Fate of Ag-NPs in Sewage Sludge after Application on Agricultural Soils
详细信息 查看全文
- 作者：Ana E. Pradas del Real ; Hiram Castillo-Michel ; Ralf Kaegi ; Brian Sinnet ; Valérie Magnin ; Nathaniel Findling ; Julie Villanova ; Marie Carrière ; Catherine Santaella ; Alejandro Fernández-Martı́nez ; Clément Levard ; Géraldine Sarret
- 刊名：Environmental Science & Technology
- 出版年：2016
- 出版时间：February 16, 2016
- 年：2016
- 卷：50
- 期：4
- 页码：1759-1768
- 全文大小：546K
- ISSN：1520-5851
文摘
The objective of this work was to investigate the fate of silver nanoparticles (Ag-NPs) in a sludge-amended soil cultivated with monocot (Wheat) and dicot (Rape) crop species. A pot experiment was performed with sludges produced in a pilot wastewater treatment plant containing realistic Ag concentrations (18 and 400 mg kg–1, 14 mg kg–1 for the control). Investigations focused on the highest dose treatment. X-ray absorption spectroscopy (XAS) showed that Ag2S was the main species in the sludge and amended soil before and after plant culture. The second most abundant species was an organic and/or amorphous Ag—S phase whose proportion slightly varied (from 24% to 36%) depending on the conditions. Micro and nano X-ray fluorescence (XRF) showed that Ag was preferentially associated with S-rich particles, including organic fragments, of the sludge and amended soils. Ag was distributed as heteroaggregates with soil components (size ranging from ≤0.5 to 1–3 μm) and as diffused zones likely corresponding to sorbed/complexed Ag species. Nano-XRF evidenced the presence of mixed metallic sulfides. Ag was weakly exchangeable and labile. However, micronutrient mobilization by plant roots and organic matter turnover may induce Ag species interconversion eventually leading to Ag release on longer time scales. Together, these data provide valuable information for risk assessment of sewage sludge application on agricultural soils.