Coagulating precipitation and electro-catalysis combined landfill leachate concentrated solution coupling hydrogen energy production process

Abstract

The invention discloses a process for coupling hydrogen energy production by treating landfill leachate concentrate through combination of coagulating sedimentation and electro-catalysis, and belongs to the technical field of landfill leachate treatment.The process comprises the following steps that S1, the landfill leachate concentrate is mixed with a coagulant; s2, adding an alkaline solution into the prepared liquid medium; s3, adding a flocculating agent into the prepared liquid medium, fully mixing the liquid medium with the flocculating agent, precipitating, and staying and buffering supernate obtained by precipitation; s4, feeding the liquid medium after staying and buffering in the step S3 into an electro-catalysis tank containing a titanium-based catalyst, and reacting with strong oxidizing hydroxyl free radicals formed by electro-catalysis; and S5, the liquid medium subjected to electro-catalysis treatment is fed into an electrolytic bath containing a nickel-based catalyst, and hydrogen is generated through electrolytic treatment. According to the invention, the standard treatment of the landfill leachate concentrated solution can be realized, the hard bone problem that the concentrated solution is difficult to treat in the landfill leachate treatment industry is solved, and high-value green hydrogen energy can be generated from household garbage.

Description

Technical Field

[0001] This invention belongs to the field of landfill leachate treatment technology, specifically, it relates to a process for coagulation and sedimentation combined with electrocatalytic treatment of landfill leachate concentrate coupled with hydrogen production. Background Technology

[0002] Landfill leachate is the liquid substance leached from municipal solid waste. It is a highly concentrated organic wastewater with an extremely complex composition and a very high pollution load; its ability to meet treatment standards directly impacts environmental safety. In leachate treatment processes, biological methods alone are insufficient to meet discharge standards; nanofiltration or reverse osmosis membrane separation technologies are required for advanced treatment, producing clear, compliant treated water. However, while membrane methods achieve pollutant retention and water separation, they inevitably concentrate and enrich most of the dissolved salts, recalcitrant organic matter, and heavy metals in the leachate, forming what is known as "concentrated liquid." This concentrated liquid typically accounts for 25% to 35% of the total leachate treated, meaning that for every 100 tons of leachate treated, 25 to 35 tons of even more problematic concentrated liquid with higher pollutant concentrations are generated.

[0003] The concentrated leachate has extremely poor water quality characteristics, with very high concentrations of recalcitrant organic pollutants and enriched with almost all the salts from the landfill leachate, especially chloride ion (Cl⁻) concentrations reaching tens of thousands of milligrams per liter. This concentrated leachate, with its high concentration of recalcitrant organic matter, high salinity, and high chloride ion content, has extremely poor biodegradability and cannot be treated using biological methods. Faced with this industry-recognized problem, various treatment methods have been explored and applied, but all face significant technical bottlenecks and economic challenges. One method, evaporation (such as MVC and MVR), uses thermal evaporation to achieve salt crystallization, theoretically achieving volume reduction and solidification. However, in actual operation, problems such as equipment coking and clogging severely affect the stable operation of the system. Furthermore, it involves huge equipment investment, extremely high energy consumption, and high operating costs. Secondly, advanced oxidation methods (such as ozone catalytic oxidation and Fenton oxidation) aim to break down the structure of recalcitrant organic matter and improve its biodegradability through strong oxidizing free radicals. However, for concentrates with high concentrations of chloride ions, the oxidation process generates byproducts, and the presence of chloride ions severely quenches the oxidant, significantly reducing oxidation efficiency, leading to a surge in reagent consumption, high treatment costs, and unstable results. Furthermore, traditional methods of refluxing concentrates to landfills or transporting them to municipal wastewater treatment plants for dilution are essentially just the transfer and dilution of pollutants. These methods not only pose environmental risks but are also becoming increasingly less feasible given today's increasingly stringent environmental policies.

[0004] In summary, landfill leachate concentrate, characterized by its large volume, complex composition, high concentration of recalcitrant organic matter, high salinity and chloride ion content, and extremely poor biodegradability, has become a "last mile" problem that existing treatment technologies struggle to completely overcome. Current mainstream technologies all face a sharp contradiction between technological stability, treatment efficiency, and operating costs, making it the most expensive, technically challenging, and troublesome link in the entire landfill leachate treatment chain. Therefore, developing efficient, stable, and economically feasible concentrate treatment technologies has become an urgent need and a key breakthrough for achieving the goals of true "reduction, harmlessness, and resource recovery" in the landfill leachate treatment industry.

