Combined car washing sewage treatment device

Abstract

The application is suitable for the technical field of car washing sewage treatment, and provides a combined car washing sewage treatment device, which comprises a pretreatment module, a flocculation and precipitation module, a photocatalytic oxidation module and a deep purification module connected in series; each module is independently arranged on a carrier, and the modules are connected in a detachable mode; the flocculation and precipitation module comprises a flocculation reaction unit, a dosing unit, a precipitation unit and an automatic flocculation discharge unit; and the photocatalytic oxidation module comprises a steady flow unit and a photocatalytic reaction unit. The application adopts a modular combination design, can be flexibly configured according to requirements, can automatically collect and discharge flocculation, and each module can be independently repaired and replaced, and has the advantages of high treatment efficiency, high automation degree, convenient maintenance and the like.

Description

Technical Field

[0001] This invention belongs to the field of car wash wastewater treatment technology, and particularly relates to a combined car wash wastewater treatment device. Background Technology

[0002] With the continuous growth of car ownership, the water consumption of the car wash industry is increasing day by day, and the treatment and reuse of car wash wastewater has become an important way to save water resources. Car wash wastewater contains a variety of pollutants such as mud, oil, detergent, and organic matter. Direct discharge not only wastes water resources but also pollutes the environment.

[0003] Currently, various car wash wastewater treatment devices have been proposed. For example, Chinese invention patent application number 202411892328.9, entitled "A Combinable Car Wash Wastewater Treatment System," includes four subsystems: a preliminary wastewater treatment system, a circulating wastewater treatment system, a tap water-grade purification system, and a drinking water-grade wastewater treatment system. Different combinations can achieve different effluent water quality requirements. Although this solution proposes a combinational concept, its subsystems are arranged in a fixed combination, lacking independence and interchangeability between modules, and lacking refined design of the internal structure of each treatment unit. Chinese invention patent application number 202410516236.4, entitled "Integrated Car Wash Wastewater Treatment and Reuse Device and Wastewater Treatment Method," connects the inlet pipe to a flocculation tank, a flow stabilization tank, and a photocatalytic treatment tank sequentially via a pump. The flocculation tank is equipped with a flocculant collection device at the top, and the flow stabilization tank is connected to the photocatalytic treatment tank via an overflow weir. Although the device has a compact structure and high processing efficiency, it is an integrated design, with all processing units integrated into the same housing. This makes it impossible to flexibly add, remove, or replace processing units according to actual processing needs, making equipment maintenance and upgrades difficult. Furthermore, if any unit malfunctions, the entire system must be shut down for repair. Summary of the Invention

[0004] The purpose of this invention is to provide a combined car wash wastewater treatment device, which aims to solve the problems mentioned in the background art.

[0005] The present invention is implemented as follows: a combined car wash wastewater treatment device includes a pretreatment module, a flocculation sedimentation module, a photocatalytic oxidation module and a deep purification module connected in series.

[0006] The pretreatment module includes an inlet pipe, a solid-liquid separation unit, and a regulating unit. The inlet pipe is connected to the car wash wastewater discharge outlet. The solid-liquid separation unit is located between the inlet pipe and the regulating unit to intercept suspended solids in the wastewater with a particle size larger than a preset value. The regulating unit is used to regulate the amount and quality of the wastewater.

[0007] The flocculation and sedimentation module includes a flocculation reaction unit, a dosing unit, a sedimentation unit, and an automatic flocculant discharge unit. The inlet of the flocculation reaction unit is connected to the outlet of the regulating unit. The dosing unit is connected to the inlet of the flocculation reaction unit and is used to add flocculant to the wastewater. The sedimentation unit is connected downstream of the flocculation reaction unit. The automatic flocculant discharge unit is located above the flocculation reaction unit and the sedimentation unit and is used to discharge the flocculants floating on the water surface.

[0008] The photocatalytic oxidation module includes a current stabilization unit and a photocatalytic reaction unit. The current stabilization unit is connected to the photocatalytic reaction unit. The photocatalytic reaction unit is equipped with a light source and a photocatalyst for photocatalytic oxidation treatment of wastewater.

