Total nitrogen water quality on-line monitor

Abstract

This invention discloses an online total nitrogen water quality monitor, comprising: an infusion module for delivering water samples or solutions; a metering module, the outlet of which is connected to the inlet of which is used to measure the volume of the liquid; a reaction module, the outlet of which is connected to the inlet of which is used to perform mixing, heating digestion, and colorimetric reaction of the water sample and reagents; and a detection module, located on the reaction module, for detecting the total nitrogen concentration of the water sample. The advantages of this invention are: it automatically completes the entire process of water sample and reagent delivery, metering, mixing, digestion, colorimetric reaction, and detection, eliminating the need for complex manual operations, significantly reducing the skill requirements for laboratory personnel, avoiding errors caused by manual operation, and improving the reliability and consistency of the detection results.

Description

Technical Field

[0001] This invention relates to the field of water quality monitoring, specifically to an online total nitrogen water quality monitoring instrument. Background Technology

[0002] Currently, the total nitrogen content in water bodies is an important indicator for measuring the degree of eutrophication of water quality, and it is widely used in environmental monitoring fields such as surface water, industrial wastewater, and domestic sewage.

[0003] Traditional total nitrogen (TNI) detection mainly relies on offline laboratory analysis methods, which have the following limitations: they require multiple steps, including manual water sample collection, reagent addition, heating digestion, and measurement; they demand high skill levels from laboratory personnel; and each test cycle is long, making it difficult to meet the needs of real-time and continuous monitoring. Therefore, developing an online TNI water quality monitoring instrument has become an urgent need in the field of water environment monitoring. Summary of the Invention

[0004] The purpose of this invention is to overcome the above-mentioned technical deficiencies and propose an online total nitrogen water quality monitoring instrument to solve the technical problems of cumbersome manual operation, long cycle and large error in the prior art.

[0005] To achieve the above-mentioned technical objectives, the present invention provides an online total nitrogen water quality monitoring instrument, including an infusion module, which is used to deliver water samples or solutions; A metering module is provided, wherein the outlet of the infusion module is connected to the inlet of the metering module, and the metering module is used to measure the volume of the liquid. The reaction module, wherein the outlet of the metering module is connected to the inlet of the reaction module, is used to achieve mixing of water sample and reagent, heating digestion, and colorimetric reaction; and, A detection module is provided on the reaction module, and the detection module is used to detect the total nitrogen concentration of the water sample.

[0006] In some embodiments, the infusion module includes a metering pump, the outlet of which is connected to the inlet of the metering module.

[0007] In some embodiments, the metering module includes a metering tube, the outlet of the metering pump is connected to the inlet of the metering tube, the outlet of the metering tube is connected to the inlet of the reaction module, and the metering tube is provided with high liquid level, medium liquid level and low liquid level, and the three liquid level detection points correspond to different metering volumes to realize multi-range metering.

[0008] In some embodiments, the metering module further includes a multi-connected valve, which has multiple interfaces for water sample, reagent A, reagent B, blank water, analytical waste liquid, and cleaning waste liquid. The multi-connected valve is interconnected with the metering tube, and the multi-connected valve works in conjunction with the metering tube to achieve the switching and delivery of different liquids.

[0009] In some embodiments, the reaction module includes a reaction tank and a digestion mechanism. The outlet of the metering tube is connected to the inlet of the reaction tank. The digestion mechanism is located inside the reaction tank and is used to heat the mixture in the reaction tank to 120°C and keep it at that temperature to achieve complete digestion of nitrogen-containing compounds in the water sample.

[0010] In some embodiments, the digestion mechanism includes a heating wire and a thermocouple sensor, the heating wire being wound around the outside of the reaction tank and the thermocouple sensor being mounted on the reaction tank.

[0011] In some embodiments, the detection module includes an emission light source and a photoelectric converter, which are respectively located on both sides of the reaction tank. The emission light source can emit monochromatic light of two wavelengths, 220nm and 275nm. The total nitrogen concentration of the water sample is converted by measuring the voltage value of the photoelectric converter.

[0012] In some embodiments, the infusion module further includes a solenoid valve one and a solenoid valve two, which are respectively installed at the inlet and outlet of the reaction tank.

[0013] Compared with the prior art, the beneficial effects of the present invention include: automatically completing the entire process of water sample and reagent transportation, metering, mixing, digestion, color development and detection, without the need for complex manual operations, greatly reducing the skill requirements for laboratory personnel, while avoiding errors caused by manual operation, and improving the reliability and consistency of detection results. Attached Figure Description

[0014] Figure 1 This is a schematic diagram of the overall structure of the online monitoring instrument provided by the present invention; Figure 2 This is a cross-sectional view of the overall structure of the reaction tank provided by the present invention.

[0015] Explanation of reference numerals in the attached figures: 1. Infusion Module; 11. Metering Pump; 12. Solenoid Valve 1; 13. Solenoid Valve 2; 2. Metering Module; 21. Metering Tube; 211. High Liquid Level; 212. Medium Liquid Level; 213. Low Liquid Level; 22. Multi-connected Valve; 221. Water Sample; 222. Reagent A; 223. Reagent B; 224. Blank Water; 225. Analytical Waste Liquid; 226. Cleaning Waste Liquid; 3. Reaction Module; 31. Reaction Cell; 32. Digestion Mechanism; 321. Heating Wire; 322. Thermocouple Sensor; 4. Detection Module; 41. Emission Light Source; 42. Photoelectric Converter. Detailed Implementation

[0016] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0017] This invention provides an online total nitrogen water quality monitor, the structure of which is as follows: Figures 1-2 As shown, it includes an infusion module 1, which is used to deliver water sample 221 or solution; Metering module 2 is connected to the outlet of infusion module 1 and the inlet of metering module 2. Metering module 2 is used to measure the volume of liquid. The outlet of reaction module 2 is connected to the inlet of reaction module 3. Reaction module 3 is used to mix water sample 221 with reagents, perform heating digestion, and conduct colorimetric reactions; and, The detection module 4 is located on the reaction module 3 and is used to detect the total nitrogen concentration of water sample 221.

[0018] During use, the infusion module 1 starts working and automatically extracts water sample 221 or various reagents according to the monitoring instructions, and smoothly delivers the liquid to the metering module 2 through the outlet. After receiving the liquid delivered by the infusion module 1, the metering module 2 accurately measures the volume of water sample 221 and reagents to ensure that the ratio of water sample 221 to reagents meets the requirements of digestion and colorimetric reaction. After the metering is completed, the qualified liquid is sequentially delivered to the reaction module 3. After receiving the metered water sample 221 and reagents, the reaction module 3 automatically completes the mixing, heating digestion and colorimetric reaction. First, water sample 221 is thoroughly mixed with the digestion solution and heated for digestion under high temperature conditions to oxidize and digest all nitrogen-containing compounds in water sample 221 into nitrate nitrogen. Then, the digested solution is mixed with the colorimetric reagent to generate a stable colorimetric product, providing a measurable reaction object for subsequent concentration detection. The detection module 4 monitors the products in the reaction module 3 in real time. By irradiating the reaction liquid with the emission light source 41, the light signal is converted into an electrical signal by utilizing the absorption characteristics of the product to light of a specific wavelength. Then, combined with the calibration curve, the concentration of total nitrogen in water sample 221 is automatically calculated, realizing the online detection of total nitrogen concentration.

[0019] In this invention, the entire process of water sample 221 and reagent delivery, metering, mixing, digestion, color development and detection is completed automatically, without the need for complicated manual operations, which greatly reduces the skill requirements for laboratory personnel, avoids errors caused by manual operation, and improves the reliability and consistency of test results.

[0020] To extract water sample 221 and reagents, please refer to... Figure 1 In a preferred embodiment, the infusion module 1 includes a metering pump 11, the outlet of which is connected to the inlet of the metering module 2.

[0021] During use, after the system starts the monitoring process, the control unit sends a delivery command to the metering pump 11. The metering pump 11, through its own precise control, quantitatively extracts a preset amount of water sample 221 or reagent. After extraction, the metering pump 11 starts the delivery action, and through the connection between its outlet and the inlet of the metering module 2, it steadily and uniformly delivers the extracted liquid to the metering module 2, ensuring that all the liquid is introduced into the metering module 2 for subsequent accurate measurement.

