SEWAGE REUSE SYSTEM
BACKGROUND
(a) Field of the Invention
The present invention relates to a sewage reuse system which introduces a part
of sewage from a plurality of places along a sewer trunk line; performs a sewage
treatment; and supplies reuse water to the neighborhood.
(b) Description of the Related Arts
Conventionally, sewage flowing through a sewer trunk line is treated by a
terminal sewage treatment plant in order to generate reuse water. The generated reuse
water is supplied to an area on the upstream side. However, the supply of reuse water
has become a problem for an area that is far away from the terminal sewage treatment
plant but needs water.
Then, in recent years, satellite treatment plant, by which sewage can be
effectively treated and reused, is put into use. Fig. 4 is an explaining diagram showing
a structure of a plurality of satellite treatment plants. As shown in Fig. 4, there is a
sewer trunk line 3. A terminal sewage treatment plant 2 is arranged at the end of the
sewer trunk line 3, and a plurality of satellite treatment plants 1 are distributed along
the sewer trunk line 3. Each satellite treatment plant 1 introduces a part of sewage
flowing through the sewer trunk line 3; purifies the sewage in order to generate reuse
water; then supplies the generated reuse water to an area that is in the neighborhood
of the satellite treatment plant 1 and is in demand for reuse water.
However, because such conventional satellite treatment plant is often located in
an urban district where it is difficult to secure ample setting space, it has become a
problem to miniaturize the setting space as much as possible.
As disclosed in the Japanese Patent Publication No. 2008-705, the present
applicant once proposed a sewage treatment apparatus used in such satellite
treatment plant. The Japanese Patent Publication No. 2008-705 describes a sewage
treatment apparatus which performs a sewage treatment through combining a
high-rate filtering means with a membrane separation active-sludge treating means.
According to the sewage treatment apparatus disclosed in the Japanese Patent
Publication No. 2008-705, it is possible to miniaturize the setting space of the whole
treatment apparatus, as well as to generate reuse water with high purity.
However, it is necessary to generate reuse water according to the demand of the
neighborhood. Furthermore, it is also necessary to prepare water tanks for temporarily
storing the generated reuse water according to different purities. Because of that, there
is an important project to generate reuse water and control water storing quantity of
reuse water according to the demand for reuse water, but this project has not been
considered in the Japanese Patent Publication No. 2008-705 mentioned above.
SUMMARY OF THE INVENTION
Therefore, in order to accomplish the project mentioned above, the present
invention aims to control the water storing quantity of reuse water which is generated
by a sewage treatment apparatus of a satellite treatment plant. Furthermore, the
present invention also aims to control and adjust water storing quantities in a plurahty
of sewage treatment apparatuses by a unified management.
An aspect of the invention is to provide a sewage reuse system, which distributes
a plurality of reuse water supply sections, each includes a water introducing opening
formed in a sewer trunk line." a treated sewage tank for storing reuse water that has
been generated through a sewage treatment; and a water level sensor for measuring a
water level of the treated sewage tank, in a demand area of reuse water along the
sewer trunk line, comprising"• a movable sewage treatment section which moves to any
of the plurality of water introducing openings, performs the sewage treatment to
generate reuse water, and supplies the generated reuse water to the treated sewage
tank; a communication section which transmits the water level data measured by the
water level sensor; and a central control section which controls a water storing
quantity of the treated sewage tank on the basis of the demand information of reuse
water and the water level data received from the communication section.
As a result, the central control section can move the sewage treatment section to
one of the reuse water supply sections, which is located in a demand area of reuse
water, on the basis of the demand information of reuse water.
Further, the sewage treatment section includes^ a water introducing portion
which is connected to the water introducing opening in order to introduce a part of
sewage; a membrane separation active-sludge portion which performs a biological
treatment on the sewage in order to generate a first treated sewage; and a membrane
highly treating portion which performs a membrane high treatment on the first treated
sewage in order to generate a second treated sewage.
Further, the treated sewage tank consists of a membrane treating tank which
stores the first treated sewage; and a membrane highly treating tank which stores the
second treated sewage.
Further, the reuse water supply section includes a draining opening which
drains a concentration liquid produced by the membrane highly treating portion or/and
a surplus sludge produced by the membrane separation active-sludge portion back to
the sewer trunk line downstream from the water introducing opening.
