Bypass precision filtration pretreatment device and intelligent pretreatment system for high-turbidity water quality

Abstract

The utility model belongs to the technical field of online measurement of volatile organic compounds on surface water. The utility model provides a bypass precision filtration pretreatment device which comprises a sampling port, a filter element bracket, a backwashing port, a water sample cup cover, a metal filter element, a water sample cup, an overflow pipe, a water inlet and a water outlet, the filter element bracket is internally provided with a hollow pipeline, the middle part is provided with an external thread, the top is provided with a sampling port and a backwashing port, and the bottom is provided with an internal thread; the metal filter element is connected with an internal thread at the bottom of the filter element bracket through a top external thread; the sampling port and the reverse cleaning port are communicated with the upper part of the hollow pipeline of the filter element bracket; the filter element bracket is connected with an internal thread of the water sample cup cover through an external thread in the middle; the metal filter element is of a hollow structure. The device provided by the utility model not only can meet the normal measurement of a water sample in a high-turbidity environment, but also can automatically carry out various intelligent quality control measures such as standard sample checking, multi-point calibration, emergency quality control and the like on the online volatile organic compound monitor.

Description

Technical Field

[0001] The utility model belongs to the technical field of online determination of volatile organic compounds in surface water. Background Art

[0002] Online volatile organic compound (VOC) measurement in surface water generally involves a pretreatment unit, a purge-and-trap unit, a chromatography or mass spectrometry analysis unit, and a control unit. The purge-and-trap unit and the detection unit are typically integrated using established laboratory instrumentation methods, with no significant differences between the various solutions. However, due to the complexity of surface water samples, the pretreatment unit significantly impacts the consistency and repeatability of sample measurements. Furthermore, due to the characteristics of VOC monitoring instruments, their long-term stability is inferior to that of traditional chemical-based instruments, requiring frequent manual maintenance and calibration during field installation.

[0003] Prior art CN117517034A is a sample pretreatment system for volatile organic pollutants in water. During flood season or in watersheds with high turbidity, the instrument will automatically activate protective measures, which will seriously affect the efficiency of test data.

[0004] As a new product form, the volatile organic compound water quality online monitor still has many pain points in application. First, since most instruments use experimental instruments or simple modified integration, it is necessary to separately design pre-treatment and sampling devices that meet the instrument and on-site monitoring needs (turbidity pretreatment, pipeline backwashing); secondly, as detectors of volatile organic compounds, instruments such as gas phase / gas phase mass spectrometry are affected by on-site environmental conditions and the complexity of surface water samples. The instrument stability and test consistency are not as good as those in the laboratory. Over time, they are prone to problems such as response attenuation and sampling line blockage. Regular standard sample verification is required to track the instrument status, and automatic calibration, multi-point linearity and other quality control work are required when necessary to ensure the accuracy and stability of the monitoring data. In summary, the volatile organic compound water quality online monitor needs to be equipped with supporting pre-treatment and intelligent quality control devices to be better used on-site.

[0005] In existing technologies: 1) If high turbidity is encountered, protective measures are activated, preventing the instrument from performing measurements. This significantly impacts data efficiency, making it unsuitable for flood season monitoring or monitoring water bodies with persistently high turbidity, significantly limiting its use cases. 2) Traditional filter cartridge filtration methods are prone to clogging. Although backwashing is provided, this approach fails to account for the reality of high turbidity waters. Due to the limited filter volume of traditional multi-stage filtration, this can lead to clogging of the pre-filter, preventing the required water sample volume for subsequent testing. 3) Filter surface flushing is incomplete. Traditional filter cartridges, such as PP cotton and activated carbon, cannot be backwashed at high pressure due to their physical properties. Backwashing only the surface of the filter cartridge fails to thoroughly clean the filter. 4) Daily quality control is labor-intensive and cannot be performed remotely. VOC standards have a short shelf life, and the standard requires them to be prepared immediately upon use. Therefore, daily quality control requires personnel to be dispatched to the site to manually prepare samples, increasing the workload. Moreover, the surface water operation and maintenance regulations stipulate that daily quality control needs to be carried out between 6 and 7 am every day, and it is unrealistic to require manual on-site preparation of standard samples in advance. The above reasons also make it impossible to perform remote quality control such as standard sample verification and multi-point calibration. 5) The traditional injection mode consumes a large amount of standard samples, and the volatile organic compound standard solution needs to be stored in a sealed manner at low temperature and away from light. The traditional injection mode requires rinsing with standard solution, which consumes a lot of water. Volatile organic compound standards, especially isotope standards, are relatively expensive. The traditional rinsing and then injection mode will greatly increase the operation and maintenance costs, making it difficult to support remote quality control functions. Utility Model Content

