KR20230090296A - wastewater treatment system - Google Patents

Abstract

The present invention relates to a wastewater treatment device, and in particular, a fibrous sand carrier in a contact aerobic tank, a fibrous sand carrier in a contact aerobic separation membrane tank, and a separation filtration membrane are arranged so that microorganisms are attached and activated in an aerobic reaction process based on the inflow of sewage, and sludge The function of removing nitrogen and phosphorus by circulation is implemented at the same time, and sludge return, decomposition of organic matter by suspended microorganisms, and nitrogen phosphorus treatment process are carried out to remove residual pollutants and discharge with reduced pollutants through the membrane function of the separation filtration membrane. It relates to a wastewater treatment system that can be used.

Description

Wastewater treatment system {wastewater treatment system}

The present invention relates to a wastewater treatment device, and in particular, a fibrous sand carrier in a contact aerobic tank, a fibrous sand carrier in a contact aerobic separation membrane tank, and a separation filtration membrane are arranged so that microorganisms are attached and activated in an aerobic reaction process based on the inflow of sewage, and sludge The function of removing nitrogen and phosphorus by circulation is implemented at the same time, and sludge return, decomposition of organic matter by suspended microorganisms, and nitrogen phosphorus treatment process are carried out to remove residual pollutants and discharge with reduced pollutants through the membrane function of the separation filtration membrane. It relates to a wastewater treatment system that can be used.

In densely populated areas of large cities, wide-area sewage treatment plants or large-scale sewage treatment plants are installed and sewage is treated in batches by connecting collection pipes within the area. Unlike general pollutants, the domestic sewage not only directly affects water pollution, but also Large and small emission sources are scattered across the country in various ways.

In particular, in the outskirts of cities or rural areas where sewage supply is insufficient, domestic sewage is mostly discharged into natural water systems and flows beyond the self-cleaning capacity of lakes or rivers, accelerating damage to the water ecosystem. In case of closed water areas of lakes or dams Nutrients such as nitrogen and phosphorus are continuously introduced into the water, resulting in frequent eutrophication, and there are places where the value of use as a source of water for living is greatly damaged.

Chemical and biological methods are applied to remove organic matter and nutrients in domestic sewage or wastewater, but when applying the process, the characteristics of untreated sewage, the type of sewage treatment method, and the required degree of nutrient salt removal must be considered.

The removal of organic matter or nutrients through the chemical method guarantees high efficiency, while the biological method with relatively little sludge is preferred due to the economic burden due to the cost of purchasing chemicals and the generation of a large amount of sludge.

As the main process of the biological method, a method of removing organic matter and nutrients by mixing sewage and microorganisms in an aerobic process to induce metabolism of microorganisms is used.

Small-scale sewage treatment equipment initially uses a lot of activated sludge or long-term aeration using floating decorative microorganisms, which often causes sludge swelling during operation, is difficult to cope with when load fluctuations are large, and generates a large amount of surplus sludge. There are problems such as

Patent Registration No. 10-2269059 applied to the above chemical method “Wastewater treatment device using neutralization treatment and flocculation sedimentation treatment” Patent Registration No. 10-1800290 “Alkaline wastewater neutralization device using carbon dioxide gas and neutralization treatment method of alkaline wastewater using the same” Patent Publication No. 10-2014-0023600 discloses a technique for “alkaline wastewater neutralization device and alkaline wastewater neutralization method using carbonic anhydrase”.

The conventional technologies disclosed as described above have disadvantages in that they are difficult to effectively install and use in industrial fields because the scale of the wastewater treatment device is large and it is difficult to treat the wastewater within a short time.

The present invention has been made to solve the above problems, and for the purpose, since a high concentration of microorganisms are attached to a fibrous yarn-based carrier applied to a contact aerobic tank to form a biofilm, an increase in the growth rate per unit surface area and an increase in metabolic activity and resistance to toxic effects increases, and the microenvironment formed on the surface of the fiber yarn has different PH, ionic strength, and concentration of organic matter compared to the entire environment. It is to provide what can be preserved and maintain a high concentration.

