System for simultaneous removal of ammonia and nitrate from low c / n wastewater

Abstract

The embodiment of the application discloses a low C / N sewage ammonia nitrogen and nitrate nitrogen synchronous removal system, which comprises an anoxic reactor, an aerobic reactor and a sedimentation module, the anoxic reactor and the aerobic reactor are connected in series, the slow-release carbon filler is filled in the anoxic reactor, the slow-release carbon filler provides a microbial attachment carrier and realizes catalytic degradation of ammonia nitrogen through iron and manganese oxides. The slow-release carbon filler realizes anaerobic ammonia oxidation under the cooperation of denitrification and Fe and Mn in the anoxic reactor, so that the ammonia nitrogen and the nitrate nitrogen in the sewage are synchronously removed. The load type biofilm filler is arranged in the aerobic reactor, the activated sludge is recycled through the sedimentation reflux device on the basis of further control of tail water COD, and the Fe and Mn catalysts are efficiently recycled. Through the low C / N sewage ammonia nitrogen and nitrate nitrogen synchronous removal system provided by the embodiment of the application, efficient denitrification of the low C / N sewage is realized. The denitrification process does not need to add an additional carbon source, the sludge reflux amount is small, and the ammonia nitrogen and the nitrate nitrogen can be synchronously removed.

Description

TECHNICAL FIELD

[0001] The embodiment of the present application relates to sewage denitrification technical field, especially to a low C / N sewage ammonia nitrogen and nitrate nitrogen synchronous removal system. BACKGROUND

[0002] At present, there are various treatment methods for nitrogen pollutants in sewage, mainly divided into physical and chemical method and biological method. Among them, the physical and chemical method includes electrodialysis method, ion membrane electrolysis method and stripping method, etc., but these treatment methods have some shortcomings, such as high operation cost, difficult to maintain, easy to produce secondary pollution and the like. Biological denitrification is the most widely used denitrification technology at present, and the process needs nitrification and denitrification to realize. But because the nitrification process is an aerobic process, and the denitrification is an anoxic process, therefore, firstly, the nitrification of ammonia nitrogen is realized by the aerobic process, and then the denitrification is realized by the anoxic process, so as to realize the removal of nitrogen pollutants in sewage. At the same time, a large amount of carbon source is needed in the denitrification process, and the carbon source needs to be added in the low C / N wastewater to ensure the smooth progress of the denitrification.

[0003] The traditional treatment process cannot achieve the purpose of simultaneous removal of ammonia nitrogen and nitrate nitrogen, in order to further reduce the energy consumption in the denitrification process, we need to find a method for simultaneous removal of ammonia nitrogen and nitrate nitrogen. SUMMARY

[0004] The present application aims at least to solve one of the problems in the prior art or related art.

[0005] Therefore, the embodiment of the present application provides a low C / N sewage ammonia nitrogen and nitrate nitrogen synchronous removal system, which comprises:

[0006] An anoxic reactor;

[0007] An aerobic reactor, the anoxic reactor is connected in series with the aerobic reactor;

[0008] A sedimentation module, the sedimentation module is connected to the output end of the aerobic reactor;

[0009] Slow-release carbon filler, the slow-release carbon filler is filled in the anoxic reactor;

[0010] Load type biofilm filler, the load type biofilm filler is filled in the aerobic reactor.

[0011] In a feasible implementation, the material for preparing the slow-release carbon filler comprises slow-release organic matter doped high-valence iron and manganese oxide.

[0012] In a feasible implementation, the material for preparing the load type biofilm filler comprises polyurethane loaded high-valence iron and manganese oxide.

[0013] In an embodiment, the system for simultaneous removal of ammonia and nitrate in low C / N wastewater further comprises an electrode assembly, wherein the electrode assembly comprises:

[0014] an inert anode plate disposed in the aerobic reactor;

[0015] an inert cathode plate disposed in the aerobic reactor;

[0016] a stabilized power supply connected to the inert anode plate and the inert cathode plate.

