East starfish circulating water aquaculture low-energy consumption efficient water treatment method

Abstract

The application discloses a kind of east star circulating water aquaculture low-energy consumption efficient water treatment methods, belong to aquaculture water treatment technical field.The particulate pollution characterization value of water to be refined is obtained, and according to the comparison result of particulate pollution characterization value and first setting range, foam separation refined treatment is carried out, and the water to be oxidized is formed;Dissolved organic pollution characterization value of water to be oxidized is obtained, and according to the comparison result of dissolved organic pollution characterization value and second setting range, ozone oxidation refined treatment is carried out, and target treatment water is obtained.The present application determines the refined treatment sequence according to the residual state of particulate pollution and dissolved organic pollution, reduces unnecessary ozone oxidation refined treatment.

Description

Technical Field

[0001] This invention relates to the field of aquaculture water treatment technology, and in particular to a low-energy-consumption and high-efficiency water treatment method for recirculating aquaculture of grouper. Background Technology

[0002] Eastern Star Grouper, scientific name Leopard Gill Spinach ( Plectropomus leopardus Leopard gill sea bass (Stichopus japonicus) are warm-water marine fish and are highly sensitive to dissolved oxygen, ammonia nitrogen, nitrite, and organic pollutants in the culture water. Factory-scale recirculating aquaculture systems typically return wastewater from the culture ponds to the ponds after solid-liquid separation, biological purification, deaeration, disinfection, and aeration, in order to reduce water consumption and maintain water quality. Chinese invention patent application CN103004668A discloses a method for high-density factory-scale recirculating aquaculture of leopard gill sea bass fry in northern regions. The culture water sequentially passes through an arc-shaped screen for solid-liquid separation, air flotation purification, biological filtration, deaeration, ultraviolet disinfection, ozone treatment, and aeration before being returned to the culture ponds. The arc-shaped screen separates uneaten feed, feces, and other solid debris; air flotation purification separates particulate matter and some organic matter; and biological filtration controls nitrogenous pollutants. This treatment method forms the basis for recirculating aquaculture purification suitable for factory-scale leopard gill sea bass farming.

[0003] In the further purification process of recirculating aquaculture systems, different treatment methods are suitable for fine particles, colloidal organic matter, and dissolved organic matter. Protein separation typically utilizes the adsorption between microbubbles and organic matter in the water, causing suspended particles, colloidal substances, and some surface-active organic matter to be discharged with the foam; ozone treatment utilizes oxidation to improve the organic pollution status in the water. Chinese invention patent application CN110679534A discloses a recirculating aquaculture system treatment system in which the aquaculture water enters a protein separator after passing through a cyclone filter and a drum microfilter. The protein separator is used to remove suspended solids, water-soluble colloids, proteins, and uneaten feed, and an ozone generator is configured to treat the recirculating water with ozone. Therefore, existing recirculating aquaculture systems can already employ different treatment units such as particle separation, protein separation, and ozone treatment to perform staged purification of the aquaculture water.

[0004] However, in existing circulating water treatment processes, protein separation and ozone oxidation are usually put into operation according to a predetermined treatment path. There is a lack of treatment methods that determine the order of fine treatment based on the remaining state of particulate and dissolved organic pollutants in the circulating water after basic treatment, making it difficult to reduce unnecessary ozone oxidation fine treatment. Summary of the Invention

[0005] The purpose of this invention is to provide a low-energy and high-efficiency water treatment method for recirculating aquaculture of grouper, which can solve the problem that the treatment sequence in existing recirculating water treatment is not determined according to the remaining state of particulate pollution and dissolved organic pollution. This method allows foam separation treatment and ozone oxidation treatment to be carried out sequentially according to the corresponding pollution state, reducing unnecessary ozone oxidation treatment.

[0006] To achieve the above objectives, the present invention provides the following solution: A low-energy, high-efficiency water treatment method for recirculating aquaculture of grouper includes: To obtain the water awaiting intensive treatment generated during the recirculating aquaculture of grouper; Obtain the particulate pollution characterization values ​​of the water to be finely treated; Based on the comparison results between the particulate pollution characterization value and the first set range, the water to be finely treated that does not meet the first set range is subjected to foam separation fine treatment until the particulate pollution characterization value of the water body after foam separation meets the first set range, and the first treated water is obtained. The water to be finely treated and the first treated water whose particulate pollution characterization value meets the first set range and has not undergone foam separation fine treatment are identified as water to be oxidized. Obtain characterization values ​​of dissolved organic pollutants in the water to be oxidized; Based on the comparison results between the dissolved organic pollution characterization value and the second set range, the water to be oxidized that does not meet the second set range is subjected to ozone oxidation fine treatment until the dissolved organic pollution characterization value of the water body after ozone oxidation meets the second set range, and the second treated water is obtained. The water to be oxidized and the second treated water, whose dissolved organic pollutant characterization values ​​meet the second set range and have not undergone ozone oxidation fine treatment, are identified as the target treated water.

[0007] Preferably, the water to be treated generated during the recirculating aquaculture of grouper includes: The basic treated water is obtained by obtaining the circulating water discharged from the grouper breeding pond and then performing solid-liquid separation and biological purification. A portion of the water from the basic treated water is used as water for further treatment. The unextracted water from the basic treatment is returned to the grouper breeding pond.

[0008] Preferably, obtaining the particulate pollution characterization values ​​of the water to be finely treated includes: Obtain the turbidity value of the water to be finely treated; Turbidity values ​​were determined as characterization values ​​for particulate pollution.

