A method for controlling the formation potential of chlorination disinfection byproducts by enhancing the photosensitization effect of algal organic matter with persulfate and its application

Abstract

This invention belongs to the field of environmental remediation and pollution control technology, specifically relating to a method and its application for controlling the formation potential of chlorination disinfection byproducts by enhancing the photosensitization effect of algal organic matter with persulfate. This invention utilizes the sunlight photosensitization effect of algal organic matter enhanced with persulfate to control the formation potential of disinfection byproducts, significantly improving the control effect on the formation potential of algal disinfection byproducts compared to existing technologies. Furthermore, it uses economically sustainable sunlight as the driving source, replacing traditional ultraviolet light, further improving the economic efficiency and feasibility of the technology. This invention synergistically removes algae and organic matter from water, significantly improving water treatment efficiency and water quality. Simultaneously, by reducing the formation of disinfection byproducts, it improves the safety of water treatment, ensuring the safety of drinking water and other water uses. Utilizing sunlight as the driving force reduces the use of chemical reagents and the energy consumption of ultraviolet light equipment, offering advantages in environmental protection and sustainability.

Description

Technical Field

[0001] This invention belongs to the field of environmental remediation and pollution control technology, specifically relating to a method for controlling the generation potential of chlorination disinfection byproducts by enhancing the photosensitization effect of algal organic matter with persulfate and its application. Background Technology

[0002] In recent years, cyanobacterial blooms have frequently led to a decline in the water quality of rivers and lakes globally, posing a significant challenge to water treatment. Organic matter (AOM) produced by algal growth, including intracellular organic matter (IOM) and extracellular organic matter (EOM), is a crucial precursor to chlorination disinfection byproducts (DBPs) and is directly linked to drinking water health issues. Chlorination disinfection byproducts have carcinogenic, teratogenic, and mutagenic effects. Long-term intake may increase the risk of cancer and birth defects, affect liver and kidney function, and potentially cause neurological problems. Chlorination disinfection byproducts of chloroform have been included as one of the 14 new pollutants under key control in my country. In the newly revised "Standards for Drinking Water Quality GB5749-2022" in my country, chlorination disinfection byproducts have been moved from non-routine indicators to routine indicators for drinking water. Therefore, controlling the generation of chlorination disinfection byproducts has become crucial for ensuring drinking water safety and health.

[0003] Algae, as the main body of photosynthesis in natural water bodies, have had their chromophores, found to be important natural photosensitizing substances in water. These chromophores can absorb photons and photosensitize under ultraviolet light and sunlight to generate a series of active substances, including triple excited states (…). 3 AOM*), hydroxyl radicals (·OH), singlet oxygen ( 1 O2), etc. Through this photosensitization effect of algal organic matter, the degradation of new pollutants remaining in water can be promoted. Therefore, microalgal photosensitization is a clean, low-carbon, and promising new pollutant degradation technology. Furthermore, IOM and EOM can generate triple excited states under sunlight (…). 3 IOM*、 3 The photosensitizing effects of active species such as EOM*, hydroxyl radicals, and singlet oxygen not only degrade pollutants in water, but also affect the formation potential of algal organic matter and algal disinfection byproducts. However, there are few reports on DBPs control technologies involving photosensitization effects.

[0004] Studies have shown that the photosensitization effect of algal organic matter alone has a certain effect on controlling the formation of algal disinfection byproducts. However, due to its susceptibility to the influence of other ions, pollutants, and light intensity in the water, the control effect of algal organic matter photosensitization on algal disinfection byproducts is limited and unstable. Therefore, developing a method based on persulfate-enhanced photosensitization of algal organic matter to control the formation potential of algal disinfection byproducts is of great strategic significance for strengthening the treatment of new pollutants. Summary of the Invention

[0005] In view of this, the purpose of this invention is to address the problems existing in the prior art by providing a method for controlling the generation potential of chlorination disinfection byproducts by enhancing the photosensitization effect of algal organic matter with persulfate.

[0006] To achieve the above objectives, the present invention adopts the following technical solution:

[0007] A method for controlling the formation potential of chlorinated disinfection byproducts by enhancing the photosensitization effect of algal organic matter with persulfate is proposed. This method utilizes persulfate to enhance the photosensitization effect of algal organic matter under sunlight, thereby controlling the formation potential of chlorinated algal disinfection byproducts.

[0008] Furthermore, the persulfate-enhanced photosensitization effect is manifested in the increased content of triple excited-state active species produced by algal organic matter.

[0009] It is worth noting that the photosensitization effect of algal organic matter is that algal organic matter undergoes a photosensitization reaction under sunlight, generating reactive oxygen species (such as singlet oxygen). 1 O2 and the triple excited-state substances of algal organic matter 3 (AOM*). These reactive oxygen species can further oxidize and decompose organic matter, enhancing water treatment efficiency. However, the photosensitization effect of algal organic matter alone is not ideal in controlling the formation potential of disinfection byproducts from chlorinated algae sources.

