Composite containing nano LaOCl as well as preparation method and application thereof

Abstract

The invention discloses a nano LaOCl-containing compound and a preparation method and application thereof, and the preparation method comprises the following steps: S10: obtaining plastic and crushing the plastic to obtain plastic powder; s20, biomass is obtained, dried and smashed, and biomass powder is obtained; s30, the plastic powder, the biomass powder and LaCl3. 7H2O are mixed according to the proportion, and a mixture is obtained; s40, the mixture is placed in a high-temperature reactor, the temperature is increased to 400 DEG C, and first-stage pyrolysis is carried out; s50, after the first-stage pyrolysis is finished, the temperature continues to rise to 700-800 DEG C, and second-stage pyrolysis is conducted; and S60, after pyrolysis is finished, residual solids are collected, and the nano LaOCl-containing compound is obtained.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of resource utilization of agricultural solid waste and the green and low-cost preparation of high-value carbon nanomaterials, in particular to a nano-LaOCl-containing composite and a preparation method and application thereof. BACKGROUND

[0002] Nanomaterials are materials with at least one dimension in the nanometer range (1-100 nm) or materials composed of such basic units. Common nanomaterials include nanometals, nanoceramics, nanofilms, and nanocarbon materials. Nanomaterials have unique small size effects, surface effects, and quantum size effects, which endow them with many excellent properties such as high strength, high hardness, high toughness, good wear resistance, and corrosion resistance. These properties make nanomaterials have wide application prospects in mechanical engineering, energy, medicine, catalysis, aerospace, and other fields.

[0003] However, the application of nanomaterials is restricted by many factors, especially in production and preparation. There are generally ① high production cost, high dependence on expensive precision instruments and ultra-clean environments; ② difficulty in ensuring stability and performance consistency; and ③ high environmental risk, as raw materials or byproducts are mostly toxic and harmful substances. Therefore, developing simple and green methods to prepare high-performance nanomaterials has become a current focus.

[0004] In the environmental field, phosphorus is an important scarce resource and an important pollution source. A large number of studies have focused on efficient treatment of phosphorus-containing wastewater and recovery of phosphorus. Among them, metal nanoparticles such as MgO, La2O3, and LaOCl have been confirmed to have good affinity with phosphorus and can be used as high-efficiency active sites for efficient treatment of phosphorus-containing wastewater. However, the preparation of metal nanoparticle-containing materials generally has high cost and high environmental risk. SUMMARY

[0005] The present application addresses the problems and needs mentioned above and proposes a nano-LaOCl-containing composite and a preparation method and application thereof. The technical features adopted enable the above technical purposes to be achieved and bring about other technical effects.

[0006] One object of the present application is to propose a preparation method of a nano-LaOCl-containing composite, comprising the following steps:

[0007] S10: obtaining plastic and crushing it to obtain plastic powder;

[0008] S20: obtaining biomass and drying and crushing it to obtain biomass powder;

[0009] S30: mixing the plastic powder, the biomass powder and LaCl3·7H2O according to a proportion to obtain a mixture;

[0010] S40: placing the mixture in a high-temperature reactor, first heating to 400℃ to perform a first-stage pyrolysis;

[0011] S50: after the first-stage pyrolysis, continuously heating to 700-800℃ to perform a second-stage pyrolysis;

[0012] S60: after the pyrolysis, collecting the residual solid to obtain the nano-LaOCl-containing composite.

[0013] In addition, the nano-LaOCl-containing composite and the preparation method and application thereof according to the present application can also have the following technical features:

[0014] In an example of the present application, in the step S10, the plastic requires a carbon yield >10% at 600℃, including polycarbonate, polyethylene terephthalate and polyvinyl chloride, wherein the plastic is crushed through a 40-mesh sieve.

[0015] In an example of the present application, in the step S20, the biomass requires a softwood with a lignin content >25%, including pine and fir, wherein the biomass is crushed through a 40-mesh sieve.

[0016] In an example of the present application, in the step S30, the plastic powder, the biomass powder and LaCl3·7H2O are mixed according to a mass ratio of 1:1:3-5.

[0017] In an example of the present application, in the step S40, first heating from room temperature to 400℃ at a heating rate of 2-5℃ / min, and keeping the temperature for 1-2h to perform the first-stage pyrolysis.

[0018] In an example of the present application, in the step S50, then continuously heating to 700-800℃ at a heating rate of 5-10℃ / min, and keeping the temperature for 2-3h to perform the second-stage pyrolysis.

[0019] Another object of the present application is to provide a nano-LaOCl-containing composite prepared according to the preparation method described above.

[0020] In an example of the present application, the size of the nano-LaOCl is 10-100nm, and uniformly attached to the surface and the pores of the composite.

[0021] Still another object of the present application is to provide an application of the nano-LaOCl-containing composite in wastewater treatment, wherein the nano-LaOCl-containing composite is used for treating phosphorus-containing wastewater.

[0022] Compared with the prior art, the present application has the following advantages:

[0023] (1) The advantages of LaOCl complex are:

[0024] ① High efficiency of phosphorus affinity and selective adsorption: The nano LaOCl in the complex serves as the main active phase, has excellent phosphorus affinity and coordination / precipitation dual removal mechanism, can efficiently capture phosphate ions in wastewater, and significantly improves the phosphorus removal efficiency per unit mass of material.

[0025] ② Rich active sites in nanoscale: The prepared LaOCl has a thin flake-like nanostructure (typical size about 20-100 nm), which is uniformly attached to the surface and pores of the composite carbon carrier, effectively increasing the specific surface area and exposed La active site density, reducing mass transfer resistance, and improving adsorption / reaction rate.

[0026] ③ Carrier-active site synergy: The carbon carrier provides a multi-level stacked pore structure and surface functional groups, which is beneficial for phosphorus enrichment and local microenvironment regulation; LaOCl provides strong phosphorus affinity active sites, and the two synergistically improve the adsorption capacity and kinetic performance, and reduce the interference of competing ions.

[0027] (2) The advantages of the method for preparing LaOCl complex are:

[0028] ① Simple method: Using plastic and biomass as carbon source, combined with LaCl3·7H2O, nano LaOCl is generated and loaded in situ by "two-step pyrolysis" one-pot method; without inert atmosphere protection, expensive equipment or subsequent complex loading / calcination steps, significantly reducing process complexity and cost.

[0029] ② In-situ nucleation-limited growth, size and dispersion controllable: Through the segmented pyrolysis of the first stage (about 400°C) and the second stage (about 700-800°C), combined with raw material ratio control (for example, plastic: biomass: LaCl3·7H2O ≈ 1:1:3-5), in-situ nucleation and limited growth of LaOCl on the carbon-based skeleton is realized, obtaining uniform size and good dispersion of nanosheets.

[0030] ③ High-value utilization of waste and resource recycling: High-carbon-yield plastics (such as PC, PET, PVC) and lignin-rich softwood (such as pine, fir) are used as co-carbon sources, which converts agricultural and plastic solid waste into high-value environmental functional materials, taking into account reduction and empowerment, with significant environmental and economic benefits.

[0031] (3) The advantages of LaOCl complex application to the treatment of phosphorus-containing wastewater are:

[0032] ① Ultra-high removal efficiency: Typical samples show very high removal rates in phosphorus-containing wastewater treatment tests, with removal rates of representative formulations ranging from 95% to 99.5% (e.g. sample 5: 98.4%, sample 7: 99.5%, samples 6 / 8 / 9 / 10: 95.2-96.4%), significantly better than comparative samples using only a single carbon source or without La system.

[0033] ② Strong anti-interference characteristics: The porous structure of the carrier and the strong phosphorus affinity of LaOCl together reduce the influence of coexisting anions, ensuring high phosphorus removal efficiency in actual complex water bodies.

[0034] ③ Huge resource recycling potential: Combined with subsequent processes, phosphorus can be enriched, recycled and reused, taking into account pollution control and resource recycling, in line with the direction of green and low-carbon development.

[0035] The most preferred embodiments of the present application will be described in more detail below with reference to the accompanying drawings, so that the features and advantages of the present application can be easily understood. BRIEF DESCRIPTION OF DRAWINGS

[0036] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings of the embodiments of the present application will be briefly introduced below. The drawings are only used to show some embodiments of the present application, and not to limit all embodiments of the present application to them.

[0037] Figure 1 Figure 1 is a graph of the phosphorus-containing wastewater treatment performance of samples 1-10 according to embodiments of the present application (50 mL, 40 mg / L concentration);

[0038] Figure 2 Figure 5 is a SEM image of sample 5 according to embodiments of the present application;

[0039] Figure 3 Figure 6 is a SEM image of sample 5 according to embodiments of the present application; Figure 2 Figure 7 is a local enlarged view of the SEM image of sample 5 according to embodiments of the present application;

[0040] Figure 4 Figure 8 is a crystal phase structure diagram of sample 5 according to embodiments of the present application. DETAILED DESCRIPTION

[0041] In order to make the purpose, technical solutions and advantages of the technical solutions of the present application more clear, the technical solutions of the embodiments of the present application will be described clearly and completely below with reference to the drawings of the specific embodiments of the present application. The same reference signs in the drawings represent the same parts. It should be noted that the described embodiments are part of the embodiments of the present application, not all embodiments. Based on the described embodiments of the present application, all other embodiments obtained by those of ordinary skill in the art without creative labor fall within the scope of the present application.

[0042] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used in the description of the application herein and the claims that follow is not intended to be limiting of the application. Likewise, the use of "first", "second", and "third" to describe various components is not intended to denote an order of importance, but to distinguish one component from another. Similarly, the use of "one" or "a" is not intended to denote a quantity of one, but to denote a quantity of at least one. The use of "including," "containing," or "comprising" is not intended to exclude other components but to include the components therein. The use of "connected", "coupled", or "pathway" is not intended to exclude the presence of an intermediate component or intervening components but rather can be interpreted in the alternative as connecting or coupling.

[0043] According to the first aspect of the present application, a preparation method of a nano-LaOCl composite comprises the following steps:

[0044] S10: obtaining plastic and crushing the plastic to obtain plastic powder;

[0045] S20: obtaining biomass and drying and crushing the biomass to obtain biomass powder;

[0046] S30: mixing the plastic powder, the biomass powder, and LaCl3·7H2O according to a proportion to obtain a mixture;

[0047] S40: placing the mixture in a high-temperature reactor, first heating to 400°C, and performing a first-stage pyrolysis;

[0048] S50: after the first-stage pyrolysis is completed, continuing to heat to 700-800°C, and performing a second-stage pyrolysis;

[0049] S60: collecting the residual solid after the pyrolysis is completed, to obtain the nano-LaOCl composite.

[0050] The preparation method of the LaOCl composite has the following advantages:

[0051] ① The method is simple: using plastic and biomass as carbon sources, combining with LaCl3·7H2O, and generating and loading the nano-LaOCl in situ through a "two-step pyrolysis" one-pot method; no inert atmosphere protection, expensive equipment, or subsequent complex loading / calcination steps are required, which significantly reduces the process complexity and cost.

[0052] ②In-situ nucleation-confined growth, controllable size and dispersity: By two-stage pyrolysis (first stage: ~400℃, second stage: ~700-800℃) and controlling the raw material ratio (e.g. plastic: biomass: LaCl3·7H2O ≈ 1:1:3-5), in-situ nucleation and confined growth of LaOCl on carbon-based skeleton are realized, and uniform-sized and well-dispersed nanosheets are obtained.

