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Goethite is a mineral of the diaspore group, consisting of iron(III) oxide-hydroxide, specifically the α-polymorph. It is found in soil and other low-temperature environments such as sediment. Goethite has been well known since ancient times for its use as a pigment. Evidence has been found of its use in paint pigment samples taken from the caves of Lascaux in France. It was first described in 1806 based on samples found in the Hollertszug Mine in Herdorf, Germany. The mineral was named after the German polymath and poet Johann Wolfgang von Goethe (1749–1832).
In organochlorine chemistry, reductive dechlorination describes any chemical reaction which cleaves the covalent bond between carbon and chlorine via reductants, to release chloride ions. Many modalities have been implemented, depending on the application. Reductive dechlorination is often applied to remediation of chlorinated pesticides or dry cleaning solvents. It is also used occasionally in the synthesis of organic compounds, e.g. as pharmaceuticals.
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In oceanography and limnology, the sediment–water interface is the boundary between bed sediment and the overlying water column. The term usually refers to a thin layer of water at the very surface of sediments on the seafloor. In the ocean, estuaries, and lakes, this layer interacts with the water above it through physical flow and chemical reactions mediated by the micro-organisms, animals, and plants living at the bottom of the water body. The topography of this interface is often dynamic, as it is affected by physical processes and biological processes. Physical, biological, and chemical processes occur at the sediment-water interface as a result of a number of gradients such as chemical potential gradients, pore water gradients, and oxygen gradients.
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The phosphorus cycle is the biogeochemical cycle that describes the movement of phosphorus through the lithosphere, hydrosphere, and biosphere. Unlike many other biogeochemical cycles, the atmosphere does not play a significant role in the movement of phosphorus, because phosphorus and phosphorus-based compounds are usually solids at the typical ranges of temperature and pressure found on Earth. The production of phosphine gas occurs in only specialized, local conditions. Therefore, the phosphorus cycle should be viewed from whole Earth system and then specifically focused on the cycle in terrestrial and aquatic systems.
Gammaproteobacteria is a class of bacteria in the phylum Pseudomonadota. It contains about 250 genera, which makes it the most genus-rich taxon of the Prokaryotes. Several medically, ecologically, and scientifically important groups of bacteria belong to this class. It is composed by all Gram-negative microbes and is the most phylogenetically and physiologically diverse class of Proteobacteria.
A redox gradient is a series of reduction-oxidation (redox) reactions sorted according to redox potential. The redox ladder displays the order in which redox reactions occur based on the free energy gained from redox pairs. These redox gradients form both spatially and temporally as a result of differences in microbial processes, chemical composition of the environment, and oxidative potential. Common environments where redox gradients exist are coastal marshes, lakes, contaminant plumes, and soils.
Crocetane, or 2,6,11,15-tetramethylhexadecane, is an isoprenoid hydrocarbon compound. Unlike its isomer phytane, crocetane has a tail-to-tail linked isoprenoid skeleton. Crocetane has been detected in modern sediments and geological records as a biomarker, often associated with anaerobic methane oxidation.
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Cable bacteria are filamentous bacteria that conduct electricity across distances over 1 cm in sediment and groundwater aquifers. Cable bacteria allow for long-distance electron transport, which connects electron donors to electron acceptors, connecting previously separated oxidation and reduction reactions. Cable bacteria couple the reduction of oxygen or nitrate at the sediment's surface to the oxidation of sulfide in the deeper, anoxic, sediment layers.
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Caroline Masiello is a biogeochemist who develops tools to better understand the cycling and fate of globally relevant elemental cycles. She is a professor at Rice University in the Department of Earth, Environmental and Planetary Sciences and holds joint appointments in the Chemistry and Biochemistry Departments. Masiello was elected as a Fellow of the Geological Society of America in 2017. She currently leads an interdisciplinary team of scientists who are developing microbial sensors for earth system science.
Saharan dust is an aeolian mineral dust from the Sahara desert, the largest hot desert in the world. The desert spans just over 9 million square kilometers, from the Atlantic Ocean to the Red Sea, from the Mediterranean sea to the Niger River valley and the Sudan region in the south.
Clare Reimers is a Distinguished Professor of Ocean Ecology and Biogeochemistry at Oregon State University's College of Earth, Ocean and Atmospheric Sciences.
Elizabeth A. Canuel is a chemical oceanographer known for her work on organic carbon cycling in aquatic environments. She is the Chancellor Professor of Marine Science at the College of William & Mary and is an elected fellow of the Geochemical Society and the European Association of Geochemistry.
