KR100731846B1 - A sewage disposal system using a hydraulic cyclone - Google Patents

Abstract

 The present invention relates to an environmental pollution prevention technology that enables environmentally-friendly and economical treatment of sewage sludge discharged from domestic sewage, industrial wastewater, and sewage treatment plants, even when the composition ratio of organic matter is relatively high. Using the two-stage hydrocyclone, which is operated inside and outside of the cone to obtain two-stage separation efficiency, the top discharge and high particulate matter having high composition ratio of organic matter are separated into concentrated bottom discharge. It is possible to maximize the treatment efficiency according to the sludge composition contained in the discharge.

       Sewage treatment, two-stage hydrocyclone, organic matter, inorganic matter

Description

       Sewage disposal system using a hydraulic cyclone {2 sewage disposal system using a hydraulic cyclone}

        1 is a processing system diagram of the system of the present invention.

        2 is a schematic diagram of a system of the present invention;

        3 is a schematic structural diagram of an agitator applied to the system of the present invention.

        4 is a schematic structural diagram of a hydraulic cyclone applied to the system of the present invention.

        5 is a structural diagram of the barrier film mounted on the artificial wetland.

        6 is a structural diagram of a distribution device mounted on a wetland.

<Explanation of symbols for main drawings>

        10: sieving and stirring 20: hydrocyclone

        30: landfill facility 40: anaerobic digestion apparatus

        50: Aerobic Adult Wetlands

The present invention relates to a sewage sludge treatment system which enables environmentally friendly and economical treatment of sewage sludge discharged from domestic sewage, industrial wastewater, and sewage treatment plants, even when the composition ratio of organic matter is relatively high. Biodegradation can reduce organic matter and landfill minerals that can be disposed of efficiently by two-stage hydrocyclones.

Generally, sewage sludge (or sewage sludge) discharged from sedimentation tanks of domestic sewage, industrial wastewater, and sewage treatment plants is composed of more than 98% of water, and the remaining 2% or less is composed of solids. It is composed in the range of 40 to 70%, and the rest is composed of inorganic matter.

Therefore, the sewage sludge discharged from the domestic sewage treatment plant has a different treatment method according to the composition ratio of organic matter, and the sewage treatment method that is attempted at a small sewage treatment plant where the composition ratio of organic matter is relatively low is discharged. After coagulating the organic matter by adding a polymer flocculant to the discharged sewage sludge, the dehydration sludge is finally landfilled after dewatering sludge having a water content of 75 to 85%.

However, this treatment method causes a lot of odor from the landfilled dewatering sludge, and in case of rain, the landfilled dewatering sludge absorbs a large amount of water and expands, thus destroying the safety of the landfill layer and making it difficult to carry out the landfill waste transport vehicle and processing equipment. Not only does this increase the risk of landfill decay, and also the polymer coagulant used delays the biochemical decomposition of the landfilled dewatering sludge, which acts as a deterrent to stabilization of the landfill waste, leaving the waste in an unreduced state. It is.

Therefore, it is difficult to apply the treatment method in the medium and large sewage treatment plants where the composition ratio of organic substances is high.

Therefore, the treatment method in this case is to remove only the coarse water and then digest the whole amount as it is, to reduce the biodegradable substances in the sludge first, and then to reduce them, and then to carry the dewatering sludge produced through the flocculation and dehydration process to vehicles and shelves. Is being dealt with by dumping at sea.

However, this treatment method requires not only excessive installation cost, facility operation cost, and labor cost due to complicated treatment process, but also final disposal method through ocean dumping is natural purification method through ocean self-cleaning ability. Dehydration sludge contains polymer coagulants, hardly decomposable organic substances, and hazardous metals, which are dispersed in seawater or deposited on tidal flats, causing widespread marine pollution, which is being discussed as a global environmental problem.

Therefore, there is an urgent need for an environment-friendly, more economical and efficient way to treat sewage sludge from sewage treatment plants.

Therefore, the present invention has been made to solve the above-mentioned problems, the organic matter is using the hydrocyclone that the sewage sludge is a centrifugal force of the swirl flow to the inside and the outside to obtain a two-stage separation efficiency than the inorganic material The upper discharges and inorganics, which are contained relatively more, are separated into the lower discharges, which contain more than the organics. The lower discharges are landfilled, and the upper discharges are reduced to organic matter through anaerobic digestion. It is treated by inflow and stabilization.

Hereinafter, the configuration of the present invention will be described in more detail with reference to the drawings.

      First, Figure 1 shows a schematic treatment process of the present invention, by introducing the sewage sludge discharged from the sedimentation tank of the domestic sewage treatment plant to remove the coarse matter contained in the sewage sludge and to prevent the sedimentation of minerals contained in the sewage sludge. The sludge agitation step and sewage sludge with coarse water are separated using concentrated centrifugal force separator to separate the sludge and inorganic sludge into organic sludge containing concentrated sludge. The sludge separation step, the sludge containing the minerals are separated into solid-liquid and separated into supernatant water and concentrated minerals, and the landfill treatment step of embedding and stabilizing only the concentrated inorganic materials, and digesting the sludge containing the organic matters include biodegradable organic matter contained in the sludge. Digestion process to reduce and semi-stabilize by gasification, and effluent of semi-stabilized sludge By early stabilization using a reed, microorganisms and animals is a soil to consist of a breathable artificial wetland treatment processing.

       At this time, the filtered coarse contains various miscellaneous material, which is not generated much but has no useful value as a resource, so it is separately stored and finally processed by landfilling when a certain amount is reached.

       Hereinafter, the configuration of the apparatus for treating the sewage sludge discharge of sewage treatment plant sewage treatment plant by the treatment method of the present invention will be described in detail with reference to the accompanying drawings, the most preferred embodiment of the present invention.

      Figure 2 shows the treatment system of the present invention, the configuration of the present invention is the sedimentation of the minerals contained in the filtering means 11 and the sewage sludge for removing the coarse matter contained in the sewage sludge discharged from the sedimentation tank of the domestic sewage treatment plant The stirring and stirring tank 10 provided with the stirring means 13 for preventing the sludge and the sludge from which the coarse flowed out from the filtering and stirring tank 10 are removed include two-stage swirl flow action. Only the two-stage separation hydrocyclone 20, which can be separated into the lower discharge and the upper discharge containing organic matter, and the concentrated inorganic material separated by solid-liquid separation of the lower discharge discharged from the hydraulic cyclone 20 Anaerobic digestion tank 40 and the anaerobic digestion tank for reducing and semi-stabilizing the upper discharge discharged to the upper discharge port 22 of the hydraulic cyclone 20, and the stabilization to It is composed of aerobic wetlands 50 to finally reduce and stabilize the semi-stabilized sludge spilled from (40).

       Hereinafter, the detailed configuration and operation of each device and facility constituting the sewage sludge treatment system will be described below.

First, as shown in FIG. 3, the filtering and stirring tank 10 is equipped with a filtering means 11 at a position where the sewage sludge first enters, and is currently provided as a filtering means 11. If the screen is used, the gap is a substance contained in the sewage sludge, and the coarse object having a diameter of 1.5 mm or more that can block the lower discharge port 27 of the hydraulic cyclone 20 can be caught. You can use the

       In this case, the coarse filtered through the filtering means 11 remains on the filtering means 11, and when a predetermined amount is accumulated, the coarse material may be removed by separating the filtering means 11 and periodically removing the coarse. In order to facilitate the collection and processing of the object, this apparatus is provided with a coarse collecting box 12, and most of the coarse collected in the collecting container 12 has little environmental hazard as seeds, coarse sand, etc. Landfill as it is, final processing.

      In addition, the stirring device 13 provided in the filtering / stirring tank 10 is usually mounted on the lower side of the device to mix sewage sludge introduced while rotating at a low speed to prevent sedimentation of the inorganic matter contained in the sewage sludge.

      Subsequently, the sewage sludge from which the coarse material is removed flows out through the outlet 14 of the filtering and stirring tank 10 and maintains a constant pressure by the pressure pump 15 to maintain the inlet 23 of the hydraulic cyclone 20. It will be transported through.

      The following is for the hydraulic cyclone 20, as shown in Figure 4, the hydraulic cyclone 20 applied to the present invention is to cause the two-stage swirl flow generated inside and outside by the inner cone 26 It is to have a conical portion 22 of a double structure.

