Apparatus and method for simulating the process of algal growth-decay affecting water quality

Abstract

The present application belongs to the technical field of water treatment, and particularly relates to a device and method for simulating the process of the influence of algal growth and death on water quality. The device comprises: an algal growth and death simulation system for providing an algal growth and death simulation environment with controllable environmental variables; a monitoring system for recording relevant water quality parameters and algal parameters; and a data transmission and storage system for providing data transmission and storage for monitoring of the device. The device is suitable for various research needs, and can simulate water body environments in different environmental factors or eutrophication stages by adjusting parameters such as light, temperature, algal species and disturbance, and is suitable for various scenarios.

Description

Technical Field

[0001] This invention relates to the field of water treatment technology, specifically to a device and method for simulating the impact of algae growth and decay on water quality. Background Technology

[0002] The description of the background art in this invention pertains to related technologies and is used merely for illustration and to facilitate understanding of the invention. It should not be construed as the applicant explicitly believing or presuming that the invention was prior art on the filing date of the first application.

[0003] Eutrophication and harmful algal blooms are major environmental problems facing lakes. During algal blooms, large numbers of algae dominate, and the original aquatic plants gradually lose out in the competition, transforming the lake from a grass-dominated lake into an algal-dominated lake. The original ecological functions of the lake, such as ecological regulation and water purification, are significantly lost, and the ecosystem balance is further disrupted. Furthermore, after the algae complete their life cycle, they decompose, releasing large amounts of organic matter, exacerbating the accumulation of organic pollutants in the lake sediment. This also leads to the cyclical release of nutrients such as nitrogen and phosphorus from the sediment, further promoting a vicious cycle of eutrophication. The key to reversing eutrophication lies in reducing the input of exogenous nutrients while strengthening the treatment of endogenous pollution sources within the lake.

[0004] In recent years, some lakes, despite relatively good external water quality, still face persistently high levels of water quality indicators such as permanganate index, total phosphorus, and total nitrogen, indicating that eutrophication has not been effectively alleviated. Against this backdrop, the release, migration, and transformation processes of endogenous pollutants have gradually gained attention, especially the contribution of algal-derived pollutants (organic matter, phosphorus, and nitrogen), which has been reported in relevant studies. However, this research still faces some unresolved methodological issues, primarily related to experimental setup and methods, as detailed below:

[0005] 1. In-situ experiments are challenging. Natural water bodies are open and complex systems. The complexity and variability of external anthropogenic factors (active sewage discharge, disturbance from waterway transportation, etc.) and natural factors (resuspending pollutants in sediment due to wind and wave disturbance, and dilution by rainfall) make it difficult for researchers to identify and quantify the contribution of various influencing factors. Consequently, the impact process and mechanism of algal growth-death on water quality are difficult to accurately analyze under natural conditions. In addition, in-situ experiments are extremely costly in terms of manpower and resources, and researchers face the risk of drowning, making it difficult to ensure their personal safety.

[0006] 2. Other devices have drawbacks. Some studies have used a single open plexiglass tank to simulate the natural decomposition process of cyanobacteria (Guo et al., 2024). This method has problems such as large footprint and repeated sampling causing changes in control variables. Other studies have used different control columns for cultivation experiments (Li Changjie, 2023). This method avoids to some extent the problems of repeated sampling caused by a single tank, such as changes in control variables (water volume, incomplete mixing, etc.). However, its simple structure makes it impossible to control key environmental variables during the experiment, or to monitor key indicators and parameters in real time. It cannot be used by researchers to conduct mechanistic studies of algal growth-death processes, nor can it meet the requirements for kinetic simulation and prediction of the impact of algal growth-death processes on water quality. Summary of the Invention

[0007] The purpose of this invention is to provide a device and method for simulating the impact of algal growth and decay on water quality, for quantitatively studying the effects of algal growth and decay on nutrients and organic matter in water bodies.

[0008] A device for simulating the impact of algal growth and decay on water quality includes:

[0009] An algal growth-death simulation system is used to provide a simulated environment with controllable environmental variables for algal growth and death.

[0010] Monitoring and control systems are used to record relevant water quality parameters and algae parameters;

[0011] The data transmission and storage system provides data transmission and storage for device monitoring.

[0012] Furthermore, the algal growth-death simulation system includes:

[0013] (1) Water tank unit: It consists of a heater, a semiconductor cooler, and a water circulation device. The heater, semiconductor cooler, and water circulation device are respectively integrated on the opposite walls of the two sides of the water tank.

[0014] (2) Columnar experimental unit: made of transparent acrylic material, each unit is evenly arranged in the water tank, maintaining equal intervals and consistent axial direction, and sampling ports are set at different heights on its side;

[0015] (3) Light control unit: It consists of a light shield with a pure black light-absorbing felt attached, a full-spectrum LED light source and an automatic control switching power supply. The light shield with the pure black light-absorbing felt attached covers the upper and side walls of the water tank light-avoidance experimental group. The full-spectrum LED light source is fixed 20cm directly above the top of the water tank light-avoidance experimental group through an adjustable bracket.

[0016] (4) Electromagnetic wave generation unit: It consists of a rotating impeller blade and an external electromagnetic field. The rotating impeller blade is rigidly connected to the center of the bottom of the columnar experimental unit through a stainless steel shaft. Its axis coincides with the geometric center of the water tank. The external electromagnetic field is symmetrically distributed on the outer side of the front and rear end faces of the water tank.

[0017] (5) Aeration unit: It consists of a stainless steel bubble refiner with a pore size of 0.5μm, a stainless steel air guide pipe, a fixed bracket and a flow regulating valve. The stainless steel bubble refiner is vertically installed at the bottom of the inner wall of the columnar experimental unit, with its micropore diffusion surface facing upward and parallel to the bottom surface. The stainless steel air guide pipe extends along the inner side of the column wall to the air inlet of the refiner.

