Method and device for degrading low-concentration diazepam in water

Abstract

The invention discloses a method and a device for degrading low-concentration diazepam in water, a water sample to be treated is irradiated by a low-pressure mercury lamp, diazepam in the water sample to be treated is degraded, the wavelengths of the low-pressure mercury lamp are 185nm and 254nm, and the concentration of diazepam is 10-100mu g / kg. A device for degrading low-concentration diazepam in water comprises a quartz water pipe, a low-pressure mercury lamp tube and a reflective mirror, the reflective mirror is of an oval structure, and the quartz water pipe and the low-pressure mercury lamp tube are arranged at two focal points in the oval reflective mirror respectively. Low-concentration diazepam in water can be effectively degraded through the low-pressure mercury lamp, in addition, the invention further provides a device for degrading the low-concentration diazepam in water, the irradiation intensity of the low-pressure mercury lamp can be effectively improved by arranging the reflective mirrors on the outer sides of the low-pressure mercury lamp and the quartz water pipe, and the time needed for degrading the diazepam in water is shortened.

Description

Technical Field

[0001] The invention belongs to the technical field of water treatment, and in particular relates to a method and a device for degrading low-concentration diazepam in water. Background Art

[0002] Diazepam, also known as diazepam, has a chemical formula of C 16 H 13 C l N2O is a hypnotic drug, which is classified as a second-class psychotropic drug for control. It is clinically used to treat depression, anxiety or other mental illnesses, and can achieve sedative hypnosis, anti-anxiety and anti-epileptic effects. Patients may experience various side effects such as drowsiness, fatigue, weakness, and memory loss after taking diazepam tablets. The use of diazepam in aquaculture can reduce the perception of fresh live fish to the outside world, reduce metabolism, and thus increase the growth rate of fish. At the same time, the use of diazepam in aquatic transportation can calm fish and reduce the stress of fish to external influences, thereby ensuring the freshness of fish during transportation. GB 31650-2019 stipulates that the concentration of diazepam in aquaculture water cannot exceed 1µg / kg, but according to many cases reported in the news, the concentration of diazepam components detected in aquatic products and aquaculture water reached 10-100µg / kg.

[0003] Diazepam in aquaculture water exists in the form of molecules, so physical filtration is not feasible. In principle, chemical treatment using certain chemicals to react with diazepam is feasible, but the chemicals put in may cause secondary pollution to aquaculture water. In addition, the concentration of diazepam in aquaculture water is very low, specifically 10-100µg / kg, 0.01-0.1ppm. The chemicals put in must have a very high concentration, otherwise the chance of the molecules of the put in and the molecules of diazepam colliding with each other in the water is very small.

[0004] We found that ultraviolet rays in certain bands can decompose diazepam in water, and the radiation of ultraviolet photons did not produce any chemical pollution in the water. The commonly used ultraviolet irradiation water treatment equipment is to insert an ultraviolet lamp into a water pipe, and the water inlet and outlet are perpendicular to the length of the water pipe to input and output the treated water. This structure is not suitable for treating water with low concentrations of diazepam. One reason is that the ultraviolet irradiation light intensity is not enough, and the second reason is that the water is input perpendicular to the length of the water pipe, which generates vortices, and the water in different parts receives ultraviolet irradiation for different times. In view of this, it is of practical value to study and develop a method and device that can decompose low concentrations of diazepam in water. Summary of the invention

[0005] In order to solve the shortcomings of the prior art, the purpose of the present invention is to provide a method and device for degrading low-concentration diazepam in water. By adopting a low-pressure mercury lamp with a wavelength of 185nm and 254nm, the low-concentration diazepam in water can be effectively degraded. In addition, the present invention also provides a device for degrading low-concentration diazepam in water. By arranging a reflector on the outside of the low-pressure mercury lamp and a quartz water pipe, the irradiation intensity of the low-pressure mercury lamp can be effectively improved, and the time required for degrading diazepam in water can be reduced.

