CN113526801A

CN113526801A - Wood vinegar and biomass charcoal combined sewage treatment method

Info

Publication number: CN113526801A
Application number: CN202110909809.6A
Authority: CN
Inventors: 宋祥云; 刘东锋; 于桂玲; 柳新伟; 崔德杰; 安琪; 王敬宽
Original assignee: Qingdao Agricultural University
Current assignee: Qingdao Agricultural University
Priority date: 2021-08-09
Filing date: 2021-08-09
Publication date: 2021-10-22

Abstract

The invention discloses a sewage treatment method combining wood vinegar and biomass charcoal, belonging to the technical field of environmental protection and comprising the following steps: the sewage enters a grid to remove suspended matters; the effluent enters a desilting basin through a lifting pump room, and particles with larger specific gravity are removed; primary precipitation; adding wood vinegar which is diluted by 900 times into water generated by primary precipitation, and carrying out biological treatment after stirring treatment; the effluent enters a secondary sedimentation tank to remove suspended matters; coagulating sedimentation, carrying out primary filtration, and adding biomass charcoal into the filtered solution: then, secondary filtration is carried out: removing solid matters in the water to obtain water; disinfecting the effluent and discharging; the sludge and flocculates are pumped into a sludge storage tank, and are transported out after dehydration treatment, the wood vinegar is added into the sludge storage tank, so that the sludge storage tank can effectively sterilize and inhibit bacteria, the biomass charcoal can well adsorb pollutants and odor in the sewage, the effect is obvious, and the market prospect is wide.

Description

Wood vinegar and biomass charcoal combined sewage treatment method

Technical Field

The invention belongs to the technical field of environmental protection, and particularly relates to a sewage treatment method combining wood vinegar and biomass charcoal.

Background

With the increase of population and the shortage of fresh water resources, the basic contradiction between population and water resources is increasingly intensified, so that the efficient recycling of water resources is imperative. The industrial equipment and process for treating sewage in China can be divided into: former sewage filters some large-scale wastes through the grid preliminary filtration, for example plastic bag, plastic bottle and branch leaf etc. then gets into primary sedimentation tank, and the purpose is for getting rid of the great solid suspended particle of density in the sewage, makes tiny suspended particle flocculation become great granule simultaneously and can promote purifying effect. The next step is biological treatment, and the main designed flow is a biological rotating disc process. The treatment method can make micro-animals such as bacteria, fungus microorganisms and protozoa grow and breed on the biological rotating disc filler carrier to form a biological film. After the sewage is primarily treated by the sedimentation tank, the sewage is contacted with the biological membrane, and microorganisms on the biological membrane absorb organic pollutants in the sewage as nutrition, so that the sewage is purified. The return sludge is one of the biological adsorption methods, and is characterized in that two processes of degradation adsorption and metabolic degradation of organic matters by activated sludge are respectively carried out in respective reactors (an adsorption tank and a regeneration tank). The method can fully improve the concentration of the activated sludge and reduce the ratio of organic nutrients to microorganisms, and uses the physical adsorption effect of the activated sludge. Then adding coagulant into the treated sewage, so that the colloid and dispersed particles of the suspended matter collide with each other and are coagulated into floccules under the action of molecular attraction force, the size and the mass of the floccules are continuously increased in the sedimentation process, and the sedimentation speed is increased along with the depth. After the precipitate generated by flocculation is removed by means of filtration again and the like. Finally, disinfection treatment is carried out, and sewage disinfection is a water treatment process for killing harmful pathogenic microorganisms in a sewage treatment system. Not only are a large number of bacterial viruses present in the wastewater, but they cannot be killed by the normal wastewater treatment process. The common biological filter in the urban sewage treatment system can only remove 80-90% of escherichia coli, and the activated sludge method can only remove 90-95%. In order to prevent the spread of diseases, the sewage is generally subjected to secondary mechanical and biochemical treatment and still needs to be disinfected, and the commonly used disinfection treatment methods comprise: chlorine disinfection, ozone disinfection, ultraviolet disinfection, and the like. Finally, the effluent can be applied to thousands of households after the water quality is qualified. It can be seen that the important operations for removing the pollutants from the water are only concentrated in two parts of precipitation and biological treatment, and the treatment process is single and is not suitable for removing various pollutants.