[0005] On the other hand, my country is currently actively building a clean, low-carbon, safe, and efficient energy system, and supporting the exploration of diversified industrial development paths for hydrogen energy, supporting the development of the entire hydrogen energy chain from production, storage, transmission, and utilization. Against this strategic backdrop, green hydrogen—hydrogen produced through renewable energy or environmentally friendly processes—has become a key direction for hydrogen energy development due to its zero-carbon emission advantage. Among the various technological routes for green hydrogen production, producing hydrogen energy from municipal solid waste is a highly promising development direction, enabling the integration of waste treatment with green energy production. The core advantage of waste-to-hydrogen production lies in achieving high-value resource and energy conversion from waste. The industry still needs to tackle the technological challenges of efficiently converting municipal solid waste into high-value hydrogen energy, while simultaneously achieving a win-win situation for both environmental and economic benefits. On the one hand, it enables efficient waste conversion and clean utilization. On the other hand, this technical route demonstrates significant economic and environmental value, reducing carbon dioxide emissions by approximately 0.5 tons per ton of waste, forming a green economic model of "waste treatment + green energy production + carbon emission reduction". Exploring waste-to-hydrogen technology can transform the "burden" of urban governance into a "treasure" for energy transformation, providing innovative solutions for my country's "zero-waste city" construction and energy revolution. Summary of the Invention

[0006] The purpose of this invention is to provide a process for coagulation and sedimentation combined with electrocatalytic treatment of landfill leachate concentrate and coupled with hydrogen production. This process not only achieves the standard treatment of landfill leachate concentrate, solving the difficult problem of concentrate treatment in the landfill leachate treatment industry, but also realizes the generation of high-value green hydrogen energy from municipal solid waste. It has the dual functions of "decontamination" and "hydrogen production", achieving a win-win situation for both environmental and economic benefits.

[0007] To achieve the objective of this invention, the technical solution adopted is: a process for coagulation and sedimentation combined with electrocatalytic treatment of landfill leachate concentrate coupled with hydrogen production, comprising the following steps: S1. Mix the concentrated leachate with the coagulant and adjust the pH of the concentrated leachate to 3.8-4.2; S2. Add an alkaline solution to the liquid medium after the coagulation reaction in step S1 to adjust the pH value of the liquid medium to 6.8-7.2. S3. Add flocculant to the liquid medium after the neutralization reaction in step S2, and precipitate it after the liquid medium and flocculant are fully mixed. Let the supernatant obtained from the precipitation remain in the buffer for 10 to 15 hours. S4. The liquid medium after being held and buffered in step S3 is fed into an electrocatalytic cell containing a titanium-based catalyst, and reacts with the strongly oxidizing hydroxyl radicals formed by electrocatalysis. S5. The liquid medium after electrocatalytic treatment is fed into an electrolytic cell containing a nickel-based catalyst, and hydrogen is generated through electrolysis.

[0008] Furthermore, the coagulant in step S1 is a ferric chloride solution, and the ratio of the concentrate to the coagulant is 75-85:1.

[0009] Furthermore, the alkaline solution in step S2 is a sodium hydroxide solution, and the liquid medium obtained after the coagulation reaction in step S1 is mixed with the alkaline solution and left to stand for 2 to 5 minutes.

[0010] Furthermore, the flocculant in step S3 is a 0.15% polyacrylamide solution, and the ratio of liquid medium to flocculant is 240-260:1.

[0011] Furthermore, the current density during electrocatalytic treatment in step S4 is 45–55 mA / cm², and the current during electrolysis treatment in step S5 is 950–1050 mA / cm².

[0012] Furthermore, the system for implementing the above process includes a coagulation tank, a neutralization tank, a flocculation tank, a sedimentation tank, a filter, a buffer tank, an electrocatalytic cell, an electrolytic hydrogen production tank, a hydrogen collection device, a gas-liquid separator, a drying tower, a mechanical compressor, a cooler, and a high-pressure gaseous hydrogen storage tank connected in sequence, and the coagulation tank, neutralization tank, flocculation tank, sedimentation tank, and filter are connected by gravity overflow.

[0013] Furthermore, the height difference between the overflow ports of two adjacent tanks in the coagulation tank, neutralization tank, flocculation tank, and sedimentation tank is 4cm to 6cm.

[0014] Furthermore, agitators are installed in the coagulation tank, neutralization tank, and flocculation tank.

