System and method for treating and recycling sludge drying condensate wastewater

Abstract

The invention relates to the technical field of wastewater treatment and recycling, and discloses a sludge drying and condensing wastewater treatment and recycling system, which comprises an adjusting tank, a heat exchanger, a hydrolysis acidification tank, at least one A / O unit and an advanced treatment unit which are sequentially arranged along the flowing direction of sludge drying and condensing wastewater, wherein each A / O unit comprises an A / O reaction tank and a sedimentation tank, the A / O reaction tank comprises an anoxic tank and an aerobic tank, the anoxic tank, the aerobic tank and the sedimentation tank are sequentially arranged in the flowing direction of the sludge drying condensed wastewater, and a filler for attachment of microorganisms is arranged in the aerobic tank; the deep treatment unit comprises a three-dimensional electrolysis reactor, a secondary flocculation sedimentation tank and a catalytic ozonation reactor which are connected in sequence. According to the system, the three-dimensional electrolysis technology is applied to sludge drying condensation waste water treatment, the process treatment capacity is high, suspended solids, COD, ammonia nitrogen and total phosphorus in the sludge drying condensation waste water can be effectively removed, the equipment operation and maintenance cost is low, and the secondary pollution problem is few.

Description

Technical Field

[0001] The invention relates to the technical field of wastewater treatment and reuse, and in particular to a sludge drying and condensation wastewater treatment and reuse system and method thereof. Background Art

[0002] After natural or artificial dehydration, the moisture content of sludge is generally 60% to 80%. At present, 80% of the sludge produced by sewage treatment plants has not been properly disposed of. The problems of random sludge stacking and the pollution and re-pollution caused by it have become prominent. Due to the high moisture content of sludge, it is difficult to meet the subsequent disposal requirements such as composting, landfilling and incineration. It is usually necessary to use technical means to reduce the moisture content of sludge. Sludge drying is an effective means to reduce the moisture content of sludge.

[0003] The water in wet sludge with a moisture content of 60% to 80% is mainly divided into capillary water, adsorbed water and internal water in the sludge. The capillary water can be further removed by drying the sludge, so that the moisture content of the sludge can be reduced to 10% to 30%; the capillary water in the sludge escapes in the form of water vapor through drying, and condenses into liquid water again through condensation to form dried condensed waste liquid; however, the high-temperature drying process will cause the microorganisms in the sludge to lyse, and the macromolecular substances such as fat and protein to hydrolyze, releasing a large amount of volatile substances, so that the condensed water contains a large amount of ammonia nitrogen and organic matter. Therefore, in addition to containing dust, the sludge drying wastewater also has the characteristics of high temperature, acidic pH, high COD, high ammonia nitrogen and imbalanced carbon-nitrogen ratio, which makes it difficult to treat.

[0004] In the current treatment methods for sludge drying and condensation wastewater, a large amount of carbon source reagents need to be added at the front-end biochemical treatment end; some processes do not have a deep treatment process at the back end, and the concentration of pollutants in the effluent water is still high. After treatment, it is discharged into the municipal pipe network again and does not meet the reuse standard; or the back-end deep treatment uses membrane or adsorption processes to meet the reuse standard, but it will produce secondary pollution problems such as concentrated water and saturated adsorbent. In addition, the conventional pretreatment + A / O method has an unsatisfactory effect on the removal of ammonia nitrogen COD / in the drying and condensation wastewater. The ammonia nitrogen in the effluent does not meet the standard after treatment, and the COD of the effluent after treatment is still greater than 50mg / L. Summary of the invention

[0005] The purpose of the present invention is to overcome the problems existing in the prior art and to provide a sludge drying and condensation wastewater treatment and reuse system and method thereof. The sludge drying and condensation wastewater treatment and reuse system described in the present invention has low operating costs, and the method is simple and efficient.

