Device for realizing ferrous autotrophic nitrogen removal of wastewater by utilizing bottom mud and starting method

Abstract

The invention relates to a device for realizing wastewater ferrous autotrophic nitrogen removal by using bottom mud and a starting method.The device comprises an inner reaction container, an outer water bath container, a stirring mechanism, a heating module and a temperature control module, the inner reaction container is arranged in the outer water bath container, and the stirring mechanism extends into the inner reaction container from the outside of the outer water bath container; the heating module is arranged in a water bath area between the inner reaction container and the outer water bath container, and a detection part of the temperature control module is arranged in the water bath area between the inner reaction container and the outer water bath container; the inner reaction container is used for placing black and odorous bottom mud, calcium nitrate and ferrous chloride, the black and odorous bottom mud is used as an inoculum, calcium nitrate and ferrous chloride are placed in the inner reaction container in stages, and wastewater ferrous autotrophic nitrogen removal is achieved. According to the device and the starting method disclosed by the invention, the problem of precipitation caused by pH regulation in the traditional ferrous type autotrophic denitrification technology is solved by utilizing the self-buffering capability of bottom mud and optimizing the iron-nitrogen ratio, and the device and the starting method belong to the technical field of biological denitrification.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of biological denitrification, and particularly relates to a device and a starting method for realizing wastewater ferrous autotrophic denitrification by using bottom mud. BACKGROUND

[0002] Nitrate pollution is a key problem in current water environment management, which mainly comes from agricultural drainage, industrial wastewater and domestic sewage. Excessive nitrate not only causes water eutrophication, but also may generate carcinogens such as nitrosamine through transformation, which directly threatens drinking water safety and public health. Therefore, there is an urgent need to develop efficient and economical advanced treatment technology for nitrate wastewater.

[0003] In the biological denitrification technology, autotrophic denitrification technology is concerned because it does not need external organic carbon source and has no secondary pollution risk. Among them, the ferrous autotrophic denitrification technology uses ferrous ions as electron donors to realize the reduction of nitrate under the catalysis of specific microorganisms, and the reaction is as follows: 5Fe 2+ +NO3 - +12H2O→5Fe(OH)3+0.5N2+9H + ; However, the engineering application of this technology still faces major challenges. Existing research generally uses activated sludge as inoculum, in which the inherent abundance of ferrous autotrophic denitrification bacteria is very low, resulting in a long system startup period, which seriously restricts its popularization and application. More importantly, the reaction process produces a large amount of H + , resulting in acidification of the system. In order to maintain the activity of microorganisms, the existing technology must continuously add external alkalinity to neutralize the acid. This operation not only increases the operation cost, but also causes serious iron precipitation problems. In the process of NRFO (ferrous autotrophic denitrification), the intermediate product of nitrate reduction, nitrite, can undergo chemical denitrification with ferrous iron, and generate secondary minerals in and outside the cells of microorganisms, resulting in cell crust, hindering the mass transfer process, inhibiting the activity of microorganisms, and eventually leading to serious performance degradation or even failure of the system after 2-3 months of operation. In addition, the traditional method needs to continuously add soluble ferrous salt as an electron donor, which not only increases the operation cost, but also intensifies the local precipitation risk caused by the instantaneous high concentration of ferrous iron. SUMMARY

[0004] In view of the technical problems existing in the prior art, the purpose of the present application is to provide a device and a starting method for realizing wastewater ferrous autotrophic denitrification by using bottom mud, which utilizes the buffering capacity and optimized iron-nitrogen ratio of the bottom mud to solve the precipitation problem caused by pH adjustment in the traditional ferrous autotrophic denitrification technology.

