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https://www.readbyqxmd.com/read/28813138/quantifying-lake-water-quality-evolution-coupled-geochemistry-hydrodynamics-and-aquatic-ecology-in-an-acidic-pit-lake
#1
S Ursula Salmon, Matthew R Hipsey, Geoffrey W Wake, Gregory N Ivey, Carolyn E Oldham
Assessment of water quality evolution in the thousands of existing and future mine pit lakes worldwide requires new numerical tools that integrate geochemical, hydrological, and biological processes. A coupled model was used to test alternative hypothesized controls on water quality in a pit lake over ∼8 years. The evolution of pH, Al, and Fe were closely linked; field observations were reproduced with generic solubility equilibrium controls on Fe(III) and Al and a commonly reported acceleration of the abiotic Fe(II) oxidation rate by 2-3 orders of magnitude...
August 16, 2017: Environmental Science & Technology
https://www.readbyqxmd.com/read/28802767/real-rock-microfluidic-flow-cell-a-test-bed-for-real-time-in-situ-analysis-of-flow-transport-and-reaction-in-a-subsurface-reactive-transport-environment
#2
Rajveer Singh, Mayandi Sivaguru, Glenn A Fried, Bruce W Fouke, Robert A Sanford, Martin Carrera, Charles J Werth
Physical, chemical, and biological interactions between groundwater and sedimentary rock directly control the fundamental subsurface properties such as porosity, permeability, and flow. This is true for a variety of subsurface scenarios, ranging from shallow groundwater aquifers to deeply buried hydrocarbon reservoirs. Microfluidic flow cells are now commonly being used to study these processes at the pore scale in simplified pore structures meant to mimic subsurface reservoirs. However, these micromodels are typically fabricated from glass, silicon, or polydimethylsiloxane (PDMS), and are therefore incapable of replicating the geochemical reactivity and complex three-dimensional pore networks present in subsurface lithologies...
August 4, 2017: Journal of Contaminant Hydrology
https://www.readbyqxmd.com/read/28771598/impacts-of-leachates-from-livestock-carcass-burial-and-manure-heap-sites-on-groundwater-geochemistry-and-microbial-community-structure
#3
Man Jae Kwon, Seong-Taek Yun, Baknoon Ham, Jeong-Ho Lee, Jun-Seop Oh, Weon-Wha Jheong
We investigated the impacts of leachates from a swine carcass burial site and a cow manure heap on the geochemical and microbiological properties of agricultural water samples, including leachate, groundwater from monitoring wells and background wells, and stream water. The leachate from the livestock burial site showed extremely high electrical conductivity, turbidity, and major ion concentrations, but low redox potential and dissolved oxygen levels. The groundwater in the monitoring wells adjacent to both sites showed severe contamination from the leachate, as indicated by the increases in EC, turbidity, Cl-, and SO42-...
2017: PloS One
https://www.readbyqxmd.com/read/28765580/quantifying-crustal-thickness-in-continental-collisional-belts-global-perspective-and-a-geologic-application
#4
Fangyang Hu, Mihai N Ducea, Shuwen Liu, James B Chapman
We present compiled geochemical data of young (mostly Pliocene-present) intermediate magmatic rocks from continental collisional belts and correlations between their whole-rock Sr/Y and La/Yb ratios and modern crustal thickness. These correlations, which are similar to those obtained from subduction-related magmatic arcs, confirm that geochemistry can be used to track changes of crustal thickness changes in ancient collisional belts. Using these results, we investigate temporal variations of crustal thickness in the Qinling Orogenic Belt in mainland China...
August 1, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28763202/paleo-ecotoxicology-what-can-lake-sediments-tell-us-about-ecosystem-responses-to-environmental-pollutants
#5
Jennifer Korosi, Joshua R Thienpont, John P Smol, Jules M Blais
The development of effective risk reduction strategies for aquatic pollutants requires a comprehensive understanding of toxic impacts on ecosystems. Classical toxicological studies are effective for characterizing pollutant impacts on biota in a controlled, simplified environment. Nonetheless, it is well-acknowledged that predictions based on the results of these studies must be tested over the long-term in a natural ecosystem setting, to account for increased complexity and multiple stressors. Paleolimnology (the study of lake sediment cores to reconstruct environmental change) can address many key knowledge gaps...
August 1, 2017: Environmental Science & Technology
https://www.readbyqxmd.com/read/28760580/landscape-scale-heterogeneity-in-the-east-turkana-ecosystem-during-the-okote-member-1-56-1-38-ma
#6
D B Patterson, D R Braun, A K Behrensmeyer, S B Lehmann, S R Merritt, J S Reeves, B A Wood, R Bobe
Placing the biological adaptations of Pleistocene hominins within a well-resolved ecological framework has been a longstanding goal of paleoanthropology. This effort, however, has been challenging due to the discontinuous nature of paleoecological data spanning many important periods in hominin evolution. Sediments from the Upper Burgi (1.98-1.87 Ma), KBS (1.87-1.56 Ma) and Okote (1.56-1.38 Ma) members of the Koobi Fora Formation at East Turkana in northern Kenya document an important time interval in the evolutionary history of the hominin genera Homo and Paranthropus...
July 28, 2017: Journal of Human Evolution
https://www.readbyqxmd.com/read/28751914/geochemical-characteristics-and-origins-of-the-crude-oil-of-triassic-yanchang-formation-in-southwestern-yishan-slope-ordos-basin
#7
Xiaoli Zhang, Jinxian He, Yande Zhao, Hongchen Wu, Zeqiang Ren
Biomarker compounds that derived from early living organisms play an important role in oil and gas geochemistry and exploration since they can record the diagenetic evolution of the parent materials of crude oil and reflect the organic geochemical characteristics of crude oil and source rocks. To offer scientific basis for oil exploration and exploitation for study area, gas chromatography-mass spectrometry method is applied to study the biomarker compounds of crude oil in Southwestern Yishan Slope of Ordos Basin, through qualitatively and quantitatively analyzing separated materials...
2017: International Journal of Analytical Chemistry
https://www.readbyqxmd.com/read/28750008/physiological-responses-of-coccolithophores-to-abrupt-exposure-of-naturally-low-ph-deep-seawater
#8
Maria Debora Iglesias-Rodriguez, Bethan M Jones, Sonia Blanco-Ameijeiras, Mervyn Greaves, Maria Huete-Ortega, Mario Lebrato
Upwelling is the process by which deep, cold, relatively high-CO2, nutrient-rich seawater rises to the sunlit surface of the ocean. This seasonal process has fueled geoengineering initiatives to fertilize the surface ocean with deep seawater to enhance productivity and thus promote the drawdown of CO2. Coccolithophores, which inhabit many upwelling regions naturally 'fertilized' by deep seawater, have been investigated in the laboratory in the context of ocean acidification to determine the extent to which nutrients and CO2 impact their physiology, but few data exist in the field except from mesocosms...
2017: PloS One
https://www.readbyqxmd.com/read/28746622/holocene-history-of-a-lake-filling-and-vegetation-dynamics-of-the-serra-sul-dos-caraj%C3%A3-s-southeast-amazonia
#9
José T F Guimarães, Prafulla K Sahoo, Pedro W M Souza-Filho, Mariana M J Costa DE Figueiredo, Luiza S Reis, Marcio S DA Silva, Tarcísio M Rodrigues
Down-core changes in sedimentary facies, elemental geochemistry, pollen, spore, δ13C, δ15N and radiocarbon records from a filled lake, named R4, of the Serra Sul dos Carajás were used to study the relationship between the paleomorphological and paleoecological processes and their significance for Holocene paleoclimatology of the southeast Amazonia. The sediment deposition of the R4 lake started around 9500 cal yr BP. Increase of detrital components from 9500 to 7000 cal yr BP suggests high weathering of surrounding catchment rocks and soils, and deposition into the lake basin under mudflows...
July 24, 2017: Anais da Academia Brasileira de Ciências
https://www.readbyqxmd.com/read/28745515/hydrology-of-the-north-klondike-river-carbon-export-water-balance-and-inter-annual-climate-influences-within-a-sub-alpine-permafrost-catchment
#10
Anthony Lapp, Ian Clark, Andrew Macumber, Tim Patterson
Arctic and sub-arctic watersheds are undergoing significant changes due to recent climate warming and degrading permafrost, engendering enhanced monitoring of arctic rivers. Smaller catchments provide understanding of discharge, solute flux and groundwater recharge at the process level that contributes to an understanding of how larger arctic watersheds are responding to climate change. The North Klondike River, located in west central Yukon, is a sub-alpine permafrost catchment, which maintains an active hydrological monitoring station with a record of >40 years...
July 26, 2017: Isotopes in Environmental and Health Studies
https://www.readbyqxmd.com/read/28733603/sediment-transport-drives-tidewater-glacier-periodicity
#11
Douglas Brinkerhoff, Martin Truffer, Andy Aschwanden
Most of Earth's glaciers are retreating, but some tidewater glaciers are advancing despite increasing temperatures and contrary to their neighbors. This can be explained by the coupling of ice and sediment dynamics: a shoal forms at the glacier terminus, reducing ice discharge and causing advance towards an unstable configuration followed by abrupt retreat, in a process known as the tidewater glacier cycle. Here we use a numerical model calibrated with observations to show that interactions between ice flow, glacial erosion, and sediment transport drive these cycles, which occur independent of climate variations...
July 21, 2017: Nature Communications
https://www.readbyqxmd.com/read/28726228/microwave-irradiation-and-citric-acid-assisted-seed-germination-and-phytoextraction-of-nickel-ni-by-brassica-napus-l-morpho-physiological-and-biochemical-alterations-under-ni-stress
#12
Mujahid Farid, Shafaqat Ali, Muhammad Rizwan, Rashid Saeed, Hafiz Muhammad Tauqeer, Rasham Sallah-Ud-Din, Ahmed Azam, Nighat Raza
The complex bio-geochemistry of soil allows pollutant to persist for a longer period of time which further decreased the fertility and natural composition of land. Nickel, an inorganic pollutant, coming from a wide range of industrial and manufacturing units possesses serious threat to soil degradation and crop productivity around the world. The present study was carried to evaluate the combined role of microwave irradiation (MR) and citric acid (CA) on the phytoextraction potential of Brassica napus L. under Ni stress...
July 20, 2017: Environmental Science and Pollution Research International
https://www.readbyqxmd.com/read/28724228/a-new-method-for-correlation-analysis-of-compositional-environmental-data-a-worked-example
#13
C Reimann, P Filzmoser, K Hron, P Kynčlová, R G Garrett
Most data in environmental sciences and geochemistry are compositional. Already the unit used to report the data (e.g., μg/l, mg/kg, wt%) implies that the analytical results for each element are not free to vary independently of the other measured variables. This is often neglected in statistical analysis, where a simple log-transformation of the single variables is insufficient to put the data into an acceptable geometry. This is also important for bivariate data analysis and for correlation analysis, for which the data need to be appropriately log-ratio transformed...
July 14, 2017: Science of the Total Environment
https://www.readbyqxmd.com/read/28711007/carbon-dynamics-in-a-late-quaternary-age-coastal-limestone-aquifer-system-undergoing-saltwater-intrusion
#14
Eliza Bryan, Karina T Meredith, Andy Baker, Martin S Andersen, Vincent E A Post
This study investigates the inorganic and organic aspects of the carbon cycle in groundwaters throughout the freshwater lens and transition zone of a carbonate island aquifer and identifies the transformation of carbon throughout the system. We determined (14)C and (13)C carbon isotope values for both DIC and DOC in groundwaters, and investigated the composition of DOC throughout the aquifer. In combination with hydrochemical and (3)H measurements, the chemical evolution of groundwaters was then traced from the unsaturated zone to the deeper saline zone...
July 12, 2017: Science of the Total Environment
https://www.readbyqxmd.com/read/28707854/a-eurasian-mineralogy-aleksandr-fersman%C3%A2-s-conception-of-the-natural-world
#15
Andy Bruno
Thoroughly a product of imperial Russia’s aristocratic culture, the mineralogist and geochemist Aleksandr Fersman rose to the top of the country’s scientific establishment after the Bolsheviks took control. He then remained a staunch supporter of various industrial projects through much of the Stalinist period. This essay puts Fersman’s thinking about the natural world in conversation with a quite distinctive mode of intellectual inquiry that developed contemporaneously. Eurasianism was a philosophical doctrine of a group of Russian émigrés who emphasized Russia’s unique status straddling Europe and Asia...
September 2016: Isis; An International Review Devoted to the History of Science and its Cultural Influences
https://www.readbyqxmd.com/read/28704663/effect-of-sulfide-on-as-iii-and-as-v-sequestration-by-ferrihydrite
#16
Zhixi Zhao, Shaofeng Wang, Yongfeng Jia
The sulfide-induced change in arsenic speciation is often coupled to iron geochemical processes, including redox reaction, adsorption/desorption and precipitation/dissolution. Knowledge about how sulfide influenced the coupled geochemistry of iron and arsenic was not explored well up to now. In this work, retention and mobilization of As(III) and As(V) on ferrihydrite in sulfide-rich environment was studied. The initial oxidation states of arsenic and the contact order of sulfide notably influenced arsenic sequestration on ferrihydrite...
October 2017: Chemosphere
https://www.readbyqxmd.com/read/28702733/isotope-and-microelement-systematics-of-gallionella-sp-containing-bacterial-mats-from-the-northwest-of-the-east-european-platform
#17
S B Felitsyn, N A Alfimova
Microelement composition of Gallionella sp.-containing bacterial mats from the environs of St. Petersburg and isotope composition of organic carbon, strontium, and neodymium from these mats have been determined. Isotope and microelement systematics of iron oxides of bacterial origin characterize the geochemistry of aquafacies that contain ferrobacteria. Certain pre-Cambrian ferruginous quartzites have a similar composition; therefore, one may assume that bacterial oxidation of iron under continental conditions had occurred upon the formation of ironstone during the Precambrian...
May 2017: Doklady Biological Sciences: Proceedings of the Academy of Sciences of the USSR, Biological Sciences Sections
https://www.readbyqxmd.com/read/28692927/coal-emissions-adverse-human-health-effects-associated-with-ultrafine-nano-particles-role-and-resultant-engineering-controls
#18
Marcos L S Oliveira, Orlando G Navarro, Tito J Crissien, Bernardo F Tutikian, Kátia da Boit, Elba C Teixeira, Juan J Cabello, Dayana M Agudelo-Castañeda, Luis F O Silva
There are multiple elements which enable coal geochemistry: (1) boiler and pollution control system design parameters, (2) temperature of flue gas at collection point, (3) feed coal and also other fuels like petroleum coke, tires and biomass geochemistry and (4) fuel feed particle size distribution homogeneity distribution, maintenance of pulverisers, etc. Even though there is a large number of hazardous element pollutants in the coal-processing industry, investigations on micrometer and nanometer-sized particles including their aqueous colloids formation reactions and their behaviour entering the environment are relatively few in numbers...
July 7, 2017: Environmental Research
https://www.readbyqxmd.com/read/28685707/lead-and-selenite-adsorption-at-water-goethite-interfaces-from-first-principles
#19
Kevin Leung, Louise J Criscenti
The complexation of toxic and/or radioactive ions on to mineral surfaces is an important topic in geochemistry. We apply periodic-boundary-conditions density functional theory (DFT) molecular dynamics simulations to examine the coordination of Pb(II), [Formula: see text], and their contact ion pairs to goethite (1 0 1) and (2 1 0) surfaces. The multitude of Pb(II) adsorption sites and possibility of Pb(II)-induced FeOH deprotonation make this a complex problem. At surface sites where Pb(II) is coordinated to three FeO and/or FeOH groups, and with judicious choices of FeOH surface group protonation states, the predicted Fe-Pb distances are in good agreement with EXAFS measurements...
September 13, 2017: Journal of Physics. Condensed Matter: An Institute of Physics Journal
https://www.readbyqxmd.com/read/28679119/biodegradable-plastic-bags-on-the-seafloor-a-future-threat-for-seagrass-meadows
#20
Elena Balestri, Virginia Menicagli, Flavia Vallerini, Claudio Lardicci
Marine plastic litter is a global concern. Carrier bags manufactured from non-biodegradable polymers constitute a large component of this litter. Because of their adverse impact on marine life, non-biodegradable bags have recently been replaced by biodegradable ones. However, growing evidence shows that these latter are not readily degradable in marine sediments and can alter benthic assemblages. The potential impact of biodegradable bags on seagrasses inhabiting sandy bottoms, which are the most widespread and productive ecosystems of the coastal zones, has been ignored...
July 2, 2017: Science of the Total Environment
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