KR20040013921A - Water processing apparatus unifying ozone reactor and filtration equipment and the method for water purification thereby - Google Patents

Abstract

PURPOSE: Provided is a raw water treatment apparatus being capable of maximizing purification efficiency by combining an ozone reactor and a filter in a single body, and further provided is a method for purifying water using the same apparatus. CONSTITUTION: The apparatus comprises a raw water tank(1), a pump(2) for transferring raw water from the raw water tank(1) to a reaction and filter tank(9), a raw water inlet pipe(3) provided between the raw water tank(1) and the reaction and filter tank(9), a valve(4) installed on the raw water inlet pipe(3) for controlling flow of raw water to the reaction and filter tank(9), an ozone generator(5) for generating ozone, an air inlet pipe(6) for supplying air to the ozone generator(5), an ozone transferring pipe(7) provided between the ozone generator(5) and the raw water inlet pipe(3), an injector(8) installed at a connection point of the ozone inlet pipe(7) and the raw water inlet pipe(3) for injecting ozone to the raw water inlet pipe(3), the reaction and filter tank(9) with a filter containing iron and manganese at a lower portion thereof and an upper space(10) for collecting ozone gas which is not dissolved in raw water and remained, a back washing water discharging pipe(11) connected to the upper space of the reaction and filter tank(9), and a residual ozone return pipe(13) for returning the collected ozone to the ozone generator(5) and a treated water outlet pipe(14) which is connected to the reaction and filter tank(9).

Description

Raw water treatment unit unifying ozone reactor and filtration system, and water purification method using same {water processing apparatus unifying ozone reactor and filtration equipment and the method for water purification

The present invention relates to a raw water treatment device unified with an ozone reactor and a filtration device, and a water purification method using the same.

Recently, water pollution is accelerating, and as the damage is serious, such as trace organic substances, pathogenic microorganisms, and chlorine disinfection by-products, which are harmful to the human body, even in tap water, the development of an efficient raw water treatment device is being actively performed.

Currently, the raw water treatment devices that are in the spotlight are highly purified water treatment devices such as advanced oxidation technology using ozone (hereinafter referred to as 'Ozone AOT'), technology using activated carbon or sand filtration, and water recycling using biological processes or membranes. Process and the like.

Ozone AOT is a technology that decomposes various pollutants in water by using ozone's powerful oxidizing power, and can purify polluted water quality in various fields with excellent efficiency.

However, this method is disadvantageous in that the initial installation cost is high, the efficiency is lowered below a certain pH, and is affected by the concentration of the wastewater component and the UV absorption ability. In addition, the ozone utilization efficiency of the currently used ozone reactor is only 60 to 70%.

A technique using a filtration device is a method using the adsorption force of the filter medium to the contaminants. Recently, a method of treating bioactive carbon, which is widely used, is a method of purifying water quality by adsorption of activated carbon and decomposition of microorganisms present therein.

This method has the advantage that it is environmentally friendly and there is little concern about additional environmental pollution in terms of using microorganisms, but due to the environmental characteristics of Korea where the raw water temperature fluctuates year-round, the activity of microorganisms is not constant and treatment efficiency may be lowered.

In order to maximize the efficiency of the above methods, AOT research has been conducted to purify the water quality by combining ozone treatment and activated carbon filtration techniques, but activated carbon has a weak durability against ozone, which may degrade and prolong its exposure to ozone. It appears that it can be difficult to maintain the purification effect, and the problems inherent in each technology have not been solved.

Meanwhile, the water reuse process is a method of purifying water quality using biological processes or membranes. Recently, the water quality requirements for treated water have been strengthened due to severe human hazards and ecosystem disturbance caused by environmental hormones in the treated water, but the current level of efficiency of treatment of current water reprocessing process is very low to meet these requirements. In order to increase the purification efficiency, additional installation of the secondary purification device, such as the use of a disinfectant or a UV lamp must be installed separately, inevitably costly.

Therefore, there is a need for an invention of a raw water treatment apparatus and a water purification method capable of purifying contaminated water quality economically and with high efficiency.

The present invention is to provide a raw water treatment apparatus and a water purification method using the same by installing an ozone reactor and a filtration device in a single reactor together to maximize the purification efficiency.

1 is a view showing the detailed structure of the raw water treatment apparatus of the present invention.

2 is a view showing the result of purifying the raw water contaminated by p- CBA using the raw water treatment apparatus of the present invention.

Figure 3 is a diagram showing the results of measuring the decomposition rate of p- CBA by the raw water treatment apparatus of the present invention by time.

