Short-cut nitrification process

Abstract

The invention relates to the technical field of water treatment, in particular to a short-cut nitrification process which comprises a water inlet area, a short-cut nitrification area and the like, nitrate nitrogen is refluxed by a circulating pump and sprayed to a filler layer through a water distribution pipe to realize denitrification, flora mass transfer and biological membrane updating are promoted by combining mechanical shear force, and a DO gradient is formed through aeration to realize coupling of synchronous nitrification and short-cut nitrification. And ammonia nitrogen and nitrite nitrogen directly generate nitrogen. According to the process, the denitrification efficiency can be improved to 95% or above, the aeration energy consumption is reduced by 40-50%, the sludge yield is reduced by 30% or above, and the process is low in equipment investment, high in adaptability and suitable for high-ammonia-nitrogen industrial wastewater treatment.

Description

Technical Field

[0001] The invention relates to the technical field of water treatment, in particular to a short-range nitrification process. Background Art

[0002] Traditional sewage denitrification processes usually adopt a segmented treatment mode of "ammonia nitrogen nitrification → nitrate nitrogen denitrification": first, ammonia nitrogen is completely nitrified into nitrate nitrogen through aeration, and then the nitrate nitrogen is transported to the anoxic zone through reflux for denitrification into nitrogen gas.

[0003] This process has significant drawbacks: First, the entire nitrification process requires extensive aeration, resulting in high energy consumption, with aeration costs accounting for 40%-60% of the total treatment cost. Second, the complex recirculation system is prone to short-circuiting, resulting in inadequate denitrification of some wastewater and a total nitrogen removal rate of only 85-90%, making it difficult to meet standards. Third, the staged treatment requires multiple tanks, resulting in large equipment investments and high sludge production. Furthermore, the traditional process has a simple bacterial community structure, with nitrification and denitrification bacteria acting in separate stages, which limits reaction efficiency and makes it particularly unsuitable for treating high-ammonia nitrogen industrial wastewater. Summary of the Invention

[0004] (1) Technical problems solved

[0005] In view of the shortcomings of the prior art, the present invention provides a short-range nitration process.

[0006] (2) Technical solution

[0007] To achieve the above object, the present invention provides the following technical solution: a short-range nitration process, comprising the following steps:

[0008] Step 1: The sewage is introduced into the water inlet area with a uniform distribution pipe, and then enters the short-range nitrification area after being distributed at the bottom of the pool;

[0009] Step 2: The short-range nitrification zone is loaded with biofilm through the suspended filler layer. The circulating pump returns the water from the outlet area to the water distribution pipe, and the water is evenly sprayed onto the filler layer through the water distribution pipe to achieve nitrate nitrogen denitrification.

[0010] Step 3: Use mechanical shear force to promote mass transfer between bacteria and sewage and to remove aged sludge;

[0011] Step 4: An aeration device is used to create an aerobic environment in the gaps of the packing, and ammonia nitrogen oxidation and short-range nitrification reactions are carried out simultaneously, so that ammonia nitrogen and nitrite nitrogen directly generate nitrogen gas, realizing the nitrification and denitrification cycle in the same pool.

[0012] Furthermore, the present invention has been improved in that the short-range nitrification zone adopts a three-dimensional filler layer structure, the filler surface is loaded with an active biofilm, and a microporous aeration device is provided at the bottom of the filler layer.

[0013] Furthermore, the present invention is improved in that the reflux ratio of the circulation pump is controlled at 30-50%, and a hydraulic circulation channel is formed through the water distribution network.

[0014] Furthermore, the present invention is improved in that the aeration device controls the dissolved oxygen (DO) gradient in the short-range nitrification zone to be: 0.2-0.5 mg / L in the anoxic zone and 1.5-2.5 mg / L in the aerobic zone.

[0015] Furthermore, the present invention is improved in that the mechanical shear force is generated by the combined action of circulating water flow and aeration to maintain the biofilm thickness at 100-200 μm.

[0016] Furthermore, the present invention has the following improvements: the porosity of the filler is maintained at >80% by a combined air-water flushing mechanism to prevent clogging.

