Sewage aerobic granular sludge culture system and method based on chopped basalt fibers
By using short-cut basalt fibers as crystal nuclei and framework in a sequencing batch reactor (SBR), the problems of difficult formation and poor stability of AGS technology in urban wastewater treatment were solved, achieving rapid start-up and long-term high efficiency in wastewater treatment.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- JIANGSU UNIV
- Filing Date
- 2025-12-30
- Publication Date
- 2026-04-24
AI Technical Summary
Existing AGS technology is difficult and slow to form when treating urban sewage, has poor long-term operational stability, and is difficult to maintain efficient operation under conditions of low organic matter concentration and fluctuations in water quality and quantity.
Short-cut basalt fibers of specific specifications are used as artificial crystal nuclei and structural frameworks to construct a sequencing batch reactor. By controlling environmental parameters, the formation and stabilization of aerobic granular sludge are promoted, thus forming a C-MBF-AGS system.
It significantly shortens the AGS formation cycle, enhances the mechanical strength and stability of the system, and achieves efficient removal of pollutants from urban sewage, especially maintaining long-term stable operation under low C/N conditions.
Smart Images
Figure CN121913627A_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the field of wastewater treatment technology, specifically a wastewater aerobic granular sludge cultivation system and method based on short-cut basalt fibers. Background Technology
[0002] With the acceleration of urbanization, the volume of urban sewage discharge continues to increase, putting increasing pressure on the aquatic environment. Urban sewage is characterized by relatively low organic matter concentration (compared to industrial or aquaculture wastewater), large fluctuations in water volume, and a low carbon-to-nitrogen ratio (C / N), which places higher demands on the stability and efficiency of biological treatment technologies.
[0003] Aerobic granular sludge (AGS) technology is considered a next-generation biological wastewater treatment technology due to its advantages such as good settling performance, high biomass, and simultaneous nitrogen and phosphorus removal. However, the application of AGS technology in treating municipal wastewater faces two major challenges:
[0004] (1) Difficulty and slow formation: The low concentration of organic matter in urban sewage leads to insufficient growth momentum of microorganisms, making the spontaneous formation process of AGS very slow and unreliable. It usually takes 30 days or even longer, which seriously restricts the rapid start-up and application of this technology.
[0005] (2) Poor long-term operational stability: During long-term operation, especially under conditions of fluctuating water quality and quantity, low temperature or low C / N ratio, the established AGS is prone to structural loosening, disintegration or even collapse, leading to deterioration of treatment effect and system failure. This instability is the main bottleneck hindering the large-scale engineering application of AGS technology.
[0006] Existing research attempts to promote granulation by adding inert carriers (such as activated carbon, zeolite, etc.) as crystal nuclei, but these materials are either too expensive or have density and morphology that are not conducive to forming a stable structure, so the effect is limited. Summary of the Invention
[0007] The technical problem to be solved by this invention is as follows: In view of the technical problems existing in the prior art, this invention provides a wastewater aerobic granular sludge cultivation system and method based on short-cut basalt fiber. By adding short-cut basalt fiber of a specific specification as an artificial crystal nucleus and structural skeleton, the cultivation time of aerobic granular sludge is significantly shortened and its structural strength is enhanced, thereby constructing a biological treatment system that can operate stably for a long time and efficiently remove pollutants from urban wastewater.
[0008] To solve the above-mentioned technical problems, the technical solution proposed by this invention is as follows:
[0009] A wastewater aerobic granular sludge cultivation system based on chopped basalt fiber includes a sequencing batch reactor, wherein chopped basalt fiber is added to the reactor at a concentration of 20-80 mg / L.
[0010] Preferably, in the above technical solution, the diameter of the chopped basalt fiber monofilament is 10-15 μm and the length is 0.3-0.45 mm.
[0011] Preferably, in the above technical solution, the sequencing batch reactor is provided with an inlet unit, an aeration unit, a sedimentation unit and a drainage unit.
