CN116409832A - A method of inhibiting the growth of target algae by dosing suspended particles - Google Patents

Abstract

The invention provides a method for inhibiting the growth of target algae by adding suspended particles. The method comprises the following steps: 1) Determining target algae in the water body, which need to be inhibited from growing; 2) Determining a growth inhibition parameter that inhibits growth of the target algae; 3) Determining a particle size parameter and an OM value of the particles to be added, and determining an expected suspended particle concentration condition of the water body according to the growth inhibition parameter, the particle size parameter and the OM value; 4) And adding the particles into the water body according to the expected suspended particle concentration condition of the water body so as to inhibit the growth of the target algae.

Description

A method of inhibiting the growth of target algae by dosing suspended particles

technical field

The invention relates to the technical fields of water environment restoration and water quality risk prevention and control, and in particular to a method for inhibiting the growth of target algae by dosing suspended particles.

Background technique

Eutrophication and harmful algal blooms have become major water quality problems in most of the world's freshwater and coastal marine ecosystems. In recent decades, under the interference of global changes and human activities, the input of a large amount of nitrogen and phosphorus nutrient pollution loads has increased the eutrophication of rivers, lakes and reservoirs, and even the outbreak of algal blooms. A large number of algae blooms not only lead to the deterioration of water quality and the death of aquatic organisms, but are often accompanied by secondary risk pollutants such as smell, algae toxins, etc., which not only endanger the health of natural water environments, but also seriously affect the safety of urban water supply and drinking water. For the risk of algal pollution, the existing prevention and control methods include chemical, physical and biological methods. As far as chemical methods are concerned, harmful algae control is often carried out through methods such as metals, photosensitizers, algaecides and other chemicals. Although chemical and physical methods can effectively and quickly remove harmful algae, they have not been widely used due to high cost, serious secondary pollution and negative impact on humans and other aquatic organisms, especially not suitable for application in natural water bodies. Biological algae control is mainly based on aquatic plants, aquatic animals and algicidal microorganisms, etc., and uses allelopathic effects, niche competition, and predator-prey relationships to limit the excessive growth of algae.

It is well known that light conditions are one of the important environmental factors affecting the growth of algae. Studies have found that there are significant differences in the adaptability of different algae species to underwater light. In nutrient-rich natural water bodies, underwater light conditions are key environmental factors that affect algal organisms and growth rates in addition to temperature. By changing underwater light conditions, specific algal communities can be regulated, and even the growth and outbreak of harmful algae can be inhibited. .

In the prior art, there have been some reported cases of controlling underwater light through water surface shading (such as floating balls, sunshade nets, etc.), such as patent application CN202021954278. A mobile water surface shading algae control device, and patent application CN202010270886.7 discloses a method for preventing and controlling green algae in seawater ponds based on a physical shading layer; but the cost and engineering effect are not ideal.

Contents of the invention

In view of this, the present invention provides a method for inhibiting the growth of target algae by adding particulate matter. The present invention determines the expected growth rate in the water body according to the obtained growth inhibition parameters of the target algae and according to the particle size and OM value of the particulate matter to be added. Concentration of suspended particulate matter, according to the determined concentration of suspended particulate matter, particles of specific particle size and OM value are added to the water body, so as to achieve the purpose of inhibiting the growth of target algae. regulation.

The present invention provides following technical scheme for achieving its purpose:

The invention provides a method for inhibiting the growth of target algae by dosing with suspended particles, comprising the following steps:

1) Determine the target algae that need to inhibit growth in the water body;

2) determining a growth inhibition parameter that inhibits the growth of the target algae, the growth inhibition parameter including at least one of turbidity, irradiance, and transparency of the water body;

3) Determine the particle size parameter and OM value of the particulate matter to be added, and determine the expected suspended particulate matter concentration condition of the water body according to the growth inhibition parameter, the particle size parameter and the OM value;

4) Dosing the particulate matter into the water body according to the expected suspended particulate matter concentration condition of the water body to inhibit the growth of the target algae.

In some embodiments, in step 3), the expected concentration conditions of suspended particulate matter in the water body are determined by substituting the growth inhibition parameter, the particle size parameter and the OM value into a pre-established relational model for calculation.

In some embodiments, the relational model includes a relational formula (I), and the relational formula (I) is the relationship between the turbidity of the water body and the suspended particulate matter concentration of the water body, the particle size parameter of the suspended particulate matter, and the OM value of the suspended particulate matter Mode;

Preferably, the relational formula (I) is established as follows:

Obtaining multiple water body samples, obtaining the turbidity, suspended particulate matter concentration and particle size parameters of each water body sample, obtaining the OM value of the suspended particulate matter in each of the water body samples, and obtaining the turbidity and the suspended particulate matter by fitting Relational formula (1) between the particle concentration, the particle size parameter of suspended particulate matter and the OM value of described suspended particulate matter:

TUR = α ₁ SPM + α ₂ Dx + α ₃ OM ₂ (I);

Among them, TUR is the turbidity of the water body, the unit is NTU; SPM is the suspended particulate matter concentration of the water body, the unit is mg/L; OM ₂ =exp(-OM); Dx is the particle size parameter of the suspended particulate matter, the unit is μm; α ₁ , α ₂ , α ₃ are coefficients in the relational formula (1);

Preferably, the particle size parameter is D10, D50, D60 or D90.

