An Innovative Passive Barrier System Using Membrane-Delivered Hydrogen Gas for the Bioremediation of Chlorinated Aliphatic Compounds
ER-1124
Objective
The proposed remediation scheme for this project utilizes a biofilm
This goal of this research is to develop an innovative passive barrier remediation technology that will reduce the costs, risks, and time required for contaminated site cleanup. The proposed research will characterize the performance of a novel passive barrier that relies on the use of an innovative membrane technology for the controlled dissolution of hydrogen (H2). The research will employ special woven hollow-fiber membranes for the passive dissolution of H2. in order to accelerate the in-situ bioremediation of groundwater contaminated with chlorinated compounds.
The objective of this project is to examine the gas transfer behavior and performance of hollow fiber membrane curtains that are installed as passive barriers. The proposed research will assess the suitability and effectiveness of the membrane for delivering H2 to accelerate the in-situ remediation of chlorinated organic compounds like trichloroethene and perchloroethene.
Technical Approach
The proposed research will investigate the behavior of the membranes in a systematic way to determine what factors control the overall remediation process. These tasks include the following: (1) the study of the gas dissolution behavior of membranes, (2) the evaluation of the impact of gas composition changes and condensation, (3) the evaluation of impact of biofilm growth on gas transfer, (4) the evaluation of solvent transformation, (5) the development of mathematical models, and (6) the development of pilot reactor studies.
Results
The column reactors have been designed and currently are being constructed. Membrane modules for use in the column reactors have been designed and will be constructed once the column reactors are complete (to ensure correct sizing). A recirculating-gas loop has been designed and constructed to control the partial pressure of H2 at a very low and constant level in the membranes. A model has been built incorporating both halorespiration and methanogenesis and the subsequent competition for H2. This model is applicable to the batch system. A model for the column system currently is under development.
Benefits
Passive barrier remediation systems are an attractive treatment option for the transformation of contaminated groundwater. H2 appears to be an effective electron donor for the biodegradation of halogenated aliphatics when it is sufficiently bioavailable. However, it is difficult to provide sufficient H2 to organisms because of its low solubility. Gas permeable membranes, used as a passive treatment barrier, could be used to provide H2 as an electron donor for in-situ bioremediation. This method of H2 delivery would be expected to provide controlled levels of bioavailable H2 that should provide the same benefits as cathodically-derived H2, without the associated problems. In addition, the project will yield the engineering data required to complete a cost analysis and transition the membrane-module remediation system technology into field-scale application.
Project Documents
Points of Contact
Principal Investigator
Dr. Michael Semmens
University of Minnesota
Phone: 612-625-9857
Fax: 612-626-7750
Project Documents
Document Types
- Fact Sheet - Brief project summary with links to related documents and points of contact.
- Final Report - Comprehensive report for every completed SERDP and ESTCP project that contains all technical results.
- Cost & Performance Report - Overview of ESTCP demonstration activities, results, and conclusions, standardized to facilitate implementation decisions.
- Technical Report - Additional interim reports, laboratory reports, demonstration reports, and technology survey reports.
- Guidance - Instructional information on technical topics such as protocols and user’s guides.
- Workshop Report - Summary of workshop discussion and findings.
- Multimedia - On demand videos, animations, and webcasts highlighting featured initiatives or technologies.
- Model/Software - Computer programs and applications available for download.
- Database - Digitally organized collection of data available to search and access.