Sensatec GmbH, an independent laboratory based in Germany, conducted a column study to compare the abilities of RemBind Plus, a product manufactured by Ziltek and distributed by Tersus Environmental, and granular activated carbon to remove perfluorinated substances from groundwater.
Sensatec packed a column with a mixture of 10% quartz sand and 90% RemBind Plus by weight. A second column contained GAC. Applying sodium chloride as a tracer, Sensatec determined hydraulic breakthrough rates and the column pore volumes. Thereafter, Sensatec ran a water solution with a total PFAS concentration of 1.85 mg/L (510 μg/L PFOS) through the columns with continuous flow to determine breakthrough rates. Sensatec collected samples from the column outlet at the following pore volume exchanges: 1, 5, 10, 20, 30, 50, and 100. Analytes included perfluorooctane sulfonate (PFOS), perfluorooctanoic acid (PFOA), potassium perfluorobutane sulfonate (PFBS) and perfluorobutyric acid (PFBA).
The tracer study determined that a flow rate of 3.1 mL per minute would exchange a pore volume at 54 minutes. Results in Figures 1 and 2 show that there was minimal breakthrough of all tested compounds after 100 pore volumes had passed through the RemBind Plus column. The GAC column had breakthrough of the smaller PFAS compounds, PFBS and PFBA, after 1 pore volume.
The adsorption capacity of RemBind Plus for the smaller chain perfluorinated substances PFBA and PFBS is vastly superior to that of GAC. This is likely due to the presence of the non-carbon components of RemBind Plus creating unique physical chemical interactions with the smaller chain PFAS compounds.