An apparatus and method for treating groundwater

Abstract

The application discloses a groundwater treatment device and a water treatment method, and belongs to the technical field of water treatment. The device comprises a dosing mixer arranged on a water inlet pipeline, an on-line pH meter signal interlocked with the dosing mixer and an oxidation filter device along the flow direction of groundwater. The oxidation filter device is internally sequentially provided with a gas-liquid separator baffle, a branch mother pipe type water distribution device, a water curtain spraying filler layer, a blower, a backwashing reserved space, a filter filler layer and a water collecting device from top to bottom. The bottom of the oxidation filter device is provided with a backwashing water inlet system and a backwashing air inlet system. The application combines conventional aeration and water spraying devices, realizes synchronous aeration oxidation and decarburization, prepositions pH adjustment, is more favorable for improving decarburization efficiency, integrates the water curtain spraying device and the filter device, simplifies equipment structure, diversifies equipment functions, realizes synchronous aeration oxidation or decarburization, and integrates decarburization equipment and filter equipment.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of water treatment, and particularly relates to a groundwater treatment device and a water treatment method. BACKGROUND

[0002] Groundwater has the characteristics of less organic matter, low turbidity, but more minerals, and contains many reducing substances such as low-valence iron, manganese bicarbonate and sulfate. Such reducing substances have more harm to subsequent membrane systems, and are usually treated by aeration, coagulation, clarification, filtration and other methods.

[0003] Natural oxidation is a technique for removing iron and manganese from groundwater. This method mainly relies on oxygen in the air as an oxidizing agent. By introducing sufficient oxygen into the groundwater system, the divalent iron (Fe2 + ) is oxidized to trivalent iron (Fe3 + ), and hydroxide precipitate is formed, thereby achieving iron removal. For manganese removal, since the oxidation-reduction potential of divalent manganese (Mn2 + ) is higher than that of divalent iron, it is difficult to increase the pH value to above 9.0 to accelerate the oxidation rate in the general pH range of groundwater (about 6.0 to 7.5), so additional alkaline substances are usually added to promote the oxidation and removal of manganese.

[0004] Contact oxidation is another effective method for removing iron and manganese from groundwater. The basic principle of this method is to introduce oxygen into groundwater through aeration, so that divalent iron (Fe2 + ) and divalent manganese (Mn2 + ) are oxidized to trivalent iron (Fe3 + ) and high-valence manganese, and then these oxidation products are removed by filtration through a filter layer.

[0005] In the contact oxidation method, the aerated groundwater passes through a filter layer filled with specific filter materials. These filter materials can adsorb the oxidized iron and manganese and gradually form a filter membrane with catalytic action to accelerate the oxidation process of iron and manganese. For example, for the manganese removal process, the hydroxide of high-valence manganese adheres to the surface of the filter material to form so-called “manganese-sand”, which has a contact catalytic effect and can effectively oxidize divalent manganese to high-valence manganese and remove it from water under lower pH conditions.

[0006] These conventional treatment systems have the characteristics of complicated and lengthy process, large floor area, large investment, etc. For example, the groundwater treatment systems mentioned in patents CN201310548069.3 and CN202022508068.4. SUMMARY

[0007] The technical problem to be solved by the present application is to provide a groundwater treatment device and a water treatment method, which can integrate carbon dioxide removal, aeration oxidation and filtration, realize the functions of aeration iron and manganese removal and carbon dioxide removal, and have a small footprint.

[0008] To achieve the above object, the technical scheme adopted by the present application is:

[0009] The groundwater treatment device comprises a dosing mixer arranged on a water inlet pipeline, an online pH meter in signal interlocking connection with the dosing mixer, and an oxidation and filtration device.

[0010] The further improvement of the technical scheme of the present application is that the oxidation and filtration device shell is a normal-pressure cylindrical container, comprising an oxidation system and a filtration and flushing system.

