CN106957438B - Preparation of modified MIL-53(Fe) metal organic framework and method for treating organic wastewater by activating persulfate - Google Patents

Preparation of modified MIL-53(Fe) metal organic framework and method for treating organic wastewater by activating persulfate Download PDF

Info

Publication number
CN106957438B
CN106957438B CN201710169590.4A CN201710169590A CN106957438B CN 106957438 B CN106957438 B CN 106957438B CN 201710169590 A CN201710169590 A CN 201710169590A CN 106957438 B CN106957438 B CN 106957438B
Authority
CN
China
Prior art keywords
wastewater
metal organic
organic framework
persulfate
mil
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Active
Application number
CN201710169590.4A
Other languages
Chinese (zh)
Other versions
CN106957438A (en
Inventor
马邕文
万金泉
王艳
濮梦婕
王九妹
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
South China University of Technology SCUT
Original Assignee
South China University of Technology SCUT
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by South China University of Technology SCUT filed Critical South China University of Technology SCUT
Priority to CN201710169590.4A priority Critical patent/CN106957438B/en
Publication of CN106957438A publication Critical patent/CN106957438A/en
Application granted granted Critical
Publication of CN106957438B publication Critical patent/CN106957438B/en
Active legal-status Critical Current
Anticipated expiration legal-status Critical

Links

Images

Classifications

    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08G—MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS
    • C08G83/00—Macromolecular compounds not provided for in groups C08G2/00 - C08G81/00
    • C08G83/008—Supramolecular polymers
    • C—CHEMISTRY; METALLURGY
    • C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F1/00—Treatment of water, waste water, or sewage
    • C02F1/72—Treatment of water, waste water, or sewage by oxidation
    • C02F1/725—Treatment of water, waste water, or sewage by oxidation by catalytic oxidation
    • C—CHEMISTRY; METALLURGY
    • C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F2101/00—Nature of the contaminant
    • C02F2101/30—Organic compounds
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
    • Y02P20/00—Technologies relating to chemical industry
    • Y02P20/50—Improvements relating to the production of bulk chemicals
    • Y02P20/582—Recycling of unreacted starting or intermediate materials

Landscapes

  • Chemical & Material Sciences (AREA)
  • Organic Chemistry (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • Polymers & Plastics (AREA)
  • Medicinal Chemistry (AREA)
  • Health & Medical Sciences (AREA)
  • Hydrology & Water Resources (AREA)
  • Engineering & Computer Science (AREA)
  • Environmental & Geological Engineering (AREA)
  • Water Supply & Treatment (AREA)
  • Catalysts (AREA)
  • Treatment Of Water By Oxidation Or Reduction (AREA)

Abstract

The invention discloses a preparation method of a modified MIL-53(Fe) metal organic framework and a method for treating organic wastewater by activating persulfate through the modified MIL-53(Fe) metal organic framework. Compared with unmodified MIL-53(Fe), the modified MIL-53(Fe) metal organic framework synthesized by the method contains more ferrous active metal centers, which are used as catalytic active sites, and can enhance the effective contact of the metal organic framework material and persulfate to generate sulfate radicals with strong oxidizing property, so that refractory pollutants in wastewater can be effectively removed. The material disclosed by the invention is high in stability, can keep the stability of a crystal structure after the persulfate is catalyzed and activated for reaction, and can still keep high catalytic activity after repeated cyclic utilization. The method for treating the organic wastewater has the advantages of environmental friendliness, simplicity and convenience in operation, low cost, high catalyst activity, good recycling property and the like. In addition, the method is also suitable for treating various organic wastewater.

Description

Preparation of modified MIL-53(Fe) metal organic framework and method for treating organic wastewater by activating persulfate
Technical Field
The invention belongs to the technical field of water pollution control, and particularly relates to a preparation method of a modified MIL-53(Fe) metal organic framework and a method for treating organic wastewater by activating persulfate through the preparation method.
Background
In recent years, activated Persulfate (PS) has been used to generate sulfate radical (SO)4 -Advanced Oxidation Technologies (AOTs) treatment of refractory organic wastewater is a research hotspot in the technical field of wastewater treatment. Compared with the traditional Fenton (Fenton) method, PThe S oxidation technology can generate SO without 3-5 acidic conditions4 -And effective degradation of the contaminants is achieved. And SO4 -Standard redox potential of (E)0+2.5 to +3.1v) of hydroxyl radical (OH. cndot.) generated by Fenton method (E)0+1.9 to +2.7v), longer stability and half-life (about 4s), lower reactivity with background organics naturally present in the wastewater, and therefore higher efficiency in the oxidative degradation of contaminants. At the same time, different from OH, SO4 -Not only can the pollutants be oxidized by C-H hydrogen abstraction and C ═ C addition, but also the pollutants tend to take electrons from benzene rings through an electron transfer path, so that the electrons are subjected to ring opening and chain scission, converted into small-molecule hydrocarbons and further oxidized into CO2And H2O, thus based on SO4 -The PS advanced oxidation method has more advantages in treating the degradation-resistant organic wastewater containing benzene rings in pollutant molecules.
Iron catalytic activation is the most common activation method for PS, and currently, the commonly used iron catalysts are mainly ferrous iron or complex ferrous iron, zero-valent iron, iron oxide, supported iron catalysts, and the like. However, the conventional iron catalysts have certain disadvantages: (1) when PS is activated by ferrous iron, a large amount of soluble Fe in the system2+Will instantaneously provide excessive catalytic active sites to make SO4 -Too fast release rate, difficult full use of contaminants, and excess Fe2+Will compete with the target contaminant for quenching SO4 -Reducing the capacity of the PS system to oxidize and degrade pollutants; (2) complexing ferrous iron with complexing agents (e.g., EDTA, EDDS, oxalic acid, citric acid, etc.) although the free Fe in solution can be controlled to some extent2+The complexing agent is an organic compound in concentration, but the introduction of the organic compound causes secondary pollution, increases COD of wastewater, and competes with pollutants for SO4 -H; (2) activation of PS with zero-valent iron (ZVI) although slowing Fe2+The release of (a) increases the oxidation efficiency of the system, but ZVI itself has strong reducibility and still rapidly provides an excess of catalytically active sites when contacted with PS having strong oxidizability. And in the process of activating PS, a ZVI surface is formedSuch as Fe3O4、α-FeOOH、α-Fe2O3And the corrosion layer composed of oxides such as FeO and the like covers part of the catalytic active sites to passivate the surface of the ZVI, so that the continuity of PS activated by the ZVI is greatly inhibited; (3) using Fe3O4、Fe2O3Or supported iron and other catalytic PS can reduce the generation of ferric hydroxide sludge, but the catalysts have the problems of long catalytic period, poor recycling property and the like in the PS activation process.
Metal Organic Frameworks (MOFs) are a class of novel hybrid materials formed by self-assembly of Metal central ions and Organic bridging ligands. Ordered crystals with active centers required by catalytic reaction can be generated by selecting proper raw materials and synthesis conditions, so that the MOFs has the advantage of structure controllability. MOFs also have large specific surface area, which can ensure sufficient dispersion of catalytically active sites during catalytic reactions. In addition, the MOFs is synthesized under high temperature and high pressure conditions, so that the MOFs has high chemical stability, and compared with the conventional catalyst, the MOFs can more easily maintain the stability of the structure thereof in a strong acid and strong oxidizing reaction system. Therefore, MOFs as a novel catalyst of PS has wide research and application prospects. At present, research of MOFs in the field of AOTs has made preliminary progress. For example, MIL-88A was successfully applied to activate PS oxidative degradation dyes rhodamine B and gold orange G (RSC Advances.2015,5: 32520-; MIL-100(Fe), [ Cu ]2(btec)(btx)1.5]nProved to be an effective Fenton-like reaction catalyst and can activate H2O2Decomposition to yield OH (Journal of Molecular Catalysis A: chemical.2015,400: 81-89; CrystEngComm.2012,14: 4210-; and the research finds ZIF-67 and Co3(BTC)2·12H2O is a highly efficient heterogeneous catalyst for the heterogeneously catalyzed activation of monoperoxybisulfate (PMS) (Journal of the Taiwan Institute of Chemical Engineers.2015,53: 40-45; Journal of Hazardous materials 2016,318: 154-. Beginning in 2014, a series of studies on the activation of PS by MOFs were carried out by a pen team, and MIL-53(Fe) was found to be an effective heterogeneous PSCatalyst, namely MIL-53(Fe) activated PS oxidizes and degrades OG under the optimal condition, after 120min of reaction, the OG mineralization rate can reach 95%, and after 5 cycles of repeated reuse, the system still has high oxidative degradation capability (Catalysis Science)&Technology.2017,7: 1129-. However, the system consumes a large amount of PS, which indicates that the PS catalysis efficiency of MIL-53(Fe) is still not high enough. Since the synthesis conditions of MOFs have a large influence on the catalytic activity, it is necessary to change the synthesis conditions of MIL-53(Fe) and improve the activity of the MOFs in catalyzing PS. It has been shown that in the synthesis of MIL-53(Fe), FeCl is used2In place of FeCl3As a precursor salt solution, the iron active center of the synthesized MIL-53(Fe) contains a large amount of + 2-valent iron, so that the catalytic H of the solution can be effectively improved2O2Activity and promotion of the transformation from the conventional structure to the Fe (BDC) (DMF, F) type structure (Dalton transformations. 2016,45: 7952-.
In view of the above discussion, the present invention discloses the synthesis of a modified MIL-53(Fe) metal organic framework and a method of using the material for heterogeneous activated persulfate treatment of organic wastewater. The method for treating the organic wastewater has the advantages of simple and convenient operation, low cost, high catalytic activity, good cyclic usability of the catalyst and the like.
Disclosure of Invention
The invention aims to solve the technical problems of insufficient active center sites, poor dispersibility, long reaction period, easy inactivation of the catalyst, poor recycling property and the like in the process of catalyzing and activating PS by using a traditional iron catalyst, and provides a preparation method of a modified MIL-53(Fe) metal organic framework and a method for activating persulfate to treat organic wastewater by using the same.
