A method for treating marine aquaculture wastewater

Abstract

This invention discloses a method for treating marine aquaculture wastewater. The method includes the following steps: S1, allowing the marine aquaculture wastewater to settle and collecting the supernatant to obtain a solution to be treated; S2, loading a first composite bacterial solution and a second composite bacterial solution onto a trimethylchlorosilane-modified porous active carrier to obtain first and second biological carriers; S3, adding the first biological carrier to the solution to be treated and reacting for 20-30 hours, during which time air is introduced for aeration, followed by filtration to obtain a pretreated solution; S4, adding the second biological carrier to the pretreated solution and reacting for 12-24 hours, during which time ozone is introduced for aeration, followed by filtration to obtain purified seawater. The first composite bacterial solution is mainly composed of a mixture of halophilic bacillus solution and sacchariphytic red bacillus solution; the second composite bacterial solution is mainly composed of a mixture of marine cyclone bacteria solution, halophilic spheroid bacteria solution, and oceanic monoclonal bacteria solution. This invention combines physical and biological methods, significantly improving the purification effect on wastewater.

Description

Technical Field

[0001] This invention relates to the field of wastewater treatment technology, and in particular to a method for treating marine aquaculture wastewater. Background Technology

[0002] In recent years, with the improvement of people's living standards, the demand for live seafood has increased, leading to a shortage of near-shore fishery resources. This has spurred the rapid development of my country's aquaculture industry. As a major aquaculture country, artificially aquaculture production accounts for a significant proportion of China's total seafood output. With the increasing demands for intensive development in aquaculture, issues such as the safety and quality of aquatic products, water pollution in aquaculture, and water recycling are receiving increasing attention.

[0003] Compared to conventional wastewater such as freshwater aquaculture wastewater, domestic sewage, and industrial wastewater, marine aquaculture wastewater is typically characterized by high salinity. Saline wastewater is generally more difficult to treat, and the types and structures of pollutants in the water are complex. In addition, the water contains a large amount of organic matter and nutrients from fish excrement and feed residue. Considering the survival safety and quality of the seafood, the main problem with marine aquaculture wastewater is the removal of these nutrients. The main factors polluting aquaculture seawater include feed residue, chemical pollution, and biological secretions and excrement, leading to an increase in nutrients in the water, elevated nitrogen and phosphorus levels, and increased BOD and ammonia nitrogen levels. This exceeds the environmental carrying capacity, causing eutrophication and affecting the normal life of farmed organisms.

[0004] Conventional treatment methods generally include physical, chemical, and biological methods. Physical methods are the most basic and easy to operate, and typically include filtration, sedimentation, flotation, and foam separation. Chemical methods for treating mariculture wastewater mainly include oxidation-reduction and coagulation technologies. Besides aeration and electrolysis, other methods require the addition of chemical additives, removing harmful pollutants and bacteria from the water through adsorption or sedimentation. Biological methods utilize aquatic plants that can directly absorb nitrogen and phosphorus from the aquaculture seawater through photosynthesis via their extensive root systems or stems and leaves, and also enrich microorganisms by attaching them to a biofilm to treat the wastewater. Using a single treatment method cannot achieve satisfactory results; therefore, this application provides a method for treating mariculture wastewater that combines physical and biological methods. Summary of the Invention

[0005] In view of the above-mentioned deficiencies in the prior art, the present invention proposes a method for treating marine aquaculture wastewater to solve the problems mentioned in the background art.

[0006] To achieve the above objectives, the present invention provides the following technical solution:

[0007] A method for treating marine aquaculture wastewater includes the following steps:

[0008] S1. Let the marine aquaculture wastewater stand for treatment, collect the supernatant, and obtain the liquid to be treated;

[0009] S2. Load the first composite bacterial solution and the second composite bacterial solution onto trimethylchlorosilane-modified porous active carriers to obtain the first biological carrier and the second biological carrier.

[0010] S3. The first biological carrier is added to the liquid to be treated and reacted for 20-30 hours. During this period, air is introduced for aeration, and the pretreated liquid is obtained by filtration.

[0011] S4. The second biological carrier is added to the pretreatment solution and reacted for 12-24 hours. During this period, ozone is introduced for aeration, and the purified seawater is obtained by filtration.

[0012] The first composite bacterial solution mainly consists of a concentration of 1.5 × 10⁻⁶. 5 ~2.0×10 8 CFU / mL of halophilic bacteria suspension and a concentration of 1.0 × 10⁻⁶ 4 ~1.8×10 6 The glycophytic red bacillus culture with a concentration of CFU / mL was prepared by mixing at a mass ratio of (0.5–2):(3–5).

[0013] Preferably, the halophilic bacillus (Latin: Salinimicrobiumcatena) was purchased from Shanghai Preservation Biotechnology Center; and the saccharovorum halorubrum (Latin: Halorubrum saccharovorum) was purchased from Shanghai Xuanke Biotechnology Co., Ltd.

