Nano zero-valent iron-loaded porous polypyrrole nano film and preparation method and application thereof
阅读说明：本技术 一种负载纳米零价铁的多孔聚吡咯纳米薄膜及制备方法和应用 (Nano zero-valent iron-loaded porous polypyrrole nano film and preparation method and application thereof ) 是由 陈勇 曹楠 李涛 于 2020-12-30 设计创作，主要内容包括：本发明提供了一种负载纳米零价铁的多孔聚吡咯纳米薄膜的制备方法,属于土壤修复剂技术领域,包括以下步骤：(1)结合电化学聚合及化学氧化法制备多孔聚吡咯纳米薄膜；(2)采用液相还原法制备负载纳米零价铁的多孔聚吡咯纳米薄膜。本发明还提供了一种采用上述方法制备的负载纳米零价铁的多孔聚吡咯纳米薄膜,以及将其作为重金属污染土壤修复剂使用。本发明的负载纳米零价铁的多孔聚吡咯纳米薄膜,解决了纳米零价铁作为土壤修复剂单分散性差、易团聚且易氧化的问题,对土壤中的重金属离子污染物具有较好的去除能力。(The invention provides a preparation method of a porous polypyrrole nano film loaded with nano zero-valent iron, belonging to the technical field of soil remediation agents and comprising the following steps: (1) preparing a porous polypyrrole nano film by combining an electrochemical polymerization method and a chemical oxidation method; (2) and preparing the porous polypyrrole nano film loaded with the nano zero-valent iron by adopting a liquid phase reduction method. The invention also provides the porous polypyrrole nano film loaded with the nano zero-valent iron prepared by the method and the application of the porous polypyrrole nano film as a heavy metal polluted soil repairing agent. The porous polypyrrole nano film loaded with the nano zero-valent iron solves the problems that the nano zero-valent iron serving as a soil remediation agent is poor in monodispersity, easy to agglomerate and easy to oxidize, and has good removal capacity for heavy metal ion pollutants in soil.)
1. A preparation method of a porous polypyrrole nano-film loaded with nano zero-valent iron is characterized by comprising the following steps:
(1) preparing a porous polypyrrole nano film by combining an electrochemical polymerization method and a chemical oxidation method;
(2) and preparing the porous polypyrrole nano film loaded with the nano zero-valent iron by adopting a liquid phase reduction method.
2. The preparation method of the nano zero-valent iron-loaded porous polypyrrole nano-film according to claim 1, wherein the process of preparing the porous polypyrrole nano-film by combining electrochemical polymerization and chemical oxidation is as follows:
polypyrrole is prepared on a CHI-660 type electrochemical workstation by adopting a cyclic voltammetry electrochemical polymerization method, and an oxidant is added for chemical doping and pore forming.
3. The preparation method of the nano zero-valent iron-loaded porous polypyrrole nano-film according to claim 2, wherein the preparation method is characterized in thatIn the preparation of the porous polypyrrole nano-film by combining electrochemical polymerization and chemical oxidation, a platinum sheet electrode is used as an auxiliary electrode, a saturated calomel electrode is used as a reference electrode, an electrolyte is a mixed solution of pyrrole monomers and dilute sulfuric acid, the concentration of the dilute sulfuric acid is 0.2-1.2 mol/L, and an oxidant is V in a three-electrode system2O5。
4. The preparation method of the nano zero-valent iron-loaded porous polypyrrole nano-film according to claim 3, wherein the electrochemical polymerization electrical parameters are controlled as follows: the polymerization voltage is 0.2-4.0V, the scanning speed is 2-20 mV/s, and the scanning period is 15-80 circles;
the chemical parameters were controlled as follows: adding 2-20 mL of pyrrole monomer into 400mL of dilute sulfuric acid, and then adding 0.02-1.80 g V2O5An oxidizing agent.
5. The method for preparing the nano zero-valent iron-loaded porous polypyrrole nano-film according to claim 1, wherein after the preparation of the porous polypyrrole nano-film by combining the electrochemical polymerization and the chemical oxidation method is completed, the method further comprises the steps of sequentially cleaning the working electrode by using dilute hydrochloric acid, ethanol and distilled water, slightly taking the product off the working electrode, and drying the product for later use.
