A device for removing micro-pollutants in sewage based on heterogeneous advanced oxidation process

Abstract

The utility model provides a device based on heterogeneous advanced oxidation method removes sewage micro -pollutant belongs to sewage treatment technical field, the utility model provides a device based on heterogeneous advanced oxidation method removes micro -pollutant, including advanced oxidation high -efficient catalytic reaction area, heterogeneous catalyst high -efficient recovery area and oxidant residual release, the utility model discloses realizes advanced oxidation high -efficient catalytic reaction, heterogeneous catalyst high -efficient recovery, oxidant residual release in the same equipment, effectively solves catalyst recovery difficult, oxidant residual amount higher technical problem, realizes equipment complete factory direct application simultaneously, has wide application prospect in the field of environmental remediation and water treatment.

Description

Technical Field

[0001] This utility model relates to the field of wastewater treatment technology, specifically to a device for removing micro-pollutants from wastewater based on heterogeneous advanced oxidation. Background Technology

[0002] Micropollutant pollution in urban domestic sewage in China has become an increasingly serious environmental and health problem. Although the concentration of organic micropollutants is low, their potential harm is enormous. They mainly include drug residues, personal care products, endocrine disruptors, and industrial chemicals. These pollutants are often difficult to remove through biodegradation using traditional activated sludge processes in domestic sewage treatment plants. For example, the removal rate of benzene antibiotics in activated sludge processes is generally less than 30%, making them a typical example of recalcitrant micropollutants in urban sewage treatment.

[0003] Advanced oxidation processes (AOPs) degrade micropollutants by generating highly oxidizing free radicals (mainly hydroxyl radicals ·OH). Their oxidation potential (2.8V) far exceeds that of ozone (2.07V) and chlorine (1.36V), enabling the non-selective mineralization of the vast majority of organic matter. For example, the free radicals generated by catalytic oxidation dominate the chain reaction, achieving highly efficient mineralization of micropollutants. Currently, existing Fenton-like catalytic oxidation advanced oxidation systems are divided into two categories: homogeneous and heterogeneous.

[0004] Fenton's reagent is a typical homogeneous catalytic system that uses ferrous iron to catalyze the production of ·OH and other substances from hydrogen peroxide, thereby achieving the mineralization and removal of organic pollutants. However, after the ferrous salts are oxidized during the reaction, they are very easy to form ferric flocs, which requires the catalyst material to be continuously replenished. This not only increases the yield of iron sludge waste, but also easily leads to excessive iron salt content in the effluent.

[0005] With technological advancements, Fenton-like heterogeneous advanced oxidation catalytic systems have gradually emerged. These systems feature high-efficiency heterogeneous catalysts that overcome acidic limitations, operating effectively under neutral and weakly alkaline conditions. Furthermore, they are recyclable with minimal environmental residue, demonstrating promising future applications. However, current practices in advanced wastewater treatment lack mature, integrated devices for removing micropollutants using heterogeneous advanced oxidation. Therefore, this invention provides a novel integrated device that enables highly efficient advanced oxidation catalytic reactions, efficient recovery of heterogeneous catalysts, and release of residual oxidant. This integrated device allows for the production of complete sets of equipment, thereby promoting the practical application of heterogeneous advanced oxidation catalysis. Utility Model Content

[0006] To address the problems mentioned above, the main objective of this invention is to provide a device for removing micro-pollutants from wastewater based on heterogeneous advanced oxidation. This device integrates an advanced oxidation high-efficiency catalytic reaction zone, a heterogeneous catalyst high-efficiency recovery zone, and an oxidant residue release zone, effectively removing pollutants from wastewater and ensuring drainage safety.

[0007] To solve the above-mentioned technical problems, the technical solution adopted by this utility model is as follows: An apparatus for removing micro-pollutants from wastewater based on heterogeneous advanced oxidation includes an advanced oxidation reaction zone, an escape heterogeneous catalyst recovery zone, and an oxidant residue release zone. The advanced oxidation reaction zone is used to remove recalcitrant pollutants from wastewater; the escape heterogeneous catalyst recovery zone is used to recover and reuse the catalyst that escapes from the advanced oxidation reaction zone after multiple rounds of reaction; and the oxidant residue release zone is used to reduce the residual oxidant to ensure that the wastewater meets discharge standards.

