Garbage transfer station car washing wastewater treatment system

Abstract

The utility model relates to a garbage transfer station car washing wastewater treatment system which comprises air floatation equipment and a two-stage DTRO system, the water outlet end of the air floatation equipment is connected with the water inlet end of a DTRO raw water tank through a pipeline, the water outlet end of the DTRO raw water tank is sequentially connected with a sand filter and a security filter, the water outlet end of the security filter is connected with the liquid inlet end of a first-stage DTRO membrane through a first-stage high-pressure pump, and the liquid inlet end of a second-stage DTRO membrane is connected with a second-stage high-pressure pump. A concentrated water outlet end of the first-stage DTRO membrane is connected with a concentrated solution tank through a pipeline, a produced water outlet end of the first-stage DTRO membrane is connected with a liquid inlet end of a second-stage DTRO membrane through a second-stage high-pressure pump, a concentrated water outlet end of the second-stage DTRO membrane is connected to a DTRO raw water tank through a pipeline to form a circulation loop, and a produced water outlet end of the second-stage DTRO membrane is connected with a degassing tower through a pipeline; compared with the prior art, the device disclosed by the utility model has the advantages that the occupied area is greatly reduced, the dosage is reduced, the overall operation stability is higher, the device is not influenced by the biodegradability of wastewater, the operation is more convenient, the overall investment is reduced, and the device is more economical.

Description

[Technical Field]

[0001] This utility model relates to the field of wastewater treatment technology, specifically a wastewater treatment system for car washes at garbage transfer stations. [Background Technology]

[0002] The wastewater from car washes at garbage transfer stations has a complex composition, containing high concentrations of suspended solids, organic matter, grease, heavy metals, and pathogenic microorganisms. It also exhibits large pH fluctuations and high levels of ammonia nitrogen and phosphorus.

[0003] In practical applications, to address these challenges, the commonly used method in recent years is: equalization tank + No. 1 sedimentation tank + acidification + bioreactor + No. 2 sedimentation tank, as shown in the attached diagram. Figure 3 As shown; specifically, after being filtered by a screen to remove large particles, the wastewater enters the equalization tank. The effluent from the equalization tank enters the No. 1 physicochemical processor to remove suspended solids and some organic matter. The effluent from the physicochemical processor enters the acidifier, where facultative anaerobic bacteria decompose large molecules and difficult-to-degrade organic matter in the wastewater into small molecules and easily degradable organic matter. The effluent from the acidifier enters the bioreactor, where most of the organic matter in the wastewater is removed by the carbonization of microorganisms, and most of the ammonia nitrogen is removed by the nitrification and denitrification of microorganisms. The effluent from the bioreactor enters the No. 2 physicochemical processor to remove color and some organic matter, and the effluent from the No. 2 physicochemical processor meets the standards for discharge into the municipal sewer system.

[0004] However, this treatment process requires a large amount of chemicals, produces a large amount of sludge, has unstable effluent quality, is complex to operate, has a high overall investment, and occupies a large area. [Utility Model Content]

[0005] The purpose of this utility model is to overcome the above-mentioned shortcomings and provide a wastewater treatment system for car washes in garbage transfer stations. This system greatly reduces the footprint, reduces the amount of chemicals required, has higher overall operational stability, is not affected by the biodegradability of wastewater, is easier to operate, and reduces overall investment, making it more economical.

