Browsing by Author "Wallen, Benjamin"
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- ItemEngaging Students Through an Interactive Mass Balance Fundamentals Demonstration(ASEE, 2020) Wallen, Benjamin; Butkus, Michael; Sheehan, Nathaniel; Ng, Andrew; Pfluger, AndrewEmploying mass balance concepts is one of the fundamental approaches to address many of the National Academy of Engineering’s Grand Challenges of the 21st century. Of the five stated grand challenges, the incorporation of mass balance principles is central to understanding and resolving four of the five technical challenges while it supports and informs decision making in the fifth. For burgeoning environmental engineers, the understanding of mass balance concepts is foundational for recognizing and solving the complex multimedia environmental problems they will face. Environmental engineering curricula therefore requires students to fully understand and demonstrate proficiency in the application of mass balance concepts. Unfortunately, many students struggle to initially visualize key aspects and understand assumptions used with the mass balance approach. A five-minute demonstration provides a visual, interactive classroom experience that improves understanding and learning for a broad spectrum of students’ learning style preferences. The approach presented in this paper has been successfully used in an introductory environmental engineering course taught predominantly to non-engineering majors as part of a three-course environmental engineering sequence. Current data suggests that the incorporation of this demo improves student understanding of mass balance concepts evidenced by improved quantitative testing scores over the past two years. Though longitudinal data is forthcoming on the efficacy on long term retention, we strive for each non-engineering major in the sequence to be able to more broadly contextualize and solve complex problems using mass balance principles by incorporating a deliberate systematic approach. Indeed, for our students to tackle the grand challenges of this century, they must be able to understand the inherent interconnectedness of global and regional environmental systems.
- ItemIn Situ Exploration of Soil Lead in Residential Communities Using X-Ray Fluorescence and Geospatial Visualization(IEEE, 2021) Roth, B. T.; Harrell, K. N.; Wallen, Benjamin; Kimball, M. A.; Wright, William C.Lead contamination in soil is a human health hazard common in residential communities that pre-date regulatory bans on lead in both gasoline and paints. New remote sensing tools allow for quicker and more affordable sampling, but there is still a challenge in interpreting the data, visualizing the results, and communicating the relevance for response and remediation. Our work builds on previous studies analyzing soil lead concentrations at West Point, NY. The federal installation and college campus hosts residential neighborhoods with historic homes that were painted with lead paint in the past and are adjacent to high traffic roadways. Previous research established several areas where the lead concentrations significantly exceeded the U.S. Environmental Protection Agency (EPA) recommended safe concentrations for soil, but further exploration was necessary to refine those results. We targeted one location where a 2019 measurement indicated lead in excess of 1200 mg/kg. We used an X-Ray Fluorescence (XRF) meter to collect 73 soil lead concentrations between the road and the home, logging the locations using ArcGIS Collector. Results indicate localized lead concentrations with distinctive patterns that may provide clues to the origin of the contamination. Our analysis suggests that in situ measurements are effective to characterize concentrations but conclusions on the severity of lead contamination should not be made using widely spaced transect investigations. The XRF, combined with geospatial visualization methods, is a quick and inexpensive way to investigate neighborhood-scale soil lead contamination and refine the potential remediation response.
- ItemInvestigation of Diurnal Fluctuations of Heat and Water Distributions Around Landmines Impacted by Soil Heterogeneity(IEEE, 2020) Wallen, Benjamin; Wright, William C.; Oxendine, C. E.The environment in which landmines are placed is heterogeneous. Such differences in soil type, packing and moisture, combined with changes in surface and climate conditions can oftentimes mask the presence of a mine. Understanding the impact of heterogeneity on heat and mass transfer behavior near landmines is paramount to properly identifying landmine locations for demining operations. This study investigates the impact of soil heterogeneity on soil moisture and temperature distributions around buried objects to increase understanding of environmental conditions most dynamic to mine detection performance. A ten-day field experiment was conducted with sensors monitoring atmospheric, surface, and subsurface conditions relative to four different conditions associated with landmine emplacement. Experimental results demonstrate distinct behaviors in soil moisture and temperature distributions above and around buried objects that change due to soil heterogeneity and different climate conditions (i.e., temperature and rain events).