Another object of the present invention is to provide a good environment for the growth of low-density attached microorganisms because the residual organic matter concentration is eliminated by attachment to the surface of the fibrous yarn-based carrier applied to the contact aerobic separation membrane tank and the hydrolyzate does not leak out, so that the surface area of the biofilm formation conditions per unit surface area is increased, and resistance to toxic substances is increased by maintenance of the balance of limited growth by the food chain, age of microorganisms, food chain, and encapsulation of bacteria, etc., and sludge that is desorbed into the floating system and becomes a factor in closing the pores of the separation filtration membrane While the generation amount is extremely small, the decomposition power of the recalcitrant material is also strengthened, and since most microorganisms are attached to the carrier surface to form / grow, the biofilm is quickly stabilized and formed with low density characteristics from an engineering point of view. In particular, the separation filtration membrane located in the center of the facility provides a membrane function that allows pollutants to be discharged in a reduced state.

Embodiments of the present invention for achieving the above object are as follows.

The wastewater treatment device of the present invention is composed of a screen tank, a flow control tank, an anaerobic anoxic tank, a contact aerobic tank, a sinking tank, a contact aerobic separation membrane tank, and a disinfection discharge tank. When sent out, the raw water transfer pump operates to drain wastewater to the post-treatment tank according to a predetermined detection value, the anaerobic anoxic tank has a wastewater supply pipe that receives wastewater from the pre-treatment tank, a DO meter capable of measuring residual dissolved oxygen concentration, and oxidation-reduction It includes an ORP meter capable of measuring a potential difference, and the contact aerobic tank includes a plurality of fiber yarn carriers and an aeration device for maintaining aerobic conditions under the fiber yarn carrier, and a DO meter capable of measuring dissolved oxygen concentration, and the sedimentation tank In the lower part, a wastewater treatment device including a sludge collection hob that collects sediment by gravity, a sludge transfer pump connected to a 'T' valve disposed on the side of the settling tank, and a sludge storage tank that stores the waste sludge transferred by external transfer Consists of

A fibrous yarn-based carrier filled with 1.5 m ³ in the 3.75 m ³ volume of the contact aerobic tank and having a volume ratio of 40%;

Both sides of the 'T' valve are divided into an upper opening/closing valve disposed to transfer activated sludge to the anaerobic anoxic tank and a lower opening/closing valve disposed to transfer waste sludge to the sludge storage tank,

At the center of the contact aerobic separation membrane tank, a plurality of micro filters that perform filtration of residual substances of heavy metals and SS to limit pneumatic MLSS generation factors are fixed to the forward frame and spaced apart at predetermined intervals on both sides of the separation filtration membrane. and fixed to a fixed frame, filled with 0.798 m ³ in the volume of 2.08 m ³ of the contact aerobic separation membrane tank and having a volume ratio of 38.4%, and the fiber yarn-based carrier applied to the contact aerobic tank and the contact aerobic separation membrane tank by primary chain knitting warp knitting. It is composed of a mesh of 1~2mm and a secondary Raschel warp knitted weave of 10~12mm.

As described above, in the present invention, the fibrous yarn carrier of the contact aerobic tank, the fibrous yarn carrier of the contact aerobic separation membrane tank, and the separation filtration membrane are arranged, and the inflow of sewage, the carrier filled in the process, and the adhesion in the aerobic condition, the suspended microorganisms are active, and the sludge The function of removing nitrogen and phosphorus by the circulation of is realized at the same time, and sludge return, decomposition of organic matter by suspended microorganisms and nitrogen phosphorus treatment process are carried out to remove residual pollutants and the membrane function of the separation filtration membrane to reduce pollutants. It is possible to obtain good results with a treatment efficiency of more than 90%, and there is an effect of discharging with a BOD of 5ppm of the final treated water.

1 is a flow-sheet diagram of the overall process of the present invention.
2 is an enlarged view of a contact aerobic tank applied to the present invention.
3 is an enlarged view of a sedimentation tank applied to the present invention.
4 is an enlarged view of a contact expiratory air separation membrane tank applied to the present invention.

Hereinafter, implementation embodiments of the present invention for implementing the technical idea of the present invention will be described with reference to the accompanying drawings, and terms or words used in the specification or claims of the present application are limited to conventional or dictionary meanings. It should not be, and the protection scope of the present application should be interpreted as meaning and concept consistent with the technical idea of the present invention, and the examples described in this specification are only one of the most preferred embodiments of the present invention, and all of the technical spirit of the present application Since it is not a representative, it should be understood that there may be various equivalents and modifications that can replace them at the time of this application.

