Sulfur autotrophic denitrification nitrogen removal method and device in printing and dyeing industrial sewage

Abstract

The invention discloses a sulfur autotrophic denitrification nitrogen removal method and device for printing and dyeing industrial sewage, the nitrogen removal device comprises an autotrophic denitrification zone, a buffer cavity and a mixed denitrification zone, the autotrophic denitrification zone comprises a microelectrolysis filler layer and a sulfur modified filler layer, a denitrifying agent filler layer, a quartz sand filler layer, a supporting layer and filter bricks are arranged in the mixed denitrification area; according to the denitrification method, wastewater passing through the micro-electrolysis filler layer is treated by the sulfur modified filler layer, so that synergy of sulfur autotrophic denitrification and sulfur disproportionation is realized, denitrification is accelerated to remove total nitrogen, high-concentration nitrogen-containing wastewater can also be efficiently removed, heterotrophic denitrification and autotrophic denitrification are coupled through the subsequent mixed denitrification region, and the nitrogen removal efficiency is improved. By combining respective advantages, efficient denitrification is realized in water pollution treatment, the nitrate reduction rate and the total nitrogen removal efficiency can both reach 90% or above, in addition, accumulation of ammonium nitrogen and nitrite in the treated water is not found, and both the ammonium nitrogen and the nitrite reach the national surface water discharge standard.

Description

Technical Field

[0001] The invention relates to the technical field of sewage treatment, and in particular to a method and a device for sulfur autotrophic denitrification in sewage from a printing and dyeing industry. Background Art

[0002] Printing and dyeing wastewater is the wastewater discharged by printing and dyeing factories that mainly process cotton, linen, chemical fibers and their blended products. The amount of printing and dyeing wastewater is large. Each printing and dyeing process of 1 ton of textile consumes 100 to 200 tons of water, of which 80 to 90% becomes wastewater. There will be some nitrogen-containing pollutants in the printing and dyeing wastewater. If the wastewater is discharged into the natural environment, it will cause serious damage to the environment.

[0003] As a key process for denitrification of printing and dyeing wastewater, denitrification has always been an important technology for the treatment of printing and dyeing wastewater. Among them, elemental sulfur-driven autotrophic denitrification (SADN) is an economical and energy-saving method for deep denitrification of sewage. However, H+ (Formula 1) will be produced during the sulfur autotrophic denitrification process, which will cause the pH of the system to drop and inhibit the metabolic activity of denitrifying bacteria. If the growth rate of autotrophic sulfur-oxidizing denitrifying bacteria is low, when the water quality and water volume change, it is easy to cause the activity of functional bacteria to be affected or even the loss of bacterial colony, thereby reducing the denitrification efficiency of the sulfur autotrophic denitrification process.

[0004]

[0005] In addition, denitrification is divided into several types. At present, the reactor realizes the combination of multiple denitrifications by introducing a diversion device in the same equipment. However, the treatment effect of the device is easily affected by the water flow, there is a risk of blockage, and the control of zoning and reaction conditions is also relatively complicated. Summary of the invention

[0006] In order to solve the problems raised in the above background technology, the purpose of the present invention is to provide a method and device for sulfur autotrophic denitrification in printing and dyeing industrial wastewater.

[0007] To achieve the above object, the present invention adopts the following technical solutions:

[0008] The first object of the present invention is to provide a sulfur autotrophic denitrification and denitrification device in printing and dyeing industrial wastewater, comprising a reactor and a sewage collection box and a water outlet trough respectively arranged before and after the reactor, the reactor comprising an autotrophic denitrification zone, a buffer cavity and a mixed denitrification zone, the buffer cavity is located between the autotrophic denitrification zone and the mixed denitrification zone, the sewage collection box is connected to the first liquid inlet of the autotrophic denitrification zone through a water inlet pump, the liquid outlet at the top of the mixed denitrification zone is connected to the second liquid inlet of the water outlet trough through a liquid outlet pipe, the water outlet trough is connected to the liquid return port at the bottom of the mixed denitrification zone through a backwash pump, a water quality sampling tube is arranged on the mixed denitrification zone, the autotrophic denitrification zone comprises a micro-electrolysis filler layer and a sulfur-modified filler layer, the sulfur-modified filler in the sulfur-modified filler layer is formed by calcining and cooling sulfur flakes, shell powder, pore-forming agent and crushed medium-pressure aerated concrete, the micro-electrolysis The packing layer is located at the bottom of the sulfur-modified packing layer. The mixed denitrification zone is provided with a denitrifying agent packing layer, a quartz sand packing layer, a supporting layer and a filter brick from top to bottom in sequence. The denitrifying agent in the denitrifying agent packing layer is a composite biomass carbon source and a sulfur-based denitrifying agent. The composite biomass carbon source and the sulfur-based denitrifying agent include a biomass carbon source with a COD of 1.1-1.2 million mg / L composed of crude glycerol and growth factors, and calcium polysulfide with a COD of 600,000-700,000 mg / L prepared by boiling quicklime, sulfur and water in a mass ratio of 1:(2-4):(10-12), wherein the biomass carbon source and the calcium polysulfide are mixed in a ratio of 1:(1-3) of the expected COD of the mixed denitrifying agent. A plurality of water distributors are arranged on the top of the mixed denitrification zone. The top of the mixed denitrification zone is connected to an exhaust port, and the bottom of the mixed denitrification zone is connected to an aeration pump.

[0009] As a further solution of the present invention: the micro-electrolytic filler layer is composed of iron powder, carbon powder, white carbon black, mica powder, chromium powder, and blast furnace slag powder in a mass ratio of (6-8):(2-3):(0.2-1):(0.1-0.3):(0.5-3.5) by weight.

[0010] As a further solution of the present invention: the micro-electrolysis filler layer is composed of iron powder, carbon powder, white carbon black, mica powder, chromium powder, and blast furnace slag powder in a ratio of 7:2.5:0.6:0.2:2 by weight.

[0011] As a further solution of the present invention: the particle size of the iron powder is 0.01-0.03mm, the particle size of the carbon powder is 0.5-0.7mm, the particle size of the white carbon black is 0.02-0.04mm, the particle size of the mica powder is 0.3-0.8mm, the particle size of the chromium powder is 0.05-0.07mm, and the particle size of the blast furnace slag powder is 0.1-0.5mm.