The invention is realized by the following technical scheme.
A preparation method of a modified MIL-53(Fe) metal organic framework comprises the following steps:
(1) terephthalic acid (1,4-BDC) and ferrous chloride tetrahydrate (FeCl)2·4H2O) and N, N-Dimethylformamide (DMF) are uniformly mixed to obtain a mixed solution;
(2) placing the mixed solution in a hydrothermal synthesis reaction kettle for heating reaction;
(3) and after the reaction is finished, naturally cooling to room temperature, washing and drying to obtain the modified MIL-53(Fe) metal organic framework.
Preferably, the molar ratio of the terephthalic acid to the ferrous chloride tetrahydrate in step (1) is 1: 1; the molar ratio of the terephthalic acid to the N, N-dimethylformamide is 1: 52-1: 65.
Preferably, the mixing time in step (1) is 20 min.
Preferably, the heating reaction in the step (2) is carried out at the temperature of 150-170 ℃ for 5-72 hours.
Preferably, the washing in step (3) is to wash the solid particles several times by using a certain amount of methanol and deionized water successively.
Preferably, the drying in step (3) is performed at 65 ℃ for several hours.
A modified MIL-53(Fe) metal organic framework made by the above-described preparation method.
The application of the modified MIL-53(Fe) metal organic framework in the treatment of organic wastewater.
Preferably, the application comprises the steps of:
(1) determination of COD of organic wastewater to be treatedCrValue and pH;
(2) persulfate (PS) and modified MIL-53(Fe) metal organic frameworks are added into organic wastewater, and the wastewater treatment reaction is carried out by fully shaking or stirring, SO that persulfate is decomposed to generate strong-oxidizing sulfate radicals (SO)4 -And (c), carrying out oxidative degradation treatment on the organic wastewater.
Further preferably, COD of the organic wastewater in the step (1)CrThe value is 120-300 mg/L; the pH value is 2-9.
Further preferably, the persulfate in the step (2) is sodium persulfate, potassium persulfate or ammonium persulfate.
Further preferably, the PS (mg/L) and the COD of the wastewater in the step (2)Cr(mg/L) has a mass concentration ratio of (30-50)/1.
Further preferably, the addition amount (mg/L) of the modified MIL-53(Fe) metal organic framework in the step (2)With the waste water CODCrThe mass concentration ratio of (mg/L) is (2.5-12.5)/1.
Further preferably, the dosage of the modified MIL-53(Fe) metal organic framework in the step (2) in the organic wastewater is 0.3-1.5 g/L, the dosage of persulfate in the organic wastewater is 4.0-7.6 g/L, and further preferably, the reaction time in the step (2) is 1.0-2.5 h. The adding amount of the modified MIL-53(Fe) metal organic framework and the PS is determined according to the COD of the treated wastewaterCrAnd then. Organic wastewater CODCrThe effect is best in the range of 120-300 mg/L, the adding amount of the modified MIL-53(Fe) metal organic framework is preferably 0.3-1.5 g/L, the adding amount of PS is preferably 4.0-7.6 g/L, the reaction time is preferably 1.0-2.5 h, and the COD isCrThe removal rate can reach 85-90%.
The pH adaptation range of the method for treating organic wastewater by activating persulfate through the modified MIL-53(Fe) metal organic framework is as follows: the pH value is 2-9. Preferably, the removal effect of the COD in the wastewater is best when the pH value is less than or equal to 3.
Compared with the prior art, the invention has the following advantages:
(1) the modified MIL-53(Fe) metal organic framework of the present invention compares to conventional MIL-53 (Fe). The relative content of iron active center + 2-valent iron is improved compared with that before the modification, more PS catalytic active sites are added, and the PS catalytic activity is improved at a certain level, so that the pollutant degradation efficiency is improved, and the treatment effect of the organic wastewater is optimized.
(2) The method adopts the modified MIL-53(Fe) metal organic framework to activate the persulfate to treat the organic wastewater, and has the advantages of simple and convenient operation and low cost. And the modified MIL-53(Fe) metal organic framework can keep the stability of a crystal structure before and after the PS reaction of catalytic activation, and compared with the traditional iron catalytic activation methods such as ferrous activation and zero-valent iron activation, the catalyst has strong cyclic usability.
Drawings
FIG. 1 is an X-ray photoelectron spectroscopy (XPS) Fe2p fine spectrum of a modified MIL-53(Fe) metal organic framework.
FIG. 2 is an X-ray diffraction (XRD) spectrum of a modified MIL-53(Fe) metal organic framework.
FIG. 3 is a Fourier Transform Infrared (FTIR) spectrum of a modified MIL-53(Fe) metal organic framework.
Detailed Description
For a better understanding of the present invention, the present invention is further described below with reference to the following examples and drawings, but the embodiments of the present invention are not limited thereto, and the scope of the present invention as claimed is not limited to the scope shown in the examples.
Example 1
The preparation of the modified MIL-53(Fe) metal organic framework and the catalytic activation of persulfate by the modified MIL-53(Fe) metal organic framework to treat the golden orange G simulated wastewater comprise the following specific operation steps:
(1) preparation method 1 of modified MIL-53(Fe) metal organic framework: 0.995g (5mmol) of FeCl were weighed out separately2·4H2O and 0.831g (5mmol) of 1,4-BDC were poured into 25mL DMF and stirred for 20min to mix well. The mixed solution was poured into a 100mL Teflon lined reactor and placed in an electrically heated constant temperature forced air drying oven preheated to 150 ℃. And taking out the reaction kettle after 5h, and naturally cooling to room temperature. Filtering or centrifuging to separate solid from liquid, and washing the solid with methanol and deionized water successively. And finally, drying the solid in an oven at 65 ℃ to obtain the modified MIL-53(Fe) metal organic framework.
(2) Preparation method 2 of modified MIL-53(Fe) metal organic framework: the difference from the method 1 is that a reaction kettle with a polytetrafluoroethylene lining is arranged in an electric heating constant temperature blast drying box which is preheated to 150 ℃. And taking out the reaction kettle after 72 hours, and naturally cooling to room temperature. The other steps are in accordance with preparation method 1.
(3) Preparation method 3 of modified MIL-53(Fe) metal organic framework: the difference from the method 1 is that FeCl is used in the method 32·4H2O and 1,4-BDC were used in amounts of 0.796g (4mmol) and 0.670g (4mmol), respectively, and the other steps were in accordance with preparation 1.
(4) Preparation method of modified MIL-53(Fe) metal organic framework 4: the difference from the method 1 is that FeCl is used in the method 42·4H2O and 1,4-BDC were used in amounts of 0.796g (4mmol) and 0.670g (4mmol), respectively, and the catalyst synthesis time was 72h, the other steps being in accordance with preparation 1.