[0009] Preferably, based on the comparison between the particulate pollution characterization value and the first set range, the water to be refined that does not meet the first set range is subjected to foam separation and refining treatment, including: The turbidity range not exceeding the first turbidity threshold is defined as the first set range; Compare the particulate pollution characterization values ​​with the first set range; When the particulate pollution characterization value is higher than the first turbidity threshold, the water to be refined is subjected to foam separation and fine treatment.

[0010] Preferably, the water to be treated that does not meet the first set range is subjected to foam separation fine treatment until the particulate pollution characterization value of the water body after foam separation meets the first set range, thereby obtaining the first treated water, including: The water to be treated is subjected to foam separation fine treatment to form water body after foam separation; The turbidity values ​​of the water body after foam separation were obtained, and these values ​​were determined as the particulate pollution characterization values ​​of the water body after foam separation. The particulate pollution characterization values ​​of the water body after foam separation are compared with the first set range; When the particulate pollution characterization value of the water body after foam separation meets the first set range, the foam separation fine treatment ends, and the water body after foam separation is identified as the first treated water.

[0011] Preferably, obtaining the characterization values ​​of dissolved organic pollutants in the water to be oxidized includes: The ultraviolet transmittance of the water to be oxidized at a wavelength of 254 nm was obtained; The ultraviolet transmittance of the water to be oxidized at a wavelength of 254 nm was determined as the characterization value for dissolved organic pollutants.

[0012] Preferably, obtaining the ultraviolet transmittance of the water to be oxidized at a wavelength of 254 nm includes: A water sample was obtained from the water to be oxidized. Particulate matter is removed from the water sample to obtain the test solution; The ultraviolet transmittance of the test solution at a wavelength of 254 nm was obtained, and the ultraviolet transmittance of the test solution at a wavelength of 254 nm was determined as the ultraviolet transmittance of the water to be oxidized at a wavelength of 254 nm.

[0013] Preferably, based on the comparison between the dissolved organic pollutant characterization value and the second set range, the water to be oxidized that does not meet the second set range is subjected to ozone oxidation treatment, including: The range of ultraviolet transmittance that is not lower than the second ultraviolet transmittance threshold is defined as the second set range; The characterization values ​​of dissolved organic pollutants were compared with the second set range; When the dissolved organic pollutant characterization value is lower than the second ultraviolet transmittance threshold, the water to be oxidized is treated with ozone oxidation.

[0014] Preferably, the water to be oxidized that does not meet the second set range is subjected to ozone oxidation treatment until the dissolved organic pollutant characterization value of the water body after ozone oxidation meets the second set range, thereby obtaining second treated water, including: The water to be oxidized is treated with ozone oxidant to form ozone-oxidized water. The ultraviolet transmittance of the water body after ozone oxidation at a wavelength of 254 nm was obtained, and the ultraviolet transmittance of the water body after ozone oxidation at a wavelength of 254 nm was determined as the characterization value of dissolved organic pollution in the water body after ozone oxidation. The dissolved organic pollution characterization values ​​of the water body after ozone oxidation were compared with the second set range; When the dissolved organic pollutant characterization value of the water body after ozone oxidation meets the second set range, the ozone oxidation fine treatment ends, and the water body after ozone oxidation is identified as the second treated water.

[0015] Preferably, the target treated water is defined as the water whose dissolved organic pollutant characterization value meets the second set range and has not undergone ozone oxidation treatment, as well as the second treated water. Water that meets the second set range for dissolved organic pollutant characterization values ​​and has not undergone ozone oxidation fine treatment is identified as the target treatment water. The second-treated water undergoes residual oxide reduction treatment; Obtain the total residual oxide concentration of the second-treated water after residual oxide reduction treatment; When the total residual oxide concentration is not higher than the preset safety threshold, the second treated water that has undergone residual oxide reduction treatment is determined as the target treated water.

[0016] The present invention discloses the following beneficial effects: (1) This invention obtains the particulate pollution characterization value of the water to be treated and compares the particulate pollution characterization value with a first set range. Only the water to be treated that does not meet the first set range is subjected to foam separation fine treatment, so that the particulate pollution reaches the set state before entering the next treatment stage. This avoids directly entering ozone oxidation fine treatment before the particulate pollution has been treated, and reduces unnecessary treatment caused by using the same fine treatment path for different pollution forms.

[0017] (2) In this invention, the water to be treated that meets the first set range of particulate pollution characterization values ​​and has not undergone foam separation fine treatment, and the first treated water that meets the first set range after foam separation, are uniformly determined as the water to be oxidized. Then, the dissolved organic pollution characterization value of the water to be oxidized is obtained. By first completing the particulate pollution determination and treatment, and then performing the dissolved organic pollution determination, the foam separation fine treatment and the ozone oxidation fine treatment correspond to different residual pollution states, thereby reducing the particulate pollution treatment load borne by the ozone oxidation fine treatment.

[0018] (3) Based on the comparison between the dissolved organic pollutant characterization value and the second set range, this invention only performs ozone oxidation fine treatment on the water to be oxidized that does not meet the second set range; for the water to be oxidized that already meets the second set range, ozone oxidation fine treatment is no longer performed. Compared with continuously performing ozone oxidation treatment on all the water to be oxidized, the amount of water that needs to enter ozone oxidation fine treatment and the treatment period are limited by the second set range, thereby reducing unnecessary ozone oxidation operation load.

