KR0165602B1 - Method and apparatus for treating waste water containing organic material - Google Patents

Abstract

The present invention relates to a method and apparatus for treating wastewater containing a high concentration of organic matter, the wastewater inlet pipe of at least two paths located at the bottom of the apparatus; Sludge granular layer and sludge blanket layer; Gas, liquid, solid separation devices and contact materials located thereon; And an effluent inflow pipe for conveying the treated water outflow and flowing into the apparatus, the amount of organic matter removed from the wastewater is improved, and the stability and treatment rate of the treatment tank is improved.

Description

Method and apparatus for treating organic wastewater

1 is a schematic diagram of an organic wastewater treatment apparatus according to the present invention.

* Explanation of symbols for main parts of the drawings

1, 2: wastewater inlet pipe 8: outflow water return pipe

3, 4: effluent inflow pipe 9: sludge granular layer

5: gas, liquid, solid separation unit 10: sludge blanket layer

6: contact material 11: exhaust pipe

7: outflow pipe

The present invention relates to an anaerobic treatment method and apparatus for organic wastewater for treating wastewater containing a high concentration of organic matter, such as food wastewater, sugar wastewater, starch wastewater, livestock wastewater, and petrochemical wastewater.

Factory wastewater and household wastewater from various factories is a cause of environmental pollution when discharged as it is, it is necessary to treat and discharge it in terms of environmental protection.

Conventional wastewater treatment methods include anaerobic treatment methods or aerobic treatment methods. Anaerobic treatment of waste water has the advantages of less energy consumption, less sludge generation, resources of methane gas generated and less nutrients consumption than aerobic treatment. However, in the case of anaerobic treatment, the sludge production rate is slow, so it takes a long time to reach a steady state, takes a longer reaction time than aerobic treatment, and is difficult to apply because it is seriously affected by some toxic substances.

J.C. Young and P.L. In the Anaerobic Filtration Process published by McCarty (Proc. 22nd Ind. Waste Conf. Purdue Univ. 1967, 559), contact materials were used to improve the stability of the treatment and the residence time of the sludge, J. Lettinger et al. Biological treatment (Biotechnology and Bioengineering 22, 669-734, 1980) using the upflow sludge blanket of sinter formed sludge particles in the lower part of the treatment tank to improve organic decomposition ability. In addition, Korean Patent Publication No. 93-1217 of Hyundai Engineering Co., Ltd. uses a curved curved contact material with 0.55-0.65H of treatment tank height (H) in the middle of the treatment tank while maintaining a high concentration of organic wastewater for 1 to 5 days. The treatment method was used.

However, these methods are unstable in the treatment of high concentrations of wastewater, consuming excessive amounts of nutrients and limiting the concentration of influent wastewater.

It is therefore an object of the present invention to solve the above problems and to provide a method and apparatus for treating organic wastewater which can stably treat high concentration organic wastewater while improving its treatment efficiency and reducing the consumption of nutrients.

The organic wastewater treatment apparatus according to the present invention comprises at least two paths of wastewater inlet pipes located at the bottom of the apparatus; Sludge granular layer and sludge blanket layer; A gas, liquid and solid separation device and a contact material disposed thereon; And an outflow water inlet pipe for transporting the outflowing treated water to be introduced into the apparatus.

In the present invention, by installing a gas, liquid, solid separation plate in the apparatus and using a ciliated contact or a plate-like contact on the upper part to improve the wastewater treatment rate while reducing the outflow of sludge; Stabilizing the pH in the treatment tank and reducing the consumption of pH adjusting chemicals and nutritional substances by directly returning a portion of the treated water to the treatment tank; By installing the wastewater inflow path in two or more downward paths, the contact between the sludge particles and the organic matter was prevented from occurring in a short circuit, and the removal of organic matter from the wastewater was improved and the treatment stability was achieved.

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

The wastewater inlet pipe is where the wastewater enters. When the wastewater is introduced into the device for a long time without changing the inflow path, a short circuit phenomenon occurs in which only a part of the sludge particles and organic matter are contacted by the driving force of the generated gas and the inflow water. Over time, the organic removal rate decreases. Therefore, in the treatment apparatus according to the present invention, at least two or more inlet pipes 1 and 2 are operated while the paths are replaced at intervals of one day, thereby preventing occurrence of a short circuit phenomenon and preventing a decrease in organic removal rate.

The wastewater introduced through the wastewater inflow pipes 1 and 2 passes through the sludge granular layer 9 and the sludge blanket layer 10, thereby removing about 80% of organic matter. The sludge granular layer 9 occupies 0.2 to 0.3H at the bottom of the treatment tank, and is a layer in which hydrolysis of organic matter and organic acids and methane are most actively produced. In order to promote the production of sludge particles, the organic matter load in the initial operation of the treatment tank is 0.5 to 1 kg. COD / ㎥.day, and then the organic matter load is increased in the range of 30% when the removal rate of the organic matter is 80% or more. do. Then, the granulation of the sludge starts to take place between 30 and 50 days, and reaches a steady state of the granular form of the size of 2-3 mm by about 90 days.

The sludge blanket layer 10 is located at 0.25 to 0.35H toward the upper side of the sludge granular layer 9 and mainly organic acid is removed.

The gas, liquid, and solid separator 5 is preferably installed so that the angle θ of the inclined plate is between 50 and 65 degrees. By having the inclination as described above, it is possible to prevent the sludge passing through the separation device from passing through the upper contact material layer, and to promote the settling of the sludge and to allow the settling sludge to reach the bottom smoothly.

The contact material layer 6 is a place where secondary treatment of untreated organic matter occurs while passing through the sludge layer, and prevents the outflow of sludge through the gas, liquid, and solid separation device 5, and at the same time, toxic substances flow into the surface. The sludge inside the tank is impacted to prevent the sludge from leaking out. The contact layer may be in the form of a ciliated or plate type, and is located above the gas, liquid, and solid separator 5.

In the conventional wastewater treatment apparatus, when the COD of the influent water becomes 4000 ppm or more, the pH of the treatment tank decreases due to the accumulation of organic acids, and the ability to remove organic matters of the entire reaction vessel drops sharply, so that a large amount of alkaline reagent for pH adjustment is prevented to prevent the pH drop. Had to be used.

In the present invention, in order to prevent the difficulty of the control according to this, by installing a downflow type effluent inflow pipe (2, 4) for conveying a part of the treated effluent between 0.075 to 0.15H of the total height (H) of the reaction tank The incoming wastewater is quickly converted to organic acid at the beginning of the inflow to prevent the pH of the treatment tank from dropping rapidly. In addition, since the pH of the treatment tank is stabilized in the range of pH 6.7 to 7.3 in which methane-forming bacteria are most active, the ability to remove organic matters is reduced and consumption of chemicals is reduced. By return of the outflow water processed in this way, COD in a processing tank does not exceed 3500-5000 ppm.

Hereinafter, the present invention will be described in more detail with reference to the following examples and comparative examples. However, this invention is not limited by the following Example and a comparative example.

Example 1

Inlet pipe is located at 0.025H and 0.03H, return liquid inlet is located at 0.08H and 0.09H, and wastewater is provided with three stages of ciliated contact material on top of gas, liquid, and solid separator installed between 0.68 and 0.82H. Glucose and acetic acid were mixed at a treatment device in a 1: 1 ratio to form a prepared wastewater. After 120 days had elapsed, a sludge particle layer was formed up to 0.23H, and a sludge blanket layer was formed up to 0.52H. Influent and COD results at each point are shown in Table 1 below.

As shown in Table 1, it can be seen that organic matter in the wastewater is removed 50.6% in the sludge particle layer, 29.8% in the sludge blanket layer and 9.2% in the contact layer.

Example 2

Wastewater from a starch plant with an influent COD of 8132 ppm was treated with a load of 8 kg. COD / m 3 .day using the same treatment equipment as in Example 1 except that the return inlet was located at 0.08H and 0.01H. The results are shown in Table 2.

Comparative Example 1

The same process as in Example 2 was conducted except that a treatment apparatus without a effluent inlet was used, and the results are shown in Table 2.

Example 3

Using the same treatment apparatus as in Example 1, except that the ciliary contact material was located between 0.85H and 0.90H, petrochemical wastewater with 15250 ppm COD of influent was loaded with a load of 7 kg. COD / m 3. The results are shown in Table 3.

Example 4

Except for using a treatment device in which the plate-shaped contact member is located between 0.85H to 0.90H and was treated in the same manner as in Example 3. The results are shown in Table 3.

Comparative Example 2

The same process as in Example 3 was conducted except that a treatment apparatus without contact material was used, and the results are shown in Table 3.

As described above, when the organic wastewater is treated using the treatment method and apparatus according to the present invention, it shows a high treatment efficiency of about 90% or more, and the stability of the wastewater treatment tank can be achieved.

Claims (4)

A raw wastewater inlet pipe having two paths located at the bottom of the apparatus; Sludge granular layer and sludge blanket layer; Gas, liquid and solid separation devices and contact materials located thereon; And an effluent inflow pipe for conveying the treated water to flow out into the apparatus and disposed above the raw waste water inflow pipe. An apparatus according to claim 1, wherein said contact material is ciliated or plate-shaped. Introducing raw wastewater into the apparatus through at least two paths; Bringing the introduced wastewater into contact with the sludge through the sludge granulation layer and the sludge blanket layer; Passing the contact material layer after gas, liquid and solid separation; Returning the treated effluent through the effluent inlet pipe located above the effluent inlet pipe in the apparatus to dilute the wastewater. 4. A method according to claim 3, wherein the amount of return of the effluent is adjusted so that the COD of the influent water entering the apparatus is maintained at 3500 to 5000 ppm.