[0005] In order to achieve the above purpose, the technical scheme adopted by the present application is as follows: The utility model provides a device for realizing wastewater ferrous autotrophic denitrification by using bottom mud, which comprises an inner reaction container, an outer water bath container, a stirring mechanism, a heating module and a temperature control module. The inner reaction container is arranged in the outer water bath container. The stirring mechanism extends into the inner reaction container from outside the outer water bath container. The heating module is arranged in the water bath area between the inner reaction container and the outer water bath container. The detection part of the temperature control module is arranged in the water bath area between the inner reaction container and the outer water bath container. The temperature control module monitors the water temperature in the outer water bath container in real time. The inner reaction container is used for placing black and odorous bottom mud, calcium nitrate and ferrous chloride. The black and odorous bottom mud is used as inoculum. The calcium nitrate and ferrous chloride are placed in the inner reaction container in stages to realize wastewater ferrous autotrophic denitrification.

[0006] As a preferred, the top of the outer water bath container is provided with an opening, the opening is connected with an end cover, the stirring mechanism is installed on the end cover, the stirring end of the stirring mechanism extends into the inner reaction container from the end cover, the end cover is in sealing connection with the top opening of the inner reaction container, the end cover is provided with a feeding port and a nitrogen blowing interface, and the feeding port and the nitrogen blowing interface are in communication with the inner reaction container; the heating end of the heating module extends into the water bath area between the inner reaction container and the outer water bath container from outside the end cover, and the detection part of the temperature control module extends into the water bath area between the inner reaction container and the outer water bath container from outside the end cover.

[0007] As a preferred, the stirring mechanism comprises a driving motor, a shaft coupling and a stirring shaft. The driving motor is installed on the end cover. The output shaft of the driving motor extends into the inner reaction container from the end cover. The shaft coupling is connected with the output shaft of the motor. The stirring shaft is connected with the shaft coupling. The stirring shaft is connected with the shaft coupling.

[0008] As a preferred, the bottom end of the inner reaction container is bonded to the inner wall bottom of the outer water bath container. The sidewall of the inner reaction container is connected with three valves. The three valves are distributed at intervals between the top end and the bottom end of the inner reaction container. The connection part of each valve with the inner reaction container is provided with a first sealing ring. The connection part of each valve with the outer water bath container is provided with a second sealing ring.

[0009] As a preferred, the outer wall of the outer water bath container is wrapped with a heat preservation layer (the heat preservation layer is black sponge, which has the functions of light shielding and heat preservation).

[0010] A starting method for realizing wastewater ferrous autotrophic denitrification by using bottom mud, which adopts the device and comprises the following steps: S1: obtaining black and odorous bottom mud; S2: treating the black and odorous bottom mud; S3: placing the treated black and odorous bottom mud into the inner reaction container, adding calcium nitrate, and taking the calcium nitrate as water inlet substrate to perform a first stage reaction; S4: In the first stage reaction process, the inner reaction container is kept constant temperature at 28-32℃ in dark, DO<0.2 mg / L, and the black and odorous sludge and calcium nitrate are stirred to make the black and odorous sludge and calcium nitrate react, and the reaction time is the first time period T1; S5: When the sulfide reaction is complete and the ferrous content in the black and odorous sludge is unchanged, the second stage reaction is carried out with ferrous chloride as the influent substrate, and the reaction time is the second time period T2; S6: The nitrate concentration in the inner reaction container is increased, and ferrous chloride is added to the inner reaction container to make the black and odorous sludge denitrify.

[0011] As a preferred, in step S2, the method for treating the black and odorous sludge is: filtering the black and odorous sludge with a 10 mesh screen to make it homogeneous, and the filtered black and odorous sludge has a water content of 80%, a pH of 7±0.3, an ORP of-194 mv, an ammonia nitrogen content of 258 mg / kg, and a sulfide content of 2651 mg / kg.

[0012] As a preferred, in step S3, the ratio of the black and odorous sludge to calcium nitrate added to the inner reaction container is 1:1.

[0013] As a preferred, in step S6, the nitrate concentration is increased to 200 mg / L, and the Fe 2+ / N molar ratio in the ferrous chloride is 1-5.

[0014] As a preferred, the starting method further comprises the following steps: by adjusting the Fe 2+ / N molar ratio in the ferrous chloride under the same nitrate concentration, the influence of different Fe 2+ / N molar ratios in the ferrous chloride on the denitrification efficiency is verified.

