Removal of reactive dye using reusable and eco-friendly composite of starch-graft-polyaniline/Fe3O4

Tạp chí Khoa học và Công nghệ, Số 31, 2018

© 2018 Trường Đại học Công nghiệp Thành phố Hồ Chí Minh

REMOVAL OF REACTIVE DYE USING REUSABLE AND ECO￾FRIENDLY COMPOSITE OF STARCH-GRAFT-POLYANILINE/Fe3O4

NGUYEN VAN CUONG, NGUYEN VAN BOI, PHAM THI HONG

Faculty of Chemical Engineering, Industrial University of Ho Chi Minh City;

[email protected]

Abstract. Magnetic composite had showed a promising candidate for applications in wastewater treatment.

In this paper, starch-g-polyaniline/Fe3O4 (St-PANI/Fe3O4) composite particles were prepared successfully

by chemical oxidation polymerization of aniline and starch in the presence of ammonium peroxydisulfate

as the catalyst. The prepared composite were characterized by Fourier transform infrared spectroscopy

(FTIR), scanning electron microscopy (SEM), x-ray powder diffraction (XRD), vibrating sample

magnetometer (VSM) and thermogravimetric analysis (TGA). The prepared composite was used for

removal of textile dyes from aqueous solution. The results showed a high efficient removal for reactive

yellow 160 dye from aqueous solution. The sorption rate was affected significantly by the initial

concentration, sorbent amount, and pH value of the solution. Batch experiments were conducted to

investigate the adsorption capacity under different initial concentration (ranging from 50 to 200 mg/L),

solution pH (3, 5, 7 and 9), and various contact times. Interestingly, the composite could be recycled

conveniently from aqueous solution with the assistance of an external magnet because of their exceptional

properties.

Keywords. Adsorption, composite, magnetic separation, polyaniline, starch

1 INTRODUCTION

Environmental issues have become exceptionally acute in the world and emerged as a high national–

international priority, is now received a globally attention. Wastewater from the textile industry is a

complex mixture of many polluting substances ranging from organochlorine-based pesticides to heavy

metals associated with dyes or the dyeing process. Reactive dyes are characterized by nitrogen-to-nitrogen

double bonds, azo bonds (N=N), and used mainly for dyeing cellulose fibres. The colour of the azo dyes is

due to this azo bond and associated chromophores. Textile dyes have found to be toxic, genotoxic and

mutagenic. Therefore, they must be removed from the polluted water to meet the increasingly stringent

environmental quality standards [1]. Current methods for wastewater treatment include precipitation,

coagulation/flotation, sedimentation, flotation, filtration, membrane processes, electrochemical techniques,

ion exchange, biological process, chemical reactions, and adsorption [2-3]. Each method has its merits and

limitations in practical application. In the past years, adsorption processes have been shown to be effective

and economical treatment process, thus it is considered a virtueless method for the removal of pollutants

from wastewater.

Adsorption is one of the effective methods for textile dyes removal from sewage, especially when the

adsorbents are cheap and easily available. Recently, polyaniline (PANI) composites are interested as

promising candidates for environmental application purpose because of its good environmental stability

and controllable electrical properties. PANI polymer composite has been studied for adsorption of heavy

metal and textile dyes [4-5]. Starch has many useful features such as biocompatibility and biodegradability

property. Starch/polyaniline and chitosan/polyaniline composites were prepared for enhanced removal of

textile dyes from synthetic effluent [6]. However, the adsorbents are not easy to separate from aqueous

solution by filtration or centrifugation. Therefore, it is a great interesting work to improve the separability

of the adsorbents having small size. Recently, magnetic separation technologies has been paid attentions.

With the aid of magnetic force, magnetic matters can be separate from the water efficiently regardless of

its size. To our knowledge, so far, there is no report on preparation of magnetic starch-PANI composite for

textile dye removal. In this research, attention has been paid to synthesizing multifunctional composite with

a magnetic core coated with conducting polymer via in situ polymerization. The adsorptive capacity of