A water quality monitoring method and monitoring system for a blue crab breeding system

Abstract

The present invention discloses a water quality monitoring method and monitoring system for a blue crab breeding system, and the present invention relates to the field of aquaculture. The method comprises the following steps: the method calculates the dissolved oxygen concentration by irradiating a light source and collecting light intensity data with an optical sensor, and corrects the result according to the water temperature and pressure. The contents of chemical parameters such as ammonia nitrogen and nitrite are further obtained, and the water quality chemical index is calculated. At the same time, the turbidity is characterized based on the light intensity, the refractive index of suspended particles and the average diameter, the conductivity is detected, and the ecosystem health index is generated. A comprehensive water quality evaluation coefficient is obtained by comprehensive analysis, and different water quality evaluation instructions are generated by comparing with the water quality evaluation threshold, so as to comprehensively evaluate the water quality of the breeding water source and ensure the health of the breeding environment. The automation and intelligence level of aquaculture water monitoring is improved, which helps to reduce the risks in the breeding process and improve the growth rate and quality of aquatic products such as blue crabs.

Description

Technical Field

[0001] The invention relates to the field of aquaculture, and in particular to a water quality monitoring method and a monitoring system for a blue crab breeding system. Background Art

[0002] In the field of aquaculture, especially in the process of blue crab farming, water quality monitoring and management is one of the key factors to ensure the success of farming and product quality. The quality of water directly affects the growth, development, and final yield and quality of farmed organisms. The influence of dissolved oxygen (DO), ammonia nitrogen, nitrite and other parameters in the aquaculture water on the aquaculture environment is particularly important, especially the dissolved oxygen concentration, which is an important indicator affecting the health and growth of blue crabs. Too low or too high dissolved oxygen concentration will cause stress response of blue crabs, affecting their feeding, growth and even death. Therefore, real-time monitoring of dissolved oxygen concentration in aquaculture water is crucial.

[0003] Traditional water quality monitoring methods mainly rely on regular sampling and laboratory analysis. This method has problems such as poor real-time performance, cumbersome operation, and high labor costs. It is difficult to adapt to the needs of modern aquaculture for accurate, continuous, and automated water quality monitoring. With the development of sensing technology and automated monitoring technology, water quality monitoring methods based on optical principles have gradually been proposed and applied. The light source is used to illuminate the water source to be monitored, and the changes in the light beam are collected by optical sensors to indirectly infer the concentration of dissolved oxygen in the water. This method can realize online and real-time monitoring, has high timeliness and accuracy, reduces manual intervention, and improves monitoring efficiency.

[0004] Existing optical monitoring methods often ignore the impact of various environmental factors on water quality, especially water temperature, pressure, chemical content, and turbidity. The influence of water temperature and pressure on dissolved oxygen concentration cannot be ignored, especially in aquaculture environments, where changes in temperature and pressure can cause fluctuations in oxygen solubility, which directly affects the calculation results of dissolved oxygen. In addition, the accumulation of harmful substances such as ammonia nitrogen and nitrite in water is often closely related to the dissolved oxygen concentration of aquaculture water bodies, especially when the aquaculture density is high. Fluctuations in the content of these chemical parameters will further affect the water quality. The traditional single optical monitoring method cannot comprehensively consider these factors and it is difficult to provide accurate water quality evaluation. Therefore, how to comprehensively consider multiple water quality parameters for comprehensive analysis based on optical monitoring has become a technical problem that needs to be solved urgently.

[0005] In the prior art, the publication number CN118584077A discloses an intelligent marine aquaculture tailwater water quality monitoring method and system, including obtaining tailwater data parameters through sensors, preprocessing the tailwater water quality data collected in real time and transmitting it to the central monitoring system, and establishing a tailwater water quality detection neural network model for water quality detection; according to the obtained tailwater water quality detection results, combined with the preset ideal water quality conditions, the state of the discharged tailwater is hierarchically divided; according to the obtained revised tailwater quality evaluation index, a safety monitoring model is established, and the output safety value is used to determine whether the system triggers the early warning mechanism. However, the target of detection in this method is tailwater, and the real-time changes in tailwater water quality may require more frequent monitoring to reflect the water quality of the aquaculture water source. At the same time, the accuracy of the neural network model depends largely on a large amount of and diverse training data. If the training data is insufficient, or the training data cannot fully represent the actual changes in tailwater water quality (for example, water quality abnormalities caused by sudden environmental pollution events or equipment failures), the prediction accuracy of the model will be reduced. Therefore, monitoring and supervision based on this scheme alone not only wastes resources, but also reduces the real-time and effectiveness of the supervision system.

[0006] The above information disclosed in this Background section is only for enhancement of understanding of the background of the present disclosure and therefore it may contain information that does not constitute the prior art that is already known to one of ordinary skill in the art. Summary of the invention

[0007] The object of the present invention is to provide a water quality monitoring method and a monitoring system for a blue crab breeding system to solve the problems raised in the above background technology.

[0008] To achieve the above object, the present invention provides the following technical solutions:

[0009] A method for monitoring water quality in a blue crab breeding system, comprising the following specific steps:

[0010] A light beam of known wavelength is emitted by a light source to illuminate the aquaculture water source to be monitored, and the light intensity before and after the light beam is incident is collected by an optical sensor, and the dissolved oxygen concentration of the aquaculture water source to be monitored is calculated based on the light intensity before and after the incident and the incident distance;

[0011] Collect the water temperature and pressure data of the aquaculture water source to be monitored, and correct the calculated dissolved oxygen concentration by combining the obtained water temperature and pressure data with the unit heat of solution when oxygen is dissolved in water to obtain the accurate dissolved oxygen concentration of the aquaculture water source;

[0012] Obtaining the chemical parameter content in the aquaculture water source to be monitored, and calculating the water quality chemical index by combining the obtained chemical parameter content with the accurate dissolved oxygen concentration obtained after correction, wherein the chemical parameters in the aquaculture water source to be monitored include ammonia nitrogen and nitrite;

[0013] Based on the light intensity before and after the incident light, the refractive index of the suspended particles and the average diameter of the suspended particles, the turbidity of the aquaculture water source to be monitored is characterized, and the conductivity of the aquaculture water source to be monitored is detected. The ecosystem health index is generated by combining the water source conductivity obtained by the test with the turbidity of the aquaculture water source obtained by the calculation;

[0014] Based on the ecosystem health index and water quality chemical index, a comprehensive evaluation coefficient of aquaculture water quality is obtained through joint analysis. The obtained comprehensive evaluation coefficient is compared with the water quality evaluation threshold, and different water quality evaluation instructions are generated according to different comparison results.

