CN104817223B - Chemical-biological combined removal nitrate nitrogen and the reactor of ammonia nitrogen - Google Patents

Abstract

The invention discloses a chemical-biological combined reactor for removing nitrate nitrogen and ammonia nitrogen. The water distribution area is provided with a mud discharge pipe and a return water inlet pipe from bottom to top; an H ₂ intake pipe is provided at the lower end of the short-range denitrification area, which communicates with the composite porous ceramic catalytic column group, and an H ₂ circulation pipe is installed at the upper end of the short-range denitrification area; The nitrification area and the anammox area are connected by flanges, and a three-hole partition is installed on which three catheter tubes are installed; the lower part of the anaerobic ammonium oxidation area is equipped with a supporting sieve plate, and the upper part is equipped with a mud-resistance sieve plate; The oxygen ammonium oxidation zone is connected to the separation zone through a flange, and a double-hole partition is provided, and a diversion pipe and a mud guide pipe are respectively installed on the plate; the side wall of the separation zone is provided with a mud discharge port and an overflow tank in sequence from bottom to top. And the water outlet pipe, a double-effect three-phase separator is installed in the center of the separation area, a return pipe is installed on the side wall of the middle part, and a detachable liquid-sealed gas collecting hood is installed on the top. The invention has the advantages of fast reaction rate, high NO ₂ ^-selectivity , no need for external carbon source, etc.; H ₂ circulation system is set up to realize efficient utilization of resources.

Description

Reactor for combined chemical-biological removal of nitrate nitrogen and ammonia nitrogen

technical field

The present invention relates to denitrification reactors. In particular, it relates to a chemical-biological combined reactor for removing nitrate nitrogen and ammonia nitrogen.

Background technique

According to the 2013 Bulletin on the State of the Environment in China, the discharge of ammonia nitrogen in wastewater reached 2.457 million tons. Lake "blooms" and offshore "red tides" frequently occur due to pollution, which have endangered agriculture, fishery, tourism and many other industries, and pose a serious threat to drinking water sanitation and food safety. Wastewater nitrogen discharge is an important cause of water eutrophication, and wastewater denitrification has become an urgent task for environmental protection.

Compared with the traditional denitrification process, the anammox process has the advantages of high volumetric efficiency, low energy consumption for oxygen supply, less sludge production, and no need for additional carbon sources, etc., and is especially suitable for the denitrification of high-concentration ammonia nitrogen wastewater deal with. In 2002, the world's first productive Anammox reactor was put into operation in the municipal sewage treatment plant in Rotterdam, the Netherlands, for the treatment of anaerobic sludge digestion liquid, and its volumetric nitrogen removal rate is as high as 9.5kg/(m3 d) , showing attractive application prospects.

However, for the control of wastewater containing nitrate and nitrogen at the same time, a single Anammox process is difficult to be effective. As far as the Anammox reaction is concerned, the reaction of ammonia and nitrite produces about 10% NO ₃ ^- (1), which cannot complete the complete denitrification. Therefore, it is of great practical significance to develop a combined process for removing ammonia nitrogen and nitrate nitrogen.

NH ₄ ⁺ +1.32NO ₂ ^- +0.066HCO ₃ ^- +0.13H ⁺ →1.02N ₂ +0.26NO ₃ ^- +

0.066CH ₂ O _0.5 N _0.15 +2.03H ₂ O (1)

Based on the anaerobic ammonium oxidation reaction, combined with the chemical catalytic short-range denitrification process (Formula 2), a chemical-biological joint removal process of nitrate nitrogen and ammonia nitrogen can be constructed, and the simultaneous removal of nitrate nitrogen and ammonia nitrogen can be realized under anaerobic conditions. This process uses H ₂ as electron donor, porous ceramic (α-Al ₂ O ₃ ) membrane as catalyst carrier, and metal catalyst Pd-Cu to realize chemical catalytic short-range denitrification without external carbon source. At the same time as ammonia nitrogen, it solves the problem of insufficient carbon source in denitrification and denitrification. The denitrification process has the advantages of high efficiency, low consumption, and complete denitrification.

Contents of the invention

The purpose of the invention is to overcome the deficiencies of the prior art and provide a chemical-biological combined reactor for removing nitrate nitrogen and ammonia nitrogen.

