CN111875181A

CN111875181A - Pretreatment tank for water body treatment system

Info

Publication number: CN111875181A
Application number: CN202010787983.3A
Authority: CN
Inventors: 许元敏; 徐琳; 黄丽华; 彭昱昱
Original assignee: Nanjing Tianhe Water Environmental Technology Co ltd
Current assignee: Nanjing Tianhe Water Environmental Technology Co ltd
Priority date: 2020-08-07
Filing date: 2020-08-07
Publication date: 2020-11-03

Abstract

The utility model provides a preliminary treatment pond for water processing system, its characterized in that is including adjusting the chamber, should adjust the chamber including water-locator, filler, aeration equipment, guide plate, separator and the smooth mud board that sets gradually from the top down, wherein guide plate, separator and smooth mud board slope setting to the same direction, the delivery port in preliminary treatment pond is located the below of guide plate, the one end of separator downward sloping is provided with the exempt from board of disturbing of the downward extension of smooth mud board of orientation. The pretreatment tank provided by the disclosure can automatically adjust working conditions according to different treatment modes, can enhance precipitation effect through a specific structure while removing large pollutants in particles, and improves biochemical performance of a treated water body by culturing microorganisms on a filler so as to improve treatment efficiency of a subsequent process.

Description

Pretreatment tank for water body treatment system

Technical Field

The present disclosure relates to water treatment technology, and more particularly, to a pretreatment tank for a water treatment system.

Background

The micro-polluted water body mainly has the characteristics of low pollutant concentration, diversified pollution sources, large water volume, turbidity in rainy days and the like. The micro-polluted water body includes natural water bodies and artificial water bodies, such as river and lake water bodies, garden landscape water bodies, aquaculture water bodies, fountains, swimming pools, water parks and the like. Along with the development of urbanization, artificial pollution or non-artificial pollution continuously generated in the urban operation process is one of the problems to be solved urgently, and at present, countries and residents have higher requirements on water quality and sanitary conditions of urban built-up areas, so that safe, efficient and economic treatment technologies for slightly polluted water bodies need to be found.

The existing system for treating micro-polluted water cannot realize rapid treatment when the water quantity is large or the water quality is poor, the water quality can be further deteriorated, and when the water quantity is small or the water quality is good, the utilization rate of the device is low, so that the waste of resources is caused. The traditional pretreatment tank for water treatment is used for filtering larger impurities of particles in a precipitation mode, has single function, has definite limitation on water inflow and pollution indexes of water inflow, and cannot adaptively change or adjust the working mode when the polluted water amount or the water quality of the water inflow fluctuates obviously.

Accordingly, it is desirable to provide a pretreatment tank for a water treatment system that is capable of changing or adjusting the mode of operation based on different influent water qualities and/or treated water volumes.

Disclosure of Invention

In order to solve at least one of the above technical problems, according to an aspect of the present disclosure, there is provided a pretreatment tank for a water treatment system, which includes a regulation chamber, the regulation chamber includes a water distributor, a filler, an aeration device, a flow guide plate, a separator, and a mud sliding plate, which are sequentially disposed from top to bottom, wherein the flow guide plate, the separator, and the mud sliding plate are disposed to be inclined in the same direction, a water outlet of the pretreatment tank is located below the flow guide plate, and one end of the separator, which is inclined downwards, is provided with an interference-free plate extending downwards towards the mud sliding plate.

According to the pretreatment tank of the embodiment of the present disclosure, optionally, the water outlet of the pretreatment tank is disposed at the uppermost portion of the region below the guide plate, and the downwardly inclined one-side end of the guide plate has a first distance from the wall of the conditioning chamber.

According to the pretreatment tank of the embodiment of the disclosure, optionally, the separation member comprises a plurality of densely arranged pipelines, the pipelines in the separation member are straight pipes or inclined pipes, the direction of the pipelines is consistent with the precipitation direction of impurities, and the interference-free plate and the mud sliding plate are spaced by a distance to allow the impurities sliding down on the mud sliding plate to pass through. The pipe run of the separating element can be in a vertical direction.

According to an embodiment of the disclosure, the pretreatment tank further comprises a separator, wherein the separator is substantially parallel to the flow guide and spaced apart from the flow guide by a second distance, the second distance being greater than the first distance.

The pretreatment tank optionally further comprises a water inlet system positioned at the upper part of the adjusting cavity, wherein the water inlet system comprises a water inlet pipe and the water distributor, one end of the water inlet pipe connected with the water distributor is provided with a slow flow section, and the cross sectional area of the slow flow section is larger than that of the other part of the water inlet pipe; the water distributor comprises a plurality of water outlets which are uniformly distributed at the upper part of the adjusting cavity.

The pretreatment tank according to the embodiment of the present disclosure optionally further comprises an inlet chamber juxtaposed with the conditioning chamber and separated from the conditioning chamber by a partition, wherein the inlet chamber comprises an inlet of the pretreatment tank disposed at a lower portion thereof and a floating type packing suspended in a chamber of the inlet chamber, and the water distributor is disposed at a top portion of the partition and a screen is disposed in front of the water distributor in a water flow direction.

The pretreatment tank according to the embodiment of the present disclosure optionally further comprises a water inlet system located at the upper part of the adjusting chamber, and the water inlet system comprises a water inlet pipe, the water distributor arranged around the water inlet pipe, and an air inlet pipe penetrating through the water distributor, wherein the water distributor is arranged as a water distribution plate and is provided with a plurality of openings with the diameter smaller than that of the filler in the adjusting chamber. The water inlet pipe is at least 20mm higher than the water distribution plate, and the air inlet pipe is at least 80mm higher than the water distribution plate.

According to the pretreatment tank of the embodiment of the present disclosure, optionally, the conditioning chamber further comprises a one-way valve disposed at the top thereof, which is closed as the water level in the conditioning chamber increases, so that the conditioning chamber forms a pressure tank.

According to the pretreatment tank of the embodiment of the present disclosure, optionally, the check valve includes a guide region and a water passing region, wherein an adjusting member moving along with a water level is disposed in the guide region, and the adjusting member includes a buoyancy member, a guide rod and a sealing member which are sequentially connected from bottom to top; the water passing area of the water passing area is not less than the area of the pipeline connected with the one-way valve.

According to the pretreatment tank of the embodiment of the present disclosure, optionally, the conditioning chamber further includes a safety valve disposed at the top thereof, an overflow port disposed at the upper portion thereof, and an automatic valve disposed at the end of the overflow port and on the chamber sidewall of the conditioning chamber, the automatic valve being opened when the pressure in the conditioning chamber reaches a set safety value of the safety valve.

According to the pretreatment tank of the embodiment of the present disclosure, optionally, the filler in the conditioning chamber is mineral particles having a density greater than water, and the floating type filler is fluidized bed filler.

According to the pretreatment tank of the embodiment of the present disclosure, optionally, the inclination angle of the guide plate is 60 to 80 degrees, the inclination angle of the mud sliding plate is greater than that of the guide plate, one end of the mud sliding plate is disposed on the wall of the adjustment cavity, and the other end of the mud sliding plate is provided with a mud discharge port.

According to another aspect of the embodiments of the present disclosure, a micro-polluted water treatment system is provided, which comprises the above pretreatment tank, and further comprises a primary precision filter, a secondary biological aerated filter and a tertiary precision filter, wherein the installation position of the pretreatment tank is higher than that of the primary precision filter, the secondary biological aerated filter and the tertiary precision filter, and the pretreatment tank, the primary precision filter, the secondary biological aerated filter and the tertiary precision filter are sequentially communicated according to the water flow direction of the water body to be treated, and the pretreatment tank and the tertiary precision filter are directly communicated with each other.

According to the micro-polluted water treatment system disclosed by the embodiment of the disclosure, a return pipeline is arranged between the water inlet of the pretreatment tank and the water outlet of the biological aerated filter, and a return pipeline is arranged between the water inlet of the secondary biological aerated filter and the water outlet of the biological aerated filter.

The embodiment of the present disclosure provides a novel pretreatment tank structure, which can automatically adjust the working conditions according to different treatment modes, and can enhance the precipitation effect through a specific structure while removing the large pollutants of particles and culture microorganisms on the filler, thereby realizing the preliminary degradation of organic matters and ammonia nitrogen, and enabling the microorganisms to enter a subsequent unit, improving the biochemical performance of the treated water body, and improving the treatment efficiency of the subsequent process. In addition, the pretreatment tank can be installed at a position higher than the subsequent process equipment, thereby saving energy. The pretreatment tank disclosed by the disclosure is not only suitable for a micro-polluted water body treatment system, but also can be used in other water body treatment systems, so that the water quality treatment efficiency is improved, and the pretreatment tank is suitable for various changes of water bodies.

It is not necessary for any product to practice the present disclosure to achieve all of the above-described advantages simultaneously. Additional features and advantages of the disclosure will be set forth in the description which follows, and in part will be obvious from the description, or may be learned by the practice of the disclosure. The objects and advantages of the embodiments of the disclosure may be realized and attained by the structure particularly pointed out in the written description and claims hereof as well as the appended drawings.

Drawings

To more clearly illustrate the technical solutions of the embodiments of the present disclosure, the drawings of the embodiments will be briefly described below, and it should be apparent that the drawings in the following description are only related to some embodiments of the present disclosure, and do not limit the present disclosure.

FIG. 1A is a schematic diagram of the structure of a micro-polluted water treatment system according to one embodiment of the present disclosure, further showing the process flow in a lift mode and the process flow in a backwash mode;

FIG. 1B is a schematic diagram of a process flow of the micro-polluted water treatment system shown in FIG. 1A in emergency mode;

FIG. 2A is a schematic structural view of a pretreatment tank and medicated module combination according to one embodiment of the present disclosure; FIG. 2B is a schematic sectional view of the pretreatment tank shown in FIG. 2A, taken along line A-A; FIG. 2C is a schematic diagram of the operation of the pretreatment tank shown in FIG. 2A; FIG. 2D is a schematic diagram of a pre-treatment tank according to another embodiment of the present disclosure; FIG. 2E is a schematic sectional view of the pretreatment tank shown in FIG. 2D, taken along line B-B; FIG. 2F is a schematic diagram of a pre-treatment tank according to yet another embodiment of the present disclosure;

FIG. 3 is a schematic structural diagram of a primary precision filter according to one embodiment of the disclosure;

FIG. 4 is a schematic structural view of a secondary biological aerated filter according to an embodiment of the disclosure;

FIG. 5 is a schematic structural diagram of a three-stage precision filter according to one embodiment of the disclosure; and

FIG. 6A is a schematic diagram of the structure of one embodiment of a one-way valve for the pretreatment tank shown in FIGS. 2A-2F; FIG. 6B is a schematic diagram of another embodiment of a one-way valve for the pretreatment tank shown in FIGS. 2A-2F; FIGS. 6C-6D are schematic views of the operation of the check valve shown in FIG. 6A;

fig. 7 is a schematic structural diagram of a water pump configuration of an integrated pump room according to one embodiment of the present disclosure.

Detailed Description

In order to make the objects, technical solutions and advantages of the embodiments of the present disclosure more apparent, the technical solutions of the embodiments of the present disclosure will be described clearly and completely with reference to the drawings of the embodiments of the present disclosure. It is to be understood that the described embodiments are only a few embodiments of the present disclosure, and not all embodiments. The various embodiments may be combined with each other to form other embodiments not shown in the following description. All other embodiments, which can be derived by a person skilled in the art from the described embodiments of the disclosure without any inventive step, are within the scope of protection of the disclosure.

Unless defined otherwise, technical or scientific terms used herein shall have the ordinary meaning as understood by one of ordinary skill in the art to which this disclosure belongs. The use of "first," "second," and similar terms in the description and claims of the present disclosure are not intended to indicate any order, quantity, or importance, but rather are used to distinguish one element from another. Also, the use of the terms "a" or "an" and the like do not necessarily denote a limitation of quantity. The word "comprising" or "comprises", and the like, means that the element or item listed before the word covers the element or item listed after the word and its equivalents, but does not exclude other elements or items. The terms "connected" or "coupled" and the like are not restricted to physical or mechanical connections, but may include electrical connections, whether direct or indirect. "upper", "lower", "left", "right", and the like are used merely to indicate relative positional relationships, and when the absolute position of the object being described is changed, the relative positional relationships may also be changed accordingly.

Fig. 1A is a schematic diagram of a micro-polluted water treatment system according to one embodiment of the present disclosure, wherein the process flow in the lift mode and the backwash mode is also shown. Fig. 1B is a schematic diagram of the process flow of the micro-polluted water treatment system shown in fig. 1A in emergency mode. As shown in fig. 1A and 1B, a micro-polluted water treatment system according to an embodiment of the present disclosure may include: a pretreatment tank 100, a first-stage precise filter 300, a second-stage biological aerated filter 400 and a third-stage precise filter 500. The micro-polluted water treatment system may further optionally include one or more of a dosing module 200, an integrated pump house 700 for extracting polluted water, a clean water tank 900 for storing treated clean water, and a backwash reservoir 800 for backwashing processes of the primary to tertiary filters.

The pretreatment tank 100 may be used to remove denser particulate matter from the water. For example, the pretreatment tank may include a cyclone filter. On the other hand, the pretreatment tank 100 can also be realized by adopting the structure according to the embodiment of the present disclosure (as shown in fig. 2A-2F), for example, wherein a filler is utilized to remove the denser particulate matter in the water and simultaneously primarily purify the water and reduce the turbidity of the water. The primary fine filter 300 is mainly used for intercepting inorganic particles, fine impurities and organic particles in water. The secondary biological aerated filter 400 is mainly used for effectively degrading organic matters in water by utilizing the adsorption effect of microorganisms. The third-stage precision filter 500 (which may have the same structure as the first-stage precision filter 300) further intercepts inorganic particles, fine impurities and organic particles in water, and enhances the water treatment effect. Examples of specific structures of the pretreatment tank 100, the primary biofilter 300, the secondary biological aerated filter 400, and the tertiary biofilter 500 will be described in detail below with reference to fig. 2A to 5.

The integrated pump house 700 takes water from a water source and utilizes a water pump to extract the water to a high location. The dosing module 200 adds a flocculating agent to the pretreatment tank, the first-stage precision filter 300 and/or the third-stage precision filter 500 as required, and the adding manner is specifically described below in combination with different process flows. The backwashing water reservoir 800 stores water discharged after backwashing the first-stage precision filter 300, the second-stage biological aerated filter 400 and the third-stage precision filter 500. The clean water tank 900 stores the purified water and may provide a source of water for backwashing of the primary to tertiary filters.

A micro-polluted water treatment system according to an embodiment of the present disclosure includes two water treatment modes, namely, an emergency mode and a lifting mode (which may also be referred to as a lifting and holding mode). The lifting mode is mainly used for lifting the water quality aiming at the water quality condition with stable water quality change, so that the ecological system can continuously and stably reach the standard. The emergency mode is mainly used for improving the transparency of the water body as soon as possible aiming at the condition that the water quality is rapidly deteriorated (for example, due to rain and the like), so that the purification function of the ecological system is recovered.

Fig. 1A illustrates a process flow of a micro-polluted water treatment system in a lift mode according to one embodiment of the present disclosure. As shown by solid arrows (namely water flow directions) (r) and (b) in fig. 1A, water to be treated enters water through a water lifting and taking mode of the integrated pump room 700, then sequentially passes through the pretreatment tank 100, the first-stage precise filter 300, the second-stage biological aerated filter 400 and the third-stage precise filter 500 of the system, and finally the treated water enters the clean water tank 900. The lifting mode further comprises a backflow mode promoting the propagation of microorganisms, see water flow direction in fig. 1A. The backflow mode will be described in detail below.

