Some Properties of Electron Beam-Irradiated Sheep Wool Linked to Cr(III) Sorption

Abstract

We examined the characteristics of an electron beam irradiated wool with an absorbed dose of (21–410) kGy in comparison with natural wool with respect to the determination of the isoelectric point (IEP), zero charge point (ZCP), mechanism of Cr(III) sorption from higher concentrated solutions, and the modelling of the wool-Cr(III) interaction. The data of ZPC and IEP differed between natural and irradiated samples. Increasing the dose shifted the pH of ZPC from 6.85 for natural wool to 6.20 for the highest dosed wool, while the natural wool IEP moved very little, from pH = 3.35 to 3.40 for all of the irradiated samples. The sorption experiments were performed in a pH bath set at 3.40, and the determination of the residual Cr(III) in the bath was performed by VIS spectrometry under optimized conditions. The resulting sorptivity showed a monotonically rising trend with increasing Cr(III) concentration in the bath. Lower doses, unlike higher doses, showed better sorptivity than the natural wool. FTIR data indicated the formation of complex chromite salts of carboxylates and cysteinates. Crosslinks via ligands coming from different keratin chains were predicted, preferably on the surface of the fibers, but to a degree that did not yet inhibit the diffusion of Cr(III)-cations into the fiber volume. We also present a concept of a complex octahedral structure.

Sheep Wool Humidity under Electron Irradiation Affects Wool Sorptivity towards Co(II) Ions

“…The pH in the solution of all samples determines the deprotonization of acidic functional groups (–COOH, –SO 3 H, -OH) located on the adsorbent surface. If the pH of the solution with immersed wool is higher than the isoelectric point of wool (pH 3.3–4.5), by which the wool brings about zero electric charge [ 41 ], acidic groups are deprotonized. The deprotonization increases the H + concentration in the solution and the pH decreases.…”

Analysis of Natural Materials’ Adsorption Efficiency Relating Co(II) Using Atomic Absorption Spectroscopy: Laboratory Experiment

“…They expressed positive opinions on waste materials use for purification of contaminated water. Some students even demonstrated an interest in elaborating on a final work related to this issue, with the titles of their works shown below by academic year. 2018–2019: Study of Selected Anion Separability Using Sheep Wool 2017–2018: Adsorption of Tensides onto Sheep Wool 2016–2017: Sheep Wool Scouring without Chemicals; Effect of Irradiated Wool Heating on Cu­(II) Sorption and Sorption of Co­(II); Effect of Post-radiation Treatment on Sorption of Cr­(III) …”

“…2016–2017: Sheep Wool Scouring without Chemicals; Effect of Irradiated Wool Heating on Cu­(II) Sorption and Sorption of Co­(II); Effect of Post-radiation Treatment on Sorption of Cr­(III)…”

From Strain Stiffening to Softening—Rheological Characterization of Keratins 8 and 18 Networks Crosslinked via Electron Irradiation

“…However, it was shown that the effect of irradiation is complex, and each dose may provoke different effects on the wool keratin structure [ 35 ]. Furthermore, several studies reported the improvement of the sorption affinity of wool keratin towards some metal cations and therefore its usefulness in environmental cleaning [ 36 , 37 , 38 , 39 , 40 ]. In a previous attempt to prepare biocompatible hair and wool keratins hydrogels via EBI, a blend with synthetic polymers was necessary to obtain a gel after irradiation [ 41 ].…”