[0015] Furthermore, the aquaculture water source to be monitored is irradiated by a light source of known wavelength, and the light intensity before and after the incident light beam of the aquaculture water source to be monitored is collected by an optical sensor. Specifically, a light source of a certain wavelength is selected to irradiate the aquaculture water source to be monitored, and the bottom light intensity is collected at the bottom of the aquaculture container by the optical sensor as the light intensity after the incident light passing through the water sample; the bottom light intensity is measured continuously for several times, and the data is transmitted to the data collection system for processing.

[0016] Furthermore, the dissolved oxygen concentration of the aquaculture water source to be monitored is calculated based on the light intensity before and after the incident light and the incident distance, wherein the formula for calculating the dissolved oxygen concentration is:

[0017]

[0018] Where DO is the dissolved oxygen concentration, α is the absorption coefficient of dissolved oxygen to the light source, l is the incident distance, I0 is the incident light intensity before passing through the water sample, and I is the incident light intensity after passing through the water sample.

[0019] Furthermore, the calculated dissolved oxygen concentration of the aquaculture water source is corrected by using the obtained water temperature and pressure data and the unit heat of solution when oxygen is dissolved in water to obtain the precise dissolved oxygen concentration of the aquaculture water source, wherein the specific formula for calculating the precise dissolved oxygen concentration is:

[0020]

[0021] In the formula, DO′ is the precise dissolved oxygen concentration, ΔH is the unit heat of solution when oxygen is dissolved in water, R is the ideal gas constant, T is the water temperature of the aquaculture water source, and T ref is the reference water temperature for blue crab culture, P is the pressure at the bottom of the blue crab culture container, P ref It is the reference pressure at the bottom of the blue crab culture container.

[0022] Furthermore, the water quality chemical index is calculated by combining the obtained chemical parameter content with the corrected accurate dissolved oxygen concentration, wherein the specific formula for calculating the water quality chemical index is:

[0023]

[0024] Where WI is the water quality chemical index, NH represents the ammonia nitrogen concentration in the aquaculture water source to be monitored, NO represents the nitrite concentration in the aquaculture water source to be monitored, b and f are the weight coefficients of the precise dissolved oxygen concentration and the chemical parameter content in the aquaculture water source to be monitored, respectively, where f>b and both b and f are greater than 0.

[0025] Furthermore, based on the light intensity before and after the incident light, the refractive index of the suspended particles and the average diameter of the suspended particles, the turbidity of the aquaculture water source to be monitored is characterized, wherein the specific formula for calculating the turbidity of the aquaculture water source to be monitored is:

[0026]

[0027] In the formula, N represents the turbidity of the aquaculture water source to be monitored, λ is the wavelength of the incident light, n is the refractive index correction value of the water source, and d is the average diameter of the suspended particles in the water source;

[0028] The method for obtaining the refractive index correction value is as follows: obtain the basic refractive index n0 of the aquaculture water source, and correct the basic refractive index of the aquaculture water source by the water source temperature and salinity to obtain the water source refractive index correction value. The formula is as follows:

[0029] The water source refractive index correction value n is corrected by the water source temperature and water source salinity, and the specific calculation formula is:

[0030] n=n0*{1+ln(1+TT ref )}*(K*S 2 )

[0031] In the formula, n0 is the basic refractive index of the aquaculture water source, that is, the actual measured refractive index of the aquaculture water source, S is the salinity of the water source, K is the proportional constant of the salinity, T is the water temperature of the aquaculture water source, T ref This is the reference water temperature for blue crab farming.

[0032] Furthermore, the ecosystem health index is generated by combining the detected water source conductivity with the calculated turbidity of the aquaculture water source, where the ecosystem health index is calculated based on the formula:

[0033]

[0034] Where, EHI is the ecosystem health index, EC is the non-salinity conductivity, ω1, ω2 and ω3 are the non-salinity conductivity weight coefficient, the mixing weight coefficient of the aquaculture water source and the exponential attenuation coefficient of the non-salinity conductivity, respectively, where ω3>ω2>ω1 and ω1, ω2 and ω3 are all greater than 0;

[0035] The non-salinity conductivity is calculated based on the conductivity of the overall water source. The specific calculation formula is:

[0036] EC=EC0-β*S

[0037] Where EC0 is the conductivity of the entire water source, and β is the salinity proportional coefficient.