[0017] In an embodiment, the system for simultaneous removal of ammonia and nitrate in low C / N wastewater further comprises an aeration assembly, wherein the aeration assembly comprises an aerator and at least two aeration heads, the aerator is connected to the aeration heads, and the aeration heads are disposed in the aerobic reactor.

[0018] In an embodiment, the system for simultaneous removal of ammonia and nitrate in low C / N wastewater further comprises a water inlet pipe connected to the anoxic reactor.

[0019] In an embodiment, the system for simultaneous removal of ammonia and nitrate in low C / N wastewater further comprises:

[0020] a sludge recovery system connected to the bottom of the anoxic reactor and the aerobic reactor.

[0021] In an embodiment, a vent hole is formed at the top of the anoxic reactor.

[0022] In an embodiment, a water outlet is formed at the top of the sedimentation module.

[0023] In an embodiment, the middle and upper part of the anoxic reactor is connected in series to the aerobic reactor.

[0024] Compared with the prior art, the present application has at least the following advantages:

[0025] The low C / N sewage ammonia nitrogen and nitrate nitrogen synchronous removal system provided by the embodiment of the application comprises an anoxic reactor, an aerobic reactor and a sedimentation module, the anoxic reactor and the aerobic reactor are connected in series, and the anoxic reactor is filled with slow-release carbon filler, which provides a microbial attachment carrier and realizes catalytic degradation of ammonia nitrogen through iron and manganese oxides. In the anoxic reactor, denitrification and anaerobic ammonia oxidation under the cooperation of Fe and Mn are realized through the slow-release carbon filler, so that the ammonia nitrogen and nitrate nitrogen in the sewage are simultaneously removed. In the aerobic reactor, a load type biofilm filler is arranged, on the basis of further controlling the tail water COD, the activated sludge is recycled through a sedimentation backflow device, and the Fe and Mn catalysts are efficiently recycled. The low C / N sewage ammonia nitrogen and nitrate nitrogen synchronous removal system provided by the embodiment of the application realizes efficient denitrification of low C / N sewage. The denitrification process does not need to add additional carbon source, the sludge backflow amount is small, and the simultaneous removal of ammonia nitrogen and nitrate nitrogen can be realized, so that the low C / N sewage treatment field containing ammonia nitrogen and nitrate nitrogen has a broad application prospect. BRIEF DESCRIPTION OF DRAWINGS

[0026] Various other advantages and benefits will become apparent to those of ordinary skill in the art upon reading the following detailed description of the preferred embodiments. The accompanying drawings are included to provide a description of the preferred embodiments and are not intended to limit the scope of the application. Moreover, the same reference numerals are used throughout the same figures. In the drawings:

[0027] Figure 1 FIG. 1 is a schematic structural diagram of a low C / N sewage ammonia nitrogen and nitrate nitrogen synchronous removal system according to an embodiment of the application.

[0028] wherein, Figure 1 The correspondence between the reference signs and the component names in the drawings is as follows:

[0029] 1 anoxic reactor, 2 aerobic reactor, 3 sedimentation module, 4 slow-release carbon filler, 5 load type biofilm filler, 6 inert cathode plate, 7 inert anode plate, 8 voltage stabilizing power supply, 9 aerator, 10 aeration head, 11 water inlet pipe, 12 sludge backflow pump, 13 air vent, 14 water outlet. DETAILED DESCRIPTION

[0030] In order to better understand the above technical solutions, the technical solutions of the embodiments of the application will be described in detail below with reference to the drawings and specific embodiments. It should be understood that the specific features in the embodiments of the application and the embodiments are detailed descriptions of the technical solutions of the embodiments of the application, and are not limitations of the technical solutions of the application. In the case of no conflict, the technical features in the embodiments of the application and the embodiments can be combined with each other.

