Application of advanced oxidation system in treatment of pollutants in water body and treatment method of pollutants in water body

Abstract

The invention belongs to the technical field of sewage treatment, and particularly relates to application of an advanced oxidation system in treatment of pollutants in a water body and a treatment method of the pollutants in the water body. According to the method, eaq <-> and H <-> generated by vacuum ultraviolet light are converted into effective free radicals RCS through chlorine-containing substances, the effective free radicals RCS participate in removal of pollutants, unfavorable consumption of dissolved oxygen is avoided, and the types of active species are enriched; meanwhile, the advanced oxidation system provided by the invention not only can generate HO <. >, but also can generate RCS, and the influence degree of the RCS by background substances in water is smaller than that of HO <. >; besides, bubbles (nanometer bubbles and / or micrometer bubbles) are introduced into the system, the bubbles can cause water turbulence, improve the mass transfer efficiency, increase light paths and generate active oxygen, the mass transfer efficiency of active species is effectively improved, and the removal efficiency of pollutants is improved.

Description

Technical Field

[0001] The invention belongs to the technical field of sewage treatment, and specifically relates to the application of an advanced oxidation system in treating pollutants in water bodies and a method for treating pollutants in water bodies. Background Art

[0002] With the continuous development of various industries, a large number of difficult-to-degrade chemicals are produced and discharged into water bodies, causing environmental risks and harming organisms and humans in the environment.

[0003] Therefore, it is necessary to degrade pollutants in water bodies. Among them, advanced oxidation technology (AOPs) is an effective treatment method. Vacuum ultraviolet (VUV) direct irradiation technology mainly uses mercury lamps, xenon lamps, etc. to generate VUV to directly irradiate water bodies, producing highly oxidizing HO· and reducing species e aq - and H·, where e aq - H· and H· are easily consumed by dissolved oxygen (DO), and the substance that plays the main role in removing pollutants is HO·, so the active species is single; at the same time, the active species HO· is easily affected by background substances in the water, resulting in a decrease in the removal efficiency of pollutants. Summary of the invention

[0004] The purpose of the present invention is to provide an application of an advanced oxidation system in treating pollutants in water bodies and a method for treating pollutants in water bodies. The advanced oxidation system provided by the present invention has a higher removal efficiency for pollutants in water bodies.

[0005] In order to achieve the above object, the present invention provides the following technical solutions:

[0006] The present invention provides an application of an advanced oxidation system in treating pollutants in water, wherein the advanced oxidation system comprises chlorine-containing substances, vacuum ultraviolet light irradiation and bubbles;

[0007] The bubbles include nanobubbles and / or microbubbles.

[0008] Preferably, the average diameter of the bubbles is 6 nm to 100 μm.

[0009] Preferably, the generator for generating the bubbles includes a hydrodynamic cavitation generator, an ultrasonic cavitation generator, an electrolytic cavitation generator or a chemical reaction generator.

[0010] Preferably, the average diameter of the bubbles generated by the hydrodynamic cavitation generator is 32 nm to 100 μm;

[0011] The average diameter of the bubbles generated by the ultrasonic cavitation generator is 6nm to 60nm;

[0012] The average diameter of the bubbles generated by the electrolytic cavitation generator is 50nm to 20μm;

[0013] The average diameter of the bubbles generated by the chemical reaction generator is 60 nm to 500 nm.

[0014] Preferably, the light source used for the vacuum ultraviolet irradiation includes at least one of a vacuum ultraviolet lamp, a xenon lamp, a low-pressure mercury lamp, a medium-pressure mercury lamp, a high-pressure mercury lamp, an amalgam ultraviolet lamp and an LED lamp.

[0015] Preferably, the chlorine-containing substance includes at least one of free chlorine, chlorine gas, chlorine dioxide and chloramine;

[0016] The free chlorine includes hypochlorous acid and / or hypochlorite; the hypochlorite includes at least one of potassium hypochlorite, sodium hypochlorite, calcium hypochlorite and ammonium hypochlorite;

[0017] The chloramine includes at least one of monochloramine, dichloramine and trichloramine.

[0018] The present invention also provides a method for treating pollutants in water, comprising the following steps:

[0019] Chlorine-containing substances are added to a water body containing pollutants, and bubbles are generated in situ in the water body by a bubble generator, while vacuum ultraviolet light is used to irradiate the water body.

