Water quality heavy metal on-line analyzer and analysis method

Abstract

The invention discloses a water quality heavy metal on-line analyzer and an analysis method, the analyzer comprises a digestion unit, a plurality of enrichment and elution units communicated with the digestion unit, an on-line analysis unit communicated with the plurality of enrichment and elution units, and a controller electrically connected with each unit, the enrichment and elution unit comprises a pH adjusting reagent tube, an elution reagent tube, a first switching valve, a mixing tube, a first peristaltic pump, a sulfydryl cotton elution tube, a second switching valve, a first waste liquid tube and a first air tube, and the first switching valve is used for selectively communicating one of the digestion unit, the pH adjusting reagent tube, the elution reagent tube and the first air tube with the mixing tube; a liquid outlet of the mixing pipe is communicated with a liquid inlet of the first peristaltic pump, a liquid outlet of the first peristaltic pump is communicated with a liquid inlet of the sulfydryl cotton elution pipe, and the second switching valve is used for selecting one of the first waste liquid pipe and the online analysis unit to be communicated with the sulfydryl cotton elution pipe. The device can effectively deal with on-line monitoring, analysis and determination of the heavy metals in the low-concentration water body, and can be used for determination of various heavy metals.

Description

Technical Field

[0001] The present invention relates to the technical field of water quality analysis, and in particular to an online water quality heavy metal analyzer and an analysis method. Background Art

[0002] Many heavy metals have significant biological toxicity, especially lead, cadmium, and mercury. These substances cannot be degraded by microorganisms in water bodies, and various forms of mutual transformation and dispersion occur in water bodies, as well as enrichment in organisms. Some heavy metals, such as mercury, are transformed into methylmercury under the action of microorganisms, thereby enhancing their biological toxicity. These heavy metals can also accumulate in organs such as the liver and kidneys of animals, causing tissue damage. Sulfur-philic heavy metal elements such as lead, cadmium, and mercury can have a particularly strong affinity with the sulfhydryl groups of some enzymes in certain tissues of the human body, which can inhibit the activity of enzymes and thus affect the normal physiological functions of the body. Even if the concentration of heavy metals in water bodies is small, they can accumulate in algae and sediments, be adsorbed on the surface of fish and shellfish, and produce food chain concentration, thereby causing public pollution. Therefore, online heavy metal monitoring and analysis is of great significance in the field of water quality monitoring and analysis. However, since the color developers of online heavy metal water quality monitoring and analyzers on the market are generally the same during the determination process, they are prone to interfere with each other in spectrophotometric analysis. At the same time, the common characteristic of this type of heavy metals in water bodies is low concentration, and the online analyzer has a certain detection limit, making it difficult to meet monitoring requirements. Summary of the invention

[0003] In view of the above problems, the object of the present invention is to provide an online analyzer and analysis method for heavy metals in water quality, so as to effectively cope with the online monitoring, analysis and determination of heavy metals in low concentration water bodies.

[0004] In order to achieve the above object, the technical solution proposed by the present invention is: A water quality heavy metal online analyzer, comprising: a digestion unit, a plurality of enrichment and elution units, an online analysis unit and a controller. The digestion unit is used to digest a water sample to obtain a digestion solution. A plurality of enrichment and elution units are connected to the digestion unit, and the enrichment and elution units are used to enrich and elute a certain heavy metal from the digestion solution to obtain an elution solution containing a certain heavy metal. An online analysis unit is connected to a plurality of the enrichment and elution units and is used to measure the eluate. The controller is electrically connected to the digestion unit, the plurality of enrichment and elution units and the online analysis unit.

[0005] The enrichment and elution unit includes: a pH adjusting reagent tube, an elution reagent tube, a first switching valve, a mixing tube, a first peristaltic pump, a thiol cotton elution tube, a second switching valve, a first waste liquid tube and a first air tube. The first switching valve is respectively connected to the digestion unit, the liquid outlet of the pH adjusting reagent tube, the liquid outlet of the elution reagent tube, the liquid inlet of the mixing tube and the air outlet of the first air tube, and is used to connect the digestion unit, the pH adjusting reagent tube, the elution reagent tube and the first air tube to the mixing tube. The liquid outlet of the mixing tube is connected to the liquid inlet of the first peristaltic pump, and the liquid outlet of the first peristaltic pump is connected to the liquid inlet of the thiol cotton elution tube. The second switching valve is respectively connected to the liquid outlet of the thiol cotton elution tube, the liquid inlet of the first waste liquid tube and the online analysis unit, and is used to connect the first waste liquid tube and the online analysis unit to the thiol cotton elution tube.

[0006] Preferably, among the several enrichment and elution units, at least one is used to separate the lead in the digestion solution, at least one is used to separate the cadmium in the digestion solution, and at least one is used to separate the mercury in the digestion solution. The enrichment and elution units input the corresponding lead pH adjusting reagent, cadmium pH adjusting reagent, or mercury pH adjusting reagent through their pH adjusting reagent tubes, and input the corresponding lead elution reagent, cadmium elution reagent, or mercury elution reagent through the elution reagent tubes.

