CN111875182B

CN111875182B - Operation method of micro-polluted water body treatment system

Info

Publication number: CN111875182B
Application number: CN202010788416.XA
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: 2023-07-04
Anticipated expiration: 2040-08-07
Also published as: CN111875182A

Abstract

The present disclosure provides a micro-polluted water body treatment system, which comprises a pretreatment tank, a primary precision filter tank, a secondary aeration biological filter tank and a tertiary precision filter tank, wherein the micro-polluted water body treatment system comprises a lifting mode and an emergency mode, which are switched between the lifting mode and the emergency mode according to the water quality condition of a water body to be treated, in the lifting mode, water flows sequentially through the pretreatment tank, the primary precision filter tank, the secondary aeration biological filter tank and the tertiary precision filter tank, and a part of water flowing out of the secondary aeration biological filter tank flows back to one or both of the water inlet end of the pretreatment tank and the water inlet end of the secondary aeration biological filter tank, in the emergency mode, the water flows respectively enter the primary precision filter tank and the tertiary precision filter tank after flowing out of the pretreatment tank. The system can quickly improve the transparency of the water body when the water quantity is large, can efficiently remove various pollutants under the condition of poor water quality, and simultaneously improves the capability of the whole system for treating ammonia nitrogen and organic matters.

Description

Operation method of micro-polluted water body treatment system

Technical Field

The present disclosure relates to water treatment technology, and in particular, to a method of operating a micro-polluted water treatment system.

Background

The micro-polluted water body has the characteristics of low pollutant concentration, diversified pollution source types, large water quantity, turbidity of the water body during raining and the like. Micro-polluted water bodies include natural water bodies and artificial water bodies, such as river and lake water bodies, landscape water bodies, culture water bodies, fountains, swimming pools, water parks and the like. With the development of urban, the persistent generation of artificial or non-artificial pollution in the urban operation process is one of the problems to be solved urgently, and the current countries and residents have higher requirements on the water quality and sanitary conditions of the urban built-up area, so that a safe, efficient and economical treatment technology for the slightly polluted water body needs to be sought.

The traditional biological filter is characterized in that microorganisms attached to a carrier are directly input, so that when the biological filter is used for treatment, the microorganisms are not fully contacted with sewage, the biological filter is not uniform, and the treatment effect and the utilization rate of the microorganisms are low. The traditional water treatment process system has definite limitation on the water inflow and various pollution indexes of the water inflow during treatment. When the polluted water quantity or the inflow water quality obviously fluctuates, the treatment device cannot be adjusted at any time, and when the water quantity is smaller or the water quality is better, the utilization rate of the device is lower, so that the resource waste is caused; when the water amount is large or the water quality is poor, the device cannot perform rapid treatment, and further deterioration of the water quality may be caused.

Accordingly, it is desirable to provide an integrated treatment process system for micro-polluted water bodies that is capable of advanced treatment of the water bodies according to different influent water qualities and/or treated water amounts.

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 an operation method of a micro-polluted water body treatment system, wherein the micro-polluted water body treatment system comprises a pretreatment tank, a primary precision filter tank, a secondary aeration biological filter tank and a tertiary precision filter tank, wherein the pretreatment tank removes particulate objects with higher density in a water body to be treated; the first-stage precise filter and the third-stage precise filter comprise a filler which is used for intercepting inorganic particles, fine impurities and organic matters in the water body to be treated; the secondary aeration biological filter utilizes the adsorption action of microorganisms to degrade organic matters in the water body to be treated; the micro-polluted water body treatment system comprises a lifting mode and an emergency mode, which are switched between the lifting mode and the emergency mode according to the water quality condition of the water body to be treated, wherein in the lifting mode, water flows sequentially pass through the pretreatment tank, the primary precision filter tank, the secondary aeration biological filter tank and the tertiary precision filter tank, and a part of water flowing out of the secondary aeration biological filter tank flows back to one or both of the water inlet end of the pretreatment tank and the water inlet end of the secondary aeration biological filter tank, in the emergency mode, the water flows respectively enter the primary precision filter tank and the tertiary precision filter tank after flowing out of the pretreatment tank,

The pretreatment tank comprises an adjusting cavity, wherein the adjusting cavity is sequentially provided with a filler, an aeration device, a guide plate, a separating piece and a sliding plate from top to bottom, the guide plate, the separating piece and the sliding plate are obliquely arranged in the same direction, a water outlet of the pretreatment tank is positioned below the guide plate, and one inclined end of the separating piece is provided with a disturbance-free plate extending downwards towards the sliding plate; the pretreatment tank can work in an emergency mode and a lifting mode, in the emergency mode, the water level in the adjusting cavity rises to form a pressure tank body, and when the water level of the adjusting cavity is lower, the pretreatment tank is in the lifting mode; the water outlet of the pretreatment tank is arranged at the uppermost part of the area below the guide plate, a water outlet slow flow area is formed between the guide plate and the separating piece, a non-disturbing area is formed above the slide plate by the separating piece and the non-disturbing plate, one part of water flow flows out of the water outlet through the slow flow area, the other part of water flow enters the non-disturbing area, and water is relatively static in the non-disturbing area after the non-disturbing area is filled with water; the separating piece comprises a plurality of pipelines which are densely arranged, the pipelines in the separating piece are basically in a vertical direction and are consistent with the precipitation direction of the impurities,

The pretreatment tank further comprises a one-way valve, the one-way valve of the pretreatment tank is closed along with the rising of the water level in the emergency mode, so that a cavity of the pretreatment tank is sealed to form a pressure tank body, and the one-way valve is conducted in the lifting mode, so that air enters the pretreatment tank.

According to the operation method of the micro-polluted water body treatment system of the embodiment of the disclosure, optionally, when the emergency mode is switched to the lifting mode, a part of water flow flowing out of the secondary aeration biological filter tank flows back to the water inlet end of the pretreatment tank.

According to the operation method of the micro-polluted water body treatment system of the embodiment of the disclosure, optionally, in the emergency mode, part of water flow passing through the primary precision filter enters the secondary biological aerated filter.

According to the operation method of the micro-polluted water body treatment system of the embodiment of the disclosure, optionally, the micro-polluted water body treatment system further comprises a dosing module for dosing a flocculating agent to water flow, in the emergency mode, the dosing module is used for dosing the flocculating agent to the front end of one or more of the pretreatment tank, the primary precision filter tank and the tertiary precision filter tank, and in the lifting mode, the dosing module is used for dosing the flocculating agent to the front end of the tertiary precision filter tank.

Optionally, the method for operating a micro-polluted water treatment system according to an embodiment of the present disclosure further comprises a backwash reservoir and a clean water basin, wherein in the lifting mode the clean water basin receives a water stream flowing from the tertiary precision filter basin; in the emergency mode, the clean water tank receives water flows flowing out of the primary precise filter tank, the secondary aeration biological filter tank and the tertiary precise filter tank; the micro-polluted water body treatment system further comprises a backwashing mode, water in the clean water tank is used for backwashing the primary precision filter tank, the secondary aeration biological filter tank and the tertiary precision filter tank in the backwashing mode, water after backwashing flows into a backwashing reservoir, and supernatant in the backwashing reservoir flows back to the pretreatment tank.

According to the running method of the micro-polluted water body treatment system of the embodiment of the disclosure, optionally, the pretreatment tank further comprises a water inlet cavity which is separated from the adjusting cavity by a partition plate, wherein the water inlet cavity comprises a water inlet of the pretreatment tank arranged at the lower part of the water inlet cavity and floating filler suspended in the cavity of the water inlet cavity, and water flow in the water inlet cavity enters the adjusting cavity through a water distributor above the partition plate.

According to the operation method of the micro-polluted water body treatment system of the embodiment of the present disclosure, optionally, the pretreatment tank further comprises a water inlet system located at the upper part of the adjustment cavity, and the water inlet system comprises a water inlet pipe, a 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 a plurality of openings with the pore diameters smaller than the diameter of the filler in the adjustment cavity are formed in the water distributor.

According to the operation method of the micro-polluted water body treatment system of the embodiment of the disclosure, optionally, the installation position of the pretreatment tank is higher than the primary precision filter tank, the secondary aeration biological filter tank and the tertiary precision filter tank, so that water flows into the primary precision filter tank, the secondary aeration biological filter tank and the tertiary precision filter tank under the action of gravity.

According to the running method of the micro-polluted water body treatment system of the embodiment of the disclosure, optionally, the one-way valve of the pretreatment tank comprises a guide area and a water passing area, wherein an adjusting piece moving along with the water level is arranged in the guide area, and comprises a buoyancy piece, a guide rod and a sealing piece which are sequentially connected from bottom to top; the water passing area of the water passing area is not smaller than the area of the pipeline connected with the one-way valve.

According to the operation method of the micro-polluted water body treatment system of the embodiment of the disclosure, optionally, the secondary biological aerated filter comprises at least one chamber with sufficient dissolved oxygen and at least one facultative chamber which are communicated, and each chamber with sufficient dissolved oxygen comprises floating filler, interception filter materials arranged at the lower part of the chamber, a supporting layer for supporting the interception filter materials and an aerator arranged below the interception filter materials; each facultative chamber includes a composite filter layer including at least two different filter material layers.

The operation method of the micro-polluted water body treatment system according to the embodiment of the present disclosure optionally further comprises an integrated pump house comprising a variable frequency pump which adjusts the operation frequency according to the water volume change of the water body to be treated.

The running method of the micro-polluted water treatment system provided by the embodiment of the disclosure can flexibly switch the water treatment mode under the lifting mode and the emergency mode according to the water quality condition, can rapidly improve the transparency of the water when the water quantity is large, and can efficiently remove various pollutants including ammonia nitrogen and organic matters under the condition of poor water quality. In addition, since the water treatment process of the embodiment of the disclosure may include a backflow from the effluent of the biofilter to the pretreatment tank and/or a backflow of the effluent of the biofilter to the water inlet end thereof, the probability and uniformity of contacting the wastewater with microorganisms may be improved, thereby improving the capacity of the entire system to treat ammonia nitrogen and organic matter. Furthermore, the embodiment of the disclosure also provides a novel pretreatment tank structure, which can automatically adjust working conditions according to different treatment modes, and can enhance a precipitation effect and realize preliminary degradation of organic matters and ammonia nitrogen through a specific structure while removing pollutants with larger particles so as to improve the treatment efficiency of a subsequent process. Furthermore, the pretreatment tank can be installed at a position higher than that of the subsequent process equipment, thereby saving energy. The biological filter provided by the embodiment of the disclosure is suitable for different water treatment modes of the whole system, improves the probability and uniformity of sewage and microorganism contact, and is convenient to install and expand due to the modularized design.

Not all of the advantages described above need be achieved at the same time in practicing any one product of the present disclosure. Additional features and advantages of the disclosure will be set forth in the description which follows, and in part will be apparent from the description, or may be learned by practice of the disclosure. The objects and advantages of the disclosed embodiments 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

In order 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 is apparent that the drawings in the following description relate only to some embodiments of the present disclosure, not to 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 illustrating the process flow in the lift mode and the process flow in the backwash mode;

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

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

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

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

FIG. 5 is a schematic view of a three stage precision filter according to one embodiment of the present disclosure; and

FIG. 6A is a schematic diagram of one embodiment of a check valve for use in the pretreatment tank as shown in FIGS. 2A-2F; FIG. 6B is a schematic diagram of another embodiment of a check valve for use in the pretreatment tank as shown in FIGS. 2A-2F; FIGS. 6C-6D are schematic views illustrating 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 house according to one embodiment of the present disclosure.

Detailed Description

For the purpose of making 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 clearly and completely described below with reference to the accompanying drawings of the embodiments of the present disclosure. It will be apparent that the described embodiments are some, but not all, of the embodiments of the present disclosure. Various embodiments may be combined with one another to form further embodiments not shown in the following description. All other embodiments, which can be made by one of ordinary skill in the art without the need for inventive faculty, are within the scope of the present disclosure, based on the described embodiments of the present disclosure.

Unless defined otherwise, technical or scientific terms used herein should be given the ordinary meaning as understood by one of ordinary skill in the art to which this disclosure belongs. The terms "first," "second," and the like in the description and in the claims, do not denote any order, quantity, or importance, but rather are used to distinguish one element from another. Likewise, 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 elements or items preceding the word are included in the element or item listed after the word and equivalents thereof, but does not exclude other elements or items. The terms "connected" or "connected," and the like, are not limited to physical or mechanical connections, but may include electrical connections, whether direct or indirect. "upper", "lower", "left", "right", etc. are used merely to indicate relative positional relationships, which may also be changed when the absolute position of the object to be described is changed.

FIG. 1A is a schematic structural diagram of a micro-polluted water treatment system in accordance with one embodiment of the present disclosure, wherein the process flow is also shown in a lifting mode and in a backwash mode. FIG. 1B is a schematic illustration of the process flow of the micro-polluted water treatment system as shown in FIG. 1A in emergency mode. As shown in fig. 1A and 1B, a micro-polluted water treatment system in accordance with one embodiment of the present disclosure may include: a pretreatment tank 100, a primary precise filter 300, a secondary aeration biological filter 400 and a tertiary precise filter 500. The micro contaminated water treatment system may also optionally include one or more of a dosing module 200, an integrated pump house 700 for extracting the contaminated water, a clean water basin 900 for storing treated clean water, and a backwash reservoir 800 for a one-stage to three-stage filter backwash process.

The pretreatment tank 100 may be used to remove particulate matter of greater density in water. For example, the pretreatment tank may include a cyclone filter. On the other hand, the pretreatment tank 100 may also be implemented, for example, with a structure according to an embodiment of the present disclosure (as shown in fig. 2A-2F), in which a filler is utilized to primarily purify a body of water and reduce turbidity of the water while removing particulate matter having a high density in the water. The primary precision filter 300 is mainly used for intercepting inorganic particles, fine impurities and organic particles in water. The secondary aeration biological filter 400 is mainly used for effectively degrading organic matters in water by utilizing the adsorption effect of microorganisms. The three-stage precise filter 500 (which may have the same structure as the first-stage precise filter 300) further intercepts inorganic particles, fine impurities and organic particles in the water, thereby enhancing the water treatment effect. Examples of specific structures of the pretreatment tank 100, the primary precise filter 300, the secondary aeration biological filter 400, and the tertiary precise filter 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 uses a water pump to extract the water to a high place. The dosing module 200 doses flocculant to the pretreatment tank, the primary precision filter 300 and/or the tertiary precision filter 500 as needed in a manner that is specifically described below in connection with different process flows. The backwash reservoir 800 stores water flowing out after backwashing the primary trickle filter 300, the secondary aeration biological filter 400, and the tertiary trickle filter 500. The clean water basin 900 stores the purified water and can provide a source of water for backwash of the primary to tertiary filters.

A micro-polluted water treatment system in accordance with an embodiment of the present disclosure includes two modes of water treatment, 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 water quality according to the water quality condition of stable water quality change, so that the ecological system is continuously stable in the water quality reaching the standard. The emergency mode is mainly used for improving the transparency of the water body as soon as possible aiming at the situation that the water quality is rapidly deteriorated (for example, due to rain and the like), so as to restore the purification function of the ecological system.

FIG. 1A illustrates a process flow of a micro-polluted water treatment system in a lifting mode, in accordance with one embodiment of the present disclosure. As shown by solid arrows in fig. 1A, namely water flows (1) and (8), the water to be treated enters through a lifting water intake mode of the integrated pump house 700, then sequentially passes through the pretreatment tank 100, the primary precise filter 300, the secondary biological aerated filter 400 and the tertiary precise filter 500 of the system, and finally the treated water enters the clean water tank 900. The lifting mode further includes a reflux mode that promotes microbial propagation, see water flow direction (8) in fig. 1A. The reflow mode will be described in detail below.

FIG. 1B illustrates a process flow of a micro-polluted water treatment system in an emergency mode, in accordance with one embodiment of the present disclosure. As shown by solid arrows (i.e., water flows (3), (4), and (5)) in fig. 1B, water to be treated is fed (i.e., water flow (3)) in an emergency water intake mode of the integrated pump house, and then is split into two parallel paths (i.e., water flows (4) and (5)) after passing through the pretreatment tank 100, one path of water enters the clean water tank 900 (i.e., water flow (4)) after passing through the primary precise filter 300, the other path of water enters the clean water tank 900 (i.e., water flow (5)) after passing through the tertiary precise filter 500, wherein the water fed into the primary precise filter 300 is split into two paths, one path of water is filtered and then directly enters the clean water tank 900, and the other path of water enters the clean water tank 900 after passing through the secondary biological aerated filter 400. In the emergency mode, the water to be treated passes through the pretreatment tank 100, and larger suspended matters, impurities and the like in the water are effectively intercepted or precipitated, and the water is subjected to preliminary filtration, so that the turbidity of the water is reduced. After the water body flows out of the pretreatment tank 100, the water body is split and simultaneously enters the primary precise filter 300 and the tertiary precise filter 500, thereby increasing the amount of water that can be treated. Here, the precision filter intercepts inorganic particles, organic particles, and/or fine impurities, etc., thereby rapidly improving transparency of the water body. Meanwhile, most of the water passing through the primary precise filter 300 directly enters the clean water tank, so that the water treatment efficiency is ensured, and a small part of the water enters the secondary aeration biological filter 400 to provide a small amount of water to ensure the survival condition of microorganisms.

In addition, as shown in fig. 1A and 1B, the micro-polluted water treatment system according to one embodiment of the present disclosure may periodically operate a backwash mode, ensuring treatment effect. The backwashing mode comprises the steps of carrying out water backwashing on each unit of the primary precise filter 300, the secondary aeration biological filter 400 and the tertiary precise filter 500 and carrying out air backwashing on the secondary aeration biological filter. During the water backwash, water is supplied from the clean water tank 900 and backwash water is delivered to the backwash reservoir 800, and backwash water supernatant in the backwash reservoir is returned to the pretreatment tank. The supernatant fluid has low pollutant content and contains a certain amount of microorganisms, and after entering the pretreatment tank, the supernatant fluid is purified again, so that the load of the backwashing reservoir is reduced. The backwash reservoir may be periodically desilting. The backwashing of the precision filter tank is mainly used for removing inorganic particles and preventing the inorganic particles or fine impurities from affecting the filtering speed. The water backwash and the air backwash in the secondary aeration biological filter will be specifically described with reference to fig. 4.

The structure of the integrated pump room 700 is not limited, and a common structure of the integrated pump room can be adopted, and only the water pump of the integrated pump room is required to change the water intake according to the requirement. For example, the integrated pump house 700 may have a variable frequency pump that can change the operating frequency based on the water intake requirements. Furthermore, the integrated pump house 700 may further include one or more fixed frequency pumps to increase the water intake when needed. The lifting water taking mode of the integrated pump house 700 refers to a situation that a water pump for lifting the water taking mode is started under the lifting mode of the micro-polluted water body treatment system, namely, under the condition 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 intake mode of the integrated pump house 700 refers to a situation that a large amount of water needs to be rapidly treated in an emergency mode of the micro-polluted water treatment system, and a water pump for the emergency water intake mode is started at this time. For example, in this case, the integrated pump house 700 may turn on a water pump to increase the water intake. Fig. 7 shows a schematic structural diagram of a water pump configuration of an integrated pump house according to one embodiment of the present disclosure. The pump house comprises two

pumps

710 and 712 connected in parallel, wherein the pump 710 may be a variable frequency pump which may adjust the operating frequency according to the water volume change, and the pump 712 is a fixed frequency pump. Both the fixed frequency pump and the variable frequency pump are turned on in the emergency water taking mode, and only the variable frequency pump can be turned on in the lifting water taking mode.

The front end of the water treatment system of the present disclosure is provided with a pretreatment tank 100, which is mainly used for precipitating and preliminarily filtering sludge. The structure of the pretreatment tank 100 according to one 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 combined apparatus of the pretreatment tank 100 and the dosing module 200 according to one embodiment of the present disclosure. Implementing them as a combined device here may make the whole system more compact. Since the pretreatment reservoir and the dosing module are functionally distinct, they can also be arranged and implemented in two separate parts, which do not affect their respective internal structure and function. Accordingly, the structures of the pretreatment tank 100 and the dosing module 200 are described below, respectively.

The pretreatment tank can be arranged at a higher position relative to the equipment of the subsequent treatment process, so that after the water body is lifted by the pump house, 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, and the water body is not required to be lifted or conveyed again by a water pump, so that the energy is saved, and the whole system is more compact.

The structure of the pretreatment tank 100 according to one 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 separated by a partition 110. The intake chamber 130 and the adjustment chamber 120 communicate at an upper portion. The water inlet chamber 130 includes an evacuation port 101 provided at the bottom of the chamber for evacuating the chamber, a water inlet 102 provided at the lower portion of the chamber, and a floating packing 103 (e.g., a lightweight porous packing such as a fluidized bed packing) suspended in the chamber. The drain 101 may be used to drain the precipitated impurities from the water inlet chamber periodically or as needed, or may be used to drain the water in the water inlet chamber when needed. The top of the partition 110 is provided with a water distributor 111, such as a triangular overflow weir, which facilitates uniform water distribution. The water distributor 111 may be provided at its forward end with a filter screen 112 which prevents floating packing 103 from entering the conditioning chamber 120 or clogging the water distributor 111. A packing 121 (e.g., a composite filter material having a density greater than that of water) is disposed in the conditioning chamber 120, and an aeration device 122 is disposed below the packing 121. The aeration device 122 aerates the water body in the chamber or turns the packing 121 as needed to realize the function of backwashing the same.

An inclined deflector 123 is provided below the aeration device 122, the deflector 123 being provided at a slope, one end of which may be fixed to the chamber wall and the other end of which has a distance S1 from the chamber wall, a water flow passage being formed at S1. The angle of inclination alpha of the deflector 123 may be about 40 deg. to 85 deg., preferably 60 deg. to 80 deg.. The uppermost portion of the lower region of the baffle 123 is provided with a water outlet pipe 124, and a water outlet hole 124A of the water outlet pipe 124 is preferably provided at a side close to the partition 110. This arrangement prevents as much of the remaining impurities of the body of water from entering the outlet pipe 124. Below the baffle 123 a separator 125 is provided, which separator 125 is preferably substantially parallel to the baffle 123 and the distance S2 between them is preferably greater than S1, which facilitates a reduction of the water flow velocity. Thus, a water-out slow flow area E is formed between the deflector 123 and the separating member 125. This arrangement allows the water flow to be slower in the slow flow zone E and to form a water flow upward along the slow flow zone, which is advantageous for light impurity precipitation. The separating member 125 may be a straight tube or an inclined tube structure having a dense geometry, and the tube direction thereof is substantially consistent with the impurity precipitation direction, for example, may be substantially vertical, and the tube shape may be, for example, square, rectangular, regular hexagon (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 tamper-proof plate 126. The immunity plate 126 extends downward (e.g., vertically downward) with a lower end at a small distance S3 from the skid plate 127, whereby the separator 125 and the immunity plate 126 form an immunity region F above the skid plate 127. The smaller distance S3 can ensure that the impurities on the skid plate 127 slide down and the impurities in the interference free region F are not affected by water flow and are smoothly precipitated. The skid plate 127 is inclined in the same direction as the deflector and the separator, and its inclination angle β is preferably smaller than the angle α, since a smaller angle is advantageous for the impurities to slide off from it. One end of the slide plate 127 extends to the partition plate 110, and a sludge discharge port 128 is provided at the bottom of the slide plate 127. Impurities entering the sludge discharge port 128 may be periodically discharged and cleaned. Furthermore, optionally, aeration means (not shown) may also be provided in the inlet chamber 130, thereby facilitating the propagation of microorganisms in the suspended filler in the lifting mode.

In addition, the top end of the regulating chamber 120 may be provided with a one-way valve 134 which may be used for air intake when the regulating chamber water level is low and to seal the chamber when the regulating chamber water level is high. The 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 regulating chamber 120 is also provided with a relief valve 129. The upper chamber part of the regulating chamber 120 may also be provided with an overflow 131. The end of the overflow 131 is connected to an automatic valve 132, which is normally closed. When the relief valve 129 senses that the pressure in the regulator chamber 120 reaches a set relief threshold, the automatic valve 132 will automatically open the drain to relieve the pressure. Further, the top of the chamber 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 working conditions according to different treatment modes to adapt to the use requirements. During the use of the pretreatment tank 100, water enters from the water inlet 102 and collides with the floating filler 103 in the water inlet cavity 130, which is beneficial to the precipitation and filtration of sludge. In addition, under the lifting mode, the floating filler 103 gradually grows out a biological film on the surface of the floating filler, so that the water body can be primarily purified, the mature biological film falls off in the water body under the impact action, and the biological film after falling off can be intercepted by the filler 121, so that organic matters in the water can be further adsorbed and degraded. Referring to the schematic of the process of water flow operation in fig. 2C (where (1) represents the water flow path and (2) represents the impurity precipitation path), in the water intake chamber 130, impurities in the water body having a precipitation velocity V2 (which depends on the weight of the particles) greater than the water flow rising velocity V1 move downward, collect at the bottom of the water intake chamber 130, and are periodically discharged through the drain 101. After the water body of the water inlet cavity 130 rises, the water flow is uniformly distributed by the water distributor 111 and enters the adjusting cavity 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 effect can turn over the filler 121 to float the lighter substances attached to the filler on the water surface, and the lighter substances are discharged from the overflow port during overflow. Heavier materials (including shed biofilm) will move down with the water flow. At this time, impurities with a settling velocity V2 greater than a water flow velocity V1 in the water body enter the bottom of the skid plate 127 through the deflector 123. In this process, the water flow enters the slow flow region E through the water flow channel at the position S1, the water flow speed V1 is further reduced, and an upward water flow state is formed, at this time, the impurities with a sedimentation speed V2 greater than the water flow speed V1 generated by the gravity of the remaining impurities in the water can continue to move downward, and at the same time, the water flow moves upward, and the opposite movement direction accelerates the impurities into the inside of the geometry of the separating member 125, so as to enter the no-disturbance region F. It can be seen that the reduced flow rate allows more impurities to enter the separator 125 and the opposite direction of movement of the water stream and impurities enhances the settling effect by at least 10% over the horizontal flow settling effect of the water stream (as demonstrated by the experiment). Due to the dense structure of the separator 125, a portion of the water flow forms a laminar flow within the geometry of the separator 125, into the immunity region F until it fills the region, creating a relatively stagnant body of water in the immunity region F. The relatively stationary immunity region F allows impurities therein to settle out into the bottom of the skid plate 127 without being affected by the water flow. Another portion of the water flow eventually exits outlet pipe 124 through buffer zone E. This portion of the water stream contains shed biofilm (which is typically present in suspension in the flowing water body) which passes from the outlet pipe 124 into the next unit. From the above operation process, it can be seen that the pretreatment tank of this embodiment forms the slow flow area E and the no-disturbance area F by precipitating step by utilizing the special structure formed by the deflector, the separating piece and the skid plate, so as to greatly shorten the precipitation time, strengthen the precipitation effect and reduce the processing load of the subsequent process. In addition, through shortening sedimentation time, can effectively reduce the height in pretreatment tank when guaranteeing sedimentation effect to be favorable to controlling entire system's volume, be convenient for the integration and the installation of system. In addition, the filler is used for filtering the water body in the pretreatment tank, so that the cultured microorganisms can enter the subsequent unit, the biochemical performance of the treated water body is improved, the subsequent treatment efficiency is improved, and especially, when the microorganisms are insufficient after backwashing of the subsequent unit, the microorganism concentration of 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 pretreatment tank 100 in the emergency mode and the lifting mode is described below. When the water level in the conditioning chamber 120 increases rapidly (e.g., in emergency mode) due to a large water throughput, a high water flow rate, or a slow filtration rate of the subsequent unit filter media, etc., the water level increases such that the check valve 134 closes. Thus, the inlet chamber 130 and the regulating chamber 120 gradually become a pressure tank, and the increase of pressure can accelerate the filtration speed of the subsequent unit. On the other hand, if the flocculating agent is added at the front end of the pretreatment tank, the pressure can be increased to ensure that the water body and the flocculating agent are more uniformly mixed in the tank body, thereby being beneficial to the formation of flocculation. 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 safe use of the tank.

In the emergency mode, the pretreatment tank 100 can perform preliminary precipitation of large particles on the water entering the device. The suspended light porous filler in the water inlet cavity 130 can effectively intercept larger suspended matters and impurities in water, and the filler with larger density in the adjusting cavity 120 can further filter the water, so that the turbidity of the water is reduced in an emergency mode. In addition, since the adjusting chamber 120 can be changed into a pressure tank in an emergency mode, an additional water pump is not required to increase the water flow speed, thereby improving the treatment efficiency and saving energy.

When the water level of the regulating chamber 120 is low (for example, in the lifting mode), aeration is required at this time because the water treatment amount is small, the water flow rate is slow, and the biofilm treatment process is required for dissolved oxygen in the lifting mode. In one aspect, air can enter the conditioning cavity 120 through the one-way valve 134. The water body realizes drop aeration during the process of flowing into the regulating cavity 120 from the overflow weir 111. On the other hand, whether the aeration device 122 is started to aerate the water body can be determined by monitoring whether the content of the dissolved oxygen in the water body meets the requirement in real time. In addition to helping oxygenate the body of water to promote microbial growth on the packing, aeration also allows lighter materials in the body of water to float on the surface of the water, while heavier materials pass from the baffle 123 through the slide plate 127 into the discharge 128.

In the lifting mode, in addition to the effect of realizing preliminary precipitation of large particles and preliminary interception of impurities and pollutants in the water body by the filler as described above, the adjustment cavity 120 is fully aerated, so that an aerobic environment is created, nitrification of organic matters can be realized, and 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 of fig. 2D at line B-B. 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 intake system. The description of the water intake system is provided below, with reference to the description of the conditioning chamber 120 of FIG. 2A above for other portions of the conditioning chamber. The water inlet is provided at an upper portion of the regulation chamber 150. The water inlet pipe 151 of the water inlet system can be arranged at the central part of the adjusting cavity 150, the tail end of the water inlet pipe 151 is provided with a slow flow section 152, the cross section of the slow flow section 152 is larger than that of the water inlet pipe, and the slow flow section can slow down the water flow speed to enable the water flow to uniformly enter the water distribution system 153 connected with the tail end of the water flow. The water outlet of the water distributor 153 can adopt a triangular overflow weir, which is beneficial to uniform water distribution. A filter screen 154 is arranged outside the water distributor 153, and can prevent filter materials from entering the water distributor 153. This water inlet system creates a uniform flow of inlet water over the entire conditioning chamber 150, providing more drop aeration area, better aeration oxygenation and more uniform distribution of water than the embodiment shown in fig. 2A.

Fig. 2F is a schematic diagram of a pretreatment 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 intake system. In fig. 2F, the water inlet system may be provided with a water inlet pipe 161 at the center of the adjustment chamber 160. A water distribution plate 162 is disposed around the water inlet pipe 161, the water distribution plate 162 is preferably a porous flushing plate, and the pore diameter 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 that of the water inlet pipe 161. In addition, the water inlet system is further provided with a plurality of air inlet pipes 163 which penetrate through the water distribution plate 162, wherein the water inlet pipe 161 can be at least 20-30mm higher than the Yu Bushui plate 162, and the air inlet pipes 163 can be at least 80-100mm higher than the Yu Bushui plate 162, so that air can enter conveniently. The water 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 air inlet pipe 163, so that falling aeration is performed. 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 tuning chamber 120 of fig. 2A.

In the embodiment of fig. 2A-2F, the check valve of the pretreatment tank may use a conventional check valve. However, in general, due to the structural limitation of the conventional one-way valve, the water passing area of the one-way 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 affected. Similarly, if a conventional one-way valve is used for one-way ventilation, its overgas area may also be affected. Fig. 6A and 6B show schematic structural views of an embodiment of a one-way valve that may be used in a pretreatment tank as shown in fig. 2A-2F, respectively. Fig. 6C-6D are schematic diagrams of the operation of the one-way valve of fig. 6A, which is also applicable to the embodiment of the one-way valve of fig. 6B. The one-way valve according to the embodiment of the disclosure is simple in structure, low in cost and capable of enabling the water passing area to meet the use requirements of pipelines of the same specification. The check valve may be connected to the pipe by different connection methods, for example, flange type, sleeve type, etc. various suitable connection methods are available. 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, such as threaded holes, formed therein. 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 connector is determined by the connection mode with the external pipe, and the structure of other parts in the check valve is not affected, so the structure of the connector shown in fig. 6A can be changed to the structure of the connector shown in fig. 6B, and vice versa, as required.

As shown in fig. 6A, the check valve further includes a valve body 62A of the check valve connected to the end of the connection member 61A, and a partition 63A is fixed inside the valve body 62A. The cross-sectional area of the two ends of the valve body 62A is smaller than the cross-sectional area of the middle portion thereof. In general, the cross-sectional area of the two ends of the valve body 62A may be the smallest cross-sectional area in the valve body 62A. The partition 63A includes a guide zone 631A and a water passing zone 632A, wherein the water passing zone 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. The guide section 631A has an adjustment member 64A mounted therein, which enables the adjustment member to freely move upward or downward in the vertical direction. The adjusting member 64A includes a lower buoyant member 641A, a guide rod 642A connected to the buoyant member 641A through the guide area 631A, and a sealing plug 643A connected to the upper side of the guide rod 642A, wherein the buoyant force generated by the buoyant member 641A is at least greater than the gravity force of the adjusting member 64A. When the water level rises, the adjustment member 64A can be guided in the guide section 631A to move upward with the water level. When the water level drops, the adjustment member 64A moves downward along the guide area 631A due to gravity. The valve body 62B, the partition 63B, the guide area 631B, the water passing area 632B, the adjustment member 64B, the buoyant member 641B, and the guide lever 642B in the check valve shown in fig. 6B are identical to the corresponding structures in the check valve shown in fig. 6A, and thus are not described in detail.

The sealing means may be composed of a spherical sealing plug 643A attached to a guide rod 642A and a sealing member 65A provided on the inner surface of the upper end of the valve body 62A (at the position where the cross section of the valve body 62A is smallest) (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 member 65B (as shown in fig. 6B) provided on the valve body 62B at the smallest cross section, wherein the sealing

members

65A and 65B are preferably made of materials with better wear resistance, higher elasticity and better water resistance. The sealing surface of the sealing plug may be planar, beveled or curved, provided that it is capable of sealing with the inner surface of the sealing member in a close fit. Thus, the shape of the sealing plug is not limited to the above-mentioned spherical or truncated cone shape, but other suitable shapes may be selected. The surface of the sealing plug may be inclined or curved as long as it cooperates with the surface of the sealing element to enable sealing. The sealing plug shown in fig. 6A and 6B may be used in a variety of different connection arrangements, such as a sleeve-type arrangement, a flange-type arrangement.

Fig. 6C is a schematic view of the closing process of the check valve shown in fig. 6A, and fig. 6D is a schematic view of the 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 regulator 64A of the check valve moves upward along the guide area by the buoyancy of the water body, so that the sealing means is activated, and the surface of the ball-shaped sealing plug 643A is brought into close contact with the sealing member 65A, thereby closing the passage. As shown in fig. 6D, when the water level drops, the regulator 64A moves downward by its own weight, thereby opening the passage. The above procedure also applies to the one-way valve shown in fig. 6B. The sealing mode can ensure the sealing performance and reduce the processing difficulty.

The above-described one-way valve may be used for both gas and liquid passages (i.e., one-way ventilation). The one-way valve automatically works by utilizing gravity and buoyancy. The check valve has a greater gas or liquid throughput due to the larger area of the water passing area inside the check valve. The water passing area of the one-way valve water passing area is at least equal to the flow area of the pipeline with the same specification connected with the one-way valve, so that the sufficient water passing area is ensured, and the one-way valve is used as a liquid channel without affecting the liquid flow.

In addition, the one-way valve according to the embodiment of the disclosure is simple in structure, easy to process while guaranteeing the sealing performance, and low in cost. The one-way valve is suitable for being used in a water treatment system, in particular a sewage treatment system, so as to assist 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 achieves progressive precipitation of impurities by its special structure, enhancing the precipitation effect. In addition, the pretreatment tank can intercept impurities through the filler, and the microorganisms are cultured on the filler to enter the follow-up unit, so that the biochemical performance of the treated water body is improved, the follow-up treatment efficiency is improved, and especially, the microorganism concentration of the follow-up unit can be quickly recovered when the follow-up unit has insufficient microorganisms after backwashing. Furthermore, the pretreatment tank according to the present disclosure may automatically adjust its operating conditions according to water quality changes and/or changes in the amount of treated water. The pretreatment tank is not only suitable for micro-polluted water treatment systems, but also can be used in other water treatment systems, improves the efficiency of water treatment and adapts to various changes of water.

After the water body entering the pretreatment tank is subjected to large-particle preliminary precipitation and preliminary purification, the supernatant enters a primary precise filter tank for further treatment, and the precipitated sludge is discharged through a periodically opened blow-down valve.

Also shown in fig. 2A is a schematic structural view of the medicated module 200. The medicated module may also be incorporated into the pretreatment tank embodiments 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 medicament that the medicated module 200 according to one embodiment of the present disclosure may administer is, for example, a flocculant. The flocculant is mainly provided with groups with positive (negative) electrical property, and is mutually close to some particles or granules which are difficult to separate and have negative (positive) electrical property in water, so that the potential of the flocculant is reduced, the flocculant is in an unstable state, the granules are concentrated by utilizing the polymerization property of the flocculant, and the flocculating constituent is separated from water phase precipitation under the action of gravity after being grown to a certain volume, so that a large amount of suspended matters in the wastewater are removed, and the flocculating constituent can be effectively formed at a water inlet end and is intercepted by a later filter tank, thereby improving the sewage treatment rate.

The point of medicament administration of a medicament administration device according to one embodiment of the present disclosure may vary depending on the mode of operation of the system. In order to avoid the inhibition effect of the reagent on the biological aerated filter, the reagent can be added to the front ends of the primary precise filter and the tertiary precise filter in an emergency mode; in the lifting mode, the method can be only added to the front end of the three-stage precise filter tank or not. In addition, in emergency and lifting modes, flocculant may also be added to the front end of the pretreatment tank 100, and floating packing in the pretreatment tank 100 may enhance the mixing of flocculant with water. The dosing module 200 delivers the medicament to one or more of the pretreatment tank, the primary, and the tertiary precision filter tanks via corresponding lines. 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 where the pipeline is positioned. The water treatment system according to embodiments of the present disclosure may control metering pumps and valves according to different modes to determine the amount of agent administered and to select the route of agent administered. For example, metering pump 201 may be controlled in the field or remotely via a communication bus such as RS485 or other industrial control methods.

As shown in fig. 3, the primary precision filter 300 may include a primary filter water inlet 301, a filler 302, a primary filter water outlet 303, an automatic vent valve 304, a vent valve 305, and a vent 306. The water flow enters the primary precision filter 300 from the primary filter water inlet 301, passes through the filler 302 and flows out from the primary filter water outlet 303. The drain 306 functions similarly to the drain 101 of the pretreatment tank, and can remove sediment and can also be used to drain the water in the filter.

In the emergency mode, the primary precise filter 300 mainly intercepts particulate organic matters, inorganic particles and fine impurities, and rapidly improves the transparency of the water body. In the lifting mode, the primary precision filter 300 can be used for intercepting inorganic particles (including inorganic particles obtained by decomposing organic matters) and fine impurities in water and continuously removing the residual organic matters in the water, so that the water treatment effect is maintained. In the emergency mode, the primary precision filter 300 functions as a rapid filter (i.e., the filler therein functions as a filter), while in the lifting mode, the primary precision filter 300 may function as a slow filter (i.e., a biofilter).

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 in the water flow direction of the water treatment, wherein the fine filter layer intercepts the microbial zoogloea in the water body, further adsorbs and degrades the organic matters in the water in addition to filtering the impurities, and the physical filter layer may be mainly used for filtering inorganic particles and fine impurities. The filter material of the fine filter layer is preferably a material with high strength, corrosion resistance, high specific surface area and high porosity, such as zeolite, ceramsite and the like, and the filter material is favorable for the colonisation growth of microorganisms. The filter material of the physical filter layer is preferably a material with rough surface, good adsorption capacity, higher dirt holding capacity and light weight, such as anthracite filter material, which is helpful for improving the filtering speed and dirt-intercepting capacity.

In the primary precise filter, the water inlet is fully contacted with the microbial film gap grown on the surface of the filler, the filtering speed can be as low as 3-7 m/h, and the filtering speed of the subsequent secondary aeration biological filter can be 2.5-6.5 m/h, and the effects of the water inlet and the microbial film gap are equivalent, so that the primary precise filter has a strengthening effect on the treatment capacity of the subsequent secondary aeration biological filter in a lifting mode. The filtering speed of the primary precision filter tank in the emergency mode can reach 20-25 m/h, and the high treatment capacity is ensured. The primary precision filter according to the embodiment of the disclosure adopts various particulate medium materials as filter materials of a filter system, and utilizes the mechanical screening effect, precipitation effect and contact flocculation effect of the filter materials to effectively intercept organic matters (including colloidal organic matters), particulate impurities and the like in water.

As shown in fig. 4, a secondary aeration biological filter according to an embodiment of the present disclosure may include two chambers a and b, which may be assembled as separate cabinets or may be integrally partitioned by a partition, where the chamber a is an environment with sufficient dissolved oxygen, and the chamber b is a facultative environment. The a chamber can comprise a secondary filter water inlet 401 arranged at the top of the a chamber, a filter screen 402 arranged at the secondary filter water inlet 401, floating filler 403 arranged at the upper layer of the chamber water body, and an aerator 404 arranged below the floating filler 403. The filter screen 402 arranged at the water inlet can prevent suspended filter materials from being backflushed into the water inlet during the operation of the backwashing mode, so that the pipeline is prevented from being blocked. The aerator 404 may oxygenate the body of water and disturb the floating packing 403. The chamber a also comprises a trapped filter material 405 arranged on the lower layer of the water body of the chamber and supported by a supporting layer 406, and an aerator 407 is arranged below the trapped filter material 405 so as to oxygenate the water body and flush the trapped filter material 405 to avoid hardening. The bottom of the a chamber is provided with a water outlet pipe 408 through which water enters the b chamber. The b chamber can comprise an aerator 410 arranged at the lower layer of the water body, a composite filter layer 412 which is supported above the aerator 410 through a bearing layer 411, and a secondary filter water 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.

Floating packing 403 is preferably a large surface area, corrosion and abrasion resistant, and less dense packing, such as a fluidized bed packing. The trapped filter 405 is preferably a dense, small particle size, high strength, and high porosity filter, such as a small particle volcanic rock. The interception filter material arranged above the water outlet of the part a can filter fluid and meanwhile has an interception function on microorganisms, so that the microorganism utilization rate is greatly improved. The composite filter layer 412 preferably comprises at least two filter material layers, a lower layer being a heavy filter material and an upper layer being a fine filter material. The arrangement can enable suspended matters in water flow to penetrate into the filter material from the bottom layer to the upper layer, so that the dirt interception capability is improved.

The stability of the indoor environment of the chamber can be kept only by carrying out air backwashing on the chamber a, so that the water backwashing of the secondary aeration biological filter can be carried out only on the chamber b. And the b chamber can be backwashed with water and air due to the thicker composite filter layer 412 and its environmental requirements. The secondary aeration biological filter is backwashed by using the water of the clean water tank, and a backwash water inlet 414 is arranged below the chamber b and is opened according to the requirement of water backwashed. The air backwashing of the secondary aeration biological filter uses a backwashing air pump of the aerator to carry out air backwashing on the biological filter. The aeration impacts the filter material above to loosen the filter material, thereby bringing out the deposited pollutants in the filter material and effectively solving the problem of hardening the filter material. Meanwhile, the aerator can adopt a backwash air pump (not shown) with adjustable air quantity, and can be used for aeration on one hand and air backwash on the other hand, so as to provide a certain dissolved oxygen for the biological filter tank, strengthen the aeration effect and provide conditions for the growth and propagation of microorganisms in the filter tank. The water backwashing and the air backwashing can be carried out at fixed time, and can also be carried out according to the working condition of the biological filter.

Further, an evacuation port and an evacuation valve (not shown) are provided in each of the a chamber and the b chamber, and function as the evacuation port and the evacuation valve in the primary precision filter.

The treatment of the water body by the secondary aeration biological filter in different modes is specifically described with reference to fig. 4. In the lifting mode, the water body enters the a chamber from the water inlet 401 of the secondary filter from the previous unit. Under the action of the water flow impact and the aeration of the aerator 404, the floating filler 403 moves freely in the water and grows a biofilm gradually on the surface thereof. Due to the shearing force of water and the friction force generated by the movement of the floating filler 403, the biological film on the surface of the floating filler 403 naturally falls off into the water body, and is further intercepted by the interception filter material 405. The water body enters the lower part of the b chamber from the water outlet pipe 408 below the a chamber, the water flow and the air 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 the inner layer of the filter material forms an anaerobic environment, so that ammonia nitrogen in the water body is finally degraded. Finally, the filtered water flows out of the secondary filter outlet 413 above the b chamber and enters the next unit. 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. From the arrangement and operation in the cavity a, the cavity a has sufficient dissolved oxygen, and the floating filler 403 and the interception filter material 405 can ensure sufficient microorganism content in the cavity a, so that COD (chemical oxygen demand) in the water body can be eliminated first, and the condition of nitration reaction is provided for microbial degradation. From the arrangement and operation of the b chamber, the water entering from the bottom is not easy to impact the composite filter layer 412, and the uniformity of the filter layer can be ensured. The facultative environment inside the filter layer provides conditions for the denitrification reaction for microbial degradation. After the nitrification and denitrification reactions, organic matters in the water body are decomposed and removed. Further, the secondary aeration biological filter can be set into more processing chambers according to the use requirement, namely a plurality of a chambers and/or a plurality of b chambers can be juxtaposed, for example, the secondary aeration biological filter is juxtaposed in an aabb mode. When a plurality of treatment chambers are juxtaposed, the water flow still forms a U-shaped trend therein, whereby the water inlet and outlet positions of the respective a and b may be varied as desired. Through the arrangement, the treatment time of water flow in the filter tank can be further prolonged, and the treatment effect is ensured. The modular structure also facilitates field installation and use. In the emergency mode, a small amount of water flow from the primary precise filter passes through the secondary biological aerated filter to keep the ecological environment in the cavity from being damaged, and in the emergency mode, aeration can be omitted.

According to the secondary aeration biological 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 better attached and fixed on the filter material and are not easy to wash away by water flow, and the microorganism quantity is effectively ensured. Meanwhile, more nitrifying bacteria are attached to the surface of the carrier under the aerobic condition, the mud age of the nitrifying bacteria can reach more than 60 days, and the denitrifying effect is good. The composite filter layer 412 in the b chamber takes various natural minerals as filter materials, and is arranged in layers from top to bottom according to the specific gravity and the thickness, and the filter precision is extremely high, so that granular and colloid organic matters and inorganic particles in polluted water bodies can be removed, and the water quality improvement effect after treatment is better.

In the secondary aeration biological filter 400, since microorganisms are mainly fixed to the surface of the filler, the total amount of microorganisms is much higher than that of the activated sludge process, and thus the impact load adaptation capacity to the change in the quality and quantity of sewage water is strong. Even if water inflow is interrupted for a short time or the process is destroyed, the performance of the biological filter is not affected fatally, and the recovery is faster. Meanwhile, the method has higher efficiency and shorter residence time, so the water quantity which can be treated is larger, and the upper limit of the requirement range for the water inflow is 3-5 times of that of the conventional aeration biological filter with the same volume. The biological membrane in the secondary aeration biological filter has lower water content than the activated sludge, the phenomenon of sludge bulking which often occurs by an activated sludge method can not occur, and the lower content of suspended matters in the effluent can be ensured, so that the operation management is more convenient. Protozoa and metazoa with higher nutrition level exist in the biological film of the secondary aeration biological filter, especially when the biological film is thicker, the anaerobic bacteria at the bottom can degrade the sludge synthesized in the aerobic process, so the output of the residual sludge is low, and the cost of sludge treatment and disposal can be reduced.

As shown in fig. 5, the tertiary precision filter 500 may include a tertiary filter water inlet 501, filler 502, a tertiary filter water outlet 503, an automatic vent valve 504, a vent valve 505, and a vent 506. The structure of the third stage precision filter 500 may be the same as that of the first stage precision filter, and thus will not be described in detail herein. The first-stage precise filter and the third-stage precise filter can increase the types and the layering quantity of the filter layers according to the requirements so as to obtain better filtering effect. Like the primary precision filter 300, in the emergency mode, the tertiary precision filter 500 functions as a fast filter, and in the lifting mode, the tertiary precision filter 500 functions as a slow filter.

Referring back to fig. 1A, in the lifting mode, to promote maximum proliferation of microorganisms, the water treatment process also includes a reflux mode (see water flow direction (8)). The reflow mode can be split into two paths: one way is that a small part of the effluent of the secondary aeration biological filter 400 flows back to the water inlet of the pretreatment tank 100, and the other way is that a small part of the effluent of the secondary aeration biological filter 400 flows back to the water inlet of the secondary aeration biological filter itself. The backflow can be realized through a separate backflow water outlet and a corresponding backflow channel on the secondary aeration biological filter 400. Each return channel includes a respective valve. When the water treatment system is switched from an emergency mode to a lifting mode, the function of the primary precise filter is switched from a rapid filter in the emergency mode to a slow filter (namely a biological filter) in the lifting mode, and most microorganisms are lost when the primary precise filter operates in the emergency mode, so that the water discharged from the secondary aeration biological filter flows back to the pretreatment tank when the lifting mode is operated, and then flows into the slow filter (namely the biological filter) from the pretreatment tank to quickly recover the microbial activity of the primary precise filter and increase biological enzymes, so that the microorganisms can be quickly proliferated when the primary precise filter operates the slow filter (biological filter), the purposes of quickly increasing the microbial quantity and improving the capability of the microorganisms to treat ammonia nitrogen and organic matters are achieved, and meanwhile, the primary precise filter has a certain capability of removing total nitrogen. When the working condition is stable in operation, the treatment efficiency is considered, the water outlet reflux of the secondary aeration biological filter can be only switched to the water inlet end of the secondary aeration biological filter, and compared with the two reflux modes which are carried out simultaneously, the flow velocity in the secondary aeration biological filter can be improved on the premise of unchanged residence time. Meanwhile, the probability and uniformity of contact between sewage and microorganisms can be improved by keeping the backflow of the effluent of the secondary aeration biological filter to the water inlet end, so that the capability of treating ammonia nitrogen and organic matters of the secondary aeration biological filter is improved. In addition, under the lifting mode, the two reflux modes can be respectively and independently or simultaneously started, so that the capability of treating ammonia nitrogen and organic matters of the precise filter and the secondary aeration biological filter can be effectively improved.

For example, the slightly polluted water treatment system according to the embodiment of the present disclosure is used for treating water in a river in a lifting mode, and the inflow rate of the treated water is 500m ³ And/d, keeping the water quality of the inlet water consistent, and comparing the treatment effects of four different backflow modes, namely that the system is not provided with backflow, only provided with backflow of the outlet water of the secondary aeration biological filter to the pretreatment tank, only provided with backflow of the outlet water of the secondary aeration biological filter to the water inlet end of the secondary aeration biological filter, and backflow of the outlet water of the secondary aeration biological filter to the water inlet end of the secondary aeration biological filter and the pretreatment tank simultaneouslyFor analysis, the water quality of the effluent in the reflux mode is basically kept stable after 15 days, and the treatment effect of the reflux mode is obvious through a comparison test. The following is the index data of each mode of effluent after 15 days, including Chemical Oxygen Demand (COD), ammonia nitrogen (N), total Nitrogen (TN), total Phosphorus (TP) and Suspended Solids (SS):

the uninterrupted data monitoring shows that the system has no reflux, only has the reflux from the water outlet of the secondary aeration biological filter to the pretreatment tank, only has the reflux from the water outlet of the secondary aeration biological filter to the water inlet end of the secondary aeration biological filter, and has the water outlet of the secondary aeration biological filter to the water inlet end of the secondary aeration biological filter and the reflux from the pretreatment tank, and the water outlet quality of the water outlet is stable after 50 days, 28 days, 26 days and 15 days respectively.

In addition, the water treatment method of the micro-polluted water body treatment system is adopted to carry out water treatment tests on river water and point source pollution respectively, and the following test results are obtained:

1. treatment of river water

In the lifting mode, the two reflux modes are adopted to treat river water in Nanjing river at the same time, and the inflow rate of treated water is 1000m ³ The ammonia nitrogen of the water quality of the inlet water is 3.358mg/L, TP 0.9mg/L, SS 50mg/L, the turbidity is 51NTU, and after treatment, the indexes of the outlet water are 0.362mg/L, TP of ammonia nitrogen, 0.2mg/L, SS of ammonia nitrogen, 3mg/L and 4.25NTU; under the emergency mode of opening after rain, the inflow water flow can reach 7500m ³ And/d, the indexes of the effluent are that the ammonia nitrogen is 0.856mg/L, TP, the ammonia nitrogen is 0.3mg/L, SS, the turbidity is 4mg/L, and the turbidity is 6.65NTU.

2. Treatment of point source pollution

In the lifting mode, the lifting mode is operated on the Nanjing point source sewage to treat river water, and the inflow rate of treated water is 1500m ³ The water quality of the inlet water is 7.25mg/L, TP, 0.8mg/L, SS, 70mg/L and turbidity is 75NTU, and the indexes of the outlet water are 0.974mg/L, TP, 0.2mg/L, SS, 5mg/L and turbidity is 6.5NTU; open after rainIn emergency mode, the water inflow can reach 10000m ³ And/d, the indexes of the effluent are 1.15mg/L, TP of ammonia nitrogen, 0.3mg/L, SS of 7mg/L and 8.45NTU of turbidity.

Generally, because of the huge difference between the parameters of river water and point source polluted water quality, the two existing water qualities generally adopt different treatment modes. Because the concentration of the pollutants polluted by the point source is relatively larger, the technology applicable to the pollution is generally poor in river water treatment effect; when the river water treatment process is used for treating point source pollution, blockage or poor treatment effect are likely to occur. However, according to the above experimental results, the water treatment process of the micro-polluted water treatment system of the present disclosure can obtain excellent and satisfactory treatment effects on the point source polluted water in addition to the micro-polluted water, so that 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, aiming at the requirements of different working conditions of high flow or high standard of the micro-polluted water body, the two modes of operation are flexibly switched, and the investment and the energy consumption are greatly saved. Aiming at black and odorous water bodies, the quality standard effect is excellent and quick from inferior V class to standard V class and standard IV class surface water environment. The highest turbidity of the water discharged by the equipment can reach 2.0NTU in the water quality emergency mode, the organic matter removal rate is high, and the ammonia nitrogen removal rate can reach 70% -90% in the water quality lifting mode. Because of the structure and process flow of the micro-polluted water body treatment system (e.g., pressure tank structure of the pretreatment tank, reflux mode in the process flow, etc.), the running cost of the system is low according to the embodiments of the present disclosure. In addition, the pretreatment tank realizes the flow of water body by utilizing a gravity flow mode, and the running cost of the system can be only 10-20% of the running cost of the same type of single-function equipment, thereby being beneficial to realizing the treatment process of green, energy-saving and environment-friendly micro-polluted water.

The foregoing is merely exemplary embodiments of the present disclosure and is not intended to limit the scope of the disclosure, which is defined by the appended claims.

Claims

1. A running method of a micro-polluted water body treatment system, wherein the micro-polluted water body treatment system comprises a pretreatment tank, a primary precise filter tank, a secondary aeration biological filter tank and a tertiary precise filter tank, wherein

The pretreatment pool is used for removing granular objects with higher density in the water body to be treated;

the first-stage precise filter and the third-stage precise filter comprise a filler which is used for intercepting inorganic particles, fine impurities and organic matters in the water body to be treated;

the secondary aeration biological filter utilizes the adsorption action of microorganisms to degrade organic matters in the water body to be treated;

the micro-polluted water body treatment system comprises a lifting mode and an emergency mode, which are switched between the lifting mode and the emergency mode according to the water quality condition of the water body to be treated, wherein in the lifting mode, water flows sequentially pass through the pretreatment tank, the primary precision filter tank, the secondary aeration biological filter tank and the tertiary precision filter tank, and a part of water flowing out of the secondary aeration biological filter tank flows back to one or both of the water inlet end of the pretreatment tank and the water inlet end of the secondary aeration biological filter tank, in the emergency mode, the water flows respectively enter the primary precision filter tank and the tertiary precision filter tank after flowing out of the pretreatment tank,

2. The method of operating a micro-polluted water treatment system as claimed in claim 1, wherein a portion of the water flow exiting the secondary biological aerated filter flows back to the water intake end of the pretreatment tank when switching from the emergency mode to the lift mode.

3. The method of operating a micro-polluted water treatment system as claimed in claim 1, wherein in the emergency mode a portion of the water flow passing through the primary precision filter enters the secondary biological aerated filter.

4. The method of operating a micro-polluted water treatment system as claimed in claim 1, wherein the micro-polluted water treatment system further comprises a dosing module for dosing a flocculant to the water flow, the dosing module dosing a flocculant to the front end of one or more of the pretreatment tank, the primary precision filter tank and the tertiary precision filter tank in the emergency mode, and the dosing module dosing a flocculant to the front end of the tertiary precision filter tank in the lifting mode.

5. A method of operating a micro-polluted water treatment system as claimed in claim 3, wherein the micro-polluted water treatment system further comprises a backwash reservoir and a clean water basin, wherein in the lifting mode the clean water basin receives a water stream flowing from the tertiary precision filter basin; in the emergency mode, the clean water tank receives water flows flowing out of the primary precise filter tank, the secondary aeration biological filter tank and the tertiary precise filter tank; the micro-polluted water body treatment system further comprises a backwashing mode, water in the clean water tank is used for backwashing the primary precision filter tank, the secondary aeration biological filter tank and the tertiary precision filter tank in the backwashing mode, water after backwashing flows into a backwashing reservoir, and supernatant in the backwashing reservoir flows back to the pretreatment tank.

6. The method of operating a micro-polluted water treatment system as claimed in claim 1, wherein the pretreatment tank further includes a water inlet system at an upper portion of the conditioning chamber including a water inlet pipe, a water distributor disposed around the water inlet pipe and an air inlet pipe passing through the water distributor, the water distributor being provided as a water distribution plate having a plurality of openings therein having a pore size smaller than a diameter of the filler in the conditioning chamber.

7. The method of operating a micro-polluted water treatment system as claimed in claim 1, wherein the pretreatment tank is installed at a position higher than the primary precision filter tank, the secondary aeration biological filter tank and the tertiary precision filter tank so that water flows into the primary precision filter tank, the secondary aeration biological filter tank and the tertiary precision filter tank under the action of gravity.

8. The method of operating a micro-polluted water treatment system as claimed in claim 1, wherein the secondary biological aerated filter includes at least one dissolved oxygen-rich chamber and at least one facultative chamber in communication, each dissolved oxygen-rich chamber including a floating packing, a retention filter material disposed in a lower portion of the chamber, a support layer supporting the retention filter material, and an aerator disposed below the retention filter material; each facultative chamber includes a composite filter layer including at least two different filter material layers.

9. The method of operating a micro-polluted water treatment system as claimed in claim 1, wherein the micro-polluted water treatment system further comprises an integrated pump house comprising a variable frequency pump which adjusts the frequency of operation in accordance with the change in the quantity of water in the water to be treated.