[0019] (4) The present invention defines the entry and termination conditions of foam separation fine treatment and ozone oxidation fine treatment by defining the first and second set ranges respectively, so that the water to be fined is finely treated in sequence according to the particulate pollution state and the dissolved organic pollution state. In view of the problem that existing circulating water treatment lacks the ability to determine the order of fine treatment according to the residual pollution form, the present invention reduces unnecessary ozone oxidation fine treatment, while maintaining the staged treatment of the two types of pollution states. Attached Figure Description

[0020] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0021] Figure 1 This is a flowchart of a low-energy, high-efficiency water treatment method for recirculating aquaculture of grouper provided in an embodiment of the present invention; Figure 2 This is a sampling layout diagram for foam separation and fine treatment provided in an embodiment of the present invention; Figure 3 This is a graph showing the change in ultraviolet transmittance during the ozone oxidation stage, provided in an embodiment of the present invention. Figure 4 This is a schematic diagram of the low-energy-consumption and high-efficiency water treatment system for recirculating aquaculture of grouper provided in an embodiment of the present invention. Detailed Implementation

[0022] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0023] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0024] Figure 1 The method flowchart provided in the embodiments of the present invention is as follows: Figure 1 As shown, this embodiment provides a low-energy, high-efficiency water treatment method for recirculating aquaculture of grouper, including: Step 100: Obtain the water to be treated during the recirculating aquaculture of grouper; Step 200: Obtain the particulate pollution characterization values ​​of the water to be finely treated; Step 300: Based on the comparison results between the particulate pollution characterization value and the first set range, the water to be treated that does not meet the first set range is subjected to foam separation fine treatment until the particulate pollution characterization value of the water body after foam separation meets the first set range, and the first treated water is obtained. Step 400: The water to be finely treated and the first treated water whose particulate pollution characterization value meets the first set range and has not undergone foam separation fine treatment are identified as water to be oxidized; Step 500: Obtain the characterization values ​​of dissolved organic pollutants in the water to be oxidized; Step 600: Based on the comparison results between the dissolved organic pollution characterization value and the second set range, the water to be oxidized that does not meet the second set range is subjected to ozone oxidation fine treatment until the dissolved organic pollution characterization value of the water body after ozone oxidation meets the second set range, and the second treated water is obtained. Step 700: The water to be oxidized and the second treated water whose dissolved organic pollutant characterization values ​​meet the second set range and have not undergone ozone oxidation fine treatment are identified as the target treated water.

[0025] In one specific embodiment, a seawater recirculating aquaculture system incorporating solid-liquid separation, biological purification, foam separation, and ozone oxidation treatment processes will be described. The recirculating water discharged from the grouper rearing pond first undergoes solid-liquid separation to remove uneaten feed, feces, and suspended solids that can be retained by the solid-liquid separation equipment, and then enters the biological purification process. The recirculating water that has undergone the aforementioned basic treatment is referred to as the basic treated water.

[0026] After the basic treated water reaches the fine treatment diversion point, part of the water returns to the grouper breeding pond along the basic circulation water path, while the other part enters the fine treatment water path. The water entering the fine treatment water path is designated as water awaiting fine treatment. The fine treatment water path is equipped with a fine treatment buffer zone. The water awaiting fine treatment first enters the fine treatment buffer zone, and then, based on the test results, it is selected whether to proceed to the foam separation stage and the ozone oxidation stage.

[0027] The fine-treatment buffer is used to maintain the mixed state of the water currently participating in detection and treatment. Let the effective volume of water participating in the current treatment within the fine-treatment buffer be... The corresponding circulation flow is The hydraulic circulation time is : (1) In the formula, This represents the time required for the water in the fine treatment buffer to complete one theoretical cycle. Indicates the effective water volume; This indicates the circulating flow rate. use express, use When indicating, The unit is .

[0028] After the water to be treated enters the treatment buffer zone, it undergoes at least one hydraulic circulation time before a test sample is obtained for particulate pollution assessment. During this period, the water in the treatment buffer zone is kept circulating so that the test sample corresponds to the already mixed water to be treated, reducing the impact of localized influent on the results of a single test.

[0029] Sampling for particulate contamination detection is conducted on the pipeline supplying water to the foam separation equipment from the fine treatment buffer zone. To begin sampling, first open the sampling valve to drain the existing water from the sampling tube. The drainage volume should be at least three times the internal volume of the sampling tube. After the water flow stabilizes, collect the water sample for testing. The sampling bottle should be pre-cleaned and rinsed with the fine treatment water flowing from the same sampling location. After obtaining the water sample, gently mix it without filtering or allowing it to settle.

[0030] This implementation uses turbidity as the characterization value for particulate pollution. Turbidity measurement employs a scattering-type turbidity detector, which is calibrated using a turbidity standard solution according to the corresponding instrument requirements. The same detection mode and turbidity unit are maintained during the threshold establishment phase and the operational detection phase.

[0031] Three stable turbidity data points were read consecutively in a single test, and denoted as follows: , and The current turbidity test value of the water to be finely treated for: (2) In the formula, As a characterization value for particulate pollution in water currently awaiting fine treatment, the unit is... If visible bubbles appear in the test cell, or if water droplets or deposits are present on the outer wall of the test cell, the test cell should be rearranged before measurement. Readings significantly affected by the aforementioned factors should not be used.

[0032] The first defined range was determined based on reference data obtained during the stable operation of the same recirculating aquaculture system. Multiple time periods were selected where the aquaculture water quality was under normal management and the solid-liquid separation and biological purification processes were operating normally. Reference turbidity values ​​were generated at the same sampling locations using the aforementioned method. The effective reference turbidity value was set as follows: , to The first turbidity threshold is denoted as : (3) In the formula, This indicates the number of valid reference data points used to establish the first defined range. It will not exceed [a certain number]. The turbidity range is determined as the first set range. Turbidity data obtained during equipment cleaning, sewage discharge, start-up and shutdown, and during abnormal sampling device operation are not used as reference data.

