Application of phosphate calixarene in catalyzing potassium permanganate and peroxymonosulfate to deeply treat wastewater containing phenolic pollutants

Abstract

The invention belongs to the field of advanced sewage treatment, and relates to application of phosphate calixarene in catalyzing potassium permanganate and peroxymonosulfate to deeply treat wastewater containing phenol pollutants. According to the method, the phosphate calixarene, the potassium permanganate and the peroxymonosulfate are put into the to-be-treated sewage, so that effective treatment of new pollutants in the sewage can be realized. The phosphate calixarene has a building unit PC4A (PC4A refers to phosphate calixarene, 4 refers to the number of units, P refers to phosphate, and C4A refers to four polymerized calixarene), the chemical formula is C24H20O20P, and the structural formula is # imgabs0 #. The Mn < 6 + > / Mn < 5 + >-PC4A can enable metastable hexavalent manganese / pentavalent manganese to stably exist, is beneficial to circularly generating heptavalent manganese to further degrade the phenolic pollutants, has good elimination capability on the phenolic pollutants, and particularly realizes rapid removal of the phenolic pollutants while improving the utilization rate of potassium permanganate.

Description

Technical Field

[0001] The invention relates to the technical field of sewage deep treatment, in particular to the application of phosphate calixarene in catalyzing potassium permanganate and peroxymonosulfate to deeply treat wastewater containing phenolic pollutants. Background Art

[0002] With the development of supramolecular chemistry, calixarene as the third type of supramolecular subject has attracted the research and attention of many scholars. For the design of calixarene, the size of its cavity and its structural properties can be controlled by controlling the number of bridging methylene phenol units and changing the bridging group of the aromatic ring, thereby achieving chemical modification and deriving a variety of highly selective compounds. Due to the rich sites and cavities rich in delocalized π electrons of calixarene, it can coordinate with most metal ions to form complexes. It can be seen that technicians can prepare calixarene derivatives that meet technical needs through appropriate chemical modification, and combine them with sewage treatment methods to improve sewage treatment efficiency.

[0003] Permanganate (Mn(VII)), as a green and selective oxidizing chemical, has attracted considerable attention due to its preferential oxidation of electron-rich parts without forming halogenated byproducts. In terms of removing emerging pollutants in water, potassium permanganate oxidation technology alone has strong selectivity and has a certain removal ability for emerging pollutants containing unsaturated bonds and electron-rich groups. However, the amount of potassium permanganate required to be added is not easy to control. Once excessive use produces residues, the chromaticity of the treated water will be significantly increased, and the reduction product of excessive potassium permanganate, manganese dioxide, is prone to cause pipe blockage. Therefore, it is very important to propose a method to enhance the oxidation efficiency of potassium permanganate and reduce its dosage. The present invention proposes a method for deep treatment of sewage using permonosulfate, permanganate, and phosphate calixarene. Summary of the invention

[0004] In order to solve the above technical problems, the present invention provides a method for deep treatment of phenol-containing wastewater by catalyzing potassium permanganate and peroxymonosulfate.

[0005] The object of the present invention is to provide an application of phosphate calixarene in catalyzing potassium permanganate and peroxymonosulfate to deeply treat wastewater containing phenolic pollutants. The structural formula of the phosphate calixarene is , molecular formula is C 24 H 20 O 20 P; the phenolic pollutants include one or more of phenol, methylphenol, nitrophenol, aminophenol, halogenated phenol, p-tert-butylphenol, nonylphenol, octylphenol, bisphenol A, bisphenol S, bisphenol F, bisphenol AF, hydroquinone and naphthol.

[0006] In some embodiments of the present invention, the method for preparing the phosphate calixarene comprises the following steps: Dissolve p-tert-butylphenol, diethyl chlorophosphate and tetrabutylammonium iodide in an organic solvent, add an alkaline solution under the protection of an inert atmosphere, stir, and heat under reflux to obtain the phosphate calixarene.

[0007] In some embodiments of the present invention, the molar ratio of p-tert-butylphenol, diethyl chlorophosphate and tetrabutylammonium iodide is 1:(4-6):0.2.

[0008] In some embodiments of the present invention, the organic solvent is selected from carbon tetrachloride and dichloromethane.

[0009] In some embodiments of the present invention, the alkaline solution includes sodium hydroxide solution and ammonia water; the mass concentration of the alkaline substance is 50-55%.

[0010] In some embodiments of the present invention, the heating temperature is 60-80° C. and the heating time is 3-5 h.

[0011] In some embodiments of the present invention, the mass ratio of the phosphate calixarene, potassium permanganate, and peroxymonosulfate is 1:(0.025-0.1):4.

[0012] In some embodiments of the present invention, the peroxymonosulfate is selected from potassium peroxymonosulfate, sodium peroxymonosulfate, and ammonium peroxymonosulfate.

[0013] In some embodiments of the present invention, the concentration of phenolic pollutants in the wastewater containing phenolic pollutants is 0.01-100 mg / L.

[0014] In some embodiments of the present invention, when treating phenol-containing wastewater, the pH of the solution is 5 to 9. For example, it can be 5, 6, 7, 8, 9, etc., or 5 to 8, 5 to 7, etc., or any interval value between any two values.

[0015] The reaction principle of the present invention is that PC4A and potassium permanganate oxidize phenolic compounds to generate hexavalent manganese / pentavalent manganese to form a stable Mn 6+ / Mn 5+ -PC4A complex. Permonosulfate can oxidize the complexed and stabilized hexavalent manganese / pentavalent manganese to regenerate heptavalent manganese (permanganate), further degrading phenolic organic pollutants. This new oxidation method greatly reduces the dosage of potassium permanganate, improves the utilization rate of potassium permanganate, and can achieve efficient removal of phenolic pollutants.

[0016] The wastewater containing phenolic pollutants described in the present invention is a common type of wastewater in the environment, and phenol is the most important pollutant therein. The reason why the present invention is applicable to phenolic pollutants is that potassium permanganate is relatively effective against phenolic compounds, and secondly, potassium permanganate can oxidize phenolic compounds to generate hexavalent manganese / pentavalent manganese, thereby forming a stable complex with PC4A, and further can undergo an electron transfer reaction with permonosulfate (PMS) to regenerate heptavalent manganese. Therefore, the present invention provides a new and efficient method for accelerating the purification of phenolic wastewater.

[0017] The above technical solution of the present invention has the following advantages compared with the prior art: The potassium permanganate of the invention is added in a small amount and will not cause the chromaticity problem of the water body.

[0018] The invention can stabilize hexavalent manganese / pentavalent manganese under near-neutral conditions, especially reduce the consumption of potassium permanganate, and can also realize the rapid removal of phenol pollutants under the condition of less potassium permanganate dosage. DETAILED DESCRIPTION

[0019] The present invention is further described below in conjunction with specific embodiments so that those skilled in the art can better understand the present invention and implement it, but the embodiments are not intended to limit the present invention.

[0020] Embodiment 1:

[0021] This embodiment provides a method for preparing phosphate calixarene, comprising the following steps: (1) In a 250 mL four-necked bottle, add 1 g of p-tert-butylphenol, 10 mL of diethyl chlorophosphate, and 115 g of tetrabutylammonium iodide and dissolve them in 100 mL of carbon tetrachloride. Under nitrogen protection, add 5 mL of 50 wt% NaOH dropwise and stir. Gradually heat to 60 °C and reflux for 4 h to obtain a reaction solution.

[0022] (2) The reaction solution obtained in step (1) was filtered to remove the solid, and the filtrate was washed with saturated brine 3 times and ultrapure water 3 times to obtain an organic phase, which was dried over anhydrous Na2SO4. The solvent was evaporated, methanol was added to dissolve the product, ethyl acetate was added to precipitate, and a white powder was obtained by filtration, namely, phosphate calixarene (PC4A) was obtained.

[0023] The phosphate calixarene in the present invention can form a highly active complex with hexavalent manganese / pentavalent manganese reduced by potassium permanganate to capture the electrons of new pollutants in sewage, thereby accelerating the removal of organic matter. It is used for the treatment of deep sewage to achieve efficient removal of new pollutants in sewage, and is also beneficial to improving the utilization rate of electrons in sewage.

[0024] Application Example 1: PC4A, potassium permanganate and potassium permonosulfate prepared in Example 1 were added to simulated sewage at a mass ratio of 1: (0.025-0.1): 4. The sewage contained 6.26 mg / L of bisphenol S, and the concentrations of PC4A, potassium permanganate and potassium permonosulfate were 13 mg / L, 0.3 mg / L and 54 mg / L, respectively. The same concentrations of potassium permanganate and potassium permonosulfate were used as a control group, and the pH was controlled at 9.

[0025] High performance liquid chromatography (HPLC) was used to determine the concentration of organic matter. The concentration of bisphenol S in the wastewater was tested over time, and the removal rate of bisphenol S is shown in Table 1.

[0026] Application Example 2: Different from Application Example 1, the pH of the mixed solution is controlled at 8. The removal rate of bisphenol S after treatment is shown in Table 1.

[0027] Application Example 3: Different from Application Example 1, the pH of the mixed solution is controlled at 7. The removal rate of bisphenol S after treatment is shown in Table 1.

[0028] Application example 4: Different from Application Example 1, the pH of the mixed solution is controlled at 6. The removal rate of bisphenol S after treatment is shown in Table 1.

[0029] Application Example 5: Different from Application Example 1, the pH of the mixed solution is controlled at 5. The removal rate of bisphenol S after treatment is shown in Table 1.

[0030] Table 1 Removal rate of bisphenol S in application examples (%)

[0031] As can be seen from Table 1, the two-component oxidation system of potassium permanganate and potassium permonosulfate works worse at lower pH, because Mn(VI) reduced by Mn(VII) is easily disproportionated under acidic conditions, which affects the oxidation capacity of the system. After adding calixarene phosphate, the oxidation effect is significantly increased. This result shows that calixarene phosphate effectively stabilizes hexavalent manganese.

[0032] Comparative Application Example 1: Different from Application Example 1, only potassium permanganate and bisphenol S of the same concentration were added to the simulated sewage. The removal rate of bisphenol S after treatment is shown in Table 2.

[0033] Application Comparative Example 2: Different from Application Example 1, only potassium permanganate, PC4A and bisphenol S of the same concentration were added to the simulated sewage. The removal rate of bisphenol S after treatment is shown in Table 2.

[0034] Application Comparative Example 3: Different from Application Example 1, only potassium permanganate, peroxymonosulfate and bisphenol S of the same concentration were added to the simulated sewage. The removal rate of bisphenol S after treatment is shown in Table 2.

[0035] Table 2 Organic matter removal rate (%)

[0036] From the data in Table 2, it can be seen that the phosphate calixarene prepared by the present invention has a good degradation effect on bisphenol S after being added to the dual oxidation component system of potassium permanganate and potassium permonosulfate. When potassium permanganate is used as a single oxidant, PC4A has no significant effect on its oxidation effect. When PC4A is not added to the dual component oxidation system of potassium permanganate and potassium permonosulfate, the oxidation effect is significantly weakened compared to the addition of PC4A. In summary, in order to achieve a more ideal bisphenol S removal effect, potassium permanganate, permonosulfate, and PC4A are indispensable.

[0037] Obviously, the above embodiments are merely examples for clear explanation and are not intended to limit the implementation methods. For those skilled in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all the implementation methods here. The obvious changes or modifications derived from these are still within the protection scope of the invention.

Claims

1. An application of phosphate calixarene in catalyzing potassium permanganate and peroxymonosulfate to deeply treat wastewater containing phenolic pollutants; the phenolic pollutants include one or more of phenol, methylphenol, nitrophenol, aminophenol, halogenated phenol, p-tert-butylphenol, nonylphenol, octylphenol, bisphenol A, bisphenol S, bisphenol F, bisphenol AF, hydroquinone and naphthol.

2. The use according to claim 1, characterized in that: The structural formula of the phosphate calixarene is , molecular formula is C 24 H 20 O 20 P.

3. The use according to claim 1, characterized in that: The preparation method of the phosphate calixarene comprises the following steps: Dissolve p-tert-butylphenol, diethyl chlorophosphate and tetrabutylammonium iodide in an organic solvent, add an alkaline solution under the protection of an inert atmosphere, stir, and heat under reflux to obtain the phosphate calixarene.

4. The use according to claim 3, characterized in that: The molar ratio of p-tert-butylphenol, diethyl chlorophosphate and tetrabutylammonium iodide is 1:(4-6):0.2; The organic solvent is selected from carbon tetrachloride and dichloromethane.

5. The use according to claim 3, characterized in that: The alkaline solution includes sodium hydroxide solution and ammonia water; the mass concentration of the alkaline substance is 50-55%.

6. The use according to claim 3, characterized in that: The heating temperature is 60-80°C and the heating time is 3-5h.

7. The use according to claim 1, characterized in that: The mass ratio of the phosphate calixarene, potassium permanganate and peroxymonosulfate is 1:(0.025-0.1):

4.

8. The use according to claim 1, characterized in that: The peroxymonosulfate is selected from one or more of potassium peroxymonosulfate, sodium peroxymonosulfate and ammonium peroxymonosulfate.

9. The use according to claim 1, characterized in that: The concentration of the phenolic pollutants is 0.01-100 mg / L.

10. The use according to claim 1, characterized in that: When treating wastewater containing phenolic pollutants, the pH of the solution is 5~9.

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