[0011] The further improvement of the technical scheme of the present application is that the oxidation and filtration device top is provided with an exhaust pipe, the backwashing water inlet system comprises a backwashing water inlet pipe arranged outside the oxidation and filtration device, the backwashing water inlet pipe is connected to the oxidation and filtration device and a wastewater pipe through a tee joint, the wastewater pipe is connected to a drainage ditch, and the backwashing water inlet pipe is provided with a water inlet valve and a backwashing water outlet valve.

[0012] The further improvement of the technical scheme of the present application is that the groundwater inlet is connected to the branch mother pipe type water distribution device, and the water curtain spray filler layer adopts a multi-surface plastic ball.

[0013] The further improvement of the technical scheme of the present application is that the air blower is arranged outside the oxidation and filtration device and extends into the oxidation and filtration device through an air inlet pipe, and the air inlet pipe is provided with a bend downwardly bent by 45° inside the device.

[0014] The further improvement of the technical scheme of the present application is that the backwashing reserved space has the same height as the filtration filler layer, the backwashing reserved space is provided with a liquid level transmitter and a backwashing water outlet, and the backwashing water outlet is connected to a backwashing water outlet valve arranged on a drainage pipeline.

[0015] The further improvement of the technical scheme of the present application is that the medicine added in the medicine mixing device includes sulfuric acid or hydrochloric acid solution, and the pH value defined by the on-line pH meter is 6-8.

[0016] A groundwater treatment method using the groundwater treatment device, comprising the following steps:

[0017] In step S1, the medicine mixing device on the groundwater inlet pipeline and the on-line pH meter are signal interlocked, the amount of medicine added is determined according to the pH value monitored by the on-line pH meter, the groundwater with the pH value meeting the requirement is sprayed into the branch manifold water distribution device, and the air blower is turned on to introduce air;

[0018] In step S2, the air introduced by the air blower and the groundwater are oxidized in the water curtain spraying filler layer, and the gas is discharged into the atmosphere through the gas-liquid separator baffle and the exhaust pipe.

[0019] In step S3, the groundwater after oxidation is filtered through the filtering filler layer to obtain clean water, which is discharged from the groundwater treatment device through the outlet pipeline and transported to the subsequent system.

[0020] The further improvement of the technical scheme of the present application is that when the oxidation and filtration device needs to be cleaned, the filtering filler layer is cleaned by forward washing and backwashing, in the backwashing, the compressed air is introduced through the backwashing air inlet pipe, and the water is introduced through the backwashing water inlet pipe to wash the filtering filler layer upwards, and the backwashing water is washed upwards to the backwashing reserved space and discharged into the drainage ditch through the backwashing drainage outlet.

[0021] The further improvement of the technical scheme of the present application is that when the oxidation and filtration device is forward washed, the groundwater enters the oxidation and filtration device through the water inlet pipeline, the medicine mixing device is not opened, and the air blower is not turned on, the groundwater is washed through the filtering filler layer by natural pressure, and the washing wastewater is discharged into the drainage ditch through the wastewater pipe.

[0022] Due to the adoption of the above technical scheme, the present application has the following technical progress:

[0023] The groundwater treatment device of the present application is integrated, the acid is added through the pipeline mixer to effectively convert the alkalinity, and the water curtain spraying and the air blowing are used to efficiently realize the oxidation of iron and manganese and the removal of carbon dioxide.

[0024] The whole device system has simple equipment configuration, mainly composed of a pipeline mixer, a water curtain spraying device, a fan, filter material and pipeline valves. The device operation control is simple, the medicine amount is adjusted through the on-line pH meter, and the operation and backwashing of the filter are controlled through the water level (or pressure difference).