[0014] The second composite bacterial solution mainly consists of a concentration of 3.0 × 10⁻⁶. 2 ~3.5×10 4 Marine cyclone bacteria solution with a concentration of 1.0 × 10⁻⁶ CFU / mL 3 ~1.2×10 6 CFU / mL of halophilic cocci and a concentration of 1.0 × 10⁻⁶ 6 ~2.5×10 9 Oceanomonas bacterial suspension with CFU / mL was prepared by mixing in a mass ratio of (0.3-1):(0.3-0.8):(4-6).

[0015] Preferably, *Thalassospiramarina* was purchased from Shanghai Preservation Biotechnology Center, product specification: SHBCC D82786; *Salinisphaera halophila* was purchased from Ningbo Mingzhou Biotechnology Co., Ltd., product code: BMZ133794; and *Oceanimonas sp.* was purchased from Shanghai Preservation Biotechnology Center, product specification: SMHCC D18298.

[0016] Preferably, the porous active support in step S2 is one of mesoporous silicon, mesoporous carbon, or ceramic particles.

[0017] Preferably, the preparation method of the trimethylchlorosilane-modified porous active support in step S2 includes calcining the porous active support at 600-700℃ for 6-12 hours, cooling it to 60-80℃, and then soaking it in 5-8 mol / L acetic acid for 5-10 hours. After soaking, the support is rinsed with deionized water until the filtrate is neutral to obtain a pretreated support. The pretreated support is then placed in trimethylchlorosilane, shaken for 10-30 minutes, allowed to stand for 12-20 hours, filtered, and the resulting support is dried to obtain the trimethylchlorosilane-modified porous active support.

[0018] Preferably, the mass ratio of the pretreatment carrier to trimethylchlorosilane is (5-8):(9-13).

[0019] Preferably, the loading in step S2 involves immersing a trimethylchlorosilane-modified porous active carrier in a first composite bacterial solution and a second composite bacterial solution, respectively, shaking and adsorbing for 10–15 h, and then allowing it to stand for 20–25 h to obtain a first biological carrier and a second biological carrier.

[0020] Preferably, the trimethylchlorosilane-modified porous active carrier is impregnated with the first composite bacterial solution and the second composite bacterial solution at a mass ratio of 1:(3-6).

[0021] Preferably, in step S3, the weight ratio of the first biological carrier to the liquid to be treated is 1:(200-500).

[0022] Preferably, in step S3, the air aeration time is 3-8 hours, the pH of the liquid to be treated is adjusted to 7.0-7.5, and the dissolved oxygen in the liquid to be treated is maintained at 1-6 mg / L.

[0023] Preferably, the weight ratio of the second biological carrier to the pretreatment solution in step S4 is 1:(1000-1500).

[0024] Preferably, in step S4, the amount of ozone added is 15-25% of the total volume of the pretreatment liquid, and the ozone concentration is 25-50 mg / L.

[0025] Compared with the prior art, the beneficial effects of the present invention are:

[0026] This invention utilizes a biological carrier to perform two stages of bioadsorption on the treated liquid, each with varying degrees of bioadsorption. First, the first biological carrier reacts with the liquid under test, and aeration with air provides a large amount of oxygen to increase the dissolved oxygen content in the water, which is then consumed by microorganisms during the degradation of organic matter. Simultaneously, wastewater from the bottom is transported upwards via air bubbles, accelerating the reaction between the microorganisms in the first composite bacterial solution and the wastewater, effectively reducing the content of nutrients such as nitrogen and phosphorus in the wastewater. Second, the pretreated liquid is treated with a second composite bacterial solution and ozone. The synergistic effect of the second composite bacterial solution and ozone further removes ammonia nitrogen, nitrite, and organic matter from the water. This technical solution addresses suspended solids and COD... Mn The removal rates of BOD5, inorganic nitrogen, and reactive phosphate were 89.74–91.98%, 98.45–98.65%, 97.83–98.0%, 98.45–99.02%, and 99.90–99.97%, respectively. Detailed Implementation

[0027] The technical solution of the present invention will be further described in detail below with reference to specific embodiments.

[0028] Example 1

[0029] A method for treating marine aquaculture wastewater includes the following steps:

[0030] S1. Let the marine aquaculture wastewater stand for 48 hours, collect the supernatant, and obtain the liquid to be treated.

