JPH0619900U - Upflow anaerobic treatment device - Google Patents

Abstract

(57) [Summary] [Objective] To maintain the PH value in the upflow anaerobic treatment equipment, the addition amount of alkali components can be prevented to the maximum by preventing sludge outflow in the separation part. A flow anaerobic treatment device is provided. [Structure] A reaction part having a biological sludge bed formed below a biological reaction tank equipped with a means for supplying treated water at the bottom and a means for discharging treated water and a means for discharging produced gas at the top, and sludge above
From the position between the treated water-separation part for separating the produced gas,
An upflow anaerobic treatment apparatus, characterized in that a circulating water extraction means for extracting treated water is provided and is connected to a treated water supply means.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to an upflow anaerobic treatment device that anaerobically biologically treats organic wastewater such as food processing wastewater and human waste.

[0002]

[Prior art]

 Conventionally, as a method for treating the organic wastewater, anaerobic microorganisms having a methane fermentation ability are granulated and held at a high density, and a biological sludge bed is formed below the biological reaction tank to generate wastewater. An upflow anaerobic treatment device (hereinafter referred to as a UASB device) that is processed by flowing upward is used.

Since the UASB device can retain and treat microorganisms at a high density, it can efficiently treat high-concentration organic wastewater, reduce the device installation area, and reduce the amount of methane gas generated. It has become popular rapidly in recent years because it can be used effectively.

In the UASB device, it is necessary to keep the biological sludge bed formed below the reaction tank in a blanket state with a constant height and to efficiently separate sludge-treated water-produced gas. Therefore, it is necessary to always control the upward flow velocity of the water to be treated within a certain range according to the state of microorganisms.

Further, in order to selectively grow and maintain a microorganism having a methanogenic ability and which is likely to be formed into particles, it is necessary to keep the pH value of the biological reaction tank within a certain range. It is adjusted by adding an alkaline component.

Further, in order to maintain the above-mentioned upward flow velocity at a constant speed without being affected by the fluctuation of the flow rate of the water to be treated and to reduce the addition amount of the alkaline component, the conventional UASB device is used. In this method, the treated water containing the alkaline components generated by the methane fermentation, which has been three-phase separated and discharged from the separation section of the biological reaction tank, is circulated to the treated water supply means.

[0007]

[Problems to be solved by the device]

 In the conventional UASB device, when the treated water that has left the separation unit is circulated, the amount of water that flows into the separation unit increases because the amount of alkaline component added to maintain the PH value is reduced. Since the upward flow velocity was high, the separation of sludge-treated water-produced gas was incomplete, leading to the loss of granular sludge, which could lead to deterioration of the treated water and deterioration of the treatment performance of the biological reaction tank. .

Therefore, conventionally, due to the above-mentioned reasons, it was not possible to sufficiently reduce the addition amount of the alkaline component. The present invention can maximize the use of alkaline components in the treated water, sufficiently reduce the amount of alkaline components added, and maintain the upward flow velocity in the separation section at a constant rate to remove granular sludge. It was made for the purpose of providing a UASB device capable of preventing the washout.

[0009]

[Means for Solving the Problems]

 In the present invention, the circulating water circulating in the water to be treated is taken from below the separation section to maintain a constant amount of water flowing into the separation section regardless of the circulating water quantity. , A reaction part with a biological sludge bed formed in the lower part of the biological reaction tank equipped with a treated water supply means in the lower part and a treated water discharge means and a produced gas discharge means in the upper part, and sludge-treated water in the upper part. -In an upflow anaerobic treatment device that provides a separation part for separating the produced gas and circulates the treated water in an upward flow, the circulation of extracting the treated water from the position between the reaction part and the separation part. The upflow anaerobic treatment apparatus is characterized in that it is provided with a water withdrawing means and is connected to a treated water supply means.

