A method for inhibiting algae and sterilization

Abstract

The application discloses an algae-inhibiting and bacteria-killing method, which comprises the following steps: adding diacetyl into water to be treated, and allowing the diacetyl to play a role under the irradiation of sunlight to inhibit the growth of algae and bacteria; the algae are Skeletonema costatum, Phaeocystis globosa, Microcystis aeruginosa or Prorocentrum donghaiense; and the bacteria are Escherichia coli or Staphylococcus aureus. The diacetyl is used as an active substance in the application, and the diacetyl can play a role in inhibiting algae and killing bacteria under natural light only. The method has good selectivity, is environment-friendly, high in economic efficiency, and is suitable for algae control and disinfection of shallow lakes, swimming pools, seawater / freshwater breeding farms and landscape water bodies.

Description

TECHNICAL FIELD

[0001] The present application belongs to the field of water treatment, and particularly relates to a method for inhibiting algae and sterilizing. BACKGROUND

[0002] With the rapid increase of industrialization and urbanization, a large amount of industrial wastewater and domestic sewage is discharged into rivers, lakes, reservoirs and oceans, resulting in the accumulation of carbon, nitrogen, phosphorus and other substances and the eutrophication of water bodies, which causes a large number of harmful algae to reproduce in the water body, not only bringing negative effects on the water ecosystem, but also threatening the safety of drinking water of human beings and causing serious economic losses to agriculture, fishery and the like.

[0003] At present, the methods for removing harmful algae mainly include physical method, chemical method and biological method. The physical method mainly relies on mechanical salvage, heating or ultraviolet sterilization, which has a quick effect, but has a high operation cost and depends on specific equipment, and is difficult to realize large-scale application. The biological method mainly relies on the filter-feeding or allelopathy of aquatic plants and animals, which has a slow effect and poor controllability. The chemical method relies on adding chemical agents to inhibit and kill harmful algae, which has the advantages of simple operation and quick effect, and is the preferred method for emergency algae control and sterilization. However, most of the chemical algae-inhibiting agents have poor selectivity and high ecological risk, which limits their application in natural water bodies and functional water bodies. Therefore, it is of great significance to develop a new method for inhibiting algae and sterilization for improving water quality and maintaining the stability of the ecological system. SUMMARY

[0004] The present application aims to provide an ecological and safe method for inhibiting algae and sterilization.

[0005] The method for inhibiting algae and sterilization comprises the following steps: adding diacetyl into the water body to be treated, and allowing the diacetyl to play a role under the irradiation of sunlight to inhibit the growth of algae and bacteria.

[0006] The chemical formula of the diacetyl is CH3COCOCH3, and the structural formula is

[0007] Preferably, the algae is Skeletonema costatum, Phaeocatena globosa, Microcystis aeruginosa or Prorocentrum donghaiense.

[0008] Preferably, the bacteria is Escherichia coli or Staphylococcus aureus.

[0009] Preferably, when the algae is inhibited, the concentration of the diacetyl in the water body to be treated is not less than 0.2mM. The effect of inhibiting algae is enhanced with the increase of the concentration of the diacetyl.

[0010] Preferably, the density of the algae ranges from 4.4x10 5 to 1.1x10 7The acetyl diacetal has the effect of inhibiting algae at the concentration of 0.2-0.6 mM. With the increase of the density of algae, the effect of the acetyl diacetal on algae is enhanced first and then slightly weakened at the same concentration.

[0011] Preferably, when the algae is Skeletonema costatum, the concentration of the acetyl diacetal in the water body to be treated is 0.2-0.6 mM.

[0012] Preferably, when the algae is Microcystis aeruginosa or Phaeocystis globosa, the concentration of the acetyl diacetal in the water body to be treated is 0.2-0.6 mM.

[0013] Preferably, when the algae is Prorocentrum donghaiense, the concentration of the acetyl diacetal in the water body to be treated is 0.4-0.6 mM.

[0014] Preferably, when the bacteria is inhibited, the concentration of the acetyl diacetal in the water body to be treated is not less than 0.1 mM, and the effect of the acetyl diacetal on the bacteria is enhanced with the increase of the concentration of the acetyl diacetal.

[0015] Preferably, the density of the bacteria ranges from 3.6 x 10 3 to 1.0 x 10 8 CFU / mL, and the treatment time of the acetyl diacetal is gradually prolonged with the increase of the density of the bacteria at the same concentration.

[0016] The water body to be treated is a shallow lake, a swimming pool, a seawater / freshwater aquaculture farm or a landscape water body.

[0017] The mechanism of the application is that the acetyl diacetal has the effect of inhibiting algae and killing bacteria, and the mechanism is that the acetyl diacetal is photolyzed to generate acetyl peroxide radicals under the irradiation of sunlight, so that the algae or bacteria cells are caused to die due to oxidative stress. The acetyl diacetal has the effect of inhibiting Microcystis aeruginosa, Phaeocystis globosa, Prorocentrum donghaiense or Skeletonema costatum, and has no effect on the growth of Chlamydomonas reinhardtii under the same conditions.

[0018] The acetyl diacetal has the advantages of environmental friendliness and economic efficiency. The acetyl diacetal is a common natural substance, widely exists in plants (lavender, tulip, strawberry, etc.), and fermented products such as wine and yogurt, and is also a metabolic product of microorganisms and human bodies, and has good biocompatibility and environmental friendliness. The acetyl diacetal has the advantages of easy availability and economic efficiency compared with other natural substances which are difficult to extract.

[0019] Beneficial effects: Compared with the prior art, the present application has the following remarkable advantages: (1) the method uses diacetyl as the active substance, which can play the role of inhibiting algae and killing bacteria under natural light, has good selectivity, and is environmentally friendly and economically efficient; (2) the method is simple to operate; (3) diacetyl is stable and safe, and is convenient to transport and operate, without the need for professional operation; (4) the method selectively inhibits Skeletonema costatum, Phaeocystis globosa, Microcystis aeruginosa, Prorocentrum donghaiense, Escherichia coli and Staphylococcus aureus. BRIEF DESCRIPTION OF DRAWINGS

[0020] Figure 1 Figure 6 is a graph of the inhibition of the algal density of Microcystis aeruginosa, Phaeocystis globosa, Skeletonema costatum and Prorocentrum donghaiense by diacetyl measured in Examples 1-4;

[0021] Figure 2 Figure 7 is a graph of the inhibition of the growth process of Chlamydomonas reinhardtii by diacetyl measured in Comparative Example 1;

[0022] Figure 3 Figure 8 is a graph of the inactivation effect of diacetyl on Microcystis aeruginosa with different initial densities measured in Example 5;

[0023] Figure 4 Figure 9 is a graph of the inactivation effect of diacetyl on Escherichia coli measured in Example 6;

[0024] Figure 5 Figure 10 is a graph of the inactivation effect of diacetyl on Staphylococcus aureus measured in Example 7;

[0025] Figure 6 Figure 11 is a graph of the effect comparison of diacetyl and other common algae-inhibiting and bacteria-killing substances measured in Comparative Example 2;

[0026] Figure 7 Figure 12 is an electron paramagnetic resonance (EPR) spectrum of diacetyl under light measured in Example 8;

[0027] Figure 8 Figure 13 is a graph of the effect of diacetyl on harmful algae and bacteria in natural water bodies measured in Examples 9 and 10. DETAILED DESCRIPTION

[0028] The technical solutions of the present application will be further described below in combination with the examples.

[0029] The diacetyl used in the examples of the present application is of analytical purity.

