CN117682726A - A device and method for removing phosphorus from eutrophic water bodies - Google Patents

Abstract

The invention discloses a device and method for removing phosphorus in eutrophic water bodies, which includes an algae decomposition tank, an electric flocculation tank, a sedimentation tank and an anoxic recovery tank; the algae decomposition tank has a vertically arranged decomposition tank body. A number of motors are provided at the upper and lower ends of the decomposition tank body. A filter press plate is provided inside the decomposition tank body. The motor at the upper end and the upper surface of the filter press plate are provided with pull ropes. The motor at the lower end is connected to the filter press plate. The lower surface of the filter press is provided with a pull rope, and the pull rope is used to control the movement of the filter press plate in the vertical direction; the filter press plate is provided with several one-way holes. Part of the phosphorus separated by the present invention is in the form of phosphate, and the anoxic recovery tank of the present invention can recover phosphate with a small additive content. The invention is simple to operate, does not require the use of large amounts of chemical agents, and avoids secondary pollution that may be caused thereby.

Description

Device and method for removing phosphorus in eutrophic water body

Technical Field

The invention belongs to the technical field of water environment treatment and sewage treatment, relates to a method for removing phosphorus in a high-algae water body, and in particular relates to a device and a method for removing phosphorus in an eutrophic water body, which avoid secondary pollution possibly caused by using a large amount of chemical agents.

Background

Phosphorus is irreplaceable in the earth life, however, high-quality recoverable phosphorus ore capable of obtaining phosphorus is gradually reduced, 80% of recovered phosphorus ore is used for agricultural production, most of phosphorus is input into lakes through rivers, water eutrophication is caused, and more than half of lakes are in an eutrophication state through statistics.

Eutrophication is often accompanied by algae biomass accumulation, and algae in lakes excessively absorb and store phosphorus in the form of phosphate, so that water quality in an algae accumulation area is rapidly deteriorated after decomposition, and the living of the environment and surrounding residents is affected, so that the recovery of algae and phosphate in the area is very important.

Algae are harvested by manual salvaging frequently when algal bloom occurs, but the salvaging efficiency is lower; in order to rapidly remove small-particle phosphorus and phosphate, chemical flocculation is commonly used, but on one hand, the chemical flocculation method needs a large amount of medicament investment, and on the other hand, the generated large amount of chemical sludge is high in treatment cost and can cause secondary pollution.

Disclosure of Invention

In order to solve the problems, the invention provides a device and a method for removing phosphorus in eutrophic water, wherein the water firstly enters an algae decomposition tank, is decomposed and pumped into an electric flocculation tank, the phosphorus in the water is removed by the electric flocculation tank and is precipitated, and finally phosphorus element is released in a phosphate form in an anoxic tank and is recovered.

In order to achieve the above purpose, the present invention adopts the following technical scheme:

the invention provides a device for removing phosphorus in eutrophic water, which comprises an algae decomposition tank, an electric flocculation tank, a sedimentation tank and an anoxic recovery tank; the algae decomposing tank comprises a decomposing tank body vertically arranged, wherein the upper end and the lower end of the decomposing tank body are respectively provided with a plurality of motors, a filter pressing plate is arranged in the decomposing tank body, the motors at the upper end and the upper surface of the filter pressing plate are provided with traction ropes, the motors at the lower end and the lower surface of the filter pressing plate are provided with traction ropes, and the movement of the filter pressing plate in the vertical direction is controlled through the traction ropes; a plurality of one-way holes are formed in the filter pressing plate;

the electric flocculation tank comprises a flocculation tank body, wherein an electrode plate bracket, an electrode plate and a constant voltage power supply are arranged in the flocculation tank body;

the sedimentation tank comprises a sedimentation tank body, and a first exhaust pipe is arranged at the upper end of the sedimentation tank body;

the anoxic recovery tank comprises a recovery tank body, and a second exhaust pipe is arranged at the upper end of the recovery tank body;

the algae decomposing tank is sequentially connected with the electric flocculation tank, the sedimentation tank and the anoxic recovery tank.

As a preferred scheme of the invention, the one-way hole comprises a plurality of cover plates capable of being opened up and down and a semi-permeable membrane, and the semi-permeable membrane is arranged below the cover plates.