[0006] In order to achieve the above-mentioned object, the present invention provides a sludge drying and condensing wastewater treatment and reuse system on the one hand, which comprises: a regulating tank, a heat exchanger, a hydrolysis acidification tank, at least one A / O unit and a deep treatment unit arranged in sequence along the flow direction of the sludge drying and condensing wastewater;

[0007] Each of the A / O units comprises an A / O reaction tank and a sedimentation tank, the A / O reaction tank comprises an anoxic tank and an aerobic tank, the anoxic tank, the aerobic tank and the sedimentation tank are sequentially arranged along the flow direction of the sludge drying and condensation wastewater, and a filler for microorganisms to attach is provided inside the aerobic tank;

[0008] The deep treatment unit comprises a three-dimensional electrolytic reactor, a secondary flocculation sedimentation tank and an ozone catalytic oxidation reactor which are connected in sequence.

[0009] Preferably, soft fillers and power plant slag fillers are provided inside the aerobic pool.

[0010] Preferably, a cyclone aerator is provided inside the aerobic tank.

[0011] Preferably, a stirrer is provided inside the anoxic tank.

[0012] Preferably, the system further comprises a primary flocculation sedimentation tank disposed between the heat exchanger and the hydrolysis acidification tank.

[0013] Preferably, the system further comprises a sludge thickening tank connected to the sludge outlet of the A / O unit.

[0014] Preferably, the system further comprises a screw stacking machine.

[0015] Preferably, the screw stacking machine is connected to the sludge outlet of the sludge thickening tank.

[0016] Preferably, the liquid phase outlet of the screw stacking machine is connected to the regulating tank.

[0017] A second aspect of the present invention provides a method for treating and reusing sludge drying and condensation wastewater, which is implemented in the above system and comprises:

[0018] The sludge drying condensed wastewater enters the regulating tank for stirring, the sludge drying condensed wastewater after stirring enters the heat exchanger for heat exchange, the sludge drying condensed wastewater after heat exchange enters the hydrolysis acidification tank for hydrolysis acidification treatment, the sludge drying condensed wastewater after hydrolysis acidification treatment enters the A / O unit (4) for biochemical treatment, and the sludge drying condensed wastewater after biochemical treatment enters the deep treatment unit for three-dimensional electrolysis reaction, secondary flocculation precipitation and ozone catalytic oxidation reaction in sequence.

[0019] Preferably, the temperature of the sludge drying condensed wastewater after heat exchange is ≤36°C.

[0020] Preferably, the pH value of the three-dimensional electrolysis reaction is 5-6.

[0021] Preferably, the conditions for the secondary flocculation precipitation include: a pH value of 8-9.

[0022] Compared with the prior art, the technical solution of the present invention has the following advantages:

[0023] (1) The system described in the present invention applies three-dimensional electrolysis technology to the treatment of sludge drying and condensation wastewater, has a large process processing capacity, and can effectively remove suspended matter, COD, ammonia nitrogen and total phosphorus in the sludge drying and condensation wastewater; the CODCr volume load can reach 1.5-2.5 kg / m 3 .d, CODCr removal rate is 80-90%, sludge yield is 0.2-0.4kg dry sludge / kgCODCr, no sludge expansion will occur during operation, and the stability of effluent water quality can be guaranteed;

[0024] (2) The structures in the system of the present invention can be reused, the equipment operation and maintenance costs are low, and the entire system does not contain saturated adsorbent and concentrated water, so there is less secondary pollution problem;

[0025] (3) The system of the present invention improves the biodegradability of the sludge drying condensation wastewater through the hydrolysis and acidification process, reduces the amount of carbon source added in the biochemical stage, and reduces the operating cost;

[0026] (4) The drugs and equipment used in the method described in the present invention are all conventional drugs and equipment sold on the market, and the system configuration is simple. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 It is a structural schematic diagram of the sludge drying and condensation wastewater treatment and reuse system according to Example 1 of the present invention;

[0028] Figure 2 It is a specific structural diagram of the A / O unit of the sludge drying and condensation wastewater treatment and reuse system described in Example 1 of the present invention.

