Method for improving water treatment effect of Fenton oxidation process

Abstract

The method comprises the following steps: adding hydrogen peroxide, a polyaniline material and soluble salt containing Fe < 2 + > or Fe < 3 + > into a to-be-treated organic wastewater solution with the pH value of 1-5, dispersing to form a suspension, and maintaining stirring until the degradation reaction of organic pollutants is completed, thereby obtaining the water treatment effect of the homogeneous Fenton oxidation process. The method can effectively reduce the addition amount of the Fe < 2 + > catalyst in the Fenton reaction, realizes reduction of the iron-containing sludge or avoids the generation of the iron-containing sludge, thereby reducing the application cost of the Fenton oxidation process, and showing huge application prospects and values.

Description

Technical Field

[0001] The present invention relates to the technical field of water treatment, and in particular to a method for improving the water treatment effect of the Fenton oxidation process. Background Art

[0002] The problem of water pollution is one of the main problems faced by the current ecological environment. The sources and types of water pollutants are numerous. Among them, the phenomenon of organic pollution is becoming increasingly serious and inevitably causes many ecological system and biological health problems. The Fenton oxidation process can catalyze the decomposition of hydrogen peroxide by divalent iron ions (Fe 2+ ), generating highly oxidizing hydroxyl radicals (oxidation potential up to 2.80 V, second only to fluorine) to achieve the degradation of organic pollutants. Therefore, it is often used in the treatment of refractory organic polluted wastewater. However, the consumption rate of Fe 2+ is much higher than its generation rate, which will significantly affect the Fenton reaction activity and is not conducive to the degradation of organic pollutants.

[0003] Since it is difficult for hydrogen peroxide to achieve the rapid regeneration of Fe 2+ , increasing the dosage of Fe 2+ is a common means to improve the reaction activity, so as to promote the decomposition of H2O2 and generate a sufficient concentration of ∙OH. Although this can improve the removal efficiency of pollutants, the presence of a large amount of Fenton reagents not only easily causes an increase in the effluent COD value and harms aquatic organisms, but also dissolved Fe 2+ or Fe 3+ will precipitate due to the pH value callback, becoming low-activity iron-containing sludge waste, increasing the cost of subsequent treatment. The above defects limit the application of the Fenton oxidation process in water treatment and need to be solved urgently.

[0004] The above information disclosed in the background art is only used to enhance the understanding of the background of the present invention, and thus may include information that does not constitute the prior art known to those of ordinary skill in the art. Summary of the Invention

[0005] Aiming at the deficiencies in the prior art, the purpose of the present invention is to provide a method for improving the water treatment effect of the Fenton oxidation process, which can strengthen the removal effect of organic pollutants without increasing the dosage of Fenton reagents.

[0006] To achieve the above purpose, the present invention provides the following technical solutions: A method for improving the water treatment effect of the Fenton oxidation process of the present invention includes: Step 1, adding hydrogen peroxide, polyaniline material, and a soluble salt containing Fe 2+ or Fe 3+ to the organic wastewater solution to be treated with a pH value of 1-5 and dispersing to form a suspension; Step 2: Start the reaction and maintain stirring until the degradation reaction of the organic pollutant is completed.

[0007] In the method described above, the mass ratio of the polyaniline material to Fe in the soluble salt 2+ or Fe 3+ is (10~50000):1.

[0008] In the method described above, the soluble salt includes ferrous salts, ferric salts, etc.

[0009] In the method described above, the polyaniline material is dispersed in the organic wastewater solution to be treated through ultrasonic treatment, stirring, oscillation or aeration to form a suspension.

[0010] In the method described above, hydrogen peroxide is added to the suspension in a one-time, batchwise or dropwise manner.

[0011] In the method described above, The polyaniline can also be filled in a column to form a packed column, and then the organic wastewater solution to be treated containing hydrogen peroxide and Fe 2+ or Fe 3+ in the soluble salt is passed through the packed column to improve the degradation effect of the organic pollutant.

[0012] In the method described above, The polyaniline can also be made into a membrane, and then the organic wastewater solution to be treated containing hydrogen peroxide and Fe 2+ or Fe 3+ in the soluble salt is passed through the polyaniline membrane to improve the degradation effect of the organic pollutant.