Disclosure of Invention

Aiming at various defects in the prior art, a method for treating sewage by combining wood vinegar with biomass charcoal is provided.

In order to achieve the purpose, the invention provides the following technical scheme:

a wood vinegar and biomass charcoal combined sewage treatment method comprises the following steps:

(1) the sewage enters a grid to remove suspended matters;

(2) the effluent enters a desilting basin through a lifting pump room, particles with larger specific gravity are removed, and the normal operation of the subsequent treatment structure is ensured;

(3) primary precipitation: the effluent obtained in the step (2) enters a primary sedimentation tank, solid suspended matters with large specific gravity and mainly containing inorganic matters in the sewage are precipitated and separated, pyroligneous liquor diluted by 900 times is added into the water generated by primary sedimentation, and the mixture is stirred;

(4) biological treatment;

(5) the effluent after biological treatment enters a secondary sedimentation tank to remove suspended matters;

(6) coagulating sedimentation: adding a flocculating agent into the effluent obtained in the step (5) for flocculating and precipitating;

(7) primary filtration: removing flocculate in the step (6) to obtain water, and adding biomass charcoal into the effluent;

(8) secondary filtration: removing the solid matters in the step (7) to obtain water;

(9) and (3) disinfection: and (4) disinfecting the effluent water in the step (8) and then discharging, pumping the sludge and flocculate into a sludge storage pool, dehydrating and transporting the sludge and flocculate out.

Preferably, in the step (4), the biological treatment adopts an activated sludge method.

Preferably, in the step (3), the wood vinegar is added to be 5uL/L of effluent.

Preferably, the water temperature of the water generated by primary precipitation is 19-21 ℃.

Preferably, in the step (3), the stirring speed is 10r/min, and the stirring time is 30 minutes.

Preferably, when the biomass charcoal is added in the step (7), the water temperature is 20-25 ℃,

preferably, the input amount of the biomass charcoal in the step (7) is 0.09-0.12 g/L of effluent.

Preferably, in the step (7), the biomass charcoal is added, then the stirring speed is 110r/min, the stirring time is 30min, the mixture is kept stand for 45-55min, and then the mixture is filtered.

Preferably, the width of the grid strip gap of the grid is 0.03m, the inclination angle of the grid is 70 degrees, and the width of the grid strip is 0.01 m.

Preferably, the step (2) adopts a horizontal flow type grit chamber, and the hydraulic retention time is 30 s.

The invention has the beneficial effects that:

1. the wood vinegar liquid can increase the yield and endogenous metabolic coefficient of the microorganism, increase the yield more obviously, reduce the saturation constant of the matrix obviously and increase the maximum specific degradation rate obviously, thereby reducing the reaction difficulty of degrading and converting the matrix by the microorganism and improving the removal rate of the system to pollutants.

2. The three organic matters with the highest content in the pyroligneous liquor are respectively acid, phenol and ketone, and the acetic acid can promote the removal of various pollutants; phenol can promote the removal of nitrogen-containing pollutants; the hydroxy acetone can promote the removal of organic matters, TN and TP; the acetic acid-phenol can promote the removal of COD, nitrogen-containing pollutants and phosphorus-containing pollutants; the hydroxyacetone acetate can promote the removal of various pollutants; the phenol-hydroxyacetone can promote the removal of organic matters and phosphorus-containing pollutants; the three components of acetic acid-phenol-hydroxyacetone can promote organic matters and NH₃-removal of N and TP.

2. The biomass carbon has a developed pore structure and a large specific surface area, the carbon surface has rich functional groups, surface charges and other physical and chemical properties, multiple hydrophobic organic pollutants such as polycyclic aromatic hydrocarbons, organic pesticides and the like and inorganic pollutants such as heavy metals and the like can be effectively adsorbed, the bioavailability of the pollutants by animals and plants is reduced, and the effect of removing the odor and the color of sewage is remarkable.

