BIOREMEDIATION OF SOIL AND GROUNDWATER POLLUTED WITH PCE AND DAUGHTER PRODUCTS (TCE, DCE, VC) USING KB-1® DECHLORINATOR AND BIOAUGMENTATION TECHNIQUE
Loading...
Authors
Grossi, Stefano
Issue Date
2009
Type
Thesis
Language
en
Keywords
Alternative Title
Abstract
During the last century, human activities have released large amounts of chlorinated solvents into the environment, and these chlorinated compounds are among the most common soil and groundwater pollutants. To remediate sites affected with these contaminants there are different techniques that can be used, such as Pump and Treat (P&T), Soil Vapor Extraction (SVE) and bioremediation. The experience accumulated in the past years indicates that P&T and SVE techniques can be used as remediation methods, but they usually require an extent period of time with consequent high costs before the remediation goals are achieved. An alternative to P&T and SVE techniques is the bioremediation. This remediation technique utilizes microorganisms to remove pollutants from contaminated sites, and it has the potential to be more cost effective and faster than P&T and SVE methods. In fact, it uses natural communities of microorganisms that in ideal environment conditions can remove the chlorinated solvents without human interference. In those sites where the natural population of microbes is absent or not sufficient to remove the chlorinated compounds from the site, the bioaugmentation is an ideal alternative. Bioaugmentation consists of the introduction of a particular group of microbial strains into a contaminated soil or groundwater that needs to be remediated. There are several microbial groups that are able to perform a good dechlorination of chlorinated solvents, but one in particular seems to achieve the best results: Dehalococcoides. This paper analyzes the effectiveness of soil and groundwater bioremediation using the bioaugmentation technique, in particular using a natural microbial culture (KB-1°) that is able to introduce the Dehalococcoides microorganism in the site that has to be treated. Data collected from bioremediation cases where KB-1® was used, indicate that this microbial culture has the capacity to promote a complete reductive dechlorination of chlorinated compounds. Furthermore, bioremediations performed with KB-1 seem to achieve good results in a shorter period of time comparing with P&T and SVE techniques.