System for solubilizing surplus sludge of wastewater treatment apparatus

Abstract

This system for solubilizing surplus sludge of a wastewater treatment apparatus comprises: an ultrasonic reaction tank which has an inner accommodation space for outputting ultrasonic waves to wastewater surplus sludge supplied with a plurality of oxidizing agents, and includes an inflow flowmeter for detecting the amount of wastewater surplus sludge that flows in; an ultrasonic output unit for outputting ultrasonic waves to the wastewater surplus sludge that flows into the ultrasonic reaction tank; an ozone supply unit for supplying ozone to the ultrasonic reaction tank; at least one ultraviolet lamp which is disposed in the inner accommodation space of the ultrasonic reaction tank and outputs ultraviolet rays; and a control unit which stores an ultrasonic output intensity, an ozone supply amount, and an ultraviolet output intensity for the amount of wastewater surplus sludge, and controls the ultrasonic output unit, the ozone supply unit, and the ultraviolet lamp so that the ultrasonic output intensity, the ozone supply amount, and the ultraviolet output intensity are provided in accordance with the amount of wastewater surplus sludge that flows into the ultrasonic reaction tank.

Description

Excess Sludge Solubilization System for Wastewater Treatment Plants

[0001] The present invention relates to a wastewater treatment device, and more specifically, to a wastewater treatment device that reduces excess wastewater sludge, increases dewatering efficiency, and improves biogasification efficiency.

[0002] Recently, the amount of wastewater generated has been increasing due to rapid urbanization and industrialization. Wastewater treatment plants are striving to minimize wastewater sludge generated during the wastewater treatment process.

[0003] However, there is a problem in that the amount of sludge generated is increasing, and as industrialization and urbanization accelerate, the amount of wastewater is rapidly increasing, and consequently, the amount of sludge generated is also steadily increasing.

[0004] In addition, there is a problem that sludge treatment facilities are insufficient compared to the amount of wastewater sludge generated.

[0005] In addition, there is a problem in that the costs incurred in the process of stabilizing and reducing wastewater sludge are continuously increasing.

[0006]

[0007] Therefore, the objective of the present invention is to provide a wastewater treatment device capable of generating high-concentration radicals from sludge generated in a wastewater treatment plant using advanced oxidation technology utilizing ultrasound, nanobubbles, oxidizers, electrolysis, ozone, and ultraviolet rays, and decomposing the cell walls and biofilms of microorganisms in the sludge with the strong oxidizing power of the radicals, thereby leaching out pore water within the microorganisms.

[0008] A system for solubilizing excess sludge of a wastewater treatment device according to the present invention for achieving the above objective comprises: an ultrasonic reaction tank having an internal receiving space formed for outputting ultrasonic waves to excess wastewater sludge supplied with a plurality of oxidizing agents, and including an inflow flow meter for detecting the amount of excess wastewater sludge flowing in; an ultrasonic output unit for outputting ultrasonic waves to excess wastewater sludge flowing into the ultrasonic reaction tank; an ozone supply unit for supplying ozone to the ultrasonic reaction tank; at least one ultraviolet lamp disposed in the internal receiving space of the ultrasonic reaction tank for outputting ultraviolet rays; and a control unit that stores the ultrasonic output intensity, ozone supply amount, and ultraviolet output intensity for the amount of excess wastewater sludge, and controls the ultrasonic output unit, the ozone supply unit, and the ultraviolet lamp so that the ultrasonic output intensity, ozone supply amount, and ultraviolet output intensity are provided in correspondence with the amount of excess wastewater sludge flowing into the ultrasonic reaction tank. By using advanced oxidation technology utilizing ultrasound, nanobubbles, oxidizers, electrolysis, ozone, and ultraviolet rays to generate high concentrations of radicals and decomposing the cell walls of microorganisms and organic matter in the sludge through the powerful oxidizing power of the radicals, it is possible to reduce wastewater sludge, increase dewatering efficiency, and improve biogasification efficiency.

[0009] Here, it is desirable that the ultrasonic reaction tank further includes multiple internal partitions arranged so that the incoming wastewater excess sludge and the ozone supplied from the ozone supply unit move along a zigzag path, which increases the contact time between ozone and ultraviolet rays, thereby increasing the generation of high-concentration radicals and reducing the wastewater excess sludge.

[0010] And the above partition wall is desirable because it includes an ozone pipe for moving ozone inside; and an ozone discharge hole formed to communicate with the ozone pipe to the outside, so that the fine ozone bubbles discharged from the entire partition wall can be exposed to ultraviolet rays, thereby increasing the amount of high-concentration radicals generated, which further increases the effect of reducing excess wastewater sludge.

