A water quality online monitoring system and method

Abstract

The present application belongs to the technical field of water quality monitoring, and provides a water quality online monitoring system and method. The water quality online monitoring system includes a digestion module, a colorimetric module, an injection module and a control module. The digestion module includes a digestion tank and a heating unit arranged in the digestion tank. The colorimetric module includes a circulation pool, a light transmitter and a light receiver. The light transmitter includes a first monochromatic light source and a second monochromatic light source. The injection module includes a multi-way valve, a plurality of reagent containers and a syringe. The above-mentioned water quality online monitoring system is easy to produce and easy to promote and apply. In addition, the above-mentioned water quality online monitoring system can reasonably arrange the monitoring order of each factor, and detect the content of ammonia nitrogen and nitrite nitrogen in the water sample to be tested while performing total phosphorus digestion, which can effectively shorten the monitoring cycle.

Description

Technical Field

[0001] The present application relates to the technical field of water quality monitoring, and in particular to an online water quality monitoring system and method. Background Art

[0002] After nearly 30 years of development, my country's surface water environment monitoring network has established a monitoring network covering the country's ten major river basins with relatively complete indicators. However, standard water quality automatic stations that can simultaneously monitor multiple factors of water bodies are difficult to build, and the number of them built is far from meeting the requirements of comprehensive monitoring. As a result, there are still a large number of river basins in my country that have not been effectively monitored, especially the monitoring of capillary rivers is still blank; in addition, the monitoring cycle of traditional standard water quality automatic stations is long, and real-time monitoring of water quality cannot be achieved. Summary of the invention

[0003] The purpose of the embodiments of the present application is to provide an online water quality monitoring system to solve the technical problems in the prior art that the construction of standard water quality automatic stations is difficult, the monitoring cycle is long, and real-time monitoring of water quality cannot be achieved.

[0004] To achieve the above purpose, the technical solution adopted in this application is: to provide an online water quality monitoring system, including:

[0005] A digestion module, comprising a digestion tank and a heating unit arranged in the digestion tank;

[0006] A colorimetric module, comprising a circulation cell, a light transmitter and a light receiver, wherein the light transmitter comprises a first monochromatic light source and a second monochromatic light source, and the light emitted by the first monochromatic light source and the light emitted by the second monochromatic light source both pass through the circulation cell and are received by the light receiver;

[0007] The injection module comprises a multi-way valve, a plurality of reagent containers and a syringe, wherein the multi-way valve has a first interface connected to the syringe, a second interface for passing the water sample to be tested, a third interface connected to the digestion tank, a fourth interface connected to the circulation pool through a capillary, and a plurality of fifth interfaces respectively connected to the corresponding reagent containers;

[0008] A control module is electrically connected to the heating unit, the light emitter, the light receiver, the multi-way valve and the syringe.

[0009] In one embodiment, the first monochromatic light source is used to emit monochromatic light with a wavelength of 695nm-705nm, and the second monochromatic light source is used to emit monochromatic light with a wavelength of 535nm-545nm.

[0010] In one embodiment, the capillary tube has a diameter of 0.5 mm to 0.7 mm.

[0011] In one embodiment, the online water quality monitoring system also includes a connected grit tank and a water pump, the water pump is electrically connected to the control module and is used to draw the water sample to be tested into the grit tank, and each of the reagent containers is arranged in the grit tank.

[0012] In one embodiment, the online water quality monitoring system further includes a first peristaltic pump and a water storage tank connected to the second interface of the multi-way valve, and the first peristaltic pump is used to transport the water sample to be tested in the sand settling tank to the water storage tank.

[0013] In one embodiment, the water quality online monitoring system further comprises a first liquid level meter disposed in the sand settling tank, the sand settling tank is provided with a first drain pipe, and the first drain pipe is provided with a first drain valve;

[0014] And / or, the water quality online monitoring system further comprises a second liquid level gauge arranged in the water storage tank, the water storage tank is provided with a second drain pipe, and the second drain pipe is provided with a second drain valve.

[0015] In one of the embodiments, the online water quality monitoring system further includes a filtering unit, and the filtering unit is disposed at the inlet end of the water intake pump.

[0016] In one of the embodiments, the water quality online monitoring system further includes a spectral detection module, which includes a spectrometer and a second peristaltic pump, and the second peristaltic pump is used to transport the water sample to be tested in the grit tank to the spectrometer.

