A composite bioglass pumice material with simultaneous nitrogen and phosphorus removal function and a preparation method and application thereof

Abstract

The application discloses a composite biological glass pumice material with a synchronous denitrification and dephosphorization function and a preparation method and application thereof, relates to the technical field of water treatment materials, and is based on an existing glass pumice material, Fe is loaded on the glass pumice through a hydrothermal reaction, active iron oxide is formed in situ through high-temperature calcination, the glass pumice loaded with the active iron oxide is subjected to a sulfide reaction to form glass pumice loaded with iron sulfide, denitrifying bacteria are cultured to the glass pumice to form the composite biological glass pumice material, and the material is applied to synchronous denitrification and dephosphorization treatment of sewage. The application combines the characteristics of good hydrophilicity and strong adsorption and filtration performance of the glass pumice material with a multifunctional micro-ecological system driven by iron sulfide, is applied to water pollution treatment, and effectively improves the multi-pollutant removal capacity of the glass pumice material.

Description

Technical Field

[0001] This invention relates to the field of water treatment materials technology, and in particular to a composite bioglass pumice material with simultaneous nitrogen and phosphorus removal functions, its preparation method, and its application. Background Technology

[0002] Glass lightweight stone materials made from the recycling of waste glass have excellent water absorption, permeability, adsorption, and filtration properties, and have shown great application potential in the fields of high-quality sponge city construction, stormwater and sewage runoff pollution control, agricultural non-point source pollution control, and water body ecological restoration.

[0003] However, existing glass pumice materials have limited and singular capabilities in removing multiple pollutants, restricting their effectiveness in environmental pollution control. Therefore, modifying and enhancing glass pumice materials to improve their simultaneous removal of multiple pollutants will significantly promote their wider application in environmental protection and has important practical value. Summary of the Invention

[0004] The purpose of this invention is to overcome the shortcomings of the above-mentioned technologies and provide a composite bio-glass pumice material with simultaneous nitrogen and phosphorus removal functions, its preparation method and application. By combining the good hydrophilicity and strong adsorption and filtration performance of glass pumice material with a multifunctional micro-ecological system driven by sulfur and iron, it is applied to water pollution control, which effectively improves the removal capacity of glass pumice material for multiple pollutants.

[0005] A method for preparing a composite bio-glass pumice material with simultaneous nitrogen and phosphorus removal functions includes the following specific steps: S1. Fe is loaded into glass pumice through a hydrothermal reaction to obtain Fe-loaded glass pumice. S2. The Fe-loaded glass pumice is calcined at high temperature to convert Fe into active iron oxide in situ, thus obtaining glass pumice loaded with active iron oxide. S3. The glass pumice loaded with active iron oxide is reacted with sulfide to convert the sulfide into ferric sulfide in situ, thus obtaining glass pumice loaded with ferric sulfide. S4. By attaching autotrophic denitrifying bacteria to glass pumice loaded with sulfide iron oxides, the desired composite bio-glass pumice material is obtained.

[0006] A further improvement of the present invention is that the specific operation steps of step S1 include: taking Fe 3+ Fe-loaded solution with a concentration of 0.01 mol / L and a pH of 2.0-3.0 was mixed with glass pumice material at a volume ratio of 2:1 and placed in a high-pressure reactor. The mixture was reacted at a temperature of 200-400℃ for 1-3 h to obtain Fe-loaded glass pumice.

[0007] A further improvement of the present invention is that the specific operation steps of step S2 include: placing Fe-loaded glass pumice in a muffle furnace and calcining it initially at a temperature of 200-300℃ for 0.5-1.5 h; then raising the temperature to 400-550℃ for a second stage of calcination for 2-3 h to obtain glass pumice loaded with active iron oxide.

[0008] A further improvement of the present invention is that the specific operation steps of step S3 include: placing glass pumice loaded with active iron oxide in a reaction column, passing a reaction gas containing 5%-100% hydrogen sulfide under the condition that the pH of the aqueous solution is 7.0-9.0, and reacting for 2-10 h at a reaction temperature of 10-25℃ to obtain glass pumice loaded with ferric sulfide.

[0009] A further improvement of the present invention is that the specific operation steps of step S4 include: passing the pre-acclimated denitrifying bacteria solution into the reaction column in step S3, continuously circulating and inoculating for 1-3 days, then introducing the nutrient solution into the reaction column, and culturing for 3-10 days under HRT=2-8h and temperature of 25℃ to obtain the desired composite bioglass pumice material.

