Organic phosphine wastewater treatment method and application

Abstract

The invention relates to the technical field of wastewater treatment, and particularly discloses an organic phosphine wastewater treatment method and application, during wastewater treatment, potassium hydrogen persulfate and sodium percarbonate are added into organic phosphorus wastewater for mixing reaction, so that organic phosphorus is degraded into orthophosphate; adjusting the pH value of the system to about 9, and adding ammonium chloride and magnesium chloride to react to generate struvite. According to the method, the organic phosphorus wastewater is treated by adopting a double-oxidation system, so that a synergistic effect is achieved, organic phosphorus can be efficiently degraded and removed, additional use of a catalyst is not needed, popularization and application are facilitated, treatment can be performed through a continuous flow reactor, and resource recycling of the organic phosphorus wastewater can be realized.

Description

Technical Field

[0001] The present invention relates to the technical field of resource utilization of organophosphorus wastewater, and specifically relates to a method for treating organophosphorus wastewater and its application. Background Art

[0002] Glyphosate (PMG) is widely used in 130 countries. Its main metabolite, aminomethylphosphonic acid (AMPA), may cause carcinogenesis in human red blood cells and chromosomal aberrations in fish. In 2015, glyphosate was classified as a "human carcinogen" by the International Agency for Research on Cancer (IARC). Compared with aromatic organic pollutants, PMG has stable chemical properties and is difficult to remove. Conventional treatment methods will cause it to generate AMPA with more stable chemical properties and stronger toxicity. Excessive phosphorus concentration in natural water bodies will cause various harms including water eutrophication.

[0003] Phosphate fertilizer is an important fertilizer in agricultural production. However, current phosphate fertilizer production mainly relies on limited phosphate rock resources and faces the dual pressures of resource depletion and environmental pollution. Struvite has the advantages of low release rate, low dissolution rate, high crop utilization rate, and ecological friendliness. It is considered a natural and environmentally friendly fertilizer raw material and has very broad application prospects.

[0004] Therefore, exploring an efficient and economical method for removing PMG from water bodies, converting organophosphorus into inorganic phosphorus, and further recovering it in the form of struvite as nitrogen and phosphorus fertilizers not only helps to solve the problem of wastewater treatment, but also realizes the effective utilization of resources and the development of circular economy. Summary of the Invention

[0005] The present invention provides a method for treating organophosphorus wastewater and its application. A dual oxidation system is used to treat organophosphorus wastewater, which has a synergistic effect and can efficiently degrade and remove organic phosphorus. It does not require the additional use of a catalyst, is convenient for popularization and application, and can be treated through a continuous flow reactor.

[0006] The technical solution of the present invention is to provide a method for treating organophosphorus wastewater, which includes the following steps: S1. Add potassium monopersulfate and sodium percarbonate to the organophosphorus wastewater for mixing reaction to degrade the organophosphorus into orthophosphate; S2. Adjust the pH of the material liquid obtained in S1 to 8-11, and add ammonium chloride and magnesium chloride to react to generate struvite.

[0007] Optionally, the mass ratio of potassium monopersulfate to sodium percarbonate is 1-3:1.

[0008] Optionally, the mass ratio of potassium monopersulfate to sodium percarbonate is 1:1.

[0009] Optionally, the concentrations of potassium monopersulfate and sodium percarbonate in the organic phosphorus wastewater in S1 are 0.1 - 0.5 g / L respectively.

[0010] Optionally, the reaction time in S1 is 1 - 60 min.

[0011] Optionally, HClO or NaOH is used to adjust the pH in S2.

[0012] Optionally, the molar concentration ratio of ammonium chloride (N), magnesium chloride (Mg) to phosphate (P) in the wastewater in S2 is N:Mg:P = 10:1:1.

[0013] Optionally, during the addition of ammonium chloride and magnesium chloride in S2, the system is bubbled.

[0014] The present invention also relates to the application of the above method in the treatment of organic phosphorus wastewater, wherein the organic phosphorus pollutants include but are not limited to glyphosate (PMG), 1-hydroxyethylidene-1,1-diphosphonic acid (HEDP) and / or aminomethylphosphonic acid (AMPA).

[0015] Optionally, the organic phosphorus wastewater is diluted to a phosphorus concentration of less than 500 μΜ before treatment.