[0031] S2. The first and second composite bacterial solutions are respectively loaded onto trimethylchlorosilane-modified porous active carriers to obtain the first and second biological carriers. The preparation method of the trimethylchlorosilane-modified porous active carrier includes calcining the porous active carrier at 600℃ for 6 hours, cooling it to 60℃, and then soaking it in 5 mol / L acetic acid for 5 hours. After soaking, it is rinsed with deionized water until the filtrate is neutral to obtain a pretreated carrier. The pretreated carrier is then placed in trimethylchlorosilane at a ratio of 5:9, shaken for 10 minutes, allowed to stand for 12 hours, filtered, and the resulting carrier is dried to obtain the trimethylchlorosilane-modified porous active carrier. The loading process involves immersing the trimethylchlorosilane-modified porous active carrier in the first and second composite bacterial solutions at a ratio of 1:3, shaking and adsorbing for 10 hours, and then allowing it to stand for 20 hours to obtain the first and second biological carriers.

[0032] S3. The first biological carrier is added to the solution to be treated and reacted for 20 hours. During this period, air is introduced for 3 hours to adjust the pH of the solution to be treated to 7.0 and maintain the dissolved oxygen in the solution to be treated at 1 mg / L. The solution is then filtered to obtain the pretreated solution. The weight ratio of the first biological carrier to the solution to be treated is 1:200.

[0033] S4. The second biological carrier is added to the pretreatment solution and reacted for 12 hours. During this period, 25 mg / L of ozone is introduced for aeration, and the purified seawater is obtained by filtration. The weight ratio of the second biological carrier to the pretreatment solution is 1:1000. The amount of ozone added is 15% of the total volume of the pretreatment solution.

[0034] The first composite bacterial solution mainly consists of a concentration of 1.5 × 10⁻⁶. 5 CFU / mL of halophilic bacteria suspension and a concentration of 1.0 × 10⁻⁶ 4 The solution was prepared by mixing glycophytic red bacillus culture at a mass ratio of 0.5:3 with CFU / mL of the solution.

[0035] The second composite bacterial solution mainly consists of a concentration of 3.0 × 10⁻⁶. 2 Marine cyclone bacteria solution with a concentration of 1.0 × 10⁻⁶ CFU / mL 3 CFU / mL of halophilic cocci and a concentration of 1.0 × 10⁻⁶ 6 The CFU / mL Oceanomonas bacterial suspension was mixed at a mass ratio of 0.3:0.3:4.

[0036] The porous active support is mesoporous silicon.

[0037] Example 2

[0038] A method for treating marine aquaculture wastewater includes the following steps:

[0039] S1. Let the marine aquaculture wastewater stand for 48 hours, collect the supernatant, and obtain the liquid to be treated.

[0040] S2. The first and second composite bacterial solutions are respectively loaded onto trimethylchlorosilane-modified porous active carriers to obtain the first and second biological carriers. The preparation method of the trimethylchlorosilane-modified porous active carrier includes calcining the porous active carrier at 700℃ for 12 hours, cooling it to 80℃, and then soaking it in 8 mol / L acetic acid for 10 hours. After soaking, it is rinsed with deionized water until the filtrate is neutral to obtain a pretreated carrier. The pretreated carrier is then placed in trimethylchlorosilane at a ratio of 8:13, shaken for 30 minutes, allowed to stand for 20 hours, filtered, and the resulting carrier is dried to obtain the trimethylchlorosilane-modified porous active carrier. The loading process involves immersing the trimethylchlorosilane-modified porous active carrier in the first and second composite bacterial solutions at a ratio of 1:6, shaking and adsorbing for 15 hours, and then allowing it to stand for 25 hours to obtain the first and second biological carriers.

[0041] S3. The first biological carrier is added to the solution to be treated and reacted for 30 hours. During this period, air is introduced for 8 hours to adjust the pH of the solution to be treated to 7.5 and maintain the dissolved oxygen in the solution to be treated at 6 mg / L. The solution is then filtered to obtain the pretreated solution. The weight ratio of the first biological carrier to the solution to be treated is 1:500.

[0042] S4. The second biological carrier is added to the pretreatment solution and reacted for 24 hours. During this period, 50 mg / L of ozone is introduced for aeration, and the purified seawater is obtained by filtration. The weight ratio of the second biological carrier to the pretreatment solution is 1:1500. The amount of ozone added is 25% of the total volume of the pretreatment solution.

[0043] The first composite bacterial solution mainly consists of a concentration of 2.0 × 10⁻⁶. 8 CFU / mL of chain-forming halophilic bacilli culture and a concentration of 1.8 × 10⁻⁶ 6 The solution of CFU / mL of glycophytic red bacillus was prepared by mixing at a mass ratio of 2:5.

[0044] The second compound bacterial solution mainly consists of a concentration of 3.5 × 10⁻⁶. 4 Marine cyclone bacteria solution with a concentration of 1.2 × 10⁻⁶ CFU / mL 6 CFU / mL of halophilic cocci and a concentration of 2.5 × 10⁻⁶ 9 The CFU / mL Oceanomonas bacterial suspension was prepared by mixing Oceanomonas bacterial suspensions at a mass ratio of 1:0.8:6.

