CN110835210B - Method and system for extracting sludge protein by using focused pulse electric field - Google Patents

Abstract

The invention discloses a method and a system for extracting sludge protein by focusing pulse electric field. The method and system flow the homogenized and flowable sludge through different electric field regions in the focused pulsed electric field sludge reactor, which are generated by the interleaving of cathode plates and anode plates. After disposal, the sludge flows out of the reactor and passes through a circulating pump. Circulating back, after the treatment is complete, it is separated by a high-speed centrifuge, and the protein is precipitated by adjusting the pH value, and then frozen in a vacuum belt filter to obtain protein solids. The invention utilizes the electroporation of the biological cells by the focused pulse electric field to cause the sludge cells to be broken, effectively release the protein in the biological cells, and has the advantages of low energy consumption, fast reaction, small consumption of pharmaceutical agents, and the purity of the extracted biological protein. High, no side effects.

Description

A method and system for extracting sludge protein by focusing pulsed electric field

technical field

The invention belongs to the technical field of sludge resource utilization, and particularly relates to a method and a system for extracting sludge protein by focusing pulse electric field.

Background technique

Urban domestic sewage treatment plants will discharge a large amount of activated sludge. According to statistics from the National Bureau of Statistics, in 2018, my country's total wastewater discharge was 70.88 billion tons, urban domestic wastewater accounted for 74.4%, and more than 85% of my country's urban sewage Activated sludge is used by all factories as the main disposal method, but this disposal method will generate a large amount of sludge. According to the calculation of 1.2 tons of absolutely dry sludge per 10,000 tons of wastewater, 5.3862 million tons of absolutely dry sludge will be produced. The direct landfill treatment of this huge excess sludge will not only generate huge disposal costs, but also bring about a series of environmental and land problems. These excess sludges contain a large amount of recyclable resources, and a large number of living organisms are an important recyclable resource in the sludge. If these resources are utilized, it will not only reduce the amount of excess sludge, but also provide additional economic value. These organisms mainly include: bacteria, algae, protozoa, metazoans, etc. The most important and most abundant component of life is biological protein, and biological protein accounts for 20% to 55% of the remaining sludge. Sludge biological protein can be processed into foam concrete foaming agent, foam fire extinguishing agent, medical protein suture and feed, etc., and has a wide range of functions. The traditional methods of extracting protein from sludge mainly include physical methods, biological enzyme methods, and chemical methods. The biggest disadvantage of traditional physical methods and biological enzyme methods is that the extraction rate is low, the reaction time is long, and the purity is low; there are two main traditional chemical methods: mainly acid method and alkaline method, the biggest disadvantage is the waste of chemical reagents, energy High consumption, high protein loss rate, and side reactions are prone to occur during the extraction process.

SUMMARY OF THE INVENTION

The purpose of the present invention is to overcome the above-mentioned deficiencies of the prior art, and to provide a method and system for extracting sludge protein by a focused pulsed electric field, which utilizes the electroporation of biological cells by the focused pulsed electric field, causing the sludge cells to be broken, and effectively destroying the biological cells. The protein is released from the extract, which has the advantages of low energy consumption, fast reaction, small consumption of pharmaceutical agents, high purity of the extracted biological protein, and no side reactions.

The technical solution is as follows:

A method for extracting sludge protein by focusing pulsed electric field, characterized in that it comprises the following steps:

1) The volume ratio of sludge and added water is 1:1 to 1:2, and the mixture is homogenized and stirred to a flowable state;

2) After homogenization, the flowable sludge flows through the different electric field areas in the focused pulse electric field sludge reactor, which are generated by the interleaving of cathode plates and anode plates. Controlled at 20～30℃, the cycle processing time is 30～45min, the distance between the cathode plate and the anode plate is 1～2cm, the power source of the focusing pulse electric field reactor is a high voltage pulse generating power source, and the basic parameters of the power source are: voltage 20～ 30kV, the frequency is 100HZ, the width of the rectangular wave pulse is 0～10μS;

3) After the sludge is completely treated, the sludge residue and the protein liquid are separated by a high-speed centrifuge. The speed of the centrifuge is 4000-5000r/min, and the protein-rich liquid is flowed into the pH adjustment tank, and the pH value is controlled. At 5 to 6, the protein is completely precipitated;

4) The mixed liquid containing protein precipitation is subjected to vacuum filtration at 4°C through a refrigerated vacuum belt filter, the pressure difference is controlled at 0.08-0.1 MPa, and the filtration precision is 30 μm, and protein solids are obtained by separation.

A system for extracting sludge protein by a focused pulsed electric field, comprising: a sludge homogenization stirring system, a focused pulsed electric field sludge reactor, a high-speed centrifuge, a pH adjustment tank and a refrigerated vacuum belt filter, wherein:

The sludge homogenization stirring system homogenizes the sludge and water with a volume ratio of 1:1 to 1:2 to a flowable state;

The focusing pulse electric field sludge reactor includes different electric field areas and temperature control devices generated by the interlacing of cathode plates and anode plates. After homogenization, the flowable sludge flows through different electric field areas for disposal, and then circulates back through a circulating pump, and the temperature is controlled. At 20～30℃, the cycle treatment time is 30～45min, the distance between the cathode plate and the anode plate is 1～2cm, the power supply of the focusing pulse electric field reactor is a high voltage pulse generating power supply, and the basic parameters of the power supply are: voltage 20～30kV , the frequency is 100HZ, and the width of the rectangular wave pulse is 0～10μS;

The high-speed centrifuge separates the sludge residue and the protein liquid through the rotating speed of 4000~5000r/min, and the protein-rich liquid flows into the pH adjustment tank, and the pH value is controlled at 5~6, so that the protein can be completely precipitated out;

The refrigerated vacuum belt filter performs vacuum filtration on the mixed liquid containing protein precipitate at 4°C, the pressure difference is controlled at 0.08-0.1 MPa, and the filtration precision is 30 μm, and the protein solid is obtained by separation.

Preferably, the cathode plate and the anode plate in the focused pulsed electric field sludge reactor are made of inert material and smooth graphite material.

Preferably, the pH adjustment tank is provided with multiple regions for adjustment of different pH value ranges to precipitate different kinds of proteins.

Preferably, the acid regulator in the pH adjustment tank is 0.05mol/L hydrochloric acid or sulfuric acid, and the alkaline regulator is 0.05mol/L sodium hydroxide solution.

When the focused pulse power supply is connected to the cathode and anode plates respectively, the cells are destroyed in the strong electric field. Since the phospholipid molecules on the cells are polar molecules, when the electric field is formed, the accumulation of charges will be formed between the cell membranes. When these charges accumulate to a certain extent, the voltage between the cell membranes will increase. The cell membrane is torn, causing cell death and rupture, so that a large amount of protein substances in the cell will be released to achieve the purpose of protein extraction.

The technical effect obtained by the present invention:

1. The biggest point of the traditional method is that the extraction time is long and the extraction rate is low. For example, hydrolase and high-temperature acidification hydrolysis are often used in the traditional method. The time of these processes is more than 4h, and the present invention directly uses the focusing pulse electric field to accurately It acts on the active cells in the sludge, with high strength and fast speed, the whole reaction process is 0.5h, and the protein extraction rate is as high as 98%;

2. The traditional method will add hydrolytic enzymes and acid-base reagents to the sludge mixture to dissolve and destroy the cells of the sludge, thereby extracting protein, but it causes waste of biological reagents and chemical reagents, and the present invention uses high-voltage pulses. The power source is used as the main energy source, and the polar plate type focusing pulse electric field sludge reactor is used as the main reactor, which can accurately act on the cells of the active substances in the sludge, completely solve the waste of energy and reagents, and the cost is only the traditional 40% of the method;

3. The peristaltic pump is used as the power for the circulating treatment of the focused pulse electric field sludge reactor, so that no new pollutants are introduced;

4. Graphite plates are used to form the disposal electric field, which is easy to manufacture and durable, and the distance between the plates can be adjusted to adapt to different types of sludge in different regions;

5. The feedback adjustment program control of the pH adjustment pool, by controlling the amount of pH reagent added, adjusts different pH ranges, thereby obtaining different kinds of pure proteins, and the purity of the protein can reach 99.8%;

6. The refrigerated vacuum belt filter improves the efficiency of protein solid-liquid separation and precisely controls the molecular weight of the extracted protein. Through the different pore sizes on the filter belt, the extraction of different molecular weight proteins is completed to obtain different products, and the refrigerated vacuum belt filter also has the advantage of continuous operation;

7. The sludge type has strong adaptability, as long as the sludge with good biochemical properties and high biological content can be applied to the device and system.

Description of drawings

Figure 1 is a schematic diagram of a system for extracting sludge proteins with a focused pulsed electric field.

