Natural formation and transformation of silver nanoparticles in the aquatic environment

Abstract

Silver nanoparticles (AgNPs) are well known for their excellent antibacterial ability and superior physiochemical properties, and are widely used in a growing number of applications, including home disinfectants, medical devices and water purificants. During the production, use and disposal of AgNP-containing products, AgNPs may be released into the environment. AgNPs are highly dynamic in aqueous systems. They could undergo different chemical and morphology transformation, which greatly affects their final fate, transport, distribution and potential bioeffects. The study on the fate and transformation of AgNPs in natural systems is the basis and prerequisite for the accurate assessment of environmental and biological safety of AgNPs. Herein, we reviewed the recent progress of the natural formation and transformation of AgNPs in the aquatic environment, including the chemical and biosynthesis of AgNPs, the aggregation, enrichment in water surface microlayer, oxidation and dissolution, sulfidation and chlorination of AgNPs in the aquatic environment. The prospects and possible directions in the field are also discussed.