[0006] In view of this, the utility model provides a bypass precision filtration pretreatment device, comprising: a sampling port, a filter element bracket, a backwash port, a water sample cup cover, a metal filter element, a water sample cup, an overflow pipe, a water inlet, and a drain port;

[0007] The filter element bracket is provided with a hollow pipe inside, an external thread in the middle, a sampling port and a backwash port at the top, and an internal thread at the bottom;

[0008] The metal filter element is connected to the internal thread at the bottom of the filter element bracket through the external thread at the top;

[0009] The sampling port and the backwash port are both connected to the upper part of the hollow pipe of the filter element support;

[0010] The backwash port is connected to the water vapor mixture through a pipeline;

[0011] The filter element bracket is connected to the internal thread of the water sample cup cover through the external thread in the middle;

[0012] The metal filter element is a hollow structure, with an external thread on the upper part connected to the internal thread at the bottom of the filter element bracket through the external thread, and the lower part is sunk into the water sample cup;

[0013] The water sample cup is sealed with the water sample cup cover;

[0014] An overflow pipe, a water inlet and a drain are provided in the water sample cup. The overflow pipe is used for liquid overflow. The water inlet and the drain are arranged at the bottom. The water inlet is used for water sample intake through a pipeline, and the drain is used for draining water sample through a pipeline.

[0015] In a specific embodiment of the present invention, the pore diameter of the metal filter element is 5 to 15 microns; the metal filter element is a stainless steel sintered filter element or a titanium-nickel alloy sintered filter element.

[0016] In a specific embodiment of the present invention, the internal volume of the metal filter element is 75 mL.

[0017] The utility model also provides an intelligent pre-treatment system for high turbidity water, comprising: a bypass precision filtration pre-treatment device, a refrigerated precision sampling unit and an intelligent quality control device;

[0018] The refrigerated precision sample injection unit includes: a refrigeration box 10, a ceramic plunger pump 11, an eight-way valve 12, a liquid storage ring 13, a three-way valve 14, a high-pressure nitrogen bottle 15, and a sample bottle 16.

[0019] The ceramic plunger pump 11 is connected to the normally open end of the three-way valve 14, the common end of the three-way valve is connected to the first end of the liquid storage ring, and the normally closed end of the three-way valve is connected to the high-pressure nitrogen cylinder.

[0020] The liquid storage ring 13 contains pure water and the second end is connected to the common end of the eight-way valve.

[0021] The common end of the eight-way valve can be connected to other ports respectively through the rotating valve body: the first end is connected to the pure water bottle; the second end is connected to the mixing cup; the third end is connected to the detection unit; the fourth end is connected to the waste liquid bottle; the fifth end is connected to the air exhaust; the sixth end is the common end and is connected to the liquid storage ring; the seventh end is connected to the sample bottle, and the eighth end is connected to the bypass precision filtration pretreatment device.

[0022] The refrigerated precision sampling unit is respectively connected to the detection unit, the bypass precision filtration pretreatment device and the intelligent quality control device.

[0023] In a specific embodiment of the present invention, the sample bottle has a screw cap with a silicone rubber-polytetrafluoroethylene liner.

[0024] The device provided by the present invention can not only meet the normal measurement of water samples in a high turbidity environment, but also automatically perform various intelligent quality control measures on the online volatile organic compound monitor, such as standard sample verification, multi-point calibration, emergency quality control, etc., to ensure the authenticity of the data, improve data efficiency, and reduce operation and maintenance costs. The system provided by the present invention can be used on-site in an unmanned surface water automatic monitoring station for a long time to ensure the authenticity of water sample measurement and the accuracy of verification / calibration. The present invention mainly solves the problem that the high turbidity of surface water interferes with the measurement results / affects the data efficiency, the instrument standard samples are difficult to store, the need to prepare them on-the-go, and there is a lot of waste during sampling, which makes it impossible for the instrument to perform unmanned intelligent quality control. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 This is a diagram of a bypass precision filtration pretreatment device.