[0017] In one of the embodiments, the online water quality monitoring system also includes a parameter monitoring module for detecting water temperature, pH value, dissolved oxygen, conductivity and turbidity of the water sample to be tested.

[0018] The present application also provides a method for online water quality monitoring, which adopts the above-mentioned online water quality monitoring system and comprises the following steps:

[0019] Putting a total phosphorus oxidant, a total phosphorus color developer, a total phosphorus reductant, an ammonia nitrogen oxidant, an ammonia nitrogen color developer, an ammonia nitrogen catalyst and a nitrite nitrogen color developer into corresponding reagent containers respectively;

[0020] The syringe extracts the water sample to be tested and the total phosphorus oxidant to form a first mixed solution, and the first mixed solution is transported to a digestion tank for digestion;

[0021] While the first mixed solution is being digested, the syringe draws the water sample to be tested, the ammonia nitrogen oxidizer, the ammonia nitrogen color developer and the ammonia nitrogen catalyst to form a second mixed solution, and the second mixed solution is transported to a circulation pool, and then the first monochromatic light source of the light transmitter emits a first light toward the circulation pool, and the first light passes through the circulation pool and is received by the light receiver, and the light receiver forms a first light signal after receiving the first light and transmits the first light signal to the control module;

[0022] Next, the syringe draws the water sample to be tested and the nitrite nitrogen color developer to form a third mixed solution, and the third mixed solution is transported to the circulation pool, and then the second monochromatic light source of the light transmitter emits a second light toward the circulation pool, and the second light passes through the circulation pool and is received by the light receiver, and the light receiver forms a second light signal after receiving the second light and transmits the second light signal to the control module;

[0023] Next, the syringe extracts the total phosphorus color developer, the total phosphorus reducing agent and the first mixed solution from the digestion tank to form a fourth mixed solution, and the fourth mixed solution is transported to the circulation pool. Subsequently, the first monochromatic light source of the light transmitter emits a third light toward the circulation pool. The third light passes through the circulation pool and is received by the light receiver. After receiving the third light, the light receiver forms a third light signal and transmits the third light signal to the control module.

[0024] The beneficial effects of the online water quality monitoring system provided by the present application are as follows: when in use, firstly, a total phosphorus oxidant, a total phosphorus color developer, a total phosphorus reductant, an ammonia nitrogen oxidant, an ammonia nitrogen color developer, an ammonia nitrogen catalyst and a nitrite nitrogen color developer are respectively loaded into corresponding reagent containers; then, a water sample to be tested and a total phosphorus oxidant are extracted by a syringe to form a first mixed solution, and the first mixed solution is transported to a digestion module for digestion; while the first mixed solution is being digested, an ammonia nitrogen oxidant, an ammonia nitrogen color developer, an ammonia nitrogen catalyst and a water sample to be tested are extracted by a syringe to form a second mixed solution, and the second mixed solution is transported to a circulation pool, and the first monochromatic light source and the light interface are used to obtain a total phosphorus oxidant. The receiver performs colorimetric analysis on the second mixed solution to monitor the ammonia nitrogen content in the water sample to be tested; then, the water sample to be tested and the nitrite nitrogen color developer are drawn out through a syringe to form a third mixed solution, and the third mixed solution is transported to the circulation pool, and the second monochromatic light source and the light receiver perform colorimetric analysis on the third mixed solution to monitor the nitrite nitrogen content in the water sample to be tested; finally, the total phosphorus color developer and the total phosphorus reducing agent and the digested first mixed solution are drawn out through a syringe to form a fourth mixed solution, and the fourth mixed solution is transported to the circulation pool, and the first monochromatic light source and the light receiver perform colorimetric analysis on the fourth mixed solution to monitor the total phosphorus content in the water sample to be tested. The above-mentioned online water quality monitoring system is easy to produce and easy to promote and apply; in addition, the above-mentioned online water quality monitoring system can reasonably arrange the monitoring order of various factors, and detect the content of ammonia nitrogen and nitrite nitrogen in the water sample to be tested while digesting total phosphorus, which can effectively shorten the monitoring period. Moreover, since the circulation pool and the fourth interface of the multi-way valve are connected by a capillary, each mixed liquid begins to develop color during the process of being transported from the syringe to the circulation pool, which can reduce the color development time and further shorten the monitoring period. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0026] Figure 1 A schematic diagram of the structure of an online water quality monitoring system provided in an embodiment of the present application;

[0027] Figure 2 This is a schematic diagram of the structures of the sampling module, colorimetric module and digestion module of the online water quality monitoring system provided in an embodiment of the present application.