[0016] The present invention has the following beneficial effects: The present invention utilizes the synergistic effect between SPC and PMS to degrade organic phosphorus pollutants into orthophosphate in the organic phosphorus removal system, and then in the inorganic phosphorus recovery system, by adjusting the pH of the system and adding ammonium chloride and magnesium chloride solutions, the orthophosphate is converted into struvite to realize the recycling of phosphorus resources.

[0017] Based on the concept of "resource utilization", on the basis of advanced oxidation technology (AOPs), the present invention selects a dual-oxidant system, and under the synergistic effect of the two, realizes the efficient removal of organic phosphorus in glyphosate wastewater, which is comparable to the catalytic oxidation ability of most heterogeneous systems, and overcomes the shortcoming that the catalyst production of most heterogeneous systems is low and cannot be scaled up. And through a continuous flow reactor, the recovery of inorganic phosphorus in the treated wastewater is realized (recovery rate > 90%), which has excellent application prospects in the field of wastewater treatment. Description of the Drawings

[0018] Figure 1 It is a comparative graph of the degradation kinetic curves of Comparative Examples 1, 2 and Example 1.

[0019] Figure 2 It is a graph of the changes in TOC and COD of the wastewater in Example 1 within 0 - 90 min.

[0020] Figure 3 It is a schematic diagram of the device of the organic phosphorus wastewater removal system and the inorganic phosphorus recovery system.

[0021] Figure 4 It is the graph of the organic phosphorus degradation rate curve and the inorganic phosphorus recovery rate curve of the continuous flow reactor in Example 2.

[0022] Figure 5 It is the real-time monitoring graph of the pH of the inorganic phosphorus recovery system.

[0023] Figure 6 It is the X-ray diffraction (XRD) spectrum of the obtained struvite.

[0024] Figure 7 It is the scanning electron microscope (SEM) image of the obtained struvite.

[0025] Figure 8 It is the comparison graph of the degradation kinetic curves in Examples 3-5.

[0026] Figure 9 It is the comparison graph of the degradation kinetic curves in Comparative Example 3-1.

[0027] Figure 10 It is the comparison graph of the degradation kinetic curves in Comparative Example 3-2.

[0028] Figure 11 It is the comparison graph of the degradation kinetic curves in Example 6. Specific embodiments

[0029] In the following examples, the experimental methods are all conventional methods unless otherwise specified. The materials used in the following examples are all commercially available products unless otherwise specified.

[0030] A method for treating organic phosphine wastewater, comprising the following steps: S1. Potassium monopersulfate and sodium percarbonate are added to the organic phosphorus wastewater for mixing reaction to degrade the organic phosphorus into orthophosphate; the mass ratio of potassium monopersulfate to sodium percarbonate is preferably 1-3:1, more preferably 1:1. The concentrations of potassium monopersulfate and sodium percarbonate in the organic phosphorus wastewater are 0.1-0.5 g / L respectively.

[0031] S2. The pH of the feed liquid obtained in S1 is adjusted to 9, and ammonium chloride and magnesium chloride are added to react to form struvite. The molar concentration ratio of ammonium chloride (N), magnesium chloride (Mg) to phosphate (P) in the wastewater is N:Mg:P = 10:1:1; during the reaction of adding ammonium chloride and magnesium chloride, the system is bubbled.

[0032] The following will describe the implementation schemes of the present invention in detail with reference to the examples. However, those skilled in the art will understand that the following examples are only used to illustrate the present invention and should not be construed as limiting the scope of the present invention.

[0033] Comparative Example 1 Take two groups of glass test tubes and add glyphosate wastewater (40 mL, diluted 2000 times from the stock solution) respectively. After preheating in a 30 °C water bath for 5 min, under magnetic stirring, add potassium monopersulfate (PMS) to it. The addition amount of PMS is 10 mg (0.25 g / L). Take out 1.5 mL of the reaction solution at 0 min, 1 min, 3 min, 5 min, 15 min, 30 min, 45 min, and 60 min respectively and place it in a 2 mL centrifuge tube, and immediately add 20 μL of sodium thiosulfate solution (Na 2 S 2 O 3 , 0.5 M) to terminate the reaction. Use the molybdenum blue spectrophotometric method to detect the concentration of PO 4 3- in the reaction solution, and draw the kinetic curve, as shown in Figure 1 .

