Azolla pinnata: An Efficient Low Cost Material for Removal of Methyl Violet 2B by Using Adsorption Method

Abstract

Azolla pinnata (AP), a floating aquatic macrophyte, was studied as a potential adsorbent for the removal of methyl violet (MV) in a batch adsorption system. Surface characterisation, effects of particle size, adsorbent dosage, pH, ionic strength and pre-treatments of adsorbent were carried out. The study of the effects of pH and ionic strength suggested that electronic interaction and hydrophobic-hydrophobic interaction might be the major forces of dye interaction. Pseudo 2nd order kinetic model best-fitted the kinetic data indicating that the adsorption process may be controlled by chemical process. The Weber-Morris and Boyd models were used for describing the diffusion mechanism which showed that intraparticle diffusion was not the rate limiting step, and film diffusion or in combination of other mechanisms might be in control. Isotherm modelling showed that the Langmuir model best-fitted the experimental data with q m of 194.2 mg g -1 at 25°C and 323.4 mg g -1 at 65°C. Thermodynamic studies showed that the adsorption process is endothermic, spontaneous and with significant change to the internal structure of adsorbent. The estimated activation energy by Arrhenius equation is 54.8 kJ mol -1 , which indicates that the adsorption process may be controlled by chemical process. Adsorbent regenerated using NaOH displayed retention of high adsorption capability almost similar to fresh adsorbent even after five consecutive cycles. Ability to regenerate coupled with good adsorption capability suggests that AP has great potential to be utilised as a low-cost adsorbent for the removal of MV in real life application.

Removal of methyl violet 2B dye from aqueous solution using Nepenthes rafflesiana pitcher and leaves

“…Similar observation was seen for the NL-MV system. Similar behaviour was also observed in our previous work on the removal of MV and malachite green dyes using Azolla pinnata (Kooh et al 2015;Kooh et al 2016c). The effect of ionic strength is as shown in Fig.…”

“…Azolla pinnata (194 mg g -1 ) (Kooh et al 2015), however, lower than water lettuce (267.6 mg g -1 ) and duckweed (332.5 mg g -1 ) .…”

Phytoextraction capability of Azolla pinnata in the removal of rhodamine B from aqueous solution: artificial neural network and random forests approaches

“…This not only allows AP to thrive in water bodies that lack nutrients, but is also responsible for AP's fast growth and high reproduction rate. Recent studies have shown that AP has the potential to be used as a water remediation material through the biosorption of textile dyes (Kooh et al 2015(Kooh et al , 2016b and by phytoextraction methods (Sood et al 2012).…”

Biosorption of Pb(II) and Cu(II) from Aqueous Solution Using Chicken Feathers: Thermodynamics and Mass Balance Studies

“…Growing interest in finding new materials for heavy metals removal has led many researchers to investigate many other adsorbent of natural origin like fern [7], mud [8], keratin, chitosan, modified wool, sawdust, nutshells, rice hulls and sugar cane bagasse, and so on [9][10][11][12][13][14][15][16]. Most of these materials are generally effective for the adsorption of Cu(II) and Pb(II).…”