Water quality testing system and method

Abstract

A water quality testing system (200), comprising: a first light source (210), which is used for irradiating a water sample to be tested contained in a water sample cell (250) with light having a wavelength range covering ultraviolet and visible light regions; a second light source (220), which is used for exciting said water sample to generate emitted light; a spectral detector (230), which is used for receiving a fluorescence spectrum of the emitted light and receiving an ultraviolet-visible spectrum of transmitted light related to the first light source (210); and a data processing device (240), which is used for controlling the first light source (210) and the second light source (220) to emit light at different time slices and calculating water quality indexes of said water sample on the basis of the fluorescence spectrum and the ultraviolet-visible spectrum. The water quality testing system uses different light sources to irradiate said water sample at different time slices, so that there is no interference between the collected spectra, and at the same time, each spectrum can focus on different states of components of a substance of concern, and thus as many components of pollutants in the water as possible are detected, thereby improving the accuracy of subsequent water quality index analysis.

Description

Water quality detection system and method

[0001] The present application claims priority to the Chinese patent application No. 202410729580.1, filed on June 5, 2024, entitled “Water quality detection system and method”, the whole content of which is incorporated herein by reference. TECHNICAL FIELD

[0002] The present application relates to the technical field of water quality detection, in particular to a water quality detection system and method. BACKGROUND

[0003] With the rapid development of human society, water resource shortage and water environmental pollution problems are becoming increasingly serious, which poses a serious threat to human health, ecological safety and social development. Therefore, water resource optimization allocation and water environmental pollution control have become key research topics for the sustainable development of future human society.

[0004] Water resource optimization allocation and water environmental pollution control first require the establishment of an online monitoring system for a wide range of observation points (including water sources, key pollution sources, rivers and lakes, irrigation areas, reservoirs, water diversion projects, etc.) to continuously and automatically monitor the water body conditions. Currently, such online monitoring systems mainly monitor the comprehensive indicators of water quality conditions. Among them, the key water quality indicators are mainly measured by chemical methods. However, chemical measurement produces a large amount of chemical waste liquid, which is easy to cause secondary pollution, and requires relatively frequent on-site operation and maintenance. Therefore, how to provide a water quality measurement method with no pollution, high accuracy and remote operation and maintenance is a technical problem that needs to be solved at present. SUMMARY

[0005] The present application provides a water quality detection system and method, which can detect water quality in real time with less pollution and high accuracy.

[0006] In a first aspect, the present application provides a water quality detection system, comprising: a first light source, a second light source, a spectrum detector and a data processing device. The first light source is configured to irradiate the water sample to be measured with light covering the ultraviolet and visible light regions. The second light source is configured to excite the water sample to be measured to generate emission light. The spectrum detector is configured to receive the fluorescence spectrum of the emission light and the ultraviolet-visible spectrum of the transmission light related to the first light source. The data processing device is configured to control the first light source and the second light source to emit light at different time slices, and calculate the water quality indicators of the water sample to be measured based on the fluorescence spectrum and the ultraviolet-visible spectrum.

[0007] In this way, the water quality detection system can irradiate the water sample to be detected by two different light sources in different time periods, and collect the light spectrum corresponding to the different light sources in different time slices through the same receiving light path. Finally, the collected light spectrum is calculated to obtain the water quality index. By using different light sources to irradiate the water sample to be detected in different time slices, the collected light spectrums do not interfere with each other, and each light spectrum can focus on the different states (such as the state of absorbing light or the state of emitting light) of the substance composition, so as to detect as many components of the polluted substance in the water as possible and improve the accuracy of subsequent water quality index analysis.

[0008] In a possible implementation, the spectral detector is located at a first side of the water sample pool, the first light source is located at a second side of the water sample pool, and the second light source is located at a third side of the water sample pool, wherein the first side and the second side are opposite sides. In this way, through a simple system architecture, the spectral detector can capture the transmitted light emitted by the first light source and passing through the water sample to be detected and the emitted light generated by the water sample to be detected, thereby reducing the complexity of the water quality detection system.

[0009] In a possible implementation, the water quality detection system further includes a first lens unit including at least one collimating lens and arranged between the first light source and the water sample pool. In this way, the first lens unit can convert the light emitted by the first light source into parallel light, so that a large amount of light can irradiate the water sample to be detected, thereby avoiding light waste.

[0010] In a possible implementation, the water quality detection system further includes a second lens unit including at least one collimating lens and arranged between the second light source and the water sample pool. In this way, the second lens unit can convert the light emitted by the second light source into parallel light, so that a large amount of light can irradiate the water sample to be detected, thereby avoiding light waste.

