CN115231781A - A sewage treatment process with low sludge yield - Google Patents

Abstract

The invention provides a sewage treatment process with low sludge yield, which relates to the technical field of sewage treatment, and includes the following steps: S1: discharge the sewage into a first-level sedimentation tank, control the pH value of the sewage to be in the range of 5-10, and configure 7.5 The flocculation solution with a concentration of %-10% is added to the sedimentation tank and mixed with the sewage; S2: put an ultrasonic generator in the sedimentation tank, and use ultrasonic waves to crack the flocculated sludge in the sewage; S3: pass the sewage into the sealed reaction tank In the first stage, hydrolysis and fermentation bacteria are added to the sewage, and the second stage is added with hydrogen-producing acetogenic bacteria; the present invention uses an ultrasonic generator to decompose the flocculated sludge, and passes three stages of hydrolysis and fermentation bacteria, hydrogen-producing bacteria, and hydrogen-producing bacteria. Acetic acid bacteria and methanogens treat the sewage, and while digesting the sludge, methane biogas is generated, and the sludge is further reduced by the action of methyl paraben. rate of more than 75%.

Description

A sewage treatment process with low sludge yield

technical field

The invention relates to the technical field of sewage treatment, in particular to a sewage treatment process with low sludge yield.

Background technique

In recent years, my country's sewage treatment work has achieved unprecedented development. Sewage treatment plants have played a huge role in solving my country's water pollution problems, and have alleviated my country's water pollution crisis to a large extent. There are more than 1,500 sewage treatment plants with a treatment scale of nearly 70 million tons per day. According to the conventional urban sewage treatment process, the excess sludge output is 2.5% of the sewage treatment volume, and the surplus wet sludge is about 1.75 million tons per day. The problem of large-scale sludge disposal has become an important technical problem in the field of urban sewage treatment.

Sludge contains a lot of toxic substances (eggs, pathogenic microorganisms, synthetic organic matter and heavy metal ions, etc.), which will cause serious pollution to the environment if handled or disposed of improperly. It is finally disposed of through incineration, sanitary landfill and land use. However, the capital investment required by the traditional disposal method is too high, which makes the sewage treatment plant embarrassed and heavy. Therefore, it is necessary to reduce the sludge production from the source of sewage treatment. Due to the wide variety of impurities in the sludge, a single treatment method has no effect on the sludge. The reduction effect is minimal, therefore, the present invention proposes a sewage treatment process with low sludge yield to solve the problems existing in the prior art.

SUMMARY OF THE INVENTION

In view of the above problems, the present invention proposes a sewage treatment process with low sludge yield. The sewage treatment process with low sludge yield has three steps of desilting, and the sludge reduction rate reaches more than 75%.

In order to achieve the purpose of the present invention, the present invention is realized through the following technical solutions: a sewage treatment process with low sludge yield, comprising the following steps:

S1: Discharge the sewage into the first-level sedimentation tank, control the pH value of the sewage in the range of 5-10, configure a flocculation solution with a concentration of 7.5%-10%, add it to the sedimentation tank, and mix it with the sewage;

S2: put an ultrasonic generator into the sedimentation tank, and use ultrasonic waves to crack the flocculated sludge in the sewage;

S3: Passing the sewage into the sealed reaction tank, adding hydrolysis and fermentation bacteria to the sewage in the first stage, adding hydrogen-producing acetogenic bacteria in the second stage, and adding methane bacteria in the third stage to generate methane biogas;

S4: pass the sewage into the secondary sedimentation tank, add methyl paraben to the sewage, and control the dosage to be 1 mg/L;

S5: Pass the sewage into the porous anion exchange resin to absorb and remove phosphorus in the sewage;

S6: put slightly acidic disinfection water into the sewage, and stir and mix;

S7: filter and adsorb the sewage, and discharge it into the collection tank for storage.

A further improvement is: in the S1, the pH value of the sewage is adjusted by adding acid or alkali, and the alkali selects the lime agent.

A further improvement is: in the S1, the preparation method of the flocculation solution is as follows: mixing modified starch and deionized water in a ratio of 1:2, adding 10% sodium citrate at 60-85 ° C, and then adding ice Acetic acid was adjusted to pH 4-5, then mixed with modified chitosan at 1.5:1, and then added with bleaching agent and divinylbenzene, and stirred at 80-85° C. to obtain a flocculation solution.

A further improvement is: in the S1, the flocculation solution is added to the sewage, and the dosage of the chemical is controlled to be 120 ppm. During the dosing process, oxygen is discharged into the sewage through the aeration pipe, and the oxygen is discharged from the pool of the first-level sedimentation tank. The bottom is aerated and discharged until the dosing is completed, the aeration is stopped, and the water body produces flocculated sludge.

A further improvement is: in the S2, an ultrasonic generator is put into the sedimentation tank, and the ultrasonic frequency is controlled to be 41 kHz. In the process of ultrasonic treatment, a heat-sensitive probe is used to detect the sludge concentration in different areas of the sewage, so as to adjust the ultrasonic generation. The position of the device is controlled, and the sludge concentration is controlled at 10-20g/L.

A further improvement is: in the S3, hydrolysis and fermentation bacteria are added to the sewage in the first stage, and the hydrolysis and fermentation bacteria include obligate anaerobic bacteria and facultative anaerobic bacteria, so that carbohydrates, proteins and fatty acids in the sewage are hydrolyzed and fermented. Into monosaccharides, amino acids, fatty acids, glycerol and carbon dioxide, hydrogen.

A further improvement is: in the S3, hydrogen-producing acetogens are added to the sewage in the second stage, and the products of the first stage are converted into hydrogen, carbon dioxide and acetic acid.

A further improvement is: in the S3, the methanogens are added in the third stage, and the methanogens select two groups of physiologically different bacteria, one group converts the hydrogen and carbon dioxide in the second stage into methane, and the other group converts the second stage bacteria. Decarboxylation of acetic acid produces methane, which produces methane biogas.

A further improvement is: in the S4, methylparaben is added to the sewage, the reaction temperature is controlled to be 20-65°C, and the reaction is stirred for 0.5-2h.

A further improvement is: in the S5, the anion exchange resin is selected as a type I quaternary amine functional group super-grade polystyrene acrylic acid strong basic anion phosphorus removal exchange resin, the regeneration agent is selected as sodium hydroxide, and the dosage of the regeneration agent is controlled to be 2BV-3BV.

The beneficial effects of the present invention are:

1. In the present invention, the flocculated sludge is decomposed by an ultrasonic generator, and the sewage is treated by three stages of hydrolysis and fermentation bacteria, hydrogen-producing acetogens and methanogens, and methane biogas is generated while digesting the sludge. The effect of methyl parahydroxybenzoate can further reduce the sludge, and the three-step sludge removal has been verified, and the sludge reduction rate has reached more than 75%.

2. The present invention has better treatment effect on sewage through the function of porous anion exchange resin and supplemented by strengthening phosphorus removal measures.

3. The present invention prepares the flocculation solution by using starch and other materials, the cost of raw materials is low, resources are saved, and it is green and environmentally friendly, and while ensuring the flocculation effect, it will not cause secondary pollution to water.

4. In the present invention, slightly acidic disinfection water is added to the sewage for disinfection, filtering and adsorption, so that the sewage reaches the direct discharge standard and the treatment is more complete.

Description of drawings

FIG. 1 is a flow chart of the present invention.

Detailed ways

In order to deepen the understanding of the present invention, the present invention will be described in further detail below with reference to the embodiments. The embodiments are only used to explain the present invention and do not constitute a limitation on the protection scope of the present invention.

Example 1

As shown in FIG. 1 , the present embodiment proposes a sewage treatment process with low sludge yield, including the following steps:

S1: Discharge the sewage into the first-level sedimentation tank, control the pH value of the sewage in the range of 5-10, configure a flocculation solution with a concentration of 7.5%-10%, add it to the sedimentation tank, and mix it with the sewage;

S2: put an ultrasonic generator into the sedimentation tank, control the ultrasonic frequency to 41kHz, and crack the flocculated sludge in the sewage;

S3: Passing the sewage into the sealed reaction tank, adding hydrolysis and fermentation bacteria to the sewage in the first stage, adding hydrogen-producing acetogenic bacteria in the second stage, and adding methane bacteria in the third stage to generate methane biogas;

S4: pass the sewage into the secondary sedimentation tank, add methyl paraben to the sewage, and control the dosage to be 1 mg/L;

S5: Pass the sewage into the porous anion exchange resin to absorb and remove phosphorus in the sewage;

S6: put slightly acidic disinfection water into the sewage, and stir and mix;

S7: filter and adsorb the sewage, and discharge it into the collection tank for storage.

In the invention, the flocculation solution is used to treat the sewage to generate flocculated sludge, and the flocculated sludge is decomposed by an ultrasonic generator, so as to carry out the first step of sludge reduction, and then through three stages of hydrolysis and fermentation bacteria, hydrogen production Acetic acid bacteria and methanogens treat the sewage, and while digesting the sludge, methane biogas is generated, which is convenient for energy utilization, so as to carry out the second step of sludge reduction, and then through the action of methyl paraben, the sludge is reduced. Further reduction, and the concentration of COD and NH+-N in the obtained water can reach the national first-class B standard, so as to carry out the third step of sludge reduction, and the sludge reduction rate is higher.