As a preferable scheme of the invention, one end of the decomposition tank body is provided with a first water inlet pipe and a first water outlet pipe, the first water inlet pipe is provided with a first water inlet valve and a first water inlet pump, and the first water outlet pipe is provided with a first water outlet valve and a first water outlet pump.

As a preferable scheme of the invention, a second water outlet pipe is arranged at the lower part of the flocculation tank body, a first circulating water pipe is connected with a first three-way pipe through a circulating water pump, one end of the second circulating water pipe is connected with the first three-way pipe, the other end of the second circulating water pipe is connected with the upper part of the flocculation tank body to form circulation, and a circulating water valve is arranged on the second circulating water pipe; the second water outlet pipe is provided with a second water outlet valve and a second water outlet pump; the upper part of the flocculation tank body is connected with an algae decomposition tank.

As a preferable scheme of the invention, a third water outlet pipe is arranged at the lower part of the sedimentation tank body, a first exhaust valve and a first exhaust pump are arranged on the first exhaust pipe, and a third water outlet valve and a third water outlet pump are arranged on the third water outlet pipe; the upper part of the sedimentation tank is connected with an electric flocculation tank.

As a preferable scheme of the invention, the lower end of the recovery tank body is provided with a second three-way pipe, the second three-way pipe is connected with the sedimentation tank, and a pH detection device is arranged in the second three-way pipe; and a second exhaust valve and a second air beating pump are arranged on the second exhaust pipe.

As a preferable scheme of the invention, the invention further comprises a pH medicament storage tank, wherein a partition plate is arranged in the pH medicament storage tank so as to keep the pH medicament storage tank to store the acidic medicament and the alkaline medicament simultaneously; the lower part of the pH medicament storage tank is provided with a medicament valve and a medicament filling pipe, and the medicament valve is connected with the second three-way pipe through the medicament filling pipe.

As a preferred embodiment of the present invention, the motors are disposed opposite to each other.

The invention also provides a method for removing phosphorus in the eutrophic water body by adopting the device, which comprises the following steps:

1) The water enters an algae decomposition pond, and the filter pressing plate is enabled to filter-press downwards through a motor and a traction rope below the filter pressing plate until the motor reaches a threshold value; the motor and the traction rope above the filter plate enable the filter plate to return to the original position upwards, and algae in the water body are fully crushed and decomposed repeatedly for a plurality of times;

2) The fully decomposed water body enters an electric flocculation tank for electric flocculation;

3) The flocculated water enters a sedimentation tank for sedimentation;

4) After the precipitation is completed, the flocculation concentrated solution at the bottom of the precipitation tank enters an anoxic recovery tank, and the gas in the anoxic recovery tank is discharged to form an anoxic atmosphere, and the formation of phosphate is waited.

Compared with the prior art, the invention has the following beneficial effects:

1) The invention can separate algae in lake water rapidly and efficiently, and reduce lake phosphorus.

2) The invention can recover phosphate with little additive content.

3) The invention has simple operation, does not need to use a large amount of chemical agents, and avoids secondary pollution possibly caused by the chemical agents.

Drawings

Fig. 1 is a schematic diagram of the present invention.

FIG. 2 is a schematic diagram of an algae decomposition pond.

FIG. 3 is a cross-sectional view A-A.

FIG. 4 is a B-B cross-sectional view.

Fig. 5 is a C-C cross-sectional view.

Fig. 6 is a schematic view of a one-way hole.

FIG. 7 is a schematic diagram of an electroflocculation cell.

FIG. 8 is a top view of an electroflocculation cell.

Fig. 9 is a schematic diagram of a sedimentation tank.

Fig. 10 is a schematic diagram of an anoxic recovery tank.

Fig. 11 is a schematic of a pH agent storage tank.

In the figure, 1, decomposing a tank body; 1-1, a first water inlet pipe; 1-2, a first water inlet valve; 1-3, a first water inlet pump; 1-4, pressing a filter plate; 1-4-1 unidirectional holes; 1-4-1-1. Cover plate; 1-4-1-2. Semipermeable membrane; 1-5 motors; 1-6, pulling a rope; 1-7, a first water outlet valve; 1-8, a first water outlet pump; 1-9, a first water outlet pipe.