[0012] As a further solution of the present invention: the mass ratio of the sulfur flakes, shell powder, pore-forming agent and crushed medium-pressure aerated concrete is 50-100%: 0-25%: 15-20%: 25-33%.

[0013] As a further solution of the present invention: the pore-forming agent is sodium bicarbonate, and the diameter of the medium-pressure aerated concrete after crushing is 0.1-4 mm.

[0014] As a further solution of the present invention: the calcination temperature of the sulfur-modified filler is 120-140° C., and the calcination time is 1-2 hours.

[0015] As a further solution of the present invention: the biomass carbon source is composed of 99-99.5% by mass of crude glycerol and 0.5-1% by mass of growth factors, wherein the growth factors refer to a class of organic substances that are necessary for regulating the normal growth and metabolism of microorganisms but cannot be synthesized by simple carbon sources and nitrogen sources, mainly including vitamins, amino acids, purines and pyrimidines, etc. In this article, growth factors mainly refer to amino acids and vitamins.

[0016] As a further solution of the present invention: the calcium polysulfide is prepared by boiling quicklime, sulfur and water in a mass ratio of 1:2:10.

[0017] The second object of the present invention is to provide a denitrification method for the above-mentioned sulfur autotrophic-heterotrophic denitrification coupled denitrification device in the printing and dyeing industrial wastewater, comprising the following steps:

[0018] Step 1: Add the printing and dyeing industrial sewage to be treated into the sewage collection tank, and transport the printing and dyeing industrial sewage to the autotrophic denitrification area through the water inlet pump;

[0019] Step 2: The wastewater first passes through the micro-electrolysis filler layer in the autotrophic denitrification zone. The micro-electrolysis filler layer is filled with iron-carbon mixed spherical fillers in the form of a fixed bed. The electron transfer generated by the micro-electrolysis filler itself is directly used to provide the required electrons for the denitrification process of the autotrophic denitrifying bacteria.

[0020] Step 3: The wastewater flowing out of the micro-electrolysis packing layer enters the sulfur-modified packing layer, where denitrifying bacteria grow in the outer layer, sulfide is produced in the inner layer, and polysulfide is synthesized. The presence of polysulfide can provide a large number of electron donors for the denitrification of the outer layer, thereby accelerating the denitrification process of the outer layer. The C / N ratio of the treated wastewater is further improved. The reaction formula is as follows:

[0021]

[0022] Step 4: The wastewater treated in the autotrophic denitrification zone enters the mixed denitrification zone through the buffer cavity, and then enters the denitrification agent filling layer through the water distributor. The denitrification agent is mainly composed of crude glycerol, vitamins, amino acids, and polysulfides. Crude glycerol, vitamins, and amino acids are used as carbon sources to significantly improve the C / N ratio in the wastewater.

[0023] Step 5: The wastewater that has passed through the denitrifying agent packing layer contains rich carbon sources and sulfur sources. The sulfur source is added to the rich carbon source through the quartz sand packing layer, so that part of the nitrate continues to be removed in the form of sulfur autotrophic denitrification, and the rest is removed by heterotrophic denitrifying bacteria through denitrification. The treated wastewater is discharged from the liquid outlet to the outlet tank, and the wastewater in the outlet tank is then pumped into the reactor through the backwash pump to backwash the reactor packing. The backwash speed is set to 6-10m / h to prevent sulfur particles from compacting in the packing.

[0024] Compared with the prior art, the present invention has the following beneficial effects:

[0025] (1) The reactor of the present invention adds a mixed denitrification zone on the basis of the autotrophic denitrification zone, combining the advantages of heterotrophic denitrification and autotrophic denitrification, and can achieve efficient denitrification in sewage and wastewater treatment. The nitrate reduction rate and total nitrogen removal efficiency can reach more than 90%, which is suitable for treating high NO 3 - Wastewater (>100mg / L), and no accumulation of ammonium nitrogen and nitrite was found in the water body, and the sulfate generation was about 70mg / L, which had reached the national Class A emission standard, and the cost was reduced by more than 30%; in addition, compared with other sulfur-based materials, calcium polysulfide has low cost, is easy to prepare, has high bioavailability, and has no secondary pollution to the environment. It is a new type of sulfur-based material that supports autotrophic denitrification. Therefore, the present invention combines the biomass carbon source with the new sulfur-based carbon source to form a new type of composite denitrification material, which is an innovative biological denitrification material; the denitrifier is a biological denitrification material without secondary pollution, environmentally friendly, low cost, and easy to prepare.

[0026] (2) The present invention provides a sulfur-modified filler layer in the autotrophic denitrification zone, realizes the synergy of sulfur autotrophic denitrification and sulfur disproportionation, accelerates denitrification to remove total nitrogen, and can also achieve efficient removal for high-concentration nitrogen-containing wastewater. The load of shells and medium-pressure aerated concrete not only provides the alkalinity required for the reaction, neutralizes the hydrogen ions generated by the denitrification reaction, and makes the interior an environment suitable for the growth of denitrifying microorganisms, avoiding the problem of functional bacteria activity being affected or even the loss of bacteria, but also has a great influence on the structure of the sulfur filler, increases the specific surface area and pore volume of the filler, and can provide more sites for the attachment and growth of microorganisms. At the same time, the sulfur-modified filler is formed by calcination and cooling, and sulfur itself, an electron donor for sulfur autotrophic denitrification and sulfur disproportionation reactions, is used as a binder to reduce unnecessary raw material addition. The calcination temperature is slightly higher than the melting point of sulfur, which ensures that the calcination is completely carried out while reducing energy consumption. In addition, the preparation method has a clear production process, strong operability, and the sulfur-modified filler has strong stability. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 It is a structural schematic diagram of the device of the present invention.

[0028] Among them, in the figure: reactor 1, sewage collection box 2, water outlet trough 3, autotrophic denitrification zone 4, micro-electrolysis filler layer 401, sulfur modified filler layer 402, buffer cavity 5, mixed denitrification zone 6, denitrification agent filler layer 601, quartz sand filler layer 602, supporting layer 603, filter brick 604, water distributor 7, water inlet pump 8, backwash pump 9, aeration pump 10, first liquid inlet 11, liquid outlet 12, second liquid inlet 13, liquid return port 14, water quality sampling tube 15, exhaust port 16. DETAILED DESCRIPTION

[0029] The present invention will be further described below in conjunction with the embodiments.

[0030] Example 1

[0031] The present embodiment provides a sulfur autotrophic denitrification and denitrification device in printing and dyeing industrial wastewater, comprising a reactor 1 and a sewage collection box 2 and a water outlet trough 3 respectively arranged before and after the reactor 1, the reactor 1 comprising an autotrophic denitrification zone 4, a buffer cavity 5 and a mixed denitrification zone 6, the buffer cavity 5 being located between the autotrophic denitrification zone 4 and the mixed denitrification zone 6, the sewage collection box 2 being connected to a first liquid inlet 11 of the autotrophic denitrification zone 4 through a water inlet pump 8, a liquid outlet 12 at the top of the mixed denitrification zone 6 being connected to a second liquid inlet 13 of the water outlet trough 3 through a liquid outlet pipe, the water outlet trough 3 being connected to a liquid return port 14 at the bottom of the mixed denitrification zone 6 through a backwash pump 9, a water quality sampling tube 15 being provided on the mixed denitrification zone 6, a sampling valve being provided on the water quality sampling tube 15, and a sampling valve being provided on the water quality sampling tube 15 Used to take sewage from the mixed denitrification zone 6 for testing. The autotrophic denitrification zone 4 includes a micro-electrolysis filler layer 401 and a sulfur-modified filler layer 402. The sulfur-modified filler in the sulfur-modified filler layer 402 is made of sulfur flakes, shell powder, pore-forming agent and crushed medium-pressure aerated concrete that is calcined and cooled. The micro-electrolysis filler layer 401 is located at the bottom of the sulfur-modified filler layer 402. The mixed denitrification zone 6 is provided with a denitrifying agent filler layer 601, a quartz sand filler layer 602, a supporting layer 603 and a filter brick 604 from top to bottom. A plurality of water distributors 7 are arranged at the top of the mixed denitrification zone 6. The top of the mixed denitrification zone 6 is connected to an exhaust port 16, which is used to discharge nitrogen generated by denitrification. The bottom of the mixed denitrification zone 6 is connected to an aeration pump 10.

[0032] Among them, the denitrifier in the denitrifier filling layer 601 is a composite biomass carbon source and sulfur source denitrifier, and the composite biomass carbon source and sulfur source denitrifier is composed of the following components: 0.393mL of biomass carbon source and 0.687g of calcium polysulfide; wherein, the biomass carbon source is composed of a mixture of 99%-99.5% crude glycerol and 0.5%-1% growth factor by mass; the calcium polysulfide boiling process: first add 10-12 parts by weight of water to the iron crucible, then put 1 part by weight of lime into the crucible, stir until the lime becomes lime slurry, take a small amount of water to dissolve and dilute 2 parts by weight of sulfur powder into a paste, slowly pour it into the crucible and stir. Continue to heat and boil, and stop heating when the color turns dark reddish brown. After cooling, filter out the residue with gauze to obtain calcium polysulfide. Finally, the biomass carbon source and calcium polysulfide are mixed and placed in a centrifuge tube, and then 3W / mL ultrasonic oscillation is used for 20 minutes to make it homogenous.

[0033] Among them, the micro-electrolysis filler layer 401 is composed of iron powder, carbon powder, white carbon black, mica powder, chromium powder, and blast furnace slag powder in a mass ratio of 6:2:0.2:0.1:0.5 according to weight components; after being evenly mixed, it is formed on an automatic former, granulated, and dried at 80°C to form a mixed spherical filler; the electron transfer generated by the micro-electrolysis filler itself is directly utilized to provide the required electrons for the denitrification process of the autotrophic denitrifying bacteria; the particle size of the iron powder is 0.01mm, the particle size of the carbon powder is 0.5mm, the particle size of the white carbon black is 0.02mm, the particle size of the mica powder is 0.3mm, the particle size of the chromium powder is 0.05mm, and the particle size of the blast furnace slag powder is 0.1mm.

[0034] Among them, the medium-pressure aerated concrete is broken into particles with a diameter of 0.1mm-4mm, 50g of sulfur flakes, 25g of shell powder and 25g of crushed medium-pressure aerated concrete are placed in a crucible with a capacity of 200ml, 15g of sodium bicarbonate powder is added as a pore-forming agent, and the above materials are stirred evenly with a medicine spoon, put into a muffle furnace, and calcine at 130°C for 1 hour. After one hour, the heating is turned off, and the door of the muffle furnace is opened to allow it to cool naturally. The cooling time is about 3 hours. After cooling to room temperature, the crucible in the muffle furnace is taken out and the crucible is inverted. At this time, the fired filler will fall off naturally, and the sulfur-modified filler can be obtained.

[0035] This device is used to treat the sewage discharged from a printing and dyeing factory. The sewage quality is: nitrate nitrogen 15-20mg / L, Chemical Oxygen Demand (COD): 25-35mg / L, Total Nitrogen (TN): 30-45mg / L, Sulfate 160-200mg / L, suspended solids (SS): 22-30mg. The denitrification method includes the following steps:

[0036] Step 1: Add the printing and dyeing industrial sewage to be treated into the sewage collection tank 2, and transport the printing and dyeing industrial sewage to the autotrophic denitrification zone 4 through the water inlet pump 8;

[0037] Step 2: The sewage first passes through the micro-electrolysis filler layer 401 in the autotrophic denitrification zone 4. The micro-electrolysis filler layer 401 is filled with iron-carbon mixed spherical fillers in the form of a fixed bed. The electron transfer generated by the micro-electrolysis filler itself is directly used to provide the required electrons for the denitrification process of the autotrophic denitrifying bacteria.

