Aramid fiber production wastewater treatment system

Abstract

The utility model discloses a treatment system for aramid fiber production wastewater. The treatment system comprises a first physicochemical treatment unit, a biochemical treatment unit and a second physicochemical treatment unit, a water outlet of the flocculation sedimentation tank of the first physicochemical treatment unit is communicated with a water inlet of the anaerobic tank of the biochemical treatment unit, and a produced water outlet of the biological aerated filter of the biochemical treatment unit is communicated with a water inlet of the disinfection tank of the second physicochemical treatment unit. The sewage treatment device has the advantages that firstly, large suspended matters, floating matters and a part of organic matters and colloids are removed through the first physicochemical treatment unit, and the biodegradability of wastewater is improved; organic matters and ammonia nitrogen in the water body can be further reduced through the biochemical treatment unit, and biological membranes and suspended particles which fall off after biological treatment are removed. And finally, the water body is disinfected and finely filtered by the second physicochemical treatment unit, so that the obtained clear water can meet the discharge requirement, and the pollution to the environment can be avoided.

Description

Technical field:

[0001] The utility model relates to a wastewater treatment system, in particular to a treatment system for aramid production wastewater. Background technology:

[0002] N,N-dimethylacetamide (DMAc) is an excellent organic solvent widely used in the production of aramid fibers. In the process of aramid fiber production, a large amount of production wastewater containing DMAc is generated, and the content of DMAc in the wastewater is as high as 40-50%. Usually, most of the DMAc can be recovered by distillation or extraction, but after recovery, wastewater containing a certain amount of DMAc will still be generated. At the same time, some pure water equipment will also produce concentrated water during operation. In the end, all the production wastewater is collected together, which is called aramid production wastewater. It has the characteristics of high COD (≥8000mg / L) and high BOD (≥1500mg / L), and is one of the difficult-to-treat industrial wastewaters.

[0003] At present, the main methods for treating this type of wastewater are physicochemical method, biological method and advanced oxidation method. Physicochemical method is often used as a pretreatment for this type of wastewater to reduce the toxicity of the wastewater and improve its biodegradability, mainly including adsorption, flotation, coagulation sedimentation and stripping. Biological method is widely used in the deep treatment of this type of wastewater, which is mainly divided into two categories: anaerobic and aerobic. It is the most economical and least polluting method. However, the removal rate of pollutants by physicochemical and biological methods is low, and the treatment effect is also poor. Advanced oxidation method has the characteristics of thorough oxidation, high efficiency and safety. Common advanced oxidation methods include ozone oxidation, Fenton oxidation, electrocatalytic oxidation and photocatalytic oxidation. This method also has limitations and cannot achieve harmless discharge of wastewater and meet treatment standards. Utility model content:

[0004] In order to solve the above problems, the purpose of the utility model is to provide a treatment system for aramid production wastewater.

[0005] The utility model is implemented by the following technical solutions:

[0006] A treatment system for aramid production wastewater, comprising a first physicochemical treatment unit, a biochemical treatment unit and a second physicochemical treatment unit;

[0007] The water outlet of the flocculation sedimentation tank of the first physicochemical treatment unit is connected to the water inlet of the anaerobic tank of the biochemical treatment unit, and the water output outlet of the aerated biological filter of the biochemical treatment unit is connected to the water inlet of the disinfection tank of the second physicochemical treatment unit.

[0008] Furthermore, the first physicochemical treatment unit includes a water collection well, an aeration regulating tank, and a flocculation sedimentation tank;

[0009] The water outlet of the water collection well is connected to the water inlet of the aeration regulating tank, the water outlet of the aeration regulating tank is connected to the inlet of the first sewage pump, and the outlet of the first sewage pump is connected to the water inlet of the flocculation sedimentation tank;

[0010] The liquid outlet of the nutrient solution storage tank is connected to the water inlet of the aeration regulating tank; the liquid outlets of the PAC storage tank and the PAM storage tank are both connected to the inlet of the flocculation sedimentation tank through pipelines.

[0011] Furthermore, a grille is provided at the water inlet of the water collection well.