[0010] A further improvement of the present invention is that the denitrifying bacteria in step S4 are screened from the anoxic denitrification tank of a sewage treatment plant.

[0011] A further improvement of the present invention is that the nutrient solution in step S4 is composed of components with the following concentrations: NaNO3=30mg / L, NaHCO3=20mg / L, K2HPO4=1mg / L, beef extract=0.1mg / L, peptone=0.1mg / L.

[0012] A further improvement of the present invention is that, in step S1, the monomer dry density of the glass pumice is 0.3~0.5 g / cm³. 3 Monomer water holding capacity: 30~40%, particle size: 10-20mm, particle size conformity: ≥80%.

[0013] This invention provides a composite bioglass pumice material with simultaneous nitrogen and phosphorus removal functions, which is prepared according to the above method.

[0014] This invention also provides an application of a composite bio-glass pumice material with simultaneous nitrogen and phosphorus removal functions in wastewater nitrogen and phosphorus removal treatment, including its application in fixed-bed, fluidized-bed bioreactors, constructed wetlands, and bioretention ponds in sponge cities and other polluted water treatment systems. The composite bio-glass pumice material in the above application scenarios has an apparent volume ratio of 10%-90%, an HRT of 0.5-3 h, a pH of 6.0-8.0, an operating temperature of 15-35℃, and a DO ≤ 0.5 mg / L.

[0015] The beneficial effects of this invention are as follows: 1. In the composite bioglass pumice material provided by the present invention, the loaded iron sulfide can act as an electron donor for autotrophic denitrifying bacteria, driving autotrophic denitrification. At the same time, the active Fe ions released in this process can react with phosphate to form precipitates, thereby simultaneously removing phosphorus pollution. Thus, the composite bioglass pumice material can simultaneously remove nitrogen and phosphorus pollution from polluted water, and has great application potential in the fields of water pollution control and environmental water body remediation.

[0016] 2. The composite bio-glass pumice material provided by this invention has a simple preparation process, the materials are inexpensive and readily available, and the resulting material is stable and efficient. This composite bio-glass pumice material combines the good hydrophilicity and strong adsorption and filtration performance of glass pumice material with a multifunctional micro-ecological system driven by sulfur and iron. The raw materials required for the loading process, such as iron salts and sulfides, are inexpensive and readily available, and the loading conditions are simple and easy to operate. Relying on the rich internal pore structure and hydrophilicity of the glass pumice matrix, biofilm formation is rapid and efficient, which can greatly shorten the system start-up cycle. This invention significantly improves the removal capacity of glass pumice material for multiple pollutants, giving it richer application potential.

[0017] 3. The composite bio-glass pumice material provided by this invention has an autotrophic denitrification process and a chemical phosphorus removal process, neither of which requires the addition of organic carbon sources. Compared with traditional denitrification and biological phosphorus removal processes, it has advantages such as low carbon emissions and low operating costs. Compared with conventional biological carrier materials, this invention has a richer pollutant treatment capacity and can adapt to more diverse water purification scenarios. At the same time, it can achieve the simultaneous removal of multiple pollutants in a limited reaction space, effectively reducing engineering investment and construction costs.

[0018] 4. The composite bioglass lightweight stone material provided by this invention is based on a multifunctional micro-ecosystem driven by sulfur and iron in the composite material. This technology can achieve simultaneous and efficient removal of nitrogen and phosphorus pollution in wastewater at a low carbon source level through the combination of autotrophic biochemical processes and physicochemical processes. It is very suitable for deep denitrification and phosphorus removal of low carbon source micro-polluted water such as rainwater runoff, river and lake water, black and odorous water bodies, and industrial wastewater. Attached Figure Description

[0019] Figure 1The images show the material morphology of the original glass pumice, the Fe-loaded glass pumice, and the glass pumice loaded with ferric sulfides in this invention.

[0020] Figure 2 The microstructure of the composite bioglass pumice material of the present invention is shown.

[0021] Figure 3 This image shows the TN removal effect of the original glass pumice material during 60 days of continuous operation in the reactor in the application of this invention.

[0022] Figure 4 This image shows the TN removal effect of the composite bioglass pumice material during 60 days of continuous operation in the reactor in the application of this invention.

[0023] Figure 5 The diagram shows the TP removal effect of the original glass pumice material during 60 days of continuous operation in the reactor in the application of this invention.

[0024] Figure 6 This image shows the TP removal effect of the composite bioglass pumice material during 60 days of continuous operation in the reactor in the application of this invention. Detailed Implementation

[0025] The technical solution of the present invention will be further described in detail below through specific embodiments and with reference to the accompanying drawings: Example

[0026] A method for preparing a composite bio-glass pumice material with simultaneous nitrogen and phosphorus removal functions includes the following specific steps: S1, Fe 3+ Fe-loaded solution with a concentration of 0.01 mol / L and a pH of 2.0 was mixed with glass pumice material at a volume ratio of 2:1 and placed in a high-pressure reactor. The mixture was reacted at a temperature of 250℃ for 3 hours to obtain Fe-loaded glass pumice. S2. Place the Fe-loaded glass pumice in a muffle furnace and calcine it at 200℃ for 1 h; then raise the temperature to 450℃ for a second calcine for 2 h to obtain glass pumice loaded with active iron oxide. S3. Place glass pumice loaded with active iron oxide in a reaction column, and under the condition of aqueous solution pH=8.5, introduce reaction gas containing 50% hydrogen sulfide, and react at a reaction temperature of 25℃ for 2 h to obtain glass pumice loaded with sulfide iron oxide. S4. The pre-acclimated denitrifying bacteria solution is introduced into the reaction column in step S3, and the internal circulation is continuously inoculated for 3 days. Then, the nutrient solution is introduced into the reaction column, the HRT is maintained at 3 h, and the culture is continuously carried out for 7 days to obtain the desired composite bioglass pumice material.

[0027] In the above implementation process, the monomer dry density of the glass pumice in step S1 is 0.3~0.5 g / cm³. 3 Monomer water holding capacity: 30~40%, particle size: 10-20mm, particle size conformity: ≥80%.

[0028] The denitrifying bacteria in step S4 were screened from the anoxic denitrification tank of the wastewater treatment plant; the nutrient solution consisted of the following components at the following concentrations: NaNO3=30mg / L, NaHCO3=20mg / L, K2HPO4=1mg / L, beef extract=0.1mg / L, and peptone=0.1mg / L. Example

[0029] A method for preparing a composite bio-glass pumice material with simultaneous nitrogen and phosphorus removal functions includes the following specific steps: S1, Fe 3+ Fe-loaded solution with a concentration of 0.01 mol / L and a pH of 2.0 was mixed with glass pumice material at a volume ratio of 2:1 and placed in a high-pressure reactor. The mixture was reacted at a temperature of 250℃ for 3 hours to obtain Fe-loaded glass pumice. S2. Place the Fe-loaded glass pumice in a muffle furnace and calcine it at 200℃ for 1 h; then raise the temperature to 450℃ for a second calcine for 2 h to obtain glass pumice loaded with active iron oxide. S3. Place glass pumice loaded with active iron oxide in a reaction column, and under the condition of aqueous solution pH=8.5, introduce reaction gas containing 50% hydrogen sulfide, and react at a reaction temperature of 25℃ for 2 h to obtain glass pumice loaded with sulfide iron oxide. S4. The pre-acclimated denitrifying bacteria solution is introduced into the reaction column in step S3, and the internal circulation is continuously inoculated for 3 days. Then, the nutrient solution is introduced into the reaction column, the HRT is maintained at 3 h, and the culture is continuously carried out for 7 days to obtain the desired composite bioglass pumice material.

[0030] In the above implementation process, the monomer dry density of the glass pumice in step S1 is 0.3~0.5 g / cm³. 3 Monomer water holding capacity: 30~40%, particle size: 10-20mm, particle size conformity: ≥80%.

[0031] The denitrifying bacteria in step S4 were screened from the anoxic denitrification tank of the wastewater treatment plant; the nutrient solution consisted of the following components at the following concentrations: NaNO3=30mg / L, NaHCO3=20mg / L, K2HPO4=1mg / L, beef extract=0.1mg / L, and peptone=0.1mg / L. Example

[0032] A method for preparing a composite bioglass pumice material with simultaneous nitrogen and phosphorus removal functions includes the following specific steps: S1, Fe 3+ Fe-loaded solution with a concentration of 0.01 mol / L and a pH of 2.5 was mixed with glass pumice material at a volume ratio of 2:1 and placed in a high-pressure reactor. The mixture was reacted at a temperature of 200℃ for 1.5 h to obtain Fe-loaded glass pumice. S2. Place the Fe-loaded glass pumice in a muffle furnace and calcine it at 250℃ for 0.75 h; then raise the temperature to 400℃ for a second calcination for 3 h to obtain glass pumice loaded with active iron oxide. S3. Place glass pumice loaded with active iron oxide in a reaction column, and under the condition of aqueous solution pH=7.0, introduce reaction gas containing 5% hydrogen sulfide, and react for 10 h at a reaction temperature of 20℃ to obtain glass pumice loaded with sulfide iron oxide. S4. The pre-acclimated denitrifying bacteria solution is introduced into the reaction column in step S3, and the internal circulation is continuously inoculated for 1 day. Then, the nutrient solution is introduced into the reaction column, the HRT is maintained at 8 h, and the culture is continuously carried out for 10 days to obtain the desired composite bioglass pumice material.

