Our next webinar is scheduled for Thursday, May 30th, 2019 12:00 PM – 1:00 PM EDT, featuring Dr. Anh Pham.
SiREM’s webinar series features guest speakers who are subject matter experts to provide the latest information on technology advances in environmental remediation and site characterization. The webinars will combine recent research and development activities for new and emerging contaminants and technologies with real word applications to characterize and remediate contaminated sites.
We hope you will join us for our next webinar:
Laboratory Testing to Evaluate Remediation Options for Unique and Emerging Contaminants
This presentation provides an overview about the remediation of two unique and emerging groundwater contaminants, chlorendic acid (CA) and sulfolane. CA, a probable carcinogen, is a polychlorinated organic compound used in the synthesis of polymeric resins, corrosion-resistant plastics, flame retardants, and other materials. Sulfolane, a neurotoxin, is an organic solvent used in the petroleum industry for the extraction of aromatic hydrocarbons and sour gas components. Both contaminants are highly mobile and resistant to natural attenuation under most subsurface conditions, which makes the containment and mitigation of CA and sulfolane plumes an extremely challenging task.
A series of bench-scale tests were conducted to explore potential in situ and ex situ remedial options for CA and sulfolane, including 1) chemical oxidation and reduction, 2) bioremediation, and 3) adsorption. For CA, a rapid loss of CA from the solution was observed following amendment with persulfate or Fenton’s reagent. However, CA concentrations often rebounded to near baseline conditions after all oxidants were consumed and the pH of the solution increased to the pre-treatment level. This CA concentration trend was attributable to the CA adsorption on and desorption from the aquifer soils, the processes which appeared to be strongly influenced by the solution pH. In the reductive treatment experiments with zero valent iron (ZVI), the loss of CA from the solution occurred concurrent with the formation of transformation products under all experimental conditions. The byproducts were identified by high resolution mass spectrometry, the result of which indicates that the transformation of CA by ZVI occurred through a step-wise dechlorination mechanism that ultimately removed all chlorine atoms from CA.
For sulfolane, preliminary tests have shown that sulfolane can be remediated by chemical oxidation, aerobic biotransformation, and adsorption. Adsorption of sulfolane on activated carbons as well as on various natural and polymeric adsorbents was further investigated to identify the most cost-effective adsorbent for ex situ treatment. Overall, the results of this study provide important insights that may help to predict the fate and transport of CA and sulfolane, as well as to develop more effective remediation strategies for different contamination scenarios.
Dr. Anh Pham is an Assistant Professor in the Department of Civil and Environmental Engineering at the University of Waterloo. His research examines the fate and transport of aqueous contaminants in natural and engineered systems. The current research focuses on developing novel technologies for the remediation of contaminated soil and groundwater, treatment of various industrial waste streams including oil sands produced water, and removal of emerging contaminants including per- and polyfluoroalkyl substances (PFAS). Dr. Pham obtained a B.S. degree in Chemical Engineering from Hanoi University of Technology (Vietnam), and M.S. and PhD degrees in Civil and Environmental Engineering from the University of California, Berkeley (USA). Prior to joining the University of Waterloo, Dr. Pham was an Assistant Professor in the Department of Civil and Environmental Engineering at Carleton University (2015 – 2018), and a postdoctoral researcher at Duke University (2012 – 2014).
Michael Healey is an environmental scientist with an Honours Bachelor Degree of Science in Chemistry from the University of Guelph. Over the past 5 years Michael has managed numerous bench-scale studies evaluating remediation technologies for contaminants including chlorinated solvents, petroleum hydrocarbons and other recalcitrant compounds in soil, sediment, and groundwater. He has also been involved in developing protocols for evaluating new technologies in the laboratory (i.e., electrokinetics, combined chemical oxidation chemistries) and new analyical techniques. Michael has several years of passive sampling experience and was a lead member in the development and commercialization of the SP3™ sampler.