[0030] The algae in the embodiments of the present application are single-cell red tide algae isolated from the coast of East China, including brown cysts, middle rib bone strips and East China protomastigote, and freshwater algae from the Freshwater Algae Culture Collection of the Chinese Academy of Sciences, including copper green microcystis FACHB-905 and chlamydomonas reinhardtii FACHB-265. The red tide algae is cultured by using f / 2 medium, and the freshwater algae is cultured by using BG11 medium.

[0031] The bacteria in the embodiments of the present application are Escherichia coli DH5α and Staphylococcus aureus ATCC25923, which are both cultured by using LB broth medium.

[0032] The term "water" in the present application refers to ultrapure water without special explanation or limitation.

[0033] The main components of f / 2 medium are: NaNO3, 75 mg / L; Na2SiO3·9H2O, 30 mg / L; NaH2PO4·3H2O, 5 mg / L; Na2EDTA·2H2O, 4.36 mg / L; FeCl3·6H2O, 3.15 mg / L; MnCl2·6H2O, 1.8 mg / L; vitamin B1, 0.1 mg / L; ZnSO4·7H2O, 22 ug / L; CoCl2·6H2O, 10 ug / L; CuSO4·5H2O, 9.8 ug / L; Na2MoO4·2H2O, 6.3 ug / L; biotin, 0.5 ug / L; vitamin B12, 0.5 ug / L.

[0034] The main components of BG11 medium are: NaNO3, 1.5 g / L; MgSO4·7H2O, 0.075 g / L; CaCl2·2H2O, 0.036 g / L; K2HPO4·3H2O, 0.04 g / L; Na2CO3, 0.02 g / L; citric acid, 6 mg / L; ferric ammonium citrate, 6 mg / L; Na2EDTA, 1 mg / L; H3BO3, 2.86 mg / L; MnCl2·4H2O, 1.86 mg / L; ZnSO4·7H2O, 0.22 mg / L; Na2MoO4·2H2O, 0.39 mg / L; CuSO4·5H2O, 0.08 mg / L; Co(NO3)2·6H2O, 0.05 mg / L.

[0035] The main components of LB broth medium are: tryptone, 10 g / L; yeast extract, 5 g / L; NaCl, 10 g / L.

[0036] In the embodiments, the absorbance (OD 680 ) at 680 nm is measured by using a UV spectrophotometer (UV-2700) to evaluate the algal inhibition performance of diacetyl.

[0037] In the example, the turbidity can be measured by a turbidimeter (2100P) to prove the effectiveness of diacetyl in inhibiting algae in natural water bodies.

[0038] Example 1: Inhibition effect of diacetyl on Phaeocystis globosa

[0039] In a sterile clean bench, Phaeocystis globosa in the exponential growth phase was taken into sterile 50 mL quartz reaction bottles and sterile six-well plates, so that the OD 680 was 0.22, and then different volumes of diacetyl diluent (100 mM) were added to the reaction bottles and sterile six-well plates to make the final concentration of diacetyl 0.2 mM, 0.4 mM, 0.6 mM, and a blank control group (CK) without adding diacetyl was set. The quartz reaction bottles were sealed with a full transparent film at the bottle mouth and placed in sunlight (50 mW / cm 2 ), and the sterile six-well plates were placed in darkness at the same time. The OD 680 was measured after 0 h, 2 h, 4 h, 6 h, 8 h, 10 h of reaction, and the algal cell density (Y, 10 5 cells / mL) was calculated according to the formula Y = 99.148 OD 680 – 0.881.

[0040] Example 2: Inhibition effect of diacetyl on Skeletonema costatum

[0041] Phaeocystis globosa in the exponential growth phase was taken into sterile 50 mL quartz reaction bottles and sterile six-well plates, so that the OD 2 was 0.14, and then different volumes of diacetyl diluent (100 mM) were added to the reaction bottles and sterile six-well plates to make the final concentration of diacetyl 0.2 mM, 0.4 mM, 0.6 mM, and a blank control group without adding diacetyl was set. The quartz reaction bottles were sealed with a full transparent film at the bottle mouth and placed in sunlight (50 mW / cm 680 ), and the sterile six-well plates were placed in darkness at the same time. The OD 680 was measured after 0 h, 2 h, 4 h, 6 h, 8 h, 10 h of reaction, and the algal cell density (Y, 10 5 cells / mL) was calculated according to the formula Y = 33.612 OD 680 – 0.546.