In the picture: 1-Sludge homogenization stirring system, 2-First valve, 3-Feed pump, 4-Focused pulse electric field sludge reactor, 5-Second valve, 6-High voltage pulse generating power supply, 7-Safety Grounding, 8-third valve, 9-circulation pump, 10-fourth valve, 11-fifth valve, 12-disposal sludge transfer pump, 13-high-speed centrifuge, 14-sixth valve, 15-sludge residue Tank, 16-pH adjustment tank, 17-seventh valve, 18-eighth valve, 19-pH regulator, 20-protein liquid transfer pump, 21-refrigerated vacuum belt filter, 22-ninth valve, 23- Protein storage tank, 24-waste liquid storage tank.

Detailed ways

In order to make those skilled in the art better understand the technical solution of the present invention, a method and system for extracting sludge protein provided by a focused pulsed electric field provided by the present invention will be described in detail below with reference to the embodiments. The following examples are only used to illustrate the present invention and not to limit the scope of the present invention.

Example 1

Figure 1 is a schematic diagram of a system for extracting sludge proteins with a focused pulsed electric field. As shown in Fig. 1, the system for extracting sludge protein by focusing pulse electric field includes: a sludge homogenization stirring system 1, a first valve 2, a feed pump 3, a focusing pulse electric field sludge reactor 4, a second valve 5, a high-voltage pulse Generating power source 6, safety grounding 7, third valve 8, circulating pump 9, fourth valve 10, fifth valve 11, disposal sludge transfer pump 12, high-speed centrifuge 13, sixth valve 14, sludge residue tank 15, pH adjustment tank 16 , seventh valve 17 , eighth valve 18 , pH adjuster 19 , protein liquid transfer pump 20 , refrigerated vacuum belt filter 21 , ninth valve 22 , protein storage tank 23 , waste liquid storage tank 24 .

When extracting protein from sludge: First, adjust the sludge to a flowable state in the sludge homogenization stirring system 1, and the ratio of sludge to distilled water is 1:1 to 1:2; after homogenization, open the valve 2, The flowable sludge is added to the focused pulse electric field sludge reactor 4 through the feed pump 3. After the sludge is added to a certain scale, the valve 2 and the feed pump 3 are closed; the valve 5, the valve 8 and the valve 10 are opened. , close the valve 11, turn on the circulating peristaltic pump 9, let the sludge flow evenly in the disposal system, and then turn on the high-voltage pulse power supply to provide pulse power for the pole plate of the focusing pulse electric field reactor 4, before this, the safety grounding 7 Connect first; the basic parameters of the power supply are: voltage 20~30kV, frequency 100HZ, pulse width 0~10μS; focusing pulse electric field reactor 4 is formed by the interleaving of cathode plates and anode plates to generate electric field regions one by one, sludge from This area is processed after flowing, and the distance between the cathode plate and the anode plate is 1-2 cm; the temperature of the focusing pulse electric field reactor 4 is controllable, which is controlled in real time by the temperature sensor and the heat exchange device, and the temperature is controlled at 20-30 ℃ ; After the treatment, the sludge flows out from the focused pulse electric field reactor 4, and is circulated back through the peristaltic pump 9 to ensure that all the sludge is completely disposed of, and the treatment process time is 30-45 minutes; The valve 11 is opened, and the completely treated sludge is pumped into the high-speed centrifuge 13 through another disposal sludge transfer pump 12. The high-speed centrifuge 13 separates the residue of the sludge residue and the protein liquid. The speed of the centrifuge is 4000-5000r/ min; open the valve 14, the protein-rich liquid flows into the pH adjustment tank 16, open the valve 18, and adjust the pH by the pH adjuster 19, so that the protein can be completely precipitated, and the extraction of the protein is realized, and the pH value is controlled at 5~ 6; Open the valve 17, pump the mixed liquid containing the protein precipitation into the refrigerated vacuum belt filter 21 through the protein liquid transfer pump 20, and perform vacuum filtration at 4°C, the pressure difference is controlled at 0.08-0.1MPa, and the filtration precision is 30μm, The protein and the liquid are separated, the protein solid is obtained above the filter belt, transferred to the protein storage tank 23 for use, the valve 22 is opened, and the extracted filtrate flows into the waste liquid storage tank 24; the valve 2 and the pump 3 are opened again, and the conditioning The good sludge is then pumped into the focused pulsed electric field reactor 4 to enter the second cycle. In this way, more protein is obtained from the sludge.

Preferably, the cathode plate and the anode plate in the focused pulsed electric field sludge reactor are made of inert material and smooth graphite material.

The pH adjustment tank can be set up in multiple areas for adjustment of different pH value ranges to precipitate different kinds of proteins. The acid regulator of the pH adjustment tank can be 0.05mol/L hydrochloric acid or sulfuric acid, and the alkaline regulator can be 0.05mol/L sodium hydroxide solution.

