Ryan A. Wymore
Ryan Wymore is an associate with CDM Smith in Denver, CO, where he serves as a technical strategy leader focused on evaluation, selection, pilot testing, design, and operation of soil and groundwater remediation technologies. He has spent the last eighteen years specializing in innovative remediation technologies, particularly in situ bioremediation, monitored natural attenuation, in situ thermal remediation, in situ chemical reduction, in situ biogeochemical transformation, and in situ chemical oxidation. He has managed projects, designed and executed pilot studies, served as lead engineer for design and implementation of full-scale remediation projects, and acted in a review/advisory capacity for dozens of remediation projects across Navy, Air Force, USACE, EPA, DOE, municipal, and industrial client sectors. He also acts as a key business development resource for assessing and pursuing new business opportunities across these same client sectors.
As a sixteen-year member of the Interstate Technology Regulatory Council, he has won four awards, had membership on eight technical teams, and has served as an instructor for four internet and classroom training seminars on DNAPL characterization/remediation technologies, which have been delivered to thousands of trainees worldwide. He recently completed a three-year term on the ITRC Board of Advisors as the industry representative. He holds a B.S. in Biological Systems Engineering from the University of Nebraska, and an M.S. in Civil/Environmental Engineering from the University of Idaho, and is a registered professional engineer in Colorado.
Incorporation of Traditional ISCO Reagents in a Shear-Thinning Fluid for Uniform Delivery and Enhanced Oxidant Longevity in Degradation of 1,4-Dioxane
In situ chemical oxidant (ISCO), which involves injections of a chemical oxidant such as permanganate, persulfate or hydrogen peroxide for degrading organic contaminants, has been used extensively in the remediation industry. Like other in situ remediation techniques, the effectiveness of ISCO is limited by a site geology. Such limitation is especially exacerbated at sites with low-permeability materials with interbedded zones of higher permeability. At these sites, employing conventional injection techniques will often result in preferential amendment delivery into the high-permeability zones. Unfortunately, the majority of contaminant mass is often found in low-permeability and organic-rich zones, rendering the in situ technique ineffective in addressing zones of high contamination. Contaminant rebound resulted from this lack of uniform vertical amendment distribution are often cited as the most significant shortcoming associated with ISCO technology. All of the aforementioned issues are often encountered at sites with 1,4-dioxane contamination that exists in a large, dilute plume.
Recently, shear-thinning fluids (STFs) have been used to improve amendment sweep efficiency into low-permeability zones reducing contaminant by-passing during injection. Specifically, STF polymer such as Xanthan Gum have been used to aid delivery of biological amendments such as LactOilÂ®. However, it is not well-understood how chemical oxidant and oxygen-releasing compounds would interact with STF polymers and how such interaction would affect amendment delivery and reactivity of the oxidants. A bench-scale treatability study was performed to evaluate the potential for and effectiveness of incorporating traditional ISCO oxidant(s) in a STF to aid i) uniform amendment delivery and distribution in aquifers with a high degree of heterogeneity, ii) enhanced oxidant stability, and iii) improved oxidant longevity for treatment of 1,4-dioxane. In addition, different mechanisms of oxidant activation for enhanced 1,4-dioxane degradation kinetics necessary for more aggressive source treatment.
Results from this bench-scale study indicate that i) several commonly-employed ISCO reagent can be incorporated in a STF which does not exert a significant oxidant demand, ii) the oxidant(s)/STF mixture remains viscous and stable long enough to be applicable for field implementation, iii) 1,4-dioxane degradation rates were similar to those observed in the absence of the STF, and iv) several activation mechanisms can be employed to achieve enhanced 1,4-dioxane degradation kinetics.