JPH0194995A - Water treatment apparatus - Google Patents

Abstract

PURPOSE:To perform continuous operation, by arranging an ozonated water injection pipe to the feed-in part of an electrode unit to open the same and injecting ozonated water on the upstream side of an electrode cell. CONSTITUTION:The sewage in a raw water tank 9 is supplied to a water treatment tank 95 by a raw water pump 91 and a proper additive is injected in said sewage from a chemical liquid container 93 by a chemical liquid injection pump 94. Further, ozonated water is injected in the water treatment apparatus or in a raw water supply route from an ozonated water generator 29 by a pump 28. The purified water treated in the water treatment apparatus 95 is sent to a flotation tank 95 to perfectly remove the residual scum in the purified water. By this method, removal capacity can be enhanced.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to an electric water treatment device that removes pollutants from a liquid.

(Prior Art) Conventionally, an electric sewage treatment apparatus shown in FIG. 10 has been proposed (Japanese Patent Laid-Open No. 59-87093).

The processing device includes a processing tank (1) formed of an insulating material.
00), the sewage inflow pipe (105) is installed at the bottom, and the outflow pipe (105) is installed at the top.
106) are connected, and two electrode plates (101) and (102) with a large number of holes (103) are arranged above and below with a gap between them, and the lower electrode plate is the positive electrode, and the upper electrode plate is the positive electrode, and the upper electrode plate is the positive electrode. The electrode plate is energized to serve as a negative electrode, and the electrolytic chamber formed between the electrode plates is filled with a large number of spherical fillers (107) made of a soluble metal with a high ionization tendency, such as an aluminum alloy. ing.

The treatment tank (100) is supplied with wastewater to which an additive for promoting the reaction, such as aluminum chloride, is added from an inflow pipe (105). This wastewater is removed from the lower electrode plate (1
01) and flows into the electrolytic chamber, and rises through the gap while coming into contact with the filler (107).

When the wastewater passes through the spaces between the fillers (107) and rises, various pollutants in the wastewater are electrically neutralized, precipitate, and coagulate. On the other hand, metal ions are eluted from the surface of the filler (107) and react with chlorine ions and the like in the wastewater to generate aluminum hydroxide.

The aluminum hydroxide causes covalent bonding, adsorption, inclusion, etc. with the precipitate, and gradually forms an insoluble floc. Further, these flocs adsorb hydrogen gas generated on the negative electrode side and oxygen gas generated on the positive electrode side, so that their apparent specific gravity becomes smaller and they float to the top of the processing tank (100).

The pollutants (scum) floating in the form of flocs flow out from the outflow pipe (106) in a two-layer flow with water, and are supplied to a well-known flotation separation tank (not shown), where the scum is removed. It will be done.

Furthermore, the above device converts pollutants into harmless and stable substances through the oxidation reaction that occurs when the wastewater passes through the positive electrode plate (101) and the reduction reaction that occurs when the wastewater passes through the negative electrode plate (92). Converts into substances and reduces BOD, COD, etc.

(Problem to be Solved) However, in the above-mentioned electric sewage treatment equipment, the negative electrode plate (102) is oxidized and the surface is covered with insulating hydroxide, reducing the electrical treatment performance. There was a problem with continuous operation during the period.

(Means for solving the problem) The inventor repeated various experiments in order to solve the above problem, and as a result, ozone water was mixed with raw water, and ozone water was applied to the electrode plate during electrochemical treatment. It was discovered that by contacting the negative electrode plate, there was less adhesion of hydroxide and reaction products to the negative electrode plate, leading to the completion of the present invention.

In the electric water treatment device according to the present invention, an ozonated water injection pipe is installed and opened at the inlet of the electrode unit, and ozonated water is injected into the upstream side of the electrode tank and passed between the electrode plates together with the raw water. In this method, ozonated water is applied to the electrode plate.
(Operations and Effects of the Invention) The raw water mixed with ozonated water to be treated is caused to flow from the inlet at the bottom of the treatment tank to the inlet at the bottom of the electrode unit, and is passed one after another through the through holes in the lowest electrode plate. It rises through the through hole to the upper electrode plate, and finally flows out from the uppermost electrode plate, filling the processing tank, and is sent out from the outlet. Since each electrode plate of the electrode unit is alternately energized positively and negatively,
When it passes through the negative electrode plate, it reacts with the metal ions of the eluted soluble metal, and when it passes through the positive electrode plate, it undergoes electrochemical action. As the raw water passes through the electrode unit, it receives alternating positive and negative electrical effects from each electrode plate.

As the pollutants are repeatedly subjected to electrochemical action whose polarity changes significantly from positive to negative and from negative to positive, the surface charge of most pollutants is neutralized, resulting in countless of metal hydroxide particles are produced.

The metal hydroxide particles are easily combined by collision with each other, and flocculation progresses sequentially. Furthermore, these flocs adsorb hydrogen gas generated on the negative electrode side and oxygen gas generated on the positive electrode side, and their apparent specific gravity decreases, causing them to float to the top of the processing tank.

Ozonated water decomposes and peels off the reaction products that adhere to the negative electrode plate, so the negative electrode plate is not covered with insulating products like in the past, and the electrolytic action can be sustained, making it suitable for water treatment equipment. Enables long-term continuous operation.

In addition, ozonated water exhibits a sterilizing effect on raw water and has a remarkable effect on improving water quality.

(Example) FIGS. 1 to 3 show an example of a sewage treatment apparatus according to the present invention.

The outer tank (1) is made of an insulating material such as FRP, and the inside is partitioned into a plurality of processing tanks (2) by partition walls (11).

A scum storage chamber (13) is formed in the upper part of the outer tank (1) adjacent to each treatment tank (2), and a scum discharge port (14) is provided at the bottom thereof.

The processing tank (2) is divided into upper and lower sections by a bottom plate (21) provided at the lower part, forming an inflow chamber (22) and a processing chamber (23).

A mounting hole (24) is made in the bottom plate (21), and an electrode unit (6) is installed in the bottom plate (21), and the water in the inflow chamber (22) rises in the electrode unit (6) and is treated, then flows into the treatment chamber. (23).

A raw water inlet (3) is arranged on the upstream side of the first stage treatment tank (2a), and a connecting pipe (31) connects the raw water inlet (3) and the inflow chamber (22) of the treatment tank. It communicates with the open inflow hole.

A treated water discharge part (4) is provided in the final stage treatment tank (2b), and communicates with the discharge part (4) through an outflow hole (41) formed in the side wall of the treatment chamber.

The outflow hole that opens into the processing chamber (23) of each processing tank and the inflow hole that opens into the inflow chamber (22) of the adjacent processing tank on the downstream side communicate with each other through a connecting pipe (25), and the processing chamber ( 23) flows through the connecting pipe (25) to the inlet chamber (2) on the downstream side.
2) and is repeatedly processed through the processing tanks (2) of each stage in sequence.

The raw water inlet section (3) is divided into three chambers by two partition plates (32) and (33), and raw water is supplied from the raw water tank (9) to the second chamber (34) by a pump (91).

A triangular weir (36) is formed on the partition plate (32) between the second chamber and the third chamber (35), and the raw water overflows from the second chamber (34) to the third chamber (35). The amount of water to be sent to the treatment tank (2a) is measured by the connecting pipe (31).

Also, the partition plate (33) between the second chamber (34) and the first chamber (37)
An adjustment plate (38) is arranged to be able to slide up and down,
The first chamber (3) extends beyond the opening (39) of the partition plate and the adjustment plate.
By adjusting the amount of raw water that flows into the tank 7) and returns to the raw water tank (9), the amount of water that exceeds the triangular weir (36), and therefore the water level in the outer tank (1), is determined.

A chemical injection nozzle (92) is arranged in the third chamber (35), and a suitable chemical solution such as aluminum sulfate, sodium chloride, calcium hydroxide, etc., which promotes the aggregation of pollutants in raw water is supplied from a chemical solution container (93). The infusion pump (94) is used to infuse the solution to a concentration of 5 to 20 ppm.

The treated water outflow part (4) is divided into two chambers by a partition plate (43) equipped with a slide plate (42), and the treated water from the outflow hole (41) of the final stage treatment tank (2b) is 1 room (4
4), overflows into the second chamber (46) over the window hole (45) of the slide plate (42), and is discharged.

A scum removal device (5) driven by a motor (51) is disposed above the outer tank (1). The device has two rotating shafts (52) passing above each treatment tank (2).
(52) are arranged in parallel, and sprockets (53) on parallel axes are installed in parallel.
) (53) Two endless chenos stretched between them (54)
A plurality of mounting rods (55) are fixed to (54), and a flexible scraping plate (56) is fixed to each mounting rod (55) at a position corresponding to the processing tank.

