A high concentration wastewater treatment system combined with a microwave hypochlorous acid water continuous reaction process

Abstract

This utility model discloses a high-concentration wastewater treatment system combined with a microwave-assisted continuous reaction process for hypochlorous acid water. The treatment system includes: a hypochlorous acid water generating device, a wastewater mixing tank, a hypochlorous acid water microwave reactor, an MVR evaporator, and a heat exchanger. The hypochlorous acid water generating device is sequentially connected to the wastewater mixing tank and the hypochlorous acid water microwave reactor. The top of the hypochlorous acid water microwave reactor is connected to the heat exchanger, and the bottom is connected to the MVR evaporator. The MVR evaporator is also directly connected to the heat exchanger.

Description

Technical Field

[0001] This utility model relates to the field of wastewater treatment technology, and more specifically to a high-concentration wastewater treatment system combined with a microwave hypochlorous acid water continuous reaction process. Background Technology

[0002] A representative method for treating recalcitrant substances is the advanced oxidation process (AOP). AOP utilizes chemicals exhibiting strong oxidizing power, such as O3 / UV, H2O2 / Fenton oxidation, O3 / H2O2, and TiO2. Compared to traditional oxidation processes that utilize ozone, chlorine, etc., to produce residual products in the oxidation reaction of specific organic substances, this method is considered more advanced. While AOP processes, which highly oxidize target substances through strong oxidizing power, are more efficient than general oxidation processes, they suffer from drawbacks such as low oxidant generation efficiency and the need for continuous generation of hydroxyl radicals (OH radicals). Various methods exist for generating OH radicals, but each has its own limitations. Fenton oxidation produces large amounts of sludge and is inefficient at high organic matter content. Ozone oxidation requires pH adjustment to improve effectiveness, Peroxone requires the appropriate ratio of ozone and hydrogen peroxide, and UV photodecomposition is affected by turbidity and color.

[0003] Conversely, when water (H2O) is mixed with dilute hydrochloric acid (HCl) as a solvent and then electrolyzed, the Cl- in the water... - At the anode, ions are oxidized to form chlorine (Cl2). This chlorine then dissolves in water, producing a large amount of slightly acidic (pH 6-7) hypochlorous acid. Hypochlorous acid at pH 6-7 has the highest oxidizing power among chlorine oxides. Its oxidation mechanism is as follows: as a substance in which one hydrogen (H) atom in a water molecule (HOH) is replaced by chlorine (Cl), the chlorine atom in the hypochlorous acid (HOCl) molecule has an oxidation number of +1, and is converted to Cl... + Cl acts as a strongly electrophilic species. + It transforms into Cl by taking two electrons (2e-) from other substances. - The process selectively acts on binding sites with high electron density, such as C=C, CN, and CN (including peptide bonds).

[0004] In addition, the chlorine ions in hypochlorous acid water generated by electrolysis usually exist in three states in an aqueous solution depending on the pH environment: when pH>7.5, it exists in the form of hypochlorite ion (OCl); when 3.5<pH<7.5, it exists in the form of hypochlorous acid (HOCl); when pH<3.5, it exists in the form of chlorine (Cl).

[0005] Wherein the order of oxidizing power from high to low is HOCl>Cl>OCl, when mixed into high-concentration wastewater, it can decompose wastewater pollutants through strong oxidation.

[0006] Among the existing utility model cases, there is CN102964017A (utility model patent): a microwave electrocatalytic oxidation treatment method for high-salinity organic wastewater, but this patent combines microwave and electrocatalytic oxidation technology for treating high-salinity organic wastewater. The scheme it adopts is: through electrolysis of chloride ions (Cl - ) to generate chlorine gas (Cl2), and the chlorine gas then reacts with water to form oxidizing agents such as hypochlorous acid (HOCl) and hypochlorite (OCl - ), and these generated oxidizing agents are irradiated by microwaves, thereby effectively decomposing organic pollutants in wastewater. This patent directly takes wastewater as the object and reacts through electrolysis with the chloride ions (Cl - ) contained in wastewater. Although hypochlorous acid exists as a by-product, what is basically generated is sodium hypochlorite (NaOCl), which is the general product of the electrolytic reaction of chloride. This patent still has limitations: it cannot be treated when there is no chloride in the wastewater, and when treating large-capacity wastewater, the high energy consumption generated by electrolyzing the entire wastewater results in poor economy.