1 is an overall processing flow chart of the present invention, FIG. 2 is an enlarged view of a contact aerobic aeration tank applied to the present invention, FIG. 3 is an enlarged view of a settling tank applied to the present invention, and FIG. 4 is an enlarged view of a contact aerobic separation membrane tank applied to the present invention. It is also

As shown in FIG. 1, the wastewater treatment apparatus of the present invention includes a screen tank, a flow control tank, an anaerobic anoxic tank, a contact aerobic tank, a sedimentation tank, a contact aerobic separation membrane tank, and a disinfection discharge tank process.

The screen unit 10 is disposed on the side of the inlet 11 through which wastewater flows, and the wastewater that has passed through the first and second filtering inside the screen unit 10 flows naturally and is discharged through post-treatment. Specifically, The gap between the plurality of bars of the coarse screen 12 disposed in the primary filter coarse solids such as stones, twigs and fragments, leaves, paper, plastic, and pieces of cloth with a gap of 15 mm or more, and disposed in the secondary The gap between the plurality of bars of the fine screen 13 is 15 mm or less, and it filters grease lumps, scum, small food debris, and foam, and the sedimentary sediment is stored at the bottom of the screen The filtered wastewater of the upper layer is discharged to the post-treatment tank through the connection passage (S1).

Here, the inflow of wastewater from the screen tank is 4.67 tons per day, which can be treated on a scale of 5 tons per day.

The flow control tank 20 has a water level sensor 21 that detects the level of wastewater introduced from the pretreatment tank, and when the sensor value sensed by the water level sensor 21 is sent to the control unit 100, the control unit sets a predetermined detected value. A raw water transfer pump (22) operated to drain wastewater to the post-treatment tank by means of a raw water transfer pump (22), and an agitator (23) for equalizing the water quality of the drainage while preventing the sediment contained in the wastewater from being stored at one side of the bottom of the flow control tank. and a plurality of aerators 24 having a preliminary auxiliary means for agitating the introduced wastewater and activated sludge at a predetermined height on the bottom of the flow control tank.

4.67 tons are introduced from the pre-treatment tank in the 5-ton scale treatment facility of the flow control tank per day, and when the water level in the tank is reached, 0.2 tons per hour are drained to the post-treatment tank through the raw water transfer pump 22.

The anaerobic anoxic tank 30 includes a wastewater supply pipe 31 receiving wastewater from the pretreatment tank, a DO meter 32 capable of measuring the residual dissolved oxygen concentration, and an internal return 33 receiving activated sludge precipitated from the posttreatment tank It is composed of a mixing agitator (34) for stirring the returned sludge and inflowed wastewater and an ORP meter (35) for measuring the difference in oxidation-reduction potential.

With the configuration of the anaerobic anoxic tank 30, the wastewater quality cannot be purified, but some contaminants are precipitated at the bottom of the tank. It can be seen that the wastewater is then drained to the post-treatment tank through the connection passage S2 in the upper part.

For reference, the proper amount of wastewater that can be introduced into the anaerobic anoxic tank is 0.75 tons, and at this time, the water quality of wastewater is BOD 267 (mg / l), SS 241 (mg / l), T-N as shown in Table 1 below. 57.3 (mg/l), T-P 6.72 (mg/l), and TOC 193 (mg/l).

As shown in FIG. 2, the contact aerobic tank 40 has a plurality of fiber yarn-based carriers 41 arranged on both sides, and a diffuser 42 disposed under each fiber yarn-based carrier, and dissolved in the tank. The DO meter 43 capable of measuring the oxygen concentration, the activated sludge return 44 in which the activated sludge precipitated in the post treatment tank is returned, and the treated water filtered in the contact aerobic tank are sent to the post treatment through the connection passage S3. It is meant to be drained.

Here, 1.5 m ³ of the fiber yarn-based carrier 41 is filled in the 3.75 m ³ volume of the contact aerobic tank to have a volume ratio of 40%.

In addition, in order to maintain the DO value in the range of 2.1 to 3.2 PPM, the air diffuser 42 is set to operate at a blowing amount of 0.3 to 1.0 ^{m 3 air/hour per 1 m 3} in the control unit 100 .

