An algae enrichment device and method

Abstract

An algae enrichment device includes a filter bottle for holding water samples and a filtration assembly. The filtration assembly comprises a filter body floating on the surface of the water sample, a drainage channel connected to the filter body for discharging the supernatant from the water sample, and a single-layer metal filter membrane covering the outer surface of the filter body to prevent algae from entering the drainage channel. The filtration assembly also includes a water pump connected to the drainage channel. This invention can efficiently enrich algae in water samples, effectively increase algae density, and ensure the algae survive without damage, thereby improving the representativeness and accuracy of the detection results.

Description

Technical Field

[0001] This invention relates to the field of ecological and environmental engineering technology, and in particular to the design of an algae enrichment device that integrates gravity sedimentation and filtration. Background Art

[0002] Algae detection in water bodies typically involves sampling, requiring specialized equipment such as microscopes to examine small samples (usually 0.1 mL). If the algal density in the sample is too low, sampling can introduce significant errors, potentially leading to incorrect results. To improve the representativeness and accuracy of the results, enrichment is necessary when the algal density in the water sample is low.

[0003] Most existing enrichment methods employ natural sedimentation, where the sample is treated with Lugol's reagent, placed in a sample cup, and allowed to settle before the supernatant is removed to obtain a concentrated solution. While this method is compatible with various algae, it relies on gravity sedimentation, is time-consuming and inefficient, and cannot meet the needs of high-frequency emergency monitoring during algal blooms. To address this issue, some technologies utilize centrifugation and membrane filtration to achieve rapid concentration and enrichment.

[0004] However, existing technologies are limited in that they cannot simultaneously meet the conditions of efficient enrichment and non-destructive preservation of live algae. Natural sedimentation is not only time-consuming and inefficient, but the use of Lugol's reagent can also damage the algae, leading to partial loss. While centrifugation can efficiently concentrate algae, it is difficult to quickly and easily enrich algae with different characteristics. For a single algal species, although the appropriate centrifugation speed and time can be determined experimentally to concentrate the algae without causing damage, in actual natural water samples, there are many different and unpredictable algal species, including diatoms, cyanobacteria, green algae, and dinoflagellates, with significant differences in morphology and density. Low-speed centrifugation effectively concentrates denser diatoms and dinoflagellates, but may not effectively concentrate cyanobacteria and green algae; high-speed centrifugation may cause some algae to be crushed and damaged; furthermore, some algae exist in a floating state, making centrifugation impossible. In the enrichment process of membrane filtration, ordinary filter membranes have problems such as low porosity, wide pore size distribution, and multi-layered fiber structure, generally requiring vacuum filtration or injection to press the filter head to accelerate the filtration process. During membrane filtration, algae and particles such as sediment can clog the filter membrane, reducing filtration efficiency. The pressure difference across the membrane can cause algae to become embedded and difficult to wash out, or even break down. The wide pore size distribution of the filter membrane means that either extremely small pores are chosen to prevent algae from passing through, but these are more prone to clogging; or large pores allow some algae to enter the waste liquid and be lost. Summary of the Invention

[0005] In view of the above-mentioned deficiencies of the prior art, the present invention provides an algae enrichment device and method, which can efficiently enrich algae in water samples, effectively increase algae density, and ensure algae survival without damage, thereby improving the representativeness and accuracy of the detection results.

[0006] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0007] An algae enrichment device, a filter bottle for holding water samples, further includes a filtration assembly comprising a filter body floating on the surface of the water sample, a drain channel connected to the filter body for discharging the supernatant of the water sample, and a single-layer metal filter membrane covering the outer surface of the filter body for preventing algae from entering the drain channel; the filtration assembly also includes a water pump connected to the drain channel.

[0008] The enrichment principle of this device is as follows: the water sample is allowed to settle in the filter bottle for a few minutes, and then the upper clear liquid in the filter bottle is extracted using the filter assembly. The filter body floats on the surface of the water sample and sinks as the liquid level drops. The waste liquid filtered by the filter body is driven by a water pump to be discharged through the drain channel. The algae are blocked by the filter body and retained in the solution in the filter bottle. Finally, the bottom of the filter bottle is left with the water sample enriched with algae, thus achieving non-destructive and efficient enrichment of algae samples.