The present invention provides a raw water treatment apparatus in which an ozone reactor and a filtration unit are unified, and a water purification method using the same.

The structure of the raw water treatment apparatus of the present invention is shown in Figure 1, the raw water storage tank (1) in which contaminated raw water is stored, the pump (2) for moving the raw water from the raw water storage tank to the reaction filtration tank (9), and reacts with the raw water storage tank A raw water inlet pipe (3) connected between the filtration tanks to provide a feed path for the raw water, an inlet valve (4) located on the raw water inlet pipe to control the opening and closing of the raw water inlet pipe, and ozone generating ozone to be used for purification of the raw water Generator (5), air inlet tube (6) for supplying air to ozone generator, ozone inlet tube (7) connected between ozone generator and raw water inlet tube to provide ozone migration path, ozone inlet tube and raw water inlet tube Injector (8) is installed at the junction point of the injecting ozone into the raw water inlet pipe, the raw water inlet pipe is connected to the upper portion, the reaction filtration tank (9) with a built-in iron or manganese-containing filter medium filling layer, the upper part of the reaction filtration tank Residual gaseous ozone, which is not located in the raw water, is collected in the upper part of the reaction filtration tank 10 so that only the raw water containing liquid ozone flows into the filter packing layer, and the backwash water discharge pipe 11 connected to the upper part of the reaction filtration tank. , A backwash water discharge pipe valve 12 located on the backwash water discharge pipe, a residual gaseous ozone moving pipe 13 connected to the upper space of the reaction filtration tank to return the remaining gaseous ozone to the ozone generator, and a process located at the bottom of the reaction filtration tank. It is characterized by consisting of a water outlet pipe (14).

Hereinafter, each part and role of the raw water treatment apparatus of the present invention will be described in detail.

In the raw water storage tank 1, raw water such as contaminated constant raw water, groundwater, seawater, domestic water and industrial wastewater is stored.

The stored raw water passes through the raw water inlet pipe (3) by the pump (2), is mixed with ozone in the middle and flows into the upper portion of the reaction filtration tank (9).

The ozone to react with the raw water is generated by the ozone generator 5, and the ozone generator is provided with an air inlet tube 6 so that oxygen in the air injected from the inlet tube is converted into ozone by a device in the ozone generator.

In the raw water treatment device of the present invention, the ozone generator may be provided with any ozone generator that has been used in the past, such as a high pressure silent discharger with a corona, an ultraviolet irradiator with a UV lamp, or an electrolyzer.

Gas ozone generated by the ozone generator is introduced into the raw water inlet pipe by an injector 8 located at the junction of the ozone inlet pipe and the raw water inlet pipe via an ozone inlet pipe 7 connected to the ozone generator.

The operating principle of the injector utilizes a phenomenon in which the differential pressure in the front and rear of the injector is generated by the fluid flow generated when the raw water is introduced into the raw water inlet pipe by the pump, and ozone is introduced into the injector by this pressure difference. Since ozone is injected by this naturally occurring pressure, there is no need to install a separate fan to transport air or ozone.

Ozone entering the injector is finely sprayed into the raw water inlet and mixed with the raw water. In the raw water treatment apparatus of the present invention, the dissolution rate of ozone by the injection of the injector is very high compared to the conventional bubbler. In addition to the injector during the ozone injection, an injection method in which ozone is permeated through the membrane and dissolved in raw water is possible.

Raw water and ozone introduced into the raw water inlet pipe are introduced into the reaction filtration tank (9). Liquid ozone dissolved in raw water in ozone primarily purifies raw water by oxidizing and sterilizing contaminants such as organic matter, inorganic matter and pathogenic microorganisms in raw water. By liquid ozone, organics are either fully oxidized or broken down into intermediate materials, inorganics are treated in the form of precipitates, and pathogenic microorganisms such as bacteria, viruses and protozoal cysts are inactivated.

Untreated organics, inorganics, pathogenic microorganisms, environmental hormones and oxidative by-products, together with the liquid ozone that has not reacted with the contaminants, are settled by gravity into the filter bed below the reaction filtration tank.

In the raw water treatment apparatus of the present invention, the filter medium includes sand having a small amount of metal oxides such as iron (Fe) and manganese (Mn) on the surface thereof, and the sand is heat-treated at a high temperature to remove natural organic matter from the surface. Can be used. Specifically, it is preferable to heat the order-spinning at 500 ° C.

