Abdulsada Zainab, Kibbee Richard, Princz Juliska, DeRosa Maria, Örmeci Banu
Department of Civil and Environmental Engineering, Carleton University, Ottawa, ON K1S 5B6, Canada.
Department of Environmental Engineering, University of Baghdad, Karrada, Al-Jadriya, Baghdad, Iraq.
Nanomaterials (Basel). 2021 Sep 7;11(9):2330. doi: 10.3390/nano11092330.
This study investigated the impact of lime stabilization on the fate and transformation of AgNPs. It also evaluated the changes in the population and diversity of the five most relevant bacterial phyla in soil after applying lime-stabilized sludge containing AgNPs. The study was performed by spiking an environmentally relevant concentration of AgNPs (2 mg AgNPs/g TS) in sludge, applying lime stabilization to increase pH to above 12 for two hours, and applying lime-treated sludge to soil samples. Transmission electron microscopy (TEM) and energy-dispersive X-ray spectroscopy (EDS) were used to investigate the morphological and compositional changes of AgNPs during lime stabilization. After the application of lime stabilized sludge to the soil, soil samples were periodically analyzed for total genomic DNA and changes in bacterial phyla diversity using quantitative polymerase chain reaction (qPCR). The results showed that lime treatment effectively removed AgNPs from the aqueous phase, and AgNPs were deposited on the lime molecules. The results revealed that AgNPs did not significantly impact the presence and diversity of the assessed phyla in the soil. However, lime stabilized sludge with AgNPs affected the abundance of each phylum over time. No significant effects on the soil total organic carbon (TOC), heterotrophic plate count (HPC), and percentage of the live cells were observed.
本研究调查了石灰稳定化对银纳米颗粒（AgNPs）归宿和转化的影响。研究还评估了施用含AgNPs的石灰稳定化污泥后，土壤中五个最相关细菌门的种群和多样性变化。该研究通过在污泥中加入与环境相关浓度的AgNPs（2 mg AgNPs/g TS），进行石灰稳定化处理以将pH提高到12以上并持续两小时，然后将石灰处理后的污泥施用于土壤样品来开展。使用透射电子显微镜（TEM）和能量色散X射线光谱（EDS）来研究石灰稳定化过程中AgNPs的形态和成分变化。在将石灰稳定化污泥施用于土壤后，定期使用定量聚合酶链反应（qPCR）分析土壤样品中的总基因组DNA和细菌门多样性的变化。结果表明，石灰处理有效地从水相中去除了AgNPs，并且AgNPs沉积在石灰分子上。结果显示，AgNPs对土壤中评估的细菌门的存在和多样性没有显著影响。然而，含AgNPs的石灰稳定化污泥随着时间的推移影响了每个细菌门的丰度。未观察到对土壤总有机碳（TOC）、异养平板计数（HPC）和活细胞百分比有显著影响。