[0010] This invention utilizes persulfate to enhance the photosensitization effect of algal organic matter under sunlight, thereby controlling the formation potential of chlorination disinfection byproducts. The method activates persulfate under sunlight, which synergistically enhances the photosensitization effect of algal organic matter. Specifically, the addition of persulfate significantly increases the steady-state concentration of reactive oxygen species generated by the photosensitization effect of algal organic matter, thus more efficiently removing algal organic matter from water, controlling disinfection byproduct precursors, and reducing the formation of algal disinfection byproducts.

[0011] In particular, this invention can efficiently remove precursor substances of algal disinfection byproducts. Traditional single technologies (such as UV-driven persulfate oxidation or photosensitization of algal organic matter alone) have certain limitations in removing algal organic matter. This invention, by coupling two technologies, can significantly improve the removal effect. Furthermore, this invention can effectively reduce the generation of DBPs. Traditional chlorination disinfection methods produce a large amount of DBPs, while this invention, by enhancing the photosensitization effect of algal organic matter through persulfate, can significantly reduce the generation of these byproducts. Simultaneously, this invention can effectively reduce treatment costs. By utilizing sunlight as the driving force, it reduces dependence on chemical reagents and UV equipment, thereby lowering the operating costs and environmental impact of water treatment.

[0012] Furthermore, the algae are cyanobacteria, and the algal organic matter includes one or more of the following: intracellular organic matter (IOM) and extracellular organic matter (EOM).

[0013] As one of the most common algae in water bodies, cyanobacteria are widely distributed in rivers and lakes and have the characteristic of rapid reproduction, easily forming algal blooms and seriously affecting water quality. In particular, cyanobacterial cells contain a large amount of organic matter, which is an important precursor to the formation of disinfection byproducts. Therefore, in order to specifically degrade the organic matter produced by cyanobacteria themselves, reduce the generation of byproducts during the disinfection process, and thus effectively remove dissolved organic matter contributed by cyanobacteria from the water and improve water quality, this invention enhances the photosensitization effect of sunlight on cyanobacterial organic matter using persulfate, reduces the precursors of disinfection byproducts, degrades the organic matter released by cyanobacteria, and reduces the precursors to form disinfection byproducts, thereby further controlling the formation potential of algal disinfection byproducts.

[0014] Furthermore, algal organic matter (AOM) includes extracellular organic matter (EOM) and intracellular organic matter (IOM). IOM is released into the water in large quantities when the cell structure or activity is damaged, while EOM is organic matter released into the environment during the normal life cycle of algal cells. Through the solar photosensitization effect of persulfate-enhanced algal organic matter, both types of algal organic matter, as important precursors of disinfection byproducts, can be effectively degraded, thereby achieving efficient control of chlorination disinfection byproducts.

[0015] Furthermore, the cyanobacteria include one or more of Microcystis aeruginosa and Anabaena.

[0016] It is worth noting that *Microcystis aeruginosa* and *Anabaena* are common harmful cyanobacteria in aquatic bodies, widely distributed in many freshwater bodies. They frequently cause algal blooms, posing a serious threat to the aquatic environment and ecosystem. This invention utilizes the photosensitization effect of *Microcystis aeruginosa* and *Anabaena* organic matter under sunlight. This not only degrades algal organic matter, the precursors to disinfection byproducts, reducing the generation of disinfection byproducts at the source, but also utilizes sunlight as an energy source, resulting in low operating costs and good economic benefits. Furthermore, it does not produce secondary pollution, which is conducive to the long-term healthy development of the aquatic ecosystem. In particular, the addition of persulfate in this invention significantly enhances the reactive oxygen species produced by the photosensitization effect of *Microcystis aeruginosa* or *Anabaena* organic matter, thereby improving the ability to oxidize and decompose organic matter in the water, and thus effectively enhancing the water treatment effect.

[0017] Furthermore, the persulfate is perdisulfate (PDS).

[0018] It is worth noting that this invention uses persulfate, represented by potassium persulfate.

[0019] Existing technologies only disclose the use of ultraviolet light to drive persulfate to control the formation potential of algal disinfection byproducts, without mentioning the effect of persulfate on the photosensitization effect of algal organic matter. This invention not only focuses on the photosensitization effect of algal organic matter under light irradiation, but also on the role of persulfate in enhancing the photosensitization reaction of algal organic matter under sunlight irradiation, thereby effectively strengthening the photosensitization effect of algal organic matter. The synergistic effect of these two technologies achieves efficient control of chlorination disinfection byproducts in drinking water.

