CN111335383A

CN111335383A - Black and odorous water body dredging system and method

Info

Publication number: CN111335383A
Application number: CN202010261418.3A
Authority: CN
Inventors: 陈捷; 李君菲; 刘方照; 王照宜
Original assignee: Guangzhou Pujing Ecological Protection Technology Co ltd
Current assignee: Guangzhou Pujing Ecological Protection Technology Co ltd
Priority date: 2020-04-03
Filing date: 2020-04-03
Publication date: 2020-06-26

Abstract

The invention discloses a black and odorous water body dredging system and method. The method comprises the following steps of arranging a barricading dredging unit at a to-be-dredged river section; through investigation, sampling and analysis, the thickness of the easily-blackened and odorous surface layer sediment is determined, the surface layer sediment is subjected to hydraulic scouring in the enclosure dredging unit, the surface layer blackened and odorous sediment is fully expanded to form a mud-water mixture, the mud-water mixture is rapidly pumped out from the enclosure dredging unit, pollution-free coarse sand particles in the mud-water mixture are separated through physical precipitation, and the residual mud-water mixture containing the easily-blackened and odorous sediment is discharged into a sewage treatment facility. The system comprises an enclosure dredging unit arranged in the water body to be dredged, a scouring system, a sand-water separation system and a gravity drain pipe. The black and odorous water dredging system and method provided by the invention have the advantages of strong dredging pertinence, convenience in operation, small operation space, flexibility in movement and low dredging cost, and can be better applied to dredging engineering of the black and odorous bottom mud on the surface layer of the small and medium-sized river channel.

Description

Black and odorous water body dredging system and method

Technical Field

The invention relates to the field of black and odorous water body treatment, in particular to a black and odorous water body dredging system and method.

Background

The black and odorous water body is generally used for removing pollutants in bottom mud of a river channel and improving river water environment.

At present, common black and odorous water body dredging methods comprise draining and dredging and underwater dredging. Dividing according to dredging machine equipment, and draining and dredging comprises direct excavation and hydraulic flushing excavation; the underwater dredging comprises grab bucket type dredging, pump suction type dredging, cutter suction type dredging and bucket wheel type dredging.

The quantity of the drainage and dredging engineering is large, the construction can be usually carried out only in the non-flood season, the construction period is limited to a certain extent, black and odorous bottom mud is exposed in the air and gives off peculiar smell, the construction efficiency is low, and meanwhile, negative social effects can be generated. In the underwater dredging method, the cutter suction type dredging and bucket wheel type dredging have large required operation space due to the huge dredging equipment, are suitable for medium and large river channels with large mud layer thickness, and cannot flexibly operate in small and medium river channels in cities; the grab type dredging is easy to cause float sludge omission and pollution diffusion, and the deep silt and original soil are severely disturbed while the sludge is removed, so that the environmental benefit is low; the pumping type dredging is easy to suck a large amount of sand grains, so that the subsequent sludge treatment workload is increased.

Common dredging methods, either drain dredging or underwater dredging, produce large quantities of mud or sludge, including black and odorous bottom mud and deep silt. In the subsequent treatment process, the dredging methods not only can generate secondary pollution, but also occupy a large-area storage yard, and the sludge treatment and disposal cost is high and the economic benefit is poor.

Research shows that compared with bottom sediment, the surface sediment has higher pollutant content and release concentration and has larger influence on water quality. And under the disturbance condition of the water body, the surface layer floating mud is easy to resuspend, so that more pollutants are released into the water body. The prior common dredging method is easy to remove the blackening and stink bottom mud and the pollution-free sand together, and has poor dredging pertinence, higher cost and low efficiency.

Therefore, in the small and medium river channel dredging practice, it is of great significance to explore a dredging system which is low in cost, high in efficiency, capable of removing black and odorous bottom mud on the surface layer in a targeted manner and capable of avoiding pollution diffusion.

Disclosure of Invention

The invention aims to provide a black and odorous water body dredging system and method, which have the advantages of strong dredging pertinence, convenient operation, small operation space and flexible movement, and can be better applied to dredging engineering of the easily-caused black and odorous bottom mud on the surface layer of a small and medium-sized river channel.