[0018] Furthermore, the monitoring and surveillance system includes:

[0019] (1) Water quality monitoring module, whose integrated probe is located in the upper middle part of the side wall of the columnar experimental unit, and the height of the sensitive end from the top of the column is 1 / 3 of the total water depth;

[0020] (2) Biochemical reaction respiratory metabolism measurement module: It consists of a multi-channel fluorescence fiber oxygen measurement host and sensor, static respiration chamber, analysis software and water environment control module, which runs vertically through the middle of the columnar experimental unit;

[0021] (3) Algae density online monitoring module: It consists of an online algae density sensor and is deployed on the same side wall of the columnar experimental unit in a co-located integrated manner with the water quality automatic monitoring module;

[0022] (4) Hyperspectral image recording module: It consists of an extension rod and a hyperspectral lens. The extension rod is fixed at the center of the bottom of the water tank. The rod extends vertically upward to 10cm above the water surface. The end is equipped with a hyperspectral lens. Its optical axis coincides with the normal of the water surface. The field of view covers the entire area of ​​the columnar experimental unit.

[0023] Furthermore, the water bath is made of plexiglass and is equipped with a heater and a semiconductor cooler with precise temperature control, as well as a water circulation device, to simulate different water temperature conditions in the natural environment, or to control the water temperature within the target temperature range for the research to be conducted.

[0024] Multiple columnar experimental units, each with a diameter of 10cm, a height of 50cm, and a volume of 2.8L;

[0025] The illumination control unit includes a light shield covered with a pure black light-absorbing felt and a full-spectrum LED light source with an illumination intensity of 60-200 µmol·m⁻². -2 ·s -1 And automatic control switching power supply;

[0026] The aeration unit includes a stainless steel bubble refiner with a pore size of 0.5μm, a stainless steel air guide pipe, a fixed bracket, and a flow regulating valve.

[0027] The electromagnetic wave generator unit includes rotating impeller blades and an external electromagnetic field. This unit simulates wind and wave disturbance conditions in a real lake by adjusting different wave heights, frequencies, and morphological parameters.

[0028] Furthermore, the automated water quality monitoring module integrates sensors for dissolved oxygen, pH, oxidation-reduction potential, and total dissolved solids to enable real-time online monitoring and recording of water quality indicators.

[0029] The biochemical reaction respiratory metabolism measurement module consists of a multi-channel fluorescence fiber optic oxygen measurement host and sensor, a static breathing chamber, analysis software and a water environment control module.

[0030] The online algae density monitoring module utilizes an online algae density sensor and employs the fluorescence method. Based on the fluorescence characteristics of specific pigments in cyanobacteria in the water, it calculates the content of cyanobacteria by measuring the fluorescence intensity released when excited by a high-energy LED.

[0031] The hyperspectral imaging recording module dynamically captures the quantitative changes in water color parameters during algal growth and decomposition using high-resolution spectral data. It combines multi-depth in-situ sampling data to establish machine learning models of algal densities at different water depths, and simultaneously analyzes the spatial heterogeneity of algal biomass decay rate and dissolved organic matter release patterns during decomposition.

[0032] Furthermore, the data transmission and storage system includes:

[0033] Terminal: Used for data acquisition, data transmission, and execution control; the terminal connects to various high-precision sensors and data acquisition modules; the terminal uses the TCP / IP protocol for efficient and stable communication; after receiving control information sent from the cloud, the terminal will immediately forward these instructions to the corresponding devices, thereby achieving precise control of the device's operating status.

[0034] Cloud: Used to receive, store, and process data uploaded by terminal devices;

[0035] User-side: Provides a human-computer interaction interface for users, enabling them to easily monitor and control the device.

[0036] Furthermore, the terminal employs a programmable microcontroller and connects to various high-precision sensors and data acquisition modules; the specific data acquired includes:

[0037] Water temperature data: Precisely measures the water temperature inside the device;

[0038] Water level data: Real-time monitoring of water level height within the device;

[0039] Water quality monitoring module data: Monitors various indicators of water quality;

[0040] Biochemical reaction measurement module data: In-depth analysis of biochemical reaction processes within the device;

[0041] Algae density detection module data: accurately detects the density of algae in the water;

[0042] Hyperspectral imaging data: Detailed image information of the device's interior is obtained through hyperspectral imaging technology;

[0043] The terminal uses the TCP / IP protocol to periodically package various types of data collected and send them to the cloud server via network cable; the terminal will listen for control information sent from the cloud in real time and will respond quickly once it receives an instruction.

[0044] After receiving control information from the cloud, the terminal forwards these instructions to the corresponding devices, thereby achieving precise control over the device's operating status; the specific controlled devices include:

[0045] Water temperature control equipment: Adjusts the water temperature according to cloud commands to keep the water temperature in the device within the set range;

[0046] Water circulation device: controls the speed and direction of water circulation;

[0047] Lighting equipment: Provides illumination according to the set illumination duration and intensity;

[0048] Bubble control equipment: Adjusts the amount and frequency of bubble generation.

[0049] Furthermore, the following services run in the cloud:

[0050] Database service: Responsible for storing various types of data uploaded by terminals, including real-time data and historical data;

[0051] Streaming media file management service: manages streaming media files such as hyperspectral image data uploaded by terminals;

[0052] Data processing and analysis services: In-depth mining and analysis of data uploaded from terminals; through data analysis, potential problems and patterns in the operation of the device can be discovered, providing users with a scientific basis for decision-making;

[0053] Device management services: Remote management and monitoring of terminal devices, including device status query, parameter setting, and software upgrade functions.

[0054] Furthermore, the user-facing interface provides a human-computer interaction interface, enabling users to monitor and control the system. Specific functions are as follows:

[0055] Data viewing: Users can view the data collected by the terminal in real time on the interface, including water temperature, water level, and water quality information; at the same time, they can also view statistical charts and analysis reports of historical data to better understand the operating status of the device;

[0056] Parameter settings: Users can set various operating parameters of the device on the interface according to actual needs. After the settings are completed, the user terminal will send these parameters to the cloud, and the cloud will forward the control information to the terminal device for execution.

