JPH10192853A - Waste water treatment apparatus, membrane filter apparatus therefor and membrane filter method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a waste water treatment apparatus capable of reducing water cleaning treatment cost by reducing operation cost by reducing membrane filter differential pressure. SOLUTION: Waste water from a water treatment plant is once stored in a conditioning basin 1 to be supplied to a raw water tank 3 subjecting waste water to sedimentation treatment to discharge the same and the treated water of the raw water tank 3 is supplied to a membrane filter apparatus 5 constituted of a precise filter membrane, and ultrafiltration filter membrane or a reverse osmosis membrane to be filtered. At this time, the waste heat from an independent power plant 12 is supplied to a heat transfer pipe or wall 13 provided to the raw water tank 3 and the raw water in the raw water tank 3 is heated to be lowered in its viscosity to reduce the load of a membrane filter pump 4.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a wastewater treatment apparatus for treating sludge water such as sand filtration backwash wastewater generated from a water purification plant, and more particularly to a membrane filtration apparatus for the wastewater treatment apparatus and a membrane filtration method therefor. is there.

[0002]

2. Description of the Related Art FIG. 4 is a diagram showing a conventional wastewater treatment apparatus using a membrane filtration membrane. The sand filtration backwash wastewater from the water treatment plant and the sludge drawn out from the coagulation sedimentation basin are supplied to the regulating pond 1 shown in FIG.
It is led to. Sludge water guided to the regulating pond 1 is treated by a wastewater treatment device using a filtration membrane. Regulating pond 1
The drainage inside is supplied to the raw water tank 3 by the drainage pump 2. The raw water in the raw water tank 3 is sent to the membrane module 5 by the membrane filtration pump 4 and is filtered. The membrane filtration flow rate at this time is a constant flow filtration operation by the constant flow valve 6. When membrane filtration is performed continuously, turbid components gradually accumulate on the membrane surface, and the membrane pressure difference increases. The differential pressure rise is measured by the differential pressure gauge 7, and when the differential pressure gauge 7 reaches about 100 KPa, the membrane filtration pump 4 is stopped, the valve 8 is opened, and pressurized air is introduced from the membrane filtration side. The turbid components deposited on the surface are peeled off. Thereafter, the valve 8 is closed to shut off the supply of the pressurized air, the valve 9 is opened, and the turbid water in the membrane module 5 is supplied to the flash tank 10 by operating the membrane filtration pump 4 to be condensed. It is returned to the raw water tank 3. The sludge deposited at the lower part of the raw water tank 3 is pulled out continuously or at an appropriate time by opening the valve 11 installed at the lower part of the raw water tank 3.

[0003]

However, when the wastewater generated in the water purification plant is filtered at a constant flux using a membrane, the membrane differential pressure in winter becomes higher than that in summer. As a result, the differential pressure of the membrane module 5 increases, which increases the load on the membrane filtration pump 4, increases power consumption, and increases the cost of water purification treatment.

In winter, the differential pressure of the membrane module 5 increases, the load on the membrane filtration pump 4 increases, and power consumption increases. This is because the viscosity of the treated water in winter increases because the temperature of the membrane filtration water in winter is lower than that in summer. Generally, the relationship between the membrane filtration flux and the membrane differential pressure can be expressed by equation (1).

ΔP = Jv · μ / K (1)

ΔP: Membrane differential pressure [KPa], Jv: Membrane filtration flux [m / day] μ: Water viscosity [Pa · s], K: Membrane module constant

[0007] The viscosity of water changes with temperature. Water temperature is 2
In summer, when the temperature is about 7 ° C, the viscosity of water is 854 [μPa ·
s], in winter when the water temperature is about 7 ° C.,
35 [μPa · s]. That is, when membrane filtration is performed at a uniform flux, the membrane differential pressure is about 1.7 times higher in winter when the water temperature is low than in summer when the water temperature is high. Therefore, in winter, there is a problem that the power cost of the membrane filtration pump is increased and the cost of water purification is increased.

[0008] The present invention has been made in view of the above problems, and a wastewater treatment apparatus capable of reducing the operation cost and the water purification treatment cost by reducing the membrane filtration differential pressure.
An object of the present invention is to provide a membrane filtration device and a membrane filtration method thereof.

[0009]

SUMMARY OF THE INVENTION The present invention has been made to achieve the above object, and in the wastewater treatment apparatus using the filtration membrane according to the first aspect of the present invention, waste heat from a private power generator is removed. As a heat source, the raw water is heated, and is characterized by being subjected to filtration by a microfiltration membrane, an ultrafiltration membrane or a reverse osmosis membrane. This is a wastewater treatment device capable of reducing the filtration pressure difference.