[0025] The groundwater treatment device of the present application has low equipment investment cost, the aeration, decarburization and filtration equipment are integrated into one device, so that the equipment manufacturing cost and the civil engineering cost caused by the equipment occupation are greatly saved. Attached Figure Description

[0026] Figure 1 This is a schematic diagram of the groundwater treatment device of the present invention;

[0027] Figure 2 This is a side view of the groundwater treatment device of the present invention;

[0028] Figure 3 This is a top view of the groundwater treatment device of the present invention;

[0029] The components include: 1. Dosing mixer; 2. Gas-liquid separator baffle; 3. Branch pipe type water distribution device; 4. Water curtain spray packing layer; 5. Backwash reserved space; 6. Filter packing layer; 7. Water collection device; 8. Blower; 9. Air inlet pipe; 10. Drainage ditch; 11. Backwash water inlet pipe; 12. Backwash air inlet pipe; 13. Exhaust pipe; 14. Wastewater pipe; and 15. Water outlet pipe. Detailed Implementation

[0030] The present invention will be further described in detail below with reference to embodiments:

[0031] like Figures 1-3 As shown, a groundwater treatment device, along the flow direction of groundwater, includes a chemical mixing unit 1, an online pH meter, and an oxidation filtration device.

[0032] The dosing mixer 1 is installed on the incoming water pipeline of the groundwater, and the online pH meter is interlocked with the dosing mixer 1. The internal structure of the oxidation filtration device, from top to bottom, consists of a gas-liquid separator baffle 2, a branch pipe type water distribution device 3, a water curtain spray packing layer 4, a blower 8, a backwash reserved space 5, a filter packing layer 6, and a water collection device 7. The bottom of the oxidation filtration device is equipped with a backwash water inlet system and a backwash air inlet system.

[0033] The oxidation filtration device has an outer shell that is an atmospheric pressure cylindrical container. The device includes an oxidation system and a filtration and rinsing system. The oxidation system includes a gas-liquid separator baffle 2, a branch-pipe type water distribution device 3, a water curtain spray packing layer 4, and a blower 8. An inlet pipe and a branch-pipe water distribution device are installed below the gas-liquid separator baffle to ensure uniform distribution of water across the container's cross-section. In a preferred embodiment, the outer shell is a can-shaped structure that is narrower at the top and wider at the bottom. The oxidation system is located in the slightly narrower upper part of the can-shaped structure, and the filtration and rinsing system is located in the slightly wider lower part.

[0034] The groundwater inlet and the branch pipe type water distribution device 3 are connected. The water curtain spraying filler layer uses multi-faceted plastic balls as filler. When water passes through the spraying filler layer, it forms stratified fine tributaries or water films, flowing from top to bottom. The height of the filler layer determines the water residence time and the contact oxidation time with air.

[0035] The filter flushing system comprises a backwashing reserved space 5, a filter filler layer 6, a water collecting device 7, a backwashing water inlet system and a backwashing air inlet system; the top of the oxidation filter device is provided with an exhaust pipe 13; the backwashing water inlet system comprises a backwashing water inlet pipe 11 arranged outside the oxidation filter device, the backwashing water inlet pipe 11 is connected to the oxidation filter device and a waste water pipe through a tee joint, the waste water pipe is connected to a drainage ditch, a water inlet valve is arranged on the backwashing water inlet pipe 11, and a backwashing water outlet valve is arranged on the waste water pipe 14.

[0036] The backwashing air inlet system comprises a backwashing air inlet pipe 12 arranged outside the oxidation filter device, the backwashing air inlet pipe 12 is connected to the oxidation filter device and a water outlet pipe through a tee joint, an air inlet valve is arranged on the backwashing air inlet pipe 12, and a water outlet valve is arranged on the water outlet pipe. The backwashing water inlet pipe 11 and the backwashing air inlet pipe 12 introduce backwashing water and compressed air, and the filter material is backwashed regularly to take out the suspended solids in the filter material layer from the container.

[0037] The air blower 8 is arranged outside the oxidation filter device and extends into the oxidation filter device through an air inlet pipe 9, the air inlet pipe is arranged below the water curtain spray filler layer at a position of 400-500 mm, and a bend downward by 45° is arranged on the air inlet pipe 9 in the device to avoid water flowing into the air inlet pipe. After the air enters the container, the air flows from bottom to top, and is fully contacted with the spray filler layer and the fine water flow or water film, which has two effects. First, according to the gas partial pressure law, the carbon dioxide in the water body will be taken into the air and rise with the air, and finally be discharged out of the container. Second, the oxygen in the air is contacted with the reducing substances in the water body to oxidize and form oxidized suspended particles, which are flushed into the water container from top to bottom.

