Wastewater treatment system for sludge anaerobic digestion and synchronous domestication and operation method of wastewater treatment system

Abstract

The invention discloses a wastewater treatment system for sludge anaerobic digestion synchronous domestication and an operation method thereof, the system comprises a synchronous domestication unit and a main reaction unit, organic wastewater respectively enters the synchronous domestication unit and the main reaction unit, the wastewater in the main reaction unit reacts with granular sludge, and the sludge in the main reaction unit reacts with the granular sludge; the main reaction unit also outputs the sludge subjected to the mixed reaction to the synchronous domestication unit, and the sludge mixed liquid is returned to the main reaction unit after the sludge is treated by the synchronous domestication unit; the synchronous domestication unit comprises a reactor and a nanoscale zero-valent iron feeding device, granular sludge is contained in the reactor, the nanoscale zero-valent iron feeding device mixes and stirs powdery nanoscale zero-valent iron and wastewater to obtain a sludge mixed solution, then the sludge mixed solution is conveyed to the reactor through a pipeline, and after the mixed solution enters the reactor, the sludge is fed into the reactor; and carrying out adsorption combination with the granular sludge under the action of gravity, and accelerating to form a structure under the action of extracellular secretion induction, so as to obtain the reinforced granular sludge and sludge mixed solution.

Description

Technical Field

[0001] The invention belongs to the field of biochemical treatment of organic wastewater, and in particular relates to a wastewater treatment system for anaerobic digestion and synchronous domestication of sludge and an operation method thereof. Background Art

[0002] With the rapid rise of large-scale integrated industrial parks, while bringing economic benefits, a large amount of wastewater is also generated. Due to the different types of industries in industrial parks, the collected organic wastewater has the following characteristics: (1) Frequent fluctuations in water quality; (2) Containing toxic and difficult-to-degrade substances and complex composition; This leads to great challenges to the efficiency of process operation. At present, there are usually two directions for the solution to this problem: (1) Rationally design the pretreatment unit and combined process according to the characteristics of the incoming water to ensure the effluent effect; (2) Modify the reaction unit to improve the treatment redundancy.

[0003] Anaerobic biochemical treatment is the core treatment process in the current high-concentration organic wastewater treatment process. Compared with aerobic microbial treatment, it not only has low energy consumption, but also can produce biogas for secondary energy utilization. In order to ensure the operation effect of the reactor, it is often required to stabilize the influent water quality and replace the sludge regularly. The startup cycle after each sludge replenishment is long, which affects the operation efficiency and economy. In order to solve the above problems, many studies have designed reactors and combined processes. However, the actual operating environment is complex and changeable. Due to the construction and operation and maintenance costs, most solutions are not suitable for large-scale wastewater treatment process facilities. Therefore, introducing exogenous enhancement measures on the basis of the original reactor has become an economical and applicable option.

[0004] Nano zero-valent iron is used in enhanced biological treatment because of its high reactivity and as a good electron donor and conductor. Crucially, because nano zero-valent iron exerts selective pressure on the microbial system, it can strengthen and enrich specific functional bacterial communities in a targeted manner, thereby increasing the redundancy of the system and significantly improving the adaptability of the reaction system to complex and fluctuating water quality. Chinese invention patent CN117486363B discloses a method for nano iron-enhanced anaerobic digestion of sulfonamide wastewater, eliminating the limitation of sulfonamide antibiotics interfering with the degradation of sulfonamide wastewater during the degradation process. The prior art also discloses a method for nano zero-valent iron to increase methane production during anaerobic digestion of sludge. The addition of nano zero-valent iron maintains the stability of the anaerobic digestion system, improves the anaerobic digestion efficiency, and promotes the dissolution and release of organic matter during the anaerobic digestion process. The prior art also discloses a method for improving the efficiency of anaerobic digestion of sludge while reducing the ecotoxicity of heavy metals. By adding a composite material loaded with nano zero-valent iron, the community structure of microorganisms is changed and the anaerobic digestion efficiency is improved. In summary, nano zero-valent iron can be used as an effective exogenous enhancement measure to improve the redundancy and treatment efficiency of the anaerobic digestion system.