[0029] Description of Reference Numerals

[0030] 1 regulating tank 2 heat exchanger

[0031] 3Hydrolysis acidification tank 4A / O unit

[0032] 6. Primary flocculation sedimentation tank 7. Sludge thickening tank

[0033] 8Screw stacking machine

[0034] 41A / O reaction tank 42 sedimentation tank

[0035] 411 Anoxic Pool 412 Aerobic Pool

[0036] 51 Three-dimensional electrolytic reactor 52 Secondary flocculation sedimentation tank

[0037] 53 Ozone catalytic oxidation reactor DETAILED DESCRIPTION

[0038] The specific embodiments of the present invention are described in detail below. It should be understood that the specific embodiments described herein are only used to illustrate and explain the present invention, and are not used to limit the present invention.

[0039] The endpoints and any values ​​of the ranges disclosed in this article are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of each range, the endpoint values ​​of each range and the individual point values, and the individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed in this article.

[0040] In the description of this application, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating relative importance or implicitly indicating the number of technical features indicated. Therefore, unless otherwise specified, features defined as "first" and "second" may explicitly or implicitly include one or more of the features; "plurality" means two or more. The term "including" and any variation thereof means non-exclusive inclusion, and one or more other features, integers, steps, operations, units, components and / or combinations thereof may exist or be added.

[0041] In addition, terms indicating orientation or positional relationships such as "upper", "lower", "inside", and "outside" are described based on the orientation or relative positional relationships shown in the drawings, and are only for the convenience of describing the simplified description of the present application, and do not indicate that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present application.

[0042] In addition, unless otherwise clearly specified and limited, the terms "connected" and "connection" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be internally connected between two elements. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0043] On one hand, the present invention provides a sludge drying and condensing wastewater treatment and reuse system, which comprises: a regulating tank 1, a heat exchanger 2, a hydrolysis acidification tank 3, at least one A / O unit 4 and a deep treatment unit arranged in sequence along the flow direction of the sludge drying and condensing wastewater;

[0044] Each of the A / O units 4 includes an A / O reaction tank 41 and a sedimentation tank 42, wherein the A / O reaction tank includes an anoxic tank 411 and an aerobic tank 412, wherein the anoxic tank 411, the aerobic tank 412 and the sedimentation tank 42 are sequentially arranged along the flow direction of the sludge drying and condensation wastewater, and the aerobic tank 412 is provided with fillers for microorganisms to attach thereto;

[0045] The deep treatment unit includes a three-dimensional electrolytic reactor 51, a secondary flocculation sedimentation tank 52 and an ozone catalytic oxidation reactor 53 which are connected in sequence.

[0046] In the system of the present invention, the regulating tank 1 stirs the sludge drying and condensing wastewater to prevent sludge deposition in the sludge drying and condensing wastewater.

[0047] In the system of the present invention, the heat exchanger 2 performs heat exchange on the sludge drying condensation wastewater, so that the temperature of the sludge drying condensation wastewater is reduced, which will not affect the growth of microorganisms during the subsequent biochemical treatment in the A / O unit 4.

[0048] In the system described in the present invention, the biodegradability of the sludge drying and condensing wastewater is improved by setting the hydrolysis acidification tank 3. Hydrolysis acidification treatment is a method between aerobic and anaerobic treatment methods. Combining with other processes can reduce treatment costs and improve treatment efficiency. The hydrolysis acidification process controls the anaerobic treatment to the first and second stages of anaerobic treatment with shorter reaction times according to the different growth rates of methanogens and hydrolytic acidogenic bacteria. Under the action of a large number of hydrolytic bacteria and acidifying bacteria, the insoluble organic matter in the sludge drying and condensing wastewater is hydrolyzed into soluble organic matter, and the macromolecular substances that are difficult to biodegrade are converted into small molecular substances that are easily biodegradable, thereby improving the biodegradability of the sludge drying and condensing wastewater.

[0049] In the system described in the present invention, a biochemical process is provided by the setting of the A / O unit 4, and the biochemical process is a combination of the A / O process and biological contact oxidation; specifically, in the anoxic tank 411, the heterotrophic bacteria hydrolyze the suspended pollutants such as fibers and carbohydrates and soluble organic matter in the sludge drying and condensing wastewater into organic acids, decompose the macromolecular organic matter into small molecular organic matter, and convert the insoluble organic matter into soluble organic matter. When these products of anaerobic hydrolysis enter the aerobic tank 412 for aerobic treatment, the biodegradability and oxygen efficiency of the sludge drying and condensing wastewater can be improved. At the same time, since fillers for microbial attachment are provided inside, space can be provided for biological attachment; in the anoxic tank 411, the heterotrophic bacteria ammine (N on the organic chain or amino group in the amino acid) the pollutants such as protein and fat to release ammonia (NH3, NH4 + ), under sufficient oxygen supply conditions, the nitrification of autotrophic bacteria converts NH3-N (NH4 + ) is oxidized to NO3 -, returned to the anoxic tank 411 through reflux control. Under anaerobic conditions, the denitrification of heterotrophic bacteria converts NO3 - It is reduced to molecular nitrogen (N2) to complete the cycle of C, N, and O in the ecology. At the same time, alkali and carbon source are added to the anoxic tank 411 and the aerobic tank 412 to ensure the alkalinity of the wastewater and a reasonable carbon-nitrogen ratio; and the sludge in the sludge drying and condensation wastewater is deposited in the sedimentation tank 42.

[0050] In the present invention, the A / O method is combined with the biological contact oxidation method. The biological contact oxidation tank is no longer a separate process flow, but is the main operating unit of the aerobic process (O stage), which consists of a tank body, filler, water distribution and gas distribution system. Wastewater and return sludge enter the anoxic tank 411 (A tank) at the same time, stay for a short time, and then flow into the aerobic tank 412 (O tank) for biological contact oxidation.

[0051] In the system described in the present invention, the deep treatment unit is provided with a three-dimensional electrolytic reactor 51, a secondary flocculation sedimentation tank 52 and an ozone catalytic oxidation reactor 53. The sludge drying and condensation wastewater undergoes a three-dimensional electrolytic reaction through the three-dimensional electrolytic reactor 51, and the toxic, long-chain and cyclic heteroatom organic matter in the sludge drying and condensation wastewater gains electrons, and degradation reactions such as ring opening and chain breaking occur. The functional groups of toxic organic matter are destroyed, the toxicity of microorganisms disappears, the long-chain organic matter that is difficult to biodegrade is broken and converted into small molecule organic matter, the cyclic and heterocyclic organic matter opens, and a part of it is finally degraded into CO2 and H2O. At the same time, the active iron in the micro-electrolytic material loses electrons and becomes ferrous ions and enters the solution. Under slightly alkaline conditions, Under the condition, flocculation occurs, and the particles with weak negative charge in the pollutants are attracted by opposite charges to form stable flocs, which are separated and removed; then, the colloids in the wastewater are destabilized and micro-aggregates are generated through the secondary flocculation sedimentation tank 52, and the destabilized colloids or micro-suspended matter are aggregated into large flocs, and the organic matter and suspended matter (SS) in the wastewater are further reduced by natural gravity precipitation in the inclined tube; finally, the catalytic oxidation of the ozone catalytic oxidation reactor 53 is used to non-selectively oxidize the residual organic matter in the wastewater by the hydroxyl radicals generated by the catalytic activation between the ozone catalyst and ozone, and the chromaticity of the wastewater is removed at the same time, so that the final effluent meets the standards. The specific values ​​are shown in the table below;

[0052] Project Name Total effluent quality pH 7.0-8.5 Suspended solids content (SS) 20mg / L <![CDATA[BOD5]]> ≤5mg / L <![CDATA[COD cr ]]> ≤30mg / L Ammonia nitrogen content ≤5mg / L Total nitrogen content Total nitrogen removal rate ≥80% Total phosphorus content ≤1.0mg / L

[0053] In a preferred embodiment, a submersible mixer is provided inside the regulating tank, and the sludge drying and condensation wastewater is stirred by the submersible mixer to prevent sludge deposition.