[0007] Therefore, how to provide a treatment system and method that can fundamentally solve the inherent problems of scaling and corrosion of high-concentration wastewater, eliminate the limiting factors for the operation of existing high-concentration wastewater treatment systems such as MVR, and thereby realize low-energy treatment of high-concentration wastewater is a technical problem urgently needed to be solved by those skilled in the art. Summary of the Utility Model

[0008] In view of this, the present utility model provides a high-concentration wastewater treatment system combined with a continuous microwave hypochlorous acid water reaction process. It can effectively purify high-concentration refractory wastewater that is difficult to treat by existing methods, and is expected to achieve various positive effects in shortening treatment time, reducing costs and other aspects.

[0009] In order to achieve the above objective, the present utility model adopts the following technical solution:

[0010] A high-concentration wastewater treatment system combined with a microwave-assisted continuous reaction process for hypochlorous acid water includes: a hypochlorous acid water generation device, a wastewater mixing tank, a microwave reactor for hypochlorous acid water, an MVR evaporator, and a heat exchanger. The hypochlorous acid water generating device is connected in sequence to the wastewater mixing tank and the hypochlorous acid water microwave reactor. The top of the hypochlorous acid water microwave reactor is connected to the heat exchanger, and the bottom is connected to the MVR evaporation device. The MVR evaporator is also directly connected to the heat exchanger.

[0011] The material used in this invention for the hypochlorite water microwave reactor can be HDPE (high-density polyethylene) to ensure chemical resistance, heat resistance, and durability in the most economical way while improving microwave transmittance. When the chemical reaction generates high heat or requires higher durability, ultra-high molecular weight PE (UHMW) or Teflon (PTFE) materials are used. The microwave waveguide outside the hypochlorite water microwave reactor is ensured to be unaffected by steam or corrosion during the wastewater reaction process, while maximizing the supply of microwaves to the wastewater inside the reactor.

[0012] Preferably, the microwave reactor for hypochlorous acid is externally covered by a reactor cover plate with a hexagonal cross-section; the reactor cover plate is made of stainless steel or a microwave-reflecting metal material, and the reactor cover plate is used to seal the microwave reactor for hypochlorous acid to prevent microwave leakage to the outside.

[0013] Each side of the reactor cover is equipped with several magnetrons, which are evenly arranged. The microwaves generated by the magnetrons are evenly irradiated into the interior of the hypochlorous acid water microwave reactor from the top, bottom, left and right, thereby expanding the contact area with the hypochlorous acid water mixed wastewater and minimizing the limitation of microwave penetration depth.

[0014] The hypochlorous acid water microwave reactor is equipped with a hexagonal mesh membrane inside. The mesh membrane is made of the same material as the reactor and is fixedly positioned around it, maintaining a certain gap from the reactor wall. When the stirring blades at the bottom of the reactor rotate at high speed, the added hypochlorous acid water mixture first distributes onto the mesh membrane, remaining dispersed within the membrane's dimensions. The wastewater then passes through the membrane and is redistributed onto the reactor wall. This facilitates the reaction with microwaves penetrating from the outside of the reactor and ensures sufficient microwave reaction time and reaction area.

[0015] The microwave reactor for hypochlorous acid water is equipped with stirring blades at the bottom. The stirring blades are set to operate at high speed continuously or intermittently according to the properties of the wastewater. The stirring blades can ensure that the mixed wastewater of hypochlorous acid water fed into the microwave reactor through the top feed pipe is evenly distributed on the reactor wall and continuously forms a thin film.

[0016] Preferably, the wastewater mixing tank is connected to a raw wastewater inflow pipe at the top; a first filter screen is installed on the raw wastewater inflow pipe; the hypochlorous acid water generating device is connected to the first filter screen through an additional hypochlorous acid water supply pipe; and the hypochlorous acid water generating device is connected to the wastewater mixing tank through a main hypochlorous acid water pipe.