[0033] The reference data for the second defined range is also taken from the system's stable operating period, but the sampling location is in the water path to be oxidized. When establishing the reference data, the same particulate matter retention method, detection wavelength, and cuvette path length are maintained as in actual operational monitoring. When water quality management conditions need to be adjusted at different aquaculture stages, the stable operating reference data for the corresponding stage is reselected.

[0034] Table 1. Detection conditions during the fine treatment stage

[0035] The testing conditions in Table 1 are kept consistent throughout the same aquaculture control cycle. The reference data establishment and operational testing use the same sampling locations and testing conditions, ensuring that the set range and actual judgment data have the same data basis.

[0036] When the particulate pollution characterization value of the water to be finely treated is already within the first set range, the water to be finely treated will not enter the foam separation equipment, but will be directly sent to the water circuit to be oxidized.

[0037] when At this time, the foam separation water path is opened. The water in the fine treatment buffer zone enters the foam separation device. After the microbubbles come into contact with the water, fine particles, colloidal substances, and some organic matter that can accumulate at the gas-liquid interface are discharged with the foam. The water after foam separation is returned to the fine treatment buffer zone.

[0038] Figure 2 This is a sampling layout diagram for foam separation and fine treatment provided in an embodiment of the present invention. Figure 2As shown, the inlet of the water to be refined is connected to the refined treatment buffer zone. The refined treatment buffer zone is connected to the foam separation device via a water supply pipeline, and a sampling port is installed on the water supply pipeline. A foam discharge point is installed at the top of the foam separation device, and the treated water outlet of the foam separation device is connected to the refined treatment buffer zone via a treated water return pipeline. The arrows in the figure indicate the direction of water flow. After the water to be refined enters the refined treatment buffer zone, it flows along the water supply pipeline to the foam separation device. The treated water after foam separation returns to the refined treatment buffer zone along the treated water return pipeline, and the foam is discharged from the top of the foam separation device.

[0039] After foam separation begins, the hydraulic circulation time is used as a guide. As the basis for determining the detection time, in this example, the first retest was conducted after one hydraulic circulation time; if the particulate pollution characterization value was still outside the first set range, the foam separation equipment continued to operate, and the retest was conducted after another detection interval. Each retest was conducted from the same location as the initial test, and the turbidity detection value was generated according to formula (2).

[0040] Let the particulate pollution characterization value before foam separation begins be... The particulate pollution characterization value obtained from the retest was ; Subscript Indicates the subscript before foam separation. This indicates the turbidity reduction rate at the current foam separation stage after foam separation. for: (4) Turbidity reduction rate is used to represent the degree of change in particulate matter characterization values ​​during foam separation. The first treated water still... Entering the first set range is a certain condition.

[0041] when When the foam separation and fine treatment of the current water body ends, the water in the fine treatment buffer that meets the first set range is used as the first treated water. If the first set range is not reached after multiple consecutive detection times, and the turbidity change between adjacent detection times is very small, the water supply to the next fine treatment stage is stopped, and the foam generation status, foam discharge status, and fine treatment cycle status are checked; after the operation status is restored, the treatment of the current water body continues.

[0042] The water to be treated, whose initial particulate pollution characterization value already meets the first set range, enters the same oxidation water path as the first treated water formed after foam separation. All of the aforementioned water bodies are considered as oxidation water. Foam separation can simultaneously affect particles, colloids, and some surface-active organic matter. In this embodiment, the particulate pollution characterization value is used as the operational criterion for the foam separation stage, and it is not limited to foam separation acting only on particulate pollutants.

[0043] After the oxidized water is formed, the dissolved organic pollution characterization value is obtained. The sampling location is set before the water inlet of the ozone oxidation equipment. During sampling, the original water in the sampling tube is first discharged, and the water sample is obtained after the water flow stabilizes. The water sample used for ultraviolet detection is then... The filter membrane traps the remaining particles, forming the detection solution. The reference data and actual operational testing use the same type of filter membrane and the same water sample treatment method.

[0044] The optical path length of the detection liquid is [missing information]. Quartz cuvettes were used with a UV-Vis spectrophotometer. Measurements were taken at the specified wavelength. Before testing, pure water was used as a reference. After the cuvette was filled with the test solution, it was checked for obvious air bubbles. The cuvette was placed in the same orientation for each measurement.

[0045] Three stable absorbance values ​​were read from the same test solution, respectively. , and , The average absorbance is denoted as : (5) Determined based on average absorbance UV transmittance : (6) In the formula, The values ​​are expressed as percentages and used as characterization values ​​for dissolved organic pollutants in the water to be oxidized. The test solution reflects the state of the test solution after particulate matter retention. The ultraviolet absorption state at that location is not directly converted into dissolved organic carbon concentration.

[0046] Assume the effective reference ultraviolet transmittance formed during the stable operation phase is . , to The second ultraviolet transmittance threshold is denoted as : (7) In the formula, This indicates the number of valid reference data points used in establishing the second defined scope. It will be no less than... The range of ultraviolet transmittance is determined as the second set range.

[0047] The water to be oxidized meets the requirements At this time, ozone oxidation treatment is not initiated, and the water to be oxidized is used as the target treated water. The water to be oxidized meets the following requirements. At this time, the water enters the ozone oxidation equipment. Ozone gas enters the ozone contact area through the gas-water mixing component, where it completes gas-liquid contact with the water to be oxidized; the exhaust gas generated in the contact area enters the exhaust gas treatment device.