Further, in the wastewater treatment apparatus using the filtration membrane according to the second aspect of the present invention, the waste heat from the private power generator
A raw water tank provided with a heat exchange means for heating the raw water, and a heated raw water sent from the raw water tank, a microfiltration membrane,
With an ultrafiltration membrane or a reverse osmosis membrane, a filtration device for performing a filtration treatment, characterized in that, in the present invention,
This is a wastewater treatment apparatus capable of reducing the membrane filtration differential pressure by heating the raw water in the raw water tank by providing the raw water tank with heat exchange means using the exhaust heat of the private power generator as a heat source.

Further, in the wastewater treatment apparatus using the filtration membrane according to the third aspect of the present invention, the wastewater treatment apparatus includes a raw water tank, a microfiltration membrane, an ultrafiltration membrane, or a reverse osmosis membrane, and discharges waste heat from the private power generator. A heat exchange unit as a heat source, which heats the raw water sent from the raw water tank, and performs a filtration process; and in the present invention, the membrane filtration device is provided with a private generator. The wastewater treatment apparatus is provided with a heat exchange means using waste heat as a heat source, thereby heating raw water to reduce a membrane filtration differential pressure.

Further, the wastewater treatment apparatus of the invention according to claim 4 is:
The invention according to claim 2 or 3, wherein the heat exchanging means comprises a heat transfer pipe or a heat transfer wall installed in a raw water tank or a filtration membrane, and steam and hot water or exhaust gas from a cooling system of the private power generator. Is supplied to a waste heat boiler, and at least one of the obtained steam is selected and supplied or circulated. In the present invention, steam or hot water from a cooling system of a private generator is transferred to a heat transfer tube or a heat transfer wall. This is a wastewater treatment apparatus that can reduce the membrane filtration differential pressure by heating raw water by circulating it inside.

According to a fifth aspect of the present invention, there is provided the wastewater treatment apparatus according to the first, second or third aspect, wherein the private power generator is a diesel engine, a gas engine and a gas engine using city gas, heavy oil or the like as fuel. The present invention is a waste heat treatment apparatus characterized in that the waste heat is generated from a private power generator such as a turbine, and the waste heat from a cooling water system can be easily circulated to a heat exchange unit.

[0014] In the membrane filtration method using a microfiltration membrane, an ultrafiltration membrane or a reverse osmosis membrane according to the invention of claim 6,
The waste heat from the private power generator is used as a heat source, and the raw water in the filtration membrane is heated and filtered by the filtration membrane.In the present invention, the temperature of the raw water can be increased, so that the filtration membrane difference is increased. This is a membrane filtration method capable of reducing pressure.

According to a seventh aspect of the present invention, there is provided the membrane filtration method according to the sixth aspect, wherein the waste heat is steam or hot water from a cooling water system of the private power generator, Steam produced by directing exhaust gas to a waste heat boiler, characterized in that at least one of these or a combination thereof is used as a heat source. In the present invention, the action of the private power generator and the action of the heat exchanger are mutually This is a membrane filtration method used.

Further, the invention according to claim 8 is a membrane filtration device for a wastewater treatment device comprising a microfiltration membrane, an ultrafiltration membrane or a reverse osmosis membrane, wherein the membrane filtration device is provided on the side where treated water is supplied. The present invention is characterized by having a heat transfer tube or a heat transfer wall, and in the present invention, a membrane filtration device for a wastewater treatment device for treating sludge water in a water purification plant, which can heat and filter treated water at a low temperature. .

[0017]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of a wastewater treatment apparatus according to a first embodiment of the present invention; FIG. 1 shows an embodiment of a wastewater treatment apparatus according to the present invention. In this wastewater treatment apparatus, sand filtration backwash wastewater generated in a water purification plant and sludge drawn out from a coagulation sedimentation tank and the like are guided to a regulating pond 1. It is a device that treats this wastewater with a filtration membrane.

In FIG. 1, a wastewater treatment device is a regulating pond 1.
A raw water tank 3 for supplying wastewater from the raw water tank 2 to condense and discharge sludge, a membrane module (membrane filtration device) 5 for supplying wastewater from the raw water tank 3 from a membrane filtration pump 4,
In the back washing step, there is provided a flash tank 10 which supplies polluting substances adhering to the filtration membrane through a valve 9 provided in a pipe connected to the polluted water side 5a of the membrane filtration device 5 to make condensed sludge. The membrane filtration device 5 is provided with a valve 8 for supplying pressurized air to the filtered water side 5b, and a constant flow valve 6 for taking out the membrane filtered water. Membrane filtration device 5
A pressure sensor for measuring the pressure on the polluted water side 5a and the filtered water side 5b is provided, and a differential pressure gauge 7 for detecting a difference between the outputs of the pressure sensors is provided. The raw water tank 3 is provided with a heat transfer tube or a heat transfer wall 13.
Is connected by a pipe to a jacket cooling system 12a of a private generator 12 such as a gas engine. The exhaust gas from the private generator 12 is guided to a waste heat boiler 14. Membrane filtration device 5
Refers to wastewater with a microfiltration membrane (hereinafter referred to as MF membrane), ultrafiltration membrane (hereinafter referred to as UF membrane) or reverse osmosis membrane (hereinafter referred to as MF membrane)
RO membrane).

