Oceanography / Limnology
Numerical Modeling
Visualization and Animation
Specialized Sampling Tools
Acid Rock Drainage
Database/Software Development

In fine grain materials, such as lake sediments and mine tailings, reactivity and fluxes of metals are best determined by collecting sediment porewaters with an instrument such as a dialysis membrane arrays (peeper).

In coarser-grained substrates (e.g., cobbles) peeper techniques are limited. A better approach involves the use of the diffusion sampler developed by Lorax which not only allows reproducible sampling in close proximity to the potentially reactive surfaces , but also integrates the chemical signature over a period of time (days to weeks), thereby accounting for temporal variability.

The Lorax Diffusion Sampler (LDS) is simply a reservoir of distilled deionized water (DDW) contained within a clean, plexiglass well, isolated from the lake water by a membrane filter.

The sampler is deployed in situ for an equilibration period of approximately two weeks, during which time dissolved constituents in the lake water diffuse across the membrane into the reservoir.

Over the deployment period, the DDW approaches a diffusive equilibrium with the adjacent lake water, such that when the sampler is retrieved, the water within the sampler is chemically indistinguishable from the test medium.