Coal chemical wastewater treatment process and system

Abstract

The present invention belongs to the field of coal chemical wastewater treatment, and relates to a coal chemical wastewater treatment process and system. The coal chemical wastewater treatment system comprises: a reaction box, a top cover is provided at the upper end of the box body, and a wastewater inlet pipe, a drain pipe and an exhaust pipe are provided on the box body. A rotating drum unit comprises a drum body, a pivot part and a driving assembly; the drum body is arranged in the reaction box and is arranged horizontally; the driving assembly can drive the drum body to rotate; the outer wall of the drum body is covered with a titanium dioxide coating. An ultraviolet lamp unit comprises a connecting seat, an arc plate, a plurality of lamp bodies and a controller; the arc plate is placed in the reaction box and is correspondingly arranged above the drum body and the concave surface is opposite to the outer peripheral surface of the drum body; the lamp bodies are dispersed on the concave surface of the arc plate. And an aeration unit. The present invention can promote the induced OH· free radicals to act together with ozone, which is beneficial to the strong oxidizing ability formed by the combination, fully oxidizes the polycyclic and heterocyclic compounds in the wastewater, generates easily degradable organic matter, and helps to improve the removal efficiency of organic matter in the wastewater.

Description

Technical Field

[0001] The present invention relates to the technical field of coal chemical wastewater treatment, and in particular to a coal chemical wastewater treatment process and system. Background Art

[0002] Coal chemical wastewater mainly comes from production processes such as coal gasification, coal coking, coal liquefaction, and wastewater generated by production auxiliary facilities. The pollutants in the wastewater mainly include phenols, polycyclic aromatic compounds, and heterocyclic compounds containing nitrogen, oxygen, and sulfur, and quinolines, indoles, pyridines, carbazoles, etc. account for a relatively large proportion. It is a typical industrial wastewater containing difficult-to-degrade organic compounds. Coal chemical wastewater contains a considerable amount of organic matter that cannot be biochemically treated, and most of them are polycyclic organic matter.

[0003] The existing coal chemical wastewater treatment processes mostly include: flotation oil removal, anoxic-aerobic biochemical treatment and other steps. Although they can achieve good treatment effects on phenolic and alkane compounds, the removal rate of quinoline, indole, pyridine, carbazole and other difficult-to-degrade organic matter is still relatively low, and the treatment process is time-consuming and energy-intensive. Therefore, it is urgent to provide a new process and new system for treating coal chemical wastewater to improve the treatment efficiency of difficult-to-degrade organic matter such as quinoline, indole, pyridine, carbazole and the like contained in the wastewater. Summary of the invention

[0004] To achieve the above-mentioned purpose, the present invention provides a coal chemical wastewater treatment process and system, which utilizes the property of titanium dioxide that can induce wastewater to produce OH· free radicals under the action of ultraviolet rays, designs a photocatalytic oxidation structure, can induce the production of a large number of OH· free radicals in the wastewater by promoting the continuous circulation of titanium dioxide and ultraviolet rays, and quickly contacting with wastewater after being induced, and finally promotes the large number of generated OH· free radicals to act together with ozone, so that the oxidation ability of the OH· free radicals themselves and the oxidation ability of ozone themselves are improved in a complementary manner, forming a mass transfer environment containing super-strong oxidizing ions, fully oxidizing polycyclic and heterocyclic compounds in the wastewater to generate easily degradable organic matter, thereby helping to reduce the difficulty of later anaerobic and / or aerobic biochemical treatment and improving the removal efficiency of organic matter in the wastewater.

[0005] The technical solution adopted by the present invention to solve the technical problem is: a coal chemical wastewater treatment system, comprising:

[0006] A reaction box, wherein the upper opening of the box body is provided with a top cover to seal the opening of the box body, a wastewater inlet pipe connected to the cavity of the box body is provided at the lower part of the box body, a drain pipe connected to the cavity of the box body is provided at the middle and upper part of the box body, and an exhaust pipe connected to the cavity of the box body is provided at the upper part of the box body;

[0007] The drum unit comprises a drum body, a pivot portion connected to the drum body, and a driving assembly matched with the pivot portion; the drum body is arranged in the cavity of the reaction box through the pivot portion, and the axis of the drum body is arranged in the horizontal direction; the driving assembly is installed outside the reaction box and can drive the drum body to rotate relative to the reaction box; a titanium dioxide coating is covered on the outer peripheral surface of the drum body;

[0008] The ultraviolet lamp unit comprises a connection seat, an arc plate, a plurality of lamp bodies and a controller; the connection seat is fixedly connected to the top cover, the arc plate is placed in the cavity of the reaction box and is correspondingly arranged directly above the cylinder; the controller is placed outside the reaction box and connected to a power supply; the concave surface of the arc plate is opposite to the outer peripheral surface of the cylinder, and the plurality of lamp bodies are dispersedly fixed on the concave surface of the arc plate, so that the ultraviolet light emitted by the lamp body can be irradiated on the outer peripheral surface of the cylinder;

[0009] And an aeration unit, wherein an aeration pipe is arranged in the cavity of the reaction box and relatively below the cylinder body, and can dispersely inject ozone bubbles into the wastewater in the reaction box.

[0010] The water level of the wastewater injected into the reaction box is required to be lower than the top surface height on the outer circumference of the cylinder, so that a part of the arc surface on the upper part of the outer circumference of the cylinder is always exposed to the wastewater, so that this part of the titanium dioxide coating can come into contact with the ultraviolet light, and during operation, it is ensured that the titanium dioxide coating distributed on the outer circumference of the cylinder can alternately come into contact with the ultraviolet light.

[0011] The gas fed into the reaction box through the aeration unit can be ozone-containing air or high-concentration ozone-containing gas obtained from an ozone storage tank. The exhaust pipe provided on the upper part of the reaction box can be connected to the aeration unit, and the ozone discharged through the exhaust pipe can be recycled back to the aeration unit to continue to participate in the oxidation treatment process of the wastewater.