[0028] Among them, the reference numerals in the figure are:

[0029] 100-digestion module; 110-digestion tank; 200-colorimetric module; 210-circulation cell; 220-light transmitter; 230-light receiver; 300-injection module; 310-multi-way valve; 311-second interface; 312-third interface; 313-fourth interface; 314-fifth interface; 320-syringe; 330-capillary; 400-spectral detection module; 410-spectrometer; 420-second peristaltic pump; 500-sand settling tank; 510-first liquid level gauge; 520-first drain pipe; 530-first drain valve; 600-water intake pump; 700-water storage tank; 710-second drain pipe; 720-second drain valve; 800-first peristaltic pump; 900-parameter monitoring module; 1000-filtration unit. DETAILED DESCRIPTION

[0030] Embodiments of the present application are described in detail below, and examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to be used to explain the present application, and should not be construed as limiting the present application.

[0031] In the description of the present application, it should be understood that the terms "upper", "lower", "inside", "outside", etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present application.

[0032] In addition, the terms "first", "second", "third", "fourth", and "fifth" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Thus, a feature defined as "first", "second", "third", "fourth", and "fifth" may explicitly or implicitly include one or more of the feature. In the description of this application, the meaning of "multiple" is two or more, unless otherwise clearly and specifically defined.

[0033] See also Figure 1 and Figure 2, the water quality online monitoring system provided by the embodiment of the present application is now described. The water quality online monitoring system includes: a digestion module 100, a colorimetric module 200, an injection module 300 and a control module (not shown in the figure), the digestion module 100 includes a digestion tank 110 and a heating unit (not shown in the figure) disposed in the digestion tank 110; the colorimetric module 200 includes a circulation pool 210, a light emitter 220 and a light receiver 230, the light emitter 220 includes a first monochromatic light source (not shown in the figure) and a second monochromatic light source (not shown in the figure), the light emitted by the first monochromatic light source and the light emitted by the second monochromatic light source both pass through the circulation pool 210 Then it is received by the light receiver 230; the injection module 300 includes a multi-way valve 310, multiple reagent containers (not shown in the figure) and a syringe 320, the multi-way valve 310 has a first interface (not shown in the figure) connected to the syringe 320, a second interface 311 for the water sample to be tested to pass through, a third interface 312 connected to the digestion tank 110, a fourth interface 313 connected to the circulation pool 210 through the capillary 330, and multiple fifth interfaces 314 respectively connected to the corresponding reagent containers; the control module is electrically connected to the heating unit, the light emitter 220, the light receiver 230, the multi-way valve 310 and the syringe 320.

[0034] It is worth noting that the digestion module 100 can provide conditions for the total phosphorus digestion reaction and the total nitrogen digestion reaction of the water sample to be tested by heating and / or pressurizing. The colorimetric module 200 can determine the solubility of the substance to be tested in the solution by comparing the color depth of the water sample to be tested after adding the reagent, such as determining the ammonia nitrogen and nitrite nitrogen content in the water sample to be tested. The control module is used to control the opening and closing of the heating unit, the light transmitter 220, the light receiver 230 and the injector 320, and control the first interface of the multi-way valve 310 to be turned on or off with the second interface 311, the third interface 312, the fourth interface 313 and the plurality of fifth interfaces 314. The number of the fifth interface 314 of the multi-way valve 310 can be set as needed, and is not uniquely limited here. The number of reagent containers corresponds to the number of the fifth interface 314. Each reagent container can be used to hold pure water for cleaning the online water quality monitoring system, and can also be used to hold various reaction reagents, such as total phosphorus oxidizer, total phosphorus color developer, total phosphorus reductant, ammonia nitrogen oxidizer, ammonia nitrogen color developer, ammonia nitrogen catalyst or nitrite nitrogen color developer, etc., which can be set according to needs and are not limited here.

