CN110885754B

CN110885754B - Method for preventing and treating biological pollution in microalgae culture process by using surfactant

Info

Publication number: CN110885754B
Application number: CN201811048054.XA
Authority: CN
Inventors: 李夜光; 丁奕; 温小斌; 彭新安; 朱晓艳; 王中杰; 耿亚洪
Original assignee: China Petroleum and Chemical Corp; Wuhan Botanical Garden of CAS
Current assignee: China Petroleum and Chemical Corp; Wuhan Botanical Garden of CAS
Priority date: 2018-09-07
Filing date: 2018-09-07
Publication date: 2021-11-12
Anticipated expiration: 2038-09-07
Also published as: CN110885754A

Abstract

The invention discloses a method for preventing and treating biological pollution in a microalgae culture process by using a surfactant, which is used for preventing or controlling harmful organisms and disease fungi pollution which are frequently generated in the microalgae culture process by adding the surfactant or a detergent containing the surfactant into a microalgae culture solution, wherein the surfactant is at least one of dodecyl benzene sulfonic acid, dodecyl benzene sulfonic acid sodium sulfonate, cocoanut oil acid diethanol amine, dodecyl sodium sulfate, fatty alcohol-polyoxyethylene ether and fatty alcohol-polyoxyethylene ether sodium sulfate. Compared with the prior art, the method can completely control the pollution of enemy organisms and the infection of pathogenic fungi, has no negative influence or little influence on the growth and the propagation of microalgae, has broad spectrum of action, can kill various enemy organisms and disease organisms, and has simple and convenient operation and low cost.

Description

Method for preventing and treating biological pollution in microalgae culture process by using surfactant

Technical Field

The invention belongs to the technical field of microalgae biology, and particularly relates to a method for preventing and controlling biological pollution in a microalgae culture process, which comprises a method for preventing and controlling enemy biological pollution and pathogenic fungal infection.

Background

Microalgae are a class of aquatic plants that can grow and reproduce through photosynthesis. The metabolites in the microalgae cells are various in types, not only are rich in proteins and amino acids, but also contain unsaturated fatty acids, carotenoids and the like, and have wide application in the industries of health care products, foods, medical treatment, cosmetics, feeds and the like (the application progress of microalgae in biomass development, green technology, 2017, 22: 128-containing organic complex 133, the comprehensive development and utilization research progress of microalgae resources, food industry, 2017, 38 (11): 275-containing organic complex 278). In addition, microalgae is considered to be one of the most potential biological resources for solving the energy crisis, the large-scale culture of oil-producing microalgae for producing microalgae biodiesel attracts wide attention at home and abroad, and intensive research is carried out (research progress on microalgae culture technology for biodiesel production. chemical and biological engineering, 2018, 35 (1): 5-11).

The microalgae mass culture is the most critical link in the utilization of microalgae biological resources, but the microalgae mass culture is notIn the open raceway pond or the closed photobioreactor, pollution organisms (including protozoa, miscellaneous algae and fungi) inevitably enter a microalgae culture system through water or gas, and biological pollution is difficult to avoid. The problem of biological pollution is not obvious in small-scale microalgae culture, but pollution is more easily caused along with gradual expansion of culture scale, and the harm is more serious. Common and more serious harmful contaminating organisms (including enemy organisms and pathogenic organisms) in the microalgae culture process mainly comprise rotifers, ciliates, amoebas, bellworms, fungi and the like, and some flagellates (such as chrysophytes) can also swallow algae cells (the research on preventing and controlling rotifers pollution in the microalgae culture process, PhD. D. St. Chinesis, 2014; Effective control of Poterioochromans malonensis in pilot-scale culture of Chlorella of Parkinson's sorbent GT-1by main utility CO₂-a programmed low cut pH. Algal Research,2017,26: 436-; isolation and characterization of an end aspect from the culture of an oleaginous microalga Graesiella sp.WBG-1.Algal Research,2017,26: 371-; a continuous microbioplankton in outdoor micro mass analysis systems, An electronic visual point, Algal Research,2016,20: 258-; the control and control of biological polutants in a mass compartmentalization micro fluidic Technology,2013,128: 745-. The harm of biological pollution is mainly shown as follows: 1. enemy organisms (e.g., protozoa, chrysophytes) ingest algae, causing a dramatic reduction in algae density; 2. pathogenic organisms (e.g., fungi) infect algae cells, causing massive death of the algae. Whether the algae is ingested in large quantities or is severely infected and killed, culture failure can result. How to effectively prevent the occurrence of hostile biological pollution and pathogenic biological infection and control and kill the polluted organisms is a key Technology of microalgae scale culture (stratages to control biological pollution and microbial Contamination of plants. Bioresource Technology,2018,252: 180-.

At present, the control method of biological pollution in microalgae culture mainly comprises the following types:

(1) removing harmful organisms by a physical method; for example, patent (WO2012/129031a2) applies an electric field of a certain intensity to the culture solution to kill harmful organisms; australian scholarika et al, using filtration methods to remove the hostile organisms (Borowitzka, M.A.,2005. Current microbiological in outdoor posts. in: Andersen, R.A. (Ed.), Algal Current techniques. academic Press, New York, pp.205-217.);

(2) the difference in tolerance of Microalgae cells and enemy organisms to the physiological environment is utilized to control the occurrence and development of biofouling, such as by increasing temperature (patent application CN 104593263A), rapid change in pH (Becher, E.W.,1994.Microalgae: Biotechnology and microbiology. Cambridge University Press, Cambridge);

(3) killing harmful organisms by adding additional chemicals, e.g. patent ZL98113428.9, to spirulina culture solution with NH content of not more than 3M₄ ⁺To kill rotifer, filamentous fungi, etc.; in the patent (ZL 201210404147.8), plant extracts such as nim, toosendan, celastrus angulatus and the like are utilized to kill harmful organisms; spanish scholars, Moreno-Garrido i. and canatate j.p. report the use of 10mg/L Quinine (Quinine) to kill ciliates appearing during the cultivation of dunaliella salina (Moreno-Garrido, i., canatate, j.p.,2001. assembly chemical compounds for controlling the expression enzymes in outdoor machines of the green algae dual naialella. aqua eng.eng.24, 107-114.); patent application (CN 104069521 a) discloses a method for treating biological pollution in microalgae cultivation process by using chlorine dioxide gas;

(4) the amount of harmful organisms is controlled by ecological environment regulation, for example, patent application (CN 104630067 a) discloses a pollution control method for microalgae cultivation, which dilutes/collects the culture solution when the cell density of harmful organisms in the culture solution reaches a certain value, thereby reducing the population density of harmful organisms and increasing the ecological competitive advantage of target microalgae.

However, the above pollution control method has the following problems: the removal and killing of the polluted organisms are not thorough, and the pollution is quickly reoccurred; or when killing harmful organisms, the cultured microalgae is also obviously damaged; or difficult operation, inconvenient large-scale use; or the treatment method is high in cost and is not suitable for large-scale use. How to establish a biological pollution control method which can thoroughly kill enemy organisms and disease organisms, has no influence or obvious influence on microalgae, is simple and convenient to operate, is economical and applicable, and is a technical problem to be solved urgently in the technical industry of microalgae biotechnology.

Disclosure of Invention

Aiming at the defects in the prior art, the invention provides a method for controlling biological pollution in a microalgae culture process by using a surfactant. The method can solve the problem of biological pollution in the open and closed microalgae culture processes, effectively kill enemy organisms such as rotifer, ciliate, chrysophyceae, amoeba, bellybird and the like and disease organisms such as fungi and the like, has no adverse effect or insignificant effect on the normal growth of the microalgae, and can keep the normal microalgae culture. The method for effectively controlling the biological pollution in the microalgae culture process by using the surfactant is found and established for the first time at home and abroad, has no adverse effect or insignificant effect on the growth of the microalgae, and has frontier and innovative properties. The important discovery provides a brand-new, economic and efficient technical method for overcoming the key technical problem of biological pollution in the large-scale culture of microalgae.

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

the technical idea of the invention is as follows: the surfactant has destructive effect on cell membrane of organism, and different organism cells have different tolerance capability to the surfactant. The invention utilizes the characteristics that the cells of the enemy organisms and pathogenic fungi such as chrysophyceae, rotifer, ciliates, amoeba and bellworms have poor tolerance to the surfactant and the cells of the microalgae have strong tolerance to the surfactant, uses a single surfactant or a surfactant composition or a detergent containing the surfactant within a proper concentration range, can selectively kill the enemy organisms and the pathogenic fungi, and does not produce negative influence or has insignificant negative influence on the normal growth of the microalgae. The method disclosed by the invention has very quick response, the swelling and final rupture and death of cells such as chrysophyceae, ciliates and rotifers can be seen after the treatment is carried out for 10 minutes by microscopic observation, and the swelling and death of amoeba and belleville can be seen after the treatment is carried out for 1 hour; and for fungi, after the fungi are treated for 12-24 hours, the fungi cell membrane is damaged through Trypan Blue staining and microscopic observation. The use concentrations of the different surfactants were determined by the following steps:

(1) culturing microalgae in a laboratory, adding various surfactants with different concentrations, surfactant compositions and detergents containing the surfactants into the microalgae liquid, mastering the influence of the surfactants on the growth of the microalgae, and determining the upper limit of the use concentration of various treating agents by taking the optical density of the microalgae which is not lower than 50% of the control optical density after adding the treating agents and culturing for 48 hours as a judgment standard;

(2) culturing microalgae under outdoor natural conditions, respectively adding various surfactants with different concentrations, surfactant compositions and detergents containing the surfactants into the algae liquid after discovering enemy biological pollution and disease fungal infection, mastering the control effect of the microalgae liquid on various enemy organisms and disease fungi, finding the lowest concentration capable of completely killing the enemy organisms and the disease fungi, and determining the lower limit of the use concentration of various treating agents for completely controlling the enemy biological pollution and the disease fungal infection;

(3) the range of concentration of each treating agent used for completely controlling the harmful biological pollution and the fungal infection is determined according to the lower limit and the upper limit of the concentration of each treating agent used.