- ItemLong-term Impact on Environmental Attitudes and Knowledge Assessed over Three Semesters of an Environmental Engineering Sequence(ASEE, 2019) Wallen, Benjamin; Sheehan, Nathaniel; Plante, Luke; Martinez, Erick; Starke, JeffreyThe pedagogy employed in a three-course environmental engineering sequence is investigated to determine the efficacy of enabling long-term improvement of knowledge and attitudes toward the environment. These three courses incorporate concepts of the five grand challenges released by the National Academy of Engineering and National Academy of Sciences and increase the breadth of knowledge for T-professionals. Previous studies of lengths from a few weeks to semester long courses evaluated the potential causality among various demographics and environmental knowledge and attitudes. The research presented herein contrasts and compares changes in environmental knowledge based upon a 12-question survey and changes in environmental attitude based upon a seven-question survey administered at the beginning and end of the environmental engineering sequence courses taught to over 200 students from a variety of disciplines. Survey results demonstrate that a positive increase (9.27%) in knowledge occurred from the start to the end of the first course and the elimination of statistical differences among numerous demographics such as sex and race. After 18 months of environmental education, an 8.6% increase in knowledge was retained compared to the initial knowledge where the female and non-white demographics increased the most but retained the least. Results regarding environmental attitudes suggest that a focus on learning about environmental issues decreased positive attitudes toward the environment, whereas focusing on solutions to environmental issues increased positive attitudes toward the environment. Evaluating changes or sustainment of improved environmental attitudes over three semesters demonstrates the potential for an environmental engineering education to have a multi-year impact on the values and environmental ethos of students across many disciplines.
- ItemThe Five-minute Adsorption Demonstration(ASEE, 2020) Butkus, Michael; Shetty, Anand; Wallen, Benjamin; Sheehan, Nathaniel; Pfluger, AndrewAdsorption is one of the most common physicochemical treatment processes in environmental engineering. Faculty typically teach this process by explaining figures and equations in texts, which can limit learning. The five minute classroom demonstration presented here replicates the adsorption experiment and data analysis, which may engage students and enhance learning without imposing substantial demands on student time. Students observe removal of Crystal violet dye or food coloring by activated carbon in real time in a column demonstration. Simultaneously, data from an adsorption experiment is collected in an accelerated video format and an animated PowerPoint presentation illustrates how experimental data is used to quantify Isotherm Model parameters. Results from the Crystal violet adsorption experiment and isotherm model parameters are presented along with an in-class example problem.
- ItemUse of X-Ray Fluorescence to Expedite Sampling to Evaluate and Visualize Soil Lead Concentrations at West Point, NY(IEEE, 2020) Wallen, Benjamin; Kimball, M. A.; Wright, William C.; Sheehan, N. P.; Flagg, T. D.; Avellaneda-Ruiz, A. R.; Bier, P.V.The concentration of heavy metals, specifically lead, in soil may create unsafe environmental conditions. Unsafe conditions may occur based upon previous exposure to lead, such as particulate pollution from leaded gasoline. Accumulation of lead in the soil is especially concerning due to the detrimental physiological effects soil lead has on populations within residential neighborhoods. This study investigates the efficacy of an X-ray fluorescence (XRF) sensor compared to use of an inductively coupled plasma (ICP) laboratory instrument to measure soil lead concentration through a comparison of 87 soils samples. Findings note a strong correlation between both measurement methods. Additionally, 206 samples were evaluated to visualize soil lead concentrations throughout the residential West Point area. The highest soil lead concentrations are along the former route 9W, at locations associated with buildings that pre-date 1940.