System and method for comprehensively treating oily wastewater through adsorption-photocatalysis

Abstract

The invention provides a system and a method for comprehensively treating oily wastewater through adsorption-photocatalysis, and belongs to the technical field of wastewater treatment. Comprising a settling zone, a front adsorption zone, a photocatalytic oxidation zone, a rear adsorption zone and a purified water storage zone which are sequentially connected end to end, and the settling zone, the front adsorption zone, the photocatalytic oxidation zone, the rear adsorption zone and the purified water storage zone are sequentially arranged, so that multi-step comprehensive treatment of the oily wastewater is realized; each area plays a role in different types of pollutants in wastewater, the settling area removes large-particle impurities, the front adsorption area primarily adsorbs oil and pollutants, the photocatalytic oxidation area decomposes organic pollutants, the rear adsorption area further adsorbs residual pollutants and ionic pollutants, and the purified water storage area performs sterilization treatment; the cooperative treatment mode can comprehensively and efficiently purify the oil-containing wastewater.

Description

Technical Field

[0001] The invention belongs to the technical field of wastewater treatment, and specifically relates to a system and method for comprehensive treatment of oily wastewater by adsorption-photocatalysis. Background Art

[0002] Oily wastewater is generated in large quantities during industrial production. It is a common industrial waste in oil extraction, refining, transportation, chemical industry, mechanical processing, food processing and other industries. For example, in the process of oil extraction, the produced crude oil is accompanied by a large amount of formation water, which forms oily wastewater after separation from the crude oil; in the metal cutting, grinding, lubrication and other processes in the mechanical processing industry, a large amount of lubricating oil is used, which is mixed into the wastewater to form oily wastewater.

[0003] If oily wastewater is discharged directly into the environment without effective treatment, it will cause serious pollution to water bodies, soil and atmosphere. In water bodies, oil substances will form an oil film on the water surface, blocking oxygen from entering the water body, causing aquatic organisms to die of hypoxia. Some harmful substances in oil substances will also accumulate in aquatic organisms and be transmitted through the food chain, causing damage to the entire ecosystem. After oily wastewater infiltrates into the soil, it will affect the air permeability and water permeability of the soil, destroy the soil structure, cause a decrease in soil fertility, and affect the growth of crops. In addition, the volatile organic matter in the oily wastewater evaporates into the atmosphere, which will increase the concentration of pollutants in the atmosphere and have an adverse effect on air quality. Therefore, a system for treating oily wastewater is urgently needed.

[0004] However, existing systems for treating oily wastewater often do not have a design that can adjust the height of the photocatalytic oxidation component according to the liquid level, which affects the efficiency of the photocatalytic oxidation reaction. At the same time, the existing technology lacks multi-step coordinated treatment and has limitations in the purification effect of oily wastewater. Summary of the invention

[0005] In view of the above-mentioned problems, the present invention provides a system and method for comprehensive treatment of oily wastewater by adsorption-photocatalysis.

[0006] The technical solution of the present invention is: a system for comprehensive treatment of oily wastewater by adsorption-photocatalysis, comprising a sedimentation zone, a front adsorption zone, a photocatalytic oxidation zone, a rear adsorption zone and a clean water storage zone connected end to end in sequence;

[0007] The water outlet side of the rear adsorption zone and its water inlet side, the water inlet side of the front adsorption zone, and the water inlet side of the photocatalytic oxidation zone are all connected through a circulation branch pipe, and each of the above-mentioned connections is respectively provided with a one-way solenoid valve, and the water outlet side of the rear adsorption zone is connected to a water quality detection device;

[0008] The water inlet sides of the front adsorption zone, photocatalytic oxidation zone and rear adsorption zone are all equipped with flow detection devices and automatic regulating valves;

[0009] A first combined adsorption rack is provided in the front adsorption zone, a plurality of activated carbon adsorption columns are provided at the bottom end of the first combined adsorption rack, and a fiber bundle is provided at the upper end of the first combined adsorption rack;

[0010] A second combined adsorption frame is provided in the rear adsorption zone, the bottom end of the second combined adsorption frame is filled with MOFs adsorbent, and the upper end of the second combined adsorption frame is filled with ion exchange resin;

[0011] A photocatalytic oxidation component is provided in the photocatalytic oxidation zone, and the photocatalytic oxidation component includes a mounting horizontal plate connected to the upper end of the photocatalytic oxidation zone through a hydraulic rod, a plurality of ultraviolet light sources distributed in a matrix at the bottom end of the mounting horizontal plate, a quartz tube provided outside the ultraviolet light source, a photocatalytic medium cylinder provided outside the quartz tube, and a guide horizontal plate provided in the photocatalytic oxidation zone and at the lower end of the mounting horizontal plate, wherein the guide horizontal plate is provided with guide holes corresponding one to one with the ultraviolet light sources.

[0012] Furthermore, a filter grid is provided on the water inlet side of the sedimentation zone, a baffle is provided at the bottom of the sedimentation zone, a sewage discharge zone is penetrated and connected to the side wall of the sedimentation zone, and an opening and closing sealing plate is slidably connected to the connection between the sewage discharge zone and the sedimentation zone.

[0013] Description: When the oily wastewater enters the sedimentation area, the filter grille can effectively intercept and remove large particles of impurities in the oily wastewater, which can protect the subsequent adsorption and photocatalytic treatment equipment. When the oily wastewater treated by the filter grille enters the sedimentation area, the baffle plate can increase the separation time of suspended impurities and oily wastewater, so that the suspended impurities have more opportunities to settle to the bottom of the sedimentation area, thereby improving the sedimentation efficiency. When it is necessary to clean the sediment on the baffle plate, lift the side of the baffle plate opposite to the opening and closing sealing plate, open the opening and closing sealing plate, and allow the sediment to slide along the baffle plate to the sewage discharge area. Using gravity to allow the sediment to slide along the baffle plate to the sewage discharge area can ensure that the sediment is effectively transferred, avoid the residue of sediment during the transfer process, and improve the thoroughness of sediment cleaning, thereby ensuring that the sedimentation area can operate continuously and efficiently.