[0012] Furthermore, the biochemical treatment unit includes an anaerobic tank, an anoxic tank, an aerobic tank, a secondary sedimentation tank, an intermediate tank and an aerated biological filter;

[0013] The water outlet of the anaerobic tank is connected to the water inlet of the anoxic tank, the water outlet of the anoxic tank is connected to the water inlet of the aerobic tank, the overflow of the aerobic tank is connected to the water inlet of the secondary sedimentation tank, the supernatant outlet of the secondary sedimentation tank is connected to the water inlet of the intermediate tank, the water outlet of the intermediate tank is connected to the water inlet of the second sewage pump, and the water outlet of the second sewage pump is connected to the water inlet of the aerated biological filter.

[0014] Furthermore, the overflow port of the aerobic tank is also connected to the water inlet of the reflux pump, and the water outlet of the reflux pump is connected to the water inlet of the anoxic tank.

[0015] Furthermore, the water outlet of the anaerobic tank is also connected to the water inlet of the anaerobic circulation pump, and the water outlet of the anaerobic circulation pump is connected to the water inlet of the anaerobic tank.

[0016] Furthermore, the second physicochemical treatment unit includes a disinfection tank, a primary activated carbon filter, a secondary activated carbon filter and a clear water tank;

[0017] The water outlet of the disinfection tank is connected to the water inlet of the third sewage pump, the water outlet of the third sewage pump is connected to the water inlet of the primary activated carbon filter, the water output outlet of the primary activated carbon filter is connected to the water inlet of the secondary activated carbon filter, and the water output outlet of the secondary activated carbon filter is connected to the water inlet of the clean water tank;

[0018] The gas outlet of the chlorine dioxide generating device is connected with one end of the connecting pipe, and the other end of the connecting pipe is placed below the liquid level in the disinfection pool.

[0019] Furthermore, the water outlet of the backwash water tank is connected to the water inlet of the first backwash water pump, the water outlet of the first backwash water pump is connected to the backwash water inlet at the bottom of the aerated biological filter, and the backwash water outlet at the top of the aerated biological filter is connected to the water inlet of the aeration regulating tank of the first physicochemical treatment unit.

[0020] Furthermore, the water outlet of the backwash water tank is also connected to the water inlet of the second backwash water pump, and the water outlet of the second backwash water pump is divided into two paths, one path is connected to the output water outlet of the first-level activated carbon filter, and the other path is connected to the output water outlet of the second-level activated carbon filter; the water inlet of the first-level activated carbon filter and the water inlet of the second-level activated carbon filter are both connected to the water inlet of the aeration regulating tank of the first physicochemical treatment unit through a pipeline.

[0021] Advantages of the utility model:

[0022] The utility model first removes larger suspended matter, floating matter, and a part of organic matter and colloid through the first physicochemical treatment unit, and increases the biodegradability of wastewater, providing basic conditions for the subsequent biochemical treatment unit to perform biochemical treatment, thereby improving the treatment effect of the biochemical treatment unit. Afterwards, the biochemical treatment unit can further reduce the organic matter and ammonia nitrogen in the water body, and remove the biofilm and suspended particles that fall off after biological treatment. Finally, after the water body is disinfected and finely filtered by the second physicochemical treatment unit, the obtained clean water can meet the discharge requirements and avoid pollution to the environment. Description of the drawings:

[0023] In order to more clearly illustrate the embodiments of the utility model or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the utility model. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0024] Figure 1 This is a schematic diagram of system connection of Example 1.

