JP3888444B2 - Waterworks treatment facility - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a tap water treatment facility equipped with a membrane filtration device.
[0002]
[Prior art]
In recent years, problems of harmful protozoa such as Cryptosporidium and Giardia have been pointed out with the deterioration of water quality of water supply sources. Although sterilization of chlorine is required by the Waterworks Law, especially Cryptosporidium is resistant to chlorine because it is contained in a strong shell called oocysts, and removal by chlorine is hardly expected It is in.
Therefore, a membrane separation method has been proposed as another method for removing such protozoa. This membrane separation method is an effective means with less energy consumption because it does not involve a phase change compared to fractional distillation, etc., and does not produce harmful substances, and has a membrane filtration device with this membrane separation function Water treatment facilities with water supply are becoming popular.
[0003]
FIG. 3A shows a conventional tap water treatment facility 40. As shown in FIG. 3 (a), this is a tap water treatment facility 40 composed of a membrane filtration device 10 ′ alone as a device having a water purification function. In this facility, the intake pump 21 ′, the landing well 3 ′, the membrane filtration device water pump 22 ′, the membrane filtration device 10 ′, the treated water tank 8 ′, and the water purification pond are sequentially arranged from the upstream side to the downstream side. 9 ', water pump 20', and water reservoir 11 'are connected and constituted. In addition, a flow path is provided in parallel between the membrane filtration device 10 ′ and the treated water tank 8 ′, and a membrane filtration device backwash pump 23 ′ is provided on one side thereof. Furthermore, a chlorine injection means 14 'is provided between the treated water tank 8' and the water purification pond 9 '. In addition, a water purification pond is a facility for adjusting the balance between the amount of water subjected to water purification and the amount of water to be sent out, and further securing predetermined water in preparation for an accident or the like . This facility is one having the simplest structure in water complete sterilization, clarification function.
[0004]
Next, FIG. 3B shows a conventional tap water treatment facility 41 in which the membrane filtration device 10 ′ is arranged at the subsequent stage of the existing tap water treatment facility.
First, in general, the existing tap water treatment facility is, in order from the upstream side to the downstream side, the intake pump 21 ′, the landing well 3 ′, the flocculant mixing basin 4 ′ and the flock formation pond 5 ′, A sedimentation basin 6 ′, a filtration basin 7 ′, a treated water tank 8 ′, a water purification pond 9 ′, a water pump 20 ′, and a water distribution basin 11 ′ are configured to communicate with each other. In addition, a flow path is provided in parallel between the filter basin 7 ′ and the treated water tank 8 ′, and a filter basin reverse cleaning pump 24 ′ is provided on one side thereof. Further, the flocculant mixing basin 4 ′ is provided with a flocculant injection means 15 ′, and a chlorine injection means 14 ′ is provided between the treated water tank 8 ′ and the water purification tank 9 ′.
[0005]
A facility provided with a membrane filtration device 10 ′ between the treated water tank 8 ′ at the rear stage of this existing waterworks water treatment facility and the water purification basin 9 ′ is a conventional waterworks water treatment facility 41. By providing the membrane filtration device 10 ′, the membrane filtration device water pump 22 ′, the membrane filtration device 10 ′, the treatment water tank 8 ″, and the water purification tank 9 are provided along the downstream direction from the treatment water tank 8 ′. 'Is placed in communication. Further, a flow path is provided in parallel between the membrane filtration device 10 ′ and the treatment water tank 8 ″, and a membrane filtration device backwash pump 23 ′ is installed on one of the flow paths, and the treatment water tank 8 ″ and the treatment water tank are installed. Chlorine injection means 14 'is installed between 9'. Therefore, in the tap water treatment facility 41, protozoa such as Cryptosporidium and Giardia that cannot be completely removed by the existing tap water treatment facility can be completely removed.