[0057] Alarm reception: When an abnormal situation occurs during the operation of the device, the user terminal will receive alarm information in a timely manner.

[0058] A method for simulating the impact of algal growth and decay on water quality, using the aforementioned apparatus, is characterized by comprising the following steps:

[0059] Fresh algal solution was collected from a depth of about 1.5m below the water surface and placed in a polyethylene tank. Large algal particles were filtered out, and the remaining fresh algal solution was used as the experimental reserve solution.

[0060] 80 ml of fresh algal solution was added to each of the 28 experimental columns, and the solution was diluted with 2.8 L of purified water to form experimental water samples. The columns were divided into two groups: a light-illuminated group and a light-protected group.

[0061] The illuminance of the full-spectrum LED lamp was set to 200 µmol·m⁻¹. -2 ·s -1 The light cycle is set to 12L / 12D, and the light-shielding group is wrapped with a light-shielding film and a light-shielding cover.

[0062] Adjust the temperature of the heating rod and turn on the water circulation device to maintain the temperature in the water column at 30±1℃;

[0063] Samples were collected on days 0, 1, 3, 5, 8, 11, 14, 18, 23, 29, 36, 43, 50, 60, and 70. Before each sampling, the DO, pH, ORP, and TDS of the experimental column were measured using a YSI portable water quality analyzer. After sampling, TP, DTP, PO43--P, TN, DTN, NH3-N (ammonia nitrogen), NO3-N, NO2-N, IMn, DOC, and three-dimensional fluorescence and UV-Vis spectra were measured.

[0064] The embodiments of the present invention have the following beneficial effects:

[0065] Convenient to operate: This experimental device allows algal samples to be retrieved from the field and then used for laboratory simulations. This avoids interference from uncontrollable factors such as sudden weather changes and hydrological fluctuations during field operations. Furthermore, it enables control experiments with different nutrient gradients and light intensity combinations through parameter presets, significantly improving the repeatability and comparability of experimental data. Especially in the monitoring of sudden algal blooms and the evaluation of ecological restoration effects, this device effectively solves the bottleneck problems of traditional field experiments, such as difficulties in equipment transportation, numerous blind spots in real-time monitoring, and high labor costs. It provides efficient and reliable technical support for algal ecology research and greatly improves convenience.

[0066] Innovative Device Design: This invention achieves standardized packaging of algal samples through modular design and automated control technology. Relying on modules such as a precision temperature control system, light regulation, and disturbance regulation, it accurately reproduces the physicochemical parameters of the target water area in a laboratory environment, maintaining consistency in experimental conditions. Simultaneously, utilizing automated water quality monitoring modules, biochemical reaction and respiration metabolism measurement modules, online algal density monitoring modules, and hyperspectral image recording modules, it synchronously acquires key indicators such as water temperature, pH, dissolved oxygen, and nitrogen and phosphorus concentrations in real time, ensuring the continuity and integrity of environmental factor data. This allows for quantitative analysis of the intensity of algal respiration and organic matter metabolic pathways, accurately reflecting the physiological state of the algal community.

[0067] Sample quantification control: Algal solution was collected at a depth of 1.5 m using an acrylic sampler to avoid interference from surface impurities. Large algal particles were removed by filtration through a plankton net with a pore size ≤50 μm, and the homogeneous algal solution was retained as a reserve solution. The sample quantity was quantified by weighing after centrifugation to eliminate the influence of sample heterogeneity on the experimental results.

[0068] Wide range of applications and ecological governance value: This device is adaptable to a variety of research needs. By adjusting parameters such as light, temperature, algae species, and disturbance, it can simulate the water environment of different environmental factors or eutrophication stages, and is suitable for various scenarios such as lakes, reservoirs, and estuaries. Attached Figure Description

[0069] Figure 1 This is a schematic diagram—top view—of a device for simulating the impact of algae growth and decay on water quality according to the present invention.

[0070] Figure 2 This is a schematic diagram—a perspective view—of a device for simulating the impact of algae growth and decay on water quality according to the present invention.

[0071] Figure 3 for Figure 2 A sectional view;

[0072] Figure 4 This describes the changes in water quality indicators during the experiment;

[0073] Figure 5 Changes in water color during the experiment;

[0074] Figure 6 This is a picture of the actual device;

[0075] Figure 7 This is a diagram of a simulation experiment. Detailed Implementation

[0076] The present application will be further described below with reference to the embodiments.

[0077] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, in the following description, different "an embodiment" or "an embodiment" do not necessarily refer to the same embodiment. Different embodiments can be substituted or combined, and for those skilled in the art, other implementation methods can be obtained based on these embodiments without creative effort.

[0078] Combination Figures 1-3 6 and 7, a device for simulating the impact of algal growth-death on water quality, comprising:

[0079] An algal growth-death simulation system is used to provide a simulated environment with controllable environmental variables for algal growth and death.

[0080] Monitoring and control systems are used to record relevant water quality parameters and algae parameters;

[0081] The data transmission and storage system provides data transmission and storage for device monitoring.

[0082] The device comprises an algae growth-death simulation system, a monitoring system, and a data transmission and storage system. Specifically: 1) The algae growth-death simulation system includes: a columnar experimental unit 5, a precise temperature control unit 6, a light regulation unit, an electromagnetic wave generator unit 8, and an aeration unit (pure oxygen, pure carbon dioxide, or a mixture of these gases), providing a controllable simulated environment for algae growth and death; 2) The monitoring system includes: a water quality physicochemical index and algae density measurement module 10, a biochemical reaction respiration and metabolism measurement module 12, and a hyperspectral image recording module 9, which can be used in combination as needed to record relevant water quality parameters, algae parameters, etc.; 3) The data transmission and storage system consists of a terminal, a cloud platform, and a user terminal. The terminal has core functions such as data acquisition, data transmission, and execution control. The cloud platform connects to various high-precision sensors and data acquisition modules, possessing data processing and management functions, and is responsible for receiving, storing, and processing data uploaded by the terminal devices. The user terminal provides an intuitive and convenient human-computer interaction interface, enabling users to easily monitor and control the device.

