Date on Master's Thesis/Doctoral Dissertation
JB Speed School of Engineering
Committee Co-Chair (if applicable)
Fly ash; iron oxide; metal removal; ion exchange; co-precipitation; wastewater
New regulations on coal-fired power plants make previously used wastewater treatment methods aimed to remove heavy metals obsolete. Therefore, there has been increased interest and investment into new technologies to treat coal-fired power plants effluent in the past few years. Traditionally, heavy metal removal technologies have been broken into three categories: physical, chemical or biological. However, with new regulations, each category by itself does not offer an ideal solution to removing acceptable concentrations of heavy metals found in the effluents at the coal-fired power plants. Here we report a novel proof-of-concept utilizing adsorption through ion-exchange/co-precipitation - chemical and physical - using the iron oxide constituents found in fly ash, as an alternate effluent treatment technology. Here we illustrate one of the by-products (fly ash) generated from coal-fired power plants can be effectively employed to treat wastewater effluent. The iron oxide constituent separated from fly ash successfully removed positively charged contaminants during ICP-AES analysis. Based on the results shown, it is proposed that the neutrally charged iron oxide nanoparticles are exchanged with the positively charged contaminants (chromium and selenium), forming insoluble metal hydroxides that are easily separated/removed from the wastewater effluent. These results demonstrate that adsorption through ion-exchange/co-precipitation, using iron oxide constituent, has the potential to be developed as an alternative effluent treatment technology. It is anticipated that the work presented will be a starting point for further development of adsorption by iron oxide constituents derived from fly ash.
Cahill, Joseph E., "Coal fly ash beneficiation for reuse and removal of Boron, Cadmium, Chromium, Copper, and Selenium in wastewater treatment." (2021). Electronic Theses and Dissertations. Paper 3905.