The wastewater treatment of the wastewater treatment apparatus of the present embodiment is as follows.
Wastewater containing sludge from the water treatment plant is sent to the regulating pond 1. The drainage (raw water) in the regulating pond 1 is supplied to the raw water tank 3 by the drain pump 2, and the raw water heated in the raw water tank 3 is passed through the membrane filtration pump 4 to the polluted water side of the filtration membrane device 5. 5a. Raw water and filtered water filtered by a filtration membrane are obtained through a constant flow valve 6. Further, in the membrane filtration device 5, at the time of back washing of the filtration membrane, the pressurized air is supplied to the filtration water side 5 b via the valve 8, the contaminants adhering to the filtration membrane are separated, and the membrane is flushed via the valve 9. The water is supplied to the tank 10, condensed, and the treated water is sent to the raw water tank 3.

The private power generator 12 used in this water purification plant
Is a gas engine using city gas as a fuel. The electric power is used as electric power for a pump and the like in a water purification plant, and a combustion exhaust gas of about 600 ° C. discharged from the gas engine is guided to a waste heat poirer 14 to generate 7 kg / High pressure steam of about 2 cm2 is produced and used as a heat source for drying sludge. Furthermore, the jacket cooling system 12a of the private generator 12 of the gas engine
Produces low-pressure steam of 1 Kgcm 2 from water at 9 ° C., guides the low-pressure steam to the heat transfer tube 13, where it is cooled until it returns to water at 90 ° C. The wastewater in the raw water tank 3 is changed by the membrane filtration device 5
Filtered.

At this time, the membrane filtration flow rate is set to a constant flow filtration operation by the constant flow valve 7. When performing membrane filtration continuously,
As the turbid component accumulates on the membrane surface, the membrane differential pressure increases, and the increase in the differential pressure is detected by the differential pressure gauge 7. Differential pressure gauge 7 is 1
When the pressure reaches about 00 KPa, the membrane filtration pump 4 is stopped, the valve 8 is opened, and pressurized air is introduced from the membrane filtration side to separate the turbid component deposited on the membrane surface from the membrane surface. Then, the valve 8 is closed, the valve 9 is opened, and the membrane filtration pump 4 is operated so that the contaminated water in the filtration membrane device 5 is passed through the flash tank 10 and then supplied to the raw water tank 3. Sludge deposited at the lower part of the raw water tank 3 is pulled out continuously or at an appropriate time by opening the valve 11 installed at the lower part of the raw water tank 3.

The waste heat generated from the private power generator in the commercial power generation process is supplied to a device for performing membrane filtration of waste water, and the membrane filtered water is heated to lower the viscosity of the raw water, thereby reducing the viscosity of the membrane filtration device. The power cost of the filtration pump can be reduced.
As a result, the efficiency of using thermoelectric power in the regular power generation process using the private power generator is increased. As a result, the operation cost is reduced by performing the regular power generation process, and the cost of water purification is reduced accordingly.

In addition, while at least part of a private generator such as a diesel engine, a gas engine, and a gas turbine using city gas or heavy oil as fuel is constantly operated to generate power, waste heat generated from the private generator is generated. Is used to heat the raw water. The heat recovery method is as follows: low-pressure steam or hot water from the jacket cooling water system 12a of the private power generator 12, exhaust gas from the private power generator 12 to the exhaust heat
In addition, there is a method in which the exhaust gas from the private power generator 12 is directly used as a heat source, and one of these heat sources or a combination thereof is used as a heat source.

Next, a waste water treatment apparatus according to another embodiment of the present invention will be described with reference to FIG. In the above embodiment, the heat transfer tube or the heat transfer wall 13 is provided in the raw water tank 3. However, in the present embodiment, the contaminated water side 5 of the filtration membrane device 5 is provided.
a. The pipe connected to the jacket cooling system 12 a of the private generator 12 is a heat transfer pipe or a heat transfer wall 13.
The exhaust gas is supplied to the waste heat boiler 14, and the high pressure steam of the waste heat boiler 14 is used for drying sludge. The other configuration is the same as that of the embodiment of FIG. 1, and the description of the configuration is omitted.

