CN219031892U - A sulfur autotrophic denitrification moving bed - Google Patents

Abstract

The utility model provides a sulfur autotrophic denitrification moving bed, which comprises a reactor water inlet end (2), a water inlet screen plate (4), a filler layer area (5), a spiral conveying rod piece (6) and a reactor water outlet end (7), wherein the bottom of the reactor moving bed is funnel-shaped; the spiral conveying rod piece (6) is positioned in the packing layer area, and the packing slowly moves from bottom to top in the rotating process of the spiral conveying rod piece by arranging the spiral conveying rod piece, and when the packing moves to the uppermost part of the threads, the packing falls back from a gap between the screw and the inner wall of the reactor. During this period, the filler particles are in mutual frictionThe nitrogen is continuously discharged in the friction process of the fillers, the fillers are not sticky and hardened, the thickness of the biological film can be effectively controlled, so that the main functional bacterial groups are directionally enriched, the mass transfer efficiency of the matrix and the actual contact residence time of sewage are effectively improved, the sewage treatment effect is improved, and the accumulation of nitrite and the greenhouse gas N are reduced ₂ O is discharged. In addition, with the improvement of the denitrification efficiency, the filling material consumption, the occupied area and the ton water investment cost of the reaction tank body are correspondingly reduced.

Description

A sulfur autotrophic denitrification moving bed

technical field

The utility model relates to the technical field of deep denitrification of sewage, in particular to a denitrification method for a sulfur autotrophic denitrification packed bed filter.

Background technique

In recent years, with the development of my country's economy and the emphasis on water resources protection, the regulatory authorities and various industries have gradually increased the water treatment standards, mainly in the high requirements for water supply quality and wastewater discharge, which makes the water treatment system Both investment and demand have increased significantly. At the same time, the discharge of various types of wastewater and domestic sewage continues to increase, and the water environment is seriously polluted, making rivers, lakes and other waters more nutrient elements, making them tend to be eutrophic. Eutrophication of water body can cause vicious algae outbreaks such as algal blooms and red tides, and then cause a series of problems such as water hypoxia, increased turbidity, odor emission, and increased levels of algal toxins, which seriously affect the quality of the water environment and the safety of water ecology. Among them, nitrogen pollutants are not only the key evaluation index of water nutrient level but also the key cause of algal bloom outbreak. Therefore, the deep reduction of total nitrogen from the source is an important way to control the eutrophication of urban water bodies and ensure the safety of ecological water use.

With the issuance of the "Water Pollution Prevention and Control Action Plan", clear and time-limited requirements have been put forward for my country's water environment improvement and sewage treatment goals, highlighting the urgency of deep removal of nitrogen pollutants in sewage.

The traditional denitrification filter uses quartz sand, ceramsite and other carriers as the film-hanging medium of denitrifying organisms, uses an appropriate amount of carbon source for denitrification reaction, and uses the interception effect of the filter medium to remove the suspended solids in the intercepted sewage and the shedding biofilm . The working principle of the traditional denitrification filter is that denitrifying bacteria convert nitrate into nitrogen in an anoxic environment, and the reaction uses organic carbon sources as electron donors. In order to obtain higher denitrification efficiency, the traditional method is to supplement carbon sources, but it will increase the cost of chemicals, which is not good for the operation of sewage treatment plants in the long run.

Sulfur autotrophic denitrification is mainly a process in which sulfur autotrophic denitrifying bacteria use sulfur and related reduced compounds as electron donors to reduce nitrate to nitrogen. Sulfur autotrophic denitrification has attracted extensive attention because it does not require external carbon sources. This reaction does not require an external carbon source and has high denitrification efficiency, which is an important technology for denitrification of low-carbon source wastewater. In the reaction process, sulfur particles are usually used as filler to provide the sulfur source required for the reaction, and limestone is added to balance the acid produced by the autotrophic denitrification reaction of sulfur element. However, the addition of limestone in traditional fillers may increase the hardness of effluent water, and consume a large amount of alkali, resulting in waste of sulfur and limestone; in recent years, the emergence of some sulfur-based composite fillers such as sulfur-iron composite fillers has overcome the natural The problem of alkalinity consumption during denitrification and alkalinity produced by iron autotrophic denitrification has gradually realized the engineering application of sulfur autotrophic denitrification technology.

At present, the process reactor mainly adopts the fixed bed form. In the fixed bed reactor, the solid particle material layer is always in a static state. With the continuous operation of the reactor, the continuous generation of nitrogen will occupy the gaps between the fillers, causing the reactor The actual gap becomes smaller, the hydraulic retention time becomes shorter, the mass transfer efficiency of the reactor becomes lower, and it cannot operate stably and efficiently. However, the surface of the filler continuously accumulates sediment, the biofilm is too thick and agglomerated, the proportion of living and dead bacteria is unbalanced, and the number of dead bacteria increases, resulting in the gradual reduction of the gaps between the fillers, forming compaction and blockage.

