JP3079604B2 - Water treatment equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a water treatment apparatus suitable for producing industrial water or drinking water using river water or lake water as raw water, and particularly to a water treatment apparatus provided with a coagulation treatment apparatus and a membrane separation apparatus. It relates to a water treatment device.

[0002]

2. Description of the Related Art As an apparatus for producing industrial water and drinking water using river water or lake water as raw water, the raw water is subjected to coagulation treatment,
In some cases, the water is introduced into a membrane separation device and the permeated water of the membrane separation device is obtained as product water.

[0003] In this case, a part of the concentrated liquid of the membrane separation device is further concentrated if necessary, and then returned to the coagulation treatment tank and used as a seed crystal.

[0004]

In the above-mentioned conventional water treatment apparatus, an adhesive substance that is impermeable to a membrane (mainly composed of a minute organic substance) accumulates on the concentration side, and the permeation rate of the membrane increases with time. There is a problem that it decreases.

[0005] In particular, such a problem becomes more remarkable when raw water having little organic pollution such as river water is targeted.

[0006]

The water treatment apparatus of the present invention comprises:
Coagulation treatment means for coagulating raw water for water purification, a membrane separation device for membrane-separating the condensed liquid from the coagulation treatment means, a solid-liquid separation means for solid-liquid separation of concentrated water of the membrane separation device, and the solid-liquid separation Means for discharging the sludge separated by the means to the outside of the system, and means for removing permeated water of the membrane separation device and clarified water separated by the solid-liquid separation means to the outside of the system as production water. It is.

[0007]

In the water treatment apparatus of the present invention, the permeated water subjected to the coagulation treatment and the membrane separation treatment is obtained as the production water. The concentrated liquid of the membrane separation device is separated into solid and liquid, clarified water is used as production water, and sludge is discharged out of the system.

[0008] Thus, the raw water is treated in a one-time manner.
Then, since the concentrated water is not returned to the coagulation treatment step, there is no accumulation of the sticky substance on the concentration side. As a result,
The membrane permeation rate is high for a long time.

[0009]

Embodiments will be described below with reference to the drawings.

FIG. 1 is a system diagram of a water treatment apparatus according to an embodiment of the present invention.

Raw water such as river water, lake water, city water, pre-treated industrial water, brackish water, and groundwater is supplied to an intake tank 10 and sent to a coagulation tank 14 via a water pump 12. Into the coagulation tank 14, a pH adjusting agent such as sulfuric acid, or a chlorine agent such as sodium hypochlorite, as well as a coagulant such as polyaluminum chloride (PAC) are stored in respective storage tanks 16,
It can be supplied from pumps 16a, 18a and 20a from pumps 18 and 20. 22 is a stirring device.

The liquid in which flocculation floc has occurred in the flocculation tank 14 is sent to a membrane separation device 26 via a pressure pump 24. Reference numeral 28 denotes a separation membrane. As the separation membrane 28, various types such as a microfiltration membrane, an ultrafiltration membrane, and a reverse osmosis membrane are used.

The permeated water of the membrane separation device 26 is sent to a production water tank 30 as production water. The concentrated water is sent to the settling tank 32 and subjected to solid-liquid separation processing. The settled sludge is discharged out of the system. The supernatant of the sedimentation tank 32 is further filtered (filter material is
Sand, anthracite, etc. are optional. ) 34,
After being filtered, it is sent to the production water tank 30.

As described above, in the apparatus of this embodiment, the raw water is treated in a one-time manner, and the concentrated liquid in the membrane separation device 26 is not returned to the coagulation tank 14. Therefore, there is no accumulation of the sticky substance on the upstream side of the separation membrane 28 of the membrane separation device 26.
For this reason, the rate of adhesion of the adhesive substance to the membrane surface of the membrane separation device 26 is extremely low, and a stable membrane separation process can be performed for a long time, and the operation stability of the entire device is significantly improved.

In the above embodiment, the sedimentation tank 32 and the filter 34 are used as the solid-liquid separation means. However, only one of the sedimentation tank 32 and the filter 34 may be provided. As the solid-liquid separating means, various kinds of solid-liquid separating means such as a pressurized flotation device can be used in addition to the sedimentation tank and the filter. Of course, various things can be adopted also as a sedimentation tank and a filter.

In the above embodiment, polyaluminum chloride is shown as the flocculant, but various types such as a sulfuric acid band and an iron-containing sulfuric acid band can be used. When such an aluminum-based inorganic coagulant is used, although it depends on the water quality, usually 1 to 10 aluminum ions are used.
It is preferred to add at a rate of mg / l.

Further, as the pH adjuster, various acids and alkalis can be used in addition to sulfuric acid.

[0018]

As described above, according to the water treatment apparatus of the present invention, the raw water is subjected to the coagulation and membrane separation processing in a transient manner, and the concentrated liquid in the membrane separation processing is not returned. Accordingly, there is no accumulation of the sticky substance on the concentration side, the membrane permeation rate of the membrane separation device is high for a long time, and a stable water treatment operation can be performed.

According to the present invention, raw water having a low SS (suspended substance) can be efficiently treated.

[Brief description of the drawings]

FIG. 1 is a system diagram of an apparatus according to an embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Intake tank 14 Coagulation tank 26 Membrane separation apparatus 30 Production water tank 32 Sedimentation tank 34 Filter

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification code FI C02F 9/00 503 C02F 9/00 503A

Claims (1)

(57) [Claims] 1. An aggregating means for aggregating raw water for water purification, a membrane separation device for membrane-separating an aggregating liquid from the aggregating means, and a solid-liquid separation means for solid-liquid separating concentrated water of the membrane separation device. Means for discharging the sludge separated by the solid-liquid separation means out of the system, and means for removing permeated water of the membrane separation device and clarified water separated by the solid-liquid separation means out of the system as production water, A water treatment device comprising: