A method for treating high-salinity wastewater discharged into the sea

Abstract

The present invention relates to a method for treating high-salt wastewater discharged into the sea, comprising five steps: ion flotation pretreatment, ozone catalytic oxidation, biochemical treatment and deep treatment; the biochemical treatment is: adding a composite salt-tolerant bacteria liquid after domestication of the first-level wastewater I to the first-level wastewater I obtained after ozone catalytic oxidation for anoxic-aerobic process treatment, the composite salt-tolerant bacteria liquid after domestication of the first-level wastewater I is obtained by inoculating lysine Bacillus, Clostridium butyricum and Hasavobacterium into a culture medium and culturing to the logarithmic phase to obtain the corresponding seed liquid, and then adding it to the domestication liquid containing the first-level wastewater I at a volume ratio of 1: (0.5-0.7): (0.3-0.6) for domestication. After the present invention compounds Hasavobacterium with lysine Bacillus and Clostridium butyricum in a certain proportion, the salt tolerance of the composite bacteria is significantly improved, thereby improving the wastewater treatment capacity, and the treated water quality reaches the fourth category seawater standard, which can be directly discharged into the sea for treatment.

Description

Technical Field

[0001] The invention belongs to the technical field of wastewater treatment, and in particular relates to a method for treating high-salinity wastewater discharged into the sea. Background Art

[0002] High-salinity wastewater refers to wastewater with a total salt content (measured in NaCl content) greater than 1%, which contains a large amount of inorganic salt ions, including Na + , Ca 2+ , Cl - 、SO4 2- Etc. High-salt wastewater is widely present in many industries such as chemical industry, pharmaceutical industry, printing and dyeing, leather making, new energy, etc. Especially with the development of new energy vehicles, a large amount of high-salt, high-ammonia nitrogen and difficult-to-biodegrade wastewater will be produced. How to reasonably treat high-salt wastewater and reduce its harmfulness is of great practical significance. At present, the commonly used methods for high-salt wastewater treatment are membrane method, multi-effect evaporation method, advanced oxidation method, biological method, etc. Among them, the membrane method refers to the separation, purification and concentration of different components through the selective permeability of the reverse osmosis membrane, but it needs to be filtered and impurity removed before separation, otherwise it is easy to cause membrane pore pollution and blockage. The multi-effect evaporation method refers to the evaporation of water through a multi-stage heating and decompression process to achieve salt concentration. If the hardness of the wastewater (mainly Ca 2+ Mg 2+ ) is too high, it is very easy to scale, reduce evaporation efficiency and even clog the container. Advanced oxidation processes (AOPs) refer to the rapid and thorough decomposition of organic pollutants by strong oxidizing substances (such as ·OH) produced in the water environment under the action of high temperature, high pressure, voltage, light or catalyst, but have no obvious effect on reducing salt content. Biological methods refer to the use of microorganisms such as bacteria, fungi and algae to absorb and fix inorganic salts during their growth and metabolism, and the use of biological enzymes to catalyze the decomposition of organic matter to purify wastewater. This treatment method is economical, efficient and harmless, but the salt content of the biochemical reaction cannot be too high, and ideal salt-tolerant bacteria need to be obtained. That is, a single treatment method either has low treatment efficiency and high operating costs, or has harsh treatment conditions. Combining multiple methods is an effective strategy to improve treatment efficiency and reduce operating costs.

[0003] The salinity of seawater is about 2.5%, so when the salinity of industrial and domestic wastewater is lower than 2.5%, it can be discharged into the sea without desalination after the pollutants meet the discharge standards. This makes economical and efficient biological methods the preferred method for discharging high-salinity wastewater into the sea, but efficient salt-tolerant bacteria are a limiting factor for this method. Summary of the invention

[0004] In order to overcome the problems in the prior art of treating high-salinity wastewater, such as low treatment efficiency, high operating cost or harsh treatment conditions, the present invention provides a method for treating high-salinity wastewater discharged into the sea. The method combines catalytic oxidation and biological methods, and adopts efficient salt-tolerant bacteria to achieve efficient, low-cost and harmless treatment of high-salinity wastewater discharged into the sea.

[0005] The present invention adopts the following scheme to achieve the above purpose:

[0006] A method for treating high-salinity wastewater discharged into the sea comprises the following steps:

[0007] (S1) Pretreatment: The high-salinity wastewater enters the ion flotation / pH adjustment tank, where air is introduced for flotation treatment. The scum is then scraped off and the pH is adjusted to obtain pretreated wastewater.

[0008] (S2) Ozone catalytic oxidation: The pretreated wastewater enters the ozone catalytic oxidation tower, and ozone enters from the bottom of the tower, contacts with the ozone catalyst and wastewater through the aeration plate and reacts to obtain primary wastewater I;

[0009] (S3) Biochemical treatment: The primary wastewater I enters the biochemical pool, and the composite salt-tolerant bacteria solution after the primary wastewater I is domesticated is added to carry out anoxic-aerobic process treatment to obtain primary wastewater II;

[0010] The composite salt-tolerant bacteria liquid after taming the primary wastewater I is obtained by inoculating lysine Bacillus, butyric Clostridium and Hassavoycetes into a culture medium and culturing them to the logarithmic phase to obtain corresponding seed liquids, and then adding the lysine Bacillus seed liquid, the butyric Clostridium seed liquid and the Hassavoycetes seed liquid to the taming liquid containing the primary wastewater I in a volume ratio of 1: (0.5-0.7): (0.3-0.6) for taming;

[0011] (S4) Advanced treatment: The primary wastewater II enters the secondary sedimentation tank for solid-liquid separation, and the separated liquid enters the secondary ozone catalytic oxidation tower for reaction to obtain secondary wastewater I; the secondary wastewater I then enters the secondary biochemical tank, where the composite salt-tolerant bacteria liquid domesticated from the secondary wastewater I is added and subjected to biological contact oxidation treatment to obtain secondary wastewater II; the secondary wastewater II is separated into solid and liquid in a high-efficiency sedimentation tank, and the supernatant is collected and directly discharged into the sea for treatment;

[0012] The composite salt-tolerant bacterial liquid after domestication of the secondary wastewater I is obtained by inoculating lysine Bacillus, butyric Clostridium and Hassavoycetes into a culture medium and culturing them to the logarithmic phase to obtain corresponding seed liquids, and then adding the lysine Bacillus seed liquid, the butyric Clostridium seed liquid and the Hassavoycetes seed liquid to the domestication liquid containing the secondary wastewater I in a volume ratio of 1: (0.5-0.7): (0.3-0.6) for domestication.

[0013] The high-salinity wastewater discharged into the sea in the present invention refers to wastewater with a salinity of ≤2.5%, a chemical oxygen demand (COD) of ≤600mg / L, and a biochemical oxygen demand (BOD) of ≤350mg / L. After treating the pollutants in the wastewater within this salinity range, it can be directly discharged into the sea without desalination. Chemical oxygen demand (COD) refers to the total amount of all reducing substances that need to be oxidized in the wastewater, including the part that cannot be biodegraded. Biochemical oxygen demand (BOD) refers to the amount of dissolved oxygen consumed to decompose organic matter in the wastewater, reflecting the part of organic matter in the wastewater that can be biodegraded.

[0014] The anoxic-aerobic process is referred to as the A / O process, which is well known to those skilled in the art. The A section is the anaerobic section, which is set in front; the O section is the aerobic section, which is set in the back; an internal loop is set between the A section and the O section, so that the wastewater treated in the O section is returned to the A section at a certain reflux ratio. The commonly used reflux ratio is generally about 1:1. In the O section, air oxygen is supplied to promote the nitrifying bacteria and nitrite bacteria in the wastewater to oxidize the ammonia nitrogen (NH3-N) in the wastewater into NO3 - 、NO2 - After the wastewater treated in Section O flows back to Section A, the NO3 - 、NO2 - It is reduced to N2 and discharged under the action of denitrifying bacteria in the wastewater.