[0020] Preferably, the pollutants include at least one of anti-epileptic drugs, antibiotics and industrial chemicals;

[0021] The anti-epileptic drugs include at least one of carbamazepine, phenytoin sodium, phenobarbital, primidone and sodium valproate;

[0022] The industrial chemical comprises at least one of nitrobenzene, cyclohexanoic acid, p-chlorobenzoic acid and trichloroethylene acid;

[0023] The antibiotics preferably include at least one of tetracyclines, quinolones, macrolides, sulfonamides, β-lactam antibiotics and broad-spectrum antibiotics.

[0024] Preferably, the concentration of pollutants in the water body is 5 to 250 μM;

[0025] The concentration of chlorine-containing substances in the water body is 50 to 1250 μM; the molar ratio of the pollutants to the chlorine-containing substances is not less than 1:1.

[0026] Preferably, the vacuum ultraviolet light irradiation time is not less than 20 minutes.

[0027] The invention provides an application of an advanced oxidation system in treating pollutants in water. The advanced oxidation system comprises chlorine-containing substances, vacuum ultraviolet light irradiation and bubbles; the bubbles comprise nanobubbles and / or micron bubbles.

[0028] In the present invention, chlorine-containing substances are used to generate vacuum ultraviolet light to obtain e aq - and H· are converted into effective free radicals RCS, participate in the removal of pollutants, avoid the adverse consumption of dissolved oxygen, and enrich the types of active species; at the same time, the advanced oxidation system provided by the present invention can not only produce HO·, but also produce RCS, and the degree of influence of RCS on the background substances in the water is less than HO·; in addition, by introducing micro / nano bubbles (Mirco / Nano-Bubble (MNB)) into the system, the micro / nano bubbles can cause water turbulence, improve mass transfer efficiency, increase the light path, generate reactive oxygen species (ROS), and effectively improve the mass transfer efficiency of active species, and improve the removal efficiency of pollutants. The present invention can improve the impact resistance to water treatment conditions by constructing a coupling system of chlorine-containing substances, vacuum ultraviolet light irradiation and bubbles (nano bubbles and / or micron bubbles), thereby significantly improving the removal efficiency of pollutants. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 is the removal efficiency of carbamazepine by VUV / FC / MNB system, VUV system, FC system and VUV / FC system;

[0030] Figure 2 The contribution of different active substances to the degradation of carbamazepine in the VUV / FC / MNB system;

[0031] Figure 3 The effect of pH value on the contribution of different active substances in the system to the degradation of carbamazepine. DETAILED DESCRIPTION

[0032] The present invention provides an application of an advanced oxidation system in treating pollutants in water, wherein the advanced oxidation system comprises chlorine-containing substances, vacuum ultraviolet light irradiation and bubbles;

[0033] The bubbles include nanobubbles and / or microbubbles.

[0034] In the present invention, the average diameter of the bubbles (MNB) is preferably 6 nm to 100 μm. In the present invention, the generator for generating the bubbles preferably includes a hydrodynamic cavitation generator, an ultrasonic cavitation generator, an electrolytic cavitation generator or a chemical reaction generator.

[0035] In the present invention, the average diameter of the bubbles generated by the hydrodynamic cavitation generator is preferably 32nm to 100μm; the average diameter of the bubbles generated by the ultrasonic cavitation generator is preferably 6nm to 60nm; the average diameter of the bubbles generated by the electrolytic cavitation generator is preferably 50nm to 20μm; the average diameter of the bubbles generated by the chemical reaction generator is preferably 60nm to 500nm. In the present invention, the light source used in the vacuum ultraviolet irradiation (VUV) preferably includes at least one of a vacuum ultraviolet lamp, a xenon lamp, a low-pressure mercury lamp, a medium-pressure mercury lamp, a high-pressure mercury lamp, an amalgam ultraviolet lamp, and an LED lamp.

[0036] In the present invention, the chlorine-containing substance (FC) preferably includes at least one of free chlorine, chlorine gas, chlorine dioxide and chloramines; the free chlorine preferably includes hypochlorous acid and / or hypochlorite; the hypochlorite preferably includes at least one of potassium hypochlorite, sodium hypochlorite, calcium hypochlorite and ammonium hypochlorite; the chloramine preferably includes at least one of monochloramine, dichloramine and trichloramine.

[0037] In the present invention, the VUV / FC / MNB system has a higher removal efficiency for pollutants. In addition to the active species generated in the two subsystems, the VUV / FC / MNB system also has a synergistic effect, which involves the conversion between the active species in the system and the improvement of the mass transfer efficiency of the active species. Specifically, the e aq - and H· can participate in the activation of chlorine-containing substances (FC), promoting the generation of active free radicals in the system. HO· itself has a good oxidation effect, but lacks selectivity in degrading a large number of pollutants. It is easily consumed by water background substances and reduces the removal efficiency of pollutants. HO· and Cl· react to produce ClO·. The redox potentials of Cl· and ClO· are 2.4V and 1.5V, respectively, which are lower than HO·. However, the selectivity of both for substances is higher than HO·, and they are not easily consumed by water background substances, which can make up for the reduced efficiency of HO·. The participation of MNB further improves the mass transfer efficiency of active species, and the removal efficiency of pollutants has been improved to a certain extent.

[0038] The present invention also provides a method for treating pollutants in water, comprising the following steps:

[0039] Chlorine-containing substances are added to a water body containing pollutants, and bubbles are generated in situ in the water body by a bubble generator, while vacuum ultraviolet light is used to irradiate the water body.

[0040] In the present invention, the pollutants preferably include at least one of anti-epileptic drugs, antibiotics and industrial chemicals; the anti-epileptic drugs preferably include at least one of carbamazepine, phenytoin sodium, phenobarbital, primidone and sodium valproate; the industrial chemicals preferably include at least one of nitrobenzene, cyclohexanoic acid, p-chlorobenzoic acid and trichloroethylene acid; the antibiotics preferably include at least one of tetracyclines, quinolones, macrolides, sulfonamides, β-lactam antibiotics and broad-spectrum antibiotics; the tetracyclines preferably include at least one of tetracycline, chlortetracycline and oxytetracycline; The quinolones preferably include at least one of norfloxacin, ciprofloxacin, ofloxacin and nalidixic acid; the macrolides preferably include at least one of erythromycin, azithromycin, roxithromycin and clarithromycin; the sulfonamides preferably include at least one of sulfamethoxazole, sulfisoxazole, sulfadiazine, sulfamethoxazole, sulfamethoxazole and sulfadimethoxine; the β-lactam antibiotics preferably include at least one of penicillin, ampicillin, amoxicillin, cefotaxime and cefadroxil; the broad-spectrum antibiotics preferably include at least one of trimethoprim, metronidazole and tinidazole.

[0041] In the present invention, the concentration of pollutants in the water is preferably 5 to 250 μM. In the present invention, the concentration of chlorine-containing substances in the water is preferably 50 to 1250 μM; the molar ratio of the pollutants to the chlorine-containing substances is preferably not less than 1:1.

[0042] In the present invention, the vacuum ultraviolet light irradiation time is preferably not less than 20 minutes.

[0043] Unless otherwise specified, the materials and equipment used in the present invention are all commercially available products in the art.

[0044] The technical solutions in the present invention will be described clearly and completely below in conjunction with the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0045] Example 1

[0046] An aqueous solution containing carbamazepine at a concentration of 5 μM was prepared as simulated wastewater, and sodium hypochlorite was added to the aqueous solution, wherein the concentration of chlorine-containing substances in the aqueous solution was 100 μM, and the molar ratio of carbamazepine to sodium hypochlorite was 1:1; an ultrasonic cavitation generator was used to in-situ generate nanobubbles with an average diameter of 60 nm in the aqueous solution, and a low-pressure mercury lamp was used to irradiate the aqueous solution (VUV / FC / MNB), and the concentration change of carbamazepine in the aqueous solution was detected during the irradiation process.

[0047] The concentration changes of carbamazepine were tested by vacuum ultraviolet irradiation (VUV) alone, adding chlorine-containing substances (FC) alone, and vacuum ultraviolet combined with chlorine-containing substances (VUV / FC) as controls. The test results are as follows: Figure 1 As shown in Table 1;

[0048] Table 1 Changes in carbamazepine concentration (20 min)

[0049] VUV / FC / MNB VUV FC VUV / FC Removal rate 94.4％ 51.4％ 0.2％ 68.3％

[0050] It can be seen from Table 1 that the VUV / FC / MNB system provided by the present invention can effectively improve the removal efficiency of pollutants in water.

[0051] Figure 2 The contribution of different active substances to the degradation of carbamazepine in the VUV / FC / MNB system is shown in Table 2. Figure 2 It can be seen that Cl· contributes the most to the degradation of the system, accounting for 59.8% of the total contribution to CBZ degradation, and plays a leading role in the degradation of CBZ in the system. The second is HO·, which accounts for 31.8% of the total contribution to CBZ degradation. Ultraviolet light alone has little effect on CBZ, and the pseudo-first-order rate often contributes only 1.9% to the system. Other free radicals are other active free radicals generated in the system due to VUV photolysis and HO· and Cl· oxidation, and their contribution to the system is 6.6%.

[0052] Figure 3 The effect of pH value on the contribution of different active substances in the system to the degradation of carbamazepine is shown in Figure 2. Figure 3 It can be seen that when the pH value increased from 6.0 to 8.4, the overall degradation efficiency of the system for CBZ decreased; the degradation efficiency of Cl· and HO·, which played the main role, for carbamazepine decreased by 71.1% and 77.9%, respectively.

[0053] Although the above embodiment describes the present invention in detail, it is only a part of the embodiments of the present invention, not all of the embodiments. Other embodiments can be obtained based on this embodiment without creativity, and these embodiments all fall within the protection scope of the present invention.

Claims

1. An application of an advanced oxidation system in treating pollutants in water, characterized in that: The advanced oxidation system includes chlorine-containing substances, vacuum ultraviolet radiation and bubbles; The bubbles include nanobubbles and / or microbubbles.

2. The use according to claim 1, characterized in that: The average value of the diameter of the bubbles is 6 nm to 100 μm.

3. The use according to claim 1 or 2, characterized in that: The generator for generating the bubbles includes a hydrodynamic cavitation generator, an ultrasonic cavitation generator, an electrolytic cavitation generator or a chemical reaction generator.

4. The use according to claim 3, characterized in that: The average diameter of the bubbles generated by the hydrodynamic cavitation generator is 32nm to 100μm; The average diameter of the bubbles generated by the ultrasonic cavitation generator is 6nm to 60nm; The average diameter of the bubbles generated by the electrolytic cavitation generator is 50nm to 20μm; The average diameter of the bubbles generated by the chemical reaction generator is 60 nm to 500 nm.

5. The use according to claim 1, characterized in that: The light source used for the vacuum ultraviolet irradiation includes at least one of a vacuum ultraviolet lamp, a xenon lamp, a low-pressure mercury lamp, a medium-pressure mercury lamp, a high-pressure mercury lamp, an amalgam ultraviolet lamp and an LED lamp.

6. The use according to claim 1, characterized in that: The chlorine-containing substance includes at least one of free chlorine, chlorine gas, chlorine dioxide and chloramine; The free chlorine includes hypochlorous acid and / or hypochlorite; the hypochlorite includes at least one of potassium hypochlorite, sodium hypochlorite, calcium hypochlorite and ammonium hypochlorite; The chloramine includes at least one of monochloramine, dichloramine and trichloramine.

7. A method for treating pollutants in water, characterized in that: The following steps are involved: Chlorine-containing substances are added to a water body containing pollutants, and bubbles are generated in situ in the water body by a bubble generator, while vacuum ultraviolet light is used to irradiate the water body.

8. The processing method according to claim 7, characterized in that: The pollutants include at least one of anti-epileptic drugs, antibiotics and industrial chemicals; The anti-epileptic drugs include at least one of carbamazepine, phenytoin sodium, phenobarbital, primidone and sodium valproate; The industrial chemical comprises at least one of nitrobenzene, cyclohexanoic acid, p-chlorobenzoic acid and trichloroethylene acid; The antibiotics preferably include at least one of tetracyclines, quinolones, macrolides, sulfonamides, β-lactam antibiotics and broad-spectrum antibiotics.

9. The processing method according to claim 7 or 8, characterized in that: The concentration of pollutants in the water body is 5 to 250 μM; The concentration of chlorine-containing substances in the water body is 50 to 1250 μM; the molar ratio of the pollutants to the chlorine-containing substances is not less than 1:

1.

10. The processing method according to claim 7, characterized in that: The vacuum ultraviolet light irradiation time is not less than 20 minutes.

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