[0031] As Figure 1As shown, the embodiment of the present application proposes a low C / N wastewater ammonia nitrogen and nitrate synchronous removal system, comprising: an anoxic reactor 1; an aerobic reactor 2, the anoxic reactor 1 and the aerobic reactor 2 are connected in series; a sedimentation module 3, the sedimentation module 3 is communicated with the output end of the aerobic reactor 2; a slow-release carbon filler 4, the slow-release carbon filler 4 is filled in the anoxic reactor 1; a load type biofilm filler 5, the load type biofilm filler 5 is filled in the aerobic reactor 2.

[0032] The low C / N wastewater ammonia nitrogen and nitrate synchronous removal system provided by the embodiment of the present application comprises an anoxic reactor 1, an aerobic reactor 2 and a sedimentation module 3, the anoxic reactor 1 and the aerobic reactor 2 are connected in series, and the slow-release carbon filler 4 is filled in the anoxic reactor 1, which provides a microbial attachment carrier and realizes catalytic degradation of ammonia nitrogen through iron and manganese oxides. The anoxic reactor 1 realizes anaerobic ammonia oxidation under the cooperation of denitrification and Fe and Mn, thereby realizing the synchronous removal of ammonia nitrogen and nitrate in wastewater. The load type biofilm filler 5 is arranged in the aerobic reactor 2, which realizes the reuse of activated sludge and the efficient recovery of Fe and Mn catalysts through the sedimentation reflux device on the basis of further controlling the tail water COD. The low C / N wastewater ammonia nitrogen and nitrate synchronous removal system provided by the embodiment of the present application realizes efficient denitrification of low C / N wastewater. The denitrification process does not need to add carbon source, the sludge reflux amount is small, and the synchronous removal of ammonia nitrogen and nitrate can be realized, which has a wide application prospect in the field of low C / N wastewater treatment containing ammonia nitrogen and nitrate.

[0033] In some examples, the slow-release carbon filler 4 can use mixed powder of rice straw and corn cob as core carbon release substrate, biodegradable high molecular polymer polyvinyl alcohol as binder, and bond the mixed powder and high-valence iron and manganese oxides into spherical carbon release fillers, and the load type biofilm filler 5 is formed by polyurethane sponge loaded with high-valence iron and manganese oxides.

[0034] The denitrification mechanism of the low C / N wastewater ammonia nitrogen and nitrate synchronous removal system is that the slow-release carbon filler 4 in the anoxic reactor 1 provides carbon source for denitrifying bacteria, and realizes effective degradation of nitrate through the denitrification process. The high-valence Fe and Mn oxides doped in the filler in the anoxic reactor 1 realize iron and manganese mediated anaerobic ammonia oxidation through electron acquisition, thereby removing ammonia nitrogen in wastewater. Finally, the synchronous removal of nitrate and ammonia nitrogen is realized under the cooperation of microorganisms in the anoxic reactor 1. The biofilm electrode operation mode is constructed in the aerobic reactor 2, the dissolved oxygen is increased through aeration to further realize the control of COD and the recovery of Fe and Mn catalysts, and the high-valence iron and manganese oxides added in the filler can induce iron and manganese oxidation function bacteria to enrich, thereby realizing further control of effluent ammonia nitrogen and COD on the basis of improving the recovery rate of catalysts.

[0035] Furthermore, both the slow-release carbon packing 4 and the supported biofilm packing 5 can serve as carriers for microbial attachment, increasing the microbial population within the device. Simultaneously, the slow-release carbon packing 4 not only provides a carbon source for denitrification, but the doped high-valence iron-manganese oxides also act as electron shuttles, enhancing electron migration efficiency during the denitrification process and thus improving denitrification efficiency.

[0036] In one feasible implementation, the material used to prepare the slow-release carbon filler 4 includes slow-release organic matter doped with high-valence iron-manganese oxides.

[0037] This technical solution further provides materials for preparing the slow-release carbon packing 4. By selecting high-valence iron-manganese oxides doped with slow-release organic matter, the anoxic reactor 1 can simultaneously provide a carrier for microbial attachment and achieve catalytic degradation of ammonia nitrogen through the iron-manganese oxides. In the anoxic reactor 1, the slow-release carbon packing 4 enables denitrification and anaerobic ammonia oxidation under the synergistic effect of Fe and Mn, thereby achieving the simultaneous removal of ammonia nitrogen and nitrate nitrogen from wastewater.

