CN113233579A

CN113233579A - Strengthening method and device for aerobic sludge granulation

Info

Publication number: CN113233579A
Application number: CN202110420891.6A
Authority: CN
Inventors: 刘喆; 成林珊; 徐信琪; 刘永军
Original assignee: Xian University of Architecture and Technology
Current assignee: Xian University of Architecture and Technology
Priority date: 2021-04-19
Filing date: 2021-04-19
Publication date: 2021-08-10

Abstract

The invention discloses an enhancing method and a device for aerobic sludge granulation, wherein the enhancing method comprises the following steps: fixing the pre-obtained aeromonas hydrophila by charcoal adsorption to obtain treated aeromonas hydrophila; and (3) putting the treated aeromonas hydrophila into the muddy water mixed solution of the aerobic sludge, and enhancing the quorum sensing of microorganisms in the aerobic sludge by using AHLs (AHLs) signal molecules secreted by the aeromonas hydrophila to increase the particle size of the granular sludge. The strengthening method or the strengthening device for aerobic sludge granulation provided by the invention can solve the technical problems of low aerobic sludge granulation efficiency and high strengthening cost in the prior art; the existence of the signal molecules can strengthen the induction effect of microorganism bodies and promote the combination and aggregation among sludge microorganisms, so that microorganism aggregates are formed, the particle size of aerobic granular sludge is increased, the structure is more compact, and the granulation speed of the aerobic sludge is accelerated.

Description

Strengthening method and device for aerobic sludge granulation

Technical Field

The invention belongs to the technical field of wastewater treatment, and particularly relates to an enhancing method and device for aerobic sludge granulation.

Background

Compared with the conventional activated sludge method, the aerobic granular sludge technology has the advantages of good sedimentation performance, high microbial biomass, strong strain capacity on organic load impact and the like, so that the aerobic granular sludge technology is widely concerned, but the engineering application of the aerobic granular sludge is still limited due to the long granulation period because the formation mechanism of the granular sludge is not clear.

In recent years, a technology for strengthening formation of aerobic granular sludge through a microbial quorum sensing effect has attracted general attention, but the currently realized method mainly comprises the steps of directly adding an exogenous signal molecule; the existing adding mode has the following defects: the signal molecules put into the system are easily degraded and cannot realize long-term positive effect; the cost of adding exogenous signal molecules is high, and the wide application of the exogenous signal molecules in practice is limited.

In view of the above, a new method and apparatus for enhancing the rapid granulation of aerobic sludge is needed.

Disclosure of Invention

The invention aims to provide an enhancing method and device for aerobic sludge granulation, which aim to solve the technical problems of low aerobic sludge granulation efficiency and high enhancing cost.

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

the invention relates to a strengthening method for aerobic sludge granulation, which comprises the following steps:

fixing the pre-obtained aeromonas hydrophila by charcoal adsorption to obtain treated aeromonas hydrophila;

and (3) putting the treated aeromonas hydrophila into the muddy water mixed solution of the aerobic sludge, and enhancing the quorum sensing of microorganisms in the aerobic sludge by using AHLs (AHLs) signal molecules secreted by the aeromonas hydrophila to increase the particle size of the granular sludge.

In a further improvement of the invention, the AHLs signal molecules are C4-HSL and C6-HSL signal molecules.

The invention is further improved in that when the treated aeromonas hydrophila is put into the sludge-water mixed liquid of the aerobic sludge, the volume ratio of the carrier formed by immobilizing the aeromonas hydrophila by utilizing the biochar to the sludge-water mixed liquid of the aerobic sludge is 1: 30.

the further improvement of the invention is that the step of adsorbing and fixing the pre-obtained aeromonas hydrophila by charcoal to obtain the treated aeromonas hydrophila specifically comprises the following steps:

inoculating the pre-obtained aeromonas hydrophila into an LB liquid culture medium, and culturing at the temperature of 30 ℃ at 170r/min until OD600 is 1.0;

centrifugally collecting thalli, washing the thalli with sterile water, and suspending the thalli in the sterile water to obtain a seed solution;

adding biochar using rice hulls as a raw material into the seed liquid, adsorbing and fixing thalli on the surface of the biochar at the temperature of 30 ℃ at 150r/min, filtering after a preset time, and leaching the biochar with sterile water to obtain the treated aeromonas hydrophila.

