Removal of anionic dyes in aqueous solution by flocculation with cellulose ampholytes

Abstract

a b s t r a c tCellulose ampholytes (CAms) prepared from biocompatible and biodegradable carboxymethyl cellulose (CMC) could represent an environmentally friendly alternative for the efficient removal of anionic dyes from water effluents. In order to evaluate their potential for this application, a series of CAms with a degree of cationic substitution (DS C ) between 0.26 and 1.08 were prepared from sodium CMC, by cationization with 2,3-epoxypropyltrimethylammonium chloride. The flocculation ability of the CAms against the anionic dye Acid Red 13 (AR13) was found to strongly depend on the DS C as well as on the pH of the solution. The highest flocculation ability was observed at lower pH and higher DS C : a color removal as high as 99% was achieved at pH 3 using a CAm with the highest DS C . The kinetic analysis revealed that the flocculation of AR13 can be accurately fitted by a pseudo-second order kinetic model, which thus allows to predict the flocculation behavior of CAms under these conditions. Besides AR13, the ampholytes also showed high flocculation ability against Acid Red 9 and Acid Blue 13. The flocculation behavior of these anionic dyes followed the Langmuir adsorption isotherm model, which revealed the maximum flocculation capacity of a CAm for these dyes. Moreover, the analysis of the flocculation isotherm data and the SEM observation of the formed flocs allowed to determine the flocculation mechanism.

Insight into the removal of Acid Blue 93 by cationic Eucalyptus cellulose with different alkyl chain lengths: properties and mechanisms

“…The peak at 2,895 cm -1 is attributed to C-H stretching vibration of the -CH 2 -groups [26]. A series of peaks at 1,162 cm -1 , 1,103 cm -1 , 1,030 cm -1 , 899 cm -1 are attributed to the -COC-group in the cellulose glucose structure [27]. As can be seen from Fig.…”

Biosorption of Methylene Blue and Orange II on deactivated lichen Parmotrema dilatatum : Modeling and kinetic studies

“…Langmuir isotherm involves monolayer adsorption on a surface containing homogeneous adsorption sites, without transmigration of adsorbates and without any interaction between the adsorbed molecules (Demirkiran, 2015). Once a site is occupied, no additional adsorption can take place, resulting in saturation of the surface (Kono and Kusumoto, 2015). The Langmuir isotherm is translated by the following relation (Langmuir, 1918) : studies.…”

Xanthan Gum as a Novel Flocculant Aid Employed in Drinking Water Treatment

“…Values obtained in the current study were slightly superior, up to 90%, due to minor differences between xanthan gum and guar gum, and differences in systems behaviors: dyes removal against drinking water treatment. Kono and Kusumoto (2015) investigated the flocculation ability of cellulose ampholytes and observed high color removal at lower concentrations and lower pH values. In this current work, pH was not controlled, but authors also observed that the remaining color (Figure 1) has a tendency to be around the same value, despite the increase in xanthan gum concentration.…”

“…In practice, synthetic flocculants are employed, such as Poly (diallyldimethyl ammonium chloride (PDADMAC), epichlorohydrin, polyacrylamide (PAM), and its methacrylate analogue is also commercially available, nonetheless they have been associated with health risks due to monomer residues in water (GARCÍA, 2011;GUPTA & AKO, 2005). Nonetheless, previous studies highlighted that natural flocculants could be used, with the advantages of low sensitivity to pH and larger and stronger flocs (KONO & KUSUMOTO, 2015;ZHANG et al, 2013;GARCÍA, 2011;BROSTOW et al, 2009;WEI et al, 2009;WANG et al, 2008;BOLTO & GREGORY, 2007;GUPTA & AKO, 2005).…”