A method for preventing and treating biological pollution in a microalgae culture process by using a surfactant comprises the following steps: the method comprises the steps of taking algae liquid every day, observing occurrence and development conditions of polluted organisms by using a microscope, adding a surfactant for preventing biological pollution in the 2 nd to 3 rd days after culture, or adding the surfactant for controlling the biological pollution when the biological pollution occurs, wherein the surfactant is at least one of dodecyl benzene sulfonic acid, sodium dodecyl benzene sulfonate, cocoanut oil acid diethanol amine, sodium dodecyl sulfate, fatty alcohol-polyoxyethylene ether and fatty alcohol-polyoxyethylene ether sodium sulfate, and the biological pollution comprises enemy biological pollution or/and disease fungal infection.

Further, the surfactant is any one of dodecyl benzene sulfonic acid, sodium dodecyl benzene sulfonate, coconut diethanol amine, sodium dodecyl sulfate, fatty alcohol-polyoxyethylene ether and fatty alcohol-polyoxyethylene ether sodium sulfate, and the use concentrations of the surfactant are respectively as follows aiming at different biological pollutions:

further, the surfactant is a combination of five of dodecyl benzene sulfonic acid or sodium dodecyl benzene sulfonate, coconut diethanol amine, sodium dodecyl sulfate, fatty alcohol-polyoxyethylene ether and fatty alcohol-polyoxyethylene ether sodium sulfate, and the composition (mass percentage) is as follows:

further, the compositions 1 to 16 were used at the following concentrations for different biofouling respectively:

further, the detergent containing the surfactant comprises a liquid detergent and a liquid laundry detergent, and the use concentrations of the detergent containing the surfactant are as follows aiming at different biological pollutants:

further, the microalgae include, but are not limited to, oil-ball algae (Graesiella), Chlorella (Chlorella), Scenedesmus (Scenedesmus).

Further, the enemy organisms include, but are not limited to, rotifers, ciliates, amoebae, bellies, and chrysophyceae ingesta.

Further, the disease fungi include but are not limited to proteus algaes and rhizophytes.

In the above method, it is critical to determine the range of concentration of various surfactants, surfactant compositions and detergents containing surfactants to be used for controlling the harmful biological contamination and fungal infection of diseases. The surfactant is a brand new technical method for controlling the biological pollution in the microalgae culture, and overcomes the defects of the prior art, including removal of polluted organisms, incomplete killing and fast reoccurrence of pollution; or when killing harmful organisms, the cultured microalgae is also obviously damaged; or difficult operation, inconvenient large-scale use; or the treatment method is high in cost and is not suitable for large-scale use. After the treatment of the surfactant, the polluted organisms are thoroughly killed, the microalgae can still grow normally without being influenced or influenced obviously, and the normal operation of microalgae culture is kept.

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

1. can completely control the pollution of enemy organisms and the infection of pathogenic fungi, and is not easy to cause repeated pollution; the growth and the propagation of the microalgae are not influenced or greatly influenced;

2. broad spectrum, a surfactant, or a surfactant composition, or a detergent containing the surfactant, can kill various enemy organisms and disease organisms;

3. simple operation and low cost. Adding the surfactant with required mass into the algae solution, dissolving completely, stirring uniformly, and then continuing culturing under normal conditions, so that the operation is time-saving and labor-saving; taking dodecyl benzene sulfonic acid as an example, the lowest concentration capable of completely controlling biological pollution and fungal infection of different enemies is 5mg L^-1-25mg L^-1Within the range, the treatment cost is only 0.05-0.25 yuan for treating 1000L of algae liquid.

Detailed Description

The method of the present invention and the effects achieved by the method will be described in further detail with reference to examples.

Example 1: effect of surfactants on microalgae growth

The biological pollution in the culture of the microalgae is controlled by using the surfactant, the influence of various surfactants (dodecyl benzene sulfonic acid, sodium dodecyl benzene sulfonate, coconut diethanol amine, sodium dodecyl sulfate, fatty alcohol-polyoxyethylene ether and sodium fatty alcohol-polyoxyethylene ether sulfate) on the growth of the microalgae is firstly known, and the concentration range of the surfactant which can be tolerated by various microalgae is determined. Three green algae, Chlorella pyrenoidosa (Chlorella pyrenoidosa), Scenedesmus obliquus (Scenedesmus obliquus) and oil-ball algae (Graesella sp.) were selected for testing. Chlorella pyrenoidosa (Chlorella pyrenoidosa) is an important economic microalgae, is commercially produced internationally and domestically, and is used as a health product for human (the application research of Chlorella pyrenoidosa in food progresses. food industry science and technology, 2017, 38 (17): 341-. Research finds that under the condition of nitrogen stress, a large amount of neutral lipid is accumulated in Chlorella cells and can be used as raw materials for producing biodiesel, so the Chlorella is also important energy microalgae (Enhanced lipid production in Chlorella by continuous culture. Bioresource technology.2014,161: 297-. The oil-producing microalgae (Graesiella sp.) is a species of oil-producing microalgae with large-scale cultivation potential, at 200m²Cultured in a runway-type open pond, the total lipid content reaches 33.4 percent (Effective culture of microbial for biological production: a pilot-scale evaluation of a novel ocean microalga Graesella sp.WBG-1, (2016)9:123.DOI10.1186/s 13068-016-0541-y). Scenedesmus obliquus (Scenedesmus obliquus) is one of microalgae widely distributed in nature, and has the advantages of rapid cell growth, high biomass yield, protein production in microalgae, and CO production₂The biological fixation and the removal of nitrogen and phosphorus in water bodies have application prospects (China fresh water algae-system, classification and ecology, 2006, Beijing: scientific publishing house; research on resource utilization of urban domestic wastewater based on Scenedesmus obliquus culture, water resource protection, 2016, 32 (3): 44-49). In the large-scale culture process of chlorella and scenedesmus, rotifer, ciliate, chrysophyceae, amoeba, bell worm and the like are often polluted, algae cells are ingested, and the culture is seriously affected (in the culture process of microalgae, the culture of chlorella is performedResearch on prevention and control of rotifer pollution, doctor paper of graduate institute of Chinese academy of sciences, 2014; effective control of Poteriocohroman as malonmensis in pilot-scale culture of Chlororella sorokiniana GT-1by main mail CO₂-a programmed low cut pH. Algal Research,2017,26: 436-; vernalophrys algivore gen. nov., sp. nov. (Rhizaria: Cercozoa: Vampyrellida), a New Algal Predator Isolated from outside door MassCulture of scene dimorphus. apple Environ Microbiol.,2015,81: 3900. sup. 3913); the frequent Occurrence of infections of endoparasitic fungi Rhizochytrium (Rhizophytium scendesmi) and ectoparasitic fungi Protococculus during the large-scale cultivation of oil cocci (Graesilla sp.) can lead to massive Algal cell death, reduced biomass production and even complete failure of cultivation (Isolation and cultivation of an endoparasite from the culture of Aspergillus oryzae Graesilla sp.WBG-1.Algal Research,2017,26: 371 and 379; anaerobic fermentation and cultivation of an exogenous microorganism bacterium culture of Escherichia coli sp.WBG-1.Journal of enzymology, 2018, etc.). To determine the effect of various surfactants on the growth of the three microalgae described above, a flask was used to culture oil globules (Graesiella sp.), Chlorella pyrenoidosa (Chlorella pyrenoidosa) and Scenedesmus obliquus (Scenedesmus obliquus). Medium composition and concentration: NaNO₃ 300mg·L^-1，K₂HPO₄·3H₂O 40mg·L^-1，MgSO₄·7H₂O 75mg·L^-1，CaCl₂·2H₂O 36mg·L^-1，Na₂CO₃ 36mg·L^-1，Fe-citrate 6mg·L^-1，Citric acid 6mg·L^-1，EDTA·Na₂5mg·L^-1And the microelement mother solution is 1 mL/L. The microelement mother liquor comprises the following components in percentage by weight: h₃BO₃ 2.86g/L，MnCl₂·4H₂O 1.8g/L，ZnSO₄·7H₂O 0.22g/L，CuSO₄·5H₂O 0.08g/L，(NH₄)₆Mo₇O₂₄·4H₂O 0.1104g/L，Co(NO₃)₂·6H₂O0.0494 g/L. The density of the inoculated algae solution is about OD₅₄₀0.1, the algae liquid is respectively filled in 300ml triangular flasks, 200ml of the algae liquid is filled in each triangular flask, the light and the dark are respectively carried out for 14 hours and 10 hours every day, the mixed gas of carbon dioxide and air (the volume ratio of the carbon dioxide to the air is 1:99) is continuously introduced into the algae liquid during the light to stir the algae liquid, and a carbon source is provided for the photosynthesis of the microalgae. Continuously introducing air into the algae solution to stir the algae solution in the dark.