[0020] Furthermore, the specific steps of the method for controlling the formation potential of chlorination disinfection byproducts by enhancing the photosensitization effect of algal organic matter with persulfate include:

[0021] S1. Add persulfate to water containing algal organic matter to obtain a mixed solution;

[0022] S2. Adjust the pH of the mixed solution obtained in step S1 to 7±0.1 using a buffer solution to obtain a neutral stock solution;

[0023] S3, homogeneous neutral stock solution at constant temperature, reacted simultaneously with sunlight irradiation;

[0024] S4. After the light reaction is complete, adjust the pH of the reaction system to 7±0.1, and add NaClO reagent with TOC:free Cl = 1:5. Chlorinate in the dark, and add ascorbic acid after chlorination to quench the chlorination, and obtain the treated water.

[0025] Traditional chlorination disinfection methods generate large amounts of DBPs. This invention utilizes persulfate to enhance the photosensitization effect of algal organic matter under sunlight, synergistically and significantly reducing the generation of disinfection byproducts. Compared to the photosensitization effect of algal organic matter alone, this greatly improves the control of algal disinfection byproducts. Furthermore, using sunlight as the driving force reduces reliance on chemical reagents and ultraviolet light equipment, lowering water treatment operating costs and environmental impact, effectively reducing treatment costs and enhancing the environmental friendliness and sustainability of water treatment processes.

[0026] Furthermore, in step S1, the concentration of algal organic matter in the water, expressed as TOC, is 2-10 mg / L, and the concentration of persulfate is 0.001-0.005 mol / L.

[0027] Furthermore, the buffer solution in step S2 is a phosphate buffer solution.

[0028] Furthermore, the sunlight in step S3 includes real sunlight or simulated sunlight by a 300W xenon lamp, and the temperature of the isothermal reaction is 25±2℃.

[0029] Furthermore, the light-protected chlorination reaction temperature in step S4 is 25°C.

[0030] It is worth noting that when chlorination disinfection was performed after irradiation of a solution containing algal organic matter under sunlight alone, the formation potential of disinfection byproducts was controlled to some extent due to the photosensitization effect of the algal organic matter under sunlight. However, the addition of persulfate significantly improved the control of the formation potential of disinfection byproducts. This is because sunlight alone generates reactive species such as triple excited states, hydroxyl radicals, and singlet oxygen in the system. The addition of persulfate significantly increased the content of triple excited state substances, which are indicative reactive species of the photosensitization effect. This further confirms that the addition of persulfate promoted the photosensitization effect of algal organic matter. Therefore, persulfate enhances the photosensitization effect of algal organic matter, resulting in better control of the formation potential of disinfection byproducts from algae.

[0031] The second objective of this invention is to provide an application of the method described above for controlling the generation potential of chlorination disinfection byproducts by enhancing the photosensitization effect of algal organic matter with persulfate.

[0032] An application of a method for controlling the generation potential of chlorination disinfection byproducts by enhancing the photosensitization effect of algal organic matter with persulfate, specifically for controlling disinfection byproducts generated during the water treatment and disinfection process of drinking water sources containing algal organic matter.

[0033] Compared with existing technologies, this invention employs a persulfate-enhanced photosensitization effect on algal organic matter to control the formation potential of chlorination disinfection byproducts. Building upon existing algal organic matter photosensitization effects, this technology significantly increases the content of key active species, such as triple excited-state substances, in the system, thereby effectively improving the control of the formation potential of algal disinfection byproducts. Furthermore, it uses economically sustainable sunlight as the driving source, replacing traditional ultraviolet light, further enhancing the technology's economic efficiency and feasibility. Thus, this invention, through the enhanced photosensitization effect of persulfate on algal organic matter, more efficiently removes algae and organic matter from water, significantly improving water treatment effectiveness and water quality. Simultaneously, by reducing the formation of disinfection byproducts, it improves water treatment safety, ensuring the safety of drinking water and other water uses. Utilizing sunlight as the driving force reduces the use of chemical reagents and the energy consumption of ultraviolet light equipment, offering advantages in environmental protection and sustainability.

[0034] Compared to the photosensitization effect of algal organic matter alone, the sulfate-enhanced photosensitization technology for algal organic matter is more efficient in removing both algae and organic matter, significantly improving water treatment results. Furthermore, by reducing the use of chemical reagents and lowering equipment requirements, this invention is highly economical and suitable for application in various water treatment scenarios. Therefore, this invention is applicable to various aquatic environments, has broad application prospects, and can play an important role in drinking water treatment, wastewater treatment, swimming pool water treatment, and industrial wastewater treatment. Attached Figure Description

[0035] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.

[0036] Figure 1 This invention demonstrates the control effect of xenon lamp simulating sunlight irradiation on the generation potential of disinfection byproducts from algae sources in Experiment Example 1. In this example, ANIOM represents the intracellular organic matter system of *Anabaena urticaria*, MAIOM represents the intracellular organic matter system of *Microcystis aeruginosa*, IOM represents the intracellular organic matter system, IOM+light represents the intracellular organic matter plus light system, and IOM+PS+light represents the intracellular organic matter + potassium persulfate + light system.

