Bioremoval mechanisms of azo dye Acid Red 14 using Wickerhamomyces anomalus yeast strain as a natural biosorbent

Abstract

Biosorption processes have recently become an economic and eco-friendly solution for the treatment of industrial wastewater. This study aimed to evaluate the potential application of Wickerhamomyces anomalus as a natural biosorbent for the removal of toxic synthetic dye Acid Red 14 (AR14). Biosorption kinetics modelling showed that the pseudo-second-order and intraparticle diffusion models were more suitable to fit the experimental data. In addition, the Langmuir model was the most appropriate isotherm to explain the AR14-W. anomalus biosorption system. Thus, the physicochemical properties of W. anomalus biomass before and after dye biosorption were characterized by scanning electron microscopy with energy dispersive X-Ray analysis, fourier-transform infrared spectroscopy, zeta potential, zero-point charge and contact angle measurement. The functional groups such as hydroxyl, carboxyl, amide, and amine present on the yeast wall surface can be responsible for AR14 biosorption. Finally, the Plackett-Burman design was used to screen the most influencing factors on the biosorption process, including dye concentration, dose of yeast biomass, temperature, shaking speed, and contact time. The latter was optimized according to the Box-Behnken design and the optimum AR14-biosorption was attained at pH 3–4, with lower initial dye concentrations (50–75 mg L− 1) and yeast biomass (1.25 g L− 1). These findings suggest that W. anomalus biomass could be used as an efficient, low-cost, and eco-friendly biosorbent for the removal of toxic dyes from the aqueous environment.

Linear and Nonlinear Regression Analysis for the Adsorption of Remazol Dye by Romanian Brewery Waste By-Product, Saccharomyces cerevisiae

“…Due to the peptide bonds of the yeast cell, the amide I and amide II bands were visible in the spectrum between 1700 and 1500 cm −1 (presence of -C=O and N-H functional groups at 1672.21 and 1654.63 cm −1 , respectively). Peaks were observed in yeast at 1538.92 cm −1 and in dye-adsorbed yeast at 1537.95 cm −1 , corresponding to C=C stretching of aromatic rings [ 32 , 35 ].…”

“…Depending on the type of interaction between the adsorbent surface and the contaminant, the biosorption process can be divided into two types: (i) chemical adsorption, an irreversible process resulting in the formation of strong chemical bonds; and (ii) physical adsorption, which is reversible and, in most cases, characterized by weak van der Waals forces, H-bonds, polarity and dipole–dipole H-bonding interactions. Furthermore, FTIR studies have demonstrated that Yoshida H-bonding, dipole–dipole H-bonding and π–π and n–π interactions can occur upon adsorption of dye molecules on yeast cells ( Figure 6 ) [ 32 , 35 , 61 ].…”