A NOVEL PERVIOUS CEMENT REACTION BARRIER (PCRB) IN SITU ARSENIC-REMEDIATION SYSTEM

Remediation of Superfund hazardous wastes sites with contaminated groundwater is a key research area. The sheer complexity of the subsurface environment, coupled with the unique characteristics and challenges of each site make it advisable to tailor remediation technologies to site-specific remediation needs. We examined a pervious cement reactive barrier system (PCRB) in which the modifier is incorporated directly into the matrix pervious cement barrier. As the groundwater flows through the barrier, contaminants will be trapped and/or modified, thereby reducing the contaminant plume and the necessity for further treatment. Such a system will require little or no active maintenance; furthermore, characterization of contaminants at the site would allow the PCRB to be “tailored” to specific characteristics. Our primary contaminants of interest are arsenic and mercury. This project used batch, column, and adsorption experiments to evaluate and model the adsorptive capacity of the PCRB for arsenic and mercury uptake. The total absorptive capacity of a PCRB was determined from the breakthrough of arsenic and mercury from column adsorption. This will form the basis for future studies, wherein we can scale the process up to assess construction and engineering constraints and to determine whether it is feasible in the field.