[0038] Furthermore, based on the ecosystem health index and water quality chemical index, the comprehensive evaluation coefficient of aquaculture water quality is obtained through joint analysis. The formula for calculating the comprehensive evaluation coefficient of aquaculture water quality is as follows:

[0039]

[0040] In the formula, ω4 and ω5 are the weight coefficients of the ecosystem health index and the water quality chemical index, respectively, EHI is the ecosystem health index, WI is the water quality chemical index, and ZH is the comprehensive evaluation coefficient of the aquaculture water quality, where ω4<ω5 and ω4 and ω5 are both greater than 0;

[0041] Based on the obtained comprehensive water quality evaluation coefficient, compared with the water quality evaluation threshold, different water quality evaluation instructions are generated according to different comparison results. The specific logic is as follows:

[0042] When ZH≥1.0*yz, a warning command is issued, indicating that the water quality of the current blue crab breeding system is in a serious pollution state and should be replaced immediately;

[0043] When 0.4*yz≤ZH<1.0*yz, an early warning command is issued, indicating that the water quality of the current blue crab breeding system is at risk of pollution and should be monitored and maintained;

[0044] When 0≤ZH<0.4*yz, a safety instruction is issued, indicating that the water quality of the current mud crab breeding system is in a suitable state and should be used;

[0045] Where yz is the preset instability coefficient.

[0046] The present invention also provides a water quality monitoring system for a blue crab breeding system, wherein the water quality monitoring system for a blue crab breeding system is used to execute the water quality monitoring method for a blue crab breeding system, and comprises:

[0047] A data acquisition and processing module is used to emit a light beam of known wavelength to illuminate the aquaculture water source to be monitored through a light source, collect the light intensity before and after the light beam is incident through an optical sensor, and calculate the dissolved oxygen concentration of the aquaculture water source to be monitored based on the light intensity before and after the incident and the incident distance;

[0048] The dissolved oxygen concentration correction module is used to collect the water temperature and pressure data of the aquaculture water source to be monitored, and to correct the calculated dissolved oxygen concentration of the aquaculture water source by combining the obtained water temperature and pressure data with the unit heat of solution when oxygen is dissolved in water, so as to obtain the accurate dissolved oxygen concentration of the aquaculture water source;

[0049] A water quality chemical index analysis module is used to obtain the chemical parameter content in the aquaculture water source to be monitored, and calculate the water quality chemical index by combining the obtained chemical parameter content with the accurate dissolved oxygen concentration obtained after correction, wherein the chemical parameters in the aquaculture water source to be monitored include ammonia nitrogen and nitrite;

[0050] The ecosystem health analysis module is used to characterize the turbidity of the aquaculture water source to be monitored based on the light intensity before and after the incident light, the refractive index of the suspended particles, and the average diameter of the suspended particles. At the same time, the conductivity of the aquaculture water source to be monitored is detected, and the ecosystem health index is generated by combining the water source conductivity obtained by the detection with the turbidity of the aquaculture water source obtained by the calculation.

[0051] The comprehensive water quality monitoring and judgment module is used to jointly analyze the ecosystem health index and the water quality chemical index to obtain the comprehensive evaluation coefficient of the aquaculture water source water quality. Based on the obtained comprehensive water quality evaluation coefficient, it is compared with the water quality evaluation threshold, and different water quality evaluation instructions are generated according to different comparison results.

[0052] Compared with the prior art, the present invention has the following beneficial effects:

[0053] First, by irradiating the aquaculture water body with a light source of known wavelength and collecting the change of light intensity, the dissolved oxygen concentration in the water can be calculated based on the change of light intensity. By further combining the water temperature and water pressure data, the calculation results are corrected, eliminating the influence of water temperature and pressure changes on the determination of dissolved oxygen concentration, and ensuring the accuracy of dissolved oxygen. This technology breaks through the problem that traditional methods cannot accurately reflect the impact of water temperature and pressure on water quality, especially in complex water environments, and can provide more accurate dissolved oxygen concentration monitoring. In addition, by collecting chemical parameter data such as ammonia nitrogen and nitrite in water, combined with the correction value of dissolved oxygen concentration, the calculation of water quality chemical index is proposed. The concentration change of pollutants in the water body can be evaluated in real time, thereby providing a more accurate decision-making basis for water quality management, avoiding the limitation of traditional methods that can only monitor certain indicators alone. Finally, the refractive index and average diameter of suspended particles and the conductivity data of the water body are included in the monitoring indicators, the turbidity of the water body is calculated based on these parameters, and the ecosystem health index is further generated in combination with the conductivity data, which can reflect the comprehensive impact of organic matter, inorganic salts and microorganisms in the water body on water quality. It can provide comprehensive and accurate water quality assessment in complex aquaculture environments. It has improved the automation and intelligence level of aquaculture water monitoring, helped reduce risks in the aquaculture process, increased the growth rate and quality of aquatic products such as blue crabs, and ultimately promoted the green development of the aquaculture industry and improved economic benefits. BRIEF DESCRIPTION OF THE DRAWINGS

[0054] Figure 1 It is a schematic diagram of the overall method flow of the present invention;

[0055] Figure 2 It is a schematic diagram of the overall system structure of the present invention. DETAILED DESCRIPTION

[0056] In order to make the objectives, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with specific embodiments.

[0057] It should be noted that, unless otherwise defined, the technical terms or scientific terms used in the present invention should be understood by people with ordinary skills in the field to which the present invention belongs. The words "first", "second" and similar words used in the present invention do not indicate any order, quantity or importance, but are only used to distinguish different components. "Include" or "comprise" and similar words mean that the elements or objects appearing before the word include the elements or objects listed after the word and their equivalents, without excluding other elements or objects. "Connect" or "connected" and similar words are not limited to physical or mechanical connections, but may include electrical connections, whether direct or indirect. "Up", "down", "left", "right" and the like are only used to indicate relative positional relationships. When the absolute position of the described object changes, the relative positional relationship may also change accordingly.

[0058] Example:

[0059] See also Figure 1 , the present invention provides a technical solution:

[0060] A method for monitoring water quality in a blue crab breeding system, comprising the following specific steps:

[0061] Step 1: A light source emits a light beam of known wavelength to illuminate the aquaculture water source to be monitored, and an optical sensor collects the light intensity before and after the light beam is incident. The dissolved oxygen concentration of the aquaculture water source to be monitored is calculated based on the light intensity before and after the incident and the incident distance.