6. The preparation method of the nano zero-valent iron-loaded porous polypyrrole nano-film according to claim 1, wherein the liquid phase reduction method is adopted to prepare the nano zero-valent iron-loaded porous polypyrrole nano-film in the following steps:
in FeSO4And adding the porous polypyrrole nano-film into the solution, adding a reducing agent, filtering after the reaction is finished, washing and drying the solid-phase product to obtain the porous polypyrrole nano-film loaded with the nano zero-valent iron.
7. The preparation method of the porous polypyrrole nano-film loaded with nano zero-valent iron of claim 6, wherein the reducing agent is NaBH 0.75mol/L4Solution, FeSO4Concentration of the solutionThe degree is 0.25 to 1 mol/L.
8. The method for preparing the nano zero-valent iron-loaded porous polypyrrole nano-film according to claim 7, wherein the liquid phase reduction method is adopted to prepare the nano zero-valent iron-loaded porous polypyrrole nano-film in the following steps:
taking 100mL of FeSO4Putting the solution into a three-neck flask, then adding 0.5-2.4 g of porous polypyrrole nano-film, and under the protection of nitrogen, dropwise adding 0.2-0.5 mL of NaBH while stirring at a constant speed4And (3) continuing stirring the solution for reaction for 20-80 min, filtering and separating after the reaction is finished to obtain a solid-phase product, washing the solid-phase product with deionized water and ethanol, and placing the product at 60 ℃ for vacuum drying for 5-12 h to obtain the porous polypyrrole nano-film loaded with nano zero-valent iron.
9. A porous polypyrrole nano-film loaded with nano zero-valent iron prepared by the preparation method of any one of claims 1 to 8.
10. The use of the nano zero-valent iron-loaded porous polypyrrole nano-film according to claim 9, wherein the nano-polypyrrole nano-film is used as a heavy metal contaminated soil remediation agent.
Technical Field
The invention belongs to the technical field of soil remediation agents, and particularly relates to a porous polypyrrole nano-film loaded with nano zero-valent iron, and a preparation method and application thereof.
Background
In recent years, soil pollution worldwide has become more serious. Under the large background that the soil quality directly influences the grain production safety, the soil remediation research taking the health of the population in the whole society as a consideration obtains continuous attention. Among many soil pollutants, heavy metal ion pollutants have very typical characteristics. It is difficult to be catabolized by microbes in soil, has the characteristics of small mobility and easy accumulation in animals and plants, and affects the growth of a large number of plants on one hand, especially the normal growth of crops. On one hand, the tumor cell is concentrated in animals and plants, the continuous accumulation of the tumor cell can directly cause the animals and plants to have malignant diseases, and the concentration of the tumor cell in human bodies can also cause malignant diseases such as various tumors and the like.
Currently, research on soil remediation is underway. A large number of researches show that the nano zero-valent iron has great application space in the field of soil pollution remediation. The method has a great number of application advantages, such as low use cost, environmental friendliness and no pollution, and has a great number of application examples in the field of remediation of water body pollution, such as removal of chlorine-containing organic pollutants and heavy metal ions in water bodies. In the field of in-situ soil remediation, nano zero-valent iron is also expected. By means of the characteristic advantages, the current researchers propose that the oxidation of the nano zero-valent iron in the soil environment can be effectively overcome, and the rapid adsorption performance of the nano zero-valent iron can be enhanced, so that the possibility is provided for the future large-scale practical application of the nano zero-valent iron. Around the above problems, a subsequent series of improvement approaches such as biochar loading, montmorillonite loading, mica sheet loading, and the like have been proposed. The above improved method overcomes the application obstacle of nanometer zero-valent iron to a certain extent, however, other modification or improvement approaches are still continuously explored. The traditional organic conjugated polymer material has special advantages in consideration of improving the environmental stability and monodispersity of the nano zero-valent iron and expanding the specific surface area of the nano zero-valent iron, for example, polypyrrole is used in the field of metal rust prevention and corrosion prevention. If the conjugated polymer material with high specific surface area can be prepared on the basis of the method, and the effective load of the conjugated polymer material on the nano zero-valent iron is realized, the large-scale soil remediation application of the nano powder can be promoted.