[0012] This invention also provides a method for cultivating aerobic granular sludge from wastewater based on short-cut basalt fibers, comprising the following steps:
[0013] S1, Inoculation and addition: Inoculate sludge into the sequencing batch reactor and add the short-cut basalt fiber;
[0014] S2, Start-up and Operation: Start the system to make the reactor run in a preset cycle, which includes at least an influent period, an aeration period, a sedimentation period and a drainage period;
[0015] S3, Environmental Control: During operation, environmental parameters within the reactor are controlled to promote the formation and stabilization of aerobic granular sludge.
[0016] Preferably, in step S1, the inoculated sludge is activated sludge from an urban wastewater treatment plant, and its initial mixed liquor suspended solids concentration is 3000-5000 mg / L.
[0017] Preferably, in step S2, the total duration of the operation cycle does not exceed 4 hours, the duration of the sedimentation period is 1-3 minutes, and the drainage volume exchange rate is 50%.
[0018] Preferably, in step S3, the environmental parameters are controlled within the following ranges: reactor temperature 15-25℃, pH value 6.5-8.5, and dissolved oxygen concentration 2.0-4.0 mg / L.
[0019] In the above technical solution, preferably, in step S2, the granular sludge prototype can be observed after 5-10 days of continuous operation, and mature aerobic granular sludge can be formed after 15-20 days of continuous operation.
[0020] Preferably, in the above technical solution, the aerobic granular sludge has short-cut basalt fibers as its internal structural framework, with an average particle size of 1.0-3.0 mm.
[0021] Preferably, in the above technical solution, the aerobic granular sludge is used to treat COD concentrations of 200-300 mg / L. When the concentration of urban wastewater is 30-50 mg / L, what are the effects on COD, The removal rates of total phosphorus and phosphorus remained stable at over 91%, over 95%, and over 75%, respectively.
[0022] The present invention provides an aerobic granular sludge cultivation system and method based on short-cut basalt fibers, which has the following advantages compared with the prior art:
[0023] (1) The wastewater aerobic granular sludge cultivation system and method based on short-cut basalt fiber of the present invention utilizes C-MBF as a highly efficient crystal nucleus, which significantly accelerates the aggregation process of microorganisms and shortens the formation cycle of AGS in urban wastewater environment from the traditional 30-50 days to 15-20 days, greatly reducing the system start-up time and cost.
[0024] (2) The wastewater aerobic granular sludge cultivation system and method based on short-cut basalt fiber of the present invention, the three-dimensional fiber skeleton structure formed by C-MBF greatly enhances the mechanical strength of AGS, enabling it to effectively resist the impact of adverse factors such as water quality and quantity fluctuations and low temperature. No obvious sludge disintegration phenomenon was found during long-term operation (such as more than 60 days), and the system stability was significantly improved.
[0025] (3) The wastewater aerobic granular sludge cultivation system and method based on short-cut basalt fiber of the present invention forms C-MBF-AGS with a typical layered structure (aerobic on the outside, anoxic / anaerobic on the inside), which can achieve simultaneous nitrification, denitrification and phosphorus removal. For typical low-concentration urban wastewater (COD: 200-300 mg / L, (30-50 mg / L, TP: 2-4 mg / L), after the system stabilizes, it will affect COD, The removal rates of TP can reach over 91%, over 95%, and over 75%, respectively. Attached Figure Description
[0026] Figure 1 This is a schematic diagram of the structure of the sequencing batch reactor of the present invention.
[0027] Figure 2 This is a macroscopic photograph of the short-cut modified basalt fiber aerobic granular sludge of the present invention.
[0028] Figure 3 Photographs of different particle sizes of the short-cut modified basalt fiber aerobic granular sludge of the present invention.
[0029] Figure 4 This is a single scanning electron microscope (SEM) image of the short-cut modified basalt fiber aerobic granular sludge of the present invention.