[0025] In the figure: a first physicochemical treatment unit 1, a water collection well 11, an aeration regulating tank 12, a first sewage pump 13, a flocculation sedimentation tank 14, a nutrient solution storage tank 15, a PAC storage tank 16, a PAM storage tank 17, a biochemical treatment unit 2, an anaerobic tank 21, an anoxic tank 22, an aerobic tank 23, a secondary sedimentation tank 24, an intermediate tank 25, a second sewage pump 26, an aerated biological filter 27, a reflux pump 28, an anaerobic circulation pump 29, a second physicochemical treatment unit 3, a disinfection tank 31, a third sewage pump 32, a primary activated carbon filter 33, a secondary activated carbon filter 34, a clear water tank 35, a chlorine dioxide generator 36, a backwash water tank 4, a first backwash water pump 5, and a second backwash water pump 6. Specific implementation method:

[0026] The following will be combined with the drawings in the embodiments of the utility model to clearly and completely describe the technical solutions in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0027] Embodiment 1:

[0028] like Figure 1 The treatment system of aramid production wastewater shown in the figure includes a first physicochemical treatment unit 1, a biochemical treatment unit 2 and a second physicochemical treatment unit 3; wherein the first physicochemical treatment unit 1 includes a water collection well 11, an aeration regulating tank 12 and a flocculation sedimentation tank 14; the biochemical treatment unit 2 includes an anaerobic tank 21, an anoxic tank 22, an aerobic tank 23, a secondary sedimentation tank 24, an intermediate tank 25 and an aerated biological filter 27; the second physicochemical treatment unit 3 includes a disinfection tank 31, a primary activated carbon filter 33, a secondary activated carbon filter 34 and a clear water tank 35.

[0029] The water outlet of the water collection well 11 is connected with the water inlet of the aeration regulating tank 12, the water outlet of the aeration regulating tank 12 is connected with the inlet of the first sewage pump 13, and the outlet of the first sewage pump 13 is connected with the water inlet of the flocculation sedimentation tank 14; the water outlet of the flocculation sedimentation tank 14 is connected with the water inlet of the anaerobic tank 21, the water outlet of the anaerobic tank 21 is connected with the water inlet of the anoxic tank 22, the water outlet of the anoxic tank 22 is connected with the water inlet of the aerobic tank 23, the overflow of the aerobic tank 23 is connected with the water inlet of the secondary sedimentation tank 24, the supernatant outlet of the secondary sedimentation tank 24 is connected with the water inlet of the intermediate tank 25, the water outlet of the intermediate tank 25 is connected with the water inlet of the second sewage pump 26, and the water outlet of the second sewage pump 26 is connected with the water inlet of the aerated biological filter 27. The water output outlet of the aerated biological filter 27 is connected to the water inlet of the disinfection tank 31, the water outlet of the disinfection tank 31 is connected to the water inlet of the third sewage pump 32, the water outlet of the third sewage pump 32 is connected to the water inlet of the primary activated carbon filter 33, the water output outlet of the primary activated carbon filter 33 is connected to the water inlet of the secondary activated carbon filter 34, and the water output outlet of the secondary activated carbon filter 34 is connected to the water inlet of the clean water tank 35.

[0030] A grid is provided at the water inlet of the water collection well 11; the liquid outlet of the nutrient solution storage tank 15 is connected to the water inlet of the aeration regulating tank 12; the liquid outlets of the PAC storage tank 16 and the PAM storage tank 17 are both connected to the inlet of the flocculation sedimentation tank 14 through pipelines. The gas outlet of the chlorine dioxide generator 36 is connected to one end of the connecting pipe, and the other end of the connecting pipe is placed below the liquid level in the disinfection tank 31.

[0031] The overflow of the aerobic tank 23 is also connected to the water inlet of the reflux pump 28, and the water outlet of the reflux pump 28 is connected to the water inlet of the anoxic tank 22. The water outlet of the anaerobic tank 21 is also connected to the water inlet of the anaerobic circulation pump 29, and the water outlet of the anaerobic circulation pump 29 is connected to the water inlet of the anaerobic tank 21, so that the hydrolysis and acidification process of the high molecular organic matter is more thorough.

[0032] The water outlet of the backwash water tank 4 is connected to the water inlet of the first backwash water pump 5, the water outlet of the first backwash water pump 5 is connected to the backwash water inlet at the bottom of the aerated biological filter 27, and the backwash water outlet at the top of the aerated biological filter 27 is connected to the water inlet of the aeration regulating tank 12 of the first physicochemical treatment unit 1.

