A method of sewage treatment
By immobilizing halophilic Bacillus and Shiquanshan Bacillus with immobilized strains combined with nano-iron particles, the problem of limited treatment efficiency for high-salt organic wastewater was solved, achieving efficient degradation of COD, ammonia nitrogen, total nitrogen, and volatile phenols.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- SHANDONG ACAD OF ENVIRONMENTAL SCI CO LTD
- Filing Date
- 2026-03-31
- Publication Date
- 2026-06-16
AI Technical Summary
High-salt organic wastewater is difficult to treat efficiently using traditional wastewater treatment processes due to its complex composition and water quality characteristics. Conventional physicochemical treatment technologies have limited effectiveness and insufficient resistance to water quality shocks. Furthermore, biological processes are not effective in treating high-salt wastewater and can easily cause secondary pollution.
Immobilized bacterial strain preparations were used to treat high-salt organic wastewater. The preparations contained halophilic Bacillus and Haloxylon ammodendron, combined with nano-iron particles as nano-synergists. By adjusting the pH to 4-6, the immobilized bacterial strain preparations were used to degrade COD, ammonia nitrogen, total nitrogen and volatile phenols in high-salt organic wastewater.
It significantly reduces the levels of COD, ammonia nitrogen, total nitrogen, and volatile phenols in high-salt organic wastewater, outperforming the treatment effects of using bacterial strains or nanoparticle synergists alone, thus achieving efficient and environmentally friendly pollutant degradation.
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Abstract
Description
Technical Field
[0001] This invention relates to the field of water, wastewater, sewage or sludge treatment technology, and specifically to a sewage treatment method. Background Technology
[0002] Wastewater refers to the total amount of water discharged during residential activities and runoff rainwater. It includes domestic sewage, industrial wastewater, and other non-water-use wastewater such as initial rainwater runoff into drainage pipes and ditches. High-salinity organic wastewater has received widespread attention due to its high salinity and complex composition. Wastewater is classified as high-salinity wastewater when its salinity is >1% (w / v) or total dissolved solids (TDS) is >3.5% (w / v). In addition to its high salinity, high-salinity organic wastewater also contains large amounts of pollutants such as phenols and other recalcitrant organic compounds.
[0003] High-salinity organic wastewater is difficult to treat efficiently using traditional wastewater treatment processes due to its complex composition and water quality characteristics. Conventional physicochemical treatment technologies generally suffer from limited treatment efficiency and insufficient resistance to water quality shocks, leading to a significant increase in system operating costs. Furthermore, the introduction of chemical agents can easily cause secondary pollution. Traditional biological processes are highly effective for treating conventional wastewater, but they are ill-suited to high-salinity wastewater, primarily due to two factors: high salt ion concentrations and recalcitrant organic matter. These factors interact to influence microbial growth and metabolism on multiple levels, rendering traditional biological processes ineffective for treating high-salinity organic wastewater. However, given the environmental friendliness and lower cost of microbial treatment, exploring new wastewater treatment methods involving microorganisms remains a worthwhile research direction. Summary of the Invention
[0004] In view of the above-mentioned prior art, the purpose of this invention is to provide a wastewater treatment method.
[0005] To achieve the above objectives, the present invention adopts the following technical solution:
[0006] In a first aspect, the present invention provides a method for wastewater treatment, wherein the pH of the wastewater is adjusted to 4-6 and then an immobilized bacterial strain preparation is added for treatment;
[0007] The wastewater in question is high-salt organic wastewater;
[0008] The immobilized bacterial strain preparation contains halophilic spores ( Bacillus halotolerans ) or Shiquanshihans ( Halomonas fontilapidosi At least one of the following;
[0009] The preservation number of the halophilic spore-forming bacteria is GDMCC NO.1.4092; the strain number of *Haloxylon ammodendron* is CICC24083.
[0010] The immobilized bacterial strain preparation also contains a nano-synergist, which is at least one of nano-iron particles, nano-iron particles, or nano-iron particles.
[0011] Furthermore, high-salinity organic wastewater has a salinity >1 w / v%, and contains organic matter including volatile phenols.
