阅读说明：本技术 一种光催化便携式水质总有机碳检测装置及检测方法 (Photocatalytic portable water quality total organic carbon detection device and method ) 是由 张延荣 徐鑫 于 2019-11-20 设计创作，主要内容包括：本发明涉及一种光催化便携式水质总有机碳检测装置及检测方法,属于环境保护监测技术领域。装置包括依次连接的进样模块、光催化反应模块和二氧化碳检测模块,光催化反应模块包括反应室和光催化片,光催化片能在紫外光照射下,催化水样中的有机物生成二氧化碳,二氧化碳检测模块检测光催化反应模块中的生成的二氧化碳的浓度,从而计算得到水样中总有机碳的含量。本发明提供的TOC检测装置,可以便携实时检测某一地点某一时段水样的TOC值。本发明与传统TOC检测仪的燃烧法不同,是利用高效光催化技术在短时间内将有机物矿化为二氧化碳进行检测,在节能环保方面具有较大的意义。(The invention relates to a photocatalytic portable water quality total organic carbon detection device and a detection method, and belongs to the technical field of environmental protection monitoring. The device is including the appearance module of advancing, photocatalytic reaction module and the carbon dioxide detection module that connects gradually, and photocatalytic reaction module includes reacting chamber and photocatalysis piece, and the photocatalysis piece can be under ultraviolet irradiation, and the organic matter in the catalysis water sample generates carbon dioxide, and carbon dioxide detection module detects the concentration of the carbon dioxide of the formation in the photocatalytic reaction module to the content of total organic carbon in the water sample is obtained in the calculation. The TOC detection device provided by the invention can be used for detecting the TOC value of a water sample at a certain place in a certain period in a portable and real-time manner. Different from the combustion method of the traditional TOC detector, the invention utilizes the high-efficiency photocatalysis technology to mineralize the organic matters into carbon dioxide for detection in a short time, and has great significance in the aspects of energy conservation and environmental protection.)

1. A portable photocatalytic water quality total organic carbon detection device is characterized by comprising a sample introduction module, a photocatalytic reaction module and a carbon dioxide detection module which are sequentially connected;

the sample introduction module comprises a sample introduction needle (1) and a sample introduction device (2), the photocatalytic reaction module comprises a reaction chamber (3) and a photocatalytic sheet (4), and the photocatalytic sheet (4) is vertically arranged in the reaction chamber (3); the sample injection device is characterized in that a sample injection port (5) is distributed on the upper surface of the reaction chamber (3), the sample injection port (5) is connected with the sample injection device (2), and the sample injection needle (1) is used for injecting a water sample into the surface of the photocatalytic sheet (4) in the reaction chamber (3) through the sample injection device (2) and the sample injection port (5); a sealing gasket (6) is arranged in the sample feeding device (2); the sealing gasket (6) is used for enabling the reaction chamber (3) to be in a sealing state when the sample injection needle (1) does not inject a water sample, and the sealing gasket (6) is used for preventing gas in the reaction chamber (3) from escaping when the sample injection needle (1) injects the water sample;

the photocatalytic reaction module further comprises an ultraviolet light source (7) and a quartz plate (8), the quartz plate (8) is hermetically connected with the reaction chamber (3), and the quartz plate (8) is used for irradiating ultraviolet light emitted by the ultraviolet light source (7) to the surface of the photocatalytic plate (4);

the carbon dioxide detection module comprises a waterproof unit (9) and a detection unit (10), wherein the waterproof unit (9) is used for blocking liquid drops generated in the reaction chamber (3) outside the detection unit (10), and the detection unit (10) is used for detecting the concentration of carbon dioxide in the reaction chamber (3).

2. The photocatalytic portable water quality total organic carbon detection device as claimed in claim 1, wherein the sample injection device (2) comprises a bolt (11) and a nut (12); the upper part and the lower part of the bolt (11) are respectively provided with an external thread structure, the external thread structure at the lower part is fixedly connected with the internal thread of the sample inlet (5), and the external thread structure at the upper part is connected with the internal thread of the nut (12); the interior of the bolt (11) is of a hollow structure, the sealing gasket (6) is positioned on the cross section of the hollow structure in the bolt (11), and the hollow diameter of the upper part of the sealing gasket (6) is larger than that of the lower part of the sealing gasket, so that the sealing gasket (6) is not easy to fall out; the upper surface of nut (12) has into appearance hole (13), sample needle (1) injects the water sample through this appearance hole (13).