Adding various surfactants into the algae solution, wherein the concentrations of the surfactants are 30mg/L, 100mg/L and 200mg/L, respectively, and determining the optical density OD of the algae solution after culturing for 48 hours by using culture without adding surfactant as Control (CK)₅₄₀. The change of optical density of the algae solution before and after culture indicates the growth of algae, and the optical density OD of the algae solution₅₄₀The more the growth, the faster the growth of the algae is indicated, which indicates that the surfactant has less inhibition effect on the growth of the algae; conversely, the slower the growth of the algae, the greater the inhibitory effect of the surfactant on the growth of the algae. The results are shown in Table 1.

TABLE 1 Effect of surfactants on growth of three microalgae

As can be seen from Table 1, the difference between the OD values of the three microalgae and the control is small at the concentration of 30mg/L, which indicates that the 6 surfactants have little influence on the growth of the three microalgae. The concentration is increased to 100mg/L, 4 surfactants of dodecyl benzene sulfonic acid, sodium dodecyl benzene sulfonate, cocoanut oil diethanol amine and lauryl sodium sulfate are used for treatment, the OD value of the algae liquid is lower than that of a control, but the reduction range is not large, and the influence on the growth is not large; the fatty alcohol polyoxyethylene ether and the fatty alcohol polyoxyethylene ether sodium sulfate are treated, and the OD values of the algae liquid are higher than 50% of the control, and are even lower than 50% of the control, which indicates that the algae liquid has great influence on growth; the concentration reaches 200mg/L, and the OD value of the algae liquid treated by 6 kinds of surface activity is far lower than 50% of the control OD value, which shows that the influence on the growth is great.

Comparing the effect of the dodecylbenzene sulfonic acid and the dodecylbenzene sulfonic acid sodium on the growth of the three microalgae, it can be seen that the effect of the dodecylbenzene sulfonic acid and the dodecylbenzene sulfonic acid sodium on the growth of the three microalgae is the same within the range of 30-200 mg/concentration.

The surfactant is used for controlling biological pollution in the culture of the microalgae, and the treatment method does not have great influence on the growth of the microalgae. The optical density of the microalgae cultured for 48 hours after the addition of the surfactant is not lower than (in individual cases, slightly lower than) 50% of the optical density of the control as a judgment standard, and the use concentration of each surfactant should not be higher than 100 mg/L.

Example 2 Effect of surfactant composition on microalgae growth

The use of surfactant compositions to control biofouling in microalgae culture requires first to understand the effect of various surfactant compositions on the growth of the microalgae in order to determine the range of surfactant concentrations that the various microalgae can tolerate. The 16 surfactant compositions were tested for their effect on the growth of oil globule algae, chlorella and scenedesmus using the method described in example 1. The components and the proportion of the surfactant composition are shown in table 2, and the influence of 16 compositions on the growth of three microalgae is shown in table 3.

TABLE 2 ingredients and proportions (in% by mass) of surfactant compositions

In the 16 compositions, the ratio (mass%) of each surfactant varied from 20% to 80%. Wherein the two surfactants, dodecylbenzene sulfonic acid and sodium dodecylbenzene sulfonate, have the same effect on the growth of microalgae (example 1), control of 7 enemy organisms (example 4) and control of 2 fungi (example 9), so that the same weight of dodecylbenzene sulfonic acid and sodium dodecylbenzene sulfonate can be substituted for each other and the effect is the same whether used alone or as a component of a composition. In the present invention, "dodecylbenzene sulfonic acid/sodium dodecylbenzene sulfonate" is used to mean dodecylbenzene sulfonic acid or sodium dodecylbenzene sulfonate, which have the same effect and can be substituted by each other.

TABLE 3 Effect of surfactant composition on growth of three microalgae

The data in Table 3 show that the concentration of the 16 compositions in the algae liquid is not more than 30mg/L, and the OD values of the algae liquid are slightly different from those of the control after 48 hours of culture, which indicates that the treatment has little influence on the growth of the three microalgae. The increase in concentration to 100mg/L showed a significant decrease in OD values for compositions 12, 13 and 16, some slightly above 50% of the control, some even below 50% of the control, and the remaining 13 compositions, although lower than the control, did not decrease much, all to a different extent above 50% of the control, indicating that the remaining compositions had little effect on growth of microalgae, except for the 3 compositions which had a greater effect on growth. The concentration reaches 200mg/L, and the OD value of the algae liquid treated by the 16 compositions is far lower than 50 percent of the OD value of a control, which shows that the growth is greatly influenced.

The surfactant composition is used for controlling biological pollution in microalgae culture, and the treatment method should not have great influence on the growth of microalgae. The optical density of the microalgae cultured for 48 hours after the surfactant composition is added is not lower than 50 percent (in some cases, slightly lower than) of the optical density of a control as a judgment standard, and the use concentration of each surfactant composition is not higher than 100 mg/L.

Example 3: effect of detergents on microalgae growth

The main effective component of commercially available washing products, such as liquid detergent and laundry detergent, is surfactant, and is generally a combination of several surfactants (application research of detecting 18 surfactants by high performance liquid chromatography tandem mass spectrometry, wo 2014, oceanic university, wo 2014, application of surfactant in liquid detergent, guangdong chemical industry, 2013, 40 (16): 251), so that the washing liquid is also used for controlling biological pollution. The use of detergents to prevent and control biofouling during microalgae culture requires knowledge of the effect of detergents on microalgae growth. The effect of different detergents on microalgae growth was tested using the method described in example 1 and the results are shown in table 4.

When the concentrations of the three detergents are 30mg/L and 100mg/L, after 48 hours of culture, the differences of the OD values of the three microalgae algal solutions and a control are small, which shows that the influences on the growth of the oil globule algae, the chlorella and the scenedesmus are small. When the concentration of the carving brand liquid detergent and the Libai liquid detergent reaches 200mg/L, although the difference between the OD value of the algae liquid and the contrast is increased, the OD value of the algae liquid is still far higher than 50% of the contrast OD value, which indicates that the influence on the growth of the microalgae is not great; blue moon laundry detergent treatment, except Scenedesmus OD value slightly higher than 50% of control, OD of oil ball algae and chlorella₅₄₀Are all lower than 50% of the control, which shows that 200mg/L of the blue moon laundry detergent has great influence on the growth of microalgae.

The detergent is used for controlling biological pollution in microalgae culture, and the treatment method should not have great influence on the growth of microalgae. The optical density of the microalgae after 48 hours of culture by adding the detergent is not lower than 50% of the reference optical density, the use concentration of the carving brand detergent and the Libai detergent can reach 200mg/L, and the concentration of the blue moon laundry detergent should not exceed 100 mg/L.

Table 4 different concentrations of detergent versus common microalgae growth (OD)₅₄₀) Influence of (2)

Example 4: method for controlling harmful biological pollution by dodecyl benzene sulfonic acid/sodium dodecyl benzene sulfonate

At 5m²The chlorella, scenedesmus and oil globules are respectively cultured in the open raceway pond, and the components and the concentration of a culture medium are as follows: NaNO₃300mg·L^-1，K₂HPO₄·3H₂O 40mg·L^-1，MgSO₄·7H₂O75mg·L^-1，CaCl₂·2H₂O36mg·L^-1，Na₂CO₃36mg·L^-1，Fe-citrate6mg·L^-1，Citric acid6mg·L^-1，EDTA·Na₂5mg·L^-1And the microelement mother solution is 1 mL/L. The microelement mother liquor comprises the following components in percentage by weight: h₃BO₃2.86g/L，MnCl₂·4H₂O1.8g/L，ZnSO₄·7H₂O0.22g/L，CuSO₄·5H₂O0.08g/L，(NH₄)₆Mo₇O₂₄·4H₂O0.1104g/L，Co(NO₃)₂·6H₂O0.0494g/L. The inoculation concentration is controlled at OD₅₄₀About 0.1, and culturing under natural light-temperature conditions. And in the culture process, carbon dioxide (steel cylinder commercial carbon dioxide) is introduced into the algae liquid to provide a carbon source for photosynthesis of the microalgae and control the pH of the algae liquid. And (3) adopting a pH controller to control the introduction of carbon dioxide on line: the microalgae photosynthesis absorbs and utilizes inorganic carbon source (CO) in the algae liquid₂，HCO₃ ^-) Raising the pH of the algae solution, opening the electromagnetic valve when the pH of the algae solution reaches the upper limit pH of 8.0 of the control range, introducing carbon dioxide into the algae solution, and absorbing CO by the algae solution₂And then the pH value is reduced, when the pH value is reduced to the lower limit pH value of 7.0 of the control range, the pH controller closes the electromagnetic valve, and the carbon dioxide stops introducing the algae liquid. The pH of the algae liquid is controlled within the set range of pH7.0-8.0 by the circulation. Taking the algae liquid from the culture pond to observe under a microscope once every morning and evening, and observing one or more harmful biological pollutions of naturally occurring chrysophyceae, ciliates, rotifers and the like in the algae liquid of chlorella, scenedesmus and oil globules after culturing for a period of time. After the biological contamination was found, the density of each enemy organism was measured in the morning and evening of the day.

The measuring method of the density of the enemy organisms comprises the following steps: taking 1.5ml of algae liquid and putting into a 2ml centrifuge tube with a cover, adding 1% osmic acid fixing solution prepared by phosphate buffer solution with pH7.0, tightly covering the centrifuge tube, and slightly shaking the centrifuge tube to uniformly disperse the fixing solution. Adding the fixed algae solution into a plankton counting frame (0.1ml specification counting frame), observing under a microscope, counting the number of enemy organisms according to a conventional method, and calculating the density of the enemy organisms.