Disclosure of Invention
The invention aims to provide a porous polypyrrole nano film loaded with nano zero-valent iron, a preparation method and application thereof aiming at the defects in the prior art, and solves the problems that nano zero-valent iron serving as a soil remediation agent is poor in monodispersity, easy to agglomerate and easy to oxidize.
The object of the invention can be achieved by the following technical measures:
the invention provides a preparation method of a porous polypyrrole nano film loaded with nano zero-valent iron, which comprises the following steps:
(1) preparing a porous polypyrrole nano film by combining an electrochemical polymerization method and a chemical oxidation method;
(2) and preparing the porous polypyrrole nano film loaded with the nano zero-valent iron by adopting a liquid phase reduction method.
Further, the process for preparing the porous polypyrrole nano-film by combining the electrochemical polymerization and the chemical oxidation method is as follows:
polypyrrole is prepared on a CHI-660 type electrochemical workstation by adopting a cyclic voltammetry electrochemical polymerization method, and an oxidant is added for chemical doping and pore forming.
Further, in the preparation of the porous polypyrrole nano-film by combining electrochemical polymerization and a chemical oxidation method, a platinum sheet electrode is adopted as an auxiliary electrode, a saturated calomel electrode is adopted as a reference electrode, an electrolyte is a mixed solution of pyrrole monomers and dilute sulfuric acid, the concentration of the dilute sulfuric acid is 0.2-1.2 mol/L, and an oxidant is V2O5。
Further, the electrochemical polymerization electrical parameters are controlled as follows: the polymerization voltage is 0.2-4.0V, the scanning speed is 2-20 mV/s, and the scanning period is 15-80 circles;
the chemical parameters were controlled as follows: adding 2-20 mL of pyrrole monomer into 400mL of dilute sulfuric acidThen adding 0.02-1.80 g V2O5An oxidizing agent.
Further, after the porous polypyrrole nano-film is prepared by combining the electrochemical polymerization and the chemical oxidation method, the method also comprises the steps of cleaning the working electrode by using dilute hydrochloric acid, ethanol and distilled water in sequence, slightly taking the product off the working electrode, and drying the product for later use.
Further, the process for preparing the porous polypyrrole nano-film loaded with the nano zero-valent iron by adopting a liquid phase reduction method comprises the following steps:
in FeSO4And adding the porous polypyrrole nano-film into the solution, adding a reducing agent, filtering after the reaction is finished, washing and drying the solid-phase product to obtain the porous polypyrrole nano-film loaded with the nano zero-valent iron.
Further, the reducing agent is NaBH of 0.75mol/L4Solution, FeSO4The concentration of the solution is 0.25-1 mol/L.
Further, the process for preparing the porous polypyrrole nano-film loaded with the nano zero-valent iron by adopting a liquid phase reduction method comprises the following steps:
taking 100mL of FeSO4Putting the solution into a three-neck flask, then adding 0.5-2.4 g of porous polypyrrole nano-film, and under the protection of nitrogen, dropwise adding 0.2-0.5 mL of NaBH while stirring at a constant speed4And (3) continuing stirring the solution for reaction for 20-80 min, filtering and separating after the reaction is finished to obtain a solid-phase product, washing the solid-phase product with deionized water and ethanol, and placing the product at 60 ℃ for vacuum drying for 5-12 h to obtain the porous polypyrrole nano-film loaded with nano zero-valent iron.
The invention also provides the porous polypyrrole nano-film loaded with the nano zero-valent iron, which is prepared by the preparation method.
The invention also provides application of the porous polypyrrole nano film loaded with the nano zero-valent iron, and the porous polypyrrole nano film is used as a heavy metal polluted soil repairing agent.