[0007] Preferably, the digestion unit comprises: a water sample tube, a first pure water tube, a heavy metal mixed standard tube, an acidic digestion reagent tube, a second waste liquid tube, a third switching valve, a second peristaltic pump, a fourth switching valve and a sample digestion retention pool. The third switching valve is respectively connected to the liquid outlet of the water sample tube, the liquid outlet of the first pure water tube, the liquid outlet of the heavy metal mixed standard tube, the liquid outlet of the acidic digestion reagent tube and the liquid inlet of the second peristaltic pump, and is used to connect the water sample tube, the first pure water tube, the heavy metal mixed standard tube and the acidic digestion reagent tube to the second peristaltic pump; the fourth switching valve is respectively connected to the liquid outlet of the second peristaltic pump, the liquid inlet of the second waste liquid tube and the liquid inlet of the sample digestion retention pool, and is used to connect the second waste liquid tube and the sample digestion retention pool to the second peristaltic pump; the liquid outlet of the sample digestion retention pool is connected to the enrichment and elution unit.

[0008] Preferably, the online analysis unit comprises: a second pure water pipe, a porphyrin color developer pipe, several pH buffer reagent pipes, a third waste liquid pipe, a second air pipe, a fourth waste liquid pipe, a third pure water pipe, a third air pipe, a fifth switching valve, a syringe pump, a reactor, a xenon lamp, a spectrometer, a third peristaltic pump, a fourth peristaltic pump, and a sixth switching valve. The fifth switching valve is respectively connected to the liquid outlet of the second pure water pipe, the liquid outlet of the porphyrin color developer pipe, the liquid outlet of each pH buffer reagent pipe, the liquid inlet of the third peristaltic pump, the liquid inlet of the third waste liquid pipe, the air outlet of the second air pipe, the syringe pump and the reactor, and the fifth switching valve is used to connect the second pure water pipe, the porphyrin color developer pipe, each pH buffer reagent pipe, the third peristaltic pump, the third waste liquid pipe, the second air pipe and the reactor to the syringe pump. The liquid outlet of the third peristaltic pump is connected to the liquid inlet of the fourth waste liquid pipe. The sixth switching valve is connected to the liquid inlet of the fourth peristaltic pump, the liquid outlet of the third pure water pipe and the air outlet of the third air pipe respectively, and is used to connect the third pure water pipe and the third air pipe to the fourth peristaltic pump. The liquid outlet of the fourth peristaltic pump is connected to the reactor. A spectrometer and a xenon lamp are installed on opposite sides of the reactor, and the spectrometer and the xenon lamp are used to measure the absorbance of the eluent in the reactor.

[0009] Preferably, the reactor has a temperature control device and a stirring device.

[0010] Preferably, it also includes a water sample detector installed on the pipeline connecting the fifth switching valve and the reactor.

[0011] Preferably, the mixing tube is a spiral mixing tube.

[0012] Preferably, the first switching valve includes: a first three-way solenoid valve, a second three-way solenoid valve and a third three-way solenoid valve. The first three-way solenoid valve is respectively connected to the first air pipe, the second three-way solenoid valve and the sample digestion retention tank, and is used to connect the first air pipe and the sample digestion retention tank to the second three-way solenoid valve. The second three-way solenoid valve is respectively connected to the pH adjustment reagent tube, the first three-way solenoid valve and the third three-way solenoid valve, and is used to connect the first three-way solenoid valve and the pH adjustment reagent tube to the third three-way solenoid valve; the third three-way solenoid valve is respectively connected to the elution reagent tube, the mixing tube and the second three-way solenoid valve, and is used to connect the elution reagent tube and the second three-way solenoid valve to the mixing tube.

[0013] Preferably, the third switching valve includes: a fourth three-way solenoid valve, a fifth three-way solenoid valve and a sixth three-way solenoid valve. The fourth three-way solenoid valve is respectively connected to the heavy metal mixed standard tube, the acid digestion reagent tube and the fifth three-way solenoid valve, and the fourth three-way solenoid valve is used to connect the heavy metal mixed standard tube and the acid digestion reagent tube to the fifth three-way solenoid valve. The fifth three-way solenoid valve is respectively connected to the first pure water pipe, the fourth three-way solenoid valve and the sixth three-way solenoid valve, and the fifth three-way solenoid valve is used to connect the first pure water pipe and the fourth three-way solenoid valve to the sixth three-way solenoid valve. The sixth three-way solenoid valve is respectively connected to the water sample tube, the fifth three-way solenoid valve and the second peristaltic pump, and the sixth three-way solenoid valve is used to connect the water sample tube and the fifth three-way solenoid valve to the second peristaltic pump.

[0014] Preferably, the online analysis unit is provided with a plurality of reactors, each of which is equipped with a xenon lamp and a spectrometer; the plurality of reactors correspond one-to-one to and are connected with a plurality of enrichment and elution units, and the plurality of reactors are respectively connected with the fifth switching valve and the fourth peristaltic pump.

