The Journal of Contaminant Hydrology featured a study entitled “The Impact of nZVI Stability on Mobility in Porous Media”. The study, through column experiments and numerical modeling, aimed to predict the impact of polymer-stabilized nZVI aggregation and settling on nZVI transport over a range of pore water velocities that may be used in the field.
Nano-scale zero valent iron (nZVI) has received significant attention because of its potential to rapidly reduce a number of priority source zone contaminants. The stability of nZVI is considered to effectively deliver nZVI to the source zone. Increasing nZVI concentration accelerates aggregation, which reduces the available time for injection before NZVI settles.
To accurately determine the size of nZVI/CMC aggregates in suspension, researchers used Brookhaven’s NanoBrook 90Plus Particle Analyzer to conduct Dynamic Light Scattering (DLS) analysis. Freshly synthesized 0.1 g/L nZVI was then prepared in 0.2% wt CMC250k solution and analyzed. For 2.5 g/L nZVI prepared in 0.8% wt. CMC250k solution, optimal light scattering was achieved by diluting nZVI in 0.8% wt. CMC250k. The results from the NanoBrook 90Plus Particle Analyzer were used as parameters, which confirmed that large aggregates are not immediately formed following synthesis.
The NanoBrook 90Plus Particle Size Analyzer can generate DLS analysis measurements in less than two minutes and helped the researchers obtain an experimental approach designed to represent conditions expected at field scale injection sites. Results from the NanoBrook 90Plus Particle Size Analyzer contributed to the success of this study, which required a model that incorporated settling at the influent boundary and changes when nZVI was given sufficient time to aggregate and settle.
Brookhaven Instruments offers only high-grade particle size analyzers designed to facilitate scientific research, which includes dynamic light scattering analysis sensitive to both small and large particles, depending on scattering angle preferred.