Electrokinetic and hydraulic emplacement of amendments at a field trial

A range of innovative contaminated site remediation technologies have been developed and implemented, including reduction and oxidation based processes. However, achievement of remediation goals at many contaminated sites is still difficult achieve due to challenges associated with delivering amendments uniformly throughout contaminated zones, including low permeability media. The goal of this study was to evaluate the extent to which electrokinetics and hydraulic injection of amendments could uniformly distribute amendments in heterogeneous porous media, including clay, at a contaminated site. Electrokinetics is uniquely suited to uniformly distribute amendments in impermeable media, such as clay. The electrokinetic phase of the field study included five distinct transects: 1) Electrokinetics + an oxidant2) Electrokinetics + nanometals3) Electrokinetics + lactate4) Electrokinetics with no amendment5) ControlThis design enabled an assessment of the ability of electrokinetics to enhance the transport of amendments. Electrokinetics can induce amendment transport due to electromigration of dissolved constituents (e.g., oxidant and lactate), electrophoresis of charged particles (e.g., nanometals) or electroosmosis (i.e., transport of the bulk water phase). The extent to which these mechanisms transport amendments in the field will be discussed.Results from the electrokinetic field trial will be compared to a field trial where nanometals were hydraulically emplaced into heterogeneous porous media that included fill. This study provides crucial information needed for the design of uniform amendment delivery at contaminated sites for subsequent contaminant degradation.