[0038] In one feasible embodiment, the material used to prepare the supported biofilm packing 5 includes polyurethane-supported high-valence iron-manganese oxide.

[0039] In this technical solution, materials for preparing the supported biofilm packing 5 are further provided. By selecting polyurethane-supported high-valence iron and manganese oxides, the aerobic reaction can further control the COD of the effluent and achieve the reuse of activated sludge through a sedimentation reflux device, thereby realizing the efficient recovery of Fe and Mn catalysts.

[0040] like Figure 1 As shown, in one feasible embodiment, the low C / N wastewater ammonia nitrogen and nitrate nitrogen simultaneous removal system further includes: an electrode assembly, which includes: an inert cathode plate 6, which is disposed in the aerobic reactor 2; an inert anode plate 7, which is disposed in the aerobic reactor 2; and a regulated power supply 8, which is connected to the inert cathode plate 6 and the inert anode plate 7.

[0041] In this technical solution, the low C / N wastewater ammonia nitrogen and nitrate nitrogen simultaneous removal system also includes an electrode assembly. Through the configuration of an inert cathode plate 6, an inert anode plate 7, and a regulated power supply 8, a biofilm electrode operating mode can be constructed, improving the catalyst recovery rate. Under the enhancement of the biofilm electrode, the aerobic reactor 2 achieves the re-oxidation and recovery of low-valence iron and manganese dissolved in the anoxic reactor 1, and degrades leaked organic matter. The catalytically activated sludge containing iron and manganese oxides regenerated in the aerobic reactor 2 is recycled and reused through the sludge return pump 12 of the sedimentation module 3.

[0042] It can be understood that the inert cathode plate 6 and the inert anode plate 7 can be arranged on both sides of the load type biofilm filler 5 respectively to improve the treatment efficiency.

[0043] As shown in Figure 1 In a feasible embodiment, the low C / N sewage ammonia nitrogen and nitrate nitrogen synchronous removal system further comprises an aeration assembly, the aeration assembly comprises an aerator 9 and at least two aeration heads 10, the aerator 9 is connected to the aeration heads 10, and the aeration heads 10 are arranged in the aerobic reactor 2.

[0044] In the technical scheme, the low C / N sewage ammonia nitrogen and nitrate nitrogen synchronous removal system further comprises the aeration assembly, through the arrangement of the aerator 9 and the aeration heads 10, the aerobic reactor 2 can be operated in an aerobic filtration mode through aeration, and the treatment efficiency is improved.

[0045] In a feasible embodiment, the low C / N sewage ammonia nitrogen and nitrate nitrogen synchronous removal system further comprises a water inlet pipe 11, the water inlet pipe 11 is communicated to the anoxic reactor 1. In this way, the supply of sewage is facilitated.

[0046] In a feasible embodiment, the low C / N sewage ammonia nitrogen and nitrate nitrogen synchronous removal system further comprises a sludge backflow pump 12, the sludge backflow pump 12 is communicated to the bottom of the anoxic reactor 1 and the aerobic reactor 2.

[0047] In the technical scheme, the low C / N sewage ammonia nitrogen and nitrate nitrogen synchronous removal system further comprises the sludge backflow pump 12. Through the arrangement of the sludge backflow pump 12, the sludge generated in the aerobic reactor 2 can be backflowed, and the recycling of the sludge and the active iron-manganese oxides is realized

[0048] As shown in Figure 1 In a feasible embodiment, the top of the anoxic reactor 1 is formed with a gas vent 13. In this way, the operation of the anoxic reactor 1 is safer.

[0049] As shown in Figure 1 In a feasible embodiment, the top of the sedimentation module 3 is formed with a water outlet 14. In this way, the discharge of the liquid treated is facilitated.

