CN103464160A - Preparation method of iron carbon catalyst applied in heterogeneous Fenton system - Google Patents

Abstract

The invention relates to a preparation method of an iron carbon catalyst applied in a heterogeneous Fenton system. The preparation method is mainly characterized in that polytetrafluoroethylene is taken as a modification raw material, and after being impregnated, iron carbon is calcinated under nitrogen protection. The catalyst prepared by the method can efficiently reduce the leaching rate of iron, prolong the service life, overcome the phenomenon that the surface of the iron carbon is easy to form scale to a certain extent, and reduce the iron cement content in effluent. The catalyst is especially applicable to the heterogeneous Fenton reaction under the nearly neutral conditions, can efficiently degrade organic waste water, has the advantages of good catalytic performance, long service life, low price and the like, and has a better application prospect in environmental protection.

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 C catalyst method of modifying that is applied to heterogeneous Fenton system.

Background technology

Fenton oxidation is that in high-level oxidation technology, important oxidation technology has the characteristics such as operating process is simple, reaction speed fast, simple equipments, environmental friendliness.Catalyst Fe is provided ²⁺the time additional H ₂o ₂thereby, by H ₂o ₂the hydroxyl radical free radical (OH) that changes into strong oxidability reaches the organic matter degradation mineralising.Course of reaction is as follows:

Fe ²⁺+H ₂O ₂→Fe ³⁺+OH ^-+·OH

At present, Fenton oxidation is mainly directly in solution, to add the homogeneous phase iron ion.But homogeneous phase iron ion pH narrow application 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 the iron concentration in solution, reduces the generation of iron mud, can also widens application range of pH.Therefore, develop excellent catalytic effect, the life-span is long, and the pH scope of application is wide, and cheap heterogeneous Fenton catalyst has great industrial application value.

Iron-carbon micro-electrolysis is at industrial application comparative maturity, normally the contained Zero-valent Iron (Fe with iron carbon filler self ⁰) reduction and micro-electrolysis after the iron ion flocculation that produces remove the pollutant in waste water.Iron carbon molecule can form a lot of small galvanic cells in solution.Fe ⁰lose electronics and become Fe in system ²⁺after, just in time can be used as the catalyst of Fenton.Although current industrial iron carbon filler price is very cheap, industrial great using value arranged, the leaching rate of its iron is high, produce a large amount of iron mud, the iron carbon surface is easily fouling also, thereby is unfavorable for the carrying out of Fenton and reduces water treatment effect, shortens catalyst life.How on the basis of iron C catalyst, to research and develop simple modification method for preparing efficiently, under the prerequisite that keeps high catalytic performance, reduce the generation of iron mud, there is important using value.

Summary of the invention

The objective of the invention is to reduce by modification the iron ion leaching rate of iron carbon filler, extend iron carbon service life, develop the heterogeneous iron C catalyst applicable in the 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, cleans for several times with absolute ethyl alcohol again after filtration.

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

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

The present invention has following outstanding feature and beneficial effect:

(1) utilize polytetrafluoroethylene (PTFE) that the iron carbon surface is coated, successfully reduced a large amount of leachings of iron ion, reduced 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, by modification, has extended catalyst service life, good economy performance.

(3) leaching of modification rear catalyst iron ion reduces 3-5 doubly, is applied in heterogeneous Fenton system, and the effectively refractory organic such as degrading phenol, and energy widens application range of pH, especially under the near-neutral pH condition.

The accompanying drawing explanation

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.

The specific embodiment

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.At first carry out the pretreatment of iron carbon, granular iron carbon filler is immersed in absolute ethyl alcohol, filter after ultrasonic 30min.Then iron carbon is immersed in to 1h in 20% polytetrafluoroethylsolution solution, after filtration, under the condition of logical nitrogen, 400 ℃ of calcining 30min get final product.

(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 covered one deck polymeric membrane, and can learn by the less accompanying drawing from Fig. 2, and what the iron carbon surface after modification covered is the film of one deck macromolecular fibre shape.After such modification, iron carbon surface structure has lowered the contact area between iron carbon and solution greatly, thereby has effectively reduced the leaching rate of iron ion.

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

As seen from the above table, the clearance of Dichlorophenol is more or less the same, and after modification, the iron ion leaching has reduced about 4.5 times.

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

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

In sum, add the price that the iron carbon filler is cheap, the iron carbon after modification has certain value on commercial Application.

Claims (2)

1. an iron C catalyst preparation method who is applied to heterogeneous Fenton system.Concrete preparation process is as follows:

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

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

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

2. the iron carbon that according to claim 1 prepared by method is applied to treatment of Organic Wastewater as heterogeneous Fenton catalyst.

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