[0022] To achieve accurate measurement across multiple ranges, please refer to... Figure 1 In a preferred embodiment, the metering module 2 includes a metering tube 21, the outlet of the metering pump 11 is connected to the inlet of the metering tube 21, the outlet of the metering tube 21 is connected to the inlet of the reaction module 3, and the metering tube 21 is provided with a high liquid level 211, a medium liquid level 212 and a low liquid level 213, with the three liquid level detection points corresponding to different metering volumes, so as to realize multi-range metering.

[0023] During operation, when the system initiates the metering process, the metering pump 11 delivers liquid into the metering tube 21. The control unit selects the corresponding liquid level detection point based on monitoring requirements. When the liquid level rises to the selected detection point, the liquid level sensor immediately triggers a signal, and the metering pump 11 immediately stops delivering liquid, ensuring that the metered volume accurately matches the preset value and achieving precise multi-range metering. The delivery action of the metering pump 11 is precisely coordinated with the liquid level detection point: when the liquid level approaches the target level, the metering pump 11 automatically reduces the delivery speed to prevent excessive liquid from entering; when the liquid level reaches the target level, the metering pump 11 immediately stops, ensuring no deviation in the metered volume. Simultaneously, the metering tube 21 contains a slender cylindrical glass tube, which reduces liquid residue, further improving metering accuracy and ensuring that the ratio of water sample 221 to reagents meets the requirements for digestion and colorimetric reactions.

[0024] To enable the switching and delivery of different liquids, please refer to... Figure 1 In a preferred embodiment, the metering module 2 further includes a multi-connected valve 22, which is provided with multiple interfaces such as water sample 221, reagent A 222, reagent B 223, blank water 224, analytical waste liquid 225, and cleaning waste liquid 226. The multi-connected valve 22 is interconnected with the metering tube 21, and the multi-connected valve 22 works with the metering tube 21 to realize the switching and delivery of different liquids.

[0025] During operation, when the system initiates the metering process, the control unit sends a switching command to the multi-connected valve 22 according to monitoring requirements. The multi-connected valve 22 precisely switches to the target liquid interface, simultaneously controlling the metering pump 11 to start. Through the interconnection channel between the multi-connected valve 22 and the metering tube 21, the water sample 221 is smoothly delivered into the metering tube 21, achieving directional delivery of a single liquid and preventing premature mixing of different liquids. The metering tube 21 achieves multi-range metering through three liquid level detection points: high, medium, and low. The switching action of the multi-connected valve 22 is linked to the metering action of the metering tube 21. When the liquid level in the metering tube 21 reaches the preset level, the liquid level detection point triggers a signal, the metering pump 11 immediately stops delivery, and the multi-connected valve 22 synchronously switches to the next target liquid interface, sequentially completing the separate metering and delivery of different liquids such as water sample 221, reagent A 222, and reagent B 223, ensuring that the metered volume of each liquid matches the reaction requirements.

[0026] To ensure a complete reaction between water sample 221 and the reagent, please refer to... Figure 2 In a preferred embodiment, the reaction module 3 includes a reaction tank 31 and a digestion mechanism 32. The outlet of the metering tube 21 is connected to the inlet of the reaction tank 31. The digestion mechanism 32 is located inside the reaction tank 31 and is used to heat the mixture in the reaction tank 31 to 120°C and keep it warm to achieve full digestion of nitrogen-containing compounds in the water sample.

[0027] During use, the water sample 221 and reagents, measured in the metering tube 21, enter the reaction tank 31 through the outlet of the metering tube 21. After mixing, the digestion mechanism 32 starts working, stably heating the mixed liquid in the reaction tank 31 to 120°C and maintaining this temperature for a set time. Under high temperature conditions, all nitrogen-containing compounds in the water sample 221 are completely oxidized and digested, uniformly converted into nitrate nitrogen, ensuring that subsequent test results accurately reflect the total nitrogen content of the water sample 221. After the heat preservation and digestion are completed, the digestion mechanism 32 stops heating.

[0028] To achieve complete digestion of nitrogen-containing compounds, please refer to... Figure 2 In a preferred embodiment, the digestion mechanism 32 includes a heating wire 321 and a thermocouple sensor 322. The heating wire 321 is wound around the outside of the reaction tank 31, and the thermocouple sensor 322 is mounted on the reaction tank 31.

[0029] During use, the heating wire 321 is wound around the outside of the reaction tank 31. After being energized, it heats the reaction tank 31 to provide the required temperature for digestion of the material inside the reaction tank 31. Thermocouple sensor 322 detects the temperature of the reaction tank 31 in real time and feeds the temperature signal back to the control terminal to realize real-time monitoring and precise temperature control of the heating temperature, ensuring that the digestion process is carried out at a stable and suitable temperature, thereby improving digestion efficiency and digestion effect.

[0030] To perform total nitrogen detection, please refer to... Figure 1 In a preferred embodiment, the detection module 4 includes an emission light source 41 and a photoelectric converter 42. The emission light source 41 and the photoelectric converter 42 are respectively disposed on both sides of the reaction tank 31. The emission light source 41 can emit monochromatic light of two wavelengths, 220nm and 275nm. The total nitrogen concentration of the water sample 221 is converted by measuring the voltage value of the photoelectric converter 42.

[0031] During operation, after digestion and color development, the emission light source 41 emits monochromatic light of two wavelengths, 220nm and 275nm, into the test liquid in the reaction tank 31. The light passes through the transparent reaction tank 31 and the internal liquid, and is received by the photoelectric converter 42 on the other side. Nitrate nitrogen in the test liquid exhibits characteristic absorption at a wavelength of 220nm, while interfering components such as turbidity and organic matter in the water body produce corresponding absorption at a wavelength of 275nm. The photoelectric converter 42 converts the received light signal into a corresponding voltage signal and transmits it to the control system. Based on the voltage values ​​at both wavelengths, the control system calculates the corrected absorbance, eliminates turbidity and background interference, and then converts the absorbance signal into the total nitrogen concentration in the water sample 221 using a built-in standard curve, achieving accurate online detection of total nitrogen.

[0032] To achieve automated control of liquid inlet, reaction, and drain, please refer to... Figure 1 In a preferred embodiment, the infusion module 1 further includes a first solenoid valve 12 and a second solenoid valve 13, which are respectively installed at the inlet and outlet of the reaction tank 31.

[0033] In operation, solenoid valve 12 is installed at the inlet of reaction tank 31, and solenoid valve 13 is installed at the outlet of reaction tank 31. Both are controlled by the control system, coordinating with the working sequence of metering module 2, reaction module 3, and detection module 4. During the liquid inlet phase, solenoid valves 12 and 13 open, allowing the metered liquid in metering tube 21 to smoothly enter the reaction tank 31 while preventing liquid outflow from the outlet, ensuring accurate liquid inlet volume. During the mixing, digestion, and detection phases, both solenoid valves 12 and 13 remain closed, creating a closed space within reaction tank 31. This ensures a stable high-temperature digestion environment, prevents liquid leakage or backflow, and guarantees reliable digestion and detection processes. During the draining and cleaning phase, solenoid valves 12 and 13 open, allowing the reaction waste liquid and cleaning waste liquid 226 in reaction tank 31 to be smoothly discharged, preparing for the next monitoring cycle.