[0015] An analysis method of a water quality heavy metal online analyzer, comprising: S1. Water sample digestion: draw water sample and acid digestion reagent into the digestion unit in sequence for heating and digestion to obtain digestion solution; S2, enrichment and elution: extracting the decomposition solution, pH adjustment reagent and elution reagent to a certain enrichment and elution unit to enrich and elute a certain heavy metal to obtain an eluent containing a certain heavy metal; specifically comprising the following sub-steps: S21, turning on the first peristaltic pump, the second switching valve and the first switching valve, the first switching valve alternately switches the mixing tube to be connected to the digestion unit and the pH adjustment reagent tube in sequence, so as to alternately extract a quantitative digestion solution and a pH adjustment reagent into the mixing tube for mixing; S22, thiol cotton adsorption: the first peristaltic pump, the second switching valve and the first switching valve are turned on, the first switching valve switches the mixing tube to be connected with the first air tube, and the mixed liquid of the pH adjustment reagent and the digestion solution passes through the thiol cotton elution tube at a certain speed, so that a certain heavy metal in the mixed liquid is adsorbed by the thiol cotton, and the other liquids are discharged through the first waste liquid pipe; S23, elution: the second switching valve is closed, the first switching valve switches the mixing tube to be connected to the elution reagent tube, the first peristaltic pump rotates, extracts the elution reagent at a certain speed to elute the heavy metals from the thiol cotton, obtains the eluent, and directly delivers it to the online analysis unit; S3, online analysis: according to the color development requirements, pH buffer solution is extracted into the online analysis unit and mixed with the eluent, and then porphyrin color developer is extracted into the online analysis unit and mixed with the eluent for color development, and then absorbance is measured; S4, cleaning the online analysis unit and waiting for the next test; S5. Repeat steps S2 to S4, extract the deionized liquid and send it to the next enrichment and elution unit to carry out enrichment, elution and determination of other heavy metals.

[0016] Preferably, a standard solution calibration test is also included, which is to prepare a heavy metal mixed standard instead of a water sample to perform steps S1 to S5.

[0017] By adopting the above technical scheme, the beneficial effects of the present invention are as follows: the water quality heavy metal online analyzer and analysis method of the present invention enrich trace heavy metals in water samples through a plurality of enrichment and elution units, so as to effectively cope with the online monitoring, analysis and determination of heavy metals in low-concentration water bodies, improve the detection sensitivity, and ensure the accuracy of the detection results. At the same time, a plurality of enrichment and elution units can be used to enrich the same heavy metal to increase the detection speed, and can also be used to enrich different heavy metals, so as to realize multi-purpose use of one machine and determine a variety of heavy metals. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 This is a water path structure diagram of the online water heavy metal analyzer of Example 1.

[0019] Figure 2 for Figure 1 Diagram of the water channel structure of the digestion unit.

[0020] Figure 3 for Figure 1 Diagram of the water channel structure of the enrichment and elution unit.

[0021] Figure 4 for Figure 1 Diagram of the waterway structure of the online analysis unit.

[0022] Wherein: 1. digestion unit; 11. water sample tube; 12. first pure water tube; 13. heavy metal mixed standard tube; 14. acid digestion reagent tube; 15. second waste liquid tube; 16. third switching valve; 161. fourth three-way solenoid valve; 162. fifth three-way solenoid valve; 163. sixth three-way solenoid valve; 17. second peristaltic pump; 18. fourth switching valve; 19. sample digestion retention pool; 2. Enrichment and elution unit; 21. pH adjustment reagent tube; 22. Elution reagent tube; 23. First switching valve; 231. First three-way solenoid valve; 232. Second three-way solenoid valve; 233. Third three-way solenoid valve; 24. Mixing tube; 25. First peristaltic pump; 26. Mercapto cotton elution tube; 27. Second switching valve; 28. First waste liquid tube; 29. ​​First air tube; 3. Online analysis unit; 31. Second pure water pipe; 32. Porphyrin colorimetric agent tube; 33. pH buffer reagent tube; 34. Third waste liquid pipe; 35. Second air pipe; 36. Fourth waste liquid pipe; 37. Third pure water pipe; 38. Third air pipe; 39. Fifth switching valve; 310. Injection pump; 311. Reactor; 312. Xenon lamp; 313. Spectrometer; 314. Third peristaltic pump; 315. Fourth peristaltic pump; 316. Sixth switching valve; 317. Water sample detector. DETAILED DESCRIPTION

[0023] The present invention will be further described below in conjunction with the accompanying drawings and specific implementation methods.

[0024] Embodiment 1 like Figure 1 to Figure 4 As shown, the water quality heavy metal online analyzer of this embodiment includes: a digestion unit 1, a plurality of enrichment and elution units 2, an online analysis unit 3 and a controller (not shown in the figure). Each enrichment and elution unit 2 is connected to the digestion unit 1 and the online analysis unit 3 respectively, and the controller is electrically connected to the digestion unit 1, each enrichment and elution unit 2 and the online analysis unit 3 respectively to realize automatic control of the online analyzer.

[0025] The digestion unit 1 of this embodiment is used to digest a water sample to convert heavy metals in the water sample into ionic state to obtain a digestion solution.

