In:
Journal of Environmental Quality, Wiley, Vol. 49, No. 6 ( 2020-11), p. 1679-1689
Abstract:
Biosolids can be a source of metals and metal nanoparticles. The objective of this study was to quantify and characterize the accumulation and transport of silver (Ag) in a natural soil that has received agronomically recommended rates of biosolids as fertilizer from 1994 to 2017. Total Ag concentrations were measured in biosolids and soil samples collected from 0 to 10 cm between 1996 and 2017. The depth distribution of Ag in soil to 60‐cm depth was measured in 2017. Electron microscopy, in combination with X‐ray spectroscopy, and X‐ray absorption spectroscopy were used to characterize the Ag. The Ag concentrations in the biosolids‐amended soil increased steadily from 1996 until 2007, after which the concentrations leveled off at about 1.25 mg Ag kg −1 soil. This corresponded with a decrease of Ag concentrations in biosolids over time. The majority of the Ag (82%) was confined to the top 10 cm of the soil, small amounts (14%) were detected at 10‐to‐20‐cm depth, and trace amounts (4%) were detected at 30‐to‐40‐cm depth. The Ag in the biosolids was identified as S‐containing nanoparticles (Ag 2 S) with a diameter of 10–12 nm; however, in soil, the Ag concentrations were too low to allow identification of Ag speciation. This study shows that in a real‐world field scenario, biosolids applied at agronomic rates represent a long‐term, economically viable source of crop nutrients without increasing the concentration of total Ag in soil above a maximum of 1.5 mg Ag kg −1 . This concentration is below estimated ecotoxicity limits for Ag 2 S in soil.
Type of Medium:
Online Resource
ISSN:
0047-2425
,
1537-2537
Language:
English
Publisher:
Wiley
Publication Date:
2020
detail.hit.zdb_id:
120525-0
detail.hit.zdb_id:
2050469-X