[0011] In a possible implementation, the water quality detection system further includes a third lens unit including at least one focusing lens and arranged between the spectral detector and the water sample pool. In this way, the third lens unit can focus the transmitted light and the emitted light on the spectral detector, thereby avoiding light waste and improving detection accuracy.

[0012] In a possible implementation, the second light source comprises an LED array, and the LED array comprises at least one LED unit, and each LED unit comprises, in sequence, a switch, an LED lamp, a filter, and an optical fiber, wherein the optical fibers in different LED units are coupled together. Since the LED lamp is stable in light emission and is not easy to be damaged, the LED lamp is used as the fluorescent light source, and the reliability of the water quality detection system can be improved. In addition, by using the LED array, the fluorescent light source can be easily expanded, and the support range of the excitation wavelength can be conveniently increased.

[0013] In a possible implementation, the wavelengths of the light emitted by different LED units are different and are not continuous. In this way, the reactions of multiple substance components to light can be detected by using light of different wavelengths, so that the detected result can reflect the light reactions of most or all substance components in the water, and the accuracy of the water quality detection result can be improved.

[0014] In a possible implementation, the LED array is in a circular or rectangular shape.

[0015] In a possible implementation, the wavelength of the light irradiated by the first light source is a continuous wavelength. In this way, the reactions of multiple substance components to light can be detected by using light of continuous wavelengths, so that the detected result can reflect the light reactions of most or all substance components in the water, and the accuracy of the water quality detection result can be improved. For example, the first light source can be a xenon lamp or a deuterium halogen lamp.

[0016] In a second aspect, the present application provides a method for water quality detection by using the water quality detection system as described in the first aspect, comprising: in the case that there is no water sample to be detected in the water sample pool, controlling the first light source to irradiate the water sample pool, and obtaining a first ultraviolet-visible spectrum related to the first light source by spectrum detection; in the case that there is a water sample to be detected in the water sample pool, controlling the first light source and the second light source to irradiate the water sample pool at different time slices, and obtaining a second ultraviolet-visible spectrum related to the first light source and a second fluorescent spectrum related to the second light source by spectrum detection; and determining a water quality index of the water sample to be detected based on the first ultraviolet-visible spectrum, the second ultraviolet-visible spectrum, and the second fluorescent spectrum.

[0017] It can be understood that the beneficial effects of the second aspect described above can be referred to the related description in the first aspect described above, and will not be described here again. BRIEF DESCRIPTION OF DRAWINGS

[0018] FIG. 1 is a schematic diagram of an application scenario of a water quality detection system according to an embodiment of the present application;

[0019] FIG. 2 is a schematic diagram of the structure of a water quality detection system according to an embodiment of the present application;

[0020] FIG. 3 is a structural schematic diagram of a fluorescent light source according to an embodiment of the present application;

[0021] FIG. 4 is a schematic diagram of an arrangement of an LED array in a fluorescent light source according to an embodiment of the present application;

[0022] FIG. 5 is a structural schematic diagram of a data processing device according to an embodiment of the present application;

[0023] FIG. 6 is a structural schematic diagram of another water quality detection system according to an embodiment of the present application;

[0024] FIG. 7 is a structural schematic diagram of still another water quality detection system according to an embodiment of the present application;

[0025] FIG. 8 is a structural schematic diagram of yet another water quality detection system according to an embodiment of the present application;

[0026] FIG. 9 is a schematic diagram of a use process of a water quality detection system at different stages according to an embodiment of the present application. DETAILED DESCRIPTION

[0027] The term "and / or" used in this document is used to describe an association relationship between associated objects, which means that there can be three relationships, for example, A and / or B can mean that there are three cases of A alone, A and B together, and B alone. The symbol " / " in this document represents an or relationship between associated objects, for example, A / B represents A or B.

[0028] The terms "first" and "second" and the like in the description and claims of this document are used to distinguish different objects, and are not used to describe a specific order of the objects. For example, the first response message and the second response message are used to distinguish different response messages, and are not used to describe a specific order of the response messages.

[0029] In the embodiments of the present application, the words "exemplary" or "for example" are used to mean serving as an example, instance, or illustration. Any embodiment or design presented as "exemplary" or "for example" in the embodiments of the present application should not be construed as being more preferred or advantageous than other embodiments or design solutions. Rather, the use of the words "exemplary" or "for example" is intended to present concepts in a concrete manner.

[0030] In the description of the embodiments of the present application, unless otherwise specified, the meaning of "a plurality of" is two or more, for example, a plurality of processing units means two or more processing units, and the like; a plurality of elements means two or more elements, and the like.

