CN114163094A

CN114163094A - Ecological treatment process for excrement

Info

Publication number: CN114163094A
Application number: CN202111340253.XA
Authority: CN
Inventors: 李保健; 王亚峰; 王�锋
Original assignee: Hebei Shangde Environmental Engineering Co ltd
Current assignee: Hebei Shangde Environmental Engineering Co ltd
Priority date: 2021-11-12
Filing date: 2021-11-12
Publication date: 2022-03-11

Abstract

The application provides a fecal ecological treatment process, which comprises the following steps: obtaining a feces mixed solution; fermenting the manure mixed liquor; obtaining a first manure mixed solution; stirring the first manure mixed liquid to obtain a second manure mixed liquid with uniform density; dehydrating the second fecal sewage mixed solution to obtain a fecal sewage stock solution; accumulating the fecal sewage stock solution to obtain a first fecal sewage solution with a preset volume; stirring the first excrement liquid to obtain a second excrement liquid with uniform density; adjusting the pH value of the second excrement liquid to be below 10; carrying out solid-liquid separation on the second excrement liquid to obtain primary clear liquid; hydrolyzing and acidifying the primary clear liquid to obtain a secondary clear liquid; denitrifying the secondary clear liquid to obtain a tertiary clear liquid; nitrifying the third-level clear liquid to obtain a fourth-level clear liquid; and performing solid-liquid separation on the four-stage clear liquid to obtain clear water.

Description

Ecological treatment process for excrement

Technical Field

The application relates to the technical field of environmental management, in particular to a fecal ecological treatment process.

Background

The increase of population and the high concentration make rural excrement and urine output increase constantly, and excrement and urine is used in the agricultural production chain as fertilizer directly mostly in the past, and at present under the impact of the chemical fertilizer that can bring apparent economic benefits, excrement and urine is in rural use amount and is shrinking day by day, if not unified management and treatment, can cause serious environmental pollution, can seriously threaten people's health and life safety moreover.

Disclosure of Invention

In view of the above-mentioned drawbacks or deficiencies of the prior art, the present application aims to provide a fecal ecological treatment process comprising the steps of:

obtaining a feces mixed solution;

fermenting the manure mixed liquor; obtaining a first manure mixed solution;

stirring the first manure mixed liquid to obtain a second manure mixed liquid with uniform density;

dehydrating the second fecal sewage mixed solution to obtain a fecal sewage stock solution;

accumulating the fecal sewage stock solution to obtain a first fecal sewage solution with a preset volume;

stirring the first excrement liquid to obtain a second excrement liquid with uniform density;

adjusting the pH value of the second excrement liquid to be below 10;

carrying out solid-liquid separation on the second excrement liquid to obtain primary clear liquid;

hydrolyzing and acidifying the primary clear liquid to obtain a secondary clear liquid;

denitrifying the secondary clear liquid to obtain a tertiary clear liquid;

nitrifying the third-level clear liquid to obtain a fourth-level clear liquid.

And performing solid-liquid separation on the four-stage clear liquid to obtain clear water.

According to the technical scheme provided by the embodiment of the application, a flocculating agent (PAC) and a coagulant aid (PAM) are added into the third fecal sewage liquid to carry out solid-liquid separation on the third fecal sewage liquid.

According to the technical scheme provided by the embodiment of the application, the pH value of the second fecal sewage liquid is adjusted by adding HCL and NaOH into the second fecal sewage liquid.

According to the technical scheme provided by the embodiment of the application, the concentration of the PAC is 10%, and the concentration of the PAM is 0.1% -0.3%.

According to the technical scheme provided by the embodiment of the application, NH in the secondary clear liquid₃When the concentration is close to 600mg/L, the quaternary clear liquid is obtained by two times of denitrification and two times of nitration.

According to the technical scheme provided by the embodiment of the application, NH in the secondary clear liquid₃The quaternary supernatant was obtained by three times of denitrification and three times of said nitrification at a concentration of approximately 600 mg/L.

According to the technical scheme provided by the embodiment of the application, during the third nitrification, the carbon source needs to be added to maintain the carbon-nitrogen balance.

According to the technical scheme provided by the embodiment of the application, sodium hypochlorite is added into the clear water for disinfection.

