KR101226035B1 - Pollutant loading reduction and high efficency of sludge-watering method and equipment for wastewater treatment system using a t-p sludge - Google Patents

Abstract

PURPOSE: A method for reducing pollutant load of a sewage and wastewater treatment facility using total phosphorus sludge and improving the efficiency of dehydration and an apparatus for the same are provided to reduce the polluted degree of feed water by transferring sludge from a total phosphorus-based treatment facility to a distributing bath. CONSTITUTION: Sewage and wastewater are arranged in a flux adjusting bath(110). Feed water is introduced into a primarily settling bath through a distributing bath(120). Colloidal pollutants are settled to be removed from the feed water in the primarily settling bath(130). Organic materials are removed from the treated water from the primarily settling step in a bio-reactor(140). The treated water from the bio-reacting step is secondarily settled in a secondarily settling bath(150). Total phosphorus is removed from the treated water from the secondarily settling bath using coagulant(160). Raw sludge and excessive sludge from the settling steps and total phosphorus sludge from the total phosphorus treatment step are introduced into a thickening bath to be thickened(170). Thickened sludge is dehydrated and discharged(200). The total phosphorus sludge is returned to the distributing bath(210). [Reference numerals] (110) Flux adjusting bath; (120) Distributing bath; (130) Primarily settling step; (140) Bio-reacting step; (150) Secondarily settling step; (160) Total phosphorus treating step; (170) Thickening step; (200) Dehydrating step; (210) Total phosphorus sludge returning step; (AA) Feed water; (BB) Raw sludge; (CC) Returned sludge; (DD) Excessive sludge; (EE) Treated water; (FF) Dehydrated cake; (GG) Returning water

Description

Pollutant loading reduction and high efficency of sludge-watering method and equipment for wastewater treatment system using a T-P sludge}

The present invention relates to a method and apparatus for reducing pollutant load and improving dewatering efficiency of a sewage treatment plant using total phosphorus (TP) sludge, and more particularly, to distribute sludge of a total phosphorus treatment plant including residual coagulation components by coagulant overinjection. Method and device for reducing pollutant load and dewatering efficiency of sewage treatment facility using total phosphorus (TP) sludge which can reduce pollutant load of influent water significantly by action of flocculant contained in total phosphorus sludge returned to tank It is about.

In general, phosphorus, which is contained in sewage or wastewater and acts as a limiting agent for algal growth and causes eutrophication, is mainly treated by biological treatment, electrolysis / agglomeration, pumice dephosphorization and chemical treatment using flocculant. Removal methods have been used.

However, biological processes are difficult to operate and are not easy to ensure continuous and stable effluent quality.

Phosphorus removal by electrolysis / agglomeration is one of the technologies that can take advantage of chemical removal technology and solve the disadvantages of chemical precipitation and electrode corrosion.

Pumice dephosphorization is one of the methods of removing phosphate from sewage, and it is one of the physical and chemical treatment methods that has shown good results, but it is possible to treat secondary sewage treatment water, but dephosphorization performance is operating pH, calcium concentration, water temperature, raw water And other types of phosphorus (polyphosphoric acid, organophosphoric acid, suspending phosphorus) should be removed by secondary functions such as filtration. There was a problem.

Therefore, the conventional method for treating phosphorus by chemical treatment in sewage and wastewater treatment plants is the most widely used.

The treatment method of phosphorus by chemical treatment is to coagulate and remove phosphorus contained in the treated water by inputting flocculant into the treated water from which most pollutants are removed through the physical treatment by precipitation and biological treatment facilities by microorganisms. Excess flocculant is used to maintain the phosphorus emission concentration below 0.2mg / L in effluent, but the flocculant is not defined as contaminant in the effluent water quality standard and SS acts as an intermediate mediator to induce crosslinking reaction in flocculation reaction. Since a relatively small amount of the component is contained in the treated water, in order to treat phosphorus, more than an appropriate amount of flocculant is used.

However, the overused flocculant remains in the system, reducing the concentration efficiency, extinguishing efficiency, and dehydration efficiency, resulting in an increase in the overall operating cost, discharged into the stream, and affecting the aquatic ecosystem's self-cleaning action. As a result of the economic loss, there is a need for a solution to this problem.

