JPH10494A - Water treatment method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a water purification treatment method using membrane separation by which solid components in raw water are separated and removed, and simultaneously manganese and soluble organic substance can be removed. SOLUTION: A contact tank 20 is provided in the front stage of a membrane separation device 10 equipped with a membrane separation means 11 fir separating solid components is raw water. Powdery activated carbon is charged into raw water and the solid components in the membrane separation device 10 are returned to the contact tank 20 and with raw water. Thereby, soluble organic substance in raw water is adsorbed on the powdery activated carbon and removed. Soluble organic substance and soluble magnates are decomposed ands removed by microorganisms contained in the solid components.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for purifying water using membrane separation, and more particularly, to a facility for purifying clean water, sewage, waste water, etc. using a membrane separation apparatus, which is contained in raw water. The present invention relates to a method for simultaneously removing not only solid components but also soluble organic substances and manganese.

[0002]

2. Description of the Related Art For example, in a water treatment facility, a membrane separation device is used to separate and remove solid components (suspended components such as solids and flocs) contained in raw water. Solid-liquid separation has been used. On the other hand, when manganese is contained in the raw water, it is necessary to provide a manganese removal facility in front of the filtration treatment facility in order to remove manganese. As this manganese removal equipment, generally, a contact filtration method using manganese sand as a filter medium is used, but since a manganese removal equipment must be installed separately from the filtration treatment equipment, a space problem occurs. This will have a significant effect on equipment costs.

[0003] Furthermore, in order to remove soluble organic substances contained in raw water, contact treatment with microorganisms is generally performed. In order to carry out all of solid-liquid separation, manganese removal and soluble organic substance removal, Each of these processing facilities had to be provided.

[0004] Therefore, the present invention provides a water purification method using a membrane separation, which can separate and remove solid components in raw water and at the same time remove manganese and soluble organic substances by simply adding simple equipment to the membrane separation apparatus. It is intended to provide.

[0005]

In order to achieve the above object, the water purification method of the present invention comprises providing a contact tank in front of a membrane separation device having a membrane separation means for separating solid components in raw water, By pouring powdered activated carbon into water, returning the solid components in the membrane separation device to the contact tank and mixing with the raw water, the soluble organic substances in the raw water are absorbed by the powdered activated carbon and removed, and the solid components are removed. It is characterized by removing the soluble organic matter and manganese contained in the raw water by the microorganisms attached to the, further, before performing the membrane separation in the membrane separation device, characterized by performing a contact treatment with a biological contact layer. I have.

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in more detail with reference to the drawings. FIG. 1 shows an example of a water purification system for carrying out the water purification system of the present invention, and a membrane separation device 10 for separating and removing solid components contained in raw water.
Is provided with a contact tank 20 at the preceding stage.

The membrane separation apparatus 10 includes a treatment tank 12 provided with a membrane separation means 11, an inflow pipe 13 into which raw water from a contact tank 20 flows, and a solid component settled at the bottom of the tank. The membrane separation means 11 is provided with an outflow pipe 15 for sending treated water from which solid components have been separated to a subsequent treatment water tank or the like.

The contact tank 20 includes a raw water inflow pipe 21 into which raw water flows, the return pipe 14 for returning solid components (sludge) from the membrane separation device 10, a powdered activated carbon charging means 22 for charging powdered activated carbon. A stirrer 23 for stirring and mixing raw water and a solid component (including powdered activated carbon), and the inflow pipe 13 for feeding the water after stirring and mixing to the membrane separation device 10 are provided.

As the membrane separation means 11, various kinds of membrane separation means using a hollow fiber membrane or the like conventionally used for this type of treatment can be used. As shown in FIG. In addition to the immersion type in which the membrane module 11a is immersed, a casing storage type in which raw water is forcibly circulated can be used. In addition, the type of the membrane is not particularly limited, and can be appropriately selected according to the state of the raw water. For example, an MF membrane, a UF membrane, or an appropriate mesh network can be used.

[0010] Raw water flows into the contact tank 20 from a raw water inflow pipe 21 and is stirred by the stirrer 23.
Is mixed with the solid component drawn out from the bottom of the pipe to the return pipe 14 and pumped by the pump P, and the powdered activated carbon charged from the powdered activated carbon charging means 22. The raw water mixed with the solid component is sent from the inflow pipe 13 to the treatment tank 12 of the membrane separation device 10, where solid-liquid separation is performed by the membrane separation means 11, and the solid component insoluble in water is separated from the water to form a treatment tank. Settle at the bottom of the twelve.

The solid component containing the powdered activated carbon precipitated at the bottom of the treatment tank 12 is returned to the return pipe 14 together with a predetermined amount of water for transportation.
And circulates in the contact tank 20 via the pump P. On the other hand, the treated water from which the soluble organic matter and manganese have been removed and which has been separated from the solid components by the membrane separation means 11 is supplied to the outlet pipe 1.
From 5 is sent to a treatment water tank or the like.

In the above-mentioned flow, manganese and soluble organic substances dissolved in the raw water are decomposed and removed by microorganisms in the solid component returned from the treatment tank 12. At this time, by adding an appropriate amount of powdered activated carbon to the raw water, the soluble organic substances contained in the raw water can be adsorbed and removed by the powdered activated carbon, and the microorganisms that decompose the soluble organic substances and manganese can be removed. Since it can be circulated in a state of being attached to the powdered activated carbon, the concentration of microorganisms in the solid component returned from the treatment tank 12 to the contact tank 20 can be increased as compared with the case of only ordinary returned sludge.

As described above, the contact tank 20 is provided before the membrane separation apparatus 10, and the sludge extracted from the membrane separation apparatus 10 is returned to the contact tank 20 and mixed with the raw water, and the powdered activated carbon is put into the raw water. As a result, not only can soluble organic substances be adsorbed and removed on the powdered activated carbon, but also soluble organic substances and soluble manganese can be decomposed and removed by microorganisms attached to the powdered activated carbon, so that solid components can be separated and removed by membrane separation. And the removal of manganese and the removal of soluble organic substances can be performed simultaneously.

In addition, by appropriately setting the amount of powdered activated carbon to be charged, the density of microorganisms in sludge (solid component) returned from the return pipe 14 to the contact tank 20 can be appropriately increased. The efficient removal of soluble manganese, that is, the removal efficiency of manganese by biosorption is improved, so that stable removal of manganese can be performed even at a low water temperature. Further, the powdered activated carbon adsorbs the fine organic substances that cause the membrane clogging in the membrane separation means 11, so that the clogging of the membrane can be suppressed.

The powdered activated carbon may be continuously charged, but usually, an appropriate amount may be charged in a batch system according to the operation state such as the amount of sludge, and the charging position may be arbitrarily selected. Can be. In particular, by introducing the powdered activated carbon at a low water temperature at which the activity of the microorganisms is reduced, many microorganisms can be attached to the powdered activated carbon, so that even at the low water temperature, the same processing efficiency as in the normal case can be obtained.

Further, as shown in FIG. 2, between the membrane separation means 11 provided at the upper part of the treatment tank 12 and the raw water inlet 13a provided at the lower part of the tank, a biological contact layer capable of increasing the biological density. By providing the base 31 and performing the biological contact treatment before performing the membrane separation, the removal efficiency of manganese and organic substances can be further improved. The structure of the biological contact layer 31 can be the same as the contact material provided in the conventional contact treatment tank, and the other components can be configured in the same manner as in FIG. 1 above. The same reference numerals are given and the detailed description is omitted.

[0017]

As described above, according to the water purification method of the present invention, manganese, soluble organic substances, and solid components can be efficiently removed with equipment having a simple apparatus configuration.

[Brief description of the drawings]

FIG. 1 is a system diagram showing one embodiment of a processing facility for carrying out the method of the present invention.

FIG. 2 is a system diagram showing another embodiment.

[Explanation of symbols]

10 membrane separator, 11 membrane separator, 12 treatment tank,
13 ... inflow pipe, 14 ... return pipe, 15 ... outflow pipe, 20 ... contact tank, 21 ... raw water inflow pipe, 22 ... powder activated carbon charging means,
23: stirrer, 31: biological contact layer

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification code Agency reference number FI Technical indication location C02F 1/44 C02F 1/44 K 1/64 1/64 A (72) Inventor Genzo Ozawa Hokkaido (72) Inventor Tatsuhiko Suzuki 1-3-3 Kyobashi, Chuo-ku, Tokyo Inside Maezawa Kogyo Co., Ltd.

Claims (2)

[Claims] 1. A contact tank is provided in front of a membrane separation device provided with a membrane separation means for separating solid components in raw water, and powdered activated carbon is charged into the raw water to separate the solid components in the membrane separation device into the contact tank. And mixed with the raw water to remove and remove the soluble organic matter in the raw water by adsorbing on the powdered activated carbon, and remove the soluble organic matter and manganese contained in the raw water by the microorganisms attached to the solid components. A water purification method characterized by the following. 2. The water purification method according to claim 1, wherein a contact treatment with a biological contact layer is performed before performing the membrane separation in the membrane separation device.