3. The photocatalytic portable water quality total organic carbon detection device as claimed in claim 1, wherein the sealing gasket (6) is a rubber gasket.

4. The photocatalytic portable water quality total organic carbon detection device as claimed in claim 1, wherein the waterproof unit (9) is a waterproof and breathable membrane of expanded polytetrafluoroethylene.

5. Such asThe device for detecting total organic carbon in water through photocatalysis in a portable way as claimed in claim 1, wherein the photocatalysis sheet (4) is a titanium sheet substrate, the surface of which is covered with TiO₂Nanotube of said TiO₂The nanotubes are loaded with WO₃And (3) granules.

6. The method for detecting the total organic carbon in water by using the photocatalytic portable device for detecting the total organic carbon in water as claimed in any one of claims 1 to 5 is characterized by comprising the following steps of:

s1: the sample injection needle (1) injects deionized water into the surface of the photocatalytic sheet (4) in the reaction chamber (3) through the sample injection device (2) and the sample injection port (5), and the detection unit (10) detects the volume concentration S of the original carbon dioxide in the reaction chamber (3)₀(ii) a Turning on an ultraviolet light source (7), irradiating ultraviolet light emitted by the ultraviolet light source (7) to the surface of a photocatalytic sheet (4), catalyzing organic matters on the photocatalytic sheet (4) to generate carbon dioxide, and measuring the volume concentration S of the carbon dioxide in the reaction chamber (3) by the detection unit (10)₀′；

S2: injecting a water sample to be detected into the surface of the photocatalytic sheet (4) in the reaction chamber (3) through the sample injection needle (1) through the sample injection device (2) and the sample injection port (5), wherein the volume of the water sample to be detected is the same as that of the deionized water in the step S1; under the irradiation of ultraviolet light emitted by an ultraviolet light source (7), a water sample to be detected on the surface of the photocatalytic sheet (4) is catalyzed to generate carbon dioxide, the numerical value displayed by the detection unit (10) continuously increases until the numerical value is stable, and the volume concentration of the carbon dioxide in the reaction chamber (3) is measured by the detection unit (10) at the moment and is S;

s3: calculating the content rho of the total organic carbon in the water sample to be detected, wherein the calculation formula is as follows: rho ═ S-S₀′-(S₀′-S₀)]*V*Ar(C)/(V_m*V_Into) Wherein V is the volume of the reaction chamber (3), Ar (C) is equal to 12, is the relative atomic mass of carbon atoms, V_m24.5L/mol, molar volume of gas at normal temperature and pressure, V_IntoIs the volume of the water sample to be measured.

7. The detection method according to claim 6, wherein the detection unit (10) detects the concentration of carbon dioxide in the reaction chamber (3) by a non-dispersive infrared method.

8. The detection method according to claim 6, wherein the volume of the water sample to be detected is 10 μ L to 30 μ L.

9. The detection method according to claim 6, wherein the water sample to be detected contains p-nitrophenol.

Technical Field

The invention belongs to the technical field of environmental protection monitoring, and relates to a photocatalytic portable water quality total organic carbon detection device and a detection method.

Background

Among various monitoring indexes of water quality, Total Organic Carbon (TOC) can intuitively represent the total amount of organic matters in a water body, and is one of important reference indexes for evaluating organic pollution of water quality. The traditional TOC instrument in a laboratory generally utilizes the principle of high-temperature catalytic combustion oxidation-non-dispersive infrared detection (NDIR), a water sample needs to be respectively combusted and mineralized in a high-temperature combustion tube at 900 ℃ and a low-temperature combustion tube at 150 ℃ under the condition of gas assistance, platinum and cobalt trioxide or cobaltous oxide are also needed to be used as catalysts in the high-temperature combustion tube, the cost is relatively high, the occupied area is large, and the TOC instrument cannot be applied to field real-time field detection. Moreover, the concentration of the test sample is generally lower than 50ppm, and errors are easily formed when high-concentration samples are detected by high-fold dilution.