[0045] The porous active support is mesoporous carbon.

[0046] Example 3

[0047] A method for treating marine aquaculture wastewater includes the following steps:

[0048] S1. Let the marine aquaculture wastewater stand for 48 hours, collect the supernatant, and obtain the liquid to be treated.

[0049] S2. The first and second composite bacterial solutions are respectively loaded onto trimethylchlorosilane-modified porous active carriers to obtain the first and second biological carriers. The preparation method of the trimethylchlorosilane-modified porous active carrier includes calcining the porous active carrier at 650℃ for 9 hours, cooling it to 70℃, and then soaking it in 7 mol / L acetic acid for 8 hours. After soaking, it is rinsed with deionized water until the filtrate is neutral to obtain a pretreated carrier. The pretreated carrier is then placed in trimethylchlorosilane, mixed at a mass ratio of 7:10, shaken for 20 minutes, allowed to stand for 18 hours, filtered, and the resulting carrier is dried to obtain the trimethylchlorosilane-modified porous active carrier. The loading process involves immersing the trimethylchlorosilane-modified porous active carrier in the first and second composite bacterial solutions at a mass ratio of 1:5, shaking and adsorbing for 12 hours, and then allowing it to stand for 22 hours to obtain the first and second biological carriers.

[0050] S3. The first biological carrier is added to the solution to be treated and reacted for 25 hours. During this period, air is introduced for 5 hours to adjust the pH of the solution to be treated to 7.1 and maintain the dissolved oxygen in the solution to be treated at 3 mg / L. The solution is then filtered to obtain the pretreated solution. The weight ratio of the first biological carrier to the solution to be treated is 1:500.

[0051] S4. The second biological carrier is added to the pretreatment solution and reacted for 20 hours. During this period, 40 mg / L of ozone is introduced for aeration, and the purified seawater is obtained by filtration. The weight ratio of the second biological carrier to the pretreatment solution is 1:1200. The amount of ozone added is 20% of the total volume of the pretreatment solution.

[0052] The first composite bacterial solution mainly consists of a concentration of 1.8 × 10⁻⁶. 7 CFU / mL of halophilic bacteria suspension and a concentration of 1.0 × 10⁻⁶ 5 The solution of CFU / mL of glycophytic red bacillus was prepared by mixing at a mass ratio of 1:4.

[0053] The second composite bacterial solution mainly consists of a concentration of 3.2 × 10⁻⁶. 3 Marine cyclone bacteria solution with a concentration of 1.1 × 10⁻⁶ CFU / mL 5 CFU / mL of halophilic cocci and a concentration of 2.0 × 10⁻⁶ 8 The CFU / mL Oceanomonas bacterial suspension was prepared by mixing at a mass ratio of 0.5:0.7:5.

[0054] The porous active carrier is ceramsite.

[0055] Comparative Example 1

[0056] The difference between this comparative example and Example 3 is that the porous active carrier is not modified, while the other components and steps remain unchanged.

[0057] A method for treating marine aquaculture wastewater includes the following steps:

[0058] S1. Let the marine aquaculture wastewater stand for 48 hours, collect the supernatant, and obtain the liquid to be treated.

[0059] S2. Load the first composite bacterial solution and the second composite bacterial solution onto ceramsite to obtain the first biological carrier and the second biological carrier; wherein the loading is carried out by immersing the ceramsite in the first composite bacterial solution and the second composite bacterial solution at a mass ratio of 1:5, shaking and adsorbing for 12 hours, and then letting it stand for 22 hours to obtain the first biological carrier and the second biological carrier.

[0060] S3. The first biological carrier is added to the solution to be treated and reacted for 25 hours. During this period, air is introduced for 5 hours to adjust the pH of the solution to be treated to 7.1 and maintain the dissolved oxygen in the solution to be treated at 3 mg / L. The solution is then filtered to obtain the pretreated solution. The weight ratio of the first biological carrier to the solution to be treated is 1:500.

[0061] S4. The second biological carrier is added to the pretreatment solution and reacted for 20 hours. During this period, 40 mg / L of ozone is introduced for aeration, and the purified seawater is obtained by filtration. The weight ratio of the second biological carrier to the pretreatment solution is 1:1200. The amount of ozone added is 20% of the total volume of the pretreatment solution.

[0062] The first composite bacterial solution mainly consists of a concentration of 1.8 × 10⁻⁶. 7 CFU / mL of halophilic bacteria suspension and a concentration of 1.0 × 10⁻⁶ 5 The solution of CFU / mL of glycophytic red bacillus was prepared by mixing at a mass ratio of 1:4.

[0063] The second composite bacterial solution mainly consists of a concentration of 3.2 × 10⁻⁶. 3 Marine cyclone bacteria solution with a concentration of 1.1 × 10⁻⁶ CFU / mL 5 CFU / mL of halophilic cocci and a concentration of 2.0 × 10⁻⁶ 8 The CFU / mL Oceanomonas bacterial suspension was prepared by mixing at a mass ratio of 0.5:0.7:5.

[0064] Comparative Example 2

[0065] The difference between this comparative example and Example 3 is that the first biological carrier is not added in step S3, while the other components and steps remain unchanged.

[0066] A method for treating marine aquaculture wastewater includes the following steps:

[0067] S1. Let the marine aquaculture wastewater stand for 48 hours, collect the supernatant, and obtain the liquid to be treated.

[0068] S3. Aerate the liquid to be treated with air for 5 hours, adjust the pH of the liquid to be treated to 7.1, maintain the dissolved oxygen in the liquid to be treated at 3 mg / L, and filter to obtain the pretreated liquid.

[0069] S2. The composite bacterial solution is loaded onto a trimethylchlorosilane-modified porous active carrier to obtain a biological carrier. The preparation method of the trimethylchlorosilane-modified porous active carrier includes calcining the porous active carrier at 650℃ for 9 hours, cooling it to 70℃, and then soaking it in 7 mol / L acetic acid for 8 hours. After soaking, it is rinsed with deionized water until the filtrate is neutral to obtain a pretreated carrier. The pretreated carrier is then placed in trimethylchlorosilane at a mass ratio of 7:10, mixed, shaken for 20 minutes, allowed to stand for 18 hours, filtered, and the resulting carrier is dried to obtain the trimethylchlorosilane-modified porous active carrier. The loading process involves immersing the trimethylchlorosilane-modified porous active carrier in the composite bacterial solution at a mass ratio of 1:5, shaking and adsorbing for 12 hours, and then allowing it to stand for 22 hours to obtain the biological carrier.

[0070] S4. The biological carrier is added to the pretreatment solution and reacted for 20 hours. During this period, 40 mg / L of ozone is introduced for aeration, and the purified seawater is obtained by filtration. The weight ratio of the biological carrier to the pretreatment solution is 1:1200. The amount of ozone added is 20% of the total volume of the pretreatment solution.

[0071] The compound bacterial solution mainly consists of a concentration of 3.2 × 10⁻⁶. 3 Marine cyclone bacteria solution with a concentration of 1.1 × 10⁻⁶ CFU / mL 5 CFU / mL of halophilic cocci and a concentration of 2.0 × 10⁻⁶ 8 The CFU / mL Oceanomonas bacterial suspension was prepared by mixing at a mass ratio of 0.5:0.7:5.

[0072] The porous active carrier is ceramsite.

[0073] Comparative Example 3

[0074] The difference between this comparative example and Example 3 is that the first biological carrier is used in steps S3 and S4, while the other components and steps remain unchanged.

[0075] A method for treating marine aquaculture wastewater includes the following steps:

[0076] S1. Let the marine aquaculture wastewater stand for 48 hours, collect the supernatant, and obtain the liquid to be treated.

[0077] S2. The first composite bacterial solution is loaded onto a trimethylchlorosilane-modified porous active carrier to obtain the first biological carrier. The preparation method of the trimethylchlorosilane-modified porous active carrier includes calcining the porous active carrier at 650℃ for 9 hours, cooling it to 70℃, and then soaking it in 7 mol / L acetic acid for 8 hours. After soaking, it is rinsed with deionized water until the filtrate is neutral to obtain a pretreated carrier. The pretreated carrier is then placed in trimethylchlorosilane, mixed at a mass ratio of 7:10, shaken for 20 minutes, allowed to stand for 18 hours, filtered, and the resulting carrier is dried to obtain the trimethylchlorosilane-modified porous active carrier. The loading process involves immersing the trimethylchlorosilane-modified porous active carrier in the first composite bacterial solution at a mass ratio of 1:5, shaking and adsorbing for 12 hours, and then allowing it to stand for 22 hours to obtain the first biological carrier.

[0078] S3. The first biological carrier is added to the solution to be treated and reacted for 25 hours. During this period, air is introduced for 5 hours to adjust the pH of the solution to be treated to 7.1 and maintain the dissolved oxygen in the solution to be treated at 3 mg / L. The solution is then filtered to obtain the pretreated solution. The weight ratio of the first biological carrier to the solution to be treated is 1:500.

[0079] S4. The first biological carrier is added to the pretreatment solution and reacted for 20 hours. During this period, 40 mg / L of ozone is introduced for aeration, and the purified seawater is obtained by filtration. The weight ratio of the second biological carrier to the pretreatment solution is 1:1200. The amount of ozone added is 20% of the total volume of the pretreatment solution.

[0080] The first composite bacterial solution mainly consists of a concentration of 1.8 × 10⁻⁶. 7 CFU / mL of halophilic bacteria suspension and a concentration of 1.0 × 10⁻⁶ 5 The solution of CFU / mL of glycophytic red bacillus was prepared by mixing at a mass ratio of 1:4.

[0081] The porous active carrier is ceramsite.

[0082] Comparative Example 4

[0083] The difference between this comparative example and Example 3 is that a second biological carrier is used in steps S3 and S4, while the other components and steps remain unchanged.

[0084] A method for treating marine aquaculture wastewater includes the following steps:

[0085] S1. Let the marine aquaculture wastewater stand for 48 hours, collect the supernatant, and obtain the liquid to be treated.

[0086] S2. The second composite bacterial solution is loaded onto a trimethylchlorosilane-modified porous active carrier to obtain a second biological carrier. The preparation method of the trimethylchlorosilane-modified porous active carrier includes calcining the porous active carrier at 650℃ for 9 hours, cooling it to 70℃, and then soaking it in 7 mol / L acetic acid for 8 hours. After soaking, it is rinsed with deionized water until the filtrate is neutral to obtain a pretreated carrier. The pretreated carrier is then placed in trimethylchlorosilane at a mass ratio of 7:10, mixed, shaken for 20 minutes, allowed to stand for 18 hours, filtered, and the resulting carrier is dried to obtain the trimethylchlorosilane-modified porous active carrier. The loading process involves immersing the trimethylchlorosilane-modified porous active carrier in the second composite bacterial solution at a mass ratio of 1:5, shaking and adsorbing for 12 hours, and then allowing it to stand for 22 hours to obtain the second biological carrier.

[0087] S3. The second biological carrier is added to the solution to be treated and reacted for 25 hours. During this period, air is introduced for 5 hours to adjust the pH of the solution to be treated to 7.1 and maintain the dissolved oxygen in the solution to be treated at 3 mg / L. The solution is then filtered to obtain the pretreated solution. The weight ratio of the first biological carrier to the solution to be treated is 1:500.

[0088] S4. The second biological carrier is added to the pretreatment solution and reacted for 20 hours. During this period, 40 mg / L of ozone is introduced for aeration, and the purified seawater is obtained by filtration. The weight ratio of the second biological carrier to the pretreatment solution is 1:1200. The amount of ozone added is 20% of the total volume of the pretreatment solution.

[0089] The second composite bacterial solution mainly consists of a concentration of 3.2 × 10⁻⁶. 3 Marine cyclone bacteria solution with a concentration of 1.1 × 10⁻⁶ CFU / mL 5 CFU / mL of halophilic cocci and a concentration of 2.0 × 10⁻⁶ 8 The CFU / mL Oceanomonas bacterial suspension was prepared by mixing at a mass ratio of 0.5:0.7:5.

[0090] The porous active carrier is ceramsite.

[0091] Comparative Example 5

[0092] The difference between this comparative example and Example 3 is that air aeration is used instead of ozone aeration in step S4, while the other components and steps remain unchanged.

[0093] A method for treating marine aquaculture wastewater includes the following steps:

[0094] S1. Let the marine aquaculture wastewater stand for 48 hours, collect the supernatant, and obtain the liquid to be treated.

[0095] S2. The first and second composite bacterial solutions are respectively loaded onto trimethylchlorosilane-modified porous active carriers to obtain the first and second biological carriers. The preparation method of the trimethylchlorosilane-modified porous active carrier includes calcining the porous active carrier at 650℃ for 9 hours, cooling it to 70℃, and then soaking it in 7 mol / L acetic acid for 8 hours. After soaking, it is rinsed with deionized water until the filtrate is neutral to obtain a pretreated carrier. The pretreated carrier is then placed in trimethylchlorosilane, mixed at a mass ratio of 7:10, shaken for 20 minutes, allowed to stand for 18 hours, filtered, and the resulting carrier is dried to obtain the trimethylchlorosilane-modified porous active carrier. The loading process involves immersing the trimethylchlorosilane-modified porous active carrier in the first and second composite bacterial solutions at a mass ratio of 1:5, shaking and adsorbing for 12 hours, and then allowing it to stand for 22 hours to obtain the first and second biological carriers.

[0096] S3. The first biological carrier is added to the solution to be treated and reacted for 25 hours. During this period, air is introduced for 5 hours to adjust the pH of the solution to be treated to 7.1 and maintain the dissolved oxygen in the solution to be treated at 3 mg / L. The solution is then filtered to obtain the pretreated solution. The weight ratio of the first biological carrier to the solution to be treated is 1:500.

[0097] S4. The second biological carrier is added to the pretreatment solution and reacted for 20 hours, during which air is introduced for 5 hours. The purified seawater is obtained by filtration. The weight ratio of the second biological carrier to the pretreatment solution is 1:1200. The pH of the solution to be treated is adjusted to 7.1, and the dissolved oxygen in the solution to be treated is maintained at 3 mg / L.

[0098] The first composite bacterial solution mainly consists of a concentration of 1.8 × 10⁻⁶. 7 CFU / mL of halophilic bacteria suspension and a concentration of 1.0 × 10⁻⁶ 5 The solution of CFU / mL of glycophytic red bacillus was prepared by mixing at a mass ratio of 1:4.

[0099] The second composite bacterial solution mainly consists of a concentration of 3.2 × 10⁻⁶. 3 Marine cyclone bacteria solution with a concentration of 1.1 × 10⁻⁶ CFU / mL 5 CFU / mL of halophilic cocci and a concentration of 2.0 × 10⁻⁶ 8 The CFU / mL Oceanomonas bacterial suspension was prepared by mixing at a mass ratio of 0.5:0.7:5.

[0100] The porous active carrier is ceramsite.

[0101] Comparative Example 6

[0102] The difference between this comparative example and Example 3 is that the bacterial solution ratio in the first composite bacterial solution is 1:1 by mass, while the other components and steps remain unchanged.

[0103] The first composite bacterial solution mainly consists of a concentration of 1.8 × 10⁻⁶. 7 CFU / mL of halophilic bacteria suspension and a concentration of 1.0 × 10⁻⁶ 5 The solution of CFU / mL of glycophytic red bacillus was prepared by mixing 1:1 by mass.

[0104] Comparative Example 7

[0105] The difference between this comparative example and Example 3 is that the bacterial solution ratio in the second composite bacterial solution is 1:1:1 by mass, while the other components and steps remain unchanged.

[0106] The second composite bacterial solution mainly consists of a concentration of 3.2 × 10⁻⁶. 3 Marine cyclone bacteria solution with a concentration of 1.1 × 10⁻⁶ CFU / mL 5 CFU / mL of halophilic cocci and a concentration of 2.0 × 10⁻⁶ 8 The CFU / mL Oceanomonas hydrophila culture was prepared by mixing Oceanomonas hydrophila in a mass ratio of 1:1:1.

[0107] Comparative Example 8

[0108] The difference between this comparative example and Example 3 is that the bacterial strains in the second compound bacterial solution are changed to Pseudomonas marineis and Escherichia coli, while the other components and steps remain unchanged.

[0109] The second compound bacterial solution mainly consists of a concentration of 2.0 × 10⁻⁶. 9 CFU / mL of Pseudomonas marineis culture and a concentration of 2.0 × 10⁻⁶ 9 The CFU / mL of *Hydrocotyle spp.* bacterial suspension was mixed at a mass ratio of 1:1.

[0110] Experimental Example 1

[0111] Wastewater from shrimp farming was collected, and testing and discharge indicators were conducted according to the methods and Class I standards provided in SC / T9103-2007 "Requirements for Wastewater Discharge from Marine Aquaculture". Before treatment, the wastewater showed suspended solids of 312 mg / L, pH 9.5, and chemical oxygen demand (COD). Mn The wastewater contained 400 mg / L of organic matter, 120 mg / L of biochemical oxygen demand (BOD5), 12.6 mg / L of zinc, 15.4 mg / L of copper, 22.6 mg / L of inorganic nitrogen, 31.2 mg / L of reactive phosphate, 12.3 mg / L of sulfide, and 18.7 mg / L of total residual chlorine. The wastewater was then treated using the methods of Examples 1-3 and Comparative Examples 1-8 of this invention, respectively. The levels of each indicator in the treated wastewater were measured, and the removal rate was calculated as (before testing - after testing) / before testing.

[0112] The test results are shown in Table 1:

[0113] Table 1 Comparison of different treatment methods for aquaculture wastewater

[0114]

[0115]

[0116] As shown in Table 1, the methods of Examples 1-3 of the present invention have good treatment effects on aquaculture wastewater, and the content of the obtained aquaculture wastewater indicators can meet the Class I standard of "Requirements for Discharge of Seawater from Aquaculture", and can be discharged into Class I and Class II sea areas specified in GB3097. Furthermore, the suspended solids and COD of Example 1 can be calculated. Mn The removal rates of suspended solids, BOD5, inorganic nitrogen, and reactive phosphate were 89.74%, 98.45%, 97.83%, 98.45%, and 99.96%, respectively; Example 2 showed the removal rates of suspended solids and COD. Mn The removal rates of suspended solids, BOD5, inorganic nitrogen, and reactive phosphate were 90.38%, 98.5%, 98.0%, 98.62%, and 99.90%, respectively; In Example 3, the removal rates of suspended solids and COD were... Mn The removal rates of BOD5, inorganic nitrogen, and reactive phosphate were 91.98%, 98.65%, 97.91%, 99.02%, and 99.97%, respectively, demonstrating a significant effect on wastewater treatment. A comparison of Example 3 and Comparative Example 1 shows that the trimethylchlorosilane-modified porous active carrier can not only adsorb more microorganisms but also increase the carrier's high-efficiency selectivity. A comparison of Example 3 and Comparative Example 2 shows that the first biological carrier has a significant impact on wastewater treatment, allowing for pre-adsorption and reducing the pressure on subsequent treatment. A comparison of Example 3 and Comparative Examples 3 and 4 shows that this technical solution is selective in the order of using the first and second biological carriers. A comparison of Example 3 and Comparative Example 5 shows that the second biological carrier and ozone treatment have a synergistic effect. A comparison of Example 3 and Comparative Examples 6 and 7 shows that this technical solution has a certain selectivity in the proportion of bacterial agent added; only by selecting an appropriate proportion can the expected treatment effect be achieved. A comparison of Example 3 and Comparative Example 8 shows that not selecting any bacterial species will achieve the effect of this technical solution.

[0117] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for treating marine aquaculture wastewater, characterized in that, Includes the following steps: S1. Let the marine aquaculture wastewater stand for treatment, collect the supernatant, and obtain the liquid to be treated; S2. Load the first composite bacterial solution and the second composite bacterial solution onto trimethylchlorosilane-modified porous active carriers to obtain the first biological carrier and the second biological carrier. The preparation method of the trimethylchlorosilane modified porous active carrier includes calcining the porous active carrier at 600-700℃ for 6-12h, cooling it to 60-80℃, and then soaking it in 5-8mol / L acetic acid for 5-10h. After soaking, the carrier is rinsed with deionized water until the filtrate is neutral to obtain a pretreated carrier. The pretreated carrier is then placed in trimethylchlorosilane, shaken for 10-30min, allowed to stand for 12-20h, filtered, and the resulting carrier is dried to obtain the trimethylchlorosilane modified porous active carrier. S3. The first biological carrier is added to the liquid to be treated and reacted for 20-30 hours. During this period, air is introduced for aeration, and the pretreated liquid is obtained by filtration. S4. The second biological carrier is added to the pretreatment solution and reacted for 12-24 hours. During this period, ozone is introduced for aeration, and the seawater is filtered to obtain purified seawater. The amount of ozone added is 15-25% of the total volume of the pretreatment liquid, and the ozone concentration is 25-50 mg / L. The first composite bacterial solution mainly consists of a concentration of 1.5 × 10⁻⁶. 5 ~2.0×10 8 CFU / mL of chain-forming halophilic bacilli culture and a concentration of 1.0 × 10⁻⁶ 4 ~1.8×10 6 The glycophytic red bacillus culture with a concentration of CFU / mL was prepared by mixing at a mass ratio of (0.5~2):(3~5); The second composite bacterial solution mainly consists of a concentration of 3.0 × 10⁻⁶. 2 ~3.5×10 4 Marine cyclone bacteria solution with a concentration of 1.0 × 10⁻⁶ CFU / mL 3 ~1.2×10 6 CFU / mL of halophilic cocci and a concentration of 1.0 × 10⁻⁶ 6 ~2.5×10 9 Oceanomonas bacterial suspension with CFU / mL was prepared by mixing in a mass ratio of (0.3~1):(0.3~0.8):(4~6).

2. The method for treating marine aquaculture wastewater according to claim 1, characterized in that, In step S2, the porous active support is one of mesoporous silicon, mesoporous carbon, or ceramic particles.

3. The method for treating marine aquaculture wastewater according to claim 1, characterized in that, The mass ratio of the pretreatment carrier to trimethylchlorosilane is (5~8):(9~13).

4. The method for treating marine aquaculture wastewater according to claim 1, characterized in that, The loading in step S2 involves immersing the trimethylchlorosilane-modified porous active carrier in the first and second composite bacterial solutions, respectively, shaking and adsorbing for 10-15 hours, and then allowing it to stand for 20-25 hours to obtain the first and second biological carriers.

5. The method for treating marine aquaculture wastewater according to claim 4, characterized in that, Trimethylchlorosilane-modified porous active carriers were impregnated with the first and second composite bacterial solutions at a mass ratio of 1:(3~6).

6. The method for treating marine aquaculture wastewater according to claim 1, characterized in that, In step S3, the weight ratio of the first biological carrier to the liquid to be treated is 1:(200~500).

7. The method for treating marine aquaculture wastewater according to claim 1, characterized in that, In step S3, the air aeration time is 3~8h, the pH of the liquid to be treated is adjusted to 7.0~7.5, and the dissolved oxygen in the liquid to be treated is maintained at 1~6mg / L.

8. The method for treating marine aquaculture wastewater according to claim 1, characterized in that, In step S4, the weight ratio of the second biological carrier to the pretreatment solution is 1:(1000~1500).

Images