[0050] In a feasible embodiment, the middle upper part of the anoxic reactor 1 is connected to the aerobic reactor 2. In this way, the liquid treated by the anoxic reactor 1 can flow into the aerobic reactor 2.

[0051] Embodiment:

[0052] As shown in Figure 1As shown, a low C / N wastewater ammonia nitrogen and nitrate synchronous removal system is provided, which comprises an anoxic reactor 1, an aerobic reactor 2, an activated sludge sedimentation zone and a sludge return device. The anoxic reactor 1 is filled with slow-release carbon filler 4, and the aerobic reactor 2 is filled with load-type biofilm filler 5. The aerobic reactor 2 is in an aerobic state by aeration.

[0053] In this example, rice straw and corn cob are pretreated respectively, mixed in a ratio of 1:1 as the core carbon release substrate of the carbon release filler, and high molecular polyvinyl alcohol is used as the binder to bond it with Fe3O4 and Mn3O4 into a spherical carbon release filler with a diameter of (15±0.2) mm. The component ratio of rice straw powder, corn cob powder, high molecular polyvinyl alcohol, Fe3O4 and Mn3O4 is 1.5:1.5:1:0.028:0.028. The microbial domestication time is 30 days, the ammonia nitrogen concentration of the influent is 19.83 mg / L-21.64 mg / L, the nitrate nitrogen concentration is 48.73 mg / L-51.69 mg / L, the hydraulic retention time of the process is 3 hours, and the sludge return ratio is 30%.

[0054] In this embodiment, the ammonia nitrogen concentration of the effluent of the low C / N wastewater ammonia nitrogen and nitrate synchronous removal system is 1.29 mg / L-2.21 mg / L, the nitrate nitrogen concentration of the effluent is 4.23 mg / L-5.02 mg / L, the average ammonia nitrogen removal rate can reach 90.87%, and the average nitrate nitrogen removal rate can reach 90.79%. The COD concentration of the effluent flowing from the anoxic reactor 1 into the aerobic reactor 2 increases by 14.21-16.53 mg / L, and the COD concentration of the effluent of the aerobic reactor 2 decreases by 13.51-18.42 mg / L. On the basis of achieving high-efficiency synchronous removal of ammonia nitrogen and nitrate, the effluent COD leakage is controlled.

[0055] In summary, the present application provides a low C / N wastewater ammonia nitrogen and nitrate synchronous removal system, which comprises an anoxic reactor 1, an aerobic reactor 2, an activated sludge sedimentation zone and a sludge return device. The anoxic reactor 1 is filled with slow-release carbon filler 4, and the aerobic reactor 2 is filled with load-type biofilm filler 5. The anoxic reactor 1, the aerobic reactor 2 and the activated sludge sedimentation zone are connected in series from left to right, an aeration system is provided in the aerobic reactor 2 to increase the dissolved oxygen content therein, an electrode is provided in the aerobic reactor 2 to promote the generation of iron and manganese solid-phase catalysts, and a sludge return pump is provided in the aerobic reactor 2 to recover the activated catalysts containing biological iron and manganese oxides.

[0056] The low C / N wastewater ammonia nitrogen and nitrate synchronous removal system can achieve high-efficiency synchronous removal of ammonia nitrogen and nitrate in low C / N wastewater, has the advantages of remarkable denitrification effect, simple operation and easy running and management, and is suitable for the technical field of low C / N wastewater denitrification.

[0057] In the present application, the terms "first", "second", "third" are used only for descriptive purposes and are not to be construed as indicating or implying relative importance of the indicated elements. The term "a plurality" refers to two or more, unless otherwise expressly specified. The terms "mounting", "connected", "connecting", "fixed", and the like are to be construed broadly in accordance with ordinary usage of these terms, for example, "connected" can be fixedly connected, or removably connected, or integrally connected, "connected" can be directly connected, or indirectly connected through an intermediate medium. For those skilled in the art, the specific meanings of the above terms in the present application can be understood according to the specific circumstances.