The preparation method of the porous polypyrrole nano-film loaded with the nano zero-valent iron has the following beneficial effects:
(1) preparation by combining electrochemical polymerization and chemical oxidationCompared with the prior art which adopts electrochemical polymerization to prepare the polypyrrole film, the porous polypyrrole nano film makes full use of the most common chemical oxidation method to pass an oxidant (such as V) in the protonic acid environment of the electrochemical polymerization2O5) Oxidizing pyrrole monomer to obtain chemically doped polypyrrole compound film, and realizing pore-forming process on the surface of polymer through polymerization reaction under proper oxidation condition to enlarge the specific surface area of the material so as to improve the overall soil remediation performance of the material.
(2) Compared with the nano zero-valent iron loaded by the non-porous polypyrrole nano film, the nano zero-valent iron loaded by the porous polypyrrole nano film can reduce the environmental oxidation degree of pure nano zero-valent iron, prevent the nano zero-valent iron from being oxidized by moisture and other substances in the environment in the early stage of application and prolong the application period of the nano zero-valent iron; on the other hand, the zero-valent iron nanoparticles can be effectively prevented from agglomerating by loading the oxidation-state polypyrrole film, so that the monodispersity and subsequent adsorption performance of the zero-valent iron nanoparticles are improved, and the aim of enhancing the soil remediation performance of the zero-valent iron nanoparticles is fulfilled.
(3) The porous polypyrrole nano-film loaded with the nano zero-valent iron has better removal capability on heavy metal ion pollutants in soil.
Drawings
In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, it is obvious that the drawings in the following description are only some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to the drawings without creative efforts.
FIG. 1 is an SEM image of a porous polypyrrole nano-film loaded with nano zero-valent iron prepared in example 1 of the present invention;
FIG. 2 is a distribution diagram of iron elements of the porous polypyrrole nano-film loaded with nano zero-valent iron prepared in example 1 of the present invention;
FIG. 3 is an infrared spectrum of the porous polypyrrole nano-film loaded with nano zero-valent iron prepared in example 1 of the present invention.
Detailed Description
In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention will be described in further detail with reference to the accompanying drawings and specific embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and do not limit the invention.
In order to make the description of the present disclosure more complete and complete, the following description is given for illustrative purposes with respect to the embodiments and examples of the present invention; it is not intended to be the only form in which the embodiments of the invention may be practiced or utilized. The embodiments are intended to cover the features of the various embodiments as well as the method steps and sequences for constructing and operating the embodiments. However, other embodiments may be utilized to achieve the same or equivalent functions and step sequences.
The invention provides a preparation method of a porous polypyrrole nano film loaded with nano zero-valent iron, which comprises the following steps:
(1) preparing a porous polypyrrole nano film by combining an electrochemical polymerization method and a chemical oxidation method;
(2) and preparing the porous polypyrrole nano film loaded with the nano zero-valent iron by adopting a liquid phase reduction method.
According to the invention, the nano zero-valent iron is loaded on the porous polypyrrole nano film, so that on one hand, loss of the nano zero-valent iron can be greatly limited, compared with a conventional process, the nano zero-valent iron is more excellent in protection, the 'non-effective oxidation' degree of the nano zero-valent iron is reduced, the high reaction activity of the nano zero-valent iron is maintained, the nano zero-valent iron is prevented from being oxidized by non-target pollutants such as water in the environment, and the service life of the nano zero-valent iron is prolonged. Meanwhile, the porous polymer nano film is loaded, so that the agglomeration phenomenon can be effectively prevented, the dispersibility, the mechanical strength and the adsorption effect of the nano zero-valent iron particles in a water phase are improved, and the nano zero-valent iron particles have better removing capacity on heavy metal ion pollutants.
The process for preparing the porous polypyrrole nano film by combining the electrochemical polymerization and the chemical oxidation method comprises the following steps:
polypyrrole is prepared on a CHI-660 type electrochemical workstation by adopting a cyclic voltammetry electrochemical polymerization method, and an oxidant is added for chemical doping and pore forming.