[0012] Furthermore, the immobilized bacterial strain preparation is prepared by the following method:
[0013] (1) Mix halophilic spore-resistant bacilli and halophilic bacilli to obtain a mixed bacterial solution;
[0014] (2) Add the mixed bacterial solution to the embedding agent and mix thoroughly to obtain the mixed solution;
[0015] (3) Add the mixture dropwise at a constant rate to a 0.1-1 mol / L calcium chloride solution while stirring continuously to obtain the encapsulated particles;
[0016] (4) The obtained embedded particles were immobilized at room temperature and the calcium chloride solution was discarded after 10-30 hours. The particles were washed with pure water 1-3 times and then freeze-dried under vacuum for 12-36 hours to obtain the immobilized strain preparation.
[0017] Furthermore, in step (1), the ratio of viable bacteria of halophilic Bacillus to Haloxylon ammodendron is (1-2):(1-2), and the total viable bacteria count in the mixed bacterial solution is 5×10⁻⁶. 8 CFU / mL.
[0018] Furthermore, in step (2), the encapsulating agent comprises the following components by weight: 1-5 parts sodium alginate, 0.01-1 parts graphene oxide, 0.01-1 parts zeolite powder, 0.01-1 parts coconut shell powder, 0.1-2 parts gelatin, 0.1-2 parts starch, 0.1-2 parts nano-synergist, and 90-110 parts pure water;
[0019] The nano-synergist used is nano-iron particles.
[0020] Furthermore, in step (2), the weight ratio of the mixed bacterial solution to the embedding agent is 1:(1-10).
[0021] Furthermore, in step (3), the diameter of the embedded particles is 1-10 mm.
[0022] In a second aspect, the present invention provides the application of the aforementioned wastewater treatment method in the following (1)-(4):
[0023] (1) Reduce the COD value in high-salt organic wastewater;
[0024] (2) Reduce the ammonia nitrogen content in high-salt organic wastewater;
[0025] (3) Reduce the total nitrogen content of high-salt organic wastewater;
[0026] (4) Reduce the volatile phenol content in high-salt organic wastewater.
[0027] The beneficial effects of this invention are:
[0028] This invention selects halophilic Bacillus and Haloxylon ammodendron, which can reduce COD and phenol content in water, as microbial agents. These agents are mixed with an encapsulating agent containing nano-synergists to form a carrier, allowing the bacterial strains to attach and immobilize on the carrier, resulting in an immobilized bacterial strain preparation. When the immobilized bacterial strain preparation is used in experiments, all pollutant indicators in each experimental group are reduced compared to the control group, indicating that the immobilized strains and their combinations have a promoting effect on pollutant degradation. Specifically, the composite group showed better results than the groups using individual halophilic Bacillus, Haloxylon ammodendron, magnesium synergists (using nano-magnesium particles), and zinc synergists (using nano-zinc particles). Therefore, the immobilized bacterial strain preparation prepared by combining halophilic Bacillus and Haloxylon ammodendron with materials containing iron nanoparticles exhibits better pollutant degradation effects on high-salt organic wastewater. Detailed Implementation
[0029] It should be noted that the following detailed descriptions are illustrative and intended to provide further explanation of this application. Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains.
[0030] To enable those skilled in the art to better understand the technical solution of this application, the technical solution of this application will be described in detail below with reference to specific embodiments.
[0031] The test materials used in the embodiments of this invention, unless otherwise specified, are all conventional test materials in the art and can be purchased through commercial channels. The halophilic spore-forming bacteria used in this invention (…) Bacillus halotolerans Purchased from Guangdong Provincial Microbial Culture Collection Center, catalog number GDMCC NO.1.4092. The *Salmonella lithospora* used was... Halomonas fontilapidosiThe following materials were purchased from the China Industrial Microbial Culture Collection Center, strain number CICC 24083: The iron nanoparticles used in this invention are magnetite (Fe3O4) magnetic microsphere powders with a particle size of 30 nm, purchased from Beijing Zhongke Keyou Technology Co., Ltd. The magnesium nanoparticles used in this invention are magnesium oxide microsphere powders with a particle size of 30 nm, purchased from Hangzhou Jiuli Biomaterials Co., Ltd. The zinc nanoparticles used in this invention are zinc oxide microsphere powders with a particle size of 30 nm, purchased from Shandong Huling New Materials Co., Ltd.
