Abinash Agrawal (Advisor), David Dominic (Committee Member), David Kempisty (Committee Member)
Master of Science (MS)
Nanoscale Zero Valent Iron (NZVI) has shown limited effectiveness in degrading chlorinated hydrocarbons (CHCs), like 1,1,1-Trichloroethane (1,1,1-TCA) and Trichloroethene (TCE), in aqueous solution. A rapid agglomeration behavior of NZVI particles due to van der waals and magnetic forces can negatively impact its overall effectiveness due to increase in particle size, and decline in CHC degradation kinetics. Different support materials, such as clays and activated carbon, have been used to stabilize NZVI particle and reduce agglomeration in aqueous solution. In this bench-scale study, NZVI supported on Powdered Activated Charcoal (PAC) was selected to prepare a composite, called PAC/NZVI, for a more effective treatment of 1,1,1-TCA and TCE in aqueous solution. The study shows that PAC/NZVI has both adsorption and degradation capability toward 1,1,1-TCA and TCE. PAC exhibited high porosity to accommodate NZVI as a suitable support in order to keep NZVI in suspension in aqueous medium and to minimize agglomeration. Bench-scale experiments with variable concentrations of PAC (0.1–0.8 g/L) and NZVI (0.2–0.6 g/L) showed that PAC/NZVI composite can be highly efficient in rapid 1,1,1-TCA removal by adsorption, and effective in overall degradation leading to production of non-chlorinated daughter products. Increase in PAC concentration in the composite was correlated with greater removal of 1,1,1-TCA by sorption whereas lower PAC concentration yielded greater degradation kinetics and higher byproduct yields. PAC/NZVI was found to be active for more than three months presumably because NZVI embedded within hydrophobic pore spaces of PAC did not get oxidized. Cu amendment to NZVI as a secondary/catalysts metal showed faster degradation and higher byproduct yields.
Department or Program
Department of Earth and Environmental Sciences
Year Degree Awarded
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