Multifunctional sludge treatment system for sewage treatment plant

Abstract

The invention discloses a sewage treatment plant multifunctional sludge treatment system which comprises a multifunctional treatment pond, a PLC intelligent controller and a sludge monitoring system, the multifunctional treatment pond comprises a biochemical pond functional area and a sedimentation pond functional area, and the multifunctional treatment pond further comprises a backflow sludge pond functional area and a residual sludge pond functional area which are connected with the sedimentation pond functional area; and valves are arranged among the functional areas, and the PLC intelligent controller controls the valves to perform automatic switching and different combination of the functional areas, so that different operation modes are realized. The online monitoring system is used for monitoring conventional indexes such as sludge layer thickness, sludge particle size and settleability or characteristic biological toxicological indexes, and different operation modes are selected according to the sludge property condition, so that the property of the activated sludge in a biochemical pool of a sewage treatment plant is improved, the adaptability to the fluctuation of water quality and water quantity of inlet water is strong, and the operation is simple. The influence of the property change of the activated sludge on the subsequent process is reduced, the occupied area is reduced, and the investment and operation cost is reduced.

Description

Technical Field

[0001] The invention relates to the technical field of water treatment, and in particular to a multifunctional sludge treatment system for a sewage treatment plant. Background Art

[0002] With the development of the economy and the improvement of living standards, the increase in urban domestic water use has led to a continuous increase in sewage discharge. In addition, due to the characteristics of urban sewage, such as numerous pollution sources, dispersion and large impact load, most urban sewage cannot be effectively treated. Large-scale urban sewage treatment plants are limited by the characteristics of urban sewage and the lag in sewage pipe network construction. It is difficult to centrally treat urban sewage. At the same time, the state has put forward higher requirements for sewage treatment emission standards.

[0003] Data show that as environmental problems in my country become increasingly prominent, the national and local governments pay more and more attention to environmental protection requirements and put forward higher requirements for sewage treatment plant discharge standards. Sewage denitrification and phosphorus removal technology has become a hot spot in the research, development and application of sewage treatment. The quality of activated sludge in the biochemical pool of sewage treatment plants is an important factor affecting the effect of denitrification and phosphorus removal. The deterioration of the properties of activated sludge will lead to the instability of the sewage treatment system of the sewage treatment plant, affecting the final effluent compliance rate of the sewage treatment plant.

[0004] Chinese patent document CN113429069A discloses a "urban sewage treatment plant operation control system". It adopts: regulating tank, sewage lifting pump, sedimentation tank, anoxic tank, aerobic tank, secondary sedimentation tank, flocculation sedimentation tank, clear water tank, sludge concentration tank, sludge pump, desludging machine, variable frequency blower, alkali liquid storage tank, alkali liquid metering pump, PAC storage tank, PAC metering pump, PAM storage tank, PAM metering pump, liquid level meter, mud level meter 1, multifunctional water quality detector 1, multifunctional water quality detector 2, mud level meter 2, mud level meter 3, sedimentation tank mud discharge electric valve, mud level meter 4, secondary sedimentation tank mud discharge electric valve, flocculation sedimentation tank mud discharge electric valve, anoxic tank air intake electric valve, aerobic tank aeration electric valve. The above technical scheme is unstable in sewage treatment, which affects the final effluent compliance rate. Summary of the invention

[0005] The present invention mainly solves the technical problem that the original technical solution has unstable sewage treatment and affects the final effluent compliance rate. It provides a multifunctional sludge treatment system for a sewage treatment plant. The system monitors conventional indicators or characteristic biotoxicological indicators including mud layer thickness, sludge particle size, sedimentation properties, etc. through an online monitoring system, and selects "unified collection and return", "selective discharge of edge sludge", "selective discharge of center sludge", "selective return 1", "selective return 2" operation modes according to the sludge properties. The system improves the properties of activated sludge in the biochemical pool of the sewage treatment plant, has strong adaptability to fluctuations in influent water quality and quantity, reduces the impact of changes in the properties of activated sludge on subsequent processes, reduces land occupation, and reduces investment and operating costs.

