Anh Pham (Curriculum Vitae)

Graduate Student Researcher
Department of Civil & Environmental Engineering
University of California Berkeley, CA, 94720

anhpham@berkeley.edu

Anh is PhD candidate in Department of Civil and Environmental Engineering. He is co-advised by Professor David Sedlak (Civil and Environmental Engineering) and Fiona Doyle (Materials Science and Engineering) working on a project investigating the remediation of Superfund Sites by H2O2 based In Situ Chemical Oxidation (ISCO). This project is funded by National Institute for Environmental Health and Science (NIEHS) through Superfund Research Program, UC Berkeley.

The aim of Anh’s research is to investigate factors affecting the efficacy of H2O2-based In ISCO. When injected into the subsurface, H2O2 will undergo a series of interaction with subsurface materials (e.g., iron-containing clays and minerals) and will be converted into strong oxidants (e.g., •OH) capable of oxidizing recalcitrant contaminants. Subsurface minerals, however, have different catalytic activity. For example, iron oxides (e.g., ferrihydrite or goethite) and manganese oxides (pyrulosite, birnessite) are very ineffective in converting H2O2 into •OH because these minerals mainly decompose H2O2 directly into O2 and H2O via two-electron transfer mechanisms (Scheme 1). In contrast, silica supported iron catalysts and iron-containing clays (e.g.,montmorillonite and nontronite), are much more effective in converting H2O2 into •OH and it is postulated these materials can catalyze the H2O2 decomposition via Haber Weiss mechanism (Scheme 2) because iron in these materials is coordinated with alumina and silica.

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Scheme 1:  Non-radical hydrogen peroxide decomposition mechanism

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Scheme 2: Haber-Weiss mechanism for the decomposition of hydrogen peroxide to •OH.

Currently Anh is investigating the role of solution conditions in the subsurface on the kinetics and efficiency of contaminants transformation. For example, he found that dissolved silica can slow the H2O2 decomposition rate and therefore increase H2O2 lifetime in the subsurface. He is also investigating the catalytic activity of real aquifer sediments that were collected from various contaminated sites.