[0038] The groundwater inlet water passes through a dosing mixer and an online pH meter first, and then is connected to the branch mother pipe water distribution device 3 through the branch mother pipe water distribution device 3 after adding appropriate reagents, mainly dilute acid, including dilute sulfuric acid and dilute hydrochloric acid, for pH acidification adjustment, and then enters the oxidation filter device, and the filler of the water curtain spray filler layer adopts a multi-surface plastic ball, such as a multi-surface hollow plastic ball.

[0039] The backwashing reserved space 5 has the same height as the filter filler layer 6, or the backwashing reserved space 5 is slightly higher than the filter filler layer 6, a liquid level transmitter and a backwashing water outlet are arranged in the backwashing reserved space 5, and a backwashing water outlet valve is arranged on the drainage pipe connected to the backwashing water outlet.

[0040] A groundwater treatment method comprises the following steps:

[0041] In step S1, the dosing mixer 1 and the online pH meter on the groundwater inlet water pipeline are signal interlocked, the amount of reagent is determined according to the pH value monitored by the online pH meter, the groundwater with a pH value meeting the requirement is sprayed through the branch mother pipe water distribution device 3, and the air blower 8 is started to introduce air.

[0042] Step S2, the air sent by the air blower 8 and the underground water are fully contacted and oxidized in the water curtain spray filler layer 4, and the gas is discharged to the atmosphere through the gas-liquid separator baffle 2 and the exhaust pipe 13;

[0043] Step S3, the underground water after oxidation is filtered through the filter filler layer 6 to obtain treated clean water, which is discharged from the groundwater treatment device through the water outlet pipe 15 to the subsequent system.

[0044] When the oxidation and filtration device needs to be cleaned, the filter filler layer 6 is cleaned by forward washing and backwashing. When backwashing, the backwashing air inlet pipe 12 is opened to introduce compressed air, and the backwashing water inlet pipe 11 is opened to introduce water to upwardly backwash the filter filler layer 6. The backwashing water is washed upward to the backwashing reserved space 5, and the gas-water is alternately scrubbed. Then, the backwashing water is discharged to the drainage ditch 10 through the backwashing water outlet. The backwashing air inlet pipe 12 is connected to compressed air, which is under pressure and can overcome the resistance of the hydrostatic pressure (water column height) in the container during backwashing. The usual backwashing mode is to first open the backwashing water inlet pipe 11 for backwashing, but the backwashing water level is controlled at a certain height, and the water is not discharged to maintain the hydrostatic pressure of the water column. At this time, the backwashing air inlet pipe 12 is ventilated, and the gas pressure can overcome the hydrostatic pressure of the water column. At this time, the gas and water are mixed, and the surface state of the filter filler layer 6 is that the gas drives the water flow to clean the filter material.

[0045] When the oxidation and filtration device is forward washed, the underground water enters the oxidation and filtration device through the water inlet pipe. The dosing mixer 1 is not opened for dosing, and the air blower 8 is not opened for blowing. The underground water is washed through the filter filler layer 6 by natural pressure, and the washing wastewater is discharged to the drainage ditch 10 through the wastewater pipe 14.

[0046] In one cleaning cycle, multiple forward and backwashing cycles are carried out in a reciprocating process.

[0047] After the groundwater treatment device is used for treatment, the water at the water outlet pipe 15 is detected, and the detection results are as follows.

[0048] Serial number Analysis item Raw water Product water 1 pH 8.5 6.5 2 HCO3 - (mg / L) 384 152.5 3 Suspended solids (mg / L) 30 10 4 Fe 2+ (mg / L) 5.0 0.5 5 Mn 2+ (mg / L)]]> 1.4 0.2

