scholarly journals Emerging investigator series: geochemistry of trace elements associated with Fe and Mn nodules in the sediment of limed boreal lakes

2018 ◽  
Vol 20 (2) ◽  
pp. 406-414 ◽  
Author(s):  
Raoul-Marie Couture ◽  
Atle Hindar ◽  
Sigurd Rognerud
Keyword(s):  
Trace Elements ◽  
Boreal Lakes ◽  
Water Interface ◽  
Fe And Mn ◽  
Acidified Lakes

We report on the geochemical legacy of the liming of acidified lakes in Norway. We document the occurrence of Fe–Mn nodules and the diagenetic redistribution of trace-elements at the sediment–water interface of limed boreal lakes.

scholarly journals The effects of zinc deficiency on homeostasis of twelve minerals and trace elements in the serum, feces, urine and liver of rats

2019 ◽  
Vol 16 (1) ◽  
Author(s):  
Qingli Yu ◽  
Xiaohan Sun ◽  
Jiali Zhao ◽  
Lan Zhao ◽  
Yanfeng Chen ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Trace Elements ◽  
Zinc Deficiency ◽  
Inductively Coupled Plasma ◽  
The Body ◽  
Renal Reabsorption ◽  
Inductively Coupled ◽  
Fe And Mn ◽  
Plasma Mass Spectrometry ◽  
Minerals And Trace Elements

Abstract Background Zinc deficiency can change the concentrations of minerals and trace elements in the body. However, previous studies still had many limitations. Objective To reveal the effects of zinc deficiency on homeostasis of 16 minerals and trace elements. Methods Forty-five rats were divided randomly into three groups: normal zinc diet (30 mg/kg), low zinc diet (10 mg/kg), and pair-fed diet(30 mg/kg). The concentrations of 16 minerals and trace elements in serum, feces, urine, and liver were measured by inductively coupled plasma mass spectrometry. The excretion of 16 elements in urine and feces were calculated and compared. Results Zinc-deficient rats exhibited significant changes in up to 12 minerals and trace elements. The low zinc diet induced decreased excretion of zinc and concentrations of zinc in serum, feces, urine, and liver. Zinc deficiency increased feces concentrations of Mg, Cu, Se, K, Ag, Fe and Mn; decreased the concentrations of Mg, Cu, Se, K in liver and urine, and a diminished amount of Ag was observed in serum. Decreased urinary concentrations of Zn Ca, Mg, Cu, Se, K, Na, As and Cr, suggested that zinc-deficient rats increased the 9 elements’ renal reabsorption. Decreased concentrations of Ca in liver, urine, and feces, decreased excretion in urine and feces and increased serum total Ca suggested that zinc deficiency increased the redistribution of Ca in serum or other tissues. Zinc deficiency increased excretion of Cu, Se, Fe; and decreased the excretion of other 8 elements except for Ag. Conclusions Zinc deficiency changed the excretion, reabsorption and redistribution of 12 minerals and trace elements in rats. Our findings are the first to show that zinc deficiency alters the concentrations of Ag, Cr, and As. Graphical abstract

scholarly journals Organic matter mineralization and trace element post-depositional redistribution in Western Siberia thermokarst lake sediments

2011 ◽  
Vol 8 (11) ◽  
pp. 3341-3358 ◽  
Author(s):  
S. Audry ◽  
O. S. Pokrovsky ◽  
L. S. Shirokova ◽  
S. N. Kirpotin ◽  
B. Dupré
Keyword(s):  
Trace Elements ◽  
Organic Matter ◽  
Organic Carbon ◽  
Lake Sediments ◽  
Water Column ◽  
Western Siberia ◽  
Ecosystem Development ◽  
Thermokarst Lake ◽  
Fe And Mn ◽  
The Impact

