Zero-discharge synergistic purification method for thermal power desulfurization wastewater

Abstract

The invention relates to the technical field of wastewater treatment, and discloses a thermal power desulfurization wastewater zero-discharge synergistic purification method which comprises the following steps: pretreating desulfurization wastewater, and removing large particles and suspended solids through preliminary precipitation and filtration; the pretreated wastewater is subjected to multiple catalytic reactions, a modified carbon material and metal nanoparticles are adopted as catalysts, and pollutants are removed through heterogeneous catalysis, photocatalysis and electro-catalysis in the multiple catalytic reactions; and introducing the wastewater subjected to catalytic treatment into microbial enhanced treatment equipment, and selecting a specific microbial population for culture. According to the method disclosed by the invention, through comprehensive application of innovative combination of the modified activated carbon and the metal nano-catalyst, efficient degradation of organic pollutants in the thermal power desulfurization wastewater is realized, the reaction rate is increased, and thorough decomposition of the pollutants is promoted, so that COD (Chemical Oxygen Demand) and suspended matter concentration of the wastewater are remarkably reduced, and an effective solution is provided for water quality improvement.

Description

Technical Field

[0001] The present invention relates to the technical field of wastewater treatment, and in particular to a zero-discharge collaborative purification method for thermal power desulfurization wastewater. Background Art

[0002] Desulfurization wastewater from thermal power plants has the characteristics of complex composition, high difficulty in treatment, and strict emission standards. Achieving zero emissions is of great significance to environmental protection and sustainable development of enterprises. The collaborative purification method aims to achieve the goal of zero emissions by efficiently and economically treating desulfurization wastewater through the comprehensive use of multiple technical means.

[0003] Conventional methods often have poor removal effects on high-concentration organic pollutants. The complex organic components and their resistance to degradation in these wastewaters make it difficult for conventional treatment processes to achieve the expected water quality standards. Treatment processes often rely on a single removal mechanism and lack effective multiple linkage mechanisms, resulting in long treatment cycles and high operating costs. This is especially true for thermal power desulfurization wastewater, where the complex composition makes conventional methods difficult to adapt, leading to low efficiency and resource waste during the treatment process. Furthermore, the selection of catalysts in existing technologies often fails to fully consider their surface properties and reaction mechanisms, resulting in insufficient catalytic activity. In traditional catalytic applications, common metal catalysts are limited in scope and conditions of use, and the reactive oxygen species they generate are insufficient to meet the requirements for rapid degradation of organic matter in wastewater. This results in a failure to effectively improve reaction efficiency despite the addition of catalysts, and instead increases operating and maintenance costs. Furthermore, conventional catalytic technologies often fail to effectively combine photocatalysis and electrocatalysis, lacking a holistic catalytic system design, resulting in an ineffective improvement in the overall performance of wastewater treatment. This design limitation prevents catalytic treatment from fully utilizing its due advantages when dealing with complex wastewaters, significantly reducing overall decontamination performance and limiting the applicability of treatment methods. Summary of the Invention

[0004] In response to the shortcomings of the existing technology, the present invention provides a zero-emission collaborative purification method for thermal power desulfurization wastewater, which solves the problems of low degradation efficiency of high-concentration organic pollutants, long treatment cycle and waste of resources.

[0005] To achieve the above objectives, the present invention is implemented through the following technical solutions: a zero-discharge collaborative purification method for thermal power desulfurization wastewater, comprising the following steps: Pre-treat desulfurization wastewater by removing larger particles and suspended solids through preliminary sedimentation and filtration; The pretreated wastewater is subjected to multiple catalytic reactions, using modified carbon materials and metal nanoparticles as catalysts. In the multiple catalytic reactions, pollutants are removed through heterogeneous catalysis, photocatalysis, and electrocatalysis. The catalytically treated wastewater is introduced into the microbial enhanced treatment equipment and a specific microbial population is selected for cultivation; Real-time monitoring equipment is used to monitor the pH, dissolved oxygen, ammonia nitrogen and COD content during the reaction process, and the catalyst dosage and microbial culture conditions are dynamically adjusted based on the real-time data; The sludge and sewage generated by the microbial enhanced treatment equipment are collected and treated, and the treated sewage is disinfected and the resources are recycled.

[0006] Preferably, the preliminary precipitation and filtration refers to introducing the thermal power desulfurization wastewater into a sedimentation tank and letting it stand for 30-60 minutes, separating larger particles and suspended matter by gravity, and then performing physical filtration with an accuracy of 20-50 μm through a polyethylene filter membrane or a ceramic filter plate.