[0005] It is further pointed out that different acclimation methods are usually used to strengthen the sludge to adapt to different environmental conditions. Chinese invention patent CN116462311A discloses a method for improving the nitrification rate of activated sludge system at low temperature based on composite pollution pre-stress, and proposes a method for improving the nitrification rate of activated sludge system at low temperature under composite pollution pre-stress of halogenated carbazole and nanomaterials. The patent proposes that the acclimation time can be shortened by pre-stress of nanomaterials, but there are many operation steps and it is still time-consuming. This is also a problem in the prior art. Most methods often require a long acclimation time and a long start-up time. In addition, directly putting nanomaterials into the reactor will produce strong irritation, and will face greater risks in actual operation. If the conditions are not properly controlled, it may cause uneven material distribution, uneven water distribution, sludge compaction / disintegration, and in severe cases, it will cause the reactor to collapse.

[0006] Therefore, the present invention proposes a wastewater treatment system for anaerobic digestion and synchronous domestication of sludge and an operation method thereof. A synchronous domestication unit is set up on the basis of the original process, in which nano zero-valent iron and its composite materials are added to achieve a directional strengthening effect of the sludge; the domesticated sludge is synchronously lifted into the anaerobic reactor to reduce the frequency of sludge replenishment and shorten the startup time. Summary of the invention

[0007] The purpose of the present invention is to provide a wastewater treatment system for anaerobic digestion and synchronous acclimation of sludge and its operation method, so as to solve the shortcomings of the current anaerobic treatment section in actual operation, such as frequent sludge replenishment, long startup cycle and poor adaptability to complex and fluctuating water quality.

[0008] Technical solution: A wastewater treatment system with anaerobic digestion and synchronous domestication of sludge, the system comprises a regulating tank, the system also comprises a synchronous domestication unit and a main reaction unit;

[0009] The synchronous acclimation unit includes a reactor and a nano zero-valent iron delivery device, wherein the reactor contains granular sludge, and the nano zero-valent iron delivery device mixes powdered nano zero-valent iron with wastewater and stirs to obtain a nano zero-valent iron mixed liquid, and then transports the nano zero-valent iron mixed liquid to the reactor through a pipeline. After the mixed liquid enters the reactor, it is adsorbed and combined with the granular sludge under the action of gravity, and the enhanced structure is accelerated to form under the induction of extracellular secretion to obtain enhanced granular sludge;

[0010] In this system, organic wastewater enters the synchronous acclimation unit and the main reaction unit respectively. In the main reaction unit, the wastewater reacts with the granular sludge to convert the organic matter in the wastewater into methane and carbon dioxide, and removes the total nitrogen at the same time. The main reaction unit also outputs the sludge after the mixed reaction to the synchronous acclimation unit. After being processed by the synchronous acclimation unit, the sludge mixed liquid is returned to the main reaction unit.

[0011] The above-mentioned main reaction unit and reactor both include anaerobic granular sludge reactors.

[0012] Furthermore, the reactor in the synchronous acclimation unit includes an upflow anaerobic reactor, the main reaction unit is an EGSB reactor, the upflow anaerobic reactor outputs enhanced sludge mixed liquor to the EGSB reactor, and the EGSB reactor outputs sludge to the upflow reactor;

[0013] The system realizes anaerobic digestion and sludge synchronous domestication in the process of organic wastewater treatment through a synchronous domestication unit.

[0014] Furthermore, the system also includes one or any combination of a sedimentation tank, a regulating tank, a mixing and heating tank, a cooling tank and a contact oxidation tank.

[0015] The reactor and the main reaction unit are provided with a three-phase separator to separate and discharge or collect sludge, water and gas.

[0016] In this system, the concentration of the nano zero-valent iron mixed liquid in the stirrer of the nano zero-valent iron delivery device is maintained at 1-5 g / L, and nitrogen is introduced before mixing to maintain an oxygen-free state in the mixing tank. The concentration of nano zero-valent iron in the stirrer is 20-150 mg / L.

[0017] The concentration of nano zero-valent iron in the synchronous domestication unit is determined according to the biodegradability of the influent. If the BOD5 / COD ratio is ≤0.3, the concentration of nano zero-valent iron in the anaerobic reactor is increased to 120-150 mg / L; if the BOD5 / COD ratio is between 0.3-0.5, the concentration in the anaerobic reactor is adjusted to 60-120 mg / L; if the BOD5 / COD ratio is ≥0.5, the concentration in the anaerobic reactor is controlled at 20-60 mg / L.

