Bench-Scale and Treatability Testing
Vertex routinely completes bench-scale and treatability testing in our in-house laboratory, such as determining the relative effectiveness of different types of oxidants, and testing the optimal dosing and/or activation methods of oxidants to remediate contaminants at specific sites.
Bench-scale testing into the effectiveness of bioremediation approaches is also completed in-house. Such testing is routinely done to allow a refined remedial design to be developed for a given site, with much more accurate estimates of cost and timeframe.
Natural Oxidant Demand Testing
Vertex offers NOD testing for various oxidants, such as sodium and potassium permanganate, sodium persulphate, hydrogen peroxide, etc.
In-situ Chemical Oxidation (ISCO) is often highly subject to the Natural Oxidant Demand (NOD) of the soil, bedrock and/or groundwater. Just as chemical oxidants react with contaminants of concern, they also react with organic and inorganic constituents present in the subsurface formation.
In some cases the NOD of the subsurface formation is much higher than that of the contamination that is present. This NOD must be “overcome” by the oxidants before the contaminants can be remediated. Therefore, it is often important to understand the NOD of the soils at a site.
Vertex offers in-house oxidant testing, usually conducted on groundwater samples collected from a site, to analyze the presence and concentration of oxidants that remain.
This service allows remediation programs to be completed in a more timely manner by minimizing “downtime” (i.e., when the oxidants have been used up) and allowing subsequent applications of oxidant to take place with more accuracy.
All oxidants degrade in the subsurface over time as they react with the subsurface formation and the contaminants that are present. In many cases, more than one application of oxidants is required to meet remedial objectives. The length of time that the oxidants will remain active in the subsurface is site-specific and cannot usually be predicted.
Vertex also offers custom-designed testing in relation to in-situ remediation programs.
These tests can involve assessing the effectiveness of different treatment trains (e.g. varying the remediation method from chemical oxidation to aerobic bioremediation as the remediation progresses to maximize efficiency) to completely customized testing.
Vertex recently completed testing into the effect on consolidation of highly organic soil resulting from the injection of a strong solution of sodium persulphate.
Vertex has also designed customized tests that can be completed in the field to confirm Zero-Valent Iron (ZVI) content during direct placement, to confirm the presence and relative quantity of mobile and non-mobile free-phased product in soil, etc.