A waste water treatment apparatus according to another embodiment of the present invention will be described with reference to FIG. In the embodiment of FIG. 3, the exhaust gas from the waste heat boiler 14 is directly supplied to the raw water tank 3 for use. Other configurations are the same as those of the embodiment of FIG.

As described above, in the present embodiment, power is generated by operating a private generator such as a diesel engine, a gas engine, and a gas turbine using city gas or heavy oil as fuel, and is used as power for a water purification plant. Waste heat generated from the private power generator is used as a heat source for a raw water tank and a membrane filtration device. The wastewater treatment apparatus performs a wastewater treatment by heating raw water supplied to the membrane filtration apparatus and supplying the heated raw water to the membrane filtration apparatus to reduce the viscosity of the raw water.

As a method of recovering exhaust heat from the private generator, a method of producing steam or hot water from a cooling water system of an engine, a method of producing steam by introducing exhaust gas from a private generator to a waste heat boiler, A method of using exhaust gas from a generator directly as a heat source may be used alone or in combination. Therefore, if a raw water tank and a membrane filtration device are installed adjacent to the private power generator, there is an advantage that the waste heat can be effectively used.

[0028]

As described above, according to the present invention,
The waste heat generated by the private power generator using the private power generator heats the wastewater and supplies it to the membrane filtration device, or heats the wastewater in the membrane filtration device, so that the operating cost of the wastewater treatment device can be reduced. It has the effect and also has the effect of reducing the cost of water purification.

[Brief description of the drawings]

FIG. 1 is a diagram showing one embodiment of a water treatment apparatus of the present invention.

FIG. 2 is a diagram showing an embodiment of the water treatment apparatus of the present invention.

FIG. 3 is a diagram showing an embodiment of the water treatment apparatus of the present invention.

FIG. 4 is a diagram showing an example of a conventional water treatment device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Regulating pond 2 Drain pump 3 Raw water tank 4 Membrane filtration pump 5 Membrane module 5a Sludge water supply side 5b Filtration water side 6 Constant flow valve 7 Differential pressure gauge 8, 9 valve 10 Flash tank 11 valve 12 Private power generator 13 Heat transfer pipe 14 Discharge Heat boiler

Claims (8)

[Claims] 1. A wastewater treatment apparatus using a filtration membrane, wherein the raw water is heated using waste heat from a private power generator as a heat source, and the wastewater is filtered through a microfiltration membrane, an ultrafiltration membrane, or a reverse osmosis membrane. Characterized wastewater treatment equipment. 2. A wastewater treatment apparatus using a filtration membrane, comprising: a raw water tank provided with heat exchange means for heating raw water by waste heat from a private power generator; and a heated water sent from the raw water tank. A wastewater treatment device comprising: a membrane filtration device for filtering raw water with a microfiltration membrane, an ultrafiltration membrane, or a reverse osmosis membrane. 3. A wastewater treatment apparatus using a filtration membrane, comprising: a raw water tank, a microfiltration membrane, an ultrafiltration membrane, or a reverse osmosis membrane, and heat exchange means using heat exhausted from a private generator as a heat source. And a membrane filtration device for heating and filtering the raw water sent from the raw water tank. 4. The wastewater treatment apparatus according to claim 2, wherein the heat exchange means includes a heat transfer pipe or a heat transfer wall installed in a raw water tank or a filtration membrane, and a cooling system for the private power generator. Waste water treatment apparatus characterized in that at least one of steam obtained by introducing steam and hot water or exhaust gas from a steam to a waste heat boiler is selected and supplied or circulated. 5. The wastewater treatment apparatus according to claim 1, wherein the private power generator is generated from a private power generator such as a diesel engine, a gas engine, and a gas turbine using city gas or heavy oil as a fuel. Wastewater treatment equipment characterized by waste heat. 6. A membrane filtration method using a microfiltration membrane, an ultrafiltration membrane or a reverse osmosis membrane, wherein waste heat from a private power generator is used as a heat source, raw water in the filtration membrane is heated, and A membrane filtration method characterized by performing filtration. 7. The membrane filtration method according to claim 6, wherein the exhaust heat is steam or hot water from a cooling water system of the private power generator, or steam produced by guiding exhaust gas of the private power generator to a waste heat boiler. Wherein at least one of these or a combination thereof is used as a heat source. 8. A membrane filtration device for a wastewater treatment device comprising a microfiltration membrane, an ultrafiltration membrane or a reverse osmosis membrane, wherein a heat transfer tube or a heat transfer wall is provided on the side of the membrane filtration device to which treated water is supplied. A membrane filtration device for a wastewater treatment device, comprising: