Method for removing pollutants in sewage

Abstract

The invention discloses a method for removing pollutants in sewage, and belongs to the technical field of water treatment. Comprising the following steps: adding 2, 2-dipyridyl-Fe (II) and permanganate into water containing organic pollutants, stirring to react, and removing unreacted 2, 2-dipyridyl-Fe (II) and permanganate; the addition amount of the 2, 2-dipyridyl-Fe (II) is 5 to 50 [mu] M; the adding amount of the permanganate is 50 to 300 [mu] M. According to the method, 2, 2-dipyridyl (BPY) is used for complexing Fe (II) to activate permanganate. BPY and Fe (II) can form a stable complex, so that free-state Fe (II) is provided for reaction, permanganate is activated to generate high-activity manganese species and strong-oxidizing free radicals, and pollutants are effectively degraded. Compared with single permanganate oxidation, the removal rate of pollutants is improved by 16%, and the removal rate reaches 100% within 10 min.

Description

Technical Field

[0001] The invention relates to the technical field of water treatment, in particular to a method for removing pollutants in sewage. Background Art

[0002] Permanganate is an environmentally friendly green oxidant. It has attracted widespread attention in the field of water treatment due to its advantages such as low cost, stability, low risk of toxic byproducts, wide pH working range and ease of use. In water treatment, permanganate is mainly used to remove pollutants such as algae toxins, iron and manganese, and antibiotics. However, it is easily affected by various factors (such as pollutant type, pH value, chelating agent, etc.) during the oxidation reaction. Activating permanganate by external methods can overcome the influence of these factors and enhance the degradation effect of pollutants. Fe(II) can catalyze the permanganate reaction, but Fe(II) is easily oxidized and loses its activity.

[0003] Therefore, it is necessary to provide a method for removing pollutants from sewage, maintain the concentration of Fe(II) in the system that can be used to activate permanganate, and improve the effective degradation rate of pollutants in water to solve the above problems. Summary of the invention

[0004] The present invention aims to solve at least one of the technical problems existing in the prior art. To this end, the present invention provides a method for removing pollutants from sewage, which can effectively improve the degradation rate of pollutants in water.

[0005] The first aspect of the present invention provides a method for removing pollutants from sewage, comprising adding 2,2-bipyridine-Fe(II) and permanganate to water containing organic pollutants, stirring the reaction and removing unreacted 2,2-bipyridine-Fe(II) and permanganate;

[0006] The dosage of the 2,2-bipyridine-Fe(II) is 5 to 50 μM; the dosage of the permanganate is 50 to 300 μM.

[0007] The preparation method according to the first aspect of the present invention has at least the following beneficial effects:

[0008] The method for removing pollutants from sewage of the present invention uses 2,2-bipyridine (BPY) to complex Fe(II) and activate permanganate. BPY can form a stable complex with Fe(II), thereby providing free Fe(II) to enter the reaction, thereby activating permanganate to generate highly active manganese species and strong oxidizing free radicals to effectively degrade pollutants. In the traditional Fe(II) / permanganate system, a part of ferrous iron is used to activate permanganate, while a part of ferrous iron is self-attenuated without entering the activation effect, resulting in the concentration of ferrous iron ions used to activate permanganate in the Fe(II) / permanganate system being lower than the actual addition concentration. However, after adding BPY in the present invention, BPY can complex ferrous iron to avoid the self-attenuation of ferrous iron ions, so that the concentration of ferrous iron ions used to activate potassium permanganate increases, and BPY plays a role in stabilizing the concentration of ferrous iron, wherein the oxidation kinetics between the initial ferrous iron ions and potassium permanganate are not changed.

[0009] The method of the present invention utilizes BPY-Fe (II) to enhance the removal of organic pollutants in water by permanganate, and the removal rate of the pollutant (diclofenac) is increased by 16% compared with the single permanganate oxidation. Specifically, the removal rates of diclofenac, phenol, p-hydroxybenzoic acid and ibuprofen within 10 minutes are 100%, 78.6%, 39.5% and 29.3%, respectively.

[0010] The preparation process of the scheme of the present invention is simple to operate and has good industrial application prospects.

[0011] According to some embodiments of the invention, the organic pollutant comprises at least one of diclofenac, phenol, p-hydroxybenzoic acid and ibuprofen.

[0012] According to some embodiments of the present invention, the dosage of the 2,2-bipyridine-Fe(II) is 10 to 50 μM.

[0013] According to some embodiments of the present invention, the dosage of the permanganate is 100-300 μM.

[0014] According to some embodiments of the present invention, the permanganate includes at least one of potassium permanganate and sodium permanganate.

[0015] According to some embodiments of the present invention, the concentration of the organic pollutant is 0.1-5 μM.

[0016] According to some embodiments of the present invention, the dosage ratio of the 2,2-bipyridine-Fe(II) and the permanganate is 1:(2-100).

[0017] Preferably, the dosage ratio of the 2,2-bipyridine-Fe(II) and permanganate is 1:(2-30).

[0018] According to some embodiments of the present invention, the stirring speed of the stirring reaction is 500-800 r / min.

[0019] Preferably, the stirring speed of the stirring reaction is 600 r / min.

[0020] According to some embodiments of the present invention, the stirring reaction time is 10 to 15 minutes.

[0021] According to some embodiments of the present invention, the water includes one of river water, lake water, domestic or industrial wastewater or sewage containing trace organic pollutants.

[0022] Other features and advantages of the present invention will be set forth in the description which follows, and in part will be apparent from the description, or may be learned by practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] The above and / or additional aspects and advantages of the present invention will become apparent and easily understood from the description of the embodiments in conjunction with the following drawings, in which:

[0024] Figure 1 It is a result diagram of the removal rate of diclofenac in Example 1, Comparative Example 1 and Comparative Example 2 of the present invention;

[0025] Figure 2 The figure is a result diagram of the removal rate of different pollutants in Example 1 and Comparative Example 1 of the present invention;

[0026] Figure 3 This is a comparison chart of the removal rate of diclofenac by potassium permanganate with different dosages in the present invention;

[0027] Figure 4 The figure is a comparison chart of the removal rate of diclofenac by different dosages of BPY-Fe(II) in the present invention. DETAILED DESCRIPTION

[0028] The embodiments of the present invention are described in detail below, and the same or similar reference numerals throughout the embodiments represent the same or similar elements or elements with the same or similar functions. The embodiments described below are exemplary and are only used to explain the present invention, and cannot be understood as limiting the present invention.

[0029] In the description of the present invention, if there is a description of first, second, etc., it is only for the purpose of distinguishing technical features, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features or implicitly indicating the order of the indicated technical features.

[0030] The words "preferably", "more preferably", etc. in the present invention refer to embodiments of the present invention that may provide certain beneficial effects in certain circumstances. However, other embodiments may also be preferred under the same circumstances or other circumstances. In addition, the description of one or more preferred embodiments does not imply that other embodiments are not applicable, nor is it intended to exclude other embodiments from the scope of the present invention.

[0031] When a numerical range is disclosed herein, the above range is considered to be continuous and includes the minimum and maximum values ​​of the range, as well as every value between such minimum and maximum values. Further, when a range refers to an integer, every integer between the minimum and maximum values ​​of the range is included. In addition, when multiple ranges are provided to describe features or characteristics, the ranges can be combined. In other words, unless otherwise indicated, all ranges disclosed herein should be understood to include any and all subranges included therein.

[0032] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. 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 the present invention.

[0033] Unless otherwise specified, the reagents, methods and equipment used in the present invention are conventional reagents, methods and equipment in the art.

[0034] Example 1

[0035] This embodiment provides a method for removing pollutants in sewage, comprising the following steps:

[0036] BPY-Fe(II) and potassium permanganate solution were added to the deionized water source containing diclofenac. The pH of the solution was 7 during the reaction. The solution was treated with a magnetic stirrer at a stirring speed of 600 r / min for 15 minutes to complete the BPY-Fe(II) enhanced permanganate oxidation to remove organic pollutants. The initial concentration of diclofenac was 5 μM, the dosage of BPY-Fe(II) was 10 μM, and the dosage of potassium permanganate was 100 μM.

[0037] In this example, the removal rate of diclofenac within 10 minutes was 100%.

[0038] Example 2

[0039] This embodiment provides a method for removing pollutants from sewage. The difference from Embodiment 1 is that the dosage of BPY-Fe(II) is 5 μM.

[0040] Example 3

[0041] This embodiment provides a method for removing pollutants from sewage, which is different from Embodiment 1 in that the dosage of BPY-Fe(II) is 7 μM.

[0042] Example 4

[0043] This embodiment provides a method for removing pollutants from sewage, which is different from Embodiment 1 in that the dosage of BPY-Fe(II) is 20 μM.

[0044] Example 5

[0045] This embodiment provides a method for removing pollutants from sewage. The difference from Embodiment 1 is that the dosage of BPY-Fe(II) is 50 μM.

[0046] Example 6

[0047] This embodiment provides a method for removing pollutants in sewage, which is different from Embodiment 1 in that the dosage of potassium permanganate is 50 μM.

[0048] Example 7

[0049] This embodiment provides a method for removing pollutants in sewage, which is different from Embodiment 1 in that the dosage of potassium permanganate is 200 μM.

[0050] Example 8

[0051] This embodiment provides a method for removing pollutants in sewage, which is different from Embodiment 1 in that the dosage of potassium permanganate is 300 μM.

[0052] Comparative Example 1

[0053] This comparative example provides a method for removing pollutants from sewage, which is different from Example 1 in that only 100 μM potassium permanganate, an oxidant, is added to the deionized water source containing diclofenac. The removal rate of diclofenac in the effluent of this comparative example is 84%.

[0054] Comparative Example 2

[0055] This comparative example provides a method for removing pollutants in sewage, which differs from Example 1 in that 10 μM Fe(II) and 100 μM potassium permanganate are added to the deionized water source containing diclofenac.

[0056] Test Example 1

[0057] In this test example, water containing 5 μM of the organic pollutants diclofenac, phenol, p-hydroxybenzoic acid and ibuprofen was prepared, and then the organic pollutants were removed according to the reaction conditions disclosed in Example 1.

[0058] The results are as follows Figure 2 As shown, the removal rates of diclofenac, phenol, p-hydroxybenzoic acid and ibuprofen in Example 1 were 100%, 78.6%, 39.5% and 29.3%, respectively.

[0059] Test Example 2

[0060] In this test example, water containing 5 μM of the organic pollutants diclofenac, phenol, p-hydroxybenzoic acid and ibuprofen was prepared, and then the organic pollutants were removed according to the reaction conditions disclosed in Comparative Example 1.

[0061] The results are as follows Figure 2 As shown, the removal rates of diclofenac, phenol, p-hydroxybenzoic acid and ibuprofen in Comparative Example 1 were 84.3%, 70.0%, 5.1% and 16.2%, respectively.

[0062] In the test example of the present invention, chromatographic methanol and prepared 0.1‰ acetic acid are used as mobile phases for liquid chromatography detection. High performance liquid chromatography (Waters) is used to detect the peak area changes of organic pollutants within the corresponding time and analyze them. The mobile phase ratio and detection wavelength of each pollutant are shown in Table 1.

[0063] Based on the measured data, the origin software is used to draw a graph to determine the removal efficiency of pollutants.

[0064] Table 1 Mobile phase ratio and detection wavelength of each pollutant

[0065] Organic pollutants Methanol(%) 1‰ acetic acid water (%) Wavelength (nm) Diclofenac 80 20 275 phenol 60 40 273 Parabens 60 40 254 Ibuprofen 75 25 220

[0066] According to the removal efficiency test results, Figure 1 As shown, the removal rate of diclofenac (Comparative Example 1) using potassium permanganate alone within 15 minutes is 84.3%; the removal rate of diclofenac (Comparative Example 2) using potassium permanganate activated by Fe(II) is 89.2%, and Example 1 can achieve 100% complete removal of diclofenac within 10 minutes, indicating that the addition of BPY can enhance the activation efficiency of Fe(II) on potassium permanganate, thereby improving the removal rate of diclofenac in water.

[0067] like Figure 2As shown in the figure, compared with the use of potassium permanganate oxidation alone, the removal rate of diclofenac in water increased from 84.3% to 100% after 15 minutes of potassium permanganate activation with BPY-Fe(II); the removal rate of phenol increased from 70% to 78.6%; the removal rate of p-hydroxybenzoic acid increased from 5.1% to 39.5%; and the removal rate of ibuprofen increased from 16.2% to 29.3%. This shows that the BPY-Fe(II) / potassium permanganate system has improved the removal rate of different organic pollutants.

[0068] like Figure 3 As shown in the figure, the removal rate comparison of diclofenac by potassium permanganate of different dosages in Example 1, Example 7 and Example 8 of the present invention shows that the removal rate and removal rate of diclofenac increase continuously with the increase of potassium permanganate dosage. Figure 4 As shown in the figure, the removal rate comparison of diclofenac by BPY-Fe(II) with different dosages in Example 1, Example 2, Example 3, Example 4 and Example 5 shows that the removal rate and removal rate of diclofenac increase continuously with the increase of the dosage of BPY-Fe(II).

[0069] The above is a detailed description of the embodiments of the present invention, but the present invention is not limited to the above embodiments. Various changes can be made within the knowledge of ordinary technicians in the relevant technical field without departing from the purpose of the present invention. In addition, the embodiments of the present invention and the features in the embodiments can be combined with each other without conflict.

Claims

1. A method for removing pollutants from sewage, characterized in that: The method comprises adding 2,2-bipyridine-Fe(II) and permanganate to water containing organic pollutants, stirring for reaction, and removing unreacted 2,2-bipyridine-Fe(II) and permanganate; The dosage of the 2,2-bipyridine-Fe(II) is 5 to 50 μM; the dosage of the permanganate is 50 to 300 μM.

2. The method according to claim 1, characterized in that The organic pollutant includes at least one of diclofenac, phenol, p-hydroxybenzoic acid and ibuprofen.

3. The method according to claim 1, characterized in that The dosage of the 2,2-bipyridine-Fe(II) is 10-50 μM.

4. The method according to claim 1, characterized in that: The dosage of the permanganate is 100-300 μM.

5. The method according to claim 1, characterized in that The dosage ratio of the 2,2-bipyridine-Fe(II) and permanganate is 1:(2-100).

6. The method according to claim 5, characterized in that The dosage ratio of the 2,2-bipyridine-Fe(II) and the permanganate is 1:(2-30).

7. The method according to claim 1, characterized in that The permanganate includes at least one of potassium permanganate and sodium permanganate.

8. The method according to claim 1, characterized in that The concentration of the organic pollutant is 0.1-5 μM.

9. The method according to claim 1, characterized in that: The stirring speed of the stirring reaction is 500-800 r / min; preferably, the stirring reaction time is 10-15 min.

10. The method according to claim 1, wherein the water comprises one of river water, lake water, domestic wastewater or industrial wastewater containing trace organic pollutants or sewage.

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