[0035] When the online water quality monitoring system provided by the present application is used, firstly, the total phosphorus oxidant, the total phosphorus color developer, the total phosphorus reductant, the ammonia nitrogen oxidant, the ammonia nitrogen color developer, the ammonia nitrogen catalyst and the nitrite nitrogen color developer are respectively loaded into corresponding reagent containers, then, the water sample to be tested and the total phosphorus oxidant are extracted through the syringe 320 to form a first mixed solution, and the first mixed solution is transported to the digestion module 100 for digestion; while the first mixed solution is being digested, the ammonia nitrogen oxidant, the ammonia nitrogen color developer, the ammonia nitrogen catalyst and the water sample to be tested are extracted through the syringe 320 to form a second mixed solution, and the second mixed solution is transported to the circulation pool 210, and the second mixed solution is irradiated by the first monochromatic light source and the light receiver 230. The mixed solution is subjected to colorimetric analysis to monitor the ammonia nitrogen content in the water sample to be tested; then, the water sample to be tested and the nitrite nitrogen color developer are extracted through the syringe 320 to form a third mixed solution, and the third mixed solution is transported to the circulation pool 210, and the second monochromatic light source and the light receiver 230 perform colorimetric analysis on the third mixed solution to monitor the nitrite nitrogen content in the water sample to be tested; finally, the total phosphorus color developer and the total phosphorus reducing agent and the digested first mixed solution are sucked by the syringe 320 to form a fourth mixed solution, and the fourth mixed solution is transported to the circulation pool 210, and the first monochromatic light source and the light receiver 230 perform colorimetric analysis on the fourth mixed solution to monitor the total phosphorus content in the water sample to be tested. The above-mentioned online water quality monitoring system is easy to produce and easy to promote and apply; in addition, the above-mentioned online water quality monitoring system can reasonably arrange the monitoring order of each factor, and detect the content of ammonia nitrogen and nitrite nitrogen in the water sample to be tested while digesting the total phosphorus, which can effectively shorten the monitoring period. Moreover, since the circulation pool 210 is connected to the fourth interface 313 of the multi-way valve 310 by a capillary 330, each mixed liquid begins to develop color during the process of being transported from the syringe 320 to the circulation pool 210, which can reduce the color development time and further shorten the monitoring period.

[0036] In addition, the water quality online monitoring system provided in the embodiment of the present application adopts a multi-way valve 310 and a syringe 320 for sample injection. The single reagent single liquid extraction volume is 10ul, which is only one percent of the reagent usage of existing equipment with the same principle. The reagent usage is small and secondary pollution is not easy to occur.

[0037] In another embodiment of the present application, the first monochromatic light source is used to emit monochromatic light with a wavelength of 695nm-705nm, and the second monochromatic light source is used to emit monochromatic light with a wavelength of 535nm-545nm.

[0038] It is worth noting that, since the same solution absorbs light of different wavelengths to different degrees, a first monochromatic light source with a wavelength between 695nm-705nm and a second monochromatic light source with a wavelength between 535nm-545nm are selected respectively, which can ensure that the second mixed solution used to detect the ammonia nitrogen content of the water sample to be tested and the fourth mixed solution used to detect the total phosphorus content of the water sample to be tested can both have good absorbance to the light emitted by the first monochromatic light source, and the third mixed solution used to detect the nitrite nitrogen content in the water sample to be tested also has good absorbance to the light emitted by the second monochromatic light source, which can improve the system integration and the monitoring accuracy of ammonia nitrogen, total phosphorus and nitrite nitrogen contents.

[0039] In another embodiment of the present application, the diameter of the capillary tube 330 is 0.5 mm-0.7 mm.

[0040] It is worth noting that the second mixed solution, the third mixed solution and the fourth mixed solution have begun to develop color rapidly during the process of being transported from the syringe 320 to the circulation pool 210 through the capillary 330. When reaching the circulation pool 210, a relatively stable color development system has been formed, which can be directly scanned by the first monochromatic light source or the second monochromatic light source, and the colorimetric signal can be collected by the light receiver 230, thereby realizing the monitoring of ammonia nitrogen, total phosphorus and nitrite nitrogen in the water sample to be tested. The water quality online monitoring system adopting the above structure can quickly develop color in the second mixed solution, the third mixed solution and the fourth mixed solution during the transportation process, and the color development time is less than 2 minutes, which is conducive to shortening the monitoring cycle.

