KR20010037974A - Circular Waterway Type Waste Water Treatment System for Nitrogen & Phosphorous Removal - Google Patents

Abstract

PURPOSE: An advanced sewage and waste water treatment system of circular water channel type is provided, which can remove nitrogen in high efficiency by denitrification without any internal water circulating pump and water flow pipes and can use an existing oxidation ditch as a denitrification facility just by installing partition walls in the ditch, so that the system can be economical in construction cost and utility cost. CONSTITUTION: The system comprises the followings: (i) an oxidation ditch (1) of circular water channel type, which is provided with an anaerobic reactor (3) and an anoxic reactor (4) by installing partition walls(5), and in which nitrification, luxury intake of phosphorous and aerobic decomposition of organic matter are proceeded; (ii) an anaerobic reactor (3) into which circulating water(11) in the oxidation ditch(1) is not flowed, and in which phosphorus is released from activated sludge; (iii) an anoxic reactor (4) into which sewage and recycling sludge are flowed and a part of the circulating water(11) is also flowed, and in which nitrogen oxide in the sewage and waste water is denitrified; and (iv) a settling basin (2).

Description

Circular Waterway Type Waste Water Treatment System for Nitrogen & Phosphorous Removal

The present invention relates to an apparatus and a method for removing organic matter and nutrients from sewage or wastewater. An anaerobic reaction tank and an aerobic reaction tank are installed in a sedimentation built-in type or an external type of oxidizing sphere, and in the anaerobic reaction tank, a phosphorus release reaction is performed and the oxygen-free reaction tank is performed. In the denitrification reaction, the oxidative sphere is ingested in excess of phosphorus, nitrification and aerobic decomposition of organic matter, so it is related to the advanced sewage treatment system that can remove nitrogen and phosphorus economically without omitting the internal circulation pump and pipeline.

Contaminants in sewage water are mainly composed of organic matter and nutrients nitrogen and phosphorus, and biological nitrogen removal is aerobic reactor for nitrification reaction and anoxic reactor for denitrification reaction. Nitrification and denitrification occur in two or more tanks separated by. In addition, in order to effectively remove phosphorus by a biological method, an anaerobic reactor that releases phosphorus from activated sludge should be added.

Types of denitrification in which nitrogen oxides are reduced are classified into total denitrification method using organic substances contained in influent wastewater and post denitrification method using organic materials from outside, and total denitrification method using organic substances in influent wastewater is economically advantageous. Although there is a side, the configuration of the device is complicated and there is a big problem of power consumption due to internal circulation.

The A ₂ O method (Anaerobic Anoxic Oxic Process) and if greater detail the configuration of a device, the anaerobic tank 101, as shown in Figure 1, which is a typical method as before denitration method as in the invention of the prior art The phosphorus release reaction is carried out from the activated sludge returned from the settling basin 111, the denitrification reaction in the oxygen-free reaction tank 102, the nitrification and organic decomposition and the excess intake of phosphorus in the aerobic reactor (103).

The aerobic reactor 103 is provided with an aeration device for decomposition and nitrification of organic matter, and an internal circulation pump 107 for circulating the reaction liquid into the oxygen-free reactor 102 should be installed. In the A ₂ O method of the above configuration, since the internal circulation pump 107 and the internal circulation pipe are installed, there are many problems in terms of facility cost and power cost, which are uneconomical and difficult in maintenance.

In addition, since the conventional oxidation sphere is a channel having a relatively long circulation distance, some sections have been vaguely claimed as nitrogen and phosphorus can be effectively removed by forming anoxic or anaerobic conditions. However, in order to prevent sludge settling in the oxidizing sphere, the flow rate of the circulating water must be maintained at about 0.3 m / sec (1 ft / sec), and at this flow rate, even in a large oxidizing sphere having a long circulating distance, for example, a large oxidizing sphere having a circulating distance of 100 M 1 Since the cycle time is less than 6 minutes, it is almost impossible to form aerobic, anaerobic, and anaerobic sections. Therefore, the removal efficiency of nitrogen and phosphorus in the oxidizing zone was not high.

In order to increase the efficiency of nitrogen and phosphorus removal using oxidizing spheres, Denmart Kreuer developed a PID method that operates by changing the flow path and intermittent aeration method by combining two or more oxidizing spheres and an external sedimentation basin. In order to pass through the four sets of reactors in order to process the process is very complicated and there is a large cost requirement.

Apparatus and method for treating sewage and wastewater for nitrogen and phosphorus removal in Korea, which the applicant invented and named as PhiCD (Phased isolated intra Clarifier Ditch) system, combines two or more sedimentation-embedded oxidizing spheres and operates the channel change and intermittent aeration method. It is composed of sewage treatment system, which is simpler than PID method and has improved treatment efficiency. However, in the phase B and phase D of the PID method, the inflow and outflow of sewage water is carried out in one aerobic oxidizing sphere, so there is no nitrogen / phosphorus removal function except that it is synthesized in microorganisms. In the PhiCD method invented by the applicant, the same problem as in PID occurs in steps (c) and (f).

Accordingly, the present invention has been made to solve the above-mentioned problems, and it is possible to maintain high nitrogen and phosphorus removal efficiency at all stages of the wastewater treatment system operated by changing the flow path and intermittent aeration by combining two or more trillion oxide spheres. Of course, a single oxidation sphere also has a nitrogen and phosphorus removal function, and to provide an economical and efficient wastewater treatment system that can omit a separate internal circulation facility.

First, in order to achieve the purpose of denitrification, in the present invention, a wastewater treatment system composed of an oxidizing sphere and a sedimentation basin, which is an aerobic reaction tank of a circulating water channel, is provided with a wall inside the oxidizing sphere, and an anoxic reaction tank is formed to treat wastewater and return sludge in the anoxic reactor. A part of the reaction solution circulated in the oxidizing sphere is also introduced into the anoxic reaction tank so that the denitrification completes the reaction liquid to the oxidizing sphere.

Referring to the operation of the wastewater treatment system having such a structure, in the anoxic reaction tank, the denitrification reaction is performed in which the microorganisms reduce nitrogen oxides in the circulating water stream flowing from the oxidizing port using the inflowing organic matter, and in the oxidizing sphere under aerobic conditions. Nitrification and decomposition of organic matter are achieved. At this time, if the circulating water flows excessively into the anoxic reaction tank, the residence time is insufficient and it is difficult to maintain the anoxic condition. Therefore, it is preferable to install a water gate at the inlet of the anoxic reaction tank to control the inflow of the circulating water.

In addition, in order to add dephosphorization function to the denitrification function, an anaerobic reaction tank is additionally installed in the front stage of the anoxic reaction tank, and sewage and return sludge flow into the anaerobic reaction tank, and the effluent and anaerobic circulation flow of the anaerobic reaction tank are introduced into the anoxic reaction tank. Configure to Referring to the action of the sewage water treatment system which can perform the biological nitrogen and phosphorus removal function, the anaerobic reaction tank is phosphorus discharge from the activated sludge, the anoxic reaction tank is denitrification reaction, the oxidation sphere nitrification reaction and excess intake of phosphorus and Aerobic decomposition of organics is achieved respectively.

In this way, an oxygen-free reaction tank is installed inside the oxidizing sphere, which is a circulating channel type reaction tank in which the reaction solution circulates, or an anaerobic reaction tank and an oxygen-free reaction tank are installed together, so that the internal circulation pump and the pipe are omitted, and the conventional AO or A ₂ O method is used. Likewise, nitrogen and phosphorus can be removed.

In addition, when the anoxic reaction tank is installed in the sedimentation basin built-in oxidizing sphere in which the sedimentation basin is built, or when the anaerobic reaction tank and the anoxic reaction tank are installed together, the sludge collecting device or the sludge conveying pump and the pipe line facility are also unnecessary, which is more economical. In particular, the method according to the present invention can be easily applied to conventional oxidized spheres and sedimentation-type oxidized spheres which have already been constructed and operated, and can be changed to a high-treatment method, and applied to the conventional PID method or the PhiCD method invented by the applicant to remove nitrogen and phosphorus. It can improve the efficiency.

(B) Phase and (D) Phase and PhiCD method of the conventional PID method by constructing the wastewater advanced water treatment system which is configured and operated in the channel change and intermittent aeration method by combining two or more sets of oxidation spheres according to the present invention. In step and (F) it is possible to reduce the outflow concentration of nitrogen and phosphorus to improve the treatment efficiency.

1 is a flow chart of a nitrogen, phosphorus removal system by a conventional total denitrification method,

2 is a schematic configuration diagram of a wastewater treatment system equipped with a nitrogen removal function according to the present invention;

3 is a schematic configuration diagram of a wastewater treatment system equipped with a nitrogen and phosphorus removing function according to the present invention;

Figure 4 is a schematic diagram of the sewage treatment system equipped with a nitrogen, phosphorus removal function and built-in sedimentation basin according to the present invention.

* Description of the symbols for the main parts of the drawings *

1: Oxidized sphere 2: Sedimentation basin

3: anaerobic reactor 4: anaerobic reactor

5: wall 6: male door

7: built-in sedimentation basin 11: circulating water flow

Hereinafter, the configuration and operation of the present invention will be described in detail through the accompanying drawings.

2 is a plan view of a circulating water channel type sewage treatment system equipped with an oxygen-free reaction tank for denitrification according to the present invention.

In the wastewater treatment system consisting of an oxidizing sphere (1) and a sedimentation basin (2), which are aerobic reaction tanks of circulation channel type, a wall (5) is installed in the oxidizing sphere to form an anaerobic reaction tank (4), and the influent wastewater and the return sludge are the anoxic reaction tank. Inflow to the structure. Part of the circulating water 11 in the oxidizing sphere flows into the anoxic reaction tank, and a water gate 6 is installed at the inlet of the anoxic reaction tank to control the inflow of the circulating water.

In the wastewater treatment system having such a structure, even without a separate internal circulation pump, the circulating water flow in the oxidizing sphere flows into the anoxic reaction tank by the circulation flow rate, thereby economically denitrifying the nitrogen oxide.

Figure 3 is a plan view of the circulating channel type sewage treatment system equipped with an anoxic reactor and an anaerobic reactor to remove nitrogen and phosphorus simultaneously according to the present invention.

In this embodiment, an anaerobic reaction tank (3) is additionally installed at the front of the anaerobic reaction tank (4) in order to perform denitrification and dephosphorization in parallel. Sewage and return sludge are introduced into the anaerobic reaction tank, and the effluent water of the anaerobic reaction tank and the circulating water flow of the oxidizing port. (11) is configured to flow into the anoxic reaction tank and the circulation water flow does not flow into the anaerobic reaction tank. Referring to the operation of the present embodiment, the anaerobic reaction tank is phosphorus discharge from the activated sludge, the anoxic reaction tank is denitrification reaction of the nitrogen oxide in the circulating water flow by the circulating flow rate from the oxidizing sphere and the nitrification reaction in the oxidizing sphere Excessive intake of phosphorus and aerobic decomposition of organics are achieved respectively.

Figure 4 is a plan view of the circulating channel type sewage treatment system in which nitrogen and phosphorus are removed and a sedimentation basin is built according to the present invention. In this embodiment, in the embodiment of FIG. 2, the sedimentation basin 7 is installed inside the oxidation sphere 1, and the sedimentation basin built-in oxidization sphere is configured to provide a more economical facility than in the other embodiments using the external sedimentation basin.

As described above, the circulating waterway type advanced sewage treatment system of the present invention is economical in facility cost and power cost because nitrogen can be removed by total denitrification without omitting a separate internal circulation pump and pipeline facility. It can be easily applied to wastewater treatment facilities by oxidizing spheres to remove nitrogen and phosphorus with high efficiency, while it is widely applied to the wastewater treatment system of oxidized spheres and intermittent aeration wastewater treatment system and sedimentation built-in oxidizing spheres. As a result, nitrogen and phosphorus removal efficiency can be improved.

Claims (5)

In the sewage treatment system consisting of an oxidizing sphere and a settling basin, an aerobic reaction tank of circulation channel type, the oxidizing sphere constitutes an anaerobic reaction tank, and the influent wastewater and return sludge flow into the anoxic reaction tank, and a part of the reaction liquid circulated in the oxidizing sphere is circulated. The circulating channel type sewage treatment system for nitrogen and phosphorus removal, characterized in that it is introduced into the anoxic reaction tank by the flow rate. The method of claim 1, wherein the oxidizing sphere further comprises an anaerobic reactor, influent wastewater and return sludge to be introduced into the anaerobic reactor, the effluent of the anaerobic reactor is nitrogen, characterized in that the inflow to the oxygen-free reactor Circulation channel type sewage treatment system for phosphorus removal. According to claim 1, wherein the inlet of the anoxic reaction tank is configured in a variable type to control the inlet cross-sectional area nitrogen, characterized in that the inlet flow of the circulating water flowing into the anoxic reaction tank is controlled to remove the nitrogen, phosphorus Waterway sewage treatment system. The method of claim 1, wherein the circulating channel type sewage treatment system is combined with two or more systems to form a flow path changing method, and the circulating channel part of the oxidizing port is operated by an intermittent aeration method of repeating aeration and aeration. Circulating channel type sewage treatment system for nitrogen and phosphorus removal. The wastewater treatment system of claim 1, wherein the sedimentation basin is installed inside the oxidizing sphere to form a sedimentation basin built-in oxidizing sphere.