KR101967421B1 - System of hybrid type constructed wetland using electro-coagulation process as pretreatment process - Google Patents

Abstract

The present invention relates to a hybrid artificial wetland processing system using an electrocoagulation process as a pretreatment step, comprising: a storage tank for storing sewage; an electrocoagulation unit for use in a pretreatment process in connection with the storage tank; A primary storage tank portion for receiving the treated primary treated water, a groundwater level for entering the primary treated water, a direct current type wetland construction portion for groundwater, a groundwater portion for receiving the secondary treated water after the direct current type wetland processing And a car-receiving tank unit.
The present invention is eco-friendly because it has few technologies for operation and maintenance and most of the treatment is adsorption and decomposition by filter media and microorganisms, thereby reducing operating costs and eliminating sludge generation.

Description

[0001] The present invention relates to a hybrid type artificial wetland process system using an electro-coagulation process as a pretreatment process,

The present invention relates to a hybrid wet type artificial wetland processing system, and more particularly, to a hybrid wet type wetland processing system capable of simultaneously removing organic matter, nitrogen, and phosphorus using an electric flocculation process in a pretreatment process.

According to the Ministry of Environment 's' 2013 Sewage Statistics', the sewerage penetration rate in urban areas is 94.9%, but the sewerage penetration rate in rural areas is 63.7%, which is about 30% lower than in urban areas. Most of these areas are scattered by sources, so it can not be solved by using a sewerage system using a sewerage system. However, most of the processes proposed by these small-scale processing facilities are low in processing efficiency, processing and operation stability, or simply applied to large-scale wastewater treatment, so that the process is very complicated and difficult to operate and difficult to maintain .

 Therefore, there is a growing need for a small-scale treatment apparatus capable of removing organic matter, nutrients such as nitrogen and phosphorus, and simple operation and maintenance. One of the alternatives to achieve this goal is the subsurface flow constructed wetland method. The artificial wetland process can be roughly divided into surface flow and subsurface flow. The groundwater marsh has been successfully applied to various types of wastewater including sewage, stormwater runoff, agricultural wastewater, and industrial wastewater, and it has advantages such as low installation cost and easy operation and maintenance as compared with general treatment system.

Underground water is divided into a horizontal flow type and a water flow type depending on the flow type, and they are used either individually or in a hybrid type in which the two are combined. Such groundwater wetland processes are effective for BOD (Biochemical Oxygen Demand), SS (Suspended Substance), and pathogen removal, but there is a limitation in the removal of nutrients because the oxygen concentration required to oxidize the ammonium ion is insufficient, This is because the adsorbability of the artificial wetland-filled soil material used is low. It is also possible to remove nutrients from the growth of plants such as reeds planted in the upper part of the underground water structure, but the efficiency and the efficiency are considerably limited. Therefore, the removal of nitrogen in nutrients is eliminated by the combination of horizontal flow and water flow, or by changing the injection method such as effluent recirculation, step-feeding or tidal flow. In the case of phosphorus, . Nitrogen is basically removed by nitrification-denitrification. However, in case of phosphorus, it is effective at the initial stage of operation even when a filling material having excellent adsorbing ability is highly dependent on the adsorbing ability of the filament filling material. However, And the desorption is also observed. Therefore, there is a problem in terms of sustainability because it is impossible to remove phosphorus after adsorption is over.

A related prior art is Korean Patent Laid-Open Publication No. 10-2016-0104841 (published on September 6, 2016).

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and it is an object of the present invention to improve the removal efficiency of nitrogen and phosphorus by using an electrocoagulation process as a pre- The present invention relates to a hybrid wetland processing system.

The technical objects to be achieved by the present invention are not limited to the above-mentioned technical problems.

In order to accomplish the above object, a hybrid wet type artificial wetland processing system using an electro-agglomeration process according to the present invention includes a storage tank for storing sewage, an electric flocculant for use in a pretreatment process in connection with a storage tank, A primary storage tank portion in which the primary treatment water is passed through the electrocoagulation process portion, a groundwater level in which the primary treatment water is introduced, and a secondary water treatment portion that receives the secondary treatment water through the groundwater level water direct current type wetland processing portion And a secondary storage tank portion.

