CN218262211U - Circulating reactor for photocatalytic reduction of Cr (VI) and recovery of Cr (III) - Google Patents

Abstract

The utility model relates to the technical field of photocatalytic reduction, in particular to a circulating reactor for photocatalytic reduction of Cr (VI) and recovery of Cr (III), which comprises a reaction tank, an alkali tank, an acid tank, a communicating component and an automatic dosing system; the reaction tank is of an open box structure, and a photocatalytic unit is arranged above the reaction tank; the alkali pool is of a cylindrical structure, and the bottom of the alkali pool is conical; the acid pool is of an open square structure; the communicating component comprises a peristaltic pump and a communicating pipeline, and the peristaltic pump and the communicating pipeline are respectively connected with the reaction tank, the alkali tank and the acid tank to form a circulating system; the automatic medicine feeding system is respectively connected with the alkali pool and the acid pool. The utility model discloses simple structure, the operation of being convenient for and change the maintenance have reduced operating cost, have prolonged the live time, utilize photocatalysis to improve reaction efficiency, have avoided the secondary pollution to the environment, move towards the industrialization from the laboratory to photocatalysis waste water treatment technique and use and have important value and impetus.

Description

Circulating reactor for photocatalytic reduction of Cr (VI) and recovery of Cr (III)

Technical Field

The utility model relates to a photocatalysis reduction technical field specifically is a circulation reactor who relates to a photocatalysis reduction Cr (VI) and retrieve Cr (III).

Background

With increasing concern about environmental safety, the Cr (VI) retained in the water environment draws more and more attention globally and becomes a hotspot problem in the field of environmental remediation. Although chromium is listed as the seventh most abundant element on the earth, china is a chromium-poor country and is widely applied to the fields of textile, tanning, electroplating, rubber, aerospace and the like. Meanwhile, the reuse rate of chromium is low, so that chromium is required to be recycled. The most common forms and species of chromium are trivalent chromium, cr (III), and hexavalent chromium (VI), which are also referred to as the highly stable primary forms. Hexavalent chromium Cr (VI) is toxic to most organisms, is carcinogenic to animals, and causes irritation and corrosion to human skin. Cr (VI) is a common organic pollutant in wastewater generated in the industrial processes of leather making, paint making and the like, can easily enter a food chain, causes great damage to a biological system, has a carcinogenic effect on a human body, and brings about a plurality of health problems. Based on the above mentioned hazards and dangerous effects of Cr (VI) on water systems and human life, profound solutions and considerations must be taken to control and prevent the direct effects of water pollution and chromium (VI) species pollution. Therefore, the selection of the most efficient, most effective remediation and treatment techniques must be focused on a number of important factors, including cost effectiveness, rapidity of operation, high concentration adaptability, energy consumption and eco-friendliness, as well as some attractive benefits and long-lasting applicability. The most desirable method for treating Cr (VI) in wastewater is to convert Cr (VI) to Cr (III), which is itself non-toxic and can be removed by the formation of Cr (OH) 3 precipitates.

The currently common methods comprise a precipitation method, an ion exchange method and a photocatalytic reduction method, wherein the photocatalytic reduction method is an energy-saving and environment-friendly method and is used for reducing Cr (VI) into Cr (III) by utilizing solar energy. Compared with other treatment methods, the photocatalytic technology has the advantages of high efficiency, low toxicity, no secondary pollution and the like, and is considered to be an effective method for solving the environmental problem. Based on these facts, catalytic and photocatalytic reduction of Cr (VI) to Cr (III) has been considered as an effective and ideal method for remediation of Cr (VI) contaminated water bodies.

However, the application of the photocatalytic technology to wastewater treatment is still basically in the laboratory stage at present, and the main reasons are that the research and development of the photocatalytic reactor are laggard, the existing photocatalytic reactor has the problems of small photocatalytic action area, low light energy utilization rate, poor mass transfer effect, difficulty in bringing the performance of the photocatalyst into full play due to the fact that most of the catalyst exists in a powder form, and the like, so that the industrial popularization and practical application of the photocatalytic reactor are severely limited.