[0031] In the description of the embodiments of the present application, the water quality detection system is mainly used for monitoring the comprehensive indexes of water quality conditions, such as turbidity, chemical oxygen demand (COD), total phosphorus (TP), total nitrogen (TN), chlorophyll, blue algae, green algae, etc. The water quality detection system can be configured at water observation points of rivers, lakes, reservoirs, irrigation areas, water diversion projects, etc., or water quality monitoring points of factory sewage outlets, urban domestic wastewater pipe networks, etc. For example, as shown in FIG. 1, the water quality detection system is applied to water quality detection of a factory sewage outlet. In FIG. 1, the water quality detection system is configured at the downstream side of the factory sewage outlet. Before the sewage discharged by the factory flows into the river through the drainage pipeline, the water quality of the sewage can be detected by the water quality detection system. During the detection, an appropriate amount of water sample to be detected can be extracted from the drainage pipeline; then, the water sample to be detected is detected by the water quality detection system; finally, after the detection is completed, the water sample can be discharged into the drainage pipeline, or into other pipelines, which is not limited here. For other application scenarios, please refer to the application scenario shown in FIG. 1, which will not be described here.

[0032] In the present embodiment, in order to avoid secondary pollution in the water quality monitoring process, the water quality detection method adopted by the water quality detection system is a spectrum detection method. The spectrum detection method mainly utilizes ultraviolet light, visible light or near-infrared light to interact with pollutants in water, and then measures the absorption (or fluorescence, Raman scattering) of light by the pollutants to infer the concentration of the pollutants.

[0033] The water quality detection system provided by the present application will be described below. The water quality detection system provided in the present embodiment mainly utilizes two different light sources to irradiate a water sample (i.e. a water sample to be detected) at different time slices, and collects the spectra corresponding to different light sources at different time slices through the same receiving light path. Finally, the collected spectra are calculated to obtain water quality indexes. Since some of the components in the water sample absorb light and some emit light, if a single light source is used, the collected spectra will interfere with each other. Therefore, by using different light sources to irradiate the water sample at different time slices, the collected spectra can be free of interference, and each spectrum can focus on different states of the components (such as the state of absorbing light or the state of emitting light), so as to detect as many components of the pollutants in water as possible and improve the accuracy of subsequent water quality index analysis.

[0034] For example, FIG. 2 shows a structural schematic diagram of a water quality detection system provided by the present application. As shown in FIG. 2, the water quality detection system 200 includes an ultraviolet-visible light source 210, a fluorescent light source 220, a spectrum detector 230, a data processing device 240, and a water sample pool 250.

[0035] The ultraviolet-visible light source 210 refers to a light source capable of emitting light in the wavelength range covering the ultraviolet and visible light regions, such as a xenon lamp, a deuterium halogen lamp, etc. Since different substances in water have different absorption degrees for light of different wavelengths, in order to detect the reaction of multiple substances to light, the ultraviolet-visible light source 210 can have the ability to emit light of continuous wavelengths. In this way, the reaction of multiple substances to light can be detected through light of continuous wavelengths, so that the detected results can reflect the light reaction of most or all substances in the water, thereby improving the accuracy of the water quality detection results. For example, light of continuous wavelengths can refer to light whose spectral components are continuously distributed within a certain range, and the characteristic is that it contains a series of light photons of continuous wavelengths from longer wavelengths to shorter wavelengths, rather than only discrete specific wavelengths. Of course, detection can also be performed by the single-wavelength light emitted by the ultraviolet-visible light source 210, which can be determined according to actual conditions and is not limited here. For example, the spectrum of the light emitted by the ultraviolet-visible light source 210 and the water body can be referred to as an “ultraviolet-visible spectrum”. For example, the ultraviolet-visible light source 210 can also be referred to as a “first light source”.