[0015] Bacillus lysinin and Clostridium butyricum are commonly used bacteria in wastewater treatment. They have a certain degree of salt tolerance, but they still show poor salt tolerance in high-salt wastewater. Hassaverella is a Gram-positive bacterium that grows best in an environment with a pH value of 6.0-8.5 and a temperature of 25-30°C. Through research, it was found that in the aerobic section of the anoxic-aerobic process, the salt-tolerant bacteria formed by the compounding of Bacillus lysinin, Clostridium butyricum and Hassaverella in a specific proportion can aerobically ferment the wastewater and degrade organic matter, and assist the nitrifying bacteria and nitrite bacteria in the wastewater to oxidize the ammonia nitrogen (NH3-N) in the wastewater into NO3 - 、NO2 - , thus achieving efficient removal of ammonia nitrogen and organic matter in water. Hassaverella itself does not have the ability to treat wastewater, but after Hassaverella is compounded with Bacillus lysinicola and Clostridium butyricum in a certain proportion, the inventor unexpectedly found that the salt tolerance of the composite bacteria is significantly improved, thereby improving the wastewater treatment capacity.

[0016] Furthermore, in step (S1), the process conditions of the flotation treatment are: hydraulic retention of 20-30 minutes, the diameter of the microbubbles generated by the air is 5-10 μm; the pH is 7.5-8.5. Ion flotation is to generate fine bubbles by introducing gas into the wastewater, so that fine suspended matter such as oils and colloids in the wastewater adhere to the bubbles and float to the water surface with the bubbles to form scum, which is then scraped off to achieve solid-liquid separation, thereby achieving the purpose of improving water quality, thereby providing water quality guarantee for subsequent catalytic oxidation.

[0017] Furthermore, in step (S2), the aeration rate of the ozone is 1-2 L / min; the reaction time is 1.5-3 h. The ozone catalytic oxidation can adopt the existing technology, for example, the catalyst can be an activated carbon catalyst loaded with Fe, Mn or Cu, and the amount thereof is 40-60 g per 1 L of wastewater.

[0018] Furthermore, in step (S3), the composite salt-tolerant bacterial solution after acclimation of the primary wastewater I is obtained by a preparation method comprising the following steps: inoculating Bacillus lysinicus, Clostridium butyricum, and Hasavilella at an inoculation rate of 1×10 9 ~5×10 9 10 ...

[0019] Furthermore, in step (S3), the raw material ratio of the culture medium is: per 1000 mL, it includes 6-10 g of peptone, 2-4 g of beef extract, 3-5 g of glucose, and the rest is pure water; the conditions for culturing to the logarithmic phase are: temperature 50-60°C, air ventilation 0.3-0.5 vvm, rotation speed 150-200 rpm, time 12-20 h, for example 13 h, 15 h, 17 h, 20 h; the raw material ratio of the acclimated liquid containing primary wastewater I is: per 1000 mL, it includes 8-15 g of peptone, 2-5 g of beef extract, 4-8 g of glucose, and the rest is primary wastewater I.

[0020] Furthermore, in step (S3), the dosage of the composite salt-tolerant bacteria liquid after acclimation of the primary wastewater I is 0.1-0.5% v / v of the primary wastewater I, preferably 0.1-0.3% v / v, which can be adjusted according to the water quality and the index requirements of the treated effluent.

[0021] Furthermore, in step (S3), in the anoxic-aerobic process, the process conditions of the anoxic section are: time 3-5 hours, and the process conditions of the aerobic section are: time 1-3 hours, and the air aeration rate is 1-2 L / min.