In particular, the fiber yarn-based carrier is characterized by having a secondary shape in which long filament filaments of short filament yarns are first knitted by chain knitting, and a part is inversely woven into other chain knitting and Raschel-type netting. Secondary Raschel-type warp knitted mesh is composed of 10-12 mm of tissue, and it was found to be desirable for increasing the activated sludge, suspended solids (MLSS), increasing the nitrification rate, and reducing DO.

As shown in FIG. 3 of the accompanying drawing of the settling tank 50, the inside of the upper part has a Wolyuware 51 for guiding it when wastewater overflows, and a rectifying device 52 for increasing the aggregation of sludge contained in wastewater in the central part And, in the lower part of the settling tank, the microbial sludge filled with phosphorus is connected to the sludge collection hob 53 that collects the sediment by gravity and its own weight, and the 'T' valve 54 disposed on the side of the settling tank 50. Transfer of the sludge On both sides of the pump 55 and the sludge transfer pump 55, an upper opening/closing valve 56 that opens and closes when activated sludge is transferred to the internal transfer 33 and waste sludge is transferred to the external transfer 57 It includes a lower opening/closing valve 58 that is opened and closed.

Here, among the waste sludge transported to the external transport 57, heavy phosphorus compounds, heavy metal components, or dead microorganisms are sent to the sludge storage tank 59, and these are collected again in a sludge enrichment tank (not shown) and treated separately.

As described above, as a result of the purification water quality of the primary treated water from the anaerobic anoxic tank 30 to the sedimentation tank 50, BOD 18.6 (mg / l), SS 16.1 (mg / l), T-N 14.9 (mg / l), T-P With 1.77 (mg / l) and TOC 15.8 (mg / l), it can be seen that the overall water quality is lowered, and the treatment efficiency at this time is shown in Table 1 below.

Anaerobic anoxic tank → sedimentation tank division Influent (mg/l) Primary treated water (mg/l) Primary treatment efficiency (%) BOD 267 18.6 93.0 S S 241 16.1 93.3 T-N 57.3 14.9 73.9 T-P 6.72 1.77 73.6 TOC 193 15.8 91.8

As described above, in order to secure a better water quality than the first water quality purification efficiency, a contact aerobic aeration separation membrane tank was placed after the secondary sedimentation tank. Similarly, a separation filtration membrane 61 having a plurality of micro filters fixed to the forward frame F1 and the separation filtration membrane 61, which performs filtering of heavy metals and residual substances of SS in the center thereof to limit the cause of floating MLSS, It is spaced apart from both sides at a predetermined interval and fixed to the fixed frame (F2), and is filled with 0.798 ^{m 3} of the 2.08 m 3 volume of the contact expiratory membrane tank and has a volume ratio of 38.4%. The aeration device 63 that simultaneously satisfies supply and agitation of the sludge and the activated sludge return 44 for returning the activated sludge to the contact aerobic tank 40 as a pretreatment tank are connected. In addition, the contact aerobic separation membrane tank 60 It consists of a water level sensor 64 that controls the amount of filtration and a suction pump 65 that discharges treated water to the post-treatment tank.

For reference, the separation filtration membrane 61 is used as a means to maintain adhered MLSS in the range of 1000 ppm or less by performing a filtration process of residual substances of heavy metals and SS and to limit the floating MLSS generation factor, and the fibrous yarn-based carrier 62 has a means for inducing the attachment of suspended sludge at a volume ratio of 38.4%, which is 0.798 m ³ of the 2.08 m ³ volume of the contact aerobic separation membrane tank 60, and the fibrous yarn-based carrier applied here is the above-mentioned contact aerobic tank (44 ) It is preferable to use the same product as the fibrous yarn-based carrier in.

As described above, in the anaerobic anoxic tank 30 composed of the pretreatment tank, the sedimentation tank 50 composed of the contact aerobic tank 40 and the post treatment tank, and the contact aerobic separation membrane tank 60, nitrogen oxides, phosphorus, etc. Simultaneous removal of is the same as the existing method.

Therefore, it was confirmed that the organic matter removal or denitrification effect was greatly improved through the separation and filtration membrane 61 in the contact aerobic separation membrane tank 60, not being satisfied with the removal of nitrogen oxides and phosphorus formed in the above circulation process.

Here, it is preferable to limit the passing particle diameter of the micro filter applied to the separation filtration membrane to the range of 0.01 to 0.2 μm.

Looking at the water quality of the secondary treated water that passed through the contact aerobic separation membrane tank 60 after the sedimentation tank 50, BOD 3.11 (mg/l), SS 1.24 (mg/l), T-N 11.02 (mg/l) , T-P 0.95 (mg / l), and TOC 9.64 (mg / l), it can be seen that the water quality is lower than the first value, and at this time, the secondary treatment efficiency and total removal rate are shown in Table 2 below.

Sedimentation tank → contact aerobic separation membrane tank division Secondary treated water (mg/l) Secondary treatment efficiency (%) Total removal rate (%) BOD 3.11 83.2 98.8 S S 1.24 92.2 99.4 T-N 11.02 26.0 80.7 T-P 0.95 46.3 85.8 TOC 9.64 38.9 95.0

It can be seen that the purified water quality in the close expiratory air separation membrane tank 60 is transferred to the disinfection discharge tank 70 through the suction pump 65 and discharged with a biological oxygen demand (BOD) of 3.11 PPM or less. In particular, by using the separation filtration membrane 61 of the micro filter as a group, it is installed to replace the existing chemical supply system, etc., and the treatment process is simplified, and the installation site is reduced due to the simplification of the process. While maintaining water quality, there is an effect of increasing treatment efficiency accordingly.

10: screen group 11: inlet
12: coarse screen 13: fine screen
20: flow control tank 21: water level sensor
22: raw water transfer pump 23: agitator
24: aeration device 30: anaerobic anoxic tank
31: wastewater supply pipe 32: DO meta
33: internal transfer 34: mixer agitator
35: ORP meta 40: contact aerobic tank
41: fibrous carrier 42: diffuser
43: DO meta 44: Return of waste activated sludge
50: sedimentation tank 51: Wolyuware
52: rectifier 53: sludge collection hose
54: 'T' valve 55: sludge transfer pump
56: upper open/close valve 57: external transfer
58: lower open/close valve 59: sludge storage tank
60: contact aerobic separation membrane tank 61: separation filtration membrane
62: fibrous carrier 63: diffuser
64: water level sensor 65: suction pump
70: disinfection and discharge tank

Claims (1)

The wastewater treatment device is composed of a screen tank, a flow control tank, an anaerobic anoxic tank, a contact aerobic tank, a sinking tank, a contact aerobic separation membrane tank, and a disinfection discharge tank. A raw water transfer pump that operates to drain wastewater to the post-treatment tank according to a set detection value, a wastewater supply pipe that receives wastewater from the pre-treatment tank in the anaerobic anoxic tank, and a DO meter capable of measuring the concentration of residual dissolved oxygen, measuring the difference in oxidation-reduction potential It includes a possible ORP meta, and the contact aerobic tank includes a plurality of fiber yarn-based carriers and an aeration device for maintaining aerobic conditions in the lower portion of the fiber yarn-based carrier, and a DO meter capable of measuring the dissolved oxygen concentration, and in the lower part of the sedimentation tank A wastewater treatment device including a sludge collection hob for collecting sediment by gravity, a sludge transfer pump connected to a 'T' valve disposed on the side of the sedimentation tank, and a sludge storage tank for storing waste sludge transferred to the outside,
A fibrous yarn-based carrier filled with 1.5 m ³ in the 3.75 m ³ volume of the contact aerobic tank and having a volume ratio of 40%;
Both sides of the 'T' valve are divided into an upper opening/closing valve disposed to transfer activated sludge to the anaerobic anoxic tank and a lower opening/closing valve disposed to transfer waste sludge to the sludge storage tank,
At the center of the contact aerobic separation membrane tank, a plurality of micro filters that perform filtration of residual substances of heavy metals and SS to limit pneumatic MLSS generation factors are fixed to the forward frame and spaced apart at predetermined intervals on both sides of the separation filtration membrane. and fixed to a fixed frame, filled with 0.798 m ³ in the volume of 2.08 m ³ of the contact aerobic separator tank and having a volume ratio of 38.4%, and the fiber yarn-based carrier applied to the contact aerobic tank and the contact aerobic separator tank, which are applied to the primary chain knitting warp knitting A wastewater treatment device characterized in that it consists of a mesh of 1 to 2 mm and a second Raschel warp knitted mesh of 10 to 12 mm.

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