At present, the method to solve the above problems of sulfur autotrophic denitrification fixed bed reaction system is mainly backwashing:

(1) Patent 202021404064.5 discloses a sulfur-iron composite double-layer denitrification filter, which includes a sulfur autotrophic denitrification layer, an intermediate water layer, an iron autotrophic denitrification layer and Pebble support layer. The filter combines the sulfur autotrophic denitrification process and the iron autotrophic denitrification process to balance the alkalinity of the effluent. By installing backwash pipes under the sulfur packing layer and the iron packing layer respectively, it also solves the problem that occurs after the packing has been used for a long time. clogging problem. The construction cost required by this method is too large, and the maintenance and operation of the backwashing pipe are complicated.

(2) Patent CN202110452114.X describes a percolation bed reaction device for sulfur autotrophic denitrification biological denitrification. The backwash system is connected to the bottom of the reaction tank, and the packing layer is connected to the inside of the reaction tank, which solves the problem of packing stripping The problem of easy clogging after the end is realized, and the non-stop backwashing process is realized. This method requires regular backwashing, but an additional backwashing reminder device is required to remind the staff of backwashing maintenance, which increases construction costs and management costs.

(3) Literature (Wang Y, Bott C, Nerenberg R. Sulfur-based denitrification: Effect of biofilm development on denitrification fluxes. Water Research, 2016, 100(sep.1): 184-193.) describes a sulfur flake The experimental results show that as the biofilm thickens, the mass transfer efficiency of the system continues to decline, and the No. 2 reaction device is obvious. After its operation for 50 days, the denitrification load begins to show a downward trend. .

In actual filter maintenance applications, backwashing is often divided into three methods: air washing, water washing, and air-water combined washing. The strength of ordinary water washing is small, and it is generally used for the removal of nitrogen in the packing layer, mainly for nitrogen driving; while air washing has a greater impact on the packing, which can effectively remove compaction. Backwashing is currently the main way to solve deep bed filter hardening and nitrogen accumulation, but it also has some negative effects on fillers: (1) The denitrification process is an anaerobic process, and air washing will introduce a large amount of oxygen, destroying The existing anaerobic environment of the filter layer. (2) Due to the existence of the backwashing process, the operation mode and structure of the filter will change, reducing the water production rate of the filter. (3) The water flow and air bubbles generated by air washing and water washing will preferentially pass through the voids with less resistance in the filter material layer, and the void channels with less impact resistance cannot completely break up the compaction, so the reflection of the deep bed filter Rinsing is often not thorough.

Utility model content

Based on the above-mentioned technical background, the present inventor has made great progress and found that: by installing a screw conveying rod in the packing layer of the sulfur autotrophic denitrification moving bed, the packing slowly moves from bottom to top under the rotation of the screw conveying rod , when moving to the end of the effective stroke of the screw rod, the filler will fall back to the surrounding wall close to the inner wall of the reactor, forming a cycle, which can effectively reduce the accumulation of nitrogen bubbles generated by denitrification in the filler layer, and the thickness of the biofilm in the filler layer will also increase. The mutual friction between the particles is reduced, and the compaction of the packing can be prevented without backwashing. At the same time, the mass transfer efficiency of the matrix and the actual contact residence time of the sewage are improved, and the sewage treatment effect, treatment efficiency and nitrate nitrogen removal load are improved. At the same time, after eliminating the negative impact of filler compaction, the thickness of the biofilm on the surface of the filler is effectively controlled with the friction between the filler particles. The reduction of the biofilm thickness promotes the renewal of the biofilm and improves the effective activity. The proportion of bacteria helps sulfur autotrophic denitrifying bacteria to become the dominant species. At the same time, nitrogen is continuously discharged during the friction process of the filler, which effectively improves the mass transfer efficiency of the matrix and the actual contact residence time of the sewage, improves the sewage treatment effect, and reduces the accumulation of nitrite and the emission of greenhouse gas N ₂ O. In addition, with the improvement of denitrification efficiency, the initial filler usage of the tank volume is effectively reduced, the operation and management costs are greatly reduced, and the utility model has a good application prospect in sewage treatment, thus completing the utility model.

The first aspect of the utility model is to provide a sulfur autotrophic denitrification moving bed. The denitrification moving bed includes a reactor water inlet 2, a uniform water distribution hole plate 4, a supporting layer area 5, a packing layer area 6, a spiral Conveying rod 7 and reactor water outlet 9;

The screw conveying rod 7 is vertically installed in the middle of the packing layer area 6, and it includes a straight rod and a screw part. The screw part is helical, and the straight rod is located in the middle of the screw part. superior.

Description of drawings

Fig. 1 shows a kind of preferred embodiment of the present invention sulfur autotrophic denitrification moving bed schematic diagram;

Fig. 2 shows the structural representation of the pulsating bed reactor of a kind of preferred embodiment of the utility model;

Fig. 3 shows a top view of a pulsating bed reactor in a preferred embodiment of the present invention.

Explanation of reference numbers

1-Inlet peristaltic pump;

2- Reactor water inlet;

3-Digital display pressure gauge;

4-Inlet sieve plate;

5- packing layer area;

6-Screw conveying rod;

7- Reactor water outlet;

8 - motor;

9-speed tuner.

