Sahar El Abbadi is a post-doctoral researcher in Energy Resources Engineering. Her research focuses on developing circular economies by transforming waste methane into useful products. Methane, a potent greenhouse gas, is emitted atmosphere by industrial sources (wastewater treatment plants, landfill, fossil fuel extraction) because it is uneconomical to capture, clean and use. However, methane-consuming bacteria can transform this harmful pollutant into protein-rich cells and biodegradable polymers. Sahar's PhD research evaluated the economic potential of using these bacteria to reduce methane emissions while providing a new source of high-quality protein that can be used as a feed for agriculture and aquaculture. Sahar continues to expand on this work in considering the path to industrialization in both the United States and Bangladesh using methane produced at landfills. Sahar completed her Bachelor's degree at UC Berkeley (2012) in Environmental Engineering Science, and her MS (2015) and PhD (2021) in Civil & Environmental Engineering at Stanford.
Honors & Awards
Justice, Equity, Diversity & Inclusion (JEDI) Graduation Award, Stanford School of Engineering (2021)
Centennial Teaching Assistant, Stanford School of Engineering (2020)
Adam Brandt, Postdoctoral Faculty Sponsor
- Displacing fishmeal with protein derived from stranded methane NATURE SUSTAINABILITY 2021
- More than a fertilizer: wastewater-derived struvite as a high value, sustainable fire retardant GREEN CHEMISTRY 2021
- Membrane and Fluid Contactors for Safe and Efficient Methane Delivery in Methanotrophic Bioreactors JOURNAL OF ENVIRONMENTAL ENGINEERING 2020; 146 (6)
Fate of Hexabromocyclododecane (HBCD), A Common Flame Retardant, In Polystyrene-Degrading Mealworms: Elevated HBCD Levels in Egested Polymer but No Bioaccumulation.
Environmental science & technology
As awareness of the ubiquity and magnitude of plastic pollution has increased, so has interest in the long term fate of plastics. To date, however, the fate of potentially toxic plastic additives has received comparatively little attention. In this study, we investigated the fate of the flame retardant hexabromocyclododecane (HBCD) in polystyrene (PS)-degrading mealworms and in mealworm-fed shrimp. Most of the commercial HBCD consumed by the mealworms was egested in frass within 24 h (1-log removal) with nearly a 3-log removal after 48 h. In mealworms fed PS containing high HBCD levels, only 0.27 ± 0.10%, of the ingested HBCD remained in the mealworm body tissue. This value did not increase over the course of the experiment, indicating little or no bioaccumulation. Additionally, no evidence of higher trophic level bioaccumulation or toxicity was observed when L. vannamei (Pacific whiteleg shrimp) were fed mealworm biomass grown with PS containing HBCD. Differences in shrimp survival were attributable to the fraction of mealworm biomass incorporated into the diet, not HBCD. We conclude that the environmental effects of PS ingestion need further evaluation as the generation of smaller, more contaminated particles is possible, and may contribute to toxicity at nanoscale.
View details for DOI 10.1021/acs.est.9b06501
View details for PubMedID 31804807
Engineering the Dark Food Chain
ENVIRONMENTAL SCIENCE & TECHNOLOGY
2019; 53 (5): 2273–87
Meeting global food needs in the face of climate change and resource limitation requires innovative approaches to food production. Here, we explore incorporation of new dark food chains into human food systems, drawing inspiration from natural ecosystems, the history of single cell protein, and opportunities for new food production through wastewater treatment, microbial protein production, and aquaculture. The envisioned dark food chains rely upon chemoautotrophy in lieu of photosynthesis, with primary production based upon assimilation of CH4 and CO2 by methane- and hydrogen-oxidizing bacteria. The stoichiometry, kinetics, and thermodynamics of these bacteria are evaluated, and opportunities for recycling of carbon, nitrogen, and water are explored. Because these processes do not require light delivery, high volumetric productivities are possible; because they are exothermic, heat is available for downstream protein processing; because the feedstock gases are cheap, existing pipeline infrastructure could facilitate low-cost energy-efficient delivery in urban environments. Potential life-cycle benefits include: a protein alternative to fishmeal; partial decoupling of animal feed from human food; climate change mitigation due to decreased land use for agriculture; efficient local cycling of carbon and nutrients that offsets the need for energy-intensive fertilizers; and production of high value products, such as the prebiotic polyhydroxybutyrate.
View details for PubMedID 30640466