[0048] Ozone oxidation employs an intermittent monitoring method. After completing one ozone treatment period, ozone supply is paused to maintain water mixing, and two water samples are simultaneously obtained from a fixed sampling location. One sample is used to determine the current total residual oxide concentration, and the other is used to determine... Ultraviolet transmittance. Two water samples were taken at the same time and from the same location.

[0049] After the water sample used for UV detection is removed, the remaining oxidation reaction is terminated first. Based on the total residual oxide concentration measured in another water sample at the same time, sodium thiosulfate solution with a predetermined reducing equivalent according to the detection method is added to the UV detection water sample; the same volume of sodium thiosulfate solution is added to the reference water sample. The water sample after the oxidation reaction is terminated is then subjected to further processing... The membrane was treated, and then measured according to formulas (5) and (6). Ultraviolet transmittance.

[0050] Ozone in seawater reacts with bromide ions to form residual oxides. Both the ozone itself and the continued oxidation reaction affect the condition of the water sample after sampling. Therefore, UV detection after ozone treatment is performed after stopping the current ozone supply and terminating the remaining oxidation reaction in the water sample. The same detection wavelength, the same cuvette path length, and the same particulate matter rejection conditions are used before and after treatment.

[0051] Measured The ozone oxidation treatment of the current water body will continue, and a new sample will be taken after the detection time is reached again. The water body will meet the requirements for the first time after ozone oxidation. The ozone supply is stopped, and water that meets the second set range is used as the second treated water.

[0052] Assume the UV transmittance before entering the ozone oxidation treatment is 100%. The UV transmittance during the formation of the second treated water is ; Subscript Indicates before ozone oxidation, subscript This represents the change in ultraviolet transmittance after ozone oxidation. for: (8) Used to indicate the current ozone oxidation process before and after. The degree of change in ultraviolet transmittance; the second treated water still uses As a determining condition.

[0053] To illustrate the formation and processing of the above detection values, a set of processing data is given below. In this example, the first turbidity threshold is set to... The second ultraviolet transmittance threshold is taken as The two thresholds are determined by the corresponding stable operation reference data according to Equation (3) and Equation (7), respectively.

[0054] Table 2. Judgment data for fine processing

[0055] The average values ​​of the three turbidity readings for the water to be treated in Table 2 are: Rounded to two decimal places Above the first turbidity threshold The corresponding water body then undergoes foam separation and fine treatment. The average turbidity obtained from the first retest was... It is still outside the first set range.

[0056] The second foam separation retest yielded the following results: Rounded to two decimal places The first set range has been met. The turbidity reduction rate from the start of foam separation to the formation of the first treated water is: The particulate pollution characterization value is from Down to Then it enters the first set range, and the current water body ends foam separation and forms the first treated water. Foam separation does not run continuously for a fixed duration, but stops after the detection results meet the termination conditions of the current stage.

[0057] After the first treated water is formed into water to be oxidized, there are three [stages] before ozone treatment. The absorbances are respectively , and The average absorbance is According to equation (6): Below the second ultraviolet transmittance threshold The water to be oxidized then undergoes ozone oxidation treatment. The average absorbance of the three values ​​after the first ozone treatment is... ,correspond: Still below the second ultraviolet transmittance threshold, ozone oxidation continued. The average absorbance of the second retest was: Will Substituting into equation (6), we get: The second set range has been entered, ending the current ozone oxidation treatment of the water body and forming the second treated water. According to formula (8), the change in ultraviolet transmittance is: In the formula, The values ​​are expressed as percentage points. In this example, ozone oxidation only operates when the dissolved organic pollutant characterization value of the water to be oxidized is outside the second set range, and stops after the second retest shows it enters the second set range. Compared to the operation mode of continuously passing the treated water through the ozone oxidation equipment without distinguishing water quality status, water bodies that meet the second set range no longer occupy ozone oxidation operation time.

[0058] Figure 3 This is a graph showing the change in ultraviolet transmittance during the ozone oxidation stage, provided in an embodiment of the present invention. The horizontal axis represents the ozone transmittance before treatment, the first ozone re-measurement, and the second ozone re-measurement, respectively, while the vertical axis represents the 254 nm ultraviolet transmittance as a percentage. The ultraviolet transmittances at the three detection times are 66.83%, 68.23%, and 69.45%, respectively. The solid line in the graph represents... As the detection time changes, the three dots correspond to the detection results at the three detection times; the horizontal dashed line represents the second ultraviolet transmittance threshold of 68.87%. The first ozone retest corresponds to 68.23%, which is lower than the second ultraviolet transmittance threshold, while the second ozone retest corresponds to 69.45%, which is higher than the second ultraviolet transmittance threshold. The broken line crosses the horizontal dashed line between the first and second ozone retests.

[0059] The second-treated water, formed after ozone oxidation, enters the residual oxide reduction stage. This second-treated water then passes through the granular activated carbon treatment area before entering the return water path. Total residual oxide samples are taken from the effluent outlet of the granular activated carbon treatment area. Stagnant water in the sampling tube is drained before sampling, and testing is completed promptly after sampling.

[0060] Total residual oxides were determined using the DPD colorimetric method suitable for seawater samples, and the results were presented using... Indicate and The calculation method is the same as that used in the preset safety threshold and in actual operation testing. When the total residual oxide concentration is higher than the preset safety threshold, the second-treated water continues to undergo the residual oxide reduction stage; when it is not higher than the preset safety threshold, the corresponding water body is used as the target treated water.

