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

Area of Science:

• Materials Science
• Radiation Chemistry
• Textile Science

Background:

• Sheep wool's potential as a sorbent for heavy metals.
• Impact of irradiation on natural fibers.
• Understanding the role of humidity in material modification.

Purpose of the Study:

• To investigate the effect of relative humidity (RH) on sheep wool's Co(II) sorption capacity after electron beam irradiation.
• To analyze the chemical changes in wool fibers under varying humidity and irradiation doses.
• To determine optimal conditions for wool's use as a sorbent.

Main Methods:

• Irradiation of wool samples at 10%, 53%, and 97% RH with electron beams (0, 109, 257 kGy).
• Batch Co(II) sorption experiments monitored by VIS spectrometry.
• FTIR spectral analysis for cysteic acid and cystine monoxide, and pH measurements of KCl extract.

Main Results:

• Co(II) sorptivity significantly depends on wool's RH during irradiation.
• Optimal Co(II) sorption observed for wool conditioned at 53% RH, suggesting practical application without pre-conditioning.
• High humidity (97% RH) with high dose (257 kGy) led to water radiolysis and reduced sorptivity.
• Non-irradiated wool also showed humidity and time-dependent sorption, indicating inherent sensitivity.

Conclusions:

• Wool's Co(II) sorption is highly sensitive to humidity during electron beam irradiation.
• Pre-conditioning wool at 53% RH maximizes Co(II) sorption, simplifying practical applications.
• Radiolysis at high humidity and dose degrades sorptivity, while non-irradiated wool also exhibits humidity-dependent behavior.