[0042] Example 3: Inhibition effect of diacetyl on Prorocentrum donghaiense

[0043] In a sterile condition, Phaeocystis globosa in the exponential growth phase was taken into sterile 50 mL quartz reaction bottles and sterile six-well plates, so that the OD 2The concentration was 0.14. Subsequently, different volumes of diacetyl dilution (100 mM) were added to the reaction flasks and sterile six-well plates to achieve final diacetyl concentrations of 0.2 mM, 0.4 mM, and 0.6 mM. A blank control group without added diacetyl was also included. The quartz reaction flasks were sealed with a fully transparent film and placed in sunlight (50 mW / cm²). 2 In this process, sterile six-well plates were placed in the dark, and samples were taken at 0h, 2h, 4h, 6h, 8h, and 10h after the reaction to measure OD. 680 And according to Y = 20.609OD 680 +0.091 Calculate algal cell density (Y, 10) 5 (cells / mL)

[0044] Example 4: Inhibitory effect of diacetyl on Microcystis aeruginosa

[0045] Microcystis aeruginosa FACHB-905 during its exponential growth phase was inoculated into a sterile 50 mL quartz reaction flask and a sterile six-well plate to induce OD. 680 The initial concentration was 0.20. Different volumes of diacetyl dilution (100 mM) were then added to the reaction flasks and sterile six-well plates to achieve final diacetyl concentrations of 0.2 mM, 0.4 mM, and 0.6 mM. A blank control group without added diacetyl was also included. The quartz reaction flasks were sealed with a fully transparent film and placed in sunlight (50 mW / cm²). 2 In this process, sterile six-well plates were placed in the dark, and samples were taken at 0h, 2h, 4h, 6h, 8h, and 10h after the reaction to measure OD. 680 And according to Y=28.660OD 680 +0.078 Calculate algal cell density (Y, 10) 6 (cells / mL).

[0046] The test results of Examples 1-4 are as follows: Figure 1 As shown.

[0047] Figure 1 This is a graph showing the algal density suppression of *Phaeocystis globosa* (a), *Skeletonema costatum* (b), *Prorocentrum donghaiense* (c), and *Microcystis aeruginosa* (d) by diacetyl under light and dark conditions, respectively. Figure 1It is evident that for *Phaeocystis globosa*, *Prorocentrum donghaiense*, and *Microcystis aeruginosa*, the effect of diacetyl treatment under light for 2 hours was not significant, having almost no impact on algal cell growth. However, diacetyl showed a significant inhibitory effect on *Skeletonema costatum* at this time. With increasing treatment time, diacetyl concentrations greater than 0.2 mM reduced the algal density of all four algae, with the inhibitory effect increasing with concentration. The 0.6 mM diacetyl showed the best inhibitory effect. 0.2 mM diacetyl had almost no inhibitory effect on *Prorocentrum donghaiense*, but effectively inhibited the other three algae, exhibiting a sustained growth-inhibiting effect within the treatment time range. Overall, the inhibitory effect of diacetyl was: *Skeletonema costatum* > *Phaeocystis globosa*, *Microcystis aeruginosa* > *Prorocentrum donghaiense*. Compared to light conditions, the algal density of the four algae treated with different concentrations of diacetyl in the dark was not significantly different from the control group, indicating that diacetyl itself did not have a significant inhibitory effect on algal cells at the treated concentrations.