12 - water inlet;

14-water distribution board;

15-supporting layer;

16 - packing layer;

17-screw rod;

18-automatic guide rail;

19-outlet pipe.

Detailed ways

The utility model will be described in detail below, and the features and advantages of the utility model will become clearer and clearer along with these descriptions.

The first aspect of the utility model is to provide a sulfur autotrophic denitrification moving bed, the denitrification moving bed includes the reactor water inlet 2, the water inlet sieve plate 4, the packing layer area 5, the screw conveying rod 6 and the reactor The water outlet 7 and the water inlet sieve plate 4 are located in the middle of the bottom of the denitrification moving bed, and the bottom of the denitrification moving bed slopes downward around the water inlet sieve plate 4, and the whole is funnel-shaped, as shown in Figure 1, which is beneficial to the screw conveyor When part 6 rotates in the moving bed, the filler at the bottom of the moving bed will "flow" to avoid packing compaction.

The included angle between the bottom of the denitrifying moving bed and its side is an obtuse angle, preferably 95-150°, more preferably 95-120°.

In the traditional sulfur autotrophic denitrification fixed bed, as the denitrification process proceeds, the nitrogen gas produced will accumulate in the gaps of the filler layer, and the organisms will continue to grow on the surface of the filler after the successful film formation. When the biofilm accumulation is too thick It will affect the diffusion of the matrix to the surface of the filler, and at the same time, the growing biofilm will also connect with each other to form a compaction. Due to the packing compaction, the mass transfer between sewage and organisms is affected, resulting in a decrease in the denitrification efficiency of the reactor. At the same time, with the thickening of the biofilm, a large amount of compaction accumulated, and some bacteria continued to die due to the difficulty in contacting the surface of the sulfur-based filler, which also led to an increase in the proportion of dead bacteria in the biofilm.

The sulfur autotrophic denitrification moving bed described in the utility model is provided with a screw conveying rod 6, which is in a spiral shape and is a mechanical device for pushing material conveying. Slow frictional movement makes the filler slowly "flow", which can avoid the compaction of the filler, and at the same time, it can effectively control the thickness of the biofilm, so that the main functional bacteria are directional enriched, and nitrogen is continuously discharged during the friction process of the filler, effectively improving the mass transfer efficiency of the matrix and the actual contact residence time of sewage, which reduces the accumulation of nitrite and the emission of greenhouse gas N ₂ O, so that the reaction system has a higher denitrification load. In addition, the screw conveying rod has a simple structure and a cross-sectional area Small size, good sealing, easy operation and so on.

The reactor water inlet 2 is located at the lowermost end of the denitrification moving bed, and is connected with the water inlet peristaltic pump 1, and the waste water to be treated is transported from the reactor water inlet 2 to the denitrification moving bed, and the screw conveys the rod 6 is in the shape of a spiral, installed vertically in the middle of the packing layer area 5, the reactor water outlet 7 is located above the packing layer area 5, and the water inlet sieve plate 4 is located between the packing layer area 5 and the reactor water inlet 2 to prevent the filling drop.

The vertical distance between the reactor water outlet 7 and the packing layer area 5 is 5-300 cm, preferably 7-200 cm, more preferably 10-200 cm.

The sulfur autotrophic denitrification moving bed adopts the upflow mode. After operation, the waste water to be treated flows into the moving bed from the reactor water inlet 2 through the water inlet peristaltic pump 1, then flows into the packing layer area 5, and finally flows from the reactor water outlet. 7 out.

The upper end of the screw conveyor rod 6 is connected to the motor 8, and the other end of the motor 8 is connected to the speed frequency regulator 9. The motor 8 drives the screw conveyor rod 6 to rotate, and the filler moves slowly from the bottom to the top of the screw conveyor rod. At the end of the effective stroke of the screw rod, the filler falls back to the inner wall of the reactor to form a cycle, and the accumulated nitrogen bubbles generated by denitrification are discharged upward from the water outlet 7 of the reactor when the filler moves to the end of the effective stroke of the screw rod. The over-thick biofilm on the filler can also fall off and float to the reactor water outlet 7 under the mutual friction between the filler particles, so as to reduce the thickness of the biofilm.

It has been found through experiments that the rotation of the screw conveying rod 6 can also renew the biofilm in time, and the mutual friction between the fillers can effectively remove the over-thick old dead bacteria, increase the proportion of live bacteria in the biofilm as a whole, and increase the proportion of related sulfur suitable bacteria , such as Thiobacillus and Sulfurimonas increased in proportion.

The rotation speed of the screw conveying rod 6 is 1-30r/min, preferably 5-20r/min, more preferably 6-10r/min.

The screw conveying rod 6 includes a straight rod and a helical part, the helical part is helical, the straight rod is located in the middle of the helical part, and the head end and the end of the helical part are fixed on the straight rod.

The material of the straight rod and the screw part in the screw conveying rod 6 is selected from one or more of nylon, 304 stainless steel, 302 stainless steel, and aluminum alloy, preferably 304 stainless steel. Under the same conditions, the screw made of 304 stainless steel has a smaller volume and is more conducive to filling.

