In Situ Measurement of PCB Pore Water Concentration Profiles in Activated Carbon-Amended Sediment Using Passive Samplers

2011 ◽  
Vol 45 (9) ◽  
pp. 4053-4059 ◽  
Author(s):  
Amy M. P. Oen ◽  
Elisabeth M. L. Janssen ◽  
Gerard Cornelissen ◽  
Gijs D. Breedveld ◽  
Espen Eek ◽  
...  
Keyword(s):  
Activated Carbon ◽  
Pore Water ◽  
Water Concentration ◽  
In Situ Measurement ◽  
Passive Samplers ◽  
Concentration Profiles

In situ measurement of dissolved Fe(ii) in sediment pore water with a novel sensor based on C18-ferrozine concentration and optical imaging detection

2019 ◽  
Vol 11 (2) ◽  
pp. 133-141 ◽  
Author(s):  
Chengrong Guo ◽  
Mingjie Ma ◽  
Dongxing Yuan ◽  
Yongming Huang ◽  
Kunning Lin ◽  
...  
Keyword(s):  
Optical Imaging ◽  
Pore Water ◽  
In Situ Measurement ◽  
Sensor System ◽  
Sediment Pore Water ◽  
Imaging Detection

A novel sensor system, which integrated sampling, enrichment, and in situ measurement of dissolved Fe(ii) in sediment pore water, was developed.

Development of passive samplers for in situ measurement of pyrethroid insecticides in surface water

2017 ◽  
Vol 224 ◽  
pp. 516-523 ◽  
Author(s):  
Jiaying Xue ◽  
Chunyang Liao ◽  
Jie Wang ◽  
Zachary Cryder ◽  
Tianbo Xu ◽  
...  
Keyword(s):  
Surface Water ◽  
In Situ Measurement ◽  
Passive Samplers ◽  
Pyrethroid Insecticides

REY distribution and concentration in bottom seawater and oxic pore water in the CCZ, NE Pacific: pilot study on the application of a DGT passive sampling method in deep sea environments

2020 ◽  
Author(s):  
Katja Schmidt ◽  
Sophie Anna Luise Paul ◽  
Cornelia Kriete
Keyword(s):  
Trace Elements ◽  
Trace Metal ◽  
Pore Water ◽  
Deep Sea ◽  
Passive Sampling ◽  
Sampling Method ◽  
Passive Samplers ◽  
Sediment Pore Water ◽  
Ce Anomaly

<p>Sampling and analysis of trace elements in open seawater and in sediment pore water in the deep sea is challenging due to small sample volumes and matrix effects. Here we evaluate an alternative method using the technique of diffusive gradients in thin films (DGT passive samplers), focussing on rare earth elements and yttrium (REY). DGT measures the labile fraction of metals in situ by fixing them on a Chelex resin after diffusion through a gel layer, providing a diffusive flux and averaged in situ concentrations of elements during the time of deployment. As the accumulated element concentrations increase with exposure time to solution, long-term deployment times overcome low trace metal concentrations in seawater and pore water. So far, no deep-sea applications of passive samplers are yet reported.</p><p>Sampling was performed in bottom seawater and surface sediments in the German licence area for manganese nodule exploration in the Clarion Clipperton Zone (CCZ, research cruise SO268 in April/May 2019), deployment times ranged from 12 hours in sediments to 4 weeks in open seawater.</p><p>Seawater DGT’s were deployed 0.5 m to 8 m above the seafloor. PAAS-normalized REY show the typical seawater pattern, with increase from LREE to HREE, a strong negative Ce anomaly, a kink from Gd to Tb, and a pronounced positive Y/Ho anomaly. The pattern and calculated concentrations agree very well with reported dissolved REY (<0.2 µm) for Pacific deep water (Alibo and Nozaki, 1999). Sediment DGT sticks were deployed in cores taken with a multicorer and cover the first 15 cm of the sediment. They provide in situ high-resolution profiles of trace metal fluxes and were analysed in 0.5 cm to 2 cm segments. We observe smooth PAAS-normalized patterns with negative Ce anomaly, an increase from LREE to MREE, and a slight decrease from Tb to Lu, sometimes accompanied by a small positive Y/Ho anomaly. The calculated concentrations generally increase with depth. Paul et al (2019) previously described very similar distribution patterns for CCZ sediment pore water and suggested Mn and Fe phases as the REY source. The pore water REY patterns clearly differ from bottom seawater already in the first centimetres of surface sediment– this sharp shift demonstrates that the dissolved pore water REY pool in the sediment surface is controlled by fluid-mineral equilibria.</p><p>The DGT passive sampling method may provide an additional tool to investigate biogeochemical processes at the deep-sea sediment-water interface and in the open ocean, and to monitor effects of anthropogenic disturbances at the seafloor on benthic trace element fluxes. We will discuss uncertainties of concentration calculation resulting from diffusion coefficients and from non-steady state conditions in pore water, and the comparability of DGT-derived distribution pattern and concentrations with results from physically filtered water. The DGT labile fraction is thought to represent the bioavailable fraction of trace elements and may also include colloids and nanoparticles (NPCs).</p><p> </p><p>Alibo and Nozaki, 1999: Geochimica et Cosmochimica Acta 63, pp. 363-372.</p><p>Paul et al, 2019: Geochimica et Cosmochimica Acta 251, pp. 56-72.</p>

In Situ Measurement of Soil Heat Flux with the Gradient Method

2003 ◽  
Vol 2 (4) ◽  
pp. 589
Author(s):  
Douglas R. Cobos ◽  
John M. Baker
Keyword(s):  
Heat Flux ◽  
Gradient Method ◽  
Soil Heat Flux ◽  
In Situ Measurement

In-Situ Measurement Technique of Stress and Structure Change

2015 ◽  
Vol 84 (8) ◽  
pp. 567-572
Author(s):  
Tadafumi HASHIMOTO ◽  
Masahito MOCHIZUKI
Keyword(s):  
Measurement Technique ◽  
Structure Change ◽  
In Situ Measurement
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