[0006] The above technical problems of the present invention are mainly solved by the following technical solutions: the present invention comprises a multifunctional treatment tank, a PLC intelligent controller (16) and a sludge monitoring system (17), wherein the multifunctional treatment tank comprises a biochemical tank (1) functional area and a sedimentation tank (2) functional area, and further comprises a return sludge tank (3) functional area and a residual sludge tank (4) functional area respectively connected to the sedimentation tank (2) functional area, wherein valves are arranged between the functional areas, and the PLC intelligent controller (16) controls the valves to automatically switch and combine the functional areas, thereby realizing different operation modes.

[0007] The multifunctional treatment pool includes functional areas such as a biochemical pool (1), a sedimentation pool (2), a return sludge pool (3), and a residual sludge pool (4). The sludge monitoring system analyzes the sludge status by monitoring various indicators of the sludge at the bottom of the sedimentation pool. The functional areas can realize automatic switching and different combinations of the functional areas through intelligent control of valves F1 to F5. The combination of the functional areas can realize five operation modes, namely, "unified collection and return", "selective discharge of edge sludge", "selective discharge of center sludge", "selective return 1", and "selective return 2".

[0008] Preferably, the valves include valve F1 arranged between the functional area of ​​the sedimentation tank (2) and the functional area of ​​the return sludge tank (3), valve F2 arranged between the functional area of ​​the sedimentation tank (2) and the functional area of ​​the residual sludge tank (4), and valve F3, valve F4 and valve F5 arranged in the functional area of ​​the sedimentation tank (2).

[0009] The "unified collection and return" operation mode is realized by opening valves F1, F2, F3, F4, and F5. The "selective discharge of edge sludge" operation mode is realized by closing valve F2, after the liquid level of the residual sludge tank is reduced, closing valve F1, closing valve F3, closing valve F5, opening valve F2, and opening valve F4. The "selective discharge of central sludge" operation mode is realized by closing valve F2, after the liquid level of the residual sludge tank is reduced, closing valve F1, closing valve F3, closing valve F4, opening valve F2, and opening valve F5. After the "selective discharge of central sludge" operation mode is completed, the "selective return sludge 2" operation mode opens valve F3, opens valve F4, closes valve F5, opens valve F1, and after the liquid level of the sludge return tank is stable, opens valve F5. After the "selective discharge of central sludge" operation mode ends, the "selective return sludge 2" operation mode opens valve F3, opens valve F4, closes valve F5, opens valve F1, and opens valve F5 after the liquid level in the sludge return tank stabilizes.

[0010] Preferably, the functional area of ​​the sedimentation tank (2) has a circular cross-section, with the center of the functional area of ​​the sedimentation tank (2) as the center, and zones I, II and III are arranged from the inside to the outside according to different radii. The tank types applicable to the operation mode include radial flow type circumferential inlet and outlet secondary sedimentation tanks, radial flow type medium inlet and outlet secondary sedimentation tanks, horizontal flow rectangular secondary sedimentation tanks, horizontal flow rectangular circumferential inlet and outlet secondary sedimentation tanks and other types of sedimentation tanks. The sludge settles to the bottom of the tank. According to the objective law of sludge sedimentation, the activated sludge with good sedimentation settles first, and the sludge with poor sedimentation settles later. Therefore, the sludge with the strongest sedimentation settles to zone I, which is closest to the water inlet end, the sludge with moderate sedimentation settles in zone II, and the sludge with the weakest sedimentation settles in zone III. The concentration at the bottom of the sedimentation tank is generally 8000-9000 mg / L in Zone I, with an SVI value between 50-80; the concentration in Zone II is generally 8000-9000 mg / L, with an SVI value between 80-120; the sludge concentration in Zone III is generally 7000-8000 mg / L, with an SVI value above 120.

[0011] Preferably, a suction scraper is provided in the functional area of ​​the sedimentation tank (2), and the suction scraper comprises a motor arranged in the center of the functional area of ​​the sedimentation tank (2) and a mud collecting tank (6) extending from the center of the sedimentation tank (2) to the inner edge of the sedimentation tank (2). The PLC intelligent controller can set the rotation speed of the sedimentation tank suction scraper and the opening degree of valves F1 to F5, which can be controlled by time synchronization in addition to the control according to the detection instrument.

[0012] Preferably, the sludge collecting tank (6) performs circular motion with the center of the functional area of ​​the sedimentation tank (2) as the center. The whole device performs circular motion with the center of the sedimentation tank. The liquid level in the sludge collecting tank is lower than that in the sedimentation tank. The sludge at the bottom of the tank is transferred to the sludge collecting tank by static pressure and transported to the return sludge tank and the residual sludge tank through the sludge collecting tube. The PLC intelligent controller can set the rotation speed of the sedimentation tank sludge suction machine at 1-3r / min. When the mud-water interface instrument monitors that the thickness of the sludge layer in the three zones is above 0.5 meters, the speed of the sludge suction machine is controlled within 1.5r / min, and the opening of all open valves is fully open. When the thickness of the mud layer is below 0.5 meters, the speed of the sludge suction machine is controlled above 1.5r / min, the opening of the F4 valve is 1 / 2, and the other valves in the open state are fully open.

[0013] Preferably, the mud collecting tank (6) is provided with valves F3, F4 and F5, and the valves F3, F4 and F5 are connected to the mud collecting barrel (8) via a siphon (7).

[0014] Preferably, the sludge collecting barrel (8) is connected to the functional area of ​​the return sludge tank (3) and the functional area of ​​the residual sludge tank (4) respectively through the sludge pipe (5).

[0015] Preferably, the valve F3 is arranged in zone II, the valve F4 is arranged in zone III, and the valve F5 is arranged in zone I. "Uniform collection and reflux" operation mode: when the sludge concentration in zone III is 7000 mg / L or above, valves F1 to F5 are fully opened.

[0016] "Selective discharge of marginal sludge" operation mode: when the sludge concentration in zone III is below 7000 mg / L, close valve F2, and after the liquid level in the residual sludge tank is lowered, close valve F1, close valve F3, close valve F5, open valve F2, and open valve F4 to achieve the effect.

[0017] "Selective discharge of central sludge" operation mode: when the online organic matter detector in Zone I detects that the MLVSS / MLSS value is less than 0.6, close valve F2, and after the liquid level in the residual sludge tank decreases, close valve F1, close valve F3, close valve F4, open valve F2, and open valve F5 to achieve the effect.

[0018] Preferably, a central tube (9) is provided in the center of the functional area of ​​the sedimentation tank (2), and the opening of the central tube (9) faces the edge of the sedimentation tank (2). Sludge and sewage are mixed and enter the sedimentation tank, and the mud-water mixture entering the sedimentation tank is distributed to the surroundings from the central tube and discharged through the water outlet weir around the pool.

[0019] Preferably, a return sludge pump (14) is provided in the functional area of ​​the return sludge tank (3), and a residual sludge pump (15) is provided in the functional area of ​​the residual sludge tank (4).

[0020] The beneficial effects of the present invention are as follows: conventional indicators or characteristic biotoxicological indicators including mud layer thickness, sludge particle size, sedimentation properties, etc. are monitored by an online monitoring system, and the operation modes of "unified collection and return", "selective discharge of edge sludge", "selective discharge of center sludge", "selective return 1", and "selective return 2" are selected according to the properties of the sludge, so that the properties of the activated sludge in the biochemical pool of the sewage treatment plant can be improved, the adaptability to fluctuations in the quality and quantity of influent water is strong, the influence of changes in the properties of the activated sludge on subsequent processes is reduced, and the land occupation, investment and operation costs are reduced. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is a principle connection structure diagram of the present invention.

[0022] Figure 2 It is a working principle diagram of circular motion of a sedimentation tank of the present invention.

[0023] Figure 3 It is a top view of the circular motion of a sedimentation tank of the present invention.

[0024] Figure 4 It is a top view of the linear reciprocating motion of a sedimentation tank of the present invention.

[0025] Figure 5 It is a working principle diagram of the linear reciprocating motion of a sedimentation tank of the present invention.

[0026] In the figure, 1 is a biochemical tank, 2 is a sedimentation tank, 3 is a return sludge tank, 4 is a residual sludge tank, 5 is a sludge pipe, 6 is a sludge collecting tank, 7 is a siphon, 8 is a sludge collecting cylinder, 9 is a central cylinder, 14 is a return sludge pump, 15 is a residual sludge pump, 16 is a PLC intelligent controller, and 17 is a sludge monitoring system. DETAILED DESCRIPTION

[0027] In order to make the objectives, technical solutions and advantages of the present invention more clearly understood, the technical solutions of the present application are further described in detail below through embodiments and in combination with the accompanying drawings. It should be understood that the specific implementation method described here is only an optimal embodiment of the present application, which is only used to explain the present application and does not limit the protection scope of the present application. All other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0028] As environmental problems in my country become increasingly prominent, the national and local governments pay more and more attention to environmental protection requirements and put forward higher requirements for sewage treatment plant discharge standards. Sewage denitrification and phosphorus removal technology has become a hot spot in the research, development and application of sewage treatment. The quality of activated sludge in the biochemical pool of sewage treatment plants is an important factor affecting the effect of denitrification and phosphorus removal. The deterioration of the properties of activated sludge will lead to the instability of the sewage treatment system of the sewage treatment plant, affecting the final effluent compliance rate of the sewage treatment plant.

[0029] The system structure of the present invention is reasonably designed, has strong adaptability to fluctuations in influent water quality and quantity, reduces the impact of changes in activated sludge properties on subsequent processes, reduces land occupation, and reduces investment and operating costs. It also adds ways and methods for regulating the properties of activated sludge in the biochemical pool.

[0030] Before discussing the exemplary embodiments in more detail, it should be mentioned that some exemplary embodiments are described as processes or methods depicted as flow charts. Although the flow charts describe the operations (or steps) as sequential processes, many of the operations (or steps) therein can be implemented in parallel, concurrently, or simultaneously. In addition, the order of the operations can be rearranged. The process can be terminated when its operation is completed, but can also have additional steps not included in the drawings; the process can correspond to a method, function, procedure, subroutine, subprogram, etc.

[0031] The technical solution of the present invention is further specifically described below through embodiments and in conjunction with the accompanying drawings.

[0032] Embodiment: A multifunctional sludge treatment system for a sewage treatment plant in this embodiment, such as Figure 1 , Figure 2 As shown, it includes a multifunctional treatment tank, a PLC intelligent controller (16) and a sludge monitoring system (17), wherein the multifunctional treatment tank includes a biochemical tank (1) functional area and a sedimentation tank (2) functional area, and also includes a return sludge tank (3) functional area and a residual sludge tank (4) functional area respectively connected to the sedimentation tank (2) functional area, wherein a return sludge pump (14) is provided in the return sludge tank (3) functional area, and a residual sludge pump (15) is provided in the residual sludge tank (4) functional area. Valves are provided between the functional areas, and the PLC intelligent controller (16) controls the valves to automatically switch and combine the functional areas, thereby realizing different operation modes.

[0033] The multifunctional treatment pool includes functional areas such as a biochemical pool (1), a sedimentation pool (2), a return sludge pool (3), and a residual sludge pool (4). The sludge monitoring system analyzes the sludge status by monitoring various indicators of the sludge at the bottom of the sedimentation pool. The functional areas can realize automatic switching and different combinations of the functional areas through intelligent control of valves F1 to F5. The combination of the functional areas can realize five operation modes, namely, "unified collection and return", "selective discharge of edge sludge", "selective discharge of center sludge", "selective return 1", and "selective return 2".

[0034] The valves include a valve F1 arranged between a functional area of ​​a sedimentation tank (2) and a functional area of ​​a return sludge tank (3), a valve F2 arranged between a functional area of ​​a sedimentation tank (2) and a functional area of ​​a residual sludge tank (4), and valves F3, F4 and F5 arranged in the functional area of ​​the sedimentation tank (2).

[0035] The "unified collection and reflux" operation mode is achieved by opening valve F1, valve F2, valve F3, valve F4, and valve F5.

[0036] The "selective discharge of marginal sludge" operation mode is achieved by closing valve F2, lowering the liquid level in the residual sludge tank, closing valve F1, closing valve F3, closing valve F5, opening valve F2, and opening valve F4.

[0037] The "selective discharge of central sludge" operation mode is achieved by closing valve F2, lowering the liquid level in the residual sludge tank, closing valve F1, closing valve F3, closing valve F4, opening valve F2, and opening valve F5.

[0038] After the "selective discharge of central sludge" operation mode ends, the "selective return sludge 2" operation mode opens valve F3, opens valve F4, closes valve F5, opens valve F1, and opens valve F5 after the liquid level in the sludge return tank stabilizes.

[0039] After the "selective discharge of central sludge" operation mode ends, the "selective return sludge 2" operation mode opens valve F3, opens valve F4, closes valve F5, opens valve F1, and opens valve F5 after the liquid level in the sludge return tank stabilizes.

[0040] like Figure 3 As shown, the cross section of the functional area of ​​the sedimentation tank (2) is circular, with the center of the functional area of ​​the sedimentation tank (2) as the center of the circle, and areas I, II and III are set from the inside to the outside according to different radii. The tank types applicable to the operation mode include radial flow type peripheral inlet and peripheral outlet secondary sedimentation tank, radial flow type medium inlet and peripheral outlet secondary sedimentation tank, horizontal flow rectangular secondary sedimentation tank, horizontal flow rectangular peripheral inlet and peripheral outlet secondary sedimentation tank and other types of sedimentation tanks. The functional area of ​​the sedimentation tank can also be as follows Figure 4 , Figure 5 The figure shows a rectangle, and the mud collecting trough performs linear reciprocating motion.

[0041] A central cylinder (9) is provided in the center of the functional area of ​​the sedimentation tank (2), and the opening of the central cylinder (9) faces the edge of the sedimentation tank (2). Sludge and sewage are mixed and enter the sedimentation tank. The mud-water mixture entering the sedimentation tank is distributed to the surrounding areas from the central cylinder and discharged through the water outlet weir around the tank. The mud collecting cylinder (8) is connected to the functional area of ​​the return sludge tank (3) and the functional area of ​​the residual sludge tank (4) respectively through the sludge pipe (5).

[0042] The sludge settles to the bottom of the pool. According to the objective law of sludge settling, the activated sludge with good settling performance settles first, and the sludge with poor settling performance settles later. Therefore, the sludge with the strongest settling performance settles to Zone I, which is closest to the water inlet end, the sludge with moderate settling performance settles to Zone II, and the sludge with the weakest settling performance settles to Zone III. Valve F3 is set in Zone II, valve F4 is set in Zone III, and valve F5 is set in Zone I. The concentration at the bottom of the sedimentation tank is generally 8000-9000 mg / L in Zone I, and the SVI value is between 50-80, the concentration value in Zone II is generally 8000-9000 mg / L, and the SVI value is between 80-120, and the sludge concentration value in Zone III is generally 7000-8000 mg / L, and the SVI value is above 120.

[0043] "Uniform collection and return" operation mode: When the sludge concentration in zone III is 7000 mg / L or above, valves F1 to F5 are fully opened.

[0044] "Selective discharge of marginal sludge" operation mode: when the sludge concentration in zone III is below 7000 mg / L, close valve F2, and after the liquid level in the residual sludge tank is lowered, close valve F1, close valve F3, close valve F5, open valve F2, and open valve F4 to achieve the effect.

[0045] "Selective discharge of central sludge" operation mode: when the online organic matter detector in Zone I detects that the MLVSS / MLSS value is less than 0.6, close valve F2, and after the liquid level in the residual sludge tank decreases, close valve F1, close valve F3, close valve F4, open valve F2, and open valve F5 to achieve the effect.

[0046] The PLC instrument collects data from the sludge concentration meter and the organic matter online detection instrument. The sludge concentration meter monitors the sludge concentration data of Zones I and III. When the sludge concentration value of Zone III is lower than 7000 mg / L, the "select edge sludge" operation mode is started. The operation time is 2 hours. After the end, it returns to the "unified collection and reflux" state. After 2 hours, the sludge concentration of Zone III is monitored again. If the sludge concentration value is still lower than 7000 mg / L, the "select edge sludge" operation mode is started again. If the value is 7000 mg / L or above, it is kept in the "unified collection and reflux" state. "Uniform collection and return" status; when the MLVSS / MLSS value detected by the online organic matter detector in Zone I is less than 0.6, the "selective discharge of central sludge" operation mode is started. The operation time is 2 hours. After the end, it is restored to the "uniform collection and return" status. The sludge concentration in Zone I is monitored again 2 hours later. If the MLVSS / MLSS value detected by the online organic matter detector is still less than 0.6, the "selective discharge of central sludge" operation mode is continued to be started. If the MLVSS / MLSS value is greater than or equal to 0.6, it is restored to the "uniform collection and return" status.

[0047] A suction and scraper is provided in the functional area of ​​the sedimentation tank (2), and the suction and scraper comprises a motor arranged at the center of the functional area of ​​the sedimentation tank (2) and a mud collecting tank (6) extending from the center of the sedimentation tank (2) to the inner edge of the sedimentation tank (2). The PLC intelligent controller can set the rotation speed of the suction and scraper of the sedimentation tank and the opening degree of valves F1 to F5, and can be controlled by time synchronization in addition to the control according to the detection instrument.

[0048] The sludge collecting tank (6) performs circular motion with the center of the functional area of ​​the sedimentation tank (2) as the center. The whole device performs circular motion with the center of the sedimentation tank. The liquid level in the sludge collecting tank is lower than the liquid level in the sedimentation tank. The sludge at the bottom of the tank is transferred to the sludge collecting tank by static pressure and transported to the return sludge tank and the residual sludge tank through the sludge collecting tube. The PLC intelligent controller can set the rotation speed of the sedimentation tank sludge suction machine to 1-3r / min. When the mud-water interface meter detects that the thickness of the sludge layer in the three zones is above 0.5 meters, the speed of the sludge suction machine is controlled within 1.5r / min, and the opening of all open valves is fully opened. When the thickness of the mud layer is below 0.5 meters, the speed of the sludge suction machine is controlled to be above 1.5r / min, the opening of the F4 valve is 1 / 2, and the other valves in the open state are fully opened. The sludge collecting tank (6) is provided with valves F3, F4 and F5. The valves F3, F4 and F5 are connected to the sludge collecting tube (8) through a siphon (7).

[0049] Example 1 A multifunctional sludge treatment tank of a sewage treatment plant and its intelligent operation mode, comprising a biochemical tank (1), a sedimentation tank (2), a return sludge tank (3), a residual sludge tank (4), a PLC intelligent controller (16), and a sludge monitoring system (17). The multifunctional treatment tank comprises functional areas such as a biochemical tank (1), a sedimentation tank (2), a return sludge tank (3), and a residual sludge tank (4). The sludge monitoring system analyzes the sludge condition by monitoring various indicators of sludge at the bottom of the sedimentation tank. The functional areas can realize automatic switching and different combinations of the functional areas through intelligent control of valves F1 to F5. The combination of the functional areas can realize five operation modes, namely, "unified collection and return", "selective discharge of edge sludge", "selective discharge of center sludge", "selective return 1", and "selective return 2".

[0050] The "unified collection and reflux" operation mode is achieved by opening valve F1, valve F2, valve F3, valve F4, and valve F5.

[0051] The "selective discharge of marginal sludge" operation mode is achieved by closing valve F2, lowering the liquid level in the residual sludge tank, closing valve F1, closing valve F3, closing valve F5, opening valve F2, and opening valve F4.

[0052] The "selective discharge of central sludge" operation mode is achieved by closing valve F2, lowering the liquid level in the residual sludge tank, closing valve F1, closing valve F3, closing valve F4, opening valve F2, and opening valve F5.

[0053] After the "selective discharge of central sludge" operation mode ends, the "selective return sludge 2" operation mode opens valve F3, opens valve F4, closes valve F5, opens valve F1, and opens valve F5 after the liquid level in the sludge return tank stabilizes.

[0054] After the "selective discharge of central sludge" operation mode ends, the "selective return sludge 2" operation mode opens valve F3, opens valve F4, closes valve F5, opens valve F1, and opens valve F5 after the liquid level in the sludge return tank stabilizes.

[0055] The PLC intelligent controller can set the rotation speed of the sedimentation tank suction machine and the opening degree of valves F1 to F5. In addition to control according to the detection instrument, it can also be controlled by time synchronization. Function of the PLC intelligent controller: The PLC instrument collects data from the sludge concentration meter and the organic matter online detection instrument. The sludge concentration meter monitors the sludge concentration data of Zones I and III. When the data received that the sludge concentration value of Zone III is lower than 7000mg / L, the "select edge sludge discharge" operation mode is started. The operation time is 2 hours. After the end, it will return to the "unified collection and reflux" state. After 2 hours, the sludge concentration of Zone III will be monitored again. If the sludge concentration value is still lower than 7000mg / L, the "select edge sludge discharge" operation mode will continue to be started. If the value is between 7000mg / L and When the above is in progress, it remains in the "unified collection and return" state; when the MLVSS / MLSS value detected by the online organic matter detector in Zone I is less than 0.6, the "selective discharge of central sludge" operation mode is started, and the operation time is 2 hours. After the end, it is restored to the "unified collection and return" state. The sludge concentration in Zone I is monitored again 2 hours later. If the MLVSS / MLSS value detected by the online organic matter detector is still less than 0.6, the "selective discharge of central sludge" operation mode is continued to be started. If the MLVSS / MLSS value is greater than or equal to 0.6, it is restored to the "unified collection and return" state.