[0026] Reference Figure 1 and Figure 2 The digestion unit 1 includes: a water sample tube 11, a first pure water tube 12, a heavy metal mixed standard tube 13, an acidic digestion reagent tube 14, a second waste liquid tube 15, a third switching valve 16, a second peristaltic pump 17, a fourth switching valve 18 and a sample digestion retention pool 19. The third switching valve 16 is connected to the liquid outlet of the water sample tube 11, the liquid outlet of the first pure water tube 12, the liquid outlet of the heavy metal mixed standard tube 13, the liquid outlet of the acidic digestion reagent tube 14, and the liquid inlet of the second peristaltic pump 17 respectively. The third switching valve 16 is used to connect the water sample tube 11, the first pure water tube 12, the heavy metal mixed standard tube 13 and the acidic digestion reagent tube 14 to the second peristaltic pump 17. The fourth switching valve 18 is connected to the liquid outlet of the second peristaltic pump 17, the liquid inlet of the second waste liquid pipe 15 and the liquid inlet of the sample digestion retention pool 19 respectively, and the fourth switching valve 18 is used to select one of the second waste liquid pipe 15 and the sample digestion retention pool 19 to be connected to the second peristaltic pump 17. The fourth switching valve 18 is used to rinse the pipeline to prevent pure water, heavy metal mixed standards and water samples from interfering with each other, and the rinsing liquid is discharged from the second waste liquid pipe 15. The liquid outlet of the sample digestion retention pool 19 is connected to the enrichment and elution unit 2.

[0027] In a feasible option of the present embodiment, the fourth switching valve 18 is a three-way solenoid valve. The third switching valve 16 includes: a fourth three-way solenoid valve 161, a fifth three-way solenoid valve 162 and a sixth three-way solenoid valve 163. The fourth three-way solenoid valve 161 is connected to the heavy metal mixed standard tube 13, the acid digestion reagent tube 14 and the fifth three-way solenoid valve 162 respectively, and the fourth three-way solenoid valve 161 is used to select one of the heavy metal mixed standard tube 13 and the acid digestion reagent tube 14 to be connected to the fifth three-way solenoid valve 162. The fifth three-way solenoid valve 162 is connected to the first pure water pipe 12, the fourth three-way solenoid valve 161 and the sixth three-way solenoid valve 163 respectively, and the fifth three-way solenoid valve 162 is used to select one of the first pure water pipe 12 and the fourth three-way solenoid valve 161 to be connected to the sixth three-way solenoid valve 163. The sixth three-way solenoid valve 163 is connected to the water sample tube 11, the fifth three-way solenoid valve 162 and the second peristaltic pump 17 respectively, and the sixth three-way solenoid valve 163 is used to connect the water sample tube 11 and the fifth three-way solenoid valve 162 to the second peristaltic pump 17. By controlling the opening and closing of the normally open end and the normally closed end of the fourth three-way solenoid valve 161, the fifth three-way solenoid valve 162, the sixth three-way solenoid valve 163 and the fourth switching valve 18, and cooperating with the second peristaltic pump 17, it is possible to selectively input water samples, pure water, heavy metal mixed standards and acidic digestion reagents into the sample digestion retention tank 19.

[0028] The enrichment and elution unit 2 of this embodiment is used to enrich and elute a certain heavy metal from the digestion solution to obtain an eluate containing the certain heavy metal.

[0029] Reference Figure 1 and Figure 3 The enrichment and elution unit 2 includes: a pH adjusting reagent tube 21, an elution reagent tube 22, a first switching valve 23, a mixing tube 24, a first peristaltic pump 25, a thiol cotton elution tube 26, a second switching valve 27, a first waste liquid tube 28 and a first air tube 29. The first switching valve 23 is respectively connected to the digestion unit 1, the liquid outlet of the pH adjusting reagent tube 21, the liquid outlet of the elution reagent tube 22, the liquid inlet of the mixing tube 24, and the air outlet of the first air tube 29. The first switching valve 23 is used to connect the digestion unit 1, the pH adjusting reagent tube 21, the elution reagent tube 22 and the first air tube 29 to the mixing tube 24. The liquid outlet of the mixing tube 24 is connected to the liquid inlet of the first peristaltic pump 25, and the liquid outlet of the first peristaltic pump 25 is connected to the liquid inlet of the thiol cotton elution tube 26. The second switching valve 27 is respectively connected to the liquid outlet of the thiol cotton elution tube 26, the liquid inlet of the first waste liquid tube 28 and the online analysis unit 3. The second switching valve 27 is used to connect one of the first waste liquid tube 28 and the online analysis unit 3 to the thiol cotton elution tube 26.

[0030] In a feasible option of the present embodiment, the mixing tube 24 adopts a spiral mixing tube, which can effectively mix the digestion solution and the pH adjusting reagent. The thiol cotton in the thiol cotton elution tube 26 is replaceable. The first switching valve 23 includes: a first three-way solenoid valve 231, a second three-way solenoid valve 232 and a third three-way solenoid valve 233. The first three-way solenoid valve 231 is connected to the first air pipe 29, the second three-way solenoid valve 232 and the sample digestion retention pool 19 respectively, and the first three-way solenoid valve 231 is used to select one of the first air pipe 29 and the sample digestion retention pool 19 to be connected to the second three-way solenoid valve 232. The second three-way solenoid valve 232 is connected to the pH adjusting reagent tube 21, the first three-way solenoid valve 231 and the third three-way solenoid valve 233 respectively, and the second three-way solenoid valve 232 is used to select one of the pH adjusting reagent tube 21 and the first three-way solenoid valve 231 to be connected to the third three-way solenoid valve 233. The third three-way solenoid valve 233 is connected to the elution reagent tube 22, the mixing tube 24 and the second three-way solenoid valve 232 respectively, and the third three-way solenoid valve 233 is used to selectively connect the elution reagent tube 22 and the second three-way solenoid valve 232 to the mixing tube 24. By controlling the opening and closing of the normally open end and the normally closed end of the first three-way solenoid valve 231, the second three-way solenoid valve 232 and the third three-way solenoid valve 233, and cooperating with the first peristaltic pump 25, the digestion solution, pH adjustment reagent, elution reagent and air are selectively input into the mixing tube 24.