[0009] The reason this device is more efficient than gravity sedimentation is that algae have a density similar to water, resulting in a relatively slow settling rate. Relying solely on gravity sedimentation requires a considerable amount of time (generally 24-48 hours) to effectively enrich the algae. This device, combined with membrane filtration, uses a pump to rapidly propel the water sample through a single-layer metal filter membrane, trapping the algae on the membrane and significantly increasing the enrichment rate. Gravity sedimentation initially enriches a portion of the algae and impurities (silt, organic matter, fibers, microorganisms, etc.), effectively reducing the amount of particulate matter in contact with the filter membrane and minimizing the risk of filter pore clogging. Then, membrane filtration efficiently filters the supernatant, rapidly reducing the water sample volume until the target volume is reached, achieving concentration and ultimately obtaining a high-density algae-rich water sample. The overall efficiency of this enrichment method is far superior to that of gravity sedimentation.

[0010] The reason this device can ensure the survival of algae during filtration is that traditional filter membranes are fibrous or porous, which easily adhere to algae. Under the combined effects of adhesion and suction, the algae are easily damaged and die. Metal membranes are usually used for surface-enhanced Raman scattering (SERS) detection, design of optical metamaterials, and catalytic reactions. This invention creatively uses a metal membrane as a filter membrane, utilizing its high porosity and smooth surface to prevent algae adhesion. This ensures a high filtration flow rate and prevents algae adhesion during water sample filtration, avoiding adsorption or entanglement that could damage the algae.

[0011] It is important to note that the metal used in the single-layer metal filter membrane of this technical solution must be corrosion-resistant, acid and alkali-resistant, and possess a certain degree of flexibility. The reason for requiring a single-layer metal filter membrane is to ensure that the surface in contact with the algae is smooth and does not trap the algae. Multi-layer metal filter membranes tend to have multiple pores, are not smooth, and trap algae, making complete elution difficult. The pore size of the single-layer metal filter membrane is limited by the specific algae size, and different algae types are considered in different application scenarios.

[0012] Preferably, the filter bottle is provided with an impurity filter pad, and there is an algae deposition zone between the impurity filter pad and the bottom of the filter bottle.

[0013] During algae enrichment, the water sample may contain other impurities (such as suspended particles and sediment). If these impurities are mixed into the final algae-enriched water sample, they will affect subsequent detection or analysis. An impurity filter pad is installed inside the filter bottle, and the algae deposition area is used for algae deposition at the bottom of the filter bottle. In use, the water sample is poured into the filter bottle. The pores of the impurity filter pad are much larger than the diameter of the algae, effectively intercepting these larger particles without blocking the algae themselves, resulting in a purer water sample after passing through the impurity filter pad. This not only improves the purity of the algae enrichment but also reduces interfering factors in subsequent treatment steps, making the algae enrichment effect more ideal.

[0014] Preferably, a vibrator is also included.

[0015] Algae have a density similar to water and settle relatively slowly. By installing a vibrator outside the filter bottle, mechanical vibration can be applied to the water sample inside. This vibration disturbs the water sample, making the movement of algae particles in the water more vigorous, thereby accelerating the algae settling process. Compared to simple gravity sedimentation, the addition of a vibrator can significantly shorten the time required for algae enrichment and improve enrichment efficiency.

[0016] During algae enrichment, impurities may adhere to a small portion of the monolayer metal filter membrane. While the monolayer metal filter membrane possesses high porosity and the characteristic of not adhering to algae, its pore size is relatively small, making it easily clogged by larger impurity particles. The vibration of the vibrator can generate minute vibrations on the monolayer metal filter membrane, helping to loosen the algae or impurities attached to the surface. The vibrator also prevents the impurity filter pad from clogging, thereby maintaining the high-flux characteristics of the impurity filter pad and ensuring the efficient enrichment of algae to the bottom of the filter bottle.

[0017] Preferably, the water pump is connected to a touch control device for controlling the water pump; the touch control device includes a touch display screen and a central controller connected to the touch display screen.

