Application of a phosphoric acid ester calixarene in the advanced treatment of phenolic pollutant-containing wastewater by catalytic potassium permanganate and persulfate

Abstract

The present invention belongs to the field of advanced wastewater treatment and relates to the application of phosphoric acid calixarene in catalytically treating wastewater containing phenolic pollutants by potassium permanganate and peroxymonosulfate. By adding phosphoric acid calixarene, potassium permanganate, and peroxymonosulfate into the wastewater to be treated, the effective treatment of new pollutants in the wastewater can be achieved. The building unit of the phosphoric acid calixarene is PC4A (PC4A refers to phosphoric acid calixarene, where 4 is the number of units, P represents phosphoric acid ester, and C4A is 4 polymerized calixarenes), and its chemical formula is C 24 H 20 O 20 P, and its structural formula is:. In the present invention, Mn 6+ / Mn 5+ -PC4A can stably exist in the metastable hexavalent manganese / pentavalent manganese state, which is beneficial to the cyclic generation of heptavalent manganese for further degradation of phenolic pollutants. It has good elimination ability for phenolic pollutants, especially achieving the rapid removal of phenolic pollutants while improving the utilization rate of potassium permanganate.

Description

Technical Field

[0001] The present invention relates to the technical field of advanced wastewater treatment, and particularly to an application of phosphoric acid ester calixarene in catalytically treating wastewater containing phenolic pollutants by potassium permanganate and peroxymonosulfate for advanced treatment. Background Art

[0002] With the development of supramolecular chemistry, calixarenes, as the third type of supramolecular host, have attracted the research and attention of many scholars. For the design of calixarenes, the cavity size can be controlled by controlling the number of bridging methylene phenol units and changing the bridging groups of aromatic rings, and their structural properties can be changed, thereby realizing chemical modification and deriving a variety of highly selective compounds. Due to the rich sites and cavities rich in delocalized π electrons of calixarenes, they can coordinate with most metal ions to form complexes. Thus, technicians can prepare calixarene derivatives meeting technical requirements through appropriate chemical modification and combine them with sewage treatment means to improve the sewage treatment efficiency.

[0003] As a green and selectively oxidizing chemical substance, permanganate (Mn(VII)) has attracted considerable attention because it preferentially oxidizes electron-rich parts without forming halogenated by-products. In terms of removing emerging pollutants in water, the single potassium permanganate oxidation technology has strong selectivity and has a certain removal ability for emerging pollutants containing unsaturated bonds and electron-rich groups. However, the dosage of potassium permanganate is not easy to master. Once the dosage is excessive and residues are produced, the chromaticity of the treated water will increase significantly, and the reduction product manganese dioxide of excessive potassium permanganate is likely to cause pipeline blockage. Therefore, it is crucial to propose a method to enhance the oxidation efficiency of potassium permanganate and reduce its dosage. The present invention proposes a method for advanced treatment of sewage using peroxymonosulfate, potassium permanganate, and phosphoric acid ester calixarene. Summary of the Invention

[0004] To solve the above technical problems, the present invention provides a method for catalytically treating phenolic wastewater by potassium permanganate and peroxymonosulfate for advanced treatment.

[0005] The purpose of the present invention is to provide an application of phosphoric acid ester calixarene in catalytically treating wastewater containing phenolic pollutants by potassium permanganate and peroxymonosulfate for advanced treatment. The structural formula of the phosphoric acid ester calixarene is , and the molecular formula is C 24 H 20 O 20 P; the phenolic pollutants include one or more of phenol, cresol, nitrophenol, aminophenol, halophenol, p-tert-butylphenol, nonylphenol, octylphenol, bisphenol A, bisphenol S, bisphenol F, bisphenol AF, benzenediol, and naphthol.

[0006] In some embodiments of the present invention, the method for preparing the phosphoric acid ester calixarene comprises the following steps:

[0007] Dissolve p-tert-butylphenol, diethyl chlorophosphate, and tetrabutylammonium iodide in an organic solvent. Under the protection of an inert atmosphere, add an alkaline solution and stir, then heat under reflux to obtain the phosphoric acid ester calixarene.

[0008] 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.

[0009] In some embodiments of the present invention, the organic solvent is selected from carbon tetrachloride and dichloromethane.