[0006] In order to achieve the above-mentioned purpose, a garbage transfer station car washing wastewater treatment system is designed, which comprises an oil separation tank 1, a flotation equipment 2, a DTRO raw water tank 3, a first DTRO membrane 4, a second DTRO membrane 5 and a degassing tower 6. The water outlet end of the oil separation tank 1 is connected to the water inlet end of the flotation equipment 2 through a pipeline. The sewage outlet of the flotation equipment 2 is connected to a sludge thickening tank 7 through a pipeline. The other end of the sludge thickening tank 7 is connected to a sludge dewatering machine 8 through a pipeline. The water outlet end of the flotation equipment 2 is connected to the water inlet end of the DTRO raw water tank 3 through a pipeline. The water outlet end of the DTRO raw water tank 3 is connected to the water inlet end of a sand filter 9 through a pipeline. The water outlet end of the sand filter 9 is connected to the water inlet end of a security filter 10 through a pipeline. The water outlet end of the security filter 10 is connected to the liquid inlet end of the first DTRO membrane 4 through a first high-pressure pump 11. The first DTRO membrane 4 is provided with a concentrated water outlet end and a water production outlet end. The concentrated water outlet end of the first DTRO membrane 4 is connected to a concentrated liquid tank through a pipeline. The water production outlet end of the first DTRO membrane 4 is connected to the liquid inlet end of the second DTRO membrane 5 through a second high-pressure pump 12. The concentrated water outlet end of the second DTRO membrane 5 is connected to the DTRO raw water tank 3 through a pipeline to form a circulation loop. The water production outlet end of the second DTRO membrane 5 is connected to the degassing tower 6 through a pipeline.

[0007] Further, the DTRO raw water tank 3 is provided with an acid adding port. The acid adding port is connected to an acid storage tank through a pipeline, and acid is added through the acid storage tank to adjust the pH value.

[0008] Further, the security filter 10 is a core filter, which is used to further remove suspended solids in the wastewater. The inlet and outlet ends of the core filter are provided with pressure sensors, and the pressure difference is automatically detected through the pressure sensors, so that the system prompts to replace the filter core when the pressure difference exceeds 2.0 bar.

[0009] Further, the first high-pressure pump 11 and the second high-pressure pump 12 are DTRO high-pressure piston pumps. Shock absorbers are arranged at the rear ends of the first DTRO high-pressure piston pump and the second DTRO high-pressure piston pump. The shock absorbers are used to absorb the pressure pulse generated by the high-pressure pump.

[0010] Further, the membrane assemblies of the first DTRO membrane 4 and the second DTRO membrane 5 all adopt disc and tube type reverse osmosis membrane columns, thereby having the advantages of strong anti-pollution and strong adaptability to wastewater, and prolonging the service life of the membranes.

[0011] Further, the liquid inlet side of the first DTRO membrane 4 is provided with a circulating pump 13. The circulating pump 13 is arranged between the first high-pressure pump 11 and the first DTRO membrane 4. The first DTRO membrane 4 is provided with a circulating liquid port. The circulating liquid port is connected to the circulating pump 13 through a pipeline to form a circulation loop, which can ensure sufficient flow rate and cross-flow velocity on the membrane surface, and avoid membrane pollution.

[0012] Furthermore, both the primary DTRO membrane 4 and the secondary DTRO membrane 5 are equipped with servo motor control valves at their concentrate ends. These servo motor control valves are used to control the pressure within the membrane module and improve the system's recovery rate.

[0013] Furthermore, the outlet of the degassing tower 6 is connected to a clean water tank via a pipe. The clean water tank is equipped with an alkali addition port, through which alkali solution is added. The outlet of the clean water tank is connected to a clean water discharge pipe, and a pH sensor is installed in the clean water discharge pipe. This enables the PLC to determine the pH value of the effluent and automatically adjust the frequency of the metering pump to adjust the amount of alkali added, ultimately ensuring that the pH value of the effluent meets the discharge requirements.

[0014] Furthermore, an inlet pump 14 is installed between the oil separator 1 and the air flotation device 2, and an inlet pump 25 is installed between the DTRO raw water tank 3 and the sand filter 9. The effluent from the DTRO raw water tank 3 is pumped into the sand filter 9 through the inlet pump 25. Pressure gauges are installed at both the inlet and outlet of the sand filter 9, so that a backwashing procedure can be performed when the pressure difference exceeds 1.5 bar.