The pitch of the helical part of the screw conveying rod 6 is 1-50 mm, preferably 3-40 mm, more preferably 5-35 mm.

The inclination angle of the spiral member is 5-20°, preferably 8-15°, more preferably 10-12°.

The ratio of the diameter of the spiral member to the diameter of the reactor is 1:1.05-1:5, preferably 1:1.2-1:4, more preferably 1:1.5-1:3. It can ensure that the filler in the packing layer area of the reactor can "flow" under the agitation of the screw conveying rod, and it can also make there is enough space between the screw and the inner wall of the reactor to ensure the flow of the filler, and at the same time avoid part of the filler due to failure Agitated to produce hardening.

When the inclination angle of the spiral part is within the above range, it is beneficial for the packing to slowly move upward under the rotation of the spiral part, and at the same time, the bubbles are continuously discharged during the rising process, reducing the accumulation of nitrogen bubbles and preventing the packing from compacting.

Packing layer region 5 includes one or more of sulfur fillers, pyrite fillers and composite fillers containing sulfur, preferably includes one or both of sulfur and sulfur-iron composite fillers, and more preferably includes 2-8mm spherical Sulfur filler.

The filling height of the packing layer region 5 is 20-500 cm, preferably 30-200 cm, more preferably 40-70 cm.

The porosity of the filler layer region 5 is 37-42%, preferably 38-41%, more preferably 39-40%.

The second aspect of the utility model is to provide a method for denitrification of sewage by using the sulfur autotrophic denitrification moving bed described in the first aspect of the utility model. In the nitrification moving bed, it is transported to the packing layer area 5 through the inlet sieve plate 4, and finally flows out from the reactor outlet 7 after being treated. During the sewage treatment process, the screw conveying rod 6 is in a state of intermittent rotation, preferably for 0.1 to 8 hours. , stop 0.1 ~ 8h, more preferably 6h stop 6h rotation.

The intermittent rotation method can not only reduce the cost of sewage treatment, but also greatly improve the sewage treatment effect and the mass transfer effect.

According to the removal requirements of the actual water quality nitrate nitrogen concentration, generally speaking, the empty bed residence time is 0.1-6h, preferably the residence time is 0.3-4h, more preferably 0.5-2h.

The sewage treatment temperature is 10-40°C, preferably 20-35°C, more preferably 25-30°C. The above treatment temperature is the most suitable temperature for Thiobacillus denitrificans.

The rotation speed of the screw conveying rod 6 is 1-30r/min, preferably 5-20r/min, more preferably 6-10r/min.

It has been found through tests that when the rotational speed of the screw conveying rods is within the above range, it is beneficial to avoid packing compaction and discharge nitrogen bubbles from the reactor, effectively reduce the nitrogen content of the effluent, and improve the sewage treatment effect.

The third aspect of the utility model is to provide a pulsed bed reactor, which is in the shape of a cuboid. Described pulsating bed reactor comprises screw rod part 17 and automatic guide rail 18, and automatic guide rail 18 is installed on the top of pulsating bed reactor, and screw rod part 17 is installed on the automatic guide rail 18, and screw rod part 17 can follow automatic guide rail 18 along The long side direction and the short side direction of the pulsating bed reactor reciprocate, as shown in Fig. 2 and Fig. 3, the screw member 17 is continuously rotated during the reciprocating movement, which can not only realize the local disturbance of the filler, but also make the The filler in the reactor moves fully as a whole, so that it has better industrial scale-up application capability.

The test found that mechanical stirring can effectively maintain the denitrification effect of the pulsating bed reactor, and at the same time, the repeated movement of the automatic guide rail can make the filling of each part of the reactor more evenly stirred, reduce the accumulation of nitrogen bubbles in the packing layer, and improve the denitrification effect .

Described automatic guide rail 18 is installed on the top of pulsating bed reactor, and automatic guide rail 18 is I-shaped, as shown in Figure 3, comprises the long guide rail installed along the long side of reactor, is positioned at the both sides of reactor top, also includes installation The short guide rail between the two long guide rails, the short guide rail is perpendicular to the long guide rail, as shown in Figure 3, the long guide rail is parallel to the long side of the pulsed bed reactor, and the short guide rail is parallel to the short side of the pulsed bed reactor.

The rotational speed of the screw member 17 is 5-40r/min, preferably 15-30r/min, more preferably 15-25r/min.

The horizontal moving speed of the screw rod 17 on the automatic guide rail 18 is 0.01-11 cm/s, preferably 0.05-5.0 cm/s, more preferably 0.1-1 cm/s.

When the moving speed of the automatic guide rail is within the above range, it is beneficial to fully move the packing as a whole, avoid the adhesion and hardening of various parts of the packing in the pulsating bed, and renew the biofilm in time, keep the biofilm at a low thickness, and make the denitrification The moving bed has a higher nitrogen removal load.

The ratio of the length of the automatic guide rail 18 to the long side of the pulsed bed reactor is (1-1.3):1, preferably (1-1.2):1, and more preferably (1-1.05):1.

