Retention of silver nanoparticles and silver ion to natural soils: effects of soil physicochemical properties
Abstract
Purpose
The mass production and widespread use of silver nanoparticles (AgNPs) have led to their wide dissimilation in the subsurface environments (e.g., natural soils). The retention propensities of AgNPs in soils dictate their fate, transport, and transformation in the subsurface environments. The aim of this study was to explore the retention behaviors of AgNPs and Ag+ ion (as a comparison) in ten natural soils with different physicochemical properties, identifying which properties dominate their mobility in soils.
Materials and methods
Ten surface (0–20 cm) soils sampled across five geographical regions of China and AgNPs coated by polyvinylpyrrolidone (PVP) with an average transmission electron microscopy (TEM) diameter of ~ 10 nm were used in this study. Batch retention experiments of AgNPs and AgNO3 in ten soils (pass through 60-mesh sieve) were conducted in triplicate at 25 °C for 24 h. Multiple regression analyses of maximum retention capacity (Qmax for AgNPs or Ag+ ion) simulated by Langmuir retention models were performed to identify which soil physicochemical properties dominate the retention behavior of AgNPs and Ag+ ion. TEM combined with energy dispersive X-ray spectroscopy (EDS) analyses was applied to visually unravel the distribution and retention behavior of AgNPs on natural soils.
Results and discussion
The results of batch retention experiments showed that Langmuir model well-approximated the retention isotherms of AgNPs and Ag+ on ten soils and that the Qmax value of AgNPs was generally lower than that of Ag+ on soils. The results of multiple regression analyses showed that the retention capacity of AgNPs on soils was positively correlated with the iron oxide content, which is visually confirmed by TEM-EDS observations, whereas retention capacity of Ag+ ions was mainly related to soil organic matter (SOM) content.
Conclusions
Maximum retention capacity of AgNPs and Ag+ ion in soils varied with soil physicochemical properties, and particularly, iron oxide and SOM contents are two pivotal parameters controlling Qmax. These findings advance our current understanding of the mechanisms controlling retention and transport of AgNPs in natural soils, which represents an important step toward predicting the fate, transport, and potential toxicity of AgNPs in the subsurface environment.
Publisher URL: https://link.springer.com/article/10.1007/s11368-018-1918-2
DOI: 10.1007/s11368-018-1918-2
Keeping up-to-date with research can feel impossible, with papers being published faster than you'll ever be able to read them. That's where Researcher comes in: we're simplifying discovery and making important discussions happen. With over 19,000 sources, including peer-reviewed journals, preprints, blogs, universities, podcasts and Live events across 10 research areas, you'll never miss what's important to you. It's like social media, but better. Oh, and we should mention - it's free.
Researcher displays publicly available abstracts and doesn’t host any full article content. If the content is open access, we will direct clicks from the abstracts to the publisher website and display the PDF copy on our platform. Clicks to view the full text will be directed to the publisher website, where only users with subscriptions or access through their institution are able to view the full article.