[0011] Here, it is desirable to further include an electrolysis unit disposed in the internal receiving space of the ultrasonic reactor to electrolyze excess wastewater sludge, as this can increase the reduction effect of excess wastewater sludge by electrolyzing excess wastewater sludge.

[0012] And the electrolysis unit comprises a positive electrode that attracts negative ions; a negative electrode that attracts positive ions; and a power supply unit that supplies power to the positive electrode and the negative electrode, and it is desirable that the positive electrode and the negative electrode are placed in an ultrasonic output path that outputs to the ultrasonic output unit so that the ultrasonic output effect can be increased while the excess wastewater sludge is concentrated on the positive electrode and the negative electrode, thereby increasing the reduction effect of excess wastewater sludge.

[0013] According to the present invention, the sludge generated in a wastewater treatment plant is treated using an advanced oxidation technology that utilizes ultrasound, nanobubbles, oxidizers, electrolysis, ozone, and ultraviolet rays to generate high-concentration radicals, and decomposes the cell walls of microorganisms and organic matter in the sludge through the strong oxidizing power of the radicals. This advanced sludge treatment technology allows for the extraction of internal pore water from microorganisms, thereby improving the reduction and dewatering capacity of wastewater sludge and the efficiency of biogasification.

[0014] In addition, the increased contact time between ozone and ultraviolet rays can increase the generation of high-concentration radicals and have the effect of reducing excess wastewater sludge.

[0015] In addition, since the fine ozone bubbles discharged from the entire partition wall can be exposed to ultraviolet rays, the amount of high-concentration radicals generated increases, which can further increase the effect of reducing excess wastewater sludge.

[0016] In addition, electrolyzing excess wastewater sludge can increase the reduction effect of excess wastewater sludge.

[0017] In addition, since the ultrasonic output effect can be increased while the excess wastewater sludge is concentrated at the positive and negative electrodes, there is an effect of increasing the reduction effect of excess wastewater sludge.

[0018] FIG. 1 is a simplified example diagram of an excess sludge solubilization system of a wastewater treatment device according to the present invention.

[0019] Figure 2 is a control block diagram of an excess sludge solubilization system of a wastewater treatment plant.

[0020] Figures 3 and 4 are examples of decomposing sludge using nano-micro bubbles and ultrasound.

[0021] Figure 5 is an example of an inline mixing device.

[0022] Figure 6 is a detailed view of the ultrasonic reaction vessel.

[0023] Figure 7 is an example of advanced oxidation using electrolysis and ultrasound.

[0024] Figure 8 is a detailed example of a bulkhead.

[0025] Figure 9 is an example diagram of injecting an oxidizing agent using a Venturi tube.

[0026]

[0027] Hereinafter, an excess sludge solubilization system (1) of a wastewater treatment device according to a preferred embodiment of the present invention will be described in detail with reference to the attached drawings.

[0028] The excess sludge solubilization system (1) of the wastewater treatment device of the present invention utilizes high-concentration radical - advanced oxidation processes (HCR-AOPs).

[0029] FIG. 1 is a simplified example diagram of an excess sludge solubilization system (1) of a wastewater treatment device according to the present invention, FIG. 2 is a control block diagram of an excess sludge solubilization system (1) of a wastewater treatment device, FIG. 3 and FIG. 4 are example diagrams of decomposing sludge using nano-micro bubbles and ultrasound, FIG. 5 is an example diagram of an inline mixing device (50), FIG. 6 is a detailed diagram of an ultrasonic reaction tank (80), FIG. 7 is an example diagram of advanced oxidation using electrolysis and ultrasound, and FIG. 8 is a detailed example diagram of a partition wall (83).

[0030] The configuration of the excess sludge solubilization system (1) of the wastewater treatment device is explained with reference to FIGS. 1 to 8.

[0031] The excess sludge solubilization system (1) of the wastewater treatment device includes a sludge storage tank (10), a microbubble supply unit (20), an oxidizing agent supply unit (30), an ultrasonic output unit (40), an inline mixing device (50), a sludge solubilization unit (60), a valve (70), an ultrasonic reaction tank (80), an electrolysis unit (90), an ozone supply unit (100), an ultraviolet lamp (110), and a control unit (120).

[0032] The sludge storage tank (10) stores excess wastewater sludge. The sludge storage tank (10) includes a screen (11), a tank (12), and a stirring device (13).

[0033] The screen (11) screens and removes large particles of foreign matter from the excess wastewater sludge flowing into the tank (12).

[0034] The tank (12) has an internal receiving space formed to store wastewater excess sludge from which large chunks have been removed by the screen (11) after it has been introduced. The tank (12) may be equipped with an IoT storage amount detection module capable of detecting the amount of excess sludge stored and transmitting a detection signal to a manager.

[0035] The stirring device (13) can stir the excess wastewater sludge that flows into and is stored in the tank (12) so that it does not sink to the bottom.