Further, the sewage treatment section further includes a power supply which
supplies the membrane separation active-sludge portion and membrane highly
treating tank with electricity, and a heating part which makes use of waste heat
released from the power supply to heat the membrane separation active-sludge portion.
According to such sewage reuse system of the present invention, on the basis of
the demand information of reuse water, the temperature, and the water level data, it is
possible to generate reuse water through the movable sewage treatment section, and
control water storing quantities of a plurality of treated sewage tanks by a unified
management.
Further, it is also possible to control the water storing quantity of the treated
sewage tank by moving the sewage treatment section to a demand area of reuse water
in order to perform the sewage treatment and supply the treated sewage tank with
reuse water, according to the demand for reuse water. As a result, there is no need to
install a plurality of sewage treating devices all over the demand area of reuse water.
Further, it is also possible to generate and store reuse water with different
purities, according to the demand information of reuse water.
Further, it is also possible to drain the surplus sludge produced by the
membrane separation active-sludge portion or/and the concentration liquid produced
by the membrane highly treating portion back to the sewer trunk line via the draining
opening which is formed downstream from the water introducing opening. As a result,
there is no need to install other treating device in additional for treating the surplus
sludge or/and the concentration liquid, so that the setting space of the whole apparatus
of the sewage treatment section 40 can be miniaturized.
Further, because the waste heat released from the power supply is collected and used
for heating the membrane separation active-sludge portion, it is possible to raise the
efficiency of the biological treatment by adjusting the temperature to a suitable temperature.
BRIEF DESCRIPTION OF THE DRAWINGS
Fig. 1 is a summary diagram showing a structure of a sewage reuse system of
the present invention.
Fig. 2 is an explaining diagram of a reuse water supply section and a sewage
treatment section.
Fig. 3 is an explaining diagram of a sewage treatment section reusing waste
heat.
Fig. 4 is an explaining diagram showing a structure of a plurality of satellite
treatment plants in prior art.
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described in detail hereinbelow
with reference to the drawings.
Fig. 1 is a summary diagram showing a structure of a sewage reuse system of
the present invention. Fig. 2 is an explaining diagram of a reuse water supply section
and a sewage treatment section. Fig. 3 is an explaining diagram of a sewage treatment
section reusing waste heat.
The sewage reuse system 10 of the present invention mainly comprises a
plurality of reuse water supply sections 20, one or more sewage treatment sections 40,
a communication section 60, and a central control section 80.
The plurality of reuse water supply sections 20 are distributed along a sewer
trunk line 3, and each reuse water supply section 20 consists of a water introducing
opening 22 formed in the sewer trunk line 12, a treated sewage tank for storing reuse
water that is generated through a sewage treatment, and a water level sensor for
measuring the water level of the treated sewage tank.
Furthermore, reuse water can be used as, for example, environment water in
parks, water for melting snow, toilet water, sprinkling water, gardening water,
domestic water in emergency and so on.
The treated sewage tank which is an attachment to the water introducing
opening 22 consists of at least 2 tanks, and is used for storing reuse water with
different purities respectively, according to the demand for reuse water. As an example,
the treated sewage tank of the present embodiment consists of a membrane treated
sewage tank 26 and a membrane highly treated sewage tank 28 (as shown in Fig. 2).
The membrane treated sewage tank 26 is used for storing the reuse water (i.e.
first treated sewage) that has been treated through a biological treatment performed
by an aftermentioned membrane separation active-sludge portion 46 comprised in the
sewage treatment section 40. The membrane treated sewage tank 26 comprises a
supply pipe and a draining pipe. The supply pipe supplies the reuse water to an area
where reuse water is in demand, and the draining pipe drains the reuse water stored in
the tank back to the sewer trunk line 12.
The membrane highly treated sewage tank 28 is used for storing the reuse water
(i.e. second treated sewage) that has been treated through a membrane separation
treatment performed by an aftermentioned membrane highly treating portion 50
comprised in the sewage treatment section 40. The membrane highly treated sewage
tank 28 comprises a supply pipe and a draining pipe. The supply pipe supplies the
reuse water to an area where reuse water is in demand, and the draining pipe drains
the reuse water stored in the tank back to the sewer trunk line 12.