When the individual density of the enemy organisms reaches more than 200/ml, the treatment can be carried out by using the surfactant to control the pollution of the enemy organisms. Taking out the algae liquid from the culture pond, and placing into a 50L incubator every time40L of algae solution was placed in each incubator. The using amount of the treating agent is calculated according to the volume of the algae liquid and the concentration of the treating agent (dodecyl benzene sulfonic acid and dodecyl benzene sodium sulfonate), the required amount of the treating agent is accurately weighed and added into the algae liquid. Fully stirring the algae liquid to ensure that the treating agent is completely dissolved and uniformly distributed. The incubator without added surfactant served as a Control (CK), which was performed in 3 replicates simultaneously with each treatment. The incubator is placed in a greenhouse and is subjected to aeration culture under the natural light-temperature condition. Continuously introducing CO into 8:00-20:00 incubator₂Mixed gas (CO) with air₂The volume ratio of the carbon source to the air is 1:99) stirring the algae liquid and providing a carbon source for the photosynthesis of the microalgae; 20: 00-8: 00 the next day, and continuously introducing air into the incubator. The effect of controlling the harmful organisms is observed after 24 hours of culture. After 24 hours of culture, the algae liquid is taken out from the culture box three times in succession and the survival condition of the enemy organisms is observed under a microscope. No viable enemy biological cells were observed in any of the three samples, and the treatment concentration was deemed to be sufficient to kill the enemy organisms, and the "survival of the enemy organisms" was counted as 0. Three times of sampling are carried out continuously, so long as living enemy biological cells are found once, even if the number of the enemy biological cells is extremely small, the killing effect of the treatment concentration is considered to be incomplete, and the survival rate of the enemy biological cells is counted to be 1.

Experiments prove that: 1. for different enemy organisms, the harmful organisms are completely killed, and the required concentration of the treating agent is different; the minimum concentration of the treating agent is the same for the same enemy organism, whether the enemy organism appears in the chlorella culture process or in the scenedesmus culture process to completely kill the enemy organism. That is, the same kind of harmful organisms appearing in different microalgae culture processes can be controlled by the same treatment method; 2. the control effect of the same concentration of the dodecyl benzene sulfonic acid and the dodecyl benzene sulfonic acid on the same kind of harmful organisms is the same. The effect of different concentrations of dodecylbenzene sulfonic acid and sodium dodecylbenzene sulfonate on 7 enemy organisms is shown in table 5.

TABLE 5 Effect of dodecyl benzene sulfonic acid/sodium dodecyl benzene sulfonate on controlling harmful organisms

As can be seen from Table 5, the lowest concentrations of dodecylbenzene sulfonic acid/sodium dodecylbenzene sulfonate required for completely killing different enemy organisms are different, 5mg/L can completely kill golden algae, 10mg/L can completely kill 2 ciliates, 15mg/L can completely kill bell-shaped insects, 20mg/L can completely kill 2 rotifers, and the concentration reaches 25mg/L can completely kill amoeba.

Considering the minimum concentration of dodecylbenzene sulfonic acid/sodium dodecylbenzene sulfonate required to completely kill the undesirable organisms and the effect on the growth of the microalgae (example 1), a suitable concentration range for dodecylbenzene sulfonic acid/sodium dodecylbenzene sulfonate to control undesirable organisms is shown in Table 6.

TABLE 6 appropriate concentration ranges for dodecylbenzene sulfonic acid/sodium dodecylbenzene sulfonate for controlling harmful organisms

Example 5: cocoanoic acid diethanolamine to control harmful bio-pollution

The method for controlling the pollution of the harmful organisms by using the coconut diethanol amine, the method for calculating the types, the culture method and the dosage of the treating agent of the microalgae, the method for weighing and adding the microalgae, the method for observing the harmful organisms, the method for measuring the density and the method for judging the survival condition are the same as the embodiment 4.

The same as the case of controlling harmful organisms by dodecyl benzene sulfonic acid/sodium dodecyl benzene sulfonate, experiments prove that: for different harmful organisms, the harmful organisms are completely killed, and the concentration of the needed cocoanut oil acid diethanol amine is different; for the same kind of enemy organism, the minimum concentration of the cocodiethanol amine is the same whether the enemy organism appears in the chlorella culture process or in the scenedesmus culture process and completely kills the enemy organism. The effect of cocodiethanol amine on the control of harmful bio-fouling is shown in table 7.

TABLE 7 control Effect of Cocoanoic diethanolamine on enemy organisms

The data in Table 7 show that the minimum concentration of cocodiethanol amine required to completely kill different enemy organisms is different, 5mg/L can completely kill golden algae, 10mg/L can completely kill bell worm (vortex crassifolia) and a ciliate (Oxytricha sp.), and 15mg/L can completely kill another ciliate (Tetrahymena roseta); 20mg/L can completely kill rotifers (Lecane inermis) and amoeba (Vanella sp.); another rotifer (Brachionus calyciflorus) was completely killed at 25 mg/L.

Considering the minimum concentration of cocodiethanol amine required to completely kill the enemy organisms and the effect on microalgae growth (example 1), a suitable concentration range for cocodiethanol amine to control the enemy organisms is shown in table 8.

TABLE 8 Cocoanoic diethanolamine concentration range suitable for control of undesirable organisms

Example 6: control of harmful biological pollution by sodium dodecyl sulfate

The pollution of harmful organisms is controlled by utilizing the lauryl sodium sulfate, and the species of microalgae, the culture method, the dosage calculation method of the treating agent, the weighing and adding method, the observation of harmful organisms, the density measurement and the survival condition judgment method are all the same as those in the embodiment 4.

The same situation of controlling harmful organisms with dodecyl benzene sulfonic acid/sodium dodecyl benzene sulfonate and coconut diethanol amine is proved by experiments that: different harmful organisms are completely killed, and the required concentration of the sodium dodecyl sulfate is different; for the same enemy organism, the lowest concentration of the sodium dodecyl sulfate is the same whether the enemy organism appears in the chlorella culture process or in the scenedesmus culture process to completely kill the enemy organism. The effect of sodium lauryl sulfate on controlling harmful biological contamination is shown in Table 9.

TABLE 9 Effect of sodium lauryl sulfate on controlling harmful organisms

The data in table 9 shows that the minimum concentration of sodium lauryl sulfate required to completely kill different enemy organisms is different. 20mg/L can completely kill chrysophyceae, ciliates (Tetrahymena rostrata), and bellmouth (vortex icella crassialis); 30mg/L can completely kill another ciliate (Oxytricha sp.). For both rotifers and amoebae, they could not be completely killed even at a concentration of 200 mg/L.

Considering the minimum concentration of sodium dodecyl sulfate required to completely kill the undesirable organisms and the effect on microalgae growth (example 1), a suitable concentration range for sodium dodecyl sulfate to control undesirable organisms is shown in Table 10.

TABLE 10 optimum concentration range for controlling harmful organisms with sodium lauryl sulfate

Example 7: fatty alcohol-polyoxyethylene ether for controlling harmful biological pollution

The method for controlling the pollution of harmful organisms by using the fatty alcohol-polyoxyethylene ether, the method for calculating the types and the culture methods of the microalgae, the method for adding the treatment agent, the method for observing the harmful organisms, the method for measuring the density and the method for judging the survival condition are the same as those in the embodiment 4.

The same situation of controlling harmful organisms with dodecyl benzene sulfonic acid/sodium dodecyl benzene sulfonate and coconut diethanol amine is proved by experiments that: completely killing different harmful organisms, wherein the concentrations of the required fatty alcohol-polyoxyethylene ether are different; for the same kind of enemy organism, the minimum concentration of the fatty alcohol-polyoxyethylene ether is the same whether the enemy organism appears in the chlorella culture process or in the scenedesmus culture process to completely kill the enemy organism. The effect of fatty alcohol polyoxyethylene ether on controlling the pollution of harmful organisms is shown in table 11.

TABLE 11 Effect of fatty alcohol polyoxyethylene ethers on controlling harmful organisms

The data in table 11 show that the minimum concentration of fatty alcohol-polyoxyethylene ether required to completely kill different enemy organisms is different. 20mg/L can completely kill chrysophyceae, 25mg/L can completely kill Bellis (vortex crassia), rotifer (Brachionus calyciflorus) and Proteus (Vanella sp.); 30mg/L can completely kill rotifer (Lecane insects) and ciliate (Tetrahymena rostrata); 50mg/L can completely kill ciliates (Oxytricha sp.).

The minimum concentration required by the fatty alcohol-polyoxyethylene ether for completely killing the harmful organisms and the influence on the growth of the microalgae are comprehensively considered (example 1), and the suitable concentration range of the fatty alcohol-polyoxyethylene ether for controlling the harmful organisms is shown in table 12.

TABLE 12 fatty alcohol polyoxyethylene ether control of the appropriate concentration range for the pest organisms

Enemy organisms	Concentration range mg/L of fatty alcohol-polyoxyethylene ether
		Lecane insects of rotifer	30-100
Brachionus calyciflorus (Brachionus cayensis) Brachionus calyciflorus	25-100
		Ciliate Oxytricha sp.	50-100
Ciliate Tetrahymena rostrata	30-100
		Amoeba sp.	25-100
The Bell insect Vorticella crassialis	25-100
		The chrysophyceae Poterichomonas sp.	20-100

Example 8: controlling harmful biological pollution by sodium fatty alcohol-polyoxyethylene ether sulfate

The method for controlling the pollution of harmful organisms by using the sodium alcohol ether sulphate is the same as the embodiment 4 in the types, the culture method, the calculation method of the using amount of the treating agent, the weighing and adding method, the observation of the harmful organisms, the density measurement and the survival condition judgment method of the microalgae.

