Water quality ammonia nitrogen / total phosphorus two-in-one automatic monitor

Abstract

According to the water quality ammonia nitrogen / total phosphorus two-in-one automatic monitor, the liquid storage ring is introduced, the precise injection pump, the multi-channel valve, the pinch valve and the liquid storage ring are matched with one another, detection reagents of ammonia nitrogen and total phosphorus are automatically metered, all the metered reagents are temporarily stored in the liquid storage ring and do not enter the injection pump any more, and therefore the water quality ammonia nitrogen / total phosphorus two-in-one automatic monitor is convenient to use. When the pipeline is purged, air is provided for the injection pump through a channel of the pinch valve, so that residual reagents and cleaning water in the pipeline are conveniently and thoroughly purged, the problem of cross contamination of the reagents is solved, the reagent volume metering precision is high, the consistency is good, and the later maintenance cost is low. The steps of pipeline rinsing, reagent metering, sample introduction, digestion, reaction, colorimetric measurement, pipeline cleaning, emptying and the like are fully automated, the ammonia nitrogen content and the total phosphorus content in water can be automatically, rapidly and accurately analyzed at the same time, and the device has the advantages of being free of reagent cross contamination, high in volume metering accuracy, low in total phosphorus digestion temperature and the like. And reliable guarantee is provided for long-term accurate monitoring of ammonia nitrogen and total phosphorus in water.

Description

Technical Field

[0001] The utility model belongs to the technical field of environmental monitoring, relates to water quality analysis technology, and more specifically to a two-in-one automatic monitoring instrument for water quality ammonia nitrogen / total phosphorus. Background Art

[0002] Ammonia nitrogen and total phosphorus are key nutrients for the growth of aquatic plants and animals, especially algae, and are important parameters reflecting water quality. my country's surface water environmental quality standards stipulate that the ammonia nitrogen content of Class III water shall not exceed 1.0 mg / L, and the total phosphorus (TP) content of lakes and reservoirs shall not exceed 0.05 mg / L. High values ​​of ammonia nitrogen and total phosphorus will cause eutrophication of water bodies, causing algal blooms and black and smelly water bodies. The current problem of water body deterioration has attracted widespread attention. Ammonia nitrogen and total phosphorus are both water quality parameters that must be measured for surface water. When conducting environmental water quality ammonia nitrogen and total phosphorus testing, automatic water quality monitoring instruments are being used more and more widely.

[0003] Traditional ammonia nitrogen and total phosphorus analyzers are single-parameter analyzers. Each device can only monitor one parameter. To monitor ammonia nitrogen and total phosphorus simultaneously, two devices are required. Not only is the equipment cost high, but the subsequent maintenance cost is also high. In terms of reagent volume measurement, some instruments use peristaltic pumps for measurement. The metering pump tube in the peristaltic pump is prone to aging and deformation during long-term rotation and extrusion, resulting in metering errors. The sulfuric acid used in total phosphorus detection is highly corrosive and will shorten the service life of the pump tube. When a syringe pump is conventionally used to measure the reagent volume, since the reagent enters the syringe pump directly, it not only affects the service life of the syringe pump, but also the piston in the syringe pump is difficult to clean. In addition, the existing technology cannot effectively solve the problem of reagent cross-contamination. For example, when ammonia nitrogen and total phosphorus are measured at the same time, the total phosphorus reagent ammonium molybdate contains a large amount of ammonium ions (NH4 + ) will seriously interfere with the measurement of ammonia nitrogen. In addition, the digestion of total phosphorus water samples needs to be carried out under high temperature (121°C) and high pressure (0.1Mpa). Not only does the digestion time take a long time, but the power consumption of the instrument is also high. Due to the certain pressure during digestion, the instrument is not safe to operate. Utility Model Content

[0004] In view of the problems existing in the prior art, the utility model proposes a two-in-one automatic monitoring instrument for ammonia nitrogen / total phosphorus in water quality with accurate metering, no reagent cross-contamination, short digestion time and low temperature. The steps of pipeline rinsing, reagent metering, sampling, digestion, reaction, colorimetric measurement, pipeline cleaning and emptying are fully automated, and automatic, rapid and accurate analysis of the ammonia nitrogen and total phosphorus content in water can be simultaneously realized. It has the advantages of no reagent cross-contamination, high volume measurement accuracy, low total phosphorus digestion temperature, etc., providing reliable guarantee for long-term and accurate monitoring of ammonia nitrogen and total phosphorus in water quality.

