A method for determining water bloom prevention measures according to total phosphorus and suspended matter thresholds

Abstract

The application discloses a method for synthetically determining water bloom prevention and treatment measures according to total phosphorus and suspended matter thresholds, and comprises the following steps: measuring total phosphorus concentration I and suspended matter concentration I of eutrophic water, then implementing algae control measures, carrying out water-algae separation, measuring total phosphorus concentration II and suspended matter concentration II of the separated water; calculating total phosphorus removal rate and suspended matter removal rate according to total phosphorus concentration I and total phosphorus concentration II, and suspended matter concentration I and suspended matter concentration II; carrying out function fitting on total phosphorus removal rate and total phosphorus concentration I, and carrying out function fitting on suspended matter removal rate and suspended matter concentration I; determining total phosphorus threshold and suspended matter threshold according to total phosphorus and suspended matter fitting curve formula; and comparing total phosphorus concentration I with the total phosphorus threshold, comparing suspended matter concentration I with the suspended matter threshold, and taking corresponding prevention and treatment measures. The application prevents lake blue-green algae water bloom by controlling total phosphorus concentration, and effectively guarantees lake water ecological environment quality.

Description

TECHNICAL FIELD

[0001] The present application relates to a method for preventing water bloom, in particular to a method for determining water bloom prevention measures according to total phosphorus and suspended matter thresholds. BACKGROUND

[0002] Water bloom outbreak can cause water eutrophication to intensify, and there is a risk of degradation, which seriously threatens the health of the water ecosystem, and also has adverse social impacts. The death of blue-green algae can cause fermentation and odor, which threatens the water safety of the surrounding people.

[0003] In eutrophic lakes such as Taihu, Erhai, and Xingyun Lake, the high value of algal biomass in the water body mainly occurs in summer and autumn. The concentration of chlorophyll a is consistent with the concentrations of total phosphorus and suspended matter, and often has a good positive correlation. In particular, total phosphorus has a greater impact on the growth of blue-green algae. Controlling the concentration of total phosphorus is often a prerequisite for preventing lake water bloom outbreak, otherwise any control measures are difficult to achieve long-term effects. The content of suspended matter is closely related to the degree of water eutrophication. High content of suspended matter can reduce water transparency, reduce dissolved oxygen content, affect the photosynthesis of aquatic plants, and increase the speed of lake siltation, causing certain negative impacts on water resources, water safety, water environment, and water ecology.

[0004] The prevention measures for blue-green algae bloom include physical methods such as aeration, chemical methods such as adding flocculants, and biological methods such as planting higher aquatic plants. Among them, the in-situ deep well pressurization algae control measure has been widely used in recent years. It uses the static water pressure of deep well to force the blue-green algae pseudo-blastula to rupture and lose activity, thereby inhibiting the proliferation of algae. It has the advantages of large treatment capacity and low operation cost, but further prevention measures need to be taken to achieve better results when the water bloom is more serious. The large-flux cyclone algae-water separation technology integrates air flotation, slag scraping, and sedimentation into one, has the advantages of small site area, good algae removal, phosphorus removal, and suspended matter removal, but the operation cost is relatively high, and the project benefit cannot be fully realized due to the low concentration of pollutants in the influent.

[0005] Therefore, it is necessary to provide a method for determining water bloom prevention measures according to total phosphorus and suspended matter thresholds, which provides a theoretical basis for selecting and implementing water bloom prevention measures under different influent total phosphorus concentrations and suspended matter concentrations, so as to fully realize the engineering benefits of water bloom prevention measures. SUMMARY

[0006] The purpose of the present application is to provide a method for determining water bloom prevention measures according to total phosphorus and suspended matter thresholds, which can effectively protect the water ecological environment quality of lakes.

[0007] The technical scheme of the present application is a method for determining water bloom prevention measures according to total phosphorus and suspended matter thresholds, which comprises the following steps:

[0008] (1) measuring total phosphorus concentration one and suspended substance concentration one of the eutrophic water body;

[0009] (2) implementing algae control measures on the eutrophic water body, then carrying out algae water separation, and measuring total phosphorus concentration two and suspended substance concentration two of the separated water body;

[0010] (3) calculating total phosphorus removal rate and suspended substance removal rate according to total phosphorus concentration one and total phosphorus concentration two, and suspended substance concentration one and suspended substance concentration two;

[0011] (4) fitting functions of total phosphorus removal rate and total phosphorus concentration one, and fitting functions of suspended substance removal rate and suspended substance concentration one;

[0012] (5) determining total phosphorus threshold value and suspended substance threshold value according to total phosphorus fitting curve formula and suspended substance fitting curve formula; comparing total phosphorus concentration one with the total phosphorus threshold value and comparing suspended substance concentration one with the suspended substance threshold value, and then taking corresponding prevention and control measures.