Karen Johnson is a British geologist who is a professor in environmental engineering at Durham University. She was awarded the 2023 Royal Society Rosalind Franklin Award.
References
- 1 2 3 4 "Caroline Slomp appointed Professor of Geomicrobiology and Biogeochemistry | Radboud University". www.ru.nl. Retrieved 2022-12-31.
- ↑ "Autobiographical sketches: Caroline Slomp". Oceanography. 27 (4): 221. December 17, 2015.
- ↑ "Prof. Slomp, C.P. (Caroline) | Radboud University". www.ru.nl. Retrieved 2022-12-31.
- ↑ Slomp, Caroline P.; Epping, Eric H. G.; Helder, Willem; Raaphorst, Wim Van (1996-11-01). "A key role for iron-bound phosphorus in authigenic apatite formation in North Atlantic continental platform sediments". Journal of Marine Research. 54 (6): 1179–1205. doi:10.1357/0022240963213745.
- ↑ Slomp, C. P.; Van der Gaast, S. J.; Van Raaphorst, W. (1996-03-01). "Phosphorus binding by poorly crystalline iron oxides in North Sea sediments". Marine Chemistry. 52 (1): 55–73. doi:10.1016/0304-4203(95)00078-X. hdl: 1874/31412 . ISSN 0304-4203. S2CID 97421756.
- ↑ Slomp, Caroline P.; Van Cappellen, Philippe (2004-08-10). "Nutrient inputs to the coastal ocean through submarine groundwater discharge: controls and potential impact". Journal of Hydrology. 295 (1): 64–86. doi:10.1016/j.jhydrol.2004.02.018. hdl: 1874/11282 . ISSN 0022-1694. S2CID 130711252.
- ↑ Slomp, Caroline P; Thomson, John; de Lange, Gert J (2004-01-15). "Controls on phosphorus regeneration and burial during formation of eastern Mediterranean sapropels". Marine Geology. 203 (1): 141–159. doi:10.1016/S0025-3227(03)00335-9. hdl: 1874/11283 . ISSN 0025-3227. S2CID 130764276.
- ↑ Egger, Matthias; Rasigraf, Olivia; Sapart, Célia J.; Jilbert, Tom; Jetten, Mike S. M.; Röckmann, Thomas; van der Veen, Carina; Bândă, Narcisa; Kartal, Boran; Ettwig, Katharina F.; Slomp, Caroline P. (2015-01-06). "Iron-Mediated Anaerobic Oxidation of Methane in Brackish Coastal Sediments". Environmental Science & Technology. 49 (1): 277–283. doi:10.1021/es503663z. hdl: 2066/135831 . ISSN 0013-936X. PMID 25412274. S2CID 206985897.
- ↑ Sulu-Gambari, Fatimah; Seitaj, Dorina; Meysman, Filip J. R.; Schauer, Regina; Polerecky, Lubos; Slomp, Caroline P. (2016-02-02). "Cable Bacteria Control Iron–Phosphorus Dynamics in Sediments of a Coastal Hypoxic Basin". Environmental Science & Technology. 50 (3): 1227–1233. doi:10.1021/acs.est.5b04369. ISSN 0013-936X. PMID 26720721.
- ↑ Hermans, Martijn; Lenstra, Wytze K.; Hidalgo-Martinez, Silvia; van Helmond, Niels A. G. M.; Witbaard, Rob; Meysman, Filip J.R.; Gonzalez, Santiago; Slomp, Caroline P. (2019-05-31). "Abundance and Biogeochemical Impact of Cable Bacteria in Baltic Sea Sediments". Environmental Science & Technology. 53 (13): 7494–7503. doi:10.1021/acs.est.9b01665. ISSN 0013-936X. PMC 6611076 . PMID 31149818.
- ↑ "Anammox bacteria allow wastewater to be used for generating electricity". phys.org. May 19, 2020. Retrieved 2022-12-31.
- ↑ "Current Fellows". www.fysiografen.se. Retrieved 2022-12-31.
- ↑ "P. Gast Lecture | European Association of Geochemistry" . Retrieved 2022-12-31.
- ↑ "Geochemistry Fellows | European Association of Geochemistry" . Retrieved 2022-12-31.
- ↑ Kan-Parker, Mirjam van (2020-02-11). "Professor Caroline Slomp elected Geochemistry Fellow". NESSC. Retrieved 2022-12-31.