Accordingly, an object of the present invention is to reduce the pollutant load of sewage wastewater treatment facilities using total phosphorus (TP) sludge, which can improve the treatment efficiency of other pollutants and reduce the operating cost while preserving the wastewater treatment facilities previously installed and operated. To provide a dewatering efficiency improvement method and apparatus therefor

An object of the present invention is to return the total insludge containing residual coagulant generated in the total phosphorus treatment plant to the inlet distribution tank to precipitate and react with colloidal contaminants in the sewage wastewater in which residual flocculant contained in the total insludge flows into It is made possible to operate stable sewage and wastewater treatment facilities by reducing and improving dewatering efficiency.

According to the method and apparatus for reducing pollutant load in a sewage wastewater treatment plant using a total phosphorus (TP) sludge according to the present invention, the suspended solids contained in the total insludge returned to the inlet distribution tank from the total phosphorus treatment plant and the suspended solids in the sewage By combining, it reduces the load of pollutants such as TP, TN, BOD, and SS on the colloid to increase the treatment efficiency of the sewage treatment facility and operate it stably, while reducing the load of pollutants to organic matter oxidation and nitrification Reduction of required air injection can reduce operating costs and CO2 emissions, improve biogas production of anaerobic digesters by improving sedimentation and concentration efficiency, and reduce the use of flocculant by decreasing the concentration of TP flowing into the total phosphorus treatment facility. In the first settling stage, residual coagulation components that affect digestion efficiency and dehydration performance By removing it, the dewatering performance is reduced by improving the dewatering performance, which reduces the sludge treatment cost.

1 is a treatment system showing the configuration of a conventional sewage treatment plant.
2 is a treatment system showing another configuration of the conventional sewage treatment plant.
Figure 3 is a treatment system showing the configuration of the wastewater treatment method according to the present invention.
4 is a treatment system showing the configuration of the sewage treatment plant according to the present invention.
Figure 5 is a treatment system showing the configuration of the wastewater treatment method according to another embodiment of the present invention.
Figure 6 is a treatment system showing the configuration of the sewage treatment plant according to another embodiment of the present invention.
7 is a turbidity change graph according to an embodiment of the present invention.
8 is a graph showing a change in the total phosphorus removal rate according to an embodiment of the present invention.
9 is a graph of sedimentation rate of the mixed sludge according to the embodiment of the present invention.

Hereinafter, with reference to the accompanying drawings will be described in detail the most preferred embodiment of the present invention. First, in describing the drawings, the same components have the same reference numerals as much as possible even though they are shown in different drawings.

3 and 4 is a treatment system diagram showing the configuration of the wastewater treatment method and treatment facility according to the present invention.

According to the drawings, the pollutant load reduction method of the wastewater treatment facility using the total phosphorus (TP) sludge of the present invention is the flow rate adjustment step 110 and the distribution tank 12 to store the introduced wastewater in the flow rate adjustment tank (11) Distribution step 120 for introducing the raw water into the primary sedimentation cell through the primary precipitation step 130 and the primary precipitation step of sedimentation and removal of the colloidal contaminants contained in the incoming raw water in the primary sedimentation tank 13 The second step in the secondary settling tank (15) by introducing the treated water flowing out from the bioreactor 14 to remove the organic matter by biological treatment in the bioreactor 14 and the treated water flowing out from the bioreaction step 14 A total phosphorus treatment step (160) and the primary precipitation step of removing the total phosphorus using a flocculant in the total phosphorus treatment facility (16) in which the sedimentation secondary sedimentation step 150 and the treated water flowing out from the secondary sedimentation step was introduced. Born from The sludge and the sludge generated in the second settling step and the total sludge generated in the total phosphorus treatment step into the concentration tank (17) to concentrate and the dehydrator (20) to dehydrate and discharge the sludge transferred from the concentration tank (20). In the wastewater treatment method consisting of a dehydration step (200) consisting of a), a total sludge conveying step 210 consisting of a conveying line 21 for conveying the total sludge generated in the total phosphorus treatment step to the distribution tank.