Photocatalytic technology was first published in n-semiconductor TiO by Japanese scientists Fujishima and Honda since 1972₂TiO has been reported to be useful for photoelectrocatalytic decomposition of water on electrodes₂The photocatalyst is widely applied to the field of photocatalytic degradation of pollutants due to unique optical properties and high photocatalytic activity. The photocatalysis technology has the advantages of simple operation, low energy consumption, no secondary pollution, high efficiency, no selectivity to pollutants and the like, and the photocatalyst (self-doping type WO) used in the invention₃Particle loading on TiO₂Nanotube) has proved to have extremely strong capability of degrading organic pollutants in a plurality of tests, and can degrade and mineralize the organic pollutants in a water sample to be tested into carbon dioxide under the irradiation of an ultraviolet light source. Therefore, the invention utilizes the excellent performances of photocatalysis to initiatively develop an instrument capable of detecting TOC of water quality,

the portable TOC detection device overcomes the defects of large occupied area, high energy consumption, easiness in damage and the like of the traditional TOC detector, utilizes a photocatalysis technology to invent the portable TOC detection device, and can realize real-time detection under field conditions.

Disclosure of Invention

The invention solves the technical defects of inaccurate measuring result, expensive catalyst requirement and large occupied area of the measuring device for the total organic carbon in water quality in the prior art. The invention provides a portable device and a method for detecting total organic carbon in water quality, which can be applied in real time in the field. The detection device does not need to provide a high-temperature environment, and does not need expensive catalysts such as platinum, cobalt trioxide or cobaltous oxide, so that the detection device is low in cost and low in energy consumption; the detection method has higher detection limit and accurate result.

According to the first aspect of the invention, the invention provides a photocatalytic portable water quality total organic carbon detection device, which comprises a sample introduction module, a photocatalytic reaction module and a carbon dioxide detection module which are sequentially connected;

the sample introduction module comprises a sample introduction needle and a sample introduction device, the photocatalytic reaction module comprises a reaction chamber and a photocatalytic sheet, and the photocatalytic sheet is vertically arranged in the reaction chamber; the sample injection needle is used for injecting a water sample into the surface of the photocatalytic sheet in the reaction chamber through the sample injection device and the sample injection port; a sealing gasket is arranged in the sample feeding device; the sealing gasket is used for enabling the reaction chamber to be in a sealing state when the sample injection needle does not inject a water sample, and is used for preventing gas in the reaction chamber from escaping when the sample injection needle injects the water sample;

the photocatalytic reaction module also comprises an ultraviolet light source and a quartz plate, the quartz plate is hermetically connected with the reaction chamber, and the quartz plate is used for irradiating ultraviolet light emitted by the ultraviolet light source to the surface of the photocatalytic plate;

the carbon dioxide detection module comprises a waterproof unit and a detection unit, the waterproof unit is used for blocking liquid drops generated in the reaction chamber outside the detection unit, and the detection unit is used for detecting the concentration of carbon dioxide in the reaction chamber.

Preferably, the sample introduction device comprises a bolt and a nut; the upper part and the lower part of the bolt are respectively provided with an external thread structure, the external thread structure at the lower part is fixedly connected with the internal thread of the sample inlet, and the external thread structure at the upper part is connected with the internal thread of the nut; the inner part of the bolt is of a hollow structure, the sealing gasket is positioned on the cross section of the hollow structure in the bolt, and the diameter of the hollow part of the upper part of the sealing gasket is larger than that of the hollow part of the lower part of the sealing gasket, so that the sealing gasket is not easy to fall out; the upper surface of the nut is provided with a sample inlet hole, and the sample injection needle injects a water sample through the sample inlet hole.

Preferably, the sealing gasket is a rubber gasket.

Preferably, the waterproof unit is an expanded polytetrafluoroethylene waterproof breathable film.

Preferably, the photocatalytic sheet is a titanium sheet substrate with TiO coated surface₂Nanotube of said TiO₂The nanotubes are loaded with WO₃And (3) granules.