SUMMERY OF THE UTILITY MODEL

Aiming at the problems, the circulating reactor for photocatalytic reduction of Cr (VI) and recovery of Cr (III) is provided, and the problem of how to convert Cr (VI) into Cr (III) by means of efficient photocatalytic reduction of Cr (VI) through the arranged reaction tank, the alkali tank, the acid tank, the communication assembly and the automatic dosing system is solved.

For solving the prior art problem, the utility model discloses a technical scheme do:

a circulating reactor for photocatalytic reduction of Cr and recovery of Cr comprises a reaction tank, an alkali tank, an acid tank, a communicating component and an automatic dosing system; the reaction tank is of an open box structure, a first liquid inlet, a first liquid outlet and a photocatalytic unit are arranged on the reaction tank, the first liquid inlet is formed in the lower portion of the side wall of the left side of the reaction tank, the first liquid outlet is formed in the upper portion of the side wall of the right side of the reaction tank, and the photocatalytic unit is arranged on the upper portion of the reaction tank; the alkali pool is of a cylindrical structure, the bottom of the alkali pool is conical, and a second liquid inlet and a second liquid outlet are formed in the peripheral wall of the alkali pool; the acid tank is of an open square structure, and a third liquid inlet and a third liquid outlet are formed in the outer side wall of the acid tank; the communicating component comprises a peristaltic pump and communicating pipelines, the peristaltic pump is provided with three ports which are fixedly connected with the communicating pipelines, and the communicating pipelines are respectively and fixedly connected with a first liquid inlet, a first liquid outlet, a second liquid inlet, a second liquid outlet, a third liquid inlet and a third liquid outlet to form a circulating system; the automatic dosing system is provided with two blocks which are respectively connected with the alkali pool and the acid pool.

Preferably, the photocatalytic unit comprises a supporting block, a photocatalytic metal mesh and a lamp source; the supporting blocks are provided with a plurality of opposite inner peripheral walls which are arranged on two sides of the reaction tank at intervals, and the supporting blocks are fixedly connected with the inner peripheral walls of the reaction tank; the photocatalytic metal mesh is arranged inside the reaction tank; the light source is suspended above the reaction tank and is opposite to the photocatalytic metal woven net.

Preferably, the photocatalytic metal mesh comprises a planar mesh and a photocatalytic material, and the lamp source comprises a hanging seat and a xenon lamp light source; the plane woven net is horizontally overlapped on the supporting block, and the surface of the plane woven net is loaded with a metal organic framework photocatalytic material; the hanging seat is hung above the reaction tank and is opposite to the central position of the planar woven net; the xenon lamp light source is fixedly arranged at the bottom of the hanging seat and is opposite to the central position of the plane woven net.

Preferably, the bottom of the alkali pool is provided with a chromium slag recovery port and a supporting platform; the chromium slag recovery port is fixedly arranged at the bottom of the alkali pool and is coaxial with the alkali pool; the supporting platform is a concave platform mechanism, the concave part is adapted to the shape of the conical lower part of the alkali pool, and supporting legs extend downwards at the corners of the supporting platform.

Preferably, a stirrer is arranged at the acid pool; the working direction of the stirrer is arranged along the vertical direction and extends to the inside of the acid tank.

Preferably, the automatic dosing system comprises a first dosing box and a second dosing box; the first dosing tank is connected with the alkali pool; the second dosing box is connected with the acid tank.

The utility model discloses compare in prior art's beneficial effect be:

1. the utility model discloses a reaction tank, alkali pond, acid pond, intercommunication subassembly and the automatic reagent feeding system that sets up have constituted complete circulation photocatalysis system, have realized the recovery to the reduction of Cr (VI) and Cr (III) with the photocatalysis high efficiency, simple structure, and the operation of being convenient for is maintained with changing, has prolonged live time, has avoided the secondary pollution to the environment, moves towards the industrialization from the laboratory to the photocatalysis waste water treatment technique and uses and have important value and impetus.

2. The utility model discloses a supporting shoe, the photocatalytic metal netting and the lamp source of setting have realized the effect of photocatalytic reaction, and the efficiency of utilization of effective performance lamp source and actinic material improves photocatalytic reaction efficiency to be convenient for change and adjust, practiced thrift operating cost.