[0005] In order to achieve the above object, the technical solution of the utility model is as follows:

[0006] A two-in-one automatic monitoring instrument for ammonia nitrogen / total phosphorus in water quality, comprising:

[0007] The reagent metering component includes a precision injection pump, a liquid storage ring connected to the precision injection pump through a Y-type three-way connector and an electromagnetic pinch valve, and a multi-channel valve connected to the liquid storage ring; each channel of the multi-channel valve is respectively connected to pure water, each detection reagent, and a liquid outlet, and the liquid outlet is connected to the electromagnetic pinch valve, so that five detection reagents are divided into three paths, which are respectively used for ammonia nitrogen color development, total phosphorus digestion, and total phosphorus color development;

[0008] The digestion component is connected to the reagent metering component through a liquid delivery channel, and includes a digestion tube, a heating element wrapped on the surface of the digestion tube, a temperature sensor for collecting the temperature of the quartz digestion tube, and an ultraviolet lamp inserted into the digestion tube; the digestion tube has a hollow interlayer, and a sample inlet is provided at the lower end, and the sample inlet is connected to the hollow interlayer;

[0009] The reaction component is connected with the reagent metering component and the digestion component through a liquid delivery channel, and includes a reaction pool and a stirring mechanism capable of stirring the liquid in the reaction pool; the reaction pool is provided with a liquid outlet;

[0010] The photoelectric detection component is connected to the reaction component and the digestion component through a liquid delivery channel, and includes a colorimetric cell, and an LED light source and a photoelectric detector respectively arranged on both sides of the colorimetric cell. The colorimetric cell and the photoelectric detector are located on the light path emitted by the LED light source;

[0011] A control circuit, used to form an electrical connection with each electronic component;

[0012] A first peristaltic pump is connected to the sample inlet of the digestion tube through a pipeline and a plurality of Y-type three-way connectors;

[0013] The second peristaltic pump is connected to the digestion tube inlet and the reaction pool respectively through pipelines, a plurality of three-way joints and an electromagnetic pinch valve;

[0014] The third peristaltic pump is connected to the reaction cell and the digestion tube inlet respectively through pipelines, a plurality of Y-type three-way connectors and an electromagnetic pinch valve;

[0015] The fourth peristaltic pump is connected to the digestion tube inlet and the reaction cell outlet respectively through pipelines, a plurality of Y-type three-way connectors and an electromagnetic clamp valve.

[0016] Furthermore, the liquid outlet is connected to the first Y-type three-way connector, and the first Y-type three-way connector is also connected to the second Y-type three-way connector and the reaction tank through an electromagnetic clamping valve, and the second Y-type three-way connector is also connected to the sixth Y-type three-way connector and the reaction tank through an electromagnetic clamping valve.

[0017] Furthermore, the liquid storage ring is made of polytetrafluoroethylene.

[0018] Furthermore, the overflow port at the upper end of the digestion component is connected to a first T-type three-way connector, which is also connected to the first and second one-way valves, respectively; the second one-way valve is connected to a second T-type three-way connector, which is also connected to the second waste liquid channel and the colorimetric cell, respectively.

[0019] Furthermore, the outer surface of the digestion tube is coated with a light-proof layer.

[0020] Furthermore, the overflow port at the upper end of the reaction tank is connected to the first waste liquid channel.

[0021] Furthermore, a heating element and a temperature sensor are attached to the surface of the reaction pool.

[0022] Furthermore, the stirring mechanism includes: a magnetic particle placed in the reaction pool, a magnet arranged at the bottom of the reaction pool for driving the magnetic particle, and a motor for driving the magnet to rotate.

[0023] Furthermore, the reaction pool and the colorimetric pool are both provided with overflow ports, and each overflow port is connected to a waste liquid channel.

[0024] Furthermore, the control circuit is electrically connected to the photoelectric detector, the heating element, the temperature sensor, and each electromagnetic pinch valve.

[0025] Furthermore, the emission wavelength of the LED light source is 700 nm.

[0026] The beneficial effects of the utility model are:

[0027] 1. The utility model equipment can detect ammonia nitrogen during the digestion of total phosphorus, and the two do not affect each other. While realizing two detection functions on the same device, the detection efficiency of ammonia nitrogen and total phosphorus in water quality is improved, the reliability of the detection data is improved, and it can effectively solve the problem of high equipment cost of the current single parameter analysis instruments of ammonia nitrogen and total phosphorus.

[0028] 2. The utility model introduces a liquid storage ring, and adopts a precision injection pump, a multi-channel valve, a pinch valve and a liquid storage ring to cooperate with each other to automatically measure the detection reagents of ammonia nitrogen and total phosphorus. All the measured reagents are temporarily stored in the liquid storage ring and no longer enter the injection pump. When purging the pipeline, air is provided to the injection pump through the channel of the pinch valve, which is convenient for thoroughly purging the residual reagents and cleaning water in the pipeline, and can effectively eliminate the problem of reagent cross contamination. Not only is the reagent volume measurement accuracy high, but also the consistency is good and the later maintenance cost is low, and the reagent measurement error caused by repeated extrusion and deformation of the pump tube when the peristaltic pump measures the reagent volume is also avoided.

[0029] 3. The total phosphorus digestion reaction of the utility model adopts ultraviolet light-assisted catalytic oxidation digestion technology, which can promote the digestion reaction, reduce the digestion reaction temperature and pressure, do not need to operate under pressure, improve safety, and shorten the total phosphorus digestion time.