[0026] Among them, 1 is the sampling port, 2 is the filter element bracket, 3 is the backwash port, 4 is the water sample cup cover, 5 is the metal filter element, 6 is the water sample cup, 7 is the overflow pipe, 8 is the water inlet, and 9 is the drain outlet.

[0027] Figure 2 This is a schematic diagram of the refrigerated precision sampling unit.

[0028] Among them, 10 is a refrigerator, 11 is a ceramic plunger pump, 12 is an eight-way valve, 13 is a liquid storage ring, 14 is a three-way valve, 15 is a high-pressure nitrogen bottle, and 16 is a sample bottle with a silicone rubber-polytetrafluoroethylene liner screw cap. DETAILED DESCRIPTION

[0029] Example

[0030] The utility model designs a set of intelligent pretreatment system for high turbidity water quality, which includes a bypass precision filtration pretreatment device, an intelligent quality control device and a refrigerated precision sampling unit. It can not only meet the normal measurement of water samples in a high turbidity environment, but also automatically perform various intelligent quality control measures such as standard sample verification, multi-point calibration, and emergency quality control on the online volatile organic compound monitor, ensuring the authenticity of the data, improving data efficiency, and reducing operation and maintenance costs.

[0031] The system provided by the utility model can be applied on-site in an unmanned surface water automatic monitoring station for a long period of time, ensuring the authenticity of water sample measurement and the accuracy of verification / calibration.

[0032] The utility model mainly solves the problems that high turbidity of surface water interferes with the measurement results / affects data efficiency, instrument standard samples are difficult to preserve, need to be prepared on demand, and there is a lot of waste during sample injection, which makes the instrument unable to perform unmanned intelligent quality control.

[0033] The intelligent quality control device is an instrument that uses an intelligent quality control sample preparation device to remotely / automatically prepare standard samples such as standard verification samples and multi-point calibration samples, and provides them to the monitoring instrument for testing corresponding quality control items after preparation.

[0034] The daily quality control is to conduct a standard sample check on the instrument every day, and determine the instrument performance through the indication error of the standard sample check result.

[0035] The high turbidity water quality intelligent pretreatment system comprises a bypass precision filtration pretreatment device, an intelligent quality control device and a refrigerated precision sampling unit.

[0036] The sampling port 1 of the bypass precision filtration pretreatment device is connected to the eighth port of the eight-way valve of the refrigerated precision sampling unit;

[0037] The third end of the eight-way valve of the refrigerated precision sampling unit is connected to the mixing cup of the intelligent quality control device;

[0038] The intelligent quality control device includes a mixing cup, a quantitative system, and a liquid power system; the mixing cup is used to configure a container for a standard sample of the required concentration; the quantitative system is used to accurately control the amount of liquid used; and the liquid power system is used to provide power and a delivery pipeline for the transfer of liquid between different containers.

[0039] The bypass precision filtration pretreatment device comprises: a sampling port, a filter element bracket, a backwash port, a water sample cup cover, a metal filter element, a water sample cup, an overflow pipe, a water inlet, and a drain outlet.

[0040] The filter element bracket is provided with a hollow pipe inside, an external thread in the middle, a sampling port and a backwash port on the top, and an internal thread at the bottom; the metal filter element is connected to the internal thread at the bottom of the filter element bracket through the external thread at the top; the sampling port and the backwash port are both connected to the upper part of the hollow pipe of the filter element bracket; the sampling port is connected to the sampling port of the precision sampling unit through a pipeline; the backwash port is connected to the water vapor mixture through a pipeline; the filter element bracket is connected to the internal thread of the water sample cup cover through the external thread in the middle; the metal filter element is a hollow structure, and the upper It is provided with an external thread and is connected to the internal thread at the bottom of the filter element bracket through the external thread, and the lower part is sunk into the water sample cup; the pore diameter of the metal filter element is 5 to 15 microns; the metal filter element is a stainless steel sintered filter element (or a titanium-nickel alloy sintered filter element) with an internal volume of 75mL; the water sample cup is sealed with the water sample cup cover; an overflow pipe, a water inlet and a drain are provided in the water sample cup, the overflow pipe is used for liquid overflow, the water inlet and the drain are arranged at the bottom, the water inlet is used for water sample intake through a pipeline, and the drain is used for emptying the water sample through a pipeline.

