An embedded iron-carbon sludge storage module SBR device for promoting granular sludge formation and stability and a running method thereof

Abstract

The present application relates to a kind of iron-carbon storage sludge module SBR device and operating method of promoting granular sludge formation and stability, including SBR main body, water inlet system, water outlet system, aeration system and iron-carbon storage sludge module;Water inlet system includes water inlet pipe and water inlet pump;Water outlet system includes water outlet pipe, water outlet pump and filter head;Iron-carbon storage sludge module includes filler net frame and iron-carbon filler;Aeration system includes annular microporous aeration pipe fixed outside filler net frame.The present application is embedded in traditional SBR reactor iron-carbon storage sludge module to promote the rapid formation of granular sludge and keep the stability of granular sludge, in aeration stage iron-carbon storage sludge module as in anoxic zone, realize simultaneous nitrification and denitrification enhanced nitrogen and phosphorus removal.Compared with traditional SBR reactor, SBR reactor with built-in iron-carbon storage sludge module can promote the rapid formation of aerobic granular sludge and keep long-term running stability, while having better nitrogen and phosphorus removal effect.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of sewage treatment, and particularly relates to an embedded iron-carbon sludge storage module SBR device for promoting formation and stability of granular sludge and an operation method thereof. BACKGROUND

[0002] The aerobic granular sludge is a granular sludge with compact structure and excellent settling performance formed by self-agglomeration of microorganisms through metabolic activity. Compared with the traditional flocculent activated sludge, the aerobic granular sludge has excellent settling performance, compact structure, high biomass and metabolic activity, tolerance to high organic load and toxic and harmful substances, and can realize simultaneous nitrification and denitrification. Therefore, the aerobic granular sludge treatment technology is a new and very promising biological wastewater treatment technology.

[0003] At present, the aerobic granular sludge treatment technology mainly uses the SBR process. However, for low C / N municipal wastewater, the rapid formation and long-term stable operation of the aerobic granular sludge are still difficult. In addition, the simultaneous nitrification and denitrification denitrification effect is limited due to the influence of dissolved oxygen, pollutant concentration and carbon source and other factors. Therefore, developing a technology capable of promoting the rapid formation and long-term stable operation of the aerobic granular sludge and strengthening the removal of nitrogen and phosphorus is a research hotspot at present. In the application, the iron-carbon sludge storage module is embedded in the bottom of the SBR device. The hydrogen corrosion and Fe(II) and Fe(III) generated in the micro-electrolysis process of the iron-carbon sludge storage module promote the flocculent sludge to agglomerate and form aggregates. Under the action of the hydraulic shear force of aeration and the selection pressure generated by the control of sedimentation time, more compact aerobic granular sludge is formed. The iron oxides on the surface of the granular sludge maintain the stability of the granular sludge through the electro-neutralization effect. When the water is fed, the iron-carbon sludge storage module embedded in the bottom of the device can convert part of the carbon source into PHAs and store them in the sludge. When aeration starts, the iron-carbon sludge storage module is an anoxic area through the non-uniform aeration of the aeration system and the oxygen consumption effect of the iron-carbon sludge storage module. The sludge in the module removes nitrate through denitrification using the stored carbon source in the anoxic area, realizing the simultaneous nitrification and denitrification of the device. The Fe(II) and Fe(III) generated in the iron-carbon micro-electrolysis process can remove phosphate in wastewater through adsorption and precipitation. The SBR device with the embedded iron-carbon sludge storage module realizes the rapid formation and long-term stability of the aerobic granular sludge, and strengthens the deep removal of nitrogen and phosphorus in wastewater. SUMMARY

[0004] In view of the above background problems, the application provides an iron-carbon storage sludge module SBR device and a running method for promoting the formation and stability of granular sludge. The application promotes the rapid formation of aerobic granular sludge and maintains the stability of long-term operation through the by-products of iron-carbon micro-electrolysis. Meanwhile, the oxygen consumption of iron-carbon micro-electrolysis, the non-uniform aeration of the aeration system and the low-dissolved oxygen running mode make the iron-carbon storage sludge module an anaerobic environment, so that the simultaneous nitrification and denitrification of the device in the aeration stage is realized, and the removal of pollutants is strengthened.

[0005] The application is realized by the following technical solutions.

[0006] The application provides an iron-carbon storage sludge module SBR device for promoting the rapid formation and stability of granular sludge, which comprises an SBR main body, a water inlet system, a water outlet system, an aeration system and an iron-carbon storage sludge module. The water inlet system comprises a water inlet pipe and a water inlet pump. The water outlet system comprises a filter head, a water outlet pipe and a water outlet pump. The iron-carbon storage sludge module comprises a filler net frame and iron-carbon filler. The aeration system comprises an annular micro-porous aeration pipe outside the filler net frame.

[0007] Preferably, the water inlet system adopts bottom slow water inlet by extending the water inlet pipe to the bottom of the reactor.