Abstract. This study reports the very first results on high-resolution sampling of sediments and their porewaters from three thermokarst (thaw) lakes representing different stages of ecosystem development located within the Nadym-Pur interfluve of the Western Siberia plain. Up to present time, the lake sediments of this and other permafrost-affected regions remain unexplored regarding their biogeochemical behavior. The aim of this study was to (i) document the early diagenesic processes in order to assess their impact on the organic carbon stored in the underlying permafrost, and (ii) characterize the post-depositional redistribution of trace elements and their impact on the water column. The estimated organic carbon (OC) stock in thermokarst lake sediments of 14 ± 2 kg m−2 is low compared to that reported for peat soils from the same region and denotes intense organic matter (OM) mineralization. Mineralization of OM in the thermokarst lake sediments proceeds under anoxic conditions in all the three lakes. In the course of the lake development, a shift in mineralization pathways from nitrate and sulfate to Fe- and Mn-oxyhydroxides as the main terminal electron acceptors in the early diagenetic reactions was suggested. This shift was likely promoted by the diagenetic consumption of nitrate and sulfate and their gradual depletion in the water column due to progressively decreasing frozen peat lixiviation occurring at the lake's borders. Trace elements were mobilized from host phases (OM and Fe- and Mn-oxyhydroxides) and partly sequestered in the sediment in the form of authigenic Fe-sulfides. Arsenic and Sb cycling was also closely linked to that of OM and Fe- and Mn-oxyhydroxides. Shallow diagenetic enrichment of particulate Sb was observed in the less mature stages. As a result of authigenic sulfide precipitation, the sediments of the early stage of ecosystem development were a sink for water column Cu, Zn, Cd, Pb and Sb. In contrast, at all stages of ecosystem development, the sediments were a source of dissolved Co, Ni and As to the water column. However, the concentrations of these trace elements remained low in the bottom waters, indicating that sorption processes on Fe-bounding particles and/or large-size organo-mineral colloids could mitigate the impact of post-depositional redistribution of toxic elements on the water column.

scholarly journals Geochemical conditions conducive for retention of trace elements and radionuclides during shale–fluid interactions

2019 ◽  
Vol 21 (10) ◽  
pp. 1764-1776
Author(s):  
Neha Mehta ◽  
Benjamin D. Kocar
Keyword(s):  
Trace Elements ◽  
Produced Water ◽  
Water Interface ◽  
Geochemical Conditions ◽  
Fluid Interactions

Geochemical interactions occurring at the shale–water interface resulting in mobilization and retardation of solutes to produced water.

scholarly journals Mobility and fluxes of trace elements and nutrients at the sediment–water interface of a lagoon under contrasting water column oxygenation conditions

2013 ◽  
Vol 31 ◽  
pp. 35-51 ◽  
Author(s):  
Sylvain Rigaud ◽  
Olivier Radakovitch ◽  
Raoul-Marie Couture ◽  
Bruno Deflandre ◽  
Daniel Cossa ◽  
...  
Keyword(s):  
Trace Elements ◽  
Water Column ◽  
Water Interface

scholarly journals Spectrophotometric Quantification of Trace Elements and Toxic Metals in Raw Milk Samples of Peshawar City, Pakistan

2021 ◽  
Vol 12 (1) ◽  
pp. 53-59
Author(s):  
Nadir Khan ◽  
Rizwan Ullah ◽  
Fazal Wahid ◽  
Qamar Sultana ◽  
Muhammad Rahim
Keyword(s):  
Trace Elements ◽  
Freezing Point ◽  
Physicochemical Characterization ◽  
Raw Milk ◽  
Average Concentration ◽  
Toxic Heavy Metals ◽  
Average Percentage ◽  
Milk Samples ◽  
Permissible Limits ◽  
Fe And Mn

The present study focused on the physicochemical characterization and spectrophotometric determination of the concentrations of trace elements (Zn, Cu, Fe and Mn) and toxic heavy metals (Cd and Pb) in raw milk samples collected from various commercial sites of Peshawar city, Pakistan. Evaluation of the nutritional values as well as the possible health concerns associated with the consumption of contaminated milk shown the average percentage composition of protein, fats, solid non-fats, lactose, salts and added water in the milk sample as 2.78, 4.81, 6.41, 3.05, 0.47 and 31.1 %, respectively. The values of pH, conductivity, density and freezing point were observed as 6.59, 3.51 mS/cm, 1.04 g/mL and -0.3674 ºC at 26 ºC. The physicochemical characteristics such as percentage protein, fat, lactose, salts, water, solid not fat, total solids, pH, conductivity and density were evaluated and found in the safe limits of the WHO/FAO. The average concentration of trace elements such as zinc and copper were found to be 1.4035 mg/L and 0.2588 mg/L, respectively. The concentration of Zn and Cu was found within permissible limits suggested by WHO. However, the average concentration of Fe, Mn, Cd and Pb were found higher than the permissible limits of WHO. The observed concentrations were: Fe = 1.5553, Mn = 0.4354, Cd = 0.1865 and Pb = 1.1162 mg/L. The presence of the non-essential and hazardous Cd and Pb in milk samples even in lower concentrations may cause severe health problems since these are the most noxious pollutants due to their non-biodegradable and bio-accumulative nature. Over-dose of Fe and Mn also leads to several health issues. A thorough and more precise investigation of raw milk consumption in Peshawar is highly recommended to ascertain the actual reasons and sources in the larger public interests.

Relative mobility of radioactive trace elements across the sediment-water interface in the MERL model ecosystems of Narragansett Bay

1987 ◽  
Vol 45 (4) ◽  
pp. 1007-1048 ◽  
Author(s):  
Peter H. Santschi ◽  
Michael Amdurer ◽  
Dennis Adler ◽  
Patricia O'Hara ◽  
Yuan-Hui Li ◽  
...  
Keyword(s):  
Trace Elements ◽  
Narragansett Bay ◽  
Water Interface ◽  
Relative Mobility ◽  
Model Ecosystems ◽  
Radioactive Trace

scholarly journals Whole-lake algal responses to a century of acidic industrial deposition on the Canadian Shield

2002 ◽  
Vol 59 (3) ◽  
pp. 483-493 ◽  
Author(s):  
Rolf D Vinebrooke ◽  
Sushil S Dixit ◽  
Mark D Graham ◽  
John M Gunn ◽  
Yu-Wei Chen ◽  
...  
Keyword(s):  
Community Structure ◽  
Light Availability ◽  
Boreal Lakes ◽  
Environmental Stressors ◽  
Algal Community ◽  
Sedimentary Pigments ◽  
Metal Levels ◽  
Lake Acidity ◽  
Algal Abundance ◽  
Acidified Lakes

A century of cultural acidification is hypothesized to have altered algal community structure in boreal lakes. To date, this hypothesis has remained untested because of both the lack of data predating the onset of industrial pollution and incomplete estimates of whole-lake algal community structure. High-pressure liquid chromatography (HPLC) of sedimentary pigments was used to quantify whole-lake algal responses to acid deposition in six boreal lakes located in Killarney Park, Ontario, Canada. Concomitant significant increases in chlorophyll and carotenoid concentrations, diatom-inferred lake acidity, and metal levels since 1900 suggested that algal abundances in four acidified lakes and one small, circumneutral lake were enhanced by aerial pollution. An alternate explanation is that increased acidity and underwater light availability in the acidified lakes shifted algal abundance towards phytobenthos and deepwater phytoplankton, whose pigment signatures were better preserved in the sediments. Taxonomically diagnostic pigment stratigraphies were consistent with shifts in algal community structure towards filamentous green phytobenthos and deepwater phytoflagellates in the acidified lakes. Our findings suggest that decades of aerial pollution have altered the base of foodwebs in boreal lakes, potentially rendering them less resilient to other environmental stressors.

scholarly journals Impacts of Possible CO2 Seepage from Sub-Seabed Storage on Trace Elements Mobility and Bacterial Distribution at Sediment-Water Interface

2012 ◽  
Vol 23 ◽  
pp. 449-461 ◽  
Author(s):  
Murat V. Ardelan ◽  
Kathrine Sundeng ◽  
Gøril A. Slinde ◽  
Nina S. Gjøsund ◽  
Trond Nordtug ◽  
...  
Keyword(s):  
Trace Elements ◽  
Water Interface
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