[0062] The aquaculture water source to be monitored is irradiated by a light source of known wavelength, and the light intensity of the aquaculture water source to be monitored before and after the light beam is incident is collected by an optical sensor. Specifically, a light source of a certain wavelength is selected to irradiate the aquaculture water source to be monitored, and the bottom light intensity is collected at the bottom of the aquaculture container by an optical sensor; the bottom light intensity is measured several times continuously, and the data is transmitted to the data collection system for processing. The specific processing is to remove the highest and lowest values, calculate the average value of the remaining bottom light intensities, and use the average value as the light intensity after incident through the water sample.

[0063] Choosing a light source with the right wavelength is key. The absorption and scattering properties of dissolved oxygen vary at different wavelengths. Common wavelength ranges are visible light and near infrared, because dissolved oxygen has obvious optical properties (such as absorption or scattering) at these wavelengths. Common wavelength choices include red light (about 600-700nm) and blue light (about 400-500nm). The light source should be placed above the water flow or near the water surface to ensure that the light source can effectively illuminate the water sample to be tested. The light source should emit light in a directional manner and be fixed in position to avoid interference from environmental factors (such as the influence of water flow, temperature, etc. on the irradiated light). The optical sensor (photodetector) should be located opposite to the light source, usually arranged in the path of the incident light and the transmitted light. The sensor should be able to accurately measure the intensity of the transmitted light through the water source. To ensure measurement accuracy, the distance between the sensor and the light source needs to be kept constant, and it is best to set it in a position where the water flow is relatively stable.

[0064] The dissolved oxygen concentration of the aquaculture water source to be monitored is calculated based on the light intensity before and after the incident light and the incident distance. The formula for calculating the dissolved oxygen concentration is:

[0065]

[0066] Where DO is the dissolved oxygen concentration, α is the absorption coefficient of dissolved oxygen to the light source, l is the incident distance, I0 is the incident light intensity before passing through the water sample, and I is the incident light intensity after passing through the water sample.

[0067] Among them, the absorption coefficient α of dissolved oxygen to light source is usually obtained through experimental measurement, specifically: prepare a standard water sample with a known dissolved oxygen concentration, use a spectrometer to measure the change in light intensity under different dissolved oxygen concentrations, and calculate the absorption coefficient according to Beer-Lambert law. The absorption coefficient α of dissolved oxygen to light is wavelength-dependent. Different light source wavelengths (such as ultraviolet, visible light, etc.) will have different absorption characteristics. Therefore, when measuring dissolved oxygen concentration, it is necessary to ensure that the wavelength of the light source matches the selected dissolved oxygen absorption characteristics. The absorption coefficient α of dissolved oxygen to light source generally ranges from 10 2 m -1 Up to 10 4 m -1 .

[0068] Step 2: Collect water temperature and pressure data of the aquaculture water source to be monitored, and use the obtained water temperature and pressure data in combination with the unit heat of solution when oxygen is dissolved in water to correct the calculated dissolved oxygen concentration of the aquaculture water source to obtain the accurate dissolved oxygen concentration of the aquaculture water source.

[0069] The calculated dissolved oxygen concentration of the aquaculture water source is corrected by the water temperature and pressure data obtained, combined with the unit heat of solution when oxygen is dissolved in water, to obtain the precise dissolved oxygen concentration of the aquaculture water source. The specific formula for calculating the precise dissolved oxygen concentration is:

[0070]

[0071] In the formula, DO′ is the exact dissolved oxygen concentration, ΔH is the unit heat of solution when oxygen is dissolved in water, and R is the ideal gas constant, which is 8.314 J·mol -1 ·K -1 , T is the water temperature of the aquaculture water source, T ref is the reference water temperature for blue crab culture, P is the pressure at the bottom of the blue crab culture container, P ref It is the reference pressure at the bottom of the blue crab culture container.

[0072] The first term of the formula is temperature influence, It is based on the Van't Hoff equation. The exponential form correction is based on the classic temperature dependence of solubility, which describes the effect of temperature change on the solubility of dissolved oxygen. The unit heat of solution of oxygen is a negative value of ΔH, that is, the dissolution process of oxygen in water is exothermic. This means that when oxygen dissolves, the system releases heat. According to Le Chatelier's principle, when the temperature rises, the thermal motion of water molecules intensifies, the hydrogen bonds between water molecules break, and the interaction between water molecules and oxygen molecules weakens. Due to the decrease in the interaction between oxygen molecules and water molecules, oxygen molecules are more likely to escape from water, thereby reducing solubility. That is, oxygen escapes from the solution into the gas phase, resulting in a decrease in solubility.

[0073] The second term of the formula is the pressure effect, It is based on Henry's law, which states that at a given temperature, the solubility of a gas is proportional to its partial pressure above the liquid. Therefore, as pressure increases, the solubility of dissolved oxygen will also increase. In the water source for blue crab farming, the depth of the water body will cause the pressure at the bottom to increase, which in turn affects the concentration of dissolved oxygen. At deeper depths underwater, the increased pressure increases the contact area between oxygen molecules and water molecules, resulting in increased oxygen solubility.

[0074] The reference water temperature for blue crab farming is T ref and the reference pressure P at the bottom of the mud crab culture container ref By consulting relevant literature or scientific research reports, we can find out the optimal water temperature range for the growth and reproduction of blue crabs. For example, the optimal growth temperature of blue crabs is usually between 25℃ and 30℃. Temperatures that are too low or too high may affect the health and growth rate of blue crabs. Or based on the actual experience of the farm, farmers usually choose a reference water temperature to optimize the breeding environment. This temperature value may be based on the growth pattern of blue crabs, the actual operating conditions of the breeding environment, and other breeding technical requirements;

[0075] The depth of the water body directly determines the pressure at the bottom of the container. Reference pressure P ref With reference water temperature T ref The acquisition method is similar, by consulting relevant literature or scientific research reports and setting them according to the actual experience of the farm.

[0076] Step 3: Obtain the chemical parameter content in the aquaculture water source to be monitored, and calculate the water quality chemical index by combining the obtained chemical parameter content with the accurate dissolved oxygen concentration obtained after correction, wherein the chemical parameters in the aquaculture water source to be monitored include ammonia nitrogen and nitrite.

[0077] The water quality chemical index is calculated by combining the obtained chemical parameter content with the corrected accurate dissolved oxygen concentration. The specific formula for calculating the water quality chemical index is:

[0078]

[0079] Where WI is the water quality chemical index, NH represents the ammonia nitrogen concentration in the aquaculture water source to be monitored, NO represents the nitrite concentration in the aquaculture water source to be monitored, b and f are the weight coefficients of the precise dissolved oxygen concentration and the chemical parameter content in the aquaculture water source to be monitored, respectively, where f>b and both b and f are greater than 0.

[0080] Among them, the larger the water quality chemical index WI is, the better the water quality is. Ammonia nitrogen is mainly in the form of ammonia gas (NH3) and ammonium ions (NH4 + ) and is usually produced by animal excrement, uneaten feed or decomposition of organic matter. The presence of ammonia nitrogen in water has the following effects on water quality: When the concentration of ammonia nitrogen increases, especially the proportion of ammonia (NH3), it will be toxic to aquatic organisms (including blue crabs, fish, etc.). The toxicity of ammonia to aquatic organisms is mainly manifested in affecting their respiratory systems, leading to poisoning or death. When the concentration of ammonia nitrogen is high, it will promote the growth of some bacteria. These bacteria need to consume dissolved oxygen, which may cause the dissolved oxygen level in the water to decrease, affecting the growth and survival of aquatic organisms. If the concentration of ammonia nitrogen is too high, it may cause the death of fish or other aquatic organisms, especially in blue crab farming. Excessive ammonia nitrogen concentrations will affect the health of blue crabs and may trigger a stress response, leading to slow growth, reduced immunity, and even death.

[0081] Nitrite itself is highly toxic to aquatic organisms, especially fish and crustaceans such as blue crabs. Nitrite affects the hemoglobin of aquatic organisms, making it unable to effectively combine with oxygen, leading to tissue hypoxia. The degradation process of nitrite usually consumes a large amount of dissolved oxygen, so high concentrations of nitrite will not only lead to the consumption of dissolved oxygen in the water, but may also further aggravate the hypoxia of the water body.

[0082] Therefore, NH and NO are inversely proportional to the water quality chemical index WI. f*(NH+NO) The exponential form of the model represents the increase in ammonia nitrogen or nitrite concentration. When the impact increases exponentially, it more accurately reflects the nonlinear effect of pollutant concentration on water quality. Especially when the concentration is high, the harm of ammonia nitrogen and nitrite to water quality may increase exponentially. The exponential model can better describe this aggravation effect, which helps to more effectively manage and optimize the aquaculture environment and avoid water quality deterioration and poisoning of aquatic organisms.

[0083] High dissolved oxygen concentrations usually indicate good water quality because there is enough dissolved oxygen in the water to meet the respiratory needs of aquatic organisms and to facilitate biological purification processes in the water. For example, water with high dissolved oxygen concentrations is conducive to the growth of beneficial bacteria, which can break down organic matter and degrade pollutants, thereby maintaining clean water quality. Therefore, the precise dissolved oxygen concentration is directly proportional to the WI.

[0084] Since the chemical parameter content in the monitored aquaculture water source has a great influence on the water quality, f>b is set and both b and f are greater than 0.

[0085] Step 4: Based on the light intensity before and after the incident light, the refractive index of the suspended particles and the average diameter of the suspended particles, the turbidity of the aquaculture water source to be monitored is characterized, and the conductivity of the aquaculture water source to be monitored is detected. The ecosystem health index is generated by combining the water source conductivity obtained by the test with the turbidity of the aquaculture water source obtained by calculation.

[0086] Based on the light intensity before and after the incident light, the refractive index of the suspended particles and the average diameter of the suspended particles, the turbidity of the aquaculture water source to be monitored is characterized. The specific formula for calculating the turbidity of the aquaculture water source to be monitored is:

[0087]

[0088] In the formula, N represents the turbidity of the aquaculture water source to be monitored, λ is the wavelength of the incident light, n is the refractive index correction value of the water source, and d is the average diameter of the suspended particles in the water source;

[0089] The method for obtaining the refractive index correction value is as follows: obtain the basic refractive index n0 of the aquaculture water source, and correct the basic refractive index of the aquaculture water source by the water source temperature and salinity to obtain the water source refractive index correction value. The formula is as follows:

[0090] The water source refractive index correction value n is corrected by the water source temperature and water source salinity, and the specific calculation formula is:

[0091] n=n0*{1+ln(1+TT ref )}*(K*S 2 )

[0092] Where n0 is the basic refractive index of the aquaculture water source, that is, the actual measured refractive index of the aquaculture water source. Specifically, the refractive index of the aquaculture water source is measured at multiple locations and the average value is taken as the basic refractive index. S is the salinity of the water source, K is the proportional constant of the salinity, T is the water temperature of the aquaculture water source, and T ref This is the reference water temperature for blue crab farming.

[0093] TT refThe difference between temperature and a reference temperature. It indicates the deviation between the actual water temperature and the standard temperature. In general, temperature changes affect the physical properties of water and the characteristics of suspended particles, and the effect of temperature on the refractive index is nonlinear. The use of a logarithmic function here reflects the gradual weakening of the effect of temperature changes on the refractive index of particles. At low temperatures, the effect of temperature on the refractive index is small; as the temperature increases, the effect gradually increases, but at high temperatures, the increase in the effect tends to be gentle. The effect of temperature changes on the refractive index of particles is not linear, because the increase in temperature may cause the diffusion of particles, changes in solubility, and changes in the density of water, which affect the refractive index. By using a logarithmic function, this change law can be simulated more accurately.

