JP2005034753A - Organic waste water treatment device and treatment method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To reduce solid matter in an organic waste water treatment by subjecting treated solid matter to heating treatment at 60 to 120°C, subjecting the treated liquid after the heating treatment to biological treatment and solid-liquid treatment, and, if required, returning the solid part to a heating treatment tank once more, and repeating the returning treatment. <P>SOLUTION: As regards the organic waste water treatment device, in an organic waste water treatment device provided with: a biological reaction tank where organic waste water is treated with aerobic microorganisms; a solid-liquid treatment tank where the treated liquid after the reaction is subjected to solid-liquid treatment; and a solubilization apparatus where the treated solid matter is subjected to solubilization treatment at 60 to 120°C, sludge equipment where the treated liquid after the solubilization treatment at 60 to 120°C is subjected to biological treatment and solid-liquid treatment is additionally installed. Preferably, in the organic waste water treatment device provided with the biological reaction tank, solid-liquid treatment tank, solid matter separation tank, and solid matter sludge equipment, a phosphorous removal apparatus is additionally installed. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

The present invention relates to an organic wastewater treatment apparatus and a treatment method.

As a method of treating organic wastewater, a method of treating organic wastewater with aerobic microorganisms in a treatment tank (aeration tank) containing aerobic microorganisms is known. In this process, since organic matter in the wastewater is ingested in the aeration tank and microorganisms grow, excess solid matter is generated as shown in FIG. In addition, when organic solids are contained in the wastewater, the solids are first processed in the settling basin, and the initial precipitated solids are generated. These solids are treated as waste, but reduction of solids is an important issue.

As a method of reducing the solid matter which is a bacterial cell occupying most of the excess solid matter, the solid matter is processed and consumed again as a nutrient source. Cell killing method, cell destruction method, cell small molecule There is a chemical method.
As a cell killing method, for example, there is a method using ozone or ultraviolet rays (Patent Document 1). As a cell destruction method, there is a method using ultrasonic waves (Patent Document 2). Alkali treatment methods (Patent Document 3) and the like are known as methods for reducing the molecular weight of cells, but they are difficult to handle, difficult to enlarge, and complicated treatments associated with chemical use. There is.

JP 2001-314886 A JP 2000-117280 A JP 2001-327988 A

On the other hand, although there is a method using high-temperature and high-pressure water (Patent Document 4), there is a disadvantage that a pressurizing device is essential and the device becomes complicated, and a method of heating to 40 to 100 ° C. (Patent Document 5) is also known. There is a drawback that the treatment effect is insufficient. Moreover, the method (patent document 6) which collect | recovers phosphorus as an iron phosphate after a process is also known.

JP 2000-218295 A Japanese Patent Laid-Open No. 9-276887 JP 2002-102862 A

In view of the above circumstances, the object of the present invention is to heat-treat the treated solid at 60 to 120 ° C., biologically treat the treated liquid after the heat treatment, perform solid-liquid separation, and if necessary, remove the solid portion. The object is to reduce the solids by returning to the heat treatment tank again and repeating the treatment.

That is, the present invention
(1) Biological reaction tank for treating organic wastewater with aerobic microorganisms, solid-liquid separation tank for solid-liquid separation of the treated liquid after the reaction, and solubilizer for performing solubilization treatment by heat treatment of the separated solid matter In the organic wastewater treatment apparatus having the above, a sludge facility for biologically treating the solubilized treatment liquid and separating it into solid and liquid is additionally installed.
(2) A phosphorus removal device may be additionally installed in the organic wastewater treatment device of claim 1 having a biological reaction tank, a solid-liquid separation tank, a solubilization device by heat treatment, and a sludge facility.
(3) Treatment method for treating organic wastewater with aerobic microorganisms, solid-liquid separation method for solid-liquid separation of the treated liquid after the treatment, and solubilization method for solubilization treatment by heat treatment of the separated solid matter A biological treatment / solid-liquid separation method is added to the organic wastewater treatment method comprising the steps of biological treatment of the treatment liquid after solubilization treatment in a sludge facility and solid-liquid separation.
(4) Treatment method for treating organic wastewater with aerobic microorganisms, solid-liquid separation method for solid-liquid separation of the treated liquid after the treatment, solubilization method for performing heat treatment of the separated solid, and solubilization treatment A method for removing phosphorus may be added to the organic wastewater treatment method described in (3), which includes each step of biologically treating a subsequent treatment liquid and performing solid-liquid separation.
(5) It has a treatment method for treating organic wastewater with aerobic microorganisms, a solid-liquid separation method for solid-liquid separation of the treated liquid after the treatment, and a solubilization method for heat treatment of the separated solid (3 ), The treatment liquid after the solubilization treatment is biologically treated in the sludge facility, solid-liquid separation is performed, the solid part is returned to the solubilizer again, and the method of performing the solubilization treatment again and removing phosphorus may be added .
(6) In (1) to (5), the heating temperature is preferably 60 to 120 ° C.

