Water quality regulation system for prawn culture in saline-alkali soil

Abstract

The present application relates to the technical field of aquaculture water quality regulation, and discloses a prawn aquaculture water quality regulation system suitable for saline-alkali land, which comprises a saline-alkali land water source pretreatment unit, a prawn aquaculture water body unit, an online monitoring unit, a water quality regulation execution unit and a control unit; the saline-alkali land water source pretreatment unit is used for carrying out precipitation, filtration, aeration oxidation and pre-dispensing before the saline-alkali land water source enters the prawn aquaculture water body unit; the online monitoring unit is used for collecting water quality parameters such as salinity, pH, total alkalinity, hardness, dissolved oxygen, temperature, ammonia nitrogen, nitrite and oxidation-reduction potential; the control unit generates a saline-alkali suitable breeding evaluation result according to multiple water quality parameters, and controls the water quality regulation execution unit to execute water replenishment, water drainage, aeration, pH regulation, alkalinity regulation, hardness regulation, calcium and magnesium ion regulation and circulating purification in an acute risk priority and saline-alkali basic state linkage regulation mode, and water quality parameters are collected again after regulation and subsequent regulation amount is corrected.

Description

Technical Field

[0001] The present invention relates to the technical field of aquaculture water quality regulation, and more particularly, to a penaeid shrimp aquaculture water quality regulation system applicable to saline-alkali land. Background Art

[0002] Penaeid shrimp aquaculture is an important part of aquaculture. Varieties such as Litopenaeus vannamei and Penaeus monodon have characteristics such as fast growth, large market demand, and relatively high aquaculture benefits. Traditional penaeid shrimp aquaculture mostly relies on seawater or brackish water resources in coastal areas. However, with the expansion of aquaculture scale, limited coastal aquaculture space, and increasing demand for inland aquaculture, using saline-alkali land water resources for penaeid shrimp aquaculture has gradually become a feasible aquaculture mode. Saline-alkali land usually has a certain salinity and alkalinity. The groundwater, ditch water, or surface water accumulation in some areas can be used for penaeid shrimp aquaculture after appropriate调配, thereby improving the utilization rate of saline-alkali land resources and expanding the penaeid shrimp aquaculture area.

[0003] However, there are obvious differences between saline-alkali land water bodies and natural seawater or conventional fresh water adjusted saline water bodies. The water sources in saline-alkali land often show characteristics such as high pH, high total alkalinity, insufficient or fluctuating hardness, unstable proportion of divalent cations such as calcium and magnesium, and unbalanced salinity composition. Penaeid shrimp are sensitive to salinity, alkalinity, hardness, and the composition of calcium and magnesium ions during growth, molting, and osmotic pressure regulation. If the saline-alkali land water source enters the aquaculture pond without sufficient pretreatment, it is easy to cause a sudden change in the saline-alkali load of the aquaculture water body, resulting in shrimp stress, decreased feeding, abnormal molting, and even death.

[0004] The existing penaeid shrimp aquaculture water quality management methods usually mainly rely on manual detection, regular water change, oxygenation, and empirical addition of regulators. There are also some aquaculture systems that have set up online monitoring devices for pH, dissolved oxygen, temperature, or salinity to achieve single-index alarm or simple linkage control. However, the above methods are mostly for ordinary seawater aquaculture, fresh water aquaculture, or recirculating water aquaculture scenarios, usually focusing on conventional indexes such as dissolved oxygen, ammonia nitrogen, nitrite, and pH, and insufficiently considering the linkage relationship between the unique salinity, total alkalinity, hardness, and calcium and magnesium ion ratios in saline-alkali land water bodies.

[0005] In the actual process of penaeid shrimp aquaculture in saline-alkali land, it is often difficult to obtain stable effects by adjusting a single index alone. For example, when the pH is high, if a large amount of acidic regulator is added only based on the pH, it may cause a rapid fluctuation in the total alkalinity, further increasing shrimp stress; when the salinity is within the appropriate range but the hardness or the ratio of calcium and magnesium ions is insufficient, if only adjusted by water change, it may not effectively improve the ionic environment required for shrimp molting; when ammonia nitrogen or nitrite increases and there is insufficient dissolved oxygen, if the salinity or alkalinity is still preferentially adjusted without timely strengthening aeration and circulation purification, it may lead to further expansion of acute water quality risks.