The invention relates to an enhancing device for aerobic sludge granulation, which comprises:

the fixing processing unit is used for fixing the pre-acquired aeromonas hydrophila through charcoal adsorption to obtain processed aeromonas hydrophila;

and the strengthening unit is used for throwing the treated aeromonas hydrophila into the muddy water mixed liquid of the aerobic sludge, and strengthening the quorum sensing of microorganisms in the aerobic sludge by using AHLs signal molecules secreted by the aeromonas hydrophila so as to increase the particle size of the granular sludge.

In the strengthening unit, AHLs signal molecules are C4-HSL and C6-HSL signal molecules.

In a further improvement of the present invention, in the enhancing unit, when the treated aeromonas hydrophila is introduced into the sludge-water mixed solution of the aerobic sludge, the volume ratio of the carrier formed by immobilizing the aeromonas hydrophila by the biochar to the sludge-water mixed solution of the aerobic sludge is 1: 30.

in a further improvement of the present invention, in the immobilization processing unit, the step of immobilizing the pre-obtained aeromonas hydrophila by charcoal adsorption to obtain the processed aeromonas hydrophila specifically includes:

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

in the invention, aeromonas hydrophila (Aeromonas hydrophila ATCC7966) capable of secreting AHLs signal molecules is selected, the aeromonas hydrophila is immobilized through a biochar base, the obtained carrier is put into an aerobic sludge granulation reaction system, the signal molecules can enhance the induction effect of microorganisms and promote the combination and aggregation among sludge microorganisms, so that microorganism aggregates are formed, the particle size of aerobic granular sludge is increased, the structure is more compact, and the aerobic sludge granulation speed is accelerated. Among them, Aeromonas hydrophila (Aeromonas hydrophylla ATCC7966) capable of secreting AHLs signal molecules can be purchased from Beijing Baiohobowenwei Biotechnology Ltd. The invention realizes the reinforcement of aerobic sludge granulation by a biological reinforcement mode, and has the advantages that aeromonas hydrophila (ATCC 7966) capable of secreting signal molecules is added, so that the quorum sensing effect of sludge microorganisms is enhanced by the biological reinforcement mode, and experimental results show that the particle size of a reinforcement group is increased by 30.84 mu m compared with that of a control group, the removal rate of COD is increased by 7.12%, the removal rate of total nitrogen is increased by 7.79%, the removal rate of total phosphorus is increased by 13%, the particle size of granular sludge is increased, particles are rapidly formed, the quality of effluent is improved, and the cost is greatly saved. In the invention, the biological carbon is adopted to immobilize the strains and put the strains into a sewage treatment process for reinforcement, so that the loss of signal molecules in a reactor caused by directly adding the strains can be avoided, and the continuous and effective function effect of the strains is ensured.

In the invention, the strain A-L3 capable of secreting C4-HSL and C6-HSL signal molecules is added, and the added strain A-L3 effectively strengthens the quorum sensing effect in the sewage, increases the particle size of the granular sludge, increases the content of suspended matters, makes the sludge structure more compact and quickly forms particles; the addition of the strain A-L3 can improve the quorum sensing effect of microorganisms in the sludge, improve the metabolic activity of the microorganisms and accelerate enzymatic reaction, so that the removal efficiency of Chemical Oxygen Demand (COD), Total Nitrogen (TN) and Total Phosphorus (TP) is improved, and the quorum sensing effect is enhanced by the strain A-L3, so that the effluent quality is improved. Thereby improving the treatment efficiency of the whole sewage treatment system. The cheap culture cost and the adding method of the bacterial strain enable the bacterial strain to be really and widely applied to actual sewage treatment, compared with the periodic signal molecule adding, the secretory strain only needs to be added once, and can keep the signal molecules to continuously and stably secrete C4-HSL and C6-HSL signal molecules, so that the efficient, convenient, economical and applicable A-L3 carrier type adding method can be suitable for various sewage treatment systems, and the sustainable development concept of resource conservation, efficient circulation, green economy and environmental protection conservation is really met.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art are briefly introduced below; it is obvious that the drawings in the following description are some embodiments of the invention, and that for a person skilled in the art, other drawings can be derived from them without inventive effort.