In the present invention, organic wastewater is first separated from aerobic microorganisms. Although organic components in the organic wastewater decrease, microorganisms grow by ingesting organic matter in the wastewater, so that excess solid matter is generated. Solid-liquid separation is performed in order to process excess solids.
Here, the solid is mainly composed of bacterial cells, shows a paste form, and is sometimes referred to as sludge.

Next, the surplus solid matter is preferably heat-treated at 60 to 120 ° C. The reason for limiting the treatment temperature of the solid material to 60 to 120 ° C. is that the bacteria are insufficiently killed at 60 ° C. or lower, and the bacteria are sufficiently killed at 120 ° C. or higher. This is because it becomes too large and is economically disadvantageous.

Instead of keeping the treatment liquid after the heat treatment in the heat treatment container to separate the solid matter, it is transferred to another container and subjected to biological treatment for solid-liquid separation. The solid matter separated here is preferably solubilized again by heat treatment at 60 to 120 ° C. By repeating solubilization at 60 to 120 ° C., it is possible to more completely reduce the solid matter.

After solubilization, the treated liquid component is treated with an iron-based compound because it contains a phosphorus-based component. The phosphorus component is treated as iron phosphate. This is because the discharge of phosphorus leads to eutrophication of the discharge destination, which is not preferable.

The treatment liquid from which phosphorus has been removed is returned to the biological reaction tank 1. This is because the dead cells treated with aerobic bacteria and the degradation products from the cells can be used again as nutrients.

In the present invention, heat is applied to the solid-liquid separated cells to kill the bacteria and decompose them. Compared to the conventionally known ozone and ultraviolet irradiation shown in FIG. 6, there are advantages due to the danger of ozone remaining, simple facilities, and easy maintenance. In addition, a sludge facility is provided, so that repeated solubilization processing is possible, and solubilization processing can be performed completely.
In the conventional method, as illustrated in FIG. 6, the biological treatment tank 1 is directly returned to the biological reaction tank 1 without performing the biological treatment. Therefore, the load amount for the treatment becomes high. On the other hand, in the method of the present invention, the return water after the solubilization treatment and the biological treatment is in principle, and the influence on the biological reaction tank 1 is small.
In addition, as shown in the broken line in FIG. 4, the conventional solid material processing equipment has an increased MLSS (abbreviation of MIXED LIQUOR SUSPENDED SOLID) concentration and needs to be discharged out of the system. In the method of the present invention, as shown by the solid line in FIG.

Embodiments of the present invention will be described below with reference to FIGS.
FIG. 1 shows the treatment of organic waste in the biological reaction tank 1, the solid-liquid separation in the solid-liquid separation tank 2, the solubilization process in the solubilizer 3, the biological treatment after the solubilization process, and It consists of sludge equipment 4 for solid-liquid separation (including solid-liquid separation using a membrane) and return of the treated product (consisting of soluble components and part solids) to the biological reaction tank 1 after solubilization treatment. The process figure of one Example of this invention which shows this invention apparatus is shown.
FIG. 2 is a process diagram showing the method of the present invention in which the solubilization process, the biological process after the solubilization process and the repetition of the solid-liquid process are added to the process of FIG.
FIG. 3 is a process diagram showing the method of the present invention in which removal of phosphorus from the treated product after the solubilization treatment is added to the process of FIG.
FIG. 4 is a diagram showing a change in MLSS concentration (mg / l) in the solid sludge facility accompanying the operation.

Organic wastewater first enters the biological reactor 1. The biological reaction tank is kept in air at 10 to 40 ° C. and stirred. Organic matter contained in the wastewater is consumed and reduced by aerobic microorganisms. In this case, a solid based on aerobic microorganisms is generated. When the decrease in the organic matter contained in the wastewater is no longer observed, it is transferred to the solid separation tank 2. The solid is separated by gravity, filtered or centrifuged, and the filtrate is discharged. The solid matter moves to the solubilizer 3.
The solubilization process in the solubilizer 3 is performed by processing at 60 to 120 ° C. for 30 to 120 minutes. By this treatment, the aerobic bacteria are killed and the organic matter constituting the bacteria is partially decomposed. The treatment liquid after the solubilization treatment is transferred to the sludge facility 4 and processed into a solid component and a liquid component. The liquid component is returned to the biological reaction tank 1.

The operation shown in FIG. 2 up to the sludge facility 4 is the same as that in FIG. 1, but the solid material after solid-liquid separation in the sludge facility 4 is returned to the solubilizer again, and the solid material from the solid-liquid separation tank 2 Combined and sent to solubilization process.