[0010] 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%.

[0011] In some embodiments of the present invention, the heating temperature is 60 - 80 °C, and the heating time is 3 - 5 h.

[0012] In some embodiments of the present invention, the mass ratio of the phosphate calixarene, potassium permanganate, and persulfate is 1:(0.025 - 0.1):4.

[0013] In some embodiments of the present invention, the persulfate is selected from potassium monopersulfate, sodium monopersulfate, and ammonium monopersulfate.

[0014] In some embodiments of the present invention, the concentration of phenolic pollutants in the wastewater containing phenolic pollutants is 0.01 - 100 mg / L.

[0015] In some embodiments of the present invention, when treating the phenolic wastewater, the pH of the solution is 5 - 9. Exemplarily, it can be 5, 6, 7, 8, 9, etc., or it can be 5 - 8, 5 - 7, etc., or any interval value between any two numerical values.

[0016] The reaction principle of the present invention: PC4A reacts with hexavalent manganese / pentavalent manganese generated by the oxidation of phenolic compounds by potassium permanganate to form a stable Mn 6+ / Mn 5+ -PC4A complex. And the persulfate can oxidize the complexed and stabilized hexavalent manganese / pentavalent manganese to regenerate heptavalent manganese (potassium permanganate), further degrading the phenolic organic pollutants. This novel oxidation method greatly reduces the dosage of potassium permanganate, improves the utilization rate of potassium permanganate, and can achieve the efficient removal of phenolic pollutants.

[0017] The wastewater containing phenolic pollutants described in the present invention is a common type of wastewater in the environment, and phenol is one of the most important pollutants among them. The reason why the present invention is applicable to phenolic pollutants is that potassium permanganate is relatively effective for phenolic compounds. Secondly, the oxidation of phenolic compounds by potassium permanganate can generate hexavalent manganese / pentavalent manganese, which can form a stable complex with PC4A, and further can undergo an electron transfer reaction with peroxymonosulfate (PMS) to regenerate heptavalent manganese. Therefore, the present invention provides a new and efficient method to accelerate the purification of phenol-containing wastewater.

[0018] The above technical solution of the present invention has the following advantages compared with the prior art:

[0019] The amount of potassium permanganate added in the present invention is small and will not cause problems with the color of the water body.

[0020] The present invention can stabilize hexavalent manganese / pentavalent manganese under near-neutral conditions, especially reducing the consumption of potassium permanganate. Under the condition of less potassium permanganate dosage, it can also achieve the rapid removal of phenolic pollutants. Specific embodiments

[0021] The following further illustrates the present invention with specific embodiments, so that those skilled in the art can better understand the present invention and be able to implement it, but the specific embodiments given are not intended to limit the present invention.

[0022] Example 1:

[0023] This example provides a preparation method of phosphoric acid ester calixarene, including the following steps:

[0024] (1) In a 250 mL four-necked flask, add 1 g of p-tert-butylphenol, 10 mL of diethyl chlorophosphate, and 115 g of tetrabutylammonium iodide dissolved in 100 mL of carbon tetrachloride. Under nitrogen protection, gradually add 5 mL of 50 wt% NaOH and stir, gradually heat to 60 °C, and reflux for 4 h to obtain a reaction solution.

[0025] (2) Filter the reaction solution obtained in step (1) to remove solids. Wash the filtrate 3 times with saturated brine and 3 times with ultrapure water to obtain an organic phase, and dry it with anhydrous Na2SO4. Evaporate the solvent, dissolve the product with methanol, add ethyl acetate to precipitate, and filter to obtain a white powder, that is, phosphoric acid ester calixarene (PC4A).

[0026] The phosphoric acid ester calixarene in the present invention can form a highly active complex with hexavalent manganese / pentavalent manganese reduced by potassium permanganate, capture the electrons of new pollutants in the sewage, thereby accelerating the removal of organic matter. It is used for the treatment of deep sewage, realizing the efficient removal of new pollutants in the sewage, and at the same time facilitating the improvement of the electron utilization rate in the sewage.

[0027] Application Example 1:

[0028] The PC4A, potassium permanganate, and potassium monopersulfate prepared in Example 1 were added to the simulated sewage at a mass ratio of 1:(0.025 - 0.1):4. The sewage contained 6.26 mg / L of bisphenol S. The concentration of PC4A added was 13 mg / L, the concentration of potassium permanganate was 0.3 mg / L, and the concentration of potassium monopersulfate was 54 mg / L. Potassium permanganate and potassium monopersulfate at the same concentration were used as the control group, and the pH was controlled at 9.

[0029] The concentration of organic matter was measured using a high-performance liquid chromatograph (HPLC). The change in the concentration of bisphenol S in the sewage was detected, and the removal rate of bisphenol S is shown in Table 1.

[0030] Application Example 2:

[0031] Differing from Application Example 1, the pH of the mixed solution was controlled at 8. The removal rate of bisphenol S after treatment is shown in Table 1.

[0032] Application Example 3:

[0033] Differing from Application Example 1, the pH of the mixed solution was controlled at 7. The removal rate of bisphenol S after treatment is shown in Table 1.

[0034] Application Example 4:

[0035] Differing from Application Example 1, the pH of the mixed solution was controlled at 6. The removal rate of bisphenol S after treatment is shown in Table 1.

[0036] Application Example 5:

[0037] Differing from Application Example 1, the pH of the mixed solution was controlled at 5. The removal rate of bisphenol S after treatment is shown in Table 1.

[0038] Table 1 Removal rate of bisphenol S in the application examples (%)

[0039]

[0040] As can be seen from Table 1, the two-component oxidation system of potassium permanganate and potassium monopersulfate functions worse at lower pH values. This is because the Mn(VI) reduced from Mn(VII) is prone to disproportionation under acidic conditions, affecting the oxidation ability of the system. However, after adding phosphacalixarene, the oxidation effect increased significantly, indicating that phosphacalixarene effectively stabilized hexavalent manganese.

[0041] Application Comparative Example 1: Differing from Application Example 1, only potassium permanganate and bisphenol S at the same concentration were added to the simulated sewage. The removal rate of bisphenol S after treatment is shown in Table 2.

[0042] Application Comparative Example 2: Differing from Application Example 1, only potassium permanganate, PC4A, and bisphenol S at the same concentration were added to the simulated sewage. The removal rate of bisphenol S after treatment is shown in Table 2.

[0043] Application Comparative Example 3: Different from Application Example 1, only potassium permanganate, peroxymonosulfate, and bisphenol S with the same concentration were added to the simulated sewage. The removal rate of bisphenol S after treatment is shown in Table 2.

[0044] Table 2 Removal rate of organic matter (%)

[0045]

[0046] From the data in Table 2, it can be seen that after the phosphoric acid ester calixarene prepared by the present invention is added to the dual-oxidant component system of potassium permanganate and potassium peroxymonosulfate, it has a good degradation effect on bisphenol S. 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 peroxymonosulfate, the oxidation effect is significantly weakened compared with that when PC4A is added. In summary, in order to achieve a more ideal removal effect of bisphenol S, potassium permanganate, peroxymonosulfate, and PC4A are all indispensable.

[0047] Obviously, the above embodiments are only examples for clear illustration and are not limitations on the implementation manners. For those of ordinary skill 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 manners here. And the obvious changes or modifications derived therefrom are still within the protection scope of the present invention.

Claims

1. An application of phosphate calixarene in catalyzing potassium permanganate and peroxymonosulfate to deeply treat wastewater containing phenolic pollutants; characterized in that: 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; the structural formula of the phosphate calixarene is , molecular formula is C 24 H 20 O 20 P; The preparation method of the phosphate calixarene comprises the following steps: Dissolving p-tert-butylphenol, diethyl chlorophosphate and tetrabutylammonium iodide in an organic solvent, adding an alkaline solution under the protection of an inert atmosphere, stirring, and heating under reflux to obtain the phosphate calixarene; The mass ratio of the phosphate calixarene, potassium permanganate and peroxymonosulfate is 1:(0.025-0.1):

4.

2. The use according to claim 1, 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.

3. The use according to claim 1, characterized in that: The alkaline solution includes sodium hydroxide solution and ammonia water; the mass concentration of the alkaline solution is 50%-55%.

4. The use according to claim 1, characterized in that: The heating temperature is 60-80°C and the heating time is 3-5h.

5. 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.

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

7. 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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