[0006] Furthermore, existing water quality monitoring methods mostly rely on single-point testing or manual sampling, making it difficult to promptly detect water quality differences between the inlet, middle, and outlet of the aquaculture pond. In saline-alkali soil aquaculture environments, due to the complex composition of the water source, significant evaporation and concentration, and rapid accumulation of uneaten feed and feces at the bottom, the aquaculture water is prone to problems such as localized increases in salinity and alkalinity, insufficient dissolved oxygen, or enrichment of nitrogenous pollutants. Without multi-node monitoring and feedback correction mechanisms, it is easy to lead to delayed or excessive regulation, affecting the stability of the aquaculture water.

[0007] Therefore, the existing technology still lacks a water quality control system specifically suitable for shrimp farming in saline-alkali land. This system should be able to pre-treat the water source from the saline-alkali land before it enters the farming pond, and simultaneously consider multiple parameters such as salinity, pH, total alkalinity, hardness, calcium-magnesium ion ratio, dissolved oxygen, ammonia nitrogen, and nitrite during the farming process. It should also dynamically control and regulate water replenishment, drainage, aeration, pH adjustment, buffering, calcium-magnesium ion replenishment, and circulation purification in a way that prioritizes acute risks and links the adjustment to the basic saline-alkali conditions.

[0008] Therefore, it is necessary to provide a water quality control system suitable for shrimp farming in saline-alkali land to solve the above problems. Summary of the Invention

[0009] The purpose of this invention is to solve the technical problems mentioned in the background section and to provide a water quality control system for shrimp farming in saline-alkali land.

[0010] The above-mentioned objective of the present invention is achieved as follows: A water quality control system for shrimp farming in saline-alkali land includes a water pretreatment unit for saline-alkali land, a shrimp farming water body unit, an online monitoring unit, a water quality control execution unit, and a control unit; The saline-alkali land water pretreatment unit is used to treat the saline-alkali land water source by at least one of sedimentation, filtration, aeration oxidation and ion regulation before the saline-alkali land water source enters the shrimp farming water body unit. The online monitoring unit is used to collect multiple water quality parameters, including salinity, pH, total alkalinity, hardness, dissolved oxygen, temperature, ammonia nitrogen, nitrite and redox potential, from the saline-alkali land water pretreatment unit and / or the shrimp farming water unit. The control unit generates a salinity-alkalinity suitability evaluation result based on the multiple water quality parameters, and controls the water quality regulation execution unit to perform at least one of the following operations on the aquaculture water body: water replenishment, drainage, aeration, pH adjustment, alkalinity adjustment, hardness adjustment, calcium and magnesium ion adjustment, and circulation purification, so that the aquaculture water body is in a salinity-alkalinity state suitable for shrimp growth.

[0011] Furthermore, the saline-alkali land water pretreatment unit includes a water storage tank, a filtration component, an aeration oxidation component, and a pre-mixing component. The control unit determines whether the pretreated water meets the conditions for entering the shrimp farming water unit based on the salinity, pH, total alkalinity, and hardness before and after pretreatment.

[0012] Furthermore, the online monitoring unit includes multiple monitoring nodes respectively set at the water pretreatment unit of saline-alkali land, the inlet end of the shrimp farming water unit, the middle of the shrimp farming water unit, and the outlet end of the shrimp farming water unit. The control unit judges the spatial uniformity of the farming water body according to the differences in water quality parameters of different monitoring nodes, and controls the water quality regulation execution unit to perform circulation mixing or oxygenation and water pushing operations when the spatial uniformity is lower than the preset requirements.

[0013] Furthermore, the control unit is configured to generate a first evaluation result based on salinity, pH, total alkalinity, hardness, and calcium-magnesium ion ratio, generate a second evaluation result based on dissolved oxygen, temperature, ammonia nitrogen, nitrite, and redox potential, and combine the first evaluation result and the second evaluation result to generate the salinity-alkali eutrophication evaluation result.

[0014] Furthermore, when generating control commands, the control unit prioritizes handling at least one acute risk among insufficient dissolved oxygen, increased ammonia nitrogen risk, and excessive nitrite, and then handles at least one slow deviation among salinity, pH, total alkalinity, hardness, and calcium-magnesium ion ratio.

