CN115322922A

CN115322922A - Method for regenerating sludge resources

Info

Publication number: CN115322922A
Application number: CN202210725154.1A
Authority: CN
Inventors: 汪善全; 王晨; 王仪萱; 石江键
Original assignee: Sun Yat Sen University
Current assignee: Sun Yat Sen University
Priority date: 2022-06-24
Filing date: 2022-06-24
Publication date: 2022-11-11

Abstract

The invention discloses a method for regenerating sludge resources, which comprises the following steps: adjusting the pH value of the original sludge to be 12 or above, heating the sludge to be above 200 ℃, realizing sludge liquefaction, inactivating bacteria in the sludge, releasing cell matrixes, and precipitating heavy metals in the sludge; separating heavy metals and insoluble acellular active substances in the sludge by using a centrifugal method; adjusting the pH value of the sludge to 6.0-7.5 to separate out and precipitate partial protein; separating the precipitated protein by using a centrifugal method to obtain a sludge concentrated solution; reducing or removing the water content in the sludge concentrated solution to obtain a sludge regeneration product. The invention can inactivate and break the cells in the sludge to release nutrient substances in the cells, remove heavy metals, adjust the protein content in the sludge to a proper degree, and finally concentrate the sludge into sludge paste or prepare a sludge regeneration product in a dry powder state, thereby having high economic value and being convenient for storage, transportation and use.

Description

Method for regenerating sludge resources

Technical Field

The invention relates to the technical field of sludge treatment, in particular to a method for regenerating sludge resources.

Background

Sludge is a byproduct generated by sewage treatment and is generally formed by sewage concentration, 40-50g of concentrated sludge can be obtained from 1L of sewage, and the components of the sludge are very complex and contain a large amount of substances harmful to the environment and human bodies, such as: heavy metals, refractory substances, micro plastics, persistent organic matters, parasitic ova, pathogenic bacteria and the like, and if the heavy metals, the refractory substances, the micro plastics, the persistent organic matters, the parasitic ova, the pathogenic bacteria and the like are not properly treated, secondary pollution to the environment can be caused, and the health of a human body can be threatened; however, since nutrients such as N, P, and K and organic matter are contained therein, sludge is also called "misplaced resource". With the progress of sludge treatment technology, the sludge resource utilization technology gradually replaces the traditional landfill and incineration disposal mode because the sludge resource utilization technology meets the requirements of environmental protection and resource regeneration at the same time, and becomes the mainstream direction.

The current stage sludge resource utilization modes mainly comprise organic fertilizer production, methane production, building material production, biochar preparation, hydrocarbon and phosphorus recovery and the like. However, the existing regeneration technology does not pay attention to the abundant bioactive substances in the sludge. The sludge is rich in various bacteria, fungi, protozoa and metazoan, has a large number of microorganism groups with extremely strong metabolic functions, and the metabolic residues of the microorganisms can be used as organic cofactors of some biochemical reactions and can provide necessary substrates for the growth of some microorganisms.

A process for treating sewage to generate activated sludge and extracting protein includes such steps as biochemical treating sewage in sewage treating field to generate a lot of activated sludge, dewatering activated sludge, adding it to enamel or stainless steel container, stirring at 15-90 deg.C, holding the temp for 5-60 min, regulating pH value to 7-12 by acid or alkali solution, stirring, holding temp for 5-30 min, filtering to obtain filtrate, which is the aqueous solution of protein, collecting filtrate, stirring, continuously detecting pH value of filtrate, laying aside when pH value reaches 7-3, depositing to obtain protein latex, discharging supernatant, and drying. The filter residue is pressed into blocks to replace firewood or be mixed with other feeds to be used as livestock feeds.

However, in the scheme, the sludge is simply filtered and then the filter residue is pressed into cakes to directly replace firewood, or the cakes are mixed with other feeds to be used as livestock feeds, the fact that the filter residue contains a large amount of heavy metal components is not considered, the filter residue enters smoke to migrate when the filter residue is used for replacing firewood to burn and influences human health, and the filter residue finally enters a human body along with a food chain after being ingested by poultry and influences human health. Meanwhile, the scheme precipitates all the proteins in the sludge and dries the precipitated proteins, but the scheme simply utilizes the proteins, does not consider active substances and trace elements in a cytoplasm matrix released by broken cells contained in the concentrated solution, and has narrow product utilization range and low economic value after sludge treatment.

Disclosure of Invention

The invention aims to overcome the defects that the sludge treatment method in the prior art is rough in treatment method, low in utilization rate of nutrient substances in the sludge and low in economic value of the prepared product, and provides a method for regenerating sludge resources. The invention can inactivate and break the cells in the sludge to release nutrients in the cells, remove heavy metals, adjust the protein content in the sludge to a proper degree, and finally concentrate the sludge into sludge paste or prepare the sludge into a sludge regeneration product in a dry powder state, thereby having high economic value and being convenient for storage, transportation and use.

The purpose of the invention can be achieved by adopting the following technical scheme:

a method for regenerating sludge resources comprises the following steps:

s1: adjusting the pH value of the original sludge to be 12 or above, heating the sludge to be above 200 ℃, realizing sludge liquefaction, inactivating bacteria in the sludge, releasing cell matrixes, and precipitating heavy metals in the sludge;

the raw sludge obtained by concentrating the sewage can be directly used as the raw sludge for regeneration treatment of the sewage with lower water content. The original sludge is subjected to thermokalite treatment, the components of the sludge are more uniform after liquefaction, the cells are more fully crushed and cracked under the condition, at the moment, the substances are in a dissolved state, pathogenic microorganisms and parasitic ova in the sludge are killed, cell membranes are dissolved and cracked, and active substances, trace elements and other nutrient substances in cell matrixes in the cells are released. After the pH value of the sludge is adjusted to 12 or more, most of the heavy metals in the sludge are precipitated.

S2: separating heavy metals and insoluble acellular active substances in the sludge by using a centrifugal method;

the centrifugal method is used for separating solid from liquid, the efficiency is higher than that of a filtering method, the filter element does not need to be replaced frequently, and the cost is lower. The ash separated by the centrifugal method comprises heavy metals and insoluble non-cellular active substances in the sludge, and the ash can be safely buried and recycled, for example, the heavy metals in the ash can be recycled after being dried and burned.

S3: adjusting the pH value of the sludge treated in the step S2 to 6.0-7.5 to separate out and precipitate partial protein;

the scheme utilizes an isoelectric point precipitation method to precipitate protein molecules, the theoretical controllable amount of protein which can be separated out by the method is 75%, the distribution of isoelectric points of the protein is mainly at a pH value of 3-12, although the precipitation rate of the protein is higher along with the reduction of the pH value, the separation speed is increased firstly and then reduced, and the scheme does not need to separate all the proteins and only needs to regulate and control to separate out 1% -6% of the protein, so that the pH value is regulated to 6.0-7.5.

S4: separating the precipitated protein by using a centrifugal method to obtain a sludge concentrated solution;

the centrifugal method is used for separating solid from liquid, the efficiency is higher than that of a filtering method, the filter element does not need to be replaced frequently, and the cost is lower. The protein that separates can carry out recycle, and in this scheme owing to separate heavy metal and insoluble non-cellular active material in the mud earlier to obtain the sludge concentration liquid, the protein that this step was separated is purer, can avoid heavy metal to gather in the domestic animal when if can regard as domestic animal fodder etc. during recycle.

S5: reducing or removing the water content in the sludge concentrated solution to obtain a sludge regeneration product.

Removing unnecessary substances to obtain sludge concentrated solution rich in nutrition, concentrating or drying the sludge concentrated solution to obtain a sludge regeneration product convenient for storage and transportation, and concentrating the sludge concentrated solution to reduce the water content by 30-40%, so that the obtained product is sludge paste; the product obtained by drying the sludge concentrated solution is sludge powder.