[0048] Comparative Example 1: Inhibitory effect of diacetyl on Chlamydomonas reinhardtii

[0049] FACHB-265 of *Chlamydomonas reinhardtii* during its exponential growth phase was inoculated into a sterile 50 mL quartz reaction bottle and a sterile six-well plate to induce OD. 680 The initial concentration was 0.20. Different volumes of diacetyl dilution (100 mM) were then added to the reaction flasks and sterile six-well plates to achieve final diacetyl concentrations of 0.2 mM, 0.4 mM, and 0.6 mM. A blank control group without added diacetyl was also included. The quartz reaction flasks were sealed with a fully transparent film and placed in sunlight (50 mW / cm²). 2 In this process, sterile six-well plates were placed in the dark, and samples were taken at 0h, 2h, 4h, 6h, 8h, and 10h after the reaction to measure OD. 680 And according to Y = 31.726OD 680 +0.087 Calculate algal cell density (Y, 10) 5 (cells / mL). Test results are as follows: Figure 2 As shown.

[0050] Figure 2 The figure shows the changes in algal density of *Chlamydomonas reinhardtii* under light and dark conditions for 10 hours in Comparative Example 1. As shown in the figure, regardless of the presence or absence of sunlight, diacetyl treatment had no effect on the growth of *Chlamydomonas reinhardtii*, indicating that *Chlamydomonas reinhardtii* is more tolerant to diacetyl than the other four algae, and that diacetyl has the ability to selectively inhibit algae growth.

[0051] Example 5: Inactivation effect of diacetyl on Microcystis aeruginosa with different initial densities

[0052] Microcystis aeruginosa FACHB-905 during its exponential growth phase was inoculated into a sterile 50 mL quartz reaction flask and a sterile six-well plate to induce OD. 6800.1, 0.2, 0.3, 0.4, then adding diacetyl dilution (100 mM) into the reaction bottle to make the final concentration of diacetyl 0.4 mM, and setting a blank control group without adding diacetyl; the quartz reaction bottle is sealed with a full transparent film at the bottle mouth and placed in sunlight (50 mW / cm 2 ) to take samples at 0 h, 2 h, 4 h, 6 h, 8 h, 10 h after the reaction to determine OD 680 , and calculating the algal cell density (Y, 10 680 cells / mL) according to Y = 28.660 OD 6 + 0.078. The test results are shown in Figure 3 .

[0053] Figure 3 The inhibition effect of 0.4 mM diacetyl on Microcystis aeruginosa with different initial densities under sunlight. As can be seen from the figure, when the algal density of Microcystis aeruginosa is in the range of 3.1 x 10 6 -1.1 x 10 7 cells / mL, diacetyl can achieve significant algae inhibition within 10 h.

[0054] Example 6: Inactivation effect of diacetyl on Escherichia coli

[0055] Escherichia coli DH5a was selected for inactivation experiment. The solution of Escherichia coli cultured at 37°C, 200 rpm vibration to logarithmic growth phase was centrifuged at 5000 rpm for 5 min, and the supernatant was discarded. The bacterial precipitate was resuspended in sterile normal saline (0.9% NaCl, pH 7.0) and centrifuged again. The above steps were repeated three times to completely remove the culture medium residue. Finally, the pure bacterial suspension was obtained by resuspension in sterile normal saline and diluted to 1.0 x 10 7 CFU / mL.

[0056] The above bacterial suspension was taken into a quartz reaction tube, and different volumes of diacetyl were added to make the final concentration of diacetyl 0.01 mM, 0.1 mM, 0.2 mM, 0.3 mM, and a blank control was set. The quartz reaction bottle was sealed with a full transparent film at the bottle mouth and placed in sunlight (50 mW / cm 2 ) to take reaction suspension at certain time intervals during the treatment, appropriately dilute, and evenly spread 0.1 mL of the diluted sample on LB agar medium plates, and count the number of bacteria formed on the plates after 24 h culture at 37°C.

[0057] Further, 0.2 mM diacetyl was selected to judge the inactivation effect on different concentrations of Escherichia coli.

