Dr. Namayandeh is a postdoctoral fellow at the Doerr School of Sustainability at Stanford University. He earned his Ph.D. in Environmental Nanoscience/Geochemistry from Virginia Tech. His research involves the formation and transformation of natural nanoparticles and their reactions with nutrients and contaminants in soils, water, and air and how these reactions impact human health. His Ph.D. work focused on the formation and transformation kinetics of iron oxy-hydroxides and the effects of adsorbed oxyanions such as arsenic, phosphate, and nitrate.
He is currently studying the generation of toxic metals in soils at extremely high temperatures. He is also involved in solving global and environmental health problems, particularly in low-income countries. He is working on a project in Bangladesh focusing on lead exposure.
He also holds an MFA in theater and uses his science and art experience to integrate environmental justice into his research. While attending Virginia Tech, he founded an organization called Art for Environmental Justice (AEJ) to amplify the voices of underrepresented groups impacted by climate change. He is a maker of eco-performance works, and the staged reading of his latest play, Rhino 2020, was performed in Hey Market Theater at Virginia Tech in 2022, which explores the intersection of social extremism and environmental degradation caused by climate change. He is currently working on a project that uses eco-theater to address the environmental justice implications of California wildfires.
Honors & Awards
PRISM Baker Fellowship, Stanford University (2022-2023)
Interdisciplinary Graduate Education Fellowship, Virginia Tech (2021-2022)
Interdisciplinary Graduate Education Fellowship, Virginia Tech (2018-2019)
Scott Fendorf, Postdoctoral Faculty Sponsor
Current Research and Scholarly Interests
Dr. Namayandeh's research interests are centered around three primary areas: 1) the formation and transformation of natural nanoparticles, 2) their interaction with contaminants and nutrients in the Earth's surface environment, and 3) how these interactions impact human health. He is currently studying the generation of toxic metals in soils at extremely high temperatures. He is also involved in solving global and environmental health problems, particularly in low-income countries. He is working on a project in Bangladesh focusing on lead exposure.
He is also interested to integrate environmental justice into his research. He conducts Eco-theater workshops at Stanford, in which participants create performing arts about the social aspects of California wildfires, including the impact on underrepresented groups such as inmate firefighters.
- Effects of Oxyanion Surface Loading on the Rate and Pathway of Ferrihydrite Transformation ACS EARTH AND SPACE CHEMISTRY 2023
Oxyanion Surface Complexes Control the Kinetics and Pathway of Ferrihydrite Transformation to Goethite and Hematite.
Environmental science & technology
The rate and pathway of ferrihydrite (Fh) transformation at oxic conditions to more stable products is controlled largely by temperature, pH, and the presence of other ions in the system such as nitrate (NO3-), sulfate (SO42-), and arsenate (AsO43-). Although the mechanism of Fh transformation and oxyanion complexation have been separately studied, the effect of surface complex type and strength on the rate and pathway remains only partly understood. We have developed a kinetic model that describes the effects of surface complex type and strength on Fh transformation to goethite (Gt) and hematite (Hm). Two sets of oxyanion-adsorbed Fh samples were prepared, nonbuffered and buffered, aged at 70 ± 1.5 °C, and then characterized using synchrotron X-ray scattering methods and wet chemical analysis. Kinetic modeling showed a significant decrease in the rate of Fh transformation for oxyanion surface complexes dominated by strong inner-sphere (SO42- and AsO43-) versus weak outer-sphere (NO3-) bonding and the control. The results also showed that the Fh transformation pathway is influenced by the type of surface complex such that with increasing strength of bonding, a smaller fraction of Gt forms compared with Hm. These findings are important for understanding and predicting the role of Fh in controlling the transport and fate of metal and metalloid oxyanions in natural and applied systems.
View details for DOI 10.1021/acs.est.2c04971
View details for PubMedID 36219790
- TRACE AND RARE EARTH ELEMENT DISTRIBUTION AND MOBILITY DURING DIAGENETIC ALTERATION OF VOLCANIC ASH TO BENTONITE IN EASTERN IRANIAN BENTONITE DEPOSITS CLAYS AND CLAY MINERALS 2020; 68 (1): 50-66
Calorimetric study of the influence of aluminum substitution in ferrihydrite on sulfate adsorption and reversibility
JOURNAL OF COLLOID AND INTERFACE SCIENCE
2019; 540: 20-29
Ferrihydrite (Fh) is a nanocrystalline iron (hydr)oxide pervasive in various surface environments. It has high specific surface areas and high density of reactive surface-sites, both of which properties impart a consequential role in determining the fate and transport of environmental nutrients and contaminants. In natural environments, Fh readily reacts with impurities, such as aluminum (Al) and has variable substituted chemical compositions and surface properties. This work examines the effect of aluminum (Al) incorporation (0%, 12% and 24 mol% Al) on the interaction energy of chloride (Cl-) and nitrate (NO3-), and adsorption/desorption of sulfate (SO42-) onto Fh. Microcalorimetry experiments were conducted at pHs 3.0 and 5.6, along with a detailed characterization of all samples. Results showed a significant increase in the energetics of the exothermic peak of NO3- and the endothermic peak of Cl- with increasing Al concentration and decreasing pH values. Furthermore, the exothermic heat of exchange, adsorption, irreversibility and fraction of inner-sphere complexes for sulfate interaction with Fh increased with more Al concentration and acidic pH.
View details for DOI 10.1016/j.jcis.2019.01.001
View details for Web of Science ID 000460710800003
View details for PubMedID 30622055
- Genesis of the Eastern Iranian bentonite deposits APPLIED CLAY SCIENCE 2019; 168: 56-67
- Characterization of Iranian bentonites to be used as pharmaceutical materials APPLIED CLAY SCIENCE 2015; 116: 193-201