[0018] Furthermore, the size of the nano zero-valent iron in at least one dimension is ≤100 nm.

[0019] The regulating tank is used to adjust the pH value of the wastewater to 6.5-7.5.

[0020] Furthermore, the granular sludge of the synchronous acclimation unit comes from the sludge discharged from the anaerobic reactor or the granular sludge added from the outside; the synchronous acclimation unit includes discharging the old sludge in the reactor unit according to the frequency, and replenishing it with the granular sludge added from the outside through the sludge injection port; when the granular sludge added from the outside is used, the proportion in the unit shall not exceed 50% of the total sludge.

[0021] The invention discloses an operation method of a wastewater treatment system for anaerobic digestion and synchronous acclimation of sludge, comprising the following steps: pre-treated wastewater enters a main reaction unit and a synchronous acclimation unit, wherein the pre-treatment comprises wastewater pH value adjustment, mixing and temperature control; in the main reaction unit, the wastewater contacts and reacts with granular sludge, and the frequency of discharging granular sludge into the reactor in the synchronous acclimation unit is controlled; nano zero-valent iron material is stirred and dispersed in a stirrer of a nano zero-valent iron delivery device, and continuously fed into the reactor to complete the synchronous acclimation operation, the nano zero-valent iron in the synchronous acclimation unit contacts and strengthens the granular sludge, and the strengthened granular sludge mixed liquid is lifted into the anaerobic reactor unit.

[0022] Furthermore, the sludge discharge frequency or amount of the main reaction unit in the system is determined according to the volumetric load, and the main reaction unit communicates sludge with the synchronous acclimation unit to adjust the treatment capacity and efficiency of the system, and controls the sludge in the main reaction unit to enter the synchronous acclimation unit for reinforcement or controls the synchronous acclimation unit to supply the main reaction unit according to the treatment effect of the organic wastewater.

[0023] Beneficial effect: The significant effect of the present invention is that by designing a synchronous acclimation unit and utilizing the strengthening effect of nano zero-valent iron and its composite materials on granular sludge, the operating stability of the anaerobic unit is improved, the frequency of sludge replenishment is reduced, and the complexity of equipment investment and operation management is reduced. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 It is a schematic diagram of the structure of the synchronous domestication unit;

[0025] Figure 2 It is a schematic diagram of the combined use structure of the synchronous acclimation unit and the anaerobic reactor;

[0026] Figure 3 It is a schematic diagram of the structure of the biochemical treatment system for organic wastewater;

[0027] Figure 4 It is the system structure diagram in comparative example 1;

[0028] Figure 5 This is the system structure diagram in Comparative Example 2. DETAILED DESCRIPTION

[0029] In order to make the technical solution disclosed in the present invention more clear and understandable, and to better understand the effects brought about by the implementation of the present invention, the present invention is further described below in conjunction with specific illustrations.

[0030] The wastewater treatment system for anaerobic digestion and synchronous acclimation of sludge provided by the present invention is designed with a synchronous acclimation unit. The structure of the unit can be seen in Figure 1 shown.

[0031] The synchronous acclimation unit includes a reactor 1, which can be preferably an upflow anaerobic reactor or an EGSB reactor, including the main reaction unit mentioned later, which can also be an anaerobic reactor or an EGSB reactor. It also includes a nano-iron feeding device 6, and there is granular sludge in the reactor 1, and a sludge feeding port 10 is provided. The granular sludge can come from the main reaction unit sludge in the system, or the granular sludge added externally can be used. The inlet water comes from the system inlet water 2, that is, the wastewater enters the reactor 1 and the main reaction unit respectively. The bottom of the reactor 1 is connected with a wastewater inlet pipe 2 and a sludge discharge pipe 3, and the upper end of the reactor 1 is provided with a feeding port 7 for inputting powdered nano zero-valent iron. Through the feeding port 7, a nano iron feeding device 6 is connected, and the nano iron feeding device 6 includes a stirrer 8. Under the full stirring and dispersing action of the stirrer 8, a high-concentration mixed liquid is obtained. Under the action of a circulating pump, the mixed liquid is input into a synchronous acclimation unit through a connecting pipe 9 at a certain flow rate, and is distributed to the sludge bed under the action of gravity and adsorbed and combined with the granular sludge. Under the induction of extracellular secretion, the formation of large-sized granular sludge with enhanced structure and performance is accelerated, and finally discharged from the bottom sludge discharge area through the sludge discharge pipe 3 and lifted to the main reaction unit of the system, the overflow water is discharged through the pipe 4, and the generated gas is discharged through the pipe 5. Here, a three-phase separator is provided to achieve separation.