The ratio of the length of the short guide rail of the automatic guide rail 18 to the short side of the pulsed bed reactor is (1-1.3):1, preferably (1-1.2):1, more preferably (1-1.05):1.

The present inventors found that when the length of the long guide rail and the short guide rail of the automatic guide rail and the ratio of the long side to the short side of the pulsating bed reactor are within the above range, the screw conveying rod can stir the filler in the entire pulsating bed to the greatest extent. Renew the biofilm in the packing layer in time.

The pulsating bed reactor also includes a water inlet 12, an outlet pipe 19, a supporting layer 15, a packing layer 16 and a water distribution plate 14. The pulsating bed reactor adopts an upflow mode, and the water inlet 12 is located in the pulsating bed reactor. The bottom of the bottom, the supporting layer 15 and the water distribution plate 14 are located between the packing layer 16 and the water inlet 12, the supporting layer 15 is located between the packing layer 16 and the water distribution plate 14, and the screw rod member 17 is helical, located in the packing layer 16 Among them, the outlet pipe 19 is located above the packing layer 16.

The screw member 17 includes a straight rod and a helical part, the helical part is helical, the straight rod is located in the middle of the helical part, and the head end and the end of the helical part are fixed on the straight rod.

The material of the straight rod of the screw rod member 17 is selected from one or both of nylon and 304 stainless steel, preferably 304 stainless steel. Under the same conditions, the screw made of 304 stainless steel has a smaller volume and is more conducive to filling.

The material of the spiral member is selected from one or both of nylon and 304 stainless steel, preferably 304 stainless steel.

The pitch of the helical part of the screw rod member 17 is 1-50 mm, preferably 3-40 mm, more preferably 5-35 mm.

The inclination angle of the spiral member is 5-20°, preferably 8-15°, more preferably 10-15°.

Since the screw rod 17 can reciprocate along the long side and short side of the pulsating bed reactor along with the automatic guide rail 18, the influence of the screw rod 17 on each point of the filler is ensured, and the maximum range of "stirring" reaction can be achieved. The filling in the container can effectively avoid the hardening of part of the filling in the pulsating bed because it is not stirred.

The supporting layer 15 is made of one or more of pebbles, stones, ceramsite and sand, preferably one or both of pebbles and ceramsite, and more preferably pebbles with a particle size of 3-8 mm.

The filling height of the support layer 15 is 3-150 cm, preferably 5-120 cm, more preferably 8-100 cm.

The porosity of the supporting layer 15 is 30-50%, preferably 33-48%, more preferably 38-46%.

The filler layer 16 includes one or more of sulfur fillers, pyrite fillers and composite fillers containing sulfur, preferably includes sulfur, and more preferably includes spherical sulfur with a particle size of 3-5 mm.

The filling height of the filler layer 16 is 5-500 cm, preferably 10-300 cm, more preferably 12-250 cm.

The porosity of the filler layer 16 is 37-42%, preferably 38-41%, more preferably 39-40%. When the porosity of the filler layer 16 is in the above range, the residence time of the waste water to be treated in the pulsating bed is suitable, and the denitrification effect and denitrification efficiency are high.

The vertical distance between the outlet pipe 19 and the packing layer 16 is 2-50 cm, preferably 6-30 cm, more preferably 8-20 cm.

The short-handle filter heads are evenly distributed on the water distribution plate 14, so that the sewage flowing in from the water inlet is evenly distributed by the short-handle filter heads on the water distribution plate 14 and flows into the supporting layer 15. The diameter of the short handle filter head is 0.5-50 mm, preferably 0.6-40 mm, more preferably 0.8-30 mm.

The distance between the adjacent short-handle filter heads on the water distribution plate 14 is equal, thereby ensuring that the installed short-handle filter heads can distribute water evenly in the overall filter tank, and the distance between adjacent short-handle filter heads is 0.1 to 10 cm. Preferably it is 0.5-8 cm, More preferably, it is 1-6 cm.

The fourth aspect of the utility model is to provide a method for denitrification of sewage using the pulsating bed reactor described in the third aspect of the utility model. The method transports the waste water to be treated from the water inlet to the sulfur autotrophic denitrification pulsating bed, From bottom to top, it passes through the uniformly distributed water orifice plate 14, the supporting layer 15 and the packing layer 16, and finally flows out from the water outlet 19 of the pulsating bed reactor.

The empty bed residence time depends on the concentration of nitrate nitrogen in the sewage to be treated, usually 0.1~6h

The sewage treatment temperature is 8-40°C, preferably 15-35°C, more preferably 20-30°C.

The rotation speed of the screw member 17 is 5-40r/min, preferably 15-30r/min, more preferably 15-25r/min. Continuous rotation or intermittent rotation state.

The horizontal movement speed of the screw rod 17 on the automatic guide rail is 0.01-11 cm/s, preferably 0.05-5.0 cm/s, more preferably 0.1-1 cm/s. Continuous reciprocating motion or intermittent rotation state.

