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https://www.readbyqxmd.com/read/29758887/arsenic-rich-shallow-groundwater-in-sandy-aquifer-systems-buffered-by-rising-carbonate-waters-a-geochemical-case-study-from-mannar-island-sri-lanka
#1
U G C Bandara, Saranga Diyabalanage, Christian Hanke, Robert van Geldern, Johannes A C Barth, Rohana Chandrajith
Major ion, trace elements, and stable isotope analyses were performed on groundwater samples collected from Mannar Island in the northern Indian Ocean. Arsenic concentrations up to 34μg/L have been observed in groundwater samples from the island. In addition, 23% of extensively used shallow drinking water wells showed higher arsenic contents than the recommended value by the World Health Organization (10μg/L). Groundwater in the island showed pH values between 6.9 and 8.9 and was dominated by Na+ , K+ , Ca2+ , Mg2+ , HCO3 - , Cl- and SO4 2- ...
August 15, 2018: Science of the Total Environment
https://www.readbyqxmd.com/read/29758429/microbial-ecology-of-two-hot-springs-of-sikkim-predominate-population-and-geochemistry
#2
Ishfaq Nabi Najar, Mingma Thundu Sherpa, Sayak Das, Saurav Das, Nagendra Thakur
Northeastern regions of India are known for their floral and faunal biodiversity. Especially the state of Sikkim lies in the eastern Himalayan ecological hotspot region. The state harbors many sulfur rich hot springs which have therapeutic and spiritual values. However, these hot springs are yet to be explored for their microbial ecology. The development of neo generation techniques such as metagenomics has provided an opportunity for inclusive study of microbial community of different environment. The present study describes the microbial diversity in two hot springs of Sikkim that is Polok and Borong with the assist of culture dependent and culture independent approaches...
May 11, 2018: Science of the Total Environment
https://www.readbyqxmd.com/read/29754092/influence-of-monsoonal-recharge-on-arsenic-and-dissolved-organic-matter-in-the-holocene-and-pleistocene-aquifers-of-the-bengal-basin
#3
Harshad V Kulkarni, Natalie Mladenov, Saugata Datta, Debashis Chatterjee
Arsenic (As) mobilization in the Bengal Basin aquifers has been studied for several decades due to the complex redox bio-geochemistry, dynamic hydrogeology and complex nature of dissolved organic matter (DOM). Earlier studies have examined the changes in groundwater As in the dry season before monsoon and during the wet season after monsoonal recharge. To investigate the more immediate influence of recharge during the active monsoon period on As mobilization and DOM character, groundwater samples were analyzed in the pre-monsoon and during the active monsoon period...
May 10, 2018: Science of the Total Environment
https://www.readbyqxmd.com/read/29737421/impacts-of-ultramafic-outcrops-in-peninsular-malaysia-and-sabah-on-soil-and-water-quality
#4
Mahsa Tashakor, Soroush Modabberi, Antony van der Ent, Guillaume Echevarria
This study focused on the influence of ultramafic terrains on soil and surface water environmental chemistry in Peninsular Malaysia and in the State of Sabah also in Malaysia. The sampling included 27 soils from four isolated outcrops at Cheroh, Bentong, Bukit Rokan, and Petasih from Peninsular Malaysia and sites near Ranau in Sabah. Water samples were also collected from rivers and subsurface waters interacting with the ultramafic bodies in these study sites. Physico-chemical parameters (including pH, EC, CEC) as well as the concentration of major and trace elements were measured in these soils and waters...
May 8, 2018: Environmental Monitoring and Assessment
https://www.readbyqxmd.com/read/29715677/radium-geochemical-monitoring-in-well-waters-at-regional-and-local-scales-an-environmental-impact-indicator-based-approach
#5
François Lagacé, Delphine Foucher, Céline Surette, Olivier Clarisse
To assess radium (226 Ra) as a potential indicator of impact in well waters, we investigated its behavior under natural conditions using a case study approach. 226 Ra geochemistry was investigated in 67 private wells of southeastern New Brunswick, Canada, a region targeted for potential shale gas exploitation. Objectives were to i) establish 226 Ra baseline in groundwater; ii) characterize 226 Ra spatial distribution and temporal variability; iii) characterize 226 Ra partitioning between dissolved phase and particulate forms in well waters; and iv) understand the mechanisms controlling 226 Ra mobility under natural environmental settings...