[0007] Preferably, the pH value of the desulfurization wastewater is between 6.0 and 8.5, the turbidity is less than 100 NTU, the suspended matter concentration is less than 500 mg / L, and the chemical oxygen demand is less than 1500 mg / L.

[0008] Preferably, the modified carbon material of the catalyst is selected from activated carbon, graphite or a composite material thereof, the material of the metal nanoparticles is silver, gold or nickel, the mass ratio of the modified carbon material to the metal ions is 10:1, and the catalyst dosage range is 0.1-5 g / L.

[0009] Preferably, the photocatalysis utilizes ultraviolet light with a wavelength of 254 nm to excite the catalyst to produce highly active free radicals, which oxidize and decompose organic pollutants in the wastewater. The electrocatalysis applies a voltage of 2-10 V to the electrode, and electrolysis produces oxidizing species to further degrade difficult-to-degrade pollutants. The reaction temperature of the catalytic reaction is 30-80°C, the reaction time is 30-120 minutes, and the pH range of the mixed reaction is 3.0-9.0.

[0010] Preferably, the addition ratio of the carbon source, nitrogen source and phosphorus source in the culture medium is: the carbon source accounts for 1%-2% of the total culture medium mass, the nitrogen source accounts for 0.05%-0.5%, and the phosphorus source accounts for 0.01%-0.1%. The culture temperature is 25-40°C, the dissolved oxygen concentration is 0.5-5 mg / L, and the reaction time is 24-48 hours.

[0011] Preferably, the real-time monitoring equipment is a pH meter, a turbidity meter, a dissolved oxygen sensor and a COD monitor.

[0012] Preferably, the method for disinfecting the treated sewage is selected from chlorination or ultraviolet disinfection.

[0013] Preferably, the sludge is treated by sedimentation or anaerobic digestion to recover the usable by-products produced.

[0014] Preferably, the microbial population is facultative anaerobic bacteria, and the facultative anaerobic bacteria is Paracoccus denitrificans of the genus Paracoccus.

[0015] The present invention provides a zero-discharge collaborative purification method for thermal power desulfurization wastewater. It has the following beneficial effects: The present invention achieves efficient degradation of organic pollutants in thermal power desulfurization wastewater through the innovative combination of modified activated carbon and metal nanocatalysts. This combination not only increases the reaction rate but also promotes the thorough decomposition of pollutants, thereby significantly reducing the COD and suspended matter concentrations of the wastewater, providing an effective solution for improving water quality. By optimizing the types and combinations of catalysts, the present invention can generate a large number of active oxygen species. These active species show excellent ability in oxidative degradation of organic pollutants. This efficient catalytic property ensures the removal of complex mercury pollutants, further improves the effect of wastewater treatment, and demonstrates the important application potential of this method in environmental governance. Based on in-depth research on the catalytic reaction mechanism, the present invention effectively reduces the energy consumption required by traditional water treatment methods. Compared with conventional treatment methods, the invention achieves the goal of obtaining higher treatment efficiency at lower energy consumption by precisely controlling the reaction conditions and catalyst properties, thereby promoting the sustainable development of the environmental protection economy. This invention demonstrates a high degree of synergy between catalyst selection and integrated application strategies, emphasizing the flexibility of catalytic system design. This method can be customized according to the needs of different water qualities and pollution categories, has strong adaptability, and provides new ideas for subsequent treatment of various types of wastewater. This invention provides an effective path for achieving water resource reuse and resource recovery. By degrading organic matter in wastewater, it not only improves water quality but also lays a good foundation for resource development and utilization. This innovative method highlights the dual advantages in environmental protection and resource recycling and has important social value. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 Schematic diagram of the method of the present invention. DETAILED DESCRIPTION

[0017] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the drawings in the present specification. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention. Example

[0018] Please see the attached Figure 1The embodiment of the present invention provides a zero-discharge collaborative purification method for thermal power desulfurization wastewater, comprising: 1. Preprocessing Steps Thermal power desulfurization wastewater first enters a sedimentation tank, where it sits for 45 minutes to remove large impurities by gravity. It is then filtered through a 35μm polyethylene filter membrane to further remove suspended particles.

[0019] 2. Catalytic reaction treatment Catalyst composition: modified activated carbon and metal nanosilver particles, mass ratio is 10:1; dosage is 2.5g / L.