[0034] Comparative Example 2 Take two groups of glass test tubes and add glyphosate wastewater (40 mL, diluted 2000 times from the stock solution) respectively. After preheating in a 30 °C water bath for 5 min, under magnetic stirring, add sodium percarbonate (SPC) to it. The addition amount of SPC is 10 mg (0.25 g / L). Take out 1.5 mL of the reaction solution at 0 min, 1 min, 3 min, 5 min, 15 min, 30 min, 45 min, and 60 min respectively and place it in a 2 mL centrifuge tube, and immediately add 20 μL of sodium thiosulfate solution (Na 2 S 2 O 3 , 0.5 M) to terminate the reaction. Use the molybdenum blue spectrophotometric method to detect the concentration of PO 4 3- in the reaction solution, and draw the kinetic curve, as shown in Figure 1 .

[0035] Example 1 Take two groups of glass test tubes and add glyphosate wastewater (40 mL, diluted 2000 times from the stock solution) respectively. After preheating in a 30 °C water bath for 5 min, under magnetic stirring, add PMS and SPC to them respectively. The addition amounts of PMS and SPC are both 10 mg (0.25 g / L). Take out 1.5 mL of the reaction solution at 0 min, 1 min, 3 min, 5 min, 15 min, 30 min, 45 min, and 60 min respectively and place it in a 2 mL centrifuge tube, and immediately add 20 μL of sodium thiosulfate solution (Na 2 S 2 O 3, (0.5 M) to terminate the reaction. The concentration of PO in the reaction solution was detected using the molybdenum blue spectrophotometry method, and the kinetic curve was plotted. See 4 3- specifically in Figure 1 . The changes in TOC and COD of the wastewater within 0 - 90 min were tested. See Figure 2 specifically in

[0036] Figure 1 . It can be seen from the comparison graph of the glyphosate wastewater degradation kinetic curves obtained from Comparative Examples 1, 2 and Example 1 that only when SPC and PMS coexist can the organic phosphorus in the wastewater be efficiently removed. Attributed to: 1) SPC (Na 2 CO 3 ·1.5H 2 O 2 ) can be regarded as solid hydrogen peroxide (H 2 O 2 ). When SPC dissolves, sodium carbonate (Na 2 CO 3 ) is released. The hydrolysis of Na 2 CO 3 provides an alkaline environment (OH - ), and OH - activates PMS to generate a large amount of reactive oxygen species (ROS); 2) SPC releases H 2 O 2 when it dissolves, and H 2 O 2 can participate in the formation of ROS. The large amount of ROS generated by their synergistic decomposition removes the organic phosphorus in the glyphosate wastewater.

[0037] Example 2 A continuous flow experiment was carried out in a continuous flow reactor. The structure of the continuous flow reactor is shown in Figure 3 . The PMS solution (2.5 g / L, 1.5 L), SPC solution (2.5 g / L, 1.5 L), and glyphosate wastewater (diluted 40 times) were respectively pumped into the organic phosphorus removal system for reaction using peristaltic pumps. Samples were taken every half hour at 60 min, 90 min, 120 min, and 150 min. The total reaction time was 10 hours. When sampling, 1.5 mL of the reaction solution was taken and placed in a 2 mL centrifuge tube, and immediately 20 μL of sodium thiosulfate solution (Na 2 S 2 O 3, (0.5 M) to terminate the reaction. The concentration of PO in the reaction solution was detected using the molybdenum blue spectrophotometry method, and the kinetic curve was plotted. See 4 3- specifically in Figure 4 . The wastewater after the reaction was collected and placed in an inorganic phosphorus recovery system, and the solution was bubbled using an air pump. Ammonium chloride, magnesium chloride, and sodium hydroxide (NaOH, 1.0 M) were pumped into the recovery system through a peristaltic pump. The molar concentration ratio of Mg (magnesium chloride): N (ammonium chloride): P (phosphate in the solution) was 10:1:1, and the pH was monitored in real-time to control the pH at around 9. See Figure 5 .

[0038] It can be seen from Figure 4 that the PMS / SPC system can convert about 90% of the organic phosphorus in the glyphosate wastewater into inorganic phosphorus, and the recovery rate of inorganic phosphorus reaches nearly 90%, realizing a high degree of recovery and utilization of phosphorus resources. Figure 6 and Figure 7 are the X-ray diffraction (XRD) pattern and scanning electron microscope (SEM) image of struvite formed by the conversion of inorganic phosphorus, respectively. The synthesized struvite has an extremely pure phase, proving the successful synthesis of struvite.