[0030] Figure 5 This is a single scanning electron microscope (SEM) image of the short-cut modified basalt fiber aerobic granular sludge of the present invention. Detailed Implementation
[0031] The following provides a detailed description of specific embodiments of the present invention. It should be understood that the specific embodiments described herein are for illustrative and explanatory purposes only and are not intended to limit the scope of the invention.
[0032] Example 1
[0033] The present invention provides a method for cultivating aerobic granular sludge from wastewater based on short-cut basalt fibers, comprising the following steps:
[0034] Step S1, Inoculation and Addition: Introducing microbial populations and short-cut basalt fibers as the core carrier into the reactor, laying the foundation for the granulation process.
[0035] First, a cylindrical sequencing batch reactor with an effective volume of 1.4 L (such as...) was selected. Figure 1 The inoculated sludge was taken from the secondary sedimentation tank return activated sludge of a municipal wastewater treatment plant. The mixed liquor was injected into the reactor to achieve an initial suspended solids concentration of approximately 4000 mg / L. Simultaneously, pretreated short-cut basalt fibers were added to the reactor. The fibers had a monofilament diameter of 13 μm and a length of 0.4 mm, with the dosage precisely controlled at 40 mg / L (based on the effective reactor volume). After addition, low-intensity aeration was used to ensure uniform dispersion of the fibers in the sludge mixture.
[0036] Step S2, Start-up and Operation: By setting and executing a specific periodic operation mode, hydraulic selective pressure is used to promote the formation and enrichment of granular sludge.
[0037] Start the automatic control system connected to the reactor, set each operating cycle to 2.4 hours, and execute the following four stages in sequence:
[0038] (1) Influent stage (12 minutes): Simulated urban sewage (average water quality: COD 250 mg / L) is introduced. (35 mg / L, TP 3 mg / L, pH 7.5) pumped into the reactor.
[0039] (2) Aeration stage (165 minutes): Start the aeration device and control the dissolved oxygen concentration in the range of 2.5-3.5 mg / L. This stage provides the oxygen and stirring shear force required for microbial degradation of pollutants, promoting the attachment and growth of microorganisms to the fiber carrier.
[0040] (3) Sedimentation stage (3 minutes): Stop aeration and allow the mixed liquor to settle. The deliberately set short sedimentation time creates a strong hydraulic selective pressure, which allows microbial aggregates with good settling properties (future granular sludge) to be retained, while flocculent sludge with poor settling properties is discharged with the supernatant.
[0041] (4) Drainage stage (5 minutes): Drain approximately 50% of the supernatant from the reactor to complete one cycle. The system runs continuously for 10 cycles per day.
[0042] Step S3, Environmental Control: By regulating key environmental parameters, optimal conditions are created for the growth and metabolism of functional microorganisms and the stability of granular sludge.
[0043] Throughout the cultivation and operation process, the reactor temperature was maintained at a constant range of 15-25℃ using a water bath. Acid / alkali solutions were added via an online pH monitor and metering pump to stabilize the pH of the mixed solution between 6.5 and 8.5. Dissolved oxygen concentration was maintained within the target range of 2.0-4.0 mg / L during the aeration phase through a dissolved oxygen meter linked to the aeration rate.
[0044] Operating using the above method, a large number of tiny particles with a diameter of approximately 0.5 mm can be observed in the reactor on day 10. Continuing operation until day 20, mature aerobic granular sludge (e.g., with an average diameter of approximately 3.0 mm, regular morphology, and dense structure) is formed. Figure 2 As shown). Scanning electron microscopy observation (e.g.) Figure 3 As shown in the image, basalt fibers are clearly encased by a large number of microorganisms, forming a solid internal framework.
[0045] Comparative Example
[0046] To verify the optimal concentration of chopped basalt fiber, all operating conditions, influent water quality, and operating parameters were identical to those in Example 1, except for the concentration of chopped basalt fiber. The following experimental groups were set up: Example 1 group (40 mg / L), Comparative Example 1 group (0 mg / L, no addition), Comparative Example 2 group (20 mg / L), and Comparative Example 3 group (80 mg / L). The comparison results are shown in Table 1.