In summary, the present application provides an ecological fecal treatment process, which includes fermenting and dehydrating the obtained fecal sewage, adjusting the pH value of the fermented and dehydrated fecal sewage, performing solid-liquid separation, performing hydrolytic acidification, denitrification and nitrification on the fermented and dehydrated fecal sewage to obtain clear water, so as to prevent the environmental pollution caused by the fecal sewage, and treating the fecal sewage to obtain clear water to recycle resources.

Drawings

FIG. 1 is a flow chart of a fecal ecological treatment process provided by the embodiments of the present application;

fig. 2 is a schematic structural diagram of an embodiment provided in the present application;

fig. 3 is a schematic structural diagram of an embodiment provided in the present application.

The text labels in the figures are represented as:

1. a first conditioning tank; 2. a second regulating reservoir; 3. a flocculation tank; 4. a sedimentation tank; 5. an anaerobic tank; 61. a first anoxic tank; 71. a first aerobic tank; 62. a second anoxic tank; 72. a second aerobic tank; 8. membrane precipitation equipment; 9. a disinfection tank; 10. a clean water tank; 11. an ecological pond; 63. a third anoxic tank; 64. a third aerobic tank; 12. sodium acetate feeding device.

Detailed Description

The present application will be described in further detail with reference to the following drawings and examples. It is to be understood that the specific embodiments described herein are merely illustrative of the relevant invention and not restrictive of the invention. It should be noted that, for convenience of description, only the portions related to the present invention are shown in the drawings.

It should be noted that the embodiments and features of the embodiments in the present application may be combined with each other without conflict. The present application will be described in detail below with reference to the embodiments with reference to the attached drawings.

As mentioned in the background art, aiming at the problem that the existing rural excrement pollutes the environment, the ecological treatment process of the excrement is provided by the application, and comprises the following steps as shown in figure 1:

obtaining a feces mixed solution; rural excrement is collected and transported to an excrement ecological treatment station through a sewage suction truck, a first adjusting tank 1 is arranged in the excrement ecological treatment station, and the rural excrement is discharged to the first adjusting tank 1 for temporary storage.

Fermenting the manure mixed liquid to obtain a first manure mixed liquid; the main purpose is to intercept the excrement containing more eggs: after the manure enters the septic tank, the manure is fermented and decomposed, loose manure blocks float up due to fermentation expansion and sink according to specific gravity, and therefore floating manure skins, intermediate-layer manure liquid and sinking manure residues are formed. Since the specific gravity of the parasites in the manure is greater than that of the manure mixed liquor, the parasites will naturally settle in the bottom-most manure residues. And intercepting the manure residues, only collecting the manure liquid and the floating manure skin in a concentration layer, and using a mixture of the manure liquid and the manure skin as the first manure mixed liquid.

Stirring the first manure mixed liquid to obtain a second manure mixed liquid with uniform density; and fully liquefying the first fecal sewage mixed solution by stirring.

Dehydrating the second fecal sewage mixed solution to obtain a fecal sewage stock solution; optionally, adopt and fold spiral shell dewatering equipment will the dirty mixed liquid of second excrement carries out dehydration, uses fold spiral shell dewatering equipment, on the one hand because this equipment includes concentrated section and dehydration section two parts, the dehydration effect is stronger, and on the other hand, fold spiral shell dewatering equipment and have on-vehicle form, need not build supporting facilities such as house, convenient and practice thrift and take up an area of.

Accumulating the fecal sewage stock solution to obtain a first fecal sewage solution with a preset volume; the volume of the sewage suction truck is limited, so that the volume of the first excrement liquid meets the preset volume according to the method, the excrement collected by the sewage suction truck for many times forms the excrement stock solution through the processes, and the excrement stock solution formed for many times is collected to the preset volume to obtain the first excrement liquid.

Stirring the first excrement liquid to obtain a second excrement liquid with uniform density; because the first excrement liquid contains the excrement stock solution of collecting many times, and every time the excrement stock solution is through the soil pick-up car is in different geographical positions, and the acquisition is collected at different times, because the people's of different geographical positions dietary habit is different, fermentation time is different, can make the concentration of pollutant is different in the excrement, so with the first excrement liquid misce bene of different solubilities, obtain the second excrement liquid.