[0012] In the above embodiment, the titanium dioxide coating on the outer peripheral surface of the cylinder can contact the ultraviolet light emitted by the lamp body with the rotation of the cylinder body, thereby inducing the wastewater to produce a large number of OH free radicals. Because the lamp body is arranged on the concave surface of the arc plate and is above the outer peripheral surface of the cylinder body, the titanium dioxide coating on the outer peripheral surface of the cylinder can be fully irradiated to react and induce the wastewater.

[0013] A concave structure and / or a convex structure of regular or irregular shape such as a groove or a rib plate can be arranged on the outer circumference of the cylinder, and a titanium dioxide coating can be applied to the outer surface of the concave structure and the outer surface of the convex structure to increase the area of ​​the titanium dioxide coating. At this time, because the lamp body is arranged on the concave surface of the arc plate and is located above the outer circumference of the cylinder, the outer surface of the concave structure and the outer surface of the convex structure can be fully irradiated by ultraviolet light, so that the size of the shadow area is effectively suppressed, which helps to increase the area of ​​the titanium dioxide coating.

[0014] Optionally, a plurality of elongated slot structures are formed on the wall of the cylinder, and the plurality of elongated slot structures are alternately distributed around the circumferential direction.

[0015] Furthermore, the notch structure is a strip-shaped notch formed on the cylinder wall of the cylinder, and the strip-shaped notch extends to both ends of the cylinder. On the same side of the strip-shaped notch around the circumferential direction, an inner folding plate extending obliquely toward the cylinder is formed, and a connecting rod is provided at the free end of the inner folding plate to be fixedly connected with the pivot part, thereby connecting the cylinder and the pivot part as a whole, so that the pivot part can drive the cylinder to rotate.

[0016] The extension length of the inner folding plate is not less than 1 / 2 of the axial length of the cylinder. The extension length of the inner folding plate can be consistent with the axial length of the cylinder, or can be greater than the axial length of the cylinder.

[0017] The cylinder can be an integrated structure; or a split structure divided into multiple sections in the axial direction. In this case, a gap in the axial direction is formed between two adjacent sections of the cylinder after assembly, and the strip-shaped notches on each section of the cylinder are matched with inner folding plates. In addition, the strip-shaped notches on each section of the cylinder can be axially penetrated in a straight line, or part of the strip-shaped notches can be axially penetrated in a straight line.

[0018] Optionally, the slot structure is a strip slot formed on the cylinder wall of the cylinder, wherein two side surfaces of the strip slot, namely the first side surface and the second side surface, are two relatively parallel planes, and both the first side surface and the second side surface extend obliquely from outside to inside in the clockwise direction.

[0019] Optionally, a plurality of protrusions are distributed on the outer circumferential surface of the cylinder, and the protrusions are discretely distributed around the circumferential direction.

[0020] Specifically, the protrusion is a spring member and / or a pyramid-shaped protrusion, so that the spring members or protrusions are arranged in rows on the outer circumferential surface of the cylinder and in the width direction, and the number of spring members or protrusions in two adjacent rows in the circumferential direction is different. Among the multiple spring members or multiple protrusions in each row, there is a position offset / misalignment in the circumferential direction between two adjacent spring members or two protrusions in the width direction.

[0021] The pyramidal protrusions may be selected from the form of triangular pyramidal protrusions, quadrangular pyramidal protrusions, and other multi-sided pyramidal protrusions, and may be a mixture of triangular pyramidal protrusions, quadrangular pyramidal protrusions, and the like.

[0022] Optionally, a plurality of protrusion groups are distributed on the outer circumferential surface of the cylinder, and the protrusion groups are distributed alternately around the circumferential direction.

[0023] The protrusion bar group includes a pair of V-shaped protrusion bars and a pair of straight protrusion bars, and the angle between the V-shaped protrusion bars is an obtuse angle. The pairs of straight protrusion bars in each protrusion bar group are relatively arranged downstream of the pairs of V-shaped protrusion bars.

[0024] The tips of the two paired V-shaped protrusions are made to face each other, forming two "eight" shapes in the circumferential direction, and the flared width of one "eight" shape facing the two straight protrusions in the same group is smaller than the flared width of the other "eight" shape.

[0025] The two straight protrusions in a pair are arranged in an "eight" shape, and the flaring width of one end of the two V-shaped protrusions in the same group is greater than the flaring width of the other end.

[0026] One end of two V-shaped protrusions in the protrusion group is expanded and extends into one end of two straight protrusions. That is, in the protrusion group, between the opposite ends of the V-shaped protrusion and the straight protrusion, the end of the V-shaped protrusion extends into the end expansion of the straight protrusion.

[0027] In two adjacent protrusion groups, between opposite ends of the straight protrusions in one group and the V-shaped protrusions in the other group, the narrowing width of the straight protrusions is smaller than the expanding width of the V-shaped protrusions.

[0028] Optionally, an electrode unit is further included, so that the electrode plate of the electrode unit is arranged in the reaction box and is located between the bottom of the cylinder and the top of the aeration port of the aeration unit.

[0029] The electrode plates include multiple groups arranged alternately up and down. Each group includes an anode plate and a cathode plate in pairs up and down, and the anode plate is located above the cathode plate. At the same time, an insulating silicone gasket is provided between the anode plate and the cathode plate.

[0030] The anode plate can be any one of carbon fiber cloth, graphite electrode, boron-doped diamond electrode, stainless steel electrode, titanium electrode and precious metal electrode. The cathode plate is a ferrite-modified carbon fiber cloth electrode.

[0031] The aeration port of the aeration unit is correspondingly arranged below the cathode plate.

[0032] Optionally, a cover plate unit is also included. The cover plate unit includes two groups of cover plates, a shaft rod and a connecting plate.

[0033] The two connecting plates are fixed on the left inner wall and the right inner wall of the reaction box respectively. The two cover plates are matched with the two connecting plates respectively, so that the two cover plates are arranged opposite to each other on the left and right and are placed on a horizontal plane passing through the axis center line of the cylinder. The extension length of the cover plate in the front-to-back direction is not less than the axial length of the cylinder. A small gap is formed between the free end of the cover plate and the left wall surface or the right wall surface of the outer peripheral surface of the cylinder. The end of the cover plate that matches the connecting plate is fixedly connected to the shaft rod. Torsion springs are arranged on the two ends of the shaft rod extending outside the reaction box, and the torsion springs can make the cover plate swing upward and downward relative to the horizontal plane in the vertical direction. The amplitude of the upward and downward swinging of the cover plate is controlled within the range of an angle of 30 degrees relative to the horizontal plane, preferably within the range of an angle of 15 degrees.