[0018] The touchscreen display provides users with an intuitive interface, allowing them to control the water pump's start, stop, and flow rate adjustment functions through simple touch operations. This method is more intuitive and convenient than traditional mechanical buttons or knobs, reducing operational complexity. The touchscreen displays the water pump's operating status in real time (such as flow rate, running time, and pressure), enabling users to monitor the enrichment process and better adjust operating parameters. Users can precisely adjust the water pump's flow rate via the touchscreen. This is crucial for algae enrichment, as different algae enrichment requirements may necessitate different flow rate settings. Precise flow control ensures that algae are not washed away by excessive flow or that enrichment efficiency is not reduced by insufficient flow. The central controller automatically controls the water pump's operation according to preset programs. The automated control via the touchscreen and central controller reduces human error, ensuring each enrichment process follows preset parameters, improving enrichment efficiency and result consistency. The introduction of the touchscreen and central controller makes the algae enrichment device more intelligent and user-friendly to operate. Even non-professionals can quickly get started, lowering the barrier to entry for using the device.

[0019] Preferably, the water pump is a peristaltic pump.

[0020] A peristaltic pump is a pump that delivers fluid by squeezing a flexible tube. Its working principle allows for very precise control of fluid flow. In this device, the peristaltic pump can precisely control the discharge rate of the supernatant, thereby better regulating the filtration process. This precision prevents algae from becoming embedded and ruptured in the filter pores due to excessive flow, or from reducing filtration efficiency due to insufficient flow. The forward and reverse rotation of the peristaltic pump effectively removes algae and impurities accumulated during metal membrane filtration, preventing clogging and ensuring filtration efficiency. Specifically, the peristaltic pump rotates forward to extract waste liquid and intermittently reverses to flush away algae and impurities accumulated near the membrane. This cycle repeats, using the combination of forward and reverse rotation to achieve both liquid extraction and clogging prevention. The peristaltic pump has a simpler structure than a conventional water pump, mainly consisting of a pump head and a flexible tube. Since the fluid is delivered only through the flexible tube, the fluid channel can be easily cleaned and disinfected when replacing the tube. This is crucial for algae enrichment devices, as different types of water samples may be involved in the algae enrichment process, requiring regular cleaning to prevent cross-contamination. This design of the peristaltic pump makes the device easier to maintain and reduces operating costs.

[0021] Preferably, the filter bottle is made of high-purity PFA.

[0022] High-purity PFA (perfluoroalkoxy polymer) is a high-performance fluoropolymer with extremely high chemical stability. The surface of high-purity PFA material is extremely smooth, with almost no rough points in its microstructure that could allow algae to attach. Algae in water samples typically seek out areas with minute surface irregularities or chemical activity to attach to, but the smooth surface of PFA makes it difficult for algae to remain or adsorb onto it. PFA material has extremely low surface energy, resulting in very weak interaction forces between it and algae. Because algae do not adhere to the inner wall of the filter bottle, they can settle more effectively to the bottom of the filter bottle during enrichment, rather than being attached to the inner wall. This leads to a higher concentration of algae at the bottom of the filter bottle and a significantly improved enrichment efficiency.

[0023] Preferably, the single-layer metal filter membrane is made of nickel.

[0024] Nickel materials can be fabricated into high-porosity single-layer metal filter membranes using special processing techniques (such as nanoporous structure fabrication). High porosity means the filter membrane has more channels per unit area, allowing more water sample to pass through, thus improving filtration efficiency. Due to the high porosity of nickel filter membranes, water samples can be quickly discharged by a pump, while algae are trapped on the membrane surface, significantly shortening the algae enrichment time and improving the overall enrichment efficiency of the device. The pore size of nickel filter membranes can be precisely controlled through processing techniques, allowing for customization based on the specific algae size. This enables the single-layer metal filter membrane to effectively block desired algae from entering the drainage channel while allowing water samples to pass through quickly, achieving highly efficient algae enrichment.

[0025] Nickel is a highly corrosion-resistant metal that remains stable in a variety of water sample environments and is not easily corroded by chemicals in the water. This is crucial for the long-term use of algae enrichment devices in different water qualities (such as acidic, alkaline, or saline samples). The corrosion resistance of nickel materials makes them less prone to damage during algae enrichment, thereby extending the service life of the filter membrane and reducing the maintenance costs of the device.

[0026] Nickel materials have a relatively smooth surface and strong chemical inertness, making them less prone to chemical adsorption onto algae. Compared to traditional fiber or porous membranes, nickel filtration membranes effectively reduce algal adhesion, preventing damage to the algae due to adsorption. Because nickel filtration membranes do not adhere to algae, the algae will not be adsorbed or entangled on the membrane surface during filtration, thus avoiding algal breakage or deformation caused by mechanical forces and ensuring the integrity of the algae during enrichment.

[0027] A method for algae enrichment involves pouring a water sample into a filter bottle for sedimentation; filtering the supernatant in the filter bottle using a filtration assembly; the filtration assembly comprising a filter body floating on the surface of the water sample, a drain channel connected to the filter body for discharging the supernatant from the water sample, and a single-layer metal filter membrane covering the outer surface of the filter body for preventing algae from entering the drain channel; the filtration assembly further comprising a pump connected to the drain channel.

[0028] Compared with the prior art, the beneficial effects of the present invention are reflected in:

[0029] 1. This invention integrates two enrichment methods: gravity sedimentation and membrane filtration. It utilizes the natural enrichment effect of gravity sedimentation while further removing residual algae from the supernatant through membrane filtration, thus achieving rapid and efficient algae enrichment. By combining gravity sedimentation and membrane filtration, this invention avoids the potentially damaging procedures involved in traditional enrichment methods. Using the algae enrichment device of this invention, algae can be efficiently enriched to the bottom of the filter bottle, resulting in a high concentration and purity of enriched algae in the water sample. This allows for a more accurate reflection of the true algae content in the water sample during testing, avoiding detection errors caused by algae dilution or loss.

[0030] 2. The single-layer metal filter membrane possesses high porosity, ensuring high filtration flow rate and preventing algal adhesion. This means that during filtration, algae will not be adsorbed or entangled on the membrane surface, thus avoiding the filtration rate reduction problem caused by membrane clogging in traditional filtration methods and ensuring the high efficiency of the filtration process. The characteristics of the single-layer metal filter membrane prevent physical damage to the algae during filtration. Traditional membrane filtration methods may cause algal rupture or deformation due to excessively small membrane pore size or excessive filtration pressure. However, the metal membrane of this invention, due to its highly ordered nanostructure, can effectively prevent the adsorption and entanglement of algae, thereby ensuring the integrity of the algae. Single-layer array metal membranes are commonly used in fields such as surface-enhanced Raman scattering (SERS) detection, design of optical metamaterials, or catalytic reactions. This invention creatively applies it to algal enrichment, utilizing its high porosity and non-adhesive algal properties to solve the problems existing in traditional enrichment methods, bringing a new breakthrough to algal enrichment technology. Attached Figure Description

[0031] Figure 1 This is a schematic diagram of the structure of Example 1.

[0032] The components include: 1. Filter bottle; 2. Filter assembly; 21. Filter body; 22. Single-layer metal filter membrane; 23. Drainage channel; 24. Water pump; 3. Impurity filter pad; 4. Vibrator; 5. Touch screen display. Detailed Implementation

[0033] To make the technical means, inventive features, objectives, and effects of the invention readily understandable, the invention is further described below with reference to specific illustrations. However, the invention is not limited to the embodiments described below.

[0034] It should be noted that the structures, proportions, sizes, etc., illustrated in the accompanying drawings of this specification are only used to complement the content disclosed in the specification for those skilled in the art to understand and read, and are not intended to limit the conditions under which the present invention can be implemented. Therefore, they have no substantial technical significance. Any modifications to the structure, changes in the proportions, or adjustments to the size, without affecting the effects and objectives that the present invention can produce, should still fall within the scope of the technical content disclosed in the present invention.

[0035] Example 1:

[0036] like Figure 1 The algae enrichment device shown includes a filter bottle 1 for holding water samples and a filter assembly 2. The filter assembly 2 includes a filter body 21 floating on the surface of the water sample, a drain channel 23 connected to the filter body 21 for draining the clear liquid on the surface of the water sample, and a single-layer metal filter membrane 22 covering the outer surface of the filter body 21 for preventing algae from entering the drain channel 23. The filter assembly 2 also includes a water pump 24 connected to the drain channel 23.

[0037] The enrichment principle of this device is as follows: the water sample is allowed to settle in filter bottle 1, and then the upper clear liquid in filter bottle 1 is extracted by filter assembly 2. The filter body 21 floats on the surface of the water sample and sinks with the liquid level. After filtration, the solution is discharged through the drain channel 23 by water pump 24. The algae are filtered, and the bottom of filter bottle 1 is finally left with water sample enriched with algae, thus achieving sample enrichment.

[0038] The reason this device is more efficient than gravity sedimentation is that algae have a density similar to water, resulting in a relatively slow settling rate. Relying solely on gravity sedimentation requires a considerable amount of time to enrich the algae to a sufficient level. This device, combined with membrane filtration, uses a pump 24 to rapidly push the water sample through a single-layer metal filter membrane 22, trapping the algae on the membrane and significantly increasing the enrichment rate. First, gravity sedimentation initially enriches a portion of the algae, causing them to accumulate at the bottom of the water sample. Then, membrane filtration filters the supernatant, reducing the sample volume and allowing the remaining algae to settle to the bottom more quickly. Ultimately, a high-density algae sample remains at the bottom of the filter bottle. The overall efficiency of this enrichment method is far superior to that of gravity sedimentation.

[0039] The reason this device can ensure algal survival during filtration is that traditional filter membranes, which are fibrous or porous, easily adhere to algae, leading to damage and death due to the combined effects of adhesion and suction. While metal membranes are typically used for surface-enhanced Raman scattering (SERS) detection, optical metamaterial design, and catalytic reactions, this invention creatively uses a metal membrane as the filter membrane. Utilizing its high porosity and non-adhesive properties, it ensures high filtration flow while preventing algal adhesion during water sample filtration, thus avoiding algal adsorption or entanglement that could damage the algae. It is important to note that the metal used in the single-layer metal filter membrane 22 in this technical solution must be corrosion-resistant, acid and alkali-resistant, and possess a certain degree of flexibility. The reason for requiring a single-layer metal filter membrane is to maintain a smooth surface in contact with the algae, preventing them from hooking onto the algae. Multi-layer metal filter membranes tend to have multiple pores, are not smooth, and hook onto algae, making complete elution difficult. The pore size of the single-layer metal filter membrane 22 is limited according to the specific algal size, as different application scenarios focus on different types of algae.

[0040] Filter bottle 1 contains an impurity filter pad 3, with an algae deposition zone between the impurity filter pad 3 and the bottom of filter bottle 1. During algae enrichment, the water sample may contain other impurities (such as suspended particles, silt, etc.). If these impurities are mixed into the final algae-enriched water sample, they will affect subsequent detection or analysis. The impurity filter pad 3 is installed inside filter bottle 1, and the algae deposition zone is used for algae deposition at the bottom of filter bottle 1. In use, the water sample is poured into filter bottle 1. The pores of the impurity filter pad 3 are much larger than the diameter of the algae, effectively intercepting these larger particles of impurities without intercepting the algae, making the water sample after passing through the impurity filter pad 3 purer. This not only improves the purity of algae enrichment but also reduces interference factors in subsequent treatment steps, making the algae enrichment effect more ideal.

[0041] The water pump 24 is connected to a touch control device for controlling it. The touch control device includes a touch display screen 5 and a central controller connected to the touch display screen 5. The touch display screen 5 can control and display pump valves, including basic functions such as controlling pump speed, running time, sample list selection, start, and pause, and can add or remove parameters as needed. The algae enrichment device needs to be set with different parameters and methods according to different water samples to achieve reasonable and efficient enrichment results. The touch display screen 5 provides users with an intuitive operating interface, allowing users to control the water pump 24's start, stop, and flow rate adjustment functions through simple touch operations. This operation method is more intuitive and convenient than traditional mechanical buttons or knobs, reducing operational complexity. The touch display screen 5 can display the water pump's operating status (such as flow rate, running time, pressure, etc.) in real time, allowing users to understand the progress of the enrichment process at any time, thereby better adjusting operating parameters. Through the touch control device, users can precisely adjust the flow rate of the water pump 24. This is very important for the algae enrichment process, as different algae enrichment requirements may require different flow rate settings. Precise flow control ensures that algae are not washed away by excessive flow during filtration, nor is reduced enrichment efficiency due to insufficient flow. The central controller automatically controls the operation of the water pump 24 according to a preset program. The automated control via the touch screen and central controller reduces human error, ensuring that each enrichment process follows preset parameters, improving enrichment efficiency and result consistency. The introduction of the touch screen 5 and central controller makes the algae enrichment device more intelligent and user-friendly. Even non-professionals can quickly learn to use it, lowering the barrier to entry.

[0042] Pump 24 is a peristaltic pump. A peristaltic pump is a pump that delivers fluid by squeezing a flexible tube; its operating principle allows for very precise control of fluid flow. In this device, the peristaltic pump can precisely control the discharge rate of the supernatant, thereby better regulating the filtration process. This precision prevents algae from being washed away due to excessive flow or reduced filtration efficiency due to insufficient flow. The peristaltic pump has a simpler structure than a conventional pump, mainly consisting of a pump head and a flexible tube. Since the fluid is delivered solely through the tube, the fluid channel can be easily cleaned and disinfected when replacing the tube. This is crucial for algae enrichment devices, as different types of water samples may be involved in the algae enrichment process, requiring regular cleaning to prevent cross-contamination. This design of the peristaltic pump makes the device easier to maintain and reduces operating costs.

[0043] Filter bottle 1 is made of high-purity PFA. High-purity PFA (perfluoroalkoxy polymer) is a high-performance fluoropolymer with extremely high chemical stability. The surface of high-purity PFA material is extremely smooth, and its microstructure has almost no rough points for algae to attach to. Algae in water samples usually seek to attach to areas with tiny bumps or chemical activity on the surface, but the smooth surface of PFA material makes it difficult for algae to stay or adsorb on it. PFA material has extremely low surface energy, and the interaction force between it and algae is very weak. Because algae do not adsorb onto the inner wall of filter bottle 1, during the enrichment process, algae can more effectively settle to the bottom of the filter bottle, rather than being attached to the inner wall. This results in a higher concentration of algae at the bottom of filter bottle 1 and a significantly improved enrichment efficiency.

[0044] The single-layer metal filter membrane 22 is made of nickel. Nickel material can be processed into a high-porosity single-layer metal filter membrane through special processing techniques (such as nanoporous structure preparation). High porosity means that the filter membrane has more channels per unit area, allowing more water sample to pass through, thereby improving filtration efficiency. Due to the high porosity of the nickel filter membrane, the water sample can be quickly discharged by the pump 24, while the algae are trapped on the membrane surface, significantly shortening the algae enrichment time and improving the enrichment efficiency of the entire device. The pore size of the nickel filter membrane can be precisely controlled through the processing technology and can be customized according to the specific algae size. This allows the single-layer metal filter membrane 22 to effectively block the desired algae from entering the drain channel 23, while allowing the water sample to pass through quickly, achieving efficient algae enrichment. Nickel is a highly corrosion-resistant metal that can remain stable in various water sample environments and is not easily corroded by chemicals in the water sample. This is very important for the long-term use of the algae enrichment device in different water qualities (such as acidic, alkaline, or saline samples). The corrosion resistance of nickel makes it less prone to damage during algae enrichment, thus extending the service life of the filter membrane and reducing the maintenance cost of the equipment. The relatively smooth surface of nickel and its strong chemical inertness make it difficult for it to chemically adsorb algae. Compared with traditional fiber or porous membranes, nickel filter membranes effectively reduce algae adhesion, preventing damage caused by adsorption. Because nickel filter membranes do not adhere to algae, the algae will not be adsorbed or entangled on the membrane surface during filtration, thus avoiding algae breakage or deformation caused by mechanical forces and ensuring the integrity of the algae during enrichment.

[0045] Example 2:

[0046] A method for algae enrichment involves pouring a water sample into a filter bottle 1 for sedimentation; filtering the supernatant in the filter bottle 1 using a filter assembly 2; the filter assembly 2 includes a filter body 21 floating on the surface of the water sample, a drain channel 23 connected to the filter body 21 for discharging the supernatant from the water sample, and a single-layer metal filter membrane 22 covering the outer surface of the filter body 21 for preventing algae from entering the drain channel 23; the filter assembly 2 also includes a water pump 24 connected to the drain channel 23.

[0047] The theoretical basis and experimental verification of this invention are as follows:

[0048] Turbidity and particle size distribution of water bodies can be detected by using a turbidity meter and a flow cytometer to establish the particle size distribution of different water samples from common rivers and lakes, as well as the percentage of impurity particles (w%) (w% is the ratio of impurity particles remaining after removing planktonic microorganisms to total particles).

[0049] The settling of particulate matter should refer to the Stokes settling formula. (Note: Vsediment is the particle settling velocity, k is the shape coefficient, g is the gravitational acceleration, r is the particle equivalent radius, d1 is the particle specific gravity, d2 is the water specific gravity, and μ is the water viscosity.) This formula is mainly applicable to non-living particles, i.e., "impurities" including silt, microplastics, and organic matter. The formula can simulate the settling time of different impurities, but the theoretical calculation results need to be further corrected by combining actual water sample settling experiments. Because phytoplankton, fungi, microorganisms, and zooplankton move autonomously, it is not applicable to theories and simulations related to natural settling.

[0050] If algal cells come into contact with the filter membrane pores, the force analysis should refer to Poiseuille's law in fluid mechanics: (Note: Q is the average flow rate of a single filter hole, ∆p is the pressure difference across the filter hole, r is the radius of the filter hole, L is the thickness of the filter hole, d1 is the specific gravity of the particles, d2 is the specific gravity of water, and μ is the viscosity of water.) The stress on the algal cells can be calculated from the pressure difference across the filter hole using ∆p.

[0051] Algae are broadly classified into more than a dozen phyla, including cyanobacteria, green algae, euglena, xanthophytes, cryptophytes, chrysophytes, diatoms, and dinoflagellates, with nearly 40,000 species further subdivided. Some algae have fragile cell membranes that are easily damaged by stress; others have siliceous cell shells that are not easily broken; still others have transparent gelatinous membranes that are not easily damaged; and some algae exist in aggregates, making them less susceptible to damage from filter membranes. Therefore, different algal species require different experimental methods tailored to their specific characteristics to ensure high efficiency and minimal or low damage rates.

[0052] In summary, the above four points can guide the construction of reasonable experimental methods for different impurity contents and different algal species, which requires a large number of verification experiments and theoretical correction coefficients. The ultimate goal is to achieve rapid and non-destructive enrichment: 1) Try to ensure that the liquid level drop rate V is less than or equal to the impurity particle settling rate V_sinking, and even allow the particles to settle for a few minutes before starting the peristaltic pump to draw the filtrate. This ensures that the filter membrane pores do not come into contact with impurity particles, which would reduce the number of effective filter pores, increase the flow rate Q of a single filter pore, and thus increase the pressure difference across the filter pore (Δp), increasing the risk of algal cell damage; 2) For different algae, while ensuring that the damage rate is within an acceptable range, increase the flow rate Q of a single filter pore to shorten the enrichment time.

[0053] The flow cytometer is a high-precision device that uses image analysis to classify and quantify algae. It can directly detect live algae in water samples, with a detection time of about 10 minutes, and can meet the needs of batch sample testing and multiple high-frequency tests per day.

[0054] When detecting algae, it is recommended to test between 500 and 1500 algal cells each time to ensure that the test is representative. If the concentration of a single sample is low and the number of algal cells detected is significantly less than 500, it is difficult to guarantee the accuracy and reliability of the test results.

[0055] Natural water samples not only contain many "impurities," but also exhibit significant differences in algal particle size, morphology, and density, making efficient enrichment of live algae a challenge. When the algal cell number density in the water sample is low (10... 4 ~10 6 (cells / L) requires enrichment to increase algal density to greater than 10. 7 A cell / L ratio is required for a flow cytometer to detect more than 500 algal cells to improve detection reliability.

[0056] Specific testing steps: 1) Collect water samples and perform pre-testing using a flow cytometer to select water samples with low algae concentration; 2) Determine the enrichment factor (10~100 times) for different low-concentration algae samples, use the algae enrichment device to enrich different samples and set the corresponding parameters; 3) Use the flow cytometer to test the enriched and sized water samples, divide the sample test result by the enrichment factor to obtain the true result of the sample, and finally output the algae test report.