The inflow chamber (22) of each treatment tank has an ozone water injection pipe (2).
) is provided, and its tip is opened below the electrode unit (6). The ozone water injection pipe (27) is connected to the ozone water generation fi (29) via a pump (28), and the ozone-containing water is supplied to the inlet (65) of the electrode unit (6).
), mixed with the water to be treated and passed through the electrode plate to prevent reaction products such as hydroxide from adhering to the electrode plate and promote peeling.

The amount of ozone water to be injected is set at a rate of 1001/hour when the amount of raw water to be treated is 6 tons/hour and the ozone water concentration is 230 mg/1001/hour.

The electrode unit (6) has various configurations, and as an example, as shown in FIG. Negative electrode plates (8) and positive electrode plates (81) are arranged alternately, and each electrode plate (8) (81) has a large number of through holes (82).
A system that enables the distribution of water to be treated by opening a water tank is used.

The housing (61) is open at the top and bottom to form a water inlet (62) and a water outlet (63), and the lower part is lower than the lowest electrode plate and has an outer backing (64) on the bottom surface. A direction flange (65) is provided protrudingly. Therefore, the electrode unit (
6) is placed on the bottom plate (21) of the processing tank (2), the lower part of the housing fits into the mounting hole (34) made in the bottom plate, the flange (65) rides on the opening edge, and the mounting hole (24)
A removable installation is carried out that closes the area.

Each electrode plate (8) (81) has a square shape with a side of 13 cm as shown in FIGS.
The number, arrangement, and diameter of 2) are arbitrary, but as an example, one in which holes with a diameter of 10 axes are opened in five rows vertically and horizontally is used.

The electrode plates (8) (81) are attached to the stays (
66), the upper and lower surfaces are fixed, and the assembly is carried out by alternately gluing the stay and installing the electrode plate. Screw in the screws (84) from the side of the housing toward each electrode plate, and the screws are divided into two groups, one screwed into the positive electrode plate (81) and the other screwed into the negative electrode plate (8). The positive and negative terminals are connected separately to a current-carrying line (7) drawn in from the outside. Screws (84) and connection wires (8) protruding from the side of the housing
5) Cover and insulate the top with an airtight insulating case (86).

The tip of the current-carrying wire (7) is connected to the processing tank (2) as shown in Figure 3.
The terminal board (1) is pulled out to the outside through a draw-out pipe (12) protruding diagonally upward from the front wall of the
71), and energizes each electrode plate of the electrode unit (6).

The negative electrode plate (8) is a titanium plate (83) with a thickness of 1 ring on the upper and lower surfaces of an aluminum plate (8) with a thickness of 10+++ m.
and cover it with plastic screws (84) on both plates (83
) (87) and is fixed in one piece. The metal component of the aluminum plate (87) is aluminum or
For example, Fe: 5.0%, Mg: 4.5%, Ni: 1.0
%, C': 0.25%, Zn: 0.25%, Cu: 0.
2%, the balance is an aluminum alloy. Note that the aluminum plate is made of iron or, for example, Ni: 1.6%, Mn:
0°9%, Cr: 0.6%, C: 0.35%, Si: 0
．． 35%, Mo: 0.3%, P: 0.01%, S: 0.
01%, and the balance can be replaced with an iron alloy or other soluble metal.

A plate of carbon such as graphite is used as the positive electrode plate (81).

FIG. 7 shows another embodiment in which the electrode unit (6) is installed in the processing tank (2), and the processing tank (2) does not include an inflow chamber.
An inflow hole (26) is provided at the lower end of the partition wall (11).

The electrode unit (6) connects the lower end of the housing (61) to the bottom wall (67).
), and an inlet (82a) is opened in the side wall of the housing to form an inflow chamber (68) on the bottom wall (67).

When the electrode unit (6) is sunk to the bottom of the processing tank (2), the inflow hole (26) and the inlet port (62a) are aligned, and the engagement surface formed on the edge of the hole fits into the engagement receiving surface. The position of the electrode unit can be determined by the fit.

As the wastewater passes through the electrode unit (6), it is electrically shaken greatly as it passes through each electrode plate, and is alternately subjected to oxidation and reduction effects.

During this time, decomposition of pollutants occurs, and chlorine ions contained in the wastewater combine with free oxygen, which becomes an oxidizing agent and reacts with the negative electrode plate. As a result, aluminum hydroxide and iron hydroxide are produced, and these are precipitated in the wastewater.

Further, hydrogen gas is generated from the surface of the negative electrode plate, and oxygen gas is generated from the surface of the positive electrode plate, and rises in the form of bubbles with a diameter of, for example, 10 to 30 μm. The rising speed of the bubbles is about 1.5~
4.5 cm/see, and these rising air bubbles generate convection between the electrode plates and within the processing chamber (23), which promotes the formation of flocs in decomposing the pollution, and the rising air bubbles adsorb these flocs. It is floated to the upper part of the processing chamber (23).

In addition, even if the wastewater supplied to the first stage treatment tank (2a) is biased towards acidity or alkalinity, the wastewater can be gradually neutralized by passing through each electrode plate in the electrode unit in sequence. The pH has converged to approximately 7 at the time the battery approaches and leaves the electrode unit (6).

The negative electrode plate (8) is subjected to a treatment mainly based on a reducing effect, and the positive electrode plate (81) is subjected to a process mainly based on an oxidizing effect, and by repeating these two stages of processing multiple times, the unique characteristics of each The decomposition and removal of pollutants are carried out.

FIG. 11 shows an electrode unit (60a) (sob) that exhibits higher processing efficiency than the electrode unit shown in FIG.
The figure shows a water treatment equipment equipped with

The outer tank (1) is partitioned with a partition wall (11) to form an upstream treatment tank (2).
a) and a downstream processing tank (2b) are formed, and a first inflow chamber (22m) and a first inflow chamber (22a) are formed at the bottom of the image processing tank, respectively.
The 0-car processing tank (2m) (2b) forming the connecting pipe (
25).

A first inflow chamber (22) formed at the bottom of the upstream treatment tank (2a)
Connect the raw water inflow pipe (30) to the downstream treatment tank (2b)
) A purified water outflow hole (41) will be established in the center of the area. Further, a first chamber (44) and a second chamber (46) are formed in communication with the outflow hole (41), and a partition wall between the two chambers (44) and (46) includes:
A triangular weir (47) is installed to adjust the water level of the outer tank (1), and purified water is sent out from the bottom of the second chamber (46).

Electrode units (
60a) (60b), and install the picture electrode unit (60b).
a) The lower opening of (Bob) is the inflow chamber (22a) (22
b).

The electrode unit (Boa) (60b) has first electrode plates (88a) (89a) and second electrode plates (88b) (89b) inside a cylindrical housing made of an insulating material such as vinyl chloride or FRP. ), and the third electrode plate (88c)
(89c) are fixed at intervals. Each electrode plate has a large number of through holes extending vertically through the electrode plate.

The first electrode plate (88a) of the upstream electrode unit (60m)
) and the third electrode plate (88c) are the positive electrode, and the second electrode plate (88c) is the positive electrode.
b) is energized so that it becomes a negative electrode, and the downstream electrode unit (
sob) first electrode plate (89a) and third electrode plate (89
Electricity is applied so that c) becomes the negative electrode and the second electrode plate (89b) becomes the positive electrode. As a result, a reaction mainly consisting of oxidation occurs in the upstream electrode unit (60a), and the downstream electrode unit (60a)
In (60b), a reaction mainly consisting of reduction occurs.

The electrolytic chamber formed between each electrode plate is filled with a large number of pipe pieces (72) each having a porous hydroxide film formed on its surface. Among the many pipe pieces (72) in the electrolysis chamber,
Most of them are made of aluminum alloy, and 2 to 5% of the total is made of iron base metal.

The pipe piece (72) made of aluminum alloy is pi-t
100 in an aqueous solution of calcium hydroxide adjusted to 11
By soaking for a period of time, a hydroxide film having a thickness of approximately 10 μm is formed on the surface. As is well known, the hydroxide film is porous (a porous layer) and can contain water.

Therefore, a large number of pipe pieces (72
) are electrically connected to each other via a water-containing hydroxide film, and at the same time, metal ions can be eluted into water through the hydroxide film.

Although the numerous pipe pieces (72) in the electrolytic chamber are in random positions, there are countless gaps between each pipe piece that communicate with each other, so the flocs can easily pass through these gaps and holes. and floats to the top of the processing layer. These flocs therefore do not accumulate between the pipe pieces.

The electrode units of the above-mentioned examples have extremely high performance, so if they are used directly on raw water containing a large amount of pollutants, a large amount of flocs of pollutants will form between the electrode plates, filling them and causing water flow. prevent. Therefore, raw water is first passed through a known water treatment device to complete the primary and secondary treatment, and a certain amount of pollutants are removed, which is used as raw water.Finally, the pollutants remaining in the water are completely removed, and the water is deodorized. It is desirable to use it for the tertiary treatment of decolorizing and clarifying.

Figure 1 shows an example in which all stages of treatment tanks (Fig. 4) are installed with electrode units, but this is a case where the raw water has already been subjected to secondary treatment.A case where the raw water is untreated In this case, it is desirable that the electrode unit (6a) shown in FIG. 8 be used in the first stage, and the electrode unit (6) shown in FIG. 4 be used in the second and subsequent stages.

The electrode unit (6a) in FIG. 8 has a housing (61) with
Electrode plates (8a) (81a) are vertically erected and arranged with alternating polarities. The raw water rises along the plane of the electrode plate, and after being subjected to one electric action to precipitate most of the pollutants, the treated water is supplied to the inlet chamber of the next stage treatment tank.
Next, since high-performance treatment is performed by the electrode unit shown in FIG. 4, the treated water becomes highly clear water that meets drinking standards.

The inventor constructed a sewage purification system as shown in FIG. 9 using the water treatment apparatus shown in FIG.

Sewage in the raw water tank (9) is supplied to a water treatment device (95) by a raw water pump (91). Note that a suitable additive is injected into this wastewater from a chemical liquid container (93) using a chemical injection pump (84). Furthermore, the ozonated water from the ozonated water generator (29) is pumped (
28). Water treatment bag! The purified water treated by (95) is further sent to a well-known flotation tank (96) to completely remove residual scum in the purified water.

The conventional apparatus shown in FIG. 10 not only has low processing efficiency, but also has the problem that flocs tend to accumulate between the spherical fillers (107), making continuous operation impossible.

In contrast, in the water treatment apparatus described above, there is almost no adhesion of products to the negative electrode plate, and continuous operation with high efficiency is possible.

It goes without saying that the configuration of each part of the present invention is not limited to the above-mentioned embodiments, and various modifications can be made within the technical scope of the claims.

For example, the effluent from the scum storage chamber shown in FIGS. 2 and 3 contains a small amount of additives added to the treated water, so after separating the scum from the effluent,
It is possible to further supply this into the device through a connecting pipe to effectively utilize the additive.

The arrangement of each electrode plate in FIG. 1 may be reversed, or
Increase the number of electrode plates (8) (81) to be arranged in the housing, increase the number of electrode units installed in the processing tank (2) to two or more, and form them in the outer tank (1). Processing tank (2
), the removal performance can be further improved.

[Brief explanation of the drawing]

Figure 1 is a partially cutaway front view showing the outline of the water treatment equipment;
Fig. 2 is a plan view of the same as above, Fig. 3 is a sectional view taken along the line ■-■ in Fig. 1, Fig. 4 is a longitudinal sectional view of the electrode unit, Fig. 5 is a plan view of the negative electrode plate, and Fig. 6 is a cross-sectional view of the same as above, FIG. 7 is a vertical cross-sectional view of an electrode unit of another embodiment, FIG. 8 is a vertical cross-sectional view of a conventional electrode unit, and FIG. 9 is an explanatory diagram of the overall system arrangement of a water treatment device. Figure 10 is a sectional view of the conventional device;
The figure is a partially cutaway front view schematically showing a water treatment device of another embodiment. (2)...Processing tank (27)...Ozone injection tube (6)...Electrode unit (8)...Negative electrode plate (8
1)... Positive electrode plate Fig. 7 Fig. 8

Claims (4)

[Claims] (1) A treatment tank with an inflow hole for raw water at the bottom and an outflow hole for treated water at the top, an inlet that is installed in the treatment tank and communicates with the inflow hole at the bottom of a cylindrical housing, and an outflow hole at the top of the housing. It is composed of an electrode unit that has a communicating outlet, and has electrode plates with alternating polarities in the housing, and an ozonated water injection tube whose tip is opened opposite the inlet of the electrode unit. Water treatment equipment. (2) The apparatus according to claim 1, wherein a plurality of processing tanks are installed, and the outflow hole of the upper processing tank communicates with the inflow hole of the lower processing tank via a connecting pipe. (3) The electrode unit has a plurality of electrode plates with a large number of through holes on the surface disposed in the housing between the inlet and the outlet, and the negative electrode plate is made of soluble metal. The device according to claim 1 or 2. (4) The electrode unit has a plurality of electrode plates with a large number of through holes on the surface disposed in the housing between the inlet and the outlet, and the electrolytic chamber formed between the electrode plates contains soluble 3. Device according to claim 1, characterized in that it is filled with pipe pieces made of metal.