Method for treating wastewater based on hydrogen peroxide system

Abstract

The invention discloses a method for treating wastewater based on a hydrogen peroxide system, and belongs to the technical field of wastewater treatment.The hydrogen peroxide system comprises hydrogen peroxide and sodium bicarbonate, the hydrogen peroxide serves as an oxidizing agent, the sodium bicarbonate serves as an activating agent, the hydrogen peroxide is activated through the sodium bicarbonate, and active oxygen species are generated; the method is used for removing COD (Chemical Oxygen Demand) in wastewater under the condition that the pH value is 3-11. The method for treating the wastewater can solve the problems that in the prior art, application of an oxidation system based on hydrogen peroxide is limited by the pH range, secondary pollution is caused by metal ion leaching, the price of a catalyst is high and the like, and energy-containing wastewater is efficiently treated under the condition that the pH is 3-11.

Description

Technical Field

[0001] This application belongs to the field of wastewater treatment technology, specifically relating to a method for treating wastewater based on a hydrogen peroxide system. Background Technology

[0002] With the acceleration of industrialization and urbanization, the amount of wastewater generated has increased dramatically. Residual pollutants can seriously impact the aquatic ecosystem, causing eutrophication, ecosystem imbalance, changes in microbial community structure, and even threatening drinking water source safety and hindering the sustainable use of water resources. In particular, traditional biological treatment methods are inefficient for energy-containing wastewater and cannot effectively reduce the concentration of its characteristic pollutant HMX (octogen) and COD content.

[0003] Advanced oxidation processes (AOPs) are characterized by high selectivity and reactivity, enabling the oxidation of organic molecules until they are completely eliminated, resulting in extremely high removal efficiency. Under the action of homogeneous and heterogeneous catalysts, the oxidant produces highly reactive substances, including singlet oxygen (…). ), hydroxyl radicals ( ), superoxide radicals ( ) and sulfate free radicals ( These substances, such as carbon dioxide and water, have strong oxidizing properties and can efficiently remove pollutants, causing them to completely degrade into carbon dioxide and water. This is a green and clean water treatment technology.

[0004] Hydrogen peroxide-based oxidation technology is characterized by rapid reaction, high diffusivity, cost-effectiveness, and the generation of hydroxyl radicals, exhibiting strong oxidizing power. Hydroxyl radicals degrade pollutants through redox reactions, dehydrogenation, and hydroxylation with organic matter, demonstrating significant application potential in wastewater treatment. Heterogeneous metal catalysts, such as metal monomers, metal oxides, sulfides, metal-supported catalysts, and metal-organic frameworks, can activate hydrogen peroxide and promote the generation of reactive oxygen species. However, these catalysts face challenges, including complex preparation processes, pH-dependent activity of metal ions, high equipment and reagent costs, and the potential for secondary pollution. Summary of the Invention

[0005] To address the shortcomings of existing technologies, this invention provides a method for treating wastewater by activating hydrogen peroxide with sodium bicarbonate, which overcomes the limitations of existing hydrogen peroxide-based oxidation systems, such as pH range restrictions, secondary pollution caused by metal ion leaching, and high cost.

[0006] The present invention adopts the following technical solution.

[0007] The application discloses a method for treating wastewater based on a hydrogen peroxide system, and the hydrogen peroxide system comprises: hydrogen peroxide and sodium bicarbonate, wherein the hydrogen peroxide serves as an oxidant, and the sodium bicarbonate serves as an activator; the hydrogen peroxide is activated by the sodium bicarbonate, and is used for removing COD in the wastewater under the condition that the pH is 3-11.

[0008] Preferably, the method comprises the following steps: The set proportion of the sodium bicarbonate and the hydrogen peroxide is added into the wastewater sample, and active oxygen species are generated through an oxidation reaction after stirring, so that the COD in the wastewater sample is removed.

[0009] Preferably, the set proportion of the sodium bicarbonate and the hydrogen peroxide is 1:2.

