1. Application of Penicillium oxalicum (Penicillium oxalicum) in rapid culture of aerobic granular sludge.

2. A method for rapidly culturing aerobic granular sludge by using penicillium oxalicum is characterized by comprising the following steps:

s1, culturing penicillium oxalicum: culturing penicillium oxalicum under aseptic conditions, uniformly mixing, and carrying out shake culture at 20-30 ℃ for 24-48 h to obtain a penicillium oxalicum granular bacterial solution;

s2, culturing aerobic granular sludge: starting a membrane bioreactor containing activated sludge, and treating the activated sludge and the penicillium oxalicum granule bacterium liquid in a volume ratio of 100: 2-5, adding the penicillium oxalicum granular bacterium liquid obtained in the step S1 into the membrane bioreactor, and culturing for 12-16 days to obtain aerobic granular sludge.

3. The method for rapidly culturing aerobic granular sludge by using penicillium oxalicum according to claim 2, wherein the penicillium oxalicum deposited in step S1 is penicillium oxalicum deposited in CICC 41676 and/or penicillium oxalicum deposited in CICC 2667 and/or penicillium oxalicum deposited in CICC 2612.

4. The method for rapidly culturing the aerobic granular sludge by using the penicillium oxalicum as the claimed in claim 2, wherein the culture medium for culturing the penicillium oxalicum in the step S1 is a zeiss culture medium, and the formula of the culture medium comprises 2.5-5 g of glucose, 0.5-1 g of ammonium chloride, 0.12-0.23 g of dipotassium hydrogen phosphate, 0.04g of magnesium sulfate, 0.012g of manganese sulfate, 0.008g of calcium chloride, 0.0006g of ferrous sulfate, 0.16g of sodium bicarbonate, 0.1g of yeast extract and 1000mL of distilled water.

5. The method for rapidly culturing aerobic granular sludge according to claim 1, wherein the shaking rate in step S1 is 150 to 200 r/min.

6. The method for rapidly culturing aerobic granular sludge by using penicillium oxalicum, as set forth in claim 2, wherein the bacterial colony concentration of the penicillium oxalicum granular bacterial liquid of step S1 is 10⁶～10⁷CFU/mL。

7. The method for rapidly culturing aerobic granular sludge by using penicillium oxalicum, according to claim 2, wherein the membrane bioreactor of step S2 is operated in a continuous flow mode, and the sludge load is 0.1-0.2 g cod/g mlss.

8. The method for rapidly culturing the aerobic granular sludge by using the penicillium oxalicum, as claimed in claim 2, wherein the DO in the aerobic zone of the membrane bioreactor in the step S2 is 1.0-3.0 mg/L, and the DO in the anaerobic zone is 0-1.0 mg/L.

9. The method for rapidly culturing the aerobic granular sludge by using the penicillium oxalicum, as claimed in claim 2, wherein the MLSS initial concentration of the membrane bioreactor in the step S2 is 2000-3000 mg/L.

10. The method for rapidly culturing the aerobic granular sludge by using the penicillium oxalicum, as set forth in claim 2, wherein the culturing period in the step S2 is 12 to 14 days.

Background

The activated sludge process is a widely applied sewage treatment process, but the traditional activated sludge process has the problems of high energy consumption, large occupied area, more excess sludge, poor settling property and the like, thereby influencing and limiting the application of the activated sludge process in sewage treatment to a certain extent. Aerobic Granular Sludge (Aerobic Granular Sludge) is Granular activated Sludge formed by microorganism self-coagulation under Aerobic conditions, and the culture and application cases of the Aerobic Granular Sludge are continuously reported since Mishima and nakamura cultured Aerobic Granular Sludge in an Aerobic upflow Sludge bed reactor for the first time in 1991. Compared with the traditional activated sludge method, the aerobic granular sludge technology has the characteristics of small occupied area, good sedimentation performance, high organic load, capability of realizing synchronous nitrification and denitrification and the like, and is concerned.

Aerobic granular sludge is usually cultured in Sequencing Batch Reactor (SBR), for example: chinese patent publication No. CN106242045A discloses a method for rapidly culturing aerobic granular sludge, wherein the formation time of the aerobic granular sludge is 25 days; chinese patent publication No. CN102583722A discloses an immobilized culture method for aerobic granular sludge, which comprises performing immobilized culture on various microorganisms in activated sludge to obtain initial seed sludge, and adding an aggregating agent and/or dominant bacteria to promote further rapid growth of granules to form granular sludge, wherein the period of the immobilized culture method is one month. However, the long time consumption in the process of preparing aerobic granular sludge by the above method is still a main problem to be solved. Therefore, shortening the start-up time of the aerobic granular sludge reactor to further promote the wide application of the aerobic granular sludge technology has important practical significance and economic value, i.e., the development of a method capable of rapidly preparing the aerobic granular sludge with good granular shape and good sedimentation performance is an urgent need of people.

