Enhancement of In Situ Bioremediation of Energetic Compounds by Coupled Abiotic/Biotic Processes
Abstract
This project was initiated by SERDP to quantify processes and determine the effectiveness of abiotic/biotic mineralization of energetics (RDX, HMX, TNT) in aquifer sediments by combinations of biostimulation (carbon, trace nutrient additions) and chemical reduction of sediment to create a reducing environment. Initially it was hypothesized that a balance of chemical reduction of sediment and biostimulation would increase the RDX, HMX, and TNT mineralization rate significantly (by a combination of abiotic and biotic processes) so that this abiotic/biotic treatment may be more efficient for remediation than biotic treatment alone in some cases. Because both abiotic and biotic processes are involved in energetic mineralization in sediments, it was further hypothesized that consideration for both abiotic reduction and microbial growth was need to optimize the sediment system for the most rapid mineralization rate. Results show that there are separate optimal abiotic/biostimulation aquifer sediment treatments for RDX/HMX and for TNT. Optimal sediment treatment for RDX and HMX (which have chemical similarities and similar degradation pathways) is mainly chemical reduction of sediment, which increased the RDX/HMX mineralization rate 100 to150 times (relative to untreated sediment), with a secondary treatment of carbon or trace nutrients, which increased the RDX/HMX mineralization rate an additional 3 to 4 times. In contrast, the optimal aquifer sediment treatment for TNT involves mainly biostimulation (glucose addition), which stimulates a TNT/glucose cometabolic degradation pathway (6.8 times more rapid than untreated sediment), with secondary treatment by chemical reduction (13 times additional rate increase). TNT is transformed to triaminotoluene, which irreversibly sorbs in reduced systems but is rapidly degraded in oxic systems.
Document Details
- Document Type
- Technical Report
- Publication Date
- Aug 01, 2007
- Accession Number
- ADA606794
Entities
People
- Ashley Fischer
- Brooks J. Devary
- C. T. Resch
- Don C. Girvin
- Fiona H Crocker
- Herb L. Fredrickson
- Jerry L. Phillips
- Jim E. Szecsody
- Karen T. Thompson
- Lisa Durkin
Organizations
- Engineer Research and Development Center