[0017] Preferably, the hypochlorous acid water microwave reactor is connected to the heat exchanger via a non-condensable gas exhaust pipe; The hypochlorous acid water main pipe is equipped with a first metering supply pump; A second quantitative supply pump is installed on the pipeline connecting the wastewater mixing tank and the hypochlorous acid water microwave reactor. A second filter screen is installed on the pipeline connecting the hypochlorous acid microwave reactor and the MVR evaporation device.

[0018] Preferably, the wastewater mixing tank is equipped with a water level regulating sensor.

[0019] Preferably, the above system further includes: a control unit; The control unit controls the temperature, water level, speed of the drive motor of the stirring blade, metering pump, power supply of the magnetron, and hypochlorous acid water generation device of the microwave reactor for hypochlorous acid water.

[0020] As can be seen from the above technical solution, compared with the prior art, this utility model has the following beneficial effects: 1. It can enhance oxidizing power and accelerate the decomposition of pollutants, as well as increase the generation of reactive free radicals. Hypochlorous acid water itself is a strong oxidant, but when it absorbs microwave energy, it decomposes and generates a large number of reactive oxygen species (ROS), such as the more reactive hydroxyl radical (•OH). Hydroxyl radicals are among the strongest oxidants available and can very effectively destroy recalcitrant organic matter, color, and odorous substances in wastewater.

[0021] 2. By increasing the decomposition rate, microwave energy directly vibrates water molecules and organic pollutants, achieving rapid and uniform heating. This lowers the activation energy required for the chemical reaction, significantly increasing the reaction rate and thus greatly accelerating the decomposition of pollutants by hypochlorous acid water, becoming a crucial factor in the construction of a hypochlorous acid water microwave reactor. In other words, through molecular motion activation and mass transfer promotion, the electromagnetic field of microwaves directly vibrates pollutant molecules and induces rotational motion. This molecular-level stirring effect increases the collision frequency between free radicals and pollutant molecules, thereby enabling the construction of a hypochlorous acid water microwave reactor for continuous processing through rapid reactions.

[0022] In detail, microwaves are a type of electromagnetic wave energy composed of alternating electric and magnetic fields (or wavelengths) that propagate at the speed of light (approximately 300,000 km / s). Microwave frequencies range from 300 to 300,000 MHz, with most microwave devices used for heating materials employing a frequency of 2,450 MHz. Materials irradiated by microwaves exhibit various polarization phenomena that react with the electromagnetic field, and these polarimetric bodies rotate with the continuously changing electric field.

[0023] Generally, when irradiated with microwaves, the target material reacts differently depending on the type of polarization it contains and the frequency band of the incident electromagnetic wave. Metals, lacking polarization capable of resonating with microwave waves, are reflected by all incident microwaves.

[0024] Even with polarization that can work in tandem with microwaves, if there is no friction when the polarization rotates, the incident microwave energy will pass through without any loss; however, if friction is generated when the polarization rotates, some of the incident energy will be converted into heat energy generated by friction, and the rest will pass through.

[0025] In other words, microwaves improve the overall reaction efficiency by promoting the material transfer process of free radicals diffusing to the surrounding pollutants, and microwave reactors for continuous processing of hypochlorous acid water are designed due to their rapid reaction speed.

[0026] 3. Improved treatment efficiency and economy. By applying microwaves to high-concentration wastewater mixed with hypochlorous acid, compared to traditional chemical treatment methods that require long reaction times, the rapid heating and reaction-promoting effect of microwaves significantly shortens the overall process time, improves treatment efficiency, and saves energy costs. With the increased reaction efficiency, it can replace existing chemical treatment costs, and the amount of hypochlorous acid required to achieve the target water quality can be adjusted, resulting in additional cost savings.

