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METHOD FOR TREATING WASTEWATER CONTAINING TRIAZOLE COMPOUNDS

20240092665 ยท 2024-03-21

    Inventors

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    International classification

    Abstract

    A method for treating wastewater containing ertriazole compounds is provided. Hypochlorous acid (HOCl) having a neutral to slightly acidic pH value is added to the wastewater containing triazole compounds for reaction, thereby effectively reacting more than 90% of triazole compounds.

    Claims

    1. A method for treating wastewater containing triazole compounds, comprising steps of: adjusting pH value of a wastewater containing triazole compounds to be between pH 3?10; and adding hypochlorous acid solution to the wastewater for reacting and treating the triazole compound to a concentration lower than a critical concentration, wherein pH value of the hypochlorous acid solution is 3-7.

    2. The method according to claim 1, wherein the pH value of the wastewater is adjusted by hydrochloric acid solution, sulfuric acid solution, sodium hydroxide solution, or a combination thereof.

    3. The method according to claim 1, wherein the pH value of the hypochlorous acid solution is 5-7.

    4. The method according to claim 1, wherein a concentration of the hypochlorous acid solution is 800-120000 ppm.

    5. The method according to claim 1, wherein a concentration ratio of the hypochlorous acid solution to the triazole compounds of the wastewater is 800-120000:5-1000.

    6. The method according to claim 1, wherein a volume ratio of the hypochlorous acid solution to the wastewater is 0.001-1:1.

    7. The method according to claim 1, wherein the critical concentration is 0.5 ppm.

    8. The method according to claim 7, wherein the critical concentration is 0.03 ppm.

    9. The method according to claim 1, wherein the concentration of the triazole compound is 10-20 ppm.

    10. The method according to claim 1, wherein the triazole compound comprises methylbenzotriazole, benzotriazole, 1,2,4-triazole, or combinations thereof.

    11. The method according to claim 1, wherein a reaction temperature of the hypochlorous acid solution for degrading the wastewater is 20-40? C.

    12. The method according to claim 1, wherein a reaction pressure of the hypochlorous acid solution for degrading the wastewater is an atmospheric pressure.

    Description

    BRIEF DESCRIPTION OF THE DRAWINGS

    [0007] The FIGURE is a flow chart of a method for treating wastewater containing triazole compounds of the present disclosure.

    DESCRIPTION OF THE PREFERRED EMBODIMENTS

    [0008] The present disclosure will be described in detail with embodiments and attached drawings below for a better understanding. In addition to the embodiments described in the specification, the present invention also applies to other embodiments. Further, any modification, variation, or substitution, which can be easily made by the persons skilled in that art according to the embodiment of the present invention, is to be also included within the scope of the present invention, which is based on the claims stated below. The definition of the patent scope shall be based on the scope of the claims. It should be noted that the drawings are only to depict the present invention schematically but not to show the real dimensions or quantities of the present invention. Besides, matterless details are not necessarily depicted in the drawings to achieve conciseness of the drawings.

    [0009] Please refer to the FIGURE, which is a flow chart of a method for treating wastewater containing triazole compounds of the present disclosure. Firstly, adjusting pH value of the wastewater containing triazole compounds using hydrochloric acid, sulfuric acid, or sodium hydroxide solution until the pH value is pH3-10 (step S1). A concentration of triazole compounds in the wastewater ranges from 5-1,000 ppm, which the optimized test effect is achieved at 5-100 ppm. In some embodiments, the hypochlorous acid solution has a neutral and slightly acidic pH value of 3-7, which has an optimized reaction effect.

    [0010] The pH value of wastewater containing triazole compounds can be adjusted by any known method in the art using hydrochloric acid, sulfuric acid, or sodium hydroxide solution until the desired pH value is reached. The amount of hydrochloric acid, sulfuric acid, or sodium hydroxide solution are added depending on the desired pH value.

    [0011] Similarly, the pH value of hypochlorous acid solution can be adjusted by any known method in the art using hydrochloric acid, sulfuric acid, or sodium hydroxide solution until the desired pH value is reached. The amount of hydrochloric acid, sulfuric acid, or sodium hydroxide solution are added depending on the desired pH value. The hypochlorous acid, sulfuric acid, or sodium hydroxide solution is commercially available.

    [0012] Next, the wastewater containing triazole compounds is reacted with hypochlorous acid solution (step S2). The pH value of the hypochlorous acid solution is 5-7, i.e. the concentration ranges from 800-120,000 ppm. The concentration ratio of the hypochlorous acid solution to the triazole compounds of the wastewater is 800-120000:5-1000. The volume ratio of the hypochlorous acid solution to the wastewater is 0.001-1:1. The temperature of the treating reaction is 20-40? C. and the pressure is an atmospheric pressure.

    [0013] The termination condition of the reaction is that the concentration (or the critical concentration) of the triazole compounds is lower than 0.5 ppm. In some embodiments, the concentration (or the critical concentration) of the triazole compounds is less than 0.03 ppm. Therefore, the amount of hypochlorous acid solution are added depending on the concentration of the triazole compounds in the wastewater or the volume of the wastewater, until the concentration of the triazole compounds in the wastewater is reduced to the critical concentration.

    [0014] Triazole compounds refer to methylbenzotriazole, benzotriazole, 1,2,4-triazole, or combinations thereof. The reaction product of methylbenzotriazole and hypochlorous acid and the reaction product of benzotriazole and hypochlorous acid are the same. The three reaction formulas are shown in Table 1 below.

    TABLE-US-00001 TABLE 1 Chemical structure of Chemical structure of Chemical structure of reaction triazole compounds hypochlorous acid product [00001]embedded image [00002]embedded image [00003]embedded image [00004]embedded image [00005]embedded image [00006]embedded image [00007]embedded image [00008]embedded image [00009]embedded image [00010]embedded image [00011]embedded image [00012]embedded image [00013]embedded image

    [0015] Comparing the clearance rate of hypochlorous acid (Table 2) and hydrogen peroxide (Table 3) to triazole compounds, obviously, hypochlorous acid can effectively remove triazole compounds.

    TABLE-US-00002 TABLE 2 Experimental groups T-450 I II Hypochlorous acid (ppm) 800 1,600 Triazole compounds (ppm) 10.53 2.14 0.03 Clearance rate (%) 79.73 99.69

    TABLE-US-00003 TABLE 3 Experimental groups T-450 I II III Hydrogen peroxide (ppm) 800 1,600 3,200 Triazole compounds (ppm) 16.1 16.1 16.0 16.0 Clearance rate (%)