[0036] The fluorescence light source 220 refers to a light source capable of exciting water substances to emit fluorescence, such as a high-pressure mercury lamp, a light emitting diode (LED) lamp, and the like. Since different wavelengths of excitation light can cause different water substances to emit different light, in order to detect the reaction of multiple substances to light, the fluorescence light source 220 can have the ability to emit light of different wavelengths. In this way, the reaction of multiple substances to light can be detected by light of different wavelengths, so that the detected results can reflect the light reaction of most or all substances in the water, thereby improving the accuracy of the water quality detection results. Since each wavelength of excitation light can interact with the water body to produce a series of wavelengths of emission light, a series of wavelengths of excitation light produces a fluorescence spectrum matrix, which can be referred to as a "three-dimensional fluorescence spectrum". Exemplarily, the three-dimensional fluorescence spectrum can also be referred to as a "fluorescence spectrum". Exemplarily, the fluorescence light source 220 can have the ability to emit continuous wavelengths of light, or the ability to emit discontinuous wavelengths. However, considering the cost, it is better to choose a light source with the ability to emit discontinuous wavelengths. As a possible implementation, as shown in FIG. 3, the fluorescence light source 220 can mainly consist of an LED array composed of multiple LED units. Each LED unit can include, in sequence, a metal-oxide-semiconductor field-effect transistor (MOS) switch 221, an LED lamp 222, a filter 223, and an optical fiber 224. The MOS switch 221 is mainly used to control the corresponding LED lamp 222 to turn on or off. The filter 223 is mainly used to selectively transmit or absorb light of a specific wavelength, which can be made of plastic or glass, but is not limited to. The optical fiber 224 is mainly used to transmit the light emitted by the LED lamp 222. In the LED array, multiple optical fibers 224 can be coupled together and output the light emitted by different LED units. For the arrangement of the LED array shown in FIG. 3, it can be a rectangular array as shown in FIG. 4(A), or a circular array as shown in FIG. 4(B), which can be determined according to actual conditions and is not limited herein. Exemplarily, the fluorescence light source 220 can also be referred to as a "second light source". Since the LED lamp emits light stably and is not easy to be damaged, using the LED lamp as the fluorescence light source can also improve the reliability of the water quality detection system. In addition, using such an LED array can also make the fluorescence light source easy to expand, and can conveniently increase the support range of excitation wavelengths.

[0037] The spectral detector 230 is mainly used to capture / receive the ultraviolet-visible absorption spectrum of the transmitted light related to the ultraviolet-visible light source 210, and capture / receive the three-dimensional fluorescence spectrum of the emitted light generated by the water sample, so as to measure and analyze the spectral characteristics (such as absorption spectrum, emission spectrum, etc.) of the substance composition in the water. For example, the spectral detector 230 can capture / receive continuous ultraviolet-visible absorption spectrum and three-dimensional fluorescence spectrum, which can cover the wavelength and light intensity range of ultraviolet-visible light, excitation fluorescence and emission fluorescence.

[0038] The data processing device 240 is mainly used to control the ultraviolet-visible light source 210 and the fluorescence light source 220 in time division, so that the two light sources can emit light at different time periods, so that the two different lights do not interfere with each other, and then the complementary interference ultraviolet-visible absorption spectrum and three-dimensional fluorescence spectrum can be obtained. In addition, the data processing device 240 can also be used to obtain the ultraviolet-visible absorption spectrum and three-dimensional fluorescence spectrum from the spectral detector 230, and perform fusion calculation on the obtained ultraviolet-visible absorption spectrum and three-dimensional fluorescence spectrum, etc. to obtain the result of the water quality pollution index. For example, the data processing device 240 can input the ultraviolet-visible absorption spectrum and three-dimensional fluorescence spectrum into a neural network model for calculation. In this embodiment, the data processing device 240 can be connected to the ultraviolet-visible light source 210, the fluorescence light source 220 and the spectral detector 230 through wired or wireless connection.

[0039] As a possible implementation, as shown in FIG. 5, the data processing device 240 can include a controller 241, a power supply driving circuit 242 and a variable resistor 243. The variable resistor 243 can be two, one variable resistor 243 is connected to the ultraviolet-visible light source 210, and the other variable resistor 243 is connected to the fluorescence light source 220. The controller 241 can be a central processing unit (CPU) or a microcontroller unit (MCU), etc., which is mainly used for data processing, and controls the power supply driving circuit 242 and the variable resistor 243 to control the light-emitting time and intensity of the ultraviolet-visible light source 210 and the fluorescence light source 220.

[0040] The water sample pool 250 is used to hold the water sample to be tested. The water sample pool 250 can be made of quartz glass or other materials. The water sample pool 250 can have an inlet and an outlet. The water sample to be tested can enter the water sample pool 250 through the inlet and flow out through the outlet. As a possible implementation, the water at the water quality monitoring point or observation point can be pumped into the water sample pool 250 by a pump, and the water sample in the water sample pool 250 can be pumped out by a pump. The method of adding and releasing the water sample into the water sample pool 250 can be determined according to actual conditions, which is not limited here.