[0010]

[Action]

 The treated water supplied as a uniform cross-sectional flow from the treated water supply means 2 provided in the lower part of the biological reaction tank 1 is pulverized into anaerobic particles while flowing upward through the biological sludge bed 8 in the reaction section A. BOD components and the like are biologically decomposed into methane gas and the like by a sex microorganism and processed.

The biologically treated treated water rises along with the generated sludge 9 that is lightened by the adhered methane gas and bubbles, and bypasses the sludge collision member 6 provided in the middle part of the biological reaction tank 1. Then, it flows into the three-phase separator 7 of the separation part B.

[0012] A part of the granular sludge 9 that has risen along with the treated water collides with the sludge colliding member 6 to separate air bubbles, settles in the biological sludge bed 8, and the produced methane gas is bypassed to perform three-phase separation. The gas is separated before it flows into the body 7, is collected in the gas pool C at the outer bottom of the three-phase separator 7, and is then discharged from the gas discharge means 4.

The treated water that has flowed into the three-phase separator 7 together with the particulate sludge 9 to which the bubbles have adhered is separated from the bubbles adhered to the granular sludge 9 while staying in the three-phase separator 7 for a certain period of time. Then, the granular sludge 9 settles on the biological sludge bed 8 to be clarified, and is discharged from the treated water discharge means 3 to the outside of the system through the overflow part at the upper end.

A part of the treated water rising in the biological reaction tank 1 is withdrawn by the circulating water withdrawing means 5 provided between the reaction section A and the separation section B, and is circulated and mixed with the water to be treated. The pH value of the water to be treated is adjusted and the flow rate is controlled.

[0015]

【Example】

 An embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a schematic vertical sectional view of a U ASB apparatus according to an embodiment of the present invention. Reference numeral 1 denotes a biological reaction tank having a rectangular structure and a closed structure, which is provided with a treated water supply means 2 at a lower portion, a treated water discharge means 3 and generated gas discharge means 4 and 4a at an upper portion, and a sludge collision member 6 at an intermediate portion.

Further, a reaction part A of a biological sludge bed 8 held at a constant height below the biological reaction tank 1 and a three-phase separator 7 for separating sludge-treated water-produced gas above. Is provided at the position between the reaction part A and the separation part B, and the treated water supply means 2 is provided with a circulating water extracting means 5 for extracting the treated water and circulatingly mixing the treated water with the treated water. It is provided by connecting.

The biological sludge bed 8 is formed of granular sludge 9 in which anaerobic microorganisms are granulated, and is fluidized at a constant height by the treated water supplied from the treated water supply means 2 Holds the blanket state. The granular sludge 9 may be self-granulating microorganisms or microbial particles carried by a fine particle carrier.

The treated water supply means 2 is arranged on the entire bottom surface of the biological reaction tank 1 so that the treated water flows upward as a uniform flow on the cross section of the biological sludge bed 8. The shape of the three-phase separating body 7 is a horizontally long rectangular body in which the lower side wall is inclined inward, and the sludge collision member 6 is a long mountain shape, and the lower end of the three-phase separating body 7 is formed. Although the treated water inflow passage is formed by and, the present invention is not limited to these shapes.

A gas reservoir C to which the generated gas discharge means 4 is connected is formed outside the inclined portion of the three-phase separator 7, and the circulating water extraction means 5 is provided at a position directly below the sludge collision member 6. Although the treated water is extracted by the circulation pump 11 and circulated and mixed with the water to be treated, the treated water may be extracted at any position between the reaction section A and the separation section B.

Reference numeral 10 denotes an alkaline storage tank which is connected to the untreated water supply means 2 and supplies an alkaline component to the untreated water with a supply pump 12 so as to keep the PH value in the biological reaction tank 1 constant. . As the alkaline component, calcium hydroxide, sodium hydroxide or the like is used, and the addition amount thereof is appropriately set together with the circulating water amount.