The same as the conditions of controlling harmful organisms by using the dodecyl benzene sulfonic acid/sodium dodecyl benzene sulfonate, the coconut diethanol amine and the fatty alcohol polyoxyethylene, experiments prove that: completely killing different harmful organisms, wherein the concentrations of the required fatty alcohol-polyoxyethylene ether are different; for the same kind of enemy organism, the minimum concentration of the sodium alcohol ether sulphate is the same whether the enemy organism appears in the process of cultivating chlorella or scenedesmus and completely kills the enemy organism. The effect of fatty alcohol polyoxyethylene ether on controlling the pollution of harmful organisms is shown in table 13.

TABLE 13 Effect of sodium fatty alcohol Ether sulfate on controlling harmful organisms

The data in table 13 show that the minimum concentration of fatty alcohol polyoxyethylene ether sulfuric acid required to completely kill different enemy organisms is different. 10mg/L can completely kill golden algae, 15mg/L can completely kill bell-shaped insects (vortex crassia) and ciliates (Tetrahymena rostrata), 30mg/L can completely kill amoeba (Vanella sp.) and ciliates (Oxytricha sp.), and 50mg/L can completely kill 2 types of rotifers.

The minimum concentration required for completely killing the harmful organisms and the influence on the growth of the microalgae are comprehensively considered (example 1), and the appropriate concentration range of the sodium alcohol ether sulfate for controlling the harmful organisms is shown in table 14.

TABLE 14 optimum concentration range for sodium alcohol Ether sulfate for control of harmful organisms

Example 9: use of dodecylbenzene sulfonic acid/sodium dodecylbenzene sulfonate for controlling fungal infection in culture of oil globule algae Graesiella sp

At 5m²The method is characterized in that the oil globule algae Graesiella sp is cultured in an open raceway pond, and the components and the concentration of a culture medium are as follows: NaNO₃300mg·L^-1，K₂HPO₄·3H₂O40mg·L^-1，MgSO₄·7H₂O75mg·L^-1，CaCl₂·2H₂O36mg·L^-1，Na₂CO₃36mg·L^-1，Fe-citrate6mg·L^-1，Citric acid6mg·L^-1，EDTA·Na₂5mg·L^-1And the microelement mother solution is 1 mL/L. The microelement mother liquor comprises the following components in percentage by weight: h₃BO₃2.86g/L，MnCl₂·4H₂O1.8g/L，ZnSO₄7H₂O0.22g/L，CuSO₄·5H₂O0.08g/L，(NH₄)₆Mo₇O₂₄·4H₂O0.1104g/L，Co(NO₃)₂·6H₂O0.0494g/L. The inoculation concentration is controlled at OD₅₄₀About 0.1, the microalgae photosynthesis absorbs and utilizes inorganic carbon source (CO) in the algae liquid₂，HCO₃ ^-) Raising the pH of the algae solution, opening the electromagnetic valve when the pH of the algae solution reaches the upper limit pH of 8.0 of the control range, introducing carbon dioxide into the algae solution, and absorbing CO by the algae solution₂And then the pH value is reduced, when the pH value is reduced to the lower limit pH value of 7.0 of the control range, the pH controller closes the electromagnetic valve, and the carbon dioxide stops introducing the algae liquid. The pH of the algae liquid is controlled within the set range of pH7.0-8.0 by the circulation. Taking the algae liquid from the culture pond to carry out microscope observation once every day in the morning and at night, and observing naturally occurring fungal infection in the algae liquid after culturing for a period of time. There are 2 kinds of fungi infecting the oil globules, endophytic fungi proteolium (amoeboepinedium protococcum) and ectomycorrhizal fungi chytrium (rhizochytrium spora). After the fungal infection was found, the infection rate of the oleococcus cells with fungal infection was determined in the morning and evening of the day.

The method for measuring the infection rate of the oil globule algae cell infected by the fungus comprises the following steps: taking an algae liquid sample, adding the algae liquid sample into a blood counting chamber, observing under a microscope, respectively counting algae cells infected by fungi and the total number of the algae cells, and calculating the infection rate of the algae cells according to the following formula:

the infection rate (number of infected algal cells/total number of algal cells) × 100%

When the infection rate of the cells reaches about 5 percent, the cells can be treated by the surfactant to control fungal infection. The algal solution was taken out of the culture pond and put into 50L incubators, 40L per incubator. According to the volume of the algae liquid and the treatment agent (dodecyl benzene sulfonic acid andsodium dodecyl benzene sulfonate) to calculate the usage amount of the treating agent, accurately weighing the required amount of the treating agent, and adding the treating agent into the algae liquid. Fully stirring the algae liquid to ensure that the treating agent is completely dissolved and uniformly distributed. Each treatment was performed in 3 replicates simultaneously, and incubation without treatment was used as a Control (CK). The incubator is placed in a greenhouse and is subjected to aeration culture under the natural light-temperature condition. Continuously introducing CO into 8:00-20:00 incubator₂Mixed gas (CO) with air₂The volume ratio to air was 1:99) stirring the algae liquid and providing a carbon source for photosynthesis of the microalgae; 20: 00-8: 00 the next day, and continuously introducing air into the incubator. After culturing for 72 hours, the fungus control effect is observed, and the fungus infection condition is observed under a microscope by continuously taking algae liquid from the incubator three times. Three repeat treatment incubators, each with three samples, were observed for no fungal infection, and the treatment concentration was deemed to be sufficient to control fungal infection, "fungal infection" was 0. Three incubators were treated in triplicate, each sampled three times in succession, and the treatment concentration was deemed not to completely control the fungal infection as long as it was found once, even if it was in an extremely small number, "fungal infection" was 1.

Experiments prove that the dodecyl benzene sulfonic acid and the sodium dodecyl benzene sulfonate with the same concentration have the same effect whether the fungus is endophytic fungus or exogenously fungal. In the following description, "dodecylbenzene sulfonic acid/sodium dodecylbenzene sulfonate" is used to indicate that dodecylbenzene sulfonic acid and sodium dodecylbenzene sulfonate have the same effect and can be substituted for each other. The effect of dodecylbenzene sulfonic acid/sodium dodecylbenzene sulfonate on the control of fungal infection in the culture of Oncococcus is shown in Table 15.

TABLE 15 controlling effect of dodecylbenzene sulfonic acid/sodium dodecylbenzene sulfonate on fungi

The dodecylbenzene sulfonic acid/dodecylbenzene sulfonic acid sodium salt with the concentration of 10-70mg/L can kill zoospores of pathogenic fungi and completely control the pollution of the pathogenic fungi. The control effect of different concentrations of dodecylbenzene sulfonic acid/sodium dodecylbenzene sulfonate on pathogenic fungal infection and the effect on the growth of the oil globules algae are considered together, and the suitable concentration ranges are shown in table 16.

TABLE 16 optimum concentration ranges for dodecylbenzene sulfonic acid/sodium dodecylbenzene sulfonate for controlling fungal infections

Example 10: control of fungal infections in oil globule algae Graesiella sp

The method for controlling the fungal contamination in the culture of oleaginous microalgae oil globule sp by using sodium dodecyl sulfate, the culture method of microalgae, the method for measuring the infection rate of algal cells infected by fungi, the method for calculating the dosage of the treating agent, the method for weighing and adding the treating agent, and the method for judging the fungal infection control effect are the same as those in the embodiment 9. The effect of sodium lauryl sulfate on fungal infection control is shown in table 17.

TABLE 17 Effect of sodium lauryl sulfate on controlling fungal infections

The ammonium dodecyl sulfate with the concentration of 50-70mg/L can kill zoospores of pathogenic fungi and completely control the pollution of the pathogenic fungi. The control effect of sodium lauryl sulfate on pathogenic fungal infection and the effect on the growth of Oncolococcus sp were considered in combination at various concentrations, and suitable concentration ranges are shown in Table 18.

TABLE 18 suitable concentration ranges for sodium lauryl sulfate for controlling fungal infections

Fungi	Sodium dodecyl sulfate concentration range mg/L
		Protococcarum proteolicus a	50-100
Rhizochytrium r	50-100

Example 11: control of fungal infections in culture of glomus sp

The method for controlling the fungal contamination in the culture of oleaginous microalgae oil globule sp by using the fatty alcohol-polyoxyethylene ether, the culture method of microalgae, the method for measuring the infection rate of algal cells infected by fungi, the method for calculating the dosage of the treating agent, the method for weighing and adding the treating agent, and the method for judging the fungal infection control effect are all the same as those in the embodiment 9. The results are shown in Table 19.

TABLE 19 fungal infection after treatment with fatty alcohol polyoxyethylene ether

The concentration reaches 30mg/L, and the fatty alcohol-polyoxyethylene ether can kill 2 pathogenic fungi zoospores and completely control the pathogenic fungi pollution. The control effect of fatty alcohol-polyoxyethylene ethers with different concentrations on pathogenic fungal infection and the influence on the growth of the glomus sp are comprehensively considered, and the appropriate concentration range is shown in table 20.

TABLE 18 fatty alcohol polyoxyethylene ether suitable concentration ranges for controlling fungal infections

Fungi	Concentration range mg/L of fatty alcohol-polyoxyethylene ether
		Protococcarum proteolicus a	30-100
Rhizochytrium r	30-100

Example 12: control of fungal contamination in culture of oil globules Graesiella sp using diethanolamine cocoate

The method for controlling fungal contamination in culture of oleaginous microalgae oil globule sp by using coconut diethanol amine, the method for culturing microalgae, the method for measuring the infection rate of algal cells infected by fungi, the method for calculating the dosage of the treating agent, the method for weighing and adding the treating agent, and the method for judging the control effect of fungal infection are all the same as those in the embodiment 9. The results are shown in Table 21.