[0015] Furthermore, the water quality control execution unit includes a freshwater supply mechanism, a saline-alkali water supply mechanism, and a drainage mechanism. The control unit controls the start-up, shutdown, and flow rate of the freshwater supply mechanism, the saline-alkali water supply mechanism, and the drainage mechanism according to the deviation direction of salinity, total alkalinity, and hardness, so as to regulate the salinity and alkalinity load of the aquaculture water body.

[0016] Furthermore, the water quality control execution unit includes an acid-base adjustment mechanism and a buffer adjustment mechanism. The control unit determines the addition method and dosage of the acidity regulator, alkalinity regulator, or buffer based on the combined state of pH and total alkalinity, so as to avoid abnormal fluctuations in total alkalinity caused by adjusting only based on pH.

[0017] Furthermore, the water quality control execution unit includes a calcium and magnesium ion replenishment mechanism, which is used to replenish calcium and / or magnesium sources to the aquaculture water. The control unit controls the amount of calcium and / or magnesium sources replenished according to hardness, salinity, and calcium-magnesium ion ratio, so as to improve the impact of the unbalanced ion composition of saline-alkali water on shrimp molting and growth.

[0018] This invention also provides a method for water quality control in shrimp farming in saline-alkali land, comprising the following steps: Pre-treatment of saline-alkali land water sources was carried out, and water quality parameters before and after pre-treatment were collected; multiple water quality parameters, including salinity, pH, total alkalinity, hardness, dissolved oxygen, temperature, ammonia nitrogen, nitrite and redox potential, were collected in shrimp farming water. Based on the aforementioned multiple water quality parameters, a salinity-alkali eutrophication evaluation result is generated; based on the salinity-alkali eutrophication evaluation result, the water quality deviation type and control priority are determined; and at least one of the following operations is performed according to the control priority: water replenishment, drainage, aeration, pH adjustment, alkalinity adjustment, hardness adjustment, calcium and magnesium ion adjustment, and circulating purification. Water quality parameters were collected again after the regulation was implemented, and the subsequent regulation amount was adjusted based on the changes in parameters before and after the regulation.

[0019] Furthermore, when insufficient dissolved oxygen, increased ammonia nitrogen risk, or excessive nitrite are detected, enhanced aeration and circulation purification operations are prioritized; when pH, total alkalinity, hardness, or calcium-magnesium ion ratio deviates from the preset range and no acute risk is detected, acid-base adjustment, buffer adjustment, or calcium-magnesium ion supplementation operations are then performed, and the next adjustment amount is adjusted according to the salinity-alkali eutrophicity evaluation results after regulation.

[0020] Compared with the prior art, the present invention has the following beneficial effects: 1. This invention establishes a pretreatment unit for saline-alkali land water sources, combining water storage, filtration, aeration oxidation, and pre-mixing. This allows the saline-alkali land water to undergo preliminary stabilization treatment before entering the shrimp farming water system. Compared to directly introducing untreated water or relying solely on subsequent adjustments within the farming pond, this invention can reduce the impact of suspended solids, reducing substances, and sudden changes in saline-alkali load on the farming pond in advance. It avoids significant fluctuations in pH, total alkalinity, hardness, and salinity within a short period, mitigating the stress response of shrimp caused by sudden changes in water quality at the source, and improving the controllability and practicality of using saline-alkali land water sources for shrimp farming.

[0021] 2. This invention comprehensively collects parameters such as salinity, pH, total alkalinity, hardness, dissolved oxygen, temperature, ammonia nitrogen, nitrite, redox potential, and calcium-magnesium ion ratio through an online monitoring unit, and uses a control unit to link and judge the basic salinity and alkalinity status and the acute risk status of aquaculture. Compared with methods that only detect and alarm for a single water quality indicator, this invention can simultaneously identify problems such as imbalances in salinity, alkalinity, hardness, and ion composition in saline-alkali water bodies, as well as short-term risk problems such as insufficient dissolved oxygen, elevated ammonia nitrogen, and excessive nitrite. During regulation, acute risks are addressed first, followed by deviations from the basic salinity and alkalinity status, avoiding the expansion of water quality risks due to improper regulation sequence, thereby improving the accuracy and safety of shrimp farming water quality management.