[0036] The microbubble supply unit (20) supplies microbubbles to excess wastewater sludge discharged from the sludge storage tank (10). The microbubble supply unit (20) includes an oxygen generator (21), an oxygen supply pipe (22), a microbubble generation unit (23), and a circulation pipe (24).

[0037] The oxygen generator (21) can produce high concentrations of oxygen.

[0038] The oxygen supply pipe (22) can supply oxygen generated from the oxygen generator (21) to the connecting pipe between the sludge storage tank (10) and the microbubble supply unit (20).

[0039] The microbubble generating unit (23) can generate oxygen microbubbles by mixing excess wastewater sludge introduced through the connecting pipe with oxygen generated from the oxygen generator (21). The nanobubble size is 30 to 1300 nm, and the dissolved amount of nanobubbles can be 1 billion / ml or more.

[0040] The circulation pipe (24) can connect the sludge storage tank (10) at one point of the connecting pipe between the microbubble generating unit (23) and the oxidizing agent supply unit (30).

[0041] The oxidizing agent supply unit (30) supplies a plurality of oxidizing agents to generate radicals in excess wastewater sludge supplied with microbubbles. The oxidizing agent supply unit (30) includes a first oxidizing agent supply unit (31), a second oxidizing agent supply unit (32), and a third oxidizing agent supply unit (33).

[0042] The oxidizing agent supply unit (30) supplies a plurality of oxidizing agents to generate radicals in excess wastewater sludge supplied with microbubbles. The oxidizing agent supply unit (30) includes a first oxidizing agent supply unit (31), a second oxidizing agent supply unit (32), and a third oxidizing agent supply unit (33).

[0043] The first oxidizer supply unit (31) includes a first oxidizer storage tank (311), a first oxidation reaction tank (312), a first oxidizer transfer pipe (313), and a first oxidizer pump (314).

[0044] The first oxidizer storage tank (311) can store at least one of iron persulfate and sodium persulfate, which are the first oxidizers. It is used in a liquid form, and the input amount can be 100 to 20,000 ppm.

[0045] The first oxidation reaction tank (312) can mix wastewater excess sludge and an oxidizing agent.

[0046] The first oxidizing agent transfer pipe (313) can provide a transfer path for transferring the oxidizing agent to the first oxidation reaction tank (312).

[0047] The first oxidizer pump (314) is positioned on the first oxidizer transfer pipe (313) and can drive the transfer of the oxidizer.

[0048] The second oxidizer supply unit (32) includes a second oxidizer storage tank (321), a second oxidation reaction tank (322), a second oxidizer transfer pipe (323), and a second oxidizer pump (324).

[0049] The second oxidizer storage tank (321) can store at least one of hydrogen peroxide, sodium hydroxide, and sodium percarbonate as the second oxidizer. The second oxidizer can be dissolved in water or diluted in water, and can be supplied in conjunction with a metering pump and a pH meter to achieve a pH of 1 to 14.

[0050] The second oxidation reaction tank (322) can mix wastewater excess sludge and an oxidizing agent.

[0051] The second oxidizing agent transfer pipe (323) can provide a transfer path for transferring the oxidizing agent to the second oxidation reaction tank (322).

[0052] The second oxidizer pump (324) is positioned on the second oxidizer transfer pipe (323) to drive the transfer of the oxidizer.

[0053] The third oxidizer supply unit (33) includes a third oxidizer storage tank (331), a third oxidation reaction tank (332), a third oxidizer transfer pipe (333), and a third oxidizer pump (334).

[0054] The third oxidizer storage tank (331) may have a third oxidizer that is a catalyst, and the catalyst may store at least one of manganese dioxide, iron, and activated carbon.

[0055] The third oxidation reaction tank (332) can mix wastewater excess sludge and an oxidizing agent.

[0056] The third oxidizing agent transfer pipe (333) can provide a transfer path for transferring the oxidizing agent to the third oxidation reaction tank (332).

[0057] The third oxidizer pump (334) is positioned on the oxidizer transfer pipe (333) and drives the transfer of the oxidizer.

[0058] The ultrasonic output unit (40) outputs ultrasonic waves to excess wastewater sludge supplied with a plurality of oxidizing agents. The ultrasonic output unit (40) includes a main ultrasonic output unit (41), a first auxiliary ultrasonic output unit (42), and a second auxiliary ultrasonic output unit (43).

[0059] The main ultrasonic output unit (41) is positioned at the rear end of the oxidizing agent supply unit (30) and can output ultrasonic waves to excess wastewater sludge supplied with multiple oxidizing agents.

[0060] The first auxiliary ultrasonic output unit (42) is positioned between the microbubble supply unit (20) and the oxidizing agent supply unit (30), and can output ultrasonic waves when the wastewater excess sludge and oxygen microbubbles are mixed.