(5) Preparation method of modified MIL-53(Fe) metal organic framework 5: the difference from the method 1 is that in the method 5, the reaction kettle is arranged in an electric heating constant temperature air blast drying oven which is preheated to 160 ℃.
(6) Preparation method of modified MIL-53(Fe) metal organic framework 6: the difference from the method 1 is that in the method 6, the reaction kettle is arranged in an electric heating constant temperature air blast drying oven which is preheated to 170 ℃.
(7) Preparation method of MIL-53 (Fe): the difference from method 1 is that the precursor iron salt is 0.995g (5mmol) FeCl2·4H2Changing O to 1.350g (5mmol) FeCl3·6H2O, the other steps are in accordance with preparation method 1.
(8) Degradation of organic wastewater: preparing COD by using a 250mL conical flask as a reaction flaskCrThe dye wastewater is 120mg/L of golden Orange G (OG), and six treatment groups are set without adjusting the pH of the wastewater: adding 7.6g/L sodium persulfate, adding 1.0g/L modified MIL-53(Fe) metal organic framework prepared by the above methods 1, 2, 3, 4, 5 and 6 as catalyst (treatment groups 1, 2, 3, 4, 5 and 6 respectively) into four groups of reaction bottles, stirring at 25 deg.C for reaction, sampling and measuring wastewater COD for 20min, 40min, 60min, 90min and 120min respectivelyCrThe results are shown in Table 1.
TABLE 1
Figure BDA0001250773840000051
The results in Table 1 show that the modified MIL-53(Fe) metal organic framework activated persulfate prepared by 6 different preparation conditions can effectively oxidize and degrade the golden orange G wastewater, and COD is COD after the reaction for 1 hourCrThe removal rate of the catalyst can reach 54 to 72 percent, and after 2 hours of reaction, COD is obtainedCrThe removal rate of the catalyst can reach 86-90 percent. This shows that the modified MIL-53(Fe) metal organic framework synthesized by the method of the present invention has high catalytic activity, but the catalytic activity of the catalysts prepared by different methods is different.
Example 2
In example 1Preparation method of modified MIL-53(Fe) metal organic framework by using material prepared under the condition of 1 as catalyst, sodium persulfate as oxidant and simulated golden orange G wastewater initial CODCrAt 120mg/L, four treatment groups were set, respectively: (1) adding 1.0G/L modified MIL-53(Fe) metal organic framework-7.6G/L sodium persulfate-golden orange G wastewater; (2) adding 1.0G/L modified MIL-53(Fe) metal organic framework-golden orange G wastewater; (3) adding 7.6G/L sodium persulfate-golden orange G wastewater; (4) 1.0G/L of unmodified MIL-53(Fe) -7.6G/L of sodium persulfate-aurantium G wastewater was added. Taking four 250mL conical flasks as reaction bottles, respectively adding the solutions set by the three treatment groups into the reaction bottles, fully stirring at 25 ℃ for reaction, respectively sampling and determining COD (chemical oxygen demand) of the wastewater when reacting for 20min, 40min, 60min, 90min and 120minCrThe results are shown in Table 2.
TABLE 2
Figure BDA0001250773840000061
The results in Table 2 show that the gold orange G wastewater cannot be effectively oxidatively degraded by using the modified MIL-53(Fe) metal organic framework and the sodium persulfate system, and the COD of the wastewater is treated by the sodium persulfate system activated by the modified MIL-53(Fe) metal organic frameworkCrThe removal effect is obvious, and COD is obtained after 120min reactionCrThe removal rate reaches 90.1 percent. Compared with the modified MIL-53(Fe) metal organic framework and the unmodified MIL-53(Fe), the former activates the sodium persulfate to oxidize and degrade the COD of the waste water generated in the process of golden orange G waste waterCrThe removal efficiency is obviously improved, which shows that the invention can rapidly and effectively treat the organic wastewater.
Example 3
Preparing COD by using a 250mL conical flask as a reaction flaskCrIn order to obtain 120mg/L of orange g (og) dye wastewater, the material prepared under the conditions of the preparation method 1 of the modified MIL-53(Fe) metal organic framework in example 1 was used as a catalyst, sodium persulfate was used as an oxidizing agent, and without adjusting pH of the wastewater, five treatment groups were set: after 7.6g/L sodium persulfate was added, 0.1g/L (treatment group 1), 0.3g/L (treatment group 2), and 0.5g/L (treatment group 3) of the catalysts were added to the five reaction flasks, respectively) 1.0g/L (treatment group 4) and 1.5g/L (treatment group 5), fully stirring at 25 ℃ for reaction, and sampling and determining COD of the wastewater when the reaction is carried out for 20min, 40min, 60min, 90min and 150minCrThe results are shown in Table 3.
TABLE 3
Figure BDA0001250773840000062
Figure BDA0001250773840000071
The results in Table 3 show that the adding amount of the modified MIL-53(Fe) metal organic framework has certain influence on the oxidative degradation of the golden orange G wastewater by activating sodium persulfate, and the COD (chemical oxygen demand) of the wastewaterCrThe removal rate increases with increasing catalyst addition: when the adding amount of the catalyst is 0.5g/L, after 2.5 hours of reaction, COD is obtainedCrThe removal rate reaches 90.5 percent; when the adding amount is 1.0g/L, after 90min of reaction, COD is obtainedCrThe removal rate reaches 88.2 percent; when the adding amount is continuously increased to 1.5g/L, the reaction is only carried out for 1.5h, and the COD isCrThe removal rate can reach 90.1 percent. The rate of the oxidative degradation reaction and the COD of the wastewater can be controlled by controlling the adding amount of the modified MIL-53(Fe) metal organic framework within the range of 0.1g/L to 1.5g/LCrThe removal rate of (3). Therefore, in practical application, the COD can be determined according to the initial COD of the wastewaterCrSize and CODCrThe dosage of the catalyst is selected according to the requirement of the removal rate so as to achieve the aim of reducing the treatment cost to the maximum extent.
Example 4
Preparing COD by using a 250mL conical flask as a reaction flaskCrIn order to obtain 120mg/L of orange g (og) dye wastewater, the material prepared under the conditions of the preparation method 1 of the modified MIL-53(Fe) metal organic framework in example 1 was used as a catalyst, sodium persulfate was used as an oxidizing agent, and without adjusting pH of the wastewater, six treatment groups were set: to six reaction flasks were added 1.9g/L (treatment group 1), 3.8g/L (treatment group 2), 5.7g/L (treatment group 3), 7.6g/L (treatment group 4), 9.5g/L (treatment group 5), and 11.4g/L (treatment group 6), respectively, sodium persulfate, and then added to all treatment groupsAdding 1.0g/L modified MIL-53(Fe) metal organic framework, stirring at 25 deg.C for reaction, sampling and determining COD in wastewater at 20min, 40min, 60min, 90min and 150min respectivelyCrThe results are shown in Table 4.
TABLE 4
Figure BDA0001250773840000072