[0015] Compared with existing technologies, this invention replaces the traditional process of sedimentation tank #1 + acidification + bioreactor + sedimentation tank #2 with an air flotation + two-stage DTRO system, greatly reducing the footprint, reducing the amount of chemicals needed, lowering the skill requirements for operation and maintenance personnel, and enabling one-button start / stop functionality. Furthermore, the air flotation + two-stage DTRO system provides higher overall operational stability, is unaffected by the biodegradability of wastewater, has strong tolerance to water quality fluctuations, a longer service life, higher automation, and easier operation, while also reducing overall investment and making it more economical. Therefore, this invention is worthy of widespread application. [Image Description]

[0016] Figure 1 This is a schematic diagram of the principle of this utility model;

[0017] Figure 2 This is a schematic diagram of the structure of this utility model;

[0018] Figure 3 This is a structural diagram of existing technology;

[0019] In the diagram: 1. Oil separator; 2. Air flotation equipment; 3. DTRO raw water tank; 4. Primary DTRO membrane; 5. Secondary DTRO membrane; 6. Deaeration tower; 7. Sludge thickening tank; 8. Sludge dewatering machine; 9. Sand filter; 10. Security filter; 11. Primary high-pressure pump; 12. Secondary high-pressure pump; 13. Circulation pump; 14. Inlet pump one; 15. Inlet pump two. [Detailed Implementation]

[0020] As attachedFigure 1 and attached Figure 2 As shown in the utility model provides a kind of garbage transfer station car wash wastewater treatment system, including oil separation tank 1, air floatation equipment 2, DTRO raw water tank 3, first DTRO membrane 4, secondary DTRO membrane 5 and degassing tower 6, the water outlet of oil separation tank 1 is connected by pipeline the water inlet of air floatation equipment 2, the blow-off port of air floatation equipment 2 is connected by pipeline sludge concentration tank 7, sludge concentration tank 7 other end is connected by pipeline with sludge dewaterer 8, the water outlet of air floatation equipment 2 is connected by pipeline the water inlet of DTRO raw water tank 3, the water outlet of DTRO raw water tank 3 is connected by pipeline the water inlet of sand filter 9, the water outlet of sand filter 9 is connected by pipeline the water inlet of security filter 10, the water outlet of security filter 10 is connected by first high-pressure pump 11 the liquid inlet end of first DTRO membrane 4, first DTRO membrane 4 is provided with concentrated water liquid outlet and water production liquid outlet, the concentrated water liquid outlet of first DTRO membrane 4 is connected by pipeline concentration liquid tank, the water production liquid outlet of first DTRO membrane 4 is connected by secondary high-pressure pump 12 the liquid inlet end of secondary DTRO membrane 5, the concentrated water liquid outlet of secondary DTRO membrane 5 is connected by pipeline to DTRO raw water tank 3 and constitutes circulation loop, the water production liquid outlet of secondary DTRO membrane 5 is connected by pipeline degassing tower 6.

[0021] DTRO raw water tank 3 is provided with acid adding port, acid adding port is connected by pipeline acid storage tank, and acid is added by acid storage tank to adjust pH value;The membrane assembly of first DTRO membrane 4 and secondary DTRO membrane 5 all uses disc tube reverse osmosis membrane column, to have the advantage of strong anti-pollution, and the adaptability to wastewater is very strong, prolongs membrane life;The liquid inlet side of first DTRO membrane 4 is provided with circulating pump 13, circulating pump 13 is located between first high-pressure pump 11 and first DTRO membrane 4, and first DTRO membrane 4 is provided with circulating liquid port, and circulating liquid port is connected by pipeline circulating pump 13 and forms circulation loop, can guarantee enough flow and cross-flow velocity on membrane surface, avoid membrane pollution;The concentrated liquid end of first DTRO membrane 4 and secondary DTRO membrane 5 is provided with servo motor control valve, and servo motor control valve is used to control the pressure in membrane group, improves the recovery rate of system.