[0013] Preferably, in step (1), the control measures are in-situ deep well pressurization algae control measures; and the method of algae water separation is a large-flux cyclone type algae water separation method.

[0014] Preferably, the total phosphorus removal rate refers to the difference between total phosphorus concentration one and total phosphorus concentration two divided by total phosphorus concentration one; and the suspended substance removal rate refers to the difference between suspended substance concentration one and suspended substance concentration two divided by suspended substance concentration one.

[0015] Preferably, in step (4), the function fitting is to take a function with a higher correlation coefficient among exponential function, power function and polynomial function as the fitting curve.

[0016] Preferably, in step (5), the total phosphorus threshold value refers to the total phosphorus concentration corresponding to the total phosphorus removal rate of 80.0% in the fitting curve; and the suspended substance threshold value refers to the suspended substance concentration corresponding to the suspended substance removal rate of 80.0% in the fitting curve.

[0017] Preferably, in step (5), if the total phosphorus concentration one is higher than the total phosphorus threshold value, algae control measures are implemented, and then algae water separation is carried out to purify the water body; if the total phosphorus concentration one is lower than the total phosphorus threshold value, and when the suspended substance concentration one is higher than the suspended substance threshold value, algae water separation is carried out, otherwise, no algae control and algae water separation measures are implemented.

[0018] Beneficial effects: Compared with the prior art, the present application has the following remarkable effects: (1) preventing lake blue-green algae bloom by controlling total phosphorus concentration, effectively guaranteeing the quality of lake water ecological environment; (2) providing a theoretical basis for how to select water bloom prevention and control measures under different total phosphorus concentration and suspended substance concentration conditions; (3) reducing the cost of water bloom prevention and control measures, and fully exerting the engineering benefits of water bloom prevention and control measures. BRIEF DESCRIPTION OF DRAWINGS

[0019] Figure 1 is a total phosphorus threshold value and suspended solids threshold value determination flowchart of an embodiment of the present application;

[0020] Figure 2 is a water bloom prevention measure selection flowchart of an embodiment of the present application;

[0021] Figure 3 is a total phosphorus concentration one, a total phosphorus concentration two and a total phosphorus removal rate of an embodiment of the present application;

[0022] Figure 4 is a suspended solids concentration one, a suspended solids concentration two and a suspended solids removal rate of an embodiment of the present application;

[0023] Figure 5 is an exponential function fitting of the total phosphorus removal rate and the total phosphorus concentration one of an embodiment of the present application;

[0024] Figure 6 is an exponential function fitting of the suspended solids removal rate and the suspended solids concentration one of an embodiment of the present application;

[0025] Figure 7 is a water bloom prevention measure implementation range demarcation of an embodiment of the present application. DETAILED DESCRIPTION

[0026] The present application will be further described in detail below.

[0027] As shown in Figure 1 , 2 , the present application provides a method for comprehensively determining water bloom prevention measures according to total phosphorus and suspended solids threshold values, which comprises the following steps:

[0028] (1) measuring a total phosphorus concentration one in a certain eutrophic lake, and the result is shown in Figure 3 ; measuring a suspended solids concentration one, and the result is shown in Figure 4 ;

[0029] (2) implementing the in-situ deep well pressurization algae control measure disclosed in patent CN107265526A, and separating algae water according to the large-flow cyclone algae water device disclosed in patent CN208414021U, measuring a total phosphorus concentration two after implementation, and the result is shown in Figure 3 ; measuring a suspended solids concentration two after implementation, and the result is shown in Figure 4 ; wherein, the algae control measure and the cyanobacteria separation measure can also be implemented by using the methods commonly used in the prior art;

[0030] (3) calculating a total phosphorus removal rate according to the total phosphorus concentration one and the total phosphorus concentration two, and the result is shown in Figure 3 ; calculating a suspended solids removal rate according to the suspended solids concentration one and the suspended solids concentration two, and the result is shown in Figure 4 ;

[0031] (4) The total phosphorus removal rate and the total phosphorus concentration are fitted with a function, an exponential function with a higher correlation coefficient is selected as the fitting curve, and the results are shown in Figure 5 ; the suspended solids removal rate and the suspended solids concentration are fitted with a function, an exponential function with a higher correlation coefficient is selected as the fitting curve, and the results are shown in Figure 6 ; wherein the formula of the total phosphorus fitting curve is as follows (1):

[0032] TP = 0.0035e 0.0514x (1)