April 18, 2018: Chemosphere
https://www.readbyqxmd.com/read/29713821/marine-influenced-microbial-communities-inhabit-terrestrial-hot-springs-on-a-remote-island-volcano
#6
Lucy C Stewart, Valerie K Stucker, Matthew B Stott, Cornel E J de Ronde
Raoul Island is a subaerial island volcano approximately 1000 km northwest of New Zealand. Its caldera contains a circumneutral closed-basin volcanic lake and several associated pools, as well as intertidal coastal hot springs, all fed by a hydrothermal system sourced from both meteoric water and seawater. Here, we report on the geochemistry, prokaryotic community diversity, and cultivatable abundance of thermophilic microorganisms of four terrestrial features and one coastal feature on Raoul. Hydrothermal fluid contributions to the volcanic lake and pools make them brackish, and consequently support unusual microbial communities dominated by Planctomycetes, Chloroflexi, Alphaproteobacteria, and Thaumarchaeota, as well as up to 3% of the rare sister phylum to Cyanobacteria, Candidatus Melainabacteria...
April 30, 2018: Extremophiles: Life Under Extreme Conditions
https://www.readbyqxmd.com/read/29709807/metals-geochemistry-and-mass-export-from-the-mississippi-atchafalaya-river-system-to-the-northern-gulf-of-mexico
#7
Jeremy H Reiman, Y Jun Xu, Songjie He, Emily M DelDuco
Discharging 680 km3 of freshwater annually to the Northern Gulf of Mexico (NGOM), the Mississippi-Atchafalaya River System (MARS) plays a significant role in transporting major and trace elements to the ocean. In this study, we analyzed total recoverable concentrations of thirty-one metals from water samples collected at five locations along the MARS during 2013-2016 to quantify their seasonal mass exports. The Atchafalaya River flows through a large swamp floodplain, allowing us to also test the hypothesis that floodplains function as a sink for metals...
April 17, 2018: Chemosphere
https://www.readbyqxmd.com/read/29707438/geologic-and-anthropogenic-sources-of-contamination-in-settled-dust-of-a-historic-mining-port-city-in-northern-chile-health-risk-implications
#8
Joseline S Tapia, Jorge Valdés, Rodrigo Orrego, Andrei Tchernitchin, Cristina Dorador, Aliro Bolados, Chris Harrod
Chile is the leading producer of copper worldwide and its richest mineral deposits are found in the Antofagasta Region of northern Chile. Mining activities have significantly increased income and employment in the region; however, there has been little assessment of the resulting environmental impacts to residents. The port of Antofagasta, located 1,430 km north of Santiago, the capital of Chile, functioned as mineral stockpile until 1998 and has served as a copper concentrate stockpile since 2014. Samples were collected in 2014 and 2016 that show elevated concentrations of As, Cu, Pb, and Zn in street dust and in residents' blood (Pb) and urine (As) samples...
2018: PeerJ
https://www.readbyqxmd.com/read/29702326/geochemistry-and-carbon-isotopic-ratio-for-assessment-of-pm-10-composition-source-and-seasonal-trends-in-urban-environment
#9
A Di Palma, F Capozzi, D Agrelli, C Amalfitano, S Giordano, V Spagnuolo, P Adamo
Investigating the nature of PM10 is crucial to differentiate sources and their relative contributions. In this study we compared the levels, and the chemical and mineralogical properties of PM10 particles sampled in different seasons at monitoring stations representative of urban background, urban traffic and suburban traffic areas of Naples city. The aims were to relate the PM10 load and characteristics to the location of the monitoring stations, to investigate the different sources contributing to PM10 and to highlight PM10 seasonal variability...
April 24, 2018: Environmental Pollution
https://www.readbyqxmd.com/read/29701636/dynamic-geochemistry-of-tetraethyl-lead-dust-during-the-20th-century-getting-the-lead-in-out-and-translational-beyond
#10
Howard W Mielke
This commentary provides a brief overview of policy decisions that permitted getting tetraethyl lead (TEL) into petrol; global geochemical lead-dust deposition evidence; 1975 catalytic converter requirements; concern about habitability of cities; a personal perspective on legacy lead research that accelerated getting TEL out of petrol; and translational beyond, including New Orleans pre- vs. post-Hurricane Katrina observations about legacy lead interventions that effectively improve urban children’s health outcomes...
