The biosignature of sparite permits the distinction between gravitational cement and endostromatolites

2020 ◽  
Vol 20 (20) ◽  
pp. 407-419
Author(s):  
Bruno Granier ◽  
Keyword(s):  
Organic Matter ◽  
Vadose Zone ◽  
Carbonate Sedimentology ◽  
Sedimentary Petrography

Following a brief summary of some fundamentals in carbonate sedimentology (sedimentary petrography) that highlights the significance of organic matter, some examples of biocrystals in carbonate grains/particles, such as bioclasts or ooids, are provided as an introductory chapter to a discussion on gravitational cements versus endostromatolites. The gravitational cements, either marine (fibrous) or continental (dog-tooth), are made of hyaline (i.e., translucent) sparitic crystals whereas endostromatolites are made of colored sparitic crystals and/or micrite. Gravitational cements forms in the vadose zone whereas endostromatolites grow in small rock cavities in the marine phreatic zone. As such the latter can grow centripetally in all directions (not only downward).

scholarly journals Radiocarbon evidence for decomposition of aged organic matter in the vadose zone as the main source of speleothem carbon

2015 ◽  
Vol 127 ◽  
pp. 37-47 ◽  
Author(s):  
Alexandra L. Noronha ◽  
Kathleen R. Johnson ◽  
John R. Southon ◽  
Chaoyong Hu ◽  
Jiaoyang Ruan ◽  
...  
Keyword(s):  
Organic Matter ◽  
Vadose Zone

scholarly journals Impact of Natural Organic Matter on Plutonium Vadose Zone Migration from an NH4Pu(V)O2CO3(s) Source

2020 ◽  
Vol 54 (5) ◽  
pp. 2688-2697
Author(s):  
Melody Maloubier ◽  
Hilary Emerson ◽  
Kathryn Peruski ◽  
Annie B. Kersting ◽  
Mavrik Zavarin ◽  
...  
Keyword(s):  
Organic Matter ◽  
Natural Organic Matter ◽  
Vadose Zone

Recycling of Nitrate and Organic Matter by Plants in the Vadose Zone of a Saturated Riparian Buffer

2021 ◽  
Vol 232 (6) ◽  
Author(s):  
Patience Bosompemaa ◽  
Eric Wade Peterson ◽  
William Perry ◽  
Wondwosen M. Seyoum
Keyword(s):  
Organic Matter ◽  
Vadose Zone ◽  
Riparian Buffer

scholarly journals Fate of effluent organic matter during soil aquifer treatment: biodegradability, chlorine reactivity and genotoxicity

2003 ◽  
Vol 1 (1) ◽  
pp. 33-44 ◽  
Author(s):  
David M. Quanrud ◽  
Robert G. Arnold ◽  
Kevin E. Lansey ◽  
Carmen Begay ◽  
Wendell Ela ◽  
...  
Keyword(s):  
Organic Matter ◽  
Vadose Zone ◽  
Wastewater Effluent ◽  
Soil Aquifer Treatment ◽  
Batch Test ◽  
Trihalomethane Formation Potential ◽  
Doc Concentration ◽  
Resin Adsorption ◽  
Light Absorbance ◽  
Mass Basis

Hydrophobic acid (HPO-A) and transphilic acid (TPI-A) fractions of dissolved organic matter (DOM) were isolated from a domestic secondary wastewater effluent that was polished via soil aquifer treatment (SAT). Fractions were isolated using XAD resin adsorption chromatography from samples obtained along the vadose zone flowpath at a full-scale basin recharge facility in Tucson, Arizona. Changes in isolate character during SAT were established via biodegradability (batch test), specific ultraviolet light absorbance (SUVA), trihalomethane formation potential (THMFP), and Ames mutagenicity assays. The dissolved organic carbon (DOC) concentration decreased by >90% during SAT. A significant fraction (up to 20%) of isolated post-SAT HPO-A was biodegradable. The (apparent) refractory nature of DOM that survives SAT may be a consequence of low DOC concentration in groundwater as well as the nature of the compounds themselves. Specific THMFP (µg THM per mg DOC) of HPO-A and TPI-A varied little as a consequence of SAT, averaging 52 and 49 µg THM per mg DOC, respectively. The nonbiodegradable fractions of HPO-A and TPI-A exhibited higher reactivities: 89 and 95 µg THM per mg DOC, respectively. Genotoxicity of HPO-A (on a per mass basis) increased after SAT, suggesting that responsible compounds are removed less efficiently than bulk organics during vadose zone transport.

Transport and retention of engineered silver nanoparticles in the presence of phosphorus

2020 ◽  
Author(s):  
Yorck Adrian ◽  
Uwe Schneidewind ◽  
Scott Bradford ◽  
Jirka Simunek ◽  
Erwin Klumpp ◽  
...  
Keyword(s):  
Silver Nanoparticles ◽  
Organic Matter ◽  
Soil Organic Matter ◽  
Vadose Zone ◽  
Sediment Surface ◽  
Background Solution ◽  
Saturated Zone ◽  
Fine Sediments ◽  
Attachment Sites ◽  
Transport Behaviour

<p>Nowadays engineered silver nanoparticles (AgNP) are being widely used for a multitude of purposes. At certain times during their life-cycle they might enter soils and freshwater resources and thus recent research has focused on their transport and fate in soils and the vadose zone as well as the saturated zone. AgNP retention in the subsurface depends on a multitude of parameters including the type and shape of the sediments through the nanoparticles are exposed to, the chemical composition of pore and groundwater acting as background solution or the type and quantity of soil organic matter present. One aspect that has received little attention so far is their transport behaviour in the presence of nutrients.</p><p>Here we study PVP-AgNP transport and retention in saturated columns containing silicate-dominated aquifer material that is also exposed to orthophosphate (NaH<sub>2</sub>PO<sub>4</sub>) or <em>myo</em>-inositol hexakisphosphate (IP6) via the background solution. In particular, we compare PVP-AgNP transport behaviour for different pH (6 and 4.5) in the background solution, for different mass concentrations of sediments <63 µm in the columns (0 and 2%) and in the presence/absence of soil organic matter (SOM). Experimental data were modelled using HYDRUS 1D.</p><p>Results of our experiments show that PVP-AgNP exhibit a higher mobility through the columns in the presence of phosphate as the latter can block attachment sites otherwise available to the nanoparticles. In the presence of SOM this mobility is even higher than in the absence of SOM as SOM and phosphate anions are both negatively charged and potentially bound to the same attachment sites. PVP-AgNP mobility also increased for both P-species when an increase in pH occurred but this increase was more pronounced in columns with orthophosphate. Results further show that PVP-AgNP are more mobile in columns with IP6 than orthophosphate in the absence of sediments <63 µm at pH 4.5. However, while for columns with material < 63 µm the overall AgNP mobility is decreased due to an overall increase in sediment surface area, AgNP are more mobile in the presence of orthophosphate as IP6 is more strongly bound to iron and aluminium oxides found in higher abundance in the fine sediments.   </p>

Denitrification in vadose zone material amended with dissolved organic matter from topsoil and subsoil

2013 ◽  
Vol 61 ◽  
pp. 96-104 ◽  
Author(s):  
M.E. Peterson ◽  
D. Curtin ◽  
S. Thomas ◽  
T.J. Clough ◽  
E.D. Meenken
Keyword(s):  
Organic Matter ◽  
Dissolved Organic Matter ◽  
Vadose Zone
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