[0008] As a preferred embodiment, the catalyst is a magnetic heterogeneous catalyst, including at least one of supported iron oxides, iron-based composite materials, and other transition metal oxides.

[0009] As a preferred embodiment, the advanced oxidation reaction zone includes a reaction vessel made of 304 stainless steel, with a cylindrical structure and an inverted conical bottom.

[0010] As a preferred embodiment, the reaction vessel is provided with a catalyst inlet near the side wall at the top, a first stirring device at the center of the top, a wastewater inlet at the upper part of the side wall, and a first electromagnet at the bottom of the vessel.

[0011] As a preferred embodiment, the first stirring device includes a stirring motor and a stirring paddle. The stirring motor is connected to the stirring paddle via a stirring shaft, which can stir the wastewater in the reaction tank, thereby promoting the efficient removal of pollutants.

[0012] As a preferred embodiment, the stirring paddle is provided with multiple paddles to ensure that the wastewater, persulfate and catalyst are in full contact, thereby improving the reaction efficiency.

[0013] As a preferred embodiment, the reaction vessel is equipped with a persulfate dissolving device on its exterior for dissolving and adding the oxidant-persulfate.

[0014] As a preferred embodiment, the persulfate dissolving device is equipped with a second stirring device to accelerate the dissolution of the oxidant and persulfate; the persulfate dissolving device is connected to the reaction tank through a first pipe, and a circulation pump is provided on the first pipe to pump the persulfate solution into the reaction tank.

[0015] As a preferred embodiment, the escaped heterogeneous catalyst recovery zone includes a recovery cylinder. A second electromagnet and a recovery funnel are located at the bottom of the recovery cylinder to enhance the recovery of the escaped magnetic heterogeneous catalyst. The recovery cylinder is connected to the lower side wall of the reaction tank via a third pipe, which is equipped with a first valve. Wastewater, after undergoing an oxidation reaction, enters the recovery cylinder through the third pipe.

[0016] As a preferred embodiment, the bottom of the recovery cylinder is connected to the bottom of the reaction tank via a second pipe. The second pipe is equipped with a second circulation pump for pumping the recovered catalyst into the reaction tank to continue catalyzing persulfate to generate strong oxidizing free radicals.

[0017] As a preferred embodiment, the residual oxidant release zone includes a reduction tank, which is connected to the recovery cylinder via a fourth pipe. A second valve is installed on the fourth pipe. The reduction tank stores a reducing liquid for reducing the residual oxidant in the oxidation reaction system, ensuring that the residual persulfate content in the effluent meets the drainage requirements. The inlet of the fourth pipe extends below the surface of the reducing liquid, ensuring that the residual oxidant can fully contact and react with the reducing liquid containing sodium bisulfite, while preventing the oxidant from directly escaping from the liquid surface and affecting the reaction efficiency.

[0018] As a preferred embodiment, the side wall of the restoration tank is provided with a sewage outlet for discharging sewage that meets drainage requirements.

[0019] The optimal pH for conventional homogeneous Fenton reactions is usually between 2 and 4. However, acidic conditions not only increase operating costs but also limit their practical application. This novel heterogeneous Fenton advanced oxidation integrated device has significant advantages over traditional homogeneous Fenton technology equipment (which uses soluble ferrous salts), making it a promising candidate for application in environmental remediation and water treatment.

[0020] The beneficial effects of this utility model are as follows: 1. This invention uses a heterogeneous catalyst, which can maintain good catalytic activity under neutral or even weakly alkaline conditions, significantly reducing treatment costs and operational complexity, and can be more directly applied to actual wastewater treatment scenarios.