[0037] Figure 2This invention demonstrates the control effect of xenon lamp simulating sunlight irradiation on the generation potential of persulfate oxidation on disinfection byproducts from algae in Experiment Example 1. ANEOM represents the extracellular organic matter system of *Anabaena urticaria*, MAEOM represents the extracellular organic matter system of *Microcystis aeruginosa*, EOM represents the extracellular organic matter system, EOM+light represents the extracellular organic matter plus light system, and EOM+PS+light represents the extracellular organic matter + potassium persulfate + light system.

[0038] Figure 3 The results show the changes in total organic carbon (TOC) in Experimental Example 1 of this invention.

[0039] Figure 4 This is an example of the effect of natural light irradiation-driven persulfate oxidation on the generation potential of disinfection byproducts from algae in Experiment 1 of this invention. In the figure, ANIOM is the intracellular organic matter system of Anabaena, MAIOM is the intracellular organic matter system of Microcystis aeruginosa, IOM is the intracellular organic matter system in the legend, IOM+light is the intracellular organic matter plus light system, and IOM+PS+light is the intracellular organic matter + potassium persulfate + light system.

[0040] Figure 5 This invention illustrates the effect of natural light irradiation-driven persulfate oxidation on the generation potential of disinfection byproducts from algae in Experiment Example 1. ANEOM represents the extracellular organic matter system of *Anabaena spp.*, MAEOM represents the extracellular organic matter system of *Microcystis aeruginosa*, EOM represents the extracellular organic matter system, EOM+light represents the extracellular organic matter plus light system, and EOM+PS+light represents the extracellular organic matter + potassium persulfate + light system.

[0041] Figure 6 In Experiment 2 of this invention, a three-dimensional fluorescence EEM was used to investigate the effects of xenon lamp-simulated sunlight on the changes in the composition of extracellular organic matter of Microcystis aeruginosa or the system of extracellular organic matter of Microcystis aeruginosa + potassium persulfate. Among them, the extracellular organic matter of Microcystis aeruginosa: (a) 0 min; extracellular organic matter of Microcystis aeruginosa + light: (b) 10 min, (c) 30 min, (d) 60 min; extracellular organic matter of Microcystis aeruginosa + potassium persulfate + light: (e) 10 min, (f) 30 min, (g) 60 min.

[0042] Figure 7 In Experiment 2 of this invention, three-dimensional fluorescence EEM was used to investigate the extracellular organic matter of Anabaena under a xenon lamp: (a) 0 min; extracellular organic matter of Anabaena + light: (b) 10 min, (c) 30 min, (d) 60 min; extracellular organic matter of Anabaena + potassium persulfate + light: (e) 10 min, (f) 30 min, (g) 60 min.

[0043] Figure 8In Experiment 2 of this invention, a three-dimensional fluorescence EEM was used to investigate the effects of xenon lamp-simulated sunlight on the changes in the composition of intracellular organic matter of Microcystis aeruginosa or the system of intracellular organic matter of Microcystis aeruginosa + potassium persulfate. Among them, the intracellular organic matter of Microcystis aeruginosa: (a) 0 min; intracellular organic matter of Microcystis aeruginosa + light: (b) 10 min, (c) 30 min, (d) 60 min; intracellular organic matter of Microcystis aeruginosa + potassium persulfate + light: (e) 10 min, (f) 30 min, (g) 60 min.

[0044] Figure 9 In Experiment 2 of this invention, a three-dimensional fluorescence EEM was used to investigate the effects of xenon lamp-simulated sunlight on the changes in the composition of intracellular organic matter or intracellular organic matter + potassium persulfate system of Anabaena. The intracellular organic matter of Anabaena was: (a) 0 min; intracellular organic matter of Anabaena + light: (b) 10 min, (c) 30 min, (d) 60 min; intracellular organic matter of Anabaena + potassium persulfate + light: (e) 10 min, (f) 30 min, (g) 60 min.

[0045] Figure 10 This experiment illustrates the effect of PS dosage on the amount of disinfection byproducts generated in Example 1 of this invention. In this example, MAIOM represents the intracellular organic matter system of Microcystis aeruginosa, MAEOM represents the extracellular organic matter system of Microcystis aeruginosa, ANIOM represents the intracellular organic matter system of Anabaena, and ANEOM represents the extracellular organic matter system of Anabaena. Detailed Implementation

[0046] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0047] The term "embodiment" used herein, as an example, is not necessarily to be construed as superior to or better than other embodiments. Performance testing in the embodiments of this application, unless otherwise specified, employs conventional testing methods in the art. It should be understood that the terminology used in this application is merely for describing particular implementations and is not intended to limit the scope of this disclosure.