      At this time, the upper space between the cone portion 22 and the inner cone portion 26 is a first stage inlet lower discharge port 24 in which granular minerals are separated and introduced from the sewage sludge, and the lower space flows out by separating the separated inorganic substances. It is to be the first stage discharge lower discharge port 27, and the lower side of the inner cone portion 26 is the second stage discharge lower discharge port 25 in which the particulate inorganic matter leaving the first stage inlet discharge port 24 is separated and discharged. will be.

      In addition, the cone portion 22 and the inner cone portion 26 has a structure in which the inner diameter gradually decreases upward.

      Therefore, the sewage sludge introduced into the hydraulic cyclone of the present invention having the double-conical portion 22 as described above, the inorganic matter of the granules is primarily separated by the centrifugal force of the swirl flow acting on the cylindrical portion 21 The first stage lower inlet discharge outlet 24 flows down while continuously turning, and is discharged through the first stage lower inlet discharge outlet 25, and the swirl flow that has passed the first stage lower inlet discharge outlet 24 is transferred to the internal cone portion 26. As the angular velocity is increased again by turning to the swirl flow, the particulate inorganic matter contained in the swirl flow is moved to the inside of the inner cone portion 26 to descend and finally discharged through the second stage lower discharge port 27. The lower discharges are introduced into the discharge reservoir 28 integrally or separately provided at the lower portion of the hydraulic cyclone 20 to be combined.

At this time, the lower discharge introduced into the discharge storage tank 28 is the sedimentation of the inorganic material by gravity sedimentation, the sedimentation of the inorganic matter is finished within 10 minutes, after the sediment, the supernatant is sent to the aerobic wetlands 50, the upper water The lower discharge composed of more than 75% of the inorganic material is removed is carried to the sanitary landfill 30 is utilized as a cover material.

      Hereinafter, when the sewage sludge is separated by using a conventional hydrocyclone (one-stage lower discharging type) and the two-stage separate hydrocyclone (two-stage lower discharging type), the total amount of inorganic matter contained in the sewage sludge is The results of experiments on the ratio of minerals in the lower emissions are shown in <Figure 1>.

Prior to this, the two-stage separation hydrocyclone used in this experiment was manufactured by applying the following formula so that the separation particle diameter (d ₅₀ ) of the first stage inlet soil outlet 24 was maintained at 5 μm, 1 A stepped bottom hydrocyclone was constructed using the same formula.

       In this formula, Kd: correction factor

                    D: Inner diameter (cm) of hydraulic cyclone cylinder

D _o : Inner diameter of the upper part of hydraulic cyclone discharge port (cm)

D _i : inner diameter of the hydrocyclone inlet (cm)

                    δ: average density of particles (g / cm 3)

                    ρ: density of the fluid (g / cm 3)

                    β: Volume ratio of solids to fluid (no units)

                     P: Inflow pressure of sludge (㎏ / ㎠)

Therefore, the hydrocyclone produced using the formula of d ₅₀ is based on the inner diameter (D) of the cylindrical portion 21, the length of the cylindrical portion 21 of the hydraulic cyclone is 9D, the length of the cone portion 22 4D was made to maximize the swirl flow centrifugal force of the sewage sludge.

       In addition, in the manufacture of the hydraulic cyclone of the present invention, the inlet pressure of the hydrocyclone inlet portion 23 was changed in the range of 0.6 to 1.8 kg / cm 2 to find an appropriate separation condition of the inorganic material.

                    <Figure 1>

In the above figure, the two-stage lower discharge hydraulic cyclone applied to the present invention at the inflow pressure 0.6kg / cm 2 was 59% of the inorganic composition to the total discharge of the lower discharge, but the composition ratio of the inorganic material was increased as the inflow pressure increased. 78% at 1.5kg / cm 2 and 79% at 1.8kg / cm 2.

       On the other hand, the first stage hydropneumatic hydrocyclone has a 28-56% range of inorganic material in the lower discharge relative to the total amount of inorganic weapons obtained at the same pressure, indicating that the separation capability of the second stage hydropneumatic cyclone applied to the present invention is considerably improved. I could confirm.

        In addition, the inorganic separation rate of the first stage hydraulic discharge cyclone was 1.8% at 1.8kg / ㎠, whereas the inorganic separation rate of the second stage hydraulic discharge cyclone was 65% at 0.9kg / ㎠ and the second stage lower Experiments proved that the separation of inorganic materials using discharged hydrocyclones was also efficient and economical.