[0041] The method for treating highly turbid water samples using a bypass precision filtration pretreatment device comprises the following steps:

[0042] First, graded sedimentation is used to remove easily settleable particles, and primary sedimentation is performed to reduce large particles of sediment. The turbidity of easily settleable water samples can usually be reduced to below 500NTU after sedimentation in the sedimentation tank.

[0043] Second, the water sample with easily settled particles removed enters the water sample cup through the water inlet. During the secondary sedimentation, the water sample is filtered from the outside to the inside of the metal filter element. After filtration, the turbidity of the water sample can be reduced from 500NTU to below 100NTU.

[0044] Third, the water sample passes through the sampling port and is supplied to the detection unit through the refrigerated precision sampling unit.

[0045] Fourth, after sampling is completed, drain the water sample in the water sample cup through the drain port.

[0046] Fifth, inject the high-pressure water-vapor mixture into the metal filter element through the backwash port, and clean the water sample cup while cleaning the filter element to achieve the purpose of thorough cleaning.

[0047] The intelligent quality control device includes: a mixing cup, a quantitative system, and a liquid power system. The sample preparation process of the intelligent quality control device is as follows:

[0048] The intelligent quality control device first calculates the required sample volume and the volume of pure water for dilution according to the required standard sample concentration, then accurately quantifies the required sample volume through the refrigerated precision injection unit, injects the sample into the mixing cup of the intelligent quality control device, and then quantifies the required pure water through the intelligent quality control device and injects it into the mixing cup for mixing.

[0049] The refrigerated precision sample injection unit is a sample injection unit with a constant temperature refrigeration function.

[0050] The refrigerated precision sample injection unit comprises: a refrigerated box, a ceramic plunger pump, an eight-way valve, a liquid storage ring, a three-way valve, a high-pressure nitrogen bottle, and a sample bottle with a silicone rubber-polytetrafluoroethylene liner screw cap.

[0051] The ceramic plunger pump is connected to the normally open end of the three-way valve, the common end of the three-way valve is connected to the first end of the liquid storage ring, the normally closed end of the three-way valve is connected to the high-pressure nitrogen bottle, a section of pure water is stored in the liquid storage ring for a long time and the second end is connected to the common end of the eight-way valve, and the common end of the eight-way valve can be connected to respectively through the rotating valve body: the pure water bottle at the first end; the mixing cup of the intelligent quality control device at the second end; the detection unit at the third end; the waste liquid bottle at the fourth end; the air exhaust at the fifth end; the common end at the sixth end; the sample bottle with a silicone rubber-polytetrafluoroethylene gasket screw cap at the seventh end; and the bypass precision filtration pretreatment device at the eighth end.

[0052] The sampling method of the refrigerated precision sampling unit comprises the following steps:

[0053] First, when quantitative measurement begins, first switch the common end of the eight-way valve to the pure water bottle at the first end of the eight-way valve, draw a certain amount of pure water, and use the pure water to clean the liquid storage ring. After cleaning, switch the common end of the eight-way valve to the waste liquid bottle at the fourth end of the eight-way valve and drain the cleaning water to the waste liquid. Then switch it to the air at the fifth end of the eight-way valve. At the same time, switch the three-way valve to the normally closed end and the common end. Use high-pressure nitrogen to purge the liquid storage ring, and then empty it from the fifth end to ensure that there is no liquid residue.

[0054] Second, when the standard sample is quantified, the eight-way valve switches the common end to the empty connection with the fifth end of the eight-way valve, extracts a certain amount of air, and then switches to the sample bottle with a silicone rubber-polytetrafluoroethylene gasket screw cap at the seventh end of the eight-way valve, and then extracts the required amount of liquid to accurately quantify the standard sample.

[0055] Third, after the quantification is completed, the common end of the eight-way valve is switched to the mixing cup at the third end and liquid is injected into the mixing cup to dilute the sample.