[0027] 4. Excellent results can be expected in removing specific pollutants. In wastewater treatment, for ammonia nitrogen removal, microwave irradiation can rapidly increase the wastewater temperature, thereby significantly improving the removal efficiency of ammonia nitrogen under pH conditions. Hypochlorous acid water is also effective for ammonia nitrogen removal; therefore, using both technologies together can achieve faster and more thorough removal. This invention not only saves on wastewater treatment operating costs but also enables wastewater treatment for multiple purposes and can be combined with various existing wastewater treatment equipment to maximize wastewater treatment efficiency. Attached Figure Description

[0028] To more clearly illustrate the technical solutions in the embodiments of this utility model 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 this utility model. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.

[0029] Figure 1 A schematic diagram of the system structure provided by this utility model; Figure 2 This is a diagram showing the external structure of the microwave reactor for hypochlorite water in this invention. Figure 3 This is a structural diagram of the internal structure of the microwave reactor for hypochlorous acid water in this utility model.

[0030] In the figure: 100-Hypochlorous acid water generation device; 101-Hypochlorous acid water microwave reactor; 102-Wastewater mixing tank; 103-Hypochlorous acid water main supply pipe; 104-First quantitative supply pump; 104-1-Second quantitative supply pump; 105-Original wastewater inflow pipe; 106-Reactor cover plate; 107-Magnetron; 108-Stirring blades; 109-Mesh diaphragm; 110-First filter screen; 110-1-Second filter screen; 111-Hypochlorous acid water auxiliary supply pipe; 112-MVR evaporator; 113-Non-condensable gas exhaust pipe; 114-Heat exchanger; 115-Water level regulating sensor; 116-Control unit. Detailed Implementation

[0031] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0032] Example 1 This embodiment provides a high-concentration wastewater treatment system combining microwave hypochlorous acid water continuous reaction process, including: hypochlorous acid water generation device 100, wastewater mixing tank 102, hypochlorous acid water microwave reactor 101, MVR evaporation device 112 and heat exchanger 114. The hypochlorous acid water generating device 100 is connected in sequence to the wastewater mixing tank 102 and the hypochlorous acid water microwave reactor 101. The top of the hypochlorous acid water microwave reactor 101 is connected to the heat exchanger 114, and the bottom is connected to the MVR evaporation device 112. The MVR evaporator 112 is also directly connected to the heat exchanger 114.

[0033] The microwave reactor 101 for hypochlorous acid water is externally covered by a reactor cover plate 106 with a hexagonal cross section. Each side of the reactor cover plate 106 is provided with a number of magnetrons 107, and the number of magnetrons 107 are evenly arranged. The microwave reactor 101 for hypochlorous acid water is equipped with a hexagonal mesh diaphragm 109 inside; The bottom of the hypochlorous acid water microwave reactor 101 is equipped with stirring blades 108.

[0034] The wastewater mixing tank 102 is connected to the top of the original wastewater inflow pipe 105; the original wastewater inflow pipe 105 is equipped with a first filter screen 110; the hypochlorous acid water generating device 100 is connected to the first filter screen 110 through the hypochlorous acid water additional supply pipe 111; the hypochlorous acid water generating device 100 is connected to the wastewater mixing tank 102 through the hypochlorous acid water main pipe 103.

[0035] Hypochlorite water microwave reactor 101 is connected to heat exchanger 114 via non-condensable gas exhaust pipe 113. A first metering pump 104 is installed on the hypochlorous acid water main pipe 103; A second quantitative supply pump 104-1 is installed on the pipeline connecting the wastewater mixing tank 102 and the hypochlorous acid water microwave reactor 101; A second filter screen 110-1 is installed on the pipeline connecting the microwave reactor 101 for hypochlorous acid water and the MVR evaporator 112.

[0036] A water level regulating sensor 115 is installed inside the wastewater mixing tank 102.

[0037] To further optimize the above technical solution, the system also includes a control unit 116.

[0038] The control unit 116 controls the temperature, water level, drive motor speed of stirring blade 108, metering pump, power supply of magnetron 107, and hypochlorous acid water generating device 100 of the microwave reactor 101 for hypochlorous acid water.