[0020] Photocatalytic conditions: UV light with a wavelength of 254 nm and a light intensity of 350 μW / cm 2 .

[0021] Electrocatalytic conditions: The voltage was set at 6 V, and the electrode used carbon cloth material.

[0022] Reaction conditions: temperature 55°C, pH controlled at 6.0, reaction time 90 minutes.

[0023] 3. Microbial Enhanced Treatment Culture medium composition: carbon source is 1.5% of the total mass of the culture medium, nitrogen source is 0.25%, and phosphorus source is 0.05%.

[0024] Reaction conditions: temperature 32°C, dissolved oxygen 2.5 mg / L, treatment time 36 hours.

[0025] Microorganism: Inoculation with Paracoccus denitrificans.

[0026] 4. Real-time monitoring and dynamic adjustment pH meters, dissolved oxygen sensors and COD monitors are used to monitor key system parameters online, and the control system automatically adjusts the catalyst addition frequency and ventilation volume based on data feedback.

[0027] 5. Sludge and clean water treatment Sludge treatment: anaerobic digestion process is adopted.

[0028] Disinfection method: Use ultraviolet radiation for disinfection, and the treated wastewater is reused in the factory's cooling system. Example

[0029] 1. Preprocessing Steps The sedimentation time was 30 minutes, and filtration was performed using a ceramic filter plate with a precision of 20 μm.

[0030] 2. Catalytic reaction treatment Catalyst composition: modified graphite and nano-gold particles, mass ratio of 10:1, dosage of 0.1 g / L.

[0031] Photocatalytic conditions: UV lamp wavelength 254nm, light intensity 200μW / cm 2 .

[0032] Electrocatalytic conditions: The voltage was set at 2V.

[0033] Reaction conditions: temperature 30°C, pH 3.0, time 30 minutes.

[0034] 3. Microbial Enhanced Treatment Culture medium composition: carbon source 1%, nitrogen source 0.05%, phosphorus source 0.01%.

[0035] Reaction conditions: temperature 25°C, dissolved oxygen 0.5 mg / L, reaction time 24 hours.

[0036] Microorganisms: Inoculation with facultative anaerobic bacterium Paracoccus denitrificans.

[0037] 4. Monitoring and Adjustment Monitor COD and dissolved oxygen changes. When COD exceeds the initial value by 10%, the system automatically increases the catalyst dosage by 10%.

[0038] 5. Sludge and clean water treatment Sludge treatment: Sedimentation separation is adopted.

[0039] Disinfection method: Chlorination treatment is used, and the residual chlorine is controlled within the reuse standard range. Example

[0040] 1. Preprocessing Steps The precipitation time was 60 minutes, and the solution was filtered using a 50 μm polyethylene filter membrane.

[0041] 2. Catalytic reaction treatment Catalyst composition: composite carbon material and nano-nickel particles, mass ratio is 10:1, dosage is 5g / L.

[0042] Photocatalytic conditions: UV lamp wavelength 254nm, light intensity 500μW / cm 2 .

[0043] Electrocatalytic conditions: voltage 10V.

[0044] Reaction conditions: temperature 80°C, pH 9.0, reaction time 120 minutes.

[0045] 3. Microbial Enhanced Treatment Culture medium composition: carbon source 2%, nitrogen source 0.5%, phosphorus source 0.1%.

[0046] Reaction conditions: temperature 40°C, dissolved oxygen 5 mg / L, reaction time 48 hours.

[0047] Microorganisms: Inoculate with highly active denitrifying bacteria Paracoccus.

[0048] 4. Monitoring and Adjustment The system automatically samples every 10 minutes and adjusts the stirring speed and oxygen supply to the microorganisms through feedback to ensure that the reaction proceeds efficiently and continuously.

[0049] 5. Sludge and clean water treatment Sludge treatment: anaerobic digestion combined with biogas recovery and utilization.

[0050] Disinfection method: After ultraviolet irradiation, the wastewater enters the reuse water pool and is used for the boiler water replenishment system.

[0051] Comparative Example 1: Compared with Example 1, the difference is that the precipitation time in the pretreatment step is reduced to 30 minutes, and a ceramic filter plate with a precision of 20 μm is used for filtration.

[0052] Comparative Example 2: Compared with Example 1, the difference is that the mass ratio of the modified activated carbon and the metal nanosilver particles in the catalytic reaction treatment is adjusted to 5:1, the dosage is reduced to 1g / L, the wavelength of the ultraviolet lamp in the photocatalytic conditions is 254nm, and the light intensity is reduced to 250μW / cm 2 , the voltage was reduced to 4 V under electrocatalytic conditions.

[0053] Comparative Example 3: Compared with Example 1, the difference is that the carbon source in the culture medium of the microbial enhancement treatment is reduced to 1%, the nitrogen source is reduced to 0.1%, and the phosphorus source is reduced to 0.02%.

[0054] Comparative Example 4: Compared with Example 1, the differences are: physical precipitation is used instead of anaerobic digestion for sludge treatment, chlorination is used as the disinfection method, residual chlorine is controlled at a low level, and ultraviolet disinfection is not used.

[0055] Experiment 1: Purpose of the experiment: Evaluate the effects of pretreatment time and filtration accuracy on COD removal rate and suspended solids removal rate of thermal power desulfurization wastewater.

[0056] Experimental steps: Sample preparation: A certain amount of thermal power desulfurization wastewater was collected to ensure that its initial properties were uniform at the beginning of the experiment (for example, the initial COD concentration was about 800 mg / L and the suspended solids concentration was about 450 mg / L).

[0057] Preprocessing stage: Example 1: Wastewater was introduced into a sedimentation tank, allowed to stand for 45 minutes, and then filtered using a polyethylene filter membrane with a precision of 35 μm.

[0058] Comparative Example 1: The wastewater was introduced into a sedimentation tank, allowed to stand for 30 minutes, and then filtered using a ceramic filter plate with a precision of 20 μm.

[0059] Catalytic reaction stage: The treated wastewater (Example 1 and Comparative Example 1) was added to the catalytic reaction device respectively.

[0060] Adding catalyst: Example 1: Modified activated carbon and metal nanosilver particles were added in a mass ratio of 10:1 and an addition amount of 2.5 g / L.

[0061] Comparative Example 1: modified activated carbon and metal nanosilver particles were added in a mass ratio of 10:1 and an addition amount of 2.5 g / L.

[0062] The reaction conditions were set (temperature 55°C, pH 6.0) and the reaction was carried out under these conditions for 90 minutes.

[0063] Microbial enhancement treatment stage: The catalytic wastewater was inoculated with Paracoccus denitrificans, and the culture conditions were controlled (temperature 32°C, dissolved oxygen 2.5 mg / L), and the reaction time was 36 hours.

[0064] Collection and testing: After each major processing step, samples were collected for analysis: COD determination: COD concentration was determined using colorimetry; Determination of suspended matter: Determined by filtration and then drying and weighing.

[0065] Record water sample data after each treatment to evaluate the removal effect.

[0066] Data recording and analysis: Record the treated wastewater data in the experimental record sheet for subsequent analysis and comparison.

[0067] Table 1: Comparison of experimental data between Example 1 and Comparative Example 1 Summary: By comparing Example 1 with Comparative Example 1, this experiment deeply explored the effects of pretreatment time and filtration accuracy on the removal rate of COD and suspended solids during the treatment of thermal power desulfurization wastewater, and further revealed the key mechanisms in the wastewater purification process. In the pretreatment stage, Example 1 adopted a longer sedimentation time and a moderately accurate filtration method to effectively remove large particle impurities in the wastewater, reducing the burden of the subsequent treatment stage, which created favorable conditions for the smooth progress of the catalytic reaction. In contrast, the shortened pretreatment time and improved filtration accuracy of Comparative Example 1 caused some unprecipitated suspended solids to be carried into the catalytic stage, affecting the activity of the catalyst and the adequacy of the reaction, resulting in a reduction in the purification effect.

[0068] In the catalytic reaction stage, we observed by comparison that the COD removal rate of Example 1 was significantly higher than that of Comparative Example 1, and this phenomenon can be attributed to the multiple synergistic effects in the catalytic process. In Example 1, a combination of modified activated carbon and metal nanosilver particles was used, which fully demonstrated the synergistic effects of heterogeneous catalysis, photocatalysis and electrocatalysis. This multiple catalytic mechanism can effectively decompose complex organic pollutants in wastewater and promote the smooth progress of redox reactions. In Comparative Example 1, since the amount of catalyst was not adjusted and the incidental suspended matter during the reaction was not effectively removed, the catalytic efficiency decreased, reaction poisoning or reactant competition occurred, thereby reducing the COD removal efficiency.

[0069] Finally, in the microbial enhanced treatment stage, Example 1 promoted the in-depth metabolism of microorganisms and the degradation of pollutants through a higher initial concentration and suitable culture conditions. This efficient microbial degradation mechanism enables the wastewater after catalytic treatment to continue to be efficiently purified at this stage, significantly reducing the concentration of final pollutants. Although Comparative Example 1 maintained the same microbial inoculation, due to insufficient early treatment effect, the concentration of pollutants entering the microbial treatment stage was higher, which significantly affected the degradation efficiency of microorganisms. Therefore, through the comparative analysis of this experiment, it is fully verified that the innovative design of integrating multiple treatment technologies proposed by the present invention is important in improving the purification efficiency of thermal power desulfurization wastewater, as well as the decisive influence of the coordination between each unit on improving the overall treatment effect.

[0070] Experiment 2: Purpose of the experiment: Evaluate the effects of catalyst dosage, photocatalytic intensity and electrocatalytic voltage on COD removal rate and reaction time of thermal power desulfurization wastewater.

[0071] Experimental steps: Sample preparation: Collect thermal power desulfurization wastewater samples with the same initial properties to ensure that the COD concentration is approximately 800 mg / L and the suspended solids concentration is approximately 450 mg / L.

[0072] Preprocessing stage: The wastewater was pretreated using the same method as in Example 1 (filtration after 45 minutes of sedimentation) to ensure consistency of comparison.

[0073] Catalytic reaction stage: The pretreated wastewater is transferred to the reaction tank for catalytic treatment: Example 1: Add modified activated carbon and metal nanosilver particles according to the set conditions, with a mass ratio of 10:1 and an addition amount of 2.5g / L. Photocatalysis uses a light intensity of 350μW / cm ² , electrical intake was set at 6 V and the temperature was controlled at 55 °C (for 90 min).

[0074] Comparative Example 2: Using the same catalyst type, the mass ratio was adjusted to 10:1, and the dosage was reduced to 1g / L. The light intensity was reduced to 250μW / cm 2 , the voltage was reduced to 4 V and the temperature was controlled at 40 °C (for 120 minutes).

[0075] Microbial enhancement treatment stage: After the catalytic treatment, the wastewater was inoculated with Paracoccus denitrificans to maintain constant microbial culture conditions (temperature 32 °C, dissolved oxygen 2.5 mg / L), and the reaction time was set to 48 h and 48 h, respectively.

[0076] Sample collection and testing: After the catalytic reaction was completed, wastewater samples were collected every 30 minutes for analysis to detect COD and suspended solids concentrations.

[0077] The COD removal rate and suspended solids removal rate after each treatment step were recorded, and the overall removal effect of the reaction was calculated.

[0078] Data recording and analysis: Various data were recorded, organized, and prepared for subsequent analysis to evaluate the impact of each treatment condition.

[0079] Table 2: Comparison of experimental data between Example 1 and Comparative Example 2 Summary: Through the comparative experiment of Example 1 and Comparative Example 2, the key influences of the dosage of a single catalyst, the photocatalytic intensity and the electrocatalytic voltage on the wastewater treatment process can be clearly revealed. The experimental results show that in Example 1, the dosage of the catalyst is 2.5g / L, which maintains a high catalytic activity and makes the redox reaction in the entire reaction system more sufficient. A larger amount of catalyst can increase the reaction interface and promote the contact between organic pollutants and the catalyst, thereby significantly improving the removal rate of difficult-to-degrade components. At the same time, the setting of light intensity and voltage under the conditions of Example 1 also optimizes the reaction environment, so that the catalytic reaction rate can be improved, and the removal efficiency of COD in sewage treatment is improved.

[0080] In Comparative Example 2, although the mass ratio of the catalysts was the same, the efficiency of the catalytic reaction decreased significantly after the dosage was reduced to 1 g / L. At this time, the electrocatalytic voltage was reduced to 4 V, and the light intensity was also reduced to 250 μW / cm 2 , which reduced the generation of reactive oxygen species within the system, directly limiting the rate and extent of pollutant degradation. The changes in reaction conditions resulted in a less-than-ideal reaction pathway, preventing some pollutants from being effectively degraded. This resulted in a final COD removal rate of only 45%, far lower than the treatment achieved in Example 1.

[0081] In addition, in the microbial enhanced treatment stage, due to the catalytic process, the COD concentration of Example 1 was reduced to 300 mg / L, and the residual suspended matter concentration was also relatively low, providing a good environment for the further degradation of microorganisms. However, Comparative Example 2, due to its higher initial COD and suspended matter concentration, reduced the degradation efficiency of microorganisms, triggered large-scale competition, and suppressed the activity of microorganisms. This phenomenon further emphasized the coordination and mutual influence between the various treatment steps in the method of the present invention, and showed that the combined strategy of photocatalysis, electrocatalysis and biological treatment can significantly improve the overall effect and efficiency of wastewater treatment, and effectively realize the recovery of resources and the protection of the environment.