And (3) extracting the first excrement liquid into the second regulating tank 2 by establishing a second regulating tank 2, and obtaining the second excrement liquid with uniform density in the second regulating tank.

Adjusting the pH value of the second excrement liquid to be controlled below 10 to obtain a third excrement liquid; preferably, the pH of the second fecal sewage liquid can be adjusted by adding HCL and NaOH, so that the acidity and alkalinity of the second fecal sewage liquid can meet the subsequent biochemical reaction, and the optimal pH range of denitrifying bacteria is within 6.5-7, and this stage is performed in the second adjusting tank 2.

Carrying out solid-liquid separation on the third excrement liquid to obtain primary clear liquid; preferably, a flocculating agent (PAC) and a coagulant aid (PAM) are added into the third fecal sewage liquid for solidification and separation, after the third fecal sewage liquid reacts with the added PAC and PAM, flocculent precipitates with larger particles are generated, the large flocculent precipitates and the precipitates are separated under the action of self gravity, and the obtained supernatant is called first-level clear liquid; preferably, the concentration of PAC is 10% and the concentration of PAM is 0.1% -0.3%.

In this embodiment, establish flocculation basin 3 and sedimentation tank 4 3 solid-liquid separation the third excrement and urine liquid obtains one-level clear liquid establish behind the flocculation basin sedimentation tank 4, the precipitate is direct to be followed the sedimentation tank discharges, be equipped with PAC charge device and PAM charge device on the flocculation basin 3, and every device all is equipped with the measuring pump, the parameter of measuring pump is Q ═ 5L/h, and P ═ 0.5MPa, and N ═ 0.37 kW.

Hydrolyzing and acidifying the primary clear liquid to obtain a secondary clear liquid; the embodiment adopts biochemical sludge to remove organic matters in the primary clear liquid, preferably, the biochemical sludge can be domestic sewage or municipal wastewater, but because of SiO₂Inorganic matters, oils and the like can exceed the standard and industrial wastewater cannot be used, the biochemical sludge contains microbial strains, the organic matters in the primary clear liquid are removed through the microbial strains, and since macromolecular organic matters in the primary clear liquid cannot enter cells of the microbial strains, the macromolecular organic matters are hydrolyzed under an anaerobic environment, and the macromolecular organic matters which are difficult to degrade are converted into easily degradable small molecular substances which can enter the cells of the microbial strains through hydrolytic bacteria in the biochemical sludge; the micromolecule substance enters the cells of the microbial strains, is converted into simpler compounds which are secreted out of the cells, and the main products are volatile fatty acid and also part of substances such as alcohols, lactic acid, carbon dioxide, ammonia and the like are generated. In addition, the phosphorus-accumulating bacteria in the microbial strains also release polyphosphate stored in the microbial strains and release energy, wherein one part of the energy is used for the aerobic phosphorus-accumulating bacteria to live in the anaerobic environment, and the other part of the energy enables the phosphorus-accumulating bacteria to absorb fermentation products in the primary clear liquid andstored in the form of poly-beta-hydroxyalkanoic acid (PHA) within the phosphorus accumulating organism.

At this stage, the microorganism bacterial species absorb the soluble organic matter to decrease the COD concentration in the primary clear solution and further NH₃-N is partially removed by cell synthesis and is NH in the primary supernatant₃Decrease in-N concentration, but NO₃The content of N is unchanged; wherein, the COD refers to the oxygen consumption when the organic matters in the water are degraded by the microorganisms; NH (NH)₃N is the ammonia nitrogen content index in the first-level clear liquid, and NO is₃And N is nitrate nitrogen, and the organic matter is decomposed to generate ammonium salt which is changed into nitrate nitrogen after being oxidized.