[0030] 4. The utility model adopts modular design to reduce the workload of instrument use and maintenance. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 A schematic structural diagram of a two-in-one automatic monitoring instrument for ammonia nitrogen and total phosphorus in water provided in an embodiment of the utility model.

[0032] Figure 2 Schematic diagram of the digestion components in the two-in-one automatic monitoring instrument for ammonia nitrogen / total phosphorus in water quality.

[0033] Figure 3 This is a schematic diagram of the reaction components in the two-in-one automatic monitoring instrument for ammonia nitrogen / total phosphorus in water quality.

[0034] Figure 4 This is a connection diagram of the electronic components in the utility model.

[0035] Description of the accompanying drawings:

[0036] A: Reagent metering component, in which A1 is a ten-channel valve, A2 is a precision injection pump, and A3 is a liquid storage ring; B: Digestion component, in which B1 is a quartz digestion tube, B2 is a heating element, B3 is a temperature sensor, and B4 is a UV lamp; C: Reaction component, in which C1 is a motor, C2 is a magnet, C3 is a stirring magnet, C4 is a temperature sensor, C5 is a reaction cell, and C6 is a heating element; D: Photoelectric detection component, in which D1 is an LED light source, D2 is a photoelectric detector, and D3 is a colorimetric cell; J1-J5: the first to fifth electromagnetic clamp valves; P1-P4: the first to fourth peristaltic pumps; Y1-Y9: the first to ninth Y-type three-way connectors; T1-T2: the first and second T-type three-way connectors; F1-F2: the first and second waste liquid channels; V1-V2: the first and second one-way valves. DETAILED DESCRIPTION

[0037] The technical solution provided by the present invention will be described in detail below in conjunction with specific embodiments. It should be understood that the following specific implementation methods are only used to illustrate the present invention and are not used to limit the scope of the present invention.

[0038] like Figure 1As shown, the structure of the two-in-one automatic monitoring instrument for ammonia nitrogen / total phosphorus in water quality provided by the utility model includes a reagent metering component A, a digestion component B, a reaction component C, a photoelectric detection component D and a control circuit. In addition, the monitor is also connected to a number of peristaltic pumps for liquid metering and transmission. The components are connected by a number of liquid delivery channels, and the liquid delivery channels include a number of pipes, joints and electromagnetic clamping valves. The reagent metering component A transports the reagent to the digestion component B and the reaction component C respectively through the liquid delivery channel, the digestion component B is connected to the reaction component C, and the reaction component C is connected to the photoelectric detection component D. All peristaltic pumps, electromagnetic clamping valves and electronic components in each component are electrically connected to the control circuit, feedback signals to the control circuit and are controlled by it. The connection diagram is shown in the figure. Figure 4 The control circuit uses the STM32 series microprocessor as the main control chip.

[0039] Specifically, the reagent metering component A includes a ten-channel valve A1, a liquid storage ring A3 connected to the ten-channel valve A1 through a pipeline, and a precision injection pump A2. The liquid storage ring is made of polytetrafluoroethylene, and the effective volume is not less than 6mL. Each channel of the ten-channel valve A1 is respectively connected to five detection reagents of pure water, ammonia nitrogen and total phosphorus and a liquid outlet. Specifically, each channel of the ten-channel valve is defined as follows: channel 1: liquid outlet, channel 2: cleaning water outlet, channel 3: cleaning liquid outlet, channel 4: ammonia nitrogen reagent R1, channel 5: ammonia nitrogen reagent R2, channel 6: total phosphorus reagent R1, channel 7: total phosphorus reagent R2, channel 8: total phosphorus reagent R3, channel 9: standby, channel 10: standby. As needed, a switching valve with more channels can also be used. When the multi-channel valve switches to the corresponding channel, the precision injection pump extracts the corresponding detection reagent, and the liquid is separated to the corresponding channel through the pipeline, the first and second electromagnetic clamp valves J1 and J2 for the detection of ammonia nitrogen and total phosphorus. Specifically, the liquid outlet of the precision injection pump A2 is connected to an interface of the third Y-type three-way connector Y3, and the other two interfaces of the third Y-type three-way connector Y3 are respectively connected to channel 1 and channel 2 of the third electromagnetic pinch valve J3. Channel 1 of the third electromagnetic pinch valve J3 is connected to the liquid storage ring A3, and channel 2 is directly connected to the air. The liquid outlet of the multichannel valve is connected to the electromagnetic pinch valve, and the five detection reagents are separated into three paths through the first and second electromagnetic pinch valves, which are used for ammonia nitrogen color development, total phosphorus digestion and total phosphorus color development respectively. Specifically, the liquid outlet is connected to one of the interfaces of the first Y-type three-way connector Y1, and one of the other two interfaces of the first Y-type three-way connector Y1 is connected to channel 1 of the first electromagnetic pinch valve J1, and the other is connected to channel 2 of the first electromagnetic pinch valve J1. Interface 1 of the first electromagnetic pinch valve J1 is connected to the reaction component C through a pipeline to transport ammonia nitrogen detection reagent to the reaction pool. The first electromagnetic pinch valve J1 channel 2 is connected to one of the interfaces of the second Y-type three-way connector Y2, and one of the other two interfaces of the second Y-type three-way connector Y2 is connected to the second electromagnetic pinch valve J2 channel 1, and the other is connected to the second electromagnetic pinch valve J2 channel 2. The second electromagnetic pinch valve J2 channel 1 is connected to the reaction component C through a pipeline to deliver the total phosphorus colorimetric reagent R2 / R3 to the reaction pool. The second electromagnetic pinch valve J2 channel 2 is connected to the sixth Y-type three-way connector Y6 through a pipeline, and the total phosphorus detection reagent R1 is delivered to the digestion tube injection port through the pipeline, the fifth Y-type three-way connector Y5, and the fourth Y-type three-way connector Y4.

[0040] like Figure 2As shown, the digestion assembly B includes a quartz digestion tube B1, a heating element B2 wrapped on the surface of the quartz tube, and a temperature sensor B3 attached to the surface of the digestion tube B1. The upper end of the digestion tube B1 is an overflow port, and the lower end is an injection port connected to the hollow interlayer of the digestion tube. The water sample and the total phosphorus digestion reagent R1 enter the hollow interlayer structure through the injection port for mixing. The outer surface of the quartz digestion tube B1 is chrome-plated (light-shielding layer) to prevent ultraviolet rays from leaking. The heating element B2 and the temperature sensor B3 are electrically connected to the control circuit respectively. The heating element B2 is controlled by the control circuit. The control circuit collects data from the temperature sensor B3 in real time and controls the heating unit B2 to turn on and off to keep the digestion temperature stable. The overflow port at the upper end of the digestion tube B1 is connected to the first T-type three-way connector T1, and the other two interfaces of the first T-type three-way connector T1 are respectively connected to the first one-way valve V1 and the second one-way valve V2. The two one-way valves are one-way to prevent liquid backflow. The first one-way valve V1 is connected to the direction of T1, and the second one-way valve V2 is connected to the direction away from T1. The first one-way valve V2 is connected to one joint of the second T-type three-way joint T2, and the other two joints of the second T-type three-way joint T2 are respectively connected to the waste liquid channel F2 and the liquid outlet at the upper end of the colorimetric cell.

[0041] The water sample and reagent flow in the interlayer of the quartz digestion tube B1. The ultraviolet lamp B4 is inserted into the digestion tube from the upper opening and is always in a lit state. The ultraviolet lamp B4 can emit ultra-short ultraviolet rays with typical emission wavelengths of 185nm and 254nm. During the digestion of total phosphorus, air is continuously blown into the digestion tube. The oxygen in the air can be converted into ozone under the irradiation of the ultraviolet lamp, which can promote the digestion of total phosphorus, thereby reducing the digestion reaction temperature. The digestion is also carried out under normal pressure.

[0042] like Figure 3 As shown, the reaction component C is composed of a motor C1, a magnet C2, a magnet C3, a temperature sensor C4, a reaction pool C5, and a heating element C6. The stirring method in the reaction component is magnetic stirring. The magnet C2 is fixed on the motor C1. After the motor C1 is powered on, it drives the magnet C2 to rotate, so that the magnet C3 placed in the reaction pool C5 rotates with it, and the liquid in the reaction pool is mixed. The upper end of the reaction pool C5 is an overflow port, and the lower end is a liquid outlet. The liquid outlet is connected to the fourth peristaltic pump P4. The fourth peristaltic pump P4 is connected to one of the interfaces of the ninth Y-type three-way connector Y9. The other two interfaces of the ninth Y-type three-way connector Y9 are respectively connected to the two channels of the fifth electromagnetic clamp valve J5. Channel 2 of the fifth electromagnetic clamp valve J5 is connected to the inlet of the digestion tube B2 through a pipeline and the fourth Y-type three-way connector Y4, so the liquid in the quartz digestion tube B1 can be pumped into the reaction pool C5 through the pipeline and the fifth electromagnetic clamp valve J5. The channel 1 of the fifth electromagnetic pinch valve J5 is connected to the sampling port at the lower end of the colorimetric cell in the photoelectric detection assembly D, and the liquid in the reaction cell C5 can be discharged through the photoelectric detection assembly D by the fourth peristaltic pump P4.

[0043] The photoelectric detection assembly D includes a quartz colorimetric cell D3, an LED light source D1 disposed on one side of the quartz colorimetric cell, and a photodetector D2 disposed on the other side of the quartz colorimetric cell D3. The LED light source D1 and the photodetector D2 are electrically connected to the control circuit respectively. The light emitted by the LED light source D1 irradiates the colorimetric cell D3, and part of the light intensity is absorbed by the solution in the colorimetric cell D3. The light passing through the colorimetric cell D3 is received by the photodetector D2 and converted into an electrical signal and transmitted to the control circuit. The typical emission wavelength of the LED light source is 700nm, and ammonia nitrogen and total phosphorus share the same detection light source.

