Bench Scale Treatability Studies

GCI maintains a fully equipped and staffed laboratory that enables us to offer our clientele bench scale treatability studies. Bench scale studies provide information about contaminant mass reductions and chemical oxidant efficiencies that can be incorporated into the design of pilot or full-scale treatment programs. During the course of all bench scale treatability studies conducted at GCI, a site-specific catalyst blend is formulated from information and data obtained from native soils and groundwater. The Site specific catalyst formulation is necessary to ensure that subsurface conditions favoring efficient and effective chemical oxidation can be established and maintained. Bench scale treatability studies can help to refine costing for pilot and full-scale chemical oxidation programs.

• Soil and Groundwater Slurries – This type of bench test is most frequently recommended by GCI. This type of bench consists of creating several batch “reactors” made up of equal quantities of site-specific soil and groundwater (50% soil/water slurry). The reactors are loaded with varying amounts of oxidant and compared to a zero-oxidant control reactor to determine the quantity of oxidant that allowed for the greatest reduction in contaminant concentrations.
  

• Column Studies – Column studies are frequently used as a visual demonstration of contaminant desorption and destruction. This bench involves loading a clear column with contaminated soils. Catalyst and oxidant are injected into the column, allowed to react with the contaminated soils and then collected as leachate. As the oxidant permeates through the soils, it desorbs and destroys contamination from the soil. Column studies are best used when contaminants are visible and strongly sorbed to soil.
  
  

• Autoclave Studies – This type of bench study is a closed system that permits oxidation in each phase to be accurately measured. A representative soil sample is put into a sealed vessel that has ports to capture leachate and offgas. Oxidant and catalyst are injected into the vessel while PID headspace, carbon dioxide and oxygen offgas are monitored to determine the progress of the reaction. When the reaction reaches completion, the soil, leachate, and offgas are recovered and analyzed to determine the efficiency of the reaction in each phase.This methodology is best suited for determining an accurate mass balance of oxidant to contaminant ratios.