[0015] Overall, the present application has the following advantages: The device and starting method of the present application have unique advantages by using the black and odorous sludge as the inoculum, including: providing potential functional bacteria that have adapted to high iron concentration environment, which can greatly shorten the acclimation time; the ferrous and sulfide stored in the sludge can be used as electron donors in the initial stage of system starting; the sludge system has natural acid-base buffering capacity, which helps to maintain stable pH. By using the buffering capacity of the black and odorous sludge itself and optimizing the iron-nitrogen ratio, the precipitation problem caused by pH adjustment in the traditional ferrous autotrophic denitrification technology is effectively solved. The stable denitrification performance is maintained under high nitrate load, which shows that the method of the present application has good engineering application potential and provides reliable technical support for efficient and stable nitrate wastewater treatment. BRIEF DESCRIPTION OF DRAWINGS

[0016] Figure 1 This is a schematic diagram of the device.

[0017] Figure 2 This is a graph showing the change in sulfide content over reaction time.

[0018] Figure 3 This is a graph showing the change in nitrate concentration over reaction time.

[0019] Figure 4 This is a graph showing the change in ferrous iron concentration over reaction time.

[0020] Figure 5 The graph shows the changes in nitrate concentration with reaction time under Fe / N ratios of 1, 3, and 5.

[0021] Figure 6 The graph shows the nitrate removal rate as a function of reaction time under the conditions of Fe / N=1, 3, and 5.

[0022] Figure 7 The graph shows the change of ferrous concentration with reaction time under the conditions of Fe / N=1, 3, and 5.

[0023] Figure 8 The graph shows the change in ferrous iron removal rate with reaction time under the conditions of Fe / N=1, 3, and 5.

[0024] Among them, 1 is the outer water bath container, 2 is the inner reaction container, 3 is the drive motor, 4 is the nitrogen purging interface, 5 is the water outlet, 6 is the sampling port, 7 is the stirring shaft, 8 is the water bath area, 9 is the water inlet, 10 is the inclined blade turbine stirring paddle, 11 is the heating module, and 12 is the end cover. Detailed Implementation

[0025] The present invention will now be described in further detail with reference to specific embodiments.

[0026] Example 1 like Figure 1 As shown in the figure, this embodiment provides a device for autotrophic denitrification of wastewater using bottom sludge, including an inner reaction container 2, an outer water bath container 1, a stirring mechanism, a heating module 11, and a temperature control module. The inner reaction container 2 is located inside the outer water bath container 1, and the stirring mechanism extends from the outside of the outer water bath container 1 into the inner reaction container 2. The heating module 11 is located in the water bath area 8 between the inner reaction container 2 and the outer water bath container 1. The detection part of the temperature control module is located in the water bath area 8 between the inner reaction container 2 and the outer water bath container 1, and the temperature control module monitors the water temperature in the outer water bath container 1 in real time. The inner reaction container 2 is used to put black and odorous bottom sludge, calcium nitrate, and ferrous chloride. Using the black and odorous bottom sludge as inoculum, calcium nitrate and ferrous chloride are added to the inner reaction container 2 in stages to achieve autotrophic denitrification of wastewater using ferrous chloride.

[0027] It should be noted that black and odorous sludge is a naturally occurring anaerobic sediment, which is rich in endogenous electron donors such as ferrous ions and sulfides. Using black and odorous sludge as inoculum has unique advantages, including: providing potential functional bacteria that have adapted to high iron concentration environment, which can greatly shorten the acclimation time; the ferrous and sulfide stored in the sludge can be used as electron donors during the initial start-up of the system; the sludge system has natural acid-base buffering capacity, which helps to maintain stable pH of the system. By utilizing the buffering capacity of black and odorous sludge itself and optimizing the iron-nitrogen ratio, the precipitation problem caused by pH adjustment in traditional ferrous autotrophic denitrification technology is effectively solved.

