High adsorptivity and recycling performance activated carbon fibers for Cu(II) adsorption

doi:10.1016/j.scitotenv.2019.134412

Science of The Total Environment

Volume 700, 15 January 2020, 134412

https://doi.org/10.1016/j.scitotenv.2019.134412 Get rights and content

Abstract

In order to develop adsorbent materials with high Cu(II) adsorptivity and renewable recycling for Cu(II), nitric acid oxidation process is optimized and ameliorated by microwave and sonication to obtain an efficient modification and regeneration processes. Microwave-assisted nitric acid oxidation process has the most significant enhancement effect to the Cu(II) adsorptivity of activated carbon fiber felts (ACFFs), which can reach 23.13 mg/g and 4.55 times of pristine felts. It is due to this process can greatly increase the ultramicropore volume and polar oxygen-containing groups. In addition, sonication-assisted-pickling regeneration process achieves efficient regenerations and enhancements of Cu(II) adsorptivity for ACFFs. The Cu(II) adsorptivity and regeneration rate of ACFFs are still up at 25.51 mg/g and 379.59% after five times recycling by the process of sonication-assisted pickling regeneration process.

Graphical abstract

Introduction

Cu(II) is a common harmful pollutant, excessive intake of Cu(II) may cause liver damage and acute poisoning in humans (Li and Bai, 2005; Hu et al., 2014). Governments have developed uniform Cu(II) emission standards, such as 2 mg/L in the US and 3 mg/L in Japan, and this standard will continue to raise with the need of human health. The field of Cu(II) purification faces a series of problems such as difficult to purify, high cost and non-recyclable (Wang et al., 2012; Li et al., 2012). The most promising purification process is the adsorption method, while activated carbon fiber felts (ACFFs) is highly efficient for specific adsorption (Macíasgarcía et al., 2017; Bhatnagar et al., 2013; Huang and Su, 2010).

Sorption mainly includes physisorption derived from the adsorption potential of the pore structure and chemisorption derived from the polar action of the surface chemical group (Yu et al., 2018a; Julien et al., 1998). Activated carbon fiber felts (ACFFs), as a porous adsorbent based on microporous structure, have a large number of micropores and abundant oxygen-containing groups on the surface, which determine its excellent physical adsorption properties and chemical adsorption properties (Kumar and Jena, 2015; Miyamoto et al., 2005). Its ultramicropores are basically the interlayer pore of graphite-like microcrystals and ultramicropores are mainly formed by the disorderly arrangement of graphite-like microcrystals. Therefore, porous adsorbent materials with high adsorption properties for specific adsorbents can be obtained by oxidation modification, which can enhance the content of pore structures and surface polar functional groups simultaneously (Kadirvelu et al., 2000).

Chen et al. (2003) modified granular activated carbon with 1.0 M critic acid. The Cu(II) adsorptivity was enhanced by 140% and there was no research on recycling performance. Lu et al. (2017) modified activated carbon fibers by chemical grafting with amidoxime, which increased U(VI) adsorptivity by 172%. Mugisidi et al. (2007) modified activated carbon by treatment with 15% sodium acetate, which increased Cu(II) adsorptivity by 120%. For the application of specific ion adsorption, the existing modification methods of activated carbon fiber are relatively simple, and the research on regeneration process is less. Therefore, activated carbon fibers having high adsorption properties and recycling properties for specific metal ions are in urgent need to be exploited.

The objective of this study is to investigate an effective modification process and regeneration process of ACFFs, which aims to enhance the Cu(II) adsorptivity and achieve recycling of ACFFs for the purification of Cu(II). In this article, ACFFs modified by nitric acid oxidation, ultrasonic-assisted nitric acid oxidation process and microwave-assisted nitric acid oxidation process were studied by using 50 mg/L Cu(II) aqueous solution as adsorbent, and the technological parameters such as nitric acid concentration, nitric acid dosage, oxidation time and oxidation temperature were optimized. Moreover, sonication-assisted-pickling regeneration process was studied for the regeneration and reutilization of ACFFs for Cu(II) adsorption.

Section snippets

Chemicals and materials

ACFFs with specific surface area of 1055.65 m²/g were provided by Carbon Fiber Engineering Technology Research Center, Shandong University. ACFFs was pretreated in a vacuum oven under the specific conditions of 0.1 MPa vacuum at the temperature of 403 K for 3 h before nitric acid oxidation process. All the chemical reagents such as nitric acid, copper sulfate pentahydrate, sodium diethyldithiocarbamate, ammonia were provided by China Pharmaceutical Group Chemical Reagents Co., Ltd. High pure

Characterization of ACFFs

The diameter of free Cu(II) in aqueous phase is 0.146 nm, and the physical adsorption of Cu(II) by ACFFs mainly comes from the adsorption potential energy of microporous structure. In this part, ultramicropores (0–0.7 nm) and supermicropores (0.7–2 nm) of ACFFs were analyzed by N₂ adsorption test. As shown in Fig. 1c and Table 1, the order of specific surface area, micropore volume and total pore volume is N_S-ACFF>N_M-ACFF>ACFF₀ > N_O-ACFF, the order of ultramicropore volume is N_M-ACFF>N_S

Acknowledgments

This work was supported by National Natural Science Foundation of China (Grant No. 51473088), National Key Research and Development Program of China (Project No. 2016YFC0301402), Key Research and Development Plan of Shandong Province (Project No. 2018GGX102029), Key Research and Development Plan of Shandong Province (Project No. 2017CXGC0409) and Shandong Post-doctoral Innovation Fund (Project No. 2017030759).