Claims

1. A groundwater treatment apparatus, characterized by: Along the flow direction of groundwater, a dosing mixer (1) is arranged on the inlet pipe, an on-line pH meter is signal interlocked with the dosing mixer (1), and an oxidation filter device is arranged, the inside of the oxidation filter device is sequentially provided from top to bottom with a gas-liquid separator baffle (2), a branch mother pipe type water distribution device (3), a water curtain spray filler layer (4), a blower (8), a backwashing reserved space (5), a filter filler layer (6) and a water collecting device (7), the bottom of the oxidation filter device is provided with a backwashing water inlet system and a backwashing air inlet system; The oxidation filter device is a normal pressure columnar container, comprising an oxidation system and a filter flushing system, the oxidation system comprises the gas-liquid separator baffle (2), the branch mother pipe type water distribution device (3), the water curtain spray filler layer (4) and the blower (8), the filter flushing system comprises the backwashing reserved space (5), the filter filler layer (6), the water collecting device (7), the backwashing water inlet system and the backwashing air inlet system; the top of the oxidation filter device is provided with an exhaust pipe (13), the backwashing water inlet system comprises a backwashing water inlet pipe (11) arranged outside the oxidation filter device, the backwashing water inlet pipe (11) is connected with the oxidation filter device and a waste water pipe (14) through a tee joint, the waste water pipe is connected to a drainage ditch, a water inlet valve is arranged on the backwashing water inlet pipe (11), and a backwashing water outlet valve is arranged on the waste water pipe (14); The backwashing air inlet system comprises a backwashing air inlet pipe (12) arranged outside the oxidation filter device, the backwashing air inlet pipe (12) is connected with the oxidation filter device and a water outlet pipe (15) through a tee joint, an air inlet valve is arranged on the backwashing air inlet pipe (12), and a water outlet valve is arranged on the water outlet pipe (15); The groundwater inlet is connected with the branch mother pipe type water distribution device (3), and the filler of the water curtain spray filler layer is a multi-surface plastic ball; The blower (8) is arranged outside the oxidation filter device and extends into the oxidation filter device through an air inlet pipe (9), the air inlet pipe (9) is provided with a bend downwardly bent by 45° inside the device; The height of the backwashing reserved space (5) is the same as that of the filter filler layer (6), a liquid level transmitter and a backwashing water outlet are arranged in the backwashing reserved space (5), and a backwashing water outlet valve is arranged on a drainage pipe connected with the backwashing water outlet; The medicine added in the dosing mixer (1) comprises a sulfuric acid or hydrochloric acid solution, and the on-line pH meter defines the pH value as 6-8.

2. A method for treating groundwater using the groundwater treatment apparatus according to claim 1, characterized by The method comprises the following steps: In step S1, the dosing mixer (1) and the on-line pH meter on the groundwater inlet pipe are signal interlocked, the amount of medicine added is determined according to the pH value monitored by the on-line pH meter, the groundwater with the pH value meeting the requirement is sprayed through the branch mother pipe type water distribution device (3), and the blower (8) is started to send in air; In step S2, the air sent in by the blower (8) and the groundwater are fully contacted and oxidized in the water curtain spray filler layer (4), and the gas is discharged to the atmosphere through the gas-liquid separator baffle (2) and the exhaust pipe (13); In step S3, the groundwater after oxidation is filtered through the filter filler layer (6) to obtain clean water treated, which is discharged from the groundwater treatment device through the water outlet pipe (15) and sent to a subsequent system.

3. A method of treating groundwater according to claim 2, characterised in that: When the oxidation filter device needs to be cleaned, the filter filler layer (6) is cleaned by forward washing and backwashing. When backwashing, the backwashing air inlet pipe (12) is opened to introduce compressed air, the backwashing water inlet pipe (11) is opened to introduce water to backwash the filter filler layer (6) upward, the backwashing water is washed upward to reach the backwashing reserved space (5), and then the water is discharged to the drainage ditch (10) through the backwashing water outlet.

4. The method of claim 3, wherein: When the oxidation filter device is forward washed, groundwater enters the oxidation filter device through the water inlet pipe. The dosing mixer (1) is not opened for dosing, and the air blower (8) is not opened for blowing. The groundwater is washed through the filter filler layer (6) by natural pressure, and the washing wastewater is discharged to the drainage ditch (10) through the wastewater pipe (14).

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