[0032] Example 1: Microbial culture test
[0033] Salt-tolerant Bacillus and Haloxylon ammodendron, both capable of surviving in high-salt environments, were cultured separately to obtain corresponding bacterial suspensions. The degradation capacity of the salt-tolerant Bacillus and Haloxylon ammodendron was tested in groups using simulated industrial wastewater with a salt content of 3.5 wt%, a COD content of 200 mg / L, and a phenol content of 20 mg / L. The test solution volume was 500 mL, the bacterial suspension volume was 20 mL, and the viable bacterial count in the suspension was 1 × 10⁻⁶. 8 CFU / mL. The culture temperature was 20℃, and the culture time was 48 h. Tests were performed after the culture period. Results are shown in Table 1.
[0034] Table 1. Degradation ability test of strains
[0035]
[0036] As shown in Table 1, compared with the untreated simulated wastewater, the organic matter COD and phenol in the simulated wastewater of each experimental group were reduced, indicating that the water quality was improved. Both halophilic spore-tolerant bacteria and halophilic bacteria can degrade organic matter in simulated wastewater and can be used for subsequent experiments.
[0037] Example 2: Preparation of the vector and immobilization of the strain
[0038] 1. Preparation of the carrier
[0039] To reduce the salinity stress of microorganisms, strains and encapsulating agents are mixed to form a carrier, which allows the strains to attach and immobilize.
[0040] The encapsulation agent comprises the following components: 2g sodium alginate, 0.1g graphene oxide, 0.1g zeolite powder, 0.1g coconut shell powder, 0.5g gelatin, 0.5g starch, 0.2g nano-synergist, and 96.5g pure water.
[0041] The nano-synergist used is nano-iron particles.
[0042] 2. Strains Immobilization
[0043] The halophilic Bacillus and Haloxylon ammodendron obtained in Example 1 were mixed at a 1:1 ratio to obtain a mixed bacterial solution with a total viable count of 5 × 10⁻⁶. 8 CFU / mL. Add the mixed bacterial solution to the embedding medium and mix thoroughly to obtain a mixture. The weight ratio of the mixed bacterial solution to the embedding medium (1 ml is denoted as 1 g) is 1 g: 5 g.
[0044] The mixture was added dropwise to a 0.2 mol / L calcium chloride solution at a uniform rate while stirring continuously to obtain embedded particles with a diameter of 2.5 ± 1 mm.
[0045] The obtained encapsulated particles were immobilized at room temperature and the calcium chloride solution was discarded after 20 hours. The particles were washed twice with pure water and then freeze-dried under vacuum at -70°C for 24 hours to obtain the immobilized bacterial strain preparation.
[0046] Example 3: Preparation of the vector and immobilization of the strain
[0047] 1. Preparation of the carrier
[0048] The encapsulation agent comprises the following components: 2g sodium alginate, 0.1g graphene oxide, 0.1g zeolite powder, 0.1g coconut shell powder, 0.5g gelatin, 0.5g starch, 0.2g nano-synergist, and 96.5g pure water.
[0049] The nano-synergist used is nano-iron particles.
[0050] 2. Strains Immobilization
[0051] The halophilic Bacillus and Haloxylon ammodendron obtained in Example 1 were mixed at a viable count ratio of 1:2 to obtain a mixed bacterial solution with a total viable count of 5 × 10⁻⁶. 8 CFU / mL. Add the mixed bacterial solution to the embedding medium and mix thoroughly to obtain a mixture. The weight ratio of the mixed bacterial solution to the embedding medium (1 ml is denoted as 1 g) is 1 g: 5 g.
[0052] The mixture was added dropwise to a 0.2 mol / L calcium chloride solution at a uniform rate while stirring continuously to obtain embedded particles with a diameter of 2.5 ± 1 mm.
