活性炭吸附重金属离子的研究外文文献原文

Materials Science and Engineering A391(2005)

121–123

Adsorption behaviors of heavy metal ions onto electrochemically

oxidized activated carbonfibers

Soo-Jin Park∗,Young-Mi Kim

Advanced Materials Division,Korea Research Institute of Chemical Technology,P.O.Box107,Yusong,Daejeon305-600,South Korea

Received4March2004;received in revised form17August2004;accepted27August2004

Abstract

In this work,the effect of electrochemical oxidation treatments of activated carbonfibers(ACFs)was studied in heavy metal adsorption behaviors.As a result,the acidic or basic anodic treatment led to increases of Cr(VI),Cu(II),and Ni(II)adsorptions,which could be attributed to the oxygen-containing functional groups of the ACF surfaces.

©2004Elsevier B.V.All rights reserved.

Keywords:Activated carbonfibers;Electrochemical treatments;Surface properties;Heavy metal ions;Adsorption

1.Introduction

As compared with conventional granular or powder activated carbons,activated carbonfibers(ACFs)have been widely used as an excellent adsorbent because of their large surface area,microporous character,and high adsorption/desorption rate[1].Also,the microstructure of ACFs is developed during activation,and influenced by many factors,such as the degree of activation and the conditions used for carbonization[2].The adsorption/desorption rate of carbonaceous adsorbents is greatly depended on not only microporous structure but also surface properties[3].Gen-erally,the electrochemical oxidation treatment of carbon in the electrolytes used can produce microstructure and surface changes of the carbon surfaces.The advantage of electro-chemical oxidation treatment is obtaining a relatively large number of oxygen-containing functional groups on ACF surfaces[4].

In this work,ACFs are modified by electrochemical ox-idation treatment with acidic or basic electrolyte to obtain oxygen-containing functional groups,and the effect of elec-

∗Corresponding author.Tel.:+82428607234;fax:+82428614151.

E-mail address:psjin@krict.re.kr(S.-J.Park).trochemical oxidation treatment on ACFs is studied in the context of heavy metal adsorption behaviors.

2.Experimental

The pitch-based ACFs(bundle type,Kureha)were washed with deionized water and dried for24h at80◦C(untreated-ACFs).All other chemicals were purchased in analytical grade purity from Aldrich Chemical Co.and used as re-ceived.The ACFs were subjected to electrolytic reaction in the aqueous solutions of10wt.%H3PO4(A-ACFs)and NH4OH(B-ACFs),whereby negative ions were attracted to the surface of the ACFs acting as an anode,thereby modi-fying the ACF surfaces.A cathode graphite plate was also submerged in the electrolyte solution,and the conditions of the surface treatment were processed in an electro-bath at7A for10min.The treated ACFs emerging from the electrolytic cell were dried for6h at110◦C.The surface properties of ACFs were measured by Boehm’s titration.The specific sur-face area and the pore structure were evaluated from nitro-gen adsorption data at77K(Micromeritics,ASAP2010)[5].

0.05g of the ACFs was placed in contact with150ml solution of20ppm concentrations of Na2CrO4·4H2O,CuCl2·2H2O, and NiCl2·6H2O.The single bottle was sealed with paraffin

0921-5093/$–see front matter©2004Elsevier B.V.All rights reserved. doi:10.1016/j.msea.2004.08.074