scholarly journals Iron Isotopic Composition of Suspended Particulate Matter in Hongfeng Lake

Water ◽  
2019 ◽  
Vol 11 (2) ◽  
pp. 396 ◽  
Author(s):  
Xiaodi Zheng ◽  
Yanguo Teng ◽  
Liuting Song
Keyword(s):  
Linear Correlation ◽  
Lake Water ◽  
Isotope Composition ◽  
Suspended Particles ◽  
Important Influence ◽  
Iron Isotopes ◽  
Iron Isotope ◽  
Chl A ◽  
Suspended Particulate ◽  
Hongfeng Lake

The geochemical study of iron isotopes is of great significance to deeply understand the surface material circulation process and its environmental effects in surface and subsurface environments. Eutrophication lakes are an important part of the surface and subsurface environment; however, knowledge of the geochemical behavior and fractionation mechanism of iron isotopes in the biogeochemical cycling of eutrophication lakes is still scarce. In this study, a eutrophic lake with seasonal anaerobic characteristics (Hongfeng Lake) was selected as the study object to systematically analyze the iron isotope composition of suspended particles in lake water in different seasons as well as examining suspended particles in the main tributaries, sediments, pore water, planktonic algae, and other samples. The results show that the value of δ56Fe in Hongfeng Lake is between −0.85‰ and +0.14‰, and the value of δ56Fe has a high linear correlation with Fe/Al, indicating that the continental source material carried by the main inflow tributaries of the lake has an important influence on the source of iron in the lake. At the same time, Hongfeng lake is a medium eutrophication lake. Algal bloom and the content of chlorophyll a (Chl-a) is high, combined with the high correlation between Chl-a and the value of δ56Fe, which indicate that the growth of algae has an important influence on the change of iron isotope composition of suspended particles matter (SPM) in lake water and the adsorption and growth absorption of Fe by algae is the main reason for the change of the value of δ56Fe, so Fe isotope can be used to trace the lake’s biological action. For the lake and its inflow tributaries, δ56Fe values are higher in summer than those in winter. And the δ56Fe value of SPM in lake that varies with depth is more obvious in summer than in winter. In addition, there is an obvious thermocline in summer, which leads to hydrochemical stratification. Moreover, according to a linear correlation analysis, the content of DOC (dissolved organic matter) in Hongfeng Lake’s upper and lower waters, respectively, has a high correlation with the value of δ56Fe. Additionally, in the upper water, it is positively correlated, while on the bottom, there is a negative correlation relationship, which indicates that the difference in algae metabolism patterns between the upper and lower water bodies of Hongfeng Lake plays an important role in the iron isotope composition of suspended particulate matters (SPM). The composition of the Fe isotope in SPM is changed by organic adsorption and growth absorption of algae in upper water. With an increase in depth, the degradation process becomes the main one. In addition, the value of δ56Fe is low and Fe/Al is high in the water bottom, which indicates that “ferrous-wheel” cycle form at the bottom of the water.

scholarly journals Iron Isotope Composition of Adakitic Rocks: The Shangcheng Pluton, Western Dabie Orogen, Central China

Minerals ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 1356
Author(s):  
Chenglai Deng ◽  
Changqing Hu ◽  
Ming Li ◽  
Wu Li
Keyword(s):  
Isotopic Composition ◽  
Partial Melting ◽  
Isotope Composition ◽  
The Other ◽  
Central China ◽  
Iron Isotopes ◽  
Iron Isotope ◽  
Dabie Orogen ◽  
Adakitic Rocks ◽  
New Evidence

There has been little research on the metal isotopic composition of adakitic rock. The main objective of our investigation was to obtain more knowledge on the iron isotopic composition of adakitic rocks and provide new evidence for the genesis of Shangcheng pluton from an iron isotope perspective. The Dabie orogen is divided into eastern and western areas by the Shangcheng-Macheng fault, and the Shangcheng pluton is located in the western Dabie orogen area. The iron isotopic composition of these rocks ranges from 0.08‰ to 0.20‰ (2SD, n = 3). The δ56Fe values of two rocks from the SGD (Sigudun) unit are relatively low (0.11 ± 0.03‰ and 0.08 ± 0.04‰), while the δ56Fe values of the other samples are basically consistent (0.18–0.2‰). Evidence from elemental geochemical characteristics and petrogenesis defines the Shangcheng pluton as adakitic rocks. Our investigation on the elemental and isotopic compositions hints that the enrichment of heavy iron isotopes cannot be explained by weathering/alteration and fluid exsolution. Fractional crystallization of magnetite may account for the enrichment of light iron isotopes in two rocks from the SGD unit, while the fractional iron isotope trend in the other five samples can be explained by Δ56Fecrystal-melt = ~0.035‰. Two investigated rocks from SGD units may have been derived from the partial melting of amphibolite, while the other five samples may have been derived from the partial melting of eclogite containing 10–15% garnet.

scholarly journals Comment on “Origin of water in the Badain Jaran Desert, China: new insight from isotopes” by Wu et al. (2017)