[0033] In the above implementation process, the monomer dry density of the glass pumice in step S1 is 0.3~0.5 g / cm³. 3 Monomer water holding capacity: 30~40%, particle size: 10-20mm, particle size conformity: ≥80%.

[0034] The denitrifying bacteria in step S4 were screened from the anoxic denitrification tank of the wastewater treatment plant; the nutrient solution consisted of the following components at the following concentrations: NaNO3=30mg / L, NaHCO3=20mg / L, K2HPO4=1mg / L, beef extract=0.1mg / L, and peptone=0.1mg / L. Example

[0035] A method for preparing a composite bioglass pumice material with simultaneous nitrogen and phosphorus removal functions includes the following specific steps: S1, Fe 3+ Fe-loaded solution with a concentration of 0.01 mol / L and a pH of 3.0 was mixed with glass pumice material at a volume ratio of 2:1 and placed in a high-pressure reactor. The mixture was reacted at a temperature of 400℃ for 1 h to obtain Fe-loaded glass pumice. S2. Place the Fe-loaded glass pumice in a muffle furnace and calcine it at 300℃ for 0.5 h; then raise the temperature to 550℃ for a second calcination of 2.5 h to obtain glass pumice loaded with active iron oxide. S3. Place glass pumice loaded with active iron oxide in a reaction column, and under the condition of aqueous solution pH=9.0, introduce reaction gas containing 100% hydrogen sulfide, and react at a reaction temperature of 10℃ for 2 h to obtain glass pumice loaded with sulfide iron oxide. S4. The pre-acclimated denitrifying bacteria solution is introduced into the reaction column in step S3, and the internal circulation is continuously inoculated for 2 days. Then, the nutrient solution is introduced into the reaction column, the HRT is maintained at 6 h, and the culture is continuously carried out for 3 days to obtain the desired composite bioglass pumice material.

[0036] In the above implementation process, the monomer dry density of the glass pumice in step S1 is 0.3~0.5 g / cm³. 3 Monomer water holding capacity: 30~40%, particle size: 10-20mm, particle size conformity: ≥80%.

[0037] The denitrifying bacteria in step S4 were screened from the anoxic denitrification tank of the wastewater treatment plant; the nutrient solution consisted of the following components at the following concentrations: NaNO3=30mg / L, NaHCO3=20mg / L, K2HPO4=1mg / L, beef extract=0.1mg / L, and peptone=0.1mg / L.

[0038] The composite bio-glass lightweight stone material with simultaneous nitrogen and phosphorus removal functions prepared by the above method has the following morphology: Figure 1 , Figure 2 As shown.

[0039] Depend on Figure 1 As can be seen, after the hydrothermal reaction, Fe is loaded onto the glass pumice, and the glass pumice material exhibits a uniform golden yellow color. EDS elemental analysis results also show that a large amount of Fe element is loaded into the material. The surface of the glass pumice material is rich in active hydroxyl groups, which can combine with Fe ions to form complexes, thereby loading Fe ions onto the surface of the glass pumice. After further loading with iron sulfide, the glass pumice material appears blackish-red, indicating that iron sulfide compounds are loaded into the pumice. EDS elemental analysis also shows that Fe and S elements are uniformly distributed in the glass pumice.

[0040] Depend on Figure 2 It is evident that after biofilm culture, a rich biofilm structure is formed inside the glass pumice. The glass pumice has a rich internal porous structure, and the loaded Fe and S elements have a good affinity for autotrophic denitrifying bacteria. Therefore, a rich and stable autotrophic denitrifying bacteria micro-ecosystem is formed inside it, which lays the foundation for the composite bioglass pumice material to exert efficient simultaneous nitrogen and phosphorus removal effects.