Next, the operation of anaerobically treating organic wastewater such as food processing wastewater and night urine by the apparatus having the above configuration will be described. The treated water is supplied from the treated water supply means 2 into the biological reaction tank 1 as a uniform cross-sectional flow, and while flowing upward through the biological sludge bed 8 in the reaction part A, BOD components in the treated water are removed. , Is decomposed into methane gas, etc. by the biological action of anaerobic microorganisms.

In the reaction part A, microorganisms are aggregated into particles and are densified to have a high apparent specific gravity. The biological sludge bed 8 in a blanket state that is fluidized at a height can be easily formed. Therefore, the contact efficiency between the water to be treated and the granular sludge 9, the treatment efficiency, etc. can be made extremely high, and the treatment operation with a high volume load becomes possible.

Further, in order to selectively grow and maintain the microorganisms that are easily made into particles and efficiently perform biological treatment, it is necessary to maintain the PH value in the biological sludge bed 8 at about 6.5 to 7.5. Therefore, the pH value of the supplied water to be treated is adjusted by the injection amount of the alkali component supplied from the alkali storage tank 10 at the supply pump 12.

The biologically treated treated water rises along with the generated sludge 9 that is lightened by the adhered methane gas and bubbles, and bypasses the sludge collision member 6 provided in the middle part of the biological reaction tank 1. Then, it flows into the three-phase separator 7 of the separation part B.

Part of the granular sludge 9 that has risen along with the treated water collides with the sludge colliding member 6 to separate air bubbles, settles in the biological sludge bed 8, and the generated methane gas is bypassed to perform three-phase separation. The gas is separated before it flows into the body 7, is stored in the gas pool C at the outer bottom of the three-phase separator 7, and is then discharged from the gas discharge means 4.

The treated water that has flowed into the three-phase separator 7 together with the particulate sludge 9 to which the bubbles have adhered is separated from the bubbles attached to the granular sludge 9 while staying in the three-phase separator 7 for a certain period of time. The granular sludge 9 settles in the biological sludge bed 8 to be clarified, and is discharged from the treated water discharge means 3 to the outside of the system as treated water through the overflow portion at the upper end. Further, the separated bubbles are discharged from the generated gas discharging means 4a at the top of the reaction tank 1.

In order to reduce the addition amount of the alkaline component for controlling the upward flow velocity and adjusting the PH value, the treated water containing the alkaline component generated by the methane fermentation in the biological reaction tank 1 is circulated by the circulating water extracting means 5. The water is extracted and circulated to the untreated water supply means 2.

[0028]

[Effect of device]

 According to the upflow anaerobic treatment apparatus of the present invention, the circulating water is extracted from the front side of the three-phase separator 7 which is the separation unit B, so that the amount of water flowing into the separation unit B is increased more than the amount to be treated. It does not affect the three-phase separation of sludge-treated water-produced gas, prevents the outflow of granular sludge, and can effectively utilize the alkaline components generated by methane fermentation. Can be saved.

[Brief description of drawings]

FIG. 1 is a schematic vertical sectional view of an upflow anaerobic treatment apparatus according to an embodiment of the present invention.

[Explanation of Codes] 1: Biological reaction tank 2: Treated water supply means 3: Treated water discharge means 4, 4a: Generated gas discharge means 5: Circulating water extraction means 6: Sludge collision member 7: Three-phase separator 8: Biological sludge bed 9: Granular sludge 10: Alkaline storage tank 11: Circulation pump 12: Supply pump A: Reaction part, B: Separation part, C: Gas reservoir.

Claims (1)

[Scope of utility model registration request] 1. A reaction section in which a biological sludge bed is formed in a lower part of a biological reaction tank equipped with a treated water supply means in a lower part and a treated water discharge means and a generated gas discharge means in an upper part, and a biological sludge bed in an upper part. In an upflow anaerobic treatment apparatus that is provided with a separation unit for separating sludge-treated water-produced gas, and treats water to be treated by flowing in an upward flow, treating from a position between the reaction unit and the separation unit. An upflow anaerobic treatment apparatus, characterized in that a circulating water withdrawing means for withdrawing water is provided and is connected to a treated water supply means.