[0048] Unless otherwise stated, the technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains; other experimental methods and technical means not specifically mentioned herein refer to experimental methods and technical means commonly used by one of ordinary skill in the art.

[0049] To better illustrate the content of this application, numerous specific details are provided in the following detailed embodiments. Those skilled in the art should understand that this application can be implemented even without certain specific details. In the embodiments, some methods, means, instruments, and devices well-known to those skilled in the art are not described in detail in order to highlight the main points of this application.

[0050] Without conflict, the technical features disclosed in the embodiments of this application can be combined arbitrarily, and the resulting technical solution belongs to the content disclosed in the embodiments of this application.

[0051] This invention proposes a method and its application for controlling the formation potential of disinfection byproducts from algae sources by enhancing the photosensitization effect of algal organic matter using persulfate, belonging to the field of environmental remediation and pollution control technology. This invention utilizes persulfate to enhance the photosensitization effect of algal organic matter under sunlight to control the formation potential of disinfection byproducts. Based on existing technologies, it significantly increases the content of triple excited-state substances in the system, thereby effectively improving the control effect of the formation potential of disinfection byproducts from algae sources. Furthermore, it uses economically sustainable sunlight as the driving source, replacing traditional ultraviolet light, further improving the economic efficiency and feasibility of the technology. Therefore, this invention, through the enhanced photosensitization effect of persulfate on algal organic matter, more efficiently removes algae and organic matter from water, significantly improving water treatment efficiency and water quality. Simultaneously, by reducing the formation of disinfection byproducts, it improves the safety of water treatment, ensuring the safety of drinking water and other water uses. Utilizing sunlight as the driving force reduces the use of chemical reagents and the energy consumption of ultraviolet light equipment, offering advantages in environmental protection and sustainability.

[0052] To better understand the present invention, the following embodiments are provided for further detailed description of the invention, but they should not be construed as limiting the invention. Any non-essential improvements and adjustments made by those skilled in the art based on the above description are also considered to fall within the protection scope of the present invention.

[0053] Example 1

[0054] A method for controlling the formation potential of chlorination disinfection byproducts by enhancing the photosensitization effect of algal organic matter with persulfate, comprising the following steps:

[0055] S1: Add 5 mmol / L potassium persulfate to 200 mL of water containing 5 mg / L (TOC) of organic matter from four algae (intracellular organic matter of Microcystis aeruginosa, extracellular organic matter of Microcystis aeruginosa, intracellular organic matter of Anabaena, and extracellular organic matter of Anabaena) to obtain a mixed solution.

[0056] S2: The pH value of the mixed solution is adjusted using a buffer solution (phosphate buffer solution: sodium dihydrogen phosphate, disodium hydrogen phosphate) to a pH value of 7±0.1 to obtain a neutral stock solution;

[0057] S3: The temperature was maintained at 25±2℃ during the light irradiation experiment using a constant temperature water bath. The original solution to be degraded was stirred using a magnetic stirrer, and a 300W xenon lamp (without a filter, light intensity of 230mW / cm²) was used. -2 The stock solution is irradiated with simulated sunlight, causing the algal organic matter in the stock solution to undergo photosensitization and react with sunlight-activated potassium persulfate to control the precursor substances of algal disinfection byproducts, thereby further controlling the generation potential of disinfection byproducts.

[0058] S4: Immediately after irradiation with a xenon lamp, the pH of 200 mL of the sample was adjusted to (7.0±0.1), and NaClO reagent (TOC: free Cl = 1:5) was added. The sample was chlorinated in the dark for 72 h (25℃). Ascorbic acid was added to the chlorinated sample for quenching.

[0059] Example 2

[0060] A method for controlling the formation potential of chlorination disinfection byproducts by enhancing the photosensitization effect of algal organic matter with persulfate, comprising the following steps:

[0061] S1: Add 5 mmol / L potassium persulfate to 200 mL of water containing 5 mg / L (TOC) of organic matter from four algae (intracellular organic matter of Microcystis aeruginosa, extracellular organic matter of Microcystis aeruginosa, intracellular organic matter of Anabaena, and extracellular organic matter of Anabaena) to obtain a mixed solution.

[0062] S2: The pH value of the mixed solution is adjusted using a buffer solution (phosphate buffer solution: sodium dihydrogen phosphate, disodium hydrogen phosphate) to a pH value of 7±0.1 to obtain a neutral stock solution;

[0063] S3: The temperature during the light irradiation experiment was kept stable at 25±2℃ using a constant temperature water bath. The original solution to be degraded was stirred with a magnetic stirrer and irradiated with real sunlight (five consecutive sunny days in summer) to cause the algal organic matter in the original solution to undergo photosensitization and react with potassium persulfate activated by sunlight, so as to control the precursor substances of algal disinfection byproducts and further control the generation potential of disinfection byproducts.