[0022] 3. This invention uses a water quality control execution unit to coordinate the control of water replenishment, drainage, aeration, pH adjustment, alkalinity adjustment, hardness adjustment, calcium and magnesium ion supplementation, and circulating purification. Water quality parameters are collected again after control to provide feedback and correction of the control effect. Compared with fixed water changes, fixed additions, or manual experience-based adjustments, this invention can dynamically adjust subsequent control amounts based on water quality changes before and after control, reducing problems such as excessive additions, excessive water changes, and repeated water quality fluctuations. Simultaneously, multi-node monitoring can detect localized enrichment, stratification, or insufficient mixing within the aquaculture pond and promptly initiate circulating mixing or aeration and water-pushing operations to maintain good spatial uniformity and stability of the aquaculture water, thereby reducing the risk of abnormal molting, decreased feeding, and mortality in shrimp, and improving the survival rate and aquaculture efficiency of shrimp in saline-alkali land. Attached Figure Description

[0023] Figure 1 This is a system block diagram of the water quality control system for shrimp farming in saline-alkali land according to the present invention. Figure 2 This is a logic diagram of the water quality control system for shrimp farming in saline-alkali land according to the present invention. Detailed Implementation

[0024] The present invention will be further described below with reference to embodiments. It should be understood that the following embodiments are used to illustrate the technical solutions of the present invention and are not intended to limit the scope of protection of the present invention. Without departing from the concept of the present invention, those skilled in the art can make adaptive adjustments to the specific water quality thresholds, equipment specifications, dosage, and control cycle according to the type of saline-alkali land water source, shrimp species, farming stage, farming density, and local climate conditions.

[0025] See Figure 1 and Figure 2 As shown, this invention provides a water quality control system for shrimp farming in saline-alkali land, including a saline-alkali land water source pretreatment unit, a shrimp farming water body unit, an online monitoring unit, a water quality control execution unit, and a control unit. The saline-alkali land water source pretreatment unit is located between the saline-alkali land water source and the shrimp farming water body unit, and is used to pretreat the saline-alkali land water source before it enters the farming pond. The shrimp farming water body unit can be an earthen pond, a factory-style farming pond, a recirculating aquaculture pond, or other water containers suitable for shrimp farming. The online monitoring unit is used to collect water quality parameters from the water source and the farming water body. The water quality control execution unit is used to perform operations such as water replenishment, drainage, aeration, pH adjustment, alkalinity adjustment, hardness adjustment, calcium and magnesium ion adjustment, and circulation purification. The control unit is communicatively connected to both the online monitoring unit and the water quality control execution unit, and is used to generate control commands based on the water quality parameters.

[0026] Example 1: The pretreatment unit for saline-alkali land water sources includes a water storage tank, a filtration assembly, an aeration and oxidation assembly, and a pre-mixing assembly. Saline-alkali land water first enters the water storage tank, where sedimentation occurs to remove silt and some suspended solids. It then passes through the filtration assembly to remove particulate impurities. Next, the aeration and oxidation assembly increases dissolved oxygen and promotes the oxidation of some reducing substances in the water. The pre-mixing assembly is used to dilute the pretreated water with freshwater, replenish saline-alkali water, buffer and regulate calcium and magnesium ions, ensuring that the water entering the aquaculture pond is as close as possible to the optimal conditions for shrimp rearing.

[0027] The online monitoring unit comprises multiple monitoring nodes, which are respectively deployed at the inlet, middle, and outlet of the saline-alkali land water pretreatment unit and the shrimp farming water unit. Each monitoring node collects water quality parameters such as salinity, pH, total alkalinity, hardness, dissolved oxygen, temperature, ammonia nitrogen, nitrite, and redox potential. After receiving these parameters, the control unit first determines whether the pretreated water is suitable for entering the shrimp farming water unit, and then determines whether the farming water requires adjustment.

[0028] In one specific embodiment, the reference target range for shrimp farming water can be set as follows: salinity of 3‰ to 18‰, pH of 7.5 to 8.8, total alkalinity of 80 mg / L to 220 mg / L, hardness of 100 mg / L to 350 mg / L, dissolved oxygen of not less than 5.0 mg / L, ammonia nitrogen of not more than 0.5 mg / L, and nitrite of not more than 0.2 mg / L. The above ranges are exemplary and are not intended to limit the scope of protection of this invention. In practical applications, adjustments can be made according to the suitable culture requirements of Litopenaeus vannamei, Penaeus monodon, or other shrimp species.