[0034] The present invention relates to a coal chemical wastewater treatment process, which comprises the following steps:

[0035] Ⅰ) Flotation treatment: the coal chemical wastewater is introduced into the flotation system and drugs such as polyaluminium chloride are added into the flotation system. The duration of the flotation treatment is controlled within 20 to 45 minutes. During the flotation treatment process, the suspended solids on the wastewater need to be continuously removed.

[0036] II) The wastewater after flotation treatment is discharged into a reaction box of any coal chemical wastewater treatment system including only the above-mentioned photocatalytic oxidation structure, and the wastewater in the reaction box is continuously subjected to photocatalytic oxidation treatment for a time period of 1.5 to 2.5 hours; during which, bubbles containing ozone are intermittently introduced into the reaction box; the ozone content in the wastewater in the reaction box is required to be maintained between 20 mg / L and 60 mg / L;

[0037] III) The wastewater after photocatalytic oxidation treatment is discharged from the reaction box to the anoxic tank for anaerobic biochemical treatment and / or to the aerobic tank for aerobic biochemical treatment; preferably, the dual biochemical treatment method of anaerobic biochemical treatment plus aerobic biochemical treatment;

[0038] IV) After anaerobic and / or aerobic treatment, the wastewater is discharged into a sedimentation tank for sedimentation treatment; the sedimentation treatment time is 2.5 hours to 6 hours.

[0039] The present invention also relates to a coal chemical wastewater treatment process, which comprises the following steps:

[0040] Ⅰ) Flotation treatment: the coal chemical wastewater is introduced into the flotation system and drugs such as polyaluminium chloride are added into the flotation system. The duration of the flotation treatment is controlled within 20 to 45 minutes. During the flotation treatment process, the suspended solids on the wastewater need to be continuously removed.

[0041] II) The wastewater after flotation treatment is discharged into a reaction box of a coal chemical wastewater treatment system including the above-mentioned photocatalytic oxidation structure and electrode oxidation-catalytic structure, and the wastewater in the reaction box is continuously subjected to photocatalytic oxidation treatment and electrode oxidation catalytic treatment for a time length of 1 to 2 hours; during which, bubbles containing ozone are intermittently introduced into the reaction box; the ozone content in the wastewater in the reaction box is required to be maintained between 30 mg / L and 80 mg / L;

[0042] III) The wastewater after the photocatalytic oxidation treatment and the electrode oxidation catalytic treatment is discharged from the reaction box to the anoxic tank for anaerobic biochemical treatment and / or to the aerobic tank for aerobic biochemical treatment; preferably, the dual biochemical treatment method of anaerobic biochemical treatment plus aerobic biochemical treatment;

[0043] IV) After anaerobic and / or aerobic treatment, the wastewater is discharged into a sedimentation tank for sedimentation treatment; the sedimentation treatment time is 2.5 hours to 6 hours.

[0044] The beneficial effects of the present invention are as follows: the coal chemical wastewater treatment process and system provided by the present invention can continuously induce wastewater to produce a large number of OH· free radicals during the cyclic contact process between titanium dioxide and ultraviolet light. The super strong oxidizing ability of a large number of OH· free radicals, combined with ozone to form a strong oxidizing environment, can fully oxidize polycyclic and heterocyclic compounds in wastewater, such as quinolines, indoles, pyridines, carbazoles, etc., so that the ring bonds of polycyclic compounds are broken to generate easily degradable organic matter. Therefore, the present invention helps to reduce the difficulty of anaerobic and / or aerobic biochemical treatment of coal chemical wastewater in the later stage, can significantly improve the removal efficiency of organic matter in wastewater, and overcome the defects of the prior art that the treatment of coal chemical wastewater is time-consuming and energy-intensive. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] Figure 1 Process flow chart for (partial process) treatment of coal chemical wastewater.

[0046] Figure 2 This is a schematic diagram of the structure of the photocatalytic device involved in the system for treating coal chemical wastewater.

[0047] Figure 3 It is a schematic diagram of the top view of the rotating drum unit in the photocatalytic device (when assembled on the reaction box).

[0048] Figure 4 This is a schematic diagram of the top view of the optimized structure of the drum unit.

[0049] Figure 5 Schematic diagram of the drum section structure of the drum unit Figure 1 .

[0050] Figure 6It is a schematic diagram of the protrusion structure arranged on the outer peripheral surface of the drum unit.

[0051] Figure 7 It is a schematic diagram of the structure of the protrusion group arranged on the outer peripheral surface of the drum unit.

[0052] Figure 8 Schematic diagram of the drum section structure of the drum unit Figure 2 .

[0053] Fig. 9 Schematic diagram of the drum section structure of the drum unit Figure 3 .

[0054] Fig.10 for Fig. 9 Schematic diagram of the AA section structure.

[0055] Fig.11 This is a schematic diagram of the structure of the photocatalytic and electrode oxidation devices involved in the system for treating coal chemical wastewater.

[0056] Fig.12 for Figure 2 Schematic diagram of the local enlarged structure at point A in the middle.

[0057] In the figure: 100 reaction box, 101 box body, 102 top cover; 200 drum unit, 201 drum body, 2011 rear drum body, 2012 middle drum body, 2013 front drum body, 202 strip notch, 203 strip slot, 1 first side surface, 2 second side surface, 204 pivot part, 205 inner folding plate, 206 connecting rod, 207 protrusion, 2071 protrusion point, 208 protrusion group, 2081 V-shaped protrusion, 2082 Straight protrusion, 209 bevel edge plate, 210 spring member; 300 UV lamp unit, 301 connecting seat, 302 arc plate, 303 lamp body, 304 controller; 400 cover plate unit, 401 cover plate, 402 shaft rod, 403 connecting plate; 500 aeration unit, 501 air distribution plate; 600 filter plate; 700 electrode unit, 701 anode plate, 702 cathode plate. DETAILED DESCRIPTION

[0058] The structures, proportions, sizes, etc. illustrated in the drawings of the specification are only used to match the contents disclosed in the specification for people familiar with this technology to understand and read, and are not used to limit the limiting conditions for the implementation of the present invention, so they have no substantial technical significance. Any modification of the structure, change of the proportion relationship or adjustment of the size, without affecting the effects and purposes that can be achieved by the present invention, should still fall within the scope of the technical contents disclosed by the present invention. At the same time, the terms such as "upper", "lower", "front", "back", "middle" and so on quoted in this specification are only for the convenience of description, and are not used to limit the scope of the implementation of the present invention. The change or adjustment of their relative relationship should also be regarded as the scope of the implementation of the present invention without substantially changing the technical contents.