[0009] The deep purification module includes an adsorption filtration unit and a membrane separation unit. The inlet of the adsorption filtration unit is connected to the outlet of the photocatalytic reaction unit, and the outlet of the membrane separation unit is connected to a recycled water tank.

[0010] Each module is connected in series using a detachable connection method, and each module is independently set on its own carrier.

[0011] In a further technical solution, the flow stabilizing unit is connected to the photocatalytic reaction unit through an overflow structure, the overflow structure including an inclined guide plate with a filter layer.

[0012] In a further technical solution, a supported photocatalytic network is provided inside the photocatalytic reaction unit, the light source is an ultraviolet light source, and an aeration device is provided at the bottom of the photocatalytic reaction unit.

[0013] In a further technical solution, the membrane separation unit has a concentrate outlet, which is connected to the inlet of the flocculation reaction unit via a reflux pipe.

[0014] In a further technical solution, the regulating unit is provided with a first liquid level detection element, the flocculation reaction unit is provided with a second liquid level detection element and a pH detection element, and the recycled water tank is provided with a third liquid level detection element and a turbidity detection element.

[0015] A further technical solution also includes a control unit, which is electrically connected to each liquid level detection element, pH detection element, turbidity detection element, dosing unit and light source, and is used to control the operating status of each actuator according to the detection signals of each detection element.

[0016] Another objective of this invention is to provide a combined car wash wastewater treatment method, based on the aforementioned apparatus, comprising the following steps:

[0017] Step 1: Preprocessing;

[0018] The wastewater from the car wash enters the pretreatment module through the inlet pipe. After the solid-liquid separation unit intercepts suspended solids with a particle size larger than the preset value, it enters the regulating unit for water quantity and quality adjustment.

[0019] Step 2: Flocculation and sedimentation;

[0020] Wastewater from the regulating unit is sent to the flocculation reaction unit. Flocculant is added to the wastewater through the dosing unit. After flocculation, the water enters the sedimentation unit for solid-liquid separation. The flocculants are discharged through the flocculant automatic discharge unit.

[0021] Step 3: Photocatalytic oxidation;

[0022] The supernatant from the sedimentation unit enters the flow stabilization unit, and after being filtered through the overflow structure's filter layer, it enters the photocatalytic reaction unit, where organic pollutants in the wastewater are photocatalytically oxidized and degraded under the combined action of a light source and a photocatalyst.

[0023] Step 4: Deep purification;

[0024] The effluent after photocatalytic oxidation treatment is sequentially processed by an adsorption filtration unit and a membrane separation unit to obtain purified water that meets the reuse standards, which is then stored in a reuse water tank for later use.

[0025] The combined car wash wastewater treatment device provided in this embodiment of the invention has the following beneficial effects:

[0026] (1) Modular combination and flexible configuration: Each processing module is independently set on its own carrier and connected in series through a detachable connection method. Users can flexibly select all or some modules to combine according to the scale of the car wash, the quality of the influent and the quality of the recycled water. They can also add or replace specific functional modules according to actual needs, making it highly adaptable.

[0027] (2) Independent maintenance and small downtime range: Each module is set up independently. When a certain module fails, it can be removed and repaired or replaced separately, while other modules can still operate normally. This greatly reduces the impact of failure on the operation of the entire system and reduces maintenance costs and time.

[0028] (3) Good treatment effect and high effluent quality: Flocculation and sedimentation remove suspended solids and some organic matter, photocatalytic oxidation deeply degrades organic pollutants and detergents, and adsorption filtration and membrane separation further refine the treatment. The multi-stage treatment process ensures that the effluent quality is stable and meets the car wash reuse standard.

[0029] (4) Intelligent control and stable operation: Through the cooperation of the control unit and each detection element, the real-time monitoring and automatic control of the operating status of each processing unit are realized, ensuring that the system operates under the best working conditions and the effluent water quality is stable and reliable. Attached Figure Description

[0030] Figure 1 This is a schematic diagram showing the overall structural module connection of the combined car wash wastewater treatment device provided in an embodiment of the present invention;

[0031] Figure 2 A flowchart of a combined car wash wastewater treatment method provided in an embodiment of the present invention.

[0032] In the attached diagram: Pretreatment module 1; Inlet pipe 11; Solid-liquid separation unit 12; Adjustment unit 13; Flocculation and sedimentation module 2; Flocculation reaction unit 21; Dosing unit 22; Sedimentation unit 23; Automatic flocculant discharge unit 24; Photocatalytic oxidation module 3; Flow stabilization unit 31; Overflow structure 32; Photocatalytic reaction unit 33; Deep purification module 4; Adsorption filtration unit 41; Membrane separation unit 42; Reclaimed water tank 43; Control unit 5. Detailed Implementation

[0033] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0034] The specific implementation of the present invention will be described in detail below with reference to specific embodiments.

[0035] like Figure 1 As shown, a combined car wash wastewater treatment device provided in an embodiment of the present invention includes a pretreatment module 1, a flocculation and sedimentation module 2, a photocatalytic oxidation module 3, and a deep purification module 4 connected in series.

[0036] The pretreatment module 1 includes an inlet pipe 11, a solid-liquid separation unit 12, and a regulating unit 13. One end of the inlet pipe 11 is connected to the wastewater discharge outlet of the car wash, and the other end is connected to the inlet of the solid-liquid separation unit 12. The solid-liquid separation unit 12 is used to intercept suspended solids in the wastewater with a particle size larger than a preset value. Its specific form can be a bar screen, a sieve, or a hydrocyclone, etc. In this embodiment, a bar screen with a mesh size of 1-5 mm is used. The outlet of the solid-liquid separation unit 12 is connected to the inlet of the regulating unit 13 via a pipe. The regulating unit 13 is used to store and regulate the wastewater after solid-liquid separation, ensuring a relatively stable influent flow and water quality for subsequent treatment units. A first liquid level detection element is installed in the regulating unit 13 for real-time monitoring of the water level within the regulating unit 13.

[0037] The flocculation and sedimentation module 2 includes a flocculation reaction unit 21, a dosing unit 22, a sedimentation unit 23, and an automatic flocculant discharge unit 24. The flocculation reaction unit 21 is connected to the regulating unit 13 via a conveying pipeline, on which a pump is installed to pump wastewater from the regulating unit 13 to the flocculation reaction unit 21. The dosing unit 22 is connected to the inlet of the flocculation reaction unit 21 and is used to add flocculants to the wastewater. In this embodiment, polyaluminum chloride and polyacrylamide are selected as flocculants. The dosing unit 22 includes a storage tank and a corresponding metering pump, which can automatically adjust the dosage according to the influent water quality. The flocculation reaction unit 21 is also equipped with a second liquid level detection element and a pH detection element, used to monitor the water level and pH value within the flocculation reaction unit 21, respectively. The sedimentation unit 23 is connected downstream of the flocculation reaction unit 21, and the water after the flocculation reaction flows by gravity into the sedimentation unit 23 for solid-liquid separation. An automatic flocculant discharge unit 24 is located above the flocculation reaction unit 21 and the sedimentation unit 23, and is used to collect and discharge the flocculants in the flocculation reaction unit 21 and the sedimentation unit 23.

[0038] The photocatalytic oxidation module 3 includes a flow stabilization unit 31 and a photocatalytic reaction unit 33. The flow stabilization unit 31 is connected to the photocatalytic reaction unit 33 via an overflow structure 32. The overflow structure 32 includes an inclined guide plate with a filter layer. The filter layer can be a quartz sand filter layer, used to further filter the supernatant from the sedimentation unit 23, removing residual fine suspended solids, while ensuring a smooth flow of water into the photocatalytic reaction unit 33. The photocatalytic reaction unit 33 contains a light source and a photocatalyst. Specifically, the photocatalyst can be a TiO2-supported photocatalytic mesh, with multiple meshes arranged in parallel within the photocatalytic reaction unit 33. The light source is an ultraviolet lamp, located inside the photocatalytic reaction unit 33. An aeration device is located at the bottom of the photocatalytic reaction unit 33 to introduce air into the reactor, providing dissolved oxygen and promoting sufficient contact between the photocatalyst and the wastewater.

[0039] The deep purification module 4 includes an adsorption filtration unit 41 and a membrane separation unit 42 connected in sequence. The adsorption filtration unit 41 is filled with granular activated carbon to adsorb and remove residual organic matter, residual chlorine, and odors from the photocatalytic effluent. The inlet of the membrane separation unit 42 is connected to the outlet of the adsorption filtration unit 41. The membrane separation unit 42 can specifically employ an ultrafiltration membrane module to further remove fine particulate matter, colloids, and some large molecular dissolved pollutants from the water. The outlet of the membrane separation unit 42 is connected to a recycled water tank 43, which is equipped with a third liquid level detection element and a turbidity detection element to monitor the water level and effluent turbidity. The concentrate outlet of the membrane separation unit 42 is connected to the inlet of the flocculation reaction unit 21 via a return pipe, allowing the concentrate to be returned for further treatment.

[0040] In this embodiment of the invention, each module (pretreatment module 1, flocculation and sedimentation module 2, photocatalytic oxidation module 3, and deep purification module 4) is independently mounted on its respective carrier. The modules are connected by detachable pipe joints. The side walls of the carrier are equipped with lifting rings and forklift holes for easy lifting and forklift transport; the top of the carrier is equipped with an openable inspection cover for convenient inspection and maintenance of the internal equipment.

[0041] like Figure 1 As shown, in a preferred embodiment of the present invention, a control unit 5 is also included. The control unit 5 is electrically connected to each liquid level detection element, pH detection element, turbidity detection element, dosing unit, and light source, and is used to control the operating state of each actuator based on the detection signals from each detection element. The control unit 5 automatically controls the operating state of each actuator according to a preset control logic based on the detection signals from each detection element. For example, when the first liquid level detection element detects that the water level in the regulating unit 13 has reached a high level, the control unit 5 starts the transfer pump to send wastewater into the flocculation reaction unit 21; when the pH detection element detects that the pH value deviates from the preset range, the control unit 5 automatically adjusts the flocculant dosage through the dosing unit 22.

[0042] like Figure 2 As shown, a combined car wash wastewater treatment method according to an embodiment of the present invention, based on the above-described apparatus, includes the following steps:

[0043] Step 1: Preprocessing;

[0044] The wastewater from the car wash enters the pretreatment module 1 through the inlet pipe 11. First, it passes through the solid-liquid separation unit 12 to intercept suspended solids, and then enters the regulating unit 13 to regulate the water volume and quality to ensure that the water quality and volume are uniform and stable.

[0045] Step 2: Flocculation and sedimentation;

[0046] Wastewater in regulating unit 13 is sent to flocculation reaction unit 21 through a conveying pipeline. Flocculant is added to the wastewater through dosing unit 22, and flocculation reaction takes place under stirring conditions. The water after flocculation reaction enters sedimentation unit 23 for solid-liquid separation. The flocs float to the water surface and are collected and discharged by flocculant automatic discharge unit 24. The settled sludge at the bottom of sedimentation unit 23 is periodically discharged through bottom sludge discharge pipe.

[0047] Step 3: Photocatalytic oxidation;

[0048] The supernatant from sedimentation unit 23 enters flow stabilization unit 31, and after being filtered through the filter layer of overflow structure 32, it enters photocatalytic reaction unit 33. Under the combined action of light source and photocatalyst, organic pollutants in wastewater undergo photocatalytic oxidation and degradation. Simultaneously, the aeration device continuously introduces air into the reactor.

[0049] Step 4: Deep purification;

[0050] The effluent from photocatalytic oxidation treatment enters adsorption filtration unit 41 for adsorption treatment. The adsorption-filtered effluent enters membrane separation unit 42 for fine filtration to obtain purified water that meets the standards for car wash reuse, which is then stored in reclaimed water tank 43 for later use. The concentrate produced by membrane separation unit 42 is returned to flocculation reaction unit 21 through a return pipe for further treatment.

[0051] After the above treatment, the effluent water quality can meet the standards for car wash reuse, fully satisfying the requirements for recycling.

[0052] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A combined car wash wastewater treatment device, characterized in that, It includes a pretreatment module, a flocculation and sedimentation module, a photocatalytic oxidation module, and a deep purification module connected in series. The pretreatment module includes an inlet pipe, a solid-liquid separation unit, and a regulating unit. The inlet pipe is connected to the car wash wastewater discharge outlet. The solid-liquid separation unit is located between the inlet pipe and the regulating unit to intercept suspended solids in the wastewater with a particle size larger than a preset value. The regulating unit is used to regulate the amount and quality of the wastewater. The flocculation and sedimentation module includes a flocculation reaction unit, a dosing unit, a sedimentation unit, and an automatic flocculant discharge unit. The inlet of the flocculation reaction unit is connected to the outlet of the regulating unit. The dosing unit is connected to the inlet of the flocculation reaction unit and is used to add flocculant to the wastewater. The sedimentation unit is connected downstream of the flocculation reaction unit. The automatic flocculant discharge unit is located above the flocculation reaction unit and the sedimentation unit and is used to discharge the flocculants floating on the water surface. The photocatalytic oxidation module includes a current stabilization unit and a photocatalytic reaction unit. The current stabilization unit is connected to the photocatalytic reaction unit. The photocatalytic reaction unit is equipped with a light source and a photocatalyst for photocatalytic oxidation treatment of wastewater. The deep purification module includes an adsorption filtration unit and a membrane separation unit. The inlet of the adsorption filtration unit is connected to the outlet of the photocatalytic reaction unit, and the outlet of the membrane separation unit is connected to a recycled water tank. Each module is connected in series using a detachable connection method, and each module is independently set on its own carrier.

2. The combined car wash wastewater treatment device according to claim 1, characterized in that, The flow stabilizing unit is connected to the photocatalytic reaction unit through an overflow structure. The overflow structure includes an inclined guide plate with a filter layer.

3. The combined car wash wastewater treatment device according to claim 1, characterized in that, The photocatalytic reaction unit is equipped with a supported photocatalytic mesh, the light source is an ultraviolet light source, and an aeration device is provided at the bottom of the photocatalytic reaction unit.

4. The combined car wash wastewater treatment device according to claim 1, characterized in that, The membrane separation unit has a concentrate outlet, which is connected to the inlet of the flocculation reaction unit via a reflux pipe.

5. The combined car wash wastewater treatment device according to claim 1, characterized in that, The regulating unit is equipped with a first liquid level detection element, the flocculation reaction unit is equipped with a second liquid level detection element and a pH detection element, and the recycled water tank is equipped with a third liquid level detection element and a turbidity detection element.

6. The combined car wash wastewater treatment device according to claim 5, characterized in that, It also includes a control unit, which is electrically connected to each liquid level detection element, pH detection element, turbidity detection element, dosing unit and light source, and is used to control the operating status of each actuator according to the detection signals of each detection element.

7. A combined car wash wastewater treatment method, based on the combined car wash wastewater treatment device according to any one of claims 1-6, characterized in that, Includes the following steps: Step 1: Preprocessing; The wastewater from the car wash enters the pretreatment module through the inlet pipe. After the solid-liquid separation unit intercepts suspended solids with a particle size larger than the preset value, it enters the regulating unit for water quantity and quality adjustment. Step 2: Flocculation and sedimentation; Wastewater from the regulating unit is sent to the flocculation reaction unit. Flocculant is added to the wastewater through the dosing unit. After flocculation, the water enters the sedimentation unit for solid-liquid separation. The flocculants are discharged through the flocculant automatic discharge unit. Step 3: Photocatalytic oxidation; The supernatant from the sedimentation unit enters the flow stabilization unit, and after being filtered through the overflow structure's filter layer, it enters the photocatalytic reaction unit, where organic pollutants in the wastewater are photocatalytically oxidized and degraded under the combined action of a light source and a photocatalyst. Step 4: Deep purification; The effluent after photocatalytic oxidation treatment is sequentially processed by an adsorption filtration unit and a membrane separation unit to obtain purified water that meets the reuse standards, which is then stored in a reuse water tank for later use.

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