Application of the NUFT Code for Subsurface Remediation by Bioventing

Nitao, J.J. ; Sun, Y. ; Demir, Z. ; Delorenzo, T.

Lawrence Livermore National Laboratory

关键词: Hydrocarbons;    02 Petroleum;    Water Tables;    Mathematical Models;    Petroleum;   

DOI  :  10.2172/792788
RP-ID  :  UCRL-ID-137967
RP-ID  :  W-7405-Eng-48
RP-ID  :  792788

美国|英语

来源: UNT Digital Library

【 摘 要 】

Bioventing (BV) is a promising, cost-effective technology for the biodegradation of soil contaminated with petroleum hydrocarbons. The goal of BV is to stimulate naturally-occurring soil microorganisms to degrade organic contaminants in the soil. In natural systems the rate of biodegradation is eventually limited by the lack of oxygen and other electron acceptors (i.e., a compound that gains electrons during biodegradation) rather than by the lack of nutrients (i.e., electron donors). In conventional bioventing systems, oxygen is delivered by an electric blower to subsurface wells. The airflow rate is usually low in contrast to soil vapor extraction, just enough to provide sufficient oxygen to maintain or enhance microbial activity. In order to design a bioventing system wisely, decision makers should understand the role that design variables may play. Those design variables include locations of injection wells, injection rates, air pressure and moisture at wells, water table control, monitoring well locations, etc. Trade-off between these variables should be made before the implementation of a bioventing system. Obviously, the mathematical model corresponding to the multiphase flow and multi-species reactive transport is essential to describing the relations between design variables and system response. The work phases for the project are: (Phase 1) building biodegradation simulation capabilities into the NUFT code and documentation, (Phase 2) determining a well-characterized and evaluated bioventing remediation site for field validation, (Phase 3) obtaining and analyzing the field data, (Phase 4) setting up the conceptual model, (Phase 5) implementing the simulation input consistent with the conceptual model, and (Phase 6) demonstrating the performance of the code by comparing it to data from the remediation site. At the time of this report, most of Phases 1,2,4,5, and portions of Phase 3 and 6 were completed.