FIG. 1 is a schematic view of an enhanced granulation reaction apparatus in an example of the present invention;

FIG. 2 is a graph showing the content of C4-HSL in examples of the present invention;

FIG. 3 is a graph showing the content of C6-HSL in examples of the present invention;

FIG. 4 is a schematic representation of the average particle size of particulate matter in an embodiment of the present invention;

FIG. 5 is a schematic diagram showing the configuration of the aerobic granular sludge of the control group in the example of the present invention;

FIG. 6 is a schematic diagram of the configuration of aerobic granular sludge in the enhanced group in the embodiment of the present invention;

FIG. 7 is a schematic diagram of a sludge volume index in an example of the present invention;

FIG. 8 is a schematic diagram of the settling velocity of sludge in the example of the present invention;

in the figure, 1, a water inlet pump; 2. a liquid level meter; 3. an electromagnetic valve; 4. an electric cabinet; 5. an air flow meter; 6. an aeration pump; 7. and a sampling port.

Detailed Description

In order to make the purpose, technical effect and technical solution of the embodiments of the present invention clearer, the following clearly and completely describes the technical solution of the embodiments of the present invention with reference to the drawings in the embodiments of the present invention; it is to be understood that the described embodiments are only some of the embodiments of the present invention. Other embodiments, which can be derived by one of ordinary skill in the art from the disclosed embodiments without inventive faculty, are intended to be within the scope of the invention.

Referring to fig. 1, an apparatus for enhancing fast granulation of aerobic sludge according to an embodiment of the present invention includes: the device comprises a water inlet pump 1, a liquid level meter 2, an electromagnetic valve 3, an electric cabinet 4, an air flow meter 5, an aeration pump 6 and a sampling port;

wherein, strengthen granulation reaction unit and carry into in matrix to strengthening the granulation groove by intake pump 1, strengthen the bottom in granulation groove and connect aeration pump 6 and carry out the aeration, still even have air flow meter 5 to control aeration intensity and dissolved oxygen concentration between aeration pump and tank bottom, the liquid level height of in-process of intaking is controlled to the inslot level gauge 2 in addition, whole device realizes the automated control of each part operation and supplies power through solenoid valve 3 through electric cabinet 4, gather the sample through the sample connection at last.

In the working process of the device of the embodiment of the invention: a sequencing batch reactor was used and two sets of cylindrical experimental equipment (SBR1 and SBR2) were operated. Each SBR column is 45cm high, 10cm internal diameter, 3L working volume. Both the SBR1 reactor (control) and the SBR2 reactor (enhanced) were operated in a 6h cyclic alternating anaerobic/aerobic sequencing batch reactor. The circulation consists of feeding water for 5min, stirring for 60min under anaerobic condition, aerating (corresponding sedimentation time) at the bottom of the reactor for 287-285 min, precipitating for 3-5 min, and discharging for 5 min. NaHCO3 was added to control the pH of the suspension to 6.5; the temperature is maintained at 25 +/-1 ℃; the content of Dissolved Oxygen (DO) is kept at 3-5 mg/L.

Referring to fig. 2 to 8, a method for enhancing rapid granulation of aerobic sludge according to an embodiment of the present invention includes the following steps:

aeromonas hydrophila (Aeromonas hydrophila ATCC7966) capable of secreting AHLs signal molecules was purchased from Baiohobwei Biotechnology Ltd, Beijing; the aeromonas hydrophila ATCC7966 is deposited as bio-05668, and then the aeromonas hydrophila ATCC7966 after being adsorbed and fixed by charcoal is put into a reaction system, and the quorum sensing of microorganisms in sludge can be enhanced by using signal molecules C4-HSL and C6-HSL secreted by A-L3, so that the particle size of the granular sludge is increased, and the aerobic sludge is rapidly granulated.

The steps of obtaining the strain of the embodiment of the invention specifically comprise:

(1) purchasing of strains: aeromonas hydrophila (Aeromonas hydrophilus ATCC7966) capable of secreting AHLs signal molecules was purchased from Beijing Baiohobowenwei Biotechnology Ltd.

(2) Identification of the signal molecule: aeromonas hydrophila (Aeromonas hydrophila ATCC7966) capable of secreting AHLs signal molecules was purchased.

Specifically, the present example utilized high performance liquid chromatography-ion trap-time of flight mass spectrometry of the Shimadzu corporation, Japan, for AHLs-like signal molecules secreted by the strain A-L3. 13 AHLs signal molecules of different molecular weights were selected as target compounds. Mobile phase a was ultrapure water containing 0.1% formic acid, mobile phase B was chromatographic grade acetonitrile containing 0.1% formic acid; the chromatographic column used was a C18 column, the temperature of the chromatographic column was set at 40 ℃, the flow rate of the mobile phase was 0.2mL/min, and the injection volume was 10. mu.L. The elution procedure for liquid chromatography was: stabilizing 10% B for 5min, increasing the concentration of the solvent B to 100% when 20min, maintaining for 2min, and acquiring data in a full scan mode to obtain a primary mass spectrogram of AHLs secreted by the strain A-L2. The reporter strain CV026 can produce purplish rhzomorph, and can detect signal molecules with side chain carbon chain lengths of C4-HSL to C8-HSL; a136 contains Ptral-lacZ fusion gene and expresses lacZ gene, when AHLs signal molecules of C4-HSL to C14-HSL or 3-oxo-C4-HSL to 3-oxo-C12-HSL exist in the environment, the reporter strain can generate color reaction, and the color is changed into green.

(3) Growth characteristics of the strain: (QS) measurement of growth curves of secretors: selecting a strain from the inclined plane in an aseptic operation platform, inoculating the strain into an LB liquid culture medium, and carrying out shake culture at the constant temperature of 37 ℃. Taking LB culture medium without adding bacteria liquid as blank control, measuring absorbance value of the culture liquid every 6h under the condition that the wavelength of a spectrophotometer is 600nm, and continuously sampling for 48 h. And drawing a growth curve of the dominant polycyclic aromatic hydrocarbon degrading bacteria by taking the culture time as an abscissa and the turbidity of the culture solution as an ordinate so as to observe the growth cycle of the bacteria.

(4) Adding a strain, and performing biological enhancement: after sludge culture for 7 days, the selected strains were added to the enhanced group 1 time per week, and the control group and the enhanced group were cultured under the same conditions. The specific detailed steps are as follows: 60 ml (60 ml/3000 ml 1:30, volume ratio 1:30) of strain suspension culture was centrifuged at 30 ℃ to OD6002.0 LB liquid medium in a high speed centrifuge for 5 minutes at 8000rpm to remove supernatant and residual bacteria was added to the boost group feeding period.

(5) The biochar using rice hulls as raw materials for microbial immobilization is prepared by calcining the rice hulls at 500 ℃, selecting and inoculating purchased aeromonas hydrophila (Aeromonas hydrophila ATCC7966) into 200mL LB liquid medium (g/L: tryptone 10.0, yeast extract 5.0, NaCl 10.0, pH 7.0-7.5) and culturing at 170r/min and 30 ℃ until OD600 is 1.0 (measured by an ultraviolet spectrophotometer). The cells were collected by centrifugation (12000r/min, 3min), washed with sterile water (repeated twice), and finally resuspended in 200mL of sterile water, which was the seed solution. 2g of rice hull is added into 200mL of seed liquid, bacteria are adsorbed and fixed on the surface of the rice hull (150r/min, 30 ℃), and after 24h, the filtration is carried out, and the biochar is leached by sterile water, so that the biochar-based microorganism immobilized body prepared by an adsorption method is obtained.

In the embodiment of the invention, in order to determine the optimal adding amount of the strain A-L3, a preliminary experiment is firstly carried out to obtain the corresponding relation between the adding amount of the strain A-L3 and the influence of aerobic granular sludge formation. The data shown in Table 1 are the content of secreted signal molecules C4-HSL and C6-HSL, the particle size of granular sludge, SVI30, and the content of MLSS measured after the granular sludge was cultured to maturity. The volume ratio of 1:30 is determined by comprehensively comparing the physicochemical properties of the sludge.

Table 1 relationship between the amount of added strain and the physicochemical properties of sludge during the preliminary test

Referring to FIG. 2 and FIG. 3, FIG. 2 and FIG. 3 show the content change of signal molecules C4-HSL and C6-HSL in the control group and the enhanced group after adding the strain A-L3 in the embodiment of the present invention; it can be seen from FIGS. 2 and 3 that the signal molecules C4-HSL and C6-HSL are increased, and although the signal molecules are increased in both the control group and the enhanced group, the increase is more significant in the enhanced group. At 7 days, the contents of C4-HSL and C6-HSL were comparable in the homogeneous phase in the control and the enhanced groups; at 28 days, the contents of C4-HSL and C6-HSL in the fortified group were significantly greater than those in the control group, and at 42 days, the contents of C4-HSL and C6-HSL in the control group and the fortified group reached the maximum values. The maximum content of C4-HSL in the two systems is 58.87 and 75.22mg/L respectively. The maximum content of C6-HSL is 35.68 mg/L and 42.98mg/L respectively, and it can be seen that the content of C4-HSL in the system is obviously increased after the biological strengthening, thereby being beneficial to enhancing the quorum sensing effect among sludge microorganisms. Is favorable for strengthening the quorum sensing effect of the microorganisms in the sludge.