The reactor for chemical-biological joint removal of nitrate nitrogen and ammonia nitrogen includes water distribution area, short-range denitrification area, anaerobic ammonium oxidation area and separation area from bottom to top; Water inlet pipe; the short-range denitrification area is directly connected with the water distribution area, and the lower end of the short _- range denitrification area is provided with an _H2 inlet pipe, which communicates with the composite porous ceramic catalytic column group. The circulation pipe is connected to the _H2 recovery pump externally and connected to the _H2 intake pipe; the short-range denitrification zone is connected to the anaerobic ammonium oxidation zone through a flange, and a three-hole partition is installed on the board, and three catheter tubes are installed on the board; The lower part of the oxygen ammonium oxidation zone is equipped with a supporting sieve plate, and the upper part is equipped with a mud-resistance sieve plate. The anaerobic ammonium oxidation zone is connected to the separation zone through a flange, and a double-hole partition is installed on the plate. Mud pipe; the side wall of the separation area is provided with a mud discharge port, an overflow tank and a water outlet pipe in sequence from bottom to top. Through the side wall of the separation area, a detachable liquid-sealed gas collection hood is installed on the top.

The cross-sectional area ratio of the short-range denitrification zone to the anammox zone is 1:1, the height ratio is 1:(1-1.5), and the volume of the composite porous ceramic catalytic column group accounts for 1% of the total volume of the short-range denitrification zone. /4～1/2.

The _H2 inlet pipe communicates with the H2 aeration main pipe, extends into the center of the cross-section of the reactor, and is connected with nine cylindrical porous ceramic catalytic columns through nine _H2 aeration branch pipes. _The diameter of the porous ceramic catalytic column is short-range The section diameter of the denitrification zone is 1/8 to 1/4, and the height is 1/3 to 2/3 of the height of the short-range denitrification zone. It is evenly arranged in a matrix of three rows and three columns. The top of the column is closed, and the supporting layer material is pores. α-Al ₂ O ₃ with a ratio of 30%-40% and an average pore size of 1 μm-100 μm.

The outer surface of the side wall of the porous ceramic catalytic column is a uniformly coated bimetallic Pd-Cu catalyst film layer with a thickness of 1nm-100μm.

The inner diameter ratio of the section of the fluid guide tube, the draft tube, the mud guide tube and the anammox zone is 1:1:1:(4-8), and the length ratio is 1:1:(0.9-1): (6-9); the catheter is distributed on the three-hole partition in the form of an equilateral triangle, and the length extending downward into the short-range denitrification zone is 7/8-9/10 of its total length.

The angle between the _H2 circulation pipe and the horizontal plane is 35°～65°, the diameter of the _H2 circulation pipe mouth is less than 30mm, the distance from the three-hole partition is 1/5～1/2 of the total length of the catheter, and the H ₂ recovery pump and connected with _H2 inlet line.

The supporting sieve plate is stacked in parallel with 3 to 5 layers of thin sieve plates, and the sieve of the supporting sieve plate is selected from 6 mesh to 10 mesh, and the aperture is 1700 μm to 3350 μm; the mud blocking sieve plate is a single layer sieve plate, and The specifications are 12 mesh to 20 mesh, and the pore size is 830 μm to 1400 μm.

The double-effect three-phase separator is cylindrical, and the ratio of its inner diameter to the inner diameter of the separation zone is 1:2; the height of the double-effect three-phase separator exposed to the liquid surface is 1/3 to 1/3 of its total height 6. The top is equipped with a liquid-sealed gas collecting hood.

The liquid-sealed gas-collecting hood is cylindrical, and the ratio of its inner diameter to the inner diameter of the double-effect three-phase separator is 1: (1.01-1.05); 2/3～4/5, the bottom end is located in the middle of the overflow notch.

Compared with the prior art, the present invention has the following advantages: 1) chemically catalyzed short-range denitrification, high reaction efficiency ^, high selectivity for NO ₂ generation, and no additional carbon source is required. 2) Install H ₂ , NO ₃ ^-reflux devices to efficiently utilize energy. 3) The support sieve plate is used to increase the retention time of anaerobic granular sludge in the anammox zone to maintain the efficient operation of the reactor; the mud-resistance sieve plate is used to reduce the floating loss of anaerobic granular sludge and ensure the water quality of the effluent. 4) A double-effect three-phase separator is installed to effectively separate the three phases of gas, liquid and solid.