The beneficial effect that the utility model has:

(1) The denitrification moving bed system described in this utility model is to add a screw conveying rod to the fixed bed system that has been maturely applied. The addition of this device can realize the fluidization of the filler and the mutual friction between the fillers, even if Exhaust the nitrogen between the packing layers, reduce the thickness of the biofilm, increase the proportion of sulfur autotrophic denitrifying bacteria on the surface of the packing, and maintain the efficient and stable denitrification performance of the reaction system. The denitrification moving bed system is used for sewage denitrification treatment. On the one hand, it can improve the stability of sewage treatment. On the other hand, compared with the fixed bed system, its denitrification rate is significantly improved. The process does not need to rely on backwashing, which avoids the damage to the packing layer caused by oxygen during air washing, the decrease in water production rate caused by backwashing, and the uneven and incomplete backwashing.

(2) Compared with the fixed bed process, the moving bed system described in the utility model can significantly increase the denitrification load, and the experiment proves that the overall increase is nearly 50%, and the smooth progress of the denitrification reaction also greatly reduces the discharge of the intermediate product _N2O , reduce the greenhouse effect. Under the same application scenario conditions, it can effectively reduce the initial filler usage of the pool volume, reduce the floor area by 20-30%, and reduce the investment cost per ton of water by 30-40%. In addition, the utility model does not need to rely on backwashing, Greatly reduced operation and management costs.

(3) The pulsating bed reactor described in this utility model installs the spiral conveying rod above the filter tank and cooperates with the braking track. When facing the enlarged development of a large filter tank, it can not only realize the local circulation fluidization of the filler, but also pass through the track. The setting can also realize the overall flow of the filler. Different from the existing air flushing and water flushing technology, the utility model can more effectively solve the problem of low backwash water production rate and backwash pipe diameter caused by the enlargement of the existing fixed bed process. Too large, the filter stops running during backwashing, etc.

(4) In view of the problems of low denitrification load, reliance on backwashing and lack of controlled regulation of denitrification efficiency in the fixed bed reaction system in the prior art, the utility model creatively proposes a moving bed process driven by a screw conveying rod, which is expected to be used in Breakthroughs in new process technologies have provided strong support for solving the urgent need for deep reduction of total nitrogen in sewage treatment plants in my country.

Example

The utility model is further elaborated below through specific examples, and these embodiments are only limited to illustrate the utility model, and are not intended to limit the scope of the utility model.

Example 1

The sulfur autotrophic denitrification moving bed includes the reactor water inlet 2, the water inlet sieve plate 4, the packing layer area 5, the screw conveying rod 6 and the reactor water outlet 7, and the water inlet sieve plate 4 is located at the bottom of the denitrification moving bed In the middle position, the bottom of the denitrification moving bed slopes downward around the inlet sieve plate 4, in the shape of a funnel. The angle between the bottom of the denitrification moving bed and its side is 100°, and the reactor inlet 2 is located in the denitrification moving bed The lowermost end is connected with the water inlet peristaltic pump 1, the packing layer area 5 is located between the reactor water outlet 7 and the reactor water inlet 2, and the screw conveying rod 6 is helical, and is vertically installed in the middle of the packing layer area 5 Position, the reactor water outlet 7 is located above the packing layer area 5 .

The packing layer area 5 of the sulfur autotrophic denitrification moving bed adopts 3-5mm sulfur spherical particles, the filling height is 50cm, the porosity is 40%, and the reactor water outlet 7 is higher than the packing layer area 5-10cm. The screw conveying rod 6 includes a straight rod and a screw part, the material of the screw part is 304 stainless steel, the pitch of the screw part is 30mm, the inclination angle of the screw part is 10 °, and the diameter of the screw part is 1 to the reactor diameter ratio: 2. The rotation speed of the screw conveying rod 6 is 10r/min, the motor power is 60W, the empty bed residence time is 1h, the influent flow rate is 39.25ml/min, and the simulated wastewater composition is: NO ₃ ^- -N 20mg·L ^{- 1.} NH ₄ ⁺ -N 2mg·L ^-1 , KH ₂ PO ⁴ -P 0.5mg·L ^-1 , NaHCO ₃ 0.3mg·L ^-1 , MgCl ₂ ·6H ₂ O 0.4mg·L ^-1 , Na ₂ S ₂ O ₃ 50mg·L ^-1 , then add trace element solution and vitamin solution at a ratio of 1mL/L, inoculate anaerobic pool sludge with a filler layer volume of 1000mg/L, and start the process. The bed residence time was adjusted to 0.5h, and the influent flow rate was increased to 78.5ml/min. After 5 days, the Na ₂ S ₂ O ₃ in the influent water was removed, and the operation was performed until the effluent was stable. The sewage treatment temperature was controlled at 30°C, and the nitric acid After the salt nitrogen and nitrite nitrogen are stabilized, the startup is considered successful.

