Low-quality cotton fibers are a low-value waste material within the cotton industry. Upcycling and transforming into high-value materials are highly desired. This study investigates upcycling fibers into hydrogel biosorbents and assesses their efficacy in dye adsorption. An effective gelation approach was employed via simply dropping droplets of suspension mixture of sodium alginate and fibers into acidic bath. Resulting composite hydrogel beads were utilized for dye removal. Composite beads successfully immobilized less than 70 wt% of fibers and achieved a significant improvement in thermal stability. Composite beads with 50 wt% fibers and alginate showed no decrease in methylene blue adsorption capacity. This outcome was unexpected considering the lower dye adsorption capacity of fibers than alginate, particularly notable since it indicated that reduced quantities of the more costly sodium alginate were sufficient to achieve comparable dye adsorption capacity. Mechanistic study unveiled that both the loose crosslinking structure and the electrostatic forces were responsible for the unexpected high adsorption capacity of 50% fiber-alginate. This study reports a promising, innovative and effective upcycle strategy for the first time that can transform fibers into high-value biosorbents without compromising dye adsorption capability.

劣质棉纤维是棉花工业中的低价值废料。人们非常希望升级回收并转化为高价值材料。本研究研究了将纤维升级改造为水凝胶生物吸附剂，并评估了它们在染料吸附方面的功效。通过简单地将海藻酸钠和纤维的悬浮混合物液滴滴入酸性浴中，采用有效的凝胶化方法。所得复合水凝胶珠用于去除染料。复合珠成功固定了少于 70 wt% 的纤维，并实现了热稳定性的显着改善。含有 50 wt% 纤维和藻酸盐的复合珠子的亚甲基蓝吸附能力没有下降。考虑到纤维的染料吸附能力比海藻酸钠低，这一结果是出乎意料的，特别值得注意的是，因为它表明更昂贵的海藻酸钠的用量减少足以实现可比的染料吸附能力。机理研究表明，松散的交联结构和静电力是 50% 纤维海藻酸盐意想不到的高吸附能力的原因。这项研究首次报告了一种有前景、创新且有效的升级回收策略，可以将纤维转化为高价值的生物吸附剂，而不会影响染料吸附能力。