[0061] The actual power consumption of the fine treatment equipment is read by the power metering device. Let the cumulative power consumption reading before the start of one fine treatment be... The cumulative energy reading at the end is The increase in electrical energy corresponding to the fine processing process is denoted as : (9) In the formula, and The data is read from the same energy metering device. When the foam separation equipment and the ozone generator are set to separate energy meters, the energy increments corresponding to the two fine treatment stages can be obtained separately.

[0062] Under the same water treatment volume and the same basic circulation conditions, when comparing the power consumption of the fixed fine treatment path with that of this embodiment, the power increment of the fixed fine treatment path is denoted as... The increase in electrical energy in this embodiment is denoted as Corresponding energy saving ratio for: (10) In the formula, the two sets of electrical energy increments are obtained from the difference in cumulative electrical energy readings during the corresponding test periods. Water awaiting fine treatment whose particulate matter characterization values ​​initially meet the first set range does not pass through the foam separation equipment; water awaiting oxidation whose dissolved organic matter characterization values ​​initially meet the second set range does not pass through the ozone oxidation equipment. The operating time of the two fine treatment stages varies depending on the current water quality status, and the electrical energy metering results can directly reflect the changes in the fine treatment operating load.

[0063] In another specific implementation, particulate pollution characterization values ​​are continuously obtained using an online turbidity detection device installed in the refined water path. The online turbidity detection device is installed at a location in the water path corresponding to the manual sampling location, and generates turbidity data according to a fixed sampling cycle. For each judgment cycle, a continuous and stable reading is selected to calculate the average value, and the first set range is still established based on stable operating reference data obtained from the same detection device.

[0064] Ultraviolet transmittance can also be obtained through a detection bypass. A small sample of the water to be oxidized is taken from the main pipeline, passes through particulate matter interception, and then enters a UV detection cell with a fixed optical path. When the water body after ozone oxidation uses the same detection bypass, a termination point for the residual oxidation reaction of the detection water sample is set before the UV detection cell; the main body of the treated water does not enter the aforementioned detection water sample treatment process.

[0065] After the first and second setting ranges are established, the corresponding detection conditions remain unchanged within the same aquaculture control cycle. When the aquaculture density, basic water treatment equipment, or fine water treatment circuit are adjusted and the stable operating water quality changes, the reference data is obtained again, and the corresponding setting range is determined according to formulas (3) and (7).

[0066] In this embodiment, the particulate pollution characterization value is used to determine whether to perform foam separation fine treatment first, and the dissolved organic pollution characterization value is used to determine whether to continue ozone oxidation fine treatment after the formation of water to be oxidized. The effects of foam separation and ozone oxidation on different forms of pollutants in actual water bodies can overlap. The two characterization values ​​are used to limit the order of fine treatment input and termination conditions, and do not limit the two treatment steps to removing only a single type of pollutant.

[0067] In this embodiment, data generated at each treatment stage are stored chronologically within the same treated water body. Turbidity values ​​before and after foam separation, UV transmittance of the water to be oxidized, and UV transmittance after ozone oxidation correspond to the current treatment stage, without crossing different treatment water body combinations. The target treated water is then returned to the return water path of the grouper recirculating aquaculture system.

[0068] In one specific implementation, such as Figure 4 As shown, the present invention also provides a low-energy-consumption and high-efficiency water treatment system for recirculating aquaculture of grouper, used to perform the aforementioned low-energy-consumption and high-efficiency water treatment method for recirculating aquaculture of grouper. The system includes a water acquisition unit to be finely treated, a particulate pollution characterization value acquisition unit, a foam separation fine treatment unit, a water to be oxidized determination unit, a dissolved organic pollution characterization value acquisition unit, an ozone oxidation fine treatment unit, and a target water determination unit.

[0069] The untreated water acquisition unit is used to acquire the untreated water generated during the recirculating aquaculture system for grouper. In practical applications, the untreated water can be generated by the diversion of the basic treated water in the recirculating aquaculture system and sent to the fining water path. The untreated water acquisition unit provides the particulate matter characterization value acquisition unit with the water body information corresponding to the current untreated water.

[0070] The particulate matter characterization value acquisition unit is used to acquire the particulate matter characterization value of the water to be finely treated. The particulate matter characterization value maintains a corresponding relationship with the water to be finely treated and is transmitted to the foam separation fine treatment unit. When using the aforementioned specific implementation method, the particulate matter characterization value can be generated from the turbidity detection result of the water to be finely treated, but the system function is not limited to a certain fixed detection device.

[0071] The foam separation and fine treatment unit is used to compare the particulate pollution characterization value with a first preset range. When the particulate pollution characterization value does not meet the first preset range, the foam separation and fine treatment unit controls the corresponding water to be finely treated to enter the foam separation and fine treatment process, and obtains the particulate pollution characterization value of the water after foam separation. If the particulate pollution characterization value of the water after foam separation still does not meet the first preset range, the foam separation and fine treatment process continues; when the first preset range is reached, the foam separation and fine treatment process of the corresponding water body ends, forming the first treated water.

[0072] Water awaiting further treatment whose particulate matter characterization values ​​already meet the first predetermined range will not proceed to the foam separation and further treatment process. The water awaiting oxidation determination unit receives the aforementioned water awaiting further treatment that has not undergone foam separation and further treatment, as well as the first treated water generated by the foam separation and further treatment unit, and determines both types of water as water awaiting oxidation. Thus, the water entering the next judgment stage has already met the first predetermined range.