Specifically, the electrocoagulation unit includes an electrolytic reaction tank having a sewage inlet and a sewage discharge port, an inner surface of which is used as a negative electrode plate, an insoluble positive electrode plate disposed therein, a pump for supplying sewage contained in the storage tank to the electrolytic reaction tank, A power supply unit for supplying power to the negative electrode plate and the insoluble positive electrode plate of the reaction tank, and an adjusting unit for adjusting the pH of the sewage water.

Specifically, when the sewage inlet is formed at the upper portion, the sewage outlet is formed at the lower portion. When the sewage inlet is formed at the lower portion, the sewage outlet is formed at the upper portion.

Specifically, the insoluble positive electrode plate may be formed by electrodepositing platinum and lithium dioxide on a meshed titanium.

Specifically, when the sewage flows into the electrolytic reaction tank, the current of the power supply unit is 13 to 15 Ampere and the reaction time is 2 to 4 hours.

Specifically, the artificial wetland processing unit includes a single reaction tank in which a primary treatment water inlet is formed in an upper portion and a primary treatment water outlet is formed in a lower portion, a single reaction tank in which primary treatment water discharged from a primary storage tank is accommodated, A pump for supplying the primary treated water to the single reaction tank, a filter medium for stacking the sand and the loess ball in order from the upper side of the single reaction tank, and a transport tank having the return pump for transporting the primary treated water to the upper side of the single reaction tank under the single reaction tank .

Specifically, the loess balls are prepared in the form of balls having a diameter of 5 to 10 mm by mixing the pulp residues of greenhouse liquid waste, loess, and clay at a ratio of 30:50:20 wt%, dried for 22 to 26 hours, And is a porous medium fired for 2 hours.

Specifically, a denitrification reaction occurs in a lower portion immersed in a single reaction tank, and a nitrification reaction occurs in an upper portion without being immersed.

Specifically, it is characterized in that the residence time of the primary treated water is 0 to 100 hours, the immersion rate is 20 to 30% of the effective volume, and the number of transported times is 20 to 30% can do.

The hybrid wet type artificial wet processing system according to the present invention is environmentally friendly because most of the processes are adsorbed and decomposed by filter media and microorganisms, so that operation cost is reduced and sludge is not generated.

In addition, by using an electrocoagulation process in the pretreatment process, it is possible to remove organic matter, nitrogen, and phosphorus at the same time as reducing the area required for the site by using a combination of existing wetland processes.

FIG. 1 is a view showing a hybrid type wetland processing system in which an electrocoagulation process according to an embodiment of the present invention is performed as a pretreatment process.
Fig. 2 is a diagram showing the configuration of the electrocoagulation unit shown in Fig. 1. Fig.
3 is a view showing the construction of the wetland processing unit shown in FIG.
4 is a graph comparing COD and TN removal efficiency according to the immersion rate in the single reaction tank shown in FIG.
FIG. 5 is a graph comparing COD and TN removal efficiency according to the residence time when the immersion ratio is 25% in the single reaction tank shown in FIG. 3. FIG.
FIG. 6 is a graph comparing COD and TN removal efficiencies according to the number of transports in the single reactor shown in FIG.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings, and the scope of the present invention is not limited to the following embodiments. In the drawings, the same components are denoted by the same reference symbols whenever possible. In the following description, well-known functions or constructions are not described in detail since they would obscure the invention in unnecessary detail.

FIG. 1 is a view showing a hybrid type wetland processing system in which an electrocoagulation process according to an embodiment of the present invention is performed as a pretreatment process.

Referring to FIG. 1, a hybrid type wetland processing system includes a storage tank unit 100, an electrocoagulation unit 200, a primary storage tank unit 300, a groundwater level direct current artificial wetland water purification unit 400, And a secondary storage tank unit (500).