In some embodiments, in the preparation of the porous polypyrrole nano-film by combining electrochemical polymerization and chemical oxidation, a platinum sheet electrode is used as an auxiliary electrode, a saturated calomel electrode is used as a reference electrode, an electrolyte is a mixed solution of pyrrole monomers and dilute sulfuric acid, the concentration of the dilute sulfuric acid is 0.2-1.2 mol/L, and an oxidant is V2O5。
Specifically, the electrochemical polymerization electrical parameters are controlled as follows: the polymerization voltage is 0.2-4.0V, the scanning speed is 2-20 mV/s, and the scanning period is 15-80 circles;
the chemical parameters were controlled as follows: adding 2-20 mL of pyrrole monomer into 400mL of dilute sulfuric acid, and then adding 0.02-1.80 g V2O5An oxidizing agent.
In some embodiments, after the preparation of the porous polypyrrole nano-film by combining the electrochemical polymerization and the chemical oxidation methods is completed, the method further comprises the steps of sequentially cleaning the working electrode by using dilute hydrochloric acid, ethanol and distilled water, slightly taking the product from the working electrode, and drying the product for later use.
The process for preparing the porous polypyrrole nano film loaded with the nano zero-valent iron by adopting a liquid phase reduction method comprises the following steps:
in FeSO4And adding the porous polypyrrole nano-film into the solution, adding a reducing agent, filtering after the reaction is finished, washing and drying the solid-phase product to obtain the porous polypyrrole nano-film loaded with the nano zero-valent iron.
In some embodiments, the reducing agent is 0.75mol/L NaBH4Solution, FeSO4The concentration of the solution is 0.25-1 mol/L.
Specifically, the process for preparing the porous polypyrrole nano-film loaded with the nano zero-valent iron by adopting a liquid phase reduction method comprises the following steps:
taking 100mL of FeSO4Putting the solution into a three-neck flask, then adding 0.5-2.4 g of porous polypyrrole nano-film, and under the protection of nitrogen, dropwise adding 0.2-0.5 mL of NaBH while stirring at a constant speed4The solution is then stirred continuouslyAnd (3) reacting for 20-80 min, filtering and separating after the reaction is finished to obtain a solid-phase product, washing the solid-phase product with deionized water and ethanol, and placing the product at the temperature of 60 ℃ for vacuum drying for 5-12 h to obtain the porous polypyrrole nano-film loaded with nano zero-valent iron.
Example 1
The preparation process of the porous polypyrrole nano film loaded with the nano zero-valent iron comprises the following steps:
(1) preparation of porous polypyrrole nano-film by combining electrochemical polymerization and chemical oxidation method
Preparing polypyrrole film on CHI-660 type electrochemical workstation by cyclic voltammetry electropolymerization2O5As an oxidizing agent. In a three-electrode system, a platinum sheet electrode is used as an auxiliary electrode, a saturated calomel electrode is used as a reference electrode, and an electrolyte is a mixed solution of pyrrole and dilute sulfuric acid (the concentration is 0.2 mol/L). The electrochemical polymerization conditions are as follows: the polymerization voltage is 0.4V, the scanning rate is 2mV/s, the scanning period is 15 circles, and the polymerization conditions are as follows: to 400mL of dilute sulfuric acid (concentration 0.2mol/L) was added 2.5mL of pyrrole monomer, followed by 0.1g V2O5And after the polymerization is finished, taking out the working electrode, sequentially cleaning the working electrode by using dilute hydrochloric acid, ethanol and distilled water, gently taking down the polymer film from the working electrode, and drying the polymer film for later use.
(2) Method for preparing porous polypyrrole nano film loaded with nano zero-valent iron by adopting liquid phase reduction method
100mL of 0.36mol/L FeSO is taken4Putting the solution into a three-neck flask, adding 0.7g of porous polypyrrole film powder into the solution, and adding 0.22mL of 0.75mol/L NaBH under the protection of nitrogen and under the mechanical stirring (the rotating speed is 120r/min)4Dropping the solution into a three-neck flask at a constant speed, continuously stirring for reacting for 35min, filtering and separating the obtained solid phase product, washing with deionized water and ethanol, and vacuum drying at 60 ℃ for 5h to obtain the porous polypyrrole nano-film loaded with nano zero-valent iron.