[0053] ③Waste high-value utilization and resource recycling: Preferably, high-carbon-yield plastics (e.g. PC, PET, PVC) and lignin-rich softwood (e.g. pine, fir) are used as co-carbon sources, and agricultural and plastic solid wastes are converted into high-value environmental functional materials, which takes into account both reduction and empowerment, and has significant environmental and economic benefits.

[0054] In an example of the present application, in the step S10, the plastic requires a carbon yield of >10% at 600℃, including polycarbonate (PC), polyethylene terephthalate (PET) and polyvinyl chloride (PVC), wherein the plastic is crushed through a 40-mesh sieve.

[0055] In an example of the present application, in the step S20, the biomass requires softwood with a lignin content of >25%, including pine and fir, wherein the biomass is crushed through a 40-mesh sieve.

[0056] In an example of the present application, in the step S30, the plastic powder, biomass powder and LaCl3·7H2O are mixed in a mass ratio of 1:1:3-5.

[0057] In an example of the present application, in the step S40, first, the temperature is raised from room temperature to 400℃ at a heating rate of 2-5℃ / min, and held for 1-2h, to perform the first-stage pyrolysis.

[0058] In an example of the present application, in the step S50, then, the temperature is continued to be raised to 700-800℃ at a heating rate of 5-10℃ / min, and held for 2-3h, to perform the second-stage pyrolysis.

[0059] According to the second aspect of the present application, a nano-LaOCl-containing composite is prepared by the preparation method described above.

[0060] The LaOCl composite has the following advantages:

[0061] ①High-efficiency phosphorus affinity and selective adsorption: The nano-LaOCl in the composite serves as the main active phase, has excellent phosphorus affinity and coordination / precipitation dual removal mechanism, can efficiently capture phosphate ions in wastewater, and significantly improves the phosphorus removal efficiency per unit mass of material.

[0062] ②Rich active sites in nanoscale: The prepared LaOCl presents a flake-like nanostructure (typical size of about 20-100 nm), which is uniformly attached to the surface and pores of the composite carbon carrier, effectively increasing the specific surface area and the density of exposed La active sites, reducing the mass transfer resistance, and improving the adsorption / reaction rate.

[0063] ③Carrier-active site synergy: The carbon carrier provides a multi-level stacked pore structure and surface functional groups, which are beneficial for phosphorus enrichment and local microenvironment regulation; LaOCl provides strong phosphorus-active sites, and the two synergistically improve the adsorption capacity and kinetic performance, and reduce the interference of competing ions.

[0064] In one example of the present application, the size of the nano-LaOCl is 10-100 nm, and is uniformly attached to the surface and pores of the composite.

[0065] According to the application of a nano-LaOCl-containing composite in wastewater treatment according to the third aspect of the present application, the nano-LaOCl-containing composite is used for the treatment of phosphorus ions in wastewater. That is, as a phosphorus-active site, the nano-LaOCl-containing composite has excellent treatment performance for phosphorus-containing wastewater.

[0066] The advantages of the LaOCl composite in the treatment of phosphorus-containing wastewater are:

[0067] ①Ultra-high removal efficiency: The typical sample showed extremely high removal rate in the treatment of phosphorus-containing wastewater, and the removal rate of the representative formula can reach the range of 95-99.5% (such as sample 5: 98.4%, sample 7: 99.5%, samples 6 / 8 / 9 / 10: 95.2-96.4%), which is significantly better than the comparative sample using only a single carbon source or without La.

[0068] ②Strong anti-interference characteristics: The porous structure of the carrier and the strong phosphorus affinity of LaOCl together reduce the influence of coexisting anions, ensuring that high-efficiency phosphorus removal can still be maintained in actual complex water bodies.

[0069] ③Great resource recycling potential: Combined with subsequent processes, phosphorus can be enriched, recycled and reused, taking into account pollution control and resource recycling, in line with the direction of green and low-carbon development.