In some embodiments, the growth inhibition parameter is the turbidity of the water body, and in the step 3), the turbidity of the water body as the growth inhibition parameter and the particle size parameter and OM of the particulate matter to be added are The value is substituted into the relational formula (I) to calculate the suspended particulate matter concentration, thereby determining the expected suspended particulate matter concentration condition of the water body.

In some embodiments, the relational model further includes relational formula (II) and relational formula (III);

Wherein, the relational expression (II) is the relational expression between the irradiance and the underwater light attenuation coefficient, and the relational expression (II) is:

Among them, K is the underwater light attenuation coefficient; z is the preset depth of the water body, in m; E(z) is the irradiance of the water body at the preset depth z, E(0) is the irradiance of the water surface, E The units of (z) and E(0) are μmol/(m ² .s);

Described relational formula (III) is the relational formula between underwater light attenuation coefficient and the turbidity of water body;

Preferably, the relational formula (III) is established as follows:

Obtain water body samples in multiple water bodies, obtain E(0) and E(z) of each water body, determine the underwater light attenuation coefficient of each water body according to relational formula (II); obtain the turbidity of each water body sample, according to the described The underwater light attenuation coefficient of each water body and the turbidity of each water body sample are obtained by fitting the linear relationship between the underwater light attenuation coefficient and the turbidity of the water body:

K＝a+b*TUR(III)

Wherein, TUR is the turbidity of the water body, and the unit is NTU; b is the slope of the relation (III), and a is the intercept of the relation (III).

In some embodiments, the growth inhibition parameter is irradiance, and the irradiance is used as the value of E(z) in the relational formula (II) to obtain the irradiance E(0) of the water surface of the water body, The underwater light attenuation coefficient of the water body is obtained by substituting the preset depth z, E(z), and E(0) into the relational formula (II);

The underwater light attenuation coefficient K is substituted into the relational formula (III) to calculate the turbidity of the water body;

Substituting the calculated turbidity of the water body and the particle size parameter and OM value of the particulate matter to be added into the relational formula (I) to calculate the suspended particulate matter concentration, thereby determining the expected suspended particulate matter concentration condition of the water body.

In some embodiments, the relational model further includes a relational expression (IV), which is a relational expression between the turbidity of the water body and the transparency of the water body;

Preferably, the relational formula (IV) is established as follows:

Obtain the turbidity and transparency of each water body sample, carry out linear fitting after the numerical value of described turbidity and described transparency are respectively carried out lg logarithmic conversion, obtain the relational expression between the turbidity of described water body and the transparency of water body :

log(SDD)＝a+b×log(TUR) (Ⅳ)

Wherein SDD is the transparency of water body, unit is cm; TUR is the turbidity of water body, unit is NTU; b is the slope of described relational formula (IV), and a is the intercept of described relational formula (IV).

In some embodiments, the growth inhibition parameter is the transparency of the water body, and in the step 3), the turbidity of the water body is calculated by substituting the transparency of the water body as the growth inhibition parameter into the relational formula (IV);

Substituting the calculated turbidity of the water body and the particle size parameter and OM value of the particulate matter to be added into the relational formula (I) to calculate the suspended particulate matter concentration, thereby determining the expected suspended particulate matter concentration of the water body condition.

In some embodiments, in step 4), after adding the particulate matter, the water body is continuously monitored, and when the water body cannot meet the requirements of the growth inhibition parameter, the particulate matter is added again; or, step 4) In, after adding the particulate matter, continuously monitor the water body, when the water body cannot meet the requirements of the growth inhibition parameters, adjust the particle size parameter and/or OM value of the particulate matter to be added, according to the steps 3) Re-determining the expected suspended particulate matter concentration condition of the water body; and then adding particulate matter to the water body according to the re-determined expected suspended particulate matter concentration condition of the water body.

In some embodiments, in step 4), the particulate matter is added by dry method or wet method;

And/or, in step 4), the particulate matter to be added is selected from one or more of clay minerals, sedimentation tank discharge sludge from water plants, activated sludge, bottom sludge from natural water bodies, and harmless industrial waste particulate matter Various.

The present invention also provides the application of the method described above, which is used in the prevention and control of algal blooms or water quality regulation.

The technical scheme provided by the invention has the following beneficial effects:

The present invention controls the growth of algae by adding particulate matter into the water body, and can effectively realize the control and prevention of algae-derived water pollution including algal blooms, smell, and taste. The method provided by the present invention has the advantages of simple and convenient operation and low cost. and ecological security.

Description of drawings

Figure 1 is a schematic diagram of the relationship between suspended particulate matter concentration-median particle size-turbidity.

Figure 2 is the fitting relationship between turbidity TUR and light attenuation coefficient K.

Figure 3 is the fitting relationship between turbidity TUR and transparency SDD after logarithmic transformation.

Fig. 4 is the relationship diagram (left) between the expected turbidity and the actual turbidity and the concentration of suspended particulates, and the relationship diagram (right) between the turbidity and the biomass of Cladophora.

Fig. 5 is a diagram of the cell density of Microcystis aeruginosa in different E(z) experimental groups.

Detailed ways

In order to facilitate understanding of the present invention, the present invention will be further described below in conjunction with examples. It should be understood that the following examples are only for better understanding of the present invention, which does not mean that the present invention is limited to the following examples.