[0022] The water outlet end of the degassing tower 6 is connected with a clean water tank through a pipeline, an alkali adding port is arranged on the clean water tank, and alkali liquor is added through the alkali adding port, the liquid outlet end of the clean water tank is connected with a clean water discharge pipeline, and a pH value sensor is installed in the clean water discharge pipeline, so that the PLC judges the pH value of the outlet water and automatically adjusts the frequency of the metering pump to adjust the alkali adding amount, and finally the pH value of the outlet water reaches the discharge requirement; the water inlet pump one 14 is arranged between the oil separation tank 1 and the air flotation equipment 2, the water inlet pump two 15 is arranged between the DTRO raw water tank 3 and the sand filter 9, the water outlet of the DTRO raw water tank 3 is pumped into the sand filter 9 through the water inlet pump two 15, and the water inlet end and the water outlet end of the sand filter 9 are both provided with pressure gauges, so that the backwashing program can be executed when the pressure difference exceeds 1.5 bar; the security filter 10 is a core filter, the core filter is used for further removing suspended solids in the wastewater, the water inlet end and the water outlet end of the core filter are both provided with pressure sensors, and the pressure difference is automatically detected through the pressure sensors, so that the system prompts to replace the filter core when the pressure difference exceeds 2.0 bar; the first high-pressure pump 11 and the second high-pressure pump 12 are both DTRO high-pressure piston pumps, and a shock absorber is arranged at the rear end of the first DTRO high-pressure piston pump and the second DTRO high-pressure piston pump, and the shock absorber is used for absorbing the pressure pulse generated by the high-pressure pump.

[0023] The utility model will be further described below in combination with the drawings and specific embodiments:

[0024] The utility model adopts oil separation + air flotation + two-stage DTRO system, wherein the DTRO concentrated water is transported to a waste incineration plant for incineration treatment, and the DTRO produced water is discharged up to standard.

[0025] The car washing wastewater first enters the oil separation tank to remove most of the oil substances, the oil separation tank outlet water enters the air flotation device to further remove the oil substances, and the air flotation outlet water enters the raw water tank; while the wastewater enters the raw water tank, the acid is added from the acid storage tank to adjust the pH value; at the same time, the acid stirring pump starts to work to mix the backflow, so as to achieve the purpose of balancing the pH value; the pH value sensor is arranged on the system raw liquid storage tank backflow pipeline, the PLC judges the raw water pH value and automatically adjusts the frequency of the metering pump to adjust the acid adding amount, so that the pH value of the raw liquid before entering the reverse osmosis reaches 6.1-6.5; if the raw water pH value is within this range, no acid adjustment is needed. The sand filter is pumped into the sand filter through the sand filter booster pump, the sand filter is designed as one, the filtration precision is 50um, and the water inlet end and the water outlet end of the sand filter are both provided with pressure gauges, so that the backwashing program must be executed when the pressure difference exceeds 1.5 bar.

[0026] The membrane system is two-stage DTRO, the first-stage DTRO needs to enter water from the core filter, and the second-stage DTRO processes the first-stage permeated water.

[0027] The sand filtered water supplies the first DTRO device, which first enters a core filter. The core filter further removes suspended solids in the wastewater. The device is equipped with a core filter set, and the inlet and outlet ends are provided with pressure sensors to automatically detect the pressure difference. When the pressure difference exceeds 2.0 bar, the system prompts to replace the filter core. The core filter has a filtering accuracy of 10 μm, which provides the last protective barrier for the membrane column. In order to prevent the scaling phenomenon caused by high concentration of various insoluble sulfates and silicates in the membrane module, and effectively prolong the service life of the membrane, a certain amount of scale inhibitor needs to be added before the first DTRO membrane. The addition amount is determined according to the concentration of insoluble salt in the raw water.

[0028] The percolate after the core filter directly enters the high-pressure plunger pump of the first DTRO. Each plunger pump of the DT membrane system is provided with a shock absorber at the rear end to absorb the pressure pulse generated by the high-pressure pump and provide a stable pressure for the membrane column. The water after the high-pressure pump enters the membrane module. The membrane module uses a disc tube type reverse osmosis membrane column, which has strong anti-pollution and strong adaptability to wastewater, and the membrane life is extended to more than 3 years. The first reverse osmosis system is provided with one section. In order to ensure sufficient flow rate and cross-flow velocity on the membrane surface, and to avoid membrane pollution, a circulating pump is arranged before the membrane module. The high-pressure and high-flow water flowing out of the circulating pump directly enters the membrane column. The water outlet of the membrane column set is divided into two parts: the first concentrated liquid and the first permeate. The concentrated liquid end is provided with a servo motor controlled valve for controlling the pressure in the membrane group to produce the necessary water recovery rate. The first permeate enters the second high-pressure pump for further processing by the second DTRO. The first concentrated liquid is discharged into the concentrated liquid tank and transported to the incineration plant for incineration disposal.

[0029] The second DTRO is used for further processing of the first DTRO permeate. The permeate after the first DT membrane system processing does not need to add any reagent and is directly sent to the second DT membrane system high-pressure pump. There is no need to set a buffer tank between the first and second levels. The system flow is automatically matched during operation. The second high-pressure pump is provided with a frequency conversion control. The running frequency and output flow of the second high-pressure pump will be automatically matched according to the feedback value of the first permeate flow sensor. At the same time, the inlet pipeline of the second high-pressure pump is provided with a concentrated liquid self-compensation, so that the operation of the second system is not affected by the water production of the first system. Since the pollutant concentration of the second DTRO inlet water has been greatly reduced, the membrane surface filtration velocity requirement is low, and the recovery rate is relatively high. Therefore, the second reverse osmosis does not need an online booster pump, and only a high-pressure pump can meet the requirements.

[0030] The second DTRO concentrated liquid end is also provided with a servo motor controlled valve for controlling the pressure and recovery rate in the membrane group. The second DTRO concentrated liquid is much better than the raw water, so it is discharged to the inlet of the first system and combined with the first DTRO inlet water for processing, which improves the recovery rate of the system. The second DTRO permeate is discharged into the degassing tower.

[0031] The degassing and pH value adjustment of the clean water. Because the wastewater contains certain dissolved gas, the reverse osmosis membrane can remove the dissolved ions but cannot remove the dissolved gas, which can cause the pH value of the water produced by the reverse osmosis membrane to be slightly lower than the discharge requirement. After the dissolved acid gas in the permeate is removed by the degassing tower, the pH value can be significantly increased to more than 6.0. If the pH value of the clean water after the degassing tower is still lower than the discharge requirement, the system will automatically add a small amount of alkali to adjust the pH value to the discharge requirement. Because the effluent is degassed by the degassing tower, only a small amount of alkali needs to be added to meet the discharge requirement. The pH value adjustment of the effluent is carried out in the clean water tank, and a pH value sensor is installed in the clean water discharge pipe. The PLC judges the pH value of the effluent and automatically adjusts the frequency of the metering pump to adjust the amount of alkali added, so that the pH value of the effluent meets the discharge requirement.

[0032] The contents not described in detail in the specification belong to the prior art known to those skilled in the art, the standard parts used therein can be purchased from the market, the special-shaped parts can be ordered according to the description and the drawings, the specific connection mode of each part adopts the conventional screw, rivet, welding and other conventional means in the prior art, the mechanical parts and equipment adopt the conventional type in the prior art, the circuit connection adopts the conventional connection mode in the prior art, and the like, which will not be described in detail herein.

[0033] The utility model is not limited by the above-mentioned embodiment, other changes, modification, replacement, combination, simplification which do not deviate from the spirit and principle of the utility model, all should be equivalent replacement mode, all are contained in the protection scope of the utility model.