Further, in the step S1, a certain amount of quicklime is added into the sludge to adjust the pH value of the sludge, and the pH value of the sludge is not less than 12, and the sludge is maintained for 1.5-2 hours at the temperature of not less than 200 ℃.

Maintaining for 1.5-2 hr under the conditions of high temperature and strong alkali, killing and dissolving pathogenic bacteria, insect eggs and other harmful organisms in the sludge, and releasing nutrients from the cells.

Further, in the step S3, HCl is added to adjust the pH value of the sludge to 6.5.

HCl is used for regulating the isoelectric point of protein, and 1% -6% of protein is separated out by regulation. Wherein, when the pH value is 6.5 and the precipitation speed of the protein is 6.5, the precipitation speed of the protein is higher, and the precipitation proportion of the protein is moderate. The HCl added at a pH below 6.5 slows down the rate of protein precipitation and precipitates only about 8% more protein when the pH is adjusted to 3 than when the pH is adjusted to 6.5.

Further, in the step S5, when sludge is treated by a dialysis method, the sludge is filled into a dialysis bag, and the sludge is placed in a dialysate, wherein the volume ratio of the sludge to the dialysate is 1.

And removing partial water in the sludge by using a dialysis method to reduce the water content in the sludge by 30-40 percent, and finally preparing the sludge paste. The sludge paste is a product similar to a yeast paste, but the total nitrogen and ammonia nitrogen content of the sludge paste prepared by the scheme is lower than that of the traditional yeast paste. And active substances contained in the sludge paste far exceed those of the yeast paste, and compared with a single yeast of the yeast paste as a donor, the raw sludge of the sludge paste is rich in various bacteria, fungi, protozoa and metazoans, so that the sludge paste contains more physiological active substances and coenzyme factors, can support more and more abundant microbial metabolic processes, and improves the functional redundancy of the system. The functional redundancy enables the microbial community to have stronger adaptability and stability when the environment is changed violently, and also enables the sludge paste to have the unique advantage of supporting the starting of the bioreactor. Meanwhile, the manufacturing cost of the sludge paste is extremely low, the raw material is recycled sludge, the resource recycling is realized, and the processing steps are simple. The dialysis bag can be selected to allow only water molecules to pass through, and can also be selected to be a semi-permeable membrane which can penetrate through small molecular substances so as to control the content of each substance in the sludge. And replacing the dialyzate for many times according to the water content of the sludge concentrated solution until the water content of the sludge concentrated solution reaches the product standard of the sludge paste.

Further, solutes in the dialysate comprise sucrose and carbowax, the mass ratio of the sucrose to the carbowax is 1.

The cane sugar and the carbon wax are prepared into solutes of the dialysate according to the mass ratio of 1.

Further, sucrose and carbowax are prepared into solutes of the dialysate according to the mass ratio of 1.

In the scheme, the optimal dialysis scheme is obtained by coordinating the dialysis speed, the dialysis time and the concentration and the cost of the dialysate.

Further, in the step S5, a spray drying method is used to remove water in the sludge concentrated solution to obtain sludge powder, and when the sludge concentrated solution is treated by the spray drying method, powder is added to the sludge.

The paste product has higher storage and transportation cost and has limitation in use scene. The sludge paste is further processed into powder, the nutrient components are unchanged, the weight is lighter, the transportation and the storage are more convenient, the powder can be added with a small amount of water to be reduced into paste again, the powder can also be directly used, the use scene is wider, if the powder can be used as a microorganism culture additive in the processes of soil improvement, bioreactor starting, sewage treatment, kitchen waste treatment and the like, the sludge paste contains rich coenzyme factors, and the production rate of strains and the yield of fermentation products can be obviously improved. During spray drying, the added powder can provide crystal nuclei to help crystallization, so that the drying efficiency is improved, and the added powder can enrich the nutritional ingredients of the sludge paste.

Further, in the step S5, the powder is industrial and agricultural waste with the cellulose content not less than 30%, the particle size of the powder is 170-230 meshes, and 50-110g of powder is required to be added in each 1L of sludge paste.