Embodiment 2

As shown in FIG. 1 , the present embodiment proposes a sewage treatment process with low sludge yield, including the following steps:

The sewage is discharged into the first-level sedimentation tank, and the pH value of the sewage is adjusted by adding acid or alkali. The alkali selects the lime agent, and the pH value of the sewage is controlled in the range of 5-10, and a flocculation solution with a concentration of 7.5%-10% is configured. , specifically: mix the modified starch and deionized water in a ratio of 1:2, add 10% sodium citrate at 60-85 ° C, then add glacial acetic acid to adjust the pH to 4-5, and then mix with the modified starch. Chitosan was mixed at 1.5:1, then added bleach and divinylbenzene, stirred at 80-85 °C to obtain a flocculation solution, added to the sedimentation tank, mixed with sewage, and the dosage of the control agent was 120ppm. In the process of using the aeration pipe to discharge oxygen into the sewage, the oxygen is aerated and discharged from the bottom of the first-level sedimentation tank until the dosing is completed, the aeration is stopped, and the water body produces flocculated sludge; The flocculation solution is prepared from materials, which has low cost of raw materials, saves resources, and is environmentally friendly. While ensuring the flocculation effect, it will not cause secondary pollution to water;

Put an ultrasonic generator into the sedimentation tank, control the ultrasonic frequency to 41kHz, and crack the flocculated sludge in the sewage. In the process of ultrasonic treatment, use the heat-sensitive probe to detect the sludge concentration in different areas of the sewage, so as to adjust the ultrasonic wave The position of the generator, the sludge concentration is controlled at 10-20g/L; the flocculated sludge is broken through the ultrasonic generator, so as to carry out the first step of sludge reduction;

The sewage is passed into the sealed reaction tank. In the first stage, hydrolysis and fermentation bacteria are added to the sewage. The hydrolysis and fermentation bacteria include obligate anaerobic bacteria and facultative anaerobic bacteria, so that carbohydrates, proteins and fatty acids in the sewage can be hydrolyzed and fermented. It is converted into monosaccharides, amino acids, fatty acids, glycerol, carbon dioxide and hydrogen. In the second stage, hydrogen-producing acetogenic bacteria are added to the sewage, and the products of the first stage are converted into hydrogen, carbon dioxide and acetic acid. In the third stage, methane bacteria are added. Methanogens select two groups of physiologically different bacteria, one group converts hydrogen and carbon dioxide in the second stage into methane, namely: 4H ₂ +CO ₂ →CH ₄ +2H ₂ O, and the other group decarboxylates the acetic acid in the second stage Methane is produced to generate methane biogas, namely: CH ₃ COOH→CH ₄ +2H ₂ O; the sewage is treated by three stages of hydrolysis and fermentation bacteria, hydrogen-producing acetogens and methanogens. While digesting the sludge, Generate methane biogas, which is convenient for energy utilization, so as to carry out the second step of sludge reduction;

The sewage is passed into the secondary sedimentation tank, and methylparaben is added to the sewage, and the dosage is controlled to 1mg/L, the reaction temperature is controlled to be 20-65°C, and the reaction is stirred for 0.5-2h; The effect of ester can further reduce the sludge, and make the COD and NH+-N concentration of the obtained water reach the national first-class B standard, so as to carry out the third step of sludge reduction;

The sewage is passed into the porous anion exchange resin to absorb and remove the phosphorus in the sewage. The anion exchange resin is selected as the I-type quaternary amine functional group super-grade polystyrene acrylic acid strong basic anion phosphorus removal exchange resin, and the regeneration agent is sodium hydroxide. Control the dosage of regenerant to 2BV-3BV; supplemented by strengthening phosphorus removal measures, the treatment effect of sewage is better;

Put slightly acidic disinfection water into the sewage, and stir and mix;

The sewage is filtered and adsorbed and discharged into the collection tank for storage. Make the sewage meet the direct discharge standard and the treatment is more perfect.

Verification example:

In the invention, the flocculation solution is used to treat the sewage to generate flocculated sludge, and the flocculated sludge is decomposed by an ultrasonic generator, so as to carry out the first step of sludge reduction, and then through three stages of hydrolysis and fermentation bacteria, hydrogen production Acetic acid bacteria and methanogens treat the sewage, and while digesting the sludge, methane biogas is generated, which is convenient for energy utilization, so as to carry out the second step of sludge reduction, and then through the action of methyl paraben, the sludge is reduced. Further reduction, and the concentration of COD and NH+-N in the obtained water can reach the national first-class B standard, so as to carry out the third step of sludge reduction, and the sludge reduction rate is higher. It is supplemented by strengthening phosphorus removal measures, and the treatment effect of sewage is better. Moreover, the present invention prepares the flocculation solution by using starch and other materials, has low cost of raw materials, saves resources, is green and environmentally friendly, and does not cause secondary pollution to water while ensuring the flocculation effect. At the same time, the present invention subsequently adds slightly acidic disinfection water to the sewage for disinfection, filtering and adsorption, so that the sewage reaches the direct discharge standard and the treatment is more complete.