Description of drawings

Fig. 1 is a schematic diagram of the reactor structure of chemical-biological combined denitrification;

Fig. 2 is the structural representation of composite porous ceramic catalytic column group of the present invention;

Fig. 3 is a three-hole partition cross-sectional view of the present invention;

Fig. 4 is a cross-sectional view of a double-hole dividing plate of the present invention;

Fig. 5 is a longitudinal sectional view of the porous ceramic catalytic column of the present invention;

In the figure: sludge discharge pipe 1, return-water inlet pipe 2, _H2 air intake pipe 3, support frame 4, composite porous ceramic catalytic column group 5, _H2 aeration main pipe 5-1, _H2 aeration branch pipe 5-2, Porous ceramic catalytic column 5-3, bimetallic Pd-Cu catalyst film layer 5-3-1, α-Al ₂ O ₃ support layer 5-3-2, H ₂ recovery pump 6, H ₂ circulation pipe 7, liquid guide Pipe 8, three-hole partition 9, support screen 10, mud-resistance screen 11, mud guide pipe 12, double-hole partition 13, mud discharge port 14, diversion pipe 15, return pipe 16, double-effect three-phase separation Device 17, overflow tank 18, water outlet pipe 19, liquid-sealed gas collecting hood 20.

detailed description

As shown in Figure 1-5, the chemical-biological joint removal of nitrate nitrogen and ammonia nitrogen reactor includes water distribution area A, short-range denitrification area B, anammox area C and separation area D from bottom to top; water distribution area Sludge discharge pipe 1 and return-water inlet pipe 2 are provided in sequence from bottom to top; the short-range denitrification zone B is directly connected to the water distribution zone A, and the lower end of the short-range denitrification zone B is provided with an _H2 intake pipe 3, which is connected with a composite porous ceramic catalytic column The group 5 is connected, and a support frame 4 is arranged beside it, and a composite porous ceramic catalytic column group 5 is fixed, and a _H2 circulation pipe 7 is arranged at the upper end, and an _H2 recovery pump 6 is connected externally and connected with the _H2 intake pipe 3. The short-range denitrification zone B is connected to the anaerobic The ammonium oxidation zone C is connected by a flange, and a three-hole partition 9 is installed on the plate, and three catheters 8 are installed on the plate; the lower part of the anaerobic ammonia oxidation zone C is provided with a supporting sieve plate 10, and the upper part is provided with a mud-resistance sieve plate 11 , the anaerobic ammonium oxidation zone C is connected to the separation zone D through a flange, and a double-hole partition 13 is provided, and a draft pipe 15 and a mud guide pipe 12 are installed on the plate respectively; the side walls of the separation zone D are sequentially arranged from bottom to top A mud outlet 14, an overflow tank 18 and an outlet pipe 19 are provided. A double-effect three-phase separator 17 is provided in the center of the separation zone D, and a return pipe 16 is provided on the side wall of the middle part of the double-effect three-phase separator 17, and passes through the separation zone D The side wall and the top are provided with a detachable liquid-sealed gas collection cover 20.

The cross-sectional area ratio of the short-range denitrification zone B and the anammox zone C is 1:1, and the height ratio is 1: (1-1.5), and the volume of the composite porous ceramic catalytic column group 5 accounts for the short-range denitrification zone B. 1/4~1/2 of the total volume.

The _H2 inlet pipe 3 communicates with the H2 aeration main pipe 5-1, extends into the center of the cross-section of the reactor, passes through nine _H2 aeration branch pipes _5-2 and nine cylindrical porous ceramic catalytic columns 5-3 Connected, the diameter of the porous ceramic catalytic column 5-3 is 1/4 to 1/8 of the cross-sectional diameter of the short-range denitrification zone B, and the height is 1/3 to 2/3 of the height of the short-range denitrification zone B, in three rows and three columns Arranged uniformly in a matrix, with closed pillar tops, the material of the supporting layer 5-3-2 is α-Al ₂ O ₃ with a porosity of 30%-40% and an average pore diameter of 1 μm-100 μm.

The outer surface of the side wall of the porous ceramic catalytic column 5-3 is a uniformly coated bimetallic Pd-Cu catalyst film layer 5-3-1 with a thickness of 1nm-100μm.

The inner diameter ratio of the described guide tube 8, the guide tube 15, the mud guide tube 12 and the section C of the anammox zone is 1:1:1:(4-8), and the length ratio is 1:1:(0.9 ～1): (6～9); the catheter tube 8 is distributed on the three-hole partition 9 in an equilateral triangle, and the length extending downward into the short-range denitrification zone B is 7/8～9/10 of its total length.

The angle between the _H2 circulating pipe 7 and the horizontal plane is 35°～65°, the diameter of the _H2 circulating pipe 7 is less than 30mm, and the distance from the three-hole partition 9 is 1/5～1/5 of the total length of the catheter 8 2. The external _H2 recovery pump 6 is connected to the _H2 intake pipe 3.