[0022] Furthermore, step (S3) also includes adding nutrients in the aerobic section, and the raw material ratio of the nutrients is: 1-2g glutamic acid, 4-6g trehalose, and 2-4g betaine are added for every 1000mL of the composite salt-tolerant bacteria liquid after acclimation of the first-level wastewater I.

[0023] Furthermore, in step (S4), the aeration rate of the ozone is 1-2 L / min, the reaction time is 20-45 min, and the biological contact oxidation treatment time is 1-2 h.

[0024] Step (S4) is a secondary ozone catalytic oxidation and biological contact oxidation treatment, which can further remove the residual organic matter and ammonia nitrogen in the primary wastewater II. The biological contact oxidation method is well known to those skilled in the art, and refers to adding a filler containing a biofilm in a biochemical pool, and the oxygenated wastewater immerses all the fillers and flows through the filler at a certain flow rate. The microorganisms are fixed on the filler in the form of a biofilm. The filler generally includes a braided bio-rope filler, a suspended ball filler or an elastic filler. For example, when it is a braided bio-rope filler, its dosage is: per 1L of the biochemical pool, its length is 8~15cm.

[0025] Furthermore, in step (S4), the acclimated liquid containing secondary wastewater I is obtained by a preparation method comprising the following steps: adding lysinibacillus seed liquid, clostridium butyricum seed liquid, and hassella seed liquid to the acclimated liquid containing secondary wastewater I, and acclimating and enriching them at room temperature for 1 to 2 days in a synchronous acclimation device to obtain a composite salt-tolerant bacterial liquid acclimated with secondary wastewater I; the total volume of lysinibacillus seed liquid, clostridium butyricum seed liquid, and hassella seed liquid is 3% to 5% of the volume of the secondary wastewater I.

[0026] Furthermore, in step (S4), the raw material ratio of the acclimation liquid containing secondary wastewater I is: 8-15 g of peptone, 2-5 g of beef extract, 4-8 g of glucose, and the rest is secondary wastewater I per 1000 mL.

[0027] Furthermore, in step (S4), the dosage of the composite salt-tolerant bacteria liquid after acclimation of the secondary wastewater I is 0.05-0.1% v / v of the secondary wastewater I, which can be adjusted according to the water quality and the index requirements of the treated effluent.

[0028] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0029] (1) The present invention combines ozone catalytic oxidation and anoxic-aerobic process to treat high-salinity wastewater. In the aerobic section of the anoxic-aerobic process, a high-efficiency salt-tolerant compound bacteria formed by compounding Bacillus lysinicus, Clostridium butyricum and Hasavilius in a specific ratio is used to aerobic ferment the wastewater and degrade organic matter, thereby assisting the nitrifying bacteria and nitrite bacteria in the wastewater to oxidize ammonia nitrogen (NH3-N) in the wastewater into NO3 - 、NO2 - After Hassellella, Bacillus lysinicola and Clostridium butyricum are compounded in a certain proportion, the salt tolerance of the composite bacteria is significantly improved, thereby improving the wastewater treatment capacity, thereby achieving efficient removal of ammonia nitrogen and organic matter in water.

[0030] (2) The method of the present invention achieves efficient, low-cost and harmless treatment of high-salinity wastewater. The treated water has good quality and meets the Class IV seawater standard and can be directly discharged into the sea for treatment. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 It is a schematic diagram of the process of the present invention. DETAILED DESCRIPTION

[0032] In order to further understand the present invention, the scheme of the present invention is described below in conjunction with embodiments, but it should be understood that these descriptions are only for further illustrating the features and advantages of the present invention, rather than limiting the present invention.

[0033] The experimental methods described in the following examples are conventional methods unless otherwise specified; the reagents and materials described are commercially available unless otherwise specified.

[0034] The ozone catalyst is Mn-loaded activated carbon, selected from Hunan Minstron Technology Co., Ltd., with a specific surface area of ​​200m 2 / g, granular, particle size about 2.5mm.