[0058] The Escherichia coli was resuspended and diluted to 1.0 x 106 -1.0 x 10 8 CFU / mL. The bacteria solution was added to a quartz reaction tube, 0.2 mM diacetyl was added, and a blank control was set. Colony counting was performed by coating. The test results are shown in Figure 4

[0059] Figure 4 The inactivation effect of diacetyl on E. coli is shown in Figure 4 (a). As shown, when the concentration of diacetyl is not less than 0.1 mM, it exhibits excellent bactericidal effect, and as the concentration of diacetyl increases, the bactericidal effect also increases. As shown in Figure 4 (b), 0.2 mM diacetyl has good inactivation effect on E. coli with a colony density of 1.0 x 10 6 -1.0 x 10 8 CFU / mL, and can achieve complete inactivation within 75 min.

[0060] Example 7: Inactivation effect of diacetyl on S. aureus

[0061] S. aureus ATCC25923 under the same culture conditions as E. coli was selected for inactivation experiments. The bacterial suspension in the logarithmic growth phase was collected and centrifuged (5000 rpm, 5 min), and the supernatant was discarded, and the precipitate was collected. The bacterial precipitate was resuspended with sterile physiological saline (0.9% NaCl, pH 7.0) and centrifuged again. This step was repeated three times to completely remove the culture medium residue. Finally, the pure bacterial suspension was resuspended in sterile physiological saline. S. aureus with a colony number of 1.0 x 10 7 CFU / mL was added to a quartz reaction tube, 0.2 mM diacetyl was added, and experiments were performed under sunlight and dark conditions, and a blank control was set. The test results are shown in Figure 5

[0062] Figure 5 The inactivation effect of diacetyl on S. aureus is shown in Figure 5 . As shown, in addition to E. coli (gram-negative bacteria), diacetyl also has obvious inactivation effect on S. aureus (gram-positive bacteria), and can completely inactivate S. aureus under sunlight irradiation for 120 min.

[0063] Comparative Example 2: Comparison of the inhibition effect of diacetyl and other common algae-killing substances on M. aeruginosa

[0064] Based on the above experimental results, M. aeruginosa was further selected as a representative species for comparative experiments. M. aeruginosa FACHB-905 in the exponential growth phase was taken and inoculated into sterile 50 mL quartz reaction bottles, and the OD 680 ​​was 0.1. Then, diacetyl, hydrogen peroxide, peroxyacetic acid, persulfate, and periodate were added to the reaction bottles to make the final concentration of 0.4 mM, and a blank control group was set without adding any algae-inhibiting substances. The quartz reaction bottles were sealed with a transparent film and placed in sunlight (50 mW / cm 2 ) to take samples at 0 h, 2 h, 4 h, 6 h, 8 h, and 10 h for measuring OD 680 , and the algae cell density (Y, 10 680 cells / mL) was calculated according to Y = 28.660 OD 6 . The test results are shown in Figure 6 .

[0065] Figure 6 is a comparison chart of the inhibitory effect of diacetyl and other common algae-inhibiting bactericides on Microcystis aeruginosa. As can be seen from the chart, hydrogen peroxide and peroxyacetic acid, strong oxidizing agents, show good algae-inhibiting effect in the early stage. Diacetyl, periodate, and persulfate have a slow effect, but diacetyl shows obvious algae-inhibiting effect in the later stage, and the final algae-inhibiting effect after 10 h of treatment is better than that of peroxyacetic acid and hydrogen peroxide.

[0066] Example 8: Electron paramagnetic resonance (EPR) spectrum of diacetyl under light

[0067] First, ultrapure water was placed in an anaerobic glove box to prepare anaerobic water, and a certain volume of diacetyl solution was prepared. Then, 5,5-dimethyl-1-pyrroline-N-oxide (DMPO) was added as a trapping agent, and the mixture was slowly added to a capillary quartz tube and sealed with vaseline. The capillary tube was placed in the cavity of the EPR instrument, and in situ light was performed at a distance of about 1 m from the sample. The EPR signals of the sample at 0 min and 5 min were measured, and the test results are shown in Figure 7 .