For measuring the water level (water storing quantity) of reuse water, water
level sensors 24 are installed in both the membrane treated sewage tank 26 and the
membrane highly treated sewage tank 28.
Each reuse water supply section 20 further comprises a draining opening 23
which is used for draining "sediment", surplus sludge, and concentration liquid that
will be referred afterwards back to the sewer trunk line 12. The draining opening 23 is
formed in the sewer trunk line 12 downstream from the water introducing opening 22.
The sewage treatment section 40 mainly comprises a water introducing portion
42, a pretreating portion 44, a membrane separation active-sludge portion 46, a
membrane highly treating portion 50, and a power supply 54. The sewage treatment
section 40 can be mounted in a vehicle to move from one reuse water supply section 20
to another.
The water introducing portion 42 is connected to the water introducing opening
22 formed in the sewer trunk line 12, and supplies a part of sewage to the pretreating
portion 44 which will be referred afterwards. The introducing portion 42 is formed, for
example, by an electromagnetic valve or a suction pump.
The pretreating portion 44 is used for removing "sediment" from the sewage
through a pretreatment before a sewage treatment which will be performed afterwards.
For example, fiber filtering material, screen and other materials can be used as the
pretreating portion 44. In details, the pretreating portion 44 separates and removes
floating trash included in the sewage as "sediment", by letting the sewage flow through
the fiber filtering material or the screen. The pretreating portion 44 comprises a
draining pipe 45 which drains the "sediment" collected during the process of the
pretreatment back to the sewer trunk line 12. The draining pipe 45 is connected to the
draining opening 23 which is formed in the sewer trunk line 12 downstream from the
water introducing opening 22. The drained "sediment" will be treated by a terminal
sewage treatment plant arranged at the end of the sewer trunk line 12.
The membrane separation active-sludge portion 46 mainly comprises an
anaerobic tank 48 and an aerobic tank 49. The anaerobic tank 48 is located in the
upstream side, and the aerobic tank 49 is located next to the anaerobic tank 48 in the
downstream side. The sewage is introduced from the pretreating portion 44 into the
anaerobic tank 48, and the anaerobic tank 48 performs a biological treatment through
active-sludge in order to generate treated sewage (i.e. the first treated sewage). Then,
the first treated sewage is introduced into the aerobic tank 49, and the aerobic tank 49
performs a membrane separation through flat membrane soaked in the tank in order to
separate the active-sludge from the first treated sewage. Afterwards, the first treated
sewage is introduced to the membrane highly treating portion 50 or the membrane
treated sewage tank 26 which will be referred afterwards. In the membrane separation
active-sludge portion 46, surplus sludge is produced as a result of the growth of the
active-sludge during the process of the biological treatment. The membrane separation
active-sludge portion 46 comprises a draining pipe 47 which drains the surplus sludge
back to the sewer trunk line 12. The draining pipe 47 is connected to the draining
opening 23 which is formed in the sewer trunk line 12 downstream from the water
introducing opening 22. The drained surplus sludge will be treated by a terminal
sewage treatment plant. Further, although as an example, the aerobic tank 49 of the
present embodiment has been described as using flat membrane as a separation
method, any other hollow thread membrane can also be used and the material of the
membrane is not restrict as long as the active-sludge can be separated from the first
treated sewage.
The membrane highly treating portion 50 is used for generating reuse water
with high purity according to different uses of the reuse water. For example, reverse
osmosis membrane (RO) and/or Nan filtration membrane (NF) can be used in the
membrane highly treating portion 50. The reverse osmosis membrane (RO) or the Nan
filtration membrane (NF) is fixed in the flow path of the first treated sewage, so that it
is possible to purify the first treated sewage by letting it flow through the membrane.
The reverse osmosis membrane can remove inorganic molecules from the first treated
sewage to generate treated sewage (i.e. second treated sewage) that has the same
purity as drinking water. Comparatively, the Nan filtration membrane can remove
pigment components from the first treated sewage to generate second treated sewage
that is transparent. In the membrane highly treating portion 50, during the process of
the membrane treatment, concentration liquid is produced as an incidental product
besides the generation of reuse water. The membrane highly treating portion 50
comprises a draining pipe 51 to drain the concentration liquid back to the sewer trunk
line 12. The draining pipe 51 is connected to the draining opening 23 which is formed in
the sewer trunk line 12 downstream from the water introducing opening 22. The
drained concentration liquid wiU be treated by a terminal sewage treatment plant.