[0070] Example One

[0071] A method for preparing a nano-LaOCl-containing composite, comprising the following steps:

[0072] A. Dry and crush pine wood, pass through a 40-mesh sieve to obtain pine powder;

[0073] B. Place the pine powder in a high-temperature reactor, first heat it from room temperature to 400°C at a heating rate of 5°C / min, and keep the temperature constant for 2 h to perform the first-stage pyrolysis;

[0074] C, after the first stage pyrolysis, continue to heat to 800℃ at a heating rate of 10℃ / min, keep constant temperature for 2h, and then carry out the second stage pyrolysis;

[0075] D, after the pyrolysis, collect the residual solid (sample 1). Observe its apparent morphology and use it to treat the phosphorus-containing wastewater. As shown in Table 1, sample 1 mainly presents a small amount of large pore structure, and the treatment performance for the phosphorus-containing wastewater is extremely poor, with a removal rate of -3.5% (see Figure 1 ).

[0076] Example Two

[0077] The simple one-pot method for preparing the nano-LaOCl composite for efficiently treating the phosphorus-containing wastewater comprises the following steps:

[0078] A, crush polycarbonate, pass through a 40-mesh sieve, and obtain polycarbonate powder;

[0079] B, place the polycarbonate powder in a high-temperature reactor, first heat from room temperature to 400℃ at a heating rate of 5℃ / min, keep constant temperature for 2h, and then carry out the first stage pyrolysis;

[0080] C, after the first stage pyrolysis, continue to heat to 800℃ at a heating rate of 10℃ / min, keep constant temperature for 2h, and then carry out the second stage pyrolysis;

[0081] D, after the pyrolysis, collect the residual solid (sample 2). Observe its apparent morphology and use it to treat the phosphorus-containing wastewater. As shown in Table 1, sample 2 mainly presents a non-porous block structure, and the removal rate for the phosphorus-containing wastewater is only 2.8% (see Figure 1 ).

[0082] Example Three

[0083] A method for preparing a nano-LaOCl composite comprises the following steps:

[0084] A, dry and crush pine wood, pass through a 40-mesh sieve, and obtain pine wood powder;

[0085] B, mix 1 part of the pine wood powder with 4 parts of LaCl3·7H2O to obtain a mixture;

[0086] C, place the mixture in a high-temperature reactor, first heat from room temperature to 400℃ at a heating rate of 5℃ / min, keep constant temperature for 2h, and then carry out the first stage pyrolysis;

[0087] D, after the first stage pyrolysis, continue to heat to 800℃ at a heating rate of 10℃ / min, keep constant temperature for 2h, and then carry out the second stage pyrolysis;

[0088] E, the pyrolysis is ended, and the residual solid (sample 3) is collected. The apparent morphology thereof is observed and used for treating the phosphorus-containing wastewater. As shown in Table 1, sample 3 mainly presents a small amount of large-pore structure, and a large amount of block stacking exists on the surface, and the removal rate of the phosphorus-containing wastewater is increased to 12.7% (see Figure 1 ). Compared with sample 1, the treatment performance of sample 3 on the phosphorus-containing wastewater is improved, indicating that the intervention of LaCl3 plays a positive role in the process.

[0089] Example Four

[0090] A method for preparing a nano-LaOCl compound, comprising the following steps:

[0091] A, polycarbonate is crushed through a 40-mesh sieve to obtain polycarbonate powder;

[0092] B, 1 part of the polycarbonate powder and 4 parts of LaCl3·7H2O are mixed to obtain a mixture;

[0093] C, the mixture is placed in a high-temperature reactor, first heated from room temperature to 400℃ at a heating rate of 5℃ / min, and kept constant for 2h to perform a first-stage pyrolysis;

[0094] D, after the first-stage pyrolysis, the temperature is continuously increased to 800℃ at a heating rate of 10℃ / min, and kept constant for 2h to perform a second-stage pyrolysis;

[0095] E, the pyrolysis is ended, and the residual solid (sample 4) is collected. The apparent morphology thereof is observed and used for treating the phosphorus-containing wastewater. As shown in Table 1, sample 4 mainly presents a non-porous block structure, and a large amount of block stacking exists on the surface, and the removal rate of the phosphorus-containing wastewater is increased to 8.9% (see Figure 1 ). Compared with sample 2, the treatment performance of sample 4 on the phosphorus-containing wastewater is improved, indicating that the intervention of LaCl3 plays a positive role in the process.

[0096] Example Five

[0097] A method for preparing a nano-LaOCl compound, comprising the following steps:

[0098] A, polycarbonate is crushed through a 40-mesh sieve to obtain polycarbonate powder;

[0099] B, pine wood is dried and crushed, and then passed through a 40-mesh sieve to obtain pine wood powder;

[0100] C, 1 part of the polycarbonate powder, 1 part of the pine wood powder and 4 parts of LaCl3·7H2O are mixed to obtain a mixture;

[0101] D. The mixture is placed in a high-temperature reactor, first heated from room temperature to 400℃ at a rate of 5℃ / min, and kept constant for 2h, to carry out the first stage pyrolysis;

[0102] E. After the first stage pyrolysis, continue to heat to 800℃ at a rate of 10℃ / min, and keep constant for 2h, to carry out the second stage pyrolysis;

[0103] F. After the pyrolysis, collect the residual solid (sample 5). Observe its apparent morphology and crystal phase composition, and use it to treat phosphorus-containing wastewater. As shown in Table 1, sample 5 mainly presents a rich multi-level stacked pore structure, with a large number of nanometer LaOCl flakes of 60-100nm in size uniformly distributed on the surface, and the removal rate of phosphorus-containing wastewater is increased to 98.4% (see Figure 1 、 Figure 2 、 Figure 3 、 Figure 4 ). From Figure 2 and Figure 3 , it can be observed that there is a rich multi-level stacked pore structure, with a large number of nanometer LaOCl flakes of 60-100nm in size uniformly distributed on the surface; from Figure 4 , it can be observed that sample 5 is mainly composed of LaOCl; compared with sample 1, sample 2, sample 3 and sample 4, the treatment performance of sample 5 for phosphorus-containing wastewater is greatly improved, indicating that the coexistence of polycarbonate, pine and LaCl3 can obtain a high-performance nanometer LaOCl-containing composite under the specified working conditions.

[0104] Example Six

[0105] A method for preparing a nanometer LaOCl-containing composite, comprising the following steps:

[0106] A. Crush the polyethylene terephthalate through a 40-mesh sieve to obtain polyethylene terephthalate powder;

[0107] B. Dry and crush the pine, and pass it through a 40-mesh sieve to obtain pine powder;

[0108] C. Mix 1 part of polyethylene terephthalate powder, 1 part of pine powder and 4 parts of LaCl3·7H2O to obtain a mixture;

[0109] D. Place the mixture in a high-temperature reactor, first heat from room temperature to 400℃ at a rate of 5℃ / min, and keep constant for 2h, to carry out the first stage pyrolysis;

[0110] E. After the first stage pyrolysis, continue to heat to 800℃ at a rate of 10℃ / min, and keep constant for 2h, to carry out the second stage pyrolysis;

[0111] F, pyrolysis is completed, and the residual solid (sample 6) is collected. The apparent morphology and crystal phase composition thereof are observed and used for treating phosphorus-containing wastewater. As shown in Table 1, sample 6 mainly presents a rich multi-level stacked pore structure, and a large number of nanometer LaOCl flake with a size of 20-70 nm are uniformly distributed on the surface, and the removal rate of the phosphorus-containing wastewater reaches 96.4% (see Figure 1 ).

[0112] Example Seven

[0113] A preparation method of a nanometer LaOCl composite, comprising the following steps:

[0114] A, polycarbonate is crushed through a 40-mesh sieve to obtain polycarbonate powder;

[0115] B, Chinese fir is dried and crushed, and then passed through a 40-mesh sieve to obtain Chinese fir powder;

[0116] C, 1 part of the polycarbonate powder, 1 part of the pine powder and 4 parts of LaCl3·7H2O are mixed to obtain a mixture;

[0117] D, the mixture is placed in a high-temperature reactor, and first heated from room temperature to 400℃ at a heating rate of 5℃ / min, and then kept at 400℃ for 2h to perform a first-stage pyrolysis;

[0118] E, after the first-stage pyrolysis, the temperature is continued to be raised to 800℃ at a heating rate of 10℃ / min, and then kept at 800℃ for 2h to perform a second-stage pyrolysis;

[0119] F, pyrolysis is completed, and the residual solid (sample 7) is collected. The apparent morphology and crystal phase composition thereof are observed and used for treating phosphorus-containing wastewater. As shown in Table 1, sample 7 mainly presents a rich multi-level stacked pore structure, and a large number of nanometer LaOCl flake with a size of 40-100 nm are uniformly distributed on the surface, and the removal rate of the phosphorus-containing wastewater reaches 99.5% (see Figure 1 ).

[0120] Example Eight :

[0121] A preparation method of a nanometer LaOCl composite, comprising the following steps:

[0122] A, polyvinyl chloride is crushed through a 40-mesh sieve to obtain polyvinyl chloride powder;

[0123] B, Chinese fir is dried and crushed, and then passed through a 40-mesh sieve to obtain Chinese fir powder;

[0124] C, 1 part of the polyvinyl chloride powder, 1 part of the pine powder and 4 parts of LaCl3·7H2O are mixed to obtain a mixture;

[0125] D, the mixture is placed in a high temperature reactor, first with a temperature rising rate of 5℃ / min from room temperature to 400℃, constant temperature for 2h, the first stage pyrolysis;

[0126] E, after the first stage pyrolysis, continue to heat to 800℃ with a temperature rising rate of 5℃ / min, constant temperature for 2h, the second stage pyrolysis;

[0127] F, the pyrolysis is completed, and the residual solid (sample 8) is collected. Its apparent morphology and crystal phase composition are observed and used for treating phosphorus-containing wastewater. As shown in Table 1, sample 8 mainly presents a rich multi-level stacked pore structure, and a large number of nanometer LaOCl flake with a size of 30-80nm are uniformly distributed on the surface, and the removal rate of phosphorus-containing wastewater reaches 95.7% (see Figure 1 ).

[0128] Example Nine

[0129] A preparation method of a nanometer LaOCl composite, comprising the following steps:

[0130] A, polyvinyl chloride is crushed through a 40-mesh sieve to obtain polyvinyl chloride powder;

[0131] B, Chinese fir is dried and crushed, and then passed through a 40-mesh sieve to obtain Chinese fir powder;

[0132] C, 1 part of the polyvinyl chloride powder, 1 part of the pine powder and 5 parts of LaCl3·7H2O are mixed to obtain a mixture;

[0133] D, the mixture is placed in a high temperature reactor, first with a temperature rising rate of 2℃ / min from room temperature to 400℃, constant temperature for 2h, the first stage pyrolysis;

[0134] E, after the first stage pyrolysis, continue to heat to 800℃ with a temperature rising rate of 5℃ / min, constant temperature for 2h, the second stage pyrolysis;

[0135] F, the pyrolysis is completed, and the residual solid (sample 9) is collected. Its apparent morphology and crystal phase composition are observed and used for treating phosphorus-containing wastewater. As shown in Table 1, sample 9 mainly presents a rich multi-level stacked pore structure, and a large number of nanometer LaOCl flake with a size of 40-100nm are uniformly distributed on the surface, and the removal rate of phosphorus-containing wastewater reaches 96.0% (see Figure 1 ).

[0136] Example Ten

[0137] A preparation method of a nanometer LaOCl composite, comprising the following steps:

[0138] A, polyvinyl chloride is crushed through a 40-mesh sieve to obtain polyvinyl chloride powder;

[0139] B, dry and crush the Chinese fir, and sieve through a 40-mesh screen to obtain Chinese fir powder;

[0140] C, mix 1 part of polyvinyl chloride powder, 1 part of pine powder and 3 parts of LaCl3·7H2O to obtain a mixture;

[0141] D, place the mixture in a high-temperature reactor, first heat from room temperature to 400°C at a heating rate of 2°C / min, and keep the temperature constant for 2h to perform the first-stage pyrolysis;

[0142] E, after the first-stage pyrolysis, continue to heat to 700°C at a heating rate of 8°C / min, and keep the temperature constant for 3h to perform the second-stage pyrolysis;

[0143] F, collect the residual solid (sample 10) after the pyrolysis. Observe the apparent morphology and crystal phase composition thereof and use it to treat phosphorus-containing wastewater. As shown in Table 1, sample 10 mainly presents a rich multi-level stacked pore structure, and a large number of nanometer LaOCl flake with a size of 20-80nm are uniformly distributed on the surface, and the removal rate of phosphorus-containing wastewater reaches 95.2% (see Figure 1 ).

[0144] Table 1 Performance and application effect of example samples

[0145]

[0146]

[0147] The above describes in detail an exemplary embodiment of a nanometer LaOCl-containing composite, a preparation method and application thereof according to the present application with reference to preferred embodiments. However, those skilled in the art can understand that various modifications and changes can be made to the above specific embodiments without departing from the concept of the present application, and various technical features and structures according to the present application can be combined without exceeding the protection scope of the present application, and the protection scope of the present application is determined by the appended claims.

Claims

1. A method for preparing a nanometer LaOCl complex-containing preparation, characterized in that, The method comprises the following steps: S10: obtaining plastic and crushing it to obtain plastic powder; S20: obtaining biomass and drying and crushing it to obtain biomass powder; S30: mixing the plastic powder, the biomass powder and LaCl3·7H2O according to a proportion to obtain a mixture; S40: placing the mixture in a high-temperature reactor, first heating it to 400°C to perform a first-stage pyrolysis; S50: after the first-stage pyrolysis, continuing to heat it to 700-800°C to perform a second-stage pyrolysis; S60: collecting residual solids after the pyrolysis to obtain the nano-LaOCl-containing composite.

2. The method according to claim 1, wherein in the step S10, the plastic is required to have a carbon yield >10% at 600°C, and includes polycarbonate, polyethylene terephthalate and polyvinyl chloride, wherein the plastic is crushed through a 40-mesh sieve.

3. The method according to claim 1, wherein in the step S20, the biomass is required to be softwood with a lignin content >25%, and includes pine and fir, wherein the biomass is crushed through a 40-mesh sieve.

4. The method according to claim 1, wherein in the step S30, the plastic powder, the biomass powder and LaCl3·7H2O are mixed according to a mass ratio of 1:1:3-5.

5. The method according to claim 1, wherein in the step S40, first heating it from room temperature to 400°C at a heating rate of 2-5°C / min, and keeping it at 400°C for 1-2h to perform the first-stage pyrolysis.

6. The method according to claim 1, wherein in the step S50, then continuing to heat it to 700-800°C at a heating rate of 5-10°C / min, and keeping it at 700-800°C for 2-3h to perform the second-stage pyrolysis.

7. A nano-LaOCl-containing composite prepared by the method according to any one of claims 1-6.

8. The nano-LaOCl-containing composite according to claim 7, wherein the nano-LaOCl has a size of 10-100nm, and is uniformly attached to the surface and the pores of the composite. The nano-LaOCl-containing composite is used for treating phosphorus-containing wastewater. ​ ​ 7. A nanocomposite comprising LaOCl complex, characterized in that, ​ ​ ​ 9. The use of a nanometer LaOCl complex in wastewater treatment, characterized in that, ​

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