Fig. 1 is an SEM image of the nano zero-valent iron-supported porous polypyrrole nano-film prepared in this example, fig. 2 is an iron element distribution diagram thereof, and fig. 3 is an infrared spectrum thereof. From FIGS. 1-2 it can be seen that polypyrazolesThe pyrrole nano-film is of a porous structure, and the nano zero-valent iron is loaded on the porous structure without agglomeration. As can be seen from FIG. 2, 1596cm-1C ═ C bond stretching vibration with polypyrrole ring, 1245cm-1C-N stretching vibration in the presence of polypyrrole, 984cm-1And 527cm-1Is due to the out-of-plane deformation vibration peak of the C-H bond in the pyrrole ring.
Example 2
The preparation process of the porous polypyrrole nano film loaded with the nano zero-valent iron comprises the following steps:
(1) preparation of porous polypyrrole nano-film by combining electrochemical polymerization and chemical oxidation method
Preparing polypyrrole film on CHI-660 type electrochemical workstation by cyclic voltammetry electropolymerization2O5As an oxidizing agent. In a three-electrode system, a platinum sheet electrode is used as an auxiliary electrode, a saturated calomel electrode is used as a reference electrode, and an electrolyte is a mixed solution of pyrrole and dilute sulfuric acid (the concentration is 0.6 mol/L). The electrochemical polymerization conditions are as follows: the polymerization voltage was 1.2V, the scanning rate was 5mV/s, the scanning period was 25 cycles, and the polymerization conditions were: to 400mL of dilute sulfuric acid (concentration 0.6mol/L) was added 7mL of pyrrole monomer, followed by 0.8g V2O5And after the polymerization is finished, taking out the working electrode, sequentially cleaning the working electrode by using dilute hydrochloric acid, ethanol and distilled water, gently taking down the polymer film from the working electrode, and drying the polymer film for later use.
(2) Method for preparing porous polypyrrole nano film loaded with nano zero-valent iron by adopting liquid phase reduction method
100mL of 0.4mol/L FeSO was taken4Putting the solution into a three-neck flask, adding 0.8g of porous polypyrrole film powder into the solution, and adding 0.22mL of 0.75mol/L NaBH under the protection of nitrogen and under the mechanical stirring (the rotating speed is 120r/min)4Dropping the solution into a three-neck flask at a constant speed, continuously stirring and reacting for 30min, filtering and separating the obtained solid phase product, washing with deionized water and ethanol, and vacuum-drying at 60 ℃ for 6h to obtain the porous polypyrrole nano-film loaded with nano zero-valent iron.
The SEM image, iron element distribution diagram and infrared spectrum of the porous polypyrrole nano-film loaded with nano zero-valent iron prepared in this example are the same as those in example 1, and the drawings are not repeated.
Example 3
The preparation process of the porous polypyrrole nano film loaded with the nano zero-valent iron comprises the following steps:
(1) preparation of porous polypyrrole nano-film by combining electrochemical polymerization and chemical oxidation method
Preparing polypyrrole film on CHI-660 type electrochemical workstation by cyclic voltammetry electropolymerization2O5As an oxidizing agent. In a three-electrode system, a platinum sheet electrode is used as an auxiliary electrode, a saturated calomel electrode is used as a reference electrode, and an electrolyte is a mixed solution of pyrrole and dilute sulfuric acid (the concentration is 1.2 mol/L). The electrochemical polymerization conditions are as follows: the polymerization voltage was 3.2V, the scan rate was 14mV/s, the scan period was 80 cycles, and the polymerization conditions were: to 400mL of dilute sulfuric acid (1.2 mol/L) was added 20mL of pyrrole monomer, followed by 1.8g V2O5And after the polymerization is finished, taking out the working electrode, sequentially cleaning the working electrode by using dilute hydrochloric acid, ethanol and distilled water, gently taking down the polymer film from the working electrode, and drying the polymer film for later use.
