| Popis: |
The increasing use of silver nanoparticles (AgNP) in a wide range of consumer and medical products represent a growing risk due to the potential for their release into the environment. However, there are few data on the fate of these nanoparticles as they transition from freshwater to brackish to marine waters, particularly as the abiotic characteristics of these environmental compartments are complex and dissimilar. Thus, in this study, the influence of abiotic parameters including electrolyte strength, pH, oxygen saturation and light intensity, and their complex interplay, on AgNP colloidal stability in freshwater, brackish waters and seawater was determined. Further, the modulating role of natural organic matter including humic and alginic acids, and proteinaceous matter was investigated. Data indicate AgNP agglomeration with increasing electrolyte strength may be greatly reduced depending on the nature of organic matter coronas formed around the nanoparticles and the kinetics of oxidative dissolution are significantly altered. Further, ultraviolet light irradiation has been shown to act against the dissolution process leading to reduction of silver ions at the surfaces of the AgNPs. These results show the complex behaviour of AgNPs as they transition from riverine to coastal waters, with a concomittant impact on their potential toxicity to biota. |