3. The utility model discloses an automatic reagent feeding system who sets up has realized the effect of maintaining pH in alkali pond and the acid vat, has guaranteed the effective of going on of whole circulation light catalytic system.

Drawings

FIG. 1 is a schematic perspective view of a recirculating reactor for photocatalytic reduction of Cr (VI) and recovery of Cr (III);

FIG. 2 is a top view of the reaction cell of a recirculating reactor for photocatalytic reduction of Cr (VI) and recovery of Cr (III);

FIG. 3 isbase:Sub>A cross-sectional view taken at A-A of FIG. 2;

FIG. 4 is an enlarged view of a portion of FIG. 3 at B;

FIG. 5 is a side view of a lamp source of a recirculating reactor for photocatalytic reduction of Cr (VI) and recovery of Cr (III);

FIG. 6 is a side view of the caustic bath of a recirculating reactor for photocatalytic Cr (VI) reduction and Cr (III) recovery;

FIG. 7 is a side view of the acid tank of a recirculating reactor for photocatalytic reduction of Cr (VI) and recovery of Cr (III).

The reference numbers in the figures are:

1-a reaction tank;

11-a first liquid inlet;

12-a first outlet port;

13-a photocatalytic unit; 131-a support block; 132-a photocatalytic metal mesh; 1321-plane mesh; 1322-a photocatalytic material; 133-a light source; 1331-xenon lamp light source;

2-an alkali pool;

21-a second liquid inlet;

22-a second liquid outlet;

23-a chromium slag recovery port;

24-a support table;

3-acid pool;

31-a third liquid inlet;

32-a third outlet;

33-a stirrer;

4-a connectivity component;

41-peristaltic pump;

42-a connecting pipe;

5-automatic medicine feeding system;

51-a first dosing box;

52-second dosing tank.

Detailed Description

For further understanding of the features and technical means of the present invention, as well as the specific objects and functions attained by the present invention, the present invention will be described in further detail with reference to the accompanying drawings and detailed description.

Referring to fig. 1 to 7: a circulating reactor for photocatalytic reduction of Cr (VI) and recovery of Cr (III) comprises a reaction tank 1, an alkali tank 2, an acid tank 3, a communicating component 4 and an automatic dosing system 5. Reaction tank 1 is open box structure, is provided with first inlet 11, first liquid outlet 12 and photocatalytic unit 13 on reaction tank 1, and first inlet 11 is seted up in the lower part of reaction tank 1 left side lateral wall, and first liquid outlet 12 is seted up on the upper portion of sending out foot right side lateral wall, and photocatalytic unit 13 sets up the upper portion at reaction tank 1. The alkali pool 2 is a cylindrical structure, the bottom of the alkali pool is conical, and a second liquid inlet 21 and a second liquid outlet 22 are arranged on the peripheral wall of the alkali pool 2. The acid tank 3 is an open square structure, and a third liquid inlet 31 and a third liquid outlet 32 are arranged on the outer side wall of the acid tank 3. The communicating component 4 comprises a peristaltic pump 41 and a communicating pipeline 42, the peristaltic pump 41 has three ports which are fixedly connected with the communicating pipeline 42, and the communicating pipeline 42 is fixedly connected with the first liquid inlet 11, the first liquid outlet 12, the second liquid inlet 21, the second liquid outlet 22, the third liquid inlet 31 and the third liquid outlet 32 to form a circulating system. The automatic medicine adding system 5 is provided with two parts and is respectively connected with the alkali pool 2 and the acid pool 3.