The storage tank unit 100 adjusts the flow rate of the sewage water and the sewage water flowing through the electrolytic reaction tank 210 is re-introduced and mixed while the reaction takes place in the electro-coagulation unit 200.

The electrocoagulation unit 200 receives sewage water from the storage tank unit 100 and performs an electrocoagulation process in a pretreatment process. A detailed description thereof will be described with reference to Fig.

Fig. 2 is a view showing a configuration of the electrocoagulated tablet 200 shown in Fig.

Referring to FIG. 2, the electrocoagulation unit 200 includes a sewage inlet 211 formed at a lower portion thereof, a sewage outlet 212 formed at an upper portion thereof, and an electrolytic cell 200 having an anode plate 213 and an insoluble cathode plate 214 A reaction tank 210, a first pump 220, a power supply unit 230, and an adjustment unit 240.

The sewage inlet 211 is an inlet through which the sewage enters the electrolytic reaction tank 210 from the storage tank 100 through the first pump 220.

The sewage discharge port 212 is an outlet that exits when sewage is moved from the electrolytic reaction tank 210 to the storage tank unit 100 or to the adjustment unit 240.

The electrolytic reaction tank 210 is used for electrolyzing the sewage supplied from the storage tank unit 100. The inner surface of the electrolytic tank 210 is used as the cathode plate 213 and the insoluble cathode plate 214 is used for effectively electrolyzing organic matters, And platinum and iridium dioxide are electrodeposited on the meshed titanium.

The first pump 220 is used to supply sewage to the electrolytic reaction tank 210 from the storage tank unit 100.

The power supply unit 230 supplies power to the negative electrode plate 213 and the insoluble positive electrode plate 214 of the electrolytic reaction tank 210.

The adjustment unit 240 checks the pH of the sewage discharged from the sewage discharge port 212 and inputs caustic soda when the sewage is acidic. When the sewage is alkaline, hydrochloric acid, sulfuric acid, or the like is added to neutralize the sewage.

The sewage discharged to the sewage discharge port 212 is discharged to the reservoir tank 100 through the first valve 610 during the reaction time by closing the inlet where the valve 610 enters the regulator 240 and opening the inlet to the storage tank 100, The first valve 610 closes an inlet opening into the storage tank unit 100 and opens an inlet opening into the adjusting unit 240 and flows into the adjusting unit 240.

Table 1 below shows the T-P removal efficiency according to the change of the current and the reaction time in the electrocoagulation unit 200.

Current and reaction time T-P removal efficiency (%) 5A-1 hour 15.5 5A-2 hours 16.0 5A-3 hours 18.3 5A-4 hours 20.9 10A-1 hour 25.8 10A-2 hours 31.0 10A-3 hours 34.7 10A-4 hours 37.3 15A-1 hour 35.1 15A-2 hours 41.2 15A-3 hours 49.2 15A-4 hours 51.4 15A (PAC) -1 hour 42.2 15A (PAC) -2 hours 46.9 15A (PAC) -3 hours 53.2 15A (PAC) -4 hours 56.5

In Table 1, A is Ampere, and A (PAC) is the result of injecting Polyaluminium chloride (aluminum chloride) in each ampere.

As a result of analyzing the electrochemical treatment efficiency by current and reaction time in the electrocoagulation unit 200, the current and reaction time were found to be most suitable for 15A and 3 hours, and the removal efficiency of T-P was 49.2%. The removal efficiency of T-P by adding the coagulant at the same current condition was increased to about 4 ~ 5%, and it was evaluated that the addition of coagulant did not show significant improvement effect on removal of organic matter and nutrients.

The electric current of the power supply unit 230 of the electrocoagulation unit 200 used in the present invention is preferably about 13 to 15 A and the reaction time is preferably about 2 to 4 hours and most preferably about 15A It is good to drive.

In the primary storage tank unit 300, primary treated water passing through the electrocoagulation unit 200 is stored.