[0041] In this embodiment, the ultraviolet-visible light source 210 and the fluorescent light source 220 can be directed to different sides of the water sample pool 250. For example, referring to FIG. 2, the ultraviolet-visible light source 210 can be directed to the bottom of the water sample pool 250, and the fluorescent light source 220 can be directed to the right side of the water sample pool 250. Alternatively, as shown in FIG. 6, the ultraviolet-visible light source 210 can be directed to the left side of the water sample pool 250, and the fluorescent light source 220 can be directed to the bottom of the water sample pool 250. Of course, the ultraviolet-visible light source 210 and the fluorescent light source 220 can also be directed to the same side of the water sample pool 250, for example, both directed to the bottom of the water sample pool 250, etc. In addition, the light emitted by the ultraviolet-visible light source 210 and the fluorescent light source 220 needs to be irradiated onto the water sample pool 250, so that the light emitted by the two can react with the substance components contained in the water sample to be tested in the water sample pool 250. At the same time, the side of the water sample pool 250 irradiated by the ultraviolet-visible light source 210 and the fluorescent light source 220 also needs to be transparent, so that the light can enter the inside of the water sample pool 250.

[0042] The spectrum detector 230 also needs to be directed to the water sample pool 250, so as to be able to capture the ultraviolet-visible absorption spectrum and the three-dimensional fluorescence spectrum. As a possible implementation, considering that the ultraviolet-visible absorption spectrum is determined based on the absorption of the light emitted by the ultraviolet-visible light source 210, and the spectrum detector 230 needs to capture the light emitted by the ultraviolet-visible light source 210 and passing through the water sample in the water sample pool 250, the spectrum detector 230 and the ultraviolet-visible light source 210 can be arranged on the same straight line, i.e. on the opposite sides of the water sample pool 250, for example, the spectrum detector 230 is located on the upper side of the water sample pool 250, and the ultraviolet-visible light source 210 is located on the lower side of the water sample pool 250, or the spectrum detector 230 is located on the right side of the water sample pool 250, and the ultraviolet-visible light source 210 is located on the left side of the water sample pool 250, etc. At the same time, the incident light path of the fluorescent light source 220 can be arranged to be orthogonal to the incident light path of the ultraviolet-visible light source 210. In this way, the detection of water quality by two different light sources can be realized at a lower cost.

[0043] In addition, when the spectral detector 230 and the ultraviolet-visible light source 210 are not arranged on the same straight line, for example, as shown in FIG. 6, the spectral detector 230 is located on the upper side of the water sample pool 250, and the ultraviolet-visible light source 210 is located on the left side of the water sample pool 250, at this time, since the ultraviolet-visible spectrum acquired by the spectral detector 230 is the transmission light captured by the ultraviolet-visible light source 210 and transmitted out of the water sample, and the spectral detector 230 and the ultraviolet-visible light source 210 are not on the same straight line, which makes the transmission light unable to enter the spectral detector 230 along the incident direction. Therefore, considering this situation, the reflection assembly 310 can be arranged on the opposite side of the ultraviolet-visible light source 210 with the water sample pool 250 as a reference (for example, the right side of the water sample pool 250 in FIG. 6), so that the transmission light can be reflected to the spectral detector 230 through the reflection assembly 310. For example, the reflection assembly 310 can be a beam splitter (BS).

[0044] Continuing to refer to FIG. 2, the light emitted by the ultraviolet-visible light source 210 and the fluorescence light source 220 is divergent, and if not focused, it will cause light waste. Therefore, as shown in FIG. 7, the lens units 260 and 270 can also be added in the water quality detection system. The lens units 260 and 270 can each include one or more collimating lenses. The lens unit 260 can be arranged on the incident light path of the ultraviolet-visible light source 210, so that the light emitted by the ultraviolet-visible light source 210 can be converted into parallel light (i.e., collimated) through the lens unit 260, so that these light rays can be irradiated onto the water sample pool 250 in large quantities, avoiding light waste. The lens unit 270 can be arranged on the excitation light path of the fluorescence light source 220, so that the excitation light emitted by the fluorescence light source 220 can be converted into parallel light through the lens unit 270, so that these light rays can be irradiated onto the water sample pool 250 in large quantities, avoiding light waste. For example, the lens unit 260 can be referred to as a "first lens unit", and the lens unit 270 can be referred to as a "second lens unit".

[0045] Continuing to refer to FIG. 2, only a part of the light passing through the water sample pool 250 and the light generated by the water sample in the water sample pool 250 can be captured by the spectrum detector 230, which results in that only a part of the water sample can be analyzed and the whole water sample cannot be analyzed, and thus a poor detection result is caused. Therefore, as shown in FIG. 7, a lens unit 280 can be added between the spectrum detector 230 and the water sample pool 250. The lens unit 280 can include one or more focusing lenses. In this way, the light passing through the water sample pool 250 (i.e. the exiting light) and the light generated by the water sample in the water sample pool 250 can be focused by the lens unit 280 and then enter the spectrum detector 230, so that the spectrum detector 230 can analyze the whole water sample. Exemplarily, the lens unit 280 can be referred to as a "third lens unit".

[0046] Similarly, when the water quality detection system is as shown in FIG. 6, a lens unit composed of a collimating lens and / or a lens unit composed of a focusing lens can also be added therein. The water quality detection system to which the lens unit composed of a collimating lens and the lens unit composed of a focusing lens are added can be as shown in FIG. 8. The lens unit 320 shown in FIG. 8 can be the same as the lens unit 280, and in addition, the two can be independently arranged or integrated together.

[0047] It should be understood that the lens units 260, 270, 280 and 320 described above can be configured alternatively (i.e. only one is configured), or two of them can be configured alternatively (i.e. any two are configured), or three of them can be configured alternatively (i.e. any three are configured), or all of them can be configured simultaneously, which can be determined according to actual conditions and is not limited herein. In addition, the number of the lens units can also be determined according to actual conditions and is not limited herein.

[0048] The above is the introduction of the water quality detection system provided by the present embodiment. When the water quality detection system is used to detect the water quality, the light intensity and the light-emitting time slice of the ultraviolet-visible light source 210 and the fluorescent light source 220 can be controlled by the data processing device 240. The ultraviolet-visible light emitted at different time slices and the excitation light respectively irradiate the water sample pool 250. The ultraviolet-visible light passing through the water sample pool 250 and the fluorescence generated by the water sample under the excitation light can be detected by the spectrum detector 230 to obtain the ultraviolet-visible absorption spectrum and the three-dimensional fluorescence spectrum respectively at different time slices through the same receiving light path. In this way, the ultraviolet-visible absorption spectrum and the three-dimensional fluorescence spectrum which do not interfere with each other can be obtained. Finally, the fusion calculation of the two types of spectrum data is performed by the data processing device 240, so as to inverse the water pollution index.

[0049] The debugging stage and the monitoring stage of the water quality detection system described above will be introduced below.

[0050] (1) Debugging stage

[0051] Referring to FIG. 9, the debugging procedure is as follows:

[0052] a) Empty the water sample in the water sample pool 250. If there is no water sample in the water sample pool 250, this step can be omitted.

[0053] b) Turn on the UV-visible light source 210.

[0054] c) The data processing device 240 acquires the UV-visible absorption spectrum collected by the spectrum detector 230 from the spectrum detector 230. At this time, the light detected by the spectrum detector 230 is only the light emitted by the UV-visible light source 210, because there is no water sample in the water sample pool 250. Therefore, the light intensity detected by the spectrum detector 230 at this time can be called "incident light intensity".

[0055] d) Adjust the light intensity of the UV-visible light source 210 by the data processing device 240, so that the maximum value of the incident light intensity is less than the maximum range of the spectrum detector 230. In this way, the spectrum detector 230 can collect all intensities of light emitted by the UV-visible light source 210.

[0056] e) Turn off the UV-visible light source 210.

[0057] f) Fill the water sample pool 250 with water sample. Of course, it can also not be full, as long as it meets the test requirements.

[0058] g) Turn on the UV-visible light source 210.

[0059] h) The data processing device 240 acquires the UV-visible absorption spectrum collected by the spectrum detector 230 from the spectrum detector 230. At this time, the light detected by the spectrum detector 230 is the light transmitted from the water sample, because the light emitted by the UV-visible light source 210 is absorbed by the components in the water sample and transmitted outside the water sample. Therefore, the light intensity detected by the spectrum detector 230 at this time can be called "transmitted light intensity".

[0060] i) Adjust the light intensity of the UV-visible light source 210 by the data processing device 240, so that the maximum value of the transmitted light intensity is less than the maximum range of the spectrum detector 230. In this way, the spectrum detector 230 can collect all intensities of light emitted by the UV-visible light source 210.

[0061] j) Turn off the UV-visible light source 210.

[0062] k) Empty the water sample in the water sample pool 250.

[0063] l) Turn on the fluorescent light source 220.

[0064] m) The data processing device 240 acquires the three-dimensional fluorescence spectrum collected by the spectral detector 230 from the spectral detector 230. Since there is no water sample in the water sample pool 250, the light detected by the spectral detector 230 at this time is only the excitation light emitted by the fluorescence light source 220, so the light intensity detected by the spectral detector 230 at this time can be referred to as the “excitation light intensity”.

[0065] n) The data processing device 240 adjusts the light intensity of the fluorescence light source 220 so that the maximum value of the excitation light intensity is less than the maximum range of the spectral detector 230. In this way, the spectral detector 230 can collect all intensities of light emitted by the fluorescence light source 220.

[0066] o) Turn off the fluorescence light source 220.

[0067] p) Fill the water sample pool 250 with a water sample. Of course, it can also be not full, as long as it meets the test requirements.

[0068] q) Turn on the fluorescence light source 220.

[0069] r) The data processing device 240 acquires the three-dimensional fluorescence spectrum collected by the spectral detector 230 from the spectral detector 230. Since there is a water sample in the water sample pool 250, the excitation light emitted by the fluorescence light source 220 will react with the substance components in the water sample and cause the substance components in the water sample to emit light, so the light detected by the spectral detector 230 at this time is the emission light from the substance components in the water sample, so the light intensity detected by the spectral detector 230 at this time can be referred to as the “emission light intensity”.

[0070] s) The data processing device 240 adjusts the light intensity of the fluorescence light source 220 so that the maximum value of the emission light intensity is less than the maximum range of the spectral detector 230. In this way, the spectral detector 230 can collect the emission light of most of the substance components in the water sample.

[0071] t) Turn off the fluorescence light source 220.

[0072] It should be understood that the order of debugging the ultraviolet-visible light source 210 and the fluorescence light source 220 can be determined according to the situation, which is not limited here. The purpose of debugging is mainly to make the maximum values of the incident light intensity and the transmission light intensity related to the ultraviolet-visible light source 210 be within the detection range of the spectral detector 230, and to make the maximum values of the excitation light intensity and the emission light intensity related to the fluorescence light source 220 also be within the detection range of the spectral detector 230.

[0073] After debugging is completed, the “monitoring phase” can be entered.

[0074] (2) Monitoring phase

[0075] With reference to FIG. 9, the monitoring stage can include at least one monitoring cycle, and the procedure of each monitoring cycle can be consistent. Of course, some monitoring steps can be adjusted based on the needs of the self without affecting the monitoring. For example, the different monitoring cycles can be spaced apart by a predetermined time length. The specific process of each monitoring cycle is as follows:

[0076] a) Empty the water sample in the water sample pool 250. If there is no water sample in the water sample pool 250, this step can be omitted.

[0077] b) Turn on the ultraviolet-visible light source 210.

[0078] c) The data processing device 240 obtains the ultraviolet-visible absorption spectrum (hereinafter referred to as "ultraviolet-visible spectrum 11") collected by the spectral detector 230 from the spectral detector 230.

[0079] d) Turn off the ultraviolet-visible light source 210.

[0080] e) Turn on the fluorescence light source 220.

[0081] f) The data processing device 240 obtains the three-dimensional fluorescence spectrum (hereinafter referred to as "three-dimensional fluorescence spectrum 21") collected by the spectral detector 230 from the spectral detector 230.

[0082] g) Turn off the fluorescence light source 220.

[0083] h) Fill the water sample pool 250 with water sample. Of course, it can also not be full, as long as it meets the monitoring requirements.

[0084] i) Turn on the ultraviolet-visible light source 210.

[0085] j) The data processing device 240 obtains the ultraviolet-visible absorption spectrum (hereinafter referred to as "ultraviolet-visible spectrum 12") collected by the spectral detector 230 from the spectral detector 230.

[0086] k) Turn off the ultraviolet-visible light source 210.

[0087] l) Turn on the fluorescence light source 220.

[0088] m) The data processing device 240 obtains the three-dimensional fluorescence spectrum (hereinafter referred to as "three-dimensional fluorescence spectrum 22") collected by the spectral detector 230 from the spectral detector 230.

[0089] n) Turn off the fluorescence light source 220.

[0090] o) The data processing device 240 inverses the water quality index, including but not limited to the concentration values of COD, TP, TN, chlorophyll, blue algae and green algae and other substance components, based on the ultraviolet-visible spectrum 11, the ultraviolet-visible spectrum 12, the three-dimensional fluorescence spectrum 21 and the three-dimensional fluorescence spectrum 22.

[0091] As can be seen from the above monitoring stage, in each monitoring stage, the first light source and the second light source need to be controlled to irradiate the water body sample pool at different time slices without the water sample to be tested in the water body sample pool, and the first ultraviolet-visible spectrum related to the first light source and the first fluorescence spectrum related to the second light source are acquired through spectral detection. Then, the first light source and the second light source are controlled to irradiate the water body sample pool at different time slices with the water sample to be tested in the water body sample pool, and the second ultraviolet-visible spectrum related to the first light source and the second fluorescence spectrum related to the second light source are acquired through spectral detection. Finally, the water quality index of the water sample to be tested is determined based on the first ultraviolet-visible spectrum, the second ultraviolet-visible spectrum, the first fluorescence spectrum and the second fluorescence spectrum.