The photocatalytic unit 13 is placed above the interior of the reaction tank 1 and is adjusted in advance, the peristaltic pump 41 for water inflow is opened, so that sewage containing Cr (VI) flows out from the third liquid outlet 32 of the acid tank 3 and flows into the bottom of the reaction tank 1 from the first liquid inlet 11, the stock solution continuously accumulates in the reaction tank 1 until the stock solution overflows the photocatalytic unit 13, the peristaltic pump 41 for water outflow is opened, the speed of the peristaltic pump 41 for liquid inflow and outflow is adjusted, so that the liquid level in the reaction tank 1 is kept unchanged, at the moment, the sewage still containing part of Cr (VI) after photocatalysis flows out from the first liquid outlet 12 under the push of the peristaltic pump 41 and enters the bottom of the alkali tank 2 from the second liquid inlet 21, precipitation is formed at the bottom of the alkali tank 2 and Cr (III) is recovered, because the reaction solution continuously accumulates in the alkali tank 2, the liquid level in the alkali tank 2 continuously rises, and the pH gradually decreases, at the moment, the automatic medicine feeding system 5 maintains the pH value of the liquid in the alkali pool 2, the pH value is gradually increased along with the continuous increase of the liquid level in the alkali pool 2 until the liquid level reaches the height of the second liquid outlet 22, the automatic medicine feeding system 5 maintains the pH value of the liquid in the acid pool 3, the sewage containing Cr (VI) is pushed by the peristaltic pump 41 in the acid pool 3 and flows out of the third liquid outlet 32 and enters the reaction pool 1 from the first liquid inlet 11, so that a circulating photocatalytic Cr (VI) system is formed in the whole process, the problem of how to efficiently reduce Cr (VI) into Cr (III) by means of photocatalysis is solved, the structure is simple, the operation and the replacement maintenance are convenient, the operation cost is reduced, the service life is prolonged, the reaction efficiency is improved by means of photocatalysis, avoids secondary pollution to the environment, and has important value and promotion effect on the photocatalytic wastewater treatment technology from the laboratory to the industrial application.

Referring to fig. 2 to 3: the photocatalytic unit 13 includes a support block 131, a photocatalytic metal mesh 132, and a light source 133. The supporting blocks 131 are arranged on the inner peripheral walls of the two sides of the reaction tank 1 at intervals, and the supporting blocks 131 are fixedly connected with the inner peripheral walls of the reaction tank 1. The photocatalytic metal mesh 132 is disposed inside the reaction cell 1. The light source 133 is suspended above the reaction tank 1 and faces the photocatalytic woven metal mesh 132.

Be provided with multiunit supporting shoe 131 on the inside wall of reaction tank 1 both sides and be used for supporting light catalytic metal woven mesh 132, and position about can freely adjusting, place lamp source 133 directly over reaction tank 1, the stock solution that contains Cr (VI) flows out from the third liquid outlet 32 of acid vat 3, bottom in flowing into reaction tank 1 by first inlet 11 through peristaltic pump 41, along with stock solution constantly accumulates in reaction tank 1, the stock solution direction flows through the cross section of light catalytic metal woven mesh 132 and carries out the photocatalytic reaction, the problem of how to utilize light catalytic reaction reduction Cr (VI) has been solved, the photocatalytic reaction efficiency has been improved, and can realize freely adjusting the distance between lamp source 133 and light catalytic metal woven mesh 132, be convenient for change or maintain, simple structure is convenient for operate, the operation cost is reduced.

Referring to fig. 4 to 5: the photocatalytic metal mesh 132 comprises a plain mesh 1321 and a photocatalytic material 1322, and the lamp source 133 comprises a hanging seat 1331 and a xenon lamp light source 1332. The plane woven net 1321 is horizontally erected on the supporting block 131, and the surface of the plane woven net 1321 is loaded with the metal organic framework photocatalytic material 1322. The hanging seat 1331 is hung above the reaction tank 1 and is opposite to the center of the plane woven net 1321. The xenon lamp 1332 is fixedly mounted at the bottom of the hanging seat and faces the center of the planar woven mesh 1321.