[0047]
[0048] As shown in the table above, the addition of C-MBF significantly promotes granulation and improves system performance. An optimal balance is achieved at a dosage of 40 mg / L in terms of granulation rate, sludge performance, treatment efficiency, and long-term stability. Dosage that is too low (20 mg / L) has little effect, while dosage that is too high (80 mg / L) may lead to overly dense particles or impaired mass transfer, which is detrimental to operational stability.
[0049] The above embodiments are merely preferred examples of the present invention and are not intended to limit the present invention in any way. Although the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the present invention. Therefore, any simple modifications, equivalent changes, and alterations made to the above embodiments based on the technical essence of the present invention without departing from the scope of the present invention should fall within the protection scope of the present invention.
Claims
1. A wastewater aerobic granular sludge cultivation system based on short-cut basalt fibers, characterized in that, The reactor includes a sequencing batch reactor, wherein short-cut basalt fibers are added to the reactor at a concentration of 20-80 mg / L.
2. The wastewater aerobic granular sludge cultivation system based on short-cut basalt fibers according to claim 1, characterized in that, The chopped basalt fibers have a single filament diameter of 10-15 μm and a length of 0.3-0.45 mm.
3. The wastewater aerobic granular sludge cultivation system based on short-cut basalt fibers according to claim 2, characterized in that, The sequencing batch reactor is equipped with an inlet unit, an aeration unit, a sedimentation unit, and a drainage unit.
4. A method for cultivating aerobic granular sludge from wastewater based on short-cut basalt fibers, characterized in that, Includes the following steps: S1, Inoculation and addition: Inoculate sludge into the sequencing batch reactor and add the short-cut basalt fiber; S2, Start-up and Operation: Start the system to make the reactor run in a preset cycle, which includes at least an influent period, an aeration period, a sedimentation period and a drainage period; S3, Environmental Control: During operation, control the environmental parameters within the reactor, and the formation and stabilization of aerobic granular sludge.
5. The method for cultivating aerobic granular sludge based on short-cut basalt fibers according to claim 4, characterized in that, In step S1, the inoculated sludge is activated sludge from an urban wastewater treatment plant, and its initial mixed liquor suspended solids concentration is 3000-5000 mg / L.
6. The method for cultivating aerobic granular sludge based on short-cut basalt fibers according to claim 4, characterized in that, In step S2, the total duration of the operation cycle does not exceed 4 hours, the duration of the sedimentation period is 1-3 minutes, and the drainage volume exchange rate is 50%.
7. The method for cultivating aerobic granular sludge based on short-cut basalt fibers according to claim 4, characterized in that, In step S3, the environmental parameters are controlled within the following ranges: reactor temperature 15-25℃, pH value 6.5-8.5, and dissolved oxygen concentration 2.0-4.0 mg / L.
8. The method for cultivating aerobic granular sludge based on short-cut basalt fibers according to claim 4, characterized in that, In step S2, the initial form of granular sludge can be observed after 5-10 days of continuous operation, and mature aerobic granular sludge can be formed after 15-20 days of continuous operation.
9. The method for cultivating aerobic granular sludge based on short-cut basalt fibers according to claim 4, characterized in that, The aerobic granular sludge has short-cut basalt fibers as its internal structural framework, with an average particle size of 1.0-3.0 mm.
10. The method for cultivating aerobic granular sludge based on short-cut basalt fibers for wastewater treatment according to claim 4, wherein the aerobic granular sludge is used to treat COD concentrations of 200-300 mg / L. When the concentration of urban wastewater is 30-50 mg / L, what are the effects on COD, The removal rates of total phosphorus and phosphorus remained stable at over 91%, over 95%, and over 75%, respectively.