1 in step (3) and pump it into the ion resin column. The mass ratio of the filtrate S1 to the dried product is 100-1000:

1. Pump and discharge until it is completely discharged. The discharged product is the filtrate S2. Pumping methanol into the ion resin column in step (17) for elution, the mass ratio of methanol to the dried product being 10-20:1, and discharging the eluate after elution; The eluate was blown dry with a nitrogen blower to obtain the protein.

2. The method for extracting sludge protein according to claim 1, characterized in that: The taxable sludge in step (1) is municipal sludge with a moisture content of 80%.

3. The method for extracting sludge protein according to claim 1, characterized in that: In the step (12), when adjusting the No. 2 mixed solution, the acid used is 0.1 mol / L nitric acid, and the base used is 0.1 mol / L sodium hydroxide.