[0073] The dissolved organic pollution characterization value acquisition unit is used to acquire the dissolved organic pollution characterization value of the water to be oxidized and to maintain the correlation between the dissolved organic pollution characterization value and the corresponding water to be oxidized. When using the aforementioned specific embodiment, the dissolved organic pollution characterization value can be formed based on the ultraviolet transmittance of the water to be oxidized at a wavelength of 254 nm.

[0074] The ozone oxidation treatment unit compares the dissolved organic pollutant characterization value with a second preset range. When the dissolved organic pollutant characterization value does not meet the second preset range, the ozone oxidation treatment unit controls the corresponding water to be oxidized to undergo ozone oxidation treatment and obtains the dissolved organic pollutant characterization value of the water after ozone oxidation. If the dissolved organic pollutant characterization value of the water after ozone oxidation still does not meet the second preset range, ozone oxidation treatment continues; when the second preset range is reached, the ozone oxidation treatment of the corresponding water body ends, forming the second treated water.

[0075] Water awaiting oxidation whose dissolved organic pollutant characterization values ​​already meet the second set range will not enter the ozone oxidation fine treatment. The target treated water determination unit receives the aforementioned water awaiting oxidation that has not undergone ozone oxidation fine treatment and the second treated water formed by the ozone oxidation fine treatment unit, and determines the two types of water as target treated water.

[0076] In this embodiment, the units for obtaining water to be finely treated, obtaining particulate pollution characterization values, obtaining foam separation fine treatment, determining water to be oxidized, obtaining dissolved organic pollution characterization values, obtaining ozone oxidation fine treatment, and determining the target treated water are sequentially established according to the water treatment state and detection data. Particulate pollution characterization values ​​are only used for the judgment in the first treatment stage, and dissolved organic pollution characterization values ​​are only used for the judgment in the second treatment stage after the formation of water to be oxidized. The water state formed in the previous stage serves as the transition condition between the two treatment stages.

[0077] In the actual system, the particulate pollution characterization value acquisition unit can be connected to the turbidity detection device, and the dissolved organic pollution characterization value acquisition unit can be connected to the ultraviolet detection device; the foam separation and fine treatment unit can control the water flow direction between the fine treatment water circuit and the foam separation equipment, and the ozone oxidation fine treatment unit can control the state of the water to be oxidized entering the ozone oxidation equipment. The aforementioned detection devices and treatment equipment are used to complete the detection and water treatment operations corresponding to each functional unit without changing the data transmission and water treatment relationships between the seven functional units.

[0078] This embodiment establishes separate detection conditions for particulate matter and dissolved organic pollutants within the same recirculating aquaculture system. The water to be treated is first evaluated based on its particulate matter characterization value to determine whether it should undergo foam separation treatment. Once the water reaches a first predetermined range after foam separation, it becomes the first treated water. Subsequently, the dissolved organic pollutant status is characterized by the 254 nm UV transmittance of the water to be oxidized. Ozone oxidation treatment is only performed if the corresponding detection value does not reach a second predetermined range, and the ozone treatment ends once the UV transmittance reaches the second predetermined range. Each treatment stage uses fixed sampling locations, the same water sample treatment method, and corresponding reference data to establish predetermined ranges, ensuring that the detection results before and after treatment correspond to the same water quality state. The ozone-treated water undergoes further total residual oxide detection and residual oxide reduction, ensuring that the target treated water entering the return water system controls both dissolved organic pollutants and residual oxides after seawater ozone treatment. The foam separation equipment and ozone generator are only put into operation when the corresponding water quality condition requires treatment, and stop operating after the corresponding termination condition is reached, reducing the time that water bodies that meet the set range continue to occupy the fine treatment equipment; together with the power metering device, the actual power increment of different fine treatment stages can be recorded, which can directly quantify the changes in the fine treatment operating load.

[0079] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on its differences from other embodiments. Similar or identical parts between embodiments can be referred to interchangeably. For the systems disclosed in the embodiments, since they correspond to the methods disclosed in the embodiments, the descriptions are relatively simple; relevant parts can be referred to the method section.

[0080] Specific examples have been used to illustrate the principles and implementation methods of this invention. The descriptions of the above embodiments are only for the purpose of helping to understand the method and core ideas of this invention. Furthermore, those skilled in the art will recognize that, based on the ideas of this invention, there will be changes in the specific implementation methods and application scope. Therefore, the content of this specification should not be construed as a limitation of this invention.

Claims

1. A low-energy, high-efficiency water treatment method for recirculating aquaculture of grouper, characterized in that, include: To obtain the water awaiting intensive treatment generated during the recirculating aquaculture of grouper; Obtain the particulate pollution characterization values ​​of the water to be finely treated; Based on the comparison result between the particulate pollution characterization value and the first set range, the water to be treated that does not meet the first set range is subjected to foam separation fine treatment until the particulate pollution characterization value of the water body after foam separation meets the first set range, and the first treated water is obtained. The water to be treated and the first treated water whose particulate pollution characterization value meets the first set range and has not undergone the foam separation fine treatment are identified as water to be oxidized. Obtain the characterization values ​​of dissolved organic pollutants in the water to be oxidized; Based on the comparison results between the dissolved organic pollution characterization value and the second set range, the water to be oxidized that does not meet the second set range is subjected to ozone oxidation treatment until the dissolved organic pollution characterization value of the water body after ozone oxidation meets the second set range, and the second treated water is obtained. The water to be oxidized and the second treated water, whose dissolved organic pollution characterization values ​​meet the second set range and have not undergone the ozone oxidation fine treatment, are identified as target treated water.