Example 2

The pulsating bed reactor comprises a water inlet 12, a water distribution plate 14, a support layer 15, a packing layer 16, a screw rod 17, an automatic guide rail 18 and an outlet pipe 19, and the water inlet 12 is located at the bottom of the pulsating bed reactor, and The water inlet peristaltic pump is connected, the supporting layer 15 and the water distribution plate 14 are located between the packing layer 16 and the water inlet end 12, the supporting layer 15 is located between the packing layer 16 and the water distribution plate 14, and the screw rod 17 is in a spiral shape, located at In the packing layer 16, the water outlet 19 is located above the packing layer 16, the automatic guide rail 18 is installed on the top of the pulsating bed reactor, the screw rod 17 is installed on the automatic guide rail 18, and the automatic guide rail 18 is I-shaped, including along the length of the reactor. Side-mounted long rails, located on both sides of the top of the reactor, and short rails mounted between the two long rails, the short rails are perpendicular to the long rails, the long rails are parallel to the long side of the pulsed bed reactor, and the short rails are parallel to the The short side of the pulsed bed reactor.

The support layer 15 of the pulsating bed reactor includes cobblestones with a diameter of 3-5mm, the filling height of the support layer 15 is 10cm, and its porosity is 44%, the packing layer 16 adopts sulfur spherical particles of 3-5mm, and the filling height is 30cm , the porosity is 40%, and the outlet pipe 19 is higher than the packing layer 16 by 15cm. The handle diameter of the short handle filter head on the water distribution plate 14 is 3cm, and the distance between adjacent short handle filter heads is 5cm. Stainless steel, the pitch of the helical part is 30mm, the inclination angle of the helical part is 15°, the ratio of the diameter of the helical part to the width of the pulsating bed reactor is 0.533, and the ratio of the length of the long guide rail of the automatic guide rail 18 to the long side of the pulsating bed reactor is 1:1, the ratio of the length of the short guide rail of the automatic guide rail 18 to the short side of the pulsating bed reactor is 1:1, the rotation speed of the screw member 17 is 23r/min, and the horizontal movement speed of the screw member 17 on the automatic guide rail 18 is 0.5cm/s, the motor power is 70W, the empty bed residence time is 1h, the influent flow rate is 9000ml/min, the simulated wastewater components are: NO ₃ ^- -N 20mg·L ^-1 , NH ₄ ⁺ -N 2mg·L ^-1 , KH ₂ PO ⁴ -P 0.5mg·L ^-1 , NaHCO ₃ 0.3mg·L ^-1 , MgCl ₂ 6H ₂ O 0.4mg·L ^-1 , Na ₂ S ₂ O ₃ 50mg·L ^-1 , Then add trace element solution and vitamin solution according to the ratio of 1mL/L, inoculate the anaerobic pool sludge according to the filler layer volume of 1000mg/L, start the process, after 5 days of continuous water inflow, adjust the empty bed residence time to 0.333h, Increase the flow rate to 2250ml/min, remove Na ₂ S ₂ O ₃ in the influent after 5 days, and run until the effluent is stable. Control the sewage treatment temperature at 30°C. to start successfully.

comparative example

Comparative example 1

Sewage denitrification is carried out in a manner similar to that of Example 1, the only difference being that the sulfur autotrophic denitrification moving bed does not include the screw conveying rod 7 .

Comparative example 2

Sewage denitrification is carried out in a manner similar to that of Example 2, the only difference is that the pulsating bed does not include the screw rod 17 and the automatic guide rail 18 .

Experimental example

Experimental Example 1 Nitrogen removal effect test

The concentration of nitrate nitrogen, nitrite nitrogen and N ₂ O in the effluent of Example 1 and Comparative Example 1 were tested, and the dynamic nitrate nitrogen concentration of the effluent is shown in Table 1 below.

As can be seen from Table 1, when the effluent of Example 1 and Comparative Example 1 is stable, the influent and effluent samples of the two are selected for 10 days. Under the same influent flow rate, the nitrate nitrogen removal concentration of the effluent of Example 1 is stable at 18mg /L or so, the removal rate is about 81%, which is much higher than the nitrate nitrogen difference in the influent and effluent water of Comparative Example 1, which is 11mg/L, and the removal rate is about 61%. The nitrate nitrogen concentration will continue to rise, while the effluent nitrate nitrogen in Example 1 remains stable.

Table 1

Similarly, there is almost no accumulation of nitrite in Example 1, and nitrite can be clearly detected in the effluent in Comparative Example 1. This is due to the smoother denitrification process that occurred in Example 1, so the implementation of Nitrite accumulation in Example 1 was low.

It can be seen that the sulfur autotrophic denitrification moving bed described in the utility model has a relatively high nitrate nitrogen removal load.

Experimental example 2 Nitrogen removal effect test

The nitrate nitrogen, nitrite nitrogen, and DO value (dissolved oxygen) reduction concentration of the effluent of Example 2 and Comparative Example 2 were tested, and the dynamic nitrate nitrogen concentration of the effluent is shown in Table 2 below.

As can be seen from Table 2, when the effluent of Example 2 and Comparative Example 2 were stabilized, the influent and effluent samples of the two were selected for 10 days. Under the same influent flow rate, the nitrate nitrogen removal concentration of the effluent of Example 2 was stable at 6mg /L, which is higher than the difference of nitrate nitrogen in the influent and effluent of Comparative Example 2 by 4mg/L, and with the continuous operation of the denitrification pulsating bed, the concentration of nitrate nitrogen in the effluent of the comparative example will continue to rise, while the effluent of Example 2 Nitrate nitrogen remains stable.