[0061] The second auxiliary ultrasonic output unit (43) is positioned at the rear end of the oxidation reaction tank (312) and can output ultrasonic waves when the wastewater excess sludge and the oxidizing agent are mixed.

[0062] The inline mixing device (50) is positioned in at least one of the connecting pipes between the sludge storage tank (10) and the microbubble supply unit (20), the connecting pipe between the microbubble supply unit (20) and the oxidant supply unit (30), and the connecting pipe between the oxidant supply unit (30) and the ultrasonic output unit (40) to mix wastewater excess sludge, oxygen microbubbles, and an oxidant. The inline mixing device (50) includes a mixing body (51), a direction changing unit (52), and an impact crushing unit (53).

[0063] The mixing body (51) may have a shape in which the diameter of the pipe widens along the direction of movement of the wastewater excess sludge.

[0064] The direction changing part (52) can be positioned inside the mixing body (51) to change the direction of movement of excess wastewater sludge.

[0065] The impact crushing section (53) can be formed so that excess wastewater sludge, whose direction has been changed by the direction changing section (52), collides with and crushes.

[0066] The sludge solubilization unit (60) includes a solubilized sludge storage tank (61), a pH sensor (62), and a pH control unit (63).

[0067] The solubilized sludge storage tank (61) is positioned at the rear end of the ultrasonic output unit (40) and can store solubilized sludge by destroying the organic matter and microbial cell walls contained in the excess sludge and releasing the microbial internal pore water.

[0068] The pH sensor (62) is placed in the solubilized sludge storage tank (61) and can measure the pH of the stored solubilized sludge.

[0069] The pH control unit (63) can control the pH of the solubilized sludge in the solubilized sludge storage tank (61).

[0070] The valve (70) is placed on the connecting pipe and various pipes to control the movement of fluid.

[0071] A flow meter (72) is placed on the connecting pipe and various pipes to measure the amount of fluid flow.

[0072] The ultrasonic reaction tank (80) includes a reaction body (81), an inflow flow meter (82), and a partition (83).

[0073] The reaction body (81) has an internal receiving space formed to output ultrasonic waves to excess wastewater sludge supplied with a plurality of oxidizing agents.

[0074] The inflow flow meter (82) detects the amount of excess sludge inflowing wastewater.

[0075] The partition wall (83) can be arranged in multiple inner sections so that the incoming wastewater excess sludge and the ozone supplied from the ozone supply unit (100) move along a zigzag path. The partition wall (83) includes an ozone pipe (831) and an ozone discharge hole (832).

[0076] The ozone pipe (831) may be hollow so that ozone can move inside.

[0077] The ozone discharge port (832) is formed to be connected to the ozone pipe (831) to the outside so that ozone moving to the ozone pipe (831) can be discharged into the internal receiving space of the reaction body (81).

[0078] The electrolysis unit (90) is placed in the internal receiving space of the ultrasonic reaction tank (80) and can electrolyze excess wastewater sludge. The electrolysis unit (90) includes a positive electrode (91), a negative electrode (92), and a power supply unit (93).

[0079] The positive electrode (91) is supplied with power to form a positive electrode and can attract negative ions.

[0080] The negative electrode (92) is supplied with power to form a negative electrode and can attract positive ions.

[0081] The positive electrode (91) and the negative electrode (92) can be placed in the ultrasonic output path that is output to the ultrasonic output unit (40).

[0082] The power supply unit (93) can supply power to the positive electrode (91) and the negative electrode (92).

[0083] The ozone supply unit (100) supplies ozone to the ultrasonic reaction tank (80).

[0084] The ultraviolet lamp (110) is at least one component that is placed in the internal receiving space of the ultrasonic reaction tank (80) and outputs ultraviolet light.

[0085] The control unit (120) stores the ultrasonic output intensity, ozone supply amount, and ultraviolet output intensity for the amount of excess wastewater sludge, and controls the ultrasonic output unit (40), ozone supply unit (100), and ultraviolet lamp (110) so that the ultrasonic output intensity, ozone supply amount, and ultraviolet output intensity are provided in response to the amount of excess wastewater sludge flowing into the ultrasonic reaction tank (80).

[0086] Figures 3 and 4 are examples of decomposing sludge using nano-micro bubbles and ultrasound.

[0087] When nano bubbles are introduced and ultrasound is applied, OH- (free radicals) are generated during the process of cavitation and water dissociation of the nano bubbles, decomposing organic matter in excess sludge, and expanding the nano bubbles to form microbubbles, thereby separating the decomposed organic matter by flotation.

[0088] Cavitation is the phenomenon in which tiny cavities are generated due to sound pressure fluctuations when ultrasound is applied to a liquid.

