KR0151355B1 - Apparatus and method for the treatment of waste water - Google Patents

Abstract

The present invention relates to a method for thermal oxidation treatment of wastewater and its apparatus, and more particularly, to collect and sewage wastewater into a storage tank for precipitation treatment; Mixing the first oxidant 400 to 2000 mg / 1 to the waste water supplied from the storage tank and introducing the first oxidant into a first vacuum reaction tank maintained at 40 to 90 ° C., and then vacuum-reacting for 15 to 45 minutes while stirring; Optionally, when the heavy metal is contained in the wastewater, mixing the heavy metal chuck 10 to 100 mg / 1 with the first oxidant 400 to ms / 1; Optionally, the second oxidant 400-2000mg / 1 is mixed with the waste water supplied from the first vacuum reaction tank and introduced into the second vacuum reaction tank maintained at 40-90 ° C., and then stirred for 15-45 minutes. Vacuuming during; And it relates to a method for thermal oxidation treatment of the waste water and the apparatus suitable for the method comprising the step of filtering the waste water subjected to the vacuum reaction treatment. By using the method and apparatus, it is possible to reuse the wastewater discharged by treating the wastewater economically and efficiently, and to protect nature by preventing pollution of water quality.

Description

Hydrochlorination treatment method of wastewater and its apparatus

(A) and (b) of FIG. 1 are schematic process diagrams according to a conventional wastewater treatment method,

2 is a schematic process diagram according to the waste water treatment method of the present invention,

3 is a schematic cross-sectional view of a vacuum reaction tank according to the method of the present invention,

FIG. 4 is a view schematically showing a cross section taken along line a-a of FIG.

* Explanation of symbols for main parts of the drawings

10: vacuum reaction tank 11: chemical tank

12: Infusion pump 13: Pressure gauge

14: discharge valve 15: stirrer

16: Inlet 17: Outlet

18: heating means 19: semi-circular partition

20: Insulation

The present invention relates to a thermal oxidation treatment method and apparatus therefor, and more particularly, it is possible to reuse waste and waste water discharged by treating waste and waste water economically and efficiently at a constant temperature and vacuum conditions. The present invention relates to a thermal oxidation treatment method of a sewage and wastewater and an apparatus thereof. As used herein, the term sewage and wastewater is used to encompass sewage, domestic sewage, and wastewater.

In the conventional wastewater treatment method, as shown in FIG. 1, after the storage tank into which the wastewater flows, a pH adjusting tank for adjusting pH of the wastewater is installed, and the contaminants are passed through the settling tank or the floating tank through the reaction tank and the flocculation tank. Or (see (a) in Figure 1). After adjusting the pH in the storage tank, the contaminant was removed by passing through the aeration tank, which is a biological treatment method through microorganisms, followed by the settling tank (see (b) of FIG. 1), or by removing the contaminants by treating the two methods in parallel. It was.

The removal rate of BOD (Bicohemical Oxigen Demand) according to the physical, chemical and biological treatment methods of this wastewater treatment method is about 30% for physical treatment, 40-50% for chemical treatment, and 70-90% for biological treatment. The treatment efficiency is low compared to the high installation and operation costs. Especially, the dyeing wastewater, printing, imitation, or leather wastewater, such as non-degradable wastewater, has very low treatment efficiency and is not economical. There was almost no.

If this incompletely treated wastewater is gradually discharged into the surrounding streams or rivers, it will pollute the natural environment, destroy ecosystems and threaten humanity. In addition, the almost impossible recycling of water will be a major impediment to the development of the industry due to the lack of industrial water.

Therefore, the present invention improves the conventional wastewater treatment method, which cannot be completely treated or has a high construction cost, and in particular, completely removes hardly degradable wastewater (heavy metals and colors), thereby preserving the natural ecosystem. The purpose of the present invention is to provide a thermal oxidation treatment method of wastewater, which can contribute 100% reuse of treated water, which can greatly contribute to the non-emission of wastewater and the reduction of operating cost through reuse of water.