[0056] The multifunctional sludge treatment tank of a sewage treatment plant and its intelligent operation mode, the monitoring indicators of the sludge online monitoring system include conventional indicators or characteristic biological toxicological indicators such as mud layer thickness, sludge particle size, and sedimentation, and the operation mode is determined according to the nature of the sludge. The operation switching form adopts valves or gates, including various other forms. The tank types applicable to the operation mode include radial flow type peripheral inlet and peripheral outlet secondary sedimentation tank, radial flow type medium inlet and peripheral outlet secondary sedimentation tank, horizontal flow rectangular secondary sedimentation tank, horizontal flow rectangular peripheral inlet and peripheral outlet secondary sedimentation tank and other forms of sedimentation tanks. The realization of the operation mode includes various other operation modes that can be realized by opening or closing all valves in this system. Valves F1~F5 include those realized by adding valves or other measures.

[0057] Example 2 In this implementation case, if Figure 2 As shown in the figure, after the sewage enters the biochemical pool, the activated sludge in the biochemical pool fully mixes with the sewage and reacts. The activated sludge absorbs the pollutants in the sewage and increases its value. The pollution degree of the sewage is reduced. The concentration of activated sludge in the biochemical pool is 3500mg / L, and the SVI value is generally between 50-150. Figure 1 , sludge and sewage are mixed and enter the sedimentation tank. The mud-water mixture entering the sedimentation tank is distributed from the central tube to the surrounding areas, and the water is discharged through the outlet weir around the pool; the sludge settles to the bottom of the pool. According to the objective law of sludge sedimentation, the activated sludge with good sedimentation settles first, and the sludge with poor sedimentation settles later. Therefore, the sludge with the strongest sedimentation settles to the area closest to the water inlet end, the sludge with moderate sedimentation settles in the area II, and the weakest sedimentation settles to the area III. The concentration at the bottom of the sedimentation tank is generally 8000-9000 mg / L in area I, and the SVI value is between 50-80, the concentration value in area II is generally 8000-9000 mg / L, and the SVI value is between 80-120, and the sludge concentration value in area III is generally 7000-8000 mg / L, and the SVI value is above 120. The sludge concentration meter equipped with PLC can regularly monitor the sludge concentration at the bottom of the pool once an hour, and the sludge interface meter can regularly monitor the mud level in each area once an hour.

[0058] The conventional operation mode is adopted. At this time, the system is in a closed state and does not require the intervention of the intelligent control system. That is, the "unified collection and reflux" operation mode is achieved by opening valves F1, F2, F3, F4 and F5.

[0059] When the system is turned on, the sludge concentration value of Zone III is generally monitored to be 7000-8000 mg / L. When the SVI value is above 120, the "selective discharge of edge sludge" operation mode is realized by closing valve F2, reducing the liquid level of the residual sludge tank, closing valve F1, closing valve F3, closing valve F5, opening valve F2, and opening valve F4. After the equipment goes around the sedimentation tank, the mode is turned off and switched to the "selective discharge of center sludge" operation mode by closing valve F2, reducing the liquid level of the residual sludge tank, closing valve F1, closing valve F3, closing valve F4, opening valve F2, and opening valve F5. PLC intelligent controller. The "PLC intelligent controller" can set the rotation speed of the sedimentation tank sludge scraper at 1-3r / min. The mud-water interface meter monitors that when the sludge layer thickness in the third zone is above 0.5m, the speed of the sludge scraper is controlled within 1.5r / min, and the opening of all open valves is fully open. When the sludge layer thickness is below 0.5m, the speed of the sludge scraper is controlled above 1.5r / min, the opening of F4 valve is 1 / 2, and the other valves in the open state are fully open.