[0021] 2. The solid catalyst of this invention achieves efficient recovery during the reaction process by means of an electromagnet, and completes online recycling through the internal reflux channels of different treatment zones, which significantly reduces the consumption cost of the catalyst and the disposal cost of the residual sludge.

[0022] 3. This device is specially equipped with a reduction zone for reducing residual oxidants in the advanced oxidation system, ensuring that the residual persulfate content in the effluent meets the drainage requirements, and especially ensuring the ecological safety of the receiving water body. Attached Figure Description

[0023] The present invention will be further described below with reference to the accompanying drawings: Figure 1 This is a schematic diagram of the device for removing micro-pollutants from wastewater based on heterogeneous advanced oxidation method according to this utility model; In the diagram: 1. Advanced oxidation reaction zone, 100. Reaction tank, 101. Stirring shaft, 102. Catalyst inlet, 103. Wastewater inlet, 104. Stirring motor, 105. Stirring blade, 106. First electromagnet, 107. First pipeline, 108. First circulation pump, 109. Persulfate dissolution device, 110. Second pipeline; 2. Escaped heterogeneous catalyst recovery zone, 200. Recovery cylinder, 201. Third pipeline, 202. First valve, 203. Second circulation pump, 204. Second electromagnet, 205. Recovery funnel; 3. Oxidant residue release zone, 301. Fourth pipeline, 302. Second valve, 303. Third pipeline; 304. Reducing liquid. Detailed Implementation

[0024] To make the objectives, technical solutions, and beneficial effects of this utility model clearer, the preferred embodiments of this utility model will be described in detail below with reference to the accompanying drawings, so as to facilitate the understanding of those skilled in the art.

[0025] like Figure 1 As shown, an apparatus for removing micropollutants from wastewater based on heterogeneous advanced oxidation is disclosed. The apparatus comprises an advanced oxidation reaction zone 1, an escaped heterogeneous catalyst recovery zone 2, and an oxidant residue release zone 3. In the advanced oxidation reaction zone 1, an oxidation reaction occurs between the catalyst, persulfate, and wastewater to remove recalcitrant pollutants from the wastewater. The escaped heterogeneous catalyst recovery zone 2 is used to recover and reuse the catalyst that escaped from the advanced oxidation reaction zone after multiple rounds of oxidation reactions. The oxidant residue release zone 3 is used to reduce the oxidant remaining in the oxidation reaction, ensuring that the wastewater meets discharge standards.

[0026] In a preferred embodiment, the catalyst is a magnetic heterogeneous catalyst, including at least one of supported iron oxides, iron-based composite materials, and other transition metal oxides.

[0027] As a preferred embodiment, the advanced oxidation reaction zone 1 includes a reaction vessel 100, which is made of 304 stainless steel, has a cylindrical structure, and an inverted conical bottom.

[0028] As a preferred embodiment, the top of the reaction tank 100 is provided with a catalyst inlet 102 near the side wall for adding a magnetic catalyst; a first stirring device is provided in the center of the top for stirring and mixing wastewater, catalyst and persulfate; a wastewater inlet 103 is provided on the upper part of the side wall for inputting wastewater into the reaction tank 100; and a first electromagnet 106 is provided at the bottom of the tank for magnetizing and precipitating the catalyst for recovery.

[0029] As a preferred embodiment, the first stirring device includes a stirring motor 104 and a stirring blade 105. The stirring motor 104 is connected to the stirring blade 105 through a stirring shaft 101, which can stir the wastewater in the reaction tank 100 and promote the efficient removal of pollutants.

[0030] As a preferred embodiment, the stirring paddle 105 is provided with multiple paddles to ensure that the wastewater, persulfate and catalyst are in full contact, thereby improving the reaction efficiency.

[0031] As a preferred embodiment, the reaction vessel 100 is provided with a persulfate dissolving device 109 on the outside, which is used to dissolve and add the oxidant-persulfate.

[0032] As a preferred embodiment, the persulfate dissolving device 109 is provided with a second stirring device for dissolving the oxidant and persulfate; the persulfate dissolving device 109 is connected to the reaction tank 100 through a first pipe 107, and a circulation pump 108 is provided on the first pipe 107 for pumping the persulfate solution into the reaction tank 100.