[0008] Preferably, the filler net frame is a cylindrical net frame with an inner diameter slightly smaller than the inner diameter of the SBR and a height of 1 / 5 of the effective water depth of the SBR.

[0009] Preferably, the iron-carbon filler is iron shavings.

[0010] The application also provides a running method of the above-mentioned iron-carbon storage sludge module SBR device. The iron-carbon storage sludge module is in an anaerobic environment. The device adopts sequential batch operation, and the reaction step sequence comprises water inlet, standing, aeration, sedimentation, drainage and idling. The device is operated for 4 cycles per day, and each cycle is 6 hours.

[0011] Preferably, the time arrangement of each reaction step sequence is as follows: water inlet for 30 minutes, standing stirring for 120 minutes, aeration for 180 minutes, and dynamic adjustment of the sedimentation time according to the sludge settling velocity. When the sludge just settles to the drainage port, the device starts to drain. A small amount of flocculent sludge is discharged in each cycle. The selective pressure formed by controlling the sedimentation time promotes the formation of granular sludge. The sedimentation time gradually decreases from 20 minutes at the beginning to 5 minutes at last. The drainage and idling time fluctuates between 10 and 25 minutes according to the change of the sedimentation time.

[0012] The technical principle of the present application for promoting the formation of aerobic granular sludge lies in that Fe(II) and Fe(III) produced by hydrogen evolution corrosion of iron-carbon in an anaerobic environment and micro-electrolysis process are adsorbed on the surface of flocculent sludge to make the flocculent sludge form aggregates with certain size and shape, and under the action of aeration hydraulic shear force, the sludge aggregates carrying iron oxides continuously collide and aggregate. Meanwhile, Fe(II) and Fe(III) can promote the secretion of a large amount of EPS by sludge microorganisms, so that the formed sludge aggregates are more compact, and under the action of hydraulic shear force and selection pressure generated by controlling the sedimentation time, more compact aerobic granular sludge is formed, and the iron oxides on the surface of the granular sludge adsorb flocculent sludge through electro-neutralization to maintain the stability of the granular sludge.

[0013] The technical principle of the present application for strengthening nitrogen and phosphorus removal lies in that the annular micro-porous aeration pipe fixed outside the iron-carbon sludge storage module causes non-uniform aeration of the system, and the oxygen absorption reaction of iron shavings in water causes the iron-carbon sludge storage module to be in an anoxic environment all the time. During the influent stage, the sludge in the iron-carbon sludge storage module can convert part of the carbon source into PHAs and store it inside the sludge, and during the aeration stage, the aerobic nitrification process of the mixed sludge in the device and the anoxic denitrification in the iron-carbon sludge storage module using the stored carbon source achieve simultaneous nitrification and denitrification, significantly enhancing the removal of total nitrogen. In addition, Fe(II) and Fe(III) produced by micro-electrolysis and FeOOH flocs generated by hydrolysis of Fe(II) and Fe(III) achieve the removal of phosphate through precipitation and adsorption.

[0014] Compared with the prior art, the present application has the following beneficial effects:

[0015] The present application embeds an iron-carbon sludge storage module with iron shavings as filler in a traditional SBR device, the iron-carbon sludge storage module converts part of the carbon source into PHAs and stores it inside the sludge during the influent stage, and strengthens the simultaneous nitrification and denitrification during the aeration stage. The products of iron shavings micro-electrolysis remove phosphorus in wastewater in the form of adsorption and precipitation, and at the same time promote the rapid formation and stability of aerobic granular sludge. Compared with the traditional SBR process, the present application can promote the rapid formation and long-term stable operation of aerobic granular sludge, and at the same time strengthen the simultaneous nitrification and denitrification process, and has better nitrogen and phosphorus removal effect. BRIEF DESCRIPTION OF DRAWINGS

[0016] In order to more clearly illustrate the embodiments of the present application, the drawings will be described as follows:

[0017] Figure 1 It is a whole structure schematic diagram of a SBR device with an embedded iron-carbon sludge storage module for an embodiment;

[0018] Explanation of reference signs: SBR main body (1), water inlet pipe (2), water inlet pump (3), filter head (4), water outlet pipe (5), water outlet pump (6), filler net frame (7), iron-carbon filler (8), annular micro-porous aeration pipe (9).

[0019] Figure 2 Figure of change of granular sludge with days for experimental group and control group in examples. DETAILED DESCRIPTION

[0020] The present application will be further described below in conjunction with the drawings and specific examples. Those skilled in the art will be able to implement the practical application of the present application based on these descriptions. In addition, the examples of the present application involved in the following descriptions are generally only examples of a part of the present application, not all examples. Therefore, all other examples obtained by those skilled in the art based on the examples in the present application without making creative efforts should belong to the scope of protection of the present application.

