Jeff Roberts, M.Sc. (Ontario) will present “Bioremediation Options for Emerging Contaminants” at 2019 RPIC Federal Contaminated Sites Regional Workshop at the Halifax Convention Centre in Halifax, NS at 2:00 – 2:30 pm on June 5, 2019.
Jeff is the operations manager at SiREM based in Ontario with more than 15 years of experience focused on laboratory assessment and field implementation of soil, sediment and groundwater remediation technologies at sites containing contaminants including chlorinated solvents, petroleum hydrocarbons and other recalcitrant compounds.
The Real Property Institute of Canada (RPIC) is well known for its Federal Contaminated Sites (FCS) Workshops, leading professional development events for federal and industry environmental professionals involved in the management and remediation of federal contaminated sites. These workshops offer a unique opportunity for the public, private, and academic sectors to meet and exchange new ideas and information with colleagues and industry representatives from across the country and abroad. The Halifax workshop will provide a forum for the contaminated sites community to learn about technical, scientific and organizational innovations, best practices for the management of sites contaminated with per and polyfluoroalkylated substances (PFAS) and other emerging contaminants.
It is the goal of the RPIC to develop and foster a high professional standard of real property management within the Federal Public Sector, and to provide a forum for information exchange and continuous improvement.
1,4-Dioxane (1,4-D) and 1,2,3-trichloropropane (TCP) are suspected carcinogens and common groundwater and drinking water contaminants. These compounds share stringent regulatory limits, elevated water solubility and produce large dilute plumes with associated remediation challenges. TCP was historically used as a paint remover, cleaning and degreasing agent and was an impurity in soil fumigants. 1,4-D is used in manufacturing, personal care products and was used as a solvent stabilizer. Options for assessing and implementing sustainable bioremediation of these two emerging contaminants is expanding; this presentation will explore recent advances in bioremediation for these contaminants as outlined further below.
Assessment of Biodegradation Processes: Specialized technologies to assess 1,4-D and TCP bioremediation include genetic tests, compound specific isotope analysis (CSIA) and biotreatability studies. These tools are particularly useful for 1,4-D and TCP, as breakdown products can be difficult to detect and site-specific degradation processes are often poorly understood. The ability to quantify key biodegraders using genetic tests or detect biodegradation using isotopic enrichment of the parent compound (CSIA) provides needed evidence for the effectiveness of enhanced bioremediation. These technologies can also be valuable for evaluating natural attenuation processes. Biotreatability studies allow testing of multiple strategies and can confirm remediation options in the laboratory, prior to field implementation.
Bioremediation of 1,4-D: 1,4-D degrades primarily under aerobic conditions and effective delivery of oxygen for in-situ or ex-situ remedial approaches is a key remedial consideration. Nevertheless, field applications of aerobic cometabolic bioventing via oxygen and alkane gas addition to groundwater have been successfully implemented. The discovery of Pseudonocardia dioxanivorans CB1190, a microorganism that uses 1,4-D as an energy source, was a milestone. Where indigenous 1,4-D biodegraders are absent, bioaugmentation with energy yielding 1,4-D degrading cultures is effective in laboratory studies and field pilot studies are pending.
Bioremediation of TCP: TCP is degraded primarily by anaerobic reductive pathways with Dehalogenimonas (Dhgm) identified as a key microorganism in the process. A bioaugmentation culture for TCP bioremediation with a high abundance of Dhgm has been developed. The research has indicated that TCP dechlorination and Dhgm growth occurred over a wide range of TCP concentrations. Furthermore, the culture has performed well in bench-scale studies, while TCP concentrations remained elevated in non-bioaugmented microcosms. Based on these results, the first field test of the culture was performed at a site in California in 2016. Initial field results are promising.
This presentation will discuss a range of monitoring and remediation approaches focusing on TCP and 1,4-D case studies. The tools and methodologies presented should be transferable to other emerging contaminants present at federal sites in Canada.
About the event: 2019 RPIC Federal Contaminated Sites Regional Workshop.
For consultation regarding Bioremediation Options for Emerging Contaminants, contact Jeff Roberts at JRoberts@Siremlab.com.
Learn more about Jeff Roberts: https://www.linkedin.com/in/jeff-roberts-209a048/.