[0064] S4: Immediately after exposure to real sunlight, the pH of 200 mL of the sample was adjusted to (7.0±0.1), and NaClO reagent (TOC: free Cl = 1:5) was added. The sample was chlorinated in the dark for 72 h (25℃). Ascorbic acid was added to the chlorinated sample for quenching.

[0065] Example 3

[0066] A method for controlling the generation potential of chlorination disinfection byproducts by enhancing the photosensitization effect of algal organic matter with persulfate, the specific steps are the same as in Example 1, except that the potassium persulfate added in step S1 is 4 mmol / L.

[0067] Example 4

[0068] A method for controlling the generation potential of chlorination disinfection byproducts by enhancing the photosensitization effect of algal organic matter with persulfate, the specific steps are the same as in Example 1, except that the potassium persulfate added in step S1 is 3 mmol / L.

[0069] Example 5

[0070] A method for controlling the generation potential of chlorination disinfection byproducts by enhancing the photosensitization effect of algal organic matter with persulfate, the specific steps are the same as in Example 1, except that the potassium persulfate added in step S1 is 2 mmol / L.

[0071] Example 6

[0072] A method for controlling the generation potential of chlorination disinfection byproducts by enhancing the photosensitization effect of algal organic matter with persulfate, the specific steps are the same as in Example 1, except that the potassium persulfate added in step S1 is 1 mmol / L.

[0073] Examples 7-10

[0074] A method for controlling the generation potential of chlorination disinfection byproducts by enhancing the photosensitization effect of algal organic matter with persulfate, the specific steps are the same as in Example 2, the difference being that the potassium persulfate added in step S1 is 4-1 mmol / L.

[0075] To further demonstrate the beneficial effects of the present invention and to better understand the present invention, the following comparative examples and experimental examples further illustrate the application performance of the method disclosed in the present invention for controlling the generation potential of disinfection byproducts by controlling the photosensitization effect of algal organic matter enhanced by persulfate. However, this should not be construed as a limitation of the present invention. Other measurement experiments or comparative examples conducted by those skilled in the art based on the above-described invention, and the application based on the above-described properties, are also considered to fall within the protection scope of the present invention.

[0076] Comparative Example 1

[0077] A method for controlling the generation potential of algal disinfection byproducts by photosensitizing a single algal organic matter under sunlight:

[0078] S1: Add 5 mg / L (in TOC) of organic matter from four algae (intracellular organic matter of Microcystis aeruginosa, extracellular organic matter of Microcystis aeruginosa, intracellular organic matter of Anabaena, and extracellular organic matter of Anabaena) to pure water to obtain a mixed solution.

[0079] S2: The pH value of the mixed solution is adjusted using a buffer solution (phosphate buffer solution: sodium dihydrogen phosphate, disodium hydrogen phosphate) to a pH value of 7±0.1 to obtain a neutral stock solution;

[0080] S3: Maintain a stable temperature of 25±2℃ during the light irradiation experiment using a constant temperature water bath. Stir the original solution to be degraded using a magnetic stirrer. Use real sunlight (five consecutive sunny days in summer) or a 300W xenon lamp (without a filter, light intensity of 230mW / cm²) for the experiment. -2 The stock solution is irradiated with simulated sunlight, causing the algal organic matter in the stock solution to undergo photosensitization, thereby controlling the precursor substances of algal disinfection byproducts and further controlling the generation potential of disinfection byproducts.

[0081] S4: Immediately adjust the pH of 200 mL of sample after exposure to real sunlight or xenon lamp (7.0±0.1). Add NaClO reagent (TOC: free Cl = 1:5), chlorinate in the dark for 72 h (25℃), and quench the chlorinated sample by adding ascorbic acid.

[0082] Effect of Experiment Example 1 on the formation potential of disinfection byproducts from algae sources

[0083] 1.1 Experimental method for determining the formation potential of algal disinfection byproducts:

[0084] Collect 25 mL of the quenched samples from Examples 1-10 into a brown capped glass bottle. After liquid-liquid extraction according to the USEPA method, chloroform (TCM), dichloroacetonitrile (DCAN), and dichloroacetic acid (DCAA) were quantitatively determined by GC / ECD.

[0085] The results are as follows Figure 10As shown, considering the total amount of the three disinfection byproducts, within the potassium persulfate dosage range of 1-5 mmol / L, the formation potential of disinfection byproducts (DBPs) gradually decreased with increasing potassium persulfate dosage. The control effect on chloroform (TCM) was most significant. When the PS dosage reached 5 mmol / L, the TCM control levels for both algal-derived organic compounds from *Microcystis aeruginosa* reached over 80%, and for both organic compounds from *Anabaena*, the control levels reached approximately 70%. Simultaneously, the control effect on DCAA was also very significant. When the PS dosage reached 5 mmol / L, the control levels in the four organic compound systems ranged from 45% to 65%. For DCAN, when the PS dosage reached 5 mmol / L, a significant control effect was observed in the extracellular organic matter (EOM) system after 5 days of illumination, with a control rate exceeding 85%. However, in the intracellular organic matter (IOM) system, the formation potential increased with increasing dosage.

[0086] 1.2 Simulated Effects of Sunlight Irradiation

[0087] The study investigated the effect of simulated sunlight and its driving persulfate oxidation on the formation potential of disinfection byproducts from algae sources by using a xenon lamp to simulate sunlight irradiation (Example 1). Figure 1 2). (The simulated light exposure duration in the experiment was one hour, and the sampling points were: 0 min, 10 min, 20 min, 30 min, 45 min, and 60 min).

[0088] The experimental results showed that, compared to Comparative Example 1, the system with added PS significantly reduced the total amount of DBPs generated by the three disinfection byproducts, achieving a maximum control efficiency of 86.5% for the total disinfection byproduct generation potential of the four algal organic matter systems. TCM was more sensitive; simulated sunlight alone could control its generation potential to some extent, with a control effect of 20%-30% within one hour of simulated sunlight. After adding PS, the total TCM generation could be further reduced, with a control level of 89%-97% compared to the system without PS. For DCAA, the system's effect on its generation potential was relatively stable, but after adding persulfate, its generation was significantly reduced compared to sunlight alone, achieving a maximum control efficiency of 78.7% in the four algal organic matter systems. For DCAN, the generation in the EOM simulated sunlight / PS system had a significant control effect compared to the single-light system, achieving a maximum control rate of 76% in the extracellular organic matter system of Anabaena. In the intracellular organic matter experimental group, an increase in generation was observed after adding PS.

[0089] 1.3 The Influence of Natural Light

[0090] To ensure the accuracy of the experiment and its potential for practical application, a simulation experiment under natural sunlight conditions was also conducted (i.e., Example 2). Figure 4 5). (The experiment was conducted over five consecutive sunny days in summer, with a duration of 5 days. The sampling time points were: 0d, 0.5d, 1d, 2d, 3d, and 5d).

[0091] Experimental results showed that the trends of the three disinfection byproducts were basically consistent with those under xenon lamp simulation conditions. Furthermore, under natural light conditions, the control efficacy against the three disinfection byproducts was more significant, with the highest control efficiency for the total disinfection byproduct formation potential of the four algal organic compounds reaching 78%-95%, further demonstrating the application potential of this invention. Changes in TOC were also detected. Figure 3 The study found that the degradation rate of TOC gradually increased with the extension of light exposure time, and the system with added PS had better degradation efficiency than the system with light exposure alone.

[0092] Mechanism Analysis of Experiment Example 2

[0093] 2.1 Three-dimensional fluorescence analysis

[0094] An analysis and investigation was conducted on AOM and its compositional changes during illumination. Figures 6-9 The study aimed to investigate the system's control over DBP precursors and its relationship with changes in the potential for subsequent disinfection byproduct formation.

[0095] This invention, using extracts from *Microcystis aeruginosa* and *Anabaena* algae, specifically targeting the EOM and IOM solutions extracted from the end-log phase, determined the TOC values ​​and then diluted them to 5 mg·L⁻¹. -1 Xenon lamp irradiation was performed with and without persulfate. Samples were taken at 0, 10, 30, and 60 min of illumination. After filtration through a 0.45 μm organic filter, excitation-emission matrix fluorescence spectra were obtained using a fluorescence spectrophotometer to analyze changes in photosensitized components of algal organic matter. Specific parameters were as follows: excitation wavelength range 200 nm–550 nm, emission wavelength range 250 nm–600 nm, sampling interval 5 nm, and scan rate 12000 nm·min. -1 The excitation and emission unit slits are both 2.5 nm, and the PMT voltage is 700 V.

[0096] Experimental results show that, without the addition of persulfate, xenon lamp irradiation leads to a gradual decrease in fluorescence intensity as irradiation time increases. This indicates that the content of DBP precursors is controlled by the photosensitization effect of algal organic matter, thus reducing the formation potential of disinfection byproducts to some extent. However, with the addition of persulfate, the precursor content further decreases, and the fluorescence intensity almost disappears after 60 minutes of irradiation. Corresponding to the test results for disinfection byproducts, the formation potential of disinfection byproducts is suppressed to an even greater extent.

[0097] 2.2 Analysis of bioactive species

[0098] To further elucidate the mechanism by which the photosensitization effect of persulfate-enhanced algal organic matter controls the generation potential of chlorination disinfection byproducts, high performance liquid chromatography was used to conduct probe experiments on the active species in the system (Table 1, Table 2).