[0033] The water outlet of the backwash water tank 4 is also connected to the water inlet of the second backwash water pump 6. The water outlet of the second backwash water pump 6 is divided into two paths, one of which is connected to the output water port of the primary activated carbon filter 33, and the other is connected to the output water outlet of the secondary activated carbon filter 34; the water inlet of the primary activated carbon filter 33 and the water inlet of the secondary activated carbon filter 34 are both connected to the water inlet of the aeration regulating tank 12 of the first physicochemical treatment unit 1 through pipelines.

[0034] The water outlet of the backwash water tank 4 is connected to the water inlet of the backwash water pump 5. The water outlet of the backwash water pump 5 is divided into three paths, one of which is connected to the backwash water inlet at the bottom of the aerated biological filter 27, one of which is connected to the output water outlet of the first activated carbon filter 33, and one of which is connected to the output water outlet of the second activated carbon filter 34; the backwash water outlet at the top of the aerated biological filter 27, the water inlet of the first activated carbon filter 33 and the water inlet of the second activated carbon filter 34 are all connected to the water inlet of the aeration regulating tank 12 of the first physicochemical treatment unit 1 through pipelines.

[0035] In this embodiment, the aeration regulating tank 12, the aerobic tank 23 and the aerated biological filter 27 are all aerated by an aeration fan. The filter material filled in the aerated biological filter 27 is ceramsite.

[0036] Job Description:

[0037] After the aramid production wastewater is intercepted by the screen to remove the larger suspended solids and floating objects in the water, the water quality and quantity are balanced in the water collection well 11, and then enter the aeration regulating tank 12. Through the aeration, a part of the ammonia nitrogen is blown off, and a certain amount of potassium dihydrogen phosphate is added to the aeration regulating tank 12 from the nutrient solution storage tank 15 to keep the wastewater at a suitable nitrogen-phosphorus ratio to adapt to the growth of microorganisms in the wastewater and increase the biodegradability of the wastewater. After that, it is pumped to the flocculation sedimentation tank 14 through the first sewage pump 13. By adding a certain amount of PAM and PAC to the flocculation sedimentation tank 14, the principle of shallow sedimentation is used to make the organic matter and colloid in the sewage become microflocculation and then remove it through sedimentation, which can reduce the chromaticity of the wastewater and the concentration of organic matter, and reduce the biological treatment load of subsequent equipment.

[0038] The effluent from the flocculation sedimentation tank 14 enters the anaerobic tank 21, where most of the organic matter in the wastewater is decomposed into methane under the action of the extracellular enzymes of anaerobic bacteria; the effluent from the anaerobic tank 21 enters the anoxic tank 22 (DO≤0.5mg / L) and the aerobic tank 23 (DO is 2-4mg / L) once. After anoxic and aerobic treatments, part of the effluent from the aerobic tank 23 is returned to the anoxic tank through the reflux pump 28, which can improve the effect of nitrogen and phosphorus removal; part of the effluent from the aerobic tank 23 enters the secondary sedimentation tank 24, The biofilm and suspended particles detached after biological treatment are allowed to settle, and the supernatant enters the intermediate tank 25 and is pumped to the aerated biological filter 27 by the second sewage pump 26. The organic matter and ammonia nitrogen in the water body are reduced through physical adsorption of the filler and nitrification and denitrification inside the aerated biological filter 27. After chlorine dioxide disinfection in the disinfection tank 31, it is once again finely filtered through the primary activated carbon filter 33 and the secondary activated carbon filter 34, and the resulting produced water enters the clear water tank 35 to meet the discharge standards.

[0039] In this embodiment, the aerated biological filter 27, the primary activated carbon filter 33 and the secondary activated carbon filter 34 can be backwashed regularly. When the system is shut down, the backwash water pump 5 is turned on for flushing. The backwash effluent generated after backwashing can flow back into the aeration regulating tank 12 and be discharged after being processed by the system to avoid direct discharge to cause environmental pollution.

[0040] Examples 2-4 are cases where different batches of aramid production wastewater were treated using the system of Example 1. The specific system inlet water quality and system outlet water quality are shown in Table 1, and both can meet the discharge standards.