As shown in Fig. 2, the power supply 54 supplies electric power to the water
introducing portion 42, the pretreating portion 44, the membrane separation
active-sludge portion 46, and the membrane highly treating portion 50. For example, a
fuel cell, or a family use generator such as a solar power source or a wind power source
can be used as the power supply 54.
Furthermore, the power supply 54 comprises a waster heat collecting part 56.
The power supply 54 releases heat in the course of generating electricity. In the present
invention, the released heat (i.e. waster heat) is collected by the waster heat collecting
part 56, and is used in the sewage treatment.
As shown in Fig. 3, the waster heat collecting part 56 collects the waste heat
released from the generator of the power supply 54 and temporarily stores it in a heat
accumulating device. The waster heat collecting part 56 is connected with a plurality of
heating parts. An embodiment of the heating part has a structure described below. The
waster heat collecting part 56 is connected with a dispersing part 53 which is mounted
in the aerobic tank 49 of the membrane separation active-sludge portion 46. The
dispersing part 53 bubbles hot air into the aerobic tank 49 so that the sewage which is
being treated in the aerobic tank 49 can be heated to a proper temperature for
biological treatment. As a result, the efficiency of the biological treatment performed
through the active-sludge can be raised accordingly. Otherwise, the heating method of
the heating part is not limit to the dispersing part 53 as long as the treated sewage and
the reuse water can be heated.
Furthermore, because the "sediment" that is newly produced by the sewage
treatment section 40, the surplus sludge, and the concentration liquid are all drained
back to the sewer trunk line 12 downstream from the water introducing opening, there
is no need to install extra treating device. As a result, the setting space of the whole
apparatus of the sewage treatment section 40 can be miniaturized.
Each water level sensor 24 comprises a data sending source, and the central
control section 80 which will be referred afterwards comprises a data receiving source.
The communication section 60 is a wired or wireless network which connects all the
data sending sources with the data receiving source. As an example, there are a
plurality of relay stations distributed among the communication section 60 according to
the distance between those data sending sources and the data receiving source, and a
wireless network system, such as a mobile system or a Wireless LAN, is used as the
means of communication of the communication section 60. As another example, the
communication section 60 comprises a data relaying portion 62, which collects the
water level data of the treated sewage tank in the reuse water supply section 20 and
performs necessary data processing for data transmission.
The data transmitted from the data sending source of the water level sensor 24
is the water storing quantity (water level data) of the membrane treated sewage tank
26 and the membrane highly treated sewage tank 28.
The central control section 80 mainly comprises a wireless receiver, a data
processing unit, and a monitor, and controls driving states of the treated sewage tank
by a unified management. Specifically, the central control section 80 receives data of
driving state from each treated sewage tank via the wireless receiver. Further, the
demand information of reuse water and the weather information in the neighborhood
of the satellite treatment plant are inputted into the data processing unit of the central
control section 80. On the basis of such information, the central control section 80
controls and adjusts the water storing quantity of each treated sewage tank.
The sewage reuse system 10, which has the structure described above, works in
the following way. The water level data of the membrane treating tanks 26 and the
membrane highly treating tanks 28 located in each water supply sections 20 is
measured by a couple of water level sensor 24, then is transmitted to the central
control section 80 via the communication section 60. Although in this embodiment, the
water level data is transmitted directly to the central control section 80 via the
communication section 60, the water level data can also be transmitted first to the data
relaying portion 62 and be temporarily remembered there. In the second case, after the
data relaying portion 62 performs a data processing which is necessary for data
transmission, the water level data is transmitted to the central control section 80 via
the communication section 60.
The communication section 60 works in the following way. Firstly, the data
sending source sends data to all relay stations that are in reach. Then each of the relay
stations forwards the received data to other relay stations that are in reach. By
repeating the step described above, the data can be transmitted to the data receiving
source of the central control section 80.
The demand information of reuse water in the neighborhood of the reuse water
supply section 20 and the weather information are inputted into the central control
section 80. When the water storing quantity of a treated sewage tank, which is located
in a demand area of reuse water, is insufficient according to the demand information of
reuse water, the central control section 80 controls the sewage treatment section 40 to
perform the sewage treatment in order to increasing the water introducing quantity of
the treated sewage tank to a desired quantity.