Claims

1. A wastewater treatment system for car washes at a garbage transfer station, characterized in that: The system includes an oil separator (1), an air flotation device (2), a DTRO raw water tank (3), a primary DTRO membrane (4), a secondary DTRO membrane (5), and a degassing tower (6). The outlet of the oil separator (1) is connected to the inlet of the air flotation device (2) via a pipe. The outlet of the air flotation device (2) is connected to a sludge thickening tank (7) via a pipe. The other end of the sludge thickening tank (7) is connected to a sludge dewatering machine (8) via a pipe. The outlet of the air flotation device (2) is connected to the inlet of the DTRO raw water tank (3) via a pipe. The outlet of the DTRO raw water tank (3) is connected to the inlet of a sand filter (9) via a pipe. The outlet of the sand filter (9) is connected to a water supply system via a pipe. The inlet of the security filter (10) and the outlet of the security filter (10) are connected to the inlet of the first-stage DTRO membrane (4) via a first-stage high-pressure pump (11). The first-stage DTRO membrane (4) is provided with a concentrate outlet and a product water outlet. The concentrate outlet of the first-stage DTRO membrane (4) is connected to the concentrate tank via a pipeline. The product water outlet of the first-stage DTRO membrane (4) is connected to the inlet of the second-stage DTRO membrane (5) via a second-stage high-pressure pump (12). The concentrate outlet of the second-stage DTRO membrane (5) is connected to the DTRO raw water tank (3) via a pipeline to form a circulation loop. The product water outlet of the second-stage DTRO membrane (5) is connected to the degassing tower (6) via a pipeline.

2. The wastewater treatment system for car washes at garbage transfer stations as described in claim 1, characterized in that: The DTRO raw water tank (3) is equipped with an acid inlet, which is connected to an acid storage tank through a pipe, and acid is added through the acid storage tank to adjust the pH value.

3. The wastewater treatment system for car washes at garbage transfer stations as described in claim 1, characterized in that: The security filter (10) is a cartridge filter, which is used to further remove suspended solids in wastewater. Pressure sensors are installed at both the inlet and outlet of the cartridge filter, and the pressure difference is automatically detected by the pressure sensors.

4. The wastewater treatment system for car washes at garbage transfer stations as described in claim 1, characterized in that: Both the primary high-pressure pump (11) and the secondary high-pressure pump (12) are DTRO high-pressure plunger pumps. Both the primary DTRO high-pressure plunger pump and the secondary DTRO high-pressure plunger pump are equipped with shock absorbers at the rear. The shock absorbers are used to absorb the pressure pulses generated by the high-pressure pumps.

5. The wastewater treatment system for car washes at garbage transfer stations as described in any one of claims 1 to 4, characterized in that: Both the primary DTRO membrane (4) and the secondary DTRO membrane (5) are made of disc tube reverse osmosis membrane columns.

6. The wastewater treatment system for car washes at garbage transfer stations as described in claim 5, characterized in that: A circulation pump (13) is provided on the inlet side of the first-stage DTRO membrane (4). The circulation pump (13) is located between the first-stage high-pressure pump (11) and the first-stage DTRO membrane (4). The first-stage DTRO membrane (4) is provided with a circulation port. The circulation port is connected to the circulation pump (13) through a pipeline to form a circulation loop.

7. The wastewater treatment system for car washes at garbage transfer stations as described in claim 5, characterized in that: Both the primary DTRO membrane (4) and the secondary DTRO membrane (5) are equipped with servo motor control valves at their concentrate ends. These servo motor control valves are used to control the pressure within the membrane assembly.

8. The wastewater treatment system for car washes at garbage transfer stations as described in claim 1, characterized in that: The outlet of the degassing tower (6) is connected to a clean water tank via a pipe. The clean water tank is equipped with an alkali addition port, through which alkali solution is added. The outlet of the clean water tank is connected to a clean water discharge pipe, and a pH sensor is installed in the clean water discharge pipe.

9. The wastewater treatment system for car washes at garbage transfer stations as described in claim 1, characterized in that: A water inlet pump (14) is installed between the oil separator (1) and the air flotation device (2), and a water inlet pump (2) is installed between the DTRO raw water tank (3) and the sand filter (9). The water effluent from the DTRO raw water tank (3) is pumped into the sand filter (9) through the water inlet pump (2) (15). Pressure gauges are installed at both the inlet and outlet of the sand filter (9).

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