New Projects for Improved Strategies for Remediating 1,4-Dioxane Mixed with Chlorinated Solvents Contaminants in Groundwater
Projects selected under the FY17 CORE Solicitation to begin in 2017 are now well underway. Several new projects under SERDP and ESTCP are researching and developing technologies for improved strategies for remediating 1,4-dioxane mixed with chlorinated solvents in groundwater.
Several projects are focused on bioremediation efforts. Dr. Alison Cupples at Michigan State University is leading a project focused on developing an anaerobic mixed culture capable of 1,4-dioxane biodegradation as well as the reductive dechlorination of the chlorinated solvents (Project Web Page). Biodegradation research also is being conducted by Dr. Shaily Mahendra and her team at UCLA. Dr. Mahendra is working on designing anaerobic/aerobic engineered microbial communities to biodegrade CVOCs and 1,4-dioxane in such a way that the inhibitory effects of CVOCs on 1,4-dioxane biodegradation is mitigated (Project Web Page). Dr. Lew Semprini and his team at Oregon State University are researching ways to develop a novel aerobic cometabolic processes based on slow-release compounds in order to treat COC mixtures. The studies will focus on a model isobutene-utilizing strain that has been shown to concurrently oxidize 1,4-dioxane and diverse CAHs, when grown on isobutene as a primary substrate (Project Web Page).
The University of Iowa’s Dr. Jerald Schnoor is working on a project focused on discovering novel strains of microorganisms to rapidly degrade 1,4-dioxane and co-contaminants to benign end-products. The goal is to take advantage of synergies by using stabilized, acclimated, and concentrated microorganisms (bioaugmentation) in tandem with phytoremediation as an improved and sustainable remediation strategy (Project Web Page).
Dr. Bruce Rittman at the Biodesign Institute at Arizona State University is leading a proof-of-concept project to explore strategies to optimize the synergistic reductive dechlorination of VOCs and 1,4-dioxane. The project will study the reduction of TCE to ethane in a membrane biofilm reactor (MBfR) and enhanced co-metabolism of 1,4-dioxane by using ethane as the primary donor substrate in a biological activated carbon column (BAC). The team will then attempt to run the MBfR and the BAC in synergy to degrade VOCs and 1,4-dioxane in concert. (Project Web Page)
There are also two ESTCP demonstrations that are focused on developing technologies to treat groundwater contaminated with comingled plumes of 1,4-dioxane and chlorinated solvents. Mr. Kyle Kirchner with NAVFAC EXWC is working on a project aimed to develop a quantitative framework for evaluating natural attenuation of mixed contaminants in groundwater. The team plans to modify the EPA’s BIOCHLOR model and develop decision matrices to analyze historical monitoring data to extract rate constants for natural degradation of key contaminants so that Remedial Project Managers (RPMs) can use the rate constants to support MNA as a remedy (Project Web Page).
Mr. Anthony Danko, also with NAVFAC EXWC is leading a project that seeks to demonstrate that a novel multiple primary substrate cometabolic biosparging technology can meet the DoD’s needs for a reliable, flexible, and cost effective treatment of comingled plumes in groundwater. The project will use multiple gaseous substrates to stimulate the aerobic degradation of 1,4-dioxane and CVOCs by distinct groups of widely distributed bacteria (Project Web Page).
Five other projects were initiated under SERDP to develop technologies for treatment of mixed contaminant groundwater plumes, specifically per- and polyfluoroalkyl substances (PFASs) comingled with chlorinated solvents. Descriptions of these projects can be found in the May 2017 blog. Updates on all projects can be found at their project web pages as research progresses.