[0031] This embodiment has a plurality of enrichment and elution units 2, each of which is independent of each other and does not interfere with each other, and can simultaneously perform heavy metal enrichment and elution. Different pH adjustment reagents and corresponding elution reagents are selected for each enrichment and elution unit 2, so that different heavy metals can be separated from the digestion solution, and the determination of multiple heavy metals can be achieved. Figure 3 As shown, the three enrichment and elution units 2 are used to separate cadmium, lead and mercury respectively, and the corresponding pH adjusting reagents used are cadmium pH adjusting reagent, lead pH adjusting reagent and mercury pH adjusting reagent, and the corresponding elution reagents used are cadmium elution reagent, lead elution reagent and mercury elution reagent.

[0032] The online analysis unit 3 of this embodiment is used to measure the absorbance of the eluent.

[0033] Reference Figure 1 and Figure 4The online analysis unit 3 includes: a second pure water tube 31, a porphyrin color developer tube 32, several pH buffer reagent tubes 33, a third waste liquid tube 34, a second air tube 35, a fourth waste liquid tube 36, a third pure water tube 37, a third air tube 38, a fifth switching valve 39, an injection pump 310, a reactor 311, a xenon lamp 312, a spectrometer 313, a third peristaltic pump 314, a fourth peristaltic pump 315, a sixth switching valve 316 and a water sample detector 317. The fifth switching valve 39 is respectively connected with the liquid outlet of the second pure water pipe 31, the liquid outlet of the porphyrin developer pipe 32, the liquid outlet of each pH buffer reagent pipe 33, the liquid inlet of the third peristaltic pump 314, the liquid inlet of the third waste liquid pipe 34, the air outlet of the second air pipe 35, the injection pump 310 and the reactor 311. The fifth switching valve 39 is used to select one of the second pure water pipe 31, the porphyrin developer pipe 32, each pH buffer reagent pipe 33, the third peristaltic pump 314, the third waste liquid pipe 34, the second air pipe 35 and the reactor 311 to be connected with the injection pump 310. The liquid outlet of the third peristaltic pump 314 is connected with the liquid inlet of the fourth waste liquid pipe 36. The water sample detector 317 is installed on the pipeline connecting the fifth switching valve 39 and the reactor 311, and the water sample detector 317 can detect whether liquid is drawn into the reactor 311. The sixth switching valve 316 is connected to the liquid inlet of the fourth peristaltic pump 315, the liquid outlet of the third pure water pipe 37 and the liquid outlet of the third air pipe 38 respectively, and the sixth switching valve 316 is used to select one of the third pure water pipe 37 and the third air pipe 38 to be connected to the fourth peristaltic pump 315. The liquid outlet of the fourth peristaltic pump 315 is connected to the reactor 311. The spectrometer 313 and the xenon lamp 312 are installed on opposite sides of the reactor 311, and the spectrometer 313 and the xenon lamp 312 are used to measure the absorbance of the eluent in the reactor 311.

[0034] The reactor 311 of this embodiment is provided with a temperature control device and a stirring device, which are used to evenly mix the eluent continuously entering the reactor 311 and accelerate the mixing of the pH buffer reagent and porphyrin color developer subsequently injected into the reactor 311 with the eluent.

[0035] Each eluent in this embodiment contains only one heavy metal, and each eluent will be subjected to colorimetric analysis in the same reaction vessel 311, and will share the same color developer, with only a difference in pH buffer. Figure 4 As shown, three pH buffer reagent tubes 33 are provided, which are used to input cadmium pH buffer reagent, lead pH buffer reagent and mercury pH buffer reagent respectively.

[0036] The analysis method of the water quality heavy metal online analyzer of this embodiment includes the following steps: S1, water sample digestion: draw water sample and acid digestion reagent to digestion unit 1 in sequence for heating and digestion to obtain digestion solution. Specifically including the following sub-steps: S11 , open the sixth three-way solenoid valve 163 , open the fourth switching valve 18 and the second peristaltic pump 17 to draw water samples into the sample digestion retention tank 19 .

[0037] S12, closing the sixth three-way electromagnetic valve 163, the second peristaltic pump 17 continues to work, extracting a certain amount of acidic digestion reagent into the sample digestion retention tank 19, and closing the second peristaltic pump 17 and the fourth switching valve 18.

[0038] S13, sample digestion The heating component inside the retention pool 19 performs heating digestion to convert the components in the water sample into ions to obtain a digestion solution.

