WO2002098800A1

WO2002098800A1 - Bioreactor for sewage and wastewater treatment

Info

Publication number: WO2002098800A1
Application number: PCT/KR2002/001055
Authority: WO
Inventors: Wan-Pyo Hong; Jin-Man Kim; Ki-Seung Choi; Hi-Weon Jung; Soon-Jong Hahn; Jong-Taek Kim
Original assignee: Sk Chemicals Co., Ltd.
Priority date: 2001-06-04
Filing date: 2002-06-03
Publication date: 2002-12-12
Also published as: JP4079876B2; KR100698549B1; EP1392608A1; KR20020094245A; ATE355256T1; CN1389408A; US7329539B2; US20030175948A1; CN1251980C; JP2004520082A; DE60218453T2; DE60218453D1; EP1392608B1

Abstract

The present invention relates to a bioreactor for sewage and wastewater treatment, which is capable of agitating and supplying oxygen simultaneously. A bioreactor of the present invention, comprises a culture drum in which microorganisms are cultured; a supplier for supplying a culture solution, and organic and inorganic media to the culture drum, the supplier including a supply tube connected to an upper side of the culture drum, and a pump connected to the supply tube for supplying the culture solution to the culture drum; an agitator for agitating the culture solution by spraying air into the culture solution in the culture drum, the air being supplied from an air blower; and a thermostatic controller for controlling a temperature of the culture solution and disinfecting the interior of the culture drum.

Description

BIOREACTOR FOR SEWAGE AND WASTEWATER TREATMENT

BACKGROUND OF THE INVENTION

(a) Field of the invention

The present invention relates to a reactor for culturing microorganism

used for treating sewage and wastewater, and more particularly to a

bioreactor for sewage and wastewater treatment, in which the bioreactor is

capable of agitating and supplying oxygen simultaneously.

(b) Description of the Related Art

Generally, methods of treating wastewater include a physical-

chemical method and a biological method. The drawbacks of the physical-

chemical method include high costs and the need to re-treat the products,

while the biological method produces a relatively little amount of product

after treatment by resolving a large amount of organism elements into

carbon dioxide to be stabilized, or by removing organic matters contained in

wastewater with the generation of methane gas.

In the biological treatment method, pollutants in wastewater can be

resolved, detoxified, and separated by using mainly microorganisms.

Hence, the method is applied to treat industrial sewage containing organic

matter and sludge generated therefrom, and to secondarily treat life sewage.

Due to the relatively low cost and the variations of work progress, the

biological method has been most widely used all over the world. Microorganisms that play a core role in biological treatment are mixed

cultures including various microorganism populations such as bacteria, fungi,

protozoa, and metazoa, which are cultured and multiplied in a bioreactor.

Such microorganisms cleanse sewage and wastewater by resolving and

removing organic pollutants, which nourish the microorganisms, while the

microorganisms multiply using oxygen dissolved in wastewater.

The bioreactor is a device that provides conditions similar to those

found in nature to allow facultative microorganisms to be efficiently cultured.

The bioreactor supplies a culture solution, organic and inorganic media, and

air to the inside of the bioreactor, and cultures and multiplies the

microorganisms.

Since the bioreactor is directly related to the culture and multiplication

of microorganisms, the efficiency of sewage and wastewater treatment or the

activation state of microorganisms depends on the bioreactor.

As a prior art method to enhance the efficiency of sewage and

wastewater treatment by employing a bioreactor, published PCT Application

WO 96/15992 discloses a method of treating sewage by injecting four types

of aerobic and anaerobic microorganisms into an aeration tank without

exhausting unpleasant odors, noxious gases, and toxic substances.

However, the above-described method is not used to multiply

microorganisms in the aeration tank, and instead is used for removing

noxious gases, etc. by applying specific microorganisms obtained from nature to the sewage sludge. A drawback of the method is that it takes long

time for the injected microorganisms to treat the sludge.

U.S. Pat. No. 5,376,275 discloses an activated sludge treatment

process, wherein a sewage sludge component is fermented for a period of at

least 15 days to form soluble carbonaceous substrates, the fermented

sludge component is contacted with influent sewage to form a conditioned

sewage, and the conditioned sewage is supplied to the activated sludge

plant.

However, the above-described process is not used for multiplying

microorganisms in the fermentation plant, and instead is used for the

dephosporization and denitrification of the sludge by using microorganisms.

This method also has the drawback that it takes long time, for example, from

15 days to 60 days, to treat the sludge.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a bioreactor for

sewage and wastewater treatment which is capable of agitating and

supplying oxygen simultaneously.