[0029] The control unit uses salinity, pH, total alkalinity, hardness, and the calcium-magnesium ion ratio as basic saline-alkali state parameters, and dissolved oxygen, temperature, ammonia nitrogen, nitrite, and redox potential as aquaculture risk state parameters. The calcium-magnesium ion ratio can be determined based on the mass concentration ratio or molar concentration ratio of calcium ions to magnesium ions in the water, and is used to determine whether the divalent cation composition in the saline-alkali water is suitable for shrimp molting and growth. For example, when the salinity is within the suitable range but the hardness is too low, or the calcium-magnesium ion ratio deviates significantly from the preset range, the control unit determines that there is a risk of ion composition imbalance in the water and controls the calcium-magnesium ion replenishment mechanism to supplement calcium and / or magnesium sources.

[0030] The water quality control unit includes a freshwater supply system, a saline-alkali water supply system, a drainage system, an aeration system, a pH adjustment system, a buffer adjustment system, a calcium and magnesium ion replenishment system, and a circulating purification system. The freshwater supply system is used for dilution when salinity, total alkalinity, or hardness loads are high; the saline-alkali water supply system is used for replenishment when salinity is insufficient or when saline-alkali water needs to be added; the drainage system is used to facilitate water exchange in conjunction with the replenishment; the aeration system is used to increase dissolved oxygen and improve the redox state; the pH adjustment and buffer adjustment systems are used to adjust pH and total alkalinity; the calcium and magnesium ion replenishment system is used to replenish calcium and / or magnesium sources; and the circulating purification system includes a solid-liquid separation module, a biological filter module, and a return water path, used to reduce ammonia nitrogen and nitrite content.

[0031] During the regulation process, the control unit employs an acute risk-priority control logic. When insufficient dissolved oxygen, increased ammonia nitrogen risk, or excessive nitrite levels are detected, the control unit prioritizes activating the aeration and circulation purification mechanisms, increasing aeration intensity and circulation flow rate. It can also simultaneously reduce feeding or suspend oxygen-consuming adjustments to prevent further accumulation of nitrogenous pollutants and water hypoxia. Once the acute risks are resolved, the control unit then addresses slow deviations in salinity, pH, total alkalinity, hardness, and calcium-magnesium ion ratio.

[0032] For example, when the pH and total alkalinity of the aquaculture water are detected to be too high, the control unit does not add large amounts of acidifiers based solely on pH. Instead, it first reduces the proportion of saline-alkaline water replenishment and performs freshwater dilution and buffering adjustments according to the water carrying capacity of the pond to avoid large fluctuations in total alkalinity in a short period of time. When the hardness is detected to be below the preset lower limit while the salinity is still within the suitable range, the control unit prioritizes controlling the calcium and magnesium ion replenishment mechanism to replenish calcium and / or magnesium sources, rather than performing a large-scale water exchange. When ammonia nitrogen or nitrite is detected to be continuously rising, the control unit increases the circulation flow rate of the circulating purification mechanism and the aeration intensity of the aeration mechanism, so that the solid-liquid separation module, the biological filter module, and the return water path work together to reduce the concentration of nitrogenous pollutants.

[0033] The control unit also determines the spatial uniformity of the aquaculture water body based on the differences in water quality parameters between different monitoring nodes. When the differences in salinity, dissolved oxygen, ammonia nitrogen, or nitrite at the inlet, middle, and outlet exceed preset values, the control unit determines that there is local enrichment, stratification, or insufficient mixing in the aquaculture water body, and activates oxygenation and water-pushing equipment or circulation pumps to create circulation within the pond. This avoids the problem of failing to detect local water quality deterioration in a timely manner due to relying solely on single-point monitoring.

[0034] After the regulation is completed, the online monitoring unit collects the water quality parameters again. The control unit compares the water quality parameters before and after the regulation to determine whether the water replenishment volume, drainage volume, aeration intensity, circulation flow rate, acid-base regulator dosage, buffer dosage, and calcium and magnesium ion supplementation have achieved the expected results. If the water quality recovers to the target range after regulation, the control unit maintains the current operating state or reduces the regulation intensity; if the target range is still not reached after regulation, the control unit continues to execute corresponding regulation according to the direction of deviation. Through the above process, this embodiment forms a dynamic control process of pretreatment of saline-alkali land water source, online monitoring, graded judgment, execution of regulation, and feedback correction.

