BACTERIAL DEGRADATION OF THE XANTHAN POLYMER: USE AS A SUBSURFACE AMENDMENT

The use of water soluble polymers has been used by the oil industry to enhance recovery in low permeable and heterogeneous aquifers. These same polymers have potential use in traditional groundwater remediation technologies by overcoming site heterogeneities and mitigating preferential flow-paths. The Xanthan polymer is a food-grade polysaccharide that is composed of repeating units of glucose, mannose, and glucuronic acid. The chemical stability and shear-thinning nature of the Xanthan polymer make it an ideal candidate to alleviate problems associated with a highly heterogenous aquifer. While the rheology and stability of the Xanthan polymer is well understood, there is limited literature on the long-term bacterial response to the injection of the polymer into the subsurface. Batch and one-dimensional column studies were conducted to gain a deeper understanding of potential bacterial responses to the injection of Xanthan polymer. These responses were studied to assess the bacterial degradation of the polymer and evaluate the potential for biological clogging of the aquifer and well screens.