[0082] Experiment 3: Purpose of the experiment: Evaluate the effect of microbial culture medium composition on the removal of pollutants from thermal power desulfurization wastewater.

[0083] Experimental steps: Sample preparation: Collect thermal power desulfurization wastewater samples with the same initial properties to ensure that the COD concentration is approximately 800 mg / L and the suspended solids concentration is approximately 450 mg / L to ensure consistency of comparison.

[0084] Preprocessing stage: The wastewater was pretreated using the same sedimentation and filtration methods as in Example 1 to ensure similar wastewater quality entering the microbial treatment stage.

[0085] Catalytic treatment stage: After the pretreatment, the wastewater was sent to the catalytic reaction device for catalytic treatment, using the conditions in Example 1 (modified activated carbon and metal nanosilver particles, dosage 2.5g / L, photocatalytic intensity 350μW / cm 2 , electrocatalytic voltage 6 V, reaction temperature 55 °C, maintained for 90 minutes).

[0086] Microbial enhancement treatment stage: After the catalytic treatment is completed, different microbial culture media are used for microbial enhancement treatment: Example 1: Standard culture medium (containing 1% glucose, 0.2% nitrogen source, and 0.05% phosphorus source) was added, the culture conditions were set to a temperature of 32°C, dissolved oxygen maintained at 2.5 mg / L, and the reaction time was 36 hours.

[0087] Comparative Example 3: A culture medium with a lower concentration (containing 0.5% glucose, 0.1% nitrogen source, and 0.02% phosphorus source) was used, the temperature was also controlled at 32°C, the dissolved oxygen was maintained at 2.5 mg / L, and the reaction time was 36 hours.

[0088] Sample collection and testing: After the microbial enhancement treatment, samples were collected for analysis: The COD and ammonia nitrogen concentrations were measured at each treatment stage.

[0089] Record the effects of microbial treatment and compare the effects of different culture media on the treatment effects.

[0090] Data recording and analysis: Record the changes in COD and ammonia nitrogen in different time periods and organize the data for subsequent analysis.

[0091] Table 3: Comparison of experimental data between Example 1 and Comparative Example 3 Summary: The comparative analysis of Example 1 and Comparative Example 2 in Experiment 2 reveals the importance of catalyst dosage, photocatalytic intensity and electrocatalytic voltage in the treatment of thermal power desulfurization wastewater. In Example 1, a higher catalyst dosage and optimized light and voltage conditions were adopted to ensure the generation of effective active species in the reaction system. Under such conditions, the catalyst surface not only provides abundant reaction sites, but also enhances the synergistic effect of photocatalysis and electrocatalysis, thereby achieving faster and more comprehensive degradation of pollutants. The synergistic effect of light and electric field enhances the activation of reactants, so that organic matter that is difficult to degrade can be converted into harmless substances through redox reactions, greatly improving the removal efficiency of COD and suspended solids.

[0092] In contrast, the amount of catalyst added and the reaction conditions in Comparative Example 2 are reduced, resulting in a significant reduction in its effectiveness in the reaction. Reducing the amount of catalyst used reduces the reaction interface, thereby reducing the frequency of contact between the catalyst and the pollutant. In the photocatalytic reaction, the reduction in light intensity reduces the number of effective photons, so the generated active oxygen species are significantly insufficient, failing to effectively promote the decomposition of organic matter. In addition, the reduction in electrocatalytic voltage weakens the electrode reaction activity, reduces the efficiency of directional electron transfer, and thus leads to a decrease in the conversion rate of the reactants. These changes are ultimately reflected in the overall effect of COD removal. The removal effect of Comparative Example 2 in this case is much lower than that of Example 1, showing the complexity of the interaction between various parameters in process design and the importance of synergistic effects.

[0093] In the microbial enhanced treatment stage, Example 1 is obviously more conducive to the activity and growth of microorganisms. The lower COD and suspended matter concentrations provide a good environment for the metabolism of microorganisms, enabling them to quickly and effectively decompose the remaining pollutants, thereby achieving almost 100% removal of ammonia nitrogen. This phenomenon shows that each link in the overall reaction system design, especially the properties of the products after catalytic treatment, directly affects the efficiency of the microbial process. It can be seen that the innovative method of comprehensive utilization of light, electrocatalysis and microbial treatment not only improves the treatment effect of thermal power desulfurization wastewater, but also provides new ideas in resource utilization and regeneration, reflecting the application potential of the present invention in the field of environmental governance.