[0035] The beneficial effects of this embodiment are as follows: water source pretreatment reduces the water quality impact caused by the direct entry of raw water from saline-alkali land into the aquaculture pond; multi-node monitoring detects water quality stratification or local deterioration in the pond; acute risk priority control avoids prioritizing treatment of slow saline-alkali deviations even when dissolved oxygen is insufficient, ammonia nitrogen is elevated, or nitrite exceeds the limit; and feedback correction after regulation avoids over-adjustment of water quality caused by fixed addition or fixed water exchange, thereby improving the stability and practicality of the water body for shrimp farming in saline-alkali land.

[0036] Example 2: This example provides a water quality control system and method for shrimp farming in saline-alkali land based on the salinity index. The system structure of this example is basically the same as that of Example 1, including a saline-alkali land water pretreatment unit, a shrimp farming water body unit, an online monitoring unit, a water quality control execution unit, and a control unit. The difference is that the control unit further calculates the salinity index based on multiple water quality parameters collected by the online monitoring unit, and determines the control strategy based on the salinity index and acute risk factors.

[0037] The control unit pre-stores target values, allowable deviation scales, and weights for each water quality parameter. For any parameter among salinity, pH, total alkalinity, hardness, calcium-magnesium ion ratio, dissolved oxygen, ammonia nitrogen, nitrite, and redox potential, the control unit calculates the individual eutrophic value based on its deviation from the target value. ; in, For the first Individual nutrient values ​​for each water quality parameter For the first Measured values ​​of the water quality parameters, For the first Measured values ​​of the water quality parameters, For the first The target value or the median of the target range for each water quality parameter To allow deviations from the scale, when When it is less than 0, the control unit treats it as 0; when When the value is greater than 1, the control unit treats it as 1. For parameters such as ammonia nitrogen and nitrite, which are safer the lower the value, the control unit can use the low-risk value as the target value and calculate the individual nutrient value according to the degree of exceedance. For parameters such as dissolved oxygen, which are safer the higher the value but have a suitable lower limit, the control unit can treat the individual nutrient value as a higher value when the dissolved oxygen is higher than the preset lower limit.

[0038] The control unit further calculates the salinity-alkali suitability index: ; in, The salinity-alkali eutrophication index. For the first The weights of each water quality parameter are assigned, and the sum of the weights is 1. The weights corresponding to salinity, pH, total alkalinity, hardness, and calcium-magnesium ion ratio are used to reflect the basic trophicity of saline-alkali water bodies; the weights corresponding to dissolved oxygen, ammonia nitrogen, nitrite, and redox potential are used to reflect the short-term safety risks during aquaculture.

[0039] In one specific embodiment, the weights can be set as follows: salinity weight 0.12, pH weight 0.10, total alkalinity weight 0.12, hardness weight 0.10, calcium-magnesium ion ratio weight 0.10, dissolved oxygen weight 0.18, ammonia nitrogen weight 0.14, nitrite weight 0.10, and redox potential weight 0.04. The above weights are merely exemplary settings, and those skilled in the art can adjust them according to the aquaculture stage. For example, the weights of salinity, hardness, and calcium-magnesium ion ratio can be increased in the early stages of stocking, while the weights of dissolved oxygen, ammonia nitrogen, and nitrite can be increased in the high-feeding aquaculture stage.

[0040] The control unit classifies water quality status based on the salinity-alkali eutrophicity index; for example, when... When the aquaculture water body is determined to be in a stable state, the control unit maintains its current operating state; when If no acute risk is detected, and the aquaculture water body is determined to be in a slightly deviated state, the control unit will perform routine adjustments; when , or although If the dissolved oxygen level is not lower than 0.60 but insufficient dissolved oxygen, increased ammonia nitrogen risk, or excessive nitrite is detected, the aquaculture water body is judged to be in a risky state, and the control unit performs priority regulation.

[0041] In priority control, the control unit does not simply mechanically control according to the numerical value of the salinity index. Instead, it first identifies acute risk factors. When dissolved oxygen is below the preset lower limit, ammonia nitrogen is above the preset upper limit, or nitrite is above the preset upper limit, even if salinity, pH, total alkalinity, or hardness are still within acceptable ranges, the control unit still prioritizes to start the aeration and circulation purification mechanisms and increases the circulation purification flow rate. After the acute risk is eliminated, it then performs freshwater replenishment, saline-alkali water replenishment, acid-base adjustment, buffer adjustment, or calcium-magnesium ion replenishment operations based on the deviation of salinity, pH, total alkalinity, hardness, and calcium-magnesium ion ratio.