Table 2

Similarly, there is almost no accumulation of nitrite in Example 2, but nitrite can be clearly detected in the effluent in Comparative Example 2. This is due to the smoother denitrification process that occurred in Example 2, so the implementation of The concentration of nitrite nitrogen salt in the effluent in Example 2 is lower.

It can be seen that the sulfur autotrophic denitrification pulsating bed described in the utility model has a relatively high nitrate nitrogen removal load.

Experimental example 3 analysis of bed clogging degree

The nitrogen accumulation rate of embodiment 1 and comparative example 1 moving bed is tested, and nitrogen accumulation rate and actual residence time are as shown in table 3:

table 3

In Table 3, the nitrogen accumulation rate of the bed in Example 1 is 14.02%, the nitrogen accumulation rate of the bed in Comparative Example 1 is 48.46%, and the nitrogen accumulation rate of the bed in Example 1 is far lower than that of the bed in Comparative Example 1. layer nitrogen accumulation rate. Correspondingly, the average actual residence time in Example 1 is 0.264h, and the average actual residence time in Comparative Example 1 is only 0.154h. The effective porosity of Example 1 is 1.668 times that of Comparative Example 1, and the actual residence time is 1.714 times that of Comparative Example 1, indicating that the nitrogen accumulation rate of the moving bed described in the present application is reduced and the residence time of sewage is prolonged.

Experimental Example 4 Biofilm Thickness Test

The biofilm thickness in the packing of embodiment 1 and comparative example 1 is tested, and after the stable operation of the reactor, sampling detection packing film thickness is tested as shown in table 4:

Table 4

As can be seen from Table 4, the biofilm thickness in Comparative Example 1 is much higher than that of Example 1. It can be seen that the biofilm in Comparative Example 1 is constantly growing too thick in the sewage treatment process, indicating that this The utility model moving bed can effectively reduce the biofilm thickness by setting the screw conveying rods.

Experimental Example 5 Live Bacteria Ratio Analysis

The staining of dead cells in the fillers of Example 1 and Comparative Example 1 was tested. After the reactor was running stably, samples were taken to detect the organisms on the filler surface. The tests were shown in Table 5:

table 5

As can be seen from Table 5, the proportion of live bacteria in the biofilm in Comparative Example 1 is much lower than that of Example 1, and from the perspective of bacteria as a whole, Comparative Example 1 is much higher than that of Example 1, so it can be seen that Comparative Example 1 More biomass means that the dead bacteria in Comparative Example 1 are also far greater than in Example 1, which brings greater mass transfer resistance for the denitrification reaction, showing that the denitrification moving bed described in the utility model can effectively reduce the dead bacteria. Bacteria ratio, reducing mass transfer resistance.

The utility model has been described in detail above in conjunction with specific implementations and illustrative examples, but these descriptions should not be construed as limiting the utility model. Those skilled in the art understand that without departing from the spirit and scope of the utility model, various equivalent replacements, modifications or improvements can be made to the technical solution of the utility model and its implementation, and these all fall within the scope of the utility model . The scope of protection of the utility model shall be determined by the appended claims.

Claims (6)

1. The sulfur autotrophic denitrification moving bed is characterized by comprising a reactor water inlet end (2), a water inlet screen plate (4), a filler layer area (5), a spiral conveying rod piece (6) and a reactor water outlet end (7), wherein the water inlet screen plate (4) is positioned at the middle position of the bottom of the denitrification moving bed, and the bottom of the denitrification moving bed is inclined downwards around the water inlet screen plate (4) and is in a funnel shape;

the spiral conveying rod piece (6) is vertically arranged in the middle of the packing layer area (5) and comprises a straight rod and a spiral part, the spiral part is spiral, the straight rod is positioned in the middle of the spiral part, and the head end and the tail end of the spiral part are fixed on the straight rod.

2. A sulfur autotrophic denitrification moving bed according to claim 1, wherein,

the water inlet end (2) of the reactor is positioned at the lowest end of the denitrification moving bed and is connected with a water inlet peristaltic pump (1), and the water outlet end (7) of the reactor is positioned above the packing layer area (5).

3. A sulfur autotrophic denitrification moving bed according to claim 1, wherein,

the pitch of the spiral component of the spiral conveying rod piece (6) is 1-50 mm;

the inclination angle of the spiral part is 5-20 degrees.

4. A sulfur autotrophic denitrification moving bed according to claim 1, wherein,

the ratio of the diameter of the spiral part to the diameter of the reactor is 1:1.05-1:5.

5. A sulfur autotrophic denitrification moving bed according to claim 2, wherein,

the vertical distance between the water outlet end (7) of the reactor and the packing layer area (5) is 5-300 cm.

6. A sulfur autotrophic denitrification moving bed according to claim 2, wherein,

the filling height of the filling layer area (5) is 20-500 cm, and the porosity of the filling layer area (5) is 37-42%.

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