When the focused pulse power supply is connected to the cathode and anode plates respectively, the cells are destroyed in the strong electric field. Since the phospholipid molecules on the cells are polar molecules, when the electric field is formed, the accumulation of charges will be formed between the cell membranes. When these charges accumulate to a certain extent, the voltage between the cell membranes will increase. The cell membrane is torn, causing cell death and rupture, so that a large amount of protein substances in the cell will be released to achieve the purpose of protein extraction.

The system for extracting sludge protein by focusing pulsed electric field of the present invention is an efficient extraction system for extracting protein from sludge, and overcomes the problems of long extraction time, low extraction rate, low purity, waste of energy and reagents, which are the biggest points of traditional methods. , Through the focusing pulse electric field sludge reactor, the protein extraction time is shortened and the protein extraction rate is improved. At the same time, by controlling the pH value in different intervals, the protein purity is improved, the process is simplified, and energy and reagents are saved. The system will be widely used in the technical field of efficient resource utilization of sludge solid waste, and can also be applied in other biological protein extraction industries.

The examples of the present invention have been described in detail above in conjunction with the embodiments, but the present invention is not limited to the above-mentioned examples, and within the scope of knowledge possessed by those of ordinary skill in the art, various Changes should also be regarded as the protection scope of the present invention.

Claims (5)

1. A method for extracting sludge protein by focusing pulsed electric field, characterized in that, comprising the following steps: 1) The volume ratio of sludge and added water is 1:1~1:2, and the mixture is homogenized and stirred to a flowable state; 2) After homogenization, the flowable sludge flows through the different electric field areas in the focused pulse electric field sludge reactor, which are generated by the interleaving of cathode plates and anode plates. The temperature is controlled at 20~30℃, the cycle processing time is 30~45min, the distance between the cathode plate and the anode plate is 1~2cm, the power source of the focusing pulse electric field reactor is a high voltage pulse generating power source, and the basic parameters of the power source are: voltage 20~ 30kV, the frequency is 100Hz, the width of the rectangular wave pulse is 0~10μS; 3) After the sludge is completely treated, the sludge residue and the protein liquid are separated by a high-speed centrifuge. The speed of the centrifuge is 4000~5000r/min, and the protein-rich liquid flows into the pH adjustment tank, and the pH value is controlled. At 5-6, the protein is completely precipitated; 4) The mixed liquid containing protein precipitation is vacuum filtered through a refrigerated vacuum belt filter at 4°C, the pressure difference is controlled at 0.08~0.1MPa, and the filtration accuracy is 30μm, and protein solids are separated. 2. A system for extracting sludge protein by a focused pulsed electric field, characterized in that it comprises: a sludge homogenization stirring system, a focused pulsed electric field sludge reactor, a high-speed centrifuge, a pH adjustment tank and a refrigerated vacuum belt filter, in: The sludge homogenization stirring system homogenizes the sludge and water with a volume ratio of 1:1~1:2 to a flowable state; The focusing pulse electric field sludge reactor includes different electric field areas and temperature control devices generated by the interlacing of cathode plates and anode plates. After homogenization, the flowable sludge flows through different electric field areas for disposal, and then circulates back through a circulating pump, and the temperature is controlled. At 20~30℃, the cycle treatment time is 30~45min, the distance between the cathode plate and the anode plate is 1~2cm, the power source of the focusing pulse electric field reactor is a high voltage pulse generator, and the basic parameters of the power source are: voltage 20~30kV , the frequency is 100Hz, and the width of the rectangular wave pulse is 0~10μS; The high-speed centrifuge separates the sludge residue and the protein liquid through the rotation speed of 4000~5000r/min, and the protein-rich liquid flows into the pH adjustment tank, and the pH value is controlled at 5~6, so that the protein is completely precipitated; The refrigerated vacuum belt filter performs vacuum filtration on the mixed liquid containing protein precipitation at 4 °C, the pressure difference is controlled at 0.08-0.1 MPa, and the filtration accuracy is 30 μm, and protein solids are separated. 3 . The system for extracting sludge protein according to claim 2 , wherein the cathode plate and the anode plate in the focused pulse electric field sludge reactor are made of inert material and smooth graphite material. 4 . 4 . The system for extracting sludge proteins by a focused pulsed electric field according to claim 2 , wherein the pH adjustment tank is provided with a plurality of regions for adjustment of different pH value ranges to precipitate different kinds of proteins. 5 . 5 . The system for extracting sludge protein according to claim 4 , wherein the acid regulator in the pH adjustment tank is 0.05mol/L hydrochloric acid or sulfuric acid, and the alkaline regulator is 0.05mol/L hydrogen peroxide. 6 . Sodium solution.

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