In the raw water treatment device of the present invention, the filter medium is also preferably a granulated iron oxide. Iron oxides are ozone degrading and have good adsorption to heavy metals and other harmful substances. In the present invention, it is preferable to use granulated natural iron minerals such as goethite (α-FeOOH) and hematite (hemathite, γ-FeOOH). When using natural iron mineral in the raw water treatment device of the present invention, the installation cost is increased compared to the sand, but the catalytic effect is strong when ozone decomposition can be expected to have a higher oxidation effect than the sand.

In the raw water treatment apparatus of the present invention, the filling rate of the filter medium in the reaction filtration tank is preferably in the range of 0.4 to 0.8.

The contaminants collected in the filter bed are subjected to a purification step in two aspects as the residence time in the reactor is extended.

First, due to the high adsorption force of the filter medium used in the raw water treatment apparatus of the present invention, contaminants that remain untreated in raw water can be removed from the raw water.

In addition, unreacted liquid ozone collected by the filter medium filling layer together with contaminants is decomposed into hydroxyl radicals (OH ·) by transition metals such as iron and manganese on the surface of the filter medium. More oxidative and reactive than (E ^o = 2.07 V) (E ^o = 3.06 V). Thus, radicals can oxidize hardly degradable microorganisms and environmental hormones that are less reactive with ozone and can sterilize microorganisms and protozoans that are resistant to oxidants. Oxidation and sterilization of such radical radicals can also bring about an effect of regenerating the filter medium.

In this way, the secondary filter is performed in the filter medium filling layer due to the adsorption of contaminants by the filter medium filling layer and the oxidation of hydroxyl radicals.

Meanwhile, as the amount of sewage treatment increases, contaminants deposited on the filter medium filling layer are removed by the backwash water discharge pipe 11 connected to the upper portion of the reaction filtration tank. The backwash water discharge pipe valve 11 and the backwash water discharge pipe valve positioned on the backwash water discharge pipe temporarily change the direction of movement of the treated water, so that contaminants in the filter medium filling layer are backwashed by the flow rate of the treated water flowing from the lower part to the upper part. The water is discharged through the discharge pipe.

On the other hand, ozone which is not dissolved in raw water and remains in a gaseous state is collected in the reaction filtration tank upper space 9. In addition to gaseous ozone, gaseous reaction by-products such as volatile organic substances are collected in the upper part of the reaction filtration tank. By providing a space for separating the unreacted gaseous ozone separately, only raw water containing liquid ozone can be introduced into the filter medium filling layer, and a cavity generated when gaseous ozone is mixed with the raw water and introduced into the filter medium filling layer is The phenomenon which inhibits the reaction between the metal catalyst and the liquid ozone on the surface of the filter medium can be prevented.

Thereafter, as the mixture of raw water and ozone is continuously introduced, the collected gaseous ozone is moved to the residual ozone moving tube 13. The residual ozone traveling tube is connected to the ozone generator, so that the remaining ozone can be reused by reinjecting into the ozone generator and reintroduced into the ozone reactor, and this circulation process is repeated continuously.

The treated water purified through the above process is discharged through the treated water outlet pipe 14 installed on the lower side of the reaction filtration tank.

By the above process, in the water purification method using the raw water treatment apparatus of the present invention, the primary purification by the liquid ozone dissolved in the raw water, and the adsorption of pollutants in the filter medium packing layer and the radical hydroxide produced in the filter medium packing layer. Secondary purification by action takes place in a single reaction filtration tank.

The raw water treatment device of the present invention and the water purification method using the same are characterized by primary purification by ozone dissolved in raw water, adsorption of contaminants occurring in the filter medium filling layer, and oxidation and sterilization of the radical hydroxide produced through the filter medium filling layer. Since the secondary purification step by step purification process, the raw water treatment efficiency is very good.

In the raw water treatment device and the water purification method using the same, the ozone reactor and the filtration device, which have been used separately, are installed together in a single reactor, thereby adding a side effect to the inherent purification effects of the two purification devices to maximize the purification efficiency. can do.

In terms of the ozone reaction, while the existing ozone purification effect is maintained, radicals that are more reactive than ozone are produced by the metal on the surface of the filter medium in the filter medium filling layer, resulting in pollutants, ozone oxidation by-products, and spore-type pathogenics that are less reactive with ozone. Since the microorganism is decomposed and sterilized again, the purification effect obtained from ozone and its derivatives can be maximized.

In terms of filtration, while the adsorption effect on the contaminants of the existing filter medium is maintained as it is, the radicals generated by the catalysis of the filter medium provide better purification and a high purification effect in a short time. Due to the complete removal of, the regeneration of the filter can also be obtained.

In addition, in the raw water treatment device and the water purification method using the same, the unreacted gaseous ozone can be returned to the ozone generator for recycling, thereby improving the use efficiency of ozone and preventing additional environmental pollution due to the release of residual ozone. As a result, the purification efficiency can be improved.

The raw water treatment apparatus and the water purification method using the same of the present invention can maintain the purification efficiency continuously over time due to the regeneration effect of the filter medium and the recycling of unreacted residual ozone.

In terms of economics, since the raw water treatment apparatus of the present invention and the water purification method using the same unify both purification apparatuses, efficient purification can be achieved at a low site area and at a low cost of construction and operation. In particular, in the present invention, since the sand or natural iron ore particles, which are much cheaper than the conventionally used filter media such as activated carbon and have strong durability against ozone, are used as the filter media, installation and operation costs can be reduced.

The raw water treatment apparatus of the present invention and the water purification method using the same can be used for the removal of substances causing a particular taste or smell, the removal and generation of THM, a carcinogenic substance, in water purification fields such as contaminated ground water or purified water. .

The raw water treatment device and the water purification method using the same in the field of leachate, dyeing wastewater, paper wastewater, dye wastewater, electronic / semiconductor wastewater, petrochemical wastewater, wastewater of various chemical wastewater, to treat toxic and hardly decomposable organic substances It can be used to

The raw water treatment apparatus of the present invention and the water purification method using the same can be used to obtain a large amount of heavy water from a wider range of sewage in the field of heavy water of living water such as beverages.

Hereinafter, the present invention will be described in detail so that those skilled in the art to which the present invention pertains can easily practice the present invention. Other objects, features, and operational advantages, including the objects, actions, and effects of the present invention will become more apparent from the embodiments.

For reference, the embodiments shown herein are merely selected to present the most preferred examples to help those skilled in the art from understanding various embodiments, and the technical spirit of the present invention is not necessarily limited or limited only by the embodiments. Various changes and modifications are possible within the scope without departing from the technical spirit of the invention, as well as other embodiments of the equally clear.

Example 1 Using Raw Water Treatment Apparatus of the Present Invention p -CBA (para-chlorobenzoic acid) Purification of Contaminated Water

The raw water contaminated with p- CBA was purified using the raw water treatment apparatus of the present invention.

p is -CBA with ozone is a highly reactive and reactive hydroxyl radical yakhana representative materials _{(k O3, p -CBA = 0.15} M -1 s -1, k OH ^{_{and, p -CBA = 5 X 10 9}} M - ¹ s ^-1 ), since it is a contaminant that is difficult to decompose only by ozone alone treatment, it was selected as a decomposable substance of this embodiment.

In order to compare the p- CBA purification efficiency when different filter media were filled in the reaction filtration tank, three reactors were respectively filled with p- CBA contaminated raw water. In each reactor, thermally treated sand, unannealed general sand and iron oxide particles were respectively added. At this time, the sand was filled to 50g / l, the iron oxide particles to 5g / l.

As mentioned above, 10 minutes passed after installing the raw water treatment apparatus model of this invention, and the p- CBA adsorption amount of each filter medium was measured.

On the other hand, after the filter medium was introduced into the reactor as described above, a small amount of water in which ozone was dissolved at a high concentration was injected and the ozone concentration in the reactor was 3 ppm. After 10 minutes, the amount of p- CBA decomposition was measured.

Each result is shown together in FIG. 2, and in FIG. 2, Baked Sand w / o SOM is heat-treated sand to remove organic matter from the surface, Sand is sand not heat-treated, and FeOOH means iron oxide particles.

As shown in FIG. 2, the heat treated sand, untreated heat sand, and iron oxide particles used as filter media in the raw water treatment device of the present invention all have high adsorptive ability to contaminants with high p- CBA decomposition ability of 70% or more. It has been shown to have. On the other hand, although not shown in Figure 2, when the filter medium is not added p -CBA decomposition hardly occurred.

In the adsorption capacity of the filter medium, the sand without heat treatment showed the best adsorption capacity by acting as a bridge between sand and p- CBA because soil organic matter (SOM) remained on the surface.

On the other hand in the catalytic activity of the filter material, in the case of the iron oxide particles becomes small, this relatively small p -CBA a specific surface area (specific surface area), which may be adsorption amount is added to the reactor than in the sand p -CBA adsorption amount Although a small amount of p- CBA decomposition is the highest, it can be seen that the activity as a catalyst for converting ozone into radical radical is the best.

Therefore, the heat-treated sand, general sand and iron oxide particles used in the present invention have high adsorption capacity for pollutants and activities as catalysts for converting ozone into radical radicals. While maintaining the same, it can be seen that the low reactivity with ozone can be decomposed with a high efficiency of the material that was difficult to process with the existing ozone reactor.

Example 2 Confirmation of Purification Efficiency Over Time of the Raw Water Treatment Apparatus of the Present Invention

The purifying efficiency over time of the raw water treatment apparatus of this invention was confirmed as follows.

As in Example 1, each reactor was filled with p- CBA contaminated raw water, and then heat-treated sand and iron oxide particles were used as filter media. Degradation rate of p- CBA was measured for each reactor by time, and the result is shown in FIG. 3.

As shown in FIG. 3, in the raw water treatment apparatus of the present invention, when about 7 minutes have elapsed between the contaminated raw water and the filter medium, more than 80% of p- CBA is removed.

Overall, more than 60% of p- CBA was removed within a few seconds immediately after ozone injection, meaning that the production of radical radicals by the reaction between ozone and the surface of the filter media occurred during a short period immediately after ozone injection. It can be seen that using the raw water treatment device can achieve a sufficient purification effect in a short time.

In addition, although the purification efficiency decreased somewhat to some extent after the above time, continuous purification was performed. In the raw water treatment device of the present invention, p- CBA adsorbed on the filter medium is radically produced by the radicals generated by the catalysis of the filter medium itself. It can be seen that subsequent decomposition results in a regeneration effect of the filter medium, and also unreacted residual ozone can be recycled and reused.

Therefore, it can be seen that the raw water treatment apparatus of the present invention can maintain the efficiency continuously while efficiently purifying the contaminated raw water within a short time.

The raw water treatment device of the present invention and the water purification method using the same have an economic effect of greatly reducing installation and operation costs by unifying the ozone reactor and the filtration device.

The raw water treatment device and the water purification method using the same of the present invention, while maintaining the oxidation effect of ozone and the adsorption effect of the filter medium packing layer as it is, further purification is made by the radicals generated by the metal catalyst on the surface of the filter medium, purification efficiency This has the effect of maximizing.

In addition, the raw water treatment apparatus of the present invention and the water purification method using the same, while showing a high purification efficiency in a short time, the efficiency can be maintained continuously.

Therefore, the raw water treatment apparatus of the present invention and the water purification method using the same can be efficiently used in a variety of water purification, such as purified water, wastewater, water treatment.

Claims (7)

Raw water storage tank where contaminated raw water is stored, pump for moving raw water from raw water storage tank to reaction filtration tank, raw water inlet pipe connected between raw water storage tank and reaction filtration tank to provide raw water movement path, and located on raw water inlet pipe An inlet pipe valve that controls the opening and closing of the inlet pipe, an ozone generator that generates ozone to be used for purification of raw water, an air inlet pipe that supplies air to the ozone generator, and a connection path between the ozone generator and the raw water inlet pipe to provide a movement path of ozone. Reaction filtration tank installed at the junction of ozone inlet pipe, ozone inlet pipe and raw water inlet pipe to inject ozone into the raw water inlet pipe, and the raw water inlet pipe is connected to the upper part, and the reaction filtration tank containing the filter layer containing iron or manganese containing filter material at the lower part. In the upper part of the reaction filtration tank, the remaining gaseous ozone which is not dissolved in raw water is collected. The upper part of the reaction filtration tank allowing only the raw water to be introduced into the filter bed, the backwash water discharge pipe connected to the upper part of the reaction filtration tank, the backwash water discharge pipe valve located on the backwash water discharge pipe, and the remaining gas phase connected to the upper space of the reaction filtration bath. Raw water treatment device comprising a residual gaseous ozone moving pipe for returning ozone to the ozone generator and a treated water outlet pipe located under the reaction filtration tank. The raw water treatment apparatus according to claim 1, wherein the filter medium uses at least one material selected from ordinary sand, heat treated sand, or granulated iron oxide. The raw water treatment apparatus according to claim 2, wherein the filling rate of the filter medium filling layer in the reaction filtration tank is 0.4 to 0.8. Water purification, characterized by primary purification by liquid ozone dissolved in raw water and secondary purification by adsorption of contaminants in the filter media packing layer and by the action of radicals produced in the filter media packing layer in a single reaction filtration tank Way The method of claim 4, wherein the reaction filtration tank is filled with a filter medium containing iron or manganese on the surface thereof. 6. The method of claim 5, wherein the filter medium uses at least one material selected from ordinary sand, heat treated sand, or granulated iron oxide. 7. The method of purifying water according to claim 6, wherein the filling rate of the filter medium filling layer in the reaction filtration tank is 0.4 to 0.8.