[0015] Furthermore, the filter is a multi-media filter.

[0016] The beneficial effects of this invention are: 1. In this invention, the concentrated leachate is transported between the coagulation tank, neutralization tank, flocculation tank, and sedimentation tank using a method of elevation difference + gravity overflow, which saves operating energy consumption.

[0017] 2. In this invention, the concentrated leachate is pretreated using a process of "coagulation + flocculation + sedimentation + filtration" before entering the electrocatalytic tank. This pretreatment removes over 70% of the large-molecule recalcitrant organic matter and over 35% of the total nitrogen from the concentrated leachate. This significantly reduces the load on the subsequent electrocatalytic reaction, greatly lowering operating costs. It also prevents the large-molecule recalcitrant organic matter from contaminating the electrode catalyst, thus extending its lifespan. The advantages after electrocatalytic treatment are significant: pollutants can be directly degraded by generating a strong oxidant in situ without the need for additional chemical oxidants. Furthermore, it effectively avoids the generation of toxic byproducts due to the high concentration of chloride ions in the concentrated leachate. Compared to evaporation methods for treating leachate concentrated leachate, this invention has lower energy consumption, eliminates the risk of equipment scaling, and is particularly resistant to high-salt and high-chlorine environments, achieving a good balance between treatment efficiency and operating costs.

[0018] 3. Since the concentrate of landfill leachate contains a high concentration of salt and has an electrical conductivity of up to tens of thousands of μs / cm, it has strong conductivity on its own without the need to add salt. In this invention, the conductivity of the concentrate can be fully utilized to carry out electrocatalytic and electrolytic reactions through electrocatalytic and electrolytic treatment, and the unit power consumption can be reduced.

[0019] 4. Since the concentrate of landfill leachate originates from municipal solid waste, this invention not only achieves compliant treatment of the concentrate, solving the difficult problem of concentrated leachate treatment in the landfill leachate treatment industry, but also generates high-value green hydrogen energy from municipal solid waste. It combines the dual functions of "decontamination" and "hydrogen production," perfectly aligning with my country's current strategy of vigorously developing hydrogen energy, and achieving a win-win situation for both environmental and economic benefits. On the one hand, it enables the efficient conversion and clean utilization of concentrate, which is essentially waste. On the other hand, it reduces carbon dioxide emissions by approximately 0.5 tons per ton of waste, forming a green economic model of "waste treatment + green energy production + carbon emission reduction," which perfectly aligns with the development concepts of "resource utilization, energy utilization, and low carbon emissions." Attached Figure Description

[0020] The accompanying drawings illustrate exemplary embodiments of the invention and, together with the description thereof, serve to explain the principles of the invention. These drawings are included to provide a further understanding of the invention and are incorporated in and constitute a part of this specification.

[0021] Figure 1 This is a flowchart of the coagulation and sedimentation combined with electrocatalytic treatment of landfill leachate concentrate coupled with hydrogen production system provided by the present invention.

[0022] The attached diagram shows the markings and corresponding component names: 1. Coagulation tank, 2. Neutralization tank, 3. Flocculation tank, 4. Sedimentation tank, 5. Filter, 6. Buffer tank, 7. Electrocatalytic tank, 8. Electrolytic hydrogen production tank, 9. Hydrogen collection device, 10. Gas-liquid separator, 11. Drying tower, 12. Mechanical compressor, 13. Cooler, 14. High-pressure gaseous hydrogen storage tank. Detailed Implementation

[0023] The present invention will now be described in further detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are for illustrative purposes only and are not intended to limit the scope of the invention. Furthermore, it should be noted that, for ease of description, only the parts relevant to the present invention are shown in the accompanying drawings.

