Objective:

This project will validate the use of a water-soluble polymer with permanganate for in situ chemical oxidation (ISCO) of organic contaminants with the dual primary objectives of (1) improving the sweep efficiency of permanganate through heterogeneous media containing lower permeability media and (2) controlling manganese dioxide (MnO₂) particles to improve oxidant delivery and flow, thereby enhancing contaminant destruction. A secondary project objective is to compare post-delivery/treatment groundwater quality for "permanganate only" and "permanganate + polymer" test areas. This is a cooperative demonstration extending to the field the laboratory investigations performed under two prior SERDP projects—Multi-Scale Experiments to Evaluate Mobility Control Methods for Enhancing the Sweep Efficiency of Injected Subsurface Remediation Amendments (ER-1486) and Control of Manganese Dioxide Particles Resulting from In Situ Chemical Oxidation Using Permanganate (ER-1484).

Technology Description:

In situ chemical oxidation using permanganate is an established remediation technology being applied at hazardous waste sites throughout the United States and abroad. Field applications of ISCO continue to grow and have demonstrated that ISCO can achieve destruction of contaminants and cleanup goals. However, some field-scale applications have had uncertain or poor in-situ treatment performance. Poor performance is often attributed to poor uniformity of oxidant delivery caused by zones of low permeability media, site heterogeneity, and excessive oxidant consumption by natural subsurface materials. A second permanganate ISCO challenge is the management of MnO₂ particles, which are a byproduct of the reaction of permanganate with organic contaminants and naturally reduced subsurface materials. These particles have the potential to deposit in the well and subsurface and impact flow in and around the well screen, filter pack, and the surrounding subsurface formation. This is a particular challenge for sites with excessive oxidant consumption due to the presence of natural materials or large masses of non-aqueous phase liquids (NAPL). This project focuses on (1) diminishing the detrimental effects of site heterogeneities with respect to the uniformity of oxidant delivery and (2) managing MnO₂ aggregation and deposition.

Water-soluble polymers will be used to improve the delivery and distribution of permanganate oxidant solutions within heterogeneous contaminated aquifers. As found in SERDP project ER-1486, water-soluble polymers can be employed with ISCO to modify fluid viscosity, which results in a smoothing of the viscous fluid front between layers of different permeability. This means the oxidant solution will be more likely to enter lower permeability zones with polymer present, as opposed to flow bypass without polymer present. As found in SERDP project ER-1484, water-soluble polymers can be employed with ISCO to also prevent MnO₂ particles from agglomerating and forming large particles that will settle/deposit. Deposition can result in formation of lower permeability areas that additional oxidant amendments will bypass. Water-soluble polymers modify the solution chemistry to enhance their potential to be more readily transported in groundwater.

Expected Benefits:

Dense non-aqueous phase liquids (DNAPL) consisting of chlorinated solvents pose the most widespread obstacle to cleanup at Department of Defense (DoD) and Department of Energy (DOE) facilities. Chlorinated solvents such as trichloroethene (TCE) and tetrachloroethene (PCE) are found at approximately 80% of all Superfund sites with groundwater contamination and more than 3,000 DoD sites in the United States. Of these sites, a large proportion are candidates for remediation via ISCO. Because most sites contain at least some degree of heterogeneity in media permeability and because MnO₂ will always be a byproduct of permanganate ISCO, this advancement to the technology can translate to substantial benefit for DoD. Delivery efficiency of the oxidant to the contaminated zone will be improved, reducing oxidant and project support costs due to reduced time-on-site requirements. (Anticipated Project Completion - 2011) 

Principal Investigator:

Dr. Michelle Crimi
Clarkson University
Environmental Health Sciences Program 
Potsdam, NY 13699-5805
Telephone: (315) 268-4174
Fax: (315) 268-7118
E-mail: mcrimi@clarkson.edu

DoD Liaison:

Dr. Nancy Ruiz
Naval Facilities Engineering Command Engineering Service Center
EV411
1100 23rd Avenue
Port Hueneme, CA 93043
Telephone: (805) 982-1155
Fax: (805) 982-4304
E-mail: nancy.ruiz@navy.mil