Division of Semiconductor and Chemical Engineering, Jeonbuk National University, Jeonju, Jeonbuk, 561-756, Republic of Korea.
School of Chemical Engineering, Jeonbuk National University, Jeonju, Jeonbuk, 561-756, Republic of Korea.
Chemosphere. 2024 Sep;364:143282. doi: 10.1016/j.chemosphere.2024.143282. Epub 2024 Sep 6.
The recovery of gold (Au) from electronic waste (e-waste) has gained significant attention due to its high Au content and economic feasibility compared to natural ores. This study presents a facile, single-step approach to prepare the chitosan-thioglycolic acid composite crosslinked with glutaraldehyde (CS-TGA-GA) and demonstrates its unique capability for precious metal management, which is a less investigated application area for thiolated chitosan materials. The novel cost-effective biosorbent CS-TGA-GA demonstrated a very high adsorption capacity of 1351.9 ± 96 mg/g and selectivity for Au(III) from an acidic e-waste solution at pH 1 and 298 K. The high adsorption capacity and selectivity of the sorbent can be attributed to the abundance of -NH, -OH, and -SH groups present on its surface. Various characterizations, such as scanning electron microscopy, energy-dispersive X-ray spectroscopy, X-ray diffractometry, Fourier-transform infrared spectroscopy, and X-ray photoelectron spectroscopy, as well as sorption experiments, including pH, kinetic, and isotherm studies, were performed. The kinetic data align with a pseudo-second-order model and the isotherm data can be well expressed by the Freundlich model. The CS-TGA-GA composite effectively facilitated the conversion of Au(III) to Au(0), leading to the formation of Au nanoparticles that aggregated in the reaction vessel over time. Subsequently, the Au-loaded CS-TGA-GA underwent an incineration procedure, yielding recovered Au with a purity of 99.6%, as measured by X-ray fluorescence. In addition to its large uptake capacity, acid stability, and recyclability, the prepared sorbent showed a highly selective uptake of Au(III) ions in a solution containing various metal ions leached from waste printed circuit boards. These results highlight the potential of CS-TGA-GA as an adsorbent for the recovery of Au from e-waste leachate, thereby contributing to sustainable resource management.
从电子废物（e-waste）中回收金（Au）因其 Au 含量高且经济可行，与天然矿石相比具有优势，因此受到了广泛关注。本研究提出了一种简便的一步法制备壳聚糖-巯基乙酸复合交联戊二醛（CS-TGA-GA）的方法，并证明了其在贵金属管理方面的独特能力，这是一个对巯基壳聚糖材料研究较少的应用领域。新型、经济高效的生物吸附剂 CS-TGA-GA 在 pH 值为 1 和 298 K 时，从酸性电子废物溶液中对 Au(III)表现出非常高的吸附容量（1351.9 ± 96 mg/g）和选择性。吸附剂的高吸附容量和选择性可归因于其表面存在丰富的 -NH、-OH 和 -SH 基团。进行了各种表征，如扫描电子显微镜、能谱、X 射线衍射、傅里叶变换红外光谱和 X 射线光电子能谱，以及吸附实验，包括 pH 值、动力学和等温线研究。动力学数据符合准二级模型，等温线数据可以很好地用 Freundlich 模型表示。CS-TGA-GA 复合材料有效地促进了 Au(III)向 Au(0)的转化，导致 Au 纳米颗粒在反应容器中随着时间的推移聚集。随后，负载 Au 的 CS-TGA-GA 进行了焚烧程序，用 X 射线荧光法测定，得到的 Au 纯度为 99.6%。除了具有较大的吸附容量、酸稳定性和可回收性外，所制备的吸附剂在含有从废印刷电路板浸出的各种金属离子的溶液中对 Au(III)离子表现出高度选择性的吸附。这些结果突出了 CS-TGA-GA 作为从电子废物浸出液中回收 Au 的吸附剂的潜力，从而有助于可持续的资源管理。