[0006]
[Problems to be solved by the invention]
However, as shown in FIGS. 3 (a) and 3 (b), in the tap water treatment facilities 40 and 41, the membrane filtration device water pump 22 ′ for supplying the treated water under pressure to the membrane filtration device 10 ′ and It is necessary to separately provide a membrane filtration device backwash pump 23 'for backwashing the membrane filtration device 10'. Therefore, in the tap water treatment facilities 40 and 41, since the membrane filtration device water pump 22 ′ and the membrane filtration device backwash pump 23 ′ are driven, there is a problem that the operation cost becomes high.
[0007]
Then, this invention is made | formed in order to solve the said problem, and makes it a subject to provide the tap water treatment facility with low operating cost.
[0008]
[Means for Solving the Problems]
The present invention according to claim 1 is a waterworks water treatment facility provided with at least a membrane filtration device, a water reservoir, and a water supply pump, wherein the water supply pump is configured to pressurize and supply treated water to the membrane filtration device. In order to send filtered water from the membrane filtration device to the distribution reservoir, the membrane filtration device is provided in communication with the preceding stage of the distribution reservoir, and the water supply pump is communicated with the preceding stage of the membrane filtration device. In order to make it possible to use the reservoir head of the distribution reservoir for back washing of the membrane filtration device, the reservoir reservoir communicates with the filtrate side of the membrane filtration device, and the reservoir head of the distribution reservoir is the A tap water treatment facility characterized by being configured to be higher with respect to the end of a flow path formed during backwashing of a membrane filtration device .
[0009]
In addition, the water supply to the distribution reservoir means not only the water supply to the distribution reservoir but also the function of supplying water to a terminal facility such as a general household.
Therefore, the supply pressure of the water pump for pressurizing and supplying the water to be treated to the membrane filtration device can be used for the water supply to the distribution reservoir of the filtered water, and by performing membrane filtration, the operating energy of the water pump Can also be used as the pressurized water supply energy to the membrane filtration device. Therefore, in the operation of the tap water treatment facility, the electric power consumed by the membrane filtration device water pump in the conventional tap water treatment facility can be reduced. At the same time, it is not necessary to install a membrane filtration device water pump independently in a conventional waterworks water treatment facility.
[0010]
Furthermore , the water head difference can be utilized in the backwashing of the membrane filtration device. That is, it is possible to reduce the power consumed by the membrane filtration device backwash pump constituting the conventional tap water treatment facility. At the same time, there is no need to separately install a membrane filter backwash pump in a conventional tap water treatment facility.
[0011]
The present invention according to claim 2 is the tap water treatment facility, characterized in that a chlorine injection means is installed in the front stage of the membrane filtration device. Here, the chlorine injection means is a means for injecting chlorine into the filtered water to disinfect and sterilize it.
Therefore, the membrane filtration device can be operated in a system in which disinfecting chlorine is always injected, and the membrane surface of the membrane filtration device can always be kept hygienic and clean.
[0012]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.
In the description of each embodiment, the same constituent elements are denoted by the same reference numerals, and redundant descriptions are omitted.
[0013]
(Composition of waterworks water treatment facility)
First, the structure of the tap water treatment facility according to the embodiment of the present invention will be described with reference to FIGS. 1 and 2. FIG. 1 is an overall schematic diagram of a waterworks water treatment facility, and FIG. 2 is an explanatory diagram of piping conditions in the vicinity of a membrane filtration device 10.
[0014]
As shown in FIG. 1, the tap water treatment facility 1 includes a landing well 3, a flocculant mixing basin 4, a flock formation basin 5, a sedimentation basin 6, and a filtration basin 7 in order from the upstream side to the downstream side. The treated water tank 8, the water purification tank 9, the membrane filtration device 10, and the distribution reservoir 11 are configured to communicate with each other. Although the flocculant mixing basin 4, the flock formation pond 5, the sedimentation basin 6, the filtration basin 7, the treated water basin 8, and the water purification basin 9 may be omitted, the membrane filtration device 10 has a high flux. It is preferable to provide these facilities in order to operate the vehicle. The downstream side of the distribution reservoir 11 is connected to a terminal facility 12 such as a general household through a flow path. However, on the downstream side of the membrane filtration device 10, there is also a flow path that can supply water to the terminal facility 12 without going through the distribution reservoir 11.