[0083] During and after the experiment, the data obtained, combined with statistical analysis, reveals the absorption and release patterns of nutrients such as nitrogen and phosphorus, as well as organic matter, during algal growth and decay. The device of this invention is compact, highly scalable, and can accurately and quantitatively control various natural environmental variables affecting this process, revealing the impact of algal growth-decay on water quality. It is suitable for studying the contribution of algal pollutants to eutrophic lakes, providing a scientific basis for the remediation of eutrophic lakes.

[0084] In some embodiments of the present invention, the algal growth-death simulation system includes:

[0085] (1) Water tank unit: consisting of a heater, a semiconductor cooler, and a water circulation device;

[0086] (2) Columnar experimental unit 5: It is made of transparent acrylic material, and sampling ports are set at different heights on its side;

[0087] (3) Illumination control unit: It consists of a light shield 1 with a pure black light-absorbing felt attached, a full-spectrum LED light source 2 and an automatic control switching power supply;

[0088] (4) Electromagnetic wave generator 8: It consists of a rotating impeller blade and an external electromagnetic field;

[0089] (5) Aeration unit 11: It consists of a stainless steel bubble refiner with a pore size of 0.5μm, a stainless steel air guide pipe, a fixed bracket and a flow regulating valve.

[0090] In some embodiments of the present invention, the monitoring system includes:

[0091] (1) Water quality monitoring module;

[0092] (2) Biochemical reaction respiratory metabolism measurement module 12: It consists of a multi-channel fluorescence fiber optic oxygen measurement host and sensor, static breathing chamber, analysis software and water environment control module;

[0093] (3) Online algae density monitoring module: composed of an online algae density sensor;

[0094] (4) Hyperspectral image recording module 9: It consists of an extension rod and a hyperspectral lens.

[0095] The water bath is made of plexiglass and is equipped with a heater and a semiconductor cooler with precise temperature control, as well as a water circulation device. It automatically turns on the heating or cooling according to the experimental conditions to precisely control the water bath temperature and ensure that the temperature inside the water bath is consistent and there is no temperature gradient. It is used to simulate different water temperature conditions in the natural environment or to control the water temperature within the target temperature range of the research to be carried out.

[0096] Multiple columnar experimental units 5 (10cm in diameter and 50cm in height), with a volume of 2.8L, allow for adjustment of the amount of algal solution added at one time to simulate different algal densities. They can also be set up under the same algal density and environmental conditions to obtain samples at different experimental endpoints, avoiding changes in experimental conditions caused by water sampling in a single experimental device. The design of the columnar experimental unit 5 takes into account factors such as the amount of water required for sample analysis (the amount of water sample required for the analysis of indicators such as total phosphorus, permanganate index, total nitrogen, ammonia nitrogen, nitrate nitrogen, nitrite nitrogen, total organic carbon, and three-dimensional fluorescence spectroscopy according to standard experimental methods), the amount of algal solution required under different algal density conditions, and the laboratory floor space.

[0097] The illumination control unit includes a light shield 1 with a pure black light-absorbing felt attached, and a full-spectrum LED light source 2 (illuminance of 60-200 µmol·m). -2 ·s -1 The unit also includes an automatic control switching power supply. This unit can automatically close or open according to experimental needs to simulate different lighting conditions such as light cycles and intensities, while ensuring air circulation between the simulation device and the outside environment.

[0098] The aeration unit (pure oxygen, pure carbon dioxide, or a mixture of these gases) includes a stainless steel bubble refiner with a 0.5μm pore size, a stainless steel air delivery pipe, a mounting bracket, and a flow regulating valve. This unit can be used in conjunction with a gas cylinder to supply oxygen, carbon dioxide, and nitrogen to the columnar experimental unit 5. The bubble refiner pore size was optimized through testing to minimize the impact of aeration evaporation on experimental conditions, while avoiding the problems of inaccurate control of dissolved oxygen and dissolved carbon dioxide levels in general aeration devices, which are prone to clogging due to microbial adhesion.

[0099] The electromagnetic wave generator unit 8 includes a rotating impeller blade and an external electromagnetic field. This unit simulates the wind and wave disturbance conditions in a real lake by adjusting parameters such as wave height, frequency, and shape.

[0100] Monitoring and surveillance module

[0101] The automated water quality monitoring module integrates sensors for dissolved oxygen (DO), pH, oxidation-reduction potential (ORP), and total dissolved solids (TDS) to achieve real-time online monitoring and recording of the above water quality indicators.

[0102] The biochemical reaction respiratory metabolism measurement module 12 consists of a multi-channel fluorescence fiber optic oxygen measurement host and sensor, a static respiration chamber, analysis software, and a water environment control module. Depending on the requirements, single-channel, four-channel, eight-channel, and more-channel measurement systems are available, capable of detecting and measuring the release amount and rate of O2, CO2, and N2 in water bodies.

[0103] The online algae density monitoring module utilizes an online algae density sensor and employs the fluorescence method. Based on the fluorescence characteristics of specific pigments in cyanobacteria in the water, it calculates the content of cyanobacteria by measuring the fluorescence intensity released through high-energy LED excitation. This method is highly efficient and fast, enabling real-time online monitoring and providing an early warning for algae reproduction.

[0104] The hyperspectral imaging recording module 9 dynamically captures the quantitative changes in water color parameters during algal growth and decomposition using high-resolution spectral data. Combined with in-situ sampling data from multiple depths, it establishes machine learning models for algal densities at different depths, simultaneously analyzing the spatial heterogeneity of algal biomass decay rates and dissolved organic matter release patterns during decomposition. The experimental system is designed to be compatible with interchangeable lens modules, providing flexible adaptability to optical monitoring modules under different experimental conditions.