In the wastewater treatment method, between the concentration tank 17 and the dehydrator 20, the concentrated sludge flows into the anaerobic digestion tank 18 as shown in FIGS. 5 and 6, and anaerobic in a state where the supply of oxygen is blocked. Anaerobic digestion step 180 to digest and sludge storage step 190 for storing the sludge discharged from the digester in the sludge storage tank 19 may be further formed.

The total sludge conveying line 21 may be composed of a valve for controlling the conveyance of the conveying pipe, the sludge pump and the sludge.

According to an embodiment of the present invention, the total insludge is conveyed to the distribution tank 12 by the total insludge conveying line 21 and mixed with the inflow source water.

In the mixing process, the colloidal particles of the influent water react with the residual flocculant in the total insludge, and improve the precipitation efficiency in the primary settler by the principle of flocculation sedimentation.

FIG. 7 shows the results of the jar-test with the total sludge mixing ratio and the settling time as variables as a result of experiments in the sewage treatment plant of C city. The higher the mixing ratio, the higher the turbidity measured when mixed by the SS component of the total sludge, but the turbidity was lower after 30 minutes of precipitation, and the composition of the SS was 20 ~ 35% lower than that of the sewage water. appear.

In addition, TCOD removal efficiency was reduced by 1%, 2%, 3%, 4% 9.62%, 22.44%, 27.24%, and 28.85%, respectively, compared to the supernatant of sewage without sludge.

This can be seen that when the total sludge is mixed with the influent water, it improves the settling efficiency of SS and T-COD removal efficiency.

Precipitation efficiency is improved in the primary sedimentation tank (13) by mixing the total insludge and inflow water, thereby reducing the concentration load of organic matter, nitrogen, and phosphorus in the solids. It will be introduced at a low level. As a result, not only the treatment efficiency of the bioreactor is improved, but the amount of oxygen required for the oxidation of organic matter and nitrogen is reduced by more than 20%, which not only reduces the power cost required for blowing air, but also the global warming material emitted during the oxidation of organic matter. _The effect of reducing emissions of ₂ can be seen.

As the efficiency of bioreactor 14 is improved, phosphorus removal efficiency is also improved, and the total phosphorus concentration of influent flowing into the total phosphorus treatment facility 16 is kept low, and the amount of coagulant introduced can be further reduced, thereby reducing the operating cost. You can do it.

FIG. 8 shows the results of the jar-test by setting the total sludge mixing ratio and the settling time as variables as a result of experiments in the sewage treatment plant of C city. It can be seen that the higher the mixing ratio, the higher the T-P removal rate.

As the total total sludge is sent to the sludge concentration tank (17) and introduced into the anaerobic digestion tank (18), the concentration and anaerobic digestion efficiency are lowered due to the residual coagulation component. By increasing the sedimentation efficiency by increasing the sedimentation efficiency of the primary sedimentation battery with high energy potential, the total sludge residual coagulant is consumed by the sewage water and coagulation reaction to improve the anaerobic digestion efficiency and gas generation. As a result of measuring the methane generation amount, the development process showed more than 20% higher than the existing process.

In addition, the dehydration cake emissions are reduced by more than 20% in accordance with the improvement of dehydration efficiency during dehydration in the dehydrator 20 can reduce the sludge treatment cost and the sludge treatment facility installation cost.

FIG. 9 is a result of the concentration of mixed sludge according to the development process as a result of the existing process of treating the total sludge without mixing the influent and the development process generated after mixing the total sludge with the influent according to the present invention. The sedimentation rate of is about 0.2 ~ 1.4 ft / hr.

The table below shows the water content after dehydration of the mixed sludge of the existing process and the mixed sludge produced by the development process.The moisture content after the dehydration of the development process is about 3 compared to the existing process. % Lower.

     [Table] Water content after dehydration of mixed sludge

As a result, the present invention improves the efficiency of each unit process by mixing the total sludge of the conventional sewage treatment plant, which has increased sludge generation and sludge dewatering efficiency due to total phosphorus sludge and the sludge treatment facility capacity is insufficient and operating cost is increased. It not only reduces sludge treatment facilities and reduces operational expenses, but also reduces CO ₂ emissions, and when applied to existing sewage treatment plants, it has the effect of minimizing renovation costs and construction period.

11: flow adjustment tank 12: distribution tank
13: primary sedimentation tank 14: bioreactor
15: secondary sedimentation tank 16: total phosphorus treatment facility
17: sludge thickener 18: anaerobic digester
19: sludge reservoir 20: dehydrator
21: total sludge return line 110: flow rate adjustment step
120: distribution step 130: first precipitation step
140: bioreaction step 150: second precipitation step
160: total phosphorus treatment step 170: sludge concentration step
180: anaerobic digestion stage 190: sludge storage stage
200: dehydration step 210: total sludge return step

Claims (4)

Pollution on colloidal phases included in the distribution step 120 and the incoming raw water flows into the primary settler through the flow adjustment step 110 and the distribution tank 12 to store the introduced wastewater into the flow adjustment tank 11 Bioreaction step of removing the organics by biological treatment by the microorganisms in the first settling step 130 and the treated water flowing out in the first settling step to precipitate the material in the primary settling basin (13) in the bioreactor 14 (140) and the total phosphorus treatment in which the treated water flowing out from the bioreaction step was introduced into the secondary precipitation step (150) for secondary precipitation in the secondary precipitation tank (15) and the treated water flowing out from the secondary precipitation step. Total phosphorus treatment step 160 to remove the total phosphorus using a flocculant in the facility (16), the fresh sludge generated in the first precipitation step and the surplus sludge generated in the second precipitation step and the total inslaught generated in the total phosphorus treatment step concentration A dehydration step (200) consisting of a condensation step (170) to flow into the condensation unit (17) and a dehydrator (20) for dewatering and discharging the concentrated sludge and a conveying line for conveying the total insludge generated in the total phosphorus treatment step to a distribution tank; Total phosphorous sludge conveying step (21) consisting of (21), characterized in that consisting of total phosphorus (TP) sludge wastewater treatment facilities reducing load and improved dewatering efficiency method. The anaerobic digestion step (180) of claim 1, wherein the concentrated sludge is introduced into the anaerobic digestion tank (18) between the concentration step (170) and the dehydration step (200) to anaerobic digestion while the supply of oxygen is blocked. Sludge storage step (190) for storing the sludge discharged from the digester in the sludge storage tank 19 is characterized in that the pollutant load reduction and dewatering efficiency improvement method of the wastewater treatment facility using total phosphorus (TP) sludge. The flow rate adjustment tank 11 for storing the introduced wastewater and the distribution tank 12 for introducing the raw water into the primary settler, and the primary sedimentation tank 13 for precipitating and removing the colloidal contaminants contained in the introduced raw water and the first The bioreactor 14 for removing organic matter by biological treatment of the treated water flowing out of the secondary settling tank and the secondary settling tank 15 for introducing the treated water flowing out of the bioreactor for secondary precipitation and the secondary settling tank Total sludge produced in the total phosphorus treatment facility (16) and the sludge generated in the primary sedimentation tank and the surplus sludge generated in the secondary sedimentation tank and the total phosphorus sludge generated in the total phosphorus treatment tank by introducing the treated water discharged from the Condensation tank 17 for introducing and concentrating the dehydrator 20 and dehydrator 20 for dewatering and discharging the concentrated sludge and total sludge generated in the total phosphorus treatment facility are returned to the distribution tank. Transmission line 21, phosphorus (P-T), load reducing pollutants and improving the dehydration efficiency of the device with waste water treatment plant with a sludge, characterized in that which is further provided. According to claim 3, Between the concentration tank 17 and the dehydrator 20 to store the anaerobic digestion tank 18 and the sludge discharged from the digester to the anaerobic digestion in the state that the supply of oxygen is blocked by the flow of concentrated sludge Sludge storage tank 19 is further characterized in that the contaminant load reduction and dewatering efficiency improvement device of the sewage wastewater treatment facility using total phosphorus (TP) sludge.

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