Method for treating perchlorate wastewater through cooperation of microorganisms and mineral materials

Abstract

The invention belongs to the technical field of wastewater treatment, and particularly discloses a microbial composite material treatment method for perchlorate wastewater. In order to solve the pollution of perchlorate wastewater and achieve the purpose of rapidly degrading perchlorate in a water body, the invention provides a treatment method based on a microbial composite material, which comprises the following steps: adding a complex microbial inoculant and a mineral material into a cylindrical reactor filled with a polyethylene material; the water treatment agent comprises the following components: 10-30 g / L of natural river sediment, 50-200 mL / L of arthrobacter, 50-200 mL / L of shewanella, 5-15 g / L of one or more of pyrite, iron powder and sulfur powder, and perchlorate can be cyclically degraded. The scheme is applied to perchlorate wastewater treatment, and the degradation effect of perchlorate is remarkable.

Description

Technical Field

[0001] This invention belongs to the field of wastewater treatment technology, specifically relating to a method for treating perchlorate wastewater by microorganisms in synergy with mineral materials. Background Technology

[0002] Perchlorate is an emerging source of water pollution, and its pollution of water bodies is persistent and difficult to degrade. Apart from a very small portion that originates naturally, the vast majority of perchlorate is synthesized artificially, such as in the fireworks and firecrackers manufacturing industry.

[0003] Currently, the mainstream technologies for perchlorate wastewater treatment can be divided into three main categories: physical methods, chemical methods, and biological methods. Among them, processes such as ion exchange adsorption, membrane separation technology, and catalytic reduction have high removal efficiencies, but still have significant technical bottlenecks. Ion exchange methods require frequent resin regeneration, and the resulting high-salt wastewater requires secondary treatment, significantly increasing operating costs. Membrane separation technology is prone to flux decline due to filter clogging, and requires frequent backwashing maintenance and expensive membrane module replacement. Catalytic reduction methods rely on precious metal catalysts (such as palladium / carbon systems), whose preparation processes are complex and material costs are high, restricting large-scale application. Summary of the Invention

[0004] To address the above problems, this invention proposes a method for treating perchlorate wastewater using a microbial-mineral synergy. A polyethylene material that facilitates biofilm formation is added to a columnar reactor. Using natural riverbed sediment as the main component, and leveraging its rich microbial community, *Arthrobacter* and *Shewanella* are sequentially added to form a composite microbial agent with significant perchlorate degradation capabilities. Common mineral materials are then added to create a method for treating perchlorate wastewater using a microbial-mineral synergy. This method is suitable for treating wastewater with perchlorate as the primary pollutant, and it features low energy consumption, high efficiency, and environmental friendliness.

[0005] The technical solution provided by this invention is: a method for treating perchlorate wastewater by microorganisms in synergistic use with mineral materials, comprising the following steps:

[0006] (1) Construction of the reactor: Polyethylene material that can be used for biofilm attachment is added to the column reactor;

[0007] (2) Addition of compound microbial agent: Add compound microbial agent to the reactor in step (1);

[0008] (3) Addition of mineral materials: Add mineral materials to the system in step (2);

[0009] (4) Recycled degradation of wastewater: Perchlorate wastewater is circulated into the system in step (3).

[0010] Preferably, in step (1), the reactor is cylindrical with a diameter-to-height ratio of 1:6-10, preferably 1:8;

[0011] Preferably, in step (1), the material used for biofilm attachment is polyethylene.

[0012] Preferably, in step (2), the complex microbial community comprises the following components: natural river sediment, Arthroblasts, and Shewanella. Specifically, it includes 10-30 g / L of natural river sediment, 50-200 mL / L of Arthroblasts, and 50-200 mL / L of Shewanella.

[0013] Further optimization revealed that the complex microbial community contained the following components: 20 g / L natural river sediment, 100 mL / L Paenarthrobacter ureafaciens-2 (available from Hunan Kaiqing Environmental Protection Technology Co., Ltd., also found in M. Gan et al. The enhanced effect of key microorganisms in chromiumcontaminated soil in Cr(VI) reduction. Chemosphere 362 (2024) 142682), and 100 mL / L Shewanella oneidensis MR-1 (a common strain, for example found in K. Zhang, N. Li, P. Liao et al. Conductive property of secondary minerals triggered Cr(VI) bioreduction by dissimilatory iron reducing bacteria. Environmental Pollution 286 (2021) 11722). River sediments contain rich microbial communities, and Shewanella can convert high-valence pollutants into low-valence forms through extracellular electron transport systems; Arthroblasts, as oligotrophic bacteria, are highly adaptable to the environment and have great potential for application in the degradation of perchlorate.

[0014] Preferably, in step (3), the mineral material comprises one or more of the following components: 5-15 g / L pyrite, iron powder and sulfur powder.