In this embodiment, an anaerobic process is completed by establishing an anaerobic tank 5, the content of dissolved oxygen in the anaerobic tank 5 is controlled to be below 0.2mg/L, the biochemical sludge is contained in the tank, anaerobic bacteria are contained in the biochemical sludge, and under the action of the anaerobic bacteria, organic matters in the primary clear liquid are removed, so that the biodegradability of the primary clear liquid is improved. The anaerobic tank 5 is a closed space, a submersible mixer is arranged in the anaerobic tank, and the selection type is QJB 0.85/8-260/3-740/C/S. Preferably, the mixed liquid suspended solid degree (MLSS) of the biochemical sludge is 3000-4000 mg/L, and SV is₃₀Within 35-50%, wherein SV₃₀The volume percentage of the biochemical sludge is expressed after the biochemical sludge is static in a measuring cylinder and is settled for 30min under the aeration condition.

Denitrifying the second clear liquid to obtain a third clear liquid;

denitrifying the secondary clear liquid in an anoxic environment, wherein the content of dissolved oxygen in the anoxic environment is generally controlled to be 0.5mg/L, and the denitrification is that denitrifying bacteria in the biochemical sludge use organic matters in the secondary clear liquid as carbon sources to reduce a large amount of NO3-N and NO2-N into nitrogen and release the nitrogen to the air, so that the concentration of COD5 and COD in the secondary clear liquid is reduced, the concentration of NO3-N is also greatly reduced, but the change of phosphorus in the secondary clear liquid is small; the COD is chemical oxygen content and can reflect the degree of pollution of the water body by reducing substances, and the organic substances are the most common reducing substances in the water body, so the COD reflects the degree of pollution of the water body by the organic substances to a certain degree, and the higher the COD is, the more serious the pollution is. At this stage, the second clear liquid is subjected to denitrification, so that the purposes of simultaneous decarbonization and denitrification are achieved, the concentrations of COD5 and COD in the second clear liquid are greatly reduced, and the third clear liquid containing lower-concentration carbon nitrogen and higher-concentration phosphorus is obtained. In this embodiment, denitrification is performed by establishing a first anoxic tank 61, the first anoxic tank 61 also contains the biochemical sludge, the concentration of the biochemical sludge is 3000mg/L, and the retention time of the secondary clear liquid in the first anoxic tank 61 is 14.4 hours.

Nitrifying the third-stage clear liquid to obtain a fourth-stage clear liquid; nitrifying the tertiary clear liquid in an aerobic environment, wherein the content of dissolved oxygen in the aerobic environment is generally 2mg/L, and the NH3 is further converted into nitrite and nitrate under the action of nitrosobacteria and nitrifying bacteria in the biochemical sludge, namely the nitrification. Thus, under the nitrification, the concentration of NH3 in the tertiary supernatant is significantly reduced and the concentration of NO3 is increased; in addition, the phosphorus-accumulating bacteria decompose the PHA in the body of the phosphorus-accumulating bacteria in the aerobic environment and release energy for providing energy for the growth of the phosphorus-accumulating bacteria, and the phosphorus-accumulating bacteria produce and absorb soluble phosphorus in the environment, and the absorbed soluble phosphorus exists in the phosphorus-accumulating bacteria in the form of phosphorus-accumulating salt, so that the concentration of phosphorus in the tertiary clear liquid is greatly reduced. Through this stage, a four-stage clear night with high nitrite and nitrate concentrations and low phosphorus concentration is formed.

In this embodiment, a first aerobic tank 71 is established for nitrification, the biochemical sludge is also contained in the first aerobic tank 71, the concentration of the biochemical sludge is 3000mg/L, the third-level clear liquid stays in the aerobic tank for 21.6 hours, part of nitrite and nitrate formed in the aerobic tank is returned to an anoxic stage through a return pump for denitrification, and the nitrification rate of denitrification is increased. The model of the reflux pump is Q-30 m³/h，H＝10m，N＝2.2kW。

