POLYMER-ENHANCED CHEMICAL OXIDATION: COMPATIBILITY AND EFFECTIVENESS FOR GROUND WATER REMEDIATION OF CHLORINATED CONTAMINANTS

Polymers floods, used by the oil industry to improve product recovery in low-permeability systems, have potential for use in heterogeneously layered aquifer systems due to the flood's increased solution viscosity over that of groundwater. This increased viscosity encourages flow into and among layers of differing permeability, and thus coupling a polymer flood with an existing groundwater remediation treatment could potentially increase the treatment's overall effectiveness. For example, oxidants used during in situ chemical oxidation (ISCO) treatments may be more efficiently delivered to lower-permeability layers when mixed with a polymer solution, consequently decreasing the probability of contaminant “rebound” from those layers. In order for this coupled treatment technique to be feasible, however, the polymer/oxidant solution must be chemically compatible and relatively stable. We present the results of multi-day experiments combining two non-toxic polymers (xanthan biopolymer and hydrolyzed polyacrylamide) with two chemical oxidants (potassium permanganate and sodium persulfate) capable of destroying chlorinated compounds. The polymers' demand for the oxidants is observed to be low, such that the oxidants' destructive capabilities should be maintained. Additionally, monitoring of solution viscosity allows the identification of the polymer/oxidant pair with the most stable viscosity. This combination is further tested to determine if the presence of polymer inhibits the ability of the oxidant to degrade the chlorinated solvents tetrachloroethene (PCE) and trichloroethene (TCE), two commonly detected organic contaminants in groundwater systems. We find that solutions of xanthan biopolymer coupled with potassium permanganate exhibit small oxidant demand, possess stable solution viscosity, and are capable of relatively similar rates of contaminant degradation as compared to pure oxidant solutions.