After being crushed, the powder containing cellulose needs to be screened by a screen with the mesh number of 170-230, the additives with the particle size not meeting the requirement return to be crushed for the second time, and the additives can be added into the sludge, and the powder fiber with the particle size can provide crystal nuclei for assisting crystallization, thereby improving the efficiency and the effect of spray drying.

Furthermore, the amount of powder required to be added per 1L of sludge paste is 80g.

Further, the time of the spray drying is controlled to be 5-30s.

Furthermore, the powder material is any one or mixture of several of straw, wheat bran, wood, cotton linter, wheat straw, rice straw, reed, hemp, mulberry bark, paper mulberry bark or bagasse.

The powder added into the sludge is also various wastes, and is crushed and screened by a screen for reuse, so that the cost is reduced, the use of new materials in the processing steps is reduced as much as possible, and the resource recycling is realized.

Further, between the steps S1 and S2, the method further includes the following steps:

adding a passivating agent into the sludge to precipitate heavy metals for the second time.

Most heavy metals can be precipitated by adjusting the pH value of the sludge, but some heavy metals cannot be removed, so that the cost of using the passivating agent is high, but when the content of the heavy metals in the use scene of the sludge paste is strict, the heavy metal content in the sludge can be further reduced by adding the step of using the passivating agent.

Further, the passivating agent is an organic precipitator MT-103, the using concentration of the passivating agent is 300-500mg/L, and the processing time of the passivating agent is 20-40min.

Adding a passivating agent into the sludge to ensure that the concentration range of the passivating agent in the sludge is 300-500mg/L, and the treatment time is 20-40min to ensure that the passivating agent fully reacts with heavy metals.

Further, the using concentration of the passivator is 400mg/L, and the treatment time of the passivator is 30min.

The scheme is the optimal scheme for the use of the passivating agent.

Compared with the prior art, the invention has the beneficial effects that:

(1) The alkaline thermal method is used for treating the sludge, the sludge is disinfected and sterilized, substances in cells are fully released, and meanwhile, most heavy metals in the sludge can be precipitated.

(2) The powder rich in cellulose is added into the sludge paste, so that the crystallization can be assisted to accelerate drying, and the nutrient substances of the sludge paste product can be enriched.

Drawings

FIG. 1 is a graph showing the concentration of heavy metals in example 1 of the present invention.

FIG. 2 is a graph showing the relative abundance of heavy metals in example 1 of the present invention.

Detailed Description

The present invention will be further described with reference to the following embodiments. Wherein the showings are for the purpose of illustration only and are shown by way of illustration only and not in actual form, and are not to be construed as limiting the present patent; to better illustrate the embodiments of the present invention, some components of the drawings may be omitted, enlarged or reduced, and do not represent the size of an actual product; it will be understood by those skilled in the art that certain well-known structures in the drawings and descriptions thereof may be omitted.

The same or similar reference numerals in the drawings of the embodiments of the present invention correspond to the same or similar components; in the description of the present invention, it should be understood that if there is an orientation or positional relationship indicated by the terms "upper", "lower", "left", "right", etc. based on the orientation or positional relationship shown in the drawings, it is only for convenience of description and simplification of description, but it is not intended to indicate or imply that the referred device or element must have a specific orientation, be constructed in a specific orientation, and be operated, and therefore, the terms describing the positional relationship in the drawings are only for illustrative purposes and are not to be construed as limitations of the present patent, and specific meanings of the above terms may be understood by those skilled in the art according to specific situations.

Example 1

A method for regenerating sludge resources comprises the following steps:

s1: adjusting the pH value of the original sludge to be 12 or above, heating the sludge to be above 200 ℃ and maintaining for 1.5 hours to realize sludge liquefaction, inactivating bacteria in the sludge and releasing cell matrixes, and precipitating heavy metals in the sludge;

the sludge is subjected to thermokalite treatment, the components of the liquefied sludge are more uniform and the cells are more fully crushed and cracked under the condition, at the moment, the substances are in a dissolved state, the sludge is maintained for 1.5 hours under the high-temperature and strong-alkali conditions, pathogenic microorganisms and parasitic ova in the sludge are fully killed, cell membranes are dissolved and broken, and nutrient substances such as active substances, trace elements and the like in cell matrixes in cells are released. After the pH of the sludge is adjusted to 12 or more, most of the heavy metals in the sludge are precipitated.