[0006] In order to achieve the above object, the present invention adopts the following technical solution: A method for degrading low-concentration diazepam in water, using a low-pressure mercury lamp to irradiate a water sample to be treated to degrade diazepam in the water sample to be treated, the wavelength of the low-pressure mercury lamp is 185nm and 254nm, and the concentration of diazepam is 10-100μg / kg.

[0007] Preferably, the mercury vapor pressure of the low-pressure mercury lamp is 1.3-13Pa.

[0008] Preferably, the power of the low-pressure mercury lamp is ≥10 W, and the surface light intensity is ≥10 mW / cm 2 .

[0009] The device for degrading low-concentration diazepam in water using the above method comprises a quartz water pipe, a low-pressure mercury lamp and a reflector. The reflector is an elliptical structure. The quartz water pipe and the low-pressure mercury lamp are respectively arranged at two focal points inside the elliptical reflector.

[0010] Preferably, the aforementioned reflectors are provided in plurality, the focal points inside the plurality of reflectors are located at the same point, forming overlapping focal points, the quartz water pipe is provided at the overlapping focal points, and a low-pressure mercury lamp is installed at the other focal point of each reflector.

[0011] Preferably, the aforementioned reflectors are provided in plurality, the focal points inside the plurality of reflectors are located on the same straight line to form a focal point connection line, the quartz water pipe is provided on the focal point connection line, and a low-pressure mercury lamp is installed at the other focal point of each reflector.

[0012] Preferably, the aforementioned plurality of low-pressure mercury lamp tubes are evenly distributed on the outer periphery of the quartz water pipe in a circumferential direction.

[0013] Preferably, the diameter of the aforementioned quartz water pipe is 5-20 cm and the wall thickness is 1-5 mm.

[0014] Preferably, the reflector is made of aluminum metal.

[0015] The benefits of the present invention are as follows: The present invention can effectively degrade low-concentration diazepam in water by adopting a low-pressure mercury lamp with a wavelength of 185nm and 254nm, and by arranging a reflector on the outside of the low-pressure mercury lamp and the quartz water pipe, the irradiation intensity of the low-pressure mercury lamp can be effectively improved, the time required to degrade diazepam in water can be reduced, and work efficiency can be improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 It is the test result of low-pressure mercury lamp degrading diazepam in low-concentration water; Figure 2 This is the working principle diagram of the reflector; Figure 3 It is a schematic diagram of a structure in which two reflectors are provided; Figure 4 It is a schematic diagram of a structure in which four reflectors are provided; Figure 5 It is a schematic diagram of the structure in which 8 reflectors are set.

[0017] The meanings of the reference numerals in the figure: 1. quartz water pipe; 2. low-pressure mercury lamp; 3. reflector. DETAILED DESCRIPTION

[0018] The present invention is described in detail below with reference to the accompanying drawings and specific embodiments.

[0019] Example 1: Effect of low-pressure mercury lamp on the degradation of diazepam in water (1) Source of diazepam: Diazepam is derived from diazepam injection, a prescription drug of the Second People's Hospital of Chuzhou City, Anhui Province, 2mL:10mg.

[0020] (2) Preparation of various low-concentration diazepam solutions: Sample 0: pure water; Sample 1: 10 mg diazepam mixed with 1 kg water, diazepam: water = 1: 100,000; Sample 2: Take 100 mL of sample 1 solution and add 900 mL of water, diazepam: water = 1:1,000,000; Sample 3: Take 100 mL of sample 2 solution and add 900 mL of water, diazepam: water = 1: 10,000,000; Sample 4: Take 100 mL of sample 3 solution and add 900 mL of water, diazepam: water = 1:100,000,000.

[0021] (3) Diazepam detection method: The colloidal gold method is adopted. The present invention uses the diazepam (tissue) rapid test card of Shenzhen Airis Instrument Co., Ltd., sucks a small amount of liquid to be tested with a pipette, injects it into the gold-labeled small cup attached to the test card package, reacts for 2 minutes, then uses a pipette to take out the reacted liquid from the gold-labeled small cup, injects it into the entrance of the test plate, and the test liquid flows into the test area of ​​the test plate through capillary action. After 2 minutes, observe the "T" line and the "C" line to judge negative (no diazepam) or positive (with diazepam).

[0022] (4) Degradation of diazepam: Using a 10-watt, 10.5-mm-diameter, 20-mm-long low-pressure mercury lamp, the irradiance test result was 10 mW / cm in air at a distance of 5 mm. 2 The lamp tube was immersed in a plastic tank with a diameter of 150 mm and a depth of 150 mm. Water containing different concentrations of diazepam was injected into the tank. Every half an hour, a small amount of liquid was sucked out and the presence of diazepam was tested by the colloidal gold method.

[0023] (5) Test results: Check card test results see Figure 1 .

[0024] Sample 0 is pure water, does not contain diazepam, and both the "T" and "C" lines are displayed.

[0025] Sample 1, diazepam: water = 1: 100,000, no “T” line, single “C” line indicating the presence of diazepam.

[0026] Sample 2, diazepam: water = 1: 1,000,000, no “T” line, single “C” line indicating the presence of diazepam.

[0027] Sample 3, diazepam: water = 1: 10,000,000, no “T” line, single “C” line indicating the presence of diazepam.

[0028] Sample 4, diazepam: water = 1: 100,000,000, no “T” line, single “C” line indicating the presence of diazepam.

[0029] Sample 3+uV, diazepam: water = 1: 10,000,000, irradiated with low-pressure mercury lamp for 1 hour, no “T” line, single “C” line shows the presence of diazepam.

[0030] Sample 3+uV2, diazepam: water = 1: 10,000,000, irradiated with low-pressure mercury lamp for 3 hours, both "T" and "C" lines show no diazepam or the concentration of diazepam is below the measurement limit, i.e. 1 µg / kg (10 -9 ) below, indicating that after 3 hours of irradiation, the concentration of diazepam in water was reduced from 100 µg / kg (10 -7 ) is degraded to 1 µg / kg (10-9 )the following.

[0031] Sample 4+uV, diazepam: water = 1: 100,000,000, irradiated with low-pressure mercury lamp for 0.5 hours, no “T” line, single “C” line shows the presence of diazepam.

[0032] Sample 4+uV2, diazepam: water = 1: 100,000,000, irradiated with low-pressure mercury lamp for 1 hour, both "T" and "C" lines show no diazepam or the concentration of diazepam is below the measurement limit, i.e. 1 µg / kg (10 -9 ) below, indicating that after 1 hour of irradiation, the concentration of diazepam in water was reduced from 10 µg / kg (10 -8 ) is degraded to 1 µg / kg (10 -9 )the following.

[0033] The device for degrading low-concentration diazepam in water using the above method comprises a quartz water pipe, a low-pressure mercury lamp and a reflector, wherein the reflector is an elliptical structure, and the quartz water pipe and the low-pressure mercury lamp are respectively arranged at two focal points inside the elliptical reflector. Aluminum can achieve a reflection efficiency of 90% at a wavelength of 300nm, indicating that the reflection coefficient of aluminum in the ultraviolet wavelength region is very high, therefore, the material of the reflector of the present invention is aluminum metal.

[0034] The diameter of the quartz water pipe is 5~20 cm, preferably 10 cm. If the diameter is too small, the flow rate will be affected; if the diameter is too large, the ultraviolet light cannot penetrate. The wall thickness is 1~5 mm. If it is too thin, the strength is insufficient, and if it is too thick, the ultraviolet light penetration ability will be affected.

[0035] The light emitted by the low-pressure mercury lamp is scattered in all directions. In order to collect light from all directions and gather it on the quartz tube with water flowing through it, the present invention uses an elliptical reflector. The ellipse has two foci. The light emitted from one focus will be reflected at any point on the surface of the ellipse and will converge to the other focus. The low-pressure mercury lamp light source is located at one of the foci of the reflector, and the quartz water pipe is located at the other focus. The light from all angles emitted by the low-pressure mercury lamp light source will be reflected by the elliptical surface and will converge on the quartz water pipe. Figure 2 shown.

[0036] Example 2, see Figure 3 There are two reflectors and two low-pressure mercury lamp tubes, and the focal points of the inner sides of the two reflectors are located at the same point, forming a coincident focus, and the quartz water pipe is arranged at the coincident focus.

[0037] Example 3, see Figure 4 There are four reflectors and four low-pressure mercury lamp tubes, and the focal points inside the four reflectors are located at the same point, forming a coincident focus, and a quartz water pipe is arranged at the coincident focus.

[0038] Example 4, see Figure 5 There are 8 reflectors and 8 low-pressure mercury lamp tubes, and the focal points inside the 8 reflectors are located at the same point, forming a coincident focus, and the quartz water pipe is arranged at the coincident focus.

[0039] Embodiment 5: A plurality of reflectors are provided, and the focal points inside the plurality of reflectors are located on the same straight line, forming a focal point connection line. A quartz water pipe is provided on the focal point connection line. A low-pressure mercury lamp is installed at the other focal point of each reflector, and the plurality of low-pressure mercury lamps are evenly distributed on the periphery of the quartz water pipe in a circumferential direction.

[0040] Performance test: The number of reflectors set around the quartz water pipe was 0, 1, 2, 4, and 8 respectively. The low-pressure mercury lamp used was 150 watts, 10.5 mm in diameter, and 1.2 m in length. The diameter of the quartz water pipe was 100 mm. The irradiation time was 3 hours. The irradiation intensity on the surface of the quartz water pipe and the time required to degrade diazepam from a concentration of 100 µg / kg to 1 µg / kg were measured respectively. The specific results are shown in Table 1.

[0041] Table 1 Degradation effect of different numbers of reflectors

[0042] It can be seen from Table 1 that the device of the present invention can effectively enhance the irradiation intensity of the surface of the quartz water pipe and shorten the degradation time of diazepam. Moreover, as the number of reflectors increases, the irradiation intensity increases and the degradation time decreases.

[0043] The above shows and describes the basic principles, main features and advantages of the present invention. Those skilled in the art should understand that the above embodiments do not limit the present invention in any form, and any technical solution obtained by equivalent replacement or equivalent transformation falls within the protection scope of the present invention.

Claims

1. A method for degrading low-concentration diazepam in water, characterized in that: A low-pressure mercury lamp is used to irradiate the water sample to be treated to degrade diazepam in the water sample to be treated, the wavelength of the low-pressure mercury lamp is 185nm and 254nm, and the concentration of the diazepam is 10-100μg / kg.

2. A method for degrading low-concentration diazepam in water according to claim 1, characterized in that: The mercury vapor pressure of the low-pressure mercury lamp is 1.3-13Pa.

3. A method for degrading low-concentration diazepam in water according to claim 1, characterized in that: The electric power of the low-pressure mercury lamp is ≥10 W, and the surface light intensity is ≥10 mW / cm 2 .

4. A device for degrading low-concentration diazepam in water using the method according to claim 1, characterized in that: It comprises a quartz water pipe, a low-pressure mercury lamp and a reflector. The reflector is an elliptical structure. The quartz water pipe and the low-pressure mercury lamp are respectively arranged at two focal points inside the elliptical reflector.

5. The device for degrading low-concentration diazepam in water according to claim 4, characterized in that: There are multiple reflectors, and the focal points inside the multiple reflectors are located at the same point to form overlapping focal points. The quartz water pipe is arranged at the overlapping focal point, and a low-pressure mercury lamp is installed at the other focal point of each reflector.

6. The device for degrading low-concentration diazepam in water according to claim 4, characterized in that: There are multiple reflectors, and the focal points inside the multiple reflectors are located on the same straight line to form a focal point connection line. The quartz water pipe is arranged on the focal point connection line, and a low-pressure mercury lamp is installed at the other focal point of each reflector.

7. The device for degrading low-concentration diazepam in water according to claim 5, characterized in that: The plurality of low-pressure mercury lamp tubes are evenly distributed on the outer periphery of the quartz water pipe in a circumferential direction.

8. The device for degrading low-concentration diazepam in water according to claim 4, characterized in that: The diameter of the quartz water pipe is 5-20 cm, and the wall thickness is 1-5 mm.

9. The device for degrading low-concentration diazepam in water according to claim 4, characterized in that: The reflector is made of aluminum metal.

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