Optimizing Supercritical Carbon Dioxide in the Bacterial Inactivation and Cleaning of Sheep Wool Fiber by Using Response Surface Methodology

ABSTRACT

In the textile industry, sheep wool undergoes treatment with a lengthy water-based procedure. In the present study, supercritical carbon dioxide (scCO₂₎ was applied as a waterless technology to clean sheep wool fiber and inactivate gram-positive bacteria (Bacillus Velezensis, Bacillus amyloliquefaciens, Exiguobacterium, Bacillus cereus) and gram-negative bacteria (Klebsiella pneumoniae and Enterobacter cloacae) present in sheep wool fiber. Response surface methodology (RSM) was used to determine the optimal experimental conditions of scCO₂ parameters (pressure, temperature, and time) on the maximum inactivation of bacteria (log survival) and whiteness index (stensby) of treated sheep wool. The optimal experimental condition of scCO₂ was determined as the pressure of 29 MPa, the temperature of 55°C for 75 min treatment time to obtain the complete inactivation of bacteria (−6.2 log survival), and 26 stensby of whiteness index. The results demonstrated that the second-order polynomial model was adequately fitted with experimental data. The analyses of the influences of scCO₂ parameters reveal that the scCO₂ pressure, temperature, time, their interection, and quadratic effects potentially influence the inactivation of bacteria and the whiteness index of sheep wool fiber.

摘要

在纺织工业中,羊毛经过漫长的水基处理. 在本研究中, 超临界二氧化碳 (scCO2) 作为一种无水技术应用于清洁羊毛纤维和灭活革兰氏阳性细菌 (Velezensis芽孢杆菌,淀粉液化芽孢杆菌,稀有细菌,蜡样芽孢杆菌) 和革兰氏阴性细菌 (肺炎克雷伯菌和阴沟肠杆菌) 存在于羊毛纤维中. 采用响应面法 (RSM) 确定了scCO2参数 (压力,温度和时间) 对经处理羊毛的最大细菌灭活率 (对数存活率) 和白度指数 (stensby) 的最佳实验条件. 确定了scCO2的最佳实验条件为: 压力29MPa,温度55°C,处理时间75min,使细菌完全失活 (−6.2log存活), 白度指数26. 结果表明,二阶多项式模型与实验数据吻合良好. 对scCO2参数影响的分析表明,scCO2压力温度和时间,它们的相互作用和二次效应可能影响细菌的灭活和羊毛纤维的白度指数.

KEYWORDS:

• Sheep wool fiber
• bacterial inactivation
• sterilization
• dry clean
• wool whiteness
• supercritical co₂

关键词:

• 羊毛纤维
• 细菌灭活
• 消毒
• 干洗
• 羊毛白度
• 超临界

Acknowledgments

The authors would like to thank the Division of Research & Innovation, Universiti Sains Malaysia for providing Research Universiti Grant (304/PTEKIND/6315313) as a financial support.

Additional information

Funding

This work was supported by the Division of Research & Innovation, Universiti Sains Malaysia [304/PTEKIND / 6315313].