Hands On Projects To Engage Non Engineering Students

Three hands-on projects intended to engage the non-engineering student in environmental issues are introduced and discussed. In the first, students use different sized agar cubes with a diffusing dye to observe how surface area to volume relationships affect mass transfer rates. Results can be used to introduce students to issues such as cellular diffusion, air stripping towers, trickling filters, and aeration processes. The second project investigates the effectiveness of toilet paper as a barrier to Escherichia coli. By working with a culture of E. coli, students learn that toilet paper is not always an effective barrier between microorganisms and skin. Results can lead to discussions on pathogens, sanitary issues and the spreading of disease, indicator organisms, and wastewater treatment processes. In the third project, students create a closed population of yeast cells and watch the population rise exponentially until it crashes several days later. Comparisons to the Earth as a closed and/or open system can follow, along with a discussion of population growth models, carrying capacity, population control, and other ethical issues.