[0068] Figure 7 is the EPR spectrum of diacetyl under light. As shown in the chart, the EPR spectrum obtained in an anaerobic environment shows six main peaks from the DMPO-CH3C(O)· adduct. In addition, a weak peak belonging to DMPO-CH3· was also detected. Under aerobic conditions, CH3C(O)· can rapidly combine with oxygen molecules to form oxidative acetyl peroxide radicals.

[0069] Example 9: Effect of diacetyl on Microcystis aeruginosa in natural water

[0070] 30 L of Tianlai River (32°7′8″N, 118°56′67″E) water was taken, and Microcystis aeruginosa FACHB-905 (OD 680= 0.6) 500 mL and cultured to the exponential growth phase, then added the appropriate volume of diacetyl mixed, so that the concentration of the treatment group is 0.5 mM, while setting no addition of diacetyl blank control group, from the 0th day to the 8th day every day timing sampling, through the turbidity determination to determine the effect of diacetyl in natural water algae, test results as shown in Figure 7

[0071] By Figure 8 (a) As shown, the control group of Microcystis aeruginosa grew vigorously, the turbidity rose to 35 NTU on the 3rd day, and maintained at about 25 NTU in the following days, while the experimental group added diacetyl the turbidity decreased to below 10 NTU within a day, and maintained at a relatively low level in the subsequent observation period.

[0072] Example 10: Effect of diacetyl treatment on bacteria in natural water

[0073] Take Tianle River (32°7'8"N, 118°56'67"E) river water 20 L, after removing impurities and plant residues by gauze filtration, placed in a polypropylene transparent water tank, placed in sunlight, and added 0.2 mM diacetyl. Regularly sampled at 0, 2, 4, 6, 8, 12 h, and appropriately diluted, 0.1 mL of diluted sample was uniformly coated on the plate, and the number of colonies formed on the plate was counted after incubation at 37°C for 18 h. Test results as shown in Figure 8 (b).

[0074] As shown in Figure 8 (b), the addition of diacetyl can quickly inactivate the bacteria in the water within 6 h, which has potential practical application.​

Claims

1. A method of algal inhibition and disinfection, characterized by, The diacetyl is added into the water body to be treated, and plays a role under the sunlight irradiation, inhibits the growth of algae, and kills bacteria; the algae are Skeletonema costatum, Phaeocystis globosa or Prorocentrum donghaiense; the bacteria are Escherichia coli or Staphylococcus aureus.

2. The method for inhibiting algae and killing bacteria according to claim 1, characterized in that, The algae are Skeletonema costatum, Phaeocystis globosa or Prorocentrum donghaiense, and the concentration of the diacetyl in the water body to be treated is not less than 0.2 mM.

3. The method of algal inhibition and disinfection according to claim 1, wherein, The bacteria are Escherichia coli or Staphylococcus aureus, and the concentration of the diacetyl in the water body to be treated is not less than 0.2 mM.

4. The method of algal inhibition and disinfection according to claim 1, wherein, The algal density ranged from 4.4 x 10 5 ~ 1.1 x 10 7 cells / mL.

5. The method of algal inhibition and disinfection according to claim 4, wherein, When the algae are Skeletonema costatum, the concentration of the diacetyl in the water body to be treated is 0.2-0.6 mM.

6. The method of algal inhibition and disinfection of claim 4, wherein, When the algae are Phaeocystis globosa, the concentration of the diacetyl in the water body to be treated is 0.2-0.6 mM.

7. The method for inhibiting algae and killing bacteria according to claim 4, characterized in that, When the algae are Prorocentrum donghaiense, the concentration of the diacetyl in the water body to be treated is 0.4-0.6 mM.

8. The method of algal inhibition and disinfection of claim 1, wherein, The fungal density ranged from 3.6 x 10 3 ~ 1.0 x 10 8 CFU / mL.

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