[0013] Compared with the prior art, the present invention has the following beneficial technical effects: 1. In the present invention, the polyaniline material is used to maintain the Fe 2+ concentration at a relatively high level in the Fenton reaction, thereby improving the reaction activity and ultimately achieving the rapid degradation of organic pollutants. The polyaniline material is cheap, easily available, easy to prepare, has a reversible redox state, and can be recycled and reused. Using it to improve the Fenton oxidation process has great application prospects and value.

[0014] 2. The present invention can also utilize the adsorption characteristics of the polyaniline material for organic pollutants with a significant negative charge to further enhance the removal effect of pollutants.

[0015] The above description is only an overview of the technical solution of the present invention. In order to make the technical means of the present invention clearer and to the extent that those skilled in the art can implement it according to the content of the specification, and in order to make the above and other purposes, features and advantages of the present invention more obvious and understandable, the following takes the specific embodiments of the present invention as examples for illustration. Brief Description of the Drawings

[0016] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings required to be used in the embodiments. Obviously, the drawings described below are only some embodiments recorded in the present invention. For those of ordinary skill in the art, other drawings can also be obtained based on these drawings.

[0017] By reading the detailed description of the preferred specific embodiments below, various other advantages and benefits of the present invention will become clear to those of ordinary skill in the art. The drawings in the specification are only for the purpose of showing the preferred embodiments and are not considered to be a limitation of the present invention. Obviously, the drawings described below are only some embodiments of the present invention. For those of ordinary skill in the art, other drawings can also be obtained based on these drawings without creative efforts. Moreover, throughout the drawings, the same reference numerals are used to represent the same components.

[0018] In the drawings: Figures 1 to 7 It is a schematic diagram of experimental data corresponding to different embodiments of the method for improving the water treatment effect of the Fenton oxidation process provided in different embodiments of the present invention.

[0019] The present invention will be further explained below in conjunction with the drawings and embodiments. Detailed Description of the Preferred Embodiments

[0020] To make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts belong to the scope of protection of the present invention.

[0021] Therefore, the following detailed description of the embodiments of the present invention provided in the drawings is not intended to limit the scope of the claimed invention, but merely represents the selected embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts belong to the scope of protection of the present invention.

[0022] It should be noted that similar reference numerals and letters denote similar items in the following drawings. Therefore, once an item is defined in one drawing, it does not need to be further defined and explained in subsequent drawings.

[0023] In the description of the present invention, it should be understood that the orientation or positional relationships indicated by terms such as "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", etc. are based on the orientation or positional relationships shown in the drawings. These are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus should not be construed as a limitation to the present invention.

[0024] In addition, the terms "first" and "second" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include one or more of such features. In the description of the present invention, "a plurality of" means two or more, unless otherwise specifically defined.

[0025] In the present invention, unless otherwise clearly specified and defined, terms such as "installed", "connected", "connected to", "fixed", etc. should be understood in a broad sense. For example, it may be a fixed connection, a detachable connection, or integrated; it may be directly connected, or indirectly connected through an intermediate medium, and may be the communication inside two elements or the interaction relationship between two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0026] In the present invention, unless otherwise clearly specified and defined, the first feature being "above" or "below" the second feature may include the first and second features being in direct contact, or may include the first and second features not being in direct contact but being in contact through additional features therebetween. Moreover, the first feature being "above", "over" and "on" the second feature includes the first feature being directly above and obliquely above the second feature, or merely indicating that the first feature has a higher horizontal height than the second feature. The first feature being "below", "beneath" and "under" the second feature includes the first feature being directly below and obliquely below the second feature, or merely indicating that the first feature has a lower horizontal height than the second feature.

[0027] To enable those skilled in the art to better understand the technical solutions of the present invention, the following will further introduce the present invention in detail with reference to the Figures 1 to 7 accompanying drawings, and each of the accompanying drawings does not constitute a limitation to the embodiments of the present invention.

[0028] In one embodiment, the present invention discloses and provides a method for improving the water treatment effect of a homogeneous Fenton oxidation process, including the following steps: Step 1, adding hydrogen peroxide, polyaniline material, and a substance containing Fe2+ or Fe 3+ The soluble salt is added to the organic wastewater solution to be treated with a pH value of 1 - 5 and dispersed to form a suspension; Step 2, start the reaction, and maintain stirring until the degradation reaction of organic pollutants is completed.

[0029] In a preferred embodiment of the method, the mass ratio of the polyaniline material to Fe in the soluble salt 2+ or Fe 3+ is (10~50000):1.

[0030] In a preferred embodiment of the method, the soluble salt includes ferrous salts, ferric salts, etc. For example, ferrous sulfate, ferric nitrate, ferric chloride, ferrous chloride, etc. Considering solubility and cost, ferrous sulfate is the best, and the influence of sulfate radical is smaller.

[0031] In a preferred embodiment of the method, the polyaniline material is dispersed in the organic wastewater solution to be treated to form a suspension via ultrasonic, stirring, oscillation or aeration.

[0032] In a preferred embodiment of the method, hydrogen peroxide is added to the suspension in a one-time, batchwise or dropwise manner.

[0033] In a preferred embodiment of the method, polyaniline can also be filled in a column to form a packed column, and then the organic wastewater solution to be treated containing hydrogen peroxide and Fe 2+ or Fe 3+ soluble salt is passed through the packed column to improve the degradation effect of organic pollutants.

[0034] In a preferred embodiment of the method, polyaniline can also be made into a membrane, and then the organic wastewater solution to be treated containing hydrogen peroxide and Fe 2+ or Fe 3+ soluble salt is passed through the polyaniline membrane to improve the degradation effect of organic pollutants.

[0035] In one embodiment, the present invention uses polyaniline material to improve the treatment effect of homogeneous Fenton oxidation process, so as to improve water treatment efficiency and reduce water treatment cost.

[0036] Hydrogen peroxide, polyaniline material, and the soluble salt containing Fe 2+ or Fe 3+ are added to the organic wastewater solution to be treated with a pH value of 1 - 5 and dispersed to form a suspension, and stirring is carried out to make the reactants evenly dispersed and continuously carry out Fenton reaction to generate strongly oxidizing active free radicals, thereby realizing the degradation of pollutants.

[0037] The polyaniline-enhanced Fenton oxidation process involved in the present invention enhances the removal effect of organic pollutants in the reaction by adding polyaniline materials to the Fenton oxidation process.

[0038] Hydrogen peroxide, polyaniline materials, and soluble salts containing Fe 2+ or Fe 3+ are added to the organic wastewater solution to be treated with a pH value of 1 - 5, and they are fully dispersed. Then, stirring is maintained until the degradation reaction of the organic pollutants is completed. In the reaction, the mass ratio of the polyaniline material to the Fenton catalyst is (10~50000):1, and the dispersion of the polyaniline material can be maintained by means such as ultrasonic, stirring, oscillation, aeration, etc. Example 1

[0039] 1) Add 0.001 g of polyaniline powder to 50 mL of rhodamine B dye wastewater solution with a pH value of 1 and containing 2 mg / L Fe 3+ ions. Ultrasonic for 30 s to highly disperse the polyaniline powder in the solution. At this time, the mass ratio of polyaniline to Fe 3+ in the solution is 10:1.

[0040] 2) Under magnetic stirring, add 10 mL of 30 wt% hydrogen peroxide to the above suspension solution and start the reaction. During the reaction, samples are taken at fixed time intervals, and after filtering with a needle, the dye concentration in the solution is measured.

[0041] The experimental results are as Figure 1 shown. After adding a small amount of polyaniline, the Fenton reaction activity is improved to a certain extent. Example 2

[0042] 1) Add 0.1 g of polyaniline powder to 50 mL of rhodamine B dye wastewater solution with a pH value of 3 and containing 2 mg / L Fe 3+ ions. Ultrasonic for 30 s to highly disperse the polyaniline powder in the solution. At this time, the mass ratio of polyaniline to Fe 3+ in the solution is 1000:1.

[0043] 2) Under magnetic stirring, add 10 mL of 30 wt% hydrogen peroxide to the above suspension solution and start the reaction. During the reaction, samples are taken at fixed time intervals, and after filtering with a needle, the dye concentration in the solution is measured.

[0044] The experimental results are as Figure 2 shown. After adding an appropriate amount of polyaniline, the Fenton reaction activity is significantly improved. Specifically, 100% degradation of the dye is basically achieved in 10 min. For the Fenton reaction without polyaniline, even at 20 min, the degradation efficiency of the dye can be basically ignored. Example 3

[0045] 1) Add 5 g of polyaniline powder to 50 mL of rhodamine B dye wastewater solution with a pH of 5 and containing 2 ppm of Fe 3+ ions. Ultrasonicate for 30 s to highly disperse the polyaniline powder in the solution. At this time, the mass ratio of polyaniline to Fe 3+ in the solution is 50000:1.

[0046] 2) Under magnetic stirring, add 10 mL of 30 wt% hydrogen peroxide to the above suspension and start the reaction. During the reaction, sample at fixed time intervals, and after filtering with a syringe filter, measure the dye concentration in the solution.

[0047] The experimental results are as Figure 3 shown. After adding sufficient polyaniline, the Fenton reaction activity is more significantly improved, specifically manifested as 100% degradation of the dye being achieved basically in 2 min. For the Fenton reaction without polyaniline, even at 20 min, the degradation efficiency of the dye can be basically ignored. Example 4

[0048] 1) Add 0.001 g of polyaniline powder to 50 mL of rhodamine B dye wastewater solution with a pH of 1 and containing 2 mg / L of Fe 2+ ions. Ultrasonicate for 30 s to highly disperse the polyaniline powder in the solution. At this time, the mass ratio of polyaniline to Fe 2+ in the solution is 10:1.

[0049] 2) Under magnetic stirring, add 10 mL of 30 wt% hydrogen peroxide to the above suspension and start the reaction. During the reaction, sample at fixed time intervals, and after filtering with a syringe filter, measure the dye concentration in the solution.

[0050] The experimental results are as Figure 4 shown. After adding a small amount of polyaniline, the Fenton reaction activity is improved to a certain extent. Example 5

[0051] 1) Add 0.1 g of polyaniline powder to 50 mL of rhodamine B dye wastewater solution with a pH of 3 and containing 2 mg / L of Fe 2+ ions. Ultrasonicate for 30 s to highly disperse the polyaniline powder in the solution. At this time, the mass ratio of polyaniline to Fe 2+ in the solution is 1000:1.

[0052] 2) Under magnetic stirring, add 10 mL of 30 wt% hydrogen peroxide to the above suspension and start the reaction. During the reaction, sample at fixed time intervals, and after filtering with a syringe filter, measure the dye concentration in the solution.

[0053] The experimental results are as follows Figure 5 shown. After adding an appropriate amount of polyaniline, the Fenton reaction activity is significantly improved. Specifically, 100% degradation of the dye is basically achieved in 10 min. For the Fenton reaction without polyaniline, only 50% of the dye is degraded at 10 min. Example 6

[0054] 1) Add 5 g of polyaniline powder to 50 mL of rhodamine B dye wastewater solution with a pH value of 5 and containing 2 ppm Fe 2+ ions. Ultrasonic for 30 s to highly disperse the polyaniline powder in the solution. At this time, the mass ratio of polyaniline to Fe 2+ in the solution is 50000:1.

[0055] 2) Under magnetic stirring, add 10 mL of 30 wt% hydrogen peroxide to the above suspension solution and start the reaction. During the reaction, samples are taken at fixed time intervals, and the dye concentration in the solution is measured after filtration with a needle.

[0056] The experimental results are as follows Figure 6 shown. After adding a sufficient amount of polyaniline, the Fenton reaction activity is even more significantly improved. Specifically, 100% degradation of the dye is basically achieved in 2 min. For the Fenton reaction without polyaniline, even at 20 min, the degradation efficiency of the dye can be basically ignored. Example 7

[0057] 1) Add 0.1 g of polyaniline powder to 50 mL of methylene blue dye wastewater solution with a pH value of 3 and containing 2 mg / L Fe 3+ ions. Ultrasonic for 30 s to highly disperse the polyaniline powder in the solution. At this time, the mass ratio of polyaniline to Fe 2+ in the solution is 1000:1.

[0058] 2) Under magnetic stirring, add 10 mL of 30 wt% hydrogen peroxide to the above suspension solution and start the reaction. During the reaction, samples are taken at fixed time intervals, and the dye concentration in the solution is measured after filtration with a needle.

[0059] The experimental results are as follows Figure 7 shown. After adding polyaniline, 100% degradation of methylene blue is basically achieved in 10 min. Example 7 proves that the applicable range of the present invention is relatively wide. From the perspective of cost performance, both Example 7 and Example 5 are 1000:1 and have achieved good results.

[0060] For all of the above embodiments, it can be found that the greater the dosage of polyaniline, the more obvious the improvement effect on the reaction activity, which further proves the key role of polyaniline in enhancing the homogeneous Fenton reaction activity.

[0061] From the perspective of improving activity, Fe 3+ ions need to be converted to Fe 2+ ions during the Fenton oxidation process. Therefore, the best implementation method is to use soluble ferrous salts, especially ferrous sulfate described above. Considering both the dosing cost and effect, the present invention selects the mass ratio of polyaniline to Fe 2+ to be 1000:1 and the pH value of the organic wastewater solution to be treated to be 3 as the best. Example 7 also proves this point. Examples with a pH value lower or higher than 3 have weaker effects than the example of the organic wastewater solution to be treated with a mass ratio of polyaniline to Fe 2+ of 1000:1 and a pH value of 3. This is because when the pH value is too low, the existence form of hydrogen peroxide will be affected, and hydrogen peroxide and hydrogen ions are prone to produce stable complexes, which is not conducive to the decomposition to generate hydroxyl radicals; when the pH value is too high, the added hydrogen peroxide is prone to decompose at this time. At the same time, iron ions are prone to exist in the form of hydroxides, thus affecting the activity of related reactions in the entire water treatment process. At the same time, the cost of a mass ratio of polyaniline to Fe 2+ of 50000:1 is higher, and the cost performance is not good, unless the cost is not considered and only the effect is pursued one-sidedly.

[0062] In one embodiment, the use method of polyaniline can be in various forms: (1) directly adding polyaniline; (2) filling polyaniline in a column to make a packing column, and then passing the wastewater through the packing column; (3) making polyaniline into a membrane, and passing the wastewater through the membrane to improve the treatment effect, etc. Especially the latter two methods have better effects. More preferably, the latter two methods can be combined and used as the optimal method.

[0063] Although the embodiments of the present invention have been described above in conjunction with the accompanying drawings, the present invention is not limited to the above specific embodiments and application fields. The above specific embodiments are merely illustrative and guiding, rather than restrictive. Under the inspiration of this specification and without departing from the scope protected by the claims of the present invention, those of ordinary skill in the art can also make many forms, such as accelerating the reduction of Fe 3+ through forms such as polyaniline packing columns and polyaniline membranes, thereby improving the water treatment effect of the Fenton oxidation process. All of these belong to the scope protected by the present invention.

Claims

1. A method for improving the water treatment effect of homogeneous Fenton oxidation process, characterized in that, It includes the following steps: Step 1, adding hydrogen peroxide, polyaniline material, and a soluble salt containing Fe 2+ or Fe 3+ into the organic wastewater solution to be treated with a pH value of 1-5 and dispersing to form a suspension; Step 2: Start the reaction and maintain stirring until the completion of the organic pollutant degradation reaction.

2. The method according to claim 1, wherein Preferably, the mass ratio of the polyaniline material to Fe in the soluble salt 2+ or Fe 3+ is (10~50000):

1.

3. The method according to claim 1, characterized in that The soluble salt includes divalent and acid radical iron salts.

4. The method according to claim 1, wherein The soluble salt includes trivalent and acid radical iron salts.

5. The method according to claim 1, characterized in that, The polyaniline material is dispersed in the organic wastewater solution to be treated via ultrasound to form a suspension.

6. The method according to claim 1, wherein The polyaniline material is dispersed in the organic wastewater solution to be treated via stirring to form a suspension.

7. The method according to claim 1, characterized in that The polyaniline material is dispersed in the organic wastewater solution to be treated via oscillation or aeration to form a suspension.

8. The method according to claim 1, wherein Hydrogen peroxide is added to the suspension in a one-time manner.

9. The method according to claim 1, characterized in that Hydrogen peroxide is added to the suspension in a batchwise manner.

10. The method according to claim 1, wherein Hydrogen peroxide is added to the suspension in a dropwise manner.

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