S2: separating heavy metals and insoluble non-cellular active substances in the sludge by using a centrifugal method;

the centrifugal method is used for separating solid from liquid, the efficiency is higher than that of a filtering method, the filter element does not need to be replaced frequently, and the cost is lower. The ash separated by the centrifugal method comprises heavy metals and insoluble non-cellular active substances in the sludge, and the ash can be safely buried and recycled, for example, the heavy metals in the ash can be recycled after drying and burning.

S3: adding HCl to adjust the pH value of the sludge treated in the step S2 to 6.5, so that part of protein is separated out and precipitated;

according to the scheme, an isoelectric point precipitation method is utilized to precipitate protein molecules, the theoretical controllable amount of protein which can be precipitated by the method is 75%, the distribution of isoelectric points of the protein is mainly controlled at a pH value of 3-12, although the precipitation rate of the protein is higher along with the reduction of the pH value, the precipitation speed is increased and then reduced, and in addition, all the proteins are not required to be separated, and only 1% -6% of the protein is separated by regulation. Wherein, when the pH value is 6.5 and the pH value is 6.5, the precipitation speed of the protein is higher, and the precipitation proportion of the protein is moderate. The rate of precipitation of added HCl from protein slows down after a pH of less than 6.5.

the centrifugal method is used for separating solid from liquid, the efficiency is higher than that of a filtering method, the filter element does not need to be replaced frequently, and the cost is lower. The protein of isolating can carry out recycle, and owing to separate heavy metal and insoluble non-cellular active material in the mud earlier in this scheme, the protein that this step was isolated is purer, can avoid heavy metal at domestic animal internal gathering when like as domestic animal fodder etc. during recycle.

S5: and (4) reducing the water content in the sludge concentrated solution by using a dialysis method to obtain sludge paste.

Removing the unwanted substances to obtain a nutrient-rich sludge solution, and concentrating or drying the sludge solution to obtain a sludge recycled product which is convenient to store and transport. And removing part of water in the sludge by using a dialysis method to reduce the water content in the sludge by 30-40 percent, and finally preparing the sludge paste. The sludge paste is a product similar to yeast paste, but the total nitrogen and ammonia nitrogen content of the prepared sludge paste is lower than that of the traditional yeast paste. And active substances contained in the sludge paste far exceed that of the yeast paste, compared with a single yeast of the yeast paste as a donor, the raw sludge of the sludge paste is rich in various bacteria, fungi, protozoans and metazoans, and the sludge paste contains more physiological active substances and coenzyme factors, so that the sludge paste can support more and more abundant microbial metabolic processes, and the functional redundancy of a system is improved. The functional redundancy enables the microbial community to have stronger adaptability and stability when the environment is changed violently, and also enables the sludge paste to have the unique advantage of supporting the start of the bioreactor. Meanwhile, the manufacturing cost of the sludge paste is extremely low, the raw material is recycled sludge, the resource recycling is realized, and the processing steps are simple.

In step S5, when sludge is treated by the dialysis method, the sludge is filled into a dialysis bag, and the sludge is placed in a dialysate, wherein the volume ratio of the sludge to the dialysate is 1.

Most of water in the sludge is taken out by using a dialysis bag dialysis method to prepare sludge paste, and the dialysis bag can select only allowed water molecules to pass through or can select a semi-permeable membrane which can permeate small molecular substances so as to control the content of each substance in the sludge.

Preparing the solutes of the dialysate from sucrose and carbon wax according to a mass ratio of 1.

In the scheme, the optimal dialysis scheme is obtained by coordinating the dialysis speed and the dialysis time with the concentration and the cost of the dialysate.