[0034] To better understand this invention, the following is combined with... Figures 1-2The working principle of the online total nitrogen water quality monitoring instrument of the present invention is described in detail below: The infusion module 1 starts working and automatically extracts water sample 221 or various reagents according to the monitoring command, and smoothly delivers the liquid to the metering module 2 through the outlet. After receiving the liquid delivered by the infusion module 1, the metering module 2 accurately measures the volume of water sample 221 and reagents to ensure that the ratio of water sample 221 to reagents meets the requirements of digestion and colorimetric reaction. After metering, the qualified liquid is sequentially delivered to the reaction module 3. After receiving the metered water sample 221 and reagents, the reaction module 3 automatically completes mixing, heating digestion, and colorimetric reaction. First, water sample 221 is thoroughly mixed with the digestion solution and heated for digestion under high temperature conditions, oxidizing and digesting all nitrogen-containing compounds in water sample 221 into nitrate nitrogen. Subsequently, the digested solution is mixed with the colorimetric reagent, and a colorimetric reaction occurs to generate a stable colorimetric product, providing a measurable reaction object for subsequent concentration detection. The detection module 4 monitors the products in the reaction module 3 in real time. By irradiating the reaction liquid with the emission light source 41, the light signal is converted into an electrical signal by utilizing the absorption characteristics of the product to light of a specific wavelength. Then, combined with the calibration curve, the concentration of total nitrogen in water sample 221 is automatically calculated, realizing the online detection of total nitrogen concentration.

[0035] The specific embodiments of the present invention described above do not constitute a limitation on the scope of protection of the present invention. Any other corresponding changes and modifications made in accordance with the technical concept of the present invention should be included within the scope of protection of the claims of the present invention.

Claims

1. An online total nitrogen water quality monitoring instrument, characterized in that, include: Infusion module (1), the infusion module (1) is used to deliver water samples or solutions; Metering module (2), the outlet of the infusion module (1) is connected to the inlet of the metering module (2), the metering module (2) is used to measure the volume of liquid; The reaction module (3) has its outlet connected to the inlet of the metering module (2). The reaction module (3) is used to achieve mixing of water samples and reagents, heating digestion, and colorimetric reaction; and, The detection module (4) is located on the reaction module (3) and is used to detect the total nitrogen concentration of the water sample.

2. The online total nitrogen water quality monitoring instrument according to claim 1, characterized in that, The infusion module (1) includes a metering pump (11), the outlet of which is connected to the inlet of the metering module (2).

3. The online total nitrogen water quality monitoring instrument according to claim 2, characterized in that, The metering module (2) includes a metering tube (21). The outlet of the metering pump (11) is connected to the inlet of the metering tube (21). The outlet of the metering tube (21) is connected to the inlet of the reaction module (3). The metering tube (21) is equipped with a high liquid level (211), a medium liquid level (212), and a low liquid level (213). The three liquid level detection points correspond to different metering volumes to achieve multi-range metering.

4. The online total nitrogen water quality monitoring instrument according to claim 3, characterized in that, The metering module (2) also includes a multi-connected valve (22), which is provided with multiple interfaces such as water sample (221), reagent A (222), reagent B (223), blank water (224), analytical waste liquid (225), and cleaning waste liquid (226). The multi-connected valve (22) is interconnected with the metering tube (21), and the multi-connected valve (22) works with the metering tube (21) to realize the switching and delivery of different liquids.

5. The online total nitrogen water quality monitoring instrument according to claim 3, characterized in that, The reaction module (3) includes a reaction tank (31) and a digestion mechanism (32). The outlet of the metering tube (21) is connected to the inlet of the reaction tank (31). The digestion mechanism (32) is located inside the reaction tank (31). The digestion mechanism (32) is used to heat the mixture in the reaction tank (31) to 120°C and keep it warm to achieve full digestion of nitrogen-containing compounds in the water sample.

6. The online total nitrogen water quality monitoring instrument according to claim 5, characterized in that, The digestion mechanism (32) includes a heating wire (321) and a thermocouple sensor (322). The heating wire (321) is wound around the outside of the reaction tank (31), and the thermocouple sensor (322) is installed on the reaction tank (31).

7. The online total nitrogen water quality monitoring instrument according to claim 5, characterized in that, The detection module (4) includes an emission light source (41) and a photoelectric converter (42). The emission light source (41) and the photoelectric converter (42) are respectively located on both sides of the reaction tank (31). The emission light source (41) can emit monochromatic light of two wavelengths, 220nm and 275nm. The total nitrogen concentration of the water sample is converted by measuring the voltage value of the photoelectric converter (42).

8. The online total nitrogen water quality monitoring instrument according to claim 5, characterized in that, The infusion module (1) also includes a solenoid valve one (12) and a solenoid valve two (13), which are respectively installed at the inlet and outlet of the reaction tank (31).

Images