(2) Method for preparing porous polypyrrole nano film loaded with nano zero-valent iron by adopting liquid phase reduction method
100mL of 1mol/L FeSO was taken4Putting the solution into a three-neck flask, then adding 2.0g of porous polypyrrole film powder into the solution, and adding 0.5mL of 0.75mol/L NaBH under the protection of nitrogen and under the mechanical stirring (the rotating speed is 120r/min)4Dropping the solution into a three-neck flask at a constant speed, continuously stirring and reacting for 80min, filtering and separating the obtained solid phase product, washing with deionized water and ethanol, and vacuum drying at 60 ℃ for 12h to obtain the porous polypyrrole nano-film loaded with nano zero-valent iron.
The SEM image, iron element distribution diagram and infrared spectrum of the porous polypyrrole nano-film loaded with nano zero-valent iron prepared in this example are the same as those in example 1, and the drawings are not repeated.
Comparative example
The difference from example 1 is that only the porous polypyrrole nano-film in example 1 is prepared, and the nano zero-valent iron loading treatment is not performed on the porous polypyrrole nano-film.
The porous polypyrrole nano-films loaded with nano zero-valent iron prepared in examples 1 to 3 and the porous polypyrrole nano-films in comparative examples are applied to heavy metal contaminated soil remediation and used as a heavy metal contaminated soil remediation agent, and the test performances are shown in the following table 1:
TABLE 1 soil samples before and after remediation of heavy metal content test results
Wherein the soil sample is taken from polluted soil around the Wuhan Steel Industrial Port in Hubei as a sample, the pH value of the soil before remediation is 6.8 +/-0.3, and the pH value is 7.1 +/-0.3 after the remediation agent is added. The porous polypyrrole nano-films loaded with nano zero-valent iron prepared in examples 1 to 3 and the porous polypyrrole nano-films in the comparative examples, which are used as heavy metal contaminated soil remediation agents, are applied in a broadcast manner according to the application amount of 25kg per mu, and then deeply turned over for 20cm for remediation for 2 weeks.
As can be seen from Table 1, the porous polypyrrole nano film loaded with nano zero-valent iron provided by the invention is used as a heavy metal polluted soil remediation agent, and has a good remediation effect on heavy metal pollution treatment.
The preparation method of the porous polypyrrole nano-film loaded with the nano zero-valent iron has the following beneficial effects:
(1) compared with the prior art which adopts electrochemical polymerization to prepare the polypyrrole film, the electrochemical polymerization and chemical oxidation method are combined to prepare the porous polypyrrole nano film, the most common chemical oxidation method is fully utilized, and an oxidant (such as V) is used in the protonic acid environment of the electrochemical polymerization2O5) Oxidizing pyrrole monomer to obtain chemically doped polypyrrole compound film, and realizing pore-forming process on the surface of polymer through polymerization reaction under proper oxidation condition to enlarge the specific surface area of the material so as to improve the overall soil remediation performance of the material.
(2) Compared with the nano zero-valent iron loaded by the non-porous polypyrrole nano film, the nano zero-valent iron loaded by the porous polypyrrole nano film can reduce the environmental oxidation degree of pure nano zero-valent iron, prevent the nano zero-valent iron from being oxidized by moisture and other substances in the environment in the early stage of application and prolong the application period of the nano zero-valent iron; on the other hand, the zero-valent iron nanoparticles can be effectively prevented from agglomerating by loading the oxidation-state polypyrrole film, so that the monodispersity and subsequent adsorption performance of the zero-valent iron nanoparticles are improved, and the aim of enhancing the soil remediation performance of the zero-valent iron nanoparticles is fulfilled.
(3) The porous polypyrrole nano-film loaded with the nano zero-valent iron has better removal capability on heavy metal ion pollutants in soil.
The above description is only for the purpose of illustrating the preferred embodiments of the present invention and is not to be construed as limiting the invention, and any modifications, equivalents and improvements made within the spirit and principle of the present invention are intended to be included within the scope of the present invention.
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