[0041] Table 1 System inlet water quality and system outlet water quality of Example 2-4

[0042]

[0043] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A system for treating aramid production wastewater, characterized in that: It includes a first physicochemical treatment unit, a biochemical treatment unit and a second physicochemical treatment unit; The water outlet of the flocculation sedimentation tank of the first physicochemical treatment unit is connected to the water inlet of the anaerobic tank of the biochemical treatment unit, and the water output outlet of the aerated biological filter of the biochemical treatment unit is connected to the water inlet of the disinfection tank of the second physicochemical treatment unit; The first physical and chemical treatment unit includes a water collection well, an aeration regulating tank and a flocculation sedimentation tank; The water outlet of the water collection well is connected to the water inlet of the aeration regulating tank, the water outlet of the aeration regulating tank is connected to the inlet of the first sewage pump, and the outlet of the first sewage pump is connected to the water inlet of the flocculation sedimentation tank; The liquid outlet of the nutrient solution storage tank is connected to the water inlet of the aeration regulating tank; the liquid outlets of the PAC storage tank and the PAM storage tank are both connected to the inlet of the flocculation sedimentation tank through pipelines; The biochemical treatment unit includes an anaerobic tank, an anoxic tank, an aerobic tank, a secondary sedimentation tank, an intermediate tank and an aerated biological filter; The water outlet of the anaerobic tank is communicated with the water inlet of the anoxic tank, the water outlet of the anoxic tank is communicated with the water inlet of the aerobic tank, the overflow of the aerobic tank is communicated with the water inlet of the secondary sedimentation tank, the supernatant outlet of the secondary sedimentation tank is communicated with the water inlet of the intermediate tank, the water outlet of the intermediate tank is communicated with the water inlet of the second sewage pump, and the water outlet of the second sewage pump is communicated with the water inlet of the aerated biological filter; The second physicochemical treatment unit includes a disinfection tank, a primary activated carbon filter, a secondary activated carbon filter and a clear water tank; The water outlet of the disinfection tank is connected to the water inlet of the third sewage pump, the water outlet of the third sewage pump is connected to the water inlet of the primary activated carbon filter, the water output outlet of the primary activated carbon filter is connected to the water inlet of the secondary activated carbon filter, and the water output outlet of the secondary activated carbon filter is connected to the water inlet of the clean water tank; The gas outlet of the chlorine dioxide generating device is connected with one end of the connecting pipe, and the other end of the connecting pipe is placed below the liquid level in the disinfection pool.

2. The aramid production wastewater treatment system according to claim 1, characterized in that: A grille is provided at the water inlet of the water collection well.

3. The aramid production wastewater treatment system according to claim 1, characterized in that: The overflow port of the aerobic pool is also communicated with the water inlet of the reflux pump, and the water outlet of the reflux pump is communicated with the water inlet of the anoxic pool.

4. The aramid production wastewater treatment system according to claim 1, characterized in that: The water outlet of the anaerobic tank is also communicated with the water inlet of the anaerobic circulation pump, and the water outlet of the anaerobic circulation pump is communicated with the water inlet of the anaerobic tank.

5. The aramid production wastewater treatment system according to claim 1, characterized in that: The water outlet of the backwash water tank is connected to the water inlet of the first backwash water pump, the water outlet of the first backwash water pump is connected to the backwash water inlet at the bottom of the aerated biological filter, and the backwash water outlet at the top of the aerated biological filter is connected to the water inlet of the aeration regulating tank of the first physicochemical treatment unit.

6. The aramid production wastewater treatment system according to claim 5, characterized in that: The water outlet of the backwash water tank is also connected to the water inlet of the second backwash water pump. The water outlet of the second backwash water pump is divided into two paths, one of which is connected to the output water outlet of the primary activated carbon filter, and the other is connected to the output water outlet of the secondary activated carbon filter; The water inlet of the primary activated carbon filter and the water inlet of the secondary activated carbon filter are both connected to the water inlet of the aeration regulating tank of the first physicochemical treatment unit through pipelines.

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