Water Resources Research Act Program

Details for Project ID 2020AZ104B

Removal of Microplastics by Soil Aquifer Treatment of Reclaimed Wastewater

Institute: Arizona
Year Established: 2020 Start Date: 2020-03-01 End Date: 2021-02-28
Total Federal Funds: $9,990 Total Non-Federal Funds: $20,113

Principal Investigators: Dr. Charles P. Gerba

Abstract: Contamination of our environment from microplastics (1 μm to 5 mm in size) is gaining significant public interest due largely to their emergence as an environmental and potential human health threat. Microplastics have been detected in surface waters and treated wastewater effluents. All of the major cities in Arizona practice soil aquifer treatment (SAT), also referred to as managed aquifer recharge (MAR), of surface and treated wastewaters. The goal of this study is to provide the first information on the potential of SAT / MAR as a treatment process to reduce/remove microplastics. This study will be conducted at the Water & Energy Sustainable Technology (WEST) Center in collaboration with the Pima County Reclamation Department who have recently acquired a Fourier Transformed Infrared (FTIR) Spectroscopic imaging system to identify and quantify types of microplastics. This instrument and its associated software provide information on the relative removal of different types of plastics (shape, size, and composition). The effluent supplied to the SAT infiltration basins and groundwater from two monitoring wells and a production well will be collected on five occasions over a period of 12 months. The wells represent SAT sites of different ages and transport time to the wells. The objective of the study is to provide data on the degree of removal of microplastics by SAT. This data can be compared to our existing data on the removal of viruses at these sites. Data will be analyzed as to log or percent removal of the different types of microplastics at the different wells considering retention time of the water in the subsurface and the age of the SAT operation.