Fly Ash Modification for Heavy Metal Capture and Water Retention in Encapsulation

Joseph Cahill University of Louisville, Luis Moreno University of Louisville, Zain Akram University of Louisville, Mona Gupta Thomas More College, Adam Mama
Faculty Sponsor(s): Gautam Gupta University of Louisville
Encapsulation has been a process of interest to researchers who are trying to eliminate harmful constituents found in electric generating unit’s (EGUs) wastewater from being reintroduced to the environment. Using the by-products from the EGU, fly ash (burnt pulverized coal), brine (processed wastewater), and adding an additive such as quicklime or Portland cement, will create an encapsulation mix. In this study, modification of fly ash was pursued in two directions, surface area enhancement and extraction of fly ash derivatives. Water retention is an issue with wastewater encapsulation because there is more processed wastewater available than fly ash after an EGU has run. Therefore, by increasing the surface area of fly ash, more wastewater can be absorbed when encapsulating. Several different acid/base treatments were performed, as the reacting fluid, under reflux conditions. The data showed increased surface area compared to the untreated fly ash up to 9.5 times. A lab-scale bleed water test was performed which revealed an increase in water retention up to ~15%. The component of fly ash (mullite and iron oxide) were successfully separated though an intensive washing process. The derivatives of fly ash were utilized for heavy metal removal from wastewater. The results revealed that ~67% Cr6+ and ~70% Pb2+ were removed from wastewater using mullite, while ~80% Cr6+ and ~75% Pb2+ removal was achieved when iron oxide component of fly ash was used as adsorbent.
Sustainability, Urban Ecology & Environmental Studies
Oral Presentation

When & Where

09:45 AM
Pharmacy & Health Sciences 212