Referring to fig. 4 to 6, fig. 4 to 6 show the changes of the average particle size of the granular sludge in the control group and the enhanced group after the addition of the strain a-L3, and it can be seen from the graphs that the average particle size of the granular sludge in the control group and the enhanced group is 46.23 μm and 45.32 μm on day 7; these particle sizes are 10.32 and 13.20 μm larger than the particle size of the primary sludge, respectively; during the formation period, the average particle size of the granular sludge of the control group and the reinforced group is rapidly increased and reaches 133.53 and 164.37 microns on the 28 th day respectively, and the average particle size of the granular sludge of the reinforced group is increased more rapidly than that of the control group. By the 42 th day, the average particle size of the granular sludge of the control group and the reinforced group is 142.59 and 161.66 microns respectively, and in addition, by comparing the shapes of the sludge, the average particle size of the granular sludge of the reinforced group is obviously larger than that of the granular sludge of the control group, so that the formation of particles is accelerated.

Referring to FIGS. 5 and 6, FIGS. 5 and 6 show the SVI in the control and enhanced groups after the addition of the strain A-L3₃₀And 1 sludge settling rate variation, as can be seen from the graph, SVI in both sets of reactors after 7 days of culture₃₀The sludge SVI of the enhanced group is reduced to 129.44mL/g and 131.32mL/g respectively, no obvious difference exists between the two, and the sludge SVI of the enhanced group is obtained at the 28 th day₃₀Sludge SVI less than that in control group₃₀44.38mL/g and 35.68mL/g, respectively, and sludge SVI of the enhanced group at day 42₃₀Sludge SVI less than that in control group₃₀46.71mL/g and 30.81mL/g respectively show that the sedimentation performance of the sludge in the reinforced group is better than that of the control group. The change of the sludge settling velocity in the two groups of reactors can be seen from the figure, after the bacterial strain A-L3 is added in the strengthening group, the sludge settling velocity is obviously higher than that of the control group, which shows that the biological strengthening mode obviously improves the settling property of the sludge.

In summary, aeromonas hydrophila (aeromonas hydrophila ATCC7966) capable of secreting AHLs signal molecules is purchased from beijing baiohobowei-wei biotechnology limited, the secreted signal molecules are respectively C4-HSL and C6-HSL, and the existence of the two signal molecules can strengthen the induction effect of the microorganisms and promote the combination and aggregation of the sludge microorganisms, so that a microorganism aggregate is formed, the grain size of the aerobic granular sludge is increased, the structure is more compact, and the granulation speed of the aerobic sludge is accelerated.

Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art can make modifications and equivalents to the embodiments of the present invention without departing from the spirit and scope of the present invention, which is set forth in the claims of the present application.

Claims

1. An enhancement method for aerobic sludge granulation is characterized by comprising the following steps:

2. The enhanced method for aerobic sludge granulation according to claim 1, wherein said AHLs signal molecules are C4-HSL and C6-HSL signal molecules.

3. The method according to claim 1, wherein when the treated aeromonas hydrophila is added to the sludge-water mixture of the aerobic sludge, the volume ratio of the carrier formed by immobilizing the aeromonas hydrophila on the biochar to the sludge-water mixture of the aerobic sludge is 1: 30.

4. the method for enhancing aerobic sludge granulation as claimed in claim 1, wherein the step of immobilizing the pre-obtained aeromonas hydrophila by charcoal adsorption to obtain the treated aeromonas hydrophila specifically comprises:

5. An enhanced device for aerobic sludge granulation, comprising:

6. The reinforcement apparatus for aerobic sludge granulation according to claim 5, wherein in said reinforcement unit, AHLs signal molecules are C4-HSL and C6-HSL signal molecules.

7. The aerobic sludge granulation strengthening device as claimed in claim 5, wherein in the strengthening unit, when the treated aeromonas hydrophila is added to the sludge-water mixed solution of the aerobic sludge, the volume ratio of the carrier formed by immobilizing the aeromonas hydrophila by the biochar to the sludge-water mixed solution of the aerobic sludge is 1: 30.

8. the strengthening device for aerobic sludge granulation as claimed in claim 5, wherein, in the fixed treatment unit, the pre-obtained aeromonas hydrophila is fixed by charcoal adsorption, and the step of obtaining the treated aeromonas hydrophila specifically comprises: