A method for non-lytic inactivation of algal cells

Abstract

This invention relates to a method for non-lytic inactivation of algal cells, comprising the following steps: S1, adding free chlorine to an algal cell suspension to cause the extracellular polymers on the algal cell surface to decompose; S2, adding monochloramine to the S1 system to inactivate the algal cells under non-lytic conditions; S3, adding aluminum chloride solution to the S2 system for coagulation and precipitation. Compared with existing technologies, this method significantly reduces the algal cell lysis rate, effectively inhibits the release of intracellular algal organic matter, and reduces the generation of disinfection byproducts; it also improves floc formation and sedimentation efficiency and reduces coagulant residues during subsequent coagulation. This invention focuses on "precise, phased control of chlorine morphology," solving the problems of algal organic matter release and disinfection byproduct risks caused by pre-chlorination of algal-containing water through a synergistic pathway of first decoupling extracellular polymer protection with free chlorine and then gentle inactivation with monochloramine.

Description

Technical Field

[0001] This invention belongs to the field of water supply system safety assurance technology, and relates to a method for non-lytic inactivation of algal cells. Background Technology

[0002] The large-scale discharge of wastewater has led to regional eutrophication in lakes and reservoirs, resulting in algal blooms and severely impacting the treatment capacity and operational stability of conventional water purification units. Currently, pre-chlorination methods, which offer rapid algae removal, are employed. However, in engineering practice, these methods suffer from incomplete inactivation, off-odors and toxin release, and increased halogenated byproducts. For example, in the case of Microcystis aeruginosa, 3 mg / L of free chlorine can cause over 88% cell destruction and lysis within 1 minute, releasing a large amount of intracellular organic matter. Simply relying on high doses of free chlorine for strong oxidation makes it difficult to balance safety and risk control.

[0003] Monochloramine, as a mild oxidant, can achieve non-lytic inactivation of algal cells and remove some bound extracellular polymers to a certain extent. However, its mass transfer and reaction are easily limited by extracellular polymers, resulting in low algae removal efficiency and making it difficult to simultaneously achieve efficient non-lytic inactivation of algal cells. Algal extracellular polymers consist of soluble microbial products and bound extracellular polymers. Bound extracellular polymers are classified into low-viscosity and high-viscosity extracellular polymers according to their adhesion strength. Extracellular polymers are rich in polysaccharides, proteins, and humic substances. The hydroxyl, carboxyl, amino, thiol, and aromatic ring sites collectively determine the oxidant's reaction selectivity, mass transfer, and depth of action. Different forms of chlorine and extracellular polymers with different viscosity exhibit significant differences in reactivity and target sites. These differences significantly affect cell damage behavior and the characteristics of disinfection byproduct formation.

[0004] Given the above situation, single oxidant strategies have inherent limitations. While high doses of free chlorine can rapidly remove algae, they easily lead to algal cell lysis and an increased risk of byproduct formation; while monochloramine alone is beneficial for non-lysis, it is hampered by extracellular polymers and its efficiency is insufficient. In engineering, there is an urgent need for a pre-oxidation pathway that strikes a balance between "weakening the extracellular polymer barrier, achieving non-lysis inactivation, and inhibiting byproduct formation." Summary of the Invention

[0005] The purpose of this invention is to overcome the shortcomings of existing algae removal technologies, such as large amounts of byproducts and insufficient efficiency, and to provide a method for non-lytic inactivation of algal cells.

[0006] The objective of this invention can be achieved through the following technical solutions: The technical solution of the present invention is to provide a method for non-lytic inactivation of algal cells, comprising the following steps: S1. Add free chlorine to the algal cell suspension to cause the extracellular polymers on the surface of the algal cells to decompose, thus weakening their protective effect on the cells. S2. Add monochloramine to the S1 system to inactivate the algal cells under non-lytic conditions; S3. Add aluminum chloride solution to the S2 system to coagulate and precipitate.

[0007] In some specific embodiments, in step S1, the ratio of free chlorine dosage to algal cell number is 1×10⁻⁶. -10 ~1.5×10 -10 mg Cl2 / each.

[0008] In some specific embodiments, in step S1, the free chlorine is selected from either sodium hypochlorite or calcium hypochlorite.

[0009] In some specific embodiments, in step S1, the mixing process parameters are: stirring at a stirring speed of 100-300 r / min for 9-60 minutes.

[0010] As a more preferred method, the ratio of free chlorine dosage to algal cell number is 1×10⁻⁶. -10 mg Cl2 / cell, stir at 100-300 r / min for 9 minutes to ensure thorough mixing and avoid strong shearing that could cause mechanical cell rupture.

[0011] In step S1 of this invention, free chlorine is added first during the raw water pretreatment stage to weaken or destroy the non-covalent entanglement and adhesion between proteins and polysaccharides in the extracellular polymeric material (EPS) on the surface of algal cells, thereby causing the EPS to dissociate from the cell surface and reducing the protective effect of EPS on algal cells.

[0012] The effects of free chlorine in step S1 on EPS include transforming the secondary structure of proteins in EPS from ordered to disordered and weakening the multi-point non-covalent interactions between proteoglycans, thereby improving the hydrophilicity and dissociability of EPS.

[0013] In some specific embodiments, in step S2, the ratio of monochloramine dosage to algal cell number is 1×10⁻⁶. -10 ~5×10 -10 mg Cl2 / each.

[0014] In some specific embodiments, the mixing process parameters for step S2 are: stirring at a stirring speed of 100-300 r / min for 9-60 minutes.

[0015] As a more preferred method, the ratio of monochloramine dosage to algal cell number is 2 × 10⁻⁶. -10 mg Cl2 / unit, stir at 100-300 r / min for 21 minutes to ensure thorough mixing. In this invention, step S2 involves adding monochloramine after step S1 to inactivate algal cells under mild oxidative conditions, maintain cell membrane integrity, and significantly inhibit the release of algal organic matter (AOM).

[0016] In this invention, the optimal reaction time for the continuous processing of steps S1 and S2 is 30 minutes. Moderate stirring is maintained to ensure mass transfer and uniform reaction, avoiding excessive turbulence that could lead to non-targeted cell lysis.

[0017] In some specific embodiments, in step S3, the ratio of aluminum chloride dosage to algal cell number is 1.5 × 10⁻⁶. -10 ~5×10 -10 mg Al / piece.

[0018] As a more preferred step, in step S3, the ratio of aluminum chloride dosage to algal cell number is 2 × 10⁻⁶. -10 mg Al / piece.

[0019] In some specific implementations, step S3, the coagulation and sedimentation process, is as follows: rapid stirring for 1~5 min, slow stirring for 15~30 min, and static settling for 30~60 min.

[0020] As a better option, step S3, the coagulation and sedimentation process is as follows: rapid stirring for 1 min, slow stirring for 15 min, and static settling for 30 min.

[0021] In some specific implementations, the speed of rapid stirring is 200 rpm, and the speed of slow stirring is 40 rpm.

[0022] Compared with the prior art, the present invention has the following advantages: (1) This invention employs a combined chlorination method of "adding a small amount of free chlorine first, followed by adding monochloramine." Specifically, a low dose of free chlorine is first used to destroy and dissociate the extracellular polymeric substances (EPS) on the surface, opening mass transfer channels. Then, monochloramine is added to implement mild and controllable oxidation and cell activity inhibition, achieving non-lytic inactivation and simultaneously reducing the risk of byproducts. Furthermore, this method enhances floc formation and sedimentation efficiency and reduces coagulant residues during subsequent coagulation. This invention provides a method for achieving moderate oxidation and non-lytic inactivation of algal cells to reduce the release of algal organic matter and the generation of disinfection byproducts, and to improve subsequent coagulation and sedimentation performance.

[0023] (2) The method of the present invention reduces the overall risk of disinfection byproduct generation. The combined chlorination strategy of first free chlorine and then monochloramine reduces cell lysis and release of intracellular organic matter while ensuring inactivation efficiency, thereby reducing the precursor load of disinfection byproducts from the source. Moreover, under the same total chlorination amount, the combined process effectively reduces the overall generation of typical disinfection byproducts such as trihalomethanes, haloacetic acids, haloacetonitrs and haloamides.

[0024] (3) The method of this invention improves the subsequent coagulation and sedimentation performance, reduces aluminum residue, and ensures stable operation of the water plant. After coagulation and sedimentation, the supernatant of algal cells treated by the combined chlorination process has a Zeta potential close to the neutral range, low aluminum residue, sufficient destabilization of colloids, rapid floc formation, dense structure, and good sedimentation performance, making it easier to achieve stable effluent turbidity and UV254 standards. Under the same effluent target, the reduction of residual aluminum reduces the burden on the filter bed and improves the operational stability of subsequent clarification and filtration units.

[0025] (4) The method of the present invention is highly compatible with existing facilities, has low modification costs, and is easy to realize online closed-loop control and standardized replication. Only time-sharing control and simple logic adjustment are required in the existing chlorination system, without the need for new large structures, which facilitates rapid project implementation. Automatic control logic can be constructed by combining signals such as ORP, residual chlorine, UV254, and turbidity. The parameter boundaries are clear, which facilitates cross-plant replication and standardized operation.

[0026] (5) This invention takes “precise staged chlorine control” as its core and solves the problem of the release of algal organic matter and disinfection byproduct risk caused by prechlorination of algae-containing raw water through a synergistic pathway of first decoupling extracellular polymer protection by free chlorine and then mild inactivation by monochloramine. It is applicable to the pretreatment of algae-rich raw water, water taken during algae outbreaks, and surface water containing Microcystis or other toxic algae. It is used to reduce AOM load and DBPs generation risk and ensure the stable operation of subsequent conventional processes. Attached Figure Description

[0027] Figure 1 This is a schematic diagram illustrating the principle of a method for achieving non-lytic inactivation of algal cells through combined chlorination proposed in this invention.

[0028] Figure 2 The images show the results of algal cell membrane integrity in Example 1, Comparative Example 1, Comparative Example 2, and Comparative Example 3.

[0029] Figure 3 The organic matter release levels from algal cells in Example 1, Comparative Example 1, Comparative Example 2, and Comparative Example 3 are shown.

[0030] Figure 4 The levels of disinfection byproduct formation in Example 1, Comparative Example 1, Comparative Example 2, and Comparative Example 3 are given.

[0031] Figure 5 The graph shows the chlorine consumption results in Example 1, Comparative Example 1, Comparative Example 2, and Comparative Example 3.

[0032] Figure 6 The images shown are scanning electron microscope images of algal cells from Example 1, Comparative Example 1, Comparative Example 2, and Comparative Example 3.

[0033] Figure 7The fluorescence of photosynthetic proteins and pigments in algal cells in Example 1, Comparative Example 1, Comparative Example 2 and Comparative Example 3.

[0034] Figure 8 The levels of oxidative stress in algal cells in Example 1, Comparative Example 1, Comparative Example 2, and Comparative Example 3 are shown.

[0035] Figure 9 The coagulation effect is shown in Example 1, Comparative Example 1, Comparative Example 2 and Comparative Example 3.

[0036] Figure 10 The images are scanning electron microscope (SEM) images of the flocs in Example 1, Comparative Example 1, Comparative Example 2, and Comparative Example 3. Detailed Implementation

[0037] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments. These embodiments are based on the technical solution of the present invention and provide detailed implementation methods and specific operating procedures. However, the scope of protection of the present invention is not limited to the following embodiments.

[0038] Unless otherwise specified, the materials and processes used in the following embodiments or examples are conventional materials and processes employed in the art to achieve the corresponding functions.

[0039] Example 1 This embodiment provides a method for achieving non-lytic inactivation of algal cells using a combination of chlorination (FC-MC), such as... Figure 1 As shown, it includes the following steps: (1) Prepare a phosphate buffer solution with an initial density of 2×10⁻⁶. 6 A 100 mL suspension of algal cells per mL was prepared, with the initial pH controlled at 7.4 using 1M sulfuric acid or sodium hydroxide solution. 1 mL of 20 mg Cl₂ / L sodium hypochlorite solution was added to the suspension, and after thorough mixing, the mixture was placed on a magnetic stirrer and reacted at 300 rpm for 9 min. Samples were taken at preset time intervals during the reaction to determine the concentrations of free chlorine, monochloramine, and total chlorine, and the fluorescence signals of phycocyanin and photosynthetic pigments were recorded simultaneously. The integrity of the algal cell membrane was measured at the end of the 9th min.

[0040] (2) At the end of the 9th minute, 1 mL of 20 mg Cl2 / L monochloramine solution was added to the reaction system, and the reaction was continued at 300 rpm for 21 minutes. During the reaction, samples were taken at preset time intervals to measure the concentrations of free chlorine, monochloramine, and total chlorine, and the fluorescence of phycocyanin and photosynthetic pigments was recorded. At the end of the 18th minute, membrane integrity and organic matter release levels were measured. At the end of the 30th minute, membrane integrity, algal cell morphology, oxidative stress level, amount of disinfection byproducts generated, and organic matter release levels were measured. The total equivalent dose of chlorine added twice was 0.4 mg Cl2 / L.

[0041] (3) Then, 1.00 mL of aluminum chloride solution with an aluminum concentration of 40 mg Al / L was added to the reaction solution, and coagulation was carried out by stirring rapidly at 200 rpm for 1 min and then slowly at 40 rpm for 15 min. The mixture was then allowed to settle for 30 min. After settling, the supernatant was collected at a depth of 2 cm below the water surface, and its zeta potential, DOC concentration and aluminum residual concentration were measured. At the same time, the algal flocs formed during settling were collected for morphological characterization.

[0042] Comparative Example 1 This comparative example is almost identical to Example 1, except that the “monochloramine solution” in step (2) is replaced with “sodium hypochlorite solution”.

[0043] This comparative example provides a process for staged chlorination (FC-FC) treatment of algal cells, including the following steps: (1) Prepare a phosphate buffer solution with an initial density of 2×10⁻⁶. 6 A 100 mL suspension of algal cells per mL was prepared, with the initial pH controlled at 7.4 using 1M sulfuric acid or sodium hydroxide solution. 1 mL of 20 mg Cl₂ / L sodium hypochlorite solution was added to the suspension, and after thorough mixing, the mixture was placed on a magnetic stirrer and reacted at 300 rpm for 9 min. Samples were taken at preset time intervals during the reaction to determine the concentrations of free chlorine, monochloramine, and total chlorine, and the fluorescence signals of phycocyanin and photosynthetic pigments were recorded simultaneously. The integrity of the algal cell membrane was measured at the end of the 9th min.

[0044] (2) At the end of the 9th minute, 1 mL of 20 mg Cl2 / L sodium hypochlorite solution was added to the reaction system, and the reaction was continued at 300 rpm for 21 minutes. During the reaction, samples were taken at preset time intervals to measure the concentrations of free chlorine, monochloramine, and total chlorine, and the fluorescence of phycocyanin and photosynthetic pigments was recorded. At the end of the 18th minute, membrane integrity and organic matter release levels were measured. At the end of the 30th minute, membrane integrity, algal cell morphology, oxidative stress level, amount of disinfection byproducts generated, and organic matter release levels were measured. The total equivalent dose of chlorine added twice was 0.4 mg Cl2 / L.

[0045] (3) Then, 1.00 mL of aluminum chloride solution with an aluminum concentration of 40 mg Al / L was added to the reaction solution, and coagulation was carried out by stirring rapidly at 200 rpm for 1 min and then slowly at 40 rpm for 15 min. The mixture was then allowed to settle for 30 min. After settling, the supernatant was collected at a depth of 2 cm below the water surface, and its zeta potential, DOC concentration and aluminum residual concentration were measured. At the same time, the algal flocs formed during settling were collected for morphological characterization.

[0046] Comparative Example 2 This comparative example is almost identical to Example 1, except that step (2) is omitted, the amount of sodium hypochlorite solution added in step (1) is increased from "1 mL" to "2 mL", and the treatment time in step (1) is extended from "9 min" to "30 min".

[0047] This comparative example provides a process for treating algal cells with free chlorine (FC) alone, comprising the following steps: (1) Prepare a phosphate buffer solution with an initial density of 2×10⁻⁶. 6 A 100 mL suspension of algal cells per mL was prepared, with the initial pH controlled at 7.4 using 1M sulfuric acid or sodium hydroxide solution. 2 mL of 20 mg Cl₂ / L sodium hypochlorite solution was added to the suspension, and after thorough mixing, the mixture was placed on a magnetic stirrer and reacted at 300 rpm for 30 min. Samples were taken at preset time intervals during the reaction to determine the concentrations of free chlorine, monochloramine, and total chlorine, and the fluorescence signals of phycocyanin and photosynthetic pigments were recorded simultaneously. At the end of min 9, algal cell membrane integrity was measured; at the end of min 18, membrane integrity and organic matter release levels were measured; at the end of min 30, membrane integrity, algal cell morphology, oxidative stress level, disinfection byproduct generation, and organic matter release levels were measured.

[0048] (2) Subsequently, 1.00 mL of aluminum chloride solution with an aluminum concentration of 40 mg Al / L was added to the reaction solution, and coagulation was carried out by stirring rapidly at 200 rpm for 1 min and then slowly at 40 rpm for 15 min. The mixture was then allowed to settle for 30 min. After settling, the supernatant was collected at a depth of 2 cm below the water surface, and its zeta potential, DOC concentration and aluminum residual concentration were measured. At the same time, the algal flocs formed during settling were collected for morphological characterization.

[0049] Comparative Example 3 This comparative example is almost identical to Example 1, with the only difference being: Step (2) is omitted, and the processing time of step (1) is extended from "9 min" to "30 min".

[0050] Replace “sodium hypochlorite solution” in step (1) with “monochloramine solution”, and increase the amount of sodium hypochlorite solution added in step (1) from “1 mL” to “2 mL”.

[0051] This comparative example provides a process for treating algal cells with monochloramine (MC) alone, comprising the following steps: (1) Prepare a phosphate buffer solution with an initial density of 2×10⁻⁶. 6A 100 mL suspension of algal cells per mL was prepared, with the initial pH controlled at 7.4 using 1M sulfuric acid or sodium hydroxide solution. 2 mL of a 20 mg Cl₂ / L monochloramine solution was added to the suspension, and after thorough mixing, the mixture was placed on a magnetic stirrer and reacted at 300 rpm for 30 min. Samples were taken at preset time intervals during the reaction to determine the concentrations of free chlorine, monochloramine, and total chlorine, and the fluorescence signals of phycocyanin and photosynthetic pigments were recorded simultaneously. At the end of min 9, algal cell membrane integrity was measured; at the end of min 18, membrane integrity and organic matter release levels were measured; at the end of min 30, membrane integrity, algal cell morphology, oxidative stress level, disinfection byproduct generation, and organic matter release levels were measured.

[0052] (2) Subsequently, 1.00 mL of aluminum chloride solution with an aluminum concentration of 40 mg Al / L was added to the reaction solution, and coagulation was carried out by stirring rapidly at 200 rpm for 1 min and then slowly at 40 rpm for 15 min. The mixture was then allowed to settle for 30 min. After settling, the supernatant was collected at a depth of 2 cm below the water surface, and its zeta potential, DOC concentration and aluminum residual concentration were measured. At the same time, the algal flocs formed during settling were collected for morphological characterization.

[0053] like Figure 2 As shown, after treatment with the FC+MC method in Example 1 for 9 min, 18 min, and 30 min, the integrity of the algal cell membrane did not show significant rupture. However, after treatment with the FC+FC method in Comparative Example 1 for 18 min and 30 min, the integrity of the algal cell membrane showed significant rupture. After treatment with the FC method in Comparative Example 2 for 9 min, 18 min, and 30 min, the integrity of the algal cell membrane showed significant rupture in all cases. After treatment with the MC method in Comparative Example 3 for 9 min, 18 min, and 30 min, the integrity of the algal cell membrane did not show significant rupture in any of these cases.

[0054] like Figure 3 As shown, after 30 min of reaction using the FC+MC method in Example 1, the release level of algal organic matter was only 12.31%. However, after treatment using the FC+FC method in Comparative Example 1, the algal organic matter release levels reached 12.15% and 14.69% at 18 min and 30 min, respectively. After treatment using the FC method in Comparative Example 2, the algal organic matter release levels reached 24%, 24.62%, and 22.61% at 9 min, 18 min, and 30 min, respectively. After treatment using the MC method in Comparative Example 3, there was no significant difference in algal organic matter release levels compared to the blank control.

[0055] like Figure 4As shown, the total disinfection byproduct yield of the combined chlorination method in Example 1 was only 5.24 μg / L. In contrast, the total disinfection byproduct yield of the segmented chlorination method in Comparative Example 1 was 6.07 μg / L, slightly higher than the combined chlorination method. The total disinfection byproduct yield of the free chlorine process alone in Comparative Example 2 was 7.36 μg / L, significantly higher than other chlorination methods. The total disinfection byproduct yield of the monochloramine process alone in Comparative Example 3 was 5.13 μg / L.

[0056] like Figure 5 As shown, the residual chlorine level after 30 min of reaction using the FC+MC method in Example 1 remained at 0.24 mg Cl2 / L, effectively ensuring the subsequent inhibitory effect on algal cells. In contrast, the residual chlorine level after 30 min of reaction using the FC+FC method in Comparative Example 1 remained at 0.14 mg Cl2 / L, with the content of dichloramine and organic chloramines generated during the reaction being 0.07 mg Cl2 / L. The organic chloramines were ineffective, significantly reducing the subsequent inhibitory effect on algal cells. In Comparative Example 2, the residual chlorine level after 30 min of reaction using the FC method remained at 0.13 mg Cl2 / L, with higher levels of dichloramine and organic chloramines than the segmented chlorination method, significantly reducing the subsequent inhibitory effect on algal cells. In Comparative Example 3, the residual chlorine level after 30 min of reaction using the MC method remained at 0.15 mg Cl2 / L, with lower levels of dichloramine and organic chloramines, indicating a certain inhibitory effect on algal cells.

[0057] like Figure 6 As shown, after treatment with the FC+MC method in Example 1, no lysis was observed in the algal cell morphology. However, after treatment with the FC+FC method in Comparative Example 1, mild lysis was observed in the algal cell morphology. After treatment with the FC method in Comparative Example 2, severe lysis was observed in the algal cell morphology. After treatment with the MC method in Comparative Example 3, no significant lysis was observed in the algal cell morphology.

[0058] pass Figure 7 Phycocyanin fluorescence and photosynthetic pigment fluorescence and Figure 8 The antioxidant activity results show that the combined chlorination process in Example 1 significantly damaged the photosynthetic active center of algal cells, increasing the degree of damage by raising the level of oxidative stress within the algal cells. In contrast, the segmented chlorination process in Comparative Example 1 significantly damaged the photosynthetic active center of algal cells, increasing the degree of damage by raising the level of oxidative stress within the algal cells. The single free chlorination process in Comparative Example 2 significantly damaged the photosynthetic active center of algal cells and also damaged the antioxidant enzymes in the algal cells, resulting in a significantly higher level of cell membrane peroxidation than other processes. The single monochloramine process in Comparative Example 3 had a poor effect on damaging the photosynthetic active center of algal cells, and the antioxidant level within the algal cells was low, indicating that monochloramine alone had a poor damaging effect on algal cells.

[0059] Figure 9 and Figure 10 The coagulation results of Example 1 showed excellent coagulation after combined chlorination treatment, with an aluminum residue of only 0.14 μg / L. In contrast, Comparative Example 1 showed poor coagulation after segmented chlorination treatment, with a higher aluminum residue than the combined chlorination process. Comparative Example 2 showed the worst coagulation after single free chlorination treatment, with a high aluminum residue. Comparative Example 3 showed good coagulation after segmented chlorination treatment, but due to poor algal cell inactivation, it faced a metabolic load caused by algal cells in subsequent treatments.

[0060] In summary, compared with the comparative example, the method of the present invention has the following advantages: (1) The cell lysis rate was significantly reduced, the release of intracellular organic matter into the water body was significantly inhibited, and the total amount of DBPs and the total amount of haloketone / haloacetic acid byproducts were significantly reduced.

[0061] (2) Membrane integrity indicators showed a significant increase in the proportion of intact cells.

[0062] (3) The release level of intracellular organic matter in the supernatant was significantly reduced.

[0063] (4) The generation of total DBPs or target DBPs populations is significantly reduced.

[0064] (5) Increased activity of superoxide dismutase (SOD) and catalase (CAT) corresponds to the stress response and non-lysis characteristics of cells under mild inactivation conditions.

[0065] The above description of the embodiments is provided to enable those skilled in the art to understand and use the invention. It will be apparent to those skilled in the art that various modifications can be made to these embodiments, and the general principles described herein can be applied to other embodiments without inventive effort. Therefore, the present invention is not limited to the above embodiments, and any improvements and modifications made by those skilled in the art based on the disclosure of the present invention without departing from the scope of the invention should be within the protection scope of the present invention.

Claims

1. A method for non-lytic inactivation of algal cells, characterized in that, Includes the following steps: S1. Add free chlorine to the algal cell suspension and mix to cause the extracellular polymers on the surface of the algal cells to decompose. S2. Add monochloramine to the S1 system to inactivate the algal cells under non-lytic conditions; S3. Add aluminum chloride solution to the S2 system to coagulate and precipitate.

2. The method for non-lytic inactivation of algal cells according to claim 1, characterized in that, In step S1, the ratio of free chlorine dosage to algal cell number is 1×10⁻⁶. -10 ~1.5×10 -10 mg Cl2 / each.

3. The method for non-lytic inactivation of algal cells according to claim 1, characterized in that, In step S1, the free chlorine is selected from either sodium hypochlorite or calcium hypochlorite.

4. The method for non-lytic inactivation of algal cells according to claim 1, characterized in that, In step S1, the mixing process parameters are: stirring at a stirring speed of 100-300 r / min for 9-60 minutes.

5. The method for non-lytic inactivation of algal cells according to claim 1, characterized in that, In step S2, the ratio of monochloramine dosage to algal cell number is 1×10⁻⁶. -10 ~5×10 -10 mg Cl2 / each.

6. The method for non-lytic inactivation of algal cells according to claim 1, characterized in that, In step S2, the mixing process parameters are: stirring at a stirring speed of 100-300 r / min for 9-60 minutes.

7. The method for non-lytic inactivation of algal cells according to claim 1, characterized in that, In step S3, the ratio of aluminum chloride dosage to algal cell number is 1.5 × 10⁻⁶. -10 ~5×10 -10 mg Al / piece.

8. The method for non-lytic inactivation of algal cells according to claim 1, characterized in that, Step S3, the coagulation and sedimentation process is as follows: rapid stirring for 1~5 min, slow stirring for 15~30 min, and static settling for 30~60 min.

9. The method for non-lytic inactivation of algal cells according to claim 8, characterized in that, The stirring speed for fast stirring is 200~300 rpm, and the stirring speed for slow stirring is 20~50 rpm.

10. The method for non-lytic inactivation of algal cells according to claim 1, characterized in that, The ratio of free chlorine dosage to algal cell number is 1×10. -10 mg Cl2 / cell, the ratio of monochloramine dosage to algal cell number is 2×10 -10 mgCl2 / cell, the ratio of aluminum chloride dosage to algal cell number is 2×10. -10 mg Al / piece.

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