April 26, 2018: International Journal of Environmental Research and Public Health
https://www.readbyqxmd.com/read/29697181/abundance-and-taxonomic-affiliation-of-molybdenum-transport-and-utilization-genes-in-tengchong-hot-springs-china
#11
Shreya Srivastava, Brandon R Briggs, Hailiang Dong
The nitrogen, sulfur, and carbon cycles all rely on critical microbial transformations that are carried out by enzymes that require molybdenum (Mo) as a cofactor. Despite Mo importance in these biogeochemical cycles, little information exists about microbial Mo utilization in extreme environments where, due to geochemical conditions, bioavailable Mo may be limited. Using metagenomic data from 9 hot springs in Tengchong, Yunnan Province, China, which range in temperature from 42°C to 96°C and pH from 2.3 to 9, the effects of pH, temperature, and spring geochemistry on the abundance and taxonomic affiliation of genes related to Mo were studied...
April 26, 2018: Environmental Microbiology
https://www.readbyqxmd.com/read/29691066/uncertainty-and-variability-in-laboratory-derived-sorption-parameters-of-sediments-from-a-uranium-in-situ-recovery-site
#12
Martin A Dangelmayr, Paul W Reimus, Raymond H Johnson, James T Clay, James J Stone
This research assesses the ability of a GC SCM to simulate uranium transport under variable geochemical conditions typically encountered at uranium in-situ recovery (ISR) sites. Sediment was taken from a monitoring well at the SRH site at depths 192 and 193 m below ground and characterized by XRD, XRF, TOC, and BET. Duplicate column studies on the different sediment depths, were flushed with synthesized restoration waters at two different alkalinities (160 mg/l CaCO3 and 360 mg/l CaCO3 ) to study the effect of alkalinity on uranium mobility...
April 18, 2018: Journal of Contaminant Hydrology
https://www.readbyqxmd.com/read/29687545/seagrass-rhizosphere-microenvironment-alters-plant-associated-microbial-community-composition
#13
Kasper Elgetti Brodersen, Nachshon Siboni, Daniel A Nielsen, Mathieu Pernice, Peter J Ralph, Justin Seymour, Michael Kühl
The seagrass rhizosphere harbors dynamic microenvironments, where plant-driven gradients of O2 and dissolved organic carbon form microhabitats that select for distinct microbial communities. To examine how seagrass-mediated alterations of rhizosphere geochemistry affect microbial communities at the microscale level, we applied 16S rRNA amplicon sequencing of artificial sediments surrounding the meristematic tissues of the seagrass Zostera muelleri together with microsensor measurements of the chemical conditions at the basal leaf meristem (BLM)...
April 24, 2018: Environmental Microbiology
https://www.readbyqxmd.com/read/29666609/direct-and-indirect-effects-of-penguin-feces-on-microbiomes-in-antarctic-ornithogenic-soils
#14
Yudong Guo, Nengfei Wang, Gaoyang Li, Gabriela Rosas, Jiaye Zang, Yue Ma, Jie Liu, Wenbing Han, Huansheng Cao
Expansion of penguin activity in maritime Antarctica, under ice thaw, increases the chances of penguin feces affecting soil microbiomes. The detail of such effects begins to be revealed. By comparing soil geochemistry and microbiome composition inside (one site) and outside (three sites) of the rookery, we found significant effects of penguin feces on both. First, penguin feces change soil geochemistry, causing increased moisture content (MC) of ornithogenic soils and nutrients C, N, P, and Si in the rookery compared to non-rookery sites, but not pH...
2018: Frontiers in Microbiology
https://www.readbyqxmd.com/read/29651192/correlations-for-the-dielectric-constants-of-h-2-s-so-2-and-sf-6
#15
Allan H Harvey, Raymond D Mountain
A new method is developed for correlating the static dielectric constant of polar fluids over wide ranges of conditions where few experimental data exist. Molecular dynamics simulations are used to establish the temperature and density dependence of the Kirkwood g -factor, and also the functional form for the increase of the effective dipole moment with density. Most parameters in the model are obtained entirely from simulation; a single proportionality constant is adjusted to obtain agreement with the limited experimental data...
October 2017: International Journal of Thermophysics
https://www.readbyqxmd.com/read/29649763/fluoride-distribution-and-contamination-in-the-water-soil-and-plants-continuum-and-its-remedial-technologies-an-indian-perspective-a-review
#16
REVIEW
Gayatri Singh, Babita Kumari, Geetgovind Sinam, Kriti, Navin Kumar, Shekhar Mallick
Fluorine is an essential element required in trace amounts but gets toxic for human beings at levels more than 1.5 mg F- L-1 primarily through drinking contaminated water. It is the 13th most abundant element and constitutes about 0.06-0.09% in the earth crust. It is electronegative in aqueous medium forming fluoride ion (F- ). Fluoride contamination in the environment occurs mostly due to anthropogenic and geogenic sources. Fluoride is widely distributed in all components of environment, air (0.1-0.6 μg L-1 ) soils (150-400 mg Kg-1 ) rocks (100-2000 mg Kg-1 ), plant (0...
April 9, 2018: Environmental Pollution
https://www.readbyqxmd.com/read/29615512/-phytophthora-palmivora-establishes-tissue-specific-intracellular-infection-structures-in-the-earliest-divergent-land-plant-lineage
#17
Philip Carella, Anna Gogleva, Marta Tomaselli, Carolin Alfs, Sebastian Schornack
The expansion of plants onto land was a formative event that brought forth profound changes to the earth's geochemistry and biota. Filamentous eukaryotic microbes developed the ability to colonize plant tissues early during the evolution of land plants, as demonstrated by intimate, symbiosis-like associations in >400 million-year-old fossils. However, the degree to which filamentous microbes establish pathogenic interactions with early divergent land plants is unclear. Here, we demonstrate that the broad host-range oomycete pathogen Phytophthora palmivora colonizes liverworts, the earliest divergent land plant lineage...
April 3, 2018: Proceedings of the National Academy of Sciences of the United States of America
https://www.readbyqxmd.com/read/29603465/silica-metal-oxide-vesicles-catalyze-comprehensive-prebiotic-chemistry
#18
Bruno Mattia Bizzarri, Lorenzo Botta, Maritza Iveth Pérez-Valverde, Raffaele Saladino, Ernesto Di Mauro, Juan Manuel Garcia Ruiz
It has recently been demonstrated that mineral self-assembled structures catalyzing prebiotic chemical reactions may form in natural waters derived from serpentinization, a geological process widespread in the early stages of Earth-like planets. We have synthesized self-assembled membranes by mixing microdrops of metal solutions with alkaline silicate solutions in the presence of formamide (NH2CHO), a single carbon molecule, at 80ºC. We found that these bilayer membranes, made of amorphous silica and metal oxide-hydroxide nanocrystals, catalyze the condensation of formamide, yielding the four nucleobases of RNA, three aminoacids and several carboxylic acids in a single pot experiment...
March 30, 2018: Chemistry: a European Journal
https://www.readbyqxmd.com/read/29593680/diversity-and-contributions-to-nitrogen-cycling-and-carbon-fixation-of-soil-salinity-shaped-microbial-communities-in-tarim-basin
#19
Min Ren, Zhufeng Zhang, Xuelian Wang, Zhiwei Zhou, Dong Chen, Hui Zeng, Shumiao Zhao, Lingling Chen, Yuanliang Hu, Changyi Zhang, Yunxiang Liang, Qunxin She, Yi Zhang, Nan Peng
Arid and semi-arid regions comprise nearly one-fifth of the earth's terrestrial surface. However, the diversities and functions of their soil microbial communities are not well understood, despite microbial ecological importance in driving biogeochemical cycling. Here, we analyzed the geochemistry and microbial communities of the desert soils from Tarim Basin, northwestern China. Our geochemical data indicated half of these soils are saline. Metagenomic analysis showed that bacterial phylotypes (89.72% on average) dominated the community, with relatively small proportions of Archaea (7...
2018: Frontiers in Microbiology
https://www.readbyqxmd.com/read/29576671/first-identification-and-characterization-of-borrobol-type-tephra-in-the-greenland-ice-cores-new-deposits-and-improved-age-estimates
#20
Eliza Cook, Siwan M Davies, Esther R Guðmundsdóttir, Peter M Abbott, Nicholas J G Pearce
Contiguous sampling of ice spanning key intervals of the deglaciation from the Greenland ice cores of NGRIP, GRIP and NEEM has revealed three new silicic cryptotephra deposits that are geochemically similar to the well-known Borrobol Tephra (BT). The BT is complex and confounded by the younger closely timed and compositionally similar Penifiler Tephra (PT). Two of the deposits found in the ice are in Greenland Interstadial 1e (GI-1e) and an older deposit is found in Greenland Stadial 2.1 (GS-2.1). Until now, the BT was confined to GI-1-equivalent lacustrine sequences in the British Isles, Sweden and Germany, and our discovery in Greenland ice extends its distribution and geochemical composition...
February 2018: Journal of Quaternary Science
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