[0021] EXAMPLE

[0022] REFERENCE Figure 1 The SBR device with embedded iron-carbon sludge storage module in the present example comprises: SBR main body 1, water inlet system, water outlet system, aeration system and iron-carbon sludge storage module. The water inlet system comprises water inlet pipe 2 and water inlet pump 3; the water outlet system comprises filter head 4, water outlet pipe 5 and water outlet pump 6; the iron-carbon sludge storage module comprises filler net frame 7 and iron-carbon filler 8; and the aeration system comprises annular micro-porous aeration pipe 9 outside the filler net frame.

[0023] In the present example, the SBR device has an inner diameter of 400 mm, a height of 1500 mm, an effective volume of 150 L, a filler net frame with an inner diameter of 300 mm and a height of 250 mm, and iron shavings are selected as the iron-carbon filler with a filling mass of 1500 g and a filling density of 10 g / L. This is used as the experimental group, and a control group with the same size is established. The difference between the control group and the experimental group is that there is no filler net frame and iron shavings, and other device parameters and operation modes are the same as those of the experimental group.

[0024] In the present example, both SBR devices are operated in a sequencing batch mode, with 4 cycles per day, each cycle being 6 h. The reaction step sequence comprises water inlet for 30 min, standing for 120 min, aeration for 180 min. In order to cultivate granular sludge, the sedimentation time is gradually decreased from 20 min at the beginning to 5 min according to the sludge settling velocity, and the drainage and idle time is 10-25 min. The water inlet amount of each cycle is 60 L, and the volume exchange rate is 40%. In the reaction process, the steps of water inlet, standing, aeration, sedimentation, water outlet and idling are controlled by time control switches.

[0025] The real wastewater of a municipal wastewater treatment plant was selected as the experimental influent in this embodiment, and the average COD of the wastewater was 180 mg / L, the average TP was 3.62 mg / L, and the average TN was 44.7 mg / L. The test results showed that the average effluent COD of the control group and the experimental group was 25.3 mg / L and 24.8 mg / L, respectively; the average effluent TP was 1.45 mg / L and 0.19 mg / L, respectively; and the average effluent TN was 19.56 mg / L and 14.5 mg / L, respectively. The SBR device with the embedded iron-carbon sludge storage module exhibited more excellent nitrogen and phosphorus removal effect.

[0026] The inoculated sludge and the stable granular sludge in this embodiment are as shown in Figure 2 As shown in the table, the experimental group formed sludge aggregates with a certain size on the 15th day, while the control group was still relatively loose flocculent sludge. The experimental group formed granular sludge more quickly, and the granular sludge in the experimental group was more stable. On the 150th day, the granular sludge in the experimental group still had a relatively regular particle, while part of the granular sludge in the control group began to break, and the proportion of flocculent sludge gradually increased. The SBR device with the embedded iron-carbon sludge storage module promoted the rapid formation of aerobic granular sludge and maintained the stability of the continuous operation of the aerobic granular sludge.

Claims

1. A septic tank reactor (SBR) device with an embedded iron-carbon sludge storage module that promotes the formation and stabilization of granular sludge, characterized in that, include: The SBR main body comprises an inlet system, an outlet system, an aeration system, and an iron-carbon sludge storage module. The inlet system includes an inlet pipe and an inlet pump. The outlet system includes a filter head, an outlet pipe, and an outlet pump. The iron-carbon sludge storage module includes a packing mesh frame and iron-carbon packing material. The packing mesh frame is a cylindrical packing mesh frame with an inner diameter slightly smaller than the inner diameter of the SBR, and its height is 1 / 5 of the effective water depth of the SBR. The aeration system consists of an annular microporous aeration pipe on the outside of the packing mesh frame.

2. The SBR device with embedded iron-carbon sludge storage module according to claim 1, characterized in that, The water inlet system extends to the bottom of the SBR via an inlet pipe to allow for slow bottom water intake.

3. The SBR device with embedded iron-carbon sludge storage module according to claim 1, characterized in that, The iron-carbon filler is iron shavings.

4. The operating method of the SBR device with embedded iron-carbon sludge storage module according to any one of claims 1-3, characterized in that, The iron-carbon sludge storage module is in an anaerobic environment; the device adopts a sequential batch operation, and the reaction steps include water inlet, settling, aeration, sedimentation, drainage and idle, with 4 cycles per day, each cycle lasting 6 hours.

5. The operation method of the SBR device with embedded iron-carbon sludge storage module according to claim 4, characterized in that, The time arrangement for each reaction step is as follows: 30 min for water influent, 120 min for settling, and 180 min for aeration. The sedimentation time is dynamically adjusted according to the sludge settling rate. The device starts to drain water whenever the sludge just settles to the drain outlet. A small amount of flocculent sludge is discharged each cycle. The selective pressure formed by controlling the sedimentation time promotes the formation of granular sludge. The sedimentation time gradually decreases from 20 min at the beginning and is finally maintained at 5 min. The drainage and idle time fluctuate from 10 to 25 min according to the changes in sedimentation time.

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