[0089] That is, organic matter in excess sludge is oxidized and decomposed using the powerful oxidizing power of OH radicals (1200 times that of ozone) to hydrolyze proteins, and environmentally friendly actions such as nitrogen oxidation (nitrification), sterilization, and adsorption are performed to oxidize and decompose the organic matter contained in excess sludge, and the decomposed organic matter is separated by flotation using nanobubbles.

[0090] FIG. 5 is an example of an inline mixing device (50).

[0091] The mixing body (51) has a shape in which the diameter widens along the direction of movement of the wastewater excess sludge, and the direction changing part (52) is positioned inside the mixing body (51) to cause the wastewater excess sludge to collide with the impact crushing part (53) positioned perpendicular to the direction changing part (52). As a result, the microorganisms in the wastewater excess sludge can be destroyed, and the microorganisms in the wastewater excess sludge can be mixed more effectively with oxygen microbubbles, oxidizing agents, and ultrasound. By doing so, the decomposition of the cell walls and organic matter of the microorganisms can be further promoted.

[0092] Here, the reaction and technology for solubilizing excess sludge using the wastewater excess sludge solubilization system (1) are explained.

[0093] The first step of the excess sludge solubilization oxidation reaction is as follows.

[0094] Excess sludge is transferred from a wastewater excess sludge storage tank or a place of generation (sedimentation tank, MBR tank, etc.) and introduced into a sludge storage tank. Before introduction, miscellaneous waste or residue contained in the excess sludge is removed before it is introduced.

[0095] The sludge storage tank is equipped with an agitator to prevent sludge from settling. The next stage consists of a screen, an excess sludge storage tank, an agitation device, a microbubble (micro-nanobubble) generator and an oxygen generator, a pressure gauge, a flow meter, a valve, a transfer pipe, an ultrasonic generator, etc.

[0096] Excess sludge is sucked in and mixed with oxygen to generate oxygen microbubbles in the excess sludge, and then reacted with the excess sludge using an ultrasonic process. At this time, hydroxyl radicals and hydroperoxy radicals are generated by the cavitation effect, which destroys the organic matter and microbial cell walls contained in the excess sludge, thereby releasing and solubilizing the internal pore water of the microorganisms.

[0097] In addition, to increase solubilization efficiency, excess sludge that has reacted with nanobubbles is circulated to a sludge storage tank to increase reactivity with microbubbles. Microbubbles that have not reacted are reacted in an ultrasonic reaction device. Ultrasonic irradiation bursts the microbubbles to increase the cavitation effect, and generates cavitation with its own ultrasound to increase radical (●) production efficiency, thereby further increasing the solubilization efficiency of excess sludge.

[0098] Microbubble application amount: 0.1% to 20% relative to excess sludge amount

[0099] Oxygen application rate: 0.01 ~ 20% relative to microbubble generator capacity

[0100] Ultrasonic capacity: 10 ~ 10,000 W / ㎥ (excess sludge), Frequency: 1 ~ 100 kHz

[0101] Ultrasound irradiation time: 1 ~ 120 minutes

[0102] The reaction mechanism of oxygen microbubbles + ultrasonic irradiation is as follows.

[0103] Oxygen microbubbles are very small bubbles that supply oxygen to wastewater, increasing the dissolved oxygen concentration. This is important for enhancing the efficiency of subsequent oxidation processes. During the microbubble generation process, mechanical mixing effects occur as the bubbles collapse.

[0104] Ultrasound transmits mechanical vibrations to a liquid, causing the formation and destruction of bubbles. This process is called ultrasonic cavitation, and as the bubbles are destroyed, regions of high temperature and high pressure are formed. This increases the reaction rate and raises solubility, thereby promoting the oxidation reaction of pollutants.

[0105] At this stage, physical mixing and increased oxygen solubility play a major role rather than direct chemical reactions.

[0106] H2O→OH + H2-O → OH+ ●H

[0107] R-H+ ●OH→R-OH

[0108] The second stage of the excess sludge solubilization oxidation reaction is as follows.

[0109] The second stage of the oxidation reaction involves reacting three or more oxidizing agents with the excess sludge to generate various radicals, which destroy the organic matter and microbial cell walls contained in the excess sludge, thereby releasing and solubilizing the internal pore water of the microorganisms.

[0110] The 2nd stage device consists of an oxidizing agent (chemical) storage tank, a metering pump for transfer, a pH meter, a mixing reaction device (mixing device), a reaction device casing, an ultrasonic generator, and transfer piping equipment.

[0111] The operation method for the second stage, the oxidation reaction stage, is as follows.