[0015] Further optimization involves selecting one of the following mineral materials: 8-12 g / L pyrite, 8-12 g / L iron powder, 7-8 g / L iron powder, and 2-3 g / L sulfur powder; preferably, it includes one of the following: 10 g / L pyrite, 10 g / L iron powder, 7.5 g / L iron powder, and 2.5 g / L sulfur powder. As an electron donor, the mineral material can serve as an energy source for microorganisms and can also adsorb other pollutants in the wastewater. Through synergistic application, perchlorate in the wastewater can be degraded through metabolism.

[0016] Preferably, in step (4), perchlorate wastewater is circulated.

[0017] Further optimization involves circulating the solution for half an hour every four hours, with a circulation volume of 35-45%, preferably 40%.

[0018] Compared with existing traditional perchlorate wastewater treatment methods, the advantages of the technical solution in this application are as follows:

[0019] The raw materials used in this invention, such as sediment, pyrite, and sulfur powder, are inexpensive and widely available. The Shewanella and Arthroblasts used in this invention are widely distributed in the natural environment and will not cause secondary pollution, making it environmentally friendly. The treatment method of this invention is simple, efficient, and easy to apply on a large industrial scale to treat wastewater with perchlorate as the main pollution source. Attached Figure Description

[0020] Figure 1 Column reactor filled with polyethylene material.

[0021] Figure 2 : Bottom sediment can be used to directly treat perchlorate wastewater.

[0022] Figure 3 Adding Arthrobacterium to treat perchlorate wastewater.

[0023] Figure 4 Adding Shewanella bacteria to treat perchlorate wastewater.

[0024] Figure 5 Adding pyrite can treat perchlorate wastewater.

[0025] Figure 6 Adding sulfur powder to treat perchlorate wastewater.

[0026] Figure 7 Adding iron powder and sulfur powder to treat perchlorate wastewater. Detailed Implementation

[0027] To more clearly illustrate the purpose, technical solution, and advantages of this invention, a detailed description will be provided below in conjunction with the accompanying drawings and specific embodiments. The drawings illustrate only exemplary embodiments of the invention and are not intended to limit its implementation. This invention can be implemented in various forms, and its design concept and core technology are not limited to the embodiments shown in the drawings. These embodiments are provided to facilitate understanding of the principles, structure, and function of this invention by those skilled in the art, thereby enabling them to better master and apply its technical solutions. The terminology used in this specification is only for describing specific embodiments and does not constitute a limitation of the invention.

[0028] Example 1:

[0029] (1) Add natural riverbed sediment separately

[0030] Take 20 g / L of sediment from a natural river and mix it with 1000 mL of simulated perchlorate wastewater with a concentration of 100 mg / L. Add this mixture to a perchlorate wastewater tank. Connect the perchlorate wastewater tank to a column reactor consisting of three reaction columns with a diameter of 1 mm and a height of 8 mm. The reaction columns are directly connected by pipes and filled with polyethylene material (such as...). Figure 1 (As shown). When perchlorate wastewater circulates through the column reactor, bacteria in the wastewater are loaded onto the surface of the polyethylene material to form a biofilm, thereby degrading the perchlorate. Controlled by a timer, the cycle is repeated for half an hour every four hours, with the pump flow rate controlled at 40%, allowing for five days of perchlorate wastewater degradation.

[0031] The results are as follows Figure 2 As shown, three days after the bottom sediment microbial community degraded the wastewater, the perchlorate concentration reached 86.12 mg / L, with a degradation efficiency of only 13.88%. On the fifth day, the perchlorate concentration in the wastewater was 77.68 mg / L, with a degradation efficiency of 22.32%.

[0032] (2) Add Paenarthrobacter ureafaciens-2

[0033] Thaw the Paenarthrobacter ureafaciens-2 bacteria stored at -18℃, inoculate them into an Erlenmeyer flask containing 250 mL of LB medium, and incubate until the bacterial concentration reaches 10⁻⁶. 8 mL -1 .

[0034] The perchlorate-simulated wastewater in the column system was drained using a peristaltic pump, and the acclimated sediment and microbial community enriched in step (1) were added. 1000 mL of 50 mg / L perchlorate-simulated wastewater was added again, along with 100 mL of cultured Arthroblastus. The system was controlled by a timer, circulating for half an hour every four hours, with the pump flow rate controlled at 40%, to degrade the perchlorate wastewater for 13 days.

[0035] The results are as follows Figure 3 As shown, after two days, the perchlorate concentration in the simulated wastewater reached 31.89 mg / L, with a degradation efficiency of 36.23%; by the sixth day, the perchlorate concentration in the simulated wastewater was 10.20 mg / L, with a degradation rate of 79.61%.

[0036] From the sixth to the thirteenth day, the efficiency of Arthroblasts in degrading perchlorate continued to decrease. It took a week to reduce the perchlorate concentration in the wastewater from 10.20 mg / L to 6.52 mg / L. The degradation rate on the thirteenth day was 3.46% higher than that on the sixth day.

[0037] (3) Add Shewanella oneidensis MR-1

[0038] Thaw Shewanella oneidensis MR-1, which had been frozen at -18°C, and inoculate it into an Erlenmeyer flask containing 250 mL of LB medium. Incubate until the bacterial concentration reaches 10⁻⁶. 8 mL -1 .

[0039] The perchlorate-simulated wastewater in the column system was drained using a peristaltic pump, and the acclimated sediment and microbial community enriched in the reaction column from step (2) were added. 1000 mL of 50 mg / L perchlorate-simulated wastewater was added again, along with 100 mL of cultured Shewanella bacteria. The system was controlled by a timer, with the cycle lasting half an hour every four hours. The flow rate of the water pump was controlled at 40%, and the perchlorate wastewater was degraded for 4 days.

[0040] The results are as follows Figure 4 As shown, by the fourth day, the concentration of perchlorate in the simulated wastewater was less than the detection limit of 0.5 mg / L, at which point the degradation efficiency exceeded 99%.

[0041] (4) Add mineral materials

[0042] The perchlorate-simulated wastewater in the column system was drained using a peristaltic pump, and the acclimated sediment and microbial community enriched in the reaction column from step (3) were added. 1000 mL of 50 mg / L perchlorate-simulated wastewater was added again, and a mixture of 10 g / L pyrite, 7.5 g / L iron powder and 2.5 g / L sulfur powder, and 10 g / L sulfur powder were weighed out. The mixture was circulated for half an hour every four hours using a timer, and the pump flow rate was controlled at 40% to degrade the perchlorate wastewater for 6 days.

[0043] The results are as follows: Figure 5 , Figure 6 and Figure 7 As shown in the figure, pyrite, as a mineral material, reduced the perchlorate concentration in the simulated wastewater from 50 mg / L to 47.54 mg / L after 6 days, with a degradation rate of 4.92%.

[0044] As a mineral material, sulfur powder reduced the concentration of perchlorate in the simulated wastewater from 50 mg / L to 42.33 mg / L after 6 days of degradation by microorganisms, with a degradation rate of 15.33%.

[0045] Using a mixture of iron powder and sulfur powder as mineral materials, after 6 days of degradation by microorganisms, the perchlorate concentration in the simulated wastewater decreased from 50 mg / L to 23.19 mg / L, achieving a degradation efficiency of 53.61%.

[0046] Finally, it is important to emphasize that the embodiments provided herein are only a portion of the embodiments of the present invention, and not all of them. All other embodiments obtained by those skilled in the art based on this invention without inventive effort should fall within the scope of protection of this invention.

Claims

1. A method for treating perchlorate wastewater using microorganisms in synergistic mineral material treatment, characterized in that, Includes the following steps: (1) Construction of the reactor: Polyethylene material that can be used for biofilm attachment is added to the column reactor; (2) Addition of compound microbial agent: Add compound microbial agent to the reactor in step (1); (3) Addition of mineral materials: Add mineral materials to the system in step (2); (4) Recycle wastewater: Perchlorate wastewater is circulated into the system in step (3).

2. The method according to claim 1, characterized in that, In step (1), the reactor is cylindrical with a diameter:height ratio of 1:6-10, preferably 1:

8.

3. The method according to claim 1, characterized in that, In step (2), the complex microbial community includes the following components: natural river sediment, Arthroblasts and Shewanella.

4. The method according to claim 3, characterized in that, In step (2), the complex microbial community contains the following components: 10-30 g / L natural river sediment, 50-200 mL / L Arthroblasts (Arthroblasts cell number ≥10). 7 50-200 mL / L Shewanella (Shewanella cell count ≥10) 7 mL); The *Arthrobacter* species is *Paenarthrobacter ureafaciens-2*, and the *Shewanella* species is *Shewanella oneidensis* MR-1.

5. The method according to claim 4, characterized in that, The complex microbial community contains the following components: 20 g / L natural river sediment, 100 mL / L Paenarthrobacter ureafaciens-2, and 100 mL / L Shewanella oneidensis MR-1.

6. The method according to claim 1, characterized in that, In step (3), the mineral material contains one or more of the following components: 5-15 g / L pyrite, iron powder and sulfur powder.

7. The method according to claim 6, characterized in that, The mineral materials include one of the following: 8-12 g / L pyrite, 8-12 g / L iron powder, 7-8 g / L iron powder, and 2-3 g / L sulfur powder.

8. The method according to claim 7, characterized in that, The mineral materials include one of the following: 10 g / L pyrite, 10 g / L iron powder, 7.5 g / L iron powder, and 2.5 g / L sulfur powder.

9. The method according to claim 1, characterized in that, In step (4), wastewater containing perchlorate is circulated through the system.

10. The method according to claim 8, characterized in that, The cycle lasts for half an hour every four hours, with a cycle volume of 35-45%, preferably 40%.

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