Publications by authors named "Ashlynn S Stillwell"

The United States has significant greenhouse gas and criteria pollutant emissions that lead to global warming, human health, ozone, and smog issues, partially attributed to its diesel-consuming transport fleet. Until fleet electrification reaches cost parity with internal combustion engines, biodiesel use can reduce these negative impacts. In this study, we analyzed and categorized the biodiesel-supporting policies of each U.

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Cellulosic biofuels are part of a portfolio of solutions to address climate change; however, their production remains expensive and federal policy interventions (e.g., Renewable Fuel Standard) have not spurred broad construction of cellulosic biorefineries.

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Article Synopsis
  • A comprehensive review of residential water consumption studies highlights the importance of understanding individual water end uses to adapt urban water systems to changing demands.
  • The paper systematically analyzes 114 studies, detailing significant findings and prioritizing which aspects of water end-use have been most explored globally.
  • It offers insights for water utilities, consumers, and researchers on key water end use characteristics and encourages analysis across diverse geographical, cultural, and socio-economic contexts.
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Drastic changes in electricity demand have been observed since March 2020 in Europe, after several countries implemented lockdown-like measures to contain the spread of COVID-19. We investigate the sensitivity of the electricity-water nexus in the European electric grid to large-scale behavior changes during the COVID-19 pandemic lockdown-like measures. We quantify changes in the blue virtual water trade between five European countries heavily affected by COVID-19 during the same period.

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Stress on water and energy utilities, including natural resource depletion, infrastructure deterioration, and growing populations, threatens the ability to provide reliable and sustainable service. This study presents a demand-side management decision-making tool to evaluate energy and water efficiency opportunities at the residential level, including both direct and indirect consumption. The energy-water nexus accounts for indirect resource consumption, including water-for-energy and energy-for-water.

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Thermoelectric power plants demand large quantities of cooling water, and can use alternative sources like treated wastewater (reclaimed water); however, such alternatives generate many uncertainties. De facto water reuse, or the incidental presence of wastewater effluent in a water source, is common at power plants, representing baseline conditions. In many cases, power plants would retrofit open-loop systems to cooling towers to use reclaimed water.

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Use of reclaimed water-municipal wastewater treatment plant effluent-in nonpotable applications can be a sustainable and efficient water management strategy. One such nonpotable application is at thermoelectric power plants since these facilities require cooling, often using large volumes of freshwater. To evaluate the geographic, technologic, and economic feasibility of using reclaimed water to cool thermoelectric power plants, we developed a spatially resolved model of existing power plants.

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This study presents a second-order energy return on investment analysis to evaluate the mutual benefits of combining an advanced wastewater treatment plant (WWTP) (with biological nutrient removal) with algal biofuel production. With conventional, independently operated systems, algae production requires significant material inputs, which require energy directly and indirectly, and the WWTP requires significant energy inputs for treatment of the waste streams. The second-order energy return on investment values for independent operation of the WWTP and the algal biofuels production facility were determined to be 0.

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Increases in corn cultivation for biofuels production, due to the Energy Independence and Security Act of 2007, are likely to lead to increases in nitrate concentrations in both surface and groundwater resources in the United States. These increases might trigger the requirement for additional energy consumption for water treatment to remove the nitrates. While these increasing concentrations of nitrate might pose a human health concern, most water resources were found to be within current maximum contaminant level (MCL) limits of 10 mg L(-1) NO(3)-N.

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