[0032] Figure 2 In this embodiment, an anaerobic reactor (EGSB reactor) is used as the main reaction unit in the system, and the synchronous acclimation unit is the above-mentioned structure. The synchronous acclimation unit also includes an anaerobic reactor. The two can cooperate with each other to improve the acclimation process and wastewater treatment. The wastewater enters the synchronous acclimation unit and the main reaction unit respectively. The wastewater reacts with the granular sludge in the anaerobic reactor, and the organic matter in the wastewater is converted into methane and carbon dioxide, and the total nitrogen is also removed at the same time; in this process, the granular sludge is discharged according to a certain frequency and transported to the synchronous acclimation unit; the nano zero-valent iron delivery device is connected to the synchronous acclimation unit, and after being evenly dispersed in the device, the high-concentration nano zero-valent iron mixed liquid is continuously input into the synchronous acclimation unit and contacts with the granular sludge; the enhanced granular sludge is lifted into the anaerobic reactor in the form of a mixed liquid under the action of a circulating pump. After the operation test, the mixed liquid in the reactor of the synchronous acclimation unit presents three layers, namely the three-phase separation zone in the upper layer, the sludge bed reaction zone in the lower layer, and the water distribution and mud discharge zone at the bottom.

[0033] This combination can effectively treat high-concentration difficult-to-degrade wastewater, improve the redundancy of the anaerobic process, and better adapt to complex and fluctuating water quality. It also reduces the complexity of equipment investment and operation management, and can achieve stable treatment effects in a short time.

[0034] In view of the above system structure, the following is an introduction to the operation mode in combination with the application and use of the system.

[0035] A method for operating a wastewater treatment system with anaerobic sludge digestion and synchronous domestication, the main steps comprising:

[0036] (1) The pretreated wastewater enters the main reaction unit and the synchronous acclimation unit;

[0037] (2) In the main reaction unit, wastewater and granular sludge come into contact and react;

[0038] (3) discharging granular sludge at a certain frequency and inputting it into a synchronous acclimation unit;

[0039] (4) The nano zero-valent iron material is stirred and dispersed in the application device and continuously input into the synchronous acclimation unit;

[0040] (5) Enhanced contact between nano-zero-valent iron and granular sludge in the synchronous acclimation unit;

[0041] (6) The enhanced granular sludge mixed liquor is lifted into the anaerobic reactor unit;

[0042] (7) Steps (5) and (6) are coordinated and controlled according to the efficiency and effect of the system (anaerobic reactor) on the biochemical treatment of organic wastewater, thereby achieving efficient and high-quality wastewater treatment.

[0043] Preferably, assuming that the volumetric load range of the main reaction unit is 15-30kgCOD / (m3·d), the rising flow rate of the wastewater in the anaerobic reactor is controlled between 4-7m / h. The sludge discharge frequency of the main reaction unit in the system is determined according to the volumetric load, and the single sludge discharge volume does not exceed 10% of the total sludge volume. The main reaction unit includes the frequency of sludge exchange with the synchronous domestication unit to adjust the processing capacity and efficiency of the system. When the volumetric load is greater than 18kgCOD / (m3·d), the exchange frequency is adjusted to 1-4 times / week; when the volumetric load is ≤18kgCOD / (m3·d), the exchange frequency is increased to 4-10 times / week to improve the processing capacity of the main reaction unit. In this scenario, the following adjustments can also be made: Considering that the synchronous acclimation unit is provided with a sludge inlet, the present invention can not only control the introduction of granular sludge into the synchronous acclimation unit through the anaerobic reactor (in the main reaction unit), but also directly add new granular sludge from the outside, and the proportion in the synchronous acclimation unit does not exceed 50% of the total sludge, which is optimal. Similarly, the synchronous acclimation unit is provided with a sludge discharge pipe, which can discharge the old sludge in the anaerobic reactor unit according to a certain frequency.