The application temperature of the sludge paste is not required to exceed 45 ℃. The usage amount of the sludge paste is 0.1-5.0%.

The sludge paste prepared by the method has the dry matter content of 60-80%, the total nitrogen content of more than or equal to 4.5%, the ammonia nitrogen content of more than or equal to 2% and the chloride content of less than or equal to 1.0%.

And detecting the heavy metal content in the original sludge, ash content, precipitated protein and sludge paste.

The method is used for treating the original sludge obtained by concentrating the sewage of the sewage plant, and the detection result is as follows, wherein the heavy metal detection method is in accordance with the national environmental protection standard of the people's republic of China (HJ 832-2017): soil and sediment-digestion of the total amount of metal elements-microwave digestion method ".

(1) In the original sludge, the contents of Cd, cr, cu, fe, mn, ni, pb and Zn are respectively as follows: 0.02427, 4.57406, 5.16690, 897.2452, 24.24439, 2.83861, 1.48636, 23.43613mg/L.

(2) In the ash, the contents of Cd, cr, cu, fe, mn, ni, pb and Zn are respectively as follows: 0.01332, 3.64363, 3.97651, 771.62101, 20.05661, 1.45509, 1.38202 and 17.54229mg/L.

(3) In the precipitated protein, the contents of Cd, cr, cu, fe, mn, ni, pb and Zn are respectively as follows: 0.00695, 0.57043, 0.45039, 93.56411, 3.28777, 0.65352, 0.03433 and 4.17385mg/L.

(4) In the sludge concentrated solution, the contents of Cd, cr, cu, fe, mn, ni, pb and Zn are respectively as follows: 0.004, 0.36, 0.74, 32.06, 0.90, 0.73, 0.07, 1.72mg/L.

(5) About 93.0% of heavy metal Pb enters ash, the amount of Fe entering ash and precipitated protein respectively accounts for 86.0% and 10.4%, the amount of Mn entering ash and precipitated protein respectively accounts for 82.7% and 13.6%, the amount of Cr entering ash and precipitated protein respectively accounts for 79.7% and 12.5%, the amount of Cu entering ash and precipitated protein respectively accounts for 77.0% and 8.7%, the amount of Zn entering ash and precipitated protein respectively accounts for 74.9% and 17.8%, the amount of Cd entering ash and precipitated protein respectively accounts for 54.9% and 28.6%, and the amount of Ni entering ash and precipitated protein respectively accounts for 51.2% and 23.0%.

The above results are shown in fig. 1 and 2, and show that most of the heavy metal contaminants enter the ash and precipitated protein during the preparation of the sludge paste, and only a small portion remains in the sludge paste.

Example 2

The present embodiment includes the following features in addition to the features of embodiment 1:

between the steps S1 and S2, the method also comprises the following steps:

adding a passivating agent into the sludge to perform secondary precipitation on the heavy metal.

Most heavy metals can be precipitated by adjusting the pH value of the sludge, but some heavy metals cannot be removed, so that the cost of the passivating agent is high, but when the requirement on the content of the heavy metals in the use scene of the sludge paste is strict, the step of using the passivating agent can be added to further reduce the content of the heavy metals in the sludge.

The passivating agent is organic precipitator MT-103, the using concentration of the passivating agent is 400mg/L, and the treatment time of the passivating agent is 30min. The scheme is the optimal scheme for the use of the passivating agent.

Example 3

This example is similar to example 2, except that: the use concentration of the passivating agent is 500mg/L, and the treatment time of the passivating agent is 20min.

Example 4

This example is similar to example 2, except that: the use concentration of the passivating agent is 300mg/L, and the treatment time of the passivating agent is 40min.

Example 5

This example is similar to any one of examples 1 to 4, except that in step S1, a certain amount of quicklime is added to the sludge to adjust the pH of the sludge, and the sludge is maintained at pH 13 and a sludge temperature of 210 ℃ for 2 hours.

In step S3, the pH value of the sludge treated in step S2 is adjusted to 6.0, so that part of protein is precipitated and precipitated.

