Method for removing algae and purifying water, related synergistic composition, application and preparation method

Abstract

The invention belongs to the technical field of algae removal and water purification, and particularly relates to an algae removal and water purification method, a related synergistic composition, application and a preparation method. An organosilicon quaternary ammonium salt modified clay SiQAS-MC material is used as a matrix, one or more of high-valence metal ions or high-charge-density polymers of the high-valence metal ions are introduced, and after a composite material is formed, the composite material is put into a water body for use; or when the SiQAS-MC is used, one or more of high-valence metal ions or polymers with high charge density are added, and the SiQAS-MC is synchronously added into the water body for use. In conclusion, the synergistic composition can significantly improve the removal efficiency of SiQAS-MC on various algae, has triple water purification effects of removing phosphorus, descending turbidity and adjusting pH, and is suitable for emergency treatment of harmful algal blooms in water and remediation of polluted water.

Description

Technical Field

[0001] The present invention belongs to the technical field of algae removal and water purification, and specifically relates to a method for algae removal and water purification and a related synergistic composition, application and preparation method. Background Art

[0002] 1. Hazards of Harmful Algal Blooms and Technical Requirements for Control: Harmful algal blooms, as abnormal phenomena in aquatic ecosystems, have a long historical record. However, since the 20th century, driven by the continued intensification of the impact of human activities and climate change on the water environment, it has evolved from a natural ecological regulation process to a frequent ecological disaster. The frequency of occurrence in global oceans, lakes, and rivers has increased, and the scope of impact has expanded, posing a serious threat to global aquatic ecosystems and human society.

[0003] Harmful algal blooms, also known as red tides, are caused by microscopic organisms such as microalgae in the ocean. In recent years, marine red tides have become frequent and widespread around the world. In 2015, a Pseudo-nitzschia bloom spread from California to the Canadian coast along the west coast of North America, creating a transregional disaster zone. From 2017 to 2018, a Karenia brevis bloom in Florida, USA, lasted for 15 months, causing massive marine mortality and clearing over 2,000 tons of dead organisms from beaches. In 2016, a red tide off the coast of Chile killed 12% of farmed salmon, resulting in direct economic losses exceeding $1 billion and triggering regional social unrest. These marine red tides disrupt food chains and release biotoxins, posing systemic risks to coastal fisheries, tourism, and public health.

[0004] Harmful algal blooms in terrestrial rivers and lakes are often called water blooms. The global threat of freshwater blooms is also becoming increasingly prominent, showing a strong correlation with the intensity of human activities. The core hazards of freshwater blooms lie in the contamination of drinking water sources through the release of algal toxins, the depletion of dissolved oxygen in water bodies, and the resulting mortality of aquatic life. They also damage the functions of scenic water bodies, creating dual pressures on the ecology and the economy.

[0005] Marine red tides and freshwater algal blooms are characterized by regional concentrations and increasing frequency. Since the first record of Noctiluca and Skeletonema blooms along the Zhejiang coast in 1933, the frequency of marine red tides has increased exponentially since the 1970s and 1980s, reaching a cumulative outbreak area of ​​210,000 square kilometers from 2000 to 2017. In 2012, a Karenia mikimotoi bloom near the Fujian coast affected nearly 300 square kilometers, causing 2 billion yuan in fishery losses, highlighting the economic destructiveness of red tides in my country's offshore aquaculture areas. Freshwater algal blooms are most prevalent in the middle and lower reaches of the Yangtze River and the lakes of the Yunnan-Guizhou Plateau. Monitoring of key lakes and reservoirs nationwide from 2015 to 2023 revealed an average of over 60 areas experiencing cyanobacterial blooms annually. The average annual duration of blooms in major lakes such as Taihu Lake, Chaohu Lake, and Dianchi Lake exceeded 120 days, highlighting the urgency of addressing eutrophication in my country's freshwater ecosystems.

[0006] The hazards of HABs are multifaceted: they disrupt aquatic ecosystems, leading to the death of organisms from hypoxia or poisoning, severely damaging fishery resources and aquaculture. They also disrupt scenic beauty by emitting unpleasant odors and altering water color, harming tourism. Some algal blooms produce toxins that travel through the food chain or directly contaminate drinking water, posing a direct threat to human health. Given these hazards, there is an urgent need to develop effective HAB mitigation technologies.

[0007] 2. Current status of development of modified clay technology for controlling harmful algal blooms: Modified clay technology is a harmful algal bloom control technology with independent intellectual property rights in my country. By modifying the surface properties of natural clay minerals, it improves their effectiveness in controlling harmful algal blooms and can be applied to both marine red tides and freshwater blooms. This technology offers significant advantages over similar technologies both domestically and internationally. Compared to traditional natural clay flocculation and sedimentation methods, the amount of modified clay used is reduced from 100-400 tons per square kilometer to 4-10 tons, significantly reducing material costs and the risk of subsequent siltation. It also has a broad spectrum of applications, effectively controlling a variety of marine red tide algae, as well as freshwater cyanobacteria and green algae. After years of research and development, three series of over ten modified clay materials have been developed for common red tide algae in my country's coastal waters and dominant freshwater algae species. Some of these materials have specialized functions such as detoxification, sterilization, oxygenation, and cyst disruption.

[0008] In practical applications, the technology was first successfully applied in 2005 to control a cyanobacterial bloom in Nanjing's Xuanwu Lake. In 2008, it successfully eliminated a red tide covering 87 square kilometers of Qingdao's coastal waters. In 2015, it effectively controlled a brown algae bloom in the coastal nuclear power plant's cooling waters, ensuring its safety. In 2021, the technology was applied to control a cyanobacterial bloom in Yunnan's Yangzonghai Lake, resulting in a 92% reduction in algal cell density within three days. To date, this technology has been successfully implemented in my country, becoming the only effective, large-scale method for controlling harmful algal blooms in the country and incorporated into national red tide control standards and emergency response plans.

[0009] In terms of international promotion, this technology was first exported to Chile in 2016 for red tide control. Since then, it has been widely adopted in the marine and freshwater areas of over 10 countries, including the United States and Peru. It has been hailed as a "made-in-China algal bloom extinguisher," providing a Chinese solution for international harmful algal bloom control. In October 2024, the Shandong Provincial Standard "Technical Specification for Modified Clay for Red Tide Control" was promulgated and implemented. As my country's first dedicated technical standard for algal bloom control, it marks a step towards standardization of this technology and lays the foundation for further expansion of its application both domestically and internationally.

[0010] In summary, modified clay treatment technology, thanks to its high efficiency, environmental friendliness, and broad applicability, plays a key role in HAB management both domestically and internationally. Given the systematic and complex nature of HAB management, continued technological innovation is necessary to address the long-term challenges it poses to aquatic ecosystems and human society.

[0011] III. Demand for upgrading and developing technologies for harmful algal bloom control: As the demand for comprehensive ecological and environmental management increases, the development of red tide control technologies is also facing higher requirements: high-quality new materials and technologies for red tide control must not only effectively eliminate red tide organisms, but also help reduce pollution levels in water bodies affected by red tide outbreaks and help render toxic and hazardous substances harmless. To meet the demand for new materials for comprehensive red tide control, the development of functional composite modified clay materials is currently a hot topic in the development of red tide control technologies both domestically and internationally.

[0012] SiQAS-MC, a red tide eliminator (CN119349673A), is a kaolin-modified organic quaternary ammonium salt modified with a silicon-containing active group. It is effective against common red tide organisms in seawater, such as Heterosigma akashiwo, achieving an algae removal efficiency of 85% at a dosage of 0.1g / L. However, further promotion revealed significant differences in the removal efficiency of red tide algae at different growth stages, with algae removal efficiency in the late stable phase being 15% to 30% lower than that in the middle and late exponential growth phase. Furthermore, the removal efficiency of red tide algae, such as Prorocentrum donghaiense, was relatively low. Therefore, as a newly developed material, SiQAS-MC's removal efficiency is not yet stable across different types and states of red tide.

[0013] Active phosphorus (PO4 3- ) is the key nutrient salt for algae growth, and the abundant PO4 in water 3-This often encourages further algal blooms, causing red tide control efforts to be merely superficial. Turbid water affects light transmittance and exacerbates hypoxia at the bottom, making it difficult to restore ecological functions without reducing turbidity. Furthermore, red tide outbreaks often lead to an increase in water pH, which not only directly affects the health of aquaculture organisms but can also induce toxic substances such as ammonia and nitrogen, leading to water pollution. Preliminary monitoring revealed that SiQAS-MC's comprehensive control effectiveness in eliminating red tide organisms is relatively low, primarily manifested in its low removal efficiency for Prorocentrum donghaiense and Prosphaerotheca robustus. Furthermore, SiQAS-MC has also been applied to algal bloom control, with good overall results, but its removal efficiency for Nannochloropsis is relatively low. Therefore, to meet the needs of comprehensive control of harmful algal blooms, the performance of SiQAS-MC materials urgently needs to be upgraded and optimized to better remediate polluted water bodies. Summary of the Invention

[0014] In order to solve the problems existing in the prior art, the present invention provides a method for removing algae and purifying water, and a related synergistic composition, application and preparation method, and introduces Fe into the SiQAS-MC technology for treating harmful algal blooms. 3+ 、Al 3+ The high-valence ions or their high-charge density polymers can form new complexes or be used in combination to improve the algae removal efficiency and enhance the PO4 3- Removal capacity, pH stability and turbidity reduction water purification effect.

[0015] The present invention solves the technical problem by adopting the following technical solution: a method for synergistic SiQAS-MC algae removal and water purification, which uses an organosilicon quaternary ammonium salt modified clay SiQAS-MC material as a matrix, introduces one or more high-valent metal ions or high-charge density polymers thereof, forms a composite material, and then puts it into a water body for use; alternatively, when using SiQAS-MC, one or more high-valent metal ions or high-charge density polymers thereof are added and simultaneously added to the water body for use.

[0016] Preferably, high-valent metal ions or high-charge-density polymers thereof include but are not limited to Fe 3+ / Al 3+ Salt or Fe 3 + / Al 3+ high molecular polymer.

[0017] Preferably, Fe 3+ / Al 3+ Salts include, but are not limited to, ferric chloride, aluminum chloride, aluminum sulfate, or ferric sulfate.

[0018] Preferably, Fe 3+ / Al 3+ The high molecular polymer includes but is not limited to polyaluminum chloride, polyferric sulfate, polyaluminum ferric chloride or polyaluminum ferric silicate.

[0019] A synergistic composition for algae removal and water purification, comprising: component A and component B, with a corresponding mass ratio of 1 to 10:1, wherein component A is organic silicon quaternary ammonium salt modified clay SiQAS-MC, and component B is Fe 3+ / Al 3+ Salt or Fe 3+ / Al 3+ high molecular polymer.

[0020] Preferably, the Fe 3+ / Al 3+ The salt is at least one of ferric chloride, aluminum chloride, aluminum sulfate, and ferric sulfate.

[0021] Preferably, the Fe-containing 3+ / Al 3+ The high molecular polymer is at least one of polyaluminum chloride, polyferric sulfate, polyaluminum ferric chloride, and polyaluminum ferric silicate.

[0022] Application of the above-mentioned synergistic composition in emergency treatment of harmful algal blooms in water bodies or restoration of polluted water bodies.

[0023] The synergistic composition is used in emergency treatment of harmful algal blooms or restoration of polluted water bodies, and the steps are as follows: S01. Prepare component A into a 25-100 g / L suspension, and prepare component B into a 25-100 g / L solution; S02. Simultaneously add the component A suspension and the component B solution of step S01 into the algal bloom-containing water body at a mass ratio of 1-10:1.

[0024] The preparation method of the above-mentioned synergistic composition comprises the steps of: S1. Preparation of SiQAS-MC: Clay is treated by surface hydroxylation activation, and then a silicon-containing organic quaternary ammonium salt modifier is added to obtain SiQAS-MC; S2. Premix SiQAS-MC and component B in a mass ratio of 1 to 10:1 and activate with water to form a composite material.

[0025] Compared with the prior art, the present invention has the following beneficial effects: 1. The present invention enhances the efficiency of organosilicon quaternary ammonium salt modified clay by introducing high-valent metal ions or their high charge density polymers, significantly improving the removal efficiency of SiQAS-MC for various algae such as Prorocentrum donghaiense, Prosodium robustum, and Nannochloropsis.

[0026] 2. The two components of the synergistic composition of the present invention can be used in combination or added separately at the same time, both of which can produce a synergistic effect. The method of use is relatively convenient and is easy to promote and apply.

[0027] 3. Ferric chloride, aluminum chloride, aluminum sulfate, ferric sulfate, polyaluminum chloride, polyferric sulfate, polyaluminum ferric chloride, and polyaluminum ferric silicate can all be used as synergists in the present invention. The material selectivity is large and the production is convenient.

[0028] 4. After implementation, the water body meets the following indicators: algae removal rate ≥ 80% when the total dosage concentration is 0.1g / L and above; PO4 3- Removal rate ≥50%; turbidity reduction ≥3NTU; pH value stable at 7.8~8.85.

[0029] In summary, the synergistic composition of the present invention can significantly improve the removal efficiency of SiQAS-MC for various algae, and has the triple water purification effects of phosphorus removal, turbidity reduction, and pH adjustment. It is suitable for emergency treatment of harmful algal blooms in water bodies and remediation of polluted water bodies. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 This is a comparison chart of the ability of different ions provided in Example 1 to enhance the algae removal efficiency of SiQAS-MC.

[0031] Figure 2 Figure 3 shows the 3-hour removal efficiency of Prorocentrum donghaiense formed by the composite material formed by SiQAS-MC provided in Example 2 and a metal salt material of an effective ion (FeCl3 as an example) at different ratios and dosages; (a) algae removal efficiency at different ratios at a total dosage of 0.1 g / L; (b) algae removal efficiency at different dosages at the optimal ratio.

[0032] Figure 3 Figure 3 shows the 3-hour removal efficiency of Prorocentrum donghaiense when SiQAS-MC and metal salt materials of effective ions (FeCl3 as an example) are added in different ratios and dosages. (a) Algae removal efficiency at different ratios at a total dosage of 0.1 g / L; (b) Algae removal efficiency at different dosages at the optimal ratio; (c) pH and turbidity changes at a total dosage of 0.1 g / L at the optimal ratio; (d) PO4 at a total dosage of 0.1 g / L at the optimal ratio. 3- change.

[0033] Figure 4 The 3-hour removal efficiency and water purification performance of the composite material formed by the SiQAS-MC provided in Example 4 and a polymer with a high effective ion charge density (taking polyaluminum chloride (PAC) as an example) at different ratios and dosages for Amphidinium robustum; wherein: (a) the algae removal efficiency at different ratios at a total dosage of 0.1 g / L; (b) the algae removal efficiency at different dosages at the optimal ratio; (c) the pH change at different dosages at the optimal ratio; and (d) the turbidity change at different dosages at the optimal ratio.

[0034] Figure 5The 3-hour removal efficiency and water purification performance of the SiQAS-MC provided in Example 5 and a polymer with a high effective ion charge density (taking polyferric sulfate (PFS) as an example) were evaluated by adding the SiQAS-MC and a polymer with a high effective ion charge density (such as polyferric sulfate (PFS)) in different ratios. The results show that (a) the algae removal efficiency at different ratios at a total dosage of 0.1 g / L; (b) the algae removal efficiency at different dosages at the optimal ratio; (c) the pH change at different dosages at the optimal ratio; and (d) the turbidity change at different dosages at the optimal ratio. DETAILED DESCRIPTION

[0035] To facilitate understanding of the present invention, the present invention will be described in more detail below with reference to the accompanying drawings and specific embodiments. However, the present invention can be implemented in many different forms and is not limited to the embodiments described in this specification. On the contrary, the purpose of providing these embodiments is to make the understanding of the present invention more thorough and comprehensive.

[0036] This invention uses SiQAS-MC as a synergistic agent, introducing high-valent ions or their high-charge-density polymers to form a complex or compound addition to achieve algae removal and water purification. The total concentration and dosage ratio can be fine-tuned based on the abundance of the algal bloom to be removed and the water environment. During use, SiQAS-MC and the high-valent ions or their high-charge-density polymers are mixed in pure water to form a solution, which is then sprayed at the algal bloom site at the appropriate concentration.

[0037] The present invention uses the typical offshore red tide organism Prorocentrum donghaiense ( Prorocentrum donghaiense ), strong front algae ( Amphidinium carterae Hulburt) and Nannochloropsis ( Nannochloris oculata ) was used as the research object, and the red tide organisms were removed by using the method of forming a complex or compound addition of SiQAS-MC with high-valent ions or their high-charge density polymers. The algal cell removal rate was determined by using a chlorophyll living fluorescence instrument, the turbidity change of the water was determined by using a turbidity agent, the pH change of the water was determined by using a pH meter, and the PO4 in the water was determined by using a nutrient analyzer. 3- Content changes.

[0038] Example 1: The SiQAS-MC used in the present invention was obtained by treating commercially available washed kaolin clay via surface hydroxylation activation, followed by the addition of a silicon-containing organic quaternary ammonium salt modifier. The metal ion materials used were: ferric chloride, aluminum chloride, magnesium chloride, calcium chloride, potassium chloride, and sodium chloride. All metal ion materials were analytical grade and purchased from Sinopharm Chemical Reagent Co., Ltd. (Shanghai, China). The steps were as follows: Step 1: Add 0.5 g of SiQAS-MC to 10 mL of pure water to prepare a 50 g / L SiQAS-MC suspension. Add the corresponding molar mass of metal ion material to 10 mL of pure water to prepare a 0.1 mol / L metal ion solution.

[0039] Step 2: The algae Prorocentrum donghaiense cultured in the Key Laboratory of Marine Ecology and Environmental Sciences, Institute of Oceanology, Chinese Academy of Sciences was used as the experimental algae species, and the algae density was maintained at 1.4×10 8 cells / L. Place the algae solution in a 50mL colorimetric tube, add SiQAS-MC to the algae solution to a concentration of 0.1g / L, and invert and mix once. Then add the metal ion solution to the algae solution to a preset concentration, invert and mix twice, and let it stand for 3 hours. After that, remove the algae solution 5cm below the liquid surface to measure the chlorophyll living fluorescence value. Calculate the corresponding algae removal rate, the results are shown in Figure 1 .

[0040] The formula for calculating the algae removal rate is: algae removal rate (%) = [1-(chlorophyll living fluorescence value of the experimental group / chlorophyll living fluorescence value of the control group)] × 100%.

[0041] Depend on Figure 1 The results show that under the condition of a fixed dosage of 0.1 g / L SiQAS-MC (basic algae removal rate of 56%), the synergistic effect of the six metal ion materials in the concentration range of 10-500 μmol / L is as follows: trivalent metal ion materials significantly improve the algae removal efficiency. FeCl3 increases the algae removal rate from 53.94%±2.05% (10 μmol / L) to 94.93%±1.70% (500 μmol / L), and AlCl3 increases it from 54.60%±1.49% to 97.13%±1.03%. At ≥100 μmol / L, the algae removal efficiency of both materials increases by more than 31 percentage points compared with the effect of SiQAS-MC alone. The synergistic effect of divalent metal ion materials is limited. At 100 μmol / L, the algae removal efficiency of MgCl2 and CaCl2 only increases by 4.25-7.44 percentage points compared with the baseline value. The monovalent metal ion materials have no significant synergistic effect. KCl and NaCl do not exceed the baseline value (56%) by more than 1.86 percentage points throughout the process. Therefore, the high-valent metal ion Fe is selected 3+ 、Al 3+ Effective ions for enhancing the synergy of SiQAS-MC.

[0042] Example 2: SiQAS-MC and effective ion metal salt materials (taking FeCl3 as an example) are both those described in Example 1.

[0043] Step 1: Add 0.5g of SiQAS-MC to 10mL of pure water to prepare a 50g / L SiQAS-MC suspension. Add 0.5g of FeCl3 to 10mL of pure water to prepare a 50g / L FeCl3 solution.

[0044] Step 2: SiQAS-MC suspension and FeCl3 solution were added to the reaction vessel in the mass ratio (1:1-10:1) and activated with room temperature water for 30 seconds to form different Fe 3+ Content SiQAS-MC—FeCl3 composite material.

[0045] Step 3: The algae Prorocentrum donghaiense cultured in the Key Laboratory of Marine Ecology and Environmental Sciences, Institute of Oceanology, Chinese Academy of Sciences was used as the experimental algae species, and the algae density was maintained at 1.4×10 8 cells / L. Place the algae solution in a 50 mL colorimetric tube and add 0.1 g / L of the SiQAS-MC-FeCl3 composite material described in Step 2. Invert and mix three times, then let it rest for 3 hours. Three parallel experiments were performed. Then, a sample of algae solution was taken 5 cm below the liquid surface to measure the chlorophyll fluorescence value. The formula for calculating algae removal efficiency is shown in Example 1.

[0046] Step 4: Select the SiQAS-MC-FeCl3 composite material with the best algae removal rate (when algae removal rates are similar, the combination with a higher proportion of SiQAS-MC is preferred). Add these composite materials to the algae solution in varying concentrations (0.05g / L-0.3g / L) according to their proportions, using the same experimental method as in Step 3.

[0047] Depend on Figure 2 (a) It can be seen that when the SiQAS-MC-FeCl3 composite material is added at a fixed total dosage of 0.1 g / L, the 1:1 mass ratio shows the strongest synergistic effect, with an algae removal rate of 87.12%±1.59%, which is 30.7 percentage points higher than that of SiQAS-MC alone (56.42%). When the ratio increases to 10:1, the efficiency drops to 53.93%±2.68%, proving that the efficiency enhancement disappears due to the imbalance of the ratio. Figure 2 (b) It can be seen that when the optimal ratio is fixed at 1:1, a total dosage of 0.2 g / L can achieve an efficient algae removal of 91.53%±4.16%. When it is increased to 0.30 g / L, it reaches a nearly complete algae removal of 98.19%±0.41%. However, the increase from 0.2 to 0.30 g / L is less than 15%, indicating that 0.2 g / L is the economically optimal dosage.

[0048] Example 3: SiQAS-MC and effective ion metal salt materials (taking FeCl3 as an example) are both those described in Example 1.

[0049] Step 1: Add 0.5 g of SiQAS-MC to 10 mL of pure water to prepare a 50 g / L SiQAS-MC suspension. Add 0.5 g of FeCl3 to 10 mL of pure water to prepare a 50 g / L FeCl3 solution.

[0050] Step 2: The algae Prorocentrum donghaiense cultured in the Key Laboratory of Marine Ecology and Environmental Sciences, Institute of Oceanology, Chinese Academy of Sciences was used as the experimental algae species, and the algae density was maintained at 1.4×10 8 cells / L. Place the algae solution in a 50mL colorimetric tube and add SiQAS-MC and FeCl3 simultaneously, controlling the mass ratio between 1:1 and 10:1. Add SiQAS-MC at a preset concentration to the algae solution and mix thoroughly by inversion once. Then, add FeCl3 solution at a preset concentration to the algae solution, mix thoroughly by inversion twice, and let it rest for 3 hours. Perform three parallel experiments. Then, remove the algae solution 5 cm below the liquid surface and measure the chlorophyll fluorescence value. The formula for calculating algae removal efficiency is shown in Example 1.

[0051] Step 3: Select the SiQAS-MC and FeCl3 combination that provides the best algae removal efficiency (when algae removal efficiency is similar, the combination with a higher SiQAS-MC ratio is preferred). Add these components to the algae solution in the following order, reaching different concentrations (0.05g / L-0.3g / L), using the same experimental method as in Step 2.

[0052] Step 4: After completing step 3, transfer the algae solution 5 cm below the liquid surface to measure the turbidity, pH and PO4 respectively. 3- content.

[0053] Depend on Figure 3 (a) It can be seen that when the composite addition is used, the 3:1 mass ratio (Si-QAS-MC:FeCl3) can achieve a stable algae removal rate of 84.95%±1.2% at a total dosage of 0.1 g / L, which is not significantly different from the algae removal efficiency of the 1:1 and 2:1 ratios. Figure 3 (b) It can be seen that when the 3:1 ratio is increased to 0.30 g / L, the algae removal rate reaches 97.60%±0.05%, proving that this ratio has high algae removal potential. Figure 3 (c), (d)): After the 3:1 compound addition, the pH of the original algae solution dropped gently from about 8.9 to 8.7, and PO4 3- The concentration dropped significantly from 333.9±8.1 μg / L to 92.8±15.1 μg / L (removal rate 72.3%), effectively inhibiting algae regeneration.

[0054] Example 4: SiQAS-MC was prepared as described in Example 1. A high charge density polymer with effective ions (for example, polyaluminium chloride (PAC)) was purchased from Guangfu Fine Chemical Research Institute (Tianjin, China) of analytical grade.

[0055] Step 1: Add 0.5g of SiQAS-MC to 10mL of pure water to prepare a 50g / L SiQAS-MC suspension. Add 0.5g of PAC to 10mL of pure water to prepare a 50g / L PAC solution.

[0056] Step 2: SiQAS-MC suspension and PAC solution were added to the reaction vessel in the mass ratio (1:1-10:1) and activated with water at room temperature for 30 seconds to form different Al 3+ Content SiQAS-MC-PAC composite material.

[0057] Step 3: The algae species cultured in the Key Laboratory of Marine Ecology and Environmental Sciences, Institute of Oceanology, Chinese Academy of Sciences were used as the experimental algae species, and the algae density was maintained at 4×10 8 cells / L. Place the algae solution in a 50 mL colorimetric tube and add 0.1 g / L of the SiQAS-MC-PAC composite material described in Step 2. Invert and mix three times, then let it rest for 3 hours. Three parallel experiments were performed. Then, a sample of algae solution was taken 5 cm below the liquid surface to measure the chlorophyll fluorescence value. The formula for calculating algae removal efficiency is shown in Example 1.

[0058] Step 4: Select the SiQAS-MC-PAC composite material with the best algae removal rate (when algae removal rates are similar, the combination with a higher proportion of SiQAS-MC is preferred). Add these composite materials to the algae solution in varying concentrations (0.05g / L-0.3g / L) according to their respective proportions, using the same experimental method as in Step 3.

[0059] Step 5: After completing step 4, transfer the algae solution 5 cm below the liquid surface to measure the turbidity and pH values.

[0060] When SiQAS-MC-PAC composite material is used in a 1:1 mass ratio: Figure 4 (a) It can be seen that at a total dosage of 0.1 g / L, the algae removal rate reached 89.13%±1.55%, which is significantly better than other ratios (such as 10:1 ratio is only 52.08%±2.61%); at the same time, this ratio increases with the total dosage ( Figure 4 (b)), the algae removal rate increased from 37.74%±3.14% at 0.05 g / L to 95.39%±0.20% at 0.30 g / L, and Figure 4 (c) and (d) show that the composite system has a mild effect on water quality: at a dosage of 0.30 g / L, the pH only dropped from the initial 8.834 to 8.542, and the turbidity dropped from 30.6 NTU to 15.4 NTU, proving that it can effectively remove algae while maintaining water stability.

[0061] Example 5: SiQAS-MC was prepared as described in Example 1. A high charge density polymer with effective ions (for example, polyferric sulfate (PFS)) was purchased from MacLean Biochemical Technology Co., Ltd. (Shanghai, China) of analytical grade.

[0062] Step 1: Add 0.5g of SiQAS-MC to 10mL of pure water to prepare a 50g / L SiQAS-MC suspension. Add 0.5g of PFS to 10mL of pure water to prepare a 50g / L PFS solution.

[0063] Step 2: Nannochloropsis spp. was cultured in the Key Laboratory of Marine Ecology and Environmental Sciences, Institute of Oceanology, Chinese Academy of Sciences as the experimental algae species, and the algae density was maintained at 5×10 9 cells / L. Place the algae solution in a 50mL colorimetric tube, add the preset concentration of SiQAS-MC, and mix thoroughly by inversion once. Then, add the preset concentration of PFS solution to the algae solution, mix thoroughly by inversion twice, and let it stand for 3 hours. Three parallel experiments were performed. Afterwards, the algae solution was aspirated 5 cm below the liquid surface to measure the chlorophyll fluorescence value. The formula for calculating algae removal efficiency is shown in Example 1.

[0064] Step 3: Select the SiQAS-MC and PFS combination that provides the best algae removal efficiency (when algae removal efficiency is similar, the combination with a higher SiQAS-MC ratio is preferred). Add these combinations to the algae solution in the same proportions (0.05g / L-0.3g / L), using the same experimental method as in Step 2.

[0065] Step 4: After completing step 3, transfer the algae solution 5 cm below the liquid surface to measure the turbidity and pH values.

[0066] Depend on Figure 5 (a) It can be seen that at a total dosage of 0.1 g / L, the algae removal rate of 2:1 ratio can reach over 80%, which is a significant improvement over the 28.36%±0.5% algae removal rate when using SiQAS-MC alone. At the same time, at a 2:1 ratio, a dosage of 0.20 g / L can reach over 90% algae removal rate. When it is increased to 0.30 g / L, it reaches 95%, which is close to complete algae removal, proving the flexibility of dosage. Figure 5 (c) and (d) show a mild change in pH: at 0.30 g / L, the pH only dropped from 8.70 to 8.37. Turbidity was efficiently controlled: at 0.30 g / L, the turbidity dropped from 23.3 NTU to 6.7 NTU, a huge decrease of 71%, indicating that algae were effectively removed and water quality was significantly improved.

[0067] There are other embodiments, which are not described in detail here. In summary, the organosilicon quaternary ammonium salt modified clay SiQAS-MC is introduced by Fe 3+ / Al 3+High-valent ions (at least one of ferric chloride, aluminum chloride, aluminum sulfate, and ferric sulfate) or their high charge density polymers (such as at least one of polyaluminum chloride PAC, polyferric sulfate PFS, polyaluminum ferric chloride, and polyaluminum ferric silicate) are used as enhancers. The use of two methods, premixing the composite or adding them simultaneously, can achieve a significant synergistic effect. Addition method: premix SiQAS-MC with the enhancer to form a composite material; or simultaneously add SiQAS-MC and the enhancer to the algae-containing water body. The mass ratio of SiQAS-MC to the enhancer is 1~10:1; the total addition concentration is 0.05–0.3 g / L. After implementation, the water body meets the following indicators: the algae removal rate is ≥80% when the total addition concentration is 0.1g / L and above; PO4 3- Removal rate ≥50%; turbidity reduction ≥3NTU; pH value stabilized at 7.8~8.85. In summary, the algae removal and water purification synergistic composition of the present invention significantly improves the removal efficiency of SiQAS-MC for various algae (such as Prorocentrum donghaiense, Amphidinium robustum, and Nannochloropsis) (up to 98%), and simultaneously achieves phosphorus removal (PO4 3- ), turbidity reduction, and pH adjustment triple water purification effects, suitable for emergency treatment of harmful algal blooms in water bodies and restoration of polluted water bodies.

[0068] The technical features of the above-mentioned embodiments can be combined arbitrarily. In order to make the description concise, not all possible combinations of the technical features in the above-mentioned embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

Claims

1. A method for synergistic SiQAS-MC algae removal and water purification, characterized in that: Using organosilicon quaternary ammonium salt modified clay SiQAS-MC material as the matrix, high-valent metal ions or one or more of its high charge density polymers are introduced to form a composite material, which is then put into the water body for use; alternatively, when using SiQAS-MC, high-valent metal ions or one or more of its high charge density polymers are added and simultaneously added to the water body for use.

2. The method for synergistic SiQAS-MC algae removal and water purification according to claim 1, characterized in that: High-valent metal ions or their high charge density polymers include but are not limited to Fe 3+ / Al 3+ Salt or Fe 3+ / Al 3+ high molecular polymer.

3. The method for synergistic SiQAS-MC algae removal and water purification according to claim 2, characterized in that: Fe 3+ / Al 3+ Salts include, but are not limited to, ferric chloride, aluminum chloride, aluminum sulfate, or ferric sulfate.

4. The method for synergistic SiQAS-MC algae removal and water purification according to claim 2, characterized in that: Fe 3+ / Al 3+ The high molecular polymer includes but is not limited to polyaluminum chloride, polyferric sulfate, polyaluminum ferric chloride or polyaluminum ferric silicate.

5. A synergistic composition for algae removal and water purification, characterized in that: include: The mass ratio of component A to component B is 1 to 10:

1. Component A is organic silicon quaternary ammonium salt modified clay SiQAS-MC, and component B is Fe 3+ / Al 3+ Salt or Fe 3+ / Al 3+ high molecular polymer.

6. The synergistic composition according to claim 5, characterized in that The Fe 3+ / Al 3+ The salt is at least one of ferric chloride, aluminum chloride, aluminum sulfate, and ferric sulfate.

7. The synergistic composition according to claim 5, characterized in that The Fe-containing 3+ / Al 3+ The high molecular polymer is at least one of polyaluminum chloride, polyferric sulfate, polyaluminum ferric chloride, and polyaluminum ferric silicate.

8. Use of the synergistic composition according to any one of claims 5 to 7 in emergency treatment of harmful algal blooms in water bodies or restoration of polluted water bodies.

9. The method for applying the synergistic composition according to claim 8, wherein: Here are the steps: S01. Prepare component A into a 25-100 g / L suspension, and prepare component B into a 25-100 g / L solution; S02. Simultaneously add the component A suspension and the component B solution of step S01 into the algal bloom-containing water body in a mass ratio of 1-10:

1.

10. The method for preparing the synergistic composition according to any one of claims 5 to 7, characterized in that: Including steps: S1. Preparation of SiQAS-MC: Clay is treated by surface hydroxylation activation, and then a silicon-containing organic quaternary ammonium salt modifier is added to obtain SiQAS-MC; S2. Premix SiQAS-MC and component B in a mass ratio of 1 to 10:1 and activate with water to form a composite material.

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