3. The wood vinegar and the biomass charcoal are low in price and easy to purchase.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

The first embodiment is as follows:

a wood vinegar and biomass charcoal combined sewage treatment method comprises the following steps: the sewage enters a grid to remove large suspended matters; the effluent enters a desilting tank through a lifting pump room, and particles with larger specific gravity, such as sand, coal cinder and the like, are removed from the sewage, so that the normal operation of the subsequent treatment structure is ensured; the effluent enters a primary sedimentation tank for primary sedimentation, solid suspended matters with large specific gravity and mainly inorganic matters in the sewage are precipitated and separated, pyroligneous liquor which is diluted by 900 times is added into the water generated by primary sedimentation, the added pyroligneous liquor is 5uL/L effluent, the water temperature of the water generated by primary sedimentation is 19-21 ℃, and stirring treatment is carried out, wherein the stirring speed is 10 r/min; the effluent added with the pyroligneous liquor is subjected to biological treatment, in the embodiment, the biological treatment adopts an activated sludge method.

The activated sludge method is characterized in that air is continuously blown into sewage in an aeration tank, and after 6 hours, activated sludge consisting of aerobic microbial floccules and the like is formed in the water, and the activated sludge can adsorb and decompose organic matters in the water, obtain energy and continuously grow and reproduce. And finally, the sewage, namely mixed liquor which flows out of the aeration tank and contains a large amount of activated sludge enters a sedimentation tank for sedimentation and separation, then clarified water is discharged, the sludge separated by sedimentation serves as seed sludge and partially flows back to the aeration tank, and the rest (proliferation) part is discharged from the sedimentation tank.

The effluent after biological treatment enters a secondary sedimentation tank to remove suspended matters; adding a flocculating agent into the discharged water from the secondary sedimentation tank, flocculating and performing flocculating settling; performing primary filtration on the substances subjected to flocculation precipitation, removing flocculates to obtain effluent, adding biomass charcoal into the effluent, adding the biomass charcoal into the effluent, stirring at a speed of 110r/min after adding the biomass charcoal, and standing for 45-55min to obtain the effluent, wherein the water temperature is 20-25 ℃, the input amount of the biomass charcoal is 0.09-0.12 g/L, and the effluent is filtered; performing secondary filtration on the effluent obtained after adding the biomass charcoal to obtain effluent; discharging the effluent after disinfecting; the sludge and flocculate are pumped into a sludge storage pool, dewatered and transported out.

The width of the grid bar gap of the grid is 0.03m, the inclination angle of the grid is 70 degrees, and the width of the grid bar is 0.01 m. The sand basin adopts a horizontal flow type sand basin, and the hydraulic retention time is 30 s.

Example two

The effluent after biological treatment enters a secondary sedimentation tank to remove suspended matters; adding a flocculating agent into the discharged water from the secondary sedimentation tank, flocculating and performing flocculating settling; performing primary filtration on the substances subjected to flocculation precipitation, removing flocculates to obtain effluent, adding biomass charcoal into the effluent, adding the biomass charcoal into the effluent, stirring at a stirring speed of 110r/min after the water temperature is 20-25 ℃ and the input amount of the biomass charcoal is 0.11g/L, standing for 50min, and filtering to obtain the effluent; performing secondary filtration on the effluent obtained after adding the biomass charcoal to obtain effluent; discharging the effluent after disinfecting; the sludge and flocculate are pumped into a sludge storage pool, dewatered and transported out.

EXAMPLE III

The effluent after biological treatment enters a secondary sedimentation tank to remove suspended matters; adding a flocculating agent into the discharged water from the secondary sedimentation tank, flocculating and performing flocculating settling; performing primary filtration on the substances subjected to flocculation precipitation, removing flocculates to obtain effluent, adding biomass charcoal into the effluent, adding the biomass charcoal into the effluent, stirring at a stirring speed of 110r/min after the water temperature is 20-25 ℃ and the input amount of the biomass charcoal is 0.12g/L, standing for 55min, and filtering to obtain the effluent; performing secondary filtration on the effluent obtained after adding the biomass charcoal to obtain effluent; discharging the effluent after disinfecting; the sludge and flocculate are pumped into a sludge storage pool, and sludge cakes are transported outside after dehydration treatment.

Test examples

Control group: the sewage enters a grid to remove large suspended matters; the effluent enters a desilting tank through a lifting pump room, and particles with larger specific gravity, such as sand, coal cinder and the like, are removed from the sewage, so that the normal operation of the subsequent treatment structure is ensured; and (3) allowing effluent to enter a primary sedimentation tank for primary sedimentation, carrying out sedimentation separation on solid suspended matters with large specific gravity mainly comprising inorganic matters in sewage, taking water generated by primary sedimentation as reference liquid, and keeping the temperature of the reference liquid at 19-21 ℃ without any treatment.