Disclosure of Invention

The invention aims to overcome the defects in the prior art and provide the application of penicillium oxalicum in rapid culture of aerobic granular sludge.

The second purpose of the invention is to provide a method for rapidly culturing aerobic granular sludge by utilizing penicillium oxalicum.

The above object of the present invention is achieved by the following technical solutions:

the research of the invention finds that when the penicillium oxalicum is added into the activated sludge to be used as seed sludge to culture aerobic granular sludge, the culture time of the aerobic granular sludge can be effectively reduced, and sludge granules with smooth surfaces, regular shapes and compact texture are formed. Therefore, the invention firstly provides the application of the penicillium oxalicum in the rapid culture of the aerobic granular sludge.

Specifically, the invention provides a method for rapidly culturing aerobic granular sludge by using penicillium oxalicum, which comprises the following steps:

s1, culturing penicillium oxalicum: culturing penicillium oxalicum under aseptic conditions, uniformly mixing, and carrying out shake culture at 20-30 ℃ for 24-48 h to obtain a penicillium oxalicum granular bacterial solution;

s2, culturing aerobic granular sludge: starting a membrane bioreactor containing activated sludge, and treating the activated sludge and the penicillium oxalicum granule bacterium liquid in a volume ratio of 100: 2-5, adding the penicillium oxalicum granular bacterium liquid obtained in the step S1 into the membrane bioreactor, and culturing for 12-16 days to obtain aerobic granular sludge.

Preferably, in step S1, the penicillium oxalicum is deposited under accession number CICC 41676 and/or the penicillium oxalicum is deposited under accession number CICC 2667 and/or the penicillium oxalicum is deposited under accession number CICC 2612.

Preferably, the culture medium for culturing penicillium oxalicum in step S1 is a zeiss culture medium, and the formula of the culture medium is 2.5-5 g of glucose, 0.5-1 g of ammonium chloride, 0.12-0.23 g of dipotassium hydrogen phosphate, 0.04g of magnesium sulfate, 0.012g of manganese sulfate, 0.008g of calcium chloride, 0.0006g of ferrous sulfate, 0.16g of sodium bicarbonate, 0.1g of yeast extract and 1000mL of distilled water.

Preferably, the oscillating speed of step S1 is 150-200 r/min.

Preferably, the bacterial colony concentration of the penicillium oxalicum granule bacterial liquid in the step S1 is 10⁶～10⁷CFU/mL。

Preferably, the membrane bioreactor in the step S2 is operated in a continuous flow mode, and the sludge load is 0.1-0.2 gCOD/gMLSS d.

Preferably, the DO of the membrane bioreactor in the step S2 is 1.0-3.0 mg/L, and the DO of the anaerobic zone is 0-1.0 mg/L.

Preferably, the initial concentration of MLSS of the membrane bioreactor in the step S2 is 2000-3000 mg/L.

Preferably, the culture time in step S2 is 12-14 days.

As a preferred embodiment, a method for rapidly culturing aerobic granular sludge using Penicillium oxalicum, comprises the steps of:

s1, culturing penicillium oxalicum: culturing Penicillium oxalicum (with the preservation number of CICC 41676) in Chua's culture medium under aseptic condition, mixing well, and performing shake culture at 30 deg.C and the shaking speed of 200r/min for 24h to obtain bacterial colony with a concentration of 10⁷CFU/mL penicillium oxalicum granule bacterial liquid;

s2, culturing aerobic granular sludge: starting a membrane bioreactor containing activated sludge, and treating the activated sludge and the penicillium oxalicum granule bacterium liquid in a volume ratio of 100: 2, adding the penicillium oxalicum granular bacterial liquid obtained in the step S1 into a membrane bioreactor, wherein the membrane bioreactor runs in a continuous flow mode, and is cultured for 14 days under the conditions that the sludge load is 0.1g COD/g MLSS.d, the DO in an aerobic zone is 3.0mg/L, the DO in an anaerobic zone is 1.0mg/L and the initial concentration of MLSS is 3000mg/L to obtain aerobic granular sludge.

Based on the practical application of the aerobic granular sludge, the application of the aerobic granular sludge prepared by the method for rapidly culturing the aerobic granular sludge by utilizing the penicillium oxalicum in denitrification of water bodies and/or treatment of organic matter polluted water bodies is also within the protection scope of the invention.

