JPS63130196A - Method and apparatus for treating waste water - Google Patents

Abstract

PURPOSE:To enhance treatment efficiency, by separating raw water after anaerobic treatment into a solid, treated water and untreated water and applying aerobic treatment to the untreated water. CONSTITUTION:Raw water enters an anaerobic reaction 4 through an inflow passage 3 by a pump 2 to treat a part of the org. substance in raw water. The waste water issued from the anaerobic reaction tank 4 is sent to a solid- liquid separation apparatus 7 under pressure by a pump 6 to be separated into a solid and water and the solid is discharged. Untreated water flows in a aerobic reaction tank 11 and the residual org. substance is removed by aerobic bacteria. The waste water passing through the aerobic reaction tank 11 passes an outflow passage 13 to be met with the inflow passage 3 while pressurized by a pump 14 and flows in the anaerobic reaction tank 4 to be again treated along with the raw water and discharged as treated water. By this method, the quantity of sludge generation can be reduced.

Description

DETAILED DESCRIPTION OF THE INVENTION [Public funds for industrial use] The present invention relates to a method and apparatus for treating organic wastewater such as public sewerage and industrial wastewater.

(Conventional technology) As shown in Figure 2, the conventional treatment method for organic wastewater is that the raw water from the adjustment tank α is treated by the activated sludge method in the aerobic reaction tank. After that, a method of performing semipermeable membrane treatment in a semipermeable membrane tank C (for example, Environmental Facility 1985 A20, pp. 56-57), or
As shown in Figure 3, the raw water from the adjustment tank a is treated in the anaerobic reaction tank d using the anaerobic treatment method, and then treated in the aerobic reaction tank using the aerobic treatment method, and then in the settling tank C. method of discharging it as treated water after
16268, νoL 23.28-37), etc. have been published.

Particularly in recent years, anaerobic treatment, especially the fluidized bed type, which produces less Yoei sludge, has been attracting attention. Further, an attempt has been made to perform aerobic treatment after anaerobic treatment to lower the BOD value in wastewater. In addition, semipermeable membranes, mainly ultrafiltration membranes, are used as an alternative to settling tanks in ordinary treatments, and have been used in many recent years due to their compactness.

In light of the above, a method that combines both of the above conventional examples, ie, a method of treating wastewater through the route shown in FIG. 4, is currently being used.

That is, the wastewater from the adjustment tank a passes through an anaerobic reaction tank d and an aerobic reaction tank in series, then enters an intermediate tank C, from which it is further processed through a solid-liquid separator f consisting of a semipermeable membrane. It is designed to be discharged as water.

[Problem that the invention seeks to solve]

The efficiency of the above conventional method was not very high. Also, a large amount of sludge was generated. Moreover, in the apparatus for carrying out the above method, an intermediate tank is required, which makes the apparatus large-scale, and the number of pumps used is also large, P1 to ps, which is at least five.

[Means and effects for solving the problems] The present invention has been made in consideration of the above-mentioned problems, and has been developed to enable highly efficient treatment of wastewater from a regulating tank and to reduce the amount of sludge generated. The purpose of this project is to provide a method for treating wastewater, which involves subjecting wastewater to anaerobic reaction treatment in an anaerobic reaction tank, and then separating it into solid content, treated water, and untreated water in a solid-liquid separator. Next, the untreated water from the solid-liquid separator is subjected to an aerobic reaction treatment in an aerobic reaction tank, and then subjected to an anaerobic reaction treatment again in an anaerobic reaction tank.

In order to carry out the above method, the present invention aims to provide a device that is compact, uses a small number of pumps, and can easily adjust the flow balance within the device, and its configuration is as follows: , an anaerobic reaction tank whose inflow side is connected to a regulating tank through an inflow channel equipped with a pump;
an aerobic reaction tank whose outflow side is connected to the inflow side of the anaerobic reaction tank via a pump; It consists of a pump, a solid-liquid separator, and a pressure reducing device, which are installed sequentially from the side.The untreated water from the solid-liquid separator is subjected to aerobic reaction treatment in an aerobic reaction tank, and then anaerobic again. Anaerobic treatment is performed in a reaction tank. The flow balance within the apparatus is controlled by adjusting the pressure and flow rate of a pump and pressure reducing device interposed between both reaction vessels.

〔Example〕

An embodiment of the present invention will be described based on FIG.

The raw water that has flowed into the adjustment tank 1 enters the anaerobic reaction tank 4 via the inlet channel 3 by the pump 2, where it is treated with anaerobic microorganisms.
Some of the BOD components, SS components, and organic substances such as nitrogen and phosphorus are treated. The wastewater that has exited the anaerobic reaction tank 4 is pressurized by a pump 6 through an outflow path 5 and is then pumped to a solid-liquid separator 7 . This solid-liquid separator 7 includes a first separation means 7G made of a filter, MF membrane, etc., and a second separation means 7B made of a cross-flow type membrane such as an ultrafiltration membrane for removing relatively small particles.
The wastewater pumped from the anaerobic reaction tank 4 by the pump 6 is first separated into solid and liquid by the first separation means 7a, and the solid content such as sludge separated here is separated by a known method (not shown). It is discharged out of the device by means.

The wastewater that has passed through the first separation means 7G is further filtered by the second separation means 7b, and this filtered water becomes treated water and is discharged to the outside through the treatment waterway 8.

The untreated water that has not been separated by the solid-liquid separator 7 has its pressure reduced to an appropriate level by the pressure reducing device IO installed in the outflow path 9, and then flows into the aerobic reaction tank 11, where it is aerobic. Remaining organic substances are removed by microorganisms. At this time, air is supplied to the aerobic reaction tank 11 from the air intake path 12.

The wastewater that has passed through the aerobic reaction tank 11 passes through the outflow passage 13 9.
The water is pressurized by the pump 14, merges with the inflow channel 3, and flows into the anaerobic reaction tank 4, where it is again subjected to the above treatment together with the raw water, and then passed through the granular solid-liquid separator 7 to the treated water channel 8 as treated water. is discharged to.

The flow rate balance in the above treatment is such that the inflow amount Q1 flowing from the adjustment tank 1 and the amount Q2 of treated water discharged from the solid-liquid separator 7 are the same.

The flow rate at this time is adjusted by controlling the pressure and flow rate of the pump 6 and pressure reducing device 10.

The anaerobic reaction tlI4 and the aerobic reaction tank 11 have a fluidized bed configuration.

〔Effect of the invention〕

According to the method of the present invention, after wastewater is subjected to anaerobic reaction treatment in the anaerobic reaction tank 4, it is separated into solid content, treated water, and untreated water in the solid-liquid separator 7, and then the solid-liquid separator 7 Since the untreated water is subjected to an aerobic reaction treatment in the aerobic reaction tank 11 and then subjected to an anaerobic reaction again in the anaerobic reaction tank 4, the wastewater from the adjustment tank 1 can be treated with high efficiency. At the same time, the amount of sludge generated can be reduced.

Furthermore, the apparatus for carrying out the above method includes an anaerobic reaction tank 4 connected to the inflow side regulating tank 1 through an inflow path equipped with a pump, and an outflow side connected to the inflow side of the anaerobic reaction tank 4 via a pump. an aerobic reaction tank 11 that is connected to Since it is composed of a separation device and a pressure reducing device, an intermediate tank is not required, and the structure can be made compact, and the number of pumps to be incorporated into the device can be reduced to three. Further, the flow balance within the apparatus can be easily adjusted using a pump and a pressure reducing device interposed between both reaction vessels 4 and 11.

[Brief explanation of the drawing]

FIG. 1 is an explanatory diagram showing an embodiment of the present invention, and FIGS. 2 to 4 are explanatory diagrams showing conventional examples. 1 is a regulating tank, 2, 6.14 is a pump, 3 is an inflow path, 4 is an anaerobic reaction tank, 7 is a solid-liquid separation device, 1O is a pressure reducing device, 1
1 is an aerobic reaction tank.

Claims (2)

[Claims] (1) After the wastewater is subjected to anaerobic reaction treatment in the anaerobic reaction tank 4, it is separated into solid content, treated water, and untreated water in the solid-liquid separator 7, and then the untreated water is separated from the solid-liquid separator 7. A wastewater treatment method characterized in that water is subjected to an aerobic reaction treatment in an aerobic reaction tank 11 and then subjected to an anaerobic reaction treatment again in an anaerobic reaction tank 4. (2) An anaerobic reaction tank 4 whose inflow side is connected to the adjustment tank 1 through an inflow channel 3 equipped with a pump 2, and a preferred system whose outflow side is connected to the inflow side of the anaerobic reaction tank via a pump 14. A pneumatic reaction tank 11, a pump 6, and a solid-liquid separation device 7, which are sequentially installed in a flow path connecting the outflow side of the anaerobic reaction tank 4 and the inflow side of the aerobic reaction tank 11 from the upstream side thereof. and pressure reducing device 1
A wastewater treatment device comprising: 0.