[0054] In the present invention, there is no special requirement for the type of the heat exchanger 2, as long as it can perform heat exchange on the sludge drying and condensation wastewater; in a preferred embodiment, the heat exchanger 2 is a closed heat exchanger.

[0055] In a preferred embodiment, the heat exchanger 2 is also provided with a temperature monitor, by which the sludge drying condensation wastewater flowing out of the heat exchanger 2 is monitored, thereby monitoring the temperature of the sludge drying condensation wastewater in real time, so that the subsequent biochemical treatment in the A / O unit 4 is not affected by excessively high temperature.

[0056] In a preferred embodiment, a submersible mixer is provided inside the hydrolysis and acidification tank 3, and the sludge drying and condensation wastewater is stirred by the submersible mixer to make the hydrolysis and acidification treatment in the hydrolysis and acidification tank 3 more complete.

[0057] In a preferred embodiment, the number of the A / O units 4 is 2, and the two A / O units 4 are arranged in series.

[0058] In a preferred embodiment, the aerobic pool 412 is provided with soft fillers and power plant slag fillers. The power plant slag has a large specific surface area and is porous, which can provide space for biological attachment. In addition, the power plant slag is used as filler, which is locally available and can reduce transportation and storage costs and realize waste resource utilization. In this embodiment, the process of combining soft fillers and power plant slag fillers can, on the one hand, make up for the defect of low service life of soft fillers, and on the other hand, realize the resource utilization of power plant slag.

[0059] In a preferred embodiment, a cyclone aerator is provided inside the aerobic tank 412, and oxygen is provided to the aerobic tank 412 through the cyclone aerator, so that the sludge drying condensation wastewater reacts more fully in the aerobic tank 412.

[0060] In a preferred embodiment, a submersible mixer is provided inside the anoxic tank 411. Through the setting of the mixer, the sludge drying and condensation wastewater can be better contacted with microorganisms, thereby enhancing the treatment effect.

[0061] In a preferred embodiment, a sludge return pump is provided inside the sedimentation tank 42, and part of the sludge in the sedimentation tank 42 can be returned to the anoxic tank 411 through the action of the sludge return pump, and the remaining sludge can be discharged.

[0062] In a preferred embodiment, the three-dimensional electrolysis reactor 51 is further provided with a pH monitor, and the pH monitor is used to monitor the pH value of the three-dimensional electrolysis reaction of the sludge drying and condensation wastewater.

[0063] In a preferred embodiment, the secondary flocculation sedimentation tank is also provided with a pH monitor, which is used to monitor the pH value of the sludge drying and condensation wastewater for secondary flocculation; at the same time, flocculation and sedimentation are carried out by adding an external flocculant, and the resulting precipitate can also adsorb a part of the pollutants.

[0064] In a preferred embodiment, the system also includes a primary flocculation sedimentation tank 6 arranged between the heat exchanger 2 and the hydrolysis acidification tank 3; the primary flocculation sedimentation tank 6 can preliminarily destabilize the colloids in the sludge drying and condensation wastewater and generate micro-aggregates, and then aggregate the destabilized colloids or micro-suspended matter into large floccules, and utilize the natural sedimentation of inclined tube gravity to reduce organic pollutants and suspended matter (SS) in the wastewater.

[0065] In a preferred embodiment, the primary flocculation sedimentation tank 6 is also provided with a pH monitor, which is used to monitor the pH value of the sludge drying and condensation wastewater for primary flocculation; preferably, the pH value of the primary flocculation is 8-8.5, and flocculation and precipitation are carried out by adding an external flocculant, and the resulting precipitate can also adsorb a part of the pollutants; preferably, the flocculant is polyaluminium chloride (PAC) and / or polyacrylamide (PAM).