[0028] The top of the outer water bath container 1 is provided with an opening, and the opening is connected with an end cover 12. A stirring mechanism is installed on the end cover 12, and a stirring end of the stirring mechanism extends into the inner reaction container 2 from the end cover 12. The end cover 12 is sealingly connected with the top opening of the inner reaction container 2. The end cover 12 is provided with a dosing port and a nitrogen purging interface 4, both of which are in communication with the inner reaction container 2. The heating end of the heating module 11 extends from the outside of the end cover 12 into the water bath area 8 between the inner reaction container 2 and the outer water bath container 1. The detection part of the temperature control module extends from the outside of the end cover 12 into the water bath area 8 between the inner reaction container 2 and the outer water bath container 1.

[0029] It should be noted that the inner reaction container 2 and the outer water bath container 1 are both hollow cylindrical structures.

[0030] The stirring mechanism includes a driving motor 3, a shaft coupling and a stirring shaft 7. The driving motor 3 is installed on the end cover 12, and the output shaft of the driving motor 3 extends into the inner reaction container 2 from the end cover 12. The shaft coupling is connected with the output shaft of the motor, and the stirring shaft 7 is connected with the shaft coupling. The stirring shaft 7 is connected with inclined blade turbine stirring paddles 10 at intervals in the axial direction. Specifically, the model of the driving motor 3 is JX-25, and the rotating speed is 0-500 rpm.

[0031] The bottom end of the inner reaction container 2 is bonded to the inner wall bottom of the outer water bath container 1. The side wall of the inner reaction container 2 is connected with three valves, which are distributed at intervals from the top end to the bottom end of the inner reaction container 2. Each valve is provided with a first sealing ring at the connection with the inner reaction container 2, and each valve is provided with a second sealing ring at the connection with the outer water bath container 1. Specifically, the three valves are respectively a water outlet 5, a sampling port 6 and a water inlet 9. The water outlet 5, the sampling port 6 and the water inlet 9 are all connected to the inner reaction container 2 from the side wall of the outer water bath container 1, and the sealing is ensured by the sealing connection of the sealing rings.

[0032] The outer wall of the outer water bath container 1 is wrapped with a heat preservation layer. The heat preservation layer is 20mm thick black heat preservation sponge, which has the functions of heat preservation and light shielding, and provides the corresponding environment for the reaction area.

[0033] It should be noted that the heating module 11 uses an existing glass heating rod, such as the readily available Risheng glass heating rod, which has a maximum heating temperature of 34 degrees Celsius. The Risheng glass heating rod integrates a temperature control module with a temperature control range of 18-32 degrees Celsius. The end cap 12 is connected to the top edge of the outer water bath container 1 via screws.

[0034] Specific application examples: The inner reaction vessel 2 has an outer diameter of 180mm, a wall thickness of 5mm, an effective height of 550mm, and a working volume of approximately 12L. The outer water bath vessel 1 has an outer diameter of 300mm, a wall thickness of 5mm, a height of 550mm, and a jacket width of 60mm. A 25W stirring mechanism is installed on the top of the end cap 12, equipped with a double-layered inclined blade turbine impeller 10, rotating at 40rpm to ensure thorough mixing of the black and odorous sediment and liquid. A heating rod is installed in the water bath area 8, working with a temperature control module to maintain the reaction system temperature at 30±2℃. The outer water bath vessel 1 is completely wrapped with a 20mm thick black insulating sponge to achieve light protection and heat preservation. The top of the outer water bath vessel 1 is equipped with a sealed cover, and high-purity nitrogen (DO < 0.2 mg / L) is introduced through a pre-reserved dosing port and nitrogen purging interface 4 to maintain an anaerobic environment.

[0035] Example 2 This embodiment provides a start-up method for achieving ferrous autotrophic denitrification of wastewater using bottom sediment. The start-up method employs a device and includes the following steps: S1: Obtain black and foul-smelling bottom sediment; S2: Treatment of black and smelly bottom sludge; S3: Put the treated black and odorous bottom sludge into the inner reaction vessel 2, add calcium nitrate, and use calcium nitrate as the influent substrate to carry out the first stage reaction; S4: During the first stage of the reaction, the inner reaction vessel 2 is kept at a constant temperature of 28-32℃ in the dark, with DO < 0.2 mg / L, and the black and odorous bottom sludge and calcium nitrate are stirred to allow the black and odorous bottom sludge and calcium nitrate to react. The reaction time is the first time period T1. S5: A sample was taken from inner reaction vessel 2, and the complete reaction of the sulfide was detected (e.g., ...). Figure 2 As shown, when the concentration of sulfide decreased from 2700 to 0 and the ferrous content in the black and odorous sediment remained unchanged, the second stage of reaction was carried out using ferrous chloride as the influent substrate, and the reaction time was the second time period T2. S6: Increase the nitrate concentration in the inner reaction vessel 2 and add ferrous chloride to the inner reaction vessel 2 to denitrify the black and odorous bottom sludge.

[0036] In step S2, the method for treating the black and odorous sediment is: filtering the black and odorous sediment with a 10-mesh screen to make it homogeneous, the moisture content of the filtered black and odorous sediment is 80%, the pH is 7±0.3, the ORP is-194mv, the ammonia nitrogen content is 258mg / kg, the sulfide content is 2651mg / kg, and the ferrous iron content is 12830mg / kg.

[0037] In step S3, the ratio of the black and odorous sediment and calcium nitrate added to the inner reaction container 2 is 1:1.

[0038] In step S6, the Fe 2+ The molar ratio of Fe

[0039] In step S6, the nitrate concentration is increased to 200mg / L.

[0040] The start-up method of the present embodiment uses black and odorous sediment to replace activated sludge as the carrier of ferrous autotrophic denitrification reaction, and based on the composition characteristics of the black and odorous sediment, the strategies of adding calcium nitrate in stages and regulating the Fe / N ratio are used to achieve rapid start-up and stable operation: in the first stage, the sulfide in the sediment is oxidized by calcium nitrate to promote the release and oxidation of ferrous ions in the sediment, and to direct the domestication of ferrous autotrophic denitrification functional flora. In the second stage, when the available ferrous concentration in the sediment decreases and the denitrification rate decreases, the exogenous ferrous salt is added according to the specific iron-nitrogen ratio to continuously maintain the electron donor level of the reaction system, and to complete the efficient domestication of the ferrous autotrophic denitrification flora. The existing technology generally uses activated sludge or specially domesticated denitrification sludge from municipal wastewater treatment plants as inoculum, which has low abundance of ferrous autotrophic denitrification bacteria, slow start-up, and requires continuous addition of alkali for acid production in the reaction, which is high in cost and causes iron precipitation. The reaction of nitrite and ferrous iron generates secondary minerals, causing cell crust, mass transfer obstruction, and system performance decline in the short term. In addition, continuous addition of ferrous salt further exacerbates the problems of precipitation and cost.

[0041] Specific application examples: The black and odorous sediment used in the experiment was taken from a river in a town. There are a large number of residential buildings around the river, and a large amount of domestic wastewater and domestic garbage is discharged into the river, causing the sediment in the river to be in an anaerobic or anoxic environment for a long time, thereby causing black and odorous phenomena. At the time of sampling, a large stainless steel spoon was used to dig the 0~20cm deep sediment with a darker color on the surface of the riverbed, and the collected black and odorous sediment was sealed in a flange barrel to avoid light storage, and then transported back to the laboratory.

[0042] In the first stage, calcium nitrate is used as the only water inlet substrate, the dosage is calculated according to N / (Fe+S)=4.5, the sludge-water ratio is controlled at 1:1, and the total effective volume is 10L. The water inlet is added to the reactor by peristaltic pump, and the reactor is operated under strict anaerobic conditions of constant temperature, light avoidance 30±2℃, mechanical stirring 40rpm, and continuous high-purity nitrogen gas supply to maintain DO<0.2mg / L. IfFigure 2 As shown, when the complete removal of sulfide and the non-significant decrease of ferrous iron concentration were monitored (about 40 days), the first stage was ended; The second stage was started, and the mixed substrate of ferrous chloride (FeCl2·4H2O) and calcium nitrate was added according to the Fe / N molar ratio of 3, and the same environmental conditions were maintained for continuous operation. As shown in Figure 3 As shown, after about 30 days of operation in the second stage, the system showed a significant decrease in NO3 - The removal rate of N reached more than 80%, and the removal rate of ferrous iron was about 83%. In this stage, the activity of functional bacteria was stimulated by adding exogenous ferrous iron. At the initial stage of operation, the denitrification rate may fluctuate due to the reconstruction of microbial community, and directional domestication of the bacterial community needs to be achieved by optimizing the iron-nitrogen ratio. When the system achieves efficient simultaneous removal of nitrate and ferrous iron at a specific iron-nitrogen ratio, it is proved that a stable ferrous autotrophic denitrification system has been formed.