[0094] Salinity of water. Increases in salinity generally affect the optical properties of water. Water with high salinity refracts light more than water with low salinity, thus increasing the refractive index of particles. The relationship between salinity and refractive index is generally nonlinear. Depending on the salinity of the water, the refractive index of the water may increase in a quadratic manner, i.e., the magnitude of the change in refractive index increases with increasing salinity. Therefore, S is used in the formula 2 to reflect this effect.

[0095] The proportional constant K of salinity and the specific degree of influence of salinity on the refractive index need to be determined through experimental data. This constant can be calibrated according to different water characteristics, types of particulate matter and experimental results, and is generally in the range of 0.001 to 0.01.

[0096] The ecosystem health index is generated by combining the detected water source conductivity with the calculated turbidity of the aquaculture water source. The formula for calculating the ecosystem health index is:

[0097]

[0098] Where, EHI is the ecosystem health index, EC is the non-salinity conductivity, ω1, ω2 and ω3 are the non-salinity conductivity weight coefficient, the mixing weight coefficient of the aquaculture water source and the exponential attenuation coefficient of the non-salinity conductivity, respectively, where ω3>ω2>ω1 and ω1, ω2 and ω3 are all greater than 0;

[0099] The non-salinity conductivity is calculated based on the conductivity of the overall water source. The specific calculation formula is:

[0100] EC=EC0-β*S

[0101] Where EC0 is the conductivity of the entire water source, and β is the salinity proportionality coefficient. It is obtained through expert experience and generally ranges from 0.02 to 0.05.

[0102] The larger the Ecosystem Health Index is, the better the water quality is. The non-salinity conductivity EC is an indicator of the ion concentration in the water body, which is usually related to the mineralization of the water, the concentration of pollutants, etc. The higher the conductivity, the more ions or salts are dissolved in the water, the water quality may be polluted or there are more organic and inorganic substances in the water body. A large number of suspended particles in the water body may mean that the water quality is poor, which affects the light penetration and the self-purification ability of the water body, and may also affect the survival of aquatic organisms. Therefore, the non-salinity conductivity EC and the turbidity of the aquaculture water source are inversely proportional to the Ecosystem Health Index EHI.

[0103] at the same time It means that the effect of non-salinity conductivity on EHI is exponentially decaying. As the non-salinity conductivity EC increases, after exceeding a certain range, EHI decreases rapidly, that is, the effect of non-salinity conductivity on the ecological health index decreases exponentially with the increase of non-salinity conductivity;

[0104] The ln(1+N) logarithmic term means that the effect of turbidity N on EHI is nonlinear. As N increases, the effect of turbidity on the health index gradually increases, but the increase gradually slows down. The logarithmic function simulates that when the water turbidity is low, the change in the health status of the water body is small; when the turbidity is high, the downward trend of water health will be more significant.

[0105] At the same time, since the increase in conductivity has a more direct and significant impact on water quality, the exponential attenuation coefficient must be greater than the water source conductivity weight coefficient, which means that when it exceeds a certain range, it will decrease exponentially with the increase in conductivity; therefore, ω3>ω2>ω1 is set, and ω1, ω2 and ω3 are all greater than 0.

[0106] Step 5: Based on the ecosystem health index and water quality chemical index, jointly analyze to obtain the comprehensive evaluation coefficient of aquaculture water quality. Based on the obtained comprehensive evaluation coefficient, compare it with the water quality evaluation threshold, and generate different water quality evaluation instructions according to different comparison results.

[0107] Based on the ecosystem health index and water quality chemical index, the comprehensive evaluation coefficient of aquaculture water quality is obtained through joint analysis. The formula for calculating the comprehensive evaluation coefficient of aquaculture water quality is as follows:

[0108]

[0109] In the formula, ω4 and ω5 are the weight coefficients of the ecosystem health index and the water quality chemical index, respectively, EHI is the ecosystem health index, WI is the water quality chemical index, and ZH is the comprehensive evaluation coefficient of the aquaculture water quality, where ω4<ω5 and ω4 and ω5 are both greater than 0;

[0110] The square is used to represent the important influence of water quality chemical index on water quality, and the square root is used to limit the influence of ecosystem health index on the comprehensive evaluation coefficient of aquaculture water quality. Since the larger the weight coefficient value of ecosystem health index and water quality chemical index is, the better the water quality is, they are directly proportional to the comprehensive evaluation coefficient of aquaculture water quality.

[0111] Since the water quality chemical index has a more direct and serious impact on water quality, ω4<ω5 is set and both ω4 and ω5 are greater than 0;

[0112] Based on the obtained comprehensive water quality evaluation coefficient, compared with the water quality evaluation threshold, different water quality evaluation instructions are generated according to different comparison results. The specific logic is as follows:

[0113] When ZH≥1.0*yz, a warning command is issued, indicating that the water quality of the current blue crab breeding system is in a serious pollution state and should be replaced immediately;

[0114] When 0.4*yz≤ZH<1.0*yz, an early warning command is issued, indicating that the water quality of the current blue crab breeding system is at risk of pollution and should be monitored and maintained;

[0115] When 0≤ZH<0.4*yz, a safety instruction is issued, indicating that the water quality of the current mud crab breeding system is in a suitable state and should be used;

[0116] Where yz is the preset instability coefficient.