The results in Table 4 show that the addition amount of sodium persulfate has certain influence on the oxidative degradation of the golden orange G wastewater by the system. When the addition amount of PS is 1.9-7.6 g/L, COD in the wastewaterCrThe removal rate is increased along with the increase of the PS adding amount, but the PS adding amount is continuously increased, and the COD of the wastewater is increasedCrThe removal rate is instead reduced. It is shown that when the amount of PS exceeds 7.6g/L, the PS is excessive, and the excessive PS causes mutual quenching of radicals generated in the system, thereby reducing the COD (chemical oxygen demand) of radical oxidationCrThe efficiency of (c). Therefore, the amount of PS added is preferably 4.0 to 7.6 g/L.
Example 5
Preparing COD by using a 250mL conical flask as a reaction flaskCrIn the case of 120mg/L of orange g (og) dye wastewater, the material prepared under the conditions of the preparation method 1 of the modified MIL-53(Fe) metal organic framework in example 1 was used as a catalyst, sodium persulfate was used as an oxidizing agent, and five treatment groups were set up: adding 7.6g/L of sodium persulfate into a reaction bottle before the reaction starts, respectively adjusting the pH value of the wastewater to 2.43 (treatment group 1), 3.07 (treatment group 2), 4.94 (treatment group 3), 6.99 (treatment group 4) and 9.47 (treatment group 5), fully stirring at 25 ℃ for reaction, then adding 1.0g/L of modified MIL-53(Fe) metal organic framework into all the treatment groups, and respectively sampling and measuring COD (chemical oxygen demand) of the wastewater when the reaction is carried out for 20min, 40min, 60min, 90min, 150min, 210min and 330minCrThe results are shown in Table 5.
TABLE 5
Figure BDA0001250773840000081
As can be seen from Table 5, when the pH was 3 or more, the system was used for wastewaterCODCrThe removal efficiency begins to decrease, when the pH is about 5, after 330min of reaction, COD is obtainedCrThe removal rate is 45.2%; when the pH is about 7, after 330min of reaction, COD is obtainedCrThe removal rate is 30.9%; when the pH is 9, after 330min of reaction, COD is obtainedCrThe removal rate only reaches 18.6 percent. The system has certain oxidative degradation capability to the wastewater when the pH is less than or equal to 9, but the effect of the oxidative degradation capability of the system is the best when the pH is less than or equal to 3.
Example 6
Preparing COD by using a 250mL conical flask as a reaction flaskCr120mg/L of golden Orange G (OG) dye wastewater, 0.5g/L of modified MIL-53(Fe) metal organic framework prepared under the condition of the preparation method 1 in the example 1 is added into a reaction bottle, then 5.7g/L of sodium persulfate is added, the mixture is fully stirred at the temperature of 25 ℃ for reaction, and samples are respectively taken and the COD of the wastewater is measured when the reaction is carried out for 20min, 40min, 60min, 90min and 150minCr(ii) a After the reaction, the catalyst was recovered, dried, and put into the same reaction system for reuse, and the cycle was repeated four times, and the results are shown in table 6.
TABLE 6
Figure BDA0001250773840000091
As can be seen from Table 6: the modified MIL-53(Fe) metal organic framework shows relatively stable repeated recycling characteristics, when the catalyst is recycled in the fourth period, PS is activated to degrade the golden orange G wastewater, and after reaction is carried out for 150min, COD (chemical oxygen demand) in the wastewater is obtainedCrThe removal rate is still as high as 80%, which shows that the modified MIL-53(Fe) metal organic framework has better recycling property.
Description of experimental tests:
the composition of the catalyst elements and the valence state of each element are characterized in that:
XPS characterization of modified MIL-53(Fe) metal organic framework and peak separation of Fe2p spectrogram are shown in FIG. 1. The iron element component of the modified MIL-53(Fe) metal organic framework presents a mixed valence state of +2 valence and +3 valence, and according to a fitting result, the content percentage of each valence state is as follows: fe2+/Fe3+＝68.52.17 for/31.5. In the course of catalytic activation of PS reaction, Fe2 +And Fe3+Can serve as accessible effective catalytic active sites compared with unmodified MIL-53(Fe)2+/Fe3+＝1.76)(Catalysis Science&Technology.2017,7:1129-1140), the modified material contains Fe2+Higher content of component due to Fe2+Is the most effective active species in the process of activating PS, so the modified catalyst has stronger activity.
Structural characterization of the catalyst:
XRD and FTIR characterization were performed on the modified MIL-53(Fe) metal-organic framework prepared under the conditions of preparation method 1 in example 1, respectively, and the results are shown in fig. 2 and 3. As can be seen from FIG. 2, the XRD pattern of the modified MIL-53(Fe) metal organic framework prepared by the method contains characteristic peaks at 2 theta values of about 9.1 degrees, 10.6 degrees, 12.5 degrees, 17.5 degrees, 18.2 degrees, 19.1 degrees, 25.3 degrees and 27.2 degrees, wherein the peak at about 10.6 degrees is a new characteristic peak compared with the MIL-53(Fe) before modification, and the appearance of the new characteristic peak indicates that the crystal structure of the modified MIL-53(Fe) synthesized by using ferrous salt as a precursor tends to be converted to the structure of Fe (BDC) (DMF, F). Can be distinguished from the traditional MIL-53(Fe) metal organic framework material by the position of a characteristic peak. Before and after the PS reaction is activated, the number and the position of characteristic peaks are not obviously changed, which indicates that the crystal structure of the modified MIL-53(Fe) is not obviously changed before and after the PS reaction is catalyzed.
As can be seen from the analysis of FIG. 3, the metal-organic framework of modified MIL-53(Fe) is 1382cm-1、1534cm-1The left and right peaks are attributed to the vibration peak of benzene ring side chain- (-O-C-O-) -1633 cm-1The peak at (A) is assigned to-C ═ O, 751cm-1And 1109cm-1At a vibration peak ascribed to a C-H bond, and 1017cm-1And 1152cm-1The peak is attributed to the vibration peak of the C-O bond, compared with the FTIR of the unmodified MIL-53(Fe), the FTIR characteristic peak position of the modified MIL-53(Fe) is not obviously changed, and the number and the position of the characteristic peak of the modified MIL-53(Fe) are not obviously changed after the PS reaction is activated, which indicates that the organic ligand part of the material is not obviously subjected to the catalysis of the PS reactionThe above conclusion shows that the synthesis of the metal organic framework material with stable structure is feasible by using ferrous salt as a precursor.
The above embodiments are preferred embodiments of the present invention, but the present invention is not limited to the above embodiments, and any other changes, modifications, substitutions, combinations, and simplifications which do not depart from the spirit and principle of the present invention should be construed as equivalents thereof, and all such changes, modifications, substitutions, combinations, and simplifications are intended to be included in the scope of the present invention.

