Carbohydrate Polymers 101 (2014) 684–691 Contents lists available at ScienceDirect Carbohydrate Polymers jo u r n al homep age: www.elsevier.com/locate/carbpol Adsorptional removal of methylene blue by guar gum–cerium (IV) tungstate hybrid cationic exchanger V.K. Gupta a,∗ , Deepak Pathania b , Pardeep Singh b , Amit Kumar b , B.S. Rathore b a Department of Chemistry, Indian Institute of Technology, Roorkee 247667, India b School of Chemistry, Shoolini University, Solan 173212, Himachal Pradesh, India a r t i c l e i n f o Article history: Received 15 August 2013 Received in revised form 21 September 2013 Accepted 27 September 2013 Available online 5 October 2013 Keywords: Hybrid ion exchanger Characterization Methylene blue Adsorption Kinetics a b s t r a c t Guar gum–cerium (IV) tungstate nanocomposite (GG/CTNC) cationic exchanger was synthesized using simple sol gel method. The GG/CTNC was characterized using X-ray diffraction (XRD), Fourier trans- mission infrared spectroscopy (FTIR), scanning electron microscopy (SEM) and energy dispersive X-ray spectrophotometer (EDX). The XRD studies confirmed amorphous and fibrous in nature of GG/CTNC. The high percentage of oxygen in the nanocomposite material confirmed the functionality tungstate (WO 4 - ). The ion exchange capacity of GG/CTNC for Na + ion was observed to be 1.30 mequiv g -1 . The hybrid exchanger was used as potential adsorbent for the removal of methylene blue (MB) from aque- ous system. The correlation coefficients value indicated a good fit of monolayer Langmuir model to the adsorption of methylene blue onto GG/CTNC. The adsorption kinetic study revealed that the adsorption process followed the pseudo second order kinetic. The Gibbs free energy (G) values confirmed the spontaneous nature of adsorption process. © 2013 Elsevier Ltd. All rights reserved. 1. Introduction The fast industrial development throughout world has sig- nificantly increased the production of wastewater from various industries such as, textile, paper, paint, and dyestuffs consume; as a consequence toxic synthetic dyes are discharged into water bodies. The discharged dyes degrade the water quality and may cause adverse effect on human health due to toxic, mutagenic and carcinogenic nature (Gupta & Ali, 2008; Gupta, Agarwal, & Saleh, 2011; Gupta, Jain, & Varshney, 2007; Gupta, Mittal, Malviya, & Mittal, 2009; Gupta, Rastogi, & Nayak, 2010; Gupta, Pathania, Agarwal, & Singh, 2012; Mittal, Gupta, Malviya, & Mittal, 2008; Mittal, Mittal, Malviya, Kaur, & Gupta, 2010). The synthetic dyes are difficult to treat, since these are resistant to biological oxi- dation/reduction, and stable to oxidizing agents. The application of conventional methods like coagulation, flocculation, precipita- tion, membrane separation, solvent extraction and adsorption, does not treat industrial dye-effluent efficiently (Vilhera, Goncalves, & Mota, 2004). In practice, no single process provides adequate treat- ment and combination of different process has been often used to improve the water quality in most greener and economic way. It is now well recognized that bio-adsorbent are gaining importance as effective and economic methods for wastewater remediation. ∗ Corresponding author. Fax: +91 1332273560. E-mail addresses: vinodfcy@gmail.com, vinodfcy@iitr.ernet.in (V.K. Gupta), dpathania74@gmail.com (D. Pathania). A large number of non-conventional bio-adsorbents such as fun- gal or bacterial biomass or biopolymers have been employed to remove toxic metals and dyes from aqueous phase (Constantin et al., 2013; Zhao, Zeng, Li, et al., 2012a; Zhao, Zeng, Hu, et al., 2012b). The bio-adsorbent are low-cost, harmless and abundantly available (Constantin et al., 2013; Yang et al., 2012). However, lower stability, difficulty in separation from aqueous phase and low recovery after desorption were the major limitations for large scale applicability of bio-absorbents (Gupta et al., 2011, 2012). Organic–inorganic nanocomposite materials are of importance because of their multifunctionality owing to a combination of dif- ferent compounds incorporated. Recently, TiO 2 , BiOCl, Fe 2 O 3 , CuS and ZnO based bio-nanocomposites have been used for dyes and metal removal from wastewater (Dong, Sun, Min, Wu, & Lee, 2012; Gupta et al., 2012; Huang & Chen, 2009; Virkutyte, Jegatheesan, & Varma, 2012). Nowadays, bio-material based nanocomposites have drawn considerable attention because of their low-cost, easy processability, high-volume application, renewable nature and possibility of recycling. There are several research efforts reporting the bio-composite with carbon nanotubes, lignin and lumiscent CdS (Nevarez et al., 2011; Park & Kadla, 2012; Yang et al., 2012). Guar is a naturally occurring polysaccharide extracted from the beans of the guar gum plant. It is used as environmental-friendly thickener to control visco-elasticity in food, personal care and oil recovery industries. Cerium (IV) derivates represent inorganic ion exchang- ers of tetravalent metal acid salts class. It has shown excellent adsorption ability for heavy metal due to its high selectivity, high thermal stability and absolute insolubility in water (Semischenko, 0144-8617/$ – see front matter © 2013 Elsevier Ltd. All rights reserved. http://dx.doi.org/10.1016/j.carbpol.2013.09.092