[0015]
Further, in order to feed raw water from the water source 2 to the landing well 3, a flow path is arranged in parallel between the intake pump 21 interposed between the water source 2 and the landing well 3, and the filtration pond 7 and the treated water tank 8. Provided between the treated water tank 8 and the membrane filtration device 10. One of the flow paths is interposed between the treated water tank 9 and the membrane filtration device 10. The water pumps 20 are respectively installed.
Furthermore, a flocculant mixing means 4 such as PAC (polyaluminum chloride) is placed in the flocculant mixing basin 4, and a chlorine injection means 14 is installed between the treated water tank 8 and the water purification pond 9.
[0016]
The treated water tank 8 is a water tank that temporarily stores the water treated in the filtration pond 7.
In addition, since the water purification pond 9 is a facility for adjusting the balance between the amount of water subjected to the water purification and the amount of water to be sent out, and for securing a predetermined amount of water in preparation for an accident, the size of the water purification basin 9 is treated. It is formed as a large facility compared to the water tank 8. Moreover, there is no problem even if the treatment water tank 8 is not installed and the water purification tank 9 is also used.
[0017]
The chlorine injection means 14 installed between the treated water tank 8 and the water purification pond 9 is a means for injecting chlorine and disinfecting the filtered water. There are dry and wet injection methods. The dry method is a method of injecting vaporized chlorine directly into filtered water, and the wet method is a method of producing concentrated chlorine water and injecting it into filtered water. In using either method, it is necessary to appropriately install a pipe at a desired injection position. Moreover, when raw | natural water is very polluted, in order to suppress the increase in bacteria, you may provide the chlorine injection | pouring means 14 before the sedimentation basin 6 or the filtration basin 7 grade | etc.,.
[0018]
The membrane filtration device 10 is for completely removing protozoa such as Cryptosporidium and Giardia. In the present invention, the type of the membrane module constituting the membrane filtration device is not particularly limited, but a membrane module having a high effect of separating the protozoa is preferable.
The treated water is stored in the distributing reservoir 11, and the retained water head is configured to be higher than the end of the flow path formed at the time of back washing of the membrane filtration device 10 described later. Thereafter, the purified water is sent to a terminal facility 12 such as a general household.
[0019]
Next, with reference to FIG. 2, the piping situation near the membrane filtration apparatus 10 will be described.
First, the case where the membrane filtration apparatus 10 is comprised by the crossflow filtration type is demonstrated.
A first valve 31 is provided in the flow path L <b> 1 between the water pump 20 and the membrane filtration device 10. Further, the flow path between the first valve 31 and the membrane filtration device 10 is branched, and the branched flow path communicates with a drainage facility (not shown) via the second valve 32. Moreover, the branched flow path may be connected to the upstream part of the water purification facility.
Furthermore, a flow path L <b> 3 is provided on the downstream side of the membrane filtration device 10, and communicates with the water purification tank 9 through the third valve 33. Moreover, the flow path L3 may be connected to the flow path L4 between the water purification tank 9 and the water pump 20.
Furthermore, on the downstream side of the membrane filtration device 10, a flow path L <b> 2 is provided between the distribution reservoir 11 and the fourth valve 34. The flow path L2 communicates with the vicinity of the bottom of the distribution reservoir 11.
Each valve can be opened and closed as appropriate.
[0020]
Moreover, the membrane filtration apparatus 10 may be comprised with a dead end filtration type (whole quantity filtration type). In this case, the flow path ahead of the second valve 32 and the flow path ahead of the third valve 33 are connected to the upstream side of the drainage facility (not shown) or the water purification facility, respectively.
