CN103464160B - A kind of iron C catalyst preparation method who is applied to heterogeneous Fenton system - Google Patents

Abstract

The present invention relates to a kind of iron C catalyst preparation method who is applied to heterogeneous Fenton system. This method is mainly taking polytetrafluoroethylene (PTFE) as modified feedstock, by after iron carbon dipping, under nitrogen protection, calcines. The standby catalyst of this legal system can reduce the leaching rate of iron effectively, increases the service life, and can solve to a certain extent the easy scale formation of iron carbon surface, has reduced the iron cement content of water outlet. This catalyst is particularly useful for the heterogeneous Fenton's reaction under nearly neutrallty condition, can efficient degradation organic wastewater, have that catalytic performance is good, a long service life, the advantage such as cheap, and there is good environmental protection application prospect.

Description

A kind of iron C catalyst preparation method who is applied to heterogeneous Fenton system

Technical field

The invention belongs to field of environment engineering technology, relate to a kind of iron carbon that is applied to heterogeneous Fenton system and urgeAgent method of modifying.

Background technology

Fenton oxidation is that in high-level oxidation technology, important oxidation technology has that operating process is simple, reactionThe features such as speed is fast, simple equipments, environmental friendliness. Catalyst Fe is provided²⁺Time additional H₂O₂Thereby,By H₂O₂The hydroxyl radical free radical (OH) that changes into strong oxidability reaches organic matter degradation mineralising. ReactedJourney is as follows:

Fe²⁺+H₂O₂→Fe³⁺+OH^-+·OH

At present, Fenton oxidation is mainly directly in solution, to add homogeneous phase iron ion. But homogeneous phase iron ion pH is suitableBy narrow range, solution is high containing concentration of iron, causes last handling process to produce a large amount of iron mud, has increased processing cost.Heterogeneous Fenton catalyst just in time can overcome these shortcomings, and the iron ion stripping of a small amount of concentration can reduce moltenIron concentration in liquid, reduces the generation of iron mud, can also widens application range of pH. Therefore, developExcellent catalytic effect, the life-span is long, and the pH scope of application is wide, and cheap heterogeneous Fenton catalyst has greatlyIndustrial application value.

Iron-carbon micro-electrolysis is at industrial application comparative maturity, normally with the contained Zero-valent Iron of iron carbon filler self(Fe⁰) reduction and micro-electrolysis after the iron ion flocculation that produces remove the pollutant in waste water. IronCarbon molecule can form a lot of small galvanic cells in solution. Fe⁰In system, lose electronics and become Fe²⁺After, just in time can be used as the catalyst of Fenton. Although current industrial iron carbon filler price is very cheap,Have great using value industrial, but the leaching rate of its iron is high, produces a large amount of iron mud, iron carbon surfaceAlso easily fouling, thus be unfavorable for the carrying out of Fenton and reduce water treatment effect, shorten catalyst life.How on the basis of iron C catalyst, to research and develop simple modification method for preparing efficiently, keeping high catalysisUnder the prerequisite of performance, reduce iron mud and produce, there is important using value.

Summary of the invention

The object of the invention is to reduce by modification the iron ion leaching rate of iron carbon filler, extend iron carbon and use the longevityLife, develops the heterogeneous iron C catalyst being suitable in Fenton system.

The catalyst preparation process that the present invention proposes is as follows:

1) iron carbon is immersed in to ultrasonic cleaning 30-60min in absolute ethyl alcohol, after filtration, cleans with absolute ethyl alcohol againFor several times.

(2) the iron carbon of getting after drying is immersed in after the polytetrafluoroethylsolution solution 1-2h of 10%-30%, suction filtration.

(3), by the iron carbon after suction filtration, under 200 DEG C of-400 DEG C of logical nitrogen protections, calcine 30-60min.

The present invention has following outstanding feature and beneficial effect:

(1) utilize polytetrafluoroethylene (PTFE) that iron carbon surface is coated, successfully reduced a large amount of leachings of iron ion,Reduce water outlet iron cement content, and solved to a certain extent iron carbon surface structure problem.

(2) preparation process is simple, is easy to suitability for industrialized production, selects industrial iron carbon filler, cheap,Catalyst service life, good economy performance are extended by modification.

(3) leaching of modification rear catalyst iron ion reduces 3-5 doubly, is applied in heterogeneous Fenton system, canThe refractory organics such as effective degrading phenol, and energy widens application range of pH, especially in nearly neutralityUnder pH condition.

Brief description of the drawings

Fig. 1 is the electron-microscope scanning figure before the modification of iron carbon.

Fig. 2 is the electron-microscope scanning figure after the modification of iron carbon.

Detailed description of the invention

The present invention is described in further detail by reference to the accompanying drawings by following examples.

(1) method of modifying of the present invention

The present invention is mainly modified industry forming iron carbon filler. First carry out the pretreatment of iron carbon, by granularIron carbon filler is immersed in absolute ethyl alcohol, after ultrasonic 30min, filters. Then iron carbon is immersed in to 20% poly-four1h in PVF solution, under the condition of logical nitrogen, calcines 30min for 400 DEG C after filtration.

(2) effect that this embodiment obtains

As shown in Figure 1, the iron carbon SEM after modification as shown in Figure 2 for iron carbon SEM before this example modification.Before can seeing modification, iron carbon surface porous, and coarse inhomogeneous; After modification, surface has obviously coveredOne deck polymeric membrane, and can learn by the less accompanying drawing from Fig. 2, the iron carbon surface after modification coversIt is the film of one deck macromolecular fibre shape. After such modification, iron carbon surface structure has lowered iron carbon and molten greatlyContact area between liquid, thus the leaching rate of iron ion effectively reduced.

Waste water is 2 of 120mg/L, 4-Dichlorophenol, and pH=6.7,0.05M anhydrous sodium sulfate is molten as electrolyteLiquid, liquor capacity is 150mL, every secondary response adds the H of 500mg/L₂O₂, the catalysis of 0.9g Modified Iron carbonAgent. The iron carbon that adopts respectively original iron carbon and modification to prepare is catalyst, and heterogeneous Fenton is processed this waste water 2hContrast on effect as following table.

As seen from the above table, the clearance of Dichlorophenol is more or less the same, and after modification, iron ion leaching has reduced approximately4.5 doubly.

Iron carbon after modification moves 10 times continuously in heterogeneous Fenton system, its Dichlorophenol clearance, TOCThe leaching amount of clearance and iron is as following table:

After reaction 2h, obtain the clearance of good Dichlorophenol and the clearance of TOC. 10 operations, everyInferior iron leaching rate, at 0.18%-0.31%, amounts to the leaching rate approximately 2.3% of iron ion, iron carbon long service life.

In sum, add the price that iron carbon filler is cheap, the iron carbon after modification has one in commercial ApplicationFixed value.

Claims (2)

1. an iron C catalyst preparation method who is applied to heterogeneous Fenton system, is characterized in that, adoptsFollowing method preparation:

(1) iron carbon is immersed in to ultrasonic cleaning 30-60min in absolute ethyl alcohol, clear with absolute ethyl alcohol again after filtrationWash for several times;

(2) the iron carbon of getting after drying is immersed in after the polytetrafluoroethylsolution solution 1-2h of 10%-30%, suction filtration;

(3), by the iron carbon after suction filtration, under 200 DEG C of-400 DEG C of logical nitrogen protections, calcine 30-60min.

2. the iron carbon that according to claim 1 prepared by method is applied to organic as heterogeneous Fenton catalystWastewater treatment.