References (44)

S. Balaji et al.
Mediated electrochemical oxidation process: electro-oxidation of cerium(III) to cerium(IV) in nitric acid medium and a study on phenol degradation by cerium(IV) oxidant
Chem. Eng. J.
(2007)
A. Bhatnagar et al.
An overview of the modification methods of activated carbon for its water treatment applications
Chem. Eng. J.
(2013)
J. Chen et al.
Surface modification of a granular activated carbon by citric acid for enhancement of copper adsorption
Carbon
(2003)
J. Collins et al.
Spectroscopic investigations of sequential nitric acid treatments on granulated activated carbon: effects of surface oxygen groups on π density
Carbon
(2013)
E. Dalodière et al.
Effect of ultrasonic frequency on H₂O₂ sonochemical formation rate in aqueous nitric acid solutions in the presence of oxygen
Ultrason. Sonochem.
(2016)
J. Deng et al.
Extraction of heavy metal from sewage sludge using ultrasound-assisted nitric acid
Chem. Eng. J.
(2009)
S. Deng et al.
Polyacrylonitrile-based fiber modified with thiosemicarbazide by microwave irradiation and its adsorption behavior for Cd(II) and Pb(II)
J. Hazard. Mater.
(2016)
Y. He et al.
Quantification of carbon nanotubes in different environmental matrices by a microwave induced heating method
Sci. Total Environ.
(2017)
C. Huang et al.
Removal of copper ions from wastewater by adsorption/electrosorption on modified activated carbon cloths
J. Hazard. Mater.
(2010)
G. Huang et al.
Removal of Cr(VI) from aqueous solution using activated carbon modified with nitric acid
Chem. Eng. J.
(2009)

F. Julien et al.

Relationship between chemical and physical surface properties of activated carbon

Water Res.

(1998)

S. Kim et al.

Purification and separation of carbon nanocapsules as a magnetic carrier for drug delivery systems

Carbon

(2008)

K.R. Ko et al.

Effect of ozone treatment on Cr(VI) and Cu(II) adsorption behaviors of activated carbon fibers

Carbon

(2004)

A. Kumar et al.

High surface area microporous activated carbons prepared from fox nut (Euryale ferox) shell by zinc chloride activation

Appl. Surf. Sci.

(2015)

N. Li et al.

Copper adsorption on chitosan-cellulose hydrogel beads: behaviors and mechanisms

Sep. Purif. Technol.

(2005)

M. Machida et al.

Prediction of simultaneous adsorption of Cu(II) and Pb(II) onto activated carbon by conventional langmuir type equations

J. Hazard. Mater.

(2005)

A. Macíasgarcía et al.

Study of the adsorption and electroadsorption process of Cu(II) ions within thermally and chemically modified activated carbon

J. Hazard. Mater.

(2017)

J.I. Miyamoto et al.

The addition of mesoporosity to activated carbon fibers by a simple reactivation process

Carbon

(2005)

D. Mugisidi et al.

Modification of activated carbon using sodium acetate and its regeneration using sodium hydroxide for the adsorption of copper from aqueous solution

Carbon

(2007)

T.X. Nguyen et al.

Characterization of activated carbon fibers using argon adsorption

Carbon

(2005)

E. Shibata et al.

Synthesis of amorphous carbon particles by an electric arc in the ultrasonic cavitation field of liquid benzene

Carbon

(2004)

R.A. Torres et al.

A comparative study of ultrasonic cavitation and fenton's reagent for bisphenol a degradation in deionised and natural waters

J. Hazard. Mater.

(2007)

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High adsorptivity and recycling performance activated carbon fibers for Cu(II) adsorption

Abstract

Graphical abstract

Introduction

Section snippets

Chemicals and materials

Characterization of ACFFs

Acknowledgments

Chem. Eng. J.

Chem. Eng. J.

Carbon

Carbon

Ultrason. Sonochem.

Chem. Eng. J.

J. Hazard. Mater.

Sci. Total Environ.

J. Hazard. Mater.

Chem. Eng. J.

Water Res.

Carbon

Carbon

Appl. Surf. Sci.

Sep. Purif. Technol.

J. Hazard. Mater.

J. Hazard. Mater.

Carbon

Carbon

Carbon

Carbon

J. Hazard. Mater.