Test group one: adding 900 times diluted wood vinegar into the above control solution, wherein the added wood vinegar is 5uL/L (control solution) of effluent, and adding 0.06g/L of biomass charcoal.

Test group two: adding 900 times diluted wood vinegar into the above control solution, wherein the added wood vinegar is 5uL/L (control solution) of effluent, and adding 0.09g/L of biomass charcoal.

Test group three: adding 900 times diluted wood vinegar into the above control solution, wherein the added wood vinegar is 5uL/L (control solution) of effluent, and adding 0.12g/L biomass charcoal.

The wood vinegar is named as wood element and is produced by salary biomass energy limited company in Boxing county of Shandong province.

The first table shows the data of the sewage after the control solution is kept stand for one hour, and the pyroligneous solution is added into the first test group, the second test group and the third test group, and then the sewage is treated at the stirring speed of 10r/min and the stirring time of 30 min. And the second table shows that the control solution is kept stand for one hour, the pyroligneous liquor is added into the first test group, the second test group and the third test group, the stirring speed is 10r/min, the stirring time is 30min, the biomass charcoal is added, the stirring speed is 110r/min, the stirring time is 30min, and after the standing is 45-55min, all the four groups are filtered by quantitative filter paper, so that four groups of filtrate are obtained and used for parameter measurement.

Watch 1

Watch two

The BOD was measured by a five-day biochemical oxygen demand BOD5 dilution inoculation method (HJ505-2008), and it was found that the concentration of the wastewater containing biochar was different from that of the control group, and as a result, the treatment effect was better in the test group II at 0.09g/L biochar.

The COD is measured by adopting a potassium permanganate method (GB11892-89), and the COD content in the sewage is gradually reduced along with the addition of the biomass carbon, so that the COD content in the sewage can be effectively reduced by adding the biomass carbon.

The ammonia nitrogen is measured by a distillation-neutralization titration method (HJ 537-.

The pH is measured by adopting a pH agent, data is recorded after the value is stable, and the pH is gradually reduced along with the addition of the biomass charcoal.

TDS's survey adopts the survey that TDS water quality testing pen goes on, treats the stable back record data of numerical value. The TDS value showed a tendency to increase with the addition of biomass char.

The conductivity is measured by a water quality detector, and data is recorded after the numerical value is stable. The value of the conductivity also shows a tendency to increase with the addition of biomass char.

Furthermore, it should be understood that although the present description refers to embodiments, not every embodiment may contain only a single embodiment, and such description is for clarity only, and those skilled in the art should integrate the description, and the embodiments may be combined as appropriate to form other embodiments understood by those skilled in the art.

Claims

1. A wood vinegar and biomass charcoal combined sewage treatment method is characterized by comprising the following steps:

(1) the sewage enters a grid to remove suspended matters;

(4) biological treatment;

2. The method according to claim 1, wherein in the step (4), the biological treatment is performed by an activated sludge process.

3. The method according to claim 1, wherein in the step (3), the wood vinegar is added in an amount of 5uL/L of effluent.

4. The method according to claim 1, wherein in the step (3), the water temperature of the water generated by the primary precipitation is 19-21 ℃.

5. The method according to claim 4, wherein in the step (3), the stirring rate is 10r/min and the stirring time is 30 minutes.

6. The method of claim 1, wherein the water temperature is 20-25 ℃ when adding the biomass char in step (7).

7. The method according to claim 6, wherein the input amount of the biomass charcoal in the step (7) is 0.09-0.12 g/L of effluent.

8. The method as claimed in claim 7, wherein in the step (7), the stirring speed is 110r/min after the biomass charcoal is added, the stirring time is 30min, the mixture is kept stand for 45-55min, and then the mixture is filtered.

9. The method of claim 1, wherein the grid has a gap width of 0.03m, a grid tilt angle of 70 °, and a grid width of 0.01 m.

10. The method of claim 1, wherein step (2) is performed using a horizontal flow grit chamber with a hydraulic retention time of 30 s.