[0039] Example 3 Two groups of glass test tubes were taken and PMG standard solution (40 mL, 200 μM) was added respectively. After preheating in a 30 °C water bath for 5 min, PMS and SPC were added sequentially under magnetic stirring. The addition amounts of PMS and SPC were both 10 mg (0.25 g / L). At 0 min, 1 min, 3 min, 5 min, 15 min, 30 min, 45 min, and 60 min, 1.5 mL of the reaction solution was taken out and placed in a 2 mL centrifuge tube, and immediately 20 μL of sodium thiosulfate solution (Na 2 S 2 O 3 , 0.5 M) was added to terminate the reaction. The concentration of PO 4 3- in the reaction solution was detected using the molybdenum blue spectrophotometry method, and the kinetic curve was plotted. See Figure 8 .

[0040] Example 4 Take two groups of glass test tubes and add HEDP standard solution (40 mL, 100 μM) respectively. After preheating in a 30 °C water bath for 5 min, under the condition of magnetic stirring, add PMS and SPC to them in sequence. The addition amounts of PMS and SPC are both 10 mg (0.25 g / L). Take out 1.5 mL of the reaction solution at 0 min, 1 min, 3 min, 5 min, 15 min, 30 min, 45 min, and 60 min respectively and place it in a 2 mL centrifuge tube, and immediately add 20 μL of sodium thiosulfate solution (Na 2 S 2 O 3 , 0.5 M) to terminate the reaction. Use the molybdenum blue spectrophotometry method to detect the concentration of PO 4 3- in the reaction solution, and draw the kinetic curve, as shown in Figure 8 .

[0041] Example 5 Take two groups of glass test tubes and add AMPA standard solution (40 mL, 200 μM) respectively. After preheating in a 30 °C water bath for 5 min, under the condition of magnetic stirring, add PMS and SPC to them in sequence. The addition amounts of PMS and SPC are both 10 mg (0.25 g / L). Take out 1.5 mL of the reaction solution at 0 min, 1 min, 3 min, 5 min, 15 min, 30 min, 45 min, and 60 min respectively and place it in a 2 mL centrifuge tube, and immediately add 20 μL of sodium thiosulfate solution (Na 2 S 2 O 3 , 0.5 M) to terminate the reaction. Use the molybdenum blue spectrophotometry method to detect the concentration of PO 4 3- in the reaction solution, and draw the kinetic curve, as shown in Figure 8 .

[0042] Figure 8 Figure for comparing the degradation kinetic curves of Examples 3 to 5. It can be seen that a large amount of ROS generated by the synergistic decomposition of PMS and SPC has good application in the treatment of organophosphorus wastewater. Organophosphorus pollutants include but are not limited to glyphosate (PMG), hydroxyethylidene diphosphonic acid (HEDP), and / or aminomethylphosphonic acid (AMPA).

[0043] Comparative Example 3 3-1. Take two groups of glass test tubes and add glyphosate wastewater (40 mL, the stock solution diluted 2000 times). After preheating in a 30 °C water bath for 5 min, under magnetic stirring, add sodium percarbonate (SPC) to it. The addition amount of SPC is 10 mg (0.25 g / L). The addition amount of other oxidants is 10 mg (0.25 g / L). The other oxidants are PDSCaSO 3 Na 2 SO 3 H 2 O 2 PMS; Take 1.5 mL of the reaction solution at 0 min, 1 min, 3 min, 5 min, 15 min, 30 min, 45 min, and 60 min respectively and place it in a 2 mL centrifuge tube, and immediately add 20 μL of sodium thiosulfate solution (Na 2 S 2 O 3 , 0.5 M) to terminate the reaction. Use the molybdenum blue spectrophotometry to detect the concentration of PO 4 3- in the reaction solution and draw the kinetic curve, as shown in Figure 9 .

[0044] 3-2. Take two groups of glass test tubes and add glyphosate wastewater (40 mL, the stock solution diluted 2000 times). After preheating in a 30 °C water bath for 5 min, under magnetic stirring, add potassium peroxymonosulfate (PMS) to it. The addition amount of PMS is 10 mg (0.25 g / L). The addition amount of other oxidants is 10 mg (0.25 g / L). The other oxidants are PDSCaSO 3 Na 2 SO 3 H 2 O 2 SPC; Take 1.5 mL of the reaction solution at 0 min, 1 min, 3 min, 5 min, 15 min, 30 min, 45 min, and 60 min respectively and place it in a 2 mL centrifuge tube, and immediately add 20 μL of sodium thiosulfate solution (Na 2 S 2 O 3 , 0.5 M) to terminate the reaction. Use the molybdenum blue spectrophotometry to detect the concentration of PO 4 3- in the reaction solution and draw the kinetic curve, as shown in Figure 10 .

[0045] Through Figure 9 and Figure 10It can be seen that only when SPC and PMS coexist can the organic phosphorus in the wastewater be efficiently removed. Attributed to: 1) SPC (Na 2 CO 3 ·1.5H 2 O 2 ) can be regarded as solid hydrogen peroxide (H 2 O 2 ). When SPC dissolves, sodium carbonate (Na 2 CO 3 ) is released. The hydrolysis of Na 2 CO 3 provides an alkaline environment (OH - ), and OH - activates PMS to generate a large amount of reactive oxygen species (ROS); 2) SPC releases H 2 O 2 when it dissolves, and H 2 O 2 can participate in the formation of ROS. The large amount of ROS generated by the synergistic decomposition of the two removes the organic phosphorus in the glyphosate wastewater.

[0046] Example 6 Take two groups of glass test tubes and add glyphosate wastewater (40 mL, diluted 2000 times from the original solution). After preheating in a 30 °C water bath for 5 min, under magnetic stirring, add sodium percarbonate (SPC) and PMS to it, where [SPC] + [PMS] = 0.5 g / L, and SPC:PMS = 0:1, 1:1, 1:2, 1:3, 3:1, 2:1, 1:0. Take out 1.5 mL of the reaction solution at 0 min, 1 min, 3 min, 5 min, 15 min, 30 min, 45 min, and 60 min and place it in a 2 mL centrifuge tube, and immediately add 20 μL of sodium thiosulfate solution (Na 2 S 2 O 3 , 0.5 M) to terminate the reaction. Use the molybdenum blue spectrophotometry method to detect the concentration of PO 4 3- in the reaction solution and draw the kinetic curve. See Figure 11 for details. It can be seen that when the mass ratio of potassium peroxymonosulfate to sodium percarbonate is 1:1, the effect is the best.

[0047] The above embodiments describe the preferred embodiments of the present invention, but the present invention is not limited thereto. Within the scope of the technical concept of the present invention, various simple modifications can be made to the technical solutions of the present invention, including any other combination of each technical feature. These simple modifications and combinations should also be regarded as the content disclosed by the present invention and fall within the protection scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the appended claims.

Claims

1. A method for treating organic phosphine wastewater, characterized in that: The following steps are involved: S1. adding potassium persulfate and sodium percarbonate to the organic phosphorus wastewater for mixed reaction, so that the organic phosphorus is degraded into orthophosphate; S2. The pH of the liquid obtained in S1 is adjusted to 8-11, and ammonium chloride and magnesium chloride are added to react to form struvite.

2. The method according to claim 1, characterized in that: The mass ratio of potassium persulfate to sodium percarbonate is 1-3:

1.

3. The method according to claim 2, characterized in that: The mass ratio of potassium persulfate to sodium percarbonate is 1:

1.

4. The method according to claim 1, characterized in that: The concentrations of potassium persulfate and sodium percarbonate in organophosphorus wastewater in S1 are 0.1~0.5g / L, respectively.

5. The method according to any one of claims 1 to 4, characterized in that: The reaction time in S1 is 1~60min.

6. The method according to claim 1, characterized in that: HClO or NaOH is used to adjust the pH in S2.

7. The method according to claim 1, characterized in that: The molar concentration ratio of ammonium chloride (N), magnesium chloride (Mg) in S2 and phosphate (P) in the wastewater is 10:1:

1.

8. The method according to claim 1, characterized in that: During the reaction of adding ammonium chloride and magnesium chloride into S2, the system is subjected to bubbling treatment.

9. Application of the method according to any one of claims 1 to 8 in the treatment of organic phosphine wastewater, characterized in that: Organic phosphine contaminants include, but are not limited to, glyphosate (PMG), hydroxyethylidene diphosphonic acid (HEDP), and / or aminomethylphosphonic acid (AMPA).

10. The use according to claim 9, characterized in that: The organic phosphine wastewater is diluted to a phosphorus concentration of less than 500 μΜ before treatment.

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