Efficient Removal of Cd(II) from Aqueous Solution by Dehydrated Hazelnut Husk Carbon

The use of Phanerochaete chrysosporium for modification of bentonite for preconcentration and determination of heavy metals

In this study, a solid phase extraction method was successfully applied in the preconcentration and determination of trace levels of Cu(II) and Cd(II) ions and Phanerochaete chrysosporium (white rot fungus) modified bentonite was used as adsorbent. After the biosorption of Cu(II) and Cd(II) ions, metal concentrations in the samples were determined by atomic absorption spectrophotometry. pH, adsorbent amount, eluent type, sample volume, and flow rate, which are effective in the adsorption of metal ions, have been studied. 1 M HCl was used for desorption of these metal ions retained (recovery 95–100%). In addition, the effect of interfered ions has also been investigated. Sorption data were examined according to Langmuir and Freundlich adsorption equations. The results obtained show that the applied method has a high metal biosorption capacity, and Cu(II) and Cd(II) ions are successfully recovered. It was also successful in applying the proposed enrichment method to real water samples.

Recovery values between 92.3% and 97.3% were obtained for the studied metal ions. According to the results, the proposed method can be successfully applied to water analysis at 95% confidence interval.

Preparation and characterization of activated carbons from winemaking wastes and their adsorption of methylene blue

This work reports the preparation of activated carbons via the hydrothermal treatment at 523 K/30 bar of two common winemaking wastes: bagasse and cluster stalks. The hydrothermal carbons produced by the above treatment were turned into activated carbons via their exposure to KOH and carbonization at 1073 K. These were then subjected to Raman spectroscopy, Fourier transform infrared spectroscopy, scanning electron microscopy examination, and the determination of their Brunauer–Emmett–Teller surface area. The ability of the activated carbons to adsorb methylene blue in aqueous solution was then examined, determining the influence of time, methylene blue concentration, and temperature. Equilibrium conditions were reached for reaction times between 180 and 240 min at pH 7. The adsorption isotherms were found to better fit the Langmuir than the Freundlich model, and the adsorption kinetics fitted a pseudo-second-order model. The maximum adsorption at 303 K was 714–847 mg g−1. Thermodynamic studies revealed the adsorption of methylene blue to be spontaneous and exothermic. These results show that high-quality activated carbons can be produced from winemaking waste.

Simultaneous adsorption of Cd2+ and reactive dye on mesoporous nanocarbons

The presence of the dye facilitated the elimination of the heavy metal. Moreover a synergic effect was observed: simultaneous adsorption enhanced each individual adsorption.