[0042] The control unit also adjusts subsequent control measures based on changes in the salinity-alkali nutrient availability index before and after the control. Specifically, the control unit records the salinity-alkali nutrient availability index before control. and the adjusted salinity-alkali eutrophication index And calculate the amount of improvement achieved through regulation: ; in, To regulate and improve the quantity, when When the preset improvement requirements are met, the control unit maintains or appropriately reduces the same control intensity in the next control cycle; when When the preset improvement requirements are not met, the control unit increases the corresponding actuator's adjustment amount based on the water quality parameter with the lowest or greatest deviation from the set value. For example, when the single nutrient value corresponding to dissolved oxygen is the lowest, the aeration intensity is increased or the aeration time is extended; when the single nutrient value corresponding to ammonia nitrogen or nitrite is the lowest, the circulation purification flow rate is increased and solid-liquid separation is strengthened; when both total alkalinity and pH are high, the saline-alkali water replenishment ratio is reduced and buffer adjustment is performed; when hardness or calcium-magnesium ion ratio is low, the replenishment of calcium and / or magnesium sources is increased.

[0043] To avoid stressing shrimp due to excessively large single adjustments, the control unit can be set with a maximum adjustment amount per cycle. For example, the amount of freshwater replenishment in a single cycle can not exceed a preset proportion of the total aquaculture water volume, the amount of pH regulator added in a single cycle can not exceed a preset safe dosage, and the amount of calcium and magnesium ion replenishment can be added in stages according to the rate of change in hardness. Through cyclical and multiple feedback adjustments, the aquaculture water volume can be gradually restored to the target state, rather than undergoing a one-time drastic change in water quality.

[0044] This embodiment can also adjust the control strategy according to the breeding stage. During the seedling acclimatization stage, the control unit increases the stability requirements of salinity, hardness and calcium-magnesium ion ratio to make the pretreated water source as close as possible to the seedling acclimatization water body before entering the breeding pond. During the rapid growth period, the control unit increases the monitoring frequency of dissolved oxygen, ammonia nitrogen and nitrite, and prioritizes ensuring circulation purification and aeration capacity. During the high temperature or high feeding stage, the control unit shortens the control cycle and uses ammonia nitrogen, nitrite and dissolved oxygen as priority judgment parameters.

[0045] Compared with conventional methods that only monitor and alarm for single points such as salinity, pH, or dissolved oxygen, the regulation method provided in this embodiment combines the pretreatment of saline-alkali land water sources with multi-parameter linkage regulation during shrimp farming. By jointly determining the regulation strategy through the saline-alkali eutrophication index and acute risk priority, it can reduce the risks of raw water impact in saline-alkali land, local deterioration of water quality in ponds, accumulation of nitrogenous pollutants, and over-regulation of water quality caused by fixed additions, thereby more stably maintaining the eutrophication status of shrimp farming water in saline-alkali land.

[0046] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A water quality control system suitable for shrimp farming in saline-alkali land, characterized in that, It includes a pretreatment unit for saline-alkali land water sources, a shrimp farming water body unit, an online monitoring unit, a water quality control execution unit, and a control unit; The saline-alkali land water pretreatment unit is used to treat the saline-alkali land water source by at least one of sedimentation, filtration, aeration oxidation and ion regulation before the saline-alkali land water source enters the shrimp farming water body unit. The online monitoring unit is used to collect multiple water quality parameters, including salinity, pH, total alkalinity, hardness, dissolved oxygen, temperature, ammonia nitrogen, nitrite and redox potential, from the saline-alkali land water pretreatment unit and / or the shrimp farming water unit. The control unit generates a salinity-alkalinity suitability evaluation result based on the multiple water quality parameters, and controls the water quality regulation execution unit to perform at least one of the following operations on the aquaculture water body: water replenishment, drainage, aeration, pH adjustment, alkalinity adjustment, hardness adjustment, calcium and magnesium ion adjustment, and circulation purification, so that the aquaculture water body is in a salinity-alkalinity state suitable for shrimp growth.

2. The water quality control system for shrimp farming in saline-alkali land according to claim 1, characterized in that, The saline-alkali land water pretreatment unit includes a water storage tank, a filtration assembly, an aeration oxidation assembly, and a pre-mixing assembly. The control unit determines whether the pretreated water meets the conditions for entering the shrimp farming water unit based on the salinity, pH, total alkalinity, and hardness before and after pretreatment.