[0044] It is further pointed out that according to the characteristics of water quality, powdered modified nano zero-valent iron such as sulfide nano zero-valent iron and EPS-coated nano zero-valent iron can be selected. The size of nano zero-valent iron is ≤100nm in at least one dimension. The present invention takes into account the biochemical reaction principle and treatment effect of nano zero-valent iron in organic wastewater treatment, and puts forward cost considerations. The existing nano zero-valent iron with a total particle size of ≤100nm is very expensive. The present invention can also select ball-milled nano iron flakes to ensure that the diameter in any direction is ≤100nm, and maintain the nano zero-valent iron concentration in the unit at 20-150mg / L, which can achieve better results.

[0045] The concentration of nano zero-valent iron in the anaerobic reactor unit is determined according to the biodegradability of the influent. If the BOD5 / COD ratio is ≤0.3, the concentration of nano zero-valent iron in the anaerobic reactor is increased to 120-150 mg / L; if the BOD5 / COD ratio is between 0.3-0.5, the concentration in the anaerobic reactor is adjusted to 60-120 mg / L; if the BOD5 / COD ratio is ≥0.5, the concentration in the anaerobic reactor is controlled at 20-60 mg / L.

[0046] Embodiment 1: Figure 3 The structure of the system described in the present invention is given. After testing, the wastewater combined process has been running continuously for 104 days. The influent comes from the effluent of the primary sedimentation tank of an industrial park in Jiangsu. The design scale is 100m 3 / d, using sulfide nano zero-valent iron as the input material, and controlling the material concentration in the synchronous acclimation unit to 20mg / L. The specific effluent quality of this combined process during the pilot period is shown in Table 1, and the CODCr removal rate is maintained at about 82%. Observation of the system found that the effluent from the synchronous acclimation unit and the EGSB reactor was in good condition, without mud running, and the effluent was relatively clear.

[0047] Example 2: Since the combined process in Example 1 has already started operation, the manufacturing cost of sulfide nano zero-valent iron is high and the supply is unstable. In this example, ball-milled nano zero-valent iron prepared on a large scale and stably is selected as the material to be used. After measurement, the single dimension is ≤100nm, which meets the use requirements, and the combined process in Example 2 is used to start the operation. The material concentration in the synchronous acclimation unit is controlled to be 50mg / L. The specific effluent water quality of this combined process during the pilot period is shown in Table 1, and the CODCr removal rate is maintained at about 84%. System observation found that the effluent from the synchronous acclimation unit and the EGSB reactor was in good condition, there was no mud running, and the effluent was relatively clear.

[0048] Example 3: This example uses the combined process in Example 1 and runs for 126 days. EPS-coated nano zero-valent iron is obtained by ball-milling nano zero-valent iron as the input material, and the material concentration in the synchronous acclimation unit is controlled to be 60 mg / L. The specific effluent water quality of this combined process during the pilot period is shown in Table 1, and the CODCr removal rate is maintained at about 91%. It was found from the system observation that the effluent of the synchronous acclimation unit and the EGSB reactor was in good condition, no mud flow phenomenon occurred, and the effluent was relatively clear.

[0049] Comparative Example 1: Combination Figure 4 This comparative example adopts the combined process in Example 1, except that the synchronous acclimation unit is not connected and nano zero-valent iron is not added. Figure 3 As shown in Figure 1, the combined process was run for 104 days. The specific effluent quality is shown in Table 1, and the CODCr removal rate was maintained at about 71%. The system was observed to find that the effluent condition of the EGSB reactor was basically good, with occasional sludge leakage.

[0050] Comparative Example 2: Combination Figure 5 This comparative example adopts the combined process in Example 1, which is basically the same as Example 2, except that the synchronous acclimation unit is not connected, and the ball-milled nano zero-valent iron delivery device is connected to the EGSB reactor, that is, the ball-milled nano zero-valent iron is directly input into the anaerobic reactor unit, and the material concentration in the synchronous acclimation unit is controlled to be 50 mg / L. This set of combined processes was run alone for 105 days. The specific effluent water quality is shown in Table 1, and the CODCr removal rate is maintained at about 75%. It was found from system observation that the effluent condition of the EGSB reactor was basically good, and the effect of the comparative example 2 was reduced. After the operation was completed, it was found that there were blockages and siltation inside, and there were many reaction dead zones, which showed that the mixed mass transfer effect of the reactor for nano zero-valent iron was not good.