[0112] The pH of the excess sludge is maintained between 2 and 12 depending on the conditions. Chemicals used for this purpose include sulfuric acid and sodium hydroxide. Oxidizing agents include persulfates, nitrogen dioxide, hydrogen peroxide, ozone, ferric sulfate, and ferric chloride. The dosage of these chemicals is 100 ppm to 20,000 ppm relative to the amount of excess sludge. Mixing devices, such as line mixers and stirring devices, are used for the mixing reaction of the oxidizing agents and other chemicals. After this process, the material is introduced into an ultrasonic reaction device to maximize the efficiency of the oxidation reaction using ultrasonic vibrations.

[0113] The ultrasonic dosage used at this time is as follows.

[0114] Ultrasonic capacity: 10 ~ 10,000 W / ㎥ (excess sludge), Frequency: 1 ~ 100 kHz

[0115] Ultrasound irradiation time: 1 ~ 120 minutes

[0116] The reaction mechanism of Fenton oxidation (sodium hydroxide / sulfuric acid + sodium persulfate + ferrous sulfate mixing reaction + ultrasonic irradiation) is as follows.

[0117] The Fenton oxidation process reacts hydrogen peroxide (H₂O₂) with iron ions (Fe²⁺) to generate hydroxyl radicals (OH·), which are powerful oxidizing agents. These hydroxyl radicals oxidize organic materials very efficiently.

[0118] The chemical reaction equation for hydroxyl radical generation is

[0119] Fe2+ ​​+ H2O2 → Fe 3 + + OH- + ●OH.

[0120] The oxidation formula of organic matter

[0121] R-H+OH→R-OH.

[0122] Here, RH refers to organic matter.

[0123] Sodium hydroxide (NaOH) optimizes the reaction between Fe² and H₂O₂ by adjusting the pH.

[0124] Sodium persulfate (Na₂S₂O) produces sulfates (S₂O²⁺), which are powerful oxidizing agents. Persulfates can also contribute to the generation of hydroxyl radicals.

[0125] S2O2 → 2 SO 4 ● - S2O2→ 2SO 4 ●

[0126] Ferrous sulfate (FeSO₄) promotes the Fenton reaction by providing Fe²⁺ ions. This reaction can be further enhanced by ultrasonic irradiation.

[0127] Ultrasound further increases the reactivity of oxidizing agents and promotes oxidation reactions through the formation and destruction of microbubbles.

[0128] The additional chemical reaction equation is as follows:

[0129] SO 4 +RH → R-SO 4 HSO 4 ● - +RH→R-SO 4 It is H.

[0130] The three stages of the excess sludge solubilization oxidation reaction are as follows.

[0131] The third stage of the oxidation reaction is the stage of irradiating with ultrasound. The cavitation effect of ultrasound generates radicals, which ultimately destroy the organic matter and microbial cell walls contained in the excess sludge, thereby releasing and solubilizing the internal pore water of the microorganisms.

[0132] Stage 3 consists of an ultrasonic generator, valve, transfer piping, solubilized sludge storage tank, transfer pump, pH meter, water level gauge, metering transfer pump, etc.

[0133] In this third stage, the unreacted microbubbles and oxidizing agents are reacted, and radicals are produced through cavitation caused by self-vibration to destroy organic matter and microbial cell walls contained in excess sludge, thereby releasing and solubilizing the internal pore water of the microorganisms.

[0134] The pH is measured using a pH meter installed in the solubilized sludge storage tank, and when it is acidic or alkaline, the pH of the excess sludge is converted to a neutral state (pH 6~8) and then transferred to the next stage.

[0135] The reaction mechanism of ultrasonic irradiation is as follows.

[0136] During the ultrasonic irradiation stage, residual contaminants are further decomposed primarily through physical and chemical interactions. Ultrasound provides powerful mechanical and thermal shock by generating and destroying bubbles within the liquid. During this process, ultrasonic cavitation occurs, and as small bubbles rupture, regions of high temperature and pressure are formed. These regions further accelerate chemical reactions and induce the additional decomposition of residual organic matter.

[0137] Although direct chemical reactions caused by ultrasound are minimal, reactions at high temperatures and pressures generated by cavitation can appear in the following forms.

[0138] H2O → ●OH+ ●HH2O → OH+ ●H

[0139] R-H+ ●OH → R-OH

[0140] By generating high concentrations of radicals (hydroxyl radicals, sulfate radicals, hydroperoxy radicals, etc.), organic matter (biofilms) and microbial cell walls contained in excess sludge are destroyed, causing the pore water inside the microorganisms to leach out and be solubilized. This allows for a significant reduction in the amount of sludge generated.

[0141] By generating high concentrations of radicals (hydroxyl radicals, sulfate radicals, hydroperoxy radicals, etc.), organic matter and microbial cell walls contained in excess sludge are destroyed, causing the pore water inside the microorganisms to leach out and be solubilized. This can significantly increase the dewatering efficiency when dewatering sludge.

[0142] High concentrations of radicals (hydroxyl radicals, sulfate radicals, hydroperoxy radicals, etc.) are generated to destroy organic matter and microbial cell walls contained in excess sludge, thereby releasing and solubilizing the internal pore water of the microorganisms. The filtrate generated when dewatering this solubilized excess sludge has a very high concentration of organic matter and can be reused as an organic carbon source.

[0143] High concentrations of radicals (hydroxyl radicals, sulfate radicals, hydroperoxy radicals, etc.) are generated to destroy organic matter and microbial cell walls contained in excess sludge, thereby releasing and solubilizing the internal pore water of the microorganisms. When this solubilized excess sludge is applied to a biogasification facility to produce methane gas, the high concentration of organic matter can increase the efficiency of methane gasification.

[0144] Figure 6 is a detailed view of the ultrasonic reaction tank (80).

[0145] The partition wall (83) is connected to one inner wall of the ultrasonic reaction tank (80) and extends to the other inner wall, forming a path for the wastewater excess sludge and ozone to move along a zigzag path. The ultrasonic output unit (41, 42, 43) is positioned at a location where the wastewater excess sludge and ozone bend along the zigzag path to output ultrasonic waves.

[0146] The flow meter (82) measures the flow rate of excess wastewater sludge flowing into the ultrasonic reaction tank (80).

[0147] Figure 7 is an example of advanced oxidation using electrolysis and ultrasound.

[0148] The positive electrode (91) and negative electrode (92) of the electrolysis unit (90) can be placed on the ultrasonic output path (A) output from the ultrasonic output unit (41, 42, 43). When power is supplied to the positive electrode (91) and the negative electrode (92), wastewater excess sludge containing negative ions and wastewater excess sludge containing positive ions are collected at the positive electrode (91) and the negative electrode (92), and additional decomposition of residual organic matter can be induced intensively by the ultrasonic waves output from the ultrasonic output unit (41, 42, 43).

[0149] Figure 8 is a detailed example of a bulkhead (83).

[0150] The partition (83) may include an ozone pipe (831) and an ozone discharge port (832), and ozone supplied from the ozone supply unit (100) may travel along the ozone pipe (831) and then be discharged into the ultrasonic reaction tank (80) through the ozone discharge port (832). At this time, as the ozone is exposed to ultraviolet rays, it generates radicals (hydroxyl radicals, sulfate radicals, hydroperoxy radicals, etc.) to destroy organic matter and microbial cell walls contained in excess wastewater sludge, thereby leaching out and solubilizing the internal pore water of the microorganisms.

[0151] Figure 9 is an example diagram of injecting an oxidizing agent using a Venturi tube.

[0152] Three venturi tubes are arranged on the main pipe through which wastewater excess sludge travels, and a first oxidizer supply unit (31), a second oxidizer supply unit (32), and a third oxidizer supply unit (33) are connected to each of the three venturi tubes. Each of the three venturi tubes is connected to a pipe that allows pressure to be transmitted to three tees placed at the static mixer at the rear end of the main pipe.

[0153] The principle is that chemicals are drawn into the Venturi tubes due to the pressure difference between the left and right sides, centered around the middle valve. The pressure on the left side is 0.5 to 2 times higher. This pressure difference allows for the precise injection of an oxidizing agent. By adjusting the sizes of the three Venturi tubes based on the volume of excess wastewater sludge, the amount of oxidizing agent injected can be controlled through the pressure difference between the left and right sides.

[0154] Modifiable embodiments other than the above embodiments are described.

[0155] The control unit stores the amount of microbubbles supplied, the amount of multiple oxidizers supplied, and the ultrasonic output intensity for the amount of excess wastewater sludge, and can control the microbubble supply unit, the oxidizer supply unit, and the ultrasonic output unit so that the amount of microbubbles, the amount of multiple oxidizers supplied, and the ultrasonic output intensity are provided in response to the amount of excess wastewater sludge discharged from the sludge storage tank.

[0156] The ultrasonic output time by the auxiliary ultrasonic output unit between the microbubble supply unit and the oxidizing agent supply unit may be 5 to 60 minutes, and the ultrasonic output time by the auxiliary ultrasonic output unit disposed at the rear end of the oxidation reaction vessel may be 5 to 60 minutes.

[0157] To improve the efficiency of the solubilization treatment, additional circulation pipes may be provided, and if it is determined that the weight reduction is not satisfactory, the sludge may be circulated to any one of the sludge storage tank (10), microbubble supply unit (20), oxidizer supply unit (30), ultrasonic output unit (40), and inline mixing device (50).