[0033] As a preferred embodiment, the second stirring device includes a second stirring motor, a second stirring paddle, and a second stirring shaft. The oxidant and persulfate are thoroughly and evenly mixed through the stirring of the second stirring device.

[0034] In a preferred embodiment, the escaped heterogeneous catalyst recovery zone 2 includes a recovery cylinder 200. A second electromagnet 204 and a recovery funnel 205 are located at the bottom of the recovery cylinder for enhanced recovery of the escaped magnetic heterogeneous catalyst. The recovery cylinder 200 is connected to the lower side wall of the reaction tank 100 via a third pipe 201, which is equipped with a first valve 202. After oxidation, wastewater enters the recovery cylinder 200 through the third pipe 201. Unreacted and escaped catalyst is drawn into the recovery funnel 205 by the action of the second electromagnet 204 and then into the reaction tank 100 by the action of the second circulation pump 203.

[0035] In a preferred embodiment, the bottom of the recovery cylinder 200 is connected to the bottom of the reaction tank 100 through a second pipe 110. A second circulation pump 203 is provided on the second pipe 110 to pump the recovered catalyst into the reaction tank to continue catalyzing persulfate to generate strong oxidizing free radicals.

[0036] In a preferred embodiment, the oxidant residue release zone 3 includes a reduction tank 300, which is connected to the recovery cylinder 200 via a fourth pipe 301. A second valve 302 is installed on the fourth pipe 301. The reduction tank 300 stores a reducing liquid 304 containing sodium bisulfite, used to reduce the residual oxidant in the oxidation reaction system, ensuring that the residual persulfate content in the effluent meets drainage requirements. The opening of the fourth pipe 301 extends below the surface of the reducing liquid 304, ensuring that the residual oxidant can fully contact and react with the reducing liquid (containing sodium bisulfite), while preventing the oxidant from directly escaping from the liquid surface and affecting reaction efficiency. By adding the reducing agent sodium bisulfite to the reduction tank 300, efficient removal of residual oxides is achieved, ensuring drainage safety.

[0037] As a preferred embodiment, the side wall of the reduction tank 300 is provided with a third pipe 303 for discharging sewage that meets the drainage requirements.

[0038] As a preferred embodiment, the working principle of this utility model is as follows: In use, in the advanced oxidation reaction zone 1, wastewater is introduced into the reaction tank 100 through the wastewater inlet 103, and the catalyst enters the reaction tank 100 through the inlet 102. The oxidant and persulfate are dissolved in the persulfate dissolving device 109 and then enter the reaction tank 100 through the circulation pump 108. Under the action of the stirring motor 104, the persulfate generates strong oxidizing free radicals under the action of the composite iron oxide catalyst. The wastewater and the strong oxidizing free radicals undergo a highly efficient oxidation reaction, thereby removing pollutants from the wastewater. After the reaction is completed, the first valve 202 is opened, and the wastewater after the oxidation reaction enters the escape heterogeneous catalyst return channel through the third pipe 201. In the recovery cylinder 200 of the recovery zone 2, unreacted and escaped catalyst is recovered to the recovery funnel 205 under the action of the bottom electromagnet 204, and then returned to the reaction tank 100 by the second circulation pump 203 to continue catalyzing persulfate to generate strong oxidizing free radicals and promote the oxidation reaction. After the recovery treatment is completed, the second valve 302 is opened, and the wastewater of the oxidation system after recovery treatment enters the reduction tank 300 of the oxidant residue release zone 3 through the fourth pipe 301. Under the action of the reducing liquid 304 containing the reducing agent sodium bisulfite, the residual oxidant in the wastewater discharged from the oxidation system is removed, realizing the efficient removal of residual oxides. The treated wastewater is discharged from the third pipe 303 to ensure drainage safety.