[0039] Example 2 This embodiment provides a method for treating high-concentration wastewater by combining a microwave-assisted continuous reaction process with hypochlorous acid, including: (1) Set the amount of wastewater flowing into the wastewater mixing tank 102 and the ratio of hypochlorous acid water according to the nature of the wastewater. When a certain amount of wastewater reaches the set mixing ratio in the wastewater mixing tank 102, open the main supply pipe 103 of hypochlorous acid water to allow the set amount of hypochlorous acid water to flow in, thereby achieving the required mixing ratio of wastewater and hypochlorous acid water. (2) The wastewater mixed in the wastewater mixing tank 102 is transported to the hypochlorous acid water microwave reactor 101. The mixed wastewater is first distributed on the mesh diaphragm 109 by the stirring blades 108. The wastewater passing through the mesh diaphragm 109 is distributed to the inner wall of the hypochlorous acid water microwave reactor 101. The microwave generated by the magnetron 107 installed on each side is evenly irradiated into the inside of the reactor from the top, bottom and left and right to treat the mixed wastewater with microwave. The microwave leakage to the outside is blocked by the reactor cover plate 106. (3) The wastewater treated by the microwave reactor 101 of hypochlorous acid water is sent to the MVR evaporator 112 for final treatment. The steam generated by the MVR evaporator 112 is heat exchanged with the heat exchanger 114. The uncondensed gas generated in the heat exchanger 114 is sent back to the microwave reactor 101 of hypochlorous acid water for oxidation treatment by the reaction of hypochlorous acid water and microwave.

[0040] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on its differences from other embodiments. Similar or identical parts between embodiments can be referred to interchangeably. For the apparatus disclosed in the embodiments, since they correspond to the methods disclosed in the embodiments, the description is relatively simple; relevant parts can be referred to the method section.

[0041] The above description of the disclosed embodiments enables those skilled in the art to make or use the present 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 present invention. Therefore, the present 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 high-concentration wastewater treatment system combined with a microwave-assisted continuous reaction process for hypochlorous acid water, characterized in that, include: Hypochlorous acid water generation device, wastewater mixing tank, hypochlorous acid water microwave reactor, MVR evaporator and heat exchanger; The hypochlorous acid water generating device is connected in sequence to the wastewater mixing tank and the hypochlorous acid water microwave reactor. The top of the hypochlorous acid water microwave reactor is connected to the heat exchanger, and the bottom is connected to the MVR evaporation device. The MVR evaporator is also directly connected to the heat exchanger.

2. The high-concentration wastewater treatment system combined with microwave hypochlorous acid water continuous reaction process according to claim 1, characterized in that, The microwave reactor for hypochlorous acid water is covered by a reactor cover plate with a hexagonal cross section. Each side of the reactor cover is provided with several magnetrons, which are evenly arranged. The microwave reactor for hypochlorous acid water is equipped with a hexagonal mesh membrane inside. The bottom of the hypochlorous acid water microwave reactor is equipped with stirring blades.

3. The high-concentration wastewater treatment system combined with microwave hypochlorous acid water continuous reaction process according to claim 2, characterized in that, The wastewater mixing tank is connected to a raw wastewater inflow pipe at the top; a first filter screen is installed on the raw wastewater inflow pipe; the hypochlorous acid water generating device is connected to the first filter screen through an additional hypochlorous acid water supply pipe; the hypochlorous acid water generating device is connected to the wastewater mixing tank through a main hypochlorous acid water pipe.

4. A high-concentration wastewater treatment system combined with a microwave-assisted continuous reaction process for hypochlorous acid water, as described in claim 3, is characterized in that... The hypochlorous acid water microwave reactor is connected to the heat exchanger via a non-condensable gas exhaust pipe. The hypochlorous acid water main pipe is equipped with a first metering supply pump; A second quantitative supply pump is installed on the pipeline connecting the wastewater mixing tank and the hypochlorous acid water microwave reactor. A second filter screen is installed on the pipeline connecting the hypochlorous acid microwave reactor and the MVR evaporation device.

5. A high-concentration wastewater treatment system combined with a microwave-assisted continuous reaction process for hypochlorous acid water, as described in claim 4, is characterized in that... The wastewater mixing tank is equipped with a water level regulating sensor.

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