[0060] like Figure 3 The whole equipment moves in a circle with the center of the sedimentation tank. The liquid level in the sludge collecting tank is lower than that in the sedimentation tank. The sludge at the bottom of the tank is pressed into the sludge collecting tank by static pressure and then transported to the return sludge tank and the residual sludge tank through the sludge collecting cylinder.

[0061] The specific embodiments described herein are merely examples of the spirit of the present invention. The above embodiments only express several implementation methods of the present application, and the descriptions thereof are relatively specific and detailed, but they cannot be construed as limiting the scope of the present application. It should be noted that a technician in the technical field to which the present application belongs may make various modifications or supplements to the described specific embodiments or replace them in a similar manner, but will not deviate from the spirit of the present application or exceed the scope defined in the attached claims. For a person of ordinary skill in the art, multiple variations and improvements may also be made without departing from the concept of the present application. Therefore, the scope of protection of this patent shall be subject to the attached claims.

Claims

1. A multifunctional sludge treatment system for a sewage treatment plant, characterized in that: The invention comprises a multifunctional treatment tank, a PLC intelligent controller (16) and a sludge monitoring system (17). The multifunctional treatment tank comprises a biochemical tank (1) functional area and a sedimentation tank (2) functional area, and also comprises a return sludge tank (3) functional area and a residual sludge tank (4) functional area respectively connected to the sedimentation tank (2) functional area. Valves are arranged between the functional areas. The PLC intelligent controller (16) controls the valves to automatically switch and combine the functional areas, thereby realizing different operation modes.

2. A multifunctional sludge treatment system for a sewage treatment plant according to claim 1, characterized in that: The valves include a valve F1 arranged between the functional area of ​​the sedimentation tank (2) and the functional area of ​​the return sludge tank (3), a valve F2 arranged between the functional area of ​​the sedimentation tank (2) and the functional area of ​​the residual sludge tank (4), and valves F3, F4 and F5 arranged in the functional area of ​​the sedimentation tank (2).

3. A multifunctional sludge treatment system for a sewage treatment plant according to claim 2, characterized in that: The cross section of the functional area of ​​the sedimentation tank (2) is circular, with the center of the functional area of ​​the sedimentation tank (2) as the center of the circle, and area I, area II and area III are arranged from the inside to the outside according to different radii.

4. A multifunctional sludge treatment system for a sewage treatment plant according to claim 3, characterized in that: A sludge scraper is provided in the functional area of ​​the sedimentation tank (2), and the sludge scraper comprises a motor arranged at the center of the functional area of ​​the sedimentation tank (2) and a sludge collecting trough (6) extending from the center of the sedimentation tank (2) to the inner edge of the sedimentation tank (2).

5. A multifunctional sludge treatment system for a sewage treatment plant according to claim 4, characterized in that: The mud collecting trough (6) performs a circular motion with the center of the functional area of ​​the sedimentation tank (2) as the center of the circle.

6. A multifunctional sludge treatment system for a sewage treatment plant according to claim 4, characterized in that: The mud collecting tank (6) is provided with valves F3, F4 and F5, and the valves F3, F4 and F5 are connected to the mud collecting barrel (8) via a siphon (7).

7. A multifunctional sludge treatment system for a sewage treatment plant according to claim 6, characterized in that: The sludge collecting cylinder (8) is respectively connected to the functional area of ​​the return sludge tank (3) and the functional area of ​​the residual sludge tank (4) through the sludge pipe (5).

8. A multifunctional sludge treatment system for a sewage treatment plant according to claim 3, 4, 5 or 6, characterized in that: The valve F3 is arranged in zone II, the valve F4 is arranged in zone III, and the valve F5 is arranged in zone I.

9. A multifunctional sludge treatment system for a sewage treatment plant according to claim 1, 2 or 3, characterized in that: A central tube (9) is provided at the center of the functional area of ​​the sedimentation tank (2), and the opening of the central tube (9) faces the edge of the sedimentation tank (2).

10. A multifunctional sludge treatment system for a sewage treatment plant according to claim 1, 2 or 3, characterized in that: A return sludge pump (14) is provided in the functional area of ​​the return sludge tank (3), and a surplus sludge pump (15) is provided in the functional area of ​​the surplus sludge tank (4).

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