20 Apr BOS 100 is More Than ZVI and AC Mixtures Could Hope to Be

In our July 2023 newsletter, we delved into the distinctiveness of BOS 100, clarifying that it is not just a blend of iron and activated carbon (AC). The energy-dispersive spectroscopy (EDS) image in Figure 1 beautifully illustrates this, revealing how the elemental iron is integral to the AC structure of BOS 100. This unique integration, where the elemental iron and AC are fused, sets BOS 100 apart as a remediation product in a league of its own, distinct from ZVIs, AC, or a combination of the two.

Figure 1. XRD shows the elemental iron is integral to the AC in BOS 100®.

Let’s examine the results of a simple laboratory test demonstrating the stark difference between ZVI, ZVI + AC, and BOS 100.

Three test vials were set up. 3.25 g of a brand-name Sulfided microscale ZVI, 3.25 g of the same ZVI mixed with 325 mg of AC, or 5 g of BOS 100, which has 325 mg of iron integrated into its AC structure, were dosed with 500 ppm of TCE in tests that were otherwise identical. The ZVI has 10x more iron by dose than the BOS 100.

In the first graph, TCE concentration versus time for the ZVI-only test shows that the TCE concentration minimally decreases (Blue line). The ZVI and AC combination fares better (Green line). The BOS 100 performs the best (Orange line). Most vendor presentations stop at this first graph, the results of which could be absorption-driven. But degradation is quintessential to environmental restoration. Solid proof of TCE degradation is chloride generation.

Graph 1. TCE concentration decreases with time. BOS 100 demonstrates the largest decrease, while ZVI alone indicates the least decrease.

In the second graph, the chloride generation over time does not mirror the TCE decrease observed in the first graph. BOS 100 leads the pack in chloride generation. In contrast, ZVI generates 8.5x less chloride than BOS 100 but still outperforms the ZVI and AC mixture—the least effective of the three.

Graph 2. Chloride generation over time is greatest for BOS 100®. ZVI generates more chloride than does ZVI and AC mixed.

The contrast between the ZVI and the ZVI and AC mixture is telling. In the first graph, the ZVI and AC mixture absorbs the TCE, lowering its concentration in the solution. The same absorption protects the TCE from the ZVI, so less chloride is produced than by ZVI alone. The BOS 100 is different. It generates 16x more chloride than the ZVI and AC mixture because the iron is integral to the AC. When TCE is absorbed, it collocates with the iron.

BOS 100 is more than ZVI and AC mixtures could even hope to be. It is incomparable.

Kind Regards,

Ed Winner, PhD, Vice President
Remediation Products, Inc.