2. A flocculation tank body; 2-1, electrode plates; 2-2, constant voltage power supply; 2-3 first circulating water pipes; 2-4, a circulating water pump; 2-5, a first three-way pipe; 2-6, a second water outlet valve; 2-7, a second water outlet pump; 2-8, a second water outlet pipe; 2-9, circulating water valve.

3. A sedimentation tank body; 3-1, a first exhaust pipe; 3-2, a first exhaust pump; 3-3, a first exhaust valve; 3-4, a third water outlet pipe; 3-5, a third water outlet valve; and 3-6, a third water outlet pump.

4. A recovery tank body; 4-1, a second exhaust pipe; 4-2, a second exhaust pump; 4-3, a second exhaust valve; 4-4, a second three-way pipe; and 4-5. A pH detection device.

A ph agent storage tank; 5-1, a medicament valve; 5-2, a medicament filling pipe; 5-3, dividing plate.

Detailed Description

The technical solutions of the embodiments of the present invention will be clearly and completely described below in conjunction with the embodiments of the present invention, and it is apparent that the described embodiments are only some embodiments of the present invention, not all embodiments. All other embodiments, which can be made by those skilled in the art based on the embodiments of the invention without making any inventive effort, are intended to be within the scope of the invention.

Referring to fig. 1, the present invention provides, first, an apparatus for removing phosphorus from an eutrophic water body, the apparatus including an algae decomposing tank, an electric flocculation tank, a sedimentation tank, and an anoxic recovery tank.

Referring to fig. 2-5, a decomposition tank body 1 is vertically arranged in the algae decomposition tank, a plurality of motors 1-5 are respectively arranged at the upper end and the lower end of the decomposition tank body 1, a filter press plate 1-4 is arranged at the top of the inside of the decomposition tank body 1, a traction rope 1-6 is arranged on the upper surfaces of the motors 1-5 at the upper end and the filter press plate 1-4, a traction rope 1-6 is arranged on the lower surfaces of the motors 1-4 at the lower end and the filter press plate 1-5, and the movement of the filter press plate 1-4 in the vertical direction is controlled through the traction rope 1-6; the filter pressing plate 1-4 is provided with a plurality of one-way holes 1-4-1; the default position of the filter pressing plate 1-4 is the top of the decomposition tank body 1, namely one side far away from the first water inlet pipe 1-1 and the first water outlet pipe 1-9

One end of the decomposition tank body 1 is provided with a first water inlet pipe 1-1 and a first water outlet pipe 1-9, the first water inlet pipe 1-1 is provided with a first water inlet valve 1-2 and a first water inlet pump 1-3, and the first water outlet pipe 1-9 is provided with a first water outlet valve 1-7 and a first water outlet pump 1-8.

Referring to fig. 6, the one-way hole 1-4-1 includes a plurality of cover plates 1-4-1-1 that can be opened up and down and a semipermeable membrane 1-4-1-2, the semipermeable membrane 1-4-1-2 being disposed under the cover plates 1-4-1-1.

Referring to fig. 7 and 8, the electric flocculation tank comprises a flocculation tank body 2, wherein an electrode plate support 2-11 (the electrode plate support 2-11 is made of nonmetal insulating materials), an electrode plate 2-1 (the electrode plate is an aluminum electrode plate) and a constant voltage power supply 2-2 (the constant voltage power supply is a 15V constant voltage power supply) are arranged in the flocculation tank body 2.

The lower part of the flocculation tank body 2 is provided with a second water outlet pipe 2-8, a first circulating water pipe 2-3, a second circulating water pipe 2-10 and a first three-way pipe 2-5, the first circulating water pipe 2-3 is connected with the first three-way pipe 2-5 through a circulating water pump 2-4, one end of the second circulating water pipe 2-10 is connected with the first three-way pipe 2-5, the other end is connected with the upper part of the flocculation tank body 2 to form circulation, and a circulating water valve 2-9 is arranged on the second circulating water pipe 2-3; the second water outlet pipe 2-8 is provided with a second water outlet valve 2-6 and a second water outlet pump 2-7; the upper part of the flocculation tank body 2 is connected with the first water outlet pipe 1-9.

Referring to fig. 9, the sedimentation tank comprises a sedimentation tank body 3, wherein a first exhaust pipe 3-1 is arranged at the upper end of the sedimentation tank body 3; the lower part of the sedimentation tank body 3 is provided with a third water outlet pipe 3-4, the first exhaust pipe 3-1 is provided with a first exhaust valve 3-3 and a first exhaust pump 3-2, and the third water outlet pipe 3-4 is provided with a third water outlet valve 3-5 and a third water outlet pump 3-6; the upper part of the sedimentation tank body 3 is connected with a second water outlet pipe 2-8.

Referring to fig. 10, the anoxic recovery tank comprises a recovery tank body 4, wherein a second exhaust pipe 4-1 is arranged at the upper end of the recovery tank body 4; the lower end of the recovery tank body 4 is provided with a second three-way pipe 4-4, the second three-way pipe 4-4 is connected with the sedimentation tank body 3, and a pH detection device 4-5 is arranged in the second three-way pipe 4-4; the second exhaust pipe 4-1 is provided with a second exhaust valve 4-3 and a second air beating pump 4-2.

Referring to fig. 11, the pH agent storage tank 5 is further included, and a partition plate 5-3 is provided in the pH agent storage tank 5 to hold the pH agent storage tank to store both the acidic agent and the alkaline agent; the lower part of the pH medicament storage tank 5 is provided with a medicament valve 5-1 and a medicament filling pipe 5-2, and the medicament valve 5-1 is connected with the second three-way pipe 4-4 through the medicament filling pipe 5-2.

Example 1

The embodiment provides a method for removing phosphorus in eutrophic water body by adopting the device, which comprises the following steps:

1) When the device is operated, first, the first water inlet valve 1-2 and the first water inlet pump 1-3 are opened, and the first water outlet valve 1-7 and the first water outlet pump 1-8 are closed. The high algae water is pumped into the decomposing tank body 1 by the first water inlet pump 1-3 through the first water inlet pipe 1-1, after the high algae water is fully filled, the first water inlet valve 1-2 and the first water inlet pump 1-3 are closed, a motor 1-5 arranged at the lower end of the decomposing tank body 1 is started, the motor 1-5 at the upper end of the decomposing tank body 1 is closed, and a traction rope 1-6 is in a free state, so that the filter pressing plate 1-4 is pulled to move downwards. During this movement, water will enter the upper portion of the filter press plate 1-4 through the semipermeable membrane 1-4-1-2 and the cover plate 1-4-1-1, and algae will remain below the filter press plate 1-4 because it cannot pass through the semipermeable membrane 1-4-1-2. Thus, as the filter press plates 1-4 move downward, the algae space is compressed, eventually breaking up the algae. Stopping running and enabling the traction rope 1-6 to be in a free state after the force applied by the motor 1-5 at the lower end of the decomposition tank body 1 reaches a threshold value; at this time, the motor 1-5 at the lower end of the decomposition tank body 1 is started to pull up the filter press plate 1-4 to the top. The algae in the high algae water body can be fully decomposed (judged according to the conductivity of the water, if the algae decomposition degree is high, the conductivity of the water is relatively high).

After algae are fully decomposed, the filter pressing plate 1-4 is at a default position, the first water inlet valve 1-2 and the first water inlet pump 1-3 are kept in a closed state, the first water outlet valve 1-7 and the first water outlet pump 1-8 are opened, and high algae water in the decomposition tank body 1 is pumped into the electric flocculation tank through the first water outlet pipe 1-9.

2) When the first water outlet valve 1-7 and the first water outlet pump 1-8 are opened to pump the high algae water into the electric flocculation tank, the constant-pressure power supply 2-2, the circulating water pump 2-4, the circulating water valve 2-9, the second water outlet valve 2-6 and the second water outlet pump 2-7 are in a closed state. When the electric flocculation tank is filled, the first water outlet valve 1-7, the first water outlet pump 1-8, the second water outlet valve 2-6 and the second water outlet pump 2-7 are kept closed, the constant voltage power supply 2-2, the circulating water pump 2-4 and the circulating water valve 2-9 are opened, and the electric flocculation process (current or voltage is set according to the area of the pole piece) is carried out.

When the electric flocculation is completed, the first water outlet pipe 1-7, the first water outlet pump 1-8, the constant voltage power supply 2-2 and the circulating water valve 2-9 are kept closed, the circulating water pump 2-4 does not operate but keeps smooth, the second water outlet valve 2-6 and the second water outlet pump 2-8 are opened, and a water body containing a large amount of floccules is pumped into the sedimentation tank.

3) When the second outlet valve 2-6 and the second outlet water pump 2-8 are opened to pump the water containing flock into the sedimentation tank, the first air discharge pump 3-2, the first air discharge valve 3-3, the third outlet valve 3-5 and the third outlet water pump 3-6 are closed. After the injection is completed, the second water outlet valve 2-6, the second water outlet pump 2-7, the third water outlet valve 3-5 and the third water outlet pump 3-6 are closed, the first exhaust pump 3-2 and the first exhaust valve 3-3 are opened, and the gas in the pool is pumped out by the first exhaust valve 3-2 to create an anoxic environment. After the exhaust is finished, all valves and pumps are closed, and the sedimentation is waited to be finished (obvious sedimentation phenomenon can be observed about 30min, the flocs generated by the electric coagulation have obvious limit with the water body, and the sedimentation can be considered to be finished by observing the flocs sinking to naked eyes). After the precipitation is finished, the third water outlet valve 3-5 and the third water outlet pump 3-6 are opened, and the flocculation concentrate at the bottom of the precipitation tank is pumped into the anoxic recovery tank.

4) The pH agent storage tank 5 is used to store a pH adjusting agent. Wherein the partition plate 5-3 divides the pH agent storage tank 5 into two parts, one part storing the acidic agent and the other part storing the basic agent. The pH medicament storage tank 5 is externally connected with a medicament filling pipe 5-2, a medicament valve 5-1 is arranged on the medicament filling pipe, and medicaments flow out by gravity.

The second three-way pipe 4-4 is connected with the water outlet pipe 3-4, the recovery tank body 4 and the medicament filling pipe 5-2.

According to the result of the pH detecting device 4-5, the pH medicament storage tank 5 releases the flocculating concentrated solution extracted by the third water outlet pump 3-6 with proper type and proper amount of medicament, so that the pH of the water body is kept at the level (pH is 7-10) which is most suitable for phosphate release.

When the third water outlet valve 3-5, the third water outlet pump 3-6 and the reagent valve 5-1 are opened to deliver the flocculated concentrate of a suitable pH into the recovery tank 4, the second air outlet pump 4-2 and the second air outlet valve 4-3 are closed. After water injection is completed, the third water outlet valve 3-5, the third water outlet pump 3-6 and the medicament valve 5-1 are closed, the second exhaust pump 4-2 and the second exhaust valve 4-3 are opened, and the gas in the recovery tank body 4 is pumped out to create an anoxic environment. After the gas is pumped out, the third water outlet valve 3-5, the third water outlet pump 3-6, the medicament valve 5-1, the second exhaust pump 4-2 and the second exhaust valve 4-3 are all closed, and the release of phosphate is waited.

Phosphate can be released into the water body in the anoxic environment, the maximum value is reached on the sixth day, the liquid in the anoxic recovery tank is extracted, and about 40 percent of phosphate can be recovered.

While the invention has been described with respect to preferred embodiments thereof, it will be understood by those skilled in the art that various modifications and additions may be made without departing from the scope of the invention. Equivalent embodiments of the present invention will be apparent to those skilled in the art having the benefit of the teachings disclosed herein, when considered in the light of the foregoing disclosure, and without departing from the spirit and scope of the invention; meanwhile, any equivalent changes, modifications and evolution of the above embodiments according to the essential technology of the present invention still fall within the scope of the technical solution of the present invention.

Claims (9)

1. A device for removing phosphorus in eutrophic water body, which is characterized by comprising an algae decomposition tank, an electric flocculation tank, a sedimentation tank and an anoxic recovery tank; the algae decomposing tank comprises a decomposing tank body vertically arranged, wherein the upper end and the lower end of the decomposing tank body are respectively provided with a plurality of motors, a filter pressing plate is arranged in the decomposing tank body, the motors at the upper end and the upper surface of the filter pressing plate are provided with traction ropes, the motors at the lower end and the lower surface of the filter pressing plate are provided with traction ropes, and the movement of the filter pressing plate in the vertical direction is controlled through the traction ropes; a plurality of one-way holes are formed in the filter pressing plate;

the electric flocculation tank comprises a flocculation tank body, wherein an electrode plate bracket, an electrode plate and a constant voltage power supply are arranged in the flocculation tank body;

the sedimentation tank comprises a sedimentation tank body, and a first exhaust pipe is arranged at the upper end of the sedimentation tank body;

the anoxic recovery tank comprises a recovery tank body, and a second exhaust pipe is arranged at the upper end of the recovery tank body;

the algae decomposing tank is sequentially connected with the electric flocculation tank, the sedimentation tank and the anoxic recovery tank.

2. The apparatus for removing phosphorus from an eutrophic water body according to claim 1, wherein the one-way hole comprises a plurality of cover plates which can be opened up and down and a semipermeable membrane, and the semipermeable membrane is arranged below the cover plates.

3. The device for removing phosphorus in a eutrophic water body according to claim 1, wherein a first water inlet pipe and a first water outlet pipe are arranged at one end of the decomposing tank body, a first water inlet valve and a first water inlet pump are arranged on the first water inlet pipe, and a first water outlet valve and a first water outlet pump are arranged on the first water outlet pipe.

4. The device for removing phosphorus in the eutrophic water body according to claim 1, wherein a second water outlet pipe is arranged at the lower part of the flocculation tank body, a first circulating water pipe is connected with a first three-way pipe, the first circulating water pipe is connected with the first three-way pipe through a circulating water pump, one end of the second circulating water pipe is connected with the first three-way pipe, the other end of the second circulating water pipe is connected with the upper part of the flocculation tank body to form circulation, and a circulating water valve is arranged on the second circulating water pipe; the second water outlet pipe is provided with a second water outlet valve and a second water outlet pump; the upper part of the flocculation tank body is connected with an algae decomposition tank.

5. The device for removing phosphorus in eutrophic water according to claim 1, wherein a third water outlet pipe is arranged at the lower part of the sedimentation tank body, a first exhaust valve and a first exhaust pump are arranged on the first exhaust pipe, and a third water outlet valve and a third water outlet pump are arranged on the third water outlet pipe; the upper part of the sedimentation tank is connected with an electric flocculation tank.

6. The device for removing phosphorus in the eutrophic water body according to claim 1, wherein a second three-way pipe is arranged at the lower end of the recovery tank body, the second three-way pipe is connected with the sedimentation tank, and a pH detection device is arranged in the second three-way pipe; and a second exhaust valve and a second air beating pump are arranged on the second exhaust pipe.

7. The apparatus for removing phosphorus from an eutrophic water according to claim 6, further comprising a pH agent storage tank having a partition plate provided therein to hold the pH agent storage tank to store both the acidic agent and the alkaline agent; the lower part of the pH medicament storage tank is provided with a medicament valve and a medicament filling pipe, and the medicament valve is connected with the second three-way pipe through the medicament filling pipe.

8. The apparatus for removing phosphorus from an eutrophic water body according to claim 1, wherein the motors are disposed opposite to each other.

9. A method for removing phosphorus from an eutrophic water body, characterized by using the apparatus as claimed in any one of claims 1 to 8, comprising the steps of:

1) The water enters an algae decomposition pond, and the filter pressing plate is enabled to filter-press downwards through a motor and a traction rope below the filter pressing plate until the motor reaches a threshold value; the motor and the traction rope above the filter plate enable the filter plate to return to the original position upwards, and algae in the water body are fully crushed and decomposed repeatedly for a plurality of times;

2) The fully decomposed water body enters an electric flocculation tank for electric flocculation;

3) The flocculated water enters a sedimentation tank for sedimentation;

4) After the precipitation is completed, the flocculation concentrated solution at the bottom of the precipitation tank enters an anoxic recovery tank, and the gas in the anoxic recovery tank is discharged to form an anoxic atmosphere, and the formation of phosphate is waited.