[0024] It should be noted that, unless otherwise specified, the embodiments and features described in this invention can be combined with each other. The invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0025] like Figure 1 As shown, the present invention provides a process for coagulation and sedimentation combined with electrocatalytic treatment of landfill leachate concentrate coupled with hydrogen production, comprising the following steps: S1. The concentrated leachate is fed into coagulation tank 1, and a 30% concentration of ferric chloride solution is added to coagulation tank 1 as a coagulant. The ratio of coagulant to concentrate is 1:80. After the coagulant and concentrate are mixed, they are left to stand for 5 minutes. After the concentrate reacts with the coagulant, the pH value of the concentrate drops from 7 to 4. S2. The liquid medium after the coagulation reaction in step S1 is sent to neutralization tank 2, and sodium hydroxide solution is added to neutralization tank 2. After the liquid medium and sodium hydroxide solution are mixed and reacted, the pH value of the liquid medium is adjusted to 7. S3. The liquid medium after neutralization reaction in step S2 is fed into flocculation tank 3, and a 0.15% polyacrylamide solution is added to flocculation tank 3 as a flocculant. The ratio of flocculant to liquid medium is 1:250. After the liquid medium and flocculant are mixed and reacted, they remain in flocculation tank 3 for 30 minutes. Then, the liquid after the reaction of liquid medium and flocculant is fed into sedimentation tank 4 and left for 60 minutes to remove the flocculent particles generated in coagulation tank 1 and flocculation tank 3. The supernatant obtained after sedimentation in sedimentation tank 4 is sent to filter 5 for filtration to separate the residual fine particles and suspended solids in the supernatant. After filtration by filter 5, the supernatant is sent into buffer tank 6 and left in buffer tank 6 for 12 hours. S4. The buffered liquid medium in the buffer tank 6 is sent into the electrocatalytic tank 7. The current density of the electrocatalytic tank 7 is 50mA / cm². The electrocatalytic tank 7 contains a titanium-based catalyst. The liquid medium reacts with the strong oxidizing hydroxyl radicals formed by electrocatalysis for 4 hours to deeply oxidize and decompose the recalcitrant organic pollutants in the landfill leachate. S5. The liquid medium after electrocatalytic treatment in step S4 is sent into the electrolytic hydrogen production tank 8. The current density of the electrolytic hydrogen production tank 8 is 1000mA / cm². The electrolytic hydrogen production tank 8 contains a nickel-based catalyst. The liquid medium reacts in the electrolytic hydrogen production tank 8 for 2 hours. Hydrogen gas is generated at the cathode of the electrolytic hydrogen production tank 8. S6. The hydrogen obtained from electrolysis in the electrolysis hydrogen production tank 8 is sent to the hydrogen collection device 9, and then sequentially sent to the gas-liquid separator 10 and the drying tower 11 to remove moisture and particulate matter from the hydrogen. Then it is compressed by the mechanical compressor 12. After being compressed by the mechanical compressor 12, the hydrogen is cooled by the cooler 13 and then enters the high-pressure gaseous hydrogen storage tank 14 for storage.

[0026] Based on the above-mentioned coagulation and sedimentation combined with electrocatalytic treatment of landfill leachate concentrate coupled with hydrogen production process, such as Figure 1 As shown, the system for implementing the process includes a coagulation tank 1, a neutralization tank 2, a flocculation tank 3, a sedimentation tank 4, a filter 5, a buffer tank 6, an electrocatalytic tank 7, an electrolytic hydrogen production tank 8, a hydrogen collection device 9, a gas-liquid separator 10, a drying tower 11, a mechanical compressor 12, a cooler 13, and a high-pressure gaseous hydrogen storage tank 14.

[0027] The coagulation tank 1 is a square tank. It is used to store the leachate concentrate and coagulant for coagulation reaction. The coagulation tank 1 is equipped with a stirrer, which fully stirs the concentrate and coagulant in the coagulation tank 1 so that the concentrate and coagulant are fully mixed and reacted in the coagulation tank 1.

[0028] Neutralization tank 2 is a square tank and is connected to coagulation tank 1. The liquid medium obtained after the coagulation tank 1 has fully reacted is sent into neutralization tank 2. Neutralization tank 2 neutralizes the liquid medium and alkaline solution. Neutralization tank 2 is equipped with a stirrer to fully stir the liquid medium and alkaline solution in neutralization tank 2, so that the liquid medium and alkaline solution are fully mixed and reacted in neutralization tank 2.

[0029] The flocculation tank 3 is a square tank and is connected to the neutralization tank 2. The liquid medium obtained after the neutralization reaction in the neutralization tank 2 is sent into the flocculation tank 3. The flocculation tank 3 performs a flocculation reaction between the neutralized liquid medium and the flocculant. The flocculation tank 3 is equipped with a stirrer, which fully stirs the neutralized liquid medium and the flocculant, so that the neutralized liquid medium and the flocculant are fully mixed in the flocculation tank 3.

[0030] The sedimentation tank 4 is connected to the flocculation tank 3, so that the liquid medium obtained after being fully mixed in the flocculation tank 3 is sent into the sedimentation tank 4, and the liquid medium settles in the sedimentation tank 4, thereby removing the flocculent particles generated in the coagulation tank 1 and the flocculation tank 3.

[0031] Filter 5 is a multi-media filter. Filter 5 is connected to sedimentation tank 4. The supernatant in sedimentation tank 4 overflows into the multi-media filter. The multi-media filter filters and separates the fine particulate matter and suspended matter remaining in the supernatant.

[0032] The buffer tank 6 is connected to the filter 5 and is used to buffer the liquid medium obtained after coagulation-flocculation-sedimentation-filtration pretreatment, so as to keep the liquid medium after coagulation-flocculation-sedimentation-filtration pretreatment stable and uniform in load.

[0033] The electrocatalytic tank 7 is connected to the buffer tank 6. The liquid medium, after being buffered by the buffer tank 6, is uniformly and gradually transported to the electrocatalytic tank 7 to prevent drastic changes in the feed load of the electrolytic tank. The liquid medium enters the electrocatalytic tank containing the titanium-based catalyst and reacts with the strong oxidizing hydroxyl radicals formed by electrocatalysis to deeply oxidize and decompose the recalcitrant organic pollutants in the landfill leachate. After electrocatalytic treatment, the effluent can meet the requirements of the GB16889-2024 discharge standard.

[0034] The electrolytic hydrogen production tank 8 is connected to the electrocatalytic tank 7. The liquid medium that has undergone electrocatalytic treatment in the electrocatalytic tank 7 is sent into the electrolytic hydrogen production tank 8. The liquid medium that has undergone electrocatalytic treatment enters the electrolytic hydrogen production tank 8 containing a nickel-based catalyst and generates hydrogen through electrolysis.

[0035] The hydrogen collection device 9 is connected to the gas outlet of the electrolytic hydrogen production tank 8, so that the hydrogen produced by the cathode of the electrolytic hydrogen production tank 8 can be sent to the hydrogen collection device 9 for collection and storage.

[0036] The gas-liquid separator 10 removes moisture and particulate matter from the hydrogen produced by the hydrogen collection device 9. The drying tower 11 dries the hydrogen separated by the gas-liquid separator 10. The mechanical compressor 12 compresses the dried hydrogen after it has been processed by the drying tower 11. Since mechanical compression causes the hydrogen temperature to rise during the compression process, which affects the safety and filling efficiency of the subsequent high-pressure gaseous hydrogen storage tank 14, the hydrogen after passing through the mechanical compressor 12 is sent to the cooler 13 for cooling before being sent to the high-pressure gaseous hydrogen storage tank 14 for storage.

[0037] In this invention, the coagulation tank 1, neutralization tank 2, and flocculation tank 3 are relatively large. To ensure the stirring effect within these tanks, multiple agitators are used, arranged in a rectangular array. When multiple agitators are used in each tank, each agitator is driven by an independent stirring motor. In this case, the central shaft of each agitator is driven by a separate stirring motor. Of course, when there are multiple agitators in the coagulation tank 1, neutralization tank 2, and flocculation tank 3, the multiple agitators in the coagulation tank 1, the multiple agitators in the neutralization tank 2, and the multiple agitators in the flocculation tank 3 can all be driven by a single agitator motor. That is, one agitator in the coagulation tank 1 is equipped with an agitator motor, and the central shaft of the agitator's agitator blade is connected to the central shaft of the agitator blades of other agitators in the coagulation tank 1 via a chain and sprocket or belt drive; one agitator in the neutralization tank 2 is equipped with an agitator motor, and the central shaft of the agitator blade is connected to the central shaft of the agitator blades of other agitators in the neutralization tank 2 via a chain and sprocket or belt drive; one agitator in the coagulation tank 1 is equipped with an agitator motor, and the central shaft of the agitator blade is connected to the central shaft of the agitator blades of other agitators in the coagulation tank 1 via a chain and sprocket or belt drive.

[0038] In this invention, the coagulation tank 1, neutralization tank 2, flocculation tank 3, and sedimentation tank 4 all flow into the next processing unit via overflow. This ensures that the precipitate generated during the mixing of the concentrated liquid in the coagulation tank 1 with the coagulant is retained within the coagulation tank 1 as much as possible; the precipitate generated during the mixing of the liquid medium in the neutralization tank 2 with the alkaline solution is retained within the neutralization tank 2 as much as possible; the precipitate generated during the mixing of the neutralized liquid medium in the flocculation tank 3 with the flocculant is retained within the flocculation tank 3 as much as possible; and the precipitate settled in the sedimentation tank 4 is retained within the sedimentation tank 4 as much as possible.

[0039] In this invention, to simplify the system structure, the coagulation tank 1, neutralization tank 2, flocculation tank 3, sedimentation tank 4, and filter 5 are connected in sequence, such that adjacent tanks are separated only by a partition wall. The upper edge of the partition wall is the overflow port, and the height of the partition wall used to separate the coagulation tank 1, neutralization tank 2, flocculation tank 3, sedimentation tank 4, and filter 5 decreases by 4cm to 6cm in sequence. The overflow port height on the sedimentation tank 4 is 4cm to 6cm lower than the height of the partition wall between the flocculation tank 3 and the sedimentation tank 4.

[0040] To facilitate the emptying of coagulation tank 1, neutralization tank 2, flocculation tank 3, sedimentation tank 4, filter 5, buffer tank 6, electrocatalytic tank 7, and electrolytic hydrogen production tank 8 during maintenance, and to facilitate the discharge of cleaning wastewater when cleaning is required later, drain pipes are installed at the bottom of coagulation tank 1, neutralization tank 2, flocculation tank 3, sedimentation tank 4, filter 5, buffer tank 6, electrocatalytic tank 7, and electrolytic hydrogen production tank 8, and the drain pipes are equipped with switch valves.

[0041] Those skilled in the art should understand that the above embodiments are merely for illustrating the present invention and are not intended to limit the scope of the invention. Those skilled in the art can make other changes or modifications based on the above disclosure, and these changes or modifications still fall within the scope of the present invention.

Claims

1. A process for treating concentrated landfill leachate by coagulation-sedimentation combined with electrocatalysis coupled with hydrogen production, characterized in that, It comprises the following steps: S1, mixing the landfill leachate concentrate with coagulant, adjusting the PH value of the concentrate to 3.8-4.2; S2, adding alkaline solution to the liquid medium after the coagulation reaction in step S1, adjusting the PH value of the liquid medium to 6.8-7.2; S3, adding flocculant to the liquid medium after the neutralization reaction in step S2, and after the liquid medium and the flocculant are fully mixed, precipitating the supernatant obtained by precipitation and buffering for 10-15 hours; S4, sending the liquid medium after buffering in step S3 into an electrocatalytic tank containing a titanium-based catalyst, and reacting with the strong oxidizing hydroxyl radicals formed by electrocatalysis; S5, sending the liquid medium after electrocatalytic treatment into an electrolytic tank containing a nickel-based catalyst, and generating hydrogen by electrolytic treatment.

2. The process according to claim 1, wherein the process is characterized in that, The coagulant in step S1 is ferric chloride solution, and the ratio of the concentrate to the coagulant is 75-85:

1.

3. The process according to claim 1, wherein the process is characterized in that, The alkaline solution in step S2 is sodium hydroxide solution, and the liquid medium obtained after the coagulation reaction in step S1 is mixed with the alkaline solution and buffered for 2-5 minutes.

4. The process according to claim 1, wherein the process is characterized in that, The flocculant in step S3 is a 0.15% polyacrylamide solution, and the ratio of the liquid medium to the flocculant is 240-260:

1.

5. The process according to claim 1, wherein the process is characterized in that, The current density during electrocatalytic treatment in step S4 is 45-55 mA / cm², and the current during electrolytic treatment in step S5 is 950-1050 mA / cm².

6. The process according to any one of claims 1 to 5, characterized in that, It also comprises a system for implementing the process, which comprises a coagulation tank (1), a neutralization tank (2), a flocculation tank (3), a precipitation tank (4), a filter (5), a buffer tank (6), an electrocatalytic tank (7), an electrolytic hydrogen production tank (8), a hydrogen collection device (9), a gas-liquid separator (10), a drying tower (11), a mechanical compressor (12), a cooler (13), and a high-pressure gaseous hydrogen storage tank (14) connected in sequence, and the coagulation tank (1), the neutralization tank (2), the flocculation tank (3), the precipitation tank (4), and the filter (5) are connected by gravity overflow.

7. The process according to claim 6, characterized in that, The overflow port height difference between two adjacent tanks in the coagulation tank (1), the neutralization tank (2), the flocculation tank (3), and the precipitation tank (4) is 4-6 cm.

8. The process according to claim 6, characterized in that, Stirrers are installed in the coagulation tank (1), the neutralization tank (2), and the flocculation tank (3).

9. The process according to claim 6, wherein the process is characterized in that, The filter (5) is a multi-media filter.

Images