Peeper keeper (Waarde 08/2000)
Peeper (Sapelo USA)
Pore water sampling (Sapelo USA)
SEDIMENT SAMPLING
Core retrievement (Charly)
Guillotine core
Sediment sampling under nitrogen atmosphere (Charly and Tom)
FIELD WORK
| BISE
(Biogeochemistry In the Scheldt Estuary) aims at advancing the mechanistic understanding
and the quantitative modeling of complex biogeochemical reaction networks in redox-stratified
sediments of the Scheldt estuary. To that purpose, field data is collected for analysis
of interstitial water and solid phase and microbial characterization. Pore waters are sampled using a pore water diffusion equilibrators ("peepers") constructed in UHMW-PE (Ultra High Molecular Weight PolyEthylene). A peeper is constituted of 35 chambers covered by a 0.2 micro diameter nylon membranes. Between preparation and deployment in the field, peepers are kept in a "peeper keeper" filled with deionized water and bubbled continuously with Argon for a minimum of 3 days. The peepers are then transported to the field site in the peeper keeper (always under anaerobic conditions). Peepers removed from the peeper keeper are immediately inserted in the sediment to prevent oxygenation of the deionized water in the peeper chambers. The peepers are left to equilibrate with the surrounding sediment for approximately four weeks before retrieval. During the time of deployment, the water inside the chambers equilibrates with the surrounding pore waters. That is, after equilibration the concentrations of dissolved species in a peeper chamber are identical to those in the surrounding pore water. After retrievement, pore water are immediately extracted using syringes by puncturing the nylon membranes under inert atmosphere (in a glove bag purged with nitrogen). pH and conductivity are immediately measuring after filtration and remaining sample are pipetted into a series of vials for alkalinity, ferric and ferrous iron, sulfide, ammonium, phosphate, sulfate and manganese colorimetric analyses. Remaining of samples are acidified with nitric acid supra pure and diluted with milliQ water for ICP/OES analyses (Al, Ca, Fe, K, Mg, Mn, Na, P, S, Si and Sr). Sediments are sampled using a guillotine core, and sectioned into slices in an anaerobic glove bag. Sediment slices are stored in sterile plastic bag at -30oC for microbiological and solid chemical analyses. |
| PORE WATER SAMPLING | ||
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Peeper keeper (Waarde 08/2000) |
Peeper (Sapelo USA) |
Pore water sampling (Sapelo USA) |
SEDIMENT SAMPLING |
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Core retrievement (Charly) |
Guillotine core |
Sediment sampling under nitrogen atmosphere (Charly and Tom) |