20 research outputs found
Corncob as an effective, eco-friendly, and economic biosorbent for removing the azo dye Direct Yellow 27 from aqueous solutions.
The corncob is an agricultural waste generated in huge quantities during corn processing. In this paper, we tested the capacity of corncob particles for water purification by removing the azo dye Direct Yellow 27 (DY27) via biosorption. The biosorption process was investigated in terms of the kinetics, equilibria, and thermodynamics. Batch biosorption studies showed that the biosorption performance has strong inverse correlations to the solution pH and the corncob particle size, and it increases quickly with increasing contact time and initial dye concentration. The pseudo-second-order kinetic model provides the best fit to the experimental data, whereas the Redlich-Peterson isotherm model is most suitable for describing the observed equilibrium biosorption. The biosorption process is exothermic, spontaneous, and physisorption in character. Fourier transform infrared (FTIR) spectroscopy and confocal scanning laser microscopy (CSLM) studies suggest that lignocellulose and proteins play key roles in the biosorption of DY27 from aqueous solutions by corncob. Furthermore, after biosorption onto the corncob, the dye can be effectively desorbed using 0.1 M NaOH solution. Therefore, the corncob can be used as a promising biosorbent to remediate DY27-contaminated water and wastewater
Influence of solution pH on DY27 biosorption capacity of corncob.
<p>Influence of solution pH on DY27 biosorption capacity of corncob.</p
Influence of initial DY27 concentration on its biosorption capacity of corncob.
<p>Influence of initial DY27 concentration on its biosorption capacity of corncob.</p
Corncob as an effective, eco-friendly, and economic biosorbent for removing the azo dye Direct Yellow 27 from aqueous solutions - Fig 9
<p>CSLM images of a) lignin (green); b) lignin and DY27 dye in green and red colors, respectively; and c) fluorescein-induced fluorescence of corncob proteins in blue color. d) An overlay image showing the interaction between the DY27 dye and the corncob proteins in violet color.</p
Different kinetic, isotherm, and thermodynamic models.
<p>Different kinetic, isotherm, and thermodynamic models.</p
Thermodynamic parameters for the biosorption.
<p>Thermodynamic parameters for the biosorption.</p
Kinetic model parameters for DY27 biosorption onto corncob at different corncob particle sizes.
<p>Kinetic model parameters for DY27 biosorption onto corncob at different corncob particle sizes.</p
Parameters of the isotherm models for the biosorption at 18°C [<i>q</i><sub><i>m exp</i></sub>: 73.71 ± 4.8 mg g<sup>-1</sup>].
<p>Parameters of the isotherm models for the biosorption at 18°C [<i>q</i><sub><i>m exp</i></sub>: 73.71 ± 4.8 mg g<sup>-1</sup>].</p
Summary of infrared spectral bands observed in the native corncob, DY27-loaded corncob, and DY27 dye.
<p>Summary of infrared spectral bands observed in the native corncob, DY27-loaded corncob, and DY27 dye.</p
Kinetic model parameters for DY27 biosorption onto corncob at different solution pH levels.
<p>Kinetic model parameters for DY27 biosorption onto corncob at different solution pH levels.</p