[0105] Data transmission and storage module

[0106] To achieve intelligent management and monitoring of the devices, we have built a complete system consisting of terminals, cloud, and user terminals. The details of these three parts will be explained below.

[0107] (1) Terminal:

[0108] ① The terminal uses a programmable microcontroller, which is securely mounted on the main body of the device and connected to a stable power supply and network cable to ensure stable operation of the equipment. This terminal has core functions such as data acquisition, data transmission, and execution control.

[0109] ② The terminal connects to various high-precision sensors and data acquisition modules, enabling it to collect a wide range of key data during device operation in real time. The specific data collected includes, but is not limited to:

[0110] Water temperature data: The precise measurement of water temperature inside the device provides an accurate basis for subsequent water temperature adjustment.

[0111] Water level data: Real-time monitoring of the water level inside the device to ensure that the device operates under suitable water level conditions.

[0112] Water quality monitoring module data: Monitors various water quality indicators, such as pH and dissolved oxygen, to understand the water quality status in a timely manner.

[0113] Biochemical reaction measurement module data: Provides in-depth analysis of biochemical reaction processes within the device, offering data support for related research and control.

[0114] Algae density detection module data: Accurate detection of algae density in water is of great significance for water quality assessment and ecological balance monitoring.

[0115] Hyperspectral imaging data: Detailed image information of the device's interior is obtained through hyperspectral imaging technology, providing an intuitive basis for further analysis and decision-making.

[0116] Data transmission: The terminal uses the TCP / IP protocol for efficient and stable communication. On one hand, it periodically packages the various types of data it collects and sends them to the cloud server via network cable to ensure timely and accurate data transmission; on the other hand, the terminal listens for control information sent from the cloud in real time and responds quickly once it receives an instruction.

[0117] Execution control: After receiving control information from the cloud, the terminal immediately forwards these instructions to the corresponding devices, thereby achieving precise control over the device's operating status. The specific controlled devices include:

[0118] Water temperature control equipment: Adjusts the water temperature according to cloud instructions to keep the water temperature in the device within the set range.

[0119] Water circulation device: controls the speed and direction of water circulation to ensure uniform and stable water quality within the device.

[0120] Lighting equipment: Provides illumination according to the set duration and intensity to meet the needs of biological or chemical reactions within the device.

[0121] Bubble control equipment: regulates the amount and frequency of bubble generation to provide the necessary gaseous environment for biological or chemical reactions within the device.

[0122] cloud

[0123] As the data processing and management center of the entire system, the cloud server undertakes the crucial task of receiving, storing, and processing data uploaded by terminal devices. Several key services run on the server, as follows:

[0124] Database service: Responsible for storing various types of data uploaded by terminals, including real-time and historical data. It employs an efficient database management system to ensure secure and stable data storage and provides fast data query and retrieval functions.

[0125] Streaming media file management service: Manages streaming media files such as hyperspectral image data uploaded by the terminal, including file storage, indexing and playback functions.

[0126] Data processing and analysis services: Utilizing advanced data analysis algorithms and models, we conduct in-depth mining and analysis of data uploaded from terminals. Through data analysis, we can discover potential problems and patterns in the device's operation, providing users with a scientific basis for decision-making.

[0127] Device management service: Enables remote management and monitoring of terminal devices, including functions such as device status inquiry, parameter setting, and software upgrades. Through this service, users can conveniently perform centralized management and maintenance of terminal devices.

[0128] User terminal

[0129] It provides users with an intuitive and convenient human-computer interaction interface, enabling users to easily monitor and control the device. Specific functions are as follows:

[0130] Data Viewing: Users can view various data collected by the terminal in real time on the interface, including water temperature, water level, water quality, and other information. They can also view historical data charts and analysis reports to better understand the device's operating status.

[0131] Parameter settings: Users can configure various operating parameters of the device on the interface according to their actual needs, such as water temperature, water level, water circulation speed, illumination duration, and the working mode of the bubble generator. After the settings are completed, the user terminal will send these parameters to the cloud, and the cloud will forward the control information to the terminal device for execution.

[0132] Alarm Reception: When abnormal conditions occur during device operation, such as excessively high water temperature or excessively low water level, the user terminal will receive alarm information in a timely manner. Alarm information can be sent to the user via sound, pop-up windows, etc., so that the user can take timely measures to handle the situation.

[0133] Through the collaborative work of the above terminals, cloud, and user terminals, the system can achieve intelligent management and monitoring of the device, improve the device's operating efficiency and stability, and provide users with more convenient and efficient services.

[0134] Example 1

[0135] The impact of algae growth and decay processes on water quality in a certain lake

[0136] A certain lake is the second largest freshwater lake in the Taihu Lake Group. With rapid economic development, the pollution load in the lake's basin is constantly increasing. Simultaneously, water pollution and eutrophication problems in the lake are becoming increasingly severe, and the entire ecosystem has deviated from a healthy state, seriously affecting the healthy and sustainable development of the local economy and society. Algal blooms occur very frequently in this lake, almost every year, and their algal density shows obvious seasonal differences: in winter, algal density is generally low in all lake areas, with *Cryptophyta* (a type of cryptophyte) being the dominant algae; in spring, algal density begins to rise rapidly, with *Scleroderma* (a type of cyanobacterium) being the dominant algae; and from May to September each year is the peak period for algal blooms in the lake, with *Microcystis* (a type of cyanobacterium) being the dominant algae, which is also highly susceptible to algal blooms. This case study uses a summer cyanobacterial bloom (*Microcystis*) in this lake as an example, employing the method described in the patent to conduct an investigation and research, exploring the impact of nutrient and organic matter release during cyanobacterial decay on water quality, achieving good results.

[0137] Operating steps:

[0138] 1. Fresh algal solution was collected from the water surface using an acrylic sampler and placed in a polyethylene container, then quickly transported back to the laboratory. In the laboratory, large algal particles were filtered out using a planktonic net, and the remaining fresh algal solution was used as a reserve solution for the experiment. Microscopic identification showed that the genus Microcystis of the cyanobacteria phylum was the absolute dominant species (over 99.0%), while other algal species such as Alternaria pumilum were also present.

[0139] 2. Add 80 ml of fresh algal solution to each of the 28 experimental columns, dilute with 2.8 L of purified water to form experimental water samples, and divide them into two groups: light group 4 and dark group 3.

[0140] 3. Set the illuminance of the full-spectrum LED lamp 3 to 200 µmol·m⁻¹. -2 ·s -1 The illumination cycle is set to 12L / 12D, and light-shielding group 3 uses light-shielding film and light-shielding cover 1 to block light.

[0141] 4. Adjust the temperature of the heating rod and turn on the water circulation device to maintain the temperature in the water column at 30±1℃;

[0142] 5. Sample testing was conducted on days 0, 1, 3, 5, 8, 11, 14, 18, 23, 29, 36, 43, 50, 60, and 70. First, the online monitoring module integrated into the device was used to measure the DO (dissolved oxygen), pH, ORP (oxidation-reduction potential), and TDS (total dissolved solids) of the experimental column. Then, water samples were taken from the experimental column to measure TP (total phosphorus), DTP (dissolved total phosphorus), and PO4. 3- -P (orthophosphate), TN (total nitrogen), DTN (dissolved total nitrogen), NH3-N (ammonia nitrogen), NO3-N (nitrate nitrogen), NO2-N (nitrite nitrogen), I Mn(Permanganate index), DOC (dissolved organic carbon), and three-dimensional fluorescence spectroscopy, UV-Vis spectroscopy, etc. This case study only presents the experimental results for phosphorus and organic matter; other results will not be elaborated upon. Phosphorus includes: TP (total phosphorus), DTP (dissolved total phosphorus), and PO4. 3- -P (orthophosphate); organic matter includes: DOC (dissolved organic matter) and I. Mn (Permanganate index).

[0143] The experimental results showed that there were significant differences in the changes of various water quality indicators between the light-illuminated group 4 and the light-shielded group 3 (experimental results are shown in the figure). Figure 4 and 5 (As shown).

[0144] Light, to a certain extent, maintained the growth activity of algae, which controlled the phosphorus speciation balance in the water column. Throughout the experiment, particulate phosphorus dominated the water column, maintaining a consistently high concentration (approximately 0.6 mg / L), while phosphate and dissolved phosphorus remained at relatively low concentrations (approximately 0.01 mg / L and 0.03 mg / L, respectively). This pattern reveals that phosphorus in the simulated experimental system is mainly stored within algal particles (algal cells). The dissolved phosphorus released by the dying algae is absorbed by newly formed algae, thus mimicking the increase in DTP. Dissolved organic matter underwent a process of increase-decrease-increase-decrease-remain essentially unchanged. That is, the dying algae released organic matter into the water, causing an increase in DOC. Under the action of degrading bacteria, this organic matter was continuously mineralized and converted into inorganic carbon such as carbon dioxide, causing a decrease in DOC. During the algal recovery and growth stage, the algae assimilated carbon dioxide to form algal organic matter, causing a renewed increase in DOC. The subsequent process of death and degradation again showed a decrease in DOC. The study, combining the changes in phosphorus and organic matter, revealed that the algae in group 4 underwent a process of extinction-revival-extinction-maintenance, and that the balance of various forms of phosphorus remained intact throughout the process. Images taken during the experiment (…) Figure 5 This indicates that the water column underwent a process of changing from green to yellowish-green to brownish-yellow to green and back to yellowish-green. During this process, in the early stage of the experiment, the algae floated on the water surface. As the experiment progressed, some dead algae sank to the bottom and continued to degrade. In the middle stage of the experiment, the algae recovered and died, absorbed and released nutrients, and synthesized and released organic matter. In the final stage of the experiment, a large number of algal remains sank to the bottom of the water.

[0145] In the dark-protected group 3, algal photosynthesis was prevented, and growth activity could not be maintained. Microbial degradation controlled the phosphorus speciation balance in the water column. In the early stage of the experiment (0-11 days), the dark-protected environment caused algal photosynthesis to stop, algal cells to die rapidly and release intracellular soluble organic matter such as polysaccharides and proteins. At the same time, the activity of heterotrophic bacteria was not fully activated, and DOC accumulated. From 11-19 days, heterotrophic bacteria became dominant under the dark conditions. They mineralized DOC into CO2 and low molecular weight organic matter through hydrolysis, resulting in a decrease in DOC concentration. After 19 days, the algal organic matter was exhausted, and microbial metabolism entered the endogenous respiration stage. The DOC concentration was limited by residual recalcitrant organic matter such as humus, reaching a dynamic equilibrium. This is different from the multi-peak fluctuation of DOC caused by the periodic recovery of algae in the light-protected group 4, indicating that light-driven processes are the core of the algal-organic matter cycle. Under light-free conditions, algae lose their metabolic activity, cell membrane integrity is disrupted, and particulate phosphorus is released into dissolved phosphorus through autolysis. DTP and phosphate accumulate rapidly in the first 30 days. Simultaneously, during the decomposition of algal residues by microorganisms, phosphatase activity is enhanced, promoting the mineralization of organic phosphorus into PO4. 3- After 30 days, the algal particulate phosphorus was basically released, and the dissolved phosphorus concentration was controlled by the adsorption-desorption balance. Simultaneously, the assimilation of phosphorus by microorganisms gradually weakened, and DTP and phosphate levels tended to stabilize. In the early stages of algal death, large amounts of readily degradable organic matter such as sugars and amino acids were released, leading to active microbial metabolism. Therefore, the permanganate index fluctuated for the first 20 days. From 20 to 36 days, readily degradable organic matter was depleted, and the oxidation efficiency of residual recalcitrant substances decreased, causing the permanganate index to decrease synchronously with DOC. After 36 days, the proportion of recalcitrant organic matter increased, making further degradation difficult, and the permanganate index tended to stabilize, reflecting the singular organic matter degradation pathway in the light-shielded group 3. Throughout the experiment, algal remains at the bottom of the light-shielded group 3 continued to settle without re-suspension, demonstrating that light regulation, by maintaining algal activity, became a key hub in the aquatic system's material cycle.

[0146] In summary, the simulation device in this invention effectively simulates the impact of algal growth and decay processes on water quality under different conditions (temperature, light, etc.). The relevant experimental results can be further explored and utilized, and corresponding experimental plans can be developed according to actual needs, effectively applied to the following scientific research or management decisions.

[0147] (1) To reveal the contribution of algal growth and extinction processes to lake organic matter. For example, as water environment management efforts continue to deepen and the load of exogenous organic pollution decreases, the permanganate index of rivers flowing into lakes is lower than that of the lake water in some lakes. Currently, it is generally believed that the release of organic matter from bottom sediments is the main cause of the permanganate index in lakes, while the impact of algal proliferation on water quality is ignored. Based on this simulation device, simulation experiments can be conducted to develop a kinetic model and calibrate parameters for the accumulation and release of algal-derived organic matter using the accumulated experimental data, revealing the accumulation and release rates of endogenous organic matter in lakes; by simultaneously measuring algal density, permanganate index, and chemical oxygen demand, the influence and contribution of algal-derived organic matter on these two indicators can be revealed.

[0148] (2) To reveal the migration and transformation processes of phosphorus, nitrogen, and other nutrients in lakes during algal blooms and decay. For example, the dominant algal species of the genus Microcystis in algal blooms can float and sink autonomously in the water column, which inevitably causes vertical concentration differences in the water. At the same time, under the influence of wind, it can also migrate horizontally and accumulate locally downwind of the lake, especially along the shore. Its decay and decomposition will also inevitably cause significant horizontal differences in nutrient concentrations in the lake water. This may lead environmental management departments to mistakenly believe that land-based input is the main factor causing the concentration differences. Using this simulation device, the amount and rate of nutrient release and accumulation during algal decay can be revealed, providing data support and decision-making basis for the formulation of relevant pollution control work.

[0149] It should be noted that the above embodiments can be freely combined as needed. The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention can have various modifications and variations. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A device for simulating the impact of algal growth and decay on water quality, characterized in that, include: An algal growth-death simulation system is used to provide a simulated environment with controllable environmental variables for algal growth and death. Monitoring and control systems are used to record relevant water quality parameters and algae parameters; The data transmission and storage system provides data transmission and storage for device monitoring; The algal growth-death simulation system includes: (1) Water tank unit: It consists of a heater, a semiconductor cooler, and a water circulation device. The heater, semiconductor cooler, and water circulation device are respectively integrated on the opposite walls of the two sides of the water tank. (2) Columnar experimental unit: made of transparent acrylic material, each unit is evenly arranged in the water tank, maintaining equal intervals and consistent axial direction, and sampling ports are set at different heights on its side; (3) Light control unit: It consists of a light shield with pure black light-absorbing felt attached, a full-spectrum LED light source and an automatic control switching power supply. The light shield with pure black light-absorbing felt attached covers the upper and side walls of the water tank light-avoidance experimental group. The full-spectrum LED light source is fixed above the water tank light-avoidance experimental group through an adjustable bracket. (4) Electromagnetic wave generation unit: It consists of a rotating impeller blade and an external electromagnetic field. The rotating impeller blade is connected to the center of the bottom of the columnar experimental unit, and its axis coincides with the geometric center of the water tank. The external electromagnetic field is symmetrically distributed on the outer side of the front and rear end faces of the water tank. (5) Aeration unit: It consists of a bubble refiner, a stainless steel air pipe, a fixed bracket and a flow regulating valve. The bubble refiner is vertically installed at the bottom of the inner wall of the columnar experimental unit, with its micropore diffusion surface facing upward and parallel to the bottom surface. The stainless steel air pipe extends along the inner side of the column wall to the air inlet of the refiner. Monitoring and surveillance systems include: (1) Water quality monitoring module, whose integrated probe is located in the upper middle part of the side wall of the columnar experimental unit, and the height of the sensitive end from the top of the column is 1 / 3 of the total water depth; (2) Biochemical reaction respiratory metabolism measurement module: It consists of a multi-channel fluorescence fiber oxygen measurement host and sensor, static respiration chamber, analysis software and water environment control module, which runs vertically through the middle of the columnar experimental unit; (3) Algae density online monitoring module: It consists of an online algae density sensor and is deployed on the same side wall of the columnar experimental unit in a co-located integrated manner with the water quality automatic monitoring module; (4) Hyperspectral image recording module: It consists of an extension rod and a hyperspectral lens. The extension rod is fixed at the center of the bottom of the water tank and extends vertically upward to below the water surface. The end of the rod is equipped with a hyperspectral lens.

2. The device for simulating the impact of algal growth-death on water quality according to claim 1, characterized in that, The water tank is made of plexiglass and is equipped with a heater and a semiconductor cooler with precise temperature control, as well as a water circulation device, to simulate different water temperature conditions in the natural environment or to control the water temperature within the target temperature range for the research to be conducted. Multiple columnar experimental units, each with a diameter of 10cm, a height of 50cm, and a volume of 2.8L; The illumination control unit includes a light shield covered with a pure black light-absorbing felt and a full-spectrum LED light source with an illumination intensity of 60-200 µmol·m⁻². -2 ·s -1 And automatic control switching power supply; The aeration unit includes a stainless steel bubble refiner with a pore size of 0.5μm, a stainless steel air guide pipe, a fixed bracket, and a flow regulating valve. The electromagnetic wave generator unit includes a rotating impeller blade and an external electromagnetic field; this unit simulates the wind and wave disturbance conditions in a real lake by adjusting different wave heights, frequencies and morphological parameters.