The sewage treatment section 40 works in the following way. Sewage is
introduced from the sewer trunk linel2 into the pretreating portion 44 through the
water introducing portion 42. The pretreating portion 44 separates and removes the
"sediment" included in the sewage in order to reduce the burden of the membranes
treatment performed in the membrane separation active-sludge portion 46 afterwards.
The collected "sediment" is drained via the draining pipe 45 to the draining opening 23
formed in the sewer trunk line 12 downstream from the water introducing opening 22.
The sewage that has been treated by the pretreating portion 44 is introduced into the
membrane separation active-sludge portion 46.
The membrane separation active-sludge portion 46 performs the biological
treatment to generate the first treated sewage through the active-sludge that has been
adjusted to a required concentration in the anaerobic tank 48 located in the forepart of
the membrane separation active-sludge portion 46. Then, the sewage that has been
treated by the active-sludge is introduced into the aerobic tank 49 located next to the
anaerobic tank 48, and is separated from the active-sludge by flat membrane soaked in
the aerobic tank 49. The surplus sludge, which is produced as a result of the growth of
the active-sludge during the process of the biological treatment, is drained back to the
sewer trunk line 12 via the draining pipe 47. A part of the first treated sewage is
introduced into the membrane highly treating portion 50, while the remaining is
introduced into the membrane treating tank 26 and temporarily stored there as reuse
water before using.
In the membrane highly treating portion 50, to generate the second treated
sewage with a purity higher than that of the first treated sewage, the reverse osmosis
membrane and/or the Nan filtration membrane is put into use according to different
uses of reuse water. The second treated sewage, which is generated through the
purification treatment, is introduced into the membrane highly treating tank 28 and
temporarily stored there as reuse water before using. Such reuse water has a purity
higher than that of the first treated sewage generated through the active-sludge.
Moreover, the power supply 54 supplies the water introducing portion 42, the
pretreating portion 44, the membrane separation active-sludge portion 46, and the
membrane highly treating portion 50 with electricity. The waster heat released from
the generator is collected and stored by the waster heat collecting part 56. Further, the
waster heat collecting part 56 is connected with the dispersing part 53 mounted in the
aerobic tank 49 of the membrane separation active-sludge portion 46, and the
dispersing part 53 bubbles hot air into the aerobic tank 49. As a result, the sewage
which is being treated in the aerobic tank 49 can be heated to a proper temperature for
biological treatment.
When the water storing quantity of a treated sewage tank, which is located in a
demand area of reuse water, is insufficient according to the demand information of
reuse water, the central control section 80 moves a movable sewage treatment section
40, for example a vehicle with a sewage treating device mounted on, to the demand
area of reuse water.' connects the water introducing portion 42 to the water introducing
opening 22 of the reuse water supply section 20 located in this area; and lets the
sewage treatment section 40 perform the sewage treatment to generate reuse water.
Then the generated reuse water is supplied to the treated sewage tank attached to the
water introducing opening 22, and is stored there.
Moreover, the central control section 80 is able to control and adjust the water
storing quantity on the basis of the use history of reuse water.
When the water storing quantity of a treated sewage tank, which is located in a
demand area of reuse water, is considered to be insufficient on the basis of the use state
of reuse water or the weather information, the central control section 80 moves the
sewage treatment section 40; lets it work to generates reuse water; and stores the
reuse water in the treated sewage tank.
Moreover, the central control section 80 is also able to moves the sewage
treatment section 40 to a demand area of reuse water, in order to generate and store
reuse water on the basis of a demand forecasting which can be predicted on the basis of
the yearly use history of reuse water or the weather information.
With such sewage reuse system, it is possible to control water storing quantities
of a plurality of treated sewage tanks by a unified management." and adjust the water
storing quantity of the reuse water generated by the sewage treatment section 40
according to the demand for reuse water. It is also possible to control the water storing
quantity of the treated sewage tank by moving the sewage treatment section 40 to a
demand area of reuse water to generated reuse water according to the demand
information of reuse water and the weather information. As a result, there is no need to
install a plurality of sewage treating devices all over the demand area of reuse water.
¦WHAT IS CLAIMED ID:
1. A sewage reuse system, which distributes a plurality of reuse water supply
sections each includes a water introducing opening formed in a sewer trunk line; a
treated sewage tank for storing reuse water that has been generated through a sewage
treatment; and a water level sensor for measuring a water level of said treated sewage
tank, in a demand area of reuse water along said sewer trunk line, comprising:
a movable sewage treatment section which moves to any of said plurality of
water introducing openings, performs said sewage treatment to generate reuse water,
and supplies the generated reuse water to said treated sewage tank;
a communication section which transmits said water level data measured by
said water level sensor; and
a central control section which controls a water storing quantity of said treated
sewage tank on the basis of the demand information of reuse water and said water
level data received from said communication section.
2. The sewage reuse system according to claim 1,
wherein said central control section moves said sewage treatment section to one
of said reuse water supply sections, which is located in a demand area of reuse water,
on the basis of said demand information of reuse water.
3. The sewage reuse system according to claim 1 or 2,
wherein said sewage treatment section includes-'
a water introducing portion which is connected to said water introducing
opening in order to introduce a part of sewage;
a membrane separation active-sludge portion which performs a biological
treatment on said sewage in order to generate a first treated sewage; and
a membrane highly treating portion which performs a membrane high
treatment on said first treated sewage in order to generate a second treated sewage.
4. The sewage reuse system according to claim 3,
wherein said treated sewage tank consists of
a membrane treating tank which stores said first treated sewage; and
a membrane highly treating tank which stores said second treated sewage.
5. A sewage reuse system, which distributes a plurality of reuse water supply
sections, each includes a water introducing opening formed in a sewer trunk line! a
treated sewage tank for storing reuse water that has been generated through a sewage
treatment; and a water level sensor for measuring a water level of said treated sewage
tank, in a demand area of reuse water along said sewer trunk line, comprising:
a movable sewage treatment section which moves to any of said plurality of
water introducing openings, performs said sewage treatment to generate reuse water,
and supplies the generated reuse water to said treated sewage tank;
a communication section which transmits said water level data measured by
said water level sensor; and
a central control section which controls a water storing quantity of said treated
sewage tank on the basis of the demand information of reuse water and said water
level data received from said communication section,
wherein said sewage treatment section includes:
a water introducing portion which is connected to said water introducing
opening in order to introduce a part of sewage;
a membrane separation active-sludge portion which performs a biological
treatment on said sewage in order to generate a first treated sewage; and
a membrane highly treating portion which performs a membrane high
treatment on said first treated sewage in order to generate a second treated sewage,
wherein said central control section moves said sewage treatment section to one
of said reuse water supply sections, which is located in a demand area of reuse water,
on the basis of said demand information of reuse water,
wherein said treated sewage tank consists of
a membrane treating tank which stores said first treated sewage; and
a membrane highly treating tank which stores said second treated sewage.
6. The sewage reuse system according to claim 1, 2 or 5,
wherein said reuse water supply section includes a draining opening which
drains a concentration liquid produced by said membrane highly treating portion
or/and a surplus sludge produced by said membrane separation active-sludge portion
back to said sewer trunk line downstream from said water introducing opening.
7. The sewage reuse system according to claim 1, 2 or 5,
wherein said sewage treatment section further includes;
a power supply which supplies said membrane separation active-sludge portion
and membrane highly treating tank with electricity, and
a heating part which makes use of waste heat released from said power supply
to heat said membrane separation active-sludge portion.

The present patent aims to control and adjust water storing quantities of a
plurality of treated sewage tanks distributed along a sewer trunk line by a unified
management. The sewage reuse system of the present invention distributes a plurality
of reuse water supply sections, each consisting of a water introducing opening formed
in a sewer trunk line; a treated sewage tank for storing reuse water that has been
generated through a sewage treatment; and a water level sensor for measuring a water
level of the treated sewage tank, in a demand area of reuse water along the sewer
trunk line, and comprises: a movable sewage treatment section which moves to any of
the plurality of water introducing openings; performs the sewage treatment to generate
reuse water; and supplies the generated reuse water to the treated sewage tank, a
communication section which transmits the water level data measured by the water
level sensor, and a central control section which controls a water storing quantity of the
treated sewage tank on the basis of the demand information of reuse water and the
water level data received from the communication section.