Comparison of microplastic extraction methodologies for drinking water sludge
Disciplines
Environmental Chemistry | Environmental Engineering
Abstract (300 words maximum)
Microplastics have been found everywhere on earth including the Arctic Circle and pristine lakes but methods of analyses have not been uniform. In this study, the National Oceanic and Atmospheric Administration (NOAA) microplastic laboratory method for quantifying microplastics specifically designed for marine environments has been applied to drinking water and drinking water sludge samples. Alternatives for difficult or expensive steps were examined. For many of the experiments, the NOAA method was followed. However, for drinking water samples, density separation by NaCl versus ZnCl2 was compared. For sludge sediment samples, the density separation which uses lithium metatungstate was compared between a short duration of 30 minutes to an hour, and a long duration of 1 to 2 days. Additionally, graduated cylinders were used instead of the density separator funnel, which was prone to clogging. The additional step of vacuum filtration was added before the microscopic examination. Based on preliminary visual inspection, a longer settling time for density separation with lithium metatungstate achieves better separation. Comparisons between outflow water samples separated with NaCl versus ZnCl2 are currently being performed. Filtered samples will be analyzed under a stereo microscope by visual inspection or with an FTIR microscope for polymer identification.
Academic department under which the project should be listed
CSM - Chemistry and Biochemistry
Primary Investigator (PI) Name
Dr. Marina Koether
Additional Faculty
Amy Gruss, Civil and Environmental Engineering, agruss@kennesaw.edu
Comparison of microplastic extraction methodologies for drinking water sludge
Microplastics have been found everywhere on earth including the Arctic Circle and pristine lakes but methods of analyses have not been uniform. In this study, the National Oceanic and Atmospheric Administration (NOAA) microplastic laboratory method for quantifying microplastics specifically designed for marine environments has been applied to drinking water and drinking water sludge samples. Alternatives for difficult or expensive steps were examined. For many of the experiments, the NOAA method was followed. However, for drinking water samples, density separation by NaCl versus ZnCl2 was compared. For sludge sediment samples, the density separation which uses lithium metatungstate was compared between a short duration of 30 minutes to an hour, and a long duration of 1 to 2 days. Additionally, graduated cylinders were used instead of the density separator funnel, which was prone to clogging. The additional step of vacuum filtration was added before the microscopic examination. Based on preliminary visual inspection, a longer settling time for density separation with lithium metatungstate achieves better separation. Comparisons between outflow water samples separated with NaCl versus ZnCl2 are currently being performed. Filtered samples will be analyzed under a stereo microscope by visual inspection or with an FTIR microscope for polymer identification.