[0158] A capacity sensor for measuring the capacity and weight of wastewater excess sludge may be further included at the downstream end where wastewater excess sludge is solubilized and discharged, and the control unit stores the normal discharge range of wastewater excess sludge per unit time, and if it is determined that the capacity and weight of wastewater excess sludge measured by the capacity sensor deviate from the normal discharge range of wastewater excess sludge per unit time, the oxygen microbubble amount, oxidizer supply amount, ultrasonic intensity, and circulation amount of wastewater excess sludge can be adjusted so that the capacity and weight of wastewater excess sludge measured by the capacity sensor are within the normal discharge range of wastewater excess sludge per unit time.

[0159] The venturi tube for injecting the oxidizing agent may be formed with a diameter adjustment section capable of adjusting the diameter. If the amount of oxidizing agent injected is to be increased, the diameter can be reduced to create a large pressure difference. This diameter adjustment section further includes a control drive unit, and the control drive unit can be driven by the control of the control unit.

[0160] The control unit stores the normal discharge range of excess wastewater sludge per unit time, and can control the control drive unit so that the oxidizing agent supply amount is adjusted when it is determined that the volume and weight of excess wastewater sludge measured by the capacity sensor deviate from the normal discharge range of excess wastewater sludge per unit time.

[0161] Due to the excess sludge solubilization system (1) of the above wastewater treatment device, the sludge generated in the wastewater treatment plant can be treated using advanced oxidation technology that uses ultrasound, nanobubbles, oxidizers, electrolysis, ozone, and ultraviolet rays to generate high-concentration radicals, and the cell walls of microorganisms and organic matter in the sludge can be decomposed by the strong oxidizing power of the radicals, thereby leaching out the internal pore water of microorganisms, thereby improving the reduction and dewatering capacity of wastewater sludge and biogasification efficiency.

[0162] In addition, the contact time between ozone and ultraviolet rays may increase, leading to increased generation of high-concentration radicals and a reduction in excess wastewater sludge.

[0163] In addition, since fine ozone bubbles discharged from the entire partition wall can be exposed to ultraviolet rays, the amount of high-concentration radicals generated increases, which can further increase the effect of reducing excess wastewater sludge.

[0164] In addition, the reduction effect of excess wastewater sludge can be increased by electrolyzing excess wastewater sludge.

[0165] In addition, the ultrasonic output effect can be increased while the excess wastewater sludge is concentrated at the positive and negative electrodes, thereby increasing the reduction effect of excess wastewater sludge.

Claims

1. A surplus sludge solubilization system of a wastewater treatment device comprising: a sludge storage tank for storing wastewater surplus sludge; a microbubble supply unit for supplying microbubbles to wastewater surplus sludge discharged from the sludge storage tank; and an oxidizing agent supply unit for supplying a plurality of oxidizing agents to generate radicals to the wastewater surplus sludge to which microbubbles have been supplied. An ultrasonic reaction tank comprising an internal receiving space for outputting ultrasound to excess wastewater sludge supplied with the plurality of oxidizing agents, and an inflow flow meter for detecting the amount of excess wastewater sludge flowing in; The ultrasonic output unit that outputs ultrasound to excess wastewater sludge introduced into the ultrasonic reaction tank; An ozone supply unit that supplies ozone to the above-mentioned ultrasonic reaction vessel; At least one ultraviolet lamp disposed in the internal receiving space of the above-mentioned ultraviolet reactor and emitting ultraviolet light; and A wastewater treatment device excess sludge solubilization system characterized by including a control unit that controls the ultrasonic output unit, the ozone supply unit, and the ultraviolet lamp to provide the ultrasonic output unit, the ozone supply unit, and the ultraviolet lamp in response to the amount of excess wastewater sludge flowing into the ultrasonic reaction tank, and storing the ultrasonic output unit, the ozone supply unit, and the ultraviolet output unit in relation to the amount of excess wastewater sludge.

2. In Paragraph 1, The above ultrasonic reaction vessel is, A wastewater treatment device excess sludge solubilization system characterized by further including a plurality of internal partitions arranged so that the incoming wastewater excess sludge and the ozone supplied from the ozone supply unit move along a zigzag path.

3. In Paragraph 2, The above bulkhead is, Ozone pipes for moving ozone inside; Excess sludge solubilization system of a wastewater treatment device characterized by including an ozone discharge hole formed to communicate with the ozone pipe to the outside.

4. In Paragraph 2, A wastewater treatment device excess sludge solubilization system characterized by further including an electrolysis unit disposed in the internal receiving space of the above-mentioned ultrasonic reaction tank for electrolyzing excess wastewater sludge.

5. In Paragraph 4, The above electrolysis unit is, Positive electrode that attracts negative ions; It includes a negative electrode that attracts positive ions; and a power supply unit that supplies power to the positive electrode and the negative electrode. A system for solubilizing excess sludge of a wastewater treatment device, characterized in that the positive electrode and the negative electrode are positioned in an ultrasonic output path output from the ultrasonic output unit.

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