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

(1) according to the invention, the penicillium oxalicum is adopted to prepare the aerobic granular sludge, the penicillium oxalicum is wide in source, strong in vitality and simple in culture condition, and granules with smooth surfaces, regular shapes and compact textures can be formed through short-time culture, so that the culture time of the aerobic granular sludge can be effectively shortened.

(2) The invention further utilizes penicillium oxalicum with the preservation number of CICC 41676 to culture aerobic granular sludge, mature aerobic granular sludge with regular appearance, good settling property and good settling property can be formed in the reactor within 14 days, and MLSS is rapidly increased from 3000mg/L to about 6500mg/L, thereby effectively shortening the starting time of the granular sludge.

Drawings

FIG. 1 is a figure showing the morphology of Penicillium oxalicum granules with deposit number CICC 41676.

FIG. 2 is a morphology chart of aerobic granular sludge prepared in example 1.

FIG. 3 shows the results of the change over time of the sludge volume index SVI and the mixed liquor suspended solids concentration MLSS in the membrane bioreactor of example 1.

Detailed Description

The invention is further described with reference to the drawings and the following detailed description, which are not intended to limit the invention in any way. Reagents, methods and apparatus used in the present invention are conventional in the art unless otherwise indicated.

Unless otherwise indicated, reagents and materials used in the following examples are commercially available.

The formula of the Chua's culture medium in the embodiment of the invention is as follows: 2.5-5 g of glucose, 0.5-1 g of ammonium chloride, 0.12-0.23 g of dipotassium hydrogen phosphate, 0.04g of magnesium sulfate, 0.012g of manganese sulfate, 0.008g of calcium chloride, 0.0006g of ferrous sulfate, 0.16g of sodium bicarbonate, 0.1g of yeast extract and 1000mL of distilled water.

Example 1 cultivation of aerobic granular sludge Using Penicillium oxalicum deposited under accession number CICC 41676

S1, culturing penicillium oxalicum: culturing Penicillium oxalicum (with the preservation number of CICC 41676) in Chua's culture medium under aseptic condition, mixing well, and performing shake culture at 30 deg.C and the shaking speed of 200r/min for 24h to obtain bacterial colony with a concentration of 10⁷CFU/mL penicillium oxalicum granule bacterial liquid;

s2, culturing aerobic granular sludge: starting a membrane bioreactor containing activated sludge, and treating the activated sludge and the penicillium oxalicum granule bacterium liquid in a volume ratio of 100: 2, adding the penicillium oxalicum granular bacterial liquid obtained in the step S1 into a membrane bioreactor, wherein the membrane bioreactor runs in a continuous flow mode, and is cultured for 14 days under the conditions that the sludge load is 0.1g COD/g MLSS.d, the DO in an aerobic zone is 3.0mg/L, the DO in an anaerobic zone is 1.0mg/L and the initial concentration of MLSS is 3000mg/L to obtain aerobic granular sludge.

The morphology of the penicillium oxalicum granules prepared in this example is shown in fig. 1. As can be seen from FIG. 1, the Penicillium oxalicum cultured in Zeitz medium for 24 hours can form granules with smooth surface, regular shape and compact texture, i.e., the Penicillium oxalicum has the property of fast granulation. The shape of the aerobic granular sludge is shown in fig. 2, and it can be seen from fig. 2 that the prepared aerobic granular sludge has a regular shape, a clear outline and a compact structure.

Example 2 cultivation of aerobic granular sludge Using Penicillium oxalicum deposited under accession number CICC 2667

S1, culturing penicillium oxalicum: culturing Penicillium oxalicum (with the preservation number of CICC 2667) in Chua's culture medium under aseptic condition, mixing well, and performing shake culture at 25 deg.C and the shaking speed of 200r/min for 48h to obtain bacterial colony with concentration of 10⁷CFU/mL Penicillium oxalicum granule.

S2, culturing aerobic granular sludge: starting a membrane bioreactor containing activated sludge, and treating the activated sludge and the penicillium oxalicum granule bacterium liquid in a volume ratio of 100: 3, adding the penicillium oxalicum granular bacterial liquid obtained in the step S1 into a membrane bioreactor, wherein the membrane bioreactor runs in a continuous flow mode, and is cultured for 12 days under the conditions that the sludge load is 0.15g COD/g MLSS.d, the DO in an aerobic zone is 2.0mg/L, the DO in an anaerobic zone is 0.5mg/L and the initial concentration of MLSS is 3000mg/L to obtain aerobic granular sludge. The aerobic granular sludge has regular shape, clear outline and compact structure.

Example 3 cultivation of aerobic granular sludge Using Penicillium oxalicum deposited under accession number CICC 2612

S1, culturing penicillium oxalicum: culturing Penicillium oxalicum (with the preservation number of CICC 2612) in Chua's culture medium under aseptic condition, mixing well, and performing shake culture at 20 deg.C and the shaking rate of 150r/min for 36h to obtain bacterial colony concentration of 10⁷CFU/mL Penicillium oxalicum granule.

S2, culturing aerobic granular sludge: starting a membrane bioreactor containing activated sludge, and treating the activated sludge and the penicillium oxalicum granule bacterium liquid in a volume ratio of 100: 5, adding the penicillium oxalicum granular bacteria liquid obtained in the step S1 into a membrane bioreactor, wherein the membrane bioreactor runs in a continuous flow mode, and culturing for 16 days under the conditions that the sludge load is 0.1g COD/g MLSS.d, the aerobic zone DO is 1.0mg/L, the anaerobic zone DO is 0mg/L and the MLSS initial concentration is 2000mg/L to obtain aerobic granular sludge. The aerobic granular sludge has regular shape, good granularity, clear outline and compact structure.

Example 4 cultivation of aerobic granular sludge Using Penicillium oxalicum deposited under accession number CICC 2667

S1, culturing penicillium oxalicum: culturing Penicillium oxalicum (with the preservation number of CICC 2667) in Chua's culture medium under aseptic condition, mixing well, and shake-culturing at 20 deg.C and the shaking speed of 180r/min for 36h to obtain the colony concentration of 2 × 10⁶CFU/mL Penicillium oxalicum granule.

S2, culturing aerobic granular sludge: starting a membrane bioreactor containing activated sludge, and treating the activated sludge and the penicillium oxalicum granule bacterium liquid in a volume ratio of 100: 3, adding the penicillium oxalicum granular bacterial liquid obtained in the step S1 into a membrane bioreactor, setting the membrane bioreactor to operate in a continuous flow mode, and culturing for 12 days under the conditions that the sludge load is 0.2g COD/g MLSS.d, the DO in an aerobic zone is 3.0mg/L, the DO in an anaerobic zone is 1.0mg/L and the initial concentration of MLSS is 2500mg/L to obtain aerobic granular sludge. The aerobic granular sludge has regular shape, clear outline and compact structure.

Example 5 cultivation of aerobic granular sludge Using Penicillium oxalicum deposited under accession number CICC 2612

S1, culturing penicillium oxalicum: culturing Penicillium oxalicum (with a preservation number of CICC 2612) in Chua's culture medium under aseptic condition, mixing well, and performing shake culture at 25 deg.C and a shaking speed of 200r/min for 40h to obtain a colony concentration of 3 × 10⁶CFU/mL Penicillium oxalicum granule.

S2, culturing aerobic granular sludge: starting a membrane bioreactor containing activated sludge, and treating the activated sludge and the penicillium oxalicum granule bacterium liquid in a volume ratio of 100: 4, adding the penicillium oxalicum granular bacteria liquid obtained in the step S1 into a membrane bioreactor, wherein the membrane bioreactor runs in a continuous flow mode, and culturing for 14 days under the conditions that the sludge load is 0.1g COD/g MLSS.d, the DO in an aerobic zone is 3.0mg/L, the DO in an anaerobic zone is 0.5mg/L and the initial concentration of MLSS is 2500mg/L to obtain aerobic granular sludge. The aerobic granular sludge has good granularity, regular shape and compact structure.

Test example 1 testing of growth rate and sedimentation Performance of aerobic granular sludge in Membrane bioreactor

100mL of aerobic granular sludge mixed liquid is taken by a measuring cylinder in the aerobic zone and the anaerobic zone of the membrane bioreactor in the embodiment 1 respectively, the mixture is kept still for 30min, the volume of supernatant and the volume of sludge sediment are measured, and the sludge volume index SVI is obtained by calculation. And filtering the mixed solution by using filter paper dried to constant weight, putting the filtered mixed solution into a drying oven at 105 ℃ for drying for 2h, taking the dried mixed solution out, cooling the dried mixed solution in the drying oven to constant temperature and constant weight, and measuring the weight difference between the front part and the rear part of the filter paper to obtain the MLSS value of the sludge.

And (4) analyzing results: the change results of the sludge volume index SVI and the mixed liquor suspended solid concentration MLSS in the membrane bioreactor along with time are shown in figure 3, the results show that the MLSS rapidly increases in a short time, the value of SVI is basically maintained at 80-150 from 3000mg/L at the 1 st day of the start of the membrane bioreactor to 6500mg/L at the 14 th day, and the formed aerobic granular sludge can rapidly grow in the membrane bioreactor and the sedimentation performance of the aerobic granular sludge is good.