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_C-AgNPs) 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_C-AgNPs 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_C-AgNPs. 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) 从制造到陆地环境的迁移途径中不可或缺的一部分。然而，关于天然有机物 (NOM) 作用的详细信息仍然有限。在这项研究中，将掺有 AgNPs 的废水混凝产生的污泥（表示为污泥_C-AgNPs）作为模型。通过一系列浸出实验，研究了腐殖酸（HA）、海藻酸盐（AA）和牛血清白蛋白（BSA）对污泥_{C-AgNPs中银释放量、动力学和形态的影响。}结果表明，浸出液中的HA、AA和BSA可以增强污泥_{C-AgNPs中银的释放。}. BSA溶液中溶解银和胶体银的浓度在动态浸出初期最高。银释放的控制步骤是在 HA 和 AA 溶液中的内部扩散，而溶解银的释放由 BSA 溶液中的化学反应和内部扩散来控制。此外，与 HA 和 AA 溶液相比，BSA 溶液中释放的胶体银部分含有更多尺寸>50 nm 的颗粒。结果表明，NOMs的性质可能是影响AgNPs从污泥向陆地环境转移的关键因素。