[0043] In the third stage, the nitrate concentration of the influent was increased to 200 mg / L (calculated as NO3 - The Fe 2+ / NO3 - -N molar ratio was 5, and ferrous chloride was added. As shown in Figure 4 Under this condition, the denitrification efficiency of the system reached 99% within 6 days. This result shows that, after domestication in the previous two stages, a high-activity ferrous autotrophic denitrification bacterial community has been successfully enriched, and the system has the ability to treat high-concentration nitrate wastewater. At the same time, the monitoring data show that the pH value of the system during the reaction process is always stable in the range of 6.8-7.5, and there is no sludge activity inhibition phenomenon caused by iron hydroxide precipitation. This verifies that the start-up method of the embodiment effectively solves the precipitation problem caused by pH adjustment in the traditional ferrous autotrophic denitrification technology by utilizing the buffer capacity of the sediment itself and optimizing the iron-nitrogen ratio. The stable denitrification performance is still maintained under a higher nitrate load, which shows that the method has good engineering application potential and provides reliable technical support for efficient and stable nitrate wastewater treatment.

[0044] As shown in Figures 5-8 In the fourth stage, the influence of iron-nitrogen ratio (Fe / N=1, 3, 5) on denitrification efficiency was explored by domesticating the ferrous autotrophic denitrification microbial community. The results show that, in the stable microbial domestication system, the treatment group with Fe / N=5 shows the best nitrate removal effect. This confirms that the microbial community that has been domesticated for a long time can efficiently utilize ferrous iron as an electron donor to realize a stable autotrophic denitrification process. A high Fe / N ratio not only provides sufficient reducing power, but also maintains the metabolic activity of the domesticated microorganisms, thereby significantly improving the denitrification efficiency and stability. The method of the embodiment verifies the effectiveness of the domestication strategy of ferrous autotrophic denitrification microorganisms, and provides a reliable technical path for low carbon-nitrogen ratio wastewater treatment.

[0045] The above embodiments are the preferred embodiments of the present application, but the embodiments of the present application are not limited to the above embodiments, and any changes, modifications, substitutions, combinations, simplifications, etc. made without departing from the spirit and principles of the present application should be equivalent replacement manners and should be included in the protection scope of the present application.

Claims

1. A device for wastewater Fe(II)-autotrophic denitrification using sediment, characterized in that: The device comprises an inner reaction container, an outer water bath container, a stirring mechanism, a heating module and a temperature control module, the inner reaction container is arranged in the outer water bath container, the stirring mechanism extends into the inner reaction container from outside the outer water bath container, the heating module is arranged in the water bath region between the inner reaction container and the outer water bath container, and the detection part of the temperature control module is arranged in the water bath region between the inner reaction container and the outer water bath container, and the temperature control module monitors the water temperature in the outer water bath container in real time; the inner reaction container is used for placing black and odorous sludge, calcium nitrate and ferrous chloride, the black and odorous sludge is used as inoculum, the calcium nitrate and the ferrous chloride are placed in the inner reaction container in stages, and the wastewater ferrous autotrophic denitrification is realized.

