Adam
Smith's Group
Bianca Costa
Smith Research Group
BS – Environmental Engineering (2018), Georgia Institute of Technology
MS – Environmental Engineering (2021), University of Southern California
PFAS fate in emerging environmental biotechnologies
Perfluoroalkyl substances (PFAS), also known as forever chemicals, are a chemical class with more than 4000 compounds with detrimental human health and environmental effects. Wastewater treatment plants are a gateway for PFAS in a potable reuse landscape and typical (aerobic biological) wastewater treatment fails to remove them. Moreover, little is known about PFAS fate in anaerobic environments and across the different stages of the treatment train. Anaerobic Digestion could offer a biologically mediated pathway for PFAS mineralization and removal. Anaerobic membrane bioreactors (AnMBRs) are an emerging biotechnology that couple membrane separation with anaerobic digestion and offers suitable conditions for biotransformation.
Bianca evaluated the potential for anaerobic biotransformation of PFAS in batch systems and learned that the anerobic digestion community (a complex network of microorganisms) is resilient even at high concentrations of PFAS. Enriched members of the community were identified as likely key players in PFAS biotransformation. With the insights learned from the batch systems, two AnMBRs were started with PFOA and 6:2 FTOH to evaluate AnMBRs as a suitable technology for PFAS biotransformation with results underway.
Bianca is currently performing a multi-factor evaluation of PFAS in local water reclamation facilities to evaluate the cycling of such compounds across different stages of the treatment for both targeted and non-targeted PFAS. Particularly non-targeted PFAS can inform which compounds we might be obviating and could be candidates of biotransformation. Such knowledge could help guide design optimal treatment configurations and placement of emerging biotechnologies in the treatment train for PFAS removal.
Christelle Bou Nehme Sawaya
Smith Research Group
BE – Civil Engineering (2019), Lebanese American University
MS – Environmental Engineering (2022), Lebanese American University
PFAS fate in emerging environmental biotechnologies
Per- and polyfluoroalkyl substances (PFAS) have emerged as a pressing environmental concern, known for their remarkable persistence, bioaccumulation potential, and adverse health effects. These chemical compounds, known for their resistance to degradation and potential health risks, pose a formidable challenge to water treatment facilities aiming to produce safe, reclaimed water. The need for efficient and sustainable solutions to address PFAS contamination is paramount. In this context, emerging biotechnologies, notably anaerobic membrane bioreactors (AnMBRs), with the unique advantages they present, have great potential to revolutionize the treatment of PFAS-contaminated waters. Leveraging their unique advantages, AnMBRs present a promising avenue to confront the stubborn challenge of PFAS removal and pave the way for a cleaner and safer effluent quality.
Christelle is currently working on developing methods to extend limits for PFAS quantification and detection in different matrices, such as biosolids and aqueous phase matrices.
Harmita Golwala
Smith Research Group
BS – Environmental Engineering (2018), Marwadi University, India
MS – Environmental Engineering (2021), University of Southern California
Improving an efficacy of Anaerobic membrane bioreactor to enhance water reclamation while mitigating antibiotic resistance and microplastics
Antimicrobials including antibiotics and antivirals are widely used to prevent and treat infections in humans, aquaculture, and crop production. However, more and more incidences are reported worldwide where bacteria and fungi have developed antimicrobial resistance and are able to defeat the drugs designed to kill them. On the other side, plastic pollution is increasing and thereby, microplastics in water and wastewater treatment systems have been receiving increasing attention given the imminent threats to ecosystems and public health.
Harmita’s research is focused on antimicrobial resistance genes in wastewater streams where microbes can develop resistance with longer stay of antibiotics in the system. This activity is further enhanced in the presence of microplastics in wastewater as antibiotics generally tend to adsorb on microplastic surfaces. This fundamental has been experimented for the first time with the continuous system and anaerobic membrane bioreactor. By shedding light on these processes, she strives to develop effective strategies to mitigate the spread of antibiotic resistance and biodegrade microplastics to enhance the performance of wastewater treatment plants.