[0099] To determine the formation of different active species, 2,4,6-trimethylphenol (TMP, 0.2 mM), furfuryl alcohol (FFA, 0.1 mM), and para-chlorobenzoic acid (p-CBA, 10 μM) were added to the reaction system as [specific examples of active species]. 3 AOM*、 1 O2 and ·OH probe compounds. The concentrations of TMP, FFA, and p-CBA were analyzed by high-performance liquid chromatography (HPLC). All samples were stored in brown HPLC vials and separated in a Brownlee Validated AQ C18 column (150 × 4.6 mm, 5 μm) with an injection volume of 50 μL. The organic mobile phase used was chromatographic grade methanol, and the aqueous phase and buffer were prepared with ultrapure water, filtered through a 0.45 μm filter to remove impurities, and sonicated for 30 min before use to remove air bubbles from the mobile phase.

[0100] Table 1

[0101]

[0102]

[0103] Table 2

[0104]

[0105] Observations on the formation of the three active species revealed that the content of all three species increased significantly after the addition of persulfate, with the steady-state concentration of each species increasing by approximately one order of magnitude. In particular, the addition of persulfate (PS) resulted in a significant increase in the triple excited state of algal organic matter, the specific active species for algal photosensitization.3 EOM*、 3 The concentration of IOM*) increased significantly, especially after the addition of persulfate, the EOM system... 3 The steady-state concentration of EOM* increased by 3.6 times. 3 The steady-state concentration of IOM* increased by 5.7 times. This also indicates that the introduction of persulfate, in addition to leveraging its own oxidation efficiency, greatly enhanced the photosensitization effect of algal organic matter under solar radiation. Persulfate enhanced the photosensitization effect of algae, greatly increasing the steady-state concentration of the three active species, including the triple excited state. This is the main reason why this enhanced coupling technology can efficiently control the generation potential of algal chlorination disinfection byproducts.

[0106] The above description of the disclosed embodiments enables those skilled in the art to make or use the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A method for controlling the formation potential of chlorination disinfection byproducts by enhancing the photosensitization effect of algal organic matter with persulfate, characterized in that, The photosensitization effect of algal organic matter on sunlight is enhanced by using persulfate to control the generation potential of disinfection byproducts from chlorinated algae sources. Specific steps include: S1. Add persulfate to water containing algal organic matter to obtain a mixed solution; the concentration of algal organic matter in the water, expressed as TOC, is 2-10 mg / L, and the concentration of persulfate is 0.001-0.005 mol / L. S2. Adjust the pH of the mixed solution obtained in step S1 to 7±0.1 using a buffer solution to obtain a neutral stock solution; S3, homogeneous neutral stock solution at constant temperature, reacted simultaneously with sunlight irradiation; S4. After the light reaction is complete, adjust the pH of the reaction system to 7±0.1, and add NaClO reagent with TOC : free Cl = 1 :

5. Chlorinate in the dark, and add ascorbic acid after chlorination to quench the reaction and obtain the treated water.

2. The method for controlling the formation potential of chlorination disinfection byproducts by enhancing the photosensitization effect of algal organic matter according to claim 1, characterized in that, The persulfate-enhanced photosensitization effect is manifested in the increased content of triple excited-state active species produced by algal organic matter.

3. The method for controlling the formation potential of chlorination disinfection byproducts by enhancing the photosensitization effect of algal organic matter according to claim 2, characterized in that, The algae are cyanobacteria, and the algal organic matter includes one or more of the following: intracellular organic matter (IOM) and extracellular organic matter (EOM).

4. The method for controlling the formation potential of chlorination disinfection byproducts by enhancing the photosensitization effect of algal organic matter according to claim 3, characterized in that, The cyanobacteria include one or more of Microcystis aeruginosa and Anabaena.

5. The method for controlling the formation potential of chlorination disinfection byproducts by enhancing the photosensitization effect of algal organic matter according to claim 2, characterized in that, The persulfate is perdisulfate.

6. The method for controlling the formation potential of chlorination disinfection byproducts by enhancing the photosensitization effect of algal organic matter according to claim 1, characterized in that, The buffer solution in S2 is a phosphate buffer solution.

7. The method for controlling the formation potential of chlorination disinfection byproducts by enhancing the photosensitization effect of algal organic matter according to claim 1, characterized in that, The sunlight in S3 includes real sunlight or simulated sunlight from a 300W xenon lamp, and the constant temperature is 25±2 ℃.

8. The application of the method for controlling the formation potential of chlorination disinfection byproducts by enhancing the photosensitization effect of algal organic matter as described in any one of claims 1 to 7, characterized in that, Control of disinfection byproducts generated during the water treatment and disinfection process of drinking water sources containing algae and organic matter.

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