And step S5, filling the sludge concentrated solution into a dialysis bag, putting the sludge into a dialysate, wherein the mass fraction of the dialysate is 25%, the volume ratio of the sludge to the dialysate is 1.

Example 6

This example is similar to any one of examples 1 to 4, except that in step S1, a certain amount of quicklime is added to the sludge to adjust the pH of the sludge, and the pH of the sludge is maintained at 14 and the temperature of the sludge is maintained at 220 ℃ for 1.8 hours.

In step S3, the pH value of the sludge treated in step S2 is adjusted to 7.5, so that part of protein is precipitated and precipitated.

In the step S5, the sludge concentrated solution is filled into a dialysis bag, the sludge is placed into the dialysate, the mass fraction of the dialysate is 45%, the volume ratio of the sludge to the dialysate is 1.

Example 7

This example is similar to any one of examples 1 to 6, except that in step S5, a spray drying method is used to remove water from the sludge concentrated solution to obtain sludge powder, and when the sludge concentrated solution is treated by the spray drying method, powder is added to the sludge concentrated solution.

The paste product has higher storage and transportation cost, and the use scene has limitation when in use. The sludge paste is further processed into powder, so that the transportation and storage are more convenient, the powder can be added with a small amount of water to be restored into paste, the powder can be directly used, the use scene is wider, if the sludge paste can be used as a microbial culture additive in the processes of soil improvement, bioreactor starting, sewage treatment, kitchen waste treatment and the like, the sludge paste contains rich coenzyme factors, and the production rate of strains and the yield of fermentation products can be obviously improved. During spray drying, the added powder can provide crystal nuclei to help crystallization, so that the drying efficiency is improved, and the added powder can enrich the nutritional ingredients of the sludge paste.

The powder is industrial and agricultural wastes with the cellulose content not less than 30 percent, the particle size of the powder is 200 meshes, and 80g of powder is required to be added in each 1L of sludge paste.

After the powder containing cellulose is crushed, the powder needs to be screened by a screen with 200 meshes, and the additive with the particle size not meeting the requirement returns to be crushed for the second time, so that the additive can be added into the sludge, and the powder fiber with the particle size can provide crystal nuclei to help crystallization, thereby improving the efficiency and the effect of spray drying.

The time for spray drying was controlled at 20s.

The powder material can be any one or mixture of straw, wheat bran, wood, cotton linter, wheat straw, rice straw, reed, hemp, mulberry bark, paper mulberry bark or bagasse.

The sludge powder paste is preserved at the temperature of 0-4 ℃ for 6 months. The using temperature of the sludge powder paste is not more than 45 ℃, and the using amount of the sludge powder paste is 0.1-5.0%.

The mud powder paste prepared by the method has dry matter content of more than or equal to 75 percent, total nitrogen content of more than or equal to 4.5 percent, ammonia nitrogen content of more than or equal to 2 percent and chloride content of less than or equal to 0.8 percent.

Example 8

This example is similar to example 7, except that 5g of powder was added per 1L of the sludge paste, and the spray-drying time was controlled to 30 seconds. The cellulose-containing powder after crushing needs to be screened by a screen with the mesh number of 170.

Example 9

This example is similar to example 7, except that in this example, 110g of powder was added per 1L of the sludge paste, and the spray-drying time was controlled to 5 seconds. The powder containing cellulose is screened by a 230-mesh screen after being crushed.

Example 10

Preparing yeast cream: centrifuging the yeast fermentation liquid to remove supernatant, and concentrating under reduced pressure at below 60 deg.C to obtain primary concentrated solution with solid matter content of 30%. Concentrating the primary concentrated solution at 55 deg.C under reduced pressure to obtain yeast extract with solid content of 60 wt%;

measuring total nitrogen, ammonia nitrogen, pH and dry matter quantity of the yeast extract and the sludge extract;

the total nitrogen determination method is according to the determination of NY/T2542-2014 fertilizer-total nitrogen content;

the amino nitrogen detection method is according to 'extraction of potassium chloride solution for determining ammonia nitrogen, nitrite nitrogen and nitrate nitrogen in HJ 634-2012 soil-spectrophotometry';

ecoli, dvH (Desulvirobrio vulgaris Hildenborough) were cultured separately under addition of yeast extract, addition of sludge extract prepared as in example 1 or 2 and medium without additives.

