1,4‐Dioxane is an emerging contaminant of environmental concern, probable human carcinogen, and it can result in diffuse groundwater plumes and is not readily treated using common remedial techniques (e.g., via air stripping or granular activated carbon). In situ bioremediation of 1,4‐dioxane has been studied at the bench‐scale and pilot‐scale. This work documents the full‐scale application of in situ propane biosparging for the treatment of 1,4‐dioxane. The subject site is located at Vandenberg Space Force Base in California. Installation of the full‐scale treatment system came after several pilot tests (e.g., Lippincott et al. 2015), stable isotope testing (Bell et al. 2016), and rebound testing conducted from 2012 to 2016. The full‐scale propane biosparge system supplies air and propane at an average of 5 kg (11 pounds) of propane per day to a network of 97 biosparge wells, or 52 g (0.11 pounds) of propane per day per biosparge well. Additionally, a bioaugmentation culture and macronutrients were delivered to the subsurface. After approximately 6 months of operation, 1,4‐dioxane was reduced at up to 99.2%, with an average global reduction of 64.1% (excluding two anomalous monitoring wells) across a treatment area of approximately 30.5 by 61 m (100 by 200 ft).
This study investigates the spatial distribution and age structure of Post Settlement Alluvium (PSA) in a section of floodplain in the upper reaches of Clear Creek Watershed in east central Iowa. The study area topography, climate, soil, and pre-settlement tallgrass prairie landcover are representative of the headwaters of many Midwest watersheds, making the findings applicable in other parts of the region. Through this investigation, I aim to further understand the volume and age structure of PSA sediments deposited on the floodplain after Euroamerican settlement. This employs multiple methods: the collection and measurement of PSA in soil cores, visual and spatial analysis of land use and stream channel morphology, PSA volume calculations, and isotope geochemistry. Using 210 Lead (Pb) and 137 Cesium (Cs) isotope geochemistry to calculate age structures of the PSA provides a more detailed, temporal resolution of physical data than erosion and deposition model predictions can generate. A detailed land use history further facilitates the understanding of depositional processes that have occurred in the study area and region. By understanding the age structure of the sediment on the floodplain, as well as sediment volumes that are stored in floodplain headwaters, I aim to make tangible connections between agricultural land use and floodplain sedimentation rates and attempt to assess the impact (if any) of potential conservation practices.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
customersupport@researchsolutions.com
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.