[0117] See also Figure 2 The present invention also provides a water quality monitoring system for a blue crab breeding system, wherein the water quality monitoring system for a blue crab breeding system is used to execute the water quality monitoring method for a blue crab breeding system, and comprises:

[0118] A data acquisition and processing module is used to emit a light beam of known wavelength to illuminate the aquaculture water source to be monitored through a light source, collect the light intensity before and after the light beam is incident through an optical sensor, and calculate the dissolved oxygen concentration of the aquaculture water source to be monitored based on the light intensity before and after the incident and the incident distance;

[0119] The dissolved oxygen concentration correction module is used to collect the water temperature and pressure data of the aquaculture water source to be monitored, and to correct the calculated dissolved oxygen concentration of the aquaculture water source by combining the obtained water temperature and pressure data with the unit heat of solution when oxygen is dissolved in water, so as to obtain the accurate dissolved oxygen concentration of the aquaculture water source;

[0120] A water quality chemical index analysis module is used to obtain the chemical parameter content in the aquaculture water source to be monitored, and calculate the water quality chemical index by combining the obtained chemical parameter content with the accurate dissolved oxygen concentration obtained after correction, wherein the chemical parameters in the aquaculture water source to be monitored include ammonia nitrogen and nitrite;

[0121] The ecosystem health analysis module is used to characterize the turbidity of the aquaculture water source to be monitored based on the light intensity before and after the incident light, the refractive index of the suspended particles, and the average diameter of the suspended particles. At the same time, the conductivity of the aquaculture water source to be monitored is detected, and the ecosystem health index is generated by combining the water source conductivity obtained by the detection with the turbidity of the aquaculture water source obtained by the calculation.

[0122] The comprehensive water quality monitoring and judgment module is used to jointly analyze the ecosystem health index and the water quality chemical index to obtain the comprehensive evaluation coefficient of the aquaculture water source water quality. Based on the obtained comprehensive water quality evaluation coefficient, it is compared with the water quality evaluation threshold, and different water quality evaluation instructions are generated according to different comparison results.

[0123] The above formulas are all dimensionless and numerical calculations. The formula is a formula for the most recent real situation obtained by collecting a large amount of data and performing software simulation. The preset parameters in the formula are set by technicians in this field according to actual conditions.

[0124] The above embodiments may be implemented in whole or in part by software, hardware, firmware or any other combination thereof. When implemented by software, the above embodiments may be implemented in whole or in part in the form of a computer program product. Those skilled in the art may appreciate that the units and algorithm steps of each example described in conjunction with the embodiments disclosed herein may be implemented by electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are performed by hardware or software methods depends on the specific application and design constraints of the technical solution.

[0125] The units described as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, and may be located in one place or distributed on multiple network units. Some or all of the units may be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0126] The above description is only a specific implementation manner of the present application, but the protection scope of the present application is not limited thereto. Any technician familiar with the technical field can easily think of changes or substitutions within the technical scope disclosed in the present application, which should be included in the protection scope of the present application.

Claims

1. A method for monitoring water quality in a mud crab breeding system, characterized in that: The specific steps include: A light source emits a light beam of known wavelength to illuminate the aquaculture water source to be monitored, an optical sensor collects the light intensity before and after the light beam is incident, and the dissolved oxygen concentration of the aquaculture water source to be monitored is calculated based on the light intensity before and after the incident and the incident distance; Collect the water temperature and pressure data of the aquaculture water source to be monitored, and correct the calculated dissolved oxygen concentration by combining the obtained water temperature and pressure data with the unit heat of solution when oxygen is dissolved in water to obtain the accurate dissolved oxygen concentration of the aquaculture water source; Obtaining the chemical parameter content in the aquaculture water source to be monitored, and calculating the water quality chemical index by combining the obtained chemical parameter content with the accurate dissolved oxygen concentration obtained after correction, wherein the chemical parameters in the aquaculture water source to be monitored include ammonia nitrogen and nitrite; Based on the light intensity before and after the incident light, the refractive index of the suspended particles and the average diameter of the suspended particles, the turbidity of the aquaculture water source to be monitored is characterized, and the conductivity of the aquaculture water source to be monitored is detected. The ecosystem health index is generated by combining the water source conductivity obtained by the test with the turbidity of the aquaculture water source obtained by the calculation; The specific formula for calculating the turbidity of the aquaculture water source to be monitored is: Where N represents the turbidity of the aquaculture water source to be monitored, λ is the wavelength of the incident light, n is the refractive index correction value of the water source, d is the average diameter of the suspended particles in the water source, I0 is the incident light intensity before passing through the water sample, and I is the incident light intensity after passing through the water sample; The method for obtaining the refractive index correction value is as follows: obtain the basic refractive index n0 of the aquaculture water source, and correct the basic refractive index of the aquaculture water source by the water source temperature and salinity to obtain the water source refractive index correction value. The formula is as follows: The water source refractive index correction value n is corrected by the water source temperature and water source salinity, and the specific calculation formula is: n=n0*{1+ln(1+T-T ref )}*(K*S 2 ) In the formula, n0 is the basic refractive index of the aquaculture water source, that is, the actual measured refractive index of the aquaculture water source, S is the salinity of the water source, K is the proportional constant of the salinity, T is the water temperature of the aquaculture water source, T ref The reference water temperature for blue crab culture; The formula for calculating the ecosystem health index is: Where, EHI is the ecosystem health index, EC is the non-salinity conductivity, ω1, ω2 and ω3 are the non-salinity conductivity weight coefficient, the mixing weight coefficient of the aquaculture water source and the exponential attenuation coefficient of the non-salinity conductivity, respectively, where ω3>ω2>ω1 and ω1, ω2 and ω3 are all greater than 0; The non-salinity conductivity is calculated based on the conductivity of the overall water source. The specific calculation formula is: EC=EC0-β*S In the formula, EC0 is the conductivity of the whole water source, and β is the salinity proportional coefficient; Based on the ecosystem health index and water quality chemical index, a comprehensive evaluation coefficient of aquaculture water quality is obtained through joint analysis. The obtained comprehensive evaluation coefficient is compared with the water quality evaluation threshold, and different water quality evaluation instructions are generated according to different comparison results.

