Metal ion binding properties of novel wool powders

Abstract

Wool fibres have shown potential for the removal and recovery of toxic chemical and metal ions; however, their slow kinetics of binding has limited their widespread application. In this study three wool powders have been prepared from chopped wool fibre using various milling operations. Brunauer, Emmett, Teller analysis (BET) showed negligible change in surface area and Positron annihilation lifetime spectroscopy indicated no change in nanoporosity of the powders on processing. Binding of the transition metal ions, Co 2þ , Cu 2þ , and Cd 2þ was investigated over the pH range 3-9 at ambient temperature (23 C) using their respective radioisotopes (i.e. for each of the wool powder was dramatically faster ($ 42 fold) than that of the wool fibre. In comparison with commercial cation exchange resins, the wool powders showed significantly higher (two to nine fold) metal ion loading capacity. Selective binding of the metal ions could be enhanced by varying pH and/or incubation times. The use of radioisotopes to monitor the metal ion binding allowed the development of a highly sensitive and rapid high-throughput analysis method for assessing wool powder binding properties. The ability to produce large quantities of wool powders and their ease of handling indicate that they have potential for application in separation and recovery of metal ions from industrial effluents and environmental waterways.

Wool micro powder as a metal ion exchanger for the removal of copper and zinc

“…Two peaks at 1,641 cm −1 (amide I) and 1,512 cm −1 (amide II) designated for -CONH 2 (Asparagine and Glutamine) and -CONH-(Peptide chains), respectively, as well as a strong peak appears at 1,439 cm −1 for -COOH (Aspartate and Glutamate acids). Finally, a prominent peak at 1,066 cm −1 for -CH 3 group (Alanine, Valine, Methionine, and Leucine) [25,28,34].…”

“…Many researchers have tried to produce wool powder by different methods, such as regeneration from keratin solution, mechanical attrition, and chemicalmechanical techniques [21][22][23][24]. Recent studies showed improvement in wool surface reactivity by converting fibers into fine powder [25][26][27]. For example, the dye uptake of wool powder was found very high compared with wool fiber or activated charcoal under the same condition.…”

Keratinous Materials as Novel Absorbent Systems for Toxic Pollutants

“…They removed around 72 to 94% metals (Ca, Mg, Fe and Mn) from water at a pH of 6-9 within 20-30 minutes 59 . Milled wool or hair powder dramatically increased the rate of metal ion absorption 70,71 ; for example, milled wool powder showed ~42 fold higher uptake of Cu than that of the wool fiber 70 .…”

The role of nuclear sensors and positrons for engineering nano and microtechnologies

“…Generating a fibrous powder from silk and wool fibres can dramatically enhance features such as rate and selectivity of metal binding properties. 3,4 PALS was used to evaluate the change in microporosity of fibres compared to jet-milled particles. PALS showed no change in size or incidence of micropores in natural fibres compared to milled samples.…”