[0033] In formula (1), TP represents the measured total phosphorus concentration, and x represents the total phosphorus removal rate;

[0034] The formula of the suspended solids fitting curve is as follows (2):

[0035] SS = 1.101e 0.038x (2)

[0036] In formula (2), SS represents the measured suspended solids concentration, and x represents the suspended solids removal rate;

[0037] (5) According to the total phosphorus and suspended solids fitting curve formula, when the total phosphorus removal rate is 80.0%, the corresponding total phosphorus concentration is 0.21 mg / L, which is set as the total phosphorus threshold value; according to the fitting curve, when the suspended solids removal rate is 80.0%, the corresponding suspended solids concentration is 23.02 mg / L, which is set as the suspended solids threshold value; the water bloom prevention and control measure implementation concentration range is determined, as shown in Figure 7 ;

[0038] (6) According to the water bloom prevention and control measure implementation concentration range, the water bloom prevention and control measures are determined: if the total phosphorus concentration is higher than 0.21 mg / L, i.e. Figure 7 Region I, in-situ deep well pressurization algae control measures and large flux cyclone algae-water separation technology are implemented and discharged into the lake body; if the total phosphorus concentration is lower than 0.21 mg / L, when the suspended solids concentration is higher than 23.02 mg / L, i.e. Figure 7 Region II, large flux cyclone algae-water separation technology is implemented and discharged into the lake body, otherwise, such as Figure 7 Region III, no measures are implemented.

Claims

1. A method for integrated determination of algal bloom control measures from total phosphorus and suspended solids thresholds, characterized in that, The method comprises the following steps: (1) measuring total phosphorus concentration one and suspended matter concentration one of the eutrophic water body; (2) implementing algae control measures on the eutrophic water body, then performing algae-water separation, and measuring total phosphorus concentration two and suspended matter concentration two of the separated water body; (3) calculating total phosphorus removal rate and suspended matter removal rate according to total phosphorus concentration one and total phosphorus concentration two, and suspended matter concentration one and suspended matter concentration two; (4) performing function fitting on total phosphorus removal rate and total phosphorus concentration one, and selecting an exponential function with a higher correlation coefficient as the fitting curve; performing function fitting on suspended matter removal rate and suspended matter concentration one, and selecting an exponential function with a higher correlation coefficient as the fitting curve; wherein the formula of the total phosphorus fitting curve is formula (1) as follows: TP = 0.0035e 0.0514x (1) In formula (1), TP represents the measured total phosphorus concentration one, and x represents the total phosphorus removal rate; the formula of the suspended matter fitting curve is formula (2) as follows: SS = 1.101e 0.038y (2) In formula (2), SS represents the measured suspended matter concentration one, and y represents the suspended matter removal rate; (5) determining total phosphorus threshold and suspended matter threshold according to the formula of the total phosphorus fitting curve and the formula of the suspended matter fitting curve; comparing total phosphorus concentration one with the total phosphorus threshold and comparing suspended matter concentration one with the suspended matter threshold, and then taking corresponding prevention and control measures.

2. The method of integrated determination of measures for prevention of water bloom according to threshold values of total phosphorus and suspended matter according to claim 1, characterized in that, In step (5), if total phosphorus concentration one is higher than the total phosphorus threshold, algae control measures are implemented, and then algae-water separation is performed to purify the water body.

3. The method of integrated determination of measures for prevention of algal blooms depending on thresholds of total phosphorus and suspended matter according to claim 1, characterized in that, In step (5), if total phosphorus concentration one is lower than the total phosphorus threshold, and when suspended matter concentration one is higher than the suspended matter threshold, algae-water separation is performed, otherwise, no algae control and algae-water separation measures are implemented.

4. The method of integrated determination of measures for prevention of algal blooms depending on thresholds of total phosphorus and suspended matter according to claim 1, characterized in that, In step (5), the total phosphorus threshold refers to the total phosphorus concentration corresponding to a total phosphorus removal rate of 80.0% in the fitting curve.

5. The method for determining algal bloom control measures based on total phosphorus and suspended solids thresholds according to claim 1, characterized in that, In step (5), the suspended matter threshold refers to the suspended matter concentration corresponding to a suspended matter removal rate of 80.0% in the fitting curve.

6. The method of integrated determination of measures for prevention of algal blooms according to threshold values of total phosphorus and suspended matter according to claim 1, characterized in that, In step (1), the algae control measures are in-situ deep-well pressurization algae control measures.

7. The method of integrated determination of measures for prevention of algal blooms depending on thresholds of total phosphorus and suspended matter according to claim 1, characterized by the fact that, In step (1), a large-flux cyclone algae-water separation device is used to perform algae-water separation.

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