Geosyntec and SiREM Practitioners Publish on Biodegradation of DIPE in Groundwater

Geosyntec and SiREM practitioners coauthored the article, "Anaerobic Attenuation of Diisopropyl Ether (DIPE) in Groundwater: Kinetics and Implications for Monitored Natural Attenuation," published on July 15, 2026, in Groundwater Monitoring & Remediation.

Geosyntec authors include Kawal Kaur, PhD; Trevor Carlson; Lonnie Mercer, PG; and Emmanuel Olisa, PhD. SiREM authors include Sandra Dworatzek, Jennifer Webb, Ioanna Malton, and Melody Vachon-Gregory of SiREM.

Other coauthors are Shailendra Ganna, George Devaull, and Joseph Lentini from Shell Global Solutions, and Eryn Torres from Vault 44.01.

The study found evidence that diisopropyl ether can attenuate under anaerobic conditions, supporting monitored natural attenuation as a potential approach for impacted groundwater plumes where aerobic conditions are limited.

Groundwater Monitoring & Remediation publishes papers that address treatment technologies and pair innovative research with practical solutions. The journal is published by the National Ground Water Association (NGWA), which advances groundwater knowledge while supporting, connecting, and advocating for members.

Abstract: "Anaerobic Attenuation of Diisopropyl Ether (DIPE) in Groundwater: Kinetics and Implications for Monitored Natural Attenuation"

Diisopropyl ether (DIPE) is a branched ether used as a solvent, extractant, and gasoline additive. While aerobic biodegradation of DIPE has been documented, attenuation under anaerobic conditions (typical of groundwater impacted by petroleum hydrocarbons and fuel oxygenates) remains poorly constrained. This study investigated DIPE attenuation under anaerobic conditions using bench-scale microcosms constructed with site-specific groundwater and sediments collected from four locations within a DIPE-impacted aquifer in Southern California. Microcosms were assembled and incubated anoxically, with sterile controls included to quantify abiotic losses from sorption and volatilization. DIPE concentrations were monitored for approximately 120 days (d). After an initial equilibration period attributable to sorption, sustained DIPE decreases were observed in microcosms from three of four locations. The most pronounced and reproducible attenuation occurred in microcosms from one location, where repeated DIPE respiking resulted in continued removal, indicating sustained attenuation capacity. First-order attenuation rate constants ranged from 0.0186 to 0.0266 d⁻¹ prior to respiking and from 0.0076 to 0.0266 d⁻¹ following respiking (estimated half-lives of 26-91 d). In contrast, sterile controls exhibited stable DIPE concentrations after sorption equilibration, supporting a biological contribution to attenuation. To evaluate microbial community shifts associated with DIPE exposure, 16S rRNA gene amplicon sequencing was performed on the MW-C microcosms. Communities shifted from taxa associated with oxic groundwater (e.g., Pseudomonas) toward enrichment of anaerobic and facultative anaerobic groups (e.g., Sulfuricurvum) during incubation. These results provide evidence that DIPE attenuation can occur under anaerobic conditions relevant to groundwater systems and support consideration of natural attenuation for DIPE-impacted plumes where aerobic conditions are limited.

More Information on Biodegradation of DIPE in Groundwater and Implications for MNA

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For more information on aerobic attenuation of diisopropyl ether in groundwater, contact Kawal Kaur at This email address is being protected from spambots. You need JavaScript enabled to view it. or Sandra Dworatzek at This email address is being protected from spambots. You need JavaScript enabled to view it..
Learn more about Kawal: Kawal Kaur, Ph.D. | LinkedIn
Learn more about Trevor: Trevor Carlson Learn more about Lonnie: Lonnie Mercer
Learn more about Emmanuel: Emmanuel Olisa, Ph.D., EIT (SK) | LinkedIn
Learn more about Sandra: Our Team - SiREM LAB
Learn more about Jennifer: Our Team - SiREM LAB
Learn more about Ioanna: Ioanna Malton | LinkedIn
Learn more about Melody: Melody Vachon-Gregory | LinkedIn