Claims (7)

1. A preparation method of a modified MIL-53(Fe) metal organic framework is characterized by comprising the following steps:
(1) uniformly mixing terephthalic acid, ferrous chloride tetrahydrate and N, N-dimethylformamide to obtain a mixed solution;
(2) placing the mixed solution in a hydrothermal synthesis reaction kettle for heating reaction; the molar ratio of the terephthalic acid to the ferrous chloride tetrahydrate is 1: 1; the molar ratio of the terephthalic acid to the N, N-dimethylformamide is 1: 52-1: 65; the temperature of the heating reaction is 150-170 ℃; the heating reaction time is 5-72 h;
(3) and after the reaction is finished, naturally cooling, washing and drying to obtain the modified MIL-53(Fe) metal organic framework.
2. A modified MIL-53(Fe) metal organic framework made by the method of claim 1.
3. The method for treating organic wastewater by using the modified MIL-53(Fe) metal organic framework activated persulfate as set forth in claim 2, which comprises the following steps:
(1) determination of COD of organic wastewater to be treatedCrValue and pH;
(2) and (3) adding persulfate and a modified MIL-53(Fe) metal organic framework into the organic wastewater, fully oscillating or stirring to perform wastewater treatment reaction, decomposing the persulfate to generate strong-oxidizing sulfate radicals, and performing oxidative degradation treatment on the organic wastewater.
4. The method according to claim 3, wherein the initial pH value of the organic wastewater in the step (1) is 2-9.
5. The method according to claim 3, wherein the persulfate in the step (2) is sodium persulfate, potassium persulfate or ammonium persulfate.
6. The method of claim 3, wherein the modified MIL-53(Fe) metal organic framework in the step (2) is added to the organic wastewater in an amount corresponding to COD in the organic wastewaterCrThe mass concentration ratio of the values is (2.5-12.5)/1.
7. The method according to any one of claims 3 to 6, wherein the persulfate is added to the organic wastewater in the step (2) in an amount corresponding to the COD in the organic wastewaterCrThe mass concentration ratio of the values is (30-50)/1.
CN201710169590.4A 2017-03-21 2017-03-21 Preparation of modified MIL-53(Fe) metal organic framework and method for treating organic wastewater by activating persulfate Active CN106957438B (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN201710169590.4A CN106957438B (en) 2017-03-21 2017-03-21 Preparation of modified MIL-53(Fe) metal organic framework and method for treating organic wastewater by activating persulfate