TABLE 21 fungal infection after treatment with Cocoanoic acid diethanolamine

As long as the concentration of the coco diethanol amine reaches 10mg/L, the infection of 2 pathogenic fungi can be completely controlled. The control effect of different concentrations of cocodiethanol amine on pathogenic fungal infection and the effect on the growth of the oil globules were considered together, and suitable concentration ranges are shown in table 22.

TABLE 22 suitable concentration ranges for sodium lauryl sulfate for controlling fungal infections

Fungi	Concentration range mg/L of fatty alcohol-polyoxyethylene ether
		Protococcarum proteolicus a	10-100
Rhizochytrium r	10-100

Example 13: control of fungal contamination in culture of glomus sp by sodium alcohol ether sulphate

The method for controlling the fungal contamination in the culture of oleaginous microalgae oil globule sp by using the sodium alcohol ether sulphate is the same as that in the embodiment 9, the culture method of microalgae, the method for measuring the infection rate of algal cells infected by fungi, the method for calculating the dosage of the treating agent, the method for weighing and adding the treating agent and the method for judging the fungal infection control effect are all the same as those in the embodiment 9. The results are shown in Table 23.

TABLE 23 fungal infection after treatment with sodium fatty alcohol Ether sulfate

As is clear from Table 23, the infection with pathogenic fungi could not be completely controlled by culturing for 72 hours after treating with sodium alcohol ether sulfate at concentrations of 10mg/L, 30mg/L, 50mg/L, 70mg/L, and 100 mg/L.

Sodium fatty alcohol polyoxyethylene ether sulphate is not suitable for controlling the infection of fungi proteus alginolyticus a. protococcum and rhizophyceae r. scendesmi in culture of gloococcus graesella sp.

Example 14: control of hostile biological contamination and fungal infections using surfactant compositions

The components and the ratio of the surfactant composition are shown in table 2.

The surfactant composition was used to control the contamination of harmful organisms during the cultivation of microalgae, and the species of microalgae, the cultivation method, the method for calculating the amount of treating agent, the method for weighing and adding, the method for observing harmful organisms, the method for measuring density, and the method for determining survival were all the same as those in example 4.

The method for controlling fungal infection in the course of culturing microalgae using the surfactant composition, the method for culturing microalgae, the method for determining the infection rate of algal cells infected with fungi, the method for calculating the amount of the treating agent, the method for weighing and adding the treating agent, and the method for determining the effect of controlling fungal infection were the same as those of example 9.

The control effect of 16 surfactant compositions on enemy biofouling and on fungal infections is shown in tables 24-39.

TABLE 24 Effect of surfactant combination 1 on controlling harmful organisms and fungi

TABLE 25 Effect of surfactant combination 2 on controlling hostile biofouling and fungal infections

TABLE 26 Effect of surfactant combination 3 on controlling hostile biofouling and fungal infections

TABLE 27 Effect of surfactant combination 4 on controlling hostile biofouling and fungal infections

TABLE 28 Effect of surfactant combination 5 on controlling hostile biofouling and fungal infections

TABLE 29 Effect of surfactant combination 6 on controlling hostile biofouling and fungal infections

TABLE 30 Effect of surfactant combination 7 on controlling hostile biofouling and fungal infections

TABLE 31 Effect of surfactant combination 8 on controlling hostile biofouling and fungal infections

TABLE 32 Effect of surfactant combination 9 on controlling hostile biofouling and fungal infections

TABLE 33 Effect of surfactant combination 10 on controlling hostile biofouling and fungal infections

TABLE 34 Effect of surfactant combination 11 on controlling hostile biofouling and fungal infections

TABLE 35 Effect of surfactant combination 12 on controlling hostile biofouling and fungal infections

TABLE 36 Effect of surfactant combination 13 on controlling hostile biofouling and fungal infections

TABLE 37 Effect of surfactant combination 14 on controlling hostile biofouling and fungal infections

TABLE 38 Effect of surfactant combination 15 on controlling hostile biofouling and fungal infections

TABLE 39 Effect of surfactant combination 16 on controlling hostile biofouling and fungal infections

A combination of the control of fouling by enemies and fungal infections and the effect on microalgae growth of different concentrations of surfactant compositions (example 2) was considered, and suitable concentration ranges for each composition are shown in tables 40-41.

TABLE 40 suitable concentration ranges for the surfactant compositions to control undesirable organisms

TABLE 41 suitable concentration ranges for surfactant compositions to control fungal infections

Example 15: detergent for controlling harmful biological pollution and fungal infection

The main effective component of washing products sold in the market, such as liquid detergent and laundry detergent, is surfactant, and is generally a combination of several surfactants (application research of detecting 18 surfactants by high performance liquid chromatography tandem mass spectrometry, university of oceans in china, thesis in shui, 2014; application of surfactant in liquid detergent, guangdong chemical industry, 2013, 40 (16): 251), so that the washing liquid is also used for controlling harmful organisms and fungal pollution.

The detergent is used to control the pollution of harmful organisms in the process of culturing microalgae, and the species, culturing method, dosage calculation method, weighing and adding method, observation of harmful organisms, density measurement and survival condition determination method of microalgae are the same as those in example 4.

The method for controlling fungal infection in the process of culturing microalgae by using the detergent, the method for culturing microalgae, the method for measuring the infection rate of algal cells infected by fungi, the method for calculating the amount of the treating agent, the method for weighing and adding the treating agent, and the method for determining the effect of controlling fungal infection are the same as those in example 9.

The control effect of the three detergents on enemy biological contamination and fungal infection is shown in tables 42-44.

Effect of detergent carved on table 42 for controlling harmful bio-pollution and fungal infection

TABLE 43 Effect of Libai detergent in controlling harmful bio-contamination and fungal infection

TABLE 44 effectiveness of the blue moon laundry detergent in controlling harmful bio-contamination and fungal infections

In combination with the control of harmful biological contamination, fungal infection and the effect on microalgae growth of the various detergents, the appropriate concentration ranges for the 3 detergents are shown in tables 45-46.

TABLE 45 appropriate concentration ranges for detergents for controlling hostile biofouling

TABLE 46 suitable concentration ranges for detergents for fungal control

Example 16: method for controlling harmful biological pollution in microalgae open pond culture by using dodecyl benzene sulfonic acid/sodium dodecyl benzene sulfonate

5m²Respectively culturing Chlorella pyrenoidosa (Chlorella) and Scenedesmus obliquus (Scenedesmus obliquus) in an open raceway pond, wherein the components and the concentration of a culture medium are as follows: NaNO₃300mg·L^-1，K₂HPO₄·3H₂O40mg·L^-1，MgSO₄·7H₂O75mg·L^-1，CaCl₂·2H₂O36mg·L^-1，Na₂CO₃36mg·L^-1，Fe-citrate6mg·L^-1，Citric acid6mg·L^-1，EDTA·Na₂5mg·L^-1And the microelement mother solution is 1 mL/L. The microelement mother liquor comprises the following components in percentage by weight: h₃BO₃2.86g/L，MnCl₂·4H₂O1.8g/L，ZnSO₄·7H₂O0.22g/L，CuSO₄·5H₂O0.08g/L，(NH₄)₆Mo₇O₂₄·4H₂O0.1104g/L，Co(NO₃)₂·6H₂O0.0494g/L. The inoculation concentration is controlled at OD₅₄₀About 0.1, and culturing under natural light-temperature conditions. And in the culture process, carbon dioxide (steel cylinder commercial carbon dioxide) is introduced into the algae liquid to provide a carbon source for photosynthesis of the microalgae and control the pH of the algae liquid. And (3) adopting a pH controller to control the introduction of carbon dioxide on line: the photosynthesis of microalgae absorbs inorganic carbon source in the algae liquid, the pH of the algae liquid rises, when the pH of the algae liquid reaches the upper limit pH of 8.0 of the control range, the pH controller opens the electromagnetic valve, carbon dioxide is introduced into the algae liquid, and the algae liquid absorbs CO₂Then the pH value is reduced, when the pH value is reduced to the lower limit pH value of 7.0 of the control range, the pH controller closes the electromagnetic valve, and the carbon dioxide stops introducing the algae liquid. Circulating in this way, the pH of the algae liquid is controlled to be setThe pH value is 7.0-8.0. Taking the algae liquid from the culture pond to observe under a microscope once every morning and evening, and observing one or more enemy biological pollutions such as naturally occurring chrysophyceae, ciliates, rotifers and the like in the chlorella and scenedesmus algae liquid after culturing for a period of time. The situation that several enemy organisms occur simultaneously is generally that one of the enemy organisms is dominant, and the quantity of other types is small. If one kind of enemy organism occurs, the enemy organism is taken as a control object, and if several kinds of enemy organisms occur simultaneously, a dominant amount of enemy organisms is taken as a control object. The density of each enemy organism was measured every morning and evening.

The measuring method of the density of the enemy organisms comprises the following steps: placing 1.5ml of the algae solution into a 2ml centrifuge tube with a cover, adding a drop of osmate 1% fixation solution prepared by phosphate buffer solution with pH7.0, tightly covering the centrifuge tube, and gently shaking the centrifuge tube to uniformly disperse the fixation solution. Adding the fixed algae solution into a plankton counting frame (0.1ml specification counting frame), observing under a microscope, counting the number of enemy organisms according to a conventional method, and calculating the density of the enemy organisms.

When the density of the individual enemy organisms as the control object reaches more than 200/ml, the algae liquid can be added with dodecyl benzene sulfonic acid/sodium dodecyl benzene sulfonate for treatment, and the lowest concentration of the dodecyl benzene sulfonic acid/sodium dodecyl benzene sulfonate which can completely control the pollution of the enemy organisms is adopted for treatment. Accurately measuring the depth of the algae liquid in the culture pond, and calculating the volume of the culture liquid according to the depth of the algae liquid and the area of the culture pond. Determining the treatment concentration of the dodecylbenzene sulfonic acid/sodium dodecylbenzene sulfonate according to the species of the enemy organisms, then calculating the dosage according to the volume of the algae liquid and the treatment concentration of the dodecylbenzene sulfonic acid/sodium dodecylbenzene sulfonate, accurately weighing the needed dodecylbenzene sulfonic acid/sodium dodecylbenzene sulfonate, and adding the dodecylbenzene sulfonic acid/sodium dodecylbenzene sulfonate into a culture pond. The impeller stirrer of the culture pond drives the algae liquid to flow, and the treating agent is quickly dissolved completely and uniformly distributed in the flowing algae liquid. After culturing for 24 hours, continuously taking the algae liquid from the culture pond for three times, observing the survival condition of the enemy organisms under a microscope, and observing no living enemy organisms after three times of sampling, wherein the treatment concentration is considered to completely kill the enemy organisms, and the survival rate of the enemy organisms is 0. Three times of sampling are carried out continuously, so long as life enemy organisms are found once, even if the number of the life enemy organisms is extremely small, the killing effect of the treatment concentration is considered to be incomplete, and the survival rate of the enemy organisms is counted to be 1.

The types of naturally occurring enemy organisms, the area of the culture pond, the depth of the algal solution, the concentration of the treating agent, the amount of the treating agent used, and the survival of the enemy organisms after 24 hours of treatment are shown in Table 47.

The treatment effect is as follows: after 24 hours of culture, the algae liquid is taken for many times for observation, and the condition of harmful biological pollution is not seen. Culturing for 7 days, and observing no harmful organisms in the algae solution.

TABLE 47 dodecylbenzene sulfonic acid/sodium dodecylbenzene sulfonate for controlling harmful biological contamination in microalgae open pond culture

Example 17: cocoanoic acid diethanolamine for controlling harmful biological pollution in microalgae open pond culture

The cocinic acid diethanolamine is used to control the pollution of harmful organisms in the process of microalgae culture, and the species, culture method, dosage calculation method, weighing and adding method, observation of harmful organisms, density measurement and survival condition determination method of microalgae are the same as those in example 16. The coconut diethanol amine can completely control the lowest concentration of harmful biological pollution for treatment.

The types of naturally occurring enemy organisms, the area of the culture pond, the depth of the algal solution, the concentration of the treating agent, the amount of the treating agent used, and the survival of the enemy organisms after 24 hours of treatment are shown in Table 48.

TABLE 48 Coco diethanol amine to control the harmful biological contamination in open pond culture of microalgae

Example 18: sodium dodecyl sulfate for controlling harmful biological pollution in microalgae open pond culture

The pollution of harmful organisms in the process of culturing the microalgae is controlled by utilizing the lauryl sodium sulfate, and the types, the culturing method, the dosage calculation method, the weighing and adding method, the observation of the harmful organisms, the density measurement and the survival condition judgment method of the microalgae are all the same as those in the embodiment 16. The lowest concentration of harmful organisms can be completely controlled by adopting the sodium dodecyl sulfate for treatment.

The types of naturally occurring enemy organisms, the area of the culture pond, the depth of the algal solution, the concentration of the treating agent, the amount of the treating agent used, and the survival of the enemy organisms after 24 hours of treatment are shown in Table 49.

TABLE 49 sodium dodecyl sulfate control of harmful biological contamination in open pond culture of microalgae

Example 19: fatty alcohol-polyoxyethylene ether for controlling harmful biological pollution in microalgae open pond culture

The method for controlling the pollution of harmful organisms in the process of culturing the microalgae by using the fatty alcohol-polyoxyethylene ether is the same as that in example 16 in the types, the culturing method, the dosage calculation method, the weighing and adding method, the observation of the harmful organisms, the density measurement and the survival condition judgment method of the microalgae. The lowest concentration of the harmful organisms can be completely controlled by adopting the fatty alcohol-polyoxyethylene ether for treatment.

The types of naturally occurring enemy organisms, the area of the culture pond, the depth of the algal solution, the concentration of the treating agent, the amount of the treating agent used, and the survival of the enemy organisms after 24 hours of treatment are shown in Table 50.

TABLE 50 fatty alcohol polyoxyethylene ether control of harmful organisms in open microalgae pond culture

Example 20: method for controlling harmful biological pollution in microalgae open pond culture by fatty alcohol-polyoxyethylene ether sodium sulfate

The method for controlling the pollution of harmful organisms in the process of culturing the microalgae by using the sodium alcohol ether sulphate is the same as that in the example 16 in the types, the culturing method, the dosage calculation method, the weighing and adding method, the observation of the harmful organisms, the density measurement and the survival condition judgment method of the microalgae. The lowest concentration of harmful organisms can be completely controlled by adopting the sodium fatty alcohol-polyoxyethylene ether sulfate for treatment.

The types of naturally occurring enemy organisms, the area of the culture pond, the depth of the algal solution, the concentration of the treating agent, the amount of the treating agent used, and the survival of the enemy organisms after 24 hours of treatment are shown in Table 51.

TABLE 51 sodium alcohol Ether sulfate control of harmful biological contamination in open pond culture of microalgae

Example 21: method for controlling fungal infection in microalgae open pond culture by using dodecyl benzene sulfonic acid/sodium dodecyl benzene sulfonate

At 5m²The method is characterized in that the oil globule algae Graesiella sp is cultured in an open raceway pond, and the components and the concentration of a culture medium are as follows: NaNO₃300mg·L^-1，K₂HPO₄·3H₂O40mg·L^-1，MgSO₄·7H₂O75mg·L^-1，CaCl₂·2H₂O36mg·L^-1，Na₂CO₃36mg·L^-1,Fe-citrate6mg·L^-1，Citric acid6mg·L^-1，EDTA·Na₂5mg·L^-1And the microelement mother solution is 1 mL/L. The microelement mother liquor comprises the following components in percentage by weight: h₃BO₃2.86g/L，MnCl₂·4H₂O1.8g/L，ZnSO₄·7H₂O0.22g/L，CuSO₄·5H₂O0.08g/L，(NH₄)₆Mo₇O₂₄·4H₂O0.1104g/L，Co(NO₃)₂·6H₂O0.0494g/L. The inoculation concentration is controlled at OD₅₄₀About 0.1, and culturing under natural light-temperature conditions. And in the culture process, carbon dioxide (steel cylinder commercial carbon dioxide) is introduced into the algae liquid to provide a carbon source for photosynthesis of the microalgae and control the pH of the algae liquid. Controlling the introduction of carbon dioxide on line by using a pH controller, absorbing an inorganic carbon source in the algae liquid by the photosynthesis of the microalgae, increasing the pH of the algae liquid, opening an electromagnetic valve by using the pH controller when the pH of the algae liquid reaches the upper limit pH of 8.0 of a control range, introducing the carbon dioxide into the algae liquid, and absorbing CO by the algae liquid₂Then the pH value is reduced, when the pH value is reduced to the lower limit pH value of 7.0 of the control range, the pH controller closes the electromagnetic valve, and the carbon dioxide stops introducing the algae liquid. The pH of the algae liquid is controlled within the set range of pH7.0-8.0 by the circulation. Taking the algae liquid from the culture pond to carry out microscope observation once every day in the morning and at night, and observing naturally occurring fungal infection in the algae liquid after culturing for a period of time. There are 2 kinds of fungi infecting the oil globules, and the endophytic fungi are variable algae-producing fungi, Amoeboaphylidium protococcum and ectomycorrhiza chytrium scendesmi. After the fungal infection is found, it is early every dayThe infection rate of the oleococcus cells with fungal infection was determined late.

When the infection rate of algae cells reaches about 5%, the algae solution can be treated by adding dodecylbenzene sulfonic acid/sodium dodecylbenzene sulfonate, and the lowest concentration of the dodecylbenzene sulfonic acid/sodium dodecylbenzene sulfonate which can completely control fungal infection is adopted for treatment. Accurately measuring the depth of the algae liquid in the culture pond, and calculating the volume of the culture liquid according to the depth of the algae liquid and the area of the culture pond. Determining the treatment concentration of the dodecylbenzene sulfonic acid/sodium dodecylbenzene sulfonate according to the type of the fungus, then calculating the dosage according to the volume of the algae liquid and the treatment concentration of the dodecylbenzene sulfonic acid/sodium dodecylbenzene sulfonate, accurately weighing the needed dodecylbenzene sulfonic acid/sodium dodecylbenzene sulfonate, and adding the dodecylbenzene sulfonic acid/sodium dodecylbenzene sulfonate into the culture pond. The impeller stirrer of the culture pond drives the algae liquid to flow, and the treating agent is quickly dissolved completely and uniformly distributed in the flowing algae liquid. After 72 hours of culture, the algae liquid is continuously taken out from the culture pond for three times, the fungal infection is observed under a microscope, and the algae cells are not infected by the fungi in the three times of sampling, so that the treatment concentration is determined to be capable of completely controlling the fungal infection, and the fungal infection is calculated to be 0. Three samples were taken in succession, and as long as an algal cell was found to be infected by a fungus at one time, the treatment concentration was considered to be insufficient for controlling the fungal infection, which was counted as 1, even though the infection rate was extremely low.

