Shandong Key Laboratory of Water Pollution Control and Resource Reuse, School of Environmental Science and Engineering, Shandong University, Jinan 250100, PR China.
Environment Research Institute, Shandong University, Qingdao 266237, PR China.
NanoImpact. 2021 Jul;23:100347. doi: 10.1016/j.impact.2021.100347. Epub 2021 Aug 10.
Sludge is an integral part in the migration pathway of silver nanoparticles (AgNPs) from manufacture to the terrestrial environment. However, the detailed information on the role of natural organic matters (NOMs) remains limited. In this study, the sludge generated from coagulation of wastewater spiked with AgNPs (denoted as sludge) was taken as the model. Effects of humic acid (HA), alginate (AA) and bovine serum albumin (BSA) on the release amount, dynamics and speciation of silver from the sludge were investigated by a series of leaching experiments. The results showed that HA, AA and BSA in the leaching solution could enhance the silver release from the sludge. The concentrations of the dissolved and colloidal silver in the BSA solution were the highest at the initial stage of dynamic leaching. The controlling step of the silver release was internal diffusion in the HA and AA solution, while the release of dissolved silver was controlled by both chemical reaction and internal diffusion in the BSA solution. In addition, the released colloidal silver fractions in the BSA solution contained more particles with size >50 nm compared with the HA and AA solutions. The results suggested that the properties of NOMs may be the key factor affecting the transfer of AgNPs from the sludge to the terrestrial environment.
污泥是银纳米粒子（AgNPs）从制造到陆地环境迁移途径中的一个组成部分。然而，关于天然有机物（NOMs）的详细信息仍然有限。在这项研究中，以凝结含 AgNPs 废水生成的污泥（记为污泥）作为模型。通过一系列浸出实验，研究了腐殖酸（HA）、海藻酸钠（AA）和牛血清白蛋白（BSA）对污泥中银释放量、动力学和形态的影响。结果表明，浸出溶液中的 HA、AA 和 BSA 均可促进污泥中银的释放。在动态浸出的初始阶段，BSA 溶液中溶解态和胶体态银的浓度最高。HA 和 AA 溶液中银释放的控制步骤为内扩散，而 BSA 溶液中溶解态银的释放则受化学反应和内扩散的共同控制。此外，BSA 溶液中释放的胶体态银部分中，粒径大于 50nm 的颗粒比 HA 和 AA 溶液中的更多。结果表明，NOMs 的性质可能是影响 AgNPs 从污泥向陆地环境迁移的关键因素。
