ABSTRACT This study evaluated the removal of silver nanoparticles (AgNPs), coated with different stabilizers, from aqueous media using the electrocoagulation technique. The AgNPs dispersions were synthesized by chemical reduction with silver nitrate as precursor, sodium borohydride as reducing agent and sodium carboxymethylcellulose (CMC), polyvinyl alcohol (PVA) and polyvinylpyrrolidone (PVP) as stabilizers with initial concentrations of 1 and 3% (w/v). The dispersions were named AgNPs-CMC1, AgNPs-CMC3, AgNPs-PVA1, AgNPs-PVA3, AgNPs-PVP1, and AgNPs-PVP3. Electrocoagulation treatments of AgNPs-PVA1, AgNPs-PVP1 and AgNPs-PVP3 dispersions resulted in total silver removals above 99.90% in 10 min. For the AgNPs-PVP3 dispersion 99.98% of removal was obtained in 20 min. After 15 min of electrolysis, The AgNPs-CMC1 and AgNPs-CMC3 dispersions showed a reduction in total silver concentration of 71.72 and 52.15%, respectively. Therefore, these results showed that the removal of AgNPs from the aqueous medium by electrocoagulation is possible, but their efficiency and viability depends on the nature, the molecular structure and the concentration of stabilizers. Furthermore, the toxicity analysis using the Vibrio fischeri bacteria demonstrated that only the dispersions stabilized with PVP became suitable for disposal after the electrocoagulation treatment. GRAPHICAL ABSTRACT

中文翻译：

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电凝聚法去除水性介质中不同稳定剂包覆的银纳米粒子

摘要 本研究评估了使用电凝技术从水性介质中去除涂有不同稳定剂的银纳米粒子 (AgNPs)。以硝酸银为前体，硼氢化钠为还原剂，羧甲基纤维素钠 (CMC)、聚乙烯醇 (PVA) 和聚乙烯吡咯烷酮 (PVP) 作为稳定剂，初始浓度为 1% 和 3% (w/v)，通过化学还原合成 AgNPs 分散体。 ）。分散体被命名为 AgNPs-CMC1、AgNPs-CMC3、AgNPs-PVA1、AgNPs-PVA3、AgNPs-PVP1 和 AgNPs-PVP3。AgNPs-PVA1、AgNPs-PVP1 和 AgNPs-PVP3 分散体的电凝处理导致 10 分钟内总银去除率超过 99.90%。对于 AgNPs-PVP3 分散体，在 20 分钟内获得了 99.98% 的去除率。电解15分钟后，AgNPs-CMC1 和 AgNPs-CMC3 分散体的总银浓度分别降低了 71.72% 和 52.15%。因此，这些结果表明通过电凝从水性介质中去除 AgNPs 是可能的，但它们的效率和活力取决于稳定剂的性质、分子结构和浓度。此外，使用费氏弧菌进行的毒性分析表明，只有用 PVP 稳定的分散体在电凝处理后才适合处置。图形概要 分子结构和稳定剂的浓度。此外，使用费氏弧菌进行的毒性分析表明，只有用 PVP 稳定的分散体在电凝处理后才适合处置。图形概要 分子结构和稳定剂的浓度。此外，使用费氏弧菌进行的毒性分析表明，只有用 PVP 稳定的分散体在电凝处理后才适合处置。图形概要