The foregoing has shown and described the basic principles, main features and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited by the above-mentioned embodiments, and the descriptions in the above-mentioned embodiments and the description are only to illustrate the principle of the present invention. Without departing from the spirit and scope of the present invention, the present invention will have Various changes and modifications fall within the scope of the claimed invention. The claimed scope of the present invention is defined by the appended claims and their equivalents.

Claims (10)

1. a low sewage treatment process of sludge output, is characterized in that, comprises the following steps: S1: Discharge the sewage into the first-level sedimentation tank, control the pH value of the sewage in the range of 5-10, configure a flocculation solution with a concentration of 7.5%-10%, add it to the sedimentation tank, and mix it with the sewage; S2: put an ultrasonic generator into the sedimentation tank, and use ultrasonic waves to crack the flocculated sludge in the sewage; S3: Passing the sewage into the sealed reaction tank, adding hydrolysis and fermentation bacteria to the sewage in the first stage, adding hydrogen-producing acetogenic bacteria in the second stage, and adding methane bacteria in the third stage to generate methane biogas; S4: pass the sewage into the secondary sedimentation tank, add methyl paraben to the sewage, and control the dosage to be 1 mg/L; S5: Pass the sewage into the porous anion exchange resin to absorb and remove phosphorus in the sewage; S6: put slightly acidic disinfection water into the sewage, and stir and mix; S7: filter and adsorb the sewage, and discharge it into the collection tank for storage. 2 . The sewage treatment process with low sludge yield according to claim 1 , wherein: in the S1 , the pH value of the sewage is adjusted by adding acid or alkali, and the alkali selects lime medicament. 3 . 3. The sewage treatment process with low sludge yield according to claim 2, wherein: in the S1, the preparation method of the flocculation solution is: the modified starch and deionized water are in a ratio of 1:2 Mix, add 10% sodium citrate at 60-85℃, then add glacial acetic acid to adjust pH to 4-5, then mix with modified chitosan 1.5:1, then add bleach and divinylbenzene , at 80-85 °C, stirring to obtain a flocculation solution. 4. The sewage treatment process with low sludge yield according to claim 3, wherein in the S1, the flocculation solution is added to the sewage, and the dosage of the control agent is 120 ppm, and in the process of dosing , use the aeration pipe to discharge oxygen into the sewage, and the oxygen is discharged from the bottom of the first-level sedimentation tank by aeration upwards, until the dosing is completed, the aeration is stopped, and the water body produces flocculated sludge. 5. a kind of sewage treatment process with low sludge output according to claim 1, is characterized in that: in described S2, put into ultrasonic generator in sedimentation tank, control ultrasonic frequency to be 41kHz, in the process of ultrasonic treatment , use the thermal probe to detect the sludge concentration in different areas in the sewage, so as to adjust the position of the ultrasonic generator, and control the sludge concentration to 10-20g/L. 6. The sewage treatment process with low sludge yield according to claim 1, characterized in that: in the S3, hydrolysis and fermentation bacteria are added to the sewage in the first stage, and the hydrolysis and fermentation bacteria include obligate anaerobic bacteria Bacteria and facultative anaerobic bacteria make the carbohydrates, proteins and fatty acids in the sewage hydrolyzed and fermented into monosaccharides, amino acids, fatty acids, glycerol, carbon dioxide and hydrogen. 7. the low sewage treatment process of a kind of sludge output according to claim 6, is characterized in that: in described S3, the second stage adds hydrogen-producing acetogenic bacteria to sewage, and the product of the first stage is converted into Hydrogen, carbon dioxide and acetic acid. 8. The sewage treatment process with low sludge yield according to claim 7, characterized in that: in said S3, methanogens are added in the third stage, and methanogens select two groups of physiologically different bacteria, one group The hydrogen and carbon dioxide in the second stage are converted into methane, and the other group decarboxylates the acetic acid in the second stage to produce methane, which generates methane biogas. 9. a kind of sewage treatment process with low sludge output according to claim 1, is characterized in that: in described S4, add methylparaben to sewage, control reaction temperature to be 20-65 ℃, stir Reaction 0.5-2h. 10. The sewage treatment process with a low sludge yield according to claim 1, characterized in that: in the S5, the anion exchange resin selects the super-grade polystyrene acrylic acid strong basic anion of the I-type quaternary amine functional group to remove the Phosphorus exchange resin, the regeneration agent is sodium hydroxide, and the dosage of the regeneration agent is controlled to be 2BV-3BV.

Images