2. The device for wastewater Fe(II)-based autotrophic denitrification using sediment according to claim 1, characterized in that: The top of the outer water bath container is provided with an opening, the opening is connected with an end cover, the stirring mechanism is installed on the end cover, the stirring end of the stirring mechanism extends into the inner reaction container from the end cover, the end cover is in sealing connection with the top opening of the inner reaction container, the end cover is provided with a feeding opening and a nitrogen blowing interface, and the feeding opening and the nitrogen blowing interface are in communication with the inner reaction container; the heating end of the heating module extends into the water bath region between the inner reaction container and the outer water bath container from outside the end cover, and the detection part of the temperature control module extends into the water bath region between the inner reaction container and the outer water bath container from outside the end cover.

3. The device for wastewater Fe(II)-autotrophic denitrification using sediment according to claim 2, characterized in that: The stirring mechanism comprises a driving motor, a shaft coupling and a stirring shaft, the driving motor is installed on the end cover, the output shaft of the driving motor extends into the inner reaction container from the end cover, the shaft coupling is connected with the output shaft of the motor, and the stirring shaft is connected with the shaft coupling; wherein the stirring shaft is connected with inclined blade turbine stirring paddles in an axial direction.

4. The device for wastewater Fe(II)-autotrophic denitrification using sediment according to claim 1, characterized in that: The bottom end of the inner reaction container is bonded to the inner wall bottom of the outer water bath container, the side wall of the inner reaction container is connected with three valves, the three valves are distributed at intervals between the top end and the bottom end of the inner reaction container, a first sealing ring is arranged at the connection between each valve and the inner reaction container, and a second sealing ring is arranged at the connection between each valve and the outer water bath container.

5. The device for wastewater Fe(II)-based autotrophic denitrification using sediment according to claim 1, characterized in that: The outer wall of the outer water bath container is wrapped with a heat preservation layer.

6. A method for starting up wastewater Fe(II)-autotrophic denitrification using sediment, characterized in that, The starting method adopts the device of any one of claims 1-5, and comprises the following steps: S1: obtaining black and odorous sludge; S2: treating the black and odorous sludge; S3: placing the treated black and odorous sludge into the inner reaction container, adding calcium nitrate, and taking the calcium nitrate as water feeding substrate to perform a first stage reaction; S4: during the first stage reaction, the inner reaction container is kept constant temperature at 28-32 DEG C in the dark, DO < 0.2 mg / L, and the black and odorous sludge and the calcium nitrate are stirred to make the black and odorous sludge and the calcium nitrate react, and the reaction time is a first time period T1; S5: when it is detected that the sulfide reaction is complete and the ferrous content in the black and odorous sludge is unchanged, taking ferrous chloride as water feeding substrate to perform a second stage reaction, and the reaction time is a second time period T2; S6: increasing the nitrate concentration in the inner reaction container, and adding ferrous chloride into the inner reaction container to make the black and odorous sludge denitrify.

7. The start-up method for achieving ferrous autotrophic denitrification of wastewater using bottom sediment according to claim 6, characterized in that, In step S2, the method for treating the black and odorous sediment is: filtering the black and odorous sediment with a 10-mesh screen to make it homogeneous, and the filtered black and odorous sediment has a water content of 80%, a pH of 7±0.3, an ORP of-194 mv, an ammonia nitrogen content of 258 mg / kg, a sulfide content of 2651 mg / kg, and a ferrous iron content of 12830 mg / kg.

8. The start-up method for achieving ferrous autotrophic denitrification of wastewater using bottom sediment according to claim 6, characterized in that: In step S3, the ratio of the black and odorous sediment to calcium nitrate added to the inner reaction container is 1:

1.

9. The start-up method for achieving ferrous autotrophic denitrification of wastewater using bottom sediment according to claim 6, characterized in that: In step S6, the nitrate concentration is increased to 200 mg / L and the Fe 2+ / N molar ratio is 1-5.

10. The start-up method for achieving ferrous autotrophic denitrification of wastewater using bottom sediment according to claim 6, characterized in that: The start-up method further comprises the following steps: verifying the influence of different Fe 2+ / N molar ratios in the ferrous chloride on the denitrification efficiency under the condition of the same nitrate concentration. 2+ / N molar ratios in the ferrous chloride on the denitrification efficiency.

Images