Fig. 1B illustrates a process flow of a micro-polluted water treatment system in emergency mode according to one embodiment of the present disclosure. As shown by the solid arrows (i.e., water flow direction (c), water flow direction (r), and water flow direction (v)) in fig. 1B, the water to be treated enters the integrated pump room in the emergency water intake mode (i.e., water flow direction (c)), then flows through the pretreatment tank 100, and then is divided into two parallel paths (i.e., water flow direction (c) and (v)), one path flows through the primary precision filter 300 and then enters the clean water tank 900 (i.e., water flow direction (c)), the other path flows through the tertiary precision filter 500 and then enters the clean water tank 900 (i.e., water flow direction (c)), wherein the water entering the primary precision filter 300 is divided into two paths, one path is filtered and then directly enters the clean water tank 900, and the other path flows through the secondary biological aerated filter 400. In the emergency mode, the water body to be treated passes through the pretreatment tank 100, and the larger suspended solid, impurities and the like in the water are effectively intercepted or precipitated, and the water body is subjected to primary filtration, so that the turbidity of the water is reduced. After the water flows out of the pretreatment tank 100, the water is divided and simultaneously enters the first-stage precision filter 300 and the third-stage precision filter 500, thereby increasing the amount of water that can be treated. Here, the fine filter intercepts inorganic particles, organic particles, and/or fine impurities, etc., thereby rapidly improving the transparency of the water body. Meanwhile, most of the water passing through the primary precision filter 300 directly enters a clean water tank to ensure the water treatment efficiency, and a small part of the water enters the secondary biological aerated filter 400 to provide a small amount of water to ensure the survival conditions of microorganisms.

In addition, as shown in fig. 1A and 1B, the micro-polluted water treatment system according to an embodiment of the present disclosure may periodically run a backwashing mode to ensure the treatment effect. The backwashing mode comprises water backwashing on each unit of the first-stage precise filter 300, the second-stage biological aerated filter 400 and the third-stage precise filter 500 and gas backwashing on the second-stage biological aerated filter. In the water backwashing process, water is supplied from a clean water tank 900, backwashing water is conveyed to a backwashing water reservoir 800, and backwashing water supernatant in the backwashing water reservoir flows back to the pretreatment tank. The supernatant fluid has low pollutant content and contains a certain amount of microorganisms, and the supernatant fluid enters the pretreatment tank and then is purified again, so that the load of the backwashing water storage tank is reduced. The backwash impounding reservoir can be periodically desilted. The backwashing of the precision filter is mainly used for removing inorganic particles and preventing the inorganic particles or fine impurities from influencing the filtering speed. The water and air backwashing in the secondary biological aerated filter will be described in detail with reference to fig. 4.

The structure of the integrated pump house 700 is not limited, the structure of a common integrated pump house can be adopted, and the water intake quantity of the water pump of the integrated pump house can be changed as required. For example, the integrated pump house 700 may have a variable frequency pump that can vary the operating frequency depending on the water demand. Furthermore, the integrated pump house 700 may further include one or more fixed frequency pumps to increase the volume of water taken when needed. The water lifting and taking mode of the integrated pump house 700 is a condition that a water pump for lifting the water taking mode is started under the lifting mode of the micro-polluted water treatment system, namely, under the conditions that the water quantity of the treated water body is relatively stable and the water quality is stable, for example, under the condition, the requirement of lifting the water quantity can be met by starting a variable frequency pump. The emergency water taking mode of the integrated pump house 700 is a condition that a large amount of water needs to be rapidly treated in the emergency mode of the micro-polluted water treatment system, and a water pump for the emergency water taking mode is started at the moment. For example, in this case, the integrated pump house 700 may turn on a pump to increase the water intake. Fig. 7 shows a schematic structural diagram of a water pump configuration of an integrated pump room according to one embodiment of the present disclosure. The pump room comprises two pumps 710 and 720 connected in parallel, wherein the pump 710 can be a variable frequency pump which can adjust the operation frequency according to the water quantity change, and the pump 720 is a fixed frequency pump. Open and decide under emergent water intaking mode and frequently pump and frequency conversion pump both, under promoting the water intaking mode, can only open the frequency conversion pump.

The front end of the water body treatment system is provided with a pretreatment tank 100 which is mainly used for settling and primarily filtering sludge. The structure of the pretreatment tank 100 according to an embodiment of the present disclosure is specifically described below with reference to fig. 2A to 2F. FIG. 2A is a schematic structural view of a pretreatment tank 100 and medicated module 200 combination device according to one embodiment of the present disclosure. Implementing them here as a combined device may make the overall system more compact. Since the pretreatment tank and the medicated module are functionally different, they can also be provided and implemented in two separate parts, which do not affect their respective internal structures and functions. Therefore, the structures of the pretreatment tank 100 and the medicated module 200 will be described below, respectively.

The pretreatment tank can be arranged at a higher position relative to equipment of a subsequent treatment process, so that after the water body is lifted by the pump room, the water body flows in the whole system (comprising the primary precise filter tank, the secondary biological aerated filter tank and the tertiary precise filter tank) under the action of gravity through the treatment of the pretreatment tank, the water body does not need to be lifted or conveyed again by using a water pump, the energy is saved, and the whole system is more compact.

The structure of the pretreatment tank 100 according to an embodiment of the present disclosure is specifically described below with reference to fig. 2A to 2F. As shown, the pretreatment tank 100 includes a relatively independent inlet chamber 130 and a conditioning chamber 120 divided by a partition 110. The inlet chamber 130 and the adjusting chamber 120 are communicated at the upper portion. The inlet chamber 130 includes a drain 101 disposed at the bottom of the chamber for draining the chamber, a water inlet 102 disposed at the lower portion of the chamber, and a floating filler 103 (e.g., a lightweight porous filler such as a fluidized bed filler) suspended in the chamber. The drain 101 may be used to drain impurities precipitated in the intake cavity on a regular or as-needed basis, or may be used to drain water from the intake cavity when needed. The top of the partition 110 is provided with a water distributor 111, such as a triangular weir, which facilitates uniform water distribution. The water distributor 111 may be provided with a screen 112 at the front end of the flow, which prevents the floating packing 103 from entering the conditioning chamber 120 or clogging the water distributor 111. A filler 121 (e.g., a composite filter material having a density greater than that of water) is disposed in the adjustment chamber 120, and an aeration device 122 is disposed below the filler 121. The aeration device 122 aerates the water in the chamber as required, or turns over the packing 121 to perform the function of backwashing it.

An inclined guide plate 123 is arranged below the aeration device 122, the guide plate 123 is arranged in a certain inclination, one end of the guide plate 123 can be fixed on the cavity wall, and the other end of the guide plate is arranged at a certain distance S1 from the cavity wall, and a water flow channel is formed at S1. The angle of inclination a of the baffle 123 may be 40 to 85, preferably 60 to 80. The uppermost portion of the area below the deflector 123 is provided with an outlet pipe 124, and the outlet hole 124A of the outlet pipe 124 is preferably provided on the side next to the partition 110. This arrangement avoids as much as possible of the remaining impurities in the water entering the outlet pipe 124. Below the baffle 123, a separating member 125 is provided, the separating member 125 preferably being substantially parallel to the baffle 123 and the distance S2 between them being preferably greater than S1, which facilitates the reduction of the water velocity. Thereby, a slow flow region E of the outlet water is formed between the baffle 123 and the separating member 125. This arrangement allows the water to flow more slowly in the slow flow region E and to form a water flow up the slow flow region, which facilitates the precipitation of light impurities. The separating elements 125 may be in the form of a closely packed geometric straight or inclined tube having a tube orientation that substantially coincides with the direction of impurity precipitation, e.g., may be substantially vertical, and may have a tube shape such as square, rectangular, regular hexagonal (as shown in fig. 2B), corrugated, etc. One end of the separating member 125 extends to the partition 110, and the other end is provided with a disturbance-free plate 126. The disturbance-free plate 126 extends downward (e.g., vertically downward) with its lower end at a small distance S3 from the slide plate 127, whereby the separating member 125 and the disturbance-free plate 126 form a disturbance-free zone F above the slide plate 127. The smaller distance S3 ensures that the impurities on the skis 127 slide down and that the impurities in the disturbance-free zone F are smoothly precipitated without being affected by the water flow. The ramp 127 is inclined in the same direction as the deflector and the separator, and its angle of inclination beta is preferably smaller than the angle alpha, since a smaller angle is advantageous for impurities to slide off it. One end of the sliding plate 127 extends to the partition 110, and the bottom of the sliding plate 127 is provided with a sludge discharge port 128. The impurities entering the sludge discharge opening 128 can be periodically discharged and cleaned. Furthermore, optionally, an aeration device (not shown) may also be optionally disposed in the intake chamber 130 to promote the growth of microorganisms in the suspended filler in the lift mode.