The naturally occurring fungal species, area of culture pond, depth of algal solution, concentration of treatment agent, amount of treatment agent and fungal infection after 72 hours of treatment are shown in Table 52.

The treatment effect is as follows: after 72 hours of culture, the algae liquid is taken for many times for observation, and the condition that the oil ball algae is infected by the fungus is not seen. The culture is continued for 7 days, the oil globule algae grows and breeds normally, and no fungal infection occurs.

TABLE 52 dodecylbenzene sulfonic acid/sodium dodecylbenzene sulfonate for controlling fungal infection in open pond culture of microalgae

Example 22: cocoanoic acid diethanolamine to control fungal contamination in open pond cultured oil globules

The method for controlling fungal infection in the open pond culture process of microalgae by using coco diethanol amine, the culture method of microalgae, the method for measuring the infection rate of algal cells infected by fungi, the method for calculating the amount of the treating agent, the method for weighing and adding the treating agent, and the method for determining the fungal infection control effect are the same as those in example 21. Treatment with cocodiethanol amine was carried out at the lowest concentration that could completely control fungal infections.

The naturally occurring fungal species, area of culture pond, depth of algal solution, concentration of treatment agent, amount of treatment agent and fungal infection after 72 hours of treatment are shown in Table 53.

TABLE 53 Cocoanoic acid diethanolamine salts for controlling fungal infections in open pond culture of microalgae

Example 23: sodium dodecyl sulfate for controlling fungal infection in microalgae open pond culture process

The lauryl sodium sulfate is used for controlling the fungal infection in the culture process of the microalgae open pond, and the lauryl sodium sulfate can be used for completely controlling the minimum concentration of fungal infection for treatment. The culture method of microalgae, the method for measuring the infection rate of algal cells infected with fungi, the method for calculating the amount of the treating agent, the method for weighing and adding, and the method for determining the effect of controlling fungal infection were the same as in example 21.

The naturally occurring fungal species, area of culture pond, depth of algal solution, concentration of treatment agent, amount of treatment agent and fungal infection after 72 hours of treatment are shown in Table 54.

TABLE 54 sodium dodecyl sulfate control of fungal infections in open pond culture of microalgae

Example 24: fatty alcohol-polyoxyethylene ether for controlling fungal infection in microalgae open pond culture

The fatty alcohol-polyoxyethylene ether is used for controlling the fungal infection in the culture process of the microalgae open pond, and the fatty alcohol-polyoxyethylene ether is used for completely controlling the minimum concentration of the fungal infection for treatment. The culture method of microalgae, the method for measuring the infection rate of algal cells infected with fungi, the method for calculating the amount of the treating agent, the method for weighing and adding, and the method for determining the effect of controlling fungal infection were the same as in example 21.

The naturally occurring fungal species, area of culture pond, depth of algal solution, concentration of treatment agent, amount of treatment agent and fungal infection after 72 hours of treatment are shown in Table 55.

TABLE 55 fatty alcohol polyoxyethylene ether for controlling fungal infection in open pond culture of microalgae

Example 25: surfactant composition for controlling harmful biological pollution in microalgae open pond culture

The surfactant composition is used for controlling the pollution of harmful organisms in the culture process of the microalgae open pond, and the lowest concentration of the harmful organisms can be completely controlled by using the surfactant composition for treatment. The kind of microalgae, the culture method, the method for calculating the amount of the treating agent, the method for weighing and adding, the method for observing the harmful organisms, the method for measuring the density and the method for determining the survival condition were the same as those in example 16.

The types of naturally occurring enemy organisms, the area of the culture pond, the depth of the algal solution, the concentration of the treating agent, the amount of the treating agent used, and the survival of the enemy organisms after 24 hours of treatment are shown in tables 56 to 71.

TABLE 56 surfactant composition 1 control of hostile biofouling in open pond culture of microalgae

TABLE 57 surfactant composition 2 control of hostile biofouling in open pond culture of microalgae

TABLE 58 surfactant composition 3 control of hostile biofouling in open pond culture of microalgae

TABLE 59 surfactant composition 4 control of hostile biofouling in open pond culture of microalgae

TABLE 60 surfactant composition 5 control of hostile biofouling in open pond culture of microalgae

TABLE 61 surfactant composition 6 control of hostile biofouling in open pond culture of microalgae

TABLE 62 surfactant composition 7 control of hostile biofouling in open pond culture of microalgae

TABLE 63 surfactant composition 8 control of hostile biofouling in open pond culture of microalgae

TABLE 64 surfactant composition 9 control of hostile biofouling in open pond culture of microalgae

TABLE 65 surfactant composition 10 control of hostile biofouling in open pond culture of microalgae

TABLE 66 surfactant composition 11 control of hostile biofouling in open pond culture of microalgae

TABLE 67 surfactant composition 12 control of hostile biofouling in open pond culture of microalgae

TABLE 68 surfactant composition 13 control of hostile biofouling in open pond culture of microalgae

TABLE 69 surfactant composition 14 control of hostile biofouling in open pond culture of microalgae

TABLE 70 surfactant composition 15 control of hostile biofouling in open pond culture of microalgae

TABLE 71 surfactant composition 16 control of hostile biofouling in open pond culture of microalgae

Example 26: surfactant compositions for controlling fungal infections in open pond culture of microalgae

The surfactant composition is used for controlling the fungal infection in the culture process of the microalgae open pond, and the lowest concentration of the fungal infection can be completely controlled by using the surfactant composition for treatment. The culture method of microalgae, the method for measuring the infection rate of algal cells infected with fungi, the method for calculating the amount of the treating agent, the method for weighing and adding, and the method for determining the effect of controlling fungal infection were the same as in example 21.

The naturally occurring fungal species, area of culture pond, depth of algal solution, concentration of treatment agent, amount of treatment agent and fungal infection after 72 hours of treatment are shown in Table 72.

TABLE 72 surfactant compositions control fungal infection in microalgae open pond culture

Example 27: detergent for controlling harmful biological pollution in culture of microalgae open pond

The detergent is used for controlling the pollution of harmful organisms in the culture of the microalgae open pond, and the lowest concentration of the harmful organisms can be completely controlled by using the detergent for treatment. The kind of microalgae, the culture method, the method for calculating the amount of the treating agent, the method for weighing and adding, the method for observing the harmful organisms, the method for measuring the density and the method for determining the survival condition were the same as those in example 16.

The types of naturally occurring enemy organisms, the area of the culture pond, the depth of the algal solution, the concentration of the treating agent, the amount of the treating agent used, and the survival of the enemy organisms after 24 hours of treatment are shown in Table 73.

TABLE 73 detergent control of harmful bio-contamination in microalgae open pond culture

Example 28: detergent for controlling fungal infection in microalgae open pond culture

The detergent is used for controlling the fungal infection in the culture process of the microalgae open pond, and the detergent can be used for completely controlling the minimum concentration of the fungal infection for treatment. The culture method of microalgae, the method for measuring the infection rate of algal cells infected with fungi, the method for calculating the amount of the treating agent, the method for weighing and adding, and the method for determining the effect of controlling fungal infection were the same as in example 21.

The naturally occurring fungal species, area of culture pond, depth of algal solution, concentration of treatment agent, amount of treatment agent and fungal infection after 72 hours of treatment are shown in Table 74.

TABLE 74 detergent control of fungal infections in microalgae open pond culture

Claims

1.A method for preventing and treating biological pollution in a microalgae culture process by using a surfactant is characterized in that the surfactant or a detergent containing the surfactant is added into a microalgae culture solution for preventing and treating the biological pollution, wherein the surfactant is at least one of dodecyl benzene sulfonic acid, sodium dodecyl benzene sulfonate, cocoanut oil diethanol amine, lauryl sodium sulfate, fatty alcohol-polyoxyethylene ether and fatty alcohol-polyoxyethylene ether sodium sulfate; the biological pollution comprises enemy organisms or/and disease fungi pollution, wherein the enemy organisms are rotifer, ciliate, amoeba, bellybutton or ingestion golden algae, the disease fungi are amoebobacillus proteoliticum (amoebobacillus proteobacterium) and Rhizophydium scoparium (Rhizophydium scendesmi), and the microalgae are gloeococcus, chlorella and scenedesmus; the surfactant concentrations used for the different biofouling were as follows:

2. the method for preventing and treating biological contamination during microalgae cultivation using surfactant as claimed in claim 1, wherein the surfactant or detergent containing surfactant is added to prevent biological contamination 2-3 days after cultivation; or observing the microalgae culture solution under a microscope, and adding the microalgae culture solution when harmful organisms or/and disease fungi are polluted to control biological pollution.

3. The method for preventing and treating biological pollution in the process of culturing microalgae according to claim 1, wherein the surfactant is dodecyl benzene sulfonic acid or a combination of five of dodecyl benzene sulfonic acid sodium salt, coco diethanol amine, sodium dodecyl sulfate, fatty alcohol-polyoxyethylene ether and fatty alcohol-polyoxyethylene ether sodium sulfate, and the composition comprises the following components in percentage by mass:

4. the method for preventing and treating biological pollution in the process of culturing microalgae according to claim 3, wherein the concentrations of the compositions 1-16 are as follows: