KR19990073316A - Biological advanced wastewater treatment method - Google Patents

Abstract

The present invention relates to an advanced treatment method for biologically simultaneously treating organic matter, nitrogen and phosphorus in waste water. In the treatment method according to the present invention, the flow of waste water is in the order of the storage tank, the first reaction tank of the non-aeration method, the third reaction tank of the aeration method, and the settling tank, and the sludge of the settling tank is introduced into the flow path changing tank and returned to the first reaction tank. The second reactor is a process I and operating in aerobic state in a batch without the inflow and outflow; The flow of the waste water is in the order of the storage tank, the second reaction tank of the non-aeration method, the third reaction tank of the aeration method, and the settling tank, and the sludge of the sedimentation tank flows into the flow channel change tank and is returned to the second reaction tank. It is characterized by repeating the operating step II. Wastewater treatment method of the present invention is a process that can utilize the incoming organic material to remove nitrogen as much as possible to treat nitrogen and phosphorus in wastewater, such as municipal sewage and livestock wastewater with a low C / N ratio (organic and nitrogen ratio). Can be effectively used.

Description

Biological Wastewater Advanced Treatment Method {BIOLOGICAL ADVANCED WASTEWATER TREATMENT METHOD}

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an advanced treatment method for biologically treating organic matter and nitrogen and phosphorus in waste water, especially organic matter contained in waste water when the ratio of organic matter and nitrogen in influent water (C / N ratio) is low. The present invention relates to a high degree of wastewater treatment method for overcoming a reduction in the treatment efficiency of nitrogen and phosphorus due to the lack of organic matter by making the most used for the treatment of nitrogen and phosphorus.

Nutrients such as nitrogen compounds and phosphates are introduced into rivers, coastal seas and lakes, and act as a source of eutrophication. This eutrophication causes depletion of dissolved oxygen due to algal blooms in the seas, algae growth in the lakes, odors caused by decay, and toxic substances in certain algae, disrupting the aquatic ecosystems, resulting in depletion of water resources. Done. This process is carried out in the natural world, but inflow of wastewater, such as domestic sewage, livestock wastewater, and factory wastewater, in which a large amount of nutrients are contained, is a cause for rapidly promoting eutrophication beyond nature's own purification ability.

Therefore, many techniques have been developed to remove nutrients (nitrogen, phosphorus) in the wastewater before entering the lake or river. Currently widely used nitrogen and phosphorus removal processes include the Bardenpho method (Bardenpho, US Pat. No. 3,964,998); Single sludge system A / O method, A ² / O method (Ref .: Hong, S., Kisenbauer, KS and Fox, VG (1981), An innovative biological nutrient removal system.In: FM Saunders, ed., Proceedings in 1981 National Conference of Environmental Engineering, Environmental Engineering Division, ASCE, Atlanta, Georgia, etc., by separating reactors and alternating anaerobic-aerobic conditions. The Kruger system, which is a process for improving nitrification efficiency by changing the energy efficiency, is included.

However, these methods have a problem in that when the ratio of organic matter and nitrogen is low, nitrogen treatment efficiency is low, facility costs and power costs are high, and operation is complicated.

The present invention has been made in view of the above problems, and in order to make the best use of the incoming organic material for denitrification, an intermittent aeration technology for inducing nitrification and denitrification reactions in one reactor and a single reactor at a predetermined time interval in batch form By applying the advantages of running batch treatment technology and flow changing technology that changes the inflow direction of the influent at regular intervals, it improves nitrification efficiency and nitrogen treatment efficiency, so that it is contained in the waste water even when the ratio of organic matter and nitrogen in the influent is low. The purpose of the present invention is to make the most of the organic matter present in the treatment of nitrogen and phosphorus to overcome the deterioration of the treatment efficiency of nitrogen and phosphorus due to the lack of organic matter.

In addition, an object of the present invention is to provide a method for removing nutrients (organic, nitrogen, phosphorus) that can reduce the operating cost required for oxygen supply by intermittently supplying oxygen.

1 is a schematic view showing a flow path with a reaction tank and a settling tank according to the process I of the present invention,

2 is a schematic view showing a flow path in which a reaction tank and a precipitation tank are disposed according to the process II of the present invention.

* Explanation of symbols for main parts of the drawings

1: first reaction tank 2: second reaction tank

3: third reaction tank 4: precipitation tank

5: Euro change (quarter)

In order to achieve the above object, in the present invention, the flow of the waste water in the order of the storage tank, the first reaction tank of the non-aeration method, the third reaction tank and the settling tank of the aeration method, the sludge of the sedimentation tank is introduced into the flow path change tank to the first Process I and return to the reactor, the second reactor is operated in aerobic state in a batch manner without inflow and outflow;

The flow of the waste water is in the order of the storage tank, the second reaction tank of the non-aeration method, the third reaction tank of the aeration method, and the settling tank, and the sludge of the sedimentation tank flows into the flow channel change tank and is returned to the second reaction tank. Provides an advanced biological wastewater treatment method that repeatedly performs Operation II.

Looking at the general nitrogen treatment method in the waste water, first, activated sludge microorganism in the aerobic aerobic state to oxidize nitrogen components (organic nitrogen, ammonia nitrogen) with nitrate nitrogen, that is, nitrification reaction; In the anoxic state after which no air is blown, the nitrogen in the water is removed by converting the previously generated nitrate nitrogen into nitrogen gas, that is, denitrification. At this time, the reaction for which the organic material is required is a denitrification reaction performed in an anoxic state. In addition, the biological phosphorus removal method first induces intracellular phosphorus release of activated sludge microorganisms under anaerobic conditions, and then removes activated phosphorus microorganisms which have excessively ingested phosphorus in water in aerobic state to the outside of the treatment process. At this time, as in nitrogen treatment, organic matter is required in the anaerobic state. Therefore, anaerobic and aerobic conditions are essential for the treatment of nitrogen and phosphorus, and it can be seen that the maximum use of organic matter is injected into the anaerobic state. In order to meet these conditions, the present invention optimizes organic matter, nitrogen, and phosphorus simultaneously by applying an intermittent aeration operation method for intermittently injecting air into a reactor and a flow path operation method for artificially changing the inflow path of wastewater. To be removed.

Hereinafter, with reference to the accompanying drawings will be described in detail the advanced wastewater treatment method according to the present invention.

In the advanced wastewater treatment method of the present invention, two reactors (first reactor and second reactor) of parallel structure using activated sludge microorganisms, and one reactor (third reactor) and precipitation tank 4 in series with these reactors (4) Including to operate. The reactor with the inflow of waste water maintains anaerobic state with only stirring without supplying air, the reactor with parallel structure maintains batch aerobic state, and the third reactor 3 is always operated with aerobic or intermittent aeration; The operation mode of the reactor and the inflow direction of the inflow water are changed at regular time intervals, and are repeatedly operated while switching to the processes I and II as shown in FIGS. 1 and 2, respectively. Hereinafter, each process is explained in full detail.

Process I

First, the process I shown in FIG. 1 is demonstrated. In the process I, the influent to be treated is introduced into the first reactor 1, and the first reactor 1 is operated at aeration during the inflow of the influent so as to maximize the denitrification of organic matter in the influent without being lost to carbon oxidation. Done. The second reactor (2) without inflow of the influent is placed in an aerobic state to induce a nitrification reaction that oxidizes the reducing nitrogen component in the influent which has been introduced before. At this time, since there is no organic matter introduced, it is possible to maximize the nitrification efficiency because it reduces the activity of other microorganisms and makes maximum use of nitrifying the supplied oxygen. The third reactor 3 is operated as a reactor that maintains aerobicity with a continuous aeration to oxidize the remaining reducing nitrogen and to improve precipitation. The sludge treated in the third reactor 3 and the treated water are transferred to the settling tank 4, and the sludge settled in the settling tank 4 is returned to the flow path change tank 5 at the front end and flows into the first reactor along with the influent. do. As described above, after the process I is performed for a predetermined time, the process is converted to the process II shown in FIG. 2.

Step II

In step II, the second reactor 2 is transformed into a non-aerated form to treat the nitrate nitrogen produced by the nitrification reaction, and the flow of the influent is changed into the second reactor 2, the third reactor 3, and the precipitation tank 4 Change to). The sludge from the settling tank 4 is returned to the branch tank at the front end and flows into the second reaction tank 2 together with the inflow water. After the operation is carried out for the predetermined time, the process returns to Process I.

The operation method is repeated in the form of Process I → Process II → Process I → Process II, and the operating time of each process is appropriately adjusted according to the characteristics of the waste water.

In addition, by appropriately attaching a timer and a solenoid valve to each reactor, treatment efficiency can be maximized by adjusting aeration time, non-aeration time, operating time between each process, and inflow flow path change time according to the characteristics of waste water in each reactor. .

In addition, each reaction tank may be operated by adding a medium or a carrier generally used to increase the concentration of microorganisms.

In addition, an anaerobic reaction tank may be further disposed between the storage tank and the branch tank 5 to improve the removal efficiency, and the sludge may be returned and operated from the settling basin.

In addition, the third reactor 3 may be operated to increase the treatment efficiency by internally circulating the sludge in the reactor of the front end is maintained anaerobic.

According to the present invention, by maximizing the treatment of nitrogen and phosphorus in the waste water, by reducing nutrients (nitrogen, phosphorus) introduced into the water source, by preventing and preventing eutrophication, it is possible to secure a water supply shortage, and to reduce the cost of water production In addition, the environment can be conserved by reducing pollutants (organic, nitrogen, phosphorus) flowing into general rivers and lakes. In particular, the wastewater treatment method of the present invention processes nitrogen and phosphorus in wastewater, such as municipal sewage and livestock wastewater, which have a low C / N ratio (a ratio of organic matter and nitrogen) as a process that can make the most of the introduced organic material for nitrogen removal. Can be used effectively.

Claims (5)

The flow of waste water is in the order of the storage tank, the first reaction tank of non-aeration method, the third reaction tank of aeration method, and the settling tank, and the sludge of the sedimentation tank flows into the flow channel change tank and is returned to the first reaction tank. Process I and operating in aerobic batch state without a; The flow of the waste water is in the order of the storage tank, the second reaction tank of the non-aeration method, the third reaction tank of the aeration method, and the settling tank, and the sludge of the sedimentation tank flows into the flow channel change tank and is returned to the second reaction tank. An advanced wastewater treatment method comprising the steps of operating step II at regular intervals. The method of claim 1, Timers and solenoid valves are properly attached to each reaction tank to maximize treatment efficiency by adjusting the aeration time and non-aeration time, operating time between each process, and inflow flow path time according to the characteristics of the waste water. How to. The method according to claim 1 or 2, Each of the reaction tank is characterized in that the operation by adding a medium or carrier generally used to increase the concentration of microorganisms. The method according to claim 1 or 2, And an anaerobic reaction tank is additionally disposed between the storage tank and the flow path changing tank (5) to transport and operate the sludge from the settling basin. The method according to claim 1 or 2, The third reactor (3) is characterized in that it is operated by circulating the sludge in the reactor of the front end is maintained anaerobic.