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN201710169590.4A CN106957438B (en) 2017-03-21 2017-03-21 Preparation of modified MIL-53(Fe) metal organic framework and method for treating organic wastewater by activating persulfate

Publications (2)

Publication Number Publication Date
CN106957438A CN106957438A (en) 2017-07-18
CN106957438B true CN106957438B (en) 2020-12-22

Family

ID=59471503

Family Applications (1)

Application Number Title Priority Date Filing Date
CN201710169590.4A Active CN106957438B (en) 2017-03-21 2017-03-21 Preparation of modified MIL-53(Fe) metal organic framework and method for treating organic wastewater by activating persulfate

Country Status (1)

Country Link
CN (1) CN106957438B (en)

Families Citing this family (19)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN107383386B (en) * 2017-08-04 2020-07-21 南京工业大学 Method for preparing two-dimensional metal organic framework material and application thereof
CN107792932B (en) * 2017-11-30 2021-01-19 华南理工大学 Advanced oxidation reactor based on MOFs activated PS and method for treating wastewater by using advanced oxidation reactor
CN108176414B (en) * 2017-12-12 2020-11-24 上海大学 Catalyst MnFe2O4-MIL-53(Al) magnetic composite material, preparation method and application thereof
CN109133321A (en) * 2018-09-12 2019-01-04 北京农学院 Activate persulfate system, degradation of contaminant, application
CN109482233B (en) * 2018-11-01 2022-03-29 华南理工大学 Ferrous metal organic framework material, normal-pressure synthesis method thereof and method for treating organic pollutants by catalytically activating persulfate
CN110170336A (en) * 2019-05-20 2019-08-27 辽宁石油化工大学 The preparation method of the open mode in the duct (Fe) metal-organic framework materials MIL-53
CN110170337A (en) * 2019-05-20 2019-08-27 辽宁石油化工大学 Metal-organic framework materials MIL-53(Fe) hole-closing structure preparation method
CN110548544B (en) * 2019-07-12 2021-09-21 华南理工大学 Iron oxide doped iron metal organic framework, green macro preparation method and application
CN110538677B (en) * 2019-07-15 2021-07-20 华南理工大学 MOFs/MIPs catalyst and in-situ growth preparation method and application thereof
CN110483788B (en) * 2019-07-19 2021-11-05 中国地质大学（武汉） MIL-53(Fe) composite material, preparation method thereof and application thereof in tetracycline degradation
CN110404526B (en) * 2019-07-25 2021-09-14 中国科学院城市环境研究所 La derived based on MOFs2O3Method for removing PPCPs and As (III) by using @ C activated persulfate
CN110964207B (en) * 2019-11-22 2021-10-26 华南理工大学 Free radical controllable release defect coordination metal organic framework, preparation method and application
CN110947385A (en) * 2019-11-30 2020-04-03 华南理工大学 Carbon-encapsulated defective iron nano catalyst, preparation method thereof and application thereof in catalyzing peroxymonosulfate to degrade emerging pollutants
CN111422966B (en) * 2020-02-21 2021-09-28 东莞理工学院 Method for treating organic wastewater by efficiently activating persulfate through metal organic framework Fe (PIP)
CN111841620B (en) * 2020-06-23 2021-11-05 华南理工大学 Millimeter-grade peroxymonosulfate activator ZSM-5- (C @ Fe) and preparation method and application thereof
CN111825201A (en) * 2020-07-20 2020-10-27 上海相出净流环保科技开发有限公司 Preparation method and application of self-adaptive liquid Fenton reaction catalyst for industrial wastewater treatment
CN114247477A (en) * 2021-12-23 2022-03-29 南京环保产业创新中心有限公司 Fenton-like reaction catalyst and preparation method and application thereof
CN115888832A (en) * 2022-10-21 2023-04-04 华南农业大学 Sediment-based MOFs (metal-organic frameworks) and preparation method and application thereof
CN116835852A (en) * 2023-07-05 2023-10-03 中交疏浚技术装备国家工程研究中心有限公司 Sediment dehydration method