[0035] Lysinibacillus was deposited in Shanghai Microbiological Collection Center with the deposit number ATCC 7055.

[0036] Clostridium butyricum was deposited in Shanghai Microbiological Collection Center with the deposit number ATCC 19398.

[0037] Hassavicella hassalis was deposited in Beina Biotech-Henan Industrial Microbial Strain Engineering Technology Research Center with the deposit number BNCC360528.

[0038] The wastewater used in the present invention is high-salt wastewater produced by a new energy industry, with a salinity of 1.9%. Other indicators of the wastewater are shown in the following table.

[0039] .

[0040] COD: Chemical oxygen demand, refers to the total amount of all reducing substances in wastewater that need to be oxidized, including those that cannot be biodegraded.

[0041] BOD: Biochemical oxygen demand, refers to the amount of dissolved oxygen consumed by the decomposition of organic matter in wastewater, reflecting the part of organic matter in wastewater that can be biodegraded.

[0042] NH3-N: refers to the ammonia nitrogen content in the wastewater; TN: refers to the total nitrogen content in the wastewater, including inorganic nitrogen and organic nitrogen; TP: refers to the total phosphorus content in the wastewater; SS: refers to the content of suspended solids in the wastewater.

[0043] Preparation of seed solution:

[0044] Specifically, glycerol-free Bacillus lysinicus, Clostridium butyricum, and Hasavil bacteria were inoculated at a rate of 2×10 9 10 / L were inoculated into the culture medium and cultured for 17 h at 55°C, 0.5 vvm air flow and 180 rpm at a pH of 6.0±0.2, i.e., cultured to the logarithmic phase to obtain the corresponding seed solution. At this time, the concentration of bacteria in the seed solution was about 0.7×10 10 ~0.8×10 10 / mL; calcium hydroxide was added during the culture process to maintain the pH of the system within the range of 6.0±0.2;

[0045] The raw material ratio of the culture medium is: per 1000mL, including 7g of peptone, 3g of beef extract, 4g of glucose, and the rest is pure water.

[0046] Example 1

[0047] (S1) Pretreatment: The wastewater enters the ion flotation / pH adjustment tank and is introduced with air for flotation treatment. The diameter of the microbubbles generated by the air during flotation treatment is controlled to be about 8 μm, and the hydraulic retention time is 30 min. After the flotation treatment, the scum is scraped off and the pH is adjusted to 8.0 to obtain the pretreated wastewater;

[0048] (S2) Ozone catalytic oxidation: The pretreated wastewater enters the ozone catalytic oxidation tower, and an ozone catalyst is added (50 g is added for every 1 L of pretreated wastewater). Ozone enters from the bottom of the tower at a rate of 1.5 L / min, contacts with the ozone catalyst and wastewater through the aeration plate, and reacts for 2 hours to obtain primary wastewater I;

[0049] (S3) Biochemical treatment: (a) Add 500 g of peptone, 150 g of beef extract and 300 g of glucose to 50 L of primary wastewater I to form a taming solution containing primary wastewater I, add 1 L of lysinic Bacillus seed solution, 0.5 L of butyric Clostridium seed solution and 0.3 L of Hasavilella seed solution to the taming solution, and taming and enriching the solution at room temperature for 2 days in a taming device to obtain a composite salt-tolerant bacterial solution tamed from primary wastewater I; (b) Add 50 m 3 The primary wastewater I is added to the anaerobic section of the biochemical pool for 4 hours of treatment and then enters the aerobic section of the biochemical pool, and 50L of the acclimated compound salt-tolerant bacteria solution of the primary wastewater I is added thereto, and air enters from the bottom of the tower at a rate of 1 L / min and contacts with the primary wastewater I through the aeration plate for aerobic treatment for 2 hours, and nutrients (100g glutamic acid, 250g trehalose and 150g betaine) are added during the aerobic treatment for 1 hour; at the same time, internal circulation is set in the anaerobic section and the aerobic section, and the wastewater treated in the aerobic section is returned to the anaerobic section at a reflux ratio of 1:1; the anoxic-aerobic process treatment is completed to obtain the primary wastewater II;

[0050] (S4) Deep treatment: (a) The primary wastewater II enters the secondary sedimentation tank for solid-liquid separation, and the separated liquid enters the secondary ozone catalytic oxidation tower, and an ozone catalyst is added (50 g per 1L of wastewater). Ozone enters from the bottom of the tower at a rate of 1.5 L / min, contacts with the ozone catalyst and wastewater through the aeration plate, and reacts for 30 minutes to obtain secondary wastewater I; (b) 500 g of peptone, 150 g of beef extract and 300 g of glucose are added to 50L of secondary wastewater I to form an acclimation solution containing secondary wastewater I, 1L of lysine Bacillus seed solution, 0.5L of butyric Clostridium seed solution and 0.3L of Hassella seed solution are placed in the above acclimation solution, and acclimation and enrichment are carried out at room temperature in the acclimation device for 2 days to obtain a composite salt-tolerant bacterial solution of secondary wastewater I after acclimation; 50m 3 Secondary wastewater I enters the secondary biochemical pool, and 25L of the domesticated compound salt-tolerant bacteria solution of secondary wastewater I is added thereto. At the same time, braided bio-rope filler is added to the secondary biochemical pool (10cm is added to every liter of the secondary biochemical pool) for biological contact oxidation treatment for 1.5h to obtain secondary wastewater II. (c) Secondary wastewater II is separated into solid and liquid in a high-efficiency sedimentation tank, and the supernatant is collected and directly discharged into the sea for treatment.

[0051] Example 2

[0052] The rest is the same as Example 1, except that, in step (S3), the composite salt-tolerant bacterial liquid after acclimation of the primary wastewater I is obtained by acclimating 1L of lysinic Bacillus seed liquid, 0.5L of butyric Clostridium seed liquid, and 0.4L of Hasabrevinia seed liquid in an acclimation liquid containing the primary wastewater I.

[0053] Example 3

[0054] The rest is the same as Example 1, except that, in step (S3), the composite salt-tolerant bacterial liquid after domestication of the primary wastewater I is obtained by domesticating 1L of lysinibacillus seed liquid, 0.6L of Clostridium butyricum seed liquid, and 0.4L of Hasabreuria seed liquid in a domestication liquid containing the primary wastewater I.

[0055] Example 4

[0056] The rest is the same as Example 1, except that, in step (S3), the composite salt-tolerant bacterial liquid after domestication of the primary wastewater I is obtained by domesticating 1L of lysinibacillus seed liquid, 0.7L of butyric Clostridium seed liquid, and 0.5L of Hasabrevinia seed liquid in a domestication liquid containing the primary wastewater I.

[0057] Example 5

[0058] The rest is the same as Example 1, except that, in step (S3), the composite salt-tolerant bacterial liquid after acclimation of the primary wastewater I is obtained by acclimating 1L of lysinibacillus seed liquid, 0.7L of Clostridium butyricum seed liquid, and 0.6L of Hasabreuria seed liquid in an acclimation liquid containing the primary wastewater I.

[0059] Comparative Example 1

[0060] The rest is the same as Example 1, except that, in step (S3), the composite salt-tolerant bacterial liquid after acclimation of the primary wastewater I is obtained by acclimating 1 L of lysinic Bacillus seed liquid and 0.5 L of butyric Clostridium seed liquid in an acclimation liquid containing the primary wastewater I, that is, the composite salt-tolerant bacterial liquid does not contain Hasabreuella.

[0061] Results and Analysis

[0062] The supernatant obtained after treating the wastewater in the embodiment and the comparative example was subjected to water quality testing. Specifically, the water quality testing adopted the national standard testing method of "Water and Wastewater Monitoring and Analysis Method" (4th edition), wherein COD was tested by the dichromate method according to the HJ828-2017 standard; BOD was tested according to the HJ / T86-2002 standard; ammonia nitrogen (NH3-N) was tested by the Nessler agent photometry according to the HJ535-2009 standard; TN was tested by alkaline potassium persulfate digestion ultraviolet spectrophotometry according to the HJ 636-2012 standard.

[0063] The test results are shown in Table 1.

[0064] Table 1 Water quality test of treated wastewater

[0065] .

[0066] It can be seen from Table 1 that the treated wastewater of the embodiment of the present invention meets the fourth category seawater standard and has good water quality. In Comparative Example 1, the composite salt-tolerant bacteria solution does not contain Hasavilella, and it can be seen that the COD, ammonia nitrogen and other indicators of the treated wastewater do not meet the standards.

[0067] The above detailed description is a specific description of one feasible embodiment of the present invention. The embodiment is not intended to limit the patent scope of the present invention. Any equivalent implementation or modification that does not deviate from the present invention should be included in the scope of the technical solution of the present invention.

Claims

1. A method for treating high-salinity wastewater discharged into the sea, characterized in that: The following steps are involved: (S1) Pretreatment: The high-salinity wastewater enters the ion flotation / pH adjustment tank, where air is introduced for flotation treatment. The scum is then scraped off and the pH is adjusted to obtain pretreated wastewater. (S2) Ozone catalytic oxidation: The pretreated wastewater enters the ozone catalytic oxidation tower, and ozone enters from the bottom of the tower, contacts with the ozone catalyst and wastewater through the aeration plate and reacts to obtain primary wastewater I; (S3) Biochemical treatment: The primary wastewater I enters the biochemical pool, and the composite salt-tolerant bacteria solution after the primary wastewater I is domesticated is added to carry out anoxic-aerobic process treatment to obtain primary wastewater II; The composite salt-tolerant bacteria liquid after taming the primary wastewater I is obtained by inoculating lysine Bacillus, butyric Clostridium and Hassavoycetes into a culture medium and culturing them to the logarithmic phase to obtain corresponding seed liquids, and then adding the lysine Bacillus seed liquid, the butyric Clostridium seed liquid and the Hassavoycetes seed liquid to the taming liquid containing the primary wastewater I in a volume ratio of 1: (0.5-0.7): (0.3-0.6) for taming; (S4) Advanced treatment: The primary wastewater II enters the secondary sedimentation tank for solid-liquid separation, and the separated liquid enters the secondary ozone catalytic oxidation tower for reaction to obtain secondary wastewater I; Secondary wastewater I then enters the secondary biochemical pool, where the salt-tolerant bacterial solution tamed in secondary wastewater I is added and subjected to biological contact oxidation treatment to obtain secondary wastewater II; secondary wastewater II is subjected to solid-liquid separation in a high-efficiency sedimentation tank, and the supernatant is collected and directly discharged into the sea for treatment; The composite salt-tolerant bacterial liquid after domestication of the secondary wastewater I is obtained by inoculating lysine Bacillus, butyric Clostridium and Hassavoycetes into a culture medium and culturing them to the logarithmic phase to obtain corresponding seed liquids, and then adding the lysine Bacillus seed liquid, the butyric Clostridium seed liquid and the Hassavoycetes seed liquid to the domestication liquid containing the secondary wastewater I in a volume ratio of 1: (0.5-0.7): (0.3-0.6) for domestication.

2. The processing method according to claim 1, characterized in that: The high-salinity wastewater discharged into the sea refers to wastewater with a salinity of ≤2.5%, a chemical oxygen demand of ≤600mg / L, and a biochemical oxygen demand of ≤350mg / L.

3. The processing method according to claim 1, characterized in that: In step (S1), the process conditions of the flotation treatment are: hydraulic retention for 20 to 30 minutes, the diameter of the microbubbles generated by the air is 5 to 10 μm; the pH is 7.5 to 8.5; and / or In step (S2), the aeration rate of the ozone is 1-2 L / min; the reaction time is 1.5-3 h; the ozone catalytic oxidation is an activated carbon catalyst loaded with Fe, Mn or Cu, and the amount thereof is 40-60 g per 1 L of wastewater.

4. The processing method according to claim 1, characterized in that: In step (S3), the composite salt-tolerant bacterial solution after acclimation of the primary wastewater I is obtained by a preparation method comprising the following steps: Bacillus lysinicus, Clostridium butyricum, and Hasavilella inoculated at an inoculation rate of 1×10 9 ~5×10 9 / L are inoculated into the culture medium respectively, and the corresponding seed solution is obtained after culturing to the logarithmic phase in the pH range of 5.5-6.5; then the lysinibacillus seed solution, the butyric clostridium seed solution, and the hassawycete seed solution are added to the acclimation solution containing the first-level wastewater I, and the bacteria are acclimated and enriched at room temperature for 1-2 days in a synchronous acclimation device to obtain a composite salt-tolerant bacteria solution after acclimation of the first-level wastewater I; the total volume of the lysinibacillus seed solution, the butyric clostridium seed solution, and the hassawycete seed solution is 3%-5% of the volume of the first-level wastewater I.

5. The processing method according to claim 1, characterized in that: In step (S3), the raw material ratio of the culture medium is: 6-10 g of peptone, 2-4 g of beef extract, 3-5 g of glucose, and the rest is pure water per 1000 mL; the conditions for culturing to the logarithmic phase are: temperature 50-60°C, air ventilation 0.3-0.5 vvm, rotation speed 150-200 rpm, and time 12-20 h; the raw material ratio of the acclimation solution containing primary wastewater I is: 8-15 g of peptone, 2-5 g of beef extract, 4-8 g of glucose, and the rest is primary wastewater I per 1000 mL.

6. The processing method according to claim 1, characterized in that: In step (S3), the dosage of the composite salt-tolerant bacteria solution after acclimation of the primary wastewater I is 0.1-0.5% v / v of the primary wastewater I; and / or In the anoxic-aerobic process, the process conditions of the anoxic section are: time 3-5 hours, the process conditions of the aerobic section are: time 1-3 hours, and the air aeration rate is 1-2 L / min.

7. The processing method according to claim 1, characterized in that: In step (S4), the aeration rate of ozone is 1-2 L / min, the reaction time is 20-45 min, and the biological contact oxidation treatment time is 1-2 h.

8. The processing method according to claim 1, characterized in that: In step (S4), the acclimated liquid containing the secondary wastewater I is obtained by a preparation method comprising the following steps: adding a lysinic Bacillus seed liquid, a butyric Clostridium seed liquid, and a Hasavosa seed liquid to the acclimated liquid containing the secondary wastewater I, acclimating and enriching at room temperature for 1 to 2 days in a synchronous acclimation device, and obtaining a composite salt-tolerant bacterial liquid after acclimation of the secondary wastewater I; The total volume of Bacillus lysinicus seed solution, Clostridium butyricum seed solution and Hassella vesiculosus seed solution is 3% to 5% of the volume of secondary wastewater I.

9. The processing method according to claim 1 or 8, characterized in that: In step (S4), the raw material ratio of the acclimation liquid containing secondary wastewater I is: 8-15 g of peptone, 2-5 g of beef extract, 4-8 g of glucose, and the rest is secondary wastewater I per 1000 mL.

10. The processing method according to claim 1, characterized in that: In step (S4), the dosage of the composite salt-tolerant bacteria liquid after acclimation of the secondary wastewater I is 0.05-0.1% v / v of the secondary wastewater I.

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