USGS Grant Number: G19AP00006
Year Established: 2018 Start Date: 2019-02-01 End Date: 2022-01-31
Total Federal Funds: $248,201 Total Non-Federal Funds: $248,438
Principal Investigators: Niveen Ismail
Abstract: Nanoparticles (NPs) are used in a variety of consumer products and their use is projected to continue to increase. Silver nanoparticles (AgNPs) are one type of NP that has many applications due to its antimicrobial properties. These NPs are considered emerging contaminants and can enter the environment in many ways. Wastewater effluent is one potential source of environmental input since AgNPs are not completely removed with traditional wastewater treatment. While engineered treatment wetlands can be used as tertiary treatment to remove recalcitrant contaminants, the behavior of AgNPs in treatment wetlands requires further research. The fate, behavior, and impact of AgNPs in complex natural environments, such as treatment wetlands, are not well understood. Our overarching project goal is to understand the overall fate and impact of AgNPs in treatment wetlands while exploring the potential roles of filter feeding zooplankton in these systems. This project goal will be achieved through three research objectives 1) Characterize and quantify AgNPs in wastewater influent and effluent to determine removal efficiency and changes in concentrations and characteristics due to seasonal variations and treatment facility location. 2) Parameterize the processes controlling the bioaccumulation of Ag from AgNP exposure in a model zooplankton species, and model the fate of AgNPs with varying properties. 3) Conduct long-term wetland mesocosm experiments to determine impacts of environmental variables and changing water quality parameters on AgNP fate and wetland performance. A variety of analytical techniques will be utilized to quantify AgNP concentrations including flow-field flow fractionation coupled with inductively coupled plasma-mass spectroscopy (FFF-ICP-MS) and single particle-ICP-MS (SP-ICP-MS). Additional techniques will be used to characterize the AgNPs such as image analysis of morphology using Transmission Electron Microscopy (TEM) and Dynamic Light Scattering (DLS) for size distribution. The data generated from these research objectives will address key knowledge gaps on environmental behavior and impacts of AgNPs, improve prediction of performance of treatment wetlands, and provide data necessary to calibrate and validate metal based NP models.