Preparation of PVA-chitosan Blend Nanofiber and Its ...

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Abstract: In this manuscript, poly(vinyl alcohol) (PVA)-chitosan blend nanofiber was prepared and its dye removal ability from colored wastewater was ...
Fibers and Polymers 0000, Vol.0, No.0, 1-9 DOI 10.1007/s12221-015-5371-1

ISSN 1229-9197 (print version) ISSN 1875-0052 (electronic version)

Preparation of PVA-chitosan Blend Nanofiber and Its Dye Removal Ability from Colored Wastewater Niyaz Mohammad Mahmoodi* and Zahra Mokhtari-Shourijeh Department of Environmental Research, Institute for Color Science and Technology, Tehran 1668814811, Iran (Received May 13, 2015; Revised July 22, 2015; Accepted July 25, 2015) Abstract: In this manuscript, poly(vinyl alcohol) (PVA)-chitosan blend nanofiber was prepared and its dye removal ability from colored wastewater was investigated. The characteristics of the adsorbent were studied using Fourier transform infrared (FTIR) and scanning electron microscopy (SEM). Direct Red 80 (DR80), Direct Red 81 (DR81) and Reactive Red 180 (RR180) were used as anionic dyes. The effects of pH, contact time, adsorbent dosage and initial dye concentration on dye removal were studied. The kinetics and isotherm of dye removal follows pseudo-second order kinetics and the Langmuir isotherm, respectively. Desorption studies showed that adsorbent could be recovered and regenerated. The results show that PVA-chitosan blend nanofiber is a suitable adsorbent with high dye adsorption capacity from colored wastewater. Keywords: Nanofiber, Poly(vinyl alcohol)-chitosan blend, Dye removal, Adsorption

and water purification applications. These properties arise as a result of protonation of -NH2 groups on the chitosan backbone. Recently, electrospun nanofibers based on chitosan have been widely researched and various nanofiber products containing chitosan have been produced by electrospinning. These nanofibers yield potential applications in various areas [10-15]. Poly(vinyl alcohol) (PVA) is a biocompatible, nontoxic and biodegradable synthetic polymer, which is widely used in biochemical and biomedical applications. PVA has good fiber forming, highly hydrophilic properties, and its fibers have been commercialized since the 1950s, and used in textiles as a silk substitute. PVA is a unique type of fiber which is easily spun, coagulated, oriented and cross-linked [13,14,16]. Chitosan nanofiber and polyvinyl alcohol nanofiber dissolved in water but chitosan-polyvinyl alcohol blend nanofiber do not dissolve in water. A literature review showed that dye removal by PVA-chitosan blend nanofiber was not studied in details. In addition, its regeneration was not investigated. In this study, PVA-chitosan blend nanofiber was prepared by electrospinning technique and its characteristics were studied by FTIR and SEM. The anionic dye adsorption of the synthesized nanofiber was describe by studying the influence of several parameters including contact time, adsorbent dosage, dye concentration, and pH of solution. Furthermore, the data were analyzed using different adsorption isotherms and kinetics. In addition, desorption studies were done to regenerate adsorbent. Direct Red 80 (DR80), Direct Red 81 (DR81) and Reactive Red 180 (RR180) were used as anionic dyes.

Introduction Industrial activity growth and increasing water usage have led to the release of various pollutants into aquatic environment, such as toxic heavy metals, dyes, pesticides, humic substances, detergents and other persistent pollutants. These kinds of pollutants are mainly characterized by marked not only persistence against chemical or biological degradation, but also high environmental mobility and strong tendency for bioaccumulation in the food chain. Several treatment methods such chemical precipitation, ion exchange, reverse osmosis (RO), oxidation/reduction, adsorption, filtration, coagulation, electrolysis, evaporation, electroplating, activated sludge, aerobic and anaerobic treatment, etc. have been used to remove the pollutants [1-7]. Among these techniques, adsorption is a common technique used for dye removal from aqueous solution, mainly because it is robust, relatively low in cost, environmentally friendly and simple. The choice of an adsorbent among the various adsorbents is a starting point in the development of an adsorption unit [7]. Dyes as adsorbate are also usually classified based on their particle charge upon dissolution in aqueous application medium [9-11] such as cationic (all basic dyes), anionic (direct, acid, and reactive dyes), and non-ionic (dispersed dyes). The largest class of dyes used in industry is the azo type. This class is usually characterized by the presence of one or more azo bands (-N=N-) and aromatic rings, which are considered toxic and mutagenic to living organisms [8-11]. Chitosan, a (1-4)-linked 2-amino-2-deoxy-D-glucopyranose, is derived from chitin, one of the most abundant natural polysaccharides. Chitosan is well known for its nontoxic, biocompatible and biodegradable properties. It can also bind pollutants, which can be beneficial for use in air cleaning

Experimental Materials and Methods Analytical reagents grade chemicals were used. Chitosan

*Corresponding author: [email protected], [email protected], [email protected] 1