JPH05185085A - Water treating method by batch type activated sludge and apparatus for treating water - Google Patents

Abstract

PURPOSE:To improve treating efficiency by increasing sludge holding volume in a tank of small size. CONSTITUTION:In a water-treating method for purifying water using an activated sludge in which processes of inflow, aeration, precipitation and discharge are carried out in order in a reaction tank 1, a carrier for fluidized bed 4, 4 and 4 consisting of a sponge, a plastic or a ceramic, etc., is provided in the reaction tank 1 and the activated sludge is allowed to attach to the surface of the carrier to increase a sludge holding volume.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improved water treatment method using batch activated sludge and an apparatus for carrying out the method.

[0002]

2. Description of the Related Art Conventionally, a batch type activated sludge water treatment method for purifying sewage and the like by sequentially performing steps of inflow, aeration, precipitation, and discharge in one reaction tank has been known as a sludge in wastewater. The sludge is dispersed and biologically purified by sludge bacteria, but in order to increase the purification efficiency, it is necessary to increase the amount of sludge retained in the reaction tank. There was a problem that the whole thing had to be large.

[0003]

The present invention has been devised in view of the above-mentioned problems of the prior art, and does not provide a water treatment method and device which can increase the sludge holding amount and the treatment efficiency with a small-sized device. The first gist of the invention is to provide a water treatment method in which the steps of inflow, aeration, precipitation, and discharge are sequentially performed in one reaction tank to perform purification treatment with activated sludge, This is to put a fluidized bed carrier such as sponge, plastic, ceramic, etc., and make the activated sludge adhere to the fluidized bed carrier for treatment. The second gist is that a fluidized bed carrier such as sponge, plastic, or ceramic to which the activated sludge adheres is placed in a reaction tank in which the steps of inflow, aeration, precipitation, and discharge are sequentially performed to perform purification treatment with activated sludge. In addition to the above, a recovery means for preventing the fluidized bed carrier from flowing out is additionally provided.

[0004]

[Function] Since a fluidized bed carrier such as sponge, plastic or ceramic is put in the reaction tank, the sludge in the tank adheres to the fluidized bed carrier and sludge bacteria are satisfactorily grown. The amount of sludge retained inside is increased, and the treatment efficiency is improved accordingly. Further, by attaching the fluidized bed carrier recovery means to the device, the fluidized bed carrier is not discharged to the outside even if the excess sludge is drawn out.

[0005]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 illustrates each step by the batch activated sludge method. First, in the inflow step, the wastewater 3 is flown into the reaction tank 1 from the outside. After the sewage 3 has flowed into the sewage 3 for a predetermined time, the process proceeds to an aeration step. In this aeration step, air bubbles are released from an air diffuser pipe or the like installed in the reaction tank 1 to disperse the sludge 2 in the sewage 3 internally. Cause convection.
After this aeration process has been performed for a predetermined time, the aeration is stopped and the process proceeds to a precipitation process. In this precipitation process, sludge 2 dispersed in sewage 3 gradually accumulates on the bottom surface side of reaction tank 1 over time. After a predetermined time, a layer of purified supernatant water is formed on the upper part of the sludge 2, so that a discharge step of extracting and discharging the supernatant water is performed. After the completion of this discharge step, new wastewater 3 is again introduced into the reaction layer 1 and the inflow step is restarted. As described above, in the batch activated sludge method, the steps of inflow, aeration, precipitation, and discharge are sequentially performed in one reaction layer to purify the wastewater.

In this example, the fluidized bed carriers 4, 4, 4 are put in the reaction bed 1.
Reference numeral 4 is made of a material such as sponge, plastic, or ceramic, and is formed into a large number of grains, sands, or the like. When the fluidized bed carriers 4, 4 and 4 are previously placed in the reaction layer 1 as described above, the sludge 2 adheres to the surfaces of the fluidized bed carriers 4, 4 and 4 and bacteria can proliferate well. In the aeration process, fluidized bed carriers 4, 4, 4 with sludge 2 attached
Will be well dispersed in the sewage 3, and the bacteria in the sludge adhering to the fluidized bed carriers 4, 4, 4 will satisfactorily decompose and purify the organic matter in the sewage 3 and further proliferate. It is possible to increase the retention amount of sludge 2 due to the growth of bacteria through each fluidized bed carrier 4, 4, 4 and the retention amount of sludge 2 existing in the reaction tank 1 as a whole becomes higher. 1
The processing efficiency is improved as compared with the conventional one, even if it is small.

As shown in FIG. 2, a sludge thickening tank 7 is provided adjacent to the reaction tank 1 in order to extract the excess sludge 2 in the reaction tank 1 to the outside and concentrate it. Excess sludge 2 is drawn into the sludge thickening tank 7 from a pump P1 installed on the bottom side of the tank 1 through a sludge drawing tube 5, and at this time, the fluidized bed carriers 4, 4, 4 are drawn together with the sludge 2. As shown in FIG. 2, a net basket 6 is provided at the downstream end of the sludge drawing pipe 5 so that the fluid bed carriers 4, 4,
4 is configured to be collected. The net basket 6 may be formed of a screen, punching metal or the like. The fluidized bed carrier 4, which is collected in the net basket 6,
Items 4 and 4 are returned to the reaction tank 1 during weekly management and inspection, for example.

In order to prevent the fluidized bed carriers 4, 4, 4 from flowing out to the outside, a net 8 is provided around the suction port of the sludge drawing pump P1 as shown in FIG. 3, for example. The net 8 can prevent the outflow of the fluidized bed carriers 4, 4, 4. Further, a treated water withdrawing pipe 9 is connected to a pump P2 for withdrawing supernatant water, and a trumpet-like baffle plate 10 is disposed below the pump P2 for preventing the sludge from rolling up. A net 11 is provided around the plate 10 and the suction port of the pump P2, and the fluidized bed carriers 4, 4, 4 are provided by the net 11.
Can be prevented from leaking to the outside.

Further, as shown in FIG. 4, also in the reaction tank 1 provided with the treated water withdrawal pipe 9 and the sludge withdrawal pipe 5 which can be opened and closed via a valve, respectively, a net 12, near the suction port of each withdrawal pipe, By providing 13, the nets 12, 13 can prevent the fluidized bed carriers 4, 4, 4 from flowing out.

[0010]

INDUSTRIAL APPLICABILITY The present invention is a water treatment method in which the steps of inflow, aeration, precipitation, and discharge are sequentially carried out in one reaction tank to carry out purification treatment with activated sludge. Since a fluidized bed carrier such as ceramics is placed and the activated sludge is adhered to the fluidized bed carrier for treatment, sludge adheres to the fluidized bed carrier and bacteria in the sludge can proliferate well, The amount of sludge retained in the reaction tank is increased, the efficiency of sewage treatment is improved, and the reaction tank can be made smaller. In addition, a fluidized bed carrier such as sponge, plastic, or ceramic to which the activated sludge adheres is put in a reaction tank in which the steps of inflow, aeration, precipitation, and discharge are sequentially performed to perform purification treatment with activated sludge, and the fluidized bed is By attaching a recovery means to prevent the carrier from flowing out,
The recovery means can prevent the outflow of the fluidized bed carrier to the outside and enhance the processing efficiency.

[Brief description of drawings]

FIG. 1 is a process explanatory view showing each process by a batch activated sludge method.

FIG. 2 is a schematic configuration diagram in which a fluidized bed carrier recovery means is provided in a sludge drawing device.

FIG. 3 is a schematic configuration diagram showing a state in which a net for preventing outflow of a fluidized bed carrier is installed around a drawing pump.

FIG. 4 is a schematic configuration diagram showing a state in which a net is arranged at a suction port of a drawn tube.

[Explanation of symbols]

 1 Reaction Tank 2 Sludge 3 Sewage 4 Fluidized Bed Carrier 5 Extraction Tube 6 Net Basket 7 Sludge Concentration Tank 8, 11, 12, 13 Net P1, P2 Pump

Claims (2)

[Claims] 1. Inflow, aeration, precipitation,
In a water treatment method in which the steps of discharging are sequentially performed to perform purification treatment with activated sludge, a fluidized bed carrier such as sponge, plastic, or ceramic is put in the reaction tank, and the activated sludge is attached to the fluidized bed carrier for treatment. A method for treating water with batch activated sludge, which is characterized by: 2. A fluidized bed carrier such as sponge, plastic or ceramic to which the activated sludge adheres is placed in a reaction tank in which the steps of inflow, aeration, precipitation and discharge are sequentially carried out for purification treatment with activated sludge, A water treatment apparatus using batch type activated sludge, which is provided with a recovery means for preventing the outflow of the fluidized bed carrier.