[0056] This concludes the quantitative analysis of the refrigerated precision sampling unit. The following is the quantitative analysis process of pure water and diluted standard solution using the intelligent quality control device:

[0057] The intelligent quality control device uses its high-precision photoelectric quantitative system to quantify the required pure water, rapidly (speed ≥ 25 ml / min) and accurately (repeatability ≤ 0.5%) preparing the required sample in a mixing cup, ensuring that the pure water and sample do not interfere with each other. After preparation, the sample, diluted to a specific concentration, is fed from the mixing cup by a refrigerated precision sampling unit to a subsequent detection unit (purge and trap) for measurement.

[0058] The solution of this utility model can effectively solve the following problems:

[0059] 1) Ensure that the filter element will not be blocked while obtaining sufficient filtered water samples. Experiments have shown that after enabling the bypass precision pretreatment, the turbidity of the water sample can be controlled below 100 NTU, and the particles in the water are all below 15 μm, ensuring that the sample inlet line will not be blocked.

[0060] 2) After each test, the filter element and sampling cup are automatically backwashed with a high-pressure water-gas mixture. In the case of high turbidity, the number of cleanings will be automatically increased to ensure the cleaning effect.

[0061] 3) By using the sampling unit in a refrigerated box, the waste of mother solution can be reduced and the consistency of the sample can be guaranteed. The standard solution can be used for a long time (>1 month) in the refrigerated precision sampling unit.

Claims

1. Bypass precision filtration pretreatment device, characterized in that, include: Sampling port, filter element bracket, backwash port, water sample cup cover, metal filter element, water sample cup, overflow pipe, water inlet, drain port; The filter element bracket is provided with a hollow pipe inside, an external thread in the middle, a sampling port and a backwash port at the top, and an internal thread at the bottom; The metal filter element is connected to the internal thread at the bottom of the filter element bracket through the external thread at the top; The sampling port and the backwash port are both connected to the upper part of the hollow pipe of the filter element support; The backwash port is connected to the water vapor mixture through a pipeline; The filter element bracket is connected to the internal thread of the water sample cup cover through the external thread in the middle; The metal filter element is a hollow structure, with an external thread on the upper part connected to the internal thread at the bottom of the filter element bracket through the external thread, and the lower part is sunk into the water sample cup; The water sample cup is sealed with the water sample cup cover; An overflow pipe, a water inlet and a drain are provided in the water sample cup. The overflow pipe is used for liquid overflow. The water inlet and the drain are arranged at the bottom. The water inlet is used for water sample intake through a pipeline, and the drain is used for draining water sample through a pipeline.

2. The bypass precision filtration pretreatment device according to claim 1, characterized in that: The pore diameter of the metal filter element is 5 to 15 microns; The metal filter element is a stainless steel sintered filter element or a titanium-nickel alloy sintered filter element.

3. The bypass precision filtration pretreatment device according to claim 2, characterized in that: The internal volume of the metal filter element is 75 mL.

4. High turbidity water quality intelligent pre-treatment system, characterized by: It includes the bypass precision filtration pretreatment device, the refrigerated precision sampling unit and the intelligent quality control device according to claim 1; The refrigerated precision sampling unit includes: a refrigerated box, a ceramic plunger pump, an eight-way valve, a liquid storage ring, a three-way valve, a high-pressure nitrogen bottle, and a sample bottle; The intelligent quality control device includes a mixing cup, a quantitative system, and a liquid power system; the mixing cup is used to configure a container for a standard sample of a required concentration; the quantitative system is used to accurately control the amount of liquid used; and the liquid power system is used to provide power and a delivery pipeline for the transfer of liquid between different containers. The ceramic plunger pump is connected to the normally open end of the three-way valve. The common end of the three-way valve is connected to the first end of the liquid storage ring. The normally closed end of the three-way valve is connected to the high-pressure nitrogen cylinder. The liquid storage ring contains pure water and the second end is connected to the common end of the eight-way valve. The common end of the eight-way valve can be connected to: the pure water bottle at the first end; the detection unit at the second end; the mixing cup at the third end; the waste liquid bottle at the fourth end; the emptying at the fifth end; the common end at the sixth end; the sample bottle at the seventh end, and the bypass precision pretreatment device at the eighth end through the rotating valve body.

5. The high turbidity water quality intelligent pre-treatment system according to claim 4 is characterized in that: The vials had silicone rubber-PTFE lined screw caps.

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