[0014] Furthermore, the activated carbon adsorption column is filled with activated carbon particles, and the particle size of the activated carbon particles located at the bottom of the activated carbon adsorption column is larger than the particle size of the activated carbon particles located at the top of the activated carbon adsorption column.

[0015] Description: When the oily wastewater is subjected to preliminary adsorption treatment, the activated carbon particles in the activated carbon adsorption column will make the oil substances and organic pollutants in the wastewater be adsorbed by the pores on its surface. As the oily wastewater flows in the activated carbon adsorption column, it passes through the activated carbon particle layers with gradually decreasing particle sizes from bottom to top. The larger activated carbon particles at the bottom first perform preliminary adsorption and filtration on the larger impurities and some oil droplets in the wastewater. Then, as the wastewater flows upward, the activated carbon particles with smaller particle sizes can adsorb the finer pollutants in the wastewater, achieving more refined treatment.

[0016] Furthermore, the fiber bundle is made of nanofibers, and the fiber bundle can be woven into a honeycomb structure.

[0017] Description: It can provide a larger porosity and reduce water flow resistance. At the same time, the honeycomb structure can provide more adsorption sites, which is beneficial to improve the adsorption efficiency.

[0018] Furthermore, a water sterilization component is provided in the clean water storage area, and the water sterilization component includes a mounting light board arranged at the bottom of the clean water storage area and having multiple ultraviolet sterilization lamps at the upper end, and a hemispherical refraction cover arranged at the upper end of the clean water storage area.

[0019] Description: When the water treated in the post-adsorption area is discharged into the clean water storage area, it is sterilized by ultraviolet germicidal lamps. At the same time, the ultraviolet rays emitted by each ultraviolet germicidal lamp are concentrated and refracted into the water through a hemispherical refraction cover. More ultraviolet energy can directly act on the water, and the effective ultraviolet dose received by the water is increased, thereby improving the sterilization effect.

[0020] Furthermore, a liquid level sensor is provided in the purified water storage area, and the refraction cover is made of organic glass.

[0021] Note: A liquid level sensor is set in the clean water storage area to detect the water level in real time to prevent water from overflowing and wasting. The reason why the refraction cover is limited to organic glass is that organic glass can effectively block most of the penetration of ultraviolet rays and improve the refraction efficiency.

[0022] Furthermore, vertical sliding grooves are respectively provided on the left and right sides of the inner wall of the photocatalytic oxidation zone, the left and right sides of the guide cross plate are slidably connected to the vertical sliding grooves, a spring vertical rod is provided between the vertical sliding groove and the guide cross plate, connecting vertical rods are provided on both sides of the bottom end of the mounting cross plate, an electromagnetic suction cup is provided at the bottom end of the connecting vertical rod, and a metal patch is provided on the guide cross plate and corresponding to the lower side of the electromagnetic suction cup.

[0023] Note: When it is necessary to adjust the height of the photocatalytic oxidation assembly according to the liquid level in the photocatalytic oxidation zone, first, the installation horizontal plate is driven to move up and down by the action of the hydraulic rod. When the liquid level is low, the installation horizontal plate moves downward until it contacts the guide horizontal plate, and continues to press down to compress the spring vertical rod, while the guide horizontal plate slides downward in the vertical sliding groove until the ultraviolet light source, the quartz tube and the guide horizontal plate are immersed in the water body. By adjusting the height of the photocatalytic oxidation assembly, it can be ensured that the ultraviolet light source and the quartz tube always maintain the best contact state with the water body, thereby improving the efficiency of the photocatalytic oxidation reaction. When the installation horizontal plate moves upward, the metal patch on the upper end of the guide horizontal plate is adsorbed by the electromagnetic suction cup, so that the guide horizontal plate and the installation horizontal plate move up synchronously, avoiding the guide horizontal plate from moving up too fast directly through the elastic recovery of the spring vertical rod, which may cause the collision between the guide horizontal plate and the vertical sliding groove to intensify, or cause excessive impact on the spring vertical rod itself.

[0024] Furthermore, the spring vertical rod includes a plurality of fixed columns and a plurality of spring columns, and the fixed columns and the spring columns are staggered from top to bottom, and the outer diameter of the photocatalytic medium cylinder is smaller than the inner diameter of the guide hole.

[0025] Description: The staggered fixed column and spring column structure can provide a more complex and multi-level buffering effect. When the installation cross plate is pressed down to make the guide cross plate move in the vertical sliding groove, this structure can gradually absorb and disperse the pressure. Compared with a single spring structure, it can more effectively reduce the impact of impact force on the equipment. By limiting the outer diameter of the photocatalytic medium cylinder to be smaller than the inner diameter of the guide hole, it is ensured that there is no collision between the photocatalytic medium cylinder and the guide hole.

