Exposure to potentially toxic metallic elements (PTME) released in watercourses by industries results in irreversible damage to living beings or even death. The removal of a PTME, such as hexavalent chromium (Cr(VI)) in industrial wastewater aligned with the reuse/modification of natural adsorbents, is a promising alternative to remedy this problem. This paper presents cellulose from eucalyptus by-products at the macro (CMS) and nanoscale (CNS), obtained through a ball-milling process, which were also modified with zirconium oxide, providing MCMS and MCNS, respectively. The samples were characterized by FTIR, TGA, DRX, and adsorption tests. The cellulose chemical structure was maintained after milling and modification, but Zr-O bands’ inclusion indicated the fiber modification. The nanostructure presented a higher modification degree, highlighted by a considerable increase in thermal stability associated with the modified cellulose surface by zirconium. This result was corroborated by XRD analysis that presented new peaks for MCNS and reduced crystallinity. The adsorption test showed that the hydroxyl groups from the cellulose structure could remove Cr(VI) from water. However, this behavior was considerably enhanced by zirconium that increased the available binding sites, especially for the modified nanostructure, which presented the removal of 54% of Cr(VI). These results highlight the potential revaluation of eucalyptus residue and the modification treatment to attain a material with great adsorption properties that could reduce water contamination.

Graphical Abstract

中文翻译：

---

桉树残渣改性纤维素粗纤维和纳米纤维吸附六价铬

暴露于工业在水道中释放的潜在有毒金属元素 (PTME) 会对生物造成不可逆转的损害甚至死亡。去除工业废水中的六价铬 (Cr(VI)) 等 PTME，并结合天然吸附剂的再利用/改性，是解决这一问题的有希望的替代方案。本文介绍了通过球磨工艺获得的宏观 (CMS) 和纳米级 (CNS) 桉树副产物纤维素，它们也用氧化锆改性，分别提供 MCMS 和 MCNS。通过 FTIR、TGA、DRX 和吸附测试对样品进行了表征。研磨改性后纤维素化学结构得以保持，但Zr-O带的夹杂表明纤维改性。纳米结构呈现出更高的改性程度，突出显示与锆改性纤维素表面相关的热稳定性显着增加。XRD 分析证实了这一结果，该分析显示了 MCNS 的新峰和降低的结晶度。吸附试验表明，纤维素结构中的羟基可以从水中去除 Cr(VI)。然而，锆显着增强了这种行为，增加了可用的结合位点，特别是对于改性的纳米结构，它去除了 54% 的 Cr(VI)。这些结果突出了桉树残渣的潜在重估和改性处理，以获得具有良好吸附性能的材料，可以减少水污染。XRD 分析证实了这一结果，该分析显示了 MCNS 的新峰和降低的结晶度。吸附试验表明，纤维素结构中的羟基可以从水中去除 Cr(VI)。然而，锆显着增强了这种行为，增加了可用的结合位点，特别是对于改性的纳米结构，它去除了 54% 的 Cr(VI)。这些结果突出了桉树残渣的潜在重估和改性处理，以获得具有良好吸附性能的材料，可以减少水污染。XRD 分析证实了这一结果，该分析显示了 MCNS 的新峰和降低的结晶度。吸附试验表明，纤维素结构中的羟基可以从水中去除 Cr(VI)。然而，锆显着增强了这种行为，增加了可用的结合位点，特别是对于改性的纳米结构，它去除了 54% 的 Cr(VI)。这些结果突出了桉树残渣的潜在重估和改性处理，以获得具有良好吸附性能的材料，可以减少水污染。锆显着增强了这种行为，增加了可用的结合位点，特别是对于改性的纳米结构，它去除了 54% 的 Cr(VI)。这些结果突出了桉树残渣的潜在重估和改性处理，以获得具有良好吸附性能的材料，可以减少水污染。锆显着增强了这种行为，增加了可用的结合位点，特别是对于改性的纳米结构，它去除了 54% 的 Cr(VI)。这些结果突出了桉树残渣的潜在重估和改性处理，以获得具有良好吸附性能的材料，可以减少水污染。

图形概要