[0038] Step 3: The sewage flowing out of the micro-electrolysis packing layer 401 enters the sulfur-modified packing layer 402, where denitrifying bacteria grow in the outer layer, and sulfide is produced in the inner layer to synthesize polysulfide. The presence of polysulfide can provide a large number of electron donors for the denitrification of the outer layer, thereby accelerating the denitrification process of the outer layer, and the C / N ratio of the treated sewage is further improved;

[0039] Step 4: The sewage treated in the autotrophic denitrification zone 4 enters the mixed denitrification zone 6 through the buffer cavity 5, and then enters the denitrification agent filling layer 601 through the water distributor 7. The denitrification agent is mainly composed of crude glycerol, vitamins, amino acids, and polysulfides. Crude glycerol, vitamins, and amino acids serve as carbon sources and can significantly improve the C / N ratio in the sewage.

[0040] Step 5: The sewage that has passed through the denitrifying agent filler layer 601 contains rich carbon sources and sulfur sources. The sulfur source is added to the rich carbon source through the quartz sand filler layer 602, so that part of the nitrate continues to be removed in the form of sulfur autotrophic denitrification, and the rest is removed by heterotrophic denitrifying bacteria through denitrification. The treated sewage is discharged from the liquid outlet 12 to the outlet tank 3. The sewage in the outlet tank 3 is then pumped into the reactor 1 through the backwash pump 9 to backwash the filler of the reactor 1. The backwash speed is set to 6-10m / h to prevent the sulfur particles from compacting in the filler.

[0041] The device was operated continuously for 276 days under this condition, and the water output results of the water outlet tank are shown in Table 1.

[0042] Example 2

[0043] The present embodiment provides a sulfur autotrophic denitrification and denitrification device in printing and dyeing industrial wastewater, comprising a reactor 1 and a sewage collection box 2 and a water outlet trough 3 respectively arranged before and after the reactor 1, the reactor 1 comprising an autotrophic denitrification zone 4, a buffer cavity 5 and a mixed denitrification zone 6, the buffer cavity 5 being located between the autotrophic denitrification zone 4 and the mixed denitrification zone 6, the sewage collection box 2 being connected to a first liquid inlet 11 of the autotrophic denitrification zone 4 through a water inlet pump 8, a liquid outlet 12 at the top of the mixed denitrification zone 6 being connected to a second liquid inlet 13 of the water outlet trough 3 through a liquid outlet pipe, the water outlet trough 3 being connected to a liquid return port 14 at the bottom of the mixed denitrification zone 6 through a backwash pump 9, a water quality sampling tube 15 being provided on the mixed denitrification zone 6, a sampling valve being provided on the water quality sampling tube 15, and a sampling valve being provided on the water quality sampling tube 15 Used to take sewage from the mixed denitrification zone 6 for testing. The autotrophic denitrification zone 4 includes a micro-electrolysis filler layer 401 and a sulfur-modified filler layer 402. The sulfur-modified filler in the sulfur-modified filler layer 402 is made of sulfur flakes, shell powder, pore-forming agent and crushed medium-pressure aerated concrete that is calcined and cooled. The micro-electrolysis filler layer 401 is located at the bottom of the sulfur-modified filler layer 402. The mixed denitrification zone 6 is provided with a denitrifying agent filler layer 601, a quartz sand filler layer 602, a supporting layer 603 and a filter brick 604 from top to bottom. A plurality of water distributors 7 are arranged at the top of the mixed denitrification zone 6. The top of the mixed denitrification zone 6 is connected to an exhaust port 16, which is used to discharge nitrogen generated by denitrification. The bottom of the mixed denitrification zone 6 is connected to an aeration pump 10.

[0044] Among them, the denitrifier in the denitrifier filling layer 601 is a composite biomass carbon source and sulfur source denitrifier, and the composite biomass carbon source and sulfur source denitrifier is composed of the following components: 0.393mL of biomass carbon source and 0.687g of calcium polysulfide; wherein, the biomass carbon source is composed of a mixture of 99%-99.5% crude glycerol and 0.5%-1% growth factor by mass; the calcium polysulfide boiling process: first add 10-12 parts by weight of water to the iron crucible, then put 1 part by weight of lime into the crucible, stir until the lime becomes lime slurry, take a small amount of water to dissolve and dilute 2 parts by weight of sulfur powder into a paste, slowly pour it into the crucible and stir. Continue to heat and boil, and stop heating when the color turns dark reddish brown. After cooling, filter out the residue with gauze to obtain calcium polysulfide. Finally, the biomass carbon source and calcium polysulfide are mixed and placed in a centrifuge tube, and then 3W / mL ultrasonic oscillation is used for 20 minutes to make it homogenous.

[0045] Among them, the micro-electrolysis filler layer 401 is composed of iron powder, carbon powder, white carbon black, mica powder, chromium powder, and blast furnace slag powder in a mass ratio of 6:2:0.2:0.1:0.5 by weight. After being mixed evenly, it is formed on an automatic former, granulated, and dried at 80°C to form a mixed spherical filler; the electron transfer generated by the micro-electrolysis filler itself is directly used to provide the required electrons for the denitrification process of the autotrophic denitrifying bacteria. The particle size of the iron powder is 0.01mm, the particle size of the carbon powder is 0.5mm, the particle size of the white carbon black is 0.02mm, the particle size of the mica powder is 0.3mm, the particle size of the chromium powder is 0.05mm, and the particle size of the blast furnace slag powder is 0.1mm.

[0046] Among them, the medium-pressure aerated concrete is broken into particles with a diameter of 0.1mm-4mm, 50g of sulfur flakes, 25g of shell powder and 25g of crushed medium-pressure aerated concrete are placed in a crucible with a capacity of 200ml, 15g of sodium bicarbonate powder is added as a pore-forming agent, and the above materials are stirred evenly with a medicine spoon, put into a muffle furnace, and calcine at 130°C for 1 hour. After one hour, the heating is turned off, and the door of the muffle furnace is opened to allow it to cool naturally. The cooling time is about 3 hours. After cooling to room temperature, the crucible in the muffle furnace is taken out and the crucible is inverted. At this time, the fired filler will fall off naturally, and the sulfur-modified filler can be obtained.

[0047] This device is used to treat the sewage discharged from a printing and dyeing factory. The sewage quality is: nitrate nitrogen 16-22mg / L, Chemical Oxygen Demand (COD): 28-40mg / L, Total Nitrogen (TN): 35-50mg / L, Sulfate 180-220mg / L, suspended solids (SS): 24-35mg. The denitrification method includes the following steps:

[0048] Step 1: Add the printing and dyeing industrial sewage to be treated into the sewage collection tank 2, and transport the printing and dyeing industrial sewage to the autotrophic denitrification zone 4 through the water inlet pump 8;

[0049] Step 2: The sewage first passes through the micro-electrolysis filler layer 401 in the autotrophic denitrification zone 4. The micro-electrolysis filler layer 401 is filled with iron-carbon mixed spherical fillers in the form of a fixed bed. The electron transfer generated by the micro-electrolysis filler itself is directly used to provide the required electrons for the denitrification process of the autotrophic denitrifying bacteria.

[0050] Step 3: The sewage flowing out of the micro-electrolysis packing layer 401 enters the sulfur-modified packing layer 402, where denitrifying bacteria grow in the outer layer, and sulfide is produced in the inner layer to synthesize polysulfide. The presence of polysulfide can provide a large number of electron donors for the denitrification of the outer layer, thereby accelerating the denitrification process of the outer layer, and the C / N ratio of the treated sewage is further improved;

[0051] Step 4: The sewage treated in the autotrophic denitrification zone 4 enters the mixed denitrification zone 6 through the buffer cavity 5, and then enters the denitrification agent filling layer 601 through the water distributor 7. The denitrification agent is mainly composed of crude glycerol, vitamins, amino acids, and polysulfides. Crude glycerol, vitamins, and amino acids serve as carbon sources and can significantly improve the C / N ratio in the sewage.

[0052] Step 5: The sewage that has passed through the denitrifying agent filler layer 601 contains rich carbon sources and sulfur sources. The sulfur source is added to the rich carbon source through the quartz sand filler layer 602, so that part of the nitrate continues to be removed in the form of sulfur autotrophic denitrification, and the rest is removed by heterotrophic denitrifying bacteria through denitrification. The treated sewage is discharged from the liquid outlet 12 to the outlet tank 3. The sewage in the outlet tank 3 is then pumped into the reactor 1 through the backwash pump 9 to backwash the filler of the reactor 1. The backwash speed is set to 6-10m / h to prevent the sulfur particles from compacting in the filler.

[0053] The device was operated continuously for 298 days under this condition, and the water output results of the water outlet tank are shown in Table 1.

[0054] Example 3

[0055] The present embodiment provides a sulfur autotrophic denitrification and denitrification device in printing and dyeing industrial wastewater, comprising a reactor 1 and a sewage collection box 2 and a water outlet trough 3 respectively arranged before and after the reactor 1, the reactor 1 comprising an autotrophic denitrification zone 4, a buffer cavity 5 and a mixed denitrification zone 6, the buffer cavity 5 being located between the autotrophic denitrification zone 4 and the mixed denitrification zone 6, the sewage collection box 2 being connected to a first liquid inlet 11 of the autotrophic denitrification zone 4 through a water inlet pump 8, a liquid outlet 12 at the top of the mixed denitrification zone 6 being connected to a second liquid inlet 13 of the water outlet trough 3 through a liquid outlet pipe, the water outlet trough 3 being connected to a liquid return port 14 at the bottom of the mixed denitrification zone 6 through a backwash pump 9, a water quality sampling tube 15 being provided on the mixed denitrification zone 6, a sampling valve being provided on the water quality sampling tube 15, and a sampling valve being provided on the water quality sampling tube 15 Used to take sewage from the mixed denitrification zone 6 for testing. The autotrophic denitrification zone 4 includes a micro-electrolysis filler layer 401 and a sulfur-modified filler layer 402. The sulfur-modified filler in the sulfur-modified filler layer 402 is made of sulfur flakes, shell powder, pore-forming agent and crushed medium-pressure aerated concrete that is calcined and cooled. The micro-electrolysis filler layer 401 is located at the bottom of the sulfur-modified filler layer 402. The mixed denitrification zone 6 is provided with a denitrifying agent filler layer 601, a quartz sand filler layer 602, a supporting layer 603 and a filter brick 604 from top to bottom. A plurality of water distributors 7 are arranged at the top of the mixed denitrification zone 6. The top of the mixed denitrification zone 6 is connected to an exhaust port 16, which is used to discharge nitrogen generated by denitrification. The bottom of the mixed denitrification zone 6 is connected to an aeration pump 10.

[0056] Among them, the denitrifier in the denitrifier filling layer 601 is a composite biomass carbon source and sulfur source denitrifier, and the composite biomass carbon source and sulfur source denitrifier is composed of the following components: 0.393mL of biomass carbon source and 0.687g of calcium polysulfide; wherein, the biomass carbon source is composed of a mixture of 99%-99.5% crude glycerol and 0.5%-1% growth factor by mass; the calcium polysulfide boiling process: first add 10-12 parts by weight of water to the iron crucible, then put 1 part by weight of lime into the crucible, stir until the lime becomes lime slurry, take a small amount of water to dissolve and dilute 2 parts by weight of sulfur powder into a paste, slowly pour it into the crucible and stir. Continue to heat and boil, and stop heating when the color turns dark reddish brown. After cooling, filter out the residue with gauze to obtain calcium polysulfide. Finally, the biomass carbon source and calcium polysulfide are mixed and placed in a centrifuge tube, and then 3W / mL ultrasonic oscillation is used for 20 minutes to make it homogenous.

[0057] Among them, the micro-electrolysis filler layer 401 is composed of iron powder, carbon powder, white carbon black, mica powder, chromium powder, and blast furnace slag powder in a mass ratio of 6:2:0.2:0.1:0.5 by weight. After being mixed evenly, it is formed on an automatic former, granulated, and dried at 80°C to form a mixed spherical filler; the electron transfer generated by the micro-electrolysis filler itself is directly used to provide the required electrons for the denitrification process of the autotrophic denitrifying bacteria. The particle size of the iron powder is 0.01mm, the particle size of the carbon powder is 0.5mm, the particle size of the white carbon black is 0.02mm, the particle size of the mica powder is 0.3mm, the particle size of the chromium powder is 0.05mm, and the particle size of the blast furnace slag powder is 0.1mm.

[0058] Among them, the medium-pressure aerated concrete is broken into particles with a diameter of 0.1mm-4mm, 50g of sulfur flakes, 25g of shell powder and 25g of crushed medium-pressure aerated concrete are placed in a crucible with a capacity of 200ml, 15g of sodium bicarbonate powder is added as a pore-forming agent, and the above materials are stirred evenly with a medicine spoon, put into a muffle furnace, and calcine at 130°C for 1 hour. After one hour, the heating is turned off, and the door of the muffle furnace is opened to allow it to cool naturally. The cooling time is about 3 hours. After cooling to room temperature, the crucible in the muffle furnace is taken out and the crucible is inverted. At this time, the fired filler will fall off naturally, and the sulfur-modified filler can be obtained.

[0059] This device is used to treat the sewage discharged from a printing and dyeing factory. The sewage quality is: nitrate nitrogen 20-28mg / L, Chemical Oxygen Demand (COD): 33-48mg / L, Total Nitrogen (TN): 40-60mg / L, Sulfate 210-270mg / L, suspended solids (SS): 30-40mg. The denitrification method includes the following steps:

[0060] Step 1: Add the printing and dyeing industrial sewage to be treated into the sewage collection tank 2, and transport the printing and dyeing industrial sewage to the autotrophic denitrification zone 4 through the water inlet pump 8;

[0061] Step 2: The sewage first passes through the micro-electrolysis filler layer 401 in the autotrophic denitrification zone 4. The micro-electrolysis filler layer 401 is filled with iron-carbon mixed spherical fillers in the form of a fixed bed. The electron transfer generated by the micro-electrolysis filler itself is directly used to provide the required electrons for the denitrification process of the autotrophic denitrifying bacteria.

[0062] Step 3: The sewage flowing out of the micro-electrolysis packing layer 401 enters the sulfur-modified packing layer 402, where denitrifying bacteria grow in the outer layer, and sulfide is produced in the inner layer to synthesize polysulfide. The presence of polysulfide can provide a large number of electron donors for the denitrification of the outer layer, thereby accelerating the denitrification process of the outer layer, and the C / N ratio of the treated sewage is further improved;

[0063] Step 4: The sewage treated in the autotrophic denitrification zone 4 enters the mixed denitrification zone 6 through the buffer cavity 5, and then enters the denitrification agent filling layer 601 through the water distributor 7. The denitrification agent is mainly composed of crude glycerol, vitamins, amino acids, and polysulfides. Crude glycerol, vitamins, and amino acids serve as carbon sources and can significantly improve the C / N ratio in the sewage.

[0064] Step 5: The sewage that has passed through the denitrifying agent filler layer 601 contains rich carbon sources and sulfur sources. The sulfur source is added to the rich carbon source through the quartz sand filler layer 602, so that part of the nitrate continues to be removed in the form of sulfur autotrophic denitrification, and the rest is removed by heterotrophic denitrifying bacteria through denitrification. The treated sewage is discharged from the liquid outlet 12 to the outlet tank 3. The sewage in the outlet tank 3 is then pumped into the reactor 1 through the backwash pump 9 to backwash the filler of the reactor 1. The backwash speed is set to 6-10m / h to prevent the sulfur particles from compacting in the filler.

[0065] The device was operated continuously for 325 days under this condition, and the water output results of the water outlet tank are shown in Table 1.

[0066] Example 4

[0067] The present embodiment provides a sulfur autotrophic denitrification and denitrification device in printing and dyeing industrial wastewater, comprising a reactor 1 and a sewage collection box 2 and a water outlet trough 3 respectively arranged before and after the reactor 1, the reactor 1 comprising an autotrophic denitrification zone 4, a buffer cavity 5 and a mixed denitrification zone 6, the buffer cavity 5 being located between the autotrophic denitrification zone 4 and the mixed denitrification zone 6, the sewage collection box 2 being connected to a first liquid inlet 11 of the autotrophic denitrification zone 4 through a water inlet pump 8, a liquid outlet 12 at the top of the mixed denitrification zone 6 being connected to a second liquid inlet 13 of the water outlet trough 3 through a liquid outlet pipe, the water outlet trough 3 being connected to a liquid return port 14 at the bottom of the mixed denitrification zone 6 through a backwash pump 9, a water quality sampling tube 15 being provided on the mixed denitrification zone 6, a sampling valve being provided on the water quality sampling tube 15, and a sampling valve being provided on the water quality sampling tube 15 Used to take sewage from the mixed denitrification zone 6 for testing. The autotrophic denitrification zone 4 includes a micro-electrolysis filler layer 401 and a sulfur-modified filler layer 402. The sulfur-modified filler in the sulfur-modified filler layer 402 is made of sulfur flakes, shell powder, pore-forming agent and crushed medium-pressure aerated concrete that is calcined and cooled. The micro-electrolysis filler layer 401 is located at the bottom of the sulfur-modified filler layer 402. The mixed denitrification zone 6 is provided with a denitrifying agent filler layer 601, a quartz sand filler layer 602, a supporting layer 603 and a filter brick 604 from top to bottom. A plurality of water distributors 7 are arranged at the top of the mixed denitrification zone 6. The top of the mixed denitrification zone 6 is connected to an exhaust port 16, which is used to discharge nitrogen generated by denitrification. The bottom of the mixed denitrification zone 6 is connected to an aeration pump 10.

[0068] Among them, the denitrifier in the denitrifier filling layer 601 is a composite biomass carbon source and sulfur source denitrifier, and the composite biomass carbon source and sulfur source denitrifier is composed of the following components: 0.393mL of biomass carbon source and 0.687g of calcium polysulfide; wherein, the biomass carbon source is composed of a mixture of 99%-99.5% crude glycerol and 0.5%-1% growth factor by mass; the calcium polysulfide boiling process: first add 10-12 parts by weight of water to the iron crucible, then put 1 part by weight of lime into the crucible, stir until the lime becomes lime slurry, take a small amount of water to dissolve and dilute 2 parts by weight of sulfur powder into a paste, slowly pour it into the crucible and stir. Continue to heat and boil, and stop heating when the color turns dark reddish brown. After cooling, filter out the residue with gauze to obtain calcium polysulfide. Finally, the biomass carbon source and calcium polysulfide are mixed and placed in a centrifuge tube, and then 3W / mL ultrasonic oscillation is used for 20 minutes to make it homogenous.

[0069] Among them, the micro-electrolysis filler layer 401 is composed of iron powder, carbon powder, white carbon black, mica powder, chromium powder, and blast furnace slag powder in a mass ratio of 6:2:0.2:0.1:0.5 by weight. After being mixed evenly, it is formed on an automatic former, granulated, and dried at 80°C to form a mixed spherical filler; the electron transfer generated by the micro-electrolysis filler itself is directly used to provide the required electrons for the denitrification process of the autotrophic denitrifying bacteria. The particle size of the iron powder is 0.01mm, the particle size of the carbon powder is 0.5mm, the particle size of the white carbon black is 0.02mm, the particle size of the mica powder is 0.3mm, the particle size of the chromium powder is 0.05mm, and the particle size of the blast furnace slag powder is 0.1mm.

[0070] Among them, the medium-pressure aerated concrete is broken into particles with a diameter of 0.1mm-4mm, 50g of sulfur flakes, 25g of shell powder and 25g of crushed medium-pressure aerated concrete are placed in a crucible with a capacity of 200ml, 15g of sodium bicarbonate powder is added as a pore-forming agent, and the above materials are stirred evenly with a medicine spoon, put into a muffle furnace, and calcine at 130°C for 1 hour. After one hour, the heating is turned off, and the door of the muffle furnace is opened to allow it to cool naturally. The cooling time is about 3 hours. After cooling to room temperature, the crucible in the muffle furnace is taken out and the crucible is inverted. At this time, the fired filler will fall off naturally, and the sulfur-modified filler can be obtained.

[0071] This device is used to treat the sewage discharged from a printing and dyeing factory. The sewage quality is: nitrate nitrogen 24-30mg / L, Chemical Oxygen Demand (COD): 40-55mg / L, Total Nitrogen (TN): 55-70mg / L, Sulfate 250-310mg / L:, suspended solids (SS): 35-45mg. The denitrification method includes the following steps:

[0072] Step 1: Add the printing and dyeing industrial sewage to be treated into the sewage collection tank 2, and transport the printing and dyeing industrial sewage to the autotrophic denitrification zone 4 through the water inlet pump 8;

[0073] Step 2: The sewage first passes through the micro-electrolysis filler layer 401 in the autotrophic denitrification zone 4. The micro-electrolysis filler layer 401 is filled with iron-carbon mixed spherical fillers in the form of a fixed bed. The electron transfer generated by the micro-electrolysis filler itself is directly used to provide the required electrons for the denitrification process of the autotrophic denitrifying bacteria.

[0074] Step 3: The sewage flowing out of the micro-electrolysis packing layer 401 enters the sulfur-modified packing layer 402, where denitrifying bacteria grow in the outer layer, and sulfide is produced in the inner layer to synthesize polysulfide. The presence of polysulfide can provide a large number of electron donors for the denitrification of the outer layer, thereby accelerating the denitrification process of the outer layer, and the C / N ratio of the treated sewage is further improved;

[0075] Step 4: The sewage treated in the autotrophic denitrification zone 4 enters the mixed denitrification zone 6 through the buffer cavity 5, and then enters the denitrification agent filling layer 601 through the water distributor 7. The denitrification agent is mainly composed of crude glycerol, vitamins, amino acids, and polysulfides. Crude glycerol, vitamins, and amino acids serve as carbon sources and can significantly improve the C / N ratio in the sewage.

[0076] Step 5: The sewage that has passed through the denitrifying agent packing layer 601 contains rich carbon sources and sulfur sources. Through the quartz sand packing layer 602, the sulfur source is added to the rich carbon source, so that part of the nitrate continues to be removed in the form of sulfur autotrophic denitrification, and the rest is removed by heterotrophic denitrifying bacteria through denitrification. The treated sewage is discharged from the liquid outlet 12 to the outlet tank 3. The sewage from the outlet tank 3 is then pumped into the reactor 1 through the backwash pump 9 to backwash the packing of the reactor 1. The backwash speed is set to 6-10m / h to prevent the sulfur particles from compacting in the packing. Example 5

[0077] The device was operated continuously for 365 days under this condition, and the water output results of the water outlet tank are shown in Table 1.

[0078] Table 1 Water outlet data table

[0079]

[0080] From the comparison of the data in the table above, it can be seen that with the increase of the operating time, the total nitrogen removal rate, COD degradation rate, The removal rate is becoming more and more stable, and the total nitrogen removal rate is above 92%. The removal rate is above 93%, and the degradation rate of COD is also good, indicating that the reactor composed of the autotrophic denitrification zone and the mixed denitrification zone has good denitrification performance.

[0081] Finally, it should be noted that the above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art can still modify the technical solutions described in the aforementioned embodiments or replace some of the technical features therein by equivalents. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A sulfur autotrophic denitrification and denitrification device in printing and dyeing industrial wastewater, comprising a reactor (1) and a sewage collection box (2) and a water outlet tank (3) respectively arranged before and after the reactor (1), wherein the reactor (1) comprises an autotrophic denitrification zone (4), a buffer cavity (5) and a mixed denitrification zone (6), wherein the buffer cavity (5) is located between the autotrophic denitrification zone (4) and the mixed denitrification zone (6), the sewage collection box (2) is connected to a first liquid inlet (11) of the autotrophic denitrification zone (4) through a water inlet pump (8), and the mixed denitrification zone (6) is connected to a first liquid inlet (11) of the autotrophic denitrification zone (4) through a water inlet pump (8), and the mixed denitrification zone (6) is connected to a first liquid inlet (11) of the autotrophic denitrification zone (4) through a water inlet pump (8). The liquid outlet (12) at the top of the nitrification zone (6) is connected to the second liquid inlet (13) of the water outlet tank (3) through a liquid outlet pipe, and the water outlet tank (3) is connected to the liquid return port (14) at the bottom of the mixed denitrification zone (6) through a backwash pump (9). The mixed denitrification zone (6) is provided with a water quality sampling tube (15). The autotrophic denitrification zone (4) includes a micro-electrolysis filler layer (401) and a sulfur-modified filler layer (402). The sulfur-modified filler in the sulfur-modified filler layer (402) is composed of sulfur flakes, shell powder, pore-forming agent and medium-pressure aeration after crushing. The concrete is calcined and cooled, the micro-electrolysis filler layer (401) is located at the bottom of the sulfur-modified filler layer (402), the mixed denitrification zone (6) is provided with a denitrifying agent filler layer (601), a quartz sand filler layer (602), a support layer (603) and a filter brick (604) from top to bottom, the denitrifying agent in the denitrifying agent filler layer (601) is a composite biomass carbon source and a sulfur-based denitrifying agent, and the composite biomass carbon source and the sulfur-based denitrifying agent include a COD of 110-120% composed of crude glycerol and growth factors. 10,000 mg / L of biomass carbon source, and calcium polysulfide with a COD of 600,000-700,000 mg / L, which is prepared by boiling quicklime, sulfur and water in a mass ratio of 1:(2-4):(10-12), wherein the biomass carbon source and the calcium polysulfide are mixed in a ratio of 1:(1-3) of the expected COD of the mixed denitrifying agent, and a plurality of water distributors (7) are arranged at the top of the mixed denitrification zone (6), the top of the mixed denitrification zone (6) is connected to an exhaust port (16), and the bottom of the mixed denitrification zone (6) is connected to an aeration pump (10).

2. The sulfur autotrophic denitrification and denitrification device in printing and dyeing industrial wastewater according to claim 1, characterized in that: The micro-electrolysis filler layer (401) is composed of iron powder, carbon powder, white carbon black, mica powder, chromium powder, and blast furnace slag powder in a mass ratio of (6-8):(2-3):(0.2-1):(0.1-0.3):(0.5-3.5) by weight.

3. The sulfur autotrophic denitrification and denitrification device in printing and dyeing industrial wastewater according to claim 1, characterized in that: The micro-electrolysis filler layer (401) is composed of iron powder, carbon powder, white carbon black, mica powder, chromium powder, and blast furnace slag powder in a ratio of 7:2.5:0.6:0.2:2 by weight.

4. The sulfur autotrophic denitrification and denitrification device in printing and dyeing industrial wastewater according to claim 2, characterized in that: The particle size of the iron powder is 0.01-0.03 mm, the particle size of the carbon powder is 0.5-0.7 mm, the particle size of the white carbon black is 0.02-0.04 mm, the particle size of the mica powder is 0.3-0.8 mm, the particle size of the chromium powder is 0.05-0.07 mm, and the particle size of the blast furnace slag powder is 0.1-0.5 mm.

5. The sulfur autotrophic denitrification and denitrification device in printing and dyeing industrial wastewater according to claim 1, characterized in that: The mass ratio of the sulfur flakes, shell powder, pore-forming agent and crushed medium-pressure aerated concrete is 50-100%: 0-25%: 15-20%: 25-33%.

6. The sulfur autotrophic denitrification and denitrification device in printing and dyeing industrial wastewater according to claim 1, characterized in that: The pore-forming agent is sodium bicarbonate, and the diameter of the medium-pressure aerated concrete after crushing is 0.1-4 mm.

7. The sulfur autotrophic denitrification and denitrification device in printing and dyeing industrial wastewater according to claim 1, characterized in that: The calcination temperature of the sulfur-modified filler is 120-140° C., and the calcination time is 1-2 hours.

8. The sulfur autotrophic denitrification and denitrification device in printing and dyeing industrial wastewater according to claim 1, characterized in that: The biomass carbon source consists of 99-99.5% by mass of crude glycerol and 0.5-1% by mass of growth factors, and the growth factors are amino acids and vitamins.

9. The sulfur autotrophic denitrification and denitrification device in printing and dyeing industrial wastewater according to claim 1, characterized in that: The calcium polysulfide is prepared by boiling quicklime, sulfur and water in a mass ratio of 1:2:

10.

10. The denitrification method of the sulfur autotrophic denitrification device in the printing and dyeing industrial wastewater according to claims 1-9, characterized in that: The following steps are involved: Step 1: Add the printing and dyeing industrial sewage to be treated into the sewage collection tank (2), and transport the printing and dyeing industrial sewage to the autotrophic denitrification zone (4) through the water inlet pump (8); Step 2: The wastewater first passes through the micro-electrolysis filler layer (401) in the autotrophic denitrification zone (4). The micro-electrolysis filler layer (401) is filled with iron-carbon mixed spherical fillers in the form of a fixed bed, and directly utilizes the electron transfer generated by the micro-electrolysis filler itself to provide the required electrons for the denitrification process of the autotrophic denitrifying bacteria; Step 3: The wastewater flowing out of the micro-electrolysis packing layer (401) enters the sulfur-modified packing layer (402), wherein the outer layer grows denitrifying bacteria, the inner layer produces sulfide, and synthesizes polysulfide. The presence of polysulfide can provide a large amount of electron donors for the denitrification of the outer layer, thereby accelerating the denitrification process of the outer layer. The C / N ratio of the treated wastewater is further improved. The reaction formula is as follows: Step 4: The wastewater treated in the autotrophic denitrification zone (4) enters the mixed denitrification zone (6) through the buffer cavity (5), and then enters the denitrification agent filling layer (601) through the water distributor (7). The denitrification agent is mainly composed of crude glycerol, vitamins, amino acids, and polysulfides. Crude glycerol, vitamins, and amino acids serve as carbon sources and can significantly improve the C / N ratio in the wastewater. Step 5: The wastewater passing through the denitrifying agent packing layer (601) contains rich carbon sources and sulfur sources. The sulfur source is added to the rich carbon source through the quartz sand packing layer (602), so that part of the nitrate continues to be removed in the form of sulfur autotrophic denitrification, and the rest is removed by heterotrophic denitrifying bacteria through denitrification. The treated wastewater is discharged from the liquid outlet (12) to the outlet tank (3). The wastewater in the outlet tank (3) is then pumped into the reactor (1) through the backwash pump (9) to backwash the packing of the reactor (1). The backwash speed is set to 6-10m / h.

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