[0057] Example 3: The difference from Example 1 is the anti-clogging design of the algae enrichment device. In Example 1, a peristaltic pump with forward and reverse rotation was used for anti-clogging. In this example, a vibrator 4 is used as a functional component.

[0058] The device also includes a vibrator 4 located at the bottom of the filter bottle 1 and in contact with it. Algae have a density similar to water and settle relatively slowly. By placing the vibrator 4 outside the filter bottle 1, a certain amount of mechanical vibration can be applied to the water sample inside the filter bottle 1. This vibration can disturb the water sample, making the movement of algae particles in the water more intense, thereby accelerating the algae settling process. Compared to simple gravity settling, the addition of the vibrator 4 can significantly shorten the time required for algae enrichment and improve enrichment efficiency.

[0059] During algae enrichment, impurities may adhere to a small portion of the single-layer metal filter membrane 22. Although the single-layer metal filter membrane 22 has high porosity and does not adhere to algae, its pore size is relatively small, making it easily clogged by larger impurity particles. The vibration of the vibrator 4 can generate slight vibrations on the single-layer metal filter membrane 22, helping to loosen the algae or impurities attached to the surface. The vibrator 4 can also prevent the impurity filter pad 3 from clogging, thereby maintaining the high-flux characteristics of the impurity filter pad 3 and ensuring the high efficiency of algae enrichment to the bottom of the filter bottle 1.

[0060] Example 4: The difference from Example 3 is the installation position of the vibrator. In this example, this operation method is more suitable for algae with stronger stress response. The vibrator is connected to the filter body 21. It is not installed at the bottom of the filter bottle 1 and vibrates the filter bottle 1. Instead, it is externally installed and provides vibration to the filter body 21. This spatial layout keeps the water sample in the filter bottle 1, especially the water sample in the middle and lower part of the filter bottle 1, quiet, preventing microorganisms from being stimulated by vibration and moving away. Providing vibration only to the filter body 21 maintains the stability of microorganisms and also provides an anti-clogging design.

Claims

1. An algae enrichment device, comprising a filter flask (1) for holding water samples, characterized in that, It also includes a filter assembly (2), which comprises a filter body (21) floating on the surface of the water sample, a drain channel (23) connected to the filter body (21) for discharging the clear liquid above the water sample, and a single-layer metal filter membrane (22) covering the outer surface of the filter body (21) for preventing algae from entering the drain channel (23); the filter assembly (2) also includes a water pump (24) connected to the drain channel (23), which is a peristaltic pump. The peristaltic pump rotates forward to extract waste liquid and intermittently reverses to flush away algae and impurities accumulated near the single-layer metal filter membrane. The combination of forward and reverse rotation is used to extract liquid while preventing blockage; the filter bottle (1) is made of high-purity PFA; the single-layer metal filter membrane (22) is made of nickel.

2. The algae enrichment device according to claim 1, characterized in that, The filter bottle (1) is provided with an impurity filter pad (3), and there is an algal deposition zone between the impurity filter pad (3) and the bottom of the filter bottle (1).

3. The algae enrichment device according to claim 2, characterized in that, It also includes a vibrator (4).

4. The algae enrichment device according to claim 3, characterized in that, The vibrator (4) is connected to the filter body (21) and provides vibration to the filter body (21).

5. The algae enrichment device according to claim 1, characterized in that, The water pump (24) is connected to a touch device for controlling the water pump (24); the touch device includes a touch screen (5) and a central controller connected to the touch screen (5).

6. A method for algae enrichment applied to the algae enrichment device of claim 1, characterized in that, The water sample is poured into the filter bottle (1) for sedimentation; the upper clear liquid in the filter bottle (1) is filtered by the filter assembly (2); the filter assembly (2) includes a filter body (21) floating on the surface of the water sample, a drain channel (23) connected to the filter body (21) for discharging the upper clear liquid of the water sample, and a single-layer metal filter membrane (22) covering the outer surface of the filter body (21) for preventing algae from entering the drain channel (23); the filter assembly (2) also includes a water pump (24) connected to the drain channel (23).

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