[0041] In another embodiment of the present application, please refer to Figure 1 The online water quality monitoring system also includes a sand settling tank 500 and a water pump 600 that are connected to each other. The water pump 600 is electrically connected to the control module and is used to pump the water sample to be tested into the sand settling tank 500. Each reagent container is arranged in the sand settling tank 500.

[0042] It is worth noting that the reagent container has various forms, such as a reagent kit, a reagent bag, etc., which is not limited here.

[0043] The online water quality monitoring system provided in the embodiment of the present application stores the reagent container containing the reagent in the grit tank 500 and immerses it below the liquid surface in the grit tank 500. The reagent can be preserved by utilizing the temperature of the water sample to be tested. While ensuring the effective preservation of the reagent, no additional storage equipment is required, which effectively simplifies the structure of the online water quality monitoring system, reduces production costs, facilitates the promotion and application of the above-mentioned online water quality monitoring system, and can reduce the maintenance frequency of the online water quality monitoring system.

[0044] In another embodiment of the present application, please refer to Figure 1The online water quality monitoring system further includes a first peristaltic pump 800 and a water storage tank 700 connected to the second interface of the multi-way valve 320. The first peristaltic pump 800 is used to transport the water sample to be tested in the grit tank 500 to the water storage tank 700. The online water quality monitoring system adopting the above structure can reduce the influence of the pressure fluctuation in the grit tank 500 on the sampling module 300, thereby further improving the monitoring accuracy of the above online water quality monitoring system.

[0045] In another embodiment of the present application, the water quality online monitoring system further includes a first liquid level meter 510 disposed in the sand settling tank 500, the sand settling tank 500 is provided with a first drain pipe 520, and the first drain pipe 520 is provided with a first drain valve 530;

[0046] And / or, the online water quality monitoring system further includes a second liquid level gauge (not shown) disposed in the water storage tank 700 , the water storage tank is provided with a second drain pipe 710 , and the second drain pipe 710 is provided with a second drain valve 720 .

[0047] The water quality online monitoring system using the above structure can ensure that the water samples to be tested in the grit tank 500 and the water storage tank 700 are at a suitable liquid level, thereby ensuring the monitoring reliability of the above water quality online monitoring system.

[0048] In another embodiment of the present application, the online water quality monitoring system further includes a filtering unit 1000, which is disposed at the inlet end of the water intake pump 600. The online water quality monitoring system using the above structure can preliminarily filter impurities such as silt in the water sample to be tested pumped into the sand settling tank 500.

[0049] In another embodiment of the present application, the online water quality monitoring system also includes a spectral detection module 400 , which includes a spectrometer 410 and a second peristaltic pump 420 . The second peristaltic pump 420 is used to transport the water sample to be tested in the grit tank 500 to the spectrometer 410 .

[0050] It is worth noting that the spectrometer 410 is an ultraviolet-visible spectrometer, which uses a xenon lamp as a light source and can provide visible light and ultraviolet light. The measurement wavelength range of the ultraviolet-visible spectrometer is 190nm to 880nm. UV254 refers to the ultraviolet absorbance of the water sample to be tested under the unit cuvette optical path at a wavelength of 254nm. The value of UV254 has a high correlation with the concentration of organic matter such as humus in the water. The water quality online monitoring system provided in this embodiment can measure the content of UV254 and nitrate nitrogen through the ultraviolet-visible spectrometer while measuring the content of ammonia nitrogen, total phosphorus and nitrite nitrogen through the sampling module 300, the digestion module 100 and the colorimetric module 200, and finally add the content of ammonia nitrogen, nitrite nitrogen and nitrate nitrogen to obtain the total nitrogen content of the water sample to be tested.

[0051] In another embodiment of the present application, the online water quality monitoring system also includes a monitoring module 900 for detecting water temperature, pH value, dissolved oxygen, conductivity and turbidity parameters of the water sample to be tested.

[0052] It is worth mentioning that the parameter monitoring module 900 includes a thermometer, a pH meter, a conductivity meter, a turbidity meter and a dissolved oxygen tester, which can be installed in a sand settling tank 500 or a water storage tank 700 to measure the temperature, pH value, dissolved oxygen, conductivity and turbidity of the water sample to be tested, thereby enriching the functions of the water quality monitoring system and improving the integration of the equipment.

[0053] The embodiment of the present application also provides a method for online water quality monitoring. The method for online water quality monitoring adopts the above-mentioned online water quality monitoring system. The method for online water quality monitoring includes the following steps:

[0054] Putting a total phosphorus oxidant, a total phosphorus color developer, a total phosphorus reductant, a nitrite nitrogen color developer, an ammonia nitrogen oxidant, an ammonia nitrogen color developer and an ammonia nitrogen catalyst into corresponding reagent containers respectively;

[0055] The syringe 320 extracts the water sample to be tested and the total phosphorus oxidant to form a first mixed solution, and transports the first mixed solution to the digestion tank 110 for digestion;

[0056] While the first mixed solution is being digested, the injector 320 extracts the water sample to be tested, the ammonia nitrogen oxidizer, the ammonia nitrogen color developer and the ammonia nitrogen catalyst to form a second mixed solution, and the second mixed solution is transported to the circulation pool 210. Subsequently, the first monochromatic light source of the light transmitter 220 emits a first light toward the circulation pool 210. The first light passes through the circulation pool 210 and is received by the light receiver 230. The light receiver 230 receives the first light and forms a first light signal and transmits the first light signal to the control module.

[0057] Next, the syringe 320 extracts the water sample to be tested and the nitrite nitrogen color developer to form a third mixed solution, and the third mixed solution is transported to the circulation cell 210. Then, the second monochromatic light source of the light transmitter 220 emits a second light toward the circulation cell 210. The second light passes through the circulation cell 210 and is received by the light receiver 230. The light receiver 230 receives the second light and forms a second light signal, and transmits the second light signal to the control module.

[0058] Next, the syringe 320 extracts the total phosphorus color developer, the total phosphorus reducing agent and the first mixed solution from the digestion tank 110 to form a fourth mixed solution, and transports the fourth mixed solution to the circulation pool 210. Then, the first monochromatic light source of the light transmitter 220 emits a third light toward the circulation pool 210. The third light passes through the circulation pool 210 and is received by the light receiver 230. After receiving the third light, the light receiver 230 forms a third light signal and transmits the third light signal to the control module.

[0059] It is worth noting that for monitoring total phosphorus in the water body to be tested, potassium persulfate solution can be first added to the water sample to be tested to perform a digestion reaction of total phosphorus, and the total phosphorus content of the first mixed solution after digestion can be measured by molybdenum antimony anti-spectrophotometry or malachite green-phosphomolybdic acid spectrophotometry. This is not a sole limitation. For monitoring ammonia nitrogen content, Nessler spectrophotometry or salicylic acid-hypochlorite spectrophotometry can be used, which is not a sole limitation. For monitoring nitrate nitrogen, diazo coupling spectrophotometry can be used, which is not a sole limitation.

[0060] It is worth noting that the online water quality monitoring method can also use the parameter monitoring module 900 to detect the temperature, pH value, dissolved oxygen, conductivity and turbidity of the water body to be tested, and / or use the spectral module to detect the UV254 and nitrate nitrogen content of the water body to be tested, and the factors to be monitored can be selected according to needs.

[0061] By adopting the online water quality monitoring method provided in this embodiment, while the first mixed solution is performing a total phosphorus digestion reaction in the digestion module 100, the content of ammonia nitrogen and nitrite nitrogen can be detected by the colorimetric module 200, thereby shortening the multi-factor monitoring cycle and quickly realizing the monitoring of total phosphorus, ammonia nitrogen and nitrite nitrogen in the water body to be tested.

[0062] The above are only preferred embodiments of the present application and are not intended to limit the present application. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present application should be included in the protection scope of the present application.