[0066] In a preferred embodiment, the system further comprises a sludge thickening tank 7 connected to the sludge outlet of the A / O unit 4; the sludge thickening tank 7 is used for thickening the sludge.

[0067] In a specific embodiment, the sludge thickening tank 7 is connected to the sludge outlet of the sedimentation tank 42 .

[0068] In a preferred embodiment, the system further comprises a screw stacker 8; the screw stacker 8 is used to dehydrate the concentrated sludge, and the dehydrated sludge enters the plant sludge drying system for further treatment, while the removed water enters the regulating tank 1 for circulation treatment.

[0069] In a specific implementation, the screw stacking machine 8 is connected to the sludge outlet of the sludge thickening tank 7 .

[0070] In a specific implementation, the liquid phase outlet of the screw stacking machine 8 is connected to the regulating tank 1 .

[0071] A second aspect of the present invention provides a method for treating and reusing sludge drying and condensation wastewater, which is implemented in the above system and comprises:

[0072] The sludge drying condensed wastewater enters the regulating tank 1 for stirring, the sludge drying condensed wastewater after stirring enters the heat exchanger 2 for heat exchange, the sludge drying condensed wastewater after heat exchange enters the hydrolysis acidification tank 3 for hydrolysis acidification treatment, the sludge drying condensed wastewater after hydrolysis acidification treatment enters the A / O unit (4) for biochemical treatment, and the sludge drying condensed wastewater after biochemical treatment enters the deep treatment unit for three-dimensional electrolysis reaction, secondary flocculation precipitation and ozone catalytic oxidation reaction in sequence.

[0073] In a preferred embodiment, the temperature of the sludge drying condensed wastewater after heat exchange is ≤36°C.

[0074] In a preferred embodiment, the pH value of the three-dimensional electrolysis reaction is 5-6.

[0075] In the present invention, there is no special requirement for the substance for adjusting the pH value of the three-dimensional electrolysis reaction, as long as the pH value of the three-dimensional electrolysis reaction can be adjusted to 5-6; preferably, ferrous sulfate is used to adjust the pH value of the three-dimensional electrolysis reaction.

[0076] In a preferred embodiment, the conditions for the secondary flocculation precipitation include: a pH value of 8-9.

[0077] In the present invention, there is no special requirement for the substance for adjusting the pH value of the secondary flocculation precipitation, as long as the pH value of the secondary flocculation can be adjusted to 8-9; preferably, sodium hydroxide and / or potassium hydroxide are used to adjust the pH value of the secondary flocculation.

[0078] In a preferred embodiment, the secondary flocculation precipitation conditions further include adding an external flocculant; preferably, the flocculant is polyaluminium chloride (PAC) and / or polyacrylamide (PAM).

[0079] The following examples further illustrate the sludge drying and condensation wastewater treatment and reuse system and method of the present invention. The examples are implemented based on the technical solution of the present invention, and provide detailed implementation methods and specific operation processes, but the protection scope of the present invention is not limited to the following examples.

[0080] Example 1

[0081] This embodiment is implemented in the following system, in conjunction with Figure 1 and Figure 2 , the system comprises:

[0082] A regulating tank 1, a heat exchanger 2, a primary flocculation sedimentation tank 6, a hydrolysis acidification tank 3, two A / O units 4 arranged in series, a deep treatment unit, a sludge thickening tank 7 and a screw stacking machine 8;

[0083] Each of the A / O units 4 includes an A / O reaction tank 41 and a sedimentation tank 42, wherein the A / O reaction tank includes an anoxic tank 411 and an aerobic tank 412, and the anoxic tank 411, the aerobic tank 412 and the sedimentation tank 42 are connected in sequence;

[0084] The deep treatment unit includes a three-dimensional electrolytic reactor 51, a secondary flocculation sedimentation tank 52 and an ozone catalytic oxidation reactor 53 connected in sequence;