The groundwater level direct current type wetland construction unit 400 receives the primary treatment water from the primary storage tank unit 300 and performs the wetland process. A detailed description thereof will be described with reference to FIG.

FIG. 3 is a view showing the construction of the constructed wetland padding unit 400 shown in FIG.

3, the artificial wetland building 400 includes a single reaction tank 410 in which a primary treatment water inlet 411 is formed at an upper portion and a primary treatment water outlet 412 is formed at a lower portion, 420, a filter medium 430, and a transport tank 440.

The primary treatment water inlet 411 is used when the primary treatment water enters the single reaction tank 410 from the primary storage tank unit 300.

The primary treated water discharge port 412 is used when the primary treated water is moved from the single reaction tank 410 to the secondary storage tank unit 500 or moved to the transfer tank 440 through the third valve 630.

Denitrification occurs in the lower portion immersed in the single reaction tank 410 and nitrification occurs in the upper portion where the immersion is not performed.

The second pump 420 is used to supply the primary treatment water from the primary storage tank unit 300 to the single reaction tank 410.

The filter material 430 is filled in the order of the sand 431 and the loess ball 432 from the top of the single reaction vessel 410. The sand 431 is 25% of the effective volume and the loess ball 432 is 75% Respectively.

The loess ball 432 is prepared in the form of a ball having a diameter of 5 to 10 mm by mixing the pulp residues of greenhouse liquid waste, loess, and clay at a ratio of 30:50:20 wt%, dried for about 22 to 26 hours, It is preferable to calcine for about 2 hours to about 2 hours, and most preferably for about 24 hours, then calcine at 900 ° C for 1 hour.

The transfer tank 440 is circulated through the primary treatment water inlet 411 using the transfer pump 441.

The primary treated water discharged to the primary treated water outlet 412 is supplied to the secondary storage tank part 500 through the third valve 630 while closing the inlet port into the secondary storage tank part 500 and opening the inlet port into the transfer tank 440 Enters the transport tank 440 and is transported to the single reaction tank 410. The third valve 630 closes the inlet opening into the transport tank 440 and opens the inlet opening into the secondary storage tank portion 500 and flows into the secondary storage tank portion 500. [

During the conveyance, the second valve 620 prevents the first treated water from flowing into the first treated water inlet 411 from the transport tank 440, Lt; / RTI > After the transportation is completed, the transfer vessel 440 is prevented from entering the primary treatment water inlet 411 and the inlet through which the primary treatment water flows from the primary storage tank unit 300 is opened.

FIG. 4 is a graph comparing COD (chemical oxygen demand) and T-N (total nitrogen) removal efficiencies according to the immersion rate in the single reaction tank 410 shown in FIG.

Referring to FIG. 4, the COD and TN removal efficiencies according to the immersion ratio are compared. As a result, the immersion rate is 25%, which is 25% higher than the 50%, and COD is 12% and TN is 14% It is considered to be a better condition.

FIG. 5 is a graph comparing COD and T-N removal efficiency according to the residence time when the immersion ratio is 25% in the single reaction tank 410 shown in FIG.

Referring to FIG. 5, COD and TN removal efficiencies at a retention time of 25% were compared with those of a retention time of 48 hours, which showed a removal efficiency of COD of 8% and TN of 11% The residence time of 96 hours is considered to be better than that of 48 hours.

FIG. 6 is a graph comparing COD and T-N removal efficiencies according to the number of transports in the single reaction tank 410 shown in FIG.

Referring to FIG. 6, COD 70%, TN 87%, and COD 73% and TN 89%, respectively, when carrying out twice, respectively. The change in the treatment efficiency was insignificant. TP was also removed from the electrophotographic flocculation unit 200 as a pretreatment to maintain a very low concentration and the effluent was discharged at a very low concentration irrespective of the number of conveyance times of the reaction tank 440 when the flood plain 400 was introduced, The comparison of star treatment efficiency is not significant. However, it was shown that T-P was removed more than once when the shipments were carried out more than 2 times. Therefore, when the conveyance is performed twice or more, it is judged that the optimal number of conveyance is two in consideration of economical efficiency and the like because the change in COD and T-N processing efficiency due to the increase in the number of conveyance is small.

4, 5 and 6, the residence time of the first treated water in the single reaction tank 410 is about 90 to 100 hours, the immersion rate is about 20 to 30% of the effective volume, When it is about 20 to 30%, it is appropriate to carry out about 2 to 4 times at the time of conveyance, and most preferably, it is preferable to operate the conveyance number twice at 96% for the retention time, 25%

The secondary storage tank unit 500 is provided with a discharge port for receiving and discharging the secondary treatment water passing through the artificial wetland water purification unit 400.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed embodiments, but, on the contrary, It will be readily apparent that such substitutions, modifications, and alterations are possible.

100: storage tank unit 200:
210: electrolytic reaction tank 211: sewage inlet
212: sewage discharge port 213: negative electrode plate
214: insoluble positive electrode plate 220: first pump
230: power supply unit 240:
300: primary storage tank part 400: groundwater level water direct current type wetland construction
410: single reaction tank 411: primary treated water inlet
412: Primary treated water outlet 420: Second pump
430: Filter material 431: Sand
432: loess ball 440: conveying tank
441: Return pump 500: Secondary storage tank section
610: first valve 620: second valve
630: third valve

Claims (9)

A storage tank portion in which sewage is received;
An electrocoagulation unit connected to the storage tank unit and used in a pretreatment process;
A primary storage tank portion in which the primary treated water passing through the electrocoagulation processing portion is received;
A groundwater level direct current type artificial wetland plant in which the primary treated water flows from the primary storage tank portion; And
And a secondary storage tank portion having a secondary water treatment water passing through the groundwater level direct current type wetland processing portion and having an outlet,
The electrolytic reaction unit may include an electrolytic reaction tank having a drainage inlet and a drainage outlet, an inner surface being used as a cathode plate, and an insoluble cathode plate disposed therein, and a first electrolytic reaction tank for supplying the sewage contained in the storage tank to the electrolytic reaction tank, And a pH adjuster for adjusting the pH of the sewage flowing through the electrolytic reaction tank, wherein the electrolytic bath comprises:
When the sewage flows into the electrolytic reaction tank, the current of the power supply unit is 13 to 15 Ampere and the reaction time is 2 to 4 hours,
The wetted wastewater treatment unit includes a single reaction tank in which a primary treatment water inlet is formed at an upper portion and a primary treatment water outlet is formed at a lower portion and the primary treatment water discharged from the primary storage tank is received; A second pump for supplying the primary treated water accommodated in the unit to the single reaction tank; And a conveying tank having a return pump for conveying the effluent of the single reaction tank to the upper portion of the single reaction tank,
The primary treatment water is operated for 90 to 100 hours, the immersion rate is 20 to 30% based on the effective volume, and the number of transportation is 20 to 30%
The sand is filled with 25% of the effective volume and the loess ball is filled with 75% of the effective volume,
The loess balls are prepared in the form of a ball having a diameter of 5 to 10 mm by mixing waste residues of raw plant waste, yellow loess, and clay at a ratio of 30:50:20 wt%, dried for 22 to 26 hours and then dried at 890 to 910 ° C for 1 to 2 Time-fired porous media,
Wherein the adjustment unit confirms the pH and inputs caustic soda if the wastewater is acidic and inputs hydrochloric acid or sulfuric acid if the wastewater is alkaline.
delete The method according to claim 1,
Wherein when the sewage inlet is formed at the upper part, the sewage outlet is formed at the lower part, and when the sewage inlet is formed at the lower part, the sewage outlet is formed at the upper part.
The method according to claim 1,
Wherein the insoluble positive electrode plate is formed by electroplating platinum and iridium dioxide on a meshed titanium.
delete delete delete The method according to claim 1,
Wherein the denitrification reaction occurs in the lower portion immersed in the single reaction tank and the nitrification reaction occurs in the upper portion not immersed in the single reaction tank.
delete

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