[0059] like Figure 2 , Fig.12 The coal chemical wastewater treatment system shown includes a reaction box 100 , a drum unit 200 , an ultraviolet lamp unit 300 , a cover unit 400 and an aeration unit 500 .

[0060] The upper end of the box body 101 of the reaction box 100 is an open structure and is provided with a top cover 102 to seal the opening. A wastewater inlet pipe communicating with the cavity of the box body 101 is provided at the lower part of the box body 101, a drain pipe communicating with the cavity of the box body 101 is provided at the middle and upper part of the box body 101, and an exhaust pipe communicating with the cavity of the box body 101 is provided at the upper part of the box body 101, which is used to discharge the gas overflowing from the wastewater to the outside of the reaction box 100.

[0061] The drum unit 200 includes an axially penetrating barrel 201, a pivot portion 204 connected to the barrel 201, and a drive assembly (not shown) matched with the pivot portion 204. The barrel 201 is arranged in the cavity of the reaction box 100 through the pivot portion 204 and the axis of the barrel 201 is arranged to extend in the horizontal direction. The axis of the barrel 201 is in a horizontal plane in the front-to-back direction in the figure. The drive assembly is installed on the outside of the reaction box 100 and can drive the barrel 201 to rotate around its axis at an angular velocity ω relative to the reaction box 100 (the rotation direction of the angular velocity ω in the figure is counterclockwise). A titanium dioxide coating is provided on the outer peripheral surface of the barrel 201.

[0062] The cylinder 201 can be made of acid-resistant, alkali-resistant and corrosion-resistant materials such as ceramics.

[0063] The ultraviolet lamp unit 300 includes a connection seat 301, an arc plate 302, a plurality of lamp bodies 303 and a controller 304. The connection seat 301 is fixedly connected to the top cover 102. The arc plate 302 and the controller 304 are fixedly connected to the connection seat 301, and the arc plate 302 is placed in the cavity of the reaction box 100 and is correspondingly arranged directly above the cylinder 201. The controller 304 is placed outside the reaction box 100 and connected to a power supply. The concave surface of the arc plate 302 faces downward and is opposite to the top of the outer peripheral surface of the cylinder 201. A plurality of lamp bodies 303 are dispersedly fixed on the concave surface of the arc plate 302, so that the ultraviolet light emitted by the lamp body 303 can be irradiated on the upper outer peripheral surface of the cylinder 201.

[0064] The cover plate unit 400 includes two groups of cover plates 401 , a shaft 402 and a connecting plate 403 .

[0065] The two connecting plates 403 are respectively fixed on the left inner wall and the right inner wall of the reaction box 100. The two cover plates 401 are respectively matched with the two connecting plates 403, so that the two cover plates 401 are arranged opposite to each other in the left-right direction and are placed on a horizontal plane passing through the extension direction of the axis of the cylinder 201.

[0066] The extension length of the cover plate 401 in the front-to-back direction (i.e., the axial extension direction of the cylinder 201) is not less than the axial length of the cylinder 201. Gaps are formed between the free end of the cover plate 401 and the left wall surface and the right wall surface of the outer peripheral surface of the cylinder 201. The end of the cover plate 401 that matches the connecting plate 403 is fixedly connected to the shaft rod 402. Torsion springs are arranged on both ends of the shaft rod 402 extending outside the reaction box 100, and the torsion of the torsion spring can enable the cover plate 401 to swing upward and downward relative to the horizontal plane in the vertical direction. The amplitude of the upward and downward swinging of the cover plate 401 is controlled within the range of an angle of 30 degrees relative to the horizontal plane (i.e., the swing angle is not greater than 30 degrees), preferably within the range of an angle of 15 degrees.

[0067] The cover plate unit 400 can block the rising of ozone-containing bubbles, which helps to significantly increase the concentration of ozone-containing bubbles in the wastewater gathered near the cylinder 201. With the rotation of the cylinder 201, the mixed mass transfer effect between OH·free radicals, ozone bubbles and wastewater is improved, which promotes the uniform dispersion of organic matter in the wastewater into the strong oxidizing environment formed by the full mixing of OH·free radicals and ozone, thereby enhancing the degree of degradation of organic matter in the wastewater and significantly improving the degradation efficiency.

[0068] When the cover plate unit 400 is provided and the protrusion 207, the protrusion point 2071, the protrusion group 208, the spring member 210, etc. mentioned later (see Figures 5 to 7 ,as well as Fig.11) can produce more ozone-containing microbubbles, which can further enhance the mixed mass transfer effect between OH free radicals and ozone, and further improve the degradation ability of organic matter after the combination of the two.

[0069] The aeration pipe discharge end of the aeration unit 500 is arranged in the cavity of the reaction box 100 and relatively below the cylinder 201, and can disperse the ozone bubbles into the wastewater in the reaction box 100. The exhaust end of the aeration unit 500 is equipped with a gas distribution plate 501 to ensure that the gas can be evenly discharged into the entire cross section / horizontal section of the reaction box 100.

[0070] At least one filter plate 600 may be arranged at the lower part of the cavity of the reaction box 100, so that the gas distribution plate 501 extends to the upper part of the uppermost filter plate 600. The filter plate 600 is mainly used to filter out large particles of impurities, floccules, etc. contained in the wastewater discharged into the reaction box 100, and prevent solid particles, floccules, etc. from moving upward with the wastewater.