[0039] S2, enrichment and elution: extract the decomposition solution, pH adjustment reagent and elution reagent to a certain enrichment and elution unit 2 to enrich and elute a certain heavy metal, and obtain an eluate containing a certain heavy metal. Specifically, it includes the following sub-steps: S21, turning on the first peristaltic pump 25 and the second switching valve 27, and the second three-way solenoid valve 232 is intermittently turned on to alternately extract the quantitative digestion solution and the pH adjustment reagent into the mixing tube 24 for mixing; S22, thiol cotton adsorption: close the second three-way solenoid valve 232, open the first three-way solenoid valve 231, the first peristaltic pump 25 and the second switching valve 27, and pass the mixed solution of pH adjustment reagent and digestion solution through the thiol cotton elution tube 26 at a certain speed, so that a certain heavy metal in the mixed solution is adsorbed by the thiol cotton, and the other liquid flows into the waste liquid pool through the first waste liquid pipe 28; S23, elution: open the first three-way solenoid valve 231 and the third three-way solenoid valve 233, close the second switching valve 27, rotate the first peristaltic pump 25, extract the elution reagent at a certain speed to elute the heavy metals from the thiol cotton, obtain the eluent, and directly transport it to the reactor 311.

[0040] S3, online analysis: according to the color development reaction requirements, pH buffer is extracted into the online analysis unit 3 and mixed with the eluent, and then the porphyrin color developer is extracted into the online analysis unit 3 and mixed with the eluent for reaction and color development, and then the absorbance is measured. Specifically, it includes the following sub-steps: S31, turn on the injection pump 310 and the fifth switching valve 39, the fifth switching valve 39 is switched to connect the injection pump 310 and a pH buffer reagent tube 33, a pH buffer reagent is drawn into the injection pump 310, the fifth switching valve 39 is switched to connect the injection pump 310 and the reactor 311, a pH buffer reagent is injected into the reactor 311, and stirred and mixed with the eluent in the reactor 311. After mixing is completed, the absorbance value is read once by the xenon lamp 312 and the spectrometer 313, and recorded in the processor.

[0041] S32, turn on the injection pump 310 and the fifth switching valve 39, the fifth switching valve 39 is switched to connect the porphyrin color developer tube 32 and the injection pump 310, the porphyrin color developer is drawn into the injection pump 310, the fifth switching valve 39 is switched to connect the injection pump 310 and the reactor 311, the porphyrin color developer is injected into the reactor 311, and is stirred and mixed with the eluent in the reactor 311 to make the inside fully colored, and the absorbance value of the color development is read by the xenon lamp 312 and the spectrometer 313, and recorded in the processor.

[0042] In step S3, the pH buffer reagent used in the online analysis unit 3 is different according to the type of heavy metal to be measured, and the amount of porphyrin developer used is different according to the measurement requirements. At the same time, in terms of the selection of light source wavelength, lead uses 470nm, cadmium uses 435nm, and mercury uses 435nm.

[0043] S4, cleaning the online analysis unit 3 and waiting for the next test. Specifically, it includes the following sub-steps: S41, emptying the waste liquid: open the fifth switching valve 39 and switch to connect the reactor 311 and the third peristaltic pump 314, the third peristaltic pump 314 is activated to pump out the waste liquid inside the reactor 311, and the fifth switching valve 39 and the third peristaltic pump 314 are closed.

[0044] S42 , cleaning: opening the sixth switching valve 316 and the fourth peristaltic pump 315 , pumping pure water into the reaction kettle 311 , and cleaning the reaction kettle 311 .

[0045] S43, repeat step S41 "emptying the waste liquid" and step S42 "cleaning" 2 to 3 times to completely clean the reactor 311 and wait for the next test process.

[0046] S5. Repeat steps S2 to S4, extract the deionized liquid and send it into the next enrichment and elution unit 2 to carry out enrichment, elution and determination of other heavy metals.

[0047] Standard solution calibration test: Prepare a heavy metal mixed standard instead of the water sample to perform steps S1 to S5 to meet the requirements of the control experiment.

[0048] Embodiment 2 The water quality heavy metal online analyzer of this embodiment is similar to the embodiment 1, and the main difference between the two is that the water quality heavy metal online analyzer of this embodiment is provided with a plurality of reactors 311, each reactor 311 is connected to the fifth switching valve 39 and the fourth peristaltic pump 315, and is equipped with a xenon lamp 312 and a spectrometer 313. The reactors 311 correspond to and are connected to the enrichment and elution units 2 one by one, and each reactor 311 is independent of each other and does not interfere with each other. Through each reactor 311, different heavy metals can be measured at the same time, thereby improving the measurement efficiency.

[0049] Although the present invention has been specifically shown and described in conjunction with the preferred embodiments, it should be understood by those skilled in the art that various changes in form and details may be made to the present invention without departing from the spirit and scope of the invention as defined in the appended claims, all of which are within the scope of protection of the present invention.