The OD values of the culture solutions under the above 9 culture conditions were measured, and the results were as follows:

TABLE 1 comparison table of total nitrogen and ammonia nitrogen of yeast extract and sludge extract

	Total nitrogen (%)	Ammonia nitrogen (%)	Dry matter (%)	pH
					Yeast cream	9.5	3.4	69	5.7
Sludge paste	4.7	2.9	65	6.2

TABLE 2 OD values of different strains under different culture conditions

(1) Compared with the traditional yeast extract, the sludge extract has lower total nitrogen and ammonia nitrogen contents and equivalent other physical and chemical indexes.

(2) For the culture of the model organism Ecoli, the cell growth can be obviously accelerated and the cell concentration can be improved by adding the yeast paste and the sludge paste, and the cells of the group added with the sludge paste grow slightly quickly.

(3) For the culture of DvH, the cells increased slightly faster in the yeast cream-supplemented group than in the non-supplemented group, and the cells increased slightly faster in the sludge cream-supplemented group than in the yeast cream-supplemented group.

It should be understood that the above-described embodiments of the present invention are merely examples for clearly illustrating the present invention and are not intended to limit the embodiments of the present invention. Other variations and modifications will be apparent to persons skilled in the art in light of the above description. This need not be, nor should it be exhaustive of all embodiments. Any modification, equivalent replacement, and improvement made within the spirit and principle of the present invention should be included in the protection scope of the claims of the present invention.

Claims

1. A method for regenerating sludge resources is characterized by comprising the following steps:

2. The method for regenerating sludge resources as claimed in claim 1, wherein in the step S1, a certain amount of quicklime is added into the sludge to adjust the pH value of the sludge, and the pH value of the sludge is not less than 12, and the temperature of the sludge is not less than 200 ℃ and is maintained for 1.5-2 hours.

3. The method for sludge resource regeneration as claimed in claim 1, wherein in the step S3, HCl is added to adjust the pH value of the sludge to 6.5.

4. The method for sludge resource regeneration according to claim 1, wherein in step S5, the water content in the sludge concentrated solution is reduced by using a dialysis method to obtain sludge paste, when the sludge concentrated solution is treated by using the dialysis method, the sludge is filled into a dialysis bag and placed into the dialysis solution, the volume ratio of the sludge to the dialysis solution is 1.

5. The method for regenerating the sludge resource as claimed in claim 4, wherein the solute in the dialysate comprises sucrose and carbon wax, the mass ratio of the sucrose to the carbon wax is 1.

6. The method for sludge resource regeneration as claimed in claim 1, wherein in step S5, the sludge powder is obtained by removing water from the sludge concentrated solution by spray drying, and the powder is added to the sludge when the sludge concentrated solution is treated by spray drying.

7. The method for sludge resource regeneration according to claim 6, wherein in step S5, the powder material is industrial and agricultural waste with cellulose content not less than 30%, the particle size of the powder material is 170-230 meshes, and 50-110g of powder material is required to be added per 1L of sludge paste.

8. The method for sludge resource regeneration as claimed in claim 7, wherein the powder is any one or more of straw, wheat bran, wood, cotton linter, wheat straw, rice straw, reed, hemp, mulberry bark, paper mulberry bark or bagasse.

9. The method for recycling sludge resources as claimed in claim 1, wherein between the steps S1 and S2, the method further comprises the following steps:

and (4) adding a passivating agent into the sludge treated in the step (S1) to perform secondary precipitation on the heavy metal.

10. The method for sludge resource regeneration as claimed in claim 9, wherein the passivating agent is organic precipitant MT-103, the usage concentration of the passivating agent is 300-500mg/L, and the treatment time of the passivating agent is 20-40min.