2. The low-energy-consumption and high-efficiency water treatment method for recirculating aquaculture of grouper according to claim 1, characterized in that, The method of obtaining the water to be treated during the recirculating aquaculture of grouper includes: The basic treated water is obtained by obtaining the circulating water discharged from the grouper breeding pond and then performing solid-liquid separation and biological purification. A portion of the water from the basic treated water is used as the water to be further treated. The unextracted water from the basic treatment water is returned to the grouper breeding pond.

3. The low-energy-consumption and high-efficiency water treatment method for recirculating aquaculture of grouper according to claim 1, characterized in that, The process of obtaining the particulate pollution characterization values ​​of the water to be finely treated includes: Obtain the turbidity value of the water to be treated; The turbidity detection value is determined as the particulate pollution characterization value.

4. The low-energy-consumption and high-efficiency water treatment method for recirculating aquaculture of grouper according to claim 3, characterized in that, The step of performing foam separation and refining treatment on the water to be refined that does not meet the first set range, based on the comparison result between the particulate pollution characterization value and the first set range, includes: The turbidity range that is not higher than the first turbidity threshold is defined as the first set range; Compare the particulate pollution characterization value with the first set range; When the particulate pollution characterization value is higher than the first turbidity threshold, the water to be refined is subjected to the foam separation and refining treatment.

5. The low-energy-consumption and high-efficiency water treatment method for recirculating aquaculture of grouper according to claim 4, characterized in that, The step of performing foam separation purification on the water to be purified that does not meet the first set range until the particulate pollution characterization value of the water body after foam separation meets the first set range, to obtain the first purified water, includes: The water to be refined is subjected to the foam separation refinement treatment to form the water body after foam separation; Obtain the turbidity detection value of the water body after foam separation, and determine the turbidity detection value of the water body after foam separation as the particulate pollution characterization value of the water body after foam separation; The particulate pollution characterization value of the water body after foam separation is compared with the first set range; When the particulate pollution characterization value of the water body after foam separation meets the first set range, the foam separation fine treatment ends, and the water body after foam separation is identified as the first treated water.

6. The low-energy-consumption and high-efficiency water treatment method for recirculating aquaculture of grouper according to claim 1, characterized in that, The process of obtaining the dissolved organic pollution characterization values ​​of the water to be oxidized includes: The ultraviolet transmittance of the water to be oxidized at a wavelength of 254 nm was obtained; The ultraviolet transmittance of the water to be oxidized at a wavelength of 254 nm was determined as the characterization value of the dissolved organic pollutants.

7. The low-energy-consumption and high-efficiency water treatment method for recirculating aquaculture of grouper according to claim 6, characterized in that, The step of obtaining the ultraviolet transmittance of the water to be oxidized at a wavelength of 254 nm includes: A test water sample was obtained from the water to be oxidized; The water sample is subjected to particulate matter retention to obtain a test solution; The ultraviolet transmittance of the test solution at a wavelength of 254 nm is obtained, and the ultraviolet transmittance of the test solution at a wavelength of 254 nm is determined as the ultraviolet transmittance of the water to be oxidized at a wavelength of 254 nm.

8. The low-energy-consumption and high-efficiency water treatment method for recirculating aquaculture of grouper according to claim 6, characterized in that, The step of performing ozone oxidation treatment on the water to be oxidized that does not meet the second set range, based on the comparison result between the dissolved organic pollutant characterization value and the second set range, includes: The range of ultraviolet transmittance that is not lower than the second ultraviolet transmittance threshold is defined as the second set range; The dissolved organic pollution characterization value is compared with the second set range; When the dissolved organic pollution characterization value is lower than the second ultraviolet transmittance threshold, the water to be oxidized is subjected to the ozone oxidation treatment.

9. The low-energy-consumption and high-efficiency water treatment method for recirculating aquaculture of grouper according to claim 8, characterized in that, The step of performing ozone oxidation treatment on the water to be oxidized that does not meet the second set range until the dissolved organic pollution characterization value of the water body after ozone oxidation meets the second set range, to obtain second treated water, includes: The water to be oxidized is subjected to ozone oxidation treatment to form the ozone-oxidized water body; The ultraviolet transmittance of the water body after ozone oxidation at a wavelength of 254 nm was obtained, and the ultraviolet transmittance of the water body after ozone oxidation at a wavelength of 254 nm was determined as the characterization value of dissolved organic pollution in the water body after ozone oxidation. The dissolved organic pollution characterization values ​​of the water body after ozone oxidation are compared with the second set range; When the dissolved organic pollution characterization value of the water body after ozone oxidation meets the second set range, the ozone oxidation fine treatment ends, and the water body after ozone oxidation is identified as the second treated water.

10. The low-energy-consumption and high-efficiency water treatment method for recirculating aquaculture of grouper according to claim 9, characterized in that, The step of defining the water to be oxidized and the second treated water as target treated water, which have dissolved organic pollution characterization values ​​that meet the second set range and have not undergone the ozone oxidation fine treatment, includes: The water to be oxidized that meets the second set range in terms of dissolved organic pollution characterization values ​​and has not undergone the ozone oxidation fine treatment is identified as the target treated water; The second treated water is subjected to residual oxide reduction treatment; Obtain the total residual oxide concentration of the second treated water after the residual oxide reduction treatment; When the total residual oxide concentration is not higher than a preset safety threshold, the second treated water that has undergone the residual oxide reduction treatment is determined as the target treated water.

Images