In this embodiment, the first clear liquid passes through the anaerobic tank 5, the first anoxic tank 61 and the first aerobic tank 71 to complete the removal of organic matters, nitrification and denitrification and the removal of phosphorus, the denitrification is performed on the premise that NH3-N can be completely nitrified, and the reflux of the first aerobic tank 71 can improve the nitrification rate. The first anoxic tank 61 and the first aerobic tank 71 are combined to complete the dephosphorization function; in order to improve the elimination of organic matters in the excrement, the primary clear liquid can be subjected to multiple nitrification denitrification and dephosphorization, so that a plurality of groups of anoxic tanks and aerobic tanks can be established, and the number of the anoxic tanks and the aerobic tanks can be determined according to NH in the primary clear liquid₃-N concentration, preferably NH, in said primary clear liquid₃-obtaining said quaternary clear liquid by two denitrification and two said nitrifications, in this case NH, in said primary clear liquid at a concentration of N close to 600mg/L₃N concentration is close to 600mg/L so that two sets of anoxic tanks and aerobic tanks are established, as shown in figure 1, including the first anoxic tank 61 and the first aerobic tank 71, and the second anoxic tank 62 and the second aerobic tank 72.

Performing solid-liquid separation on the fourth-stage clear solution to obtain clear water; the first-stage clear water passes through the anaerobic tank 5, the two anoxic tanks and the aerobic tank to obtain clear water without organic matters, but the clear water is mixed with the biochemical sludge, so the clear water is taken out through mud-water separation. In this embodiment, the membrane precipitation device 8 is arranged to separate sludge and water, the membrane precipitation device 8 includes a plurality of layers of wires composed of a plurality of wires, and a membrane composed of a plurality of layers of wires, each wire is a hollow tube having an outer diameter of 1-2 mm, a plurality of small holes are arranged on the wall of the hollow tube, the diameter of each small hole is small, only clean water is allowed to flow in, and water is pumped out from the hollow tube through a vacuum pump, so that clean water is obtained.

Preferably, the silk material is PVDF fiber, the nominal size of the silk is 0.05 microns, the silk material has good oxidation resistance, in the fecal pollution treatment, the pores of the silk are often blocked by microorganism and organic matter pollution, and chemical cleaning through an oxidant is the most effective means for recovering the smoothness of the silk, so PVDF with strong oxidation resistance is selected. When the membrane is flushed, the membrane can be cleaned by a high-pressure water gun, and the PVDF has stronger tensile strength and compressive strength, so that the service life of the membrane can be prolonged.

Further, sodium hypochlorite is added into the clean water to disinfect the clean water, the four-stage clean water is subjected to mud-water separation to form the clean water, but microorganisms in the ecological sludge may exist in the clean water, the sodium hypochlorite is put into the water to be collected and is instantaneously decomposed into chloric acid and hypochlorite, the chloric acid is a small neutral molecule, can be rapidly diffused to the surface of the microorganism virus body with negative electricity and can penetrate into the virus body through a cell wall, and the hypochlorous acid destroys enzyme systems such as protein on the virus through strong oxidizability, so that the virus in the microorganisms is killed, and the clean water is disinfected. In this embodiment, it is right through establishing disinfection pond 9 the clear water is disinfected set up sodium hypochlorite charge device above disinfection pond 9 to set up the sodium hypochlorite measuring pump, its lectotype is Q5L/h, P0.5 MPa, N0.37 kW.

Furthermore, the disinfected clean water is pumped into a clean water tank 10, after the detected water quality reaches the standard, the clean water is pumped into an ecological pond 11, an ecological floating island and aquatic plants are arranged in the ecological pond 11, and the aquatic plants have important ecological functions of purifying water quality, inhibiting algae, providing aquatic animal food, breeding habitat and the like. The aquatic plants absorb water and part of nutrient substances in the bottom mud by the root system, which is beneficial to long-term improvement of the water bottom, and the aquatic plants can improve the landscape effect of the aquatic ecological pond 11. In this embodiment, aquatic plant management is performed in an ecological floating island manner. Aiming at eutrophicated water quality, the aquatic ecological floating island degrades COD, nitrogen and phosphorus in water by using an ecological engineering principle; meanwhile, animals such as fish and shrimps are added into the ecological pond 11 to form an ecological chain of microorganism-aquatic plant-animal-microorganism, the aquatic ecological floating island takes aquatic plants as a main body, the soilless culture principle is applied, the intergrowth relationship among species is applied, and the ecological niche and the nutritional ecological niche of the water space are fully utilized, so that a high-efficiency artificial ecological system is established to reduce the pollution load in the water. By the ecological floating island, the water quality index is improved, the transparency of the water body can be greatly improved, and the phenomena of water body fishy smell and eutrophication caused by the insufficient sealing or self-circulation of the water body are reduced.

Example 2

In this embodiment, the same points as those in embodiment 1 are not described in detail, but the differences are as follows: NH in the primary clear liquid₃-said quaternary supernatant is obtained by three denitrification and three said nitrations when the N concentration is close to 800 mg/L. In this embodiment, three anoxic tanks and aerobic tanks are established behind the anaerobic tank 5, and the primary clear liquid is subjected to three times of denitrification and nitrification to achieve the purposes of removing organic matters, nitrogen and phosphorus. As shown in fig. 2, the anoxic tank and the aerobic tank further include a third anoxic tank 63 and a third aerobic tank 64. Preferably, during the third time of the nitrification, carbon-nitrogen balance is required to be maintained by adding carbon source, the amount of C source in the biochemical sludge is reduced due to the former two times of the denitrification and the nitrification, and in order to maintain the survival rate of microorganisms in the biochemical sludge, the C source is required to be added in the aerobic pool of the third group to maintain C, N balance. In this embodiment, a sodium acetate feeding device 12 is arranged on the third aerobic tank 73 to feed sodium acetate to increase the C source.

Example 3

On the basis of the embodiment 1 and the embodiment 2, an ammonia absorption tower is added, and larger ammonia is generated in the anaerobic, anoxic and aerobic stages which are one-stage subsequent to the fecal sewage fermentation stage, and the ammonia can generate a large amount of nitrogen under the denitrification effect, and the nitrogen can cause microbial poisoning in the biochemical sludge, so the ammonia absorption tower is added to reduce the ammonia in the whole process, maintain the carbon-nitrogen balance in the biochemical sludge, maintain the elimination rate of microbial organic matters in the biochemical sludge and improve the stability of the fecal sewage treatment process.

The principles and embodiments of the present application are explained herein using specific examples, which are provided only to help understand the method and the core idea of the present application. The foregoing is only a preferred embodiment of the present application, and it should be noted that there are no specific structures which are objectively limitless due to the limited character expressions, and it will be apparent to those skilled in the art that a plurality of modifications, decorations or changes can be made without departing from the principle of the present invention, and the technical features mentioned above can be combined in a suitable manner; such modifications, variations, combinations, or adaptations of the invention in other instances, which may or may not be practiced, are intended to be within the scope of the present application.

Claims

1. The ecological treatment process of the excrement is characterized by comprising the following steps of:

obtaining a feces mixed solution;

fermenting the manure mixed liquid to obtain a first manure mixed liquid;

adjusting the pH value of the second excrement liquid to be controlled below 10 to obtain a third excrement liquid;

carrying out solid-liquid separation on the third excrement liquid to obtain primary clear liquid;

denitrifying the secondary clear liquid to obtain a tertiary clear liquid;

nitrifying the third-level clear liquid to obtain a fourth-level clear liquid;

2. The ecological fecal treatment process according to claim 1, characterized in that: and adding a flocculating agent (PAC) and a coagulant aid (PAM) into the third fecal sewage liquid to carry out solid-liquid separation.

3. The ecological fecal treatment process according to claim 1, characterized in that: adjusting the pH value of the second fecal sewage liquid by adding HCL and NaOH into the second fecal sewage liquid.

4. The ecological fecal treatment process according to claim 2, characterized in that: the concentration of PAC is 10 percent, and the concentration of PAM is 0.1 to 0.3 percent.

5. The ecological fecal treatment process according to claim 1, characterized in that: NH in the primary clear liquid₃-said quaternary supernatant is obtained by two denitrification and two said nitrations, at a concentration of N close to 600 mg/L.

6. The ecological fecal treatment process according to claim 1, characterized in that: NH in the primary clear liquid₃-said quaternary supernatant is obtained by three denitrification and three said nitrations when the N concentration is close to 800 mg/L.

7. The ecological fecal treatment process according to claim 6, characterized in that: in the third nitrification, a carbon source needs to be added to maintain a carbon-nitrogen balance.

8. The ecological fecal treatment process according to claim 1, characterized in that: and adding sodium hypochlorite into the clear water for disinfection.