According to another aspect of the present invention, there is provided a method for detecting total organic carbon in water by using any one of the above-mentioned portable photocatalytic water quality total organic carbon detection devices, comprising the steps of:

s1: the sample injection needle injects deionized water into the surface of the photocatalytic sheet in the reaction chamber through the sample injection device and the sample injection port, and the detection unit detects the volume concentration S of the original carbon dioxide in the reaction chamber₀(ii) a Turning on an ultraviolet light source to enable ultraviolet light emitted by the ultraviolet light source to irradiate the surface of a photocatalytic sheet, catalyzing organic matters on the photocatalytic sheet to generate carbon dioxide, and measuring the volume concentration S of the carbon dioxide in the reaction chamber by the detection unit₀′；

S2: injecting a water sample to be detected into the surface of the photocatalytic sheet in the reaction chamber through a sample injection device and a sample injection port by a sample injection needle, wherein the volume of the water sample to be detected is the same as that of the deionized water in the step S1; under the irradiation of ultraviolet light emitted by an ultraviolet light source, a water sample to be detected on the surface of the photocatalytic sheet is catalyzed to generate carbon dioxide, and after the numerical value displayed by the detection unit continuously increases until the numerical value is stable, the volume concentration of the carbon dioxide in the reaction chamber is measured by the detection unit to be S;

s3: calculating the content rho of the total organic carbon in the water sample to be detected, wherein the calculation formula is as follows: rho ═ S-S₀′-(S₀′-S₀)]*V*Ar(C)/(V_m*V_Into) Wherein V is the volume of the reaction chamber, Ar (C) is equal to 12 and is a carbon atomRelative atomic mass, V_m24.5L/mol, molar volume of gas at normal temperature and pressure, V_IntoIs the volume of the water sample to be measured.

Preferably, the detection unit detects the concentration of carbon dioxide in the reaction chamber by using a non-dispersive infrared method.

Preferably, the volume of the water sample to be detected is 10-30 muL.

Preferably, the water sample to be detected contains p-nitrophenol.

Generally, compared with the prior art, the above technical solution conceived by the present invention mainly has the following technical advantages:

(1) the TOC detection device provided by the invention can be used for detecting the TOC value of a water sample at a certain place in a certain period in a portable and real-time manner. Different from the combustion method of the traditional TOC detector, the invention utilizes the high-efficiency photocatalysis technology to mineralize the organic matters into carbon dioxide for detection in a short time, and has great significance in the aspects of energy conservation and environmental protection.

(2) Compared with the high-temperature catalytic combustion method, the photocatalysis method used in the invention does not need to provide a high-temperature environment, and does not need expensive catalysts such as platinum, cobalt trioxide or cobaltous oxide, so the invention has low cost and low energy consumption.

(3) Compared with the traditional high-temperature catalytic combustion TOC analyzer, the detection limit is higher, the content of organic carbon in a water sample is detected within 800ppm, and errors caused by dilution in the test process are reduced.

(4) Compared with the traditional high-temperature catalytic combustion TOC analyzer, the portable high-temperature catalytic combustion TOC analyzer has small volume, can realize portable carrying, and is convenient for environmental protection supervision and supervision departments to spot check or field research and investigation.

(5) The error between the test value of the detection method and the theoretical TOC value of the water sample is about 5 percent, and the result of repeated test has consistency, which shows that the device can be repeatedly used for many times while ensuring the result.

(6) Compared with the traditional high-temperature catalytic combustion TOC analyzer, the invention has the advantages of simple structure, low disassembly cost and convenient repair and maintenance in the using process.

Drawings

Fig. 1 to fig. 3 are schematic structural diagrams of a photocatalytic portable water quality total organic carbon detection device provided by the invention, fig. 1 is a schematic front view, fig. 2 is a schematic side view, and fig. 3 is a partially enlarged view of a sample injection device; the device comprises a sample injection needle 1, a sample injection device 2, a reaction chamber 3, a photocatalytic sheet 4, a sample injection port 5, a sealing gasket 6, an ultraviolet light source 7, a quartz sheet 8, a waterproof unit 9, a detection unit 10, a bolt 11, a nut 12 and a sample injection hole 13.

FIG. 4 is a graph of mineralization measured on a p-nitrophenol solution.

FIG. 5 is a graph of mineralization measured in real lake waters.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention is described in further detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention. In addition, the technical features involved in the embodiments of the present invention described below may be combined with each other as long as they do not conflict with each other.