[0044] In addition, the water quality ammonia nitrogen / total phosphorus two-in-one automatic monitoring instrument also includes a first peristaltic pump P1, a second peristaltic pump P2, and a third peristaltic pump P3. The first peristaltic pump P1 is connected to the fourth and fifth Y-type three-way joints Y4 and Y5 through a pipeline, and is used to blow air into the digestion tube to promote the digestion of total phosphorus. The second peristaltic pump P2 injects a quantitative water sample into the digestion tube and the reaction tank through a pipeline, the seventh and eighth Y-type three-way joints Y7, Y8 and the fourth electromagnetic clamp valve J4. The third peristaltic pump injects a quantitative amount of cleaning water into the reaction tank and the digestion tube through the seventh and eighth Y-type three-way joints and the fourth electromagnetic clamp valve J4 for pipeline cleaning during ammonia nitrogen and total phosphorus measurement. More specifically, the first peristaltic pump P1 is connected to an interface of the fifth Y-type three-way joint Y5 through a pipeline, and the other two interfaces of the fifth Y-type three-way joint Y5 are respectively connected to the fourth Y-type three-way joint Y4 and the sixth Y-type three-way joint Y6. The two interfaces of the seventh Y-type three-way connector Y7 are respectively connected to the second peristaltic pump P2 and the third peristaltic pump P3, the third interface of the seventh Y-type three-way connector Y7 is connected to an interface of the eighth Y-type three-way connector Y8, and the other two interfaces of the eighth Y-type three-way connector Y8 are respectively connected to the channel 1 and channel 2 of the fourth electromagnetic clamp valve J4. The second peristaltic pump P2 is connected to the water sample to be tested. The channel 1 of the fourth electromagnetic clamp valve J4 is connected to an interface of the sixth Y-type three-way connector Y6, and the channel 2 is connected to the reaction tank through a pipeline.

[0045] The utility model is based on the above-mentioned water quality ammonia nitrogen / total phosphorus two-in-one automatic monitoring instrument, which can simultaneously detect ammonia nitrogen and total phosphorus. The reagent compositions of the two tests are as follows:

[0046] (1) Ammonia nitrogen detection reagent:

[0047] Reagent 1: sodium hydroxide and sodium hypochlorite;

[0048] Reagent 2: sodium hydroxide, salicylic acid, L-tartaric acid and sodium nitrosoferrocyanide.

[0049] (2) Total phosphorus detection reagent:

[0050] Reagent 1: potassium persulfate, sulfuric acid;

[0051] Reagent 2: ascorbic acid, sodium molybdate, potassium antimony tartrate, sodium hydroxide and citric acid.

[0052] The reagent used in the traditional total phosphorus detection method is ammonium molybdate. In the ammonia nitrogen / total phosphorus two-in-one instrument, due to the presence of a large amount of NH4 + , which will seriously interfere with the measurement of ammonia nitrogen. The applicant found through experiments that replacing ammonium molybdate with sodium molybdate can eliminate NH4 + However, sodium molybdate is unstable and easily deteriorates and loses effectiveness. By adding citric acid and sodium hydroxide to the reagent to form a sodium citrate-citric acid buffer solution, the sodium molybdate can be effectively protected and the shelf life of the reagent can be extended.

[0053] The initial states of the first to fifth electromagnetic pinch valves (J1-J5) are as follows: channel 1 is in a normally open state, channel 2 is in a normally closed state, channel 2 is blocked when no power is supplied, and channel 2 opens and channel 1 closes when power is supplied.

[0054] The process of measuring the reagent volume by multi-channel valve and precision injection pump (taking total phosphorus reagent 1 as an example):

[0055] (1) The first and second electromagnetic clamp valves (J1, J2) are energized, the multichannel valve A1 is switched to channel 6, and the control circuit drives the precision injection pump A2 to extract 2 mL of total phosphorus detection reagent 1. The reagent enters the liquid storage ring, and then the multichannel valve A1 is switched to the liquid outlet (channel 1) to pump the reagent along the pipeline into the digestion tube B1.

[0056] (2) The third electromagnetic pinch valve J3 is energized, and the control circuit drives the precision syringe pump A2 to extract 5 mL of air. Then the multichannel valve A1 switches to the liquid outlet (channel 1) to blow the residual reagent in the pipeline into the digestion tube B1.

[0057] (3) The first and second electromagnetic clamp valves (J1, J2) are energized, the multichannel valve A1 switches to channel 2, and the control circuit drives the precision injection pump A2 to extract 5 mL of cleaning water. At this time, the cleaning water will enter the liquid storage ring, and then the multichannel valve A1 switches to the cleaning liquid outlet (channel 3) to empty the cleaning water along the pipeline.

[0058] Typically, the utility model includes the following 15 steps when detecting ammonia nitrogen and total phosphorus:

[0059] Step 1: Pipeline flushing

[0060] The fourth electromagnetic pinch valve J4 is energized, and the second peristaltic pump P2 rotates counterclockwise for 10 seconds, and 10 mL of the water sample is added to the reaction tank C5 along the pipeline through the Y-type three-way connectors Y7 and Y8 to the channel 2 of the electromagnetic pinch valve J4; then the fourth electromagnetic pinch valve J4 is de-energized, and the second peristaltic pump P2 rotates counterclockwise for 10 seconds, and the 10 mL of the water sample is added to the reaction tank C5 along the pipeline through the Y-type three-way connectors Y7 and Y8 to the channel 1 of the electromagnetic pinch valve J4, and then sequentially through the Y-type three-way connectors Y6, Y5, and Y4 to the quartz digestion tube B1; then the fifth electromagnetic pinch valve J5 is energized, and the fourth peristaltic pump P4 rotates counterclockwise for 15 seconds, and the water sample in the quartz digestion tube B1 is added to the reaction tank C5 along the pipeline, and then the fifth electromagnetic pinch valve J5 is de-energized, and the fourth peristaltic pump P4 rotates clockwise for 30 seconds, and the rinse solution is emptied to the second waste liquid channel F2 through the pipeline and the colorimetric cell D3.

[0061] Step 2: Ammonia nitrogen water sample measurement

[0062] The fourth electromagnetic pinch valve J4 is energized, and the second peristaltic pump P2 rotates counterclockwise for 10 seconds to add 10 mL of water sample into the reaction tank C5 along the pipeline.

[0063] Step 3: Ammonia nitrogen reagent measurement

[0064] The first and third electromagnetic clamp valves (J1, J3) are not energized, and the multi-channel valve A1 switches to channel 4 and channel 5 respectively. The control circuit drives the precision injection pump A2 to extract 1 mL of ammonia nitrogen detection reagent 1 and reagent 2 respectively and add them to the reaction tank C5 along the pipeline.

[0065] Step 4, ammonia nitrogen reaction

[0066] After ammonia nitrogen detection reagents 1 and 2 are added to the reaction tank C5, the control circuit starts the stirring motor C1 to rotate and mix the water sample and reagents in the reaction tank C5. At this time, the heating element C6 on the surface of the reaction tank C5 starts heating, and the temperature sensor C4 collects the temperature in real time, maintaining the reaction temperature at about 40°C, and starts the timed reaction for 5 minutes.

[0067] Step 5: Total phosphorus digestion reagent measurement

[0068] The first and second electromagnetic pinch valves (J1, J2) are energized, the third electromagnetic pinch valve J3 is not energized, the multichannel valve A1 switches to channel 6, and the control circuit drives the precision injection pump A2 to extract 2 mL of total phosphorus detection reagent 1 along the pipeline and add it to the digestion tube B1.

[0069] Step 6: Total phosphorus water sample measurement

[0070] The fourth electromagnetic pinch valve J4 is not energized, the second peristaltic pump P2 rotates counterclockwise for 15 seconds, and 15 mL of water sample is added to the quartz digestion tube B1 through the pipeline.

[0071] Step 7, Total Phosphorus Water Sample Digestion

[0072] After the total phosphorus digestion reagent and water sample are mixed in the quartz digestion tube B1, the heating element B2 on the surface of the digestion tube B1 is powered on to start heating, the ultraviolet lamp B4 is turned on, and the temperature sensor B3 collects the temperature in real time. When the mixed liquid in the digestion tube B1 is heated to 90°C, the first peristaltic pump P1 rotates counterclockwise (30r / min) to blow air into the digestion tube B2 along the pipeline and starts timing for 15 minutes. The oxygen in the air will be converted into ozone under the irradiation of the ultraviolet lamp B4, which promotes the digestion of total phosphorus.

[0073] Step 8: Quantitative detection of ammonia nitrogen

[0074] While the total phosphorus is being digested, the ammonia nitrogen completes the reaction, the fifth electromagnetic pinch valve J5 is not energized, the fourth peristaltic pump P4 rotates clockwise for 6 seconds, and part of the ammonia nitrogen colorimetric solution is pumped into the colorimetric cell D3 through the pipeline for quantitative analysis, and the absorbance of ammonia nitrogen is obtained as A = 0.57. After the analysis is completed, the fourth peristaltic pump P4 continues to rotate for 10 seconds to empty the ammonia nitrogen colorimetric solution in the reaction cell C5, and all waste liquid is emptied along the pipeline and the colorimetric cell D3.

[0075] Step 9: Cleaning of ammonia nitrogen pipeline

[0076] The fourth electromagnetic pinch valve J4 is energized, the third peristaltic pump P3 rotates counterclockwise for 10 seconds, 10 mL of cleaning water enters the reaction tank C5 through the pipeline, the control circuit starts the motor C1 for stirring, and then the fifth electromagnetic pinch valve J5 is de-energized, the fourth peristaltic pump P4 rotates clockwise for 15 seconds, and the cleaning liquid is discharged through the pipeline colorimetric pool D3.

[0077] Step 10, Total Phosphorus Blank Test

[0078] After the total phosphorus digestion is completed, the fifth electromagnetic pinch valve J5 is energized, and the fourth peristaltic pump P4 rotates counterclockwise for 20 seconds, allowing the digestion solution to enter the reaction tank C5 through the pipeline; then the fifth electromagnetic pinch valve J5 is not energized, and the fourth peristaltic pump P4 rotates clockwise for 6 seconds, and part of the total phosphorus digestion solution is pumped into the colorimetric cell D3 through the pipeline for blank measurement, and the background absorbance A1=0.02 is obtained.

[0079] Step 11, total phosphorus colorimetric reagent measurement

[0080] The first electromagnetic clamp valve J1 is energized, the second and third electromagnetic clamp valves (J2, J3) are not energized, the multi-channel valve A1 switches to channel 7 and channel 8 respectively, and the control circuit drives the precision injection pump A2 to extract 1mL of total phosphorus colorimetric reagent 2 and reagent 3 respectively and add them to the reaction pool C5 along the pipeline.

[0081] Step 12, total phosphorus color reaction

[0082] After the total phosphorus colorimetric reagent is added to the reaction pool C5, the control circuit starts the motor C1 to mix the liquid in the reaction pool C5. At this time, the heating element C6 on the surface of the reaction pool C5 starts heating, and the temperature sensor C4 collects the temperature in real time, maintaining the reaction temperature at about 40°C, and the reaction is timed for 4 minutes.

[0083] Step 13, Quantitative detection of total phosphorus

[0084] After the total phosphorus reaction is completed, the fifth electromagnetic pinch valve J5 is not energized, and the fourth peristaltic pump P4 rotates clockwise for 8 seconds, and part of the total phosphorus color development solution is pumped into the colorimetric cell D3 through the pipeline for quantitative analysis, and the color development solution absorbance A2 = 0.15 is obtained, and the absorbance value of the water sample is A' = A2-A1 = 0.15-0.02 = 0.13. After the analysis is completed, the fourth peristaltic pump P4 continues to rotate for 10 seconds to empty the color development solution in the reaction cell C5 and the pipeline.

[0085] Step 14: Total phosphorus pipeline cleaning

[0086] The fourth electromagnetic pinch valve J4 is not energized, the third peristaltic pump P3 rotates counterclockwise for 10 seconds, 10 mL of cleaning water enters the digestion tube B2 through the pipeline, and then the fifth electromagnetic pinch valve J5 is energized, the fourth peristaltic pump P4 rotates counterclockwise for 15 seconds, the cleaning water in the digestion tube B2 enters the reaction tank C5 through the pipeline, the control circuit starts the motor C1 for stirring, and then the fifth electromagnetic pinch valve J5 is not energized, the fourth peristaltic pump P4 rotates clockwise for 15 seconds, and the cleaning liquid is discharged through the pipeline and the colorimetric cell D3.

[0087] Step 15, drain the pipeline

[0088] The fourth electromagnetic pinch valve J4 is energized, and the second peristaltic pump P2 rotates clockwise for 10 seconds to drain the water sample going to the reaction tank C5 through the pipeline; the fourth electromagnetic pinch valve J4 is not energized, and the second peristaltic pump P2 rotates clockwise for 10 seconds to drain the water sample going to the total phosphorus digestion tube B2 through the pipeline.

[0089] According to the built-in standard curve of ammonia nitrogen and total phosphorus in the instrument, A=K*C+b, where A is absorbance, K is the slope of the curve, C is the concentration of the substance to be tested, and b is the intercept of the curve. Substitute the absorbance obtained from ammonia nitrogen and total phosphorus into the corresponding standard curve, and the results are: ammonia nitrogen C1=0.46mg / L, total phosphorus C2=0.121mg / L.

[0090] The results of the method of the present invention and the results of on-site sampling and manual analysis in the laboratory according to the standard method are compared, and the results are shown in Table 1:

[0091] Table 1 Comparison of the analysis and test results of ammonia nitrogen and total phosphorus in water samples

[0092]

[0093] It can be seen from the test data of the water samples in the embodiment that the relative error of the ammonia nitrogen measurement is 6.98%, and the relative error of the total phosphorus measurement is -5.47%, which can meet the error requirements specified in the current Chinese standard "Technical Specifications for Automatic Monitoring of Surface Water (Trial)" (HJ915-2017), indicating that the water quality ammonia nitrogen / total phosphorus two-in-one automatic monitoring instrument provided by the utility model can accurately and reliably monitor the content of ammonia nitrogen and total phosphorus at the same time.

[0094] It should be noted that the above content only illustrates the technical idea of ​​the utility model and cannot be used to limit the protection scope of the utility model. For ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the utility model. These improvements and modifications all fall within the protection scope of the claims of the utility model.

Claims

1. A two-in-one automatic monitoring instrument for ammonia nitrogen and total phosphorus in water quality, characterized in that: include: The reagent metering component includes a precision injection pump, a liquid storage ring connected to the precision injection pump through a Y-type three-way connector and an electromagnetic pinch valve, and a multi-channel valve connected to the liquid storage ring; each channel of the multi-channel valve is respectively connected to pure water, each detection reagent, and a liquid outlet, and the liquid outlet is connected to the electromagnetic pinch valve, so that five detection reagents are divided into three paths, which are respectively used for ammonia nitrogen color development, total phosphorus digestion, and total phosphorus color development; The digestion component is connected to the reagent metering component through a liquid delivery channel, and includes a digestion tube, a heating element wrapped on the surface of the digestion tube, a temperature sensor for collecting the temperature of the quartz digestion tube, and an ultraviolet lamp inserted into the digestion tube; the digestion tube has a hollow interlayer, and a sample inlet is provided at the lower end, and the sample inlet is connected to the hollow interlayer; The reaction component is connected with the reagent metering component and the digestion component through a liquid delivery channel, and includes a reaction pool and a stirring mechanism capable of stirring the liquid in the reaction pool; the reaction pool is provided with a liquid outlet; The photoelectric detection component is connected to the reaction component and the digestion component through a liquid delivery channel, and includes a colorimetric cell, and an LED light source and a photoelectric detector respectively arranged on both sides of the colorimetric cell. The colorimetric cell and the photoelectric detector are located on the light path emitted by the LED light source; A control circuit, used to form an electrical connection with each electronic component; A first peristaltic pump is connected to the sample inlet of the digestion tube through a pipeline and a plurality of Y-type three-way connectors; The second peristaltic pump is connected to the digestion tube inlet and the reaction pool respectively through pipelines, a plurality of three-way joints and an electromagnetic pinch valve; The third peristaltic pump is connected to the reaction pool and the digestion tube inlet through pipelines, a plurality of Y-type three-way connectors and an electromagnetic pinch valve; The fourth peristaltic pump is connected to the digestion tube inlet and the reaction cell outlet respectively through pipelines, a plurality of Y-type three-way connectors and an electromagnetic clamp valve.

2. The water quality ammonia nitrogen / total phosphorus two-in-one automatic monitoring instrument according to claim 1 is characterized in that: The liquid outlet is connected to the first Y-type three-way connector, and the first Y-type three-way connector is also connected to the second Y-type three-way connector and the reaction pool through an electromagnetic clamping valve, and the second Y-type three-way connector is also connected to the sixth Y-type three-way connector and the reaction pool through an electromagnetic clamping valve.

3. The water quality ammonia nitrogen / total phosphorus two-in-one automatic monitoring instrument according to claim 1 is characterized in that: The liquid storage ring is made of polytetrafluoroethylene.

4. The water quality ammonia nitrogen / total phosphorus two-in-one automatic monitoring instrument according to claim 1, characterized in that: The overflow port at the upper end of the digestion component is connected to the first T-type three-way connector, the first T-type three-way connector is also connected to the first and second one-way valves respectively, the second one-way valve is connected to the second T-type three-way connector, and the second T-type three-way connector is also connected to the second waste liquid channel and the colorimetric cell respectively.

5. The water quality ammonia nitrogen / total phosphorus two-in-one automatic monitoring instrument according to claim 1, characterized in that: The outer surface of the digestion tube is coated with a light-proof layer.

6. The water quality ammonia nitrogen / total phosphorus two-in-one automatic monitoring instrument according to claim 1, characterized in that: A heating element and a temperature sensor are attached to the surface of the reaction pool.

7. The water quality ammonia nitrogen / total phosphorus two-in-one automatic monitoring instrument according to claim 1, characterized in that: The stirring mechanism comprises: a magnetic particle placed in the reaction pool, a magnet arranged at the bottom of the reaction pool for driving the magnetic particle, and a motor for driving the magnet to rotate.

8. The water quality ammonia nitrogen / total phosphorus two-in-one automatic monitoring instrument according to claim 1, characterized in that: The reaction pool and the colorimetric pool are both provided with overflow ports, and each overflow port is connected to a waste liquid channel.

9. The water quality ammonia nitrogen / total phosphorus two-in-one automatic monitoring instrument according to claim 1, characterized in that: The control circuit is electrically connected to the photoelectric detector, the heating element, the temperature sensor and each electromagnetic pinch valve.

10. The water quality ammonia nitrogen / total phosphorus two-in-one automatic monitoring instrument according to claim 1, characterized in that: The LED light source emits a wavelength of 700 nm.

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