Another object of the present invention is to provide an apparatus suitable for carrying out the method.

The method of the present invention for achieving the above object is a step of collecting sewage and sewage in the storage tank; mixing the first oxidant 100 ~ 5000mg / l to the waste water supplied from the storage tank to maintain at 40 ~ 90 ℃ After the introduction into the first vacuum reaction tank is a vacuum reaction for 15 to 45 minutes while stirring; If the heavy metal is contained in the waste water, optionally the heavy metal treatment agent with the first oxidant 100 ~ 5000mg / l 10 Mixing ˜100 mg / l; Optionally, 100-5000 mg / l of the second oxidant is mixed with the waste water supplied from the first vacuum reaction tank and introduced into the second vacuum reaction tank maintained at 40-90 ° C., and then stirred for 15-45 minutes. Vacuuming during; And filtering the vacuum treated wastewater.

The device for achieving another object of the present invention is the discharge port is formed on one side of the sealed cylindrical structure and the inlet and the opposite side to move the waste water, the semi-circular partition is opened at the inlet and outlet of the inlet and outlet It is installed to keep the residence time of the waste water is kept constant, the stirrer is installed in the inner center of the structure, the outer insulation is coated outside, the pressure gauge and the gas discharge valve is formed on one side of the upper surface of the gas When saturation occurs, the gas is transferred to the storage tank through the gas discharge pipe or introduced into the inlet pipe, and heating means capable of applying heat to the inside of the structure is installed in parallel with the structure.

Hereinafter, the method of the present invention will be described in more detail with reference to the accompanying drawings.

According to the wastewater treatment process of the present invention, as shown in FIG. 2, the vacuum reaction tank 10 of the fully-sealed structure is used instead of the conventional pH adjustment tank or aeration tank in the next step of collecting the wastewater. Or connected by direct heat, the waste water passed through the vacuum reaction tank (10) through the pH adjustment and sedimentation tank, and the liquid separation tank to the first treatment, and then through the activated carbon filtration tank and discharge tank in order to secondary treatment .

On the other hand, in the vacuum reaction tank 10 is installed a chemical tank 11 of the mixed oxidant and heavy metal treatment agent, the oxidizing agent and heavy metal treatment agent of the chemical tank 11 is introduced into the reaction tank by a metering pump 12. It is designed to react with the mixed waste water. The term vacuum reaction tank is used interchangeably with a reaction tank or a reaction tank below.

At this time, the heating means 18 is attached to promote the reaction of the oxidant mixed with the waste water introduced into the vacuum reaction tank 10, the first oxidant and the second oxidant prepared by the present inventors as an oxidant An oxidant was used. The heating means 18 is to promote the oxidation reaction by maintaining the reaction temperature of the oxidant at 40 ~ 90 ℃, preferably 70 ~ 90 ℃, it is possible to use a variety of heating means such as electric heating or steam boiler. Optionally, when treating wastewater containing heavy metals, a heavy metal treatment agent may be used with the first oxidant. On the other hand, the reaction treatment time in the vacuum reaction step is preferably treated for 15 to 40 minutes, preferably 30 to 40 minutes for each reaction tank in terms of treatment efficiency. Meanwhile, sulfuric acid (H ₂ SO ₄ ) and caustic soda (NaoH) were used as the pH adjusting agent administered to the pH adjustment and precipitation tank.

The first oxidizing agent used in the present invention is selected from one or more selected from the group consisting of H ₂ O ₂ , MnO ₂ , HNO ₃ and KMnO ₄ , it is preferable to use selectively depending on the type of waste water. Do. In general, it is preferable to the first oxidizing agent is mixed at a concentration of the H2O2 and KMnO _4, respectively 10 ~ 40mg / l, and KMnO ₄ 4000 ~ 80,000mg / l handle most wastewater. The concentration of the first oxidant into the wastewater is in a range of 100 to 5000 mg / l is preferable for treating a conventional wastewater, but may be out of the range according to the concentration of BOD and COD of the wastewater.

In addition, the second oxidizing agent is selected from the group consisting of NaClO ₃ , KMnO ₄ , NaOCl, KCr ₂ O ₇ , KNO ₃ , NaNO ₃ , K ₂ S ₂ O ₈ and H ₂ SO ₄ , KMnO ₄ , The mixture consisting of K ₂ S ₂ O ₈ and H ₂ SO ₄ is concentrated at 4000-80,000 mg / l, 1000-3000 mg / l and 70-150 mg / l, or KMnO ₄ , NaOCl and K ₂ S ₂ O ₈ , respectively. The mixture is composed of 4000 ~ 80,000mg / l, 1000 ~ 2000mg / l and 1000 ~ 3000mg / l respectively can treat most of the waste water, the concentration of the second oxidant to the waste water is the first oxidant Similarly, it is 100-5000 mg / l. The range may also be a preferred range for treating ordinary wastewater, but may be out of the range depending on the concentration of BOD and COD of the wastewater.

In addition, the heavy metal treatment agent used in conjunction with the first oxidizing agent can be used in any commercially available products, preferably Yeongil Chemical Co., Ltd. EPOFLOC L-1, Anguk Chemical Co., Ltd. ORITOL-S and NaOH alone Alternatively, the mixture may be selectively used for wastewater containing heavy metals, and the wastewater may be used in the range of 10 to 100 mg / l, preferably 20 to 50 mg / l, in terms of cost and efficiency. In conclusion, the types and concentrations of the first and second oxidants may vary depending on the type of wastewater, but may be treated with the preferred examples mentioned above except for special cases.

On the other hand, the reaction tank 10 according to the present invention is a closed cylindrical structure is formed with an inlet port 16 and the outlet port 17 on one side, the mouth of the inlet 16 and the outlet port 17 A semicircular partition 19 having a lower opening is installed at an outlet, a stirrer 15 is installed at an inner center of the structure, a heat insulating material 20 is coated on the outside, and a pressure gauge on one side of an upper surface of the outer surface. 13 and the gas discharge valve 14 RK, and has a structure in which the heating means 18 is installed in parallel to the outside of the structure.

In other words, one or several agitators 15 may be installed inside the reaction tank 10, and a heating unit 18 is installed outside thereof to maintain the temperature of the reaction tank 10 at 40 to 90 ° C. In addition, the outside of the gas measurement is equipped with a discharge valve 14 for saturation gas discharge attached to the pressure gauge 13, when the saturation of the gas is sent to the storage tank through the gas discharge pipe or to be introduced into the inlet pipe. That is, the discharge valve 14 may prevent secondary pollution by connecting a gas generated while the waste water and the oxidant are mixed in the sealed vacuum reaction tank 10 to the inlet pipe. In addition, in order to reduce the heat loss of the reaction tank (10) by covering the insulation 20 to the outside to consider the effect of reducing the operating cost. The heat insulating material 20 can be used for all of the heat insulating materials that are usually used for thermal insulation.

In addition, referring to FIG. 4, a semicircular partition 19 having a lower opening is opened to the inlet 16 and the outlet 17 of the reactor in order to give sufficient reaction time between the oxidant and the waste water in the reactor. It was installed so that the waste water was supplied from the bottom of the reactor.

In this process, if a conventional open reaction tank is used instead of the vacuum reaction tank or the temperature is not raised to a temperature range of 40 to 90 ° C., a complete reaction does not occur, and heat loss is high, and high operating cost and efficiency drop below 50%. As the use value is significantly reduced.

According to the present invention, when the sewage and waste water is collected and flowed into the storage tank, the pumps are automatically pumped to the operation in the central control room (not shown) by the detection of the level switch, and the machines of all the processes are operated. The wastewater from the storage tank starts to flow into the reaction tank, and at the same time, the injection pump 12 connected to the chemical tank (II) is operated so that the oxidant in the chemical tank (II) is fed and supplied into the reaction tank in a mixed state with the waste water. After the reaction, the mixture is stirred by the stirrer 15 inside the completely sealed vacuum reaction tank 10, and the reaction is completely performed by heating by the heating means 18. Then, the pH is adjusted and transferred to the settling tank to the treated water and sludge. After the solids and liquids are separated, they are completely processed through a filter (active carbon filter and ion exchange resin tower), and then discharged into a reuse tank, where final treatment is performed. At this time, the sludge settled to the lower part of the settling tank is treated by a conventional sludge treatment method.

On the other hand, the treated water transferred to the reuse tank can be reused as the water of the production process, in the case of the treated water of sewage can not be reused even in the washroom or wash of each building or factory.

Although the effects of the present invention will be described in more detail with reference to the following examples and comparative examples, the scope of the present invention is not limited to the following examples.

Dye Wastewater

The method of the present invention and the method of the present invention were applied to wastewater flowing into the terminal treatment plant in Banwol industrial complex in Ansan-si. The wastewater is wastewater generated during bleaching, refining and washing, and the daily generation amount of the wastewater is 100,000 m3 / day.

In this case, the experimental results of the average concentration of raw wastewater are as follows.

* pH: 6 ~ 7

Biochemical Oxigen Demand (BOD): about 300mg / l

Chemical Oxigen Demand (COD): about 400mg / l

SS (Suspended Solid): about 120mg / l

N-H (Normal Hexan): dir35mg / l

Chromaticity: 800 degrees

Comparative Example 1

After adjusting the pH to 6-8 with NaOH in the wastewater collection tank, the first biological treatment was carried out by introducing a standard activated sludge method of biological treatment, and then H ₂ O ₂ , FeCL ₃ and Al ₂ (SO ₄ ) Secondary chemical treatment with a mixture of ₃ · 17H ₂ O in a volume ratio of 1: 1: 1 causes the following problems.

1) Lack of site requirements: There is no room to be confirmed.

2) Limit of treatment efficiency: Limit of treatment efficiency of existing treatment method.

3) Water cannot be recycled: effluent BOD = 50mg / l, chromaticity = 100 degrees

4) It could be summed up as the suppression of production facility investment by factories in the complex due to the limitation of wastewater treatment plant.

Example 1

The waste water was subjected to solid and liquid separation through the first and second reaction tanks of the present invention shown in FIGS. 3 and 4, as shown in Table 1 below. At this time, the first oxidant mixed with the wastewater introduced into the reaction tank was mixed 35% H ₂ O ₂ and 2.5NKMnO ₄ in a volume ratio of 1:20, the second oxidant 2.5N KMnO ₄ , 0.01MK ₂ S ₂ O ₈ and 17% H ₂ SO ₄ was mixed in a volume ratio of 10: 1: 2.5, and the heavy metal treatment agent was EPOFLOC L-1 of Youngil Chemical Co., Ltd. ORITOL-S and 0.1N NaOH of Anguk Chemical Co., Ltd. Was prepared by mixing in a ratio of 1: 1: 100. Meanwhile, the first oxidant and the heavy metal treatment agent were administered to the first reactor, and the second oxidant was administered to the second reactor. The temperature of each reactor was maintained at 70-90 ° C., and the reaction time was reacted for about 30 minutes in each reactor. On the other hand, the conventional treatment method was used to separate the solid and liquid using a flocculant or a coagulant in the pre-sedimentation tank step, the sedimentation state of the sludge is good in this treatment method, the natural water sedimentation method was used after pH adjustment.

Example 2

Sewage with analyte concentration of BOD = 240 mg / l was treated by the method of the present invention and the results are shown in Table 2 below. At this time, the treatment method showed treatment efficiency according to the heating temperature, and the treatment method used only the second oxidizing agent and the neutralizing agent used in Example 1 (sewage does not include heavy metals), and only one reactor was used. .

Example 3

When the analytical treatment concentration of the waste water was cod = 400 mg / l, it was treated by the method of the present invention, and the results are shown in Table 3 below. The results show when the wastewater was treated by reaction time. The maximal treatment method and the concentration of the oxidizing agent were the same as in Example 1.

As can be seen in Tables 1, 2 and 3, it can be seen that there is a difference in removal efficiency depending on the input concentration of the first and second oxidizing agents and the heavy metal treatment agent, the heating temperature and the reaction time. In other words, the concentration of oxidant should be adjusted to the appropriate amount according to the pollution degree of wastewater and the recycled or discharged water of wastewater, and the treated water or recyclable industrial water is required only by adjusting the temperature and reaction time of a certain time. You can get it.

For example, when the raw wastewater is COD = 400mg / l, the first and second oxidizing agents need about 1,100mg / l, the neutralizing agent needs 100mg / l, when the reaction temperature is over 80 ℃ and the reaction time is over 35 minutes. COD and chromaticity are almost completely removed, and in the case of heavy metal-containing wastewater, 10 to 100 mg / l of heavy metal treatment agent is added to complete treatment to increase water treatment efficiency.

Therefore, the method of the present invention has the effect of economically and efficiently treating the wastewater, which makes it possible to reuse almost the wastewater discharged and to protect nature by preventing pollution of water quality.

Claims (7)

A method of treating water by chemical and oxidation treatment, the method comprising the steps of: collecting sewage and sewage in a storage tank for precipitation treatment; After mixing the first oxidizing agent 100 ~ 5000mg / l in the waste water supplied from the storage tank into the first vacuum reaction tank maintained at 40 ~ 90 ℃, the vacuum reaction for 15 to 45 minutes while stirring When the heavy water is contained in the waste water, mixing the heavy metal treatment agent 10 to 100 mg / 1 with the first oxidant 100 to 5000 mg / 1; 100-5000 mg / 1 of the second oxidant is mixed with the waste water supplied from the first vacuum reaction tank and introduced into the second vacuum reaction tank maintained at 40-90 ° C., followed by vacuum reaction for 15 to 45 minutes with stirring. And a step; And filtration of the wastewater subjected to the vacuum reaction treatment. The method of thermally treating wastewater according to claim 1, wherein the first oxidant is selected from the group consisting of H ₂ O ₂ , MnO ₂ , HNO ₃ and KMnO ₄ . The thermal oxidation treatment method of waste water according to claim 1 or 2, wherein the first oxidizing agent is comprised of 10-40 mg H ₂ O ₂ and 4,000-80,000 mg KMnO _{4 based} on 1 L of water. The method of claim 1, wherein the second oxidant is selected from the group consisting of NaClO ₃ , KMnO ₄ , NaOCl, KCr ₂ O ₇ , KNO ₃ , NaNO ₃ , K ₂ S ₂ O ₈ and H ₂ SO ₄ Thermal oxidation treatment method of waste water, characterized in that. The method according to claim 1 or 4, wherein the second oxidizing agent is composed of 4000 to 80,000 mg of KMnO ₄ 1,000 to 30,000 mg of K ₂ S ₂ O ₈ and 70 to 150 mg of H ₂ SO _{4 based} on 1 L of water. Thermal coral treatment method of wastewater. The method according to claim 1 or 4, wherein the second oxidizing agent is composed of 4,000-80,000 mg of KMnO ₄ , 1,000-2,000 mg of NaOCL and 1,000-3,000 mg of K ₂ S ₂ O ₈ with respect to 1 L of water. Thermal oxidation treatment method of wastewater The method of claim 1, wherein the method further comprises an activated carbon filtration step and an ion exchange resin treatment step after the filtration step.