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. As may be used herein, the term "and/or" includes any and all combinations of one or more of the associated listed items.

Where specific experimental steps or conditions are not indicated in the examples, it can be carried out according to the operation or conditions of the corresponding conventional experimental steps in the technical field. The reagents or instruments used were not indicated by the manufacturer, and they were all commercially available conventional products.

The invention provides a method for inhibiting the growth of target algae by adding suspended particles, which mainly includes the following steps:

1) Determine the target algae that need to inhibit growth in the water body;

2) determining a growth inhibition parameter that inhibits the growth of the target algae, the growth inhibition parameter including at least one of turbidity, irradiance, and transparency of the water body;

3) Determine the particle size parameter and OM value (that is, the organic matter mass ratio of the particulate matter) of the particulate matter to be added to the water body that needs to inhibit the target algae (i.e. "the particulate matter to be added"), according to the growth inhibition parameters and to be injected The particle size parameters and OM value of the particulate matter are added to determine the expected suspended particulate matter concentration condition of the water body;

4) According to the concentration condition of the expected suspended particulate matter in the water body determined in step 3), add particulate matter (that is, the particulate matter to be added with the above-mentioned particle size parameter and OM value) to the water body to inhibit the growth of the target algae .

Wherein, the target algae in step 1) is the algae whose growth needs to be inhibited in the water body, specifically, the algae species that bring algae-derived pollutants in the water body, etc., and the target algae can be determined according to the actual water environment problems.

In step 2), the determination of the growth inhibition parameters for inhibiting the growth of the target algae can be determined through existing literature records. growth will be inhibited, then according to the report of the literature, the transparency data or turbidity data of the water body are used as growth inhibition parameters; or, for example, the literature reports the optimum growth light intensity (i.e. the optimum irradiation degree), the irradiance that can inhibit the growth of the target algae can be set according to the literature report, for example, lower than the above-mentioned optimum irradiance; if there is a research or data basis, the growth inhibition of the target algae growth can also be determined experimentally The parameters are not limited to the reports in the literature, and the specific method for determining the algae growth inhibition parameters can be known or understood by those skilled in the art based on the existing experimental methods, conventional technical knowledge and/or common knowledge.

In step 3) of the present invention, the expected suspended particulate matter concentration condition in the water body is determined by substituting the growth inhibition parameter, the particle size parameter and the OM value of the particulate matter to be added into a pre-established relational model for calculation.

In some embodiments, the relational model includes a relational expression (I), and the relational expression (I) is a relational expression between the turbidity of the water body and the suspended particulate matter concentration of the water body, and the particle size parameter of the suspended particulate matter and the OM value of the suspended particulate matter.

Specifically, the relational expression (I) is established in the following way:

Obtain multiple water body samples, for example, the number of water body samples is not less than 500. Water body samples, for example, can be collected in lakes, reservoirs, pits, ponds, streams, and rivers (covering common surface water body types) in different scenarios (including sunny days, rainy , after the rain). Obtain the turbidity, suspended particulate matter concentration, and particle size distribution and OM value of suspended particulate matter in each water body sample. The OM value can be determined by filtering, drying and burning off the suspended particulate matter in each water body sample; through The turbidity of the above-mentioned water body sample, the concentration of suspended particles, the particle size parameter and the OM value of the suspended particles are fitted to obtain the relational formula (I) between the turbidity and the concentration of suspended particles, the particle size parameter and the OM value:

TUR = α ₁ SPM + α ₂ Dx + α ₃ OM ₂ (I);

Among them, TUR is the turbidity of the water body, the unit is NTU; SPM is the suspended particulate matter concentration of the water body, the unit is mg/L; Dx is the particle size parameter of the suspended particulate matter, the unit is μm; OM ₂ = exp(-OM); α ₁ , α ₂ , α ₃ are coefficients in the relational formula (I).

The above-mentioned particle size parameter Dx may be a parameter that can represent the characteristic particle size of the suspended particulate matter, such as D10, D50, D60 or D90.

In some embodiments, the relational model also includes relational formula (II) and relational formula (III); Wherein, relational formula (II) is the relational formula between irradiance and underwater light attenuation coefficient, relational formula (II) is :

Among them, K is the underwater light attenuation coefficient; z is the preset depth of the water body, in m; E(z) is the irradiance of the water body at the preset depth of z, and E(0) is the irradiance of the water surface , the units of E(z) and E(0) are μmol/(m ² .s);

The relational expression (III) is the relational expression between the underwater light attenuation coefficient and the turbidity of the water body.

Specifically, the relational formula (III) is established in the following way:

Obtain water samples from multiple water bodies, obtain the irradiance E(0) of the water surface of each water body and the irradiance E(z) of the water body at a preset depth of z, and calculate according to the above relationship (II) Determine the underwater light attenuation coefficient of each water body related to the preset depth z; obtain the turbidity of each water body sample; obtain the turbidity of each water body sample, and the underwater light attenuation coefficient of each water body related to the preset depth z Fitting is performed to obtain the linear relationship between the underwater light attenuation coefficient K and the turbidity TUR of the water body:

K＝a+b*TUR(III)

Among them, TUR is the turbidity of the water body, the unit is NTU; b is the slope of the relationship (III), and a is the intercept of the relationship (III).

In some embodiments, the relational model further includes a relational expression (IV), and the relational expression (IV) is a relational expression between the turbidity of the water body and the transparency of the water body.

Specifically, relational expression (IV) is established in the following way:

Obtain water body samples from multiple water bodies, obtain the turbidity and transparency of each water body sample, perform logarithmic conversion on the turbidity and transparency values respectively, and then perform linear fitting to obtain the relationship between the turbidity of the water body and the transparency of the water body The relational formula:

log(SDD)＝a+b×log(TUR) (Ⅳ)

Wherein SDD is the transparency of water body, unit is cm; TUR is the turbidity of water body, unit is NTU; b is the slope of described relational formula (IV), and a is the intercept of described relational formula (IV).

The following is an exemplary introduction to the establishment process of the above-mentioned relational model. The following is only the establishment process of the relational model in a specific embodiment. Its purpose is to facilitate the understanding of the establishment of the relational model of the present invention, but it should not be understood as The present invention is only limited to this:

S1) establish relational formula (I):

Obtain water body samples. The number of water body samples shall not be less than 500. Water body samples shall be tested in different scenarios (including sunny, rainy, and after rain) in lakes, reservoirs, pits, ponds, streams, and rivers (covering common surface water types). obtain. Determination of the suspended particulate matter concentration (SPM) of each water body sample is determined by the gravimetric method (national standard: GB 11901-89). Specifically, 500ml of water samples are filtered on a 0.45μm CN-CA filter membrane with a known constant weight. After the end, dry in an oven at 105°C for 1 hour, then cool to room temperature in a desiccator, repeatedly dry, cool, and weigh until the weight is constant, and then calculate the SPM concentration based on the weight difference; then place the filter membrane in a horse Burn at 450°C for 4 hours in a Furnace to remove organic matter. According to the formula OM=(B-C)/(B-A), the proportion of organic matter in suspended particles is calculated as OM. In the formula, A is the weight of filter membrane + weighing bottle, g; B C is the weight of suspended matter + filter membrane + weighing bottle, g; C is the weight of inorganic suspended matter + filter membrane + weighing bottle, g. The determination of the above-mentioned SPM concentration and OM value is well known to those skilled in the art, and those not described in detail can be known or understood by those skilled in the art according to the conventional technical knowledge or common knowledge they have mastered.

In this example, the particle size parameter of the suspended particulate matter is the particle size distribution, which is measured by a Malvern laser particle size analyzer (MASTERSIZER 3000E), with D50 as the particle size parameter of the suspended particulate matter (D50 is the particle size corresponding to when the cumulative particle size distribution percentage reaches 50%) diameter); the turbidity TUR of the water body was measured in situ at the sampling site by a portable multi-parameter water quality analyzer (YSI Professional Plus).

Fit TUR and SPM, D50 and OM data by means of multiple linear fitting, and convert the OM value according to OM ₂ =exp(-OM), and remove the insignificant intercept during the establishment of the relational formula (I) item, and finally obtain the following relationship (I):

TUR＝α ₁ SPM+α ₂ D50+α ₃ OM ₂ (I)

该关系式(I)的R²＝0.87，参数假设检验对应的p值均小于0.05。In this example,

R ² of the relational formula (I) is 0.87, and the p values corresponding to the parameter hypothesis tests are all less than 0.05.

Figure 1 shows the fitting relationship between turbidity, suspended particulate matter concentration and D50 in the example for reference.

S2) relational expression (II) and relational expression (III)

Relational expression (II) is the relational expression between irradiance and underwater light attenuation coefficient, and the calculation formula of underwater light attenuation coefficient K is as follows:

Among them, K is the underwater light attenuation coefficient, z is the preset depth of the water body, the unit is m; E(z) is the irradiance of the water body at the preset depth z, the unit is μmol/(m ² .s), E(0 ) is the irradiance on the water surface, in μmol/(m ² .s). The irradiance was measured with an underwater full-spectrum photosynthetically active radiation meter (MQ-510). The preset depth can be specifically determined according to the prevention and control requirements of the target algae in the target water body in the actual application scenario.

The relationship (III) is established as follows:

Obtain a plurality of water body samples in a plurality of water bodies, measure E(0) of each water body and E(z) at preset depth z, calculate and determine the underwater light attenuation coefficient of each water body according to relational formula (II); Obtain The turbidity of each water body sample; the underwater light attenuation coefficient of each water body obtained and the turbidity of each water body sample are fitted to obtain the relational formula (II), specifically: K=(2.39±0.20)+(0.14±0.013 )×TUR,R ² =0.62. See Figure 2 for a schematic diagram of the fitting relationship.

S3) Establish relational formula (IV)

By measuring the turbidity TUR of each water body sample and the corresponding transparency SDD (transparency SDD is measured by the Secchi transparency disc), a series of turbidity and transparency data are obtained, and the turbidity and transparency data are lg converted, after conversion The SDD and TUR have a better unary linear relationship (see Figure 3), and the relationship (IV) is obtained through linear fitting. In this example, the relationship (IV) is specifically TUR=10 ^{(2.48243-lg(SDD)) /0.68243} . See Figure 3 for a schematic diagram of the fitting relationship.