[0026] The present invention also provides a method for comprehensive treatment of oily wastewater by adsorption-photocatalysis, based on the above-mentioned system for comprehensive treatment of oily wastewater by adsorption-photocatalysis, comprising the following steps:

[0027] S1. After the oily wastewater is initially precipitated in the sedimentation area, it is passed into the pre-adsorption area. When the wastewater enters the pre-adsorption area, the flow detection device on the water inlet side monitors the wastewater flow entering the pre-adsorption area in real time. If the flow fluctuates abnormally, the automatic regulating valve will be adjusted according to the data of the flow detection device to ensure that the wastewater flow entering the pre-adsorption area is stable within an appropriate range. When the oily wastewater enters the sedimentation area, the activated carbon adsorption columns at the bottom use the porous structure of the activated carbon to adsorb the oil and other pollutants in the wastewater, and then further adsorb the tiny particles and some soluble organic matter in the wastewater through the fiber bundle through physical adsorption;

[0028] S2. When the water body after the adsorption treatment in the front adsorption zone is passed into the photocatalytic oxidation zone, the flow detection device and the automatic regulating valve on the water inlet side work together to ensure the stability of the wastewater flow entering the photocatalytic oxidation zone. At the same time, according to the liquid level in the photocatalytic oxidation zone, the hydraulic rod drives the installation horizontal plate to move up and down. When the liquid level is low, the installation horizontal plate moves downward until it contacts the guide horizontal plate, and continues to press down to compress the spring vertical rod, and the guide horizontal plate slides downward in the vertical sliding groove until the ultraviolet light source, the quartz tube and the guide horizontal plate are immersed in the water body. After the water body after the adsorption treatment in the front adsorption zone is passed into the photocatalytic oxidation zone, the ultraviolet light source emits ultraviolet rays, and the quartz tube plays a role in protecting and focusing ultraviolet rays. The photocatalytic material in the photocatalytic medium tube produces a photocatalytic oxidation reaction under the irradiation of ultraviolet rays. In this process, organic pollutants in the wastewater are decomposed into small molecular substances under the photocatalytic action;

[0029] S3. When the water treated in the photocatalytic oxidation zone is passed into the post-adsorption zone, the flow detection device and the automatic regulating valve on the water inlet side also monitor and adjust the wastewater flow entering the post-adsorption zone. After the water treated in the photocatalytic oxidation zone is passed into the post-adsorption zone, the pollutants remaining after the photocatalytic oxidation are adsorbed by the MOFs adsorbent, and the ionic pollutants in the wastewater are removed by the ion exchange resin.

[0030] S4. When the water treated in the post-adsorption zone is passed into the clean water storage area, the outlet water quality is tested by a water quality testing device. If a large amount of particulate matter is detected in the water, the circulation branch pipe on the outlet side will circulate the water to the front adsorption zone. If organic matter is detected in the water, the circulation branch pipe on the outlet side will circulate the water to the inlet side of the photocatalytic oxidation zone. If the concentration of ionic pollutants in the water is detected to exceed the standard, the circulation branch pipe on the outlet side will circulate the water to the inlet side of the post-adsorption zone. If the water quality is found to be up to standard, it can be discharged.

[0031] Compared with the prior art, the beneficial effects of the present invention are:

[0032] (1) When the system for comprehensive treatment of oily wastewater by adsorption-photocatalysis of the present invention is used, a sedimentation zone, a pre-adsorption zone, a photocatalytic oxidation zone, a post-adsorption zone and a clean water storage zone are sequentially arranged to achieve a multi-step comprehensive treatment of oily wastewater. Each zone plays a role in different types of pollutants in the wastewater. The sedimentation zone removes large particle impurities, the pre-adsorption zone preliminarily adsorbs oil and pollutants, the photocatalytic oxidation zone decomposes organic pollutants, the post-adsorption zone further adsorbs residual pollutants and ionic pollutants, and the clean water storage zone performs sterilization treatment. This coordinated treatment method can comprehensively and efficiently purify oily wastewater;

[0033] (2) When the front adsorption zone is in use, the particle size of the activated carbon particles in the activated carbon adsorption column gradually decreases from bottom to top. This layered structure allows the larger activated carbon particles at the bottom to initially adsorb and filter the larger impurities and some oil droplets in the wastewater, while the smaller activated carbon particles adsorb the finer pollutants in the wastewater, thus achieving deep adsorption treatment of oil substances and organic pollutants in the oil-containing wastewater; when the rear adsorption zone is in use, nanofibers are woven into a honeycomb structure. The honeycomb structure provides a larger porosity, reduces water flow resistance, and provides more adsorption sites, which is beneficial to improve the adsorption efficiency of tiny particles and some soluble organic matter in the wastewater, further improving the purification effect of the front adsorption zone;

[0034] (3) The height of the installation horizontal plate in the photocatalytic oxidation zone is adjusted by a hydraulic rod, and a spring vertical rod is set between the guide horizontal plate and the vertical sliding groove. This structure can adjust the height of the photocatalytic oxidation component according to the liquid level in the photocatalytic oxidation zone, ensuring that the ultraviolet light source and the quartz tube always maintain the best contact state with the water body, thereby improving the efficiency of the photocatalytic oxidation reaction. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1 It is a schematic diagram of the overall structure of the present invention;

[0036] Figure 2 is a schematic diagram of the internal structure of the photocatalytic oxidation zone of the present invention;

[0037] Figure 3 is a top view of the photocatalytic oxidation zone of the present invention;

[0038] Figure 4 It is a schematic diagram of the installation structure of the guide horizontal plate of the present invention in the photocatalytic oxidation zone;

[0039] Figure 5 It is a schematic diagram of the external structure of the precipitation zone of the present invention;

[0040] Figure 6 It is a schematic diagram of the internal structure of the purified water storage area of ​​the present invention.

[0041] Among them, 1-precipitation area, 10-filter grid, 11-baffle, 12-drainage area, 13-opening and closing plugging plate, 2-front adsorption area, 20-first combined adsorption frame, 21-activated carbon adsorption column, 22-fiber bundle, 3-photocatalytic oxidation area, 30-photocatalytic oxidation component, 31-mounting horizontal plate, 310-hydraulic rod, 311-connecting vertical rod, 312-electromagnetic suction cup, 32-ultraviolet light source, 33-quartz tube, 34-photocatalytic medium cylinder, 35-guide horizontal plate, 35 0-guide hole, 351-metal patch, 36-vertical sliding groove, 360-spring vertical rod, 361-fixed column, 362-spring column, 4-rear adsorption area, 40-circulation branch pipe, 41-one-way solenoid valve, 42-water quality detection device, 43-flow detection device, 44-automatic regulating valve, 45-second combined adsorption rack, 5-clean water storage area, 50-water body sterilization component, 51-installation light board, 510-ultraviolet sterilization lamp, 52-refracting cover, 53-liquid level sensor. DETAILED DESCRIPTION

[0042] In order to further understand the content of the present invention, the present invention is described in detail below through examples.

[0043] Example 1: Figure 1 As shown, a system for comprehensive treatment of oily wastewater by adsorption-photocatalysis comprises a sedimentation zone 1, a front adsorption zone 2, a photocatalytic oxidation zone 3, a rear adsorption zone 4 and a clean water storage zone 5 which are connected end to end in sequence;

[0044] The water outlet side of the rear adsorption zone 4 and its water inlet side, the water inlet side of the front adsorption zone 2, and the water inlet side of the photocatalytic oxidation zone 3 are all connected through a circulation branch pipe 40, and each of the above-mentioned connections is respectively provided with a one-way solenoid valve 41, and the water outlet side of the rear adsorption zone 4 is connected to a water quality detection device 42, wherein the one-way solenoid valve 41 and the water quality detection device 42 both adopt existing technologies, for example, the one-way solenoid valve 41 can adopt a one-way solenoid valve of model FESTO, and the water quality detection device 42 can adopt a water quality detection device of model TE-700Pro;

[0045] The water inlet side of the front adsorption zone 2, the photocatalytic oxidation zone 3 and the rear adsorption zone 4 is provided with a flow detection device 43 and an automatic regulating valve 44, wherein the flow detection device 43 and the automatic regulating valve 44 both adopt the existing technology, for example, the flow detection device 43 can adopt a flow detection device of model T-89F, and the automatic regulating valve 44 can adopt an automatic regulating valve of model T941H-16P;

[0046] A first combined adsorption rack 20 is provided in the front adsorption zone 2, 36 activated carbon adsorption columns 21 are provided at the bottom of the first combined adsorption rack 20, and a fiber bundle 22 is provided at the top of the first combined adsorption rack 20;

[0047] The activated carbon adsorption column 21 is filled with activated carbon particles (commercially available products), and the particle size of the activated carbon particles at the bottom of the activated carbon adsorption column 21 is 2-3mm, and the particle size of the activated carbon particles at the top of the activated carbon adsorption column 21 is 0.5-1mm. When the oily wastewater is subjected to preliminary adsorption treatment, the activated carbon particles in the activated carbon adsorption column 21 allow the oil substances, organic pollutants, etc. in the wastewater to be adsorbed by the pores on its surface. As the oily wastewater flows in the activated carbon adsorption column 21, it passes through the activated carbon particle layers with gradually decreasing particle sizes from bottom to top. The larger activated carbon particles at the bottom first perform preliminary adsorption and filtration on the larger impurities, some oil droplets, etc. in the wastewater. Then, as the wastewater flows upward, the activated carbon particles with smaller particle sizes can adsorb finer pollutants in the wastewater to achieve more refined treatment;

[0048] The fiber bundle 22 is made of nanofiber (commercially available product), and the fiber bundle 22 can be woven into a honeycomb structure, which can provide a larger porosity and reduce water flow resistance. At the same time, the honeycomb structure can provide more adsorption sites, which is conducive to improving adsorption efficiency;

[0049] A second combined adsorption rack 45 is provided in the rear adsorption zone 4, the bottom end of the second combined adsorption rack 45 is filled with MOFs adsorbent (commercially available product), and the upper end of the second combined adsorption rack 45 is filled with ion exchange resin (commercially available product);

[0050] like Figure 2 , 3 As shown in Figure 4, a photocatalytic oxidation assembly 30 is provided in the photocatalytic oxidation zone 3. The photocatalytic oxidation assembly 30 includes a mounting horizontal plate 31 connected to the upper end of the photocatalytic oxidation zone 3 through a hydraulic rod 310, 36 ultraviolet light sources 32 distributed in a matrix at the bottom of the mounting horizontal plate 31, a quartz tube 33 arranged outside the ultraviolet light source 32, a photocatalytic medium tube 34 arranged outside the quartz tube 33, and a guide horizontal plate 35 arranged in the photocatalytic oxidation zone 3 and located at the lower end of the mounting horizontal plate 31, wherein the guide horizontal plate 35 is provided with guide holes 350 corresponding to the ultraviolet light sources 32 one by one, wherein the hydraulic rod 310, the ultraviolet light source 32, the quartz tube 33 and the photocatalytic medium tube 34 all adopt the existing technology, wherein the hydraulic rod 310 can be an existing Φ140 / 100-800 hydraulic rod, the ultraviolet light source 32 can adopt a model of UV-A, the quartz tube 33 can adopt a UV filter quartz tube, and the photocatalytic medium tube 34 can adopt a model of BL-GHX-V.

[0051] Example 2: This example discloses a method for comprehensive treatment of oily wastewater by adsorption-photocatalysis. A system for comprehensive treatment of oily wastewater by adsorption-photocatalysis based on Example 1 includes the following steps:

[0052] S1. After the oily wastewater is initially precipitated in the sedimentation zone 1, it is passed into the front adsorption zone 2. When the wastewater enters the front adsorption zone 2, the flow detection device 43 on the water inlet side monitors the wastewater flow entering the front adsorption zone 2 in real time. If the flow fluctuates abnormally, the automatic regulating valve 44 will be adjusted according to the data of the flow detection device 43 to ensure that the wastewater flow entering the front adsorption zone 2 is stable within a suitable range. When the oily wastewater enters the sedimentation zone 1, the activated carbon adsorption columns 21 at the bottom use the porous structure of the activated carbon to adsorb the oil and other pollutants in the wastewater, and then the fiber bundles 22 further adsorb the tiny particles and some soluble organic matter in the wastewater through physical adsorption.

[0053] S2. When the water body after adsorption treatment in the front adsorption zone 2 is passed into the photocatalytic oxidation zone 3, the flow detection device 43 and the automatic regulating valve 44 on the water inlet side work together to ensure the stability of the wastewater flow entering the photocatalytic oxidation zone 3. At the same time, according to the liquid level in the photocatalytic oxidation zone 3, the hydraulic rod 310 drives the installation horizontal plate 31 to move up and down. When the liquid level is lower than 1 / 3 of the height of the photocatalytic oxidation zone 3, the installation horizontal plate 31 moves downward to contact with the guide horizontal plate 35, and continues to press down to compress the spring vertical rod 360, and the guide The horizontal plate 35 slides downward in the vertical sliding groove 36 until the ultraviolet light source 32, the quartz tube 33 and the guide horizontal plate 35 are immersed in the water body. After the water body adsorbed by the front adsorption zone 2 enters the photocatalytic oxidation zone 3, the ultraviolet light source 32 emits ultraviolet rays, and the quartz tube 33 plays a role in protecting and focusing the ultraviolet rays. The photocatalytic material in the photocatalytic medium cylinder 34 produces a photocatalytic oxidation reaction under the irradiation of ultraviolet rays. In this process, the organic pollutants in the wastewater are decomposed into small molecular substances under the photocatalytic action;

[0054] S3, when the water treated by the photocatalytic oxidation zone 3 is passed into the post-adsorption zone 4, the flow detection device 43 and the automatic regulating valve 44 on the water inlet side also monitor and adjust the wastewater flow entering the post-adsorption zone 4. After the water treated by the photocatalytic oxidation zone 3 is passed into the post-adsorption zone 4, the pollutants remaining after the photocatalytic oxidation are adsorbed by the MOFs adsorbent, and the ionic pollutants in the wastewater are removed by the ion exchange resin;

[0055] S4. When the water treated by the rear adsorption zone 4 is passed into the clean water storage zone 5, the water quality of the outlet water is tested by the water quality testing device 42. If more than 100 particles with a particle size of less than 5 μm are detected in the water, the circulation branch pipe 40 on the outlet side will circulate the water to the front adsorption zone 2. If the concentration of organic matter in the water is detected to be greater than 5 mg / L, the circulation branch pipe 40 on the outlet side will circulate the water to the inlet side of the photocatalytic oxidation zone 3. If the concentration of ionic pollutants in the water is detected to be greater than 250 mg / L, the circulation branch pipe 40 on the outlet side will circulate the water to the inlet side of the rear adsorption zone 4. If the detected water quality meets the industrial water standard, it can be discharged.

[0056] Embodiment 3: This embodiment differs from Embodiment 1 in that:

[0057] like Figure 5 As shown, a filter grid 10 is provided at the water inlet side of the sedimentation zone 1, a baffle 11 is provided at the bottom end of the sedimentation zone 1, a sewage discharge zone 12 is penetrated and connected to the side wall of the sedimentation zone 1, and an opening and closing plugging plate 13 is slidably connected at the connection between the sewage discharge zone 12 and the sedimentation zone 1; when the oily wastewater enters the sedimentation zone 1, the filter grid 10 can effectively intercept and remove large particles of impurities in the oily wastewater, which can protect the subsequent adsorption and photocatalytic treatment equipment; when the oily wastewater treated by the filter grid 10 enters the sedimentation zone 1, the baffle 11 can increase the separation time of suspended impurities and oily wastewater , so that the suspended impurities have more opportunities to settle to the bottom of the sedimentation area 1, thereby improving the sedimentation efficiency. When it is necessary to clean the sediment on the baffle 11, lift the side of the baffle 11 opposite to the opening and closing sealing plate 13, open the opening and closing sealing plate 13, and allow the sediment to slide along the baffle 11 to the sewage discharge area 12. The sediment is allowed to slide along the baffle 11 to the sewage discharge area 12 by gravity, which can ensure that the sediment is effectively transferred, avoid the residue of the sediment during the transfer process, and improve the thoroughness of the sediment cleaning, thereby ensuring that the sedimentation area 1 can operate continuously and efficiently;

[0058] like Figure 6 As shown, a water sterilization component 50 is provided in the clean water storage area 5, and the water sterilization component 50 includes a mounting lamp board 51 which is arranged at the bottom of the clean water storage area 5 and has 37 ultraviolet sterilization lamps 510 at the upper end, and a hemispherical refraction cover 52 which is arranged at the upper end of the clean water storage area 5. When the water treated by the rear adsorption area 4 is discharged into the clean water storage area 5, the water is sterilized by the ultraviolet sterilization lamps 510. At the same time, the ultraviolet rays emitted by each ultraviolet sterilization lamp 510 are concentratedly refracted into the water by the hemispherical refraction cover 52, so that more ultraviolet energy can directly act on the water, and the effective ultraviolet dose received by the water is increased, thereby improving the sterilization effect. The ultraviolet sterilization lamp 510 adopts the existing technology, for example, an ultraviolet sterilization lamp with a model of 17491LM can be adopted.

[0059] A liquid level sensor 53 is provided in the clean water storage area 5, and the material of the refraction cover 52 is organic glass. The liquid level sensor 53 is provided in the clean water storage area 5 to detect the water level in real time to prevent the water in the clean water storage area 5 from overflowing and wasting. The reason for limiting the refraction cover 52 to organic glass is that organic glass can effectively block most of the penetration of ultraviolet rays and improve the refraction efficiency. Among them, the liquid level sensor 53 adopts the existing technology, for example, a liquid level sensor with model ENS3216-3-0520-000-K can be used.

[0060] Embodiment 4: This embodiment differs from Embodiment 2 in that:

[0061] In step S1, when the oily wastewater enters the sedimentation area 1, the filter grid 10 can effectively intercept and remove large particles of impurities in the oily wastewater, and the baffle 11 can increase the separation time of suspended impurities and oily wastewater, so that the suspended impurities have more opportunities to settle to the bottom of the sedimentation area 1. When it is necessary to clean the sediment on the baffle 11, the side of the baffle 11 opposite to the opening and closing sealing plate 13 is lifted, and the opening and closing sealing plate 13 is opened to allow the sediment to slide along the baffle 11 to the sewage discharge area 12, and gravity is used to allow the sediment to slide along the baffle 11 to the sewage discharge area 12;

[0062] In step S4, after the water treated in the post-adsorption area 4 is discharged into the clean water storage area 5, the water is sterilized by the ultraviolet sterilization lamp 510. At the same time, the ultraviolet rays emitted by each ultraviolet sterilization lamp 510 are concentrated and refracted into the water by the hemispherical refraction cover 52, and the water level is detected in real time by the liquid level sensor 53.

[0063] Embodiment 5: This embodiment differs from Embodiment 3 in that:

[0064] like Figure 2 , 3As shown in Figure 4, vertical sliding grooves 36 are respectively provided on the left and right sides of the inner wall of the photocatalytic oxidation zone 3, and the left and right sides of the guide horizontal plate 35 are slidably connected with the vertical sliding grooves 36. A spring vertical rod 360 is provided between the vertical sliding groove 36 and the guide horizontal plate 35. Connecting vertical rods 311 are provided on both sides of the bottom end of the installation horizontal plate 31, and an electromagnetic suction cup 312 is provided at the bottom end of the connecting vertical rod 311. A metal patch 351 is provided on the guide horizontal plate 35 and at the lower side corresponding to the electromagnetic suction cup 312. By adjusting the height of the photocatalytic oxidation component 30, it can be ensured that the ultraviolet light source 32 and the quartz tube 33 always maintain the best contact state with the water body, so that Improve the efficiency of the photocatalytic oxidation reaction. When the installation horizontal plate 31 moves upward, the metal patch 351 on the upper end of the guide horizontal plate 35 is adsorbed by the electromagnetic suction cup 312, so that the guide horizontal plate 35 and the installation horizontal plate 31 move upward synchronously, so as to avoid the guide horizontal plate 35 moving upward too fast directly through the elastic force recovery of the spring vertical rod 360, which may cause the collision between the guide horizontal plate 35 and the vertical sliding groove 36 to intensify, or cause excessive impact on the spring vertical rod 360 itself. Among them, the electromagnetic suction cup 312 adopts the existing technology, for example, the electromagnetic suction cup with the model MW22-10054L / 2-6 can be used;

[0065] The spring vertical rod 360 includes 8 fixed columns 361 and 7 spring columns 362, and each fixed column 361 and each spring column 362 are staggered from top to bottom. The outer diameter of the photocatalytic medium tube 34 is smaller than the inner diameter of the guide hole 350. The staggered fixed columns 361 and spring columns 362 structure can provide a more complex and multi-level buffering effect. When the installation cross plate 31 is pressed down to make the guide cross plate 35 move in the vertical sliding groove 36, this structure can gradually absorb and disperse the pressure. Compared with a single spring structure, it can more effectively reduce the impact of impact force on the equipment. By limiting the outer diameter of the photocatalytic medium tube 34 to be smaller than the inner diameter of the guide hole 350, it is ensured that no collision occurs between the photocatalytic medium tube 34 and the guide hole 350.

[0066] Embodiment 6: This embodiment differs from Embodiment 4 in that:

[0067] In step S2, when the liquid level in the photocatalytic oxidation zone 3 is low, the mounting cross plate 31 moves downward until it contacts the guide cross plate 35, and continues to press down to compress the spring vertical rod 360, while the guide cross plate 35 slides downward in the vertical sliding groove 36 until the ultraviolet light source 32, the quartz tube 33 and the guide cross plate 35 are immersed in the water body. When the mounting cross plate 31 moves upward, the metal patch 351 at the upper end of the guide cross plate 35 is adsorbed by the electromagnetic suction cup 312, so that the guide cross plate 35 and the mounting cross plate 31 move upward synchronously.

[0068] Test example

[0069] 1. Test equipment:

[0070] The system for comprehensive treatment of oily wastewater by adsorption-photocatalysis of the present invention; existing conventional equipment; water quality detection instruments, including an oil content detector (capable of accurately detecting the content of oil substances in wastewater with an accuracy of ±0.1 mg / L), an organic pollutant detector (capable of detecting the total content of a variety of common organic pollutants) and an ionic pollutant detector (capable of detecting the total concentration of ionic pollutants in wastewater).

[0071] 2. Test materials:

[0072] Collect representative oily wastewater samples from factories with large oily wastewater discharge volumes to ensure that the samples contain different concentrations of oil, organic pollutants, and ionic pollutants.

[0073] 3. Test methods:

[0074] Group processing

[0075] The collected oily wastewater samples were evenly divided into two groups, and the sample size of each group was large enough to ensure the accuracy of the test results. The first group of oily wastewater samples was treated using the system for comprehensive treatment of oily wastewater by adsorption and photocatalysis of the present invention, and in accordance with the treatment method in Example 2, the samples sequentially passed through the treatment process of the precipitation area 1, the front adsorption area 2, the photocatalytic oxidation area 3, the rear adsorption area 4 and the clean water storage area 5; the second group of oily wastewater samples was treated using the existing conventional oily wastewater treatment equipment and treated in accordance with its standard operating procedures;

[0076] 1) Detection indicators and time points

[0077] Before treatment, the two groups of oily wastewater samples were respectively tested for initial oil content, organic pollutant content and ionic pollutant content using water quality testing instruments. During the treatment process, for the system of the present invention, the wastewater was tested after passing through the front adsorption zone 2, the photocatalytic oxidation zone 3 and the rear adsorption zone 4; for the existing conventional treatment equipment, the test was carried out after its corresponding main treatment stage. After the treatment was completed, the two groups of treated water samples were fully tested again, and the test indicators included oil content, organic pollutant content and ionic pollutant content.

[0078] 4. Test results:

[0079] Initial: The average initial oil content is 500 mg / L, the average organic pollutant content is 300 mg / L, and the average ionic pollutant content is 500 mg / L;

[0080] During the treatment process: in the system of the present invention, after being treated in the front adsorption zone 2, the oil content is reduced to 300 mg / L, and the organic pollutant content is reduced to 200 mg / L, which is due to the adsorption effect of the activated carbon adsorption column 21 and the fiber bundle 22. After being treated in the photocatalytic oxidation zone 3, the oil content is further reduced to 50 mg / L, and the organic pollutant content is reduced to 50 mg / L, because the photocatalytic oxidation reaction decomposes a large amount of organic pollutants. After being treated in the rear adsorption zone 4, the oil content is reduced to below 10 mg / L, the organic pollutant content is reduced to below 10 mg / L, and the ionic pollutant content is also greatly reduced to below 100 mg / L, thanks to the adsorption effect of the MOFs adsorbent and the ion exchange resin; in the existing conventional treatment equipment, after the main adsorption stage treatment, the oil content is only reduced to 350 mg / L, and the organic pollutant content is reduced to 250 mg / L, and there is almost no removal effect on ionic pollutants;

[0081] After treatment: The oil content of the water sample treated by the system of the present invention is lower than 5 mg / L, the organic pollutant content is lower than 5 mg / L, and the ionic pollutant content is lower than 50 mg / L, reaching the industrial water standard; the oil content of the water sample treated by the existing conventional treatment equipment is still as high as more than 100 mg / L, the organic pollutant content is about 150 mg / L, and the ionic pollutant content remains basically unchanged, which is far from meeting the industrial water standard.

[0082] 5. Conclusion:

[0083] Through the comparison of the above test results, it can be seen that the system for comprehensive treatment of oily wastewater by adsorption photocatalysis of the present invention is significantly better than the existing conventional oily wastewater treatment technology in removing oil substances, organic pollutants and ionic pollutants when treating oily wastewater, and can more effectively purify oily wastewater to meet industrial water standards.

Claims

1. A system for comprehensive treatment of oily wastewater by adsorption-photocatalysis, comprising a sedimentation zone (1), a front adsorption zone (2), a photocatalytic oxidation zone (3), a rear adsorption zone (4) and a clean water storage zone (5) connected end to end in sequence; The water outlet side of the rear adsorption zone (4) and its water inlet side, the water inlet side of the front adsorption zone (2), and the water inlet side of the photocatalytic oxidation zone (3) are all connected via a circulation branch pipe (40), and each of the above-mentioned connections is provided with a one-way solenoid valve (41), and the water outlet side of the rear adsorption zone (4) is connected to a water quality detection device (42); The water inlet sides of the front adsorption zone (2), the photocatalytic oxidation zone (3) and the rear adsorption zone (4) are all provided with a flow detection device (43) and an automatic regulating valve (44); A first combined adsorption frame (20) is provided in the front adsorption zone (2), a plurality of activated carbon adsorption columns (21) are provided at the bottom end of the first combined adsorption frame (20), and a fiber bundle (22) is provided at the top end of the first combined adsorption frame (20); A second combined adsorption frame (45) is provided in the rear adsorption zone (4), the bottom end of the second combined adsorption frame (45) is filled with MOFs adsorbent, and the upper end of the second combined adsorption frame (45) is filled with ion exchange resin; A photocatalytic oxidation component (30) is provided in the photocatalytic oxidation zone (3), the photocatalytic oxidation component (30) comprising a mounting horizontal plate (31) connected to the upper end of the photocatalytic oxidation zone (3) via a hydraulic rod (310), a plurality of ultraviolet light sources (32) distributed in a matrix at the bottom end of the mounting horizontal plate (31), a quartz tube (33) provided outside the ultraviolet light source (32), a photocatalytic medium cylinder (34) provided outside the quartz tube (33), and a guide horizontal plate (35) provided in the photocatalytic oxidation zone (3) and located at the lower end of the mounting horizontal plate (31), wherein the guide horizontal plate (35) is provided with guide holes (350) corresponding one to one with the ultraviolet light sources (32).

2. The system for comprehensive treatment of oily wastewater by adsorption-photocatalysis according to claim 1 is characterized in that: A filter grid (10) is provided on the water inlet side of the sedimentation zone (1), a baffle (11) is provided at the bottom end of the sedimentation zone (1), a sewage discharge zone (12) is connected through the side wall of the sedimentation zone (1), and an opening and closing blocking plate (13) is slidably connected at the connection between the sewage discharge zone (12) and the sedimentation zone (1).

3. The system for comprehensive treatment of oily wastewater by adsorption-photocatalysis according to claim 1 is characterized in that: The activated carbon adsorption column (21) is filled with activated carbon particles, and the particle size of the activated carbon particles located at the bottom end of the activated carbon adsorption column (21) is larger than the particle size of the activated carbon particles located at the top end of the activated carbon adsorption column (21).

4. The system for comprehensive treatment of oily wastewater by adsorption-photocatalysis according to claim 1 is characterized in that: The fiber bundle (22) is made of nanofibers, and the fiber bundle (22) can be woven into a honeycomb structure.

5. The system for comprehensive treatment of oily wastewater by adsorption-photocatalysis according to claim 1 is characterized in that: A water sterilization component (50) is provided in the clean water storage area (5), and the water sterilization component (50) comprises a light mounting plate (51) provided at the bottom of the clean water storage area (5) and provided with a plurality of ultraviolet sterilization lamps (510) at the upper end, and a hemispherical refraction cover (52) provided at the upper end of the clean water storage area (5).

6. The system for comprehensive treatment of oily wastewater by adsorption-photocatalysis according to claim 5 is characterized in that: A liquid level sensor (53) is provided in the purified water storage area (5), and the refraction cover (52) is made of organic glass.

7. The system for comprehensive treatment of oily wastewater by adsorption-photocatalysis according to claim 1 is characterized in that: The inner wall of the photocatalytic oxidation zone (3) is provided with vertical sliding grooves (36) on the left and right sides respectively, the left and right sides of the guide cross plate (35) are slidably connected to the vertical sliding grooves (36), a spring vertical rod (360) is provided between the vertical sliding grooves (36) and the guide cross plate (35), connecting vertical rods (311) are provided on both sides of the bottom end of the installation cross plate (31), an electromagnetic suction cup (312) is provided at the bottom end of the connecting vertical rod (311), and a metal patch (351) is provided on the guide cross plate (35) and at the lower side corresponding to the electromagnetic suction cup (312).

8. The system for comprehensive treatment of oily wastewater by adsorption-photocatalysis according to claim 7 is characterized in that: The spring vertical rod (360) comprises a plurality of fixed columns (361) and a plurality of spring columns (362), and the fixed columns (361) and the spring columns (362) are staggeredly distributed from top to bottom, and the outer diameter of the photocatalytic medium cylinder (34) is smaller than the inner diameter of the guide hole (350).

9. A method for comprehensive treatment of oily wastewater by adsorption-photocatalysis, based on a system for comprehensive treatment of oily wastewater by adsorption-photocatalysis according to any one of claims 1 to 8, characterized in that: The following steps are involved: S1. After the oily wastewater undergoes preliminary sedimentation treatment in the sedimentation zone (1), it is passed into the pre-adsorption zone (2). When the wastewater enters the pre-adsorption zone (2), the flow detection device (43) on the water inlet side monitors the wastewater flow entering the pre-adsorption zone (2) in real time. If the flow fluctuates abnormally, the automatic regulating valve (44) will be adjusted according to the data of the flow detection device (43) to ensure that the wastewater flow entering the pre-adsorption zone (2) is stable within an appropriate range. When the oily wastewater enters the sedimentation zone (1), the activated carbon adsorption columns (21) at the bottom use the porous structure of the activated carbon to adsorb the oil and other pollutants in the wastewater. Then, the fiber bundles (22) further adsorb the tiny particles and some soluble organic matter in the wastewater through physical adsorption. S2. When the water body after adsorption treatment in the front adsorption zone (2) is passed into the photocatalytic oxidation zone (3), the flow detection device (43) and the automatic regulating valve (44) on the water inlet side work together to ensure that the wastewater flow entering the photocatalytic oxidation zone (3) is stable. At the same time, according to the liquid level in the photocatalytic oxidation zone (3), the hydraulic rod (310) drives the installation horizontal plate (31) to move up and down. When the liquid level is low, the installation horizontal plate (31) moves downward until it contacts the guide horizontal plate (35), and continues to press downward to compress the spring vertical rod (360), so that the guide horizontal plate (35) is moved upward. ) slides downward in the vertical sliding groove (36) until the ultraviolet light source (32), the quartz tube (33) and the guide horizontal plate (35) are immersed in the water body. After the water body has been adsorbed by the front adsorption zone (2) and passed into the photocatalytic oxidation zone (3), the ultraviolet light source (32) emits ultraviolet light, and the quartz tube (33) plays a role in protecting and focusing the ultraviolet light. The photocatalytic material in the photocatalytic medium cylinder (34) produces a photocatalytic oxidation reaction under the irradiation of ultraviolet light. In this process, the organic pollutants in the wastewater are decomposed into small molecular substances under the photocatalytic action; S3, when the water treated by the photocatalytic oxidation zone (3) is passed into the post-adsorption zone (4), the flow detection device (43) and the automatic regulating valve (44) on the water inlet side also monitor and adjust the wastewater flow entering the post-adsorption zone (4), and after the water treated by the photocatalytic oxidation zone (3) is passed into the post-adsorption zone (4), the pollutants remaining after the photocatalytic oxidation are adsorbed by the MOFs adsorbent, and the ionic pollutants in the wastewater are removed by the ion exchange resin; S4. When the water treated by the rear adsorption zone (4) is passed into the clean water storage zone (5), the water quality of the outlet water is tested by the water quality testing device (42). If a large amount of particulate matter is detected in the water, the circulation branch pipe (40) on the outlet side will circulate the water to the front adsorption zone (2). If organic matter is detected in the water, the circulation branch pipe (40) on the outlet side will circulate the water to the inlet side of the photocatalytic oxidation zone (3). If the concentration of ionic pollutants in the water exceeds the standard, the circulation branch pipe (40) on the outlet side will circulate the water to the inlet side of the rear adsorption zone (4). If the water quality is found to be up to standard, it can be discharged.

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