The operation shown in FIG. 3 is the same as the operation shown in FIG. 2 up to the sludge facility. However, in the operation shown in FIG. 3, the liquid portion of the sludge facility 4 is subjected to phosphorus removal processing by the phosphorus removal processing device 5 and returned to the biological reaction tank 1.

The relationship between the number of days elapsed when the operations shown in FIGS. 1 to 3 were repeated and the MLSS concentration (mg / L) in the solid matter (biological treatment) facility was shown.

(1) The organic wastewater treatment method of the present invention is a method for reducing solids to be discarded by heat-treating solids generated by aerobic bacteria culture treatment and subsequent solid-liquid treatment. It is possible to reduce the solid matter.
(2) Since chemicals such as ozone and ultraviolet rays are not used for solids separation, there is no danger of ozone remaining, and there are advantages that the equipment is simple and maintenance is easy.
(3) Since no chemicals such as alkali are used, the apparatus itself can be simplified.
(4) It is preferable to remove phosphorus, and it is possible to avoid eutrophication of waste water. It is also possible to recover phosphorus as a resource.

The organic wastewater treatment apparatus and treatment method of the present invention include not only relatively small-scale treatment apparatuses such as general household wastewater treatment apparatuses and wastewater treatment apparatuses in specific areas, but also relatively large-scale organicity performed by municipalities. It can also be used for wastewater treatment, and it can be used as natural energy and biomass energy as a heat source, greatly contributing to the industry.

Treatment of organic waste in the biological reaction tank 1, solid-liquid treatment in the solid-liquid treatment tank 2, solubilization treatment in the solubilizer 3, and subsequent biological treatment and solid-liquid separation after the solubilization treatment The process figure of one Example of this invention which shows the apparatus of this invention which consists of the solid substance sludge equipment 4 for this and the return of the processed material after a solubilization process to the biological reaction tank is shown. It is process drawing which shows the method of this invention which added the repetition of the solubilization process, the solubilization process, the biological treatment after the solubilization process, and solid-liquid separation to the process of FIG. It is process drawing which shows the method of this invention which added the removal of the phosphorus of the processed material after a solubilization process to the process of FIG. It is a figure which shows MLSS density | concentration (mg / L) change in the sludge installation (solid substance storage installation) by this invention method and a normal method. It is process drawing which shows the process in a prior art example. It is process drawing of the prior art example which used ozone treatment together.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Biological reaction tank 2 Solid-liquid processing tank 3 Solubilization apparatus 4 Sludge equipment 5 Phosphorus removal apparatus 6 Solid substance storage equipment 7 Ozone processing equipment

Claims (6)

Organic having a biological reaction tank that treats organic wastewater with aerobic microorganisms, a solid-liquid separation tank that performs solid-liquid separation of the treated liquid after the reaction, and a solubilizer that performs solubilization treatment by heat treatment of the separated solid matter An organic wastewater treatment apparatus, wherein a sludge facility for biologically treating the solubilized treatment liquid and separating it into solid and liquid is additionally installed in the wastewater treatment apparatus. An organic wastewater treatment apparatus comprising a biological reaction tank, a solid-liquid separation tank, a solubilization apparatus by heat treatment, and a sludge facility, wherein an organic wastewater treatment apparatus according to claim 1 is additionally provided with a phosphorus removal apparatus. Organic consisting of a treatment method for treating organic wastewater with aerobic microorganisms, a solid-liquid separation method for solid-liquid separation of the treated liquid after the treatment, and a solubilization method for solubilization treatment by heat treatment of the separated solid matter Organic wastewater treatment method characterized by the addition of a biological treatment / solid-liquid separation method to solid-liquid separation by biological treatment of the treatment liquid after solubilization treatment in a sludge facility. Treatment method for treating organic wastewater with aerobic microorganisms, solid-liquid separation method for solid-liquid separation of the treated liquid after the treatment, solubilization method for heat treatment of the separated solid, treatment after solubilization treatment The organic wastewater treatment method according to claim 3, comprising each step of biologically treating the liquid and performing solid-liquid separation.
An organic wastewater treatment method characterized by adding a method for removing phosphorus. The method according to claim 3, further comprising: a treatment method for treating organic wastewater with an aerobic microorganism, a solid-liquid separation method for solid-liquid separation of the treated liquid after the treatment, and a solubilization method for heat treatment of the separated solid matter. The treatment liquid after the solubilization treatment is biologically treated in the sludge facility, solid-liquid separation is performed, and the solid matter part is returned to the solubilizer again to perform the solubilization treatment and phosphorus removal method. Organic wastewater treatment method. In Claim 1-7, heating temperature is 60-120 degreeC, The organic solid substance processing apparatus characterized by the above-mentioned.

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