2. The water quality monitoring method of a blue crab breeding system according to claim 1, characterized in that: The aquaculture water source to be monitored is illuminated by a light source of known wavelength, and the light intensity of the aquaculture water source to be monitored before and after the incident light beam is collected by an optical sensor. Specifically, a light source of a certain wavelength is selected to illuminate the aquaculture water source to be monitored, and the bottom light intensity is collected at the bottom of the aquaculture container by an optical sensor as the light intensity after the incident light passing through the water sample; The bottom light intensity is measured several times continuously and the data is transmitted to the data collection system for processing.

3. The water quality monitoring method of a blue crab breeding system according to claim 2, characterized in that: The dissolved oxygen concentration of the aquaculture water source to be monitored is calculated based on the light intensity before and after the incident light and the incident distance. The formula for calculating the dissolved oxygen concentration is: Where DO is the dissolved oxygen concentration, α is the absorption coefficient of dissolved oxygen to the light source, l is the incident distance, I0 is the incident light intensity before passing through the water sample, and I is the incident light intensity after passing through the water sample.

4. The water quality monitoring method of a blue crab breeding system according to claim 3, characterized in that: The calculated dissolved oxygen concentration of the aquaculture water source is corrected by the water temperature and pressure data obtained, combined with the unit heat of solution when oxygen is dissolved in water, to obtain the precise dissolved oxygen concentration of the aquaculture water source. The specific formula for calculating the precise dissolved oxygen concentration is: In the formula, DO′ is the precise dissolved oxygen concentration, ΔH is the unit heat of solution when oxygen is dissolved in water, R is the ideal gas constant, T is the water temperature of the aquaculture water source, and T ref is the reference water temperature for blue crab culture, P is the pressure at the bottom of the blue crab culture container, P ref It is the reference pressure at the bottom of the blue crab culture container.

5. The water quality monitoring method of a blue crab breeding system according to claim 4, characterized in that: The water quality chemical index is calculated by combining the obtained chemical parameter content with the corrected accurate dissolved oxygen concentration. The specific formula for calculating the water quality chemical index is: Where WI is the water quality chemical index, NH represents the ammonia nitrogen concentration in the aquaculture water source to be monitored, NO represents the nitrite concentration in the aquaculture water source to be monitored, b and f are the weight coefficients of the precise dissolved oxygen concentration and the chemical parameter content in the aquaculture water source to be monitored, respectively, where f>b and both b and f are greater than 0.

6. The water quality monitoring method of a blue crab breeding system according to claim 1, characterized in that: Based on the ecosystem health index and water quality chemical index, the comprehensive evaluation coefficient of aquaculture water quality is obtained through joint analysis. The formula for calculating the comprehensive evaluation coefficient of aquaculture water quality is as follows: In the formula, ω4 and ω5 are the weight coefficients of the ecosystem health index and the water quality chemical index, respectively, EHI is the ecosystem health index, WI is the water quality chemical index, and ZH is the comprehensive evaluation coefficient of the aquaculture water quality, where ω4<ω5 and ω4 and ω5 are both greater than 0; Based on the obtained comprehensive water quality evaluation coefficient, compared with the water quality evaluation threshold, different water quality evaluation instructions are generated according to different comparison results. The specific logic is as follows: When ZH≥1.0*yz, a warning command is issued, indicating that the water quality of the current blue crab breeding system is in a serious pollution state and should be replaced immediately; When 0.4*yz≤ZH<1.0*yz, an early warning command is issued, indicating that the water quality of the current blue crab breeding system is at risk of pollution and should be monitored and maintained; When 0≤ZH<0.4*yz, a safety instruction is issued, indicating that the water quality of the current mud crab breeding system is in a suitable state and should be used; Where yz is the preset instability coefficient.

7. A water quality monitoring system for a blue crab breeding system, characterized in that: The water quality monitoring system of the blue crab breeding system is used to implement the water quality monitoring method of the blue crab breeding system according to any one of claims 1 to 6, comprising: A data acquisition and processing module is used to emit a light beam of known wavelength to illuminate the aquaculture water source to be monitored through a light source, collect the light intensity before and after the light beam is incident through an optical sensor, and calculate the dissolved oxygen concentration of the aquaculture water source to be monitored based on the light intensity before and after the incident and the incident distance; The dissolved oxygen concentration correction module is used to collect the water temperature and pressure data of the aquaculture water source to be monitored, and to correct the calculated dissolved oxygen concentration of the aquaculture water source by combining the obtained water temperature and pressure data with the unit heat of solution when oxygen is dissolved in water, so as to obtain the accurate dissolved oxygen concentration of the aquaculture water source; A water quality chemical index analysis module is used to obtain the chemical parameter content in the aquaculture water source to be monitored, and calculate the water quality chemical index by combining the obtained chemical parameter content with the accurate dissolved oxygen concentration obtained after correction, wherein the chemical parameters in the aquaculture water source to be monitored include ammonia nitrogen and nitrite; The ecosystem health analysis module is used to characterize the turbidity of the aquaculture water source to be monitored based on the light intensity before and after the incident light, the refractive index of the suspended particles, and the average diameter of the suspended particles. At the same time, the conductivity of the aquaculture water source to be monitored is detected, and the ecosystem health index is generated by combining the water source conductivity obtained by the detection with the turbidity of the aquaculture water source obtained by the calculation. The comprehensive water quality monitoring and judgment module is used to jointly analyze the ecosystem health index and the water quality chemical index to obtain the comprehensive evaluation coefficient of the aquaculture water source water quality. Based on the obtained comprehensive water quality evaluation coefficient, it is compared with the water quality evaluation threshold, and different water quality evaluation instructions are generated according to different comparison results.

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