It is still yet another object of the present invention to provide a

bioreactor for sewage and wastewater treatment which is capable of

accomplishing disinfection and culture through a swift change of temperature.

It is still yet another object of the present invention to provide a

bioreactor for sewage and wastewater treatment which is capable of minimizing heat efflux.

It is still yet another object of the present invention to provide a

bioreactor for sewage and wastewater treatment which is capable of bringing

an aeration solution of an external wastewater disposal plant into the

bioreactor to ease the culture of microorganisms.

It is still yet another object of the present invention to provide a

bioreactor for sewage and wastewater treatment which is capable of easily

activating the microorganisms.

In order to achieve the objects, a bioreactor according to a preferred

embodiment of the present invention includes a culture drum in which

microorganisms are cultured; a supplier for supplying a culture solution, and

organic and inorganic media to the culture drum; and an agitator for agitating

the culture solution while injecting air into the culture drum.

The present invention further includes a thermostatic controller

provided in the culture drum, the thermostatic controller being for controlling

a temperature of the culture solution.

The supplier includes a supply tube connected to an upper side of

the culture drum, and a pump for supplying the culture solution to the culture

drum, the pump being connected to the supply tube. The supplier may also

include a valve for opening and shutting the supply tube, and a pressure

gauge.

The agitator includes an air blower for air supply, an injection pipe provided in the culture drum for injecting the air supplied from the air blower

to the culture drum, and an injection nozzle arranged on the injection pipe in

a predetermined direction for circulating the culture solution in the culture

drum.

The thermostatic controller includes a low temperature heater and a

high temperature heater provided in the culture drum, and a heater controller.

BRIEF DESCRIPTION OF THE DRAWINGS

A more complete appreciation of the invention, and many of the

attendant advantages thereof, will be readily apparent as the same becomes

better understood by reference to the following detailed description when

considered in conjunction with the accompanying drawings, wherein:

Fig. 1 is a schematic view of a bioreactor according to a preferred

embodiment of the present invention.

Fig. 2 is a plan view of the bioreactor of Fig. 1 .

Fig. 3 is a schematic sectional view of the bioreactor of Fig. 1 .

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

In the following detailed description, only the preferred embodiment

of the invention has been shown and described, simply by way of illustration

of the best mode contemplated by the inventors of carrying out the invention.

Fig. 1 is a schematic view of a bioreactor according to a preferred

embodiment of the present invention, Fig. 2 is a plan view of the bioreactor, and Fig. 3 is a schematic sectional view of the bioreactor.

Referring to Figs. 1 through 3, a bioreactor according to a preferred

embodiment of the present invention comprises a culture drum 20 vertically

provided on a base frame 10 in the shape of a cylinder, a supply tube 30

connected to an upper side of the culture drum for injecting a culture solution

into the culture drum 20, a pump 31 provided on the base frame 10 and

connected to the supply tube 30 for transferring the culture solution through

the supply tube 30, an air blower 40 provided on the base frame 10 for air

supply, an air supply hose 41 connected to the air blower 40 for transfer of

air therethrough, injection pipes 60 and 61 connected to the air supply hose

41 at a vertically predetermined interval inside the culture drum 20, the

injection pipe 60 having a ring shape, injection nozzles 62 and 63 arranged

along outer circumferences of the injection pipes 60 and 61 at an angle of a

predetermined angle for agitating the culture solution, a low temperature

heater 50 provided inside the culture drum 20 for heating the culture solution,

a high temperature heater 51 provided inside the culture drum 20 for

disinfecting the inside of the culture drum 20 at a high temperature after

discharging the culture solution, and a heater controller 52.

To the overall outer surface of the culture drum 20 is attached a heat

shield material 25 such as polyurethane. The culture drum 20 is provided

with an inlet 21 on the upper side thereof for supplying culture media etc.,

and the inlet 21 is provided with a cover 22 for closing the inlet 21. A level gauge 23 provided to the outer side of the culture drum 20. The

level gauge 23 is a transparent tube that is vertically arranged to allow the

water level in the culture drum 20 to be visually verified. A thermometer

(not shown) is provided to a side of the culture drum 20 for observing the

temperature of the culture solution, and a discharge tube 24 is provided to

the bottom of the culture drum 20 for discharging the culture solution that

has been cultured.

The pump 31 is fixedly provided on the base frame 10, and is

connected to an aeration tank of a wastewater treatment plant, which is

located outside the culture drum 20, through the supply tube 30. The pump

31 draws an aeration solution, etc. from the wastewater treatment plant, and

injects the aeration solution, etc. into the culture drum 20 through the supply

tube 30 connected to the upper side of the culture drum 20. In addition, a

pressure gauge 32 is provided to a side of the supply tube 30.