Claims

1. A water quality heavy metal online analyzer, characterized in that: include: A digestion unit (1) is used to digest the water sample to obtain a digestion solution; A plurality of enrichment and elution units (2) are connected to the digestion unit (1), and the enrichment and elution units (2) are used to enrich and elute a certain heavy metal from the digestion solution to obtain an eluate containing the certain heavy metal; An online analysis unit (3) connected to the plurality of the enrichment and elution units (2) for measuring the eluate; A controller electrically connected to the digestion unit (1), the plurality of enrichment and elution units (2) and the online analysis unit (3); The enrichment and elution unit (2) comprises: a pH adjustment reagent tube (21), an elution reagent tube (22), a first switching valve (23), a mixing tube (24), a first peristaltic pump (25), a thiol cotton elution tube (26), a second switching valve (27), a first waste liquid tube (28) and a first air tube (29); The first switching valve (23) is respectively connected to the digestion unit (1), the liquid outlet of the pH adjustment reagent tube (21), the liquid outlet of the elution reagent tube (22), the liquid inlet of the mixing tube (24), and the air outlet of the first air tube (29), and is used to connect the digestion unit (1), the pH adjustment reagent tube (21), the elution reagent tube (22), and the first air tube (29) to the mixing tube (24); the liquid outlet of the mixing tube (24) is connected to the liquid inlet of the first peristaltic pump (25), and the liquid outlet of the first peristaltic pump (25) is connected to the liquid inlet of the thiol cotton elution tube (26); the second switching valve (27) is respectively connected to the liquid outlet of the thiol cotton elution tube (26), the liquid inlet of the first waste liquid tube (28), and the online analysis unit (3), and is used to connect the first waste liquid tube (28) and the online analysis unit (3) to the thiol cotton elution tube (26).

2. The water quality heavy metal online analyzer according to claim 1, characterized in that: Among the plurality of the enrichment and elution units (2), at least one is used for separating lead in the digestion solution, at least one is used for separating cadmium in the digestion solution, and at least one is used for separating mercury in the digestion solution; The enrichment and elution unit (2) inputs the corresponding lead pH adjusting reagent, cadmium pH adjusting reagent or mercury pH adjusting reagent through its pH adjusting reagent tube (21), and inputs the corresponding lead elution reagent, cadmium elution reagent or mercury elution reagent through the elution reagent tube (22).

3. The water quality heavy metal online analyzer according to claim 1, characterized in that: The digestion unit (1) comprises: a water sample tube (11), a first pure water tube (12), a heavy metal mixed standard tube (13), an acid digestion reagent tube (14), a second waste liquid tube (15), a third switching valve (16), a second peristaltic pump (17), a fourth switching valve (18) and a sample digestion retention pool (19); The third switching valve (16) is respectively connected to the liquid outlet of the water sample tube (11), the liquid outlet of the first pure water tube (12), the liquid outlet of the heavy metal mixed standard tube (13), the liquid outlet of the acid digestion reagent tube (14), and the liquid inlet of the second peristaltic pump (17), and is used to connect the water sample tube (11), the first pure water tube (12), the heavy metal mixed standard tube (13) and the acid digestion reagent tube (14) to the second peristaltic pump (17); the fourth switching valve (18) is respectively connected to the liquid outlet of the second peristaltic pump (17), the liquid inlet of the second waste liquid tube (15) and the liquid inlet of the sample digestion retention tank (19), and is used to connect the second waste liquid tube (15) and the sample digestion retention tank (19) to the second peristaltic pump (17); the liquid outlet of the sample digestion retention tank (19) is connected to the enrichment and elution unit (2).

4. The water quality heavy metal online analyzer according to claim 1, characterized in that: The online analysis unit (3) comprises: a second pure water pipe (31), a porphyrin colorimetric reagent pipe (32), a plurality of pH buffer reagent pipes (33), a third waste liquid pipe (34), a second air pipe (35), a fourth waste liquid pipe (36), a third pure water pipe (37), a third air pipe (38), a fifth switching valve (39), an injection pump (310), a reaction kettle (311), a xenon lamp (312), a spectrometer (313), a third peristaltic pump (314), a fourth peristaltic pump (315), and a sixth switching valve (316); The fifth switching valve (39) is respectively connected to the liquid outlet of the second pure water pipe (31), the liquid outlet of the porphyrin color developer pipe (32), the liquid outlets of each pH buffer reagent pipe (33), the liquid inlet of the third peristaltic pump (314), the liquid inlet of the third waste liquid pipe (34), the air outlet of the second air pipe (35), the injection pump (310) and the reaction kettle (311), and is used to connect the second pure water pipe (31), the porphyrin color developer pipe (32), each pH buffer reagent pipe (33), the third peristaltic pump (314), the third waste liquid pipe (34), the second air pipe (35) and the reaction kettle (311) to the injection pump (310); the third peristaltic pump (314) The liquid outlet is connected to the liquid inlet of the fourth waste liquid pipe (36); the sixth switching valve (316) is respectively connected to the liquid inlet of the fourth peristaltic pump (315), the liquid outlet of the third pure water pipe (37) and the air outlet of the third air pipe (38), and is used to connect the third pure water pipe (37) and the third air pipe (38) to the fourth peristaltic pump (315); the liquid outlet of the fourth peristaltic pump (315) is connected to the reactor (311); a spectrometer (313) and a xenon lamp (312) are installed on opposite sides of the reactor (311), and the spectrometer (313) and the xenon lamp (312) are used to measure the absorbance of the eluent in the reactor (311).

5. The water quality heavy metal online analyzer according to claim 4, characterized in that: It also includes a water sample detector (317) installed on a pipeline connecting the fifth switching valve (39) and the reaction kettle (311); The reaction kettle (311) has a temperature control device and a stirring device.

6. The water quality heavy metal online analyzer according to claim 1, characterized in that: The mixing tube (24) is a spiral mixing tube.

7. The water quality heavy metal online analyzer according to claim 3 is characterized in that: The first switching valve (23) comprises: a first three-way solenoid valve (231), a second three-way solenoid valve (232) and a third three-way solenoid valve (233); the first three-way solenoid valve (231) is connected to the first air pipe (29), the second three-way solenoid valve (232) and the sample digestion retention pool (19) respectively, and is used to connect the first air pipe (29) and the sample digestion retention pool (19) to the second three-way solenoid valve (232); the second three-way solenoid valve (232) is connected to the pH adjustment device (19) respectively. The reagent tube (21), the first three-way solenoid valve (231) and the third three-way solenoid valve (233) are connected to each other, and are used to connect the first three-way solenoid valve (231) and the pH adjustment reagent tube (21) to the third three-way solenoid valve (233); the third three-way solenoid valve (233) is respectively connected to the elution reagent tube (22), the mixing tube (24) and the second three-way solenoid valve (232), and is used to connect the elution reagent tube (22) and the second three-way solenoid valve (232) to the mixing tube (24); The third switching valve (16) comprises: a fourth three-way solenoid valve (161), a fifth three-way solenoid valve (162) and a sixth three-way solenoid valve (163); The fourth three-way solenoid valve (161) is respectively connected to the heavy metal mixed standard tube (13), the acid digestion reagent tube (14) and the fifth three-way solenoid valve (162), and is used to connect the heavy metal mixed standard tube (13) and the acid digestion reagent tube (14) to the fifth three-way solenoid valve (162); The fifth three-way solenoid valve (162) is respectively connected to the first pure water pipe (12), the fourth three-way solenoid valve (161) and the sixth three-way solenoid valve (163), and is used to connect the first pure water pipe (12) and the fourth three-way solenoid valve (161) to the sixth three-way solenoid valve (163); The sixth three-way solenoid valve (163) is respectively connected to the water sample tube (11), the fifth three-way solenoid valve (162) and the second peristaltic pump (17), and is used to connect the water sample tube (11) and the fifth three-way solenoid valve (162) to the second peristaltic pump (17).

8. The water quality heavy metal online analyzer according to claim 4, characterized in that: The online analysis unit (3) is provided with a plurality of reaction kettles (311), each of which is equipped with a xenon lamp (312) and a spectrometer (313); the plurality of reaction kettles (311) correspond to and are connected to the plurality of enrichment and elution units (2) one by one, and the plurality of reaction kettles (311) are respectively connected to the fifth switching valve (39) and the fourth peristaltic pump (315).

9. An analysis method for an online water heavy metal analyzer according to any one of claims 1 to 7, characterized in that: include: S1, water sample digestion: draw water sample and acid digestion reagent into digestion unit (1) in sequence for heating and digestion to obtain digestion solution; S2, enrichment and elution: extracting the decomposition solution, pH adjustment reagent and elution reagent to a certain enrichment and elution unit (2) to enrich and elute a certain heavy metal, and obtain an eluate containing a certain heavy metal; specifically, the following sub-steps are included: S21, turning on the first peristaltic pump (25), the second switching valve (27) and the first switching valve (23), wherein the first switching valve (23) switches the mixing tube (24) alternately to be connected to the digestion unit (1) and the pH adjustment reagent tube (21), so as to alternately draw a quantitative digestion solution and a pH adjustment reagent into the mixing tube (24) for mixing; S22, mercapto cotton adsorption: the first peristaltic pump (25), the second switching valve (27) and the first switching valve (23) are turned on, the first switching valve (23) switches the mixing tube (24) to be connected to the first air tube (29), and the mixed liquid of the pH adjustment reagent and the digestion solution passes through the mercapto cotton elution tube (26) at a certain speed, so that a certain heavy metal in the mixed liquid is adsorbed by the mercapto cotton, and the other liquid is discharged through the first waste liquid pipe (28); S23, elution: the second switching valve (27) is closed, the first switching valve (23) switches the mixing tube (24) to be connected to the elution reagent tube (22), the first peristaltic pump (25) rotates, extracts the elution reagent at a certain speed to elute the heavy metals from the thiol cotton, obtains the eluate, and directly delivers it to the online analysis unit (3); S3, online analysis: according to the color development reaction requirements, pH buffer solution is extracted into the online analysis unit (3) and mixed with the eluent, and then porphyrin color developing agent is extracted into the online analysis unit (3) and mixed with the eluent to react and develop color, and then absorbance is measured; S4, cleaning the online analysis unit (3) and waiting for the next test; S5. Repeat steps S2 to S4, extract the deionized liquid and send it to the next enrichment and elution unit (2) to carry out enrichment, elution and determination of other heavy metals.

10. The analysis method of the water quality heavy metal online analyzer according to claim 9, characterized in that: The method also includes a standard solution calibration test, which is to prepare a heavy metal mixed standard instead of a water sample to perform steps S1 to S5.

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