[0085] The regulating tank 1 is connected to the primary flocculation sedimentation tank 6;

[0086] The primary flocculation sedimentation tank 6 is connected to the heat exchanger 2;

[0087] The heat exchanger 2 is connected to the hydrolysis acidification tank 3;

[0088] The hydrolysis acidification tank 3 is connected to the anoxic tank 411;

[0089] The sludge outlet of the sedimentation tank 42 is connected to the anoxic tank 411 and the sludge concentration tank 7 respectively, and the liquid phase outlet of the sedimentation tank 42 is connected to the three-dimensional electrolytic reactor 51;

[0090] The sludge thickening tank 7 is connected to the screw stacking machine 8;

[0091] The screw stacking machine 8 is connected to the regulating tank 1 .

[0092] The process flow of treating sludge drying and condensation waste liquid is as follows:

[0093] The sludge drying and condensing wastewater to be treated flows by gravity into the regulating tank 1 for homogenization and equalization. A submersible mixer is provided inside the regulating tank 1 to stir the sludge drying and condensing wastewater. The sludge drying and condensing wastewater (≥55°C) in the regulating tank 1 is pumped to the closed heat exchanger 2 for heat exchange. The temperature of the sludge drying and condensing wastewater after heat exchange is ≤36°C.

[0094] After the heat exchange, the sludge drying and condensing wastewater flows by gravity into the primary flocculation sedimentation tank 6, and an alkali agent (NaOH solution) is added to adjust the pH value of the primary flocculation of the sludge drying and condensing wastewater to 8-8.5, and then PAC and PAM are added to remove the colloid in the sludge drying and condensing wastewater;

[0095] The effluent from the primary flocculation sedimentation tank 6 flows by gravity into the hydrolysis acidification tank 3 for hydrolysis acidification treatment, where the insoluble organic matter in the wastewater is hydrolyzed into soluble organic matter, and the macromolecular substances that are difficult to biodegrade are converted into small molecular substances that are easily biodegradable, thereby improving the biodegradability of the sludge drying and condensation wastewater;

[0096] The effluent from the hydrolysis acidification tank 3 passes through a two-stage A / O unit 4 (enters anoxic tank 411, aerobic tank 412, sedimentation tank 42, anoxic tank 411, aerobic tank 412 and sedimentation tank 42 in sequence) to remove organic matter and ammonia nitrogen pollutants in the wastewater. A submersible mixer is provided inside the anoxic tank 411, a cyclone aerator is provided inside the aerobic tank 412, and a sludge return pump is provided inside the sedimentation tank 42. A portion of the sludge is returned to the anoxic tank 411 by the sludge return pump, and the remaining sludge enters the sludge thickening tank 7 for thickening by the sludge return pump; the thickened sludge enters the screw stacking machine 8 for dehydration, the dehydrated sludge is recycled, and the removed water enters the regulating tank 1 for re-treatment;

[0097] The effluent from the sedimentation tank 42 flows by gravity into the three-dimensional electrolytic reactor 51 for a three-dimensional electrolytic reaction, thereby effectively degrading heterocyclic organic matter and organic matter containing toxic functional groups or chromogenic groups in the wastewater; the effluent from the three-dimensional electrolytic reactor 51 flows by gravity into the secondary flocculation sedimentation tank 52, and the pH value of the secondary flocculation precipitation of the sludge drying and condensation wastewater is adjusted to 8-9 by adding an alkali agent (NaOH solution), and then PAC and PAM are added to further remove the colloids and organic matter in the wastewater; the effluent from the secondary flocculation sedimentation tank 52 flows by gravity into the ozone catalytic oxidation reactor 53 for ozone catalytic oxidation, thereby removing residual organic matter in the wastewater and removing the chromaticity of the wastewater.

[0098] Comparative Example 1

[0099] The method of Example 1 is followed, except that the sludge drying and condensation wastewater does not enter the deep treatment unit, that is, the sludge drying and condensation wastewater does not undergo three-dimensional electrolysis, secondary flocculation and ozone catalytic oxidation.