This result is, firstly, the coarse particle of centrifugal force is discharged into the first stage discharge outlet 25 at the bottom of the cylindrical portion 22, and the fine mineral of the fine centrifugal force is gradually reduced in diameter. 26) it was turned into a cyclone inner wall under greater centrifugal force and discharged into the second stage lower discharge port 25, indicating a high separation rate.

In addition, the two-stage lower discharge hydrocyclone has an improved separation ability not only for the separation of inorganic substances but also for the separation of harmful chemical components such as heavy metals, which is harmful to the lower and upper discharges at an inlet pressure of 1.5 kg / cm 2. This can be proved by the material analysis result table.

       <Comparison of Hazardous Chemical Components of Hydrocyclone Top Discharge and Bottom Discharge>

 Unit: ㎍ / ㎏

 division  As  CD  Cr  Mn  Ni  Pb  Top discharge  102  13  293  565  133  121  Bottom discharge  33  5  87  161  43  32

       According to the above analysis table, the contents of harmful chemicals of the upper and lower discharges are different depending on the components, but overall, the contents of the hazardous chemicals in the lower discharges are considerably lower than those of the upper discharges (25-33%). As a result, it was found that the problem of landfilling of the lower discharges is less trouble than before.

       On the other hand, the swirl flow reached to the lower portion of the inner cone portion 26 of the hydraulic cyclone 20 is turned in the opposite direction from the inlet of the two-stage lower discharge port 27 to the upper direction toward the upper discharge port 29 The upper discharge is transferred into the digester 40 through the inlet 41 of the digester 40 installed to reduce organic matter.

Subsequently, the top discharge delivered to the digester 40 stays in the digester 40 for about 15-30 days while the organic matter contained in the top discharge is biodegraded and gasified into CH ₄ , C0 ₂ , H ₂ 0, and the like. In this way, the top discharge having the organic composition ratio reduced by about 50% is finally supplied to the aerobic wetlands 50 through the lower outlet 42.

      The aerobic artificial wetland 50 has a diameter of 600 mm or more for collecting sewage membrane 51 for preventing the outflow of the upper inflow of incoming inflow, and the sludge which is installed on the ordered membrane 51 and constitutes about 98% of the upper discharge. Perforated pipe 52 and the gravel layer 53 filled between the perforated pipe 52, the sewage feed pipe 54 for transferring the sewage collected in the perforated pipe 52 to the sewage treatment plant and the like, the digester 40 It comprises a transfer pump 55 for transferring the effluent to the aerobic wetlands 40 and a distribution device 56 for uniformly distributing the effluent.

       First, before the digester effluent is supplied to the lower aerobic wetlands, the gravel layer 53 is planted with reeds 57 and normally grown, and then the slurry is supplied from mid-March to mid-November.

       Sewage sludge discharged from domestic sewage treatment plant from late November to early March should be stored separately and transported to aerobic adult wetland from mid-March.

       Accordingly, the outflow of the digester 40 is transferred to the center box 56a formed at the center of the distribution device 56 by the transfer pump 55, and the distribution pipe 56b having an inclination installed on both sides of the center box 56a. The reed 57 is inhabited in the reeds and the digester effluent which has already been supplied and decomposed by being supplied to the artificial wetland portion where the reeds 57 are grown along the distribution port 56c installed at a predetermined interval in the lower portion of the distribution pipe 56b. It is decomposed and absorbed by the action of soil animals such as microorganisms and earthworms to remove organic matter, nitrogen and phosphorus contained in the digester effluent.

     In addition, due to the effect of the reed roots in which many earthworms inhabit and move in addition to microorganisms in the artificial wetlands, moisture occupying more than 98% of the digester effluent flows into the perforated pipes 52 installed at the bottom without clogging. When sewage is collected up to half of the inner height of the perforated pipe 52, the pump is operated by the installed water level sensor to be transferred to a facility such as a sewage terminal treatment plant.

      At this time, the natural aeration is maintained at 50% or more of the internal volume of the perforated pipe, so that the lower part of the artificial wetland is always aerobic or semi-aerobic, and the decomposition is promoted and the odor is minimized by maintaining this state.