[0021]
Moreover, it is preferable to provide the water reservoir 11 with a water level meter for measuring the water level of the stored water so that the water storage status can be grasped. Furthermore, the flow path communicating with the distribution reservoir 11 on the downstream side of the fourth valve 34 may be branched, and water may be stored in preparation for the case where water stored in the distribution reservoir 11 ahead cannot be used as cleaning water.
[0022]
(Operation and effects of waterworks treatment facilities)
Next, the operation and effect of the membrane filtration treatment facility 1 according to the embodiment of the present invention will be described with reference to FIG.
First, the process in which raw | natural water is purified is demonstrated as a whole about the normal driving | operation of the membrane filtration water treatment facility 1. FIG.
First, raw water from a water source 2 such as a lake or river is sent to a landing well 3 by a water intake pump 21. In the landing well 3, the water level and amount of the taken-in water are adjusted and guided to the flocculant mixing basin 4. Here, a flocculant 15 such as polyaluminum chloride is added, and the raw water and the flocculant 15 are mixed by a mixer or the like. Thereafter, the flocs are formed in the floc formation pond 5 and gently stirred to promote the growth of aggregated flocs. Furthermore, after that, it is led to the sink pond 6 to sink the floc formed in the water. Then, after being guided to the filtration basin 7 and filtered, it is temporarily stored in the treated water tank 8. And after chlorine is inject | poured and sterilized by the chlorine injection | pouring means 14, it is guide | induced to the water purification basin 9, and the balance of the amount of water purified and the amount of water sent out to a downstream facility is adjusted. Thereafter, the water is pumped to the membrane filtration device 10 by the water pump 20, and protozoa such as Cryptosporidium are completely removed and stored in the distribution reservoir 11. Then, water is sent to the terminal facility 12. In addition, when there is much usage-amount of water in a terminal facility, the water may be directly sent to the terminal facility 12 without going through the reservoir 11.
[0023]
Furthermore, the opening / closing state of each valve in the vicinity of the membrane filtration device 10 and the retained water head of the reservoir 11 will be described with reference to FIG.
First, the case where the membrane filtration apparatus 10 is comprised with a crossflow filtration type | mold is demonstrated. During normal operation, the first valve 31, the third valve 33, and the fourth valve 34 are opened, and the second valve 32 is closed. Therefore, the water stored in the water purification tank 9 is sent to the membrane filtration device 10 via the first valve 31 by the operation of the water supply pump 20. Part of the water pressure-fed to the membrane filtration device 10 passes through a membrane module (not shown) constituting the membrane filtration device 10, passes through the third valve 33, passes through the flow path L <b> 3, and is purified. Return to pond 9 and circulate. Moreover, when other water passes the membrane filtration apparatus 10, it is filtered. The filtered water passes through the flow path 2 via the fourth valve 34 and is then fed into the distribution reservoir 11.
Furthermore, the reservoir head of the distributing reservoir 11 is configured to be higher (Δh) with respect to the end position of the flow path formed during backwashing of the membrane filtration device 10 to be described later.
[0024]
Furthermore, since the water pump 20 is installed between the water purification tank 9 and the membrane filtration apparatus 10, the water pump 20 can be used as a pressurizing means when water is supplied to the membrane filtration apparatus 10. Therefore, the energy for operating the water pump 20 when water is supplied to the distribution reservoir 11 can also be used as the water supply energy to the membrane filtration device 10. That is, it is not necessary to separately install and operate a water pump as a pressurizing means for the membrane filtration device 10. Therefore, it is possible to reduce the power consumed when the pump is operated separately and the cost of installing the pump separately.