In addition, the top end of the adjustment chamber 120 may be provided with a check valve 134, which may be used for air intake when the water level of the adjustment chamber is low and may make the chamber airtight when the water level of the adjustment chamber is high. Check valve 134 may be a conventional check valve. The check valve 134 according to one embodiment of the present disclosure will be described in detail below with reference to fig. 6A-6D. The top of the adjustment chamber 120 is also provided with a safety valve 129. The upper part of the chamber of the adjustment chamber 120 may also be provided with an overflow 131. The end of the overflow port 131 is connected to an automatic valve 132 which is normally closed. When the safety valve 129 senses that the pressure in the regulating chamber 120 reaches a set safety threshold, the automatic valve 132 will automatically open the drain for pressure relief. Further, the chamber top of the conditioning chamber 120 may be provided with a service well 133 to facilitate maintenance and repair thereof.

The pretreatment tank 100 can automatically adjust the working conditions to adapt to the use requirements according to different treatment modes. During the use process of the pretreatment tank 100, water enters from the water inlet 102 and collides with the floating type filler 103 in the water inlet chamber 130, which is beneficial to the sedimentation and filtration of sludge. In addition, under the promotion mode, the biofilm that grows out on floating filler 103 gradually its surface, can carry out preliminary purification to the water, and ripe biofilm drops in the water under the striking effect, and the biofilm after dropping can be held back by filler 121, further adsorbs and degrades the organic matter in the aquatic. Referring to fig. 2C, a schematic process of water flow operation (wherein: represents a water flow operation path, and: represents an impurity precipitation path), in the water inlet chamber 130, impurities in the water body with a precipitation velocity V2 (which depends on the weight of particles) greater than a water flow rising velocity V1 move downward, are collected at the bottom of the water inlet chamber 130, and are periodically removed through the drain 101. After the water body in the inlet chamber 130 rises, the water flow passes through the water distributor 111 to be uniformly distributed and enters the regulating chamber 120.

In the conditioning chamber 120, the packing 121 traps a portion of the suspended matter and biofilm in the water stream. The aeration device 122 aerates the water body, and the aeration can also turn over the filter material 121 to enable the lighter substances attached to the filter material to float on the water surface and be discharged from the overflow port during overflow. Heavier materials, including sloughed off biofilm, will move down with the water flow. At this time, the impurities with the settling velocity V2 being greater than the water flow velocity V1 in the water body enter the bottom of the sliding mud plate 127 through the guide plate 123. In the process, the water flow enters the slow flow region E through the water flow passage at S1, the water flow velocity V1 is further reduced and an upward water flow state is formed, and the impurities with the settling velocity V2 generated by the gravity of the residual impurities in the water being greater than the water flow velocity V1 can continue to move downwards, and the water flow moves upwards, and the opposite moving direction accelerates the impurities into the geometric interior of the separating member 125, thereby entering the undisturbed region F. It can be seen that the reduction in flow rate allows more impurities to enter the separating member 125 and that the opposite direction of movement of the water flow and impurities results in at least a 10% increase in settling effect over advection of the water flow (verified by experiments). Due to the dense structure of the separating members 125, a portion of the water flow forms a laminar flow within the geometry of the separating members 125, entering the undisturbed zone F, where a relatively static body of water is formed, until it fills the zone. The relatively stationary disturbance-free zone F allows the impurities therein to settle out of the water flow into the bottom of the slip sheet 127. Another portion of the water flow passes through the slow flow region E and finally flows out of the water outlet pipe 124. This portion of the water flow contains detached biofilm (which is typically present in a suspended state in the flowing body of water) that passes from the outlet pipe 124 to the next unit. From the operation process, the pretreatment tank of the embodiment forms the slow flow region E and the disturbance-free region F by step precipitation and utilizing the special structure formed by the guide plate, the separating piece and the mud sliding plate, thereby greatly shortening the precipitation time, enhancing the precipitation effect and reducing the treatment load of the subsequent process. In addition, through shortening the settling time, the height of the pretreatment tank can be effectively reduced while the settling effect is ensured, so that the volume of the whole system is favorably controlled, and the integration and installation of the system are facilitated. In addition, the filler is used for filtering the water body in the pretreatment tank, so that the cultured microorganisms can enter a subsequent unit, the biochemical performance of the treated water body is improved, the subsequent treatment efficiency is improved, and especially when the microorganisms in the subsequent unit are insufficient after being backwashed, the microorganism concentration in the subsequent unit can be quickly recovered.

The pretreatment tank can automatically adjust working conditions according to different treatment modes to adapt to use requirements. The operation of the pre-treatment pool 100 in the limp-home mode and the lift mode is described below. When the water level in the adjustment chamber 120 is rapidly increased (e.g., in emergency mode) due to a large water treatment capacity, a fast water flow rate, or a slow filtration rate of the filter media of the subsequent unit, the water level is increased such that the check valve 134 is closed. Thus, the inlet chamber 130 and the adjustment chamber 120 gradually become a pressure tank, and the increase of the pressure can accelerate the filtering speed of the subsequent unit. On the other hand, if the flocculating agent is added at the front end of the pretreatment tank, the water body and the flocculating agent can be more uniformly mixed in the tank body due to the increase of the pressure, and the flocculation is favorably formed. When the pressure of the pressure tank reaches the safety value set by the safety valve 129, the automatic valve 132 opens the automatic overflow to ensure the safe use of the tank.

In the emergency mode, the pretreatment tank 100 may perform large particle preliminary sedimentation of the water entering the apparatus. The light porous filler in the suspension state in the water inlet cavity 130 can effectively intercept larger suspended matters and impurities in water, and the filler with higher density in the adjusting cavity 120 can further filter the water body, so that the water turbidity is reduced in an emergency mode. In addition, because the adjustment chamber 120 can become a pressure tank body in the emergency mode, an additional water pump is not required to increase the water flow rate, thereby improving the treatment efficiency and saving energy.

When the conditioning chamber 120 is low in water level (e.g., in the lift mode), aeration is required at this time because of the low water throughput, slow water flow rate, and the requirement for dissolved oxygen for the biofilm process in the lift mode. In one aspect, air can enter the regulated chamber 120 through the one-way valve 134. The water body achieves drop aeration during the flow from the overflow weir 111 into the conditioning chamber 120. On the other hand, whether the content of dissolved oxygen in the water body meets the requirement or not can be monitored in real time, and whether the aeration device 122 is started to aerate the water body or not is determined. In addition to assisting in oxygenating the body of water to promote the growth of microorganisms on the fill material, aeration also enables lighter materials in the body of water to float on the surface of the water, while heavier materials pass from the deflector 123 through the slide 127 and into the mud port 128.

Under the lifting mode, besides the effect of realizing the large-particle preliminary sedimentation and the preliminary interception of the filler to impurities and pollutants in the water body, the adjusting cavity 120 is fully aerated, so that an aerobic environment is created, the nitrification of organic matters can be realized, and the water quality is further improved.

Fig. 2D is a schematic structural view of a pretreatment tank according to another embodiment of the present disclosure, and fig. 2E is a schematic sectional view at line B-B of fig. 2D. In contrast to the previous embodiment, the pretreatment tank shown in FIG. 2D is provided with only one conditioning chamber 150. The conditioning chamber 150 differs from the conditioning chamber 120 of the pretreatment tank shown in FIG. 2A primarily in the water inlet system. The following description is directed to the water inlet system, and the remainder of the conditioning chamber is described above with reference to the conditioning chamber 120 of FIG. 2A. The water inlet is provided at an upper portion of the conditioning chamber 150. The inlet pipe 151 of the inlet system may be disposed at the center of the adjusting chamber 150, and the end of the inlet pipe 151 is provided with a slow flow section 152, the slow flow section 152 has a larger cross section than the inlet pipe, which can slow down the water flow speed to make the water flow uniformly enter the water distribution system 153 connected to the end. The water outlet of the water distributor 153 can be a triangular overflow weir, which is beneficial to uniform water distribution. The water distributor 153 is externally provided with a filter screen 154, which can prevent the filter material from entering the water distributor 153. This water inlet system forms a uniform inlet flow over the entire conditioning chamber 150, and compared to the embodiment shown in fig. 2A, the drop aeration area is larger, the aeration oxygenation effect is better, and the water distribution is more uniform.

FIG. 2F is a schematic diagram of a pre-treatment tank according to yet another embodiment of the present disclosure. Fig. 2F differs from the embodiment shown in fig. 2D only in the structure of the water inlet system. In fig. 2F, the water inlet system may be provided with a water inlet pipe 161 at a central portion of the conditioning chamber 160. A water distribution plate 162 is arranged around the water inlet pipe 161, the water distribution plate 162 is preferably a porous flushing plate, the pore size of the water distribution plate 162 is preferably smaller than the diameter of the filler 121, so as to prevent the filler from entering the upper layer of the water distribution plate, and the water passing area is larger than the area of the water inlet pipe 161. In addition, the water inlet system is further provided with a plurality of air inlet pipes 163 which pass through the water distribution plate 162, wherein the air inlet pipes 161 can be at least 20-30mm higher than the water distribution plate 162, and the air inlet pipes 161 can be at least 80-100mm higher than the water distribution plate 162, so as to facilitate the air inlet. The water body enters the water distribution plate 162 through the water inlet pipe 161, falls from the holes of the water distribution plate 162, and the gas enters through the gas inlet pipe 163, thereby performing the falling aeration. The water inlet system has a relatively simple structure and uniform water distribution. The remainder of the tuning chamber is described above with reference to the tuning chamber 120 of fig. 2A.

In the embodiment of fig. 2A-2F, the one-way valve of the pretreatment tank may use a conventional one-way valve. However, generally speaking, due to the structural limitation of the conventional check valve, the water passing area of the check valve is much smaller than that of a pipeline with the same specification, and the water flow resistance is large, so that the use effect is influenced. Similarly, if a conventional check valve is used for one-way ventilation, its air flow area is also affected. Fig. 6A and 6B show schematic structural views of embodiments of one-way valves that may be used in the pretreatment tank shown in fig. 2A-2F, respectively. Fig. 6C-6D are schematic views of the operation of the check valve shown in fig. 6A, which is also applicable to the embodiment of the check valve shown in fig. 6B. The check valve according to the embodiment of the disclosure has the advantages of simple structure, low cost and water passing area meeting the use requirements of pipelines with the same specification. The one-way valve may be connected to the pipe by different connection means, for example, flange type, sleeve type, etc. various suitable connection means may be used. As shown in fig. 6A, the check valve includes

connectors

61A and 66A connected to the external pipe in a flange type connection. The

connectors

61A and 66A have openings therein, such as threaded holes. As shown in fig. 2, the check valve includes

connectors

61B and 66B connected to the external pipe in a sleeve type connection. The structure of the above-described coupling is determined by the manner of connection with the external pipe, and does not affect the structure of other components in the check valve, so that the structure of the coupling shown in fig. 6A may be changed to the structure of the coupling shown in fig. 6B, and vice versa, as necessary.

As shown in fig. 6A, the check valve further includes a valve body 62A of the check valve connected to the distal end of the connector 61A, and a partition 63A is fixed inside the valve body 62A. The cross-sectional area of both ends of the valve body 62A is smaller than the cross-sectional area of the middle portion thereof. Generally, the cross-sectional area of the ends of the valve body 62A may be the smallest cross-sectional area in the valve body 62A. The partition 63A includes a guiding area 631A and a water passing area 632A, wherein the water passing area 632A has a water passing area greater than or at least equal to the flow area of the same-sized pipe to which the check valve is connected. Mounted within the guide area 631A is an adjuster 64A that allows the adjuster to move freely up or down in the vertical direction. Adjuster 64A includes a lower buoyancy member 641A, a guide rod 642A connected to buoyancy member 641A through guide area 631A, and a sealing plug 643A connected to an upper side of guide rod 642A, wherein buoyancy member 641A generates buoyancy at least greater than the weight of adjuster 64A. The adjusting member 64A can be guided in the guide area 631A to move upward with the water level when the water level rises. When the water level drops, the regulating member 64A moves downward along the guide section 631A due to gravity. The valve body 62B, the partition plate 63B, the guide section 631B, the water passing section 632B, the adjusting member 64B, the buoyancy member 641B, and the guide rod 642B of the check valve shown in fig. 6B are the same as those of the check valve shown in fig. 6A, and thus, detailed description thereof is omitted.

The sealing means may be composed of a spherical sealing plug 643A connected to the guide rod 642A and a sealing member 65A provided on the upper end inner surface of the valve body 62A (located at the smallest cross section of the valve body 62A) (as shown in fig. 6A). The sealing device may also be composed of a truncated cone 643B connected to the guide rod 642B and a sealing element 65B (shown in fig. 6B) disposed at the smallest cross section of the valve body 62B, wherein the

sealing elements

65A and 65B are preferably made of a material having high wear resistance, high elasticity, and high water resistance. The sealing surface of the bore seal may be flat, bevelled or curved as long as it is able to mate with the inner surface of the sealing member to effect a seal. Thus, the shape of the bore seal is not limited to the spherical or frusto-conical shape described above, and other suitable shapes may be selected. The surface of the sealing plug can be an inclined plane or a curved surface as long as the surface of the sealing plug is matched with the surface of the sealing piece to realize sealing. The sealing plug shown in fig. 6A and 6B may be used in a variety of different connections, such as a sleeve-type construction, a flange-type construction.

Fig. 6C is a schematic view of a closing process of the check valve shown in fig. 6A, and fig. 6D is a schematic view of an opening process of the check valve shown in fig. 6A. The direction of movement of the adjustment member is indicated by an arrow. As shown in fig. 6C, when the water level rises, the adjuster 64A of the check valve moves upward along the guide area by the buoyancy of the water body, so that the sealing means is actuated and the surface of the ball 643A comes into close contact with the sealing member 65A, thereby closing the passage. As shown in fig. 6D, when the water level drops, the regulating member 64A moves downward by its own weight, thereby opening the passage. The above procedure is also applicable to the check valve shown in fig. 6B. The sealing mode can ensure the sealing performance and reduce the processing difficulty at the same time.

The one-way valve described above can be used for both gas and liquid passages (i.e., one-way venting). The one-way valve automatically works by utilizing gravity and buoyancy. The one-way valve has a large gas or liquid throughput due to the large area of the water passing area inside the one-way valve. The water passing area of the one-way valve is at least equal to the flow area of a pipeline which is connected with the one-way valve and has the same specification, so that the sufficient water passing area is ensured, and the one-way valve does not influence the liquid flow when being used as a liquid channel.

In addition, the one-way valve according to the embodiment of the disclosure has the advantages of simple structure, easy processing and low cost while ensuring the sealing performance. The one-way valve is suitable for a water treatment system, particularly a sewage treatment system, and is used for assisting in realizing the automatic regulation function of the sewage treatment system under the condition of water flow change.

The pretreatment tank of the embodiment shown in fig. 2A-2F realizes the gradual precipitation of impurities through a special structure, and enhances the precipitation effect. In addition, the pretreatment tank can intercept impurities through the filler, and the microorganisms cultured on the filler enter the subsequent unit, so that the biochemical performance of the treated water body is improved, the subsequent treatment efficiency is improved, and especially, when the microorganisms in the subsequent unit are insufficient after the subsequent unit is subjected to back washing, the microorganism concentration in the subsequent unit can be quickly recovered. Furthermore, the pretreatment tank can automatically adjust the working condition according to the change of water quality and/or the change of the treated water quantity. The pretreatment tank is not only suitable for a micro-polluted water body treatment system, but also can be used in other water body treatment systems, improves the water quality treatment efficiency and adapts to various changes of water bodies.

After the water body entering the pretreatment tank is subjected to large-particle preliminary precipitation and preliminary purification, supernatant liquid enters a primary precision filter tank to be treated next step, and precipitated sludge is discharged through a periodically opened drain valve.

Also shown in FIG. 2A is a schematic of the structure of medicated module 200. The medicated module can also be incorporated into the embodiment of the pretreatment tank shown in fig. 2D and 2F. The dosing module 200 mainly comprises a dosing metering pump 201, a stirrer 202, a stirring impeller 203 and a dosing tank 204. The medicine that the medicine adding module 200 according to one embodiment of the present disclosure can add is, for example, a flocculant. The flocculating agent is mainly a group with positive (negative) electric property, is close to particles or granules which have negative (positive) electric property and are difficult to separate in water, reduces the potential of the particles, enables the particles to be in an unstable state, and utilizes the polymerization property of the particles to concentrate the particles, and flocculating constituents grow to a certain volume and then separate from a water phase under the action of gravity to precipitate, so that a large amount of suspended matters in wastewater are removed, and the flocculating constituents can be effectively formed at a water inlet end and intercepted by a post-stage filter, so that the sewage treatment rate is improved.

The drug administration point of the drug administration device according to one embodiment of the present disclosure may be different according to different modes of system operation. In order to avoid the inhibiting effect of the medicament on the biological aerated filter, the medicament can be added to the front ends of the first-stage precise filter and the third-stage precise filter in an emergency mode; in the lifting mode, the water can be only added to the front end of the three-stage precise filter or not added. In addition, in the emergency and lift mode, the flocculant may also be added to the front end of the pretreatment tank 100, and the floating type filler in the pretreatment tank 100 may enhance the mixing of the flocculant with water. The dosing module 200 conveys the medicament to one or more of the pretreatment tank, the primary precision filter and the tertiary precision filter through corresponding pipelines. The metering pump 201 in the dosing module is used for adjusting the flow of the medicament, and can have the function of accurately adjusting the flow of the medicament. Each pipeline is provided with a corresponding valve for controlling the opening and closing of the pipeline. According to the water body treatment system disclosed by the embodiment of the disclosure, the metering pump and the valve can be controlled according to different modes so as to determine the dose of the added medicament and select the path of the added medicament. For example, the metering pump 201 may be controlled in the field or remotely via a communication bus such as RS485 or other industrial control method.

As shown in FIG. 3, the primary fine filter 300 may comprise a primary filter inlet 301, a filler 302, a primary filter outlet 303, an automatic air release valve 304, an evacuation valve 305 and an evacuation port 306. The water flow enters the first-stage precision filter 300 from the first-stage filter inlet 301, passes through the filler 302 and then flows out from the first-stage filter outlet 303. The function of the evacuation port 306 is similar to that of the evacuation port 101 of the pretreatment tank, so that sediment can be removed, and the evacuation port can also be used for discharging water in the filter tank.

In the emergency mode, the primary precision filter 300 mainly intercepts granular organic matters, inorganic particles and fine impurities, and rapidly improves the transparency of the water body. In the lifting mode, the primary fine filter 300 can be used for intercepting inorganic particles (including inorganic particles obtained by decomposing organic matters) in water and fine impurities and continuously removing the residual organic matters in the water, so as to maintain the water treatment effect. In the emergency mode, the first-stage microfiltration tank 300 functions as a fast tank (i.e., the filler therein functions as a filter), while in the lift mode, the first-stage microfiltration tank 300 functions as a slow tank (i.e., a biological tank).

The filler 302 includes a composite filter layer, for example, a fine filter layer and a physical filter layer (not specifically shown in the figure) may be sequentially included along the water flow direction of the water treatment, wherein the fine filter layer intercepts microbial micelles in the water body, and further performs adsorption degradation on organic matters in the water in addition to filtering impurities, and the physical filter layer may be mainly used for filtering inorganic particles and fine impurities. The filtering material of the fine filtering layer is preferably a material with high strength, corrosion resistance, high specific surface area and large porosity, such as zeolite, ceramsite and the like, and the filtering material is favorable for the inhabitation and growth of microorganisms. The filter material of the physical filter layer is preferably a material which has a rough surface, good adsorption capacity, high pollutant carrying capacity and light weight, such as an anthracite filter material, and contributes to the improvement of the filter speed and the pollutant interception capacity.

In the primary precise filter, the gap between the inlet water and the microbial film growing on the surface of the filler is fully contacted, the filtering speed can be as low as 3-7 m/h, the filtering speed of the subsequent secondary biological aerated filter can be 2.5-6.5 m/h, and the two effects are equivalent, so that the primary precise filter has an enhancement effect on the treatment capacity of the subsequent secondary biological aerated filter in a lifting mode. The filtering speed of the primary precision filter can reach 20-25 m/h in an emergency mode, and high throughput is guaranteed. According to the first-stage precision filter disclosed by the embodiment of the disclosure, a plurality of particle medium materials are adopted as filter materials of the filter system, and organic matters (including colloid organic matters), particle impurities and the like in a water body are effectively intercepted by utilizing the mechanical screening effect, the sedimentation effect and the contact flocculation effect of the filter materials.

As shown in fig. 4, the secondary biological aerated filter according to an embodiment of the disclosure may include two chambers a and b, which may be assembled in a single cabinet type or separated by a partition plate in an integral type, where the chamber a is an environment with sufficient dissolved oxygen and the chamber b is a facultative environment. The chamber a can comprise a secondary filter water inlet 401 arranged at the top of the chamber, a filter screen 402 arranged at the secondary filter water inlet 401, floating type packing 403 arranged at the upper layer of the water body of the chamber, and an aerator 404 arranged below the floating type packing 403. The filter screen 402 arranged at the water inlet can prevent the suspended filter material from being backflushed into the water inlet when the backwashing mode is operated, so that the pipeline is prevented from being blocked. The aerator 404 may oxygenate the body of water and agitate the buoyant fillers 403. The chamber a also comprises an interception filter material 405 arranged at the lower layer of the water body in the chamber, which is supported by a supporting layer 406, and an aerator 407 is arranged below the interception filter material 405 to oxygenate the water body and wash the interception filter material 405 to avoid hardening. The bottom of the chamber a is provided with a water outlet pipe 408 through which water enters the chamber b. The chamber b can comprise an aerator 410 arranged in the lower layer of the water body, a composite filter layer 412 supported above the aerator 410 through a bearing layer 411, and a secondary filter outlet 413 arranged at the top end of the chamber. In addition, the bottom of the b-chamber is also provided with a backwash water inlet 414.

The floating type packing 403 is preferably a packing having a large surface area, good corrosion and abrasion resistance, and a small density, such as a fluidized bed packing. The entrapment filter 405 is preferably a dense, small particle size, high strength, and high porosity filter, such as a small particle size volcanic rock. The interception filter material arranged above the part a of water outlets can intercept microorganisms while filtering the fluid, so that the utilization rate of the microorganisms is greatly improved. The composite filter layer 412 preferably includes at least two filter layers, a lower layer being coarse heavy filter material and an upper layer being fine filter material. The arrangement can lead suspended matters in the water flow to penetrate into the upper layer of filter material from the bottom layer, thereby improving the sewage interception capability.

The chamber a can keep the stability of the environment in the chamber only by performing gas backwashing, so that the water backwashing of the secondary biological aerated filter can only be directed at the chamber b. While the b chamber allows for water and gas backwashing due to the thicker composite filter layer 412 and its environmental requirements. And (3) performing water backwashing on the secondary biological aerated filter by using water in the clean water tank, wherein a backwashing water inlet 414 is arranged below the chamber b part and is opened according to the requirements of the water backwashing. The air backwashing of the second-stage aeration biological filter utilizes a backwashing air pump of the aerator to carry out air backwashing on the biological filter. The aeration impacts the upper filter material to loosen the upper filter material, thereby bringing out the pollutants deposited in the filter material and effectively solving the problem of hardening of the filter material. Meanwhile, the aerator can adopt a backwashing air pump (not shown) with adjustable air volume, and the aerator can be used for aeration on one hand and air backwashing on the other hand, so that certain dissolved oxygen is provided for the biological filter, the aeration effect is enhanced, and conditions are provided for the growth and propagation of microorganisms in the filter. The water backwashing and the gas backwashing can be carried out at regular time or according to the working condition of the biological filter.

Furthermore, a drain port and a drain valve (not shown) are arranged in the chamber a and the chamber b, and the functions of the drain port and the drain valve are the same as those of the drain port and the drain valve in the primary precision filter.

The treatment of the water body by the secondary biological aerated filter in different modes is specifically described by referring to fig. 4. In the lifting mode, water enters the chamber a from the water inlet 401 of the secondary filter tank by the last unit. Under the action of water flow impact and aeration of the aerator 404, the floating filler 403 moves freely in the water and grows a biofilm on the surface of the floating filler. Due to the shearing force of water and the friction force generated by the movement of the floating type filler 403, the biological membrane on the surface of the floating type filler 403 naturally falls off and enters the water body, and then is further intercepted by the intercepting filter material 405. The water body enters the lower part of the cavity b from a water outlet pipe 408 below the cavity a, water flow and bubbles generated by the aerator 410 enter the composite filter layer 412 together, aerobic conditions are formed on the surface of the filter material, and an anaerobic environment is formed in the inner layer of the filter material, so that ammonia nitrogen in the water body is degraded finally. Finally, the filtered water flow enters the next unit from the water outlet 413 of the secondary filter chamber above the chamber b. Because the water flow forms a U-shaped trend, the water flow can be fully contacted with microorganisms on the filter material to degrade organic matters. As can be seen from the arrangement and operation in the chamber a, the chamber a has sufficient dissolved oxygen, and the floating filler 403 and the interception filter material 405 can ensure sufficient microorganism content in the chamber a, so that COD (chemical oxygen demand) in the water body can be eliminated firstly, and the nitrification condition is provided for the microbial degradation. As can be seen from the arrangement and operation of the chamber b, the composite filter layer 412 is not easy to be impacted by water entering from the bottom, and the uniformity of the filter layer can be ensured. The facultative environment inside the filter layer provides the conditions for the denitrification reaction for the microbial degradation. After the nitrification and denitrification reactions, the organic matters in the water body are decomposed and removed. Further, the secondary biological aerated filter can be provided with more treatment chambers according to the use requirement, namely a plurality of a chambers and/or a plurality of b chambers can be juxtaposed, for example, in an aabb mode. When a plurality of treatment chambers are juxtaposed, the water flow still forms a U-shaped course therein, whereby the water inlet position and the water outlet position of each a and b may be changed as desired. Through such setting, can further prolong the treatment time of rivers in the filter tank, guarantee the treatment effect. The modular structure can also be convenient for field installation and use. In the emergency mode, a small amount of water flow from the first-stage precise filter passes through the second-stage biological aerated filter to keep the ecological environment in the chamber from being damaged, and in the emergency mode, aeration can be omitted.

According to the second-stage biological aerated filter disclosed by the embodiment of the disclosure, the interception filter material is arranged above the water outlet pipe of the cavity a, so that microorganisms are well attached and fixed on the filter material and are not easily washed away by water flow, and the number of microorganisms is effectively ensured. Meanwhile, under aerobic conditions, more nitrifying bacteria are attached to the surface of the carrier, the sludge age of the carrier can reach more than 60 days, and the carrier has a good denitrification effect. The composite filter layer 412 in the chamber b takes a plurality of natural mineral substances as filter materials, and is arranged in a layered mode from top to bottom according to the specific gravity and the thickness degree, the filter precision is extremely high, granular and colloidal organic matters and inorganic particles in polluted water can be removed, and the effect of improving the water quality after treatment is good.

In the secondary biological aerated filter 400, because microorganisms are mainly fixed on the surface of the filler, the total amount of the microorganisms is much higher than that of a specific sludge method, and thus, the secondary biological aerated filter has strong adaptability to impact load caused by the change of the quality and the quantity of sewage. Even if water inlet is interrupted for a short time or the process is damaged, the performance of the biological filter is not affected fatally, and the biological filter recovers quickly. Meanwhile, the method has high efficiency and short required retention time, so that the water quantity which can be treated is large, and the upper limit of the required range of the water inflow is 3-5 times of that of the conventional biological aerated filter with the same volume. The water content of the biological membrane in the secondary biological aerated filter is lower than that of the specific sludge, the sludge bulking phenomenon which is frequently caused by an activated sludge method can not occur, the content of suspended matters in the effluent can be ensured to be lower, and therefore, the operation and the management are more convenient. The biological membrane of the secondary biological aerated filter contains protozoa and metazoan with higher nutrition level, especially when the biological membrane is thicker, the anaerobic bacteria at the bottom can degrade the sludge synthesized in the aerobic process, so the yield of the residual sludge is low, and the cost of sludge treatment and disposal can be reduced.

As shown in FIG. 5, the three-stage fine filter 500 may comprise a three-stage filter inlet 501, a filler 502, a three-stage filter outlet 503, an automatic exhaust valve 504, an exhaust valve 505 and an exhaust 506. The structure of the third stage microfiltration tank 500 may be the same as that of the first stage microfiltration tank and will not be described in detail herein. The types and the layering number of the filter layers of the first-stage precise filter and the third-stage precise filter can be increased according to requirements, so that a better filtering effect can be obtained. Like the first-stage precision filter 300, the third-stage precision filter 500 functions as a fast filter in the emergency mode, and the third-stage precision filter 500 functions as a slow filter in the lift mode.

Referring back to fig. 1A, in the lift mode, to promote the maximum proliferation of microorganisms, the water treatment process further includes a backflow mode (see water flow direction). The reflux mode can be divided into two paths: one path is that a small part of the outlet water of the secondary biological aerated filter 400 flows back to the water inlet of the pretreatment tank 100, and the other path is that a small part of the outlet water of the secondary biological aerated filter 400 flows back to the water inlet of the secondary biological aerated filter. The backflow can be realized through a single backflow water outlet and a corresponding backflow channel on the secondary biological aerated filter 400. Each return channel includes a respective valve. When the water body treatment system is switched from an emergency mode to a lifting mode, the function of the first-stage precise filter tank is switched from a fast filter tank in the emergency mode to a slow filter tank (namely a biological filter tank) in the lifting mode, and most of microorganisms are lost when the first-stage precise filter tank operates in the emergency mode, so that the effluent water flows back to the pretreatment tank through the second-stage aeration biological filter tank when the lifting mode is operated, and then flows into the slow filter tank (namely the biological filter tank) from the pretreatment tank to rapidly recover the microbial activity of the first-stage precise filter tank and increase the biological enzymes, so that the microorganisms can be rapidly proliferated when the first-stage precise filter tank operates in the slow filter tank (the biological filter tank), the microbial biomass is rapidly increased, the capability of the microorganisms for treating ammonia nitrogen and organic matters is improved, and the capability of removing total. When the working condition is stable, the effluent reflux of the secondary biological aerated filter can be switched to the water inlet end of the secondary biological aerated filter only in consideration of the treatment efficiency, and compared with the simultaneous operation of two reflux modes, the flow speed in the secondary biological aerated filter can be improved on the premise of keeping the retention time unchanged. Meanwhile, the water outlet of the secondary biological aerated filter is kept to flow back to the water inlet end, so that the contact probability and uniformity of sewage and microorganisms can be improved, and the ammonia nitrogen and organic matter treatment capacity of the secondary biological aerated filter is improved. In addition, under the lifting mode, the two backflow modes can be respectively and independently or simultaneously started, so that the ammonia nitrogen and organic matter treatment capacity of the precision filter and the secondary biological aerated filter can be effectively improved.

For example, the slightly polluted water treatment system according to the embodiment of the disclosure is adopted to treat water in a river in a lifting mode, and the inlet water flow rate of the treatment is 500m³D, keeping the quality of the inlet water consistent, respectively comparing and analyzing the treatment effects of four different backflow modes, namely, the system is not provided with backflow, only the backflow from the outlet water of the secondary biological aerated filter to the pretreatment tank is provided, only the backflow from the outlet water of the secondary biological aerated filter to the water inlet end of the secondary biological aerated filter is provided, and the backflow from the outlet water of the secondary biological aerated filter to the water inlet end of the secondary biological aerated filter and the backflow of the pretreatment tank are provided at the same time, and experiments show that the treatment effects in the backflowThe quality of the effluent is basically kept stable, and the treatment effect of the backflow mode is obvious through a comparison test. The following index data of the effluent in each mode after 15 days comprise Chemical Oxygen Demand (COD), ammonia nitrogen (N), Total Nitrogen (TN), Total Phosphorus (TP) and suspended matters (SS):

the continuous data monitoring shows that the system does not have backflow, only has the backflow from the water outlet of the secondary biological aerated filter to the pretreatment tank, only has the backflow from the water outlet of the secondary biological aerated filter to the water inlet end of the secondary biological aerated filter, and has the water outlet of the secondary biological aerated filter simultaneously flows to the water inlet end of the secondary biological aerated filter and the backflow of the pretreatment tank, and the effluent water with four different backflow modes reaches the stable water quality after 50, 28, 26 and 15 days respectively.

In addition, the water treatment test is respectively carried out on river water and point source pollution by adopting the water treatment mode of the micro-polluted water body treatment system according to the disclosure, and the following test results are obtained:

1. treatment of river water

Under the lifting mode, the two reflux modes are simultaneously adopted to carry out river water treatment on a certain river of Nanjing, and the treated inflow rate is 1000m³D, the ammonia nitrogen of the inlet water is 3.358mg/L, TP and is 0.9mg/L, SS and is 50mg/L, the turbidity is 51NTU, and the indexes of the outlet water after treatment are that the ammonia nitrogen is 0.362mg/L, TP and is 0.2mg/L, SS and is 3mg/L, and the turbidity is 4.25 NTU; under the emergency mode of opening after rain, the water inlet flow can reach 7500m³And d, the indexes of the effluent are that the ammonia nitrogen is 0.856mg/L, TP to 0.3mg/L, SS to 4mg/L, and the turbidity is 6.65 NTU.

2. Treatment of point source contamination

Under the lifting mode, the lifting mode is operated on the source sewage of Nanjing to treat the river water, and the treated water inflow rate is 1500m³The water quality of the inlet water is that ammonia nitrogen is 7.25mg/L, TP is 0.8mg/L, SS is 70mg/L, turbidity is 75NTU,the indexes of the effluent are that ammonia nitrogen is 0.974mg/L, TP to be 0.2mg/L, SS to be 5mg/L and turbidity is 6.5 NTU; when the emergency mode is started after rain, the water inlet flow can reach 10000m³The indexes of the effluent are that ammonia nitrogen is 1.15mg/L, TP is 0.3mg/L, SS is 7mg/L, and turbidity is 8.45 NTU.

Generally, because the parameters of the water quality of river water and point source pollution are greatly different, different treatment modes are generally selected for the two existing water qualities. Because the concentration of the pollutants of point source pollution is relatively higher, the applicable process usually has poor river water treatment effect; when point source pollution is treated by using a river water treatment process, blockage is easy to occur or the treatment effect is poor. However, according to the above experimental results, the water treatment process of the micro-polluted water treatment system of the present disclosure can obtain an excellent and satisfactory treatment effect for the water treatment of point source pollution in addition to the micro-polluted water, and thus the system can be widely applied to various water bodies including micro-pollution, point source pollution, and the like.

According to the micro-polluted water body treatment system disclosed by the embodiment of the disclosure, aiming at different working condition requirements of large flow or high standard of micro-polluted water body, the operation of flexibly switching two modes is realized, and the beneficial effects of greatly saving investment and energy consumption are achieved. The standard effect of the environmental quality of the surface water from the poor V class to the standard V class and the standard IV class of the black and odorous water body is excellent and quick. The turbidity of the water discharged from the equipment can reach 2.0NTU at most in the water quality emergency mode, the removal rate of organic matters is high, and the removal rate of ammonia nitrogen can reach 70-90% in the water quality lifting mode. Due to the structure and process flow of the micro-polluted water treatment system according to the embodiments of the present disclosure (e.g., pressure tank structure of the pretreatment tank, reflux mode in the process flow, etc.), the operation cost of the system is low. In addition, the pretreatment tank realizes the flow of the water body in a gravity flow mode, the operation cost of the system can be only 10-20% of that of single-function equipment of the same type, and the method is favorable for realizing the green, energy-saving and environment-friendly treatment process of micro-polluted water.

The above description is intended to be exemplary of the present disclosure, and not to limit the scope of the present disclosure, which is defined by the claims appended hereto.

Claims

1. The utility model provides a preliminary treatment pond for water processing system which characterized in that is including adjusting the chamber, should adjust the chamber including from the top down water-locator that sets gradually, pack, aeration equipment, guide plate, separator and smooth mud board, wherein guide plate, separator and smooth mud board slope setting to the same direction, the delivery port in preliminary treatment pond is located the below of guide plate, the one end of separator downward sloping is provided with the board of exempting from to disturb towards smooth mud board downwardly extending.

2. The pretreatment tank as claimed in claim 1, wherein the water outlet of the pretreatment tank is disposed at the uppermost portion of the region below the baffle, and the downwardly inclined one-side end portion of the baffle has a first distance from the wall of the conditioning chamber.

3. The pretreatment tank according to claim 1 or 2, wherein said separation member comprises a plurality of densely arranged pipes, the pipes in the separation member are straight pipes or inclined pipes, the pipe direction is consistent with the precipitation direction of the impurities, and said disturbance-free plate is spaced from said slide-mud plate by a distance to allow the impurities sliding down on the slide-mud plate to pass through.

4. The pretreatment tank of claim 1, wherein said separator is substantially parallel to said baffle and is spaced a second distance greater than said first distance.

5. The pretreatment tank of claim 1, further comprising a water inlet system located at an upper portion of the conditioning chamber and including a water inlet pipe and the water distributor, wherein the water inlet pipe is provided at an end connected to the water distributor with a slow flow section having a larger cross-sectional area than other portions of the water inlet pipe; the water distributor comprises a plurality of water outlets which are uniformly distributed at the upper part of the adjusting cavity.

6. The pretreatment tank of claim 1, further comprising an inlet chamber juxtaposed to said conditioning chamber and separated from said conditioning chamber by a partition, wherein the inlet chamber comprises an inlet of the pretreatment tank disposed at a lower portion thereof and a floating type packing suspended in a chamber of the inlet chamber, and said water distributor is disposed at a top portion of said partition and a screen is disposed in front of said water distributor in a water flow direction.

7. The pretreatment tank of claim 1, further comprising a water inlet system located at an upper portion of the conditioning chamber and including a water inlet pipe, the water distributor disposed around the water inlet pipe, and an air inlet pipe passing through the water distributor, the water distributor being configured as a water distribution plate having a plurality of openings therein with a diameter smaller than a diameter of the packing in the conditioning chamber.

8. The pretreatment tank of any one of claims 1 and 5 to 7, wherein said conditioning chamber further comprises a one-way valve disposed at the top thereof which closes as the water level in said conditioning chamber increases such that said conditioning chamber forms a pressure tank.

9. The pretreatment tank of claim 8, wherein the one-way valve comprises a guide region and a water passing region, wherein an adjusting member moving along with the water level is arranged in the guide region, and the adjusting member comprises a buoyancy member, a guide rod and a sealing member which are connected in sequence from bottom to top; the water passing area of the water passing area is not less than the area of the pipeline connected with the one-way valve.

10. The pretreatment tank as claimed in any one of claims 1 and 5 to 7, wherein the conditioning chamber further comprises a safety valve provided at the top thereof and an overflow port provided at the upper portion thereof and an automatic valve provided at the end of the overflow port and located on the chamber side wall of the conditioning chamber, the automatic valve being opened when the pressure in the conditioning chamber reaches a set safety value of the safety valve.

11. The pretreatment tank of claim 6, wherein the packing in the conditioning chamber is mineral particles having a density greater than water, and the floating packing is fluidized bed packing.