Adsorption of Organic Dyes by TiO₂@Yeast‐Carbon Composite Microspheres and Their In Situ Regeneration Evaluation

Abstract

TiO2@yeast-carbon microspheres with raspberry-like morphology were fabricated based on the pyrolysis method. The obtained products were characterized by field emission scanning electron microscopy (FE-SEM), energy dispersive spectrometry (EDS), and X-ray diffraction (XRD). Effects of initial dye concentration and contact time on adsorption capacity of TiO2@yeast-carbon for cationic dye methylene blue (MB) and anionic dye congo red (CR) were investigated. Experimental data were described by Langmuir, Freundlich, Temkin, and Koble-Corrigan isotherm models, respectively. It was found that the equilibrium data of MB adsorption were best represented by Koble-Corrigan, and CR adsorption was best described by both Freundlich and Koble-Corrigan isotherm models. The kinetic data of MB and CR adsorption fitted pseudo-second-order kinetic model well. The results demonstrated that TiO2@yeast-carbon microspheres achieved favorable removal for the cationic MB in comparison with that for the anionic CR. In addition, regeneration experimental results showed that TiO2@yeast-carbon exhibited good recycling stability, reusability, and in situ renewability, suggesting that the as-prepared TiO2@yeast-carbon might be used as the potential low cost alternative for recalcitrant dye removal from industrial wastewater. One possible mechanism for regenerating dye-loaded TiO2@yeast in situ was also proposed.

Removal of phosphate from aqueous solutions by adsorption onto Ca(OH) 2 treated natural clinoptilolite

“…As combined form of Langmuir and Freundlich models, the Koble-Corrigan isotherm can better fit the experimental data for both low and high solute concentrations [33]. This model is used for heterogeneous adsorption surfaces and is transformed to Langmuir isotherm when n = 1 [54]. The n values at 288 and 308 K suggested an adsorption reaction stoichiometry of more than 1 solute molecule per free sorbent binding site [55].…”

Color-Tunable and High-Efficiency Dye-Encapsulated Metal–Organic Framework Composites Used for Smart White-Light-Emitting Diodes

“…Figures d and S8 exhibit the emission maximum as a function of the dye concentration of the Rh@bio-MOF-1 composites. The relationship between the dye concentration and the emission peak can be well-fitted by using Koble–Corrigan equation − wherein C e refers to the dye concentration, Q e refers to the emission peak wavelength, and A KC , B KC , and n are Koble–Corrigan isotherm constants. According to eq , the Rh@bio-MOF-1 composites with a very broad range of emission wavelengths can be obtained easily by formulating a dye impregnation solution with a corresponding concentration.…”

Fe-TiO2/AC and Co-TiO2/AC Composites: Novel Photocatalysts Prepared from Waste Streams for the Efficient Removal and Photocatalytic Degradation of Cibacron Yellow F-4G Dye

“…Furthermore, it could be observed that the estimated q e values were in line with the experimental ones in contrast to the PFO and Elovich models. These findings suggest that one of the rate-determining steps could be chemical sorption, implying valence forces via electron exchanges or shares [73].…”