The supporting sieve plate 10 is stacked in parallel with 3 to 5 layers of thin sieve plates, and the sieve used for the supporting sieve plate 10 has a specification of 6 mesh to 10 mesh and an aperture of 1700 μm to 3350 μm; the mud-repelling sieve plate 11 is a single-layer sieve plate , the selected specifications are 12 mesh to 20 mesh, and the pore size is 830 μm to 1400 μm.

The double-effect three-phase separator 17 is cylindrical, and the ratio of its inner diameter to the inner diameter of the separation zone D is 1:2; the height of the part exposed to the liquid surface of the double-effect three-phase separator 17 is 1/3 of its total height ~1/6, the top is provided with a liquid-sealed gas collecting hood 20.

The liquid-sealed gas-collecting hood 20 is cylindrical, and the ratio of its inner diameter to the inner diameter of the double-effect three-phase separator 17 is 1: (1.01-1.05); the height of the liquid-sealed gas-collecting hood 20 exposed to the liquid surface is 2/3～4/5 of the total height, and its bottom is located in the middle of the 18 mouths of the overflow tank.

The present invention can be constructed with plexiglass and steel plates, and sequentially includes a water distribution area, a short-range denitrification area, an anammox area and a separation area from bottom to top. _The reaction solution enters the short _- range denitrification area through the water distribution area, and fully contacts with the composite porous ceramic catalytic column group in the short-range denitrification area. Because the top of the catalytic column is closed, _H2 overflows from the pores of the side wall of the catalytic column, and contacts with the reaction substrate on the outer layer of the catalytic column. Nitrite nitrogen. At the same time, unreacted _H2 accumulates at the top of the short-path denitrification zone and forms an air chamber with the help of the blocking effect of the three-hole partition. During operation, the bottom end of the air chamber should always be lower than the _H2 circulation nozzle but higher than the bottom end of the catheter tube. The accumulated H2 in the air chamber is collected by the _H2 recovery pump through the _H2 circulation pipe and then injected into _H2 . ₂ intake pipe, and finally return to the lower end of the short-range denitrification zone to realize _H2 recycling. The reaction solution after the reaction in the short-range denitrification zone enters the anaerobic ammonium oxidation reaction zone through the catheter, and fully contacts with the anaerobic granular sludge in this zone, so that nitrous nitrogen and ammonia nitrogen react to generate N ₂ . The nitrate nitrogen in the product flows back to the water distribution area through the return pipe of the separation area along with the reaction liquid, and continues to participate in the short-range denitrification reaction. This design largely breaks through the bottleneck that the anaerobic ammonium oxidation reaction cannot achieve complete denitrification. The support sieve plate at the lower part of the anammox reaction zone plays the role of supporting the anaerobic ammonium oxidation granular sludge layer, increasing the sludge concentration and maintaining the efficient operation of the reactor. The upper mud-resistance sieve plate can chop up the floating anammox granular sludge, make the air bubbles inside the granular sludge overflow, restore the settling performance, and reduce the floating loss of sludge. The reaction liquid enters the separation area after passing through the anaerobic ammonium oxidation reaction area for three-phase separation of gas, liquid and solid. N ₂ passes upward through the liquid-sealed gas-collecting hood at the top of the separation zone and is discharged from the reactor. The bottom of the liquid-sealed gas-collecting hood is submerged into the liquid surface of the anaerobic ammonium oxidation reaction zone to realize a liquid seal and prevent the escape of the generated gas. The excess effluent is overflowed The tank is discharged from the outlet pipe, and the floating anaerobic granular sludge is discharged through the sludge discharge port.

Claims (9)

1. a chemical-biological combined removal nitrate nitrogen and the reactor of ammonia nitrogen, it is characterised in that reactor includes water distribution area (A), short-cut denitrification district (B), Anammox district (C) and Disengagement zone (D) from top to bottom；Water distribution area (A) is sequentially provided with discharge pipeline (1), backflow-water inlet pipe (2) from top to bottom；Short-cut denitrification district (B) is joined directly together with water distribution area (A), and short-cut denitrification district (B) lower end sets H₂Air inlet pipe (3), communicates with composite porous ceramic catalysis post group (5), and side sets fixing composite porous ceramic catalysis post group (5) of bracing frame (4), and short-cut denitrification district (B) upper end sets H₂Circulation pipe (7), external H₂Recovery pump (6) and H₂Air inlet pipe (3) is connected；Short-cut denitrification district (B) is connected by flange with Anammox district (C), if three hole dividing plates (9), plate is equipped with three catheters (8)；Anammox district (C) bottom sets supporting screening plate (10) and top handicapping mud sieve plate (11), Anammox district (C) is connected by flange with Disengagement zone (D), separately set a diplopore dividing plate (13), plate is equipped with mozzle (15) and mud guiding tube (12) respectively；Disengagement zone (D) sidewall sets mud discharging mouth (14), overflow launder (18) and outlet pipe (19) the most successively, Disengagement zone (D) central authorities set economic benefits and social benefits three phase separator (17), economic benefits and social benefits three phase separator (17) middle part sidewall sets return duct (16), and through Disengagement zone (D) sidewall, top sets dismountable fluid-tight gas skirt (20).

A kind of chemical-biological combined removal nitrate nitrogen the most according to claim 1 and the reactor of ammonia nitrogen, it is characterized in that described short-cut denitrification district (B) is 1:1 with the sectional area ratio in Anammox district (C), aspect ratio is 1:(1 ~ 1.5), the volume of composite porous ceramic catalysis post group (5) accounts for the 1/4 ~ 1/2 of short-cut denitrification district (B) cumulative volume.

A kind of chemical-biological combined removal nitrate nitrogen the most according to claim 1 and the reactor of ammonia nitrogen, it is characterised in that described H₂Air inlet pipe (3) UNICOM H₂Aeration supervisor (5-1), stretches into reactor cross-section circle centre position, by nine H₂Aeration branch pipe (5-2) is connected with nine column type porous ceramicss catalysis post (5-3), the 1/8 ~ 1/4 of a diameter of short-cut denitrification district (B) diameter of section of porous ceramics catalysis post (5-3), it is highly the 1/3 ~ 2/3 of short-cut denitrification district (B) height, evenly distributed in three row three column matrix formulas, capital is closed, and its supporting layer (5-3-2) material is porosity 30%-40%, the α-Al of average pore size 1 μm-100 μm₂O₃。

A kind of chemical-biological combined removal nitrate nitrogen the most according to claim 3 and the reactor of ammonia nitrogen, it is characterized in that bimetallic Pd-Cu catalyst film layer (5-3-1) that wall outer surface is even spread of described porous ceramics catalysis post (5-3), thickness is 1nm-100 μm.

A kind of chemical-biological combined removal nitrate nitrogen the most according to claim 1 and the reactor of ammonia nitrogen, it is characterized in that the internal diameter in described catheter (8), mozzle (15), mud guiding tube (12) and Anammox district (C) cross section is than for 1:1:1:(4 ~ 8), length is than for 1:1:(0.9 ~ 1): (6 ~ 9)；Catheter (8) is distributed in equilateral triangle on three hole dividing plates (9), extend downwardly into short-cut denitrification district (B) its overall length a length of 7/8 ~ 9/10.

A kind of chemical-biological combined removal nitrate nitrogen the most according to claim 1 and the reactor of ammonia nitrogen, it is characterised in that described H₂Circulation pipe (7) and horizontal plane angle are 35 ° ~ 65 °, H₂Circulation pipe (7) mouth diameter is less than 30mm, away from distance is catheter (8) overall length the 1/5 ~ 1/2 of three hole dividing plates (9), external H₂Recovery pump (6) and H₂Air inlet pipe (3) is connected.

A kind of chemical-biological combined removal nitrate nitrogen the most according to claim 1 and the reactor of ammonia nitrogen, it is characterized in that described supporting screening plate (10) is stacked by 3 ~ 5 layers of thin sieve plate is parallel, the sieve of supporting screening plate (10) selects specification to be 6 mesh ~ 10 mesh, and aperture is 1700 μm ~ 3350 μm；Resistance mud sieve plate (11) is one side sieve, and it selects specification to be 12 mesh ~ 20 mesh, and aperture is 830 μm ~ 1400 μm.

A kind of chemical-biological combined removal nitrate nitrogen the most according to claim 1 and the reactor of ammonia nitrogen, it is characterised in that described economic benefits and social benefits three phase separator (17) is cylinder type, its internal diameter is 1:2 with the ratio of Disengagement zone (D) internal diameter；Economic benefits and social benefits three phase separator (17) exposes height is its total height the 1/3 ~ 1/6 of liquid level part, and top is provided with fluid-tight gas skirt (20).

A kind of chemical-biological combined removal nitrate nitrogen the most according to claim 1 and the reactor of ammonia nitrogen, it is characterised in that described fluid-tight gas skirt (20) is cylinder type, its internal diameter is 1:(1.01 ~ 1.05 with the ratio of economic benefits and social benefits three phase separator (17) internal diameter)；Fluid-tight gas skirt (20) exposes height is its total height the 2/3 ~ 4/5 of liquid level part, and its bottom is positioned in the middle part of overflow launder (18) mouth.