Concentration dependent aerosol substrates: UV-vis attenuation measurement

Ultraviolet and visible (UV/vis) light were used to determine the composition of aerosol samples taken from several military bases located in the Middle East. The aerosols were collected using a cascade impactor placing time resolved aerosols on strips of Mylar. These strips were then fed into a fiber optic UV/vis spectrometer which passes light through the Mylar strip and detects the amount of transmitted light relative to a blank standard. By measuring the light transmitted, the amount of aerosol on the Mylar strip was determined proportional to a calibration curve of standard mass depositions. The UV/vis tests were then compared to results from β-gauge analysis performed on the same samples to determine the validity of optical transparency as a substitute for electron attenuation studies. It was determined that the UV/vis data is largely comparable to the β -gauge data showing that UV/vis is a viable alternative to the β -gauge method as well as being more convenient, expedient, and easier to perform

Detection of hydrocarbon contaminants in groundwater systems

We present a study of groundwater contaminants from infiltration of heavy hydrocarbon pollution sources. This study primarily focuses on the volatile and non-volatile components of crude and processed oils. Many storage terminals and buried pipelines have experienced historical failures and present industrialized Northwest Indiana with a source of legacy pollution. We examine the aqueous phase and gas phase components of crude and diesel oils for identification of groundwater matrix markers from hydrocarbon emulsions

Air quality monitoring and anthropogenic correlations in Northwest Indiana

Currently, there are seven PurpleAir sensors deployed throughout Lake and Porter counties in cities including Gary, Chesterton, Valparaiso, and Schererville as part of the North Lake County Environmental Partnership (NLCEP). Communities have been partnering with Valparaiso University in order to set up and help maintain the PurpleAir sensors in their municipalities. In addition to setup and monitoring, communities are learning about their local air quality and the monitoring systems in place. We additionally observe air quality metrics for these sensors with attention to particulate concentrations and compare to spatial and meteorological factors. Within the Gary and Valparaiso areas, sensors have qualitative trends. Relative to a 5-mile radius in the Gary area, the distributions of particulates are not the same within the 95% confidence interval. Meteorological factors like humidity and pressure have an effect on the particulate concentrations and trends in pressure where particulate concentrations data show a transposed relationship. Anthropogenic spikes in particulate matter (PM1.0) are modeled with meteorological data with the Hybrid Single-Particle Lagrangian Integrated Trajectory Model (HYSPLIT) to evaluate particulate origin

Detection of hydrocarbon contaminants in groundwater systems

We present a study of groundwater contaminants from infiltration of heavy hydrocarbon pollution sources. This study primarily focuses on the volatile and non-volatile components of crude and processed oils. Many storage terminals and buried pipelines have experienced historical failures and present industrialized Northwest Indiana with a source of legacy pollution. We examine the aqueous phase and gas phase components of crude and diesel oils for identification of groundwater matrix markers from hydrocarbon emulsions

The effect of polypropylene on the formation of byssal threads produced by Dreissena polymorpha (zebra mussels)

The presence of microfibers and microplastics in the environment is an ever-growing ecological concern. Accumulation of microplastics (plastic particles smaller than 5 mm) in aquatic environments and the subsequent exposure of these particles to organisms have been shown to have negative effects on aquatic biota. As an invasive, filter-feeding bivalve found across Indiana freshwater ecosystems, the zebra mussel (Dreissena polymorpha) serves as a good model organism for studying microplastics’ effects on physiological and behavioral functions of affected organisms. We have studied the impacts of microplastic exposure on a freshwater mollusk, the zebra mussel. We collected zebra mussels from Stone Lake, Indiana, in late fall of 2019. Individual zebra mussels were exposed to polypropylene rope fibers (concentration of rope fibers in the environment of one zebra mussel was ~400 microfibers per L) for 24-hour trials and assessed the effects by production of byssal threads, which are produced by the zebra mussel for anchorage and in response to predation threats. Results from a comparison between unexposed control mussels (n=70) and mussels exposed to rope fibers (n=70) revealed no significant difference in motility nor the number of byssal threads produced. Despite using microplastic concentrations that were higher than that found in the Great Lakes, a 24 hour exposure time may still not have been enough to significantly impact the animals. Continued research on the attachment strength of Dreissena polymorpha exposed to rope fibers will provide clearer evidence of any direct effect of these microplastics on the ecologically important mussel species

Ion Mobility Studies of Electronically Excited States of Atomic Transition Metal Cations: Development of an Ion Mobility Source for Guided Ion Beam Experiments

The design of an ion mobility source developed to couple to a guided ion beam tandem mass spectrometer is presented. In these exploratory studies, metal ions are created continuously by electron ionization of the volatile hexacarbonyls of the three group 6 transition metals. These ions are focused into a linear hexapole ion trap, which collects the ions and then creates high intensity pulses of ions, avoiding excessive ion losses resulting from the low duty cycle of pulsed operation. The ion pulses are injected into a six-ring drift cell filled with helium where ions having different electronic configurations can separate because they have different ion mobilities. Such separation is observed for chromium ions and compares favorably with the pioneering work of Kemper and Bowers (J. Phys. Chem. 1991, 95, 5134). The results are then extended to Mo+ and W+, which also show efficient configuration separation. The source conditions needed for high intensities and good configuration separation are discussed in detail and suggestions for further improvements are also provided

Investigation of a Local Plastic Pollution Incident and Presentation of a Potential Remediation Strategy

Microplastic (MP) pollution is ubiquitous in environments across the globe, since plastics are known to fragment into smaller pieces over time. Microplastics are contaminants of emerging concern and the full extent of their effects is unknown. In some areas, microplastics heavily contaminate surface waters and are susceptible to chemical weathering, which alters their properties. These pollutants have the potential to enter the trophic levels and disrupt biological systems, as well as serve as a vector for other environmental contaminants through adsorption. The increase in the input of MP pollution into the environment requires technical remediation strategies, as there is no natural mechanism for remediation of these pollutants. In Hammond, Indiana, the company that manufactures polyethylene (PE) portable toilets has released PE waste into the adjacent wetland. The current methods of remediation for the wetland involve using oil booms to contain the pollution. In this study, water and sediment samples were collected from the freshwater marsh and its adjoining lake that are contaminated with the PE shavings. Laboratory analyses of the samples indicate a pollution load of over 1000 MP per sample. Laboratory experiments were also conducted to investigate a potential means for plastic remediation using an agglomeration technique. The results of using different polymers, particle sizes, and chemical additives will be presented. This pollution incident exhibits the critical need for effective remediation strategies, as well as regulations that will protect the world’s surface waters

Concentration Dependent Aerosol Substrates: UV-VIS Attenuation Measurements

Ultraviolet and visible (UV/vis) light were used to determine the composition of aerosol samples taken from several military bases located in the Middle East. The aerosols were collected using a cascade impactor placing time resolved aerosols on strips of mylar. These strips were then fed into a fiber optic UV/vis spectrometer which passes light through the mylar strip and detects the amount of transmitted light relative to a blank standard. By measuring the light transmitted, the amount of aerosol on the mylar strip was determined proportional to a calibration curve of standard mass depositions. The UV/vis tests were then compared to results from -gauge analysis performed on the same samples to determine the validity of optical transparency as a substitute for electron attenuation studies. It was determined that the UV/vis data is largely comparable to the -gauge data showing that UV/vis is a viable alternative to the -gauge method as well as being more convenient, expedient, and easier to perform