3. The water quality control system for shrimp farming in saline-alkali land according to claim 1, characterized in that, The online monitoring unit includes multiple monitoring nodes respectively set at the water pretreatment unit of saline-alkali land, the water inlet of the shrimp farming water unit, the middle of the shrimp farming water unit, and the water outlet of the shrimp farming water unit. The control unit judges the spatial uniformity of the farming water body according to the differences in water quality parameters of different monitoring nodes, and controls the water quality regulation execution unit to perform circulation mixing or oxygenation and water pushing operations when the spatial uniformity is lower than the preset requirements.

4. The water quality control system for shrimp farming in saline-alkali land according to claim 1, characterized in that, The control unit is configured to generate a first evaluation result based on salinity, pH, total alkalinity, hardness, and calcium-magnesium ion ratio; generate a second evaluation result based on dissolved oxygen, temperature, ammonia nitrogen, nitrite, and redox potential; and combine the first and second evaluation results to generate the salinity-alkali eutrophication evaluation result.

5. The water quality control system for shrimp farming in saline-alkali land according to claim 4, characterized in that, When generating control commands, the control unit prioritizes handling at least one acute risk among insufficient dissolved oxygen, increased ammonia nitrogen risk, and excessive nitrite, and then handles at least one slow deviation among salinity, pH, total alkalinity, hardness, and calcium-magnesium ion ratio.

6. The water quality control system for shrimp farming in saline-alkali land according to claim 1, characterized in that, The water quality control execution unit includes a freshwater supply mechanism, a saline-alkali water supply mechanism, and a drainage mechanism. The control unit controls the start-up, shutdown, and flow rate of the freshwater supply mechanism, the saline-alkali water supply mechanism, and the drainage mechanism according to the deviation direction of salinity, total alkalinity, and hardness, so as to regulate the salinity and alkalinity load of the aquaculture water body.

7. The water quality control system for shrimp farming in saline-alkali land according to claim 1, characterized in that, The water quality control execution unit includes an acid-base adjustment mechanism and a buffer adjustment mechanism. The control unit determines the addition method and dosage of acidity regulator, alkalinity regulator or buffer based on the combined state of pH and total alkalinity, so as to avoid abnormal fluctuations in total alkalinity caused by adjusting only based on pH.

8. The water quality control system for shrimp farming in saline-alkali land according to claim 1, characterized in that, The water quality control execution unit includes a calcium and magnesium ion replenishment mechanism, which is used to replenish calcium and / or magnesium sources to the aquaculture water. The control unit controls the amount of calcium and / or magnesium sources replenished according to hardness, salinity, and calcium-magnesium ion ratio to improve the impact of unbalanced ion composition in saline-alkali water on shrimp molting and growth.

9. A method for water quality control in shrimp farming in saline-alkali land, characterized in that, The system implementation according to any one of claims 1-8 includes the following steps: Pre-treatment of saline-alkali land water sources was carried out, and water quality parameters before and after pre-treatment were collected; multiple water quality parameters, including salinity, pH, total alkalinity, hardness, dissolved oxygen, temperature, ammonia nitrogen, nitrite and redox potential, were collected in shrimp farming water. Based on the aforementioned multiple water quality parameters, a salinity-alkalinity eutrophication evaluation result is generated; Based on the salinity-alkali eutrophication evaluation results, determine the water quality deviation type and control priority; Perform at least one of the following operations according to the control priority: water replenishment, drainage, aeration, pH adjustment, alkalinity adjustment, hardness adjustment, calcium and magnesium ion adjustment, and circulation purification. Water quality parameters were collected again after the regulation was implemented, and the subsequent regulation amount was adjusted based on the changes in parameters before and after the regulation.

10. The method for water quality control in shrimp farming in saline-alkali land according to claim 9, characterized in that, When insufficient dissolved oxygen, increased ammonia nitrogen risk, or excessive nitrite are detected, enhanced aeration and circulation purification operations are prioritized. When pH, total alkalinity, hardness, or calcium-magnesium ion ratio deviates from the preset range and no acute risk is detected, acid-base adjustment, buffer adjustment, or calcium-magnesium ion supplementation operations are then performed, and the next adjustment amount is adjusted according to the salinity-alkali eutrophicity evaluation results after adjustment.

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