[0041] An application of a composite bio-glass pumice material with simultaneous nitrogen and phosphorus removal functions in wastewater dephosphorization and denitrification treatment: The composite bio-glass pumice material prepared in Example 1 above was loaded into a fluidized bed reactor with a height of 70 cm, a diameter of 8 cm, and a filling volume ratio of 60%. The bio-glass pumice reactor was operated with a HRT of 3 h, a temperature of 25 °C, DO ≤ 0.5 mg / L, and an internal circulation was set up.

[0042] The influent conditions were set as follows: COD = 10 mg / L, TN = 50 mg / L (from NO3). - Composition), TP=3 mg / L, pH=7.0-8.0.

[0043] A control group was set up, with all operating conditions identical to the above except that the original glass pumice was used.

[0044] Depend on Figure 3 , Figure 4 As can be seen, the composite bio-glass pumice material exhibits a highly efficient and stable TN removal rate. The influent TN is around 50 mg / L, while the effluent TN is significantly reduced to around 5.0 mg / L, with an average removal rate of up to 90%. In contrast, the original pumice glass material hardly removes any TN. These results indicate that the composite bio-glass pumice material prepared in this invention has excellent TN removal performance, mainly due to the Fe and S elements and autotrophic denitrifying microorganisms loaded on it.

[0045] Depend on Figure 5 , Figure 6 As can be seen, the composite bio-glass pumice material exhibits excellent TP removal rate, with influent TP around 5.0 mg / L and effluent TP reduced to around 0.4 mg / L, achieving a TP removal rate of over 90%. In contrast, the original pumice glass has a very limited TP removal rate of only about 20%. These results demonstrate that the composite bio-glass pumice material prepared in this invention has a highly efficient TP removal effect. This is mainly due to the Fe element loaded on it being converted into free active iron ions during the interaction with microorganisms, which then react with phosphate to precipitate, thus achieving TP removal.

[0046] Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of the present invention without departing from the principles and spirit of the present invention. Any simple modifications, equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention shall still fall within the scope of the technical solution of the present invention.

Claims

1. A method for preparing a composite bioglass pumice material with simultaneous nitrogen and phosphorus removal functions, characterized in that, The specific steps include the following: S1. Mix Fe-loaded solution with Fe3+ concentration = 0.01 mol / L and pH of 2.0-3.0 with glass pumice material at a volume ratio of 2:1, place in a high-pressure reactor, and react for 1-3 h at a temperature of 200-400℃ to obtain Fe-loaded glass pumice. S2. Place the Fe-loaded glass pumice in a muffle furnace and calcine it at 200-300℃ for 0.5-1.5 h; then raise the temperature to 400-550℃ for a second stage of calcine for 2-3 h to obtain glass pumice loaded with active iron oxide. S3. Place glass pumice loaded with active iron oxide in a reaction column, and pass a reaction gas containing 5%-100% hydrogen sulfide into the aqueous solution at a pH of 7.0-9.

0. The reaction time is 2-10 h at a reaction temperature of 10-25℃ to obtain glass pumice loaded with ferric sulfide. S4. Pass the pre-acclimated denitrifying bacteria solution into the reaction column in step S3, continuously inoculate internally for 1-3 days, then introduce the nutrient solution into the reaction column, and culture for 3-10 days under HRT=2-8 h and temperature of 25℃ to obtain the desired composite bioglass lightweight material.

2. The method for preparing a composite bioglass pumice material with simultaneous nitrogen and phosphorus removal functions according to claim 1, characterized in that, The denitrifying bacteria in step S4 are selected from the anoxic denitrification tank of the wastewater treatment plant.

3. The method for preparing a composite bioglass pumice material with simultaneous nitrogen and phosphorus removal functions according to claim 1, characterized in that, The nutrient solution in step S4 consists of the following components at the following concentrations: NaNO3 = 30 mg / L, NaHCO3 = 20 mg / L, K2HPO4 = 1 mg / L, beef extract = 0.1 mg / L, and peptone = 0.1 mg / L.

4. The method for preparing a composite bioglass pumice material with simultaneous nitrogen and phosphorus removal functions according to claim 1, characterized in that, In step S1, the monomer dry density of the glass pumice is 0.3-0.5 g / cm³. 3 Monomer water holding capacity: 30-40%, particle size: 10-20mm, particle size conformity: ≥80%.

5. A composite bio-glass lightweight stone material with simultaneous nitrogen and phosphorus removal functions, characterized in that, Prepared according to any one of claims 1-4.

6. The application of a composite bio-glass pumice material with simultaneous nitrogen and phosphorus removal function as described in claim 5 in wastewater nitrogen and phosphorus removal treatment.

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