In one embodiment, the growth inhibition parameter determined in step 2) is the turbidity of the water body, for example, for the target algae, its growth will be inhibited under a certain water body turbidity. In step 3), it mainly includes the following links: determining the particle size parameter and OM value of the particulate matter to be added to the water body, the turbidity of the water body as a growth inhibition parameter, and the particle size parameter of the particulate matter to be added to the water body value (corresponding to the particle size parameter Dx in the relational formula (I)) and the OM value are substituted into the established relational formula (I) to calculate the suspended particulate matter concentration, thereby determining the expected suspended particulate matter concentration condition in the water body. In step 4), the desired amount of particulate matter to be added is added to the water body according to the determined expected concentration of suspended particulate matter in the water body, so as to achieve the purpose of inhibiting the growth of target algae. In this embodiment, the suspended particulate matter concentration required to reach the target turbidity can be determined according to the particle size parameter value and OM value of the suspended particulate matter combined with the water body turbidity as a growth inhibition parameter.

In another embodiment, the growth inhibition parameter determined in step 2) is irradiance, for example, the target algae will be inhibited in growth under a certain irradiance. In step 3), it mainly includes the following links: using the above-mentioned irradiance as the growth inhibition parameter as the value of E(z) in the relational formula (II), and determining the irradiance E(0) of the water surface of the water body , substituting E(z) and the preset depth z of the water body of E(0) into the relational formula (II) to calculate the underwater light attenuation coefficient K;

Substitute the calculated underwater light attenuation coefficient K into the established relationship (III) to calculate the turbidity of the water body. The calculated turbidity of the water body, and the particle size parameter (corresponding to Dx in the relational formula (I)) and the OM value of the particles to be added to the water body determined in advance, are substituted into the established relational formula (I) The concentration of suspended particulate matter is calculated to determine the expected concentration of suspended particulate matter in the water body. Afterwards, in step 4), the suspended particulate matter is added to the water body according to the determined concentration condition of the expected suspended particulate matter in the water body, so as to achieve the purpose of inhibiting the growth of the target algae.

In another embodiment, the growth inhibition parameter determined in step 2) is the transparency of the water body, for example, for target algae, it will be subject to growth inhibition under a certain water body transparency; or it is inconvenient to test the turbidity, and When it is convenient to test the transparency of the water body, step 3) can be carried out in the following manner: in step 3), the transparency of the water body as the growth inhibition parameter is substituted into the established relationship (IV) to calculate the turbidity of the water body. Then, the particle size parameter (corresponding to Dx in the relational formula (I)) and the OM value of the particulate matter that will be added to the water body in advance will be determined, and the turbidity of the calculated water body is substituted into the relational formula (I ) to obtain the suspended particulate matter concentration, thereby determining the expected suspended particulate matter concentration condition of the water body. Afterwards, in step 4), the particulate matter is added to the water body according to the determined suspended particulate matter concentration condition, so as to achieve the purpose of inhibiting the growth of the target algae.

In the method provided by the present invention, the concentration of suspended particulate matter in the water body required to achieve the growth inhibition of the target algae can be flexibly determined through a variety of different growth inhibition parameter information, and the growth inhibition purpose of the target algae can be achieved by adding the required amount of particulate matter. Convenient and flexible, easy to implement. And in the relationship model established by the present invention, the conversion relationship between turbidity and irradiance, turbidity and water transparency can be established, and finally the relationship between turbidity and suspended particulate matter concentration, particle size parameter and OM value can be used To guide the dosing operation of suspended particulate matter, the concentration of suspended particulate matter can be determined based on the particle size parameters and OM value of the particulate matter to be added and the turbidity, which has a strong practical guiding effect on the addition of particulate matter and the growth inhibition of target algae.

In a preferred embodiment, in step 4), after adding particulate matter to the water body, the relevant parameters of the water body are continuously monitored. When the water body cannot meet the requirements of growth inhibition parameters, the particulate matter can be added again, for example, adding again meets the preceding steps 3) The particle size parameters and OM value of the particles to be added, such as resuspending the particles deposited in the water body, so as to achieve the required concentration of suspended particles again, and meet the requirements of growth inhibition parameters, to achieve sustainable growth of the target algae purpose of inhibiting growth. Or, in step 4), after adding the particulate matter, continuously monitor the water body, and when the water body cannot meet the requirements of the growth inhibition parameter, adjust the particle size parameter and/or OM value of the particulate matter to be added , such as reducing the particle size of the particles to be added, such as increasing the OM value of the particles to be added, etc. to facilitate the increase of the suspension of the particles, that is, reselecting the particles to be added, and re-determining the expected suspension of the water body according to the step 3) Particulate matter concentration conditions; then add particulate matter into the water body according to the re-determined expected suspended particulate matter concentration conditions of the water body.

In step 4) of the present invention, the granular matter can be added by dry method or wet method. In step 4), the particulate matter for adding can be selected from clay minerals, sedimentation tank discharge sludge of water works (such as waterworks), activated sludge, bottom sludge of natural water bodies and harmless industrial waste particulate matter (such as pulverized coal Ash, etc.); wherein the clay minerals can be natural or commercial clay minerals, such as bank soil, sediment, kaolin, diatomaceous earth and bentonite.

In order to facilitate understanding of the present invention, the present invention will be further described below in conjunction with examples. It should be understood that the following examples are only for better understanding of the present invention, which does not mean that the present invention is limited to the following examples.

Example 1

The target algae of this example is Cladophora.

Cladophytes are filamentous green macroalgae (Chlorophyta, Cladophyceae), which often cause outbreaks of filamentous Cladophytes in eutrophic lakes, which affect the growth of submerged plants and the restoration of vegetation, while In some artificial water delivery channels, outbreaks of Cladoides often occur, and a large amount of Cladoides biomass moves downstream with hydraulic scouring, which may cause troubles for water production in water plants. Previous studies have found that water transparency can affect the growth of Cladophora, which will affect the intensity of underwater light and thus affect the photosynthesis of algae. At the same time, the reduction of turbidity will expand the available area for Cladophyll to settle on the surface of aquatic plants, thereby increasing its abundance; The turbidity of the water body whose growth is inhibited is about 20NTU (Guo Liangliang et al. 2022).

In this example, a pond with an area of ^600m2 and an average water depth of 2m in a certain village was selected for the experiment, and six closed enclosures were built in the middle of the pond (construction of enclosed enclosures was carried out through polyethylene transparent film) for the experiment, and the experiment numbers were recorded respectively. For B1 (blank control), B2, B3, B4, B5, B6. During the experiment, the algal biomass per unit area in the enclosure was collected at a fixed time every week, and five replicate samples were taken in parallel for each enclosure. The collected Cladophora samples were rinsed with deionized water to remove attachments, by weighing the wet weight biomass in each sample, and then drying the samples to constant weight at 60 °C, and according to the wet weight/dry weight ratio of the samples Calculate the total dry mass in each sample to estimate the biomass per unit area. The turbidity of the water body was obtained by a portable multi-parameter water quality analyzer (YSI Professional Plus), and the transparency of the water body was measured by a Secchi transparency disc. The turbidity gradient designed in this experiment is: 5NTU, 10NTU, 15NTU, 20NTU, 25NTU. The initial turbidity of the water body before adding suspended particles in the enclosure is 2.2NTU.

It is pre-determined that the particulate matter to be added is high-purity kaolin (Shanlin Shiyu Mineral Products Co., Ltd., purity >99.5%), its OM value is 0, and its D50 is 1 μm. The initial turbidity of the water body is deducted from each turbidity of the above-mentioned design, and the OM value and D50 of the suspended particulate matter that have been determined are substituted into the relational formula (I) (TUR=0.89SPM-0.08D50+6.56OM ₂ ) to calculate, and the The previously designed turbidity gradients of 5NTU, 10NTU, 15NTU, 20NTU, and 25NTU respectively correspond to the suspended particulate matter concentration (ie SPM value): 3.24mg/L, 8.85mg/L, 14.47mg/L, 22.34mg/L, 25.70mg/L L.

According to the suspended particle size concentration gradient obtained by the above calculation, add particulate matter to the enclosure. Measure the turbidity of the water body after adding particulate matter, that is, the actual turbidity, and compare the actual turbidity with the expected turbidity (that is, the turbidity of the aforementioned experimental design), see the left diagram of Figure 4; it can be seen from the figure that the dosage Although there are some deviations between the actual turbidity and the expected turbidity after particulate matter, the two are very close; the reason for the deviation may be that the turbidity of the water body is not only affected by suspended particulate matter, but also affected by the process of colored dissolved organic matter in the water body and particulate matter flocculation. Influence.

During the whole experiment process, the relationship between the estimated biomass per unit area and the relative turbidity in the enclosure obtained is shown in the right figure in Figure 4, because the added suspended particles will cause the enclosure to The turbidity is in a process of change, so the data corresponding to the biomass of multiple different turbidities can be obtained in five closed enclosures. The maximum turbidity value 26NTU in the figure appears in the 25NTU experimental group, and the minimum turbidity value 2NTU appears in the blank control group. From the results of this figure, it can be shown that when the turbidity exceeds 20NTU, the biomass is maintained at a low level, indicating that the growth of Cladophora is inhibited. At the same time, when the turbidity is less than 5NTU, there is no significant difference between the biomass and the biomass of the blank control group, indicating that when the turbidity is less than 5NTU, the biomass of Cladophora is not affected by turbidity. During the experiment, in the enclosure with turbidity above 10NTU, the biomass of Cladophylla originally had high in the water body, but after adding particulate matter, the biomass began to decrease; in the enclosure with turbidity of 20NTU, the biomass decreased. to the lowest, and the turbidity in the range of 10-20NTU, the biomass decreased the fastest.

It can be seen from the above experimental results that in this embodiment, through the corresponding relationship model, the particle size parameter and OM value of the particles to be added and the determined growth inhibition parameters are used to determine the concentration of suspended particles. Dosing particulate matter in the body can achieve the effect of preventing and controlling the outbreak of Cladophorus algae. In general, the simulation results of the in-situ experiments carried out in this example are similar to the relationship between water turbidity and Cladophora biomass in previous studies.

Example 2

The target algae of this example is Microcystis aeruginosa (FACHB 905, from the Freshwater Algae Species Bank of the Institute of Hydrobiology, Chinese Academy of Sciences). Previous studies have found that the optimum growth light intensity (irradiance) of Microcystis aeruginosa is 77.4 μmol/(m ² .s) (Chen Xuechu et al., 2007), and the saturated light intensity is 40-100 μmol/(m ² .s ) (Wang Chong et al., 2010).

The test was cultivated in a light incubator with a 5L open beaker (ie, a culture bottle), and the periphery of the beaker was wrapped with tinfoil to avoid the influence of side light. Due to the low depth of the culture bottle, in order to simulate the daily average light conditions under natural conditions, the light intensity of the light incubator was set at 200 μmol/(m ² .s).

The average light intensity (ie, irradiance) gradient in the culture flask was designed to be 10, 20, 40, 70, 100 and 120 μmol/(m ² .s), that is, the design gradient of irradiance E(z). Use 20cm below the water surface of the culture bottle as the average light intensity replacement depth, ie the preset depth z=0.2m. The irradiance E(0) of the water surface of the culture flask is 200 μmol/(m ² .s); Substitute E(z), E(0) and z into the relational formula (II):

The calculated and designed K values corresponding to each irradiance are: 15.0, 11.5, 8.0, 5.2, 3.5, 2.6

Substituting the above calculated K values into the relational formula (III) (K=(2.39±0.20)+(0.14±0.013)×TUR), the corresponding turbidity gradients (i.e. expected turbidity) are calculated as follows: 90NTU, 65NTU, 40NTU, 20NTU, 8NTU, 2NTU.

The particulate matter to be added is the same as in Example 1, with an OM value of 0 and a particle size D50 of 1 μm. Substituting each turbidity in the turbidity gradient calculated above and the determined OM value and D50 of the particulate matter into the relational formula (I) (TUR=0.89SPM-0.08D50+6.56OM ₂ )) for calculation, each turbidity Suspended particulate matter concentration (ie SPM value) corresponding to the degree gradient: 101mg/L, 73mg/L, 45mg/L, 23mg/L, 9mg/L, 2mg/L.

According to the concentration of suspended particulate matter calculated above, add corresponding amount of particulate matter to the culture bottle, mix evenly in the shaker after adding, and carry out the cultivation of Microcystis aeruginosa. Samples were taken on the 1st, 2nd, 5th, 7th, 12th, 14th, and 16th days of the experiment, and the turbidity and cell density were measured. It was found that the actual turbidity after adding particulate matter was very close to the expected turbidity, similar to the results of Example 1; During the experiment, if the turbidity is lower than the above-mentioned expected turbidity, additional particulate matter can be added to achieve the expected turbidity.

See Figure 5 for the experimental results. Each curve in Fig. 5 corresponds to the cell density measured at different experimental days in the pre-designed experimental group of each irradiance.

It can be seen from Figure 5 that in different experimental groups, the growth of Microcystis aeruginosa under different underwater light conditions regulated by suspended particles showed great differences. In the experimental groups with E(z) values of 10 μmol/(m ² s) and 20 μmol/(m ² s), the cell density was less than 1×10 ⁶ cells/ml throughout the experiment, indicating that the high turbidity condition The growth of Microcystis aeruginosa was limited by the low light environment under low light conditions. A certain light limitation phenomenon also occurred in the experimental group whose E(z) value was 120 μmol/(m ² ·s) after adding a small amount of particulate matter. The cell density The experimental group should be lower than the value of E(z) at 40-100μmol/(m ² ·s).

From the experimental results of this embodiment, it can be seen that after obtaining the optimal growth light intensity and saturated light intensity information of Microcystis aeruginosa, the irradiance parameters for inhibiting Microcystis aeruginosa can be predicted, and then through the relational model of the present invention, it can Based on the particle size parameters and OM value of the particles to be added and the determined growth inhibition parameters, the concentration conditions of suspended particles are determined, and the particles are added to the water body according to the calculated concentration data of suspended particles, which can achieve the purpose of growth inhibition of Microcystis aeruginosa .

Under laboratory conditions, by adding particles to control turbidity and light attenuation coefficient to change the underwater light intensity, observing the growth of Microcystis aeruginosa under different underwater light intensities, we can find that through the particle addition regulation proposed by the present invention The method and the corresponding relationship system can effectively control the underwater light conditions, and through experiments we found that for the toxic cyanobacteria Microcystis aeruginosa, low light conditions (below 20μmol/(m ² ·s)) can be effective Inhibits the growth of algae.

It is easy to understand that the above-mentioned embodiments are only examples for clear description, and do not mean that the present invention is limited thereto. For those of ordinary skill in the art, other changes or changes in different forms can be made on the basis of the above description. It is not necessary and impossible to exhaustively list all the implementation manners here. And the obvious changes or changes derived therefrom are still within the scope of protection of the present invention.

Claims (10)

1. The method for inhibiting the growth of the target algae by using the suspended particulate matter is characterized by comprising the following steps of:

1) Determining target algae in the water body, which need to be inhibited from growing;

2) Determining a growth inhibition parameter that inhibits growth of the target algae, the growth inhibition parameter comprising at least one of turbidity of the water body, irradiance, transparency of the water body;

3) Determining a particle size parameter and an OM value of the particles to be added, and determining an expected suspended particle concentration condition of the water body according to the growth inhibition parameter, the particle size parameter and the OM value;

4) And adding the particles into the water body according to the expected suspended particle concentration condition of the water body so as to inhibit the growth of the target algae.