[0092] It should be understood that in each monitoring period, the order of acquiring the ultraviolet-visible spectrum and the fluorescence spectrum when there is no water sample in the water body sample pool and acquiring the ultraviolet-visible spectrum and the fluorescence spectrum when there is water sample in the water body sample pool can be determined according to actual conditions, which is not limited here. For example, the water sample can be first added to the water body sample pool 250, and the ultraviolet-visible spectrum and the fluorescence spectrum are acquired; then, the water sample in the water body sample pool 250 is emptied, and the ultraviolet-visible spectrum and the fluorescence spectrum are acquired. In addition, since the spectrum acquired when there is no water sample and the spectrum acquired when there is water sample are both needed in the calculation of the water quality index in each monitoring period, if the spectrum acquired when there is no water sample is not acquired in the current monitoring period, but the spectrum acquired when there is no water sample in other monitoring periods is used, the device parameters used in the same monitoring period can be inconsistent, which can cause errors in the detection results. Considering this situation, it is better to acquire the spectrum when there is no water sample and the spectrum when there is water sample in each monitoring period.

[0093] It should be understood that in the debugging stage and the monitoring stage of the water quality detection system, when there is no water sample in the water body sample pool, the second light source can also be selected not to irradiate the water body sample pool, that is, the first fluorescence spectrum mentioned above can be selected not to be acquired at this time. In this case, the water quality index of the water sample to be tested can be determined based on the first ultraviolet-visible spectrum, the second ultraviolet-visible spectrum and the second fluorescence spectrum.

[0094] It can be understood that the various numerical numbers involved in the embodiments of the present application are only for convenient differentiation, and do not limit the scope of the embodiments of the present application.

[0095] Finally, it should be noted that: the above examples are used to illustrate the technical solutions of the present application, but not limited to them; although the present application is described in detail with reference to the foregoing examples, those skilled in the art should understand that: it can still modify the technical solutions recorded in the foregoing examples, or make equivalent replacement for part of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the protection scope of the technical solutions of the embodiments of the present application.

Claims

1. A water quality detection system, characterized by, The application relates to a water quality testing device, comprising: a first light source for irradiating a water sample to be tested with light in a wavelength range covering the ultraviolet and visible light regions; a second light source for exciting the water sample to be tested to generate emission light; a spectrum detector for receiving a fluorescence spectrum of the emission light and an ultraviolet-visible spectrum of the transmission light related to the first light source; a data processing device for controlling the first light source and the second light source to emit light at different time intervals and calculating a water quality index of the water sample to be tested based on the fluorescence spectrum and the ultraviolet-visible spectrum.

2. The water quality detection system of claim 1, wherein The spectrum detector is located at a first side of the water sample pool, the first light source is located at a second side of the water sample pool, and the second light source is located at a third side of the water sample pool, wherein the first side and the second side are opposite sides.

3. The water quality detection system according to claim 1 or 2, characterized in that, Further comprising: a first lens unit comprising at least one collimating lens arranged between the first light source and the water sample pool.

4. The water quality detection system according to any one of claims 1-3, characterized in that, Further comprising: a second lens unit comprising at least one collimating lens arranged between the second light source and the water sample pool.

5. The water quality detection system according to any one of claims 1-4, wherein Further comprising: a third lens unit comprising at least one focusing lens arranged between the spectrum detector and the water sample pool.

6. The water quality detection system according to any one of claims 1-5, wherein, The second light source comprises an LED array, and the LED array comprises at least one LED unit, each of which comprises a switch, an LED lamp, a filter and an optical fiber connected in sequence, wherein the optical fibers in different LED units are coupled together.

7. The water quality detection system of claim 6, wherein The wavelengths of the light emitted by different LED units are different and discontinuous.

8. The water quality detection system according to claim 6 or 7, characterized in that, The LED array is circular or rectangular.

9. The water quality detection system according to any one of claims 1-8, wherein, The wavelength of the light irradiated by the first light source is continuous.

10. A method for water quality detection using the water quality detection system according to any one of claims 1-9, characterized in that, The application further relates to a water quality testing method, comprising: controlling the first light source to irradiate the water sample pool in the absence of a water sample to be tested in the water sample pool and acquiring a first ultraviolet-visible spectrum related to the first light source through the spectrum detector; controlling the first light source and the second light source to irradiate the water sample pool at different time intervals in the presence of a water sample to be tested in the water sample pool and acquiring a second ultraviolet-visible spectrum related to the first light source and a second fluorescence spectrum related to the second light source through the spectrum detector; determining a water quality index of the water sample to be tested based on the first ultraviolet-visible spectrum, the second ultraviolet-visible spectrum and the second fluorescence spectrum.

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