[0039] In summary, the integrated device of this utility model, through the synergistic effect of the advanced oxidation reaction zone 1, the escape heterogeneous catalyst recovery zone 2, and the oxidant residue release zone 3, can effectively remove pollutants from domestic sewage, enabling the sewage to meet drainage requirements, and in particular, ensuring the ecological safety of the receiving water body.

[0040] The above embodiments are merely preferred technical solutions of this utility model and should not be considered as limitations on this utility model. The protection scope of this utility model should be the technical solution described in the claims, including equivalent substitutions of the technical features described in the claims. That is, equivalent substitutions and improvements within this scope are also within the protection scope of this utility model.

Claims

1. A device for removing micropollutants from wastewater based on heterogeneous advanced oxidation, characterized in that: The device includes an advanced oxidation reaction zone (1), an escape heterogeneous catalyst recovery zone (2), and an oxidant residue release zone (3). The advanced oxidation reaction zone (1) is used to remove recalcitrant pollutants from wastewater through oxidation reactions. The escape heterogeneous catalyst recovery zone (2) is used to recover and reuse the catalyst that escapes from the advanced oxidation reaction zone after multiple rounds of oxidation reactions. The oxidant residue release zone (3) is used to reduce the oxidant remaining in the oxidation reaction to ensure that the wastewater meets the discharge standards.

2. The device for removing micropollutants from wastewater based on heterogeneous advanced oxidation as described in claim 1, characterized in that: The advanced oxidation reaction zone (1) includes a reaction vessel (100), which is made of 304 stainless steel and has a cylindrical structure with an inverted conical bottom.

3. The device for removing micropollutants from wastewater based on heterogeneous advanced oxidation as described in claim 2, characterized in that: The reaction tank (100) has a catalyst inlet (102) near the side wall at the top, a first stirring device at the center of the top, a sewage inlet (103) at the upper part of the side wall, and a first electromagnet (106) at the bottom of the tank.

4. The device for removing micropollutants from wastewater based on heterogeneous advanced oxidation as described in claim 3, characterized in that: The first stirring device includes a stirring motor (104) and a stirring blade (105). The stirring motor (104) is connected to the stirring blade (105) through a stirring shaft (101) to stir the wastewater in the reaction tank (100).

5. The apparatus for removing micropollutants from wastewater based on heterogeneous advanced oxidation as described in claim 4, characterized in that: The stirring blades (105) are provided in multiple parts to promote full contact between wastewater and oxidant.

6. The apparatus for removing micropollutants from wastewater based on heterogeneous advanced oxidation as described in claim 2, characterized in that: The reaction vessel (100) is equipped with a persulfate dissolving device (109) on the outside for dissolving and adding the oxidant-persulfate.

7. The apparatus for removing micropollutants from wastewater based on heterogeneous advanced oxidation as described in claim 1, characterized in that: The escape heterogeneous catalyst recovery zone (2) includes a recovery cylinder (200), and a second electromagnet (204) and a recovery funnel (205) are provided at the bottom of the recovery cylinder; the recovery cylinder (200) is connected to the lower part of the side wall of the reaction vessel (100) through a third pipe (201), and a first valve (202) is provided on the third pipe (201).

8. The apparatus for removing micropollutants from wastewater based on heterogeneous advanced oxidation as described in claim 7, characterized in that: The bottom of the recovery cylinder (200) is connected to the bottom of the reaction tank (100) through a second pipe (110). A second circulation pump (203) is provided on the second pipe (110) to pump the recovered catalyst into the reaction tank.

9. The apparatus for removing micropollutants from wastewater based on heterogeneous advanced oxidation as described in claim 1, characterized in that: The oxidant residue release zone (3) includes a reduction tank (300), which is connected to the recovery cylinder (200) through a fourth pipe (301). A second valve (302) is provided on the fourth pipe (301).

10. The apparatus for removing micropollutants from wastewater based on heterogeneous advanced oxidation as described in claim 9, characterized in that: The reduction tank (300) contains a reducing liquid (304), and the opening of the fourth pipe (301) extends below the surface of the reducing liquid (304).

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