[0017] Furthermore, the present invention is improved in that the chemical equation of the short-range nitration reaction is: NH4++NO2-→N2↑+2H2O.

[0018] Furthermore, the present invention has the following improvements: the reflux ratio and aeration intensity are adjusted in real time by an intelligent control system to optimize the denitrification efficiency.

[0019] (3) Beneficial effects

[0020] Compared with the prior art, the present invention provides a short-range nitration process with the following beneficial effects:

[0021] Efficient denitrification: Short-range nitrification coupled with denitrification is achieved in the same pool, and the denitrification efficiency is increased from 85-90% of the traditional process to more than 95%, and the total nitrogen removal is more thorough.

[0022] Energy saving and consumption reduction: no need for full-process aeration, aeration energy consumption is reduced by 40-50%, there is no loss in the reflux of a single pool in the circulation system, and the operating cost is significantly reduced.

[0023] Equipment simplification: The traditional segmented multi-tank design is eliminated and a single-tank partitioned modular structure is adopted, which reduces equipment investment by 20-30% and reduces the floor space.

[0024] Sludge reduction: The biofilm renewal mechanism reduces sludge production by more than 30%, reducing subsequent sludge treatment costs.

[0025] Strong adaptability: The complex bacterial community can metabolize synergistically and tolerate high ammonia nitrogen loads. It is particularly suitable for the treatment of high ammonia nitrogen industrial wastewater in the chemical, pharmaceutical and other industries. DETAILED DESCRIPTION

[0026] The following is a clear and complete description of the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making any creative efforts are within the scope of protection of the present invention.

[0027] The short-range nitration process of the present invention comprises the following steps:

[0028] Step 1: The sewage is introduced into the water inlet area with a uniform distribution pipe, and then enters the short-range nitrification area after being distributed at the bottom of the pool;

[0029] Step 2: The short-range nitrification zone is loaded with biofilm through the suspended filler layer. The circulating pump returns the water from the outlet area to the water distribution pipe, and the water is evenly sprayed onto the filler layer through the water distribution pipe to achieve nitrate nitrogen denitrification.

[0030] Step 3: Use mechanical shear force to promote mass transfer between bacteria and sewage and to remove aged sludge;

[0031] Step 4: An aeration device is used to create an aerobic environment in the gaps of the packing, and ammonia nitrogen oxidation and short-range nitrification reactions are carried out simultaneously, so that ammonia nitrogen and nitrite nitrogen directly generate nitrogen gas, realizing the nitrification and denitrification cycle in the same pool.

[0032] The short-range nitrification zone adopts a three-dimensional filler layer structure, the filler surface is loaded with active biofilm, and a microporous aeration device is arranged at the bottom of the filler layer.

[0033] The reflux ratio of the circulation pump is controlled at 30-50%, and a hydraulic circulation channel is formed through the water distribution pipe network.

[0034] The aeration device controls the dissolved oxygen (DO) gradient in the short-range nitrification zone to be 0.2-0.5 mg / L in the anoxic zone and 1.5-2.5 mg / L in the aerobic zone.

[0035] The mechanical shear force is generated by the combined action of circulating water flow and aeration, maintaining the biofilm thickness at 100-200 μm.

[0036] The porosity of the packing is maintained at >80% through the air-water combined flushing mechanism to prevent clogging.

[0037] The chemical equation of the short-range nitration reaction is: NH4++NO2-→N2↑+2H2O.

[0038] The intelligent control system adjusts the reflow ratio and aeration intensity in real time to optimize the denitrification efficiency.

[0039] System structure:

[0040] The short-cut nitrification reactor utilizes a modular, zoned design, consisting of an inlet area, a short-cut nitrification zone, and an outlet area. The circulation system consists of a circulating pump and a water distribution network, with a microporous aeration device installed at the bottom of the packing layer. The inlet area utilizes a uniformly distributed network of pipes to achieve uniform water distribution across the tank floor. The short-cut nitrification zone features a suspended, three-dimensional packing layer, with short-cut nitrifying bacteria forming a biofilm on the packing surface.

[0041] Operation process:

[0042] Sewage enters the reactor through the inlet distribution pipe, where it comes into contact with the biofilm in the packing layer in the short-range nitrification zone. A circulating pump returns nitrate nitrogen from the outlet to the water distribution pipe at a 40% return ratio. The water from the water distribution pipe is sprayed onto the packing layer, where it is reduced by short-range nitrifying bacteria under anoxic conditions. Simultaneously, an aeration device maintains a DO gradient within the packing voids of 0.3 mg / L in the anoxic zone and 2.0 mg / L in the aerobic zone. Ammonia nitrogen is oxidized to nitrite nitrogen in the aerobic zone, which then directly reacts with ammonia nitrogen to produce nitrogen gas. Mechanical shear force, generated by the circulating water and aeration, maintains a biofilm thickness of 150 μm. Combined air-water scouring maintains a packing porosity of 85%.

[0043] Control parameters:

[0044] The intelligent control system adjusts the recirculation ratio (30-50%) and aeration intensity in real time, stabilizing the denitrification efficiency at over 95%. The aeration energy consumption is reduced by 45% compared with the traditional process, and the sludge production is reduced by 35%.

[0045] In the description herein, it should be noted that relational terms such as first and second, etc., are used only to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Furthermore, the terms "include," "comprise," or any other variations thereof are intended to encompass non-exclusive inclusion, such that a process, method, article, or apparatus that includes a list of elements includes not only those elements but also other elements not explicitly listed, or elements inherent to such process, method, article, or apparatus.

[0046] While the embodiments of the present invention have been shown and described, it will be apparent to those skilled in the art that various changes, modifications, substitutions, and alterations can be made to the embodiments without departing from the principles and spirit of the invention.

Claims

1. Short-cut nitration process, characterized by: The following steps are involved: Step 1: The sewage is introduced into the water inlet area with a uniform distribution pipe, and then enters the short-range nitrification area after being distributed at the bottom of the pool; Step 2: The short-range nitrification zone is loaded with biofilm through the suspended filler layer. The circulating pump returns the water from the outlet area to the water distribution pipe, and the water is evenly sprayed onto the filler layer through the water distribution pipe to achieve nitrate nitrogen denitrification. Step 3: Use mechanical shear force to promote mass transfer between bacteria and sewage and to remove aged sludge; Step 4: An aeration device is used to create an aerobic environment in the gaps of the packing, and ammonia nitrogen oxidation and short-range nitrification reactions are carried out simultaneously, so that ammonia nitrogen and nitrite nitrogen directly generate nitrogen gas, realizing the nitrification and denitrification cycle in the same pool.

2. The short-cut nitration process according to claim 1, wherein: The short-range nitrification zone adopts a three-dimensional filler layer structure, the filler surface is loaded with active biofilm, and a microporous aeration device is arranged at the bottom of the filler layer.

3. The short-cut nitration process according to claim 2, wherein: The reflux ratio of the circulation pump is controlled at 30-50%, and a hydraulic circulation channel is formed through the water distribution pipe network.

4. The short-cut nitration process according to claim 3, wherein: The aeration device controls the dissolved oxygen (DO) gradient in the short-range nitrification zone to be 0.2-0.5 mg / L in the anoxic zone and 1.5-2.5 mg / L in the aerobic zone.

5. The short-cut nitration process according to claim 4, characterized in that: The mechanical shear force is generated by the combined action of circulating water flow and aeration, maintaining the biofilm thickness at 100-200 μm.

6. The short-cut nitration process according to claim 5, characterized in that: The porosity of the packing is maintained at >80% through the air-water combined flushing mechanism to prevent clogging.

7. The short-cut nitration process according to claim 6, characterized in that: The chemical equation of the short-range nitration reaction is: NH4++NO2-→N2↑+2H2O.

8. The short-cut nitration process according to claim 7, characterized in that: The intelligent control system adjusts the reflow ratio and aeration intensity in real time to optimize the denitrification efficiency.