5 research outputs found
The mobility of silver nanoparticles and silver ions in the soil-plant system
The widespread use of silver nanoparticles (AgNPs) as a bactericide will ultimately result in their increased concentration in soils. We sought to determine the likely mobility, toxicity, and plant uptake of Ag applied to soil as either AgNPs or Agâș. We measured the solubility, toxicity, and plant uptake of both AgNPs and Agâș in an immature Pallic soil, a Templeton loamy silt (pH = 5.1), and a granular silt loam (pH = 6.0). The sorption of AgNPs by the test soils was significantly greater than Agâș, and both moieties were more strongly sorbed at lower concentrations and higher pH values. Between pH 4 and 8, distribution coefficient (KD) values increased from 100 mg kgâ»Âč significantly reduced the biomass of Lolium perenne L. and resulted in foliar concentrations of up to 10 mg kgâ»Âč dry matter. At a soil concentration of 70 mg kgâ»Âč, silverbeet [Beta vulgaris L. ssp. maritima (L.) Arcang.] and spinach (Spinacia oleracea L.) accumulated 5 to 10 mg Ag kgâ»Âč, which may present a human health risk. Regarding citrate-coated AgNPs, the environmental impact of release is largely determined by the equivalent mass concentration of Agâș, into which they will ultimately transform. Given the widespread interest in AgNPs, there is limited knowledge on the behavior of Agâș in soil and this should be the subject of future research