[0100] Test Case

[0101] The treated wastewater of the embodiment and the comparative example was tested, and the test results are shown in Table 1.

[0102] Table 1

[0103]

[0104]

[0105] It can be seen from the results in Table 1 that the use of the system and method described in the present invention to treat the sludge drying and condensation wastewater can significantly reduce the suspended solids content, BOD5 value, CODcr value, ammonia nitrogen content, total nitrogen content and total phosphorus content of the wastewater, and the treated wastewater meets the effluent reuse standard.

[0106] The preferred embodiments of the present invention are described in detail above, but the present invention is not limited thereto. Within the technical concept of the present invention, the technical solution of the present invention can be subjected to a variety of simple modifications, including the combination of various technical features in any other suitable manner, and these simple modifications and combinations should also be regarded as the contents disclosed by the present invention and belong to the protection scope of the present invention.

Claims

1. A sludge drying and condensation wastewater treatment and reuse system, It is characterized in that The system comprises: a regulating tank (1), a heat exchanger (2), a hydrolysis acidification tank (3), at least one A / O unit (4) and a deep treatment unit which are arranged in sequence along the flow direction of sludge drying and condensation wastewater; Each of the A / O units (4) comprises an A / O reaction tank (41) and a sedimentation tank (42), the A / O reaction tank comprises an anoxic tank (411) and an aerobic tank (412), the anoxic tank (411), the aerobic tank (412) and the sedimentation tank (42) are arranged in sequence along the flow direction of the sludge drying and condensation wastewater, and a filler for microorganisms to attach is provided inside the aerobic tank (412); The deep treatment unit comprises a three-dimensional electrolytic reactor (51), a secondary flocculation sedimentation tank (52) and an ozone catalytic oxidation reactor (53) which are connected in sequence.

2. The system according to claim 1, It is characterized in that The aerobic pool (412) is provided with soft fillers and power plant slag fillers; Preferably, a cyclone aerator is provided inside the aerobic tank (412).

3. The system according to claim 1 or 2, It is characterized in that The anoxic tank (411) is provided with a stirrer inside.

4. The system according to claim 3, It is characterized in that The system further comprises a primary flocculation sedimentation tank (6) arranged between the heat exchanger (2) and the hydrolysis acidification tank (3).

5. The system according to claim 4, It is characterized in that The system further comprises a sludge thickening tank (7) connected to the sludge outlet of the A / O unit (4).

6. The system according to claim 5, It is characterized in that The system also includes a screw stacking machine (9).

7. The system according to claim 6, It is characterized in that The screw stacking machine (8) is connected to the sludge outlet of the sludge thickening tank (7); Preferably, the liquid phase outlet of the screw stacking machine (8) is connected to the regulating tank (1).

8. A method for treating and reusing sludge drying and condensation wastewater. It is characterized in that The method is implemented in the system according to any one of claims 1 to 7, and the method comprises: The sludge drying condensed wastewater enters the regulating tank (1) for stirring, the sludge drying condensed wastewater after stirring enters the heat exchanger (2) for heat exchange, the sludge drying condensed wastewater after heat exchange enters the hydrolysis acidification tank (3) for hydrolysis acidification treatment, the sludge drying condensed wastewater after hydrolysis acidification treatment enters the A / O unit (4) for biochemical treatment, and the sludge drying condensed wastewater after biochemical treatment enters the deep treatment unit for three-dimensional electrolysis reaction, secondary flocculation precipitation and ozone catalytic oxidation reaction in sequence.

9. The method according to claim 8, It is characterized in that The temperature of the sludge drying condensed wastewater after heat exchange is ≤36℃.

10. The method according to claim 8 or 9, It is characterized in that The pH value of the three-dimensional electrolysis reaction is 5-6; Preferably, the conditions for the secondary flocculation precipitation include: a pH value of 8-9.

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