Controlled delivery and release of amendments is an important concept for improving the science and engineering behind subsurface remediation. Many current approaches to managing groundwater contamination rely on further advances in amendment delivery to initiate and sustain contaminant degradation or immobilization. The PI?s research integrates laboratory experiments across multiple scales to better understand how engineers can control the placement and flux of remedial amendments within the contaminated subsurface environment. Emphasis in this project is placed on the addition of alkalinity using oil-in-water emulsions. Interest in harnessing coupled physical, chemical and biological processes for remediation and stewardship of contaminated sites often necessitates control of pH during treatment and, in some cases, long thereafter. The central hypothesis of this research is that oil-in-water emulsions can be effective tools for modulating alkalinity release during remediation. This project aims to elucidate the mechanisms that control alkalinity release from oil-in-water emulsions designed to contain nano- or submicron-size carbonate and metal oxide particles. Project objectives are: (i) assess mechanisms controlling particle stability within soybean oil; (ii) create and optimize emulsions containing alkalinity release particles within a dispersed soybean oil phase; (iii) elucidate the influence of soybean oil composition on the rate of alkalinity release; and (iv) analyze the ability of oil-in-water emulsions to deliver and release alkalinity for control of groundwater pH. Model Eliciting Activities related to filtration theory and subsurface pH adjustment will be developed and deployed to motivate and engage learners in the geoenvironmental engineering thread of the civil engineering curriculum at Tufts. The PI is committed working with Tufts Center for STEM Diversity - an umbrella organization that coordinates all STEM diversity efforts at Tufts University - to enhance diversity within research and learning environments. Project results will be disseminated to a broad spectrum of students and researchers.