[0071] In order to promote the wastewater to have a strong upward flow ability in the reaction box 100, a circulation pump unit can be arranged outside the reaction box 100. The water inlet pipe opening of the circulation pump unit corresponds to the upper part of the water surface of the wastewater in the reaction box 100, and the outlet pipe opening corresponds to the lower part of the reaction box 100 and is relatively above the filter plate 600.

[0072] The water level of the wastewater injected into the reaction box 100 is required to be lower than the top surface height of the outer circumference of the cylinder 201, so that a part of the arc surface on the upper part of the outer circumference of the cylinder 201 is always exposed to the wastewater, so that the titanium dioxide coating on this part of the outer circumference is in contact with ultraviolet light.

[0073] The gas fed into the reaction box 100 through the aeration unit 500 may be ozone-containing air or a high-concentration ozone-containing gas obtained from an ozone storage tank. The exhaust pipe provided at the top of the reaction box 100 may be connected to the aeration unit 500, and the ozone discharged through the exhaust pipe may be cyclically fed back to the aeration unit 500 to continue to participate in the oxidation treatment process of the wastewater.

[0074] As the cylinder 201 rotates, the titanium dioxide coating on the outer circumference of the cylinder 201 can contact the ultraviolet light emitted by the lamp body 303 to induce the wastewater to produce a large number of OH free radicals. Because the lamp body 303 is arranged on the concave surface of the arc plate 302 and is above the outer circumference of the cylinder 201, the titanium dioxide coating on the outer circumference of the cylinder 201 can be fully irradiated and reacted to induce the wastewater to produce OH free radicals.

[0075] A concave structure and / or a convex structure of regular or irregular shape such as a groove or a rib plate may be provided on the outer circumference of the cylinder 201, and a titanium dioxide coating may be provided on the outer surface of the concave structure and the outer surface of the convex structure to increase the area of ​​the titanium dioxide coating. At this time, because the lamp body 303 is discretely arranged on the concave surface of the arc plate 302 and is located above the outer circumference of the cylinder 201, the outer surface of the concave structure and the outer surface of the convex structure can be fully irradiated by ultraviolet light, so that the size of the shadow area is effectively suppressed.

[0076] like Figures 2 to 5 , Figure 8 As shown, three or eight long strip-shaped notch structures (ie, the strip-shaped notches 202 shown in the figure) are formed on the wall of the cylinder 201, and the plurality of long strip-shaped notch structures are alternately distributed around the circumferential direction.

[0077] After the notch structure is provided on the wall of the cylinder 201, the circulation convection effect of the wastewater between the cylinder cavity and the outside of the cylinder cavity of the cylinder 201 can be promoted, and the mixed mass transfer effect between the induced OH free radicals, ozone bubbles and wastewater can be improved.

[0078] Specifically, Figure 2 , Figure 3 As shown, the strip-shaped notch 202 formed on the cylinder wall of the cylinder 201 penetrates both ends of the cylinder 201. An inner folding plate 205 is formed on the same side of the strip-shaped notch 202 in the circumferential direction and extends obliquely toward the inside of the cylinder 201. A connecting rod 206 is provided at the free end of the inner folding plate 205 and is fixedly connected to the pivot part 204, thereby connecting the cylinder 201 and the pivot part 204 as a whole, so that the pivot part 204 can rotate with the cylinder 201.

[0079] When the inner folding plate 205 is combined with the strip notch 202, the convection intensity of the wastewater between the outside and inside of the cylinder cavity of the cylinder 201 can be enhanced, which helps to better promote the mixed mass transfer effect between OH free radicals, ozone bubbles and wastewater, and achieves the technical purpose of enhancing the oxidation capacity and oxidation effect.

[0080] The extension length of the inner folding plate 205 is consistent with the axial length of the cylinder 201. The connection position between the inner folding plate 205 and the connecting rod 206 forms a nearly right angle, that is, floating near an angle of 90 degrees.

[0081] The inner folding plate 205 may form a discontinuous notch in the middle of the plate body along the axial extension direction of the cylinder 201, so that the inner folding plate 205 is formed into multiple pieces to reduce water resistance and increase the turbulence effect.

[0082] Specifically, Figure 4 As shown, the cylinder 201 includes a rear cylinder 2011, an intermediate cylinder 2012 and a front cylinder 2013. Figure 2 , Figure 3 The cylinder 201 shown is divided into three sections, with a gap / spacing in the axial direction formed between two adjacent sections; correspondingly, the inner folding plate 205 on each section of the cylinder 201 is naturally divided into three sections in the axial extension direction of the cylinder 201.

[0083] The strip notches 202 on the rear cylinder 2011, the middle cylinder 2012 and the front cylinder 2013 are all provided with inner folding plates 205. In addition, the strip notches 202 on the rear cylinder 2011, the middle cylinder 2012 and the front cylinder 2013 can be arranged in a straight line along the axial direction of the cylinder 201 (such as Figure 4 As shown in the figure), it may also be a situation that some of the strip-shaped gaps 202 penetrate in a straight line along the axial direction, or it may be a situation that all the strip-shaped gaps 202 do not penetrate in a straight line.

[0084] Figure 4 The embodiment of the cylinder 201 shown is compared with Figure 2 , Figure 3 The implementation structure can, on the one hand, reduce the water resistance encountered by the cylinder 201 when it rotates in the wastewater, and on the other hand, can also enhance the disturbance effect caused by the rotation of the cylinder 201 on the wastewater, and can better promote the mixing of OH free radicals, ozone bubbles and wastewater, thereby improving the mass transfer effect, and helping to improve the uniformity and sufficiency of the oxidation treatment of the wastewater.

[0085] Specifically, Figure 8 As shown, compared to Figure 2 , Figure 3 The main difference between the embodiment shown is the number of strip notches 202 and the change in the outer dimensions of the inner folding plate 205, that is, the oblique edge plate 209 shown is a deformation of the inner folding plate 205. This embodiment can also relatively reduce the water resistance of the cylinder 201 when it rotates.