Claims

1. A method for online water quality monitoring, characterized in that: The water quality online monitoring method comprises the following steps: Putting a total phosphorus oxidant, a total phosphorus color developer, a total phosphorus reductant, an ammonia nitrogen oxidant, an ammonia nitrogen color developer, an ammonia nitrogen catalyst and a nitrite nitrogen color developer into corresponding reagent containers respectively; The syringe extracts the water sample to be tested and the total phosphorus oxidant to form a first mixed solution, and the first mixed solution is transported to a digestion tank for digestion; While the first mixed solution is being digested, the syringe draws the water sample to be tested, the ammonia nitrogen oxidizer, the ammonia nitrogen color developer and the ammonia nitrogen catalyst to form a second mixed solution, and the second mixed solution is transported to a circulation pool, and then the first monochromatic light source of the light transmitter emits a first light toward the circulation pool, and the first light passes through the circulation pool and is received by the light receiver, and the light receiver forms a first light signal after receiving the first light and transmits the first light signal to the control module; Next, the syringe draws the water sample to be tested and the nitrite nitrogen color developer to form a third mixed solution, and the third mixed solution is transported to the circulation pool, and then the second monochromatic light source of the light transmitter emits a second light toward the circulation pool, and the second light passes through the circulation pool and is received by the light receiver, and the light receiver forms a second light signal after receiving the second light and transmits the second light signal to the control module; Next, the syringe draws the total phosphorus color developer, the total phosphorus reducing agent and the first mixed solution drawn from the digestion tank to form a fourth mixed solution, and the fourth mixed solution is transported to the circulation pool. Subsequently, the first monochromatic light source of the light transmitter emits a third light toward the circulation pool. The third light passes through the circulation pool and is received by the light receiver. After receiving the third light, the light receiver forms a third light signal and transmits the third light signal to the control module.

2. An online water quality monitoring system applied to the online water quality monitoring method according to claim 1, characterized in that: include: A digestion module, comprising a digestion tank and a heating unit arranged in the digestion tank; A colorimetric module, comprising a circulation cell, a light transmitter and a light receiver, wherein the light transmitter comprises a first monochromatic light source and a second monochromatic light source, and the light emitted by the first monochromatic light source and the light emitted by the second monochromatic light source both pass through the circulation cell and are received by the light receiver; The injection module comprises a multi-way valve, a plurality of reagent containers and a syringe, wherein the multi-way valve has a first interface connected to the syringe, a second interface for passing the water sample to be tested, a third interface connected to the digestion tank, a fourth interface connected to the circulation pool through a capillary, and a plurality of fifth interfaces respectively connected to the corresponding reagent containers; A control module is electrically connected to the heating unit, the light emitter, the light receiver, the multi-way valve and the syringe.

3. The water quality online monitoring system according to claim 2, characterized in that: The first monochromatic light source is used to emit monochromatic light with a wavelength of 695nm-705nm, and the second monochromatic light source is used to emit monochromatic light with a wavelength of 535nm-545nm.

4. The water quality online monitoring system according to claim 2, characterized in that: The capillary tube has a diameter of 0.5 mm to 0.7 mm.

5. The water quality online monitoring system according to claim 2, characterized in that: The water quality online monitoring system also includes a sand settling tank and a water pump that are connected to each other. The water pump is electrically connected to the control module and is used to draw the water sample to be tested into the sand settling tank. Each of the reagent containers is arranged in the sand settling tank.

6. The water quality online monitoring system according to claim 5, characterized in that: The online water quality monitoring system also includes a first peristaltic pump and a water storage tank connected to the second interface of the multi-way valve, and the first peristaltic pump is used to transport the water sample to be tested in the sand settling tank to the water storage tank.

7. The water quality online monitoring system according to claim 6, characterized in that: The water quality online monitoring system further comprises a first liquid level gauge disposed in the sand settling tank, the sand settling tank is provided with a first drain pipe, and the first drain pipe is provided with a first drain valve; And / or, the water quality online monitoring system further comprises a second liquid level gauge arranged in the water storage tank, the water storage tank is provided with a second drain pipe, and the second drain pipe is provided with a second drain valve.

8. The water quality online monitoring system according to claim 5, characterized in that: The water quality online monitoring system further comprises a filtering unit, and the filtering unit is arranged at the inlet end of the water intake pump.

9. The water quality online monitoring system according to claim 5, characterized in that: The water quality online monitoring system further comprises a spectrum detection module, which comprises a spectrometer and a second peristaltic pump, wherein the second peristaltic pump is used to transport the water sample to be tested in the grit tank to the spectrometer.

10. The water quality online monitoring system according to any one of claims 2 to 9, characterized in that: The water quality online monitoring system also includes a parameter monitoring module for detecting water temperature, pH value, dissolved oxygen, conductivity and turbidity of the water sample to be tested.

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