[0053] The obtained encapsulated particles were immobilized at room temperature and the calcium chloride solution was discarded after 20 hours. The particles were washed twice with pure water and then freeze-dried under vacuum at -70°C for 24 hours to obtain the immobilized bacterial strain preparation.
[0054] Example 4: Preparation of the vector and immobilization of the strain
[0055] 1. Preparation of the carrier
[0056] The encapsulation agent comprises the following components: 2g sodium alginate, 0.1g graphene oxide, 0.1g zeolite powder, 0.1g coconut shell powder, 0.5g gelatin, 0.5g starch, 0.2g nano-synergist, and 96.5g pure water.
[0057] The nano-synergist used is nano-iron particles.
[0058] 2. Strains Immobilization
[0059] The halophilic Bacillus and Haloxylon ammodendron obtained in Example 1 were mixed at a viable count ratio of 2:1 to obtain a mixed bacterial solution with a total viable count of 5 × 10⁻⁶. 8 CFU / mL. Add the mixed bacterial solution to the embedding medium and mix thoroughly to obtain a mixture. The weight ratio of the mixed bacterial solution to the embedding medium (1 ml is denoted as 1 g) is 1 g: 5 g.
[0060] The mixture was added dropwise to a 0.2 mol / L calcium chloride solution at a uniform rate while stirring continuously to obtain embedded particles with a diameter of 2.5 ± 1 mm.
[0061] The obtained encapsulated particles were immobilized at room temperature and the calcium chloride solution was discarded after 20 hours. The particles were washed twice with pure water and then freeze-dried under vacuum at -70°C for 24 hours to obtain the immobilized bacterial strain preparation.
[0062] Comparative Example 1
[0063] The difference between Comparative Example 1 and Example 2 is that the immobilized strain preparation contains only salt-resistant Bacillus. The specific steps are as follows:
[0064] 1. Preparation of the carrier
[0065] The encapsulation agent comprises the following components: 2g sodium alginate, 0.1g graphene oxide, 0.1g zeolite powder, 0.1g coconut shell powder, 0.5g gelatin, 0.5g starch, 0.2g nano-synergist, and 96.5g pure water.
[0066] The nano-synergist used is nano-iron particles.
[0067] 2. Strains Immobilization
[0068] The halophilic Bacillus bacterial suspension obtained in Example 1 was added to the embedding agent and mixed thoroughly to obtain a mixture. The total viable count in the bacterial suspension was 5 × 10⁻⁶. 8 CFU / mL, the weight ratio of bacterial solution to embedding agent (1 ml is recorded as 1 g) is 1 g: 5 g.
[0069] The mixture was added dropwise to a 0.2 mol / L calcium chloride solution at a uniform rate while stirring continuously to obtain embedded particles with a diameter of 2.5 ± 1 mm.
[0070] The obtained encapsulated particles were immobilized at room temperature and the calcium chloride solution was discarded after 20 hours. The particles were washed twice with pure water and then freeze-dried under vacuum at -70°C for 24 hours to obtain the immobilized bacterial strain preparation.
[0071] Comparative Example 2
[0072] The difference between Comparative Example 2 and Example 2 is that the immobilized strain preparation contains only *Salmonella lithospora*. The specific steps are as follows:
[0073] 1. Preparation of the carrier
[0074] The encapsulation agent comprises the following components: 2g sodium alginate, 0.1g graphene oxide, 0.1g zeolite powder, 0.1g coconut shell powder, 0.5g gelatin, 0.5g starch, 0.2g nano-synergist, and 96.5g pure water.
[0075] The nano-synergist used is nano-iron particles.
[0076] 2. Strains Immobilization
[0077] The *Salmonella lithospora* bacterial suspension obtained in Example 1 was added to the embedding agent and mixed thoroughly to obtain a mixture. The total viable count in the bacterial suspension was 5 × 10⁻⁶. 8 CFU / mL, the weight ratio of bacterial solution to embedding agent (1 ml is recorded as 1 g) is 1 g: 5 g.
[0078] The mixture was added dropwise to a 0.2 mol / L calcium chloride solution at a uniform rate while stirring continuously to obtain embedded particles with a diameter of 2.5 ± 1 mm.
[0079] The obtained encapsulated particles were immobilized at room temperature and the calcium chloride solution was discarded after 20 hours. The particles were washed twice with pure water and then freeze-dried under vacuum at -70°C for 24 hours to obtain the immobilized bacterial strain preparation.
[0080] Comparative Example 3
[0081] The difference between this comparative example and Example 2 is that the nano-synergist used is magnesium nanoparticles.
[0082] 1. Preparation of the carrier
[0083] To reduce the salinity stress of microorganisms, strains and encapsulating agents are mixed to form a carrier, which allows the strains to attach and immobilize.
[0084] The encapsulation agent comprises the following components: 2g sodium alginate, 0.1g graphene oxide, 0.1g zeolite powder, 0.1g coconut shell powder, 0.5g gelatin, 0.5g starch, 0.2g nano-synergist, and 96.5g pure water.
[0085] The nano-synergist used is magnesium nanoparticles.
[0086] 2. Strains Immobilization
[0087] The halophilic Bacillus and Haloxylon ammodendron obtained in Example 1 were mixed at a 1:1 ratio to obtain a mixed bacterial solution with a total viable count of 5 × 10⁻⁶. 8 CFU / mL. Add the mixed bacterial solution to the embedding medium and mix thoroughly to obtain a mixture. The weight ratio of the mixed bacterial solution to the embedding medium (1 ml is denoted as 1 g) is 1 g: 5 g.
[0088] The mixture was added dropwise to a 0.2 mol / L calcium chloride solution at a uniform rate while stirring continuously to obtain embedded particles with a diameter of 2.5 ± 1 mm.
[0089] The obtained encapsulated particles were immobilized at room temperature and the calcium chloride solution was discarded after 20 hours. The particles were washed twice with pure water and then freeze-dried under vacuum at -70°C for 24 hours to obtain the immobilized bacterial strain preparation.
[0090] Comparative Example 4
[0091] The difference between this comparative example and Example 2 is that the nano-synergist used is nano-zinc particles.
[0092] 1. Preparation of the carrier
[0093] To reduce the salinity stress of microorganisms, strains and encapsulating agents are mixed to form a carrier, which allows the strains to attach and immobilize.
[0094] The encapsulation agent comprises the following components: 2g sodium alginate, 0.1g graphene oxide, 0.1g zeolite powder, 0.1g coconut shell powder, 0.5g gelatin, 0.5g starch, 0.2g nano-synergist, and 96.5g pure water.
[0095] The nano-synergist used is nano-zinc particles.
[0096] 2. Strains Immobilization
[0097] The halophilic Bacillus and Haloxylon ammodendron obtained in Example 1 were mixed at a 1:1 ratio to obtain a mixed bacterial solution with a total viable count of 5 × 10⁻⁶. 8 CFU / mL. Add the mixed bacterial solution to the embedding medium and mix thoroughly to obtain a mixture. The weight ratio of the mixed bacterial solution to the embedding medium (1 ml is denoted as 1 g) is 1 g: 5 g.
[0098] The mixture was added dropwise to a 0.2 mol / L calcium chloride solution at a uniform rate while stirring continuously to obtain embedded particles with a diameter of 2.5 ± 1 mm.
[0099] The obtained encapsulated particles were immobilized at room temperature and the calcium chloride solution was discarded after 20 hours. The particles were washed twice with pure water and then freeze-dried under vacuum at -70°C for 24 hours to obtain the immobilized bacterial strain preparation.
[0100] Experimental Example 1
[0101] The immobilized bacterial strains from Examples 2 and 1-4 were added to high-salt organic wastewater for degradation capacity testing. The high-salt organic wastewater contained 3.5 wt% salt, and the water quality indicators were: COD 802.7 mg / L, ammonia nitrogen 156.1 mg / L, total nitrogen 202.8 mg / L, and volatile phenols 57.3 mg / L. A pH adjuster was added to the high-salt organic wastewater to adjust the pH to 4.0-6.0 for use as the test solution. Five experimental groups were set up, and a control group was also set up. The control group's test solution did not contain the immobilized bacterial strains. The group settings are shown in Table 2.
[0102] Table 2 Experimental Groups
[0103]
[0104] Immobilized bacterial strain preparation was added to the test solution of the experimental group at a ratio of 4% (w / v). The volume of high-salt organic wastewater in each group was 5L. The culture temperature was 20℃, the culture time was 24h, and the stirring speed was 50rpm. After the culture was completed, the water quality indicators were tested according to "GB16171-2012 Emission Standard of Pollutants for Coking Chemical Industry". The results are shown in Table 3.
[0105] Table 3 Degradation test of high-salt organic wastewater
[0106]
[0107] As shown in Table 3, compared with the control group, all pollutant indicators in each experimental group were reduced, indicating that the immobilized strains and their combinations promoted the degradation of pollutants. Among them, the composite group showed better results than the groups using single strains of *Bacillus halophilus*, *Haloxylon ammodendron*, magnesium synergist (using nano-magnesium particles), and zinc synergist (using nano-zinc particles). Therefore, the immobilized strain preparation prepared by combining *Bacillus halophilus* and *Haloxylon ammodendron* with materials containing iron nanoparticles has a better pollutant degradation effect on high-salt organic wastewater.
[0108] The above description is merely a preferred embodiment of this application and is not intended to limit this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.
Claims
1. A method for wastewater treatment, characterized in that, After adjusting the pH of the wastewater to 4-6, immobilized bacterial strain preparations were added for treatment. The wastewater in question is high-salt organic wastewater; The immobilized bacterial strain preparation contains halophilic spores ( Bacillus halotolerans ) and Shiquanshi (Salmonella) Halomonas fontilapidosi ); The preservation number of the halophilic spore-forming bacteria is GDMCC NO.1.4092; the strain number of *Haloxylon ammodendron* is CICC24083. The immobilized strain preparation also contains a nano-synergist, which is a nano-iron particle, specifically a magnetic microsphere powder of iron oxide. The immobilized bacterial strain preparation is prepared by the following method: (1) Mix halophilic spore-resistant bacilli and halophilic bacilli to obtain a mixed bacterial solution; (2) Add the mixed bacterial solution to the embedding agent and mix thoroughly to obtain the mixed solution; (3) Add the mixture dropwise at a constant rate to a 0.1-1 mol / L calcium chloride solution while stirring continuously to obtain the encapsulated particles; (4) The obtained embedded particles were immobilized at room temperature and the calcium chloride solution was discarded after 10-30 hours. The particles were washed with pure water 1-3 times and then freeze-dried under vacuum for 12-36 hours to obtain the immobilized strain preparation. The encapsulating agent comprises the following components by weight: 1-5 parts sodium alginate, 0.01-1 parts graphene oxide, 0.01-1 parts zeolite powder, 0.01-1 parts coconut shell powder, 0.1-2 parts gelatin, 0.1-2 parts starch, 0.1-2 parts nano-synergist, and 90-110 parts pure water.
2. The wastewater treatment method according to claim 1, characterized in that, High-salt organic wastewater has a salinity >1 w / v% and contains organic matter including volatile phenols.
3. The wastewater treatment method according to claim 1, characterized in that, In step (1), the ratio of viable bacteria of halophilic Bacillus and Haloxylon ammodendron is (1-2):(1-2), and the total viable bacteria count in the mixed bacterial solution is 5×10⁻⁶. 8 CFU / mL.
4. The wastewater treatment method according to claim 1, characterized in that, In step (2), the weight ratio of the mixed bacterial solution to the embedding agent is 1:(1-10).
5. The wastewater treatment method according to claim 1, characterized in that, In step (3), the diameter of the embedded particles is 1-10 mm.
6. The application of the wastewater treatment method according to any one of claims 1-5 in the following (1)-(4): (1) Reduce the COD value in high-salt organic wastewater; (2) Reduce the ammonia nitrogen content in high-salt organic wastewater; (3) Reduce the total nitrogen content of high-salt organic wastewater; (4) Reduce the volatile phenol content in high-salt organic wastewater.