[0010] Preferably, the amount of the hydrogen peroxide ranges from 0.1 to 0.6 M.

[0011] Preferably, the amount of the sodium bicarbonate ranges from 0.1 to 0.3 M.

[0012] Preferably, the amount of the hydrogen peroxide is 0.4 M, and the amount of the sodium bicarbonate is 0.2 M.

[0013] Preferably, the active oxygen species comprises singlet oxygen, hydroxyl radicals and superoxide radicals.

[0014] Preferably, the stirring mode is magnetic stirring, and the rotating speed ranges from 400 to 600 r / min.

[0015] Compared with the prior art, the application has at least the following beneficial effects: The application adopts the mode that the sodium bicarbonate activates the hydrogen peroxide to construct a wastewater treatment system, improves the efficiency of the hydrogen peroxide system in oxidizing and degrading organic matters, avoids using metal ions and other catalysts, is low in cost, reduces secondary pollution caused by metal dissolution or generation of organic byproducts, and solves the problems that the activity of metal ions is easily affected by pH and easily forms complexes with inorganic ions, thereby reducing the activity.

[0016] The sodium bicarbonate adopted in the application is easy to dissolve in water and low in cost, is widely present in nature, is a green and sustainable technical means, can realize efficient degradation of pollutants in a short time for energy-containing wastewater, can effectively remove the COD of the wastewater in 60 min of reaction time, makes the residual COD meet the first-level A standard of pollutant discharge of a municipal wastewater treatment plant, realizes more optimal discharge up to the standard, and relieves the environmental pressure.

[0017] The wastewater treatment system of this invention can effectively remove COD from wastewater treatment plant effluent within an initial pH range of 3-11, breaking through the limitations of many existing technologies that are subject to stringent pH conditions. It also works with different concentrations of common inorganic anions (…). , , and Under the condition that these conditions exist, the method of the present invention can effectively remove COD from wastewater, enhancing the stability and reliability of treatment under complex water composition.

[0018] This invention has high application value for energy-containing wastewater, and can significantly reduce the concentration of characteristic pollutant octogen and COD content. Attached Figure Description

[0019] Figure 1 The effect of different sodium bicarbonate:hydrogen peroxide addition ratios on the COD removal efficiency of water samples in Implementation Method 1.

[0020] Figure 2 The COD removal effect is shown in the experimental system (Implementation Method 1) and the control system (Implementation Method 2).

[0021] Figure 3 The effect of different pH values ​​on the COD removal efficiency of water samples in Implementation Method 3 and the first-order kinetic constant of the reaction.

[0022] Figure 4 For different implementation methods in Implementation Four The effect of concentration on COD removal efficiency in water samples and the first-order kinetic constant of the reaction.

[0023] Figure 5 For different implementation methods in Implementation Four The effect of concentration on COD removal efficiency in water samples and the first-order kinetic constant of the reaction.

[0024] Figure 6 For different implementation methods in Implementation Four The effect of concentration on COD removal efficiency in water samples and the first-order kinetic constant of the reaction.

[0025] Figure 7 For different implementation methods in Implementation Four The effect of concentration on COD removal efficiency in water samples and the first-order kinetic constant of the reaction.

[0026] Figure 8 The effect of the quenching agent on the removal effect of COD in the water sample in Implementation Method 5 and the first-order kinetic constant of the reaction.

[0027] Figure 9 The degradation curves of COD and characteristic pollutant HMX in the laboratory small-scale test water sample in Implementation Method 6 are shown. Detailed Implementation

[0028] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of this invention. The embodiments described in this application are merely some embodiments of this invention, and not all embodiments. Based on the spirit of this invention, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of this invention.

[0029] Sodium bicarbonate is inexpensive, can diffuse evenly in water, has relatively low toxicity, and is widely available in nature. It can serve as a sustainable green wastewater treatment solution. Furthermore, traditional hydrogen peroxide oxidation technology mainly relies on hydroxyl radicals (…). The inventors' team realized through numerous experiments that the wastewater treatment system using sodium bicarbonate to activate hydrogen peroxide could not only produce strong oxidizing degradation pollutants, but also... And it can also generate and· All of them can disrupt the molecular structure of octogen, and their contributions are relatively balanced, not solely dependent on it. The aforementioned multiple reactive oxygen species work together to improve the degradation efficiency of characteristic pollutants.

[0030] Therefore, Embodiment 1 of the present invention provides a hydrogen peroxide system comprising hydrogen peroxide and sodium bicarbonate, wherein the hydrogen peroxide acts as an oxidant and the sodium bicarbonate acts as an activator.

[0031] Embodiment 2 of the present invention provides a method for treating wastewater based on a hydrogen peroxide system. Sodium bicarbonate and hydrogen peroxide are added sequentially to a wastewater effluent sample from a wastewater treatment plant. After stirring, the reactive oxygen species generated by the oxidation reaction are used to remove COD.

[0032] In the entire reaction system, the amount of hydrogen peroxide used ranges from 0.1 to 0.6 M, and preferably, the system concentration of hydrogen peroxide used is 0.4 M. The amount of sodium bicarbonate used ranges from 0.1 to 0.3 M, and preferably, the system concentration of sodium bicarbonate used is 0.2 M.

[0033] More preferably, the stirring method is magnetic stirring, with a rotation speed of 400-600 r / min.

[0034] The reactive oxygen species include singlet oxygen, hydroxyl radicals, and superoxide radicals.

[0035] In the reaction system described in this invention, the presence of sodium bicarbonate broadens the applicable pH range, maintaining a high COD removal rate at pH 3–11. The remaining COD meets the Class A standard for pollutant discharge from municipal wastewater treatment plants. Furthermore, the system exhibits enhanced resistance to interference from inorganic anions, reducing the inhibitory effect caused by the easy complexation of metal ions with inorganic ions in existing technologies. Simultaneously, the system of this invention utilizes multiple reactive oxygen species working synergistically, reducing the influence of single reactive oxygen species. This reduces reliance on technology and improves its stability.

[0036] Specifically, under acidic conditions, hydrogen peroxide is more likely to undergo a chain reaction to generate reactive free radicals, which non-selectively attack the various chemical bonds of octogen molecules, a characteristic pollutant in energetic wastewater, causing them to break and degrade, thus destroying their molecular structure and reducing COD concentration; in the neutral to weakly alkaline range, the system... The ionization and hydrolysis equilibrium is relatively stable, which promotes the activation of hydrogen peroxide. Under alkaline conditions, the hydrogen ion concentration decreases, which inhibits the disproportionation reaction of superoxide free radicals, maintains its high stability, promotes the degradation of pollutants, and reduces COD concentration.

[0037] This invention determines the optimal reagent dosage for the sodium bicarbonate-activated hydrogen peroxide system to degrade COD in energetic wastewater, ensuring a high COD removal rate while avoiding resource waste and pollution caused by excessive reagent dosage.

[0038] The following description, in conjunction with the accompanying drawings, further illustrates the present invention's method for activating a hydrogen peroxide system using sodium bicarbonate and removing COD from wastewater.

[0039] The materials and equipment used in the following experiments are as follows.

[0040] Experimental materials: 30% hydrogen peroxide, sodium bicarbonate, potassium titanium oxalate, concentrated sulfuric acid, p-benzoquinone (p-BQ), tert-butanol, furfuryl alcohol, and Hach reagent.

[0041] Experimental equipment: UV spectrophotometer, COD analyzer, digester, Milli-Q Gradient ultrapure water system, BS223S electronic analytical balance, benchtop pH / ORP meter.

[0042] Implementation Method 1 Take 50 mL of wastewater sample into a 150 mL beaker. Under magnetic stirring, add different doses of sodium bicarbonate (0.1 M, 0.2 M, 0.25 M, 0.3 M) and hydrogen peroxide solution (0.1 M, 0.2 M, 0.3 M, 0.4 M, 0.5 M, 0.6 M). Take the reaction samples after 0, 10, 20, 40, and 60 min, filter them through a 0.22 μm polyethersulfone membrane and quench them with 100 mM sodium thiosulfate solution to obtain 2 mL of reaction suspension. Measure the COD using a COD meter.

[0043] like Figure 1 As shown, the results indicate that the COD degradation rate is higher when the ratio of sodium bicarbonate to hydrogen peroxide is 1:2, and the optimal treatment system is determined to be 0.2 M sodium bicarbonate – 0.4 M hydrogen peroxide.

[0044] Implementation Method 2 Take 50 mL of wastewater sample into a 150 mL beaker, add 0.4 M hydrogen peroxide solution while magnetically stirring, and take a sample and determine COD at the same reaction time as in Embodiment 1. Figure 2 As shown in the comparison, the addition of sodium bicarbonate improved the COD degradation rate, indicating that the system produced more active species to exert an oxidizing effect.

[0045] Implementation Method 3 Take 50 mL of wastewater sample into a 150 mL beaker, adjust the initial pH to 3, 5, 7, 9 and 11 with dilute hydrochloric acid and sodium hydroxide, respectively, and then add 0.2 M sodium bicarbonate and 0.4 M hydrogen peroxide. Take samples at specific reaction times and determine COD.

[0046] like Figure 3 As shown, the results indicate that the COD removal rate is between 40% and 60% under different pH conditions, and the COD values ​​of the degraded water samples all meet the Class A standard for pollutant discharge from urban wastewater treatment plants, indicating that the sodium bicarbonate-hydrogen peroxide system is applicable within a wide pH range.

[0047] Implementation Method 4 Take a 50 mL wastewater sample and place it in a 150 mL beaker. Add NaCl and NaCl to the beaker separately. , and ,make , , and COD was measured at concentrations of 1 mM, 2 mM, 5 mM and 10 mM at specific reaction times.

[0048] likeFigures 4-7 As shown, with As ion concentration increases, COD degradation rate is gradually suppressed, and the first-order kinetic constant of the reaction also shows a gradual decreasing trend. and The reaction produces Its low activity inhibited the removal of COD from the water sample.

[0049] lower concentration It inhibits the reaction rate, and high concentrations can offset some of the inhibitory effect. However, different concentrations... The system's COD removal rate remained essentially unchanged at 65%, indicating that... It has virtually no impact on the system's COD removal efficiency.

[0050] Suitable concentration (2 mM) can increase the reaction rate of the system, but higher (5 mM or 10 mM) or lower concentrations... (1 mM) inhibited the reaction rate of the system. However, within a reaction time of 60 min, different concentrations of [agent name] [did not affect the reaction rate]. It has a relatively small inhibitory effect on the COD degradation rate of the system, and the COD values ​​all meet the Class A standard for pollutant discharge from urban wastewater treatment plants.

[0051] along with As the concentration increased, the COD degradation rate of the system showed a gradual increasing trend, indicating that... It may have a synergistic pathway with substances in the water sample, promoting the enhancement of the system's oxidative properties.

[0052] Implementation Method 5 Take 50 mL of wastewater sample into a 150 mL beaker, add 50 mM tert-butanol (TBA), 5 mM p-benzoquinone (p-BQ) and 10 mM furfuryl alcohol (FA), then add 0.2 M sodium bicarbonate and 0.4 M hydrogen peroxide. Take samples at specific reaction times and determine COD.

[0053] like Figure 8 As shown, compared with Implementation Method 1, the COD degradation rate decreased in all cases. Calculations showed that the contribution of the three free radicals was ranked in the following order: (37%) > (35%)> (28%) indicates and It played an important role.

[0054] Implementation Method Six Take 2 L of water sample into a 3.6 L rectangular reaction vessel. Under magnetic stirring, add 33.6 g of NaHCO3 and 81.6 mL of H2O2 solution to make their concentrations 0.2 M and 0.4 M, respectively. Take the sample after reaction at 0, 10, 20, 40 and 60 min to determine the COD value.

[0055] like Figure 9 As shown in the figure, the small-scale experiment showed that the COD value decreased to 48.2 mg / L, the removal rate reached 47.6%, and the COD value after treatment met the Class A standard (50 mg / L) for pollutant discharge from urban wastewater treatment plants.

[0056] Compared with the prior art, the beneficial effects of the present invention include at least the following: This invention constructs a wastewater treatment system by activating hydrogen peroxide with sodium bicarbonate, thereby improving the efficiency of hydrogen peroxide system in oxidizing and degrading organic matter. It avoids the use of catalysts such as metal ions, which is not only low-cost, but also reduces secondary pollution caused by metal leaching or the generation of organic byproducts. It also solves the problem that the activity of metal ions is easily affected by pH and easily forms complexes with inorganic ions, thus reducing their activity.

[0057] The sodium bicarbonate used in this invention is readily soluble in water, inexpensive, and widely available in nature. It is a green and sustainable technology that can achieve highly efficient pollutant degradation in energy-containing wastewater within a short time. It can effectively remove COD from wastewater within a 60-minute reaction time, ensuring that the remaining COD meets the Class A standard for pollutant discharge from urban wastewater treatment plants, achieving better compliance and alleviating environmental pressure.

[0058] The wastewater treatment system of this invention can effectively remove COD from wastewater treatment plant effluent within an initial pH range of 3-11, breaking through the limitations of many existing technologies that are subject to stringent pH conditions. It also works with different concentrations of common inorganic anions (…). , , and Under the condition that these conditions exist, the method of the present invention can effectively remove COD from wastewater, enhancing the stability and reliability of treatment under complex water composition.

[0059] This invention has high application value for energy-containing wastewater, and can significantly reduce the concentration of characteristic pollutant octogen and COD content.

[0060] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit it. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that modifications or equivalent substitutions can still be made to the specific implementation of the present invention. Any modifications or equivalent substitutions that do not depart from the spirit and scope of the present invention should be covered within the protection scope of the claims of the present invention.

Claims

1. A method for treating wastewater based on a hydrogen peroxide system, characterized in that, The hydrogen peroxide system includes hydrogen peroxide and sodium bicarbonate, wherein hydrogen peroxide acts as an oxidant and sodium bicarbonate acts as an activator. Hydrogen peroxide is activated by sodium bicarbonate to remove COD from wastewater under conditions of pH 3 to 11.

2. The method for treating wastewater based on a hydrogen peroxide system according to claim 1, characterized in that, The method includes the following steps: A set ratio of sodium bicarbonate and hydrogen peroxide is added to the wastewater sample. After stirring, reactive oxygen species are generated through an oxidation reaction, which removes COD from the wastewater sample.

3. The method for treating wastewater based on a hydrogen peroxide system according to claim 2, characterized in that, The ratio of sodium bicarbonate to hydrogen peroxide is set at 1:

2.

4. The method for treating wastewater based on a hydrogen peroxide system according to claim 2, characterized in that, The amount of hydrogen peroxide used is in the range of 0.1 - 0.6 M.

5. The method for treating wastewater based on a hydrogen peroxide system according to claim 2, characterized in that, The amount of sodium bicarbonate used ranges from 0.1 to 0.3 M.

6. The method for treating wastewater based on a hydrogen peroxide system according to claim 2, characterized in that, The amount of hydrogen peroxide used is 0.4 M, and the amount of sodium bicarbonate used is 0.2 M.

7. The method for treating wastewater based on a hydrogen peroxide system according to claim 2, characterized in that, The reactive oxygen species include singlet oxygen, hydroxyl radicals, and superoxide radicals.

8. The method for treating wastewater based on a hydrogen peroxide system according to claim 1, characterized in that, The stirring method is magnetic stirring, with a rotation speed of 400-600 r / min.

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