[0025]
Next, the reverse cleaning of the membrane filtration device 10 will be described with reference to FIG. At the time of reverse cleaning of the membrane filtration device 10, the second valve 32 and the fourth valve 34 are opened, and the first valve 31 and the third valve 33 are closed. Therefore, when the membrane filtration device 10 is back-washed, a flow path is formed from the reservoir 11 to the drainage facility (not shown) through the fourth valve 34, the membrane filtration device 10, and the second valve 32. . At that time, the reservoir head of the reservoir 11 is stored so as to be high (Δh) with respect to the formed flow path end, so that the potential energy due to gravity flows out as a driving force. The water that flows out passes through the fourth valve 34, then back-washes the membrane surface of the membrane module (not shown) constituting the membrane filtration apparatus 10, and passes through the second valve 32 to drain the facility (not shown). To be drained. That is, since the membrane filtration device backwash pump 23 'in the conventional tap water treatment facility 41 is not required, the power consumed by the conventional membrane filtration device backwash pump 23' can be reduced.
[0026]
Further, when the membrane filtration device 10 is configured as a dead end type (total amount filtration type), during normal operation, the first valve 31 and the fourth valve 34 are opened, and the second valve 32 and the third valve 33 are Closed. When the membrane filtration device 10 is back-washed, the fourth valve 34 is opened, the first valve 31 is closed, and at least one of the second valve 32 and the third valve 33 is opened. Therefore, the membrane filtration device 10 is back-washed with the water stored in the distribution reservoir 11.
[0027]
Moreover, since the chlorine injection means 14 is installed between the treated water tank 8 and the water purification pond 9, the membrane filtration apparatus 10 is always operated in a system in which chlorine for disinfection is injected. Therefore, the membrane surface of the membrane module constituting the membrane filtration device 10 can always maintain a sanitized state.
[0028]
As mentioned above, although an example about the suitable embodiment of the present invention was explained, the present invention is not limited to the above-mentioned embodiment, and design change is possible suitably in the range which does not deviate from the meaning of the present invention.
[0029]
【The invention's effect】
According to the present invention, it is possible to provide a tap water treatment facility with low operation costs.
[Brief description of the drawings]
FIG. 1 is an overall schematic diagram of a tap water treatment facility according to an embodiment of the present invention.
FIGS. 2A and 2B are explanatory diagrams of piping conditions in the vicinity of a membrane filtration device in a waterworks water treatment facility according to an embodiment of the present invention, wherein FIG. 2A is a normal operation, and FIG. 2B is a backwashing of the membrane filtration device. It is.
FIGS. 3A and 3B are general schematic views of a conventional tap water treatment facility.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Waterworks water treatment facility 2 Water source 3 Landing well 4 Coagulant mixing pond 5 Flock formation pond 6 Sedimentation basin 7 Filtration basin 8 Treated water tank 9 Purification pond 10 Membrane filtration device 11 Distribution pond 12 Terminal facility 14 Chlorine injection means 15 Coagulant injection means 20 Water Pump 21 Water Intake Pump 22 Membrane Filtration Device Water Pump 23 Membrane Filtration Device Backwash Pump 24 Filter Pond Backwash Pump 31, 32, 33, 34 Valve 40 Conventional Waterworks Water Treatment Facility 41 Using Membrane Filtration Device Alone Membrane Conventional waterworks water treatment facilities L1, L2, L3, and L4 flow paths in which a filtration device is disposed after the existing water purification facility

Claims (2)

A tap water treatment facility comprising at least a membrane filtration device, a water reservoir, and a water pump, wherein the filtered water from the membrane filtration device is supplied by the water pump for pressurizing and supplying treated water to the membrane filtration device. In order to send water to the distribution reservoir, the membrane filtration device is provided in communication with the front stage of the distribution reservoir, and the water supply pump is provided in communication with the front stage of the membrane filtration device ,
In order to use the retained water head of the distribution reservoir for back washing of the membrane filtration device, the reservoir and the filtered water side of the membrane filtration device communicate with each other, and the retained water head of the distribution reservoir is the membrane filtration A tap water treatment facility characterized by being configured to be higher than a terminal end of a flow path formed at the time of back washing of an apparatus . The tap water treatment facility according to claim 1, wherein a chlorine injection means is installed in the front stage of the membrane filtration device.

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