In order to achieve the aim, the invention provides a black and odorous water body dredging method, which comprises the following steps of arranging a closed enclosure dredging unit with the top higher than the water surface at a section of a water body to be dredged; performing hydraulic scouring on the bottom mud of the water body in the enclosure dredging unit to enable the blackening and stinky bottom mud with lighter specific gravity to fully float up to form a mud-water mixture; and (3) quickly pumping the mud-water mixture out of the enclosure desilting unit, separating the pollution-free coarse sand grains by physical precipitation, and discharging the residual mud-water mixture containing the bottom mud with lighter specific gravity and causing black and odor.

As a further improvement of the invention, the mud-water mixture containing the blackening smelling bottom mud is discharged into a municipal sewage pipe network or a sewage treatment facility.

As a further improvement of the method, the thickness of the black and odorous bottom mud is determined through investigation, sampling and analysis; when hydraulic flushing is carried out, only surface sediment with specified thickness is flushed, and disturbance of deep sediment is avoided.

As a further improvement of the invention, the section of the water body to be desilted is divided into at least two parts, and each part is provided with an enclosure desilting unit; when the hydraulic flushing is carried out, the water level in the enclosure dredging unit is controlled to ensure that the height of the water level is not higher than 50 cm.

As a further improvement of the invention, when the enclosure dredging unit is arranged, the enclosure dredging unit is built according to one side edge of the water body, and the wall body is closed by taking the water body edge as one side; the width of the enclosure dredging unit is slightly smaller than that of the water body, and a water passing channel is reserved between the enclosure dredging unit and the water body.

In order to achieve the purpose, the invention also provides a black and odorous water body dredging system which comprises an enclosure dredging unit arranged in the water body to be dredged, a scouring system for conveying scouring water, and a sand-water separation system communicated with the enclosure dredging unit.

As a further improvement of the invention, the flushing system comprises a water supply pipe, a high-pressure water pump, a flushing pipe and a flushing water gun which are sequentially connected along the water flow direction; the input of feed pipe is located the outside of enclosing and separating the desilting unit, it is located the inboard of enclosing and separating the desilting unit to erode the squirt.

As a further improvement of the invention, the barricade dredging unit is a temporarily built cofferdam, the cofferdam comprises a main body frame and a waterproof fabric, and the waterproof fabric surrounds the outer side of the main body frame; the main body frame is a scaffold or a cofferdam wall formed by stacking a plurality of sandbags.

As a further improvement of the invention, the sand-water separation system comprises a water delivery pipe, a slurry pump and a grit chamber which are connected in sequence; the input end of the water conveying pipe is connected with the enclosure dredging unit; the grit chamber is a rectangular tank body, and the water outlet end of the grit chamber is higher than the water inlet end; the bottom of the grit chamber is provided with a plurality of sand collecting hoppers along the direction from the water inlet end to the water outlet end.

As a further improvement of the invention, the water outlet end of the sand-water separation system is connected with a gravity drain pipe, and the drained water is sent to sewage treatment facilities such as a sewage pipe network or a sewage treatment station.

Advantageous effects

Compared with the prior art, the black and odorous water body dredging system and method have the advantages that:

1. through setting up the enclosure desilting unit that the cofferdam formed, when carrying out the water conservancy of desilting in-process and erodeing the step, be favorable to through reducing the working area, prevent that the proportion that floats is lighter to cause black smelly bed mud to spread on a large scale, can take out mud-water mixture fast with the small-size equipment and handle, reduce the problem that causes black smelly bed mud to expose and pungent smell diffusion. The amount of the mud-water mixture pumped out from the enclosure desilting unit is small, and the small sand-water separation system is convenient to separate and treat quickly. The components of the dredging system have small occupied area and flexible and convenient operation, and can be better applied to dredging projects of black and odorous bottom mud of small and medium water bodies such as ponds, ditches, canals, riverways and the like.

2. Be equipped with water channel on enclosing and separating desilting unit one side, do not influence the river course and cross water, ensure river course flood discharge function, reduce and enclose and separate the upstream thrust that desilting unit received, the guarantee is enclosed and is separated desilting unit structure safety and river course water safety. Meanwhile, the water channel is narrow in width, the flow rate of the river is high, when the water channel is flushed and cleared, the bottom sludge can be stirred up by the high-pressure water flow of the flushing water gun, and the sludge is flushed to the downstream quickly by the hydraulic flushing of the narrow water channel, so that the bottom sludge at the water channel can be cleared, and the construction cost is reduced.

3. The water scouring action is utilized to suspend the blackening and stink bottom mud with light specific gravity and small particle size on the surface layer of the bottom of the water body to form a mixture of water, blackening and stink bottom mud and silt. After the silt is precipitated by the sand-water separation system, the upper layer mud-water mixture contains the blackening and odorous bottom mud with light specific gravity and small particle size, and the partial mud-water mixture is discharged into a municipal sewage pipeline along the river nearby, so that the blackening and odorous bottom mud can be removed in a targeted manner, the generation amount of the silt is reduced, and the silt treatment cost is reduced.

4. Because the invention cleans the black and odorous sediment at the bottom of the water body in a small range, the size of each part of the system is small, the occupied area is small, the operation space is small, and the invention has the advantages of flexible movement and convenient loading and unloading. The barricade dredging unit is convenient to assemble and disassemble, and can be gradually pushed forward along the dredging river section, so that the dredging of the whole river section can be realized.

5. When carrying out water conservancy and erodeing, the control encloses the water level that separates in the desilting unit, makes the water level height not more than 50cm, can reduce and erode the resistance, lets bottom blackening smelly bed mud fully float when receiving to erode, and the scouring effect is better.

6. Constructors operate the scouring water gun in the enclosure dredging unit, and can scour the black and odorous bottom mud in the enclosure dredging unit, so that the operation is convenient.

7. The sand-water separation system is a grit chamber which separates pollution-free sand grains in the mud-water mixture through physical precipitation, no additional energy is needed, the structure is simple, and the separation effect is good. The water outlet end of the grit chamber is higher than the water inlet end, so that sand can be conveniently precipitated. The bottom of the grit chamber is provided with a plurality of sand collecting hoppers along the direction from the water inlet end to the water outlet end, so that settled sand particles can be cleaned conveniently.

8. The system makes full use of the existing sewage pipe network to accept the discharged sewage, reduces the pollution of the river channel and conveys the sewage to the downstream river channel, and is environment-friendly. The settled silt is simply washed and then backfilled into the river channel, and the riverbed is covered by clean silt, so that the disposal amount of silt is reduced, and the release of bottom mud pollutants in the deep layer of the riverbed is reduced.

The invention will become more apparent from the following description when taken in conjunction with the accompanying drawings, which illustrate embodiments of the invention.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, it is obvious that the drawings in the following description are only some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to the drawings without creative efforts.

FIG. 1 is a top view of a black and odorous water body dredging system;

fig. 2 is a side view of the black and odorous water body desilting system in the horizontal direction.

Detailed Description

Embodiments of the present invention will now be described with reference to the accompanying drawings.

Examples

The specific implementation mode of the invention is shown in fig. 1 to 2, and the black and odorous water dredging system comprises an enclosure dredging unit 1 arranged in a water body to be dredged, a flushing system 2 for conveying flushing water, and a sand-water separation system 3 communicated with the enclosure dredging unit 1.

The flushing system 2 comprises a water supply pipe 21, a high-pressure water pump 22, a flushing pipe 23 and a flushing water gun 24 which are sequentially connected along the water flow direction, wherein the flushing pipe 23 is a hose. The input end of the water supply pipe 21 is positioned at the outer side of the enclosure dredging unit 1, and the flushing water gun 24 is positioned at the inner side of the enclosure dredging unit 1.

The barricade dredging unit 1 is a temporarily built cofferdam which comprises a main body frame 11 and a waterproof fabric 12, wherein the waterproof fabric 12 covers the outer side of the main body frame 11. The main body frame 11 can be a cofferdam wall formed by stacking a plurality of sandbags; the main body frame 11 can also be built by a scaffold which is formed by connecting steel pipes and fasteners. The waterproof fabric 12 may be a waterproof cloth. The enclosure dredging unit 1 is built according to one side edge of the water body, and the water body edge is used as one side to seal the wall body.

The width of the enclosure dredging unit 1 is slightly smaller than that of a water body to be dredged, and a water passing channel 4 is reserved between the enclosure dredging unit and the water body to be dredged.

The sand-water separation system 3 comprises a water pipe 33, a mud pump 34 and a grit chamber 31 which are connected in sequence. The input end of the water pipe 33 is positioned inside the enclosure dredging unit 1. The water inlet end of the grit chamber 31 is connected with the output end of the water pipe 33 through a mud pump 34. The grit chamber 31 is a rectangular chamber body, and is formed by splicing and assembling simple materials (stainless steel, organic glass and the like). The water outlet end of the grit chamber 31 is higher than the water inlet end, so that sand can be conveniently precipitated. The bottom of the grit chamber 31 is provided with a plurality of sand collecting hoppers 32 along the direction from the water inlet end to the water outlet end, so that settled sand particles can be cleaned conveniently.

The water outlet end of the grit chamber 31 of the sand-water separation system 3 is connected with a gravity drain pipe 5. The gravity drain pipe 5 is communicated with sewage treatment facilities such as a sewage pipe network or a sewage treatment station.

In this embodiment, a river is taken as a main dredging body, and the method for dredging black and odorous water in the river comprises the following steps:

sediment investigation should be carried out before dredging, shape characteristics of a riverway bed are determined through measurement, information such as sediment thickness, pollutant layered distribution characteristics in the sediment, particle size and density of the blackening and stinky sediment and the like is determined through sediment sampling analysis, and distribution conditions of the blackening and stinky sediment and deep silt on the surface layer are confirmed. The sediment investigation result can provide theoretical support for purposefully removing the blackening and smelly sediment on the surface layer in the subsequent dredging operation process. Wherein, the thickness and the texture of the sediment are related to parameters such as dredging thickness, water pressure of hydraulic scouring, flow, scouring time and the like. The larger the thickness of the sediment is, the firmer the texture is, the larger the water pressure and the flow rate during hydraulic flushing are, and the longer the flushing time is; if the thickness of the sediment is smaller and the texture is looser, the hydraulic pressure and flow of the hydraulic flushing are smaller, and the flushing time is shorter. The size of the enclosure dredging unit 1, the width of the water passing channel 4 and the hydraulic scouring parameters need to be judged according to the river channel condition and field tests.

After the earlier stage sediment investigation is completed, the section to be desilted of the river channel is divided into at least two parts, and each part is provided with a closed barricading desilting unit 1 with the top higher than the current river water level. In the embodiment, the river width is 10-15m, the area of each temporary barricading dredging unit is set to be 20-25 square meters, the height is 1.5 meters, and the width of the water passing channel is 1 meter. The enclosure dredging units 1 can be sequentially built along the river flow direction, and the next enclosure dredging unit 1 can also be built after one enclosure dredging unit 1 is cleaned. When the barricade dredging unit 1 is built, one side of the waterproof fabric 12 is pressed on the bottom of a river by a sand bag, and then the sand bag is piled continuously until the water level of the river is higher than the water level of the river, so that a main body frame 11 of the barricade dredging unit 1 is formed. And pulling up the other side of the waterproof fabric 12, and enclosing along the outer side of the sandbag to form a double-layer structure of the inner sandbag and the outer waterproof fabric 12, and finally forming the enclosure dredging unit 1. The purpose of pressing one side of the waterproof cloth on the river bottom is to prevent water from entering the bottom of the barricading dredging unit 1. When the main body frame 11 adopts a scaffold, the construction of the enclosure dredging unit 1 is similar to that of a sand bag. The size of the temporary enclosing and separating dredging unit is set according to construction conditions, the range of the enclosing and separating dredging unit is reduced as far as possible on the premise of reserving enough construction sites, and the problems of pollution diffusion, incomplete slurry collection and the like caused by overlarge construction area are avoided while the dredging effect is ensured. The temporary containment dredging unit 1 may be regular or irregular in shape, depending on the channel terrain conditions.

When setting up and enclosing and separating desilting unit 1, every encloses along the river course and separates and leave water channel 4 between 1 one side of desilting unit and the river course, ensures that the river course crosses water or flood discharge function, reduces and encloses and separates the upstream thrust that desilting unit 1 received, and the guarantee encloses and separates 1 structure safety and the river course water safety of desilting unit. The width of the water passing channel 4 is determined according to the conditions of the river, so that the water passing channel with enough width is ensured while the desilting operation surface is ensured to cover the width of the desilting river channel as much as possible. The water channel is relatively narrow in width, the flow speed of the river water body at the position is high, when the water channel 4 is flushed for dredging, the bottom sludge can be directly stirred by the high-pressure water flow of the flushing water gun 24, the sludge is conveyed by the hydraulic power of the torrent of the narrow water channel and can be flushed to the downstream quickly, and the bottom sludge at the position of the water channel 4 can be cleared.

After the enclosure dredging unit 1 is built, the input end of the water supply pipe 21 is placed into a water body outside the enclosure dredging unit 1, and a constructor performs hydraulic scouring on a mud layer at the bottom of a river channel by operating a scouring water gun 24 in the enclosure dredging unit 1, so that the blackish and odorous sediment with lighter specific gravity can be fully floated to form a mud-water mixture. The water pressure, the flow and the scouring time of the scouring water gun 24 are controlled to bring up all blackening and smelly bottom mud as far as possible, and meanwhile, deep silt at the bottom of a river channel is prevented from being disturbed as far as possible, and the mixing of the deep silt and the water body is reduced.

The water pipe 33 pumps the mud-water mixture out of the enclosure dredging unit 1 and conveys the mud-water mixture into the grit chamber 31 under the action of a mud pump 34. During hydraulic flushing, the water level in the enclosure dredging unit is controlled by the mud pump 34 to avoid the overflow of water in the enclosure dredging unit 1, and the water level is preferably not higher than 50 cm. In order to prevent the floating sludge in the enclosure dredging unit from precipitating again, a short distance is kept between the flushing area of the flushing water gun 24 and the input end of the water delivery pipe 33, so that the flushed sludge-water mixture can be pumped away in time, and the hydraulic flushing and the conveying of the sludge-water mixture to the sand-water separation system 3 are carried out simultaneously. And stopping flushing when no obvious black mud is mixed in the water body in the temporary enclosure dredging unit.

In this embodiment, the grit chamber 31 has a length of 5m, a width of 1 m, and a height of 0.5 m. After the mud-water mixture is settled in the grit chamber 31, the mud and sand with a heavier specific gravity are separated from the mud-water mixture due to physical sedimentation. The upper layer mud-water mixture containing the sludge with lighter specific gravity needs to be treated separately, and the upper layer mud-water mixture is discharged into a sewage pipe network on the riverway edge shore nearby through the gravity drain pipe 5, so that the black and odorous bottom mud on the surface layer of the black and odorous water body is effectively removed. The silt with heavier specific gravity can be backfilled to the river channel after being simply washed, so that the disposal cost of the silt is reduced to the maximum extent. And when the water body in the temporary barricading dredging unit is not mixed with obvious black mud, the dredging operation can be finished.

Regarding the construction mode, if the width of the river channel is small, the full-width construction is preferentially adopted, namely, only one row of barricading dredging units are built in the construction river reach, and the silt is sequentially removed, but a water channel is reserved. If the river width is large, the flow is large and the flood discharge requirement is high, half-width construction can be considered. The half construction is divided into a left half and a right half, a left row and a right row of enclosure dredging units are built, and after dredging at one side is completed, dredging at the other side is carried out.

The dredging method adopted by the technical scheme is similar to the hydraulic excavation method for draining and dredging, but the dredging method and the hydraulic excavation method are essentially different in design idea, river drainage, mud sedimentation, sludge treatment and the like, so that the cost and the benefit are different. The design idea of this scheme has apparent difference with traditional desilting mode, utilizes the mixing action of water, takes away the mud-water mixture that contains the smelly bed mud of blackening on top layer together, when getting rid of the smelly bed mud of blackening pertinence, provides the water conservancy condition for follow-up discharge smelly bed mud of blackening. The hydraulic flushing is constructed on the premise of draining river water, a high-pressure water gun of a hydraulic flushing unit is used for flushing sediment, the sediment is disturbed into slurry, the flowing slurry is collected into a preset low-lying area, is sucked by a mud pump and is conveyed by a pipeline, and the slurry is conveyed to a storage yard or a slurry collection pool on the shore. The method has large engineering quantity, the construction period is influenced by weather, the sludge re-precipitation effect in the generated slurry is obvious, and the subsequent sludge treatment cost is high. Compared with a hydraulic flushing method, the black and odorous water dredging method mainly removes black and odorous bottom mud on the surface layer, discharges the black and odorous bottom mud with lighter specific gravity into a sewage pipe network on the edge of the river channel, and backfills separated silt into the river channel after simple flushing.

The present invention has been described in connection with the preferred embodiments, but the present invention is not limited to the embodiments disclosed above, and is intended to cover various modifications, equivalent combinations, which are made in accordance with the spirit of the present invention.

Claims

1. A black and odorous water body dredging method is characterized by comprising the following steps that an enclosed dredging unit (1) with the top higher than the water surface and closed is arranged at a section of a water body to be dredged; performing hydraulic scouring on the bottom mud of the water body in the enclosure dredging unit (1) to enable the black and odorous bottom mud with lighter specific gravity to fully float up to form a mud-water mixture; the mud-water mixture is rapidly pumped out of the enclosure desilting unit (1), after the pollution-free sand grains are separated by physical sedimentation, the residual mud-water mixture containing the black and odor bottom mud is discharged.

2. The method according to claim 1, wherein the sludge-water mixture containing the black and odorous bottom sludge is discharged into a sewage treatment facility.

3. The black and odorous water body dredging method according to claim 1, characterized in that the thickness of the black and odorous bottom mud is determined through investigation, sampling and analysis; when the hydraulic flushing is carried out, only the bottom sediment with the specified thickness is flushed, and the disturbance of the deep sediment is avoided.

4. The method according to claim 1, wherein the section of the water body to be desilted is divided into at least two parts, and each part is provided with one barricading desilting unit (1); when the hydraulic flushing is carried out, the water level in the enclosure dredging unit (1) is controlled to ensure that the height of the water level is not higher than 50 cm.

5. The method for dredging the black and odorous water body according to claim 1, wherein when the enclosure dredging unit (1) is arranged, the enclosure dredging unit (1) is built according to one side edge of the water body, and the wall body is closed by taking the edge of the water body as one surface; the width of the enclosure dredging unit (1) is slightly less than the width of the water body, and a water passing channel (4) is reserved between the enclosure dredging unit and the water body.

6. The utility model provides a black and odorous water body desilting system, its characterized in that, including setting up in the wall desilting unit (1) of treating the desilting water, carry scouring system (2) of scouring water, still include with sand-water separation system (3) that wall desilting unit (1) intercommunication.

7. The black and odorous water body dredging system according to claim 6, wherein the flushing system (2) comprises a water supply pipe (21), a high pressure water pump (22), a flushing pipe (23) and a flushing water gun (24) which are connected in sequence along the water flow direction; the input of feed pipe (21) is located the outside of enclosing and separating desilting unit (1), wash squirt (24) and be located the inboard of enclosing and separating desilting unit (1).

8. The black and odorous water body dredging system according to claim 6, wherein the barricade dredging unit (1) is a temporarily built cofferdam, the cofferdam comprises a main body frame (11) and a waterproof fabric (12), and the waterproof fabric (12) is enclosed outside the main body frame (11); the main body frame (11) is a scaffold or a cofferdam wall formed by stacking a plurality of sandbags.

9. The black and odorous water body dredging system according to claim 6, wherein the sand-water separation system (3) comprises a water delivery pipe (33), a mud pump (34) and a grit chamber (31) which are connected in sequence; the input end of the water delivery pipe (33) is connected with the enclosure dredging unit (1); the grit chamber (31) is a rectangular tank body, and the water outlet end of the grit chamber (31) is higher than the water inlet end; the bottom of the grit chamber (31) is provided with a plurality of sand collecting hoppers (32) along the direction from the water inlet end to the water outlet end.

10. The black and odorous water body dredging system according to claim 1, wherein the water outlet end of the sand-water separation system (3) is connected with a gravity drain pipe (5) for connecting a municipal sewer network or a sewage treatment facility.