[0051] Table 1 is the measured water quality during operation in the embodiments and comparative examples.

[0052]

[0053] The prior art discloses an SBR device and operation method of an embedded iron-carbon sludge storage module that promotes the formation and stabilization of granular sludge. This method can embed different types of sludge storage modules into the main reaction unit according to demand. Conceptually, the microbial community in the reactor can also be strengthened by using nano zero-valent iron, and the sludge in the reactor can be supplemented. The structure is simple and can be flexibly adjusted. However, the disadvantage is that although nano zero-valent iron has been combined with the sludge storage module, it still belongs to a large-dose material in the anaerobic reactor. If you want to continuously input low doses, you need to replace the module frequently, and the operating cost is high. Secondly, the preparation of the sludge storage module also requires a supporting independent main reaction unit, and it is necessary to design water inlet, pretreatment, subsequent treatment and other steps. If simulated wastewater is selected for domestication, it may not be able to adapt to real wastewater, resulting in unsatisfactory treatment effects. Therefore, the connection of a synchronous domestication device to the original process can greatly shorten the domestication adaptation and startup reaction time, and save investment.

[0054] The system and implementation of the present invention have the following significant effects:

[0055] (1) The present invention sets a synchronous acclimation unit at the front end of the anaerobic digestion reactor, which reduces the difficulty of process modification and can reduce investment costs. The acclimated sludge can be continuously input into the reactor as a sludge replenishment source for the reactor, thereby reducing the sludge replenishment frequency.

[0056] (2) Nano-zero-valent iron is added in the synchronous acclimation unit. The distribution of the material in the unit is more uniform than that in the anaerobic reactor, which enables it to interact more fully with microorganisms and quickly achieve directional enhancement of the sludge microbial community.

[0057] (3) Avoid adding materials directly into the anaerobic digestion reactor to prevent potential negative effects that affect the normal operation of the entire system. In the short term, the stimulation of high-dose materials directly entering the system is too strong, which will cause acute inhibition of the microbial community. In the long term, the addition of nanomaterials may cause changes in the stability and activity of the sludge structure, resulting in irreversible consequences. Therefore, placing the addition link in advance can provide room for flexible adjustment.

[0058] (4) The surface activity of the nano zero-valent iron material obtained by the synchronous domestication unit has been significantly reduced, and the outer layer is wrapped with natural extracellular polymers. After entering the anaerobic reactor, the biocompatibility with the microbial system has been significantly improved, thereby further improving the interaction effect with the microbial community.

[0059] (5) For different types of incoming water, different nano-zero-valent iron and its composite materials are added and the dosage is controlled to induce the differential evolution of microbial communities, thereby achieving flexible regulation effects, simple control, and easy operation.

Claims

1. A wastewater treatment system for sludge anaerobic digestion and synchronous domestication, the system comprising a regulating tank, characterized in that: The system also includes a synchronous acclimation unit and a main reaction unit; The synchronous acclimation unit includes a reactor and a nano zero-valent iron delivery device, wherein the reactor contains granular sludge, and the nano zero-valent iron delivery device mixes powdered nano zero-valent iron with wastewater and stirs to obtain a nano zero-valent iron mixed liquid, and then transports the nano zero-valent iron mixed liquid to the reactor through a pipeline. After the mixed liquid enters the reactor, it is adsorbed and combined with the granular sludge under the action of gravity, and the enhanced structure is accelerated to form under the induction of extracellular secretion to obtain enhanced granular sludge; In this system, organic wastewater enters the synchronous acclimation unit and the main reaction unit respectively. In the main reaction unit, the wastewater reacts with the granular sludge to convert the organic matter in the wastewater into methane and carbon dioxide, and removes the total nitrogen at the same time. The main reaction unit also outputs the sludge after the mixed reaction to the synchronous acclimation unit. After being processed by the synchronous acclimation unit, the sludge mixed liquid is returned to the main reaction unit. The above-mentioned main reaction unit and reactor both include anaerobic granular sludge reactors.