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN104310565A (en) * 2014-10-15 2015-01-28 济南大学 Method of treating organic wastewater based on Fenton-like reaction of iron-based organic-framework material
CN104525266A (en) * 2014-12-30 2015-04-22 河南理工大学 Preparation method of metal-organic framework material photocatalyst and application
CN105923738A (en) * 2016-06-20 2016-09-07 华南理工大学 Method for utilizing metal organic skeleton to carry out efficient catalytic activation on persulfate or peroxymonosulfate to process organic wastewater

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN104310565A (en) * 2014-10-15 2015-01-28 济南大学 Method of treating organic wastewater based on Fenton-like reaction of iron-based organic-framework material
CN104525266A (en) * 2014-12-30 2015-04-22 河南理工大学 Preparation method of metal-organic framework material photocatalyst and application
CN105923738A (en) * 2016-06-20 2016-09-07 华南理工大学 Method for utilizing metal organic skeleton to carry out efficient catalytic activation on persulfate or peroxymonosulfate to process organic wastewater

Non-Patent Citations (2)

* Cited by examiner, † Cited by third party
Title
Controlled synthesis of mixed-valent Fe-containing metal organic frameworks for the degradation of phenol under mild conditions;Qiao Sun等;《Dalton Transactions》;20160201;第45卷(第19期);第7952-7959页 *
Qiao Sun等.Controlled synthesis of mixed-valent Fe-containing metal organic frameworks for the degradation of phenol under mild conditions.《Dalton Transactions》.2016,第45卷(第19期),第7952-7959页. *

Also Published As

Publication number Publication date
CN106957438A (en) 2017-07-18

Similar Documents

Publication Publication Date Title
CN106957438B (en) Preparation of modified MIL-53(Fe) metal organic framework and method for treating organic wastewater by activating persulfate
CN109054033B (en) Iron/cobalt bimetal organic framework material and preparation method and application thereof
CN112675851B (en) Fe-MOFs peroxyacetic acid catalyst and preparation method and application thereof
Liu et al. Efficient removal of Cu (II) organic complexes by polymer-supported, nanosized, and hydrated Fe (III) oxides through a Fenton-like process
CN112206828A (en) Preparation method, product and application of ferrous-doped Fe-MOFs Fenton catalyst
CN113856725B (en) g-C 3 N 4 /Fe/MoS 2 Ternary flower-like heterojunction material and preparation method and application thereof
CN109622055B (en) Iron-manganese bimetallic catalyst based on iron carbide-based MOFS (metal oxide semiconductor) and preparation method thereof
CN111422966B (en) Method for treating organic wastewater by efficiently activating persulfate through metal organic framework Fe (PIP)
CN113941343A (en) Sludge-based composite catalyst and preparation method and application thereof
Zhang et al. Efficient degradation of metronidazole wastewater over MIL-101 (Fe) Fenton catalysts
CN114849783A (en) Catalytic material for oxidative degradation of phenolic compound wastewater by microwave activation of persulfate and preparation and application methods thereof
Luo et al. CoFe-LDO nanoparticles as a novel catalyst of peroxymonosulfate (PMS) for histidine removal
Zhao et al. ZIF-8-derived hollow carbon polyhedra with highly accessible single Mn-N6 sites as peroxymonosulfate activators for efficient sulfamethoxazole degradation
CN114425348B (en) Nano composite oxide, preparation method and application thereof
CN102008965A (en) Method for preparing ozone catalytic oxidation catalyst for treating cyanide waste water
CN113559883A (en) Preparation method of modified iron sulfide Fenton catalyst
Lv et al. Persulfate activation by ferrocene-based metal–organic framework microspheres for efficient oxidation of orange acid 7
CN114950432B (en) Iron/nitrogen doped carbon-based catalyst with three-dimensional hollow structure, and preparation method and application thereof
CN115301269B (en) Preparation method and application of ruthenium monoatomic catalyst
CN112138661A (en) Application of nano metal oxide in catalyzing persulfate to degrade organic dye
Deng et al. Highly-separated Co anchored on S, O-doped carbon nitride for enhanced peroxymonosulfate activation: Insights into radical and non-radical pathways
CN109621975A (en) A kind of support type ozone catalytic oxidation catalyst and its preparation method and application
CN111302475B (en) Method for treating organic wastewater by efficiently activating persulfate through metal organic framework Fe (Nic)
He et al. Metal-doped alumina pellets catalyze the quick degradation of humic acid using oxygen as the oxidant at low temperatures
CN112058295A (en) Diaminopyridine sinter composite praseodymium oxide and ferroferric oxide heterogeneous catalyst, application thereof and in-situ preparation method

Legal Events

Date Code Title Description
PB01 Publication
PB01 Publication
SE01 Entry into force of request for substantive examination
SE01 Entry into force of request for substantive examination
GR01 Patent grant
GR01 Patent grant