2. The method of claim 1, wherein in step 3), the calculation is performed by substituting the growth inhibition parameter, the particle size parameter, and the OM value into a pre-established relational model to determine the expected suspended particulate matter concentration condition of the body of water;

the relation model comprises a relation formula (I), wherein the relation formula (I) is a relation formula between turbidity of a water body, suspended particulate matter concentration of the water body, granularity parameters of suspended particulate matters and OM values of the suspended particulate matters;

preferably, the relation (I) is established by:

acquiring a plurality of water body samples, acquiring turbidity, suspended particulate matter concentration and suspended particulate matter granularity parameters of each water body sample, acquiring an OM value of suspended particulate matters in each water body sample, and fitting to obtain a relational expression (I) between the turbidity and the suspended particulate matter concentration, the suspended particulate matter granularity parameters and the suspended particulate matter OM value:

TUR＝α ₁ SPM+α ₂ Dx+α ₃ OM ₂ (I)；

TUR is the turbidity of the water body, and the unit is NTU; SPM is the concentration of suspended particles in water in mg/L; OM (OM) ₂ =exp (-OM); dx is the particle size parameter of the suspended particulate matter in μm; alpha ₁ 、α ₂ 、α ₃ Is a coefficient in the relation (I);

preferably, the particle size parameter is D10, D50, D60 or D90.

3. The method according to claim 2, wherein the growth inhibition parameter is turbidity of a water body, and in the step 3), the turbidity of the water body, which is the growth inhibition parameter, and the particle size parameter and OM value of the particulate matter to be added are substituted into the relation (I) to calculate the suspended particulate matter concentration, thereby determining the expected suspended particulate matter concentration condition of the water body.

4. The method of claim 2, wherein the relational model further comprises relational expression (II) and relational expression (III);

wherein the relation (II) is a relation between irradiance and underwater light attenuation coefficient, and the relation (II) is:

wherein K is the underwater light attenuation coefficient; z is the preset depth of the water body, and is the unit m; e (z) is irradiance of the water body at a preset depth z, E (0) is irradiance of the water surface, and units of E (z) and E (0) are mu mol/(m) ² .s)；

The relation (III) is a relation between the underwater light attenuation coefficient and the turbidity of the water body;

preferably, the relation (III) is established by:

acquiring water body samples from a plurality of water bodies, acquiring E (0) and E (z) of each water body, and determining the underwater light attenuation coefficient of each water body according to a relation formula (II); acquiring the turbidity of each water body sample, and obtaining a linear relation between the underwater light attenuation coefficient and the turbidity of the water body through fitting according to the underwater light attenuation coefficient of each water body and the turbidity of each water body sample:

K＝a+b*TUR(III)

TUR is the turbidity of the water body, and the unit is NTU; b is the slope of the relation (III) and a is the intercept of the relation (III).

5. The method according to claim 4, wherein the growth inhibition parameter is irradiance, the irradiance is taken as a value of E (z) in a relation (II), irradiance E (0) of the water surface of the water body is obtained, and preset depths z, E (z) and E (0) are substituted into the relation (II) to obtain the underwater light attenuation coefficient of the water body;

substituting the underwater light attenuation coefficient K into the relation (III) to calculate to obtain the turbidity of the water body;

substituting the calculated turbidity of the water body, the granularity parameter and the OM value of the particulate matters to be added into the relational expression (I) to calculate the concentration of the suspended particulate matters, thereby determining the expected concentration condition of the suspended particulate matters of the water body.

6. The method of claim 2, wherein the relationship model further comprises a relationship (IV) between turbidity of the body of water and transparency of the body of water;

preferably, the relation (IV) is established by:

obtaining turbidity and transparency of each water body sample, performing lg logarithmic conversion on the values of the turbidity and the transparency respectively, and then performing linear fitting to obtain a relational expression between the turbidity of the water body and the transparency of the water body:

log(SDD)＝a+b×log(TUR) (Ⅳ)

wherein SDD is transparency of the water body, and the unit is cm; TUR is the turbidity of the water body, and the unit is NTU; b is the slope of the relation (iv) and a is the intercept of the relation (iv).

7. The method according to claim 6, wherein the growth inhibition parameter is transparency of a water body, and in the step 3), the transparency of the water body as the growth inhibition parameter is substituted into the relation (IV) to calculate turbidity of the water body;

substituting the calculated turbidity of the water body, the granularity parameter and the OM value of the particulate matters to be added into the relational expression (I) to calculate the concentration of the suspended particulate matters, thereby determining the expected concentration condition of the suspended particulate matters of the water body.

8. The method according to any one of claims 1-7, wherein in step 4) after the particulate matter is dosed, the body of water is continuously monitored, and when the body of water fails to meet the requirement of the growth inhibition parameter, the particulate matter is dosed again;

or in the step 4), after the particulate matters are added, continuously monitoring the water body, and when the water body can not meet the requirement of the growth inhibition parameters, adjusting the granularity parameters and/or the OM values of the particulate matters to be added, and determining the expected suspended particulate matter concentration condition of the water body again according to the step 3); and then adding particles into the water body according to the redetermined expected suspended particle concentration condition of the water body.

9. The method according to any one of claims 1 to 7, wherein in step 4) the particulate matter is added by dry or wet methods;

and/or in the step 4), the particulate matters to be added are selected from one or more of clay minerals, sludge discharged from a sedimentation tank of a water plant, activated sludge, bottom sludge of a natural water body and harmless industrial waste particulate matters.

10. Use of the method according to any one of claims 1-9, characterized in that the method is used in algal bloom prevention or water quality regulation.

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