The air blower 40 is fixedly provided to a side of the base frame 10.

The air supply hose 41 connected to the air blower 40 includes an air filter 42

on an end thereof. The air filter 42 filters out impurities contained in the air

then supplies the fresh air, which is required as a condition for culturing, to

the culture solution. A solenoid valve 43 is provided to the air supply hose

41 , the solenoid valve 43 being located before and behind the air filter 42.

The air supply hose 41 is vertically mounted along the sidewall of the

culture drum 20, and branch lines 43 and 44 are extended from the lower end and the part above the lower end of the air supply hose 41 , respectively,

to the inside of the culture drum 20 through the sidewall of the culture drum

20. The injection pipes 60 and 61 , which has ring shape, are provided at

the end of each of the branch lines 43 and 44.

The injection pipes 60 and 61 are located at the center of the culture

drum 20 at a predetermined distance from the inner wall of the culture drum

20, and supported by connecting an end thereof with the end of the branch

lines 43 and 44. Alternatively, the injection pipes 60 and 61 may be

supported by providing a connecting tube that crosses the center of the

injection pipes 60 and 61 , and by connecting the connecting tube to the

branch lines 60 and 61 that are introduced into the culture drum 20 and bent

downward at the center of the culture drum 20. In this case, the air would

be transferred to the injection pipes 60 and 61 via the air supply hose 41 and

the branch lines 43 and 44 through the connecting tube.

A solenoid valve 45 is provided on each of the branch lines 43 and

44 that are extended from the air supply hose 41. The solenoid valves 45

open and close each of the branch lines 43 and 44.

The low temperature heater 50 is used to ensure an optimum

temperature of the culture solution, a change in the physical properties of the

culture solution, and the effective conditions of the culture solution. The

surface temperature of the low temperature heater 50 is raised to less than

about 60 ^°C . The high temperature heater 51 is used for disinfection. The surface temperature of the high temperature heater 51 is raised to more than

about 60 T .

The above two heaters 50 and 51 are provided in the culture drum

20 at a predetermined interval, and are supplied with electric power by the

heater controller 52 provided on the outer surface of the culture drum 20.

The heater controller 52 supplies electric power to a hot wire of the

low temperature heater 50 so as to satisfy the effective culture conditions of

the culture solution, and can maintain the temperature of the culture solution

at an optimum level.

The injection nozzles 62 and 63 provided on the injection pipes 60

and 61 , respectively,' mix the culture solution by supplying air to the culture

solution and controlling the direction of the injected air. As shown in Fig. 3,

a plurality of injection nozzles 62 is located at the outer surface of the upper

injection pipe 60. The injection nozzles 62 extend from the outward

direction to the downward direction along the outer circumference of the ring-

shaped injection pipe 60. Also, a plurality of injection nozzles 63 is located

at the outer surface of the lower injection pipe 61 . The injection nozzles 63

extend from the inward direction to the upward direction along the outer

circumference of the ring-shaped injection pipe 61 .

Since each of the injection nozzles 62 and 63 provided to the upper

and lower injection pipes 60 and 61 are formed at a predetermined angle

with each other, the culture solution is raised at the interior of the injection pipes 60 and 61 and lowered at the exterior of the injection pipes 60 and 61 ,

and thus is circulated by the air injected from the injection nozzles 62 and 63.

During the above process, the culture solution can be mixed sufficiently.

An operation of the present invention will now be described.

A solution including microorganisms intended for culturing is

transferred to the culture drum 20 through the supply tube 30 by the pump

31 ._, The quantity of the supplied culture solution can be determined by

observing the level gauge 23 provided to the sidewall of the culture drum 20.

When the optimum quantity of the culture solution in the culture drum

20 has been reached, operation of the pump 31 is discontinued and the

culture solution is heated to a predetermined temperature by supplying

electric power to the low temperature heater 50.

Since the low temperature heater 50 is provided inside the culture

drum 20, and thus is immersed in the culture solution, the heat generated

from the heater 50 can be directly transferred to the culture solution so as to

heat the culture solution to an optimum temperature.

The low temperature heater 50 can maintain the culture solution at

a predetermined temperature (about 25±5 ^°C), while the surface temperature

of the heater 50 is kept at a predetermined level (usually 30+ 10^°C) by the

heater controller 52.

Culture media together with the culture solution are supplied into

the culture drum 20 through the inlet 21 provided on the upper side of the culture drum 20 so as to activate culturing.

The culture solution is mixed with the culture media, and the mixture

supplies the cultured microorganism with oxygen. The culture can be

activated as a result.

The air blower 40 supplies air to each of the branch lines 43 and 44

through the air supply hose 41 . The supplied air is transferred to the

injection pipes 60 and 61 connected to the branch lines 43 and 44,

respectively, and is finally sprayed to the culture solution through the

injection nozzle 62 and 63 arranged along the outer circumference of the

injection pipes 60 and 61 , respectively.

The air through the injection nozzle 62 that is provided to the upper

injection pipe 60 is sprayed in the directions ranging from the downward and

outward directions of the ring-shaped injection pipe 60, so that the culture

solution flows downward with the sprayed air.

On the other hand, the air through the injection nozzle 63 that is

provided to the lower injection pipe 61 is sprayed in the directions ranging

from the upward and inward directions of the ring-shaped injection pipe 61 ,

so that the culture solution flows upward passing through the center of the

injection pipe 61 with the sprayed air.

Therefore, the culture solution flows downward between the upper

injection pipe 60 and the inner wall of the culture drum 20, then flows upward

passing through the center of the lower injection pipe 61 by the injection nozzles 62 and 63, and thus the culture solution can circulate. During the

above process, the culture solution and the culture media are mixed

uniformly, and the supplied oxygen can be transferred uniformly to the

microorganisms.

Accordingly, a bioreactor of the present invention is capable of

agitating the culture solution and supplying oxygen thereto simultaneously by

the injected air, without the use of an additional agitator.

After the culture has been completed, the culture solution is

discharged through opening of the discharging tube 24 provided on the

bottom of the culture drum 20, and the interior of the culture drum 20 is

disinfected under high temperature conditions by operation of the high

temperature heater 51. The interior of the culture drum 20 is rapidly heated

and disinfected at a temperature used for this operation (about 95+ 5TJ) by

operation of the high temperature heater 51 .

The case where a bioreactor of the present invention is practically

applied to wastewater treatment is described as follows.

Aeration solution of an aeration tank is directly introduced to the

culture drum 20 through the supply tube 30, then microorganisms are mixed

with the aeration solution under the same conditions as in the above.

Such microorganisms are supplied to wastewater through the

injection nozzles 62 and 63 of the injection pipes 60 and 61. The

microorganisms cleanse the sewage and wastewater by resolving and removing organic pollutants, which nourish the microorganisms, while the

microorganisms are multiplied by using oxygen dissolved in wastewater.

The bioreactor according to the preferred embodiment of the

present invention can easily culture the microorganisms by introducing the

solution intended for culturing from the outside.

Further, the bioreactor according to the preferred embodiment of the present invention can increase the efficiency of wastewater treatment by

directly culturing the aeration solution of the aeration tank.

The bioreactor according to the preferred embodiment of the present invention can also simplify structure by stirring the culture solution by

the oxygen supplied into the culture drum without the use of an additional agitator.

While the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art will

appreciate that various modifications and substitutions can be made thereto

without departing from the spirit and scope of the present invention as set

forth in the appended claims.

Claims

WHAT IS CLAIMED IS:

1. • A bioreactor comprising:

a culture drum in which microorganisms are cultured;

a supplier for supplying a culture solution, and organic and inorganic

media to the culture drum, the supplier including a supply tube connected to

an upper side of the culture drum, and a pump connected to the supply tube

for supplying the culture solution to the culture drum;

an agitator for agitating the culture solution by spraying air to the

culture solution in the culture drum, the air being supplied from an air blower;

and

a thermostatic controller for controlling a temperature of the culture

solution and disinfecting the interior of the culture drum, the thermostatic

controller including at least a heater provided in the culture drum, and a

heater controller.

2. The bioreactor of claim 1 , wherein the agitator includes

an air supply hose which is vertically provided along the sidewall of

the culture drum and connected to the air blower;

two branch lines which are extended from the air supply hose to the

inside of the culture drum through the sidewall of the culture drum;

ring-shaped injection pipes which are provided at the end of each

branch line; a first group of injection nozzles which are located at the outer

surface of the upper injection pipe, and are extended from the outward

direction to the downward direction along the outer circumference of the ring-

shaped injection pipe; and

a second group of injection nozzles which are located at the outer

surface of the lower injection pipe, and are extended from the inward

direction to the upward direction along the outer circumference of the ring- shaped injection pipe.

3. The bioreactor of claim 1 , wherein a heat shield material such as polyurethane is attached to the outer surface of the culture drum.

4. The bioreactor of claim 1 , wherein the thermostatic controller includes a low temperature heater for effecting a temperature condition needed for

culturing by being heated to less than 60 ^°C, and a high temperature heater

for disinfecting the culture solution by being heated to more than 60 ^°C .