      Hereinafter, a one-year removal rate of organic matter, nitrogen, and phosphorus when the digester effluent in the aerobic wetlands applied to the present invention was supplied at a thickness of 25 cm was presented.

    <1 year removal rate of organic matter, nitrogen and phosphorus in aerobic wetlands of reed plants>

                                                                  unit : %

       division        Organic matter          nitrogen         sign         Removal rate         78.3          72.6        37.1

      FIG. 5 is a plan view of installing a perforated pipe that collects wetland effluent and maintains the bottom of the wetland layer as aerobic and semi-aerobic. By drilling at intervals of 10 cm left and right, the function of the perforated tube is sufficiently made.

      In addition, the perforated pipe 52 is installed at equal intervals in the direction of either the vertical or horizontal, and the same hole between the installed perforated pipe 52, the perforated pipe 52 of the same standard installed at right angles of the perforated pipe By preventing movement, the water collecting action and the compressive strength can be improved.

      In addition, the gravel layer 53 is filled with gravel having a long axis length of 3 ~ 6cm up to about 10cm above the perforated tube 52 so that there is no problem in the growth of reeds.

      FIG. 6 is a structural diagram of a manual or automatic digester discharge sludge dispensing device installed at the center of an artificial wetland, each having four wheels 56e having four wheels at the upper and lower portions of the H-shaped steel constituting the upper portion of the fixed structure 56d. By installing and fixing the dispensing device 56 therein, flexibility and safety of dispensing device movement can be maintained.

       Therefore, the sewage treatment system of the present invention uses a two-stage hydraulic cyclone

It is possible to induce particulate inorganic sedimentation by obtaining a separation effect obtained by connecting multiple hydraulic cyclones in series with one hydrocyclone.

       Therefore, the inorganic material is landfilled and finally treated according to the separated composition of the discharge, and the organic material is finally processed through reduction and stabilization through digestion, thereby allowing processing considering both environmental friendliness and economic efficiency.

       In particular, in the case of the hydraulic cyclone used in this system, instead of connecting two hydraulic cyclones in series, one hydraulic cyclone can obtain a desired result, which reduces the manufacturing and operating power costs of the hydraulic cyclone device by about 50%. The savings can be achieved.

       Therefore, the present invention can solve the secondary environmental pollution problem caused by forced dehydration, chemical use problem and ocean dumping, which are absolutely necessary for the conventional sewage sludge treatment technology, as an environmentally friendly purification technology for treating sewage sludge physically and biologically. Since all the facilities can be operated and managed by one person, it has the characteristics as an environmentally friendly treatment technology if it is more economical than any treatment technology.

Claims (4)

Filtering for removing coarse matter contained in sludge and preventing sedimentation of minerals · Stirring tank (10) and sludge from which coarse has been removed in two stages of swirl flow action. And a two-stage separation hydrocyclone 20 capable of separating organic and organic substances into upper discharges, which are relatively higher than inorganic, and a landfill facility 30 for stabilizing concentrated inorganics by solid-liquid separation of the lower discharges; Anaerobic digestion tank 40 for reducing and semi-stabilizing the upper discharge through digestion, and two stages consisting of aerobic wetlands 50 for finally stabilizing the semi-stabilized sludge flowing out of the anaerobic digestion tank 40 Treatment apparatus for sewage sludge using separate hydrocyclone. 2. The two-stage separation according to claim 1, wherein the hydraulic cyclone (20) has a dual-conical portion (22) in which two stages of swirl flow are generated inside and out by the inner cone portion (26). Treatment equipment for sewage sludge using drinking hydrocyclone. According to claim 1, The aerobic air wetlands 50 is a water-repellent membrane 51 for preventing the outflow of sludge, the oil hole pipe 52 for collecting sewage is installed on the water-repellent film 51, and the oil hole pipe ( 52 is filled with gravel layer 53, the sewage transport pipe 54 for the external discharge of the sewage collected into the oil pipe (52), and the transfer pump for transporting the inflow of the digester (40) And 55, and a sewage sludge treatment apparatus using a two-stage hydraulic cyclone to which a dispensing device 56 for distributing the effluent of the digester 40 is applied. 4. The treatment of sewage sludge using a two-stage hydraulic cyclone according to claim 3, wherein the dispensing device 56 is fixed to a movable table 56e formed on the upper part of the fixed structure 56d. Device.

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