The method comprises the steps of erecting a flat woven mesh 1321 on a supporting block 131, placing a loaded metal woven mesh photocatalytic material 1322, turning on a xenon lamp light source 1331, freely adjusting the upper and lower positions of the flat woven mesh 1321 to enable the distance between the flat woven mesh 1321 and the xenon lamp light source 1331 to be within 5-15cm, enabling the xenon lamp light source 1332 required by the reaction to be a 300W xenon lamp light source 1332, simulating sunlight for 360-760 nm, and enabling the photocatalytic reaction time to be 1-4h, wherein if the photocatalytic material 1322 needs to be replaced and the light source intensity needs to be adjusted, only the photocatalytic material 1322 loaded on the flat woven mesh 1321 needs to be taken out, other photocatalytic material 1322 loaded on the flat woven mesh 1321 is placed again, the intensity of the lamp light source 1332 can be set, the problem of how to carry out the photocatalytic reaction is solved, the transverse mode of the xenon lamp light source 1332 and the flat porous woven mesh enables the photocatalytic material to be irradiated by light to the maximum extent, the utilization efficiency of the lamp light source 1332 and the photocatalytic material 1322 are effectively exerted, the efficiency of the photocatalytic reaction is improved, the photocatalytic material and the replacement of the light source 1322 are convenient, and the cost of the xenon lamp is saved, and the recovery of the light source is also saved (the recovery of the catalyst).

See fig. 6 for an illustration: the bottom of the alkali pool 2 is provided with a chromium slag recovery port 23 and a supporting platform 24. The chromium slag recovery port 23 is fixedly arranged at the bottom of the alkali pool 2 and is coaxial with the alkali pool 2. The supporting platform 24 is a concave platform mechanism, the concave part is adapted to the shape of the conical lower part of the alkali pool 2, and supporting legs extend downwards at the corners of the supporting platform 24.

When Cr (VI) -containing stock solution flows out of a third liquid outlet 32 of the acid tank 3 and enters the reaction tank 1 from a first liquid inlet 11 through a peristaltic pump 41, the stock solution flows through the cross section of the planar woven mesh 1321 in the direction, flows out of a first liquid outlet 12 at the top, and flows into the bottom of the alkali tank 2 from a second liquid inlet 21 through the peristaltic pump 41 to be reduced into Cr (III) solution, cr (III) is nontoxic and can form CrOH3 precipitate in the alkali tank 2, and Cr (III) is recovered through a chromium residue recovery port 23 at the bottom of the alkali tank 2, the support table 24 provides good stability for the alkali tank 2 and lifts the alkali tank 2 to enable the chromium residue recovery port 23 to be higher than the ground, the problem that the recovered Cr (III) is difficult to recover due to mixing with a powder photocatalyst is solved, and the operation cost is saved.

Referring to FIG. 7: the acid tank 3 is provided with a stirrer 33. The agitator 33 is disposed in a vertical direction and extends to the inside of the acid tank 3.

Along with the reaction liquid constantly accumulates in alkali pond 2, the liquid level can constantly rise in alkali pond 2 pond, just at this moment, flow out by second liquid outlet 22 and get into acid tank 3 from third liquid inlet 31 under peristaltic pump 41's promotion, automatic reagent feeding system 5 maintains the pH of liquid in the acid tank 3, start agitator 33 and carry out abundant stirring to the reaction liquid in the acid tank 3 this moment, the problem of how to stir the reaction liquid in the acid tank 3 has been solved, make the reaction liquid and the abundant mixture of automatic reagent feeding system 5's addition liquid, guaranteed the effective of whole circulation system work and gone on, do benefit to the reduction of Cr (VI) and the recovery of Cr (III).

Referring to fig. 6 to 7: the automatic medicine adding system 5 includes a first medicine adding box 51 and a second medicine adding box 52. The first dosing tank 51 is connected to the alkali pool 2. The second dosing tank 52 is connected to the acid tank 3.

The alkaline tank 2 and the acid tank 3 are respectively connected with the first dosing tank 51 and the second dosing tank 52 to adjust the pH value of liquid in the tank, SO that the range of the acidic pH value is between 2.3 and 2.5, the range of the alkaline pH value is between 7 and 10, the acidic pH value is adjusted by H2SO4, and the alkaline pH value is adjusted by NaOH, thereby solving the problem of how to automatically maintain the pH value of the liquid in the tank, ensuring the normal operation of reduction reaction and the effective work of the whole circulating system, and being beneficial to forming and recovering Cr (III) precipitate.

The above examples are merely illustrative of one or more embodiments of the present invention, and the description thereof is more specific and detailed, but not intended to be construed as limiting the scope of the invention. It should be noted that, for those skilled in the art, without departing from the spirit of the present invention, several variations and modifications can be made, which are within the scope of the present invention. Therefore, the protection scope of the present invention should be subject to the appended claims.

Claims (6)

1. A circulating reactor for photocatalytic reduction of Cr (VI) and recovery of Cr (III) is characterized by comprising a reaction tank (1), an alkali tank (2), an acid tank (3), a communicating component (4) and an automatic dosing system (5);

the reaction tank (1) is of an open box structure, a first liquid inlet (11), a first liquid outlet (12) and a photocatalytic unit (13) are arranged on the reaction tank (1), the first liquid inlet (11) is formed in the lower portion of the left side wall of the reaction tank (1), the first liquid outlet (12) is formed in the upper portion of the right side wall of the reaction tank (1), and the photocatalytic unit (13) is arranged on the upper portion of the reaction tank (1);

the alkali pool (2) is of a cylindrical structure, the bottom of the alkali pool is conical, and a second liquid inlet (21) and a second liquid outlet (22) are formed in the peripheral wall of the alkali pool (2);

the acid tank (3) is of an open square structure, and a third liquid inlet (31) and a third liquid outlet (32) are formed in the outer side wall of the acid tank (3);

the communicating component (4) comprises a peristaltic pump (41) and a communicating pipeline (42), the peristaltic pump (41) is provided with three ports which are fixedly connected with the communicating pipeline (42), and the communicating pipeline (42) is respectively and fixedly connected with a first liquid inlet (11), a first liquid outlet (12), a second liquid inlet (21), a second liquid outlet (22), a third liquid inlet (31) and a third liquid outlet (32) to form a circulating system;

the automatic medicine adding system (5) is provided with two blocks which are respectively connected with the alkali pool (2) and the acid pool (3).

2. The recycling reactor for photo-catalytically reducing Cr (VI) and recovering Cr (III) as claimed in claim 1, wherein the photo-catalytic unit (13) comprises a support block (131), a photo-catalytic metal mesh (132) and a light source (133);

the supporting blocks (131) are arranged on the inner peripheral walls of the two sides of the reaction tank (1) at intervals, and the supporting blocks (131) are fixedly connected with the inner peripheral walls of the reaction tank (1);

the photocatalytic metal mesh (132) is arranged inside the reaction tank (1);

the light source (133) is hung above the reaction tank (1) and is opposite to the photocatalytic metal woven net (132).

3. The recycling reactor for photocatalytic Cr (VI) reduction and Cr (III) recovery as claimed in claim 2, wherein the photocatalytic metallic mesh (132) comprises a plain mesh (1321) and a photocatalytic material (1322), the light source (133) comprises a hanging seat and a xenon light source (1331);

the plane woven net (1321) is horizontally erected on the supporting block (131), and the surface of the plane woven net (1321) is loaded with a metal organic framework photocatalytic material (1322);

the hanging seat is hung above the reaction tank (1) and is opposite to the central position of the plane woven net (1321);

the xenon lamp light source (1331) is fixedly arranged at the bottom of the hanging seat and is opposite to the central position of the plane woven net (1321).

4. The circulating reactor for photocatalytic reduction of Cr (VI) and recovery of Cr (III) as claimed in claim 1, wherein the bottom of the alkali pool (2) is provided with a chromium slag recovery port (23) and a support platform (24);

the chromium slag recovery port (23) is fixedly arranged at the bottom of the alkali pool (2) and is coaxial with the alkali pool (2);

the supporting table (24) is a concave platform mechanism, the concave part is adapted to the shape of the conical lower part of the alkali pool (2), and supporting legs extend downwards at the corners of the supporting table (24).

5. A recirculating reactor for the photocatalytic reduction of Cr (VI) and recovery of Cr (III) according to claim 1, characterized in that an agitator (33) is provided at the acid tank (3);

the working direction of the stirrer (33) is arranged along the vertical direction and extends to the interior of the acid tank (3).

6. The reactor according to claim 1, wherein the automatic dosing system (5) comprises a first dosing tank (51) and a second dosing tank (52);

the first dosing box (51) is connected with the alkali pool (2);

the second dosing tank (52) is connected with the acid tank (3).

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