[0058] In the description of the present application, it should be understood that the terms "upper", "lower", "left", "right", "front", "back", and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only for the purpose of facilitating the description of the present application and simplifying the description, and do not indicate or imply that the device or unit referred to must have a particular direction, be constructed and operated in a particular orientation, therefore, it cannot be understood as a limitation of the present application.

[0059] In the description of the present application, the terms "one embodiment", "some embodiments", "a specific embodiment", and the like, mean that the specific features, structures, materials or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present application. In the present specification, the illustrative description of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

[0060] The above is only the preferred embodiment of the present application, and is not intended to limit the present application. For those skilled in the art, the present application can have various modifications and changes. Any modification, equivalent replacement, improvement, etc. made within the spirit and principles of the present application shall be included in the protection scope of the present application.

Claims

1. A low C / N sewage ammonia nitrogen and nitrate nitrogen synchronous removal system, characterized in that, It comprises: an anoxic reactor; an aerobic reactor, the anoxic reactor being connected in series with the aerobic reactor; a sedimentation module, the sedimentation module being connected to the output end of the aerobic reactor; slow-release carbon filler, the slow-release carbon filler being filled in the anoxic reactor; supported biofilm filler, the supported biofilm filler being filled in the aerobic reactor; the material for preparing the slow-release carbon filler comprises slow-release organic matter doped high-valence iron-manganese oxide; the material for preparing the supported biofilm filler comprises polyurethane-supported high-valence iron-manganese oxide; an electrode assembly, the electrode assembly comprising: an inert anode plate, the inert anode plate being arranged in the aerobic reactor; an inert cathode plate, the inert cathode plate being arranged in the aerobic reactor; a stabilized power supply, the stabilized power supply being connected to the inert anode plate and the inert cathode plate; wherein, the low C / N sewage ammonia nitrogen and nitrate nitrogen synchronous removal method comprises: pretreating rice straw and corn cob respectively, then mixing them in a ratio of 1:1 to serve as the core carbon release base material of the carbon release filler, and using high molecular polyvinyl alcohol as a binder to bond the core carbon release base material with Fe3O4 and Mn3O4 into a spherical carbon release filler, the diameter of the spherical carbon release filler being 14.8mm to 15.2mm; wherein the component ratio of the rice straw powder, the corn cob powder, the high molecular polyvinyl alcohol, and Fe3O4 and Mn3O4 is 1.5:1.5:1:0.028:0.028; the microbial domestication time is 30 days, the ammonia nitrogen concentration of the influent during the experiment period is 19.83mg / L-21.64mg / L, the nitrate nitrogen concentration is 48.73mg / L-51.69mg / L, the process hydraulic retention time is 3 hours, and the sludge return ratio is 30%.

2. The low C / N sewage ammonia nitrogen and nitrate nitrogen synchronous removal system according to claim 1, characterized in that, It further comprises an aeration assembly, the aeration assembly comprising an aerator and at least two aeration heads, the aerator being connected to the aeration heads, and the aeration heads being arranged in the aerobic reactor.

3. The low C / N sewage ammonia-nitrogen and nitrate-nitrogen synchronous removal system according to claim 1, characterized in that, It further comprises: an influent pipe, the influent pipe being connected to the anoxic reactor.

4. The low C / N sewage ammonia-nitrogen and nitrate-nitrogen synchronous removal system according to claim 1, characterized in that, It further comprises: a sludge recovery system, the sludge recovery system being connected to the bottom of the anoxic reactor and the aerobic reactor.

5. The low C / N sewage ammonia nitrogen and nitrate nitrogen synchronous removal system according to claim 1, wherein a gas vent is formed at the top of the anoxic reactor.

6. The low C / N sewage ammonia nitrogen and nitrate nitrogen synchronous removal system according to claim 1, wherein a water outlet is formed at the top of the sedimentation module.

7. The low C / N sewage ammonia nitrogen and nitrate nitrogen synchronous removal system according to claim 1, wherein the middle upper part of the anoxic reactor is connected in series with the aerobic reactor.

Images