2. The wastewater treatment system for anaerobic digestion and simultaneous acclimation of sludge according to claim 1, characterized in that: The reactor in the synchronous acclimation unit includes an upflow anaerobic reactor, the main reaction unit is an EGSB reactor, the upflow anaerobic reactor outputs enhanced sludge mixed liquor to the EGSB reactor, and the EGSB reactor outputs sludge to the upflow reactor; The system realizes anaerobic digestion and sludge synchronous domestication in the process of organic wastewater treatment through a synchronous domestication unit.

3. The wastewater treatment system for anaerobic digestion and simultaneous acclimation of sludge according to claim 1, characterized in that: The system also includes one or any combination of a sedimentation tank, a regulating tank, a mixing and heating tank, a cooling tank and a contact oxidation tank.

4. The wastewater treatment system for anaerobic digestion and simultaneous acclimation of sludge according to claim 1, characterized in that: The reactor and the main reaction unit are provided with a three-phase separator to separate and discharge or collect sludge, water and gas.

5. The wastewater treatment system for anaerobic digestion and simultaneous acclimation of sludge according to claim 1, characterized in that: In this system, the concentration of the nano zero-valent iron mixed liquid in the stirrer of the nano zero-valent iron delivery device is maintained at 1-5 g / L, and nitrogen is introduced before mixing to maintain an oxygen-free state in the mixing tank. The concentration of the nano zero-valent iron in the stirrer is 20-150 mg / L. The concentration of nano zero-valent iron in the synchronous domestication unit is determined according to the biodegradability of the influent. If the BOD5 / COD ratio is ≤0.3, the concentration of nano zero-valent iron in the anaerobic reactor is increased to 120-150 mg / L; if the BOD5 / COD ratio is between 0.3-0.5, the concentration in the anaerobic reactor is adjusted to 60-120 mg / L; if the BOD5 / COD ratio is ≥0.5, the concentration in the anaerobic reactor is controlled at 20-60 mg / L.

6. The wastewater treatment system for anaerobic digestion and simultaneous acclimation of sludge according to claim 5, characterized in that: The size of the nano zero-valent iron in at least one dimension is ≤100 nm.

7. The wastewater treatment system with simultaneous anaerobic digestion and acclimation of sludge according to claim 1, wherein the regulating tank is used to adjust the pH value of the wastewater to 6.5-7.

5.

8. The wastewater treatment system for anaerobic digestion and simultaneous acclimation of sludge according to claim 1, characterized in that: The granular sludge of the synchronous acclimation unit comes from the sludge discharged from the anaerobic reactor or the granular sludge added from outside. When the granular sludge added from outside is used, it shall not exceed 50% of the total sludge in the unit. The synchronous acclimation unit includes discharging old sludge in the reactor unit at a fixed frequency or period, and replenishing it with external granular sludge through the sludge injection port. The frequency or period is determined according to the treatment effect of the organic wastewater.

9. A method for operating a wastewater treatment system with anaerobic sludge digestion and simultaneous acclimation, characterized in that: The method comprises the following steps: the wastewater after pretreatment enters the main reaction unit and the synchronous acclimation unit, wherein the pretreatment comprises wastewater pH value adjustment, mixing and temperature control; in the main reaction unit, the wastewater contacts and reacts with the granular sludge, and the frequency of discharging the granular sludge into the reactor in the synchronous acclimation unit is controlled; The nano zero-valent iron material is stirred and dispersed in the stirrer of the nano zero-valent iron delivery device and continuously input into the reactor to complete the synchronous acclimation operation. The contact between the nano zero-valent iron and the granular sludge in the synchronous acclimation unit is strengthened, and the strengthened granular sludge mixed liquid is lifted into the anaerobic reactor unit.

10. The method for operating a wastewater treatment system for anaerobic digestion and simultaneous acclimation of sludge according to claim 9, characterized in that: The sludge discharge frequency or amount of the main reaction unit in the system is determined according to the volumetric load. The main reaction unit communicates sludge with the synchronous acclimation unit to adjust the treatment capacity and efficiency of the system. According to the treatment effect of organic wastewater, the sludge in the main reaction unit is controlled to enter the synchronous acclimation unit for reinforcement or the synchronous acclimation unit is controlled to supply the main reaction unit.

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