3. The device for simulating the impact of algal growth and decay on water quality according to claim 2, characterized in that, An automated water quality monitoring module integrates sensors for dissolved oxygen, pH, oxidation-reduction potential, and total dissolved solids to enable real-time online monitoring and recording of water quality indicators. The biochemical reaction respiratory metabolism measurement module consists of a multi-channel fluorescence fiber optic oxygen measurement host and sensor, a static breathing chamber, analysis software and a water environment control module. The online algae density monitoring module utilizes an online algae density sensor and employs the fluorescence method. Based on the fluorescence characteristics of cyanobacteria pigments in the water, it calculates the content of cyanobacteria by measuring the fluorescence intensity released by high-energy LED excitation. The hyperspectral imaging recording module dynamically captures the quantitative changes in water color parameters during algal growth and decomposition using high-resolution spectral data. It combines multi-depth in-situ sampling data to establish machine learning models of algal densities at different water depths, and simultaneously analyzes the spatial heterogeneity of algal biomass decay rate and dissolved organic matter release patterns during decomposition.

4. The device for simulating the impact of algal growth and decay on water quality according to claim 1, characterized in that, Data transmission and storage systems include: Terminal: Used for data acquisition, data transmission, and execution control; the terminal connects to various high-precision sensors and data acquisition modules; the terminal uses the TCP / IP protocol for efficient and stable communication; after receiving control information sent from the cloud, the terminal will immediately forward these instructions to the corresponding devices, thereby achieving precise control of the device's operating status; Cloud: Used to receive, store, and process data uploaded by terminal devices; User-side: Provides a human-computer interaction interface for users, enabling them to easily monitor and control the device.

5. The device for simulating the impact of algal growth and decay on water quality according to claim 4, characterized in that, The terminal uses a programmable microcontroller and connects to various high-precision sensors and data acquisition modules; the specific data acquired includes: Water temperature data: Precisely measures the water temperature inside the device; Water level data: Real-time monitoring of water level height within the device; Water quality monitoring module data: Monitors various indicators of water quality; Biochemical reaction measurement module data: In-depth analysis of biochemical reaction processes within the device; Algae density detection module data: accurately detects the density of algae in the water; Hyperspectral imaging data: Detailed image information of the device's interior is obtained through hyperspectral imaging technology; The terminal uses the TCP / IP protocol to periodically package various types of collected data and send them to the cloud server via network cable; the terminal will listen for control information sent from the cloud in real time, and will respond quickly once it receives an instruction; After receiving control information from the cloud, the terminal forwards these instructions to the corresponding devices, thereby achieving precise control over the device's operating status; the specific controlled devices include: Water temperature control equipment: Adjusts the water temperature according to cloud commands to keep the water temperature in the device within the set range; Water circulation device: controls the speed and direction of water circulation; Lighting equipment: Provides illumination according to the set illumination duration and intensity; Bubble control equipment: Adjusts the amount and frequency of bubble generation.

6. The device for simulating the impact of algal growth and decay on water quality according to claim 4, characterized in that, The following services run in the cloud: Database service: Responsible for storing various types of data uploaded by terminals, including real-time data and historical data; Streaming media file management service: manages hyperspectral image data streaming media files uploaded by the terminal; Data processing and analysis services: In-depth mining and analysis of data uploaded from terminals; through data analysis, potential problems and patterns in the operation of the device can be discovered, providing users with a scientific basis for decision-making; Device management services: Remote management and monitoring of terminal devices, including device status query, parameter setting, and software upgrade functions.

7. The device for simulating the impact of algal growth and decay on water quality according to claim 4, characterized in that, The client provides a human-computer interaction interface, enabling users to monitor and control the system; specific functions are as follows: Data viewing: Users can view the data collected by the terminal in real time on the interface, including water temperature, water level, and water quality information; at the same time, they can also view statistical charts and analysis reports of historical data to better understand the operating status of the device; Parameter settings: Users can set various operating parameters of the device on the interface according to actual needs. After the settings are completed, the user terminal will send these parameters to the cloud, and the cloud will forward the control information to the terminal device for execution. Alarm reception: When an abnormal situation occurs during the operation of the device, the user terminal will receive alarm information in a timely manner.

8. A method for simulating the impact of algal growth and decay on water quality, performed using the apparatus described in any one of claims 1-7, characterized in that, Includes the following steps: Fresh algal solution was collected from a depth of about 1.5m below the water surface and placed in a polyethylene tank. Large algal particles were filtered out, and the remaining fresh algal solution was used as the experimental reserve solution. 80 ml of fresh algal solution was added to each of the 28 experimental columns, and the solution was diluted with 2.8 L of purified water to form experimental water samples. The columns were divided into two groups: a light-illuminated group and a light-protected group. The illuminance of the full-spectrum LED lamp was set to 200 µmol·m⁻¹. -2 ·s -1 The light cycle is set to 12L / 12D, and the light-shielding group is wrapped with a light-shielding film and a light-shielding cover. Adjust the temperature of the heating rod and turn on the water circulation device to maintain the temperature in the water column at 30±1℃; Samples were collected on days 0, 1, 3, 5, 8, 11, 14, 18, 23, 29, 36, 43, 50, 60, and 70. Before each sampling, the DO, pH, ORP, and TDS of the experimental column were measured using a YSI portable water quality analyzer. After sampling, TP, DTP, PO43--P, TN, DTN, NH3-N (ammonia nitrogen), NO3-N, NO2-N, IMn, DOC, three-dimensional fluorescence spectrum, and UV-Vis spectrum were measured.

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