[0086] Specifically, Figures 5 to 7 The scheme shown in Figure 2 , Figure 3The implementation structure shown has a protrusion 207 added. The outer surface of the protrusion 207 is covered with a titanium dioxide coating. With the help of the protrusion 207, on the one hand, the disturbance effect caused by the rotation of the cylinder 201 on the wastewater can be enhanced, and the mixed mass transfer effect can be further improved; on the other hand, the bubbles containing ozone can be sheared to cause the bubbles containing ozone to split into more small bubbles and microbubbles. These small bubbles and microbubbles containing ozone gather near the titanium dioxide coating, and will gradually mix with the wastewater that converges near the cylinder 201 along with the rotation of the cylinder 201. During this period, ozone gradually combines with the OH· free radicals continuously generated after the titanium dioxide is induced, which can improve the mixed mass transfer effect between ozone, OH· free radicals and wastewater, and thus can improve the oxidation and degradation effect of organic matter in the wastewater.

[0087] like Figure 6 As shown, a plurality of protrusions 207 are distributed on the outer circumferential surface of the cylinder 201 and the protrusions 207 are discretely distributed around the circumferential direction.

[0088] The protrusions 207 are pyramid-shaped protrusions 2071, and the protrusions 2071 are arranged alternately in rows in the width direction (i.e., the front-rear direction) of the outer circumferential surface of the cylinder 201, and the number of protrusions 2071 included in two adjacent rows of protrusions 2071 in the circumferential direction is different. Among the multiple protrusions 2071 in each row, position deviation / misalignment is formed between two adjacent protrusions 2071 in the width direction in the circumferential direction.

[0089] The pyramidal protrusions 2071 may be triangular pyramidal protrusions (see Figure 6 ), and other multi-faceted pyramidal protrusions such as tetrahedral pyramidal protrusions can also be selected. In the figure, the distributed triangular pyramidal protrusions 2071 can promote the axial convection of the wastewater near the outer peripheral surface of the cylinder 201 to be more intense, and can promote the ozone bubbles contained in the wastewater around the cylinder 201 to be more evenly dispersed, thereby improving the homogenization effect of the ozone bubbles. At the same time, the edges of the triangular pyramid can shear the bubbles to form more and denser small bubbles and microbubbles, which helps to further enhance the mixed mass transfer effect between ozone and OH free radicals and organic matter in the wastewater, improve the oxidation capacity, increase the ability to degrade and treat the wastewater, help promote the adequacy and thoroughness of the degradation of organic matter in the wastewater, and improve the treatment efficiency.

[0090] like Figure 7 As shown, a plurality of protrusion groups 208 are distributed on the outer circumferential surface of the cylinder 201, and the protrusion groups 208 are distributed alternately around the circumferential direction.

[0091] The protrusion group 208 includes a pair of V-shaped protrusions 2081 and a pair of straight protrusions 2082. The angle between the V-shaped protrusions 2081 and the straight protrusions 2082 is an obtuse angle. The pair of straight protrusions 2082 in each protrusion group 208 is relatively arranged downstream of the pair of V-shaped protrusions 2081. Figure 6 , Figure 7 As shown, the direction indicated by the arrow is the flow direction of the wastewater relative to the outer peripheral surface of the cylinder 201.

[0092] The tips of the two paired V-shaped protrusions 2081 are opposite to each other and form two "eight" shapes in the circumferential direction, and the flared width of one "eight" shape (free end) facing the two straight protrusions 2082 in the same group is smaller than the flared width of the other "eight" shape (free end). The two paired straight protrusions 2082 are arranged in an "eight" shape, and the flared width of one end facing the two V-shaped protrusions 2081 in the same group is larger than the flared width of the other end. The flared ends of the two V-shaped protrusions 2081 in the protrusion group 208 extend into the flared ends of the two straight protrusions 2082.

[0093] In two adjacent groups of protrusion groups 208 , between opposite ends of the straight protrusions 2082 in one group and the V-shaped protrusions 2081 in the other group, the shrinking width of the straight protrusions 2082 is smaller than the expanding width of the V-shaped protrusions 2081 .

[0094] The distribution form of the ridge group 208 shown in the figure can enhance the degree of axial convection of the wastewater near the outer peripheral surface of the cylinder 201, and can promote a more uniform distribution of ozone bubbles contained in the wastewater near the cylinder 201. At the same time, the edges of the ridges can shear the bubbles to form more and denser small bubbles and microbubbles, which can further enhance the mixed mass transfer effect of ozone and OH free radicals and organic matter in the wastewater, enhance the oxidation capacity, and improve the degree of wastewater degradation treatment, which helps to promote the sufficiency and thoroughness of the degradation of organic matter in the wastewater and improve the treatment efficiency.

[0095] like Figures 9 and 10 As shown, the slot structure is twelve strip slots 203 formed on the cylinder wall of the cylinder 201. The cylinder 201 rotates in a counterclockwise direction. The two sides of the strip slots 203, namely the first side 1 and the second side 2, are two relatively parallel planes, and the first side 1 and the second side 2 both extend obliquely from the outside to the inside in the clockwise direction. The distribution of the strip slots 203 can promote the convection degree of wastewater inside and outside the cylinder cavity of the cylinder 201, and can promote the mixed mass transfer effect of ozone and OH free radicals and organic matter in the wastewater.

[0096] like Fig.11 The cylinder 201 involved is relatively Fig. 9A spring member 210 is added to the solution shown. The spring member 210 can be understood as the protrusion 207 mentioned above. A titanium dioxide coating is also coated on the outer surface of the spring member 210. The spring member 210 can shear bubbles, causing turbulence in the wastewater near the cylinder 210, and can improve the mixing and mass transfer effect.

[0097] like Fig.11 As shown, an electrode unit 700 is also configured. The electrode plate of the electrode unit 700 is arranged below the cylinder 201, and the electrode plate includes multiple groups arranged alternately up and down, each group includes an anode plate 701 and a cathode plate 702 arranged alternately up and down, and the anode plate 701 is located above the cathode plate 702 (only one anode plate 701 and one cathode plate 702 are shown in the figure for simplified view). An insulating silicone gasket (belonging to the scope of the prior art, not shown) is provided between the anode plate 701 and the cathode plate 702.

[0098] The anode plate 701 is selected from any one of carbon fiber cloth, graphite electrode, boron-doped diamond electrode, stainless steel electrode, titanium electrode, and noble metal electrode. The cathode plate 702 is selected from a ferrite-modified carbon fiber cloth electrode.

[0099] The aeration port of the aeration unit 500 is correspondingly arranged below the cathode plate 702 .

[0100] The cathode plate 702 is a ferrite-modified carbon fiber cloth electrode, which can simultaneously catalyze the decomposition of ozone and hydrogen peroxide to generate OH· free radicals, and can improve the degradation capacity of the electrolytic oxidation system. At the same time, a large number of hydroxide ions and a large number of cations generated by electrolytic oxidation flow upward with the wastewater, and after mixing with the wastewater outside the cylinder 201, the generation of OH· free radicals can be significantly increased, and the concentration can be increased, so that the oxidation capacity of the entire device is doubled, and the polycyclic and heterocyclic organic substances in the wastewater can be degraded into substances with smaller molecular weight, which are easier to degrade, which helps to further reduce the difficulty of subsequent anaerobic and / or aerobic biochemical treatment, and further improve the removal efficiency of organic matter in the wastewater.

[0101] In addition, the ferrite-modified modified carbon fiber electrochemical cathode itself helps to improve the degradation performance of the electrochemical / O3 coupling system for organic pollutants in wastewater. The special crystal structure formed by the metal particles with microporous structure on its electrode forms oxygen defects, which can not only catalyze the reaction, but also provide channels for electron transfer, and at the same time make the carbon cloth electrode have adsorption properties, forming an adsorption-catalytic degradation process, so that pollutants can be degraded efficiently.

[0102] like Figure 1 A coal chemical wastewater treatment process shown includes the following steps:

[0103] 1) Flotation treatment: coal chemical sewage / wastewater is supplied to the flotation system, during which drugs such as polyaluminium chloride need to be added to the flotation system; the duration of flotation treatment is controlled between 20 minutes and 45 minutes; during the flotation treatment process, suspended solids on the wastewater need to be continuously removed;

[0104] 2) The wastewater after flotation treatment is discharged into the coal chemical wastewater treatment system including the above-mentioned photocatalytic oxidation structure and electrode oxidation-catalytic structure (such as Fig.11 The wastewater in the reaction box 100 is placed in a reaction box 100 (a case shown in the figure), and the wastewater in the reaction box 100 is continuously subjected to photocatalytic oxidation treatment and electrode oxidation-catalytic treatment, and the treatment time is controlled to be between 1 hour and 2 hours; during this period, bubbles containing ozone need to be intermittently introduced into the reaction box 100; the ozone content of the wastewater in the reaction box 100 is required to be maintained between 30 mg / L and 80 mg / L;

[0105] 3) The wastewater after the photocatalytic oxidation treatment and the electrode oxidation catalytic treatment is discharged from the reaction box 100 and sent to the anoxic tank for anaerobic biochemical treatment and / or to the aerobic tank for aerobic biochemical treatment; the anaerobic biochemical treatment may be carried out first, and then the multi-stage aerobic biochemical treatment may be carried out;

[0106] 4) After anaerobic biochemical treatment and / or aerobic biochemical treatment, the wastewater is discharged into the sedimentation tank for sedimentation treatment; the sedimentation treatment time is 2.5 hours to 6 hours.

[0107] Other treatment steps can be added between the above steps, such as between step 2) and step 3), a step of acidifying the wastewater can be added. The wastewater after photocatalytic oxidation treatment and electrode oxidation catalytic treatment is first discharged into the hydrolysis acidification tank for hydrolysis acidification treatment, and the retention treatment time is controlled between 8 hours and 12 hours. The hydrolysis acidification tank can be inoculated with anaerobic sludge accounting for 1 / 3 to 2 / 5 of the volume of the hydrolysis acidification tank, and iron powder or rust is added to the hydrolysis acidification tank at intervals during the hydrolysis acidification process, and the water temperature is controlled between 35 degrees Celsius and 40 degrees Celsius, and the pH value is controlled between 5 and 6.

[0108] exist Figure 2 , Fig.11 In the figure, the arrows located inside and outside the cylinder 201 indicate the condition in which the wastewater generates turbulence near the cylinder 201 when the cylinder 201 rotates counterclockwise at an angular velocity ω. As shown by the arrows in the figure, the wastewater can generate turbulence at the periphery of the cylinder 201 and between the inside and outside of the cylinder cavity, and the flow direction is variable and uncertain. Therefore, the arrows in the figure indicate the relative flow direction of the wastewater at the periphery of the outer peripheral surface of the cylinder 201, as well as the flow direction of the turbulence in the cylinder cavity of the cylinder 201. However, the turbulence flow direction in the cylinder cavity is only a schematic expression, and the actual turbulence flow state is much more complicated. Figure 2 , Fig.11 The arrows at various pipe locations indicate the feed-in and discharge locations and directions of wastewater, the discharge locations and directions of exhaust gas, and the feed-in locations and directions of air or ozone.

[0109] The above embodiments are merely illustrative of the principles and effects of the present invention, and are not intended to limit the present invention. The present invention can be improved in many aspects without violating the overall concept, and those familiar with the technology can modify or change the above embodiments without violating the spirit and scope of the present invention. Therefore, all equivalent modifications or changes made by those with ordinary knowledge in the technical field without departing from the spirit and technical ideas disclosed by the present invention should still be covered by the claims of the present invention.

Claims

1. A coal chemical wastewater treatment system, characterized in that: include: A reaction box (100), the upper opening of the box body (101) is sealed with a top cover (102), and a wastewater inlet pipe, a drain pipe and an exhaust pipe are distributed from bottom to top on the box body (101); The drum unit (200) comprises a drum body (201), a pivot portion (204) connected to the drum body (201), and a drive assembly matched with the pivot portion (204); the drum body (201) is arranged in the cavity of the reaction box (100) and the axis of the drum body (201) is arranged in the horizontal direction; the drive assembly is installed outside the reaction box (100) and can drive the drum body (201) to rotate relative to the reaction box (100); a titanium dioxide coating is provided on the outer peripheral surface of the drum body (201); and the upper outer peripheral surface of the drum body (201) is partially exposed outside the wastewater; The ultraviolet lamp unit (300) comprises a connection seat (301), an arc plate (302), a plurality of lamp bodies (303) and a controller (304); the connection seat (301) is connected to the top cover (102); the arc plate (302) is placed in the reaction box (100) and is correspondingly arranged above the cylinder (201); the controller (304) is placed outside the reaction box (100) and is connected to a power supply; the concave surface of the arc plate (302) is opposite to the outer peripheral surface of the cylinder (201); the plurality of lamp bodies (303) are dispersedly fixed on the concave surface of the arc plate (302), so that the ultraviolet light emitted by the lamp body (303) can be irradiated on the outer peripheral surface of the cylinder (201); and an aeration unit (500), wherein the aeration pipe is arranged in the reaction box (100) and relatively below the cylinder (201), and can dispersedly inject ozone-containing bubbles into the wastewater in the reaction box (100); A plurality of elongated notch structures are formed on the wall of the cylinder (201), and the plurality of elongated notch structures are alternately distributed in a circumferential direction; The notch structure is a strip-shaped notch (202) formed on the cylinder wall of the cylinder (201), and the strip-shaped notch (202) penetrates both ends of the cylinder (201); an inner folding plate (205) is formed on the same side of the strip-shaped notch (202) around the circumferential direction and extends obliquely toward the inside of the cylinder (201); a connecting rod (206) is provided at the free end of the inner folding plate (205) to be fixedly connected to the pivot part (204), so that the cylinder (201) and the pivot part (204) are connected as a whole; It also includes a cover plate unit (400); the cover plate unit (400) includes two groups of cover plates (401), a shaft (402) and a connecting plate (403); The two connecting plates (403) are respectively fixed on the left inner wall and the right inner wall of the reaction box (100); The two cover plates (401) are matched with the two connecting plates (403) respectively, and the two cover plates (401) are placed opposite to each other on a plane passing through the axis of the cylinder (201); The extension length of the cover plate (401) in the front-to-back direction is not less than the axial length of the cylinder (201); a gap is formed between the free end of the cover plate (401) and the left wall surface or the right wall surface of the outer peripheral surface of the cylinder (201); one end of the cover plate (401) matching with the connecting plate (403) is fixedly connected to the shaft rod (402); torsion springs are arranged on both ends of the shaft rod (402) extending outside the reaction box (100), and the torsion springs can make the cover plate (401) swing upward and downward relative to the horizontal plane in the vertical direction.

2. The coal chemical wastewater treatment system according to claim 1, characterized in that: A concave structure and / or a convex structure is formed on the outer peripheral surface of the cylinder (201), and the outer surface of the concave structure and the outer surface of the convex structure are both covered with a titanium dioxide coating.

3. The coal chemical wastewater treatment system according to claim 1, characterized in that: A plurality of protrusions (207) are distributed on the outer circumferential surface of the cylinder (201), and the protrusions (207) are distributed discretely around the circumferential direction; The protrusion (207) is a spring member (210) and / or a pyramid-shaped protrusion (2071), so that the spring members (210) or the protrusions (2071) are arranged in rows on the outer circumferential surface of the cylinder (201) and in a width direction, and the number of spring members (210) or the number of protrusions (2071) included in two adjacent rows in the circumferential direction are different; Among the multiple spring members (210) or multiple protrusions (2071) in each row, positional misalignment is formed in the circumferential direction between two spring members (210) or two protrusions (2071) adjacent in the width direction.

4. The coal chemical wastewater treatment system according to claim 1, characterized in that: A plurality of protrusion groups (208) are distributed on the outer circumferential surface of the cylinder (201), and the protrusion groups (208) are alternately distributed around the circumferential direction; the protrusion groups (208) include a pair of V-shaped protrusions (2081) and a pair of straight protrusions (2082), and the included angle of the V-shaped protrusions (2081) is an obtuse angle; the pair of straight protrusions (2082) in each protrusion group (208) is relatively arranged downstream of the pair of V-shaped protrusions (2081); The tips of the two paired V-shaped protrusions (2081) are opposite to each other, forming two "eight" shapes in the circumferential direction, and the expanded width of one "eight" shape facing the two straight protrusions (2082) in the same group is smaller than the expanded width of the other "eight" shape; The two straight protrusions (2082) in a pair are arranged in an "eight" shape, and the expanded width of one end facing the two V-shaped protrusions (2081) in the same group is greater than the expanded width of the other end; One end of the two V-shaped protrusions (2081) in the protrusion group (208) is expanded and extends into the expansion of one end of the two straight protrusions (2082); In two adjacent groups of protrusion strips (208), between the opposite ends of the straight protrusion strips (2082) in one group and the V-shaped protrusion strips (2081) in the other group, the shrinking width of the straight protrusion strips (2082) is smaller than the expanding width of the V-shaped protrusion strips (2081).

5. The coal chemical wastewater treatment system according to claim 1, characterized in that: It also includes an electrode unit (700), wherein an electrode plate of the electrode unit (700) is arranged in the reaction box (100) and is located between the bottom of the cylinder (201) and the top of the aeration port of the aeration unit (500); The electrode plates include multiple groups arranged alternately up and down; each group includes an anode plate (701) and a cathode plate (702) in an upper and lower pair, and the anode plate (701) is located above the cathode plate (702), and an insulating gasket is provided between the anode plate (701) and the cathode plate (702); the cathode plate (702) is a ferrite-modified carbon fiber cloth electrode.

6. A coal chemical wastewater treatment process, characterized in that: Includes steps: Ⅰ) Flotation treatment: send the coal chemical wastewater to the flotation system, and the flotation treatment time is controlled within 20 minutes to 45 minutes; II) discharging the wastewater after flotation treatment into a reaction box (100) of any coal chemical wastewater treatment system according to any one of claims 1 to 5; subjecting the wastewater in the reaction box (100) to continuous photocatalytic oxidation treatment for a treatment time of 1.5 to 2.5 hours; during which, bubbles containing ozone need to be intermittently introduced into the reaction box (100); III) The wastewater after the photocatalytic oxidation treatment is discharged from the reaction box (100) to an anoxic tank for anaerobic treatment and / or to an aerobic tank for aerobic treatment.

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