[0094] Experiment 4: Purpose of the experiment: Evaluate the removal efficiency of different catalysts (such as nickel-based catalysts, iron-based catalysts and copper-based catalysts) in the treatment of thermal power desulfurization wastewater.

[0095] Experimental steps: Sample preparation: A sample of thermal power desulfurization wastewater was collected from the same source, ensuring that its initial COD concentration was maintained at 800 mg / L and the suspended solids concentration was maintained at 450 mg / L. This sample was used for treatment experiments with different catalysts.

[0096] Preprocessing stage: The collected wastewater was pretreated by using a sedimentation method and allowed to stand for 45 minutes, and then filtered through a 35 μm grade filter to remove large particle impurities.

[0097] Catalytic treatment stage: The pre-treated wastewater was divided into four groups and catalytically treated using different types of catalysts. The dosage of each catalyst was 2.5g / L. The catalytic treatment process was as follows: Example 1 (Modified activated carbon and metal nanosilver catalyst): Light intensity was set to 350 μW / cm 2 , the electrocatalytic voltage was set to 6 V, the reaction temperature was controlled at 55 °C, and maintained for 90 min.

[0098] Control group 1 (nickel-based catalyst): light intensity was set to 300 μW / cm 2 , the voltage was set to 5 V, the temperature was maintained at 50 °C, and the reaction time was 90 min.

[0099] Control group 2 (iron-based catalyst): light intensity was set at 320 μW / cm 2 , the voltage was set to 4 V, the temperature was controlled at 45 °C, and the reaction time was 90 min.

[0100] Control group 3 (copper-based catalyst): light intensity was set to 330 μW / cm 2 , the voltage was set to 5.5 V, the temperature was maintained at 48 °C, and the reaction time was 90 min.

[0101] Sample collection and testing: After the catalytic treatment, samples were collected from each group, COD and suspended solids were measured, and the data were recorded for comparative analysis.

[0102] Data recording and analysis: Record the verification and performance data of each treatment step and organize the results by time period to facilitate subsequent analysis of the impact of each catalyst on the sewage treatment effect.

[0103] Table 4: Data comparison of the treatment effects of different catalysts on thermal power desulfurization wastewater Summary: The comparative results of Experiment 4 clearly demonstrate the performance differences between different catalyst types in treating thermal power desulfurization wastewater. This phenomenon stems from the catalyst surface properties and their influence on the reaction mechanism. The combination of modified activated carbon and metallic nanosilver exhibited the best catalytic effect, primarily due to the catalyst's ability to be excited across a wide spectral range, generating a large number of reactive oxygen species. These reactive oxygen species effectively carry out advanced oxidation reactions when degrading organic pollutants, significantly improving the removal efficiency of difficult-to-degrade organic matter. In contrast, while other types of catalysts (such as nickel-, iron-, and copper-based catalysts) can also exert a certain catalytic effect under certain conditions, their lower catalytic activity results in insufficient generation of reactive species, failing to effectively promote pollutant degradation.

[0104] Although the nickel-based catalyst showed an acceptable COD removal rate in the experiment, it was still lower than the combination of modified activated carbon and nanosilver. This can be attributed to the fact that the nickel-based catalyst has better conductivity than some other metals, but its ability to generate active species is weak and cannot be fully utilized under specific reaction conditions. This means that the application conditions of the catalyst need to be further optimized to adapt to redox reactions in complex wastewater environments. In addition, the relatively large particle size of iron-based and copper-based catalysts leads to a small specific surface area, which reduces the catalytic efficiency. This further proves the important influence of the surface properties of the catalyst on the reaction process.

[0105] The results of this experiment emphasize the importance of catalyst selection, especially in achieving effective water treatment, where the combination of activity and selectivity is the key to improving removal efficiency. The synergistic application of modified activated carbon and metal nanosilver not only improves the degradation effect of organic pollutants, but also effectively shortens the reaction time. This discovery provides a practical reference for innovative methods of comprehensive utilization of photocatalysis, electrocatalysis and chemical catalysis, demonstrates the huge potential of the synergistic effect of multiple catalytic technologies, and further promotes the development of more efficient and sustainable wastewater treatment technologies. By combining the characteristics of different catalysts, we can continue to explore the optimal catalyst combination to achieve more efficient water resource recovery and environmental protection in industrial applications.

[0106] The device of this embodiment can be used to execute the above method embodiment, and its principles and technical effects are similar, so they will not be repeated here.

[0107] While embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions, and variations may be made to these embodiments without departing from the principles and spirit of the invention, and that the scope of the invention is defined by the appended claims and their equivalents.

Claims

1. A zero-discharge collaborative purification method for thermal power desulfurization wastewater, characterized in that: The following steps are involved: Pre-treat desulfurization wastewater by removing larger particles and suspended solids through preliminary sedimentation and filtration; The pretreated wastewater is subjected to multiple catalytic reactions, using modified carbon materials and metal nanoparticles as catalysts. In the multiple catalytic reactions, pollutants are removed through heterogeneous catalysis, photocatalysis, and electrocatalysis. The catalytically treated wastewater is introduced into the microbial enhanced treatment equipment and a specific microbial population is selected for cultivation; Real-time monitoring equipment is used to monitor the pH, dissolved oxygen, ammonia nitrogen and COD content during the reaction process, and the catalyst dosage and microbial culture conditions are dynamically adjusted based on the real-time data; The sludge and sewage generated by the microbial enhanced treatment equipment are collected and treated, and the treated sewage is disinfected and the resources are recycled.

2. The zero-discharge collaborative purification method for thermal power desulfurization wastewater according to claim 1, characterized in that: The preliminary sedimentation and filtration refers to introducing the thermal power desulfurization wastewater into a sedimentation tank and letting it stand for 30-60 minutes, using gravity to separate larger particles and suspended matter, and then performing physical filtration with an accuracy of 20-50μm through a polyethylene filter membrane or ceramic filter plate.

3. The zero-discharge collaborative purification method for thermal power desulfurization wastewater according to claim 1, characterized in that: The pH value of the desulfurization wastewater is between 6.0 and 8.5, the turbidity is less than 100 NTU, the suspended matter concentration is less than 500 mg / L, and the chemical oxygen demand is less than 1500 mg / L.

4. The zero-discharge collaborative purification method for thermal power desulfurization wastewater according to claim 1, characterized in that: The modified carbon material of the catalyst is selected from activated carbon, graphite or a composite material thereof, the material of the metal nanoparticles is silver, gold or nickel, the mass ratio of the modified carbon material to the metal ions is 10:1, and the catalyst dosage range is 0.1-5g / L.

5. The zero-discharge collaborative purification method for thermal power desulfurization wastewater according to claim 1, characterized in that: The photocatalysis uses ultraviolet light with a wavelength of 254nm to excite the catalyst to produce highly active free radicals, which oxidize and decompose organic pollutants in the wastewater. The electrocatalysis applies a voltage of 2-10V to the electrode, and electrolysis produces oxidizing species that further degrade difficult-to-degrade pollutants. The reaction temperature of the catalytic reaction is 30-80°C, the reaction time is 30-120 minutes, and the pH range of the mixed reaction is 3.0-9.

0.

6. The zero-discharge collaborative purification method for thermal power desulfurization wastewater according to claim 1, characterized in that: The addition ratio of the carbon source, nitrogen source and phosphorus source in the culture medium is: the carbon source accounts for 1%-2% of the total culture medium mass, the nitrogen source accounts for 0.05%-0.5%, and the phosphorus source accounts for 0.01%-0.1%. The culture temperature is 25-40°C, the dissolved oxygen concentration is 0.5-5 mg / L, and the reaction time is 24-48 hours.

7. The zero-discharge collaborative purification method for thermal power desulfurization wastewater according to claim 1, characterized in that: The real-time monitoring equipment includes a pH meter, a turbidity meter, a dissolved oxygen sensor and a COD monitor.

8. The zero-discharge collaborative purification method for thermal power desulfurization wastewater according to claim 1, characterized in that: The method for disinfecting the treated sewage is selected from chlorination or ultraviolet disinfection.

9. The zero-discharge collaborative purification method for thermal power desulfurization wastewater according to claim 1, characterized in that: The sludge is treated by sedimentation or anaerobic digestion to recover the usable by-products produced.

10. The zero-discharge collaborative purification method for thermal power desulfurization wastewater according to claim 1, characterized in that: The microbial population is facultative anaerobic bacteria, and the facultative anaerobic bacteria is Paracoccus denitrifying bacteria of the genus Paracoccus.

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