2018 ◽  
Vol 22 (8) ◽  
pp. 4449-4454 ◽  
Author(s):  
Lucheng Zhan ◽  
Jiansheng Chen ◽  
Ling Li ◽  
David A. Barry
Keyword(s):  
Lake Water ◽  
Meteoric Water ◽  
Isotope Composition ◽  
Qilian Mountains ◽  
Precipitation Rate ◽  
Badain Jaran Desert ◽  
Isotopic Evidence ◽  
Isotope Data ◽  
Local Areas ◽  
The Qilian Mountains

Abstract. Precipitation isotope data were used to determine the origin of groundwater in the Badain Jaran Desert (BJD) in the study of Wu et al. (2017). Both precipitation and its isotope composition vary seasonally, so arithmetic averages of precipitation isotope values poorly represent the isotope composition of meteoric water. Their finding that the BJD groundwater is recharged by modern meteoric water from local areas including the southeastern adjacent mountains was based on arithmetic averaging. However, this conclusion is not supported by the corrected mean precipitation isotope values, which are weighted by the precipitation rate. Indeed, the available isotopic evidence shows that modern precipitation on the Qilian Mountains is more likely to be the main source of the groundwater and lake water in the BJD, as found by Chen et al. (2004).

Effects of Liming on the Distribution of Cadmium in Water, Sediment, and Organisms in a Swedish Lake

1988 ◽  
Vol 45 (7) ◽  
pp. 1154-1162 ◽  
Author(s):  
Paul Andersson ◽  
Hans Borg
Keyword(s):  
Lake Water ◽  
Cadmium Concentration ◽  
Northern Pike ◽  
Esox Lucius ◽  
Suspended Particles ◽  
Fish Liver ◽  
Free Swimming ◽  
Pike Esox Lucius ◽  
Insect Larva ◽  
Before And After

We studied the cadmium concentrations in water, sediment, suspended particles, a free-swimming insect larva (Chaoborus), a sediment-bound insect larva (Chironomus), and liver of northern pike (Esox lucius) before and after liming operations in Lake Långsjön, Sweden. In accordance with the higher pH levels obtained in the lake water after the limings, cadmium concentration decreased in the water but increased in the sediment. Cadmium concentration in fish liver and Chironomus decreased after the limings whereas the concentration in Chaoborus larvae increased after the first liming. Possible mechanisms are discussed.

scholarly journals Effects of Water Particles in the Jinjiang River Estuary on the Physiological and Biochemical Characteristics of Microcystit Flos-Aquae

2021 ◽  
Author(s):  
Yiting Nan ◽  
Peiyong Guo ◽  
Hui Xing ◽  
Sijia Chen ◽  
Bo Hu ◽  
...  
Keyword(s):  
Particle Size ◽  
Particulate Matter ◽  
Protein Content ◽  
Suspended Particulate Matter ◽  
Soluble Protein ◽  
Suspended Particles ◽  
Dose Effect ◽  
Soluble Protein Content ◽  
Sod Activity ◽  
Suspended Particulate

Abstract The effects of different concentrations (100,150,200,250 mg/L) and different particle sizes (0–75µm, 75–120µm, 120–150µm, 150–500µm) on soluble protein content, SOD and CAT activity, MDA content, chlorophyll a content and photosynthetic parameters of Microcystis flos-aquae were studied, the mechanism of the effect of suspended particulate matter on the physiology and biochemistry of Microcystis flos-aquae was discussed. The results showed that the soluble protein content of Microcystis flos-aquae did not change obviously after being stressed by suspended particles of different concentration/diameter. The SOD activity of Microcystis flos-aquae increased at first and then decreased with the increase of the concentration of suspended particulate matter. The SOD activity of Microcystis flos-aquae reached 28.03 U/mL when the concentration of suspended particulate matter was 100 mg/L. The CAT activity of Microcystis flos-aquae increased with the increase of the concentration of suspended particles, and reached the maximum value of 12.45 U/mgprot in the concentration group of 250 mg/L, showing a certain dose-effect. The effect of small particle size on SOD, CAT and MDA of Microcystis flos-aquae was more significant than that of large particle size. The larger the concentration and the smaller the particle size, the stronger the attenuation of light and the lower the content of chlorophyll a. Both Fv/Fm and Fv/F0 of Microcystis flos-aquae increased at first and then decreased under different concentration/size of suspended particles. The relative electron transfer rate gradually returned to the normal level with the passage of time. There was no significant difference in α value between treatment group and control group, ETRmax and Ik decreased.

scholarly journals Iron isotope evidence for very rapid accretion and differentiation of the proto-Earth

2020 ◽  
Vol 6 (7) ◽  
pp. eaay7604 ◽  
Author(s):  
Martin Schiller ◽  
Martin Bizzarro ◽  
Julien Siebert
Keyword(s):  
Solar System ◽  
Isotope Composition ◽  
Terrestrial Planets ◽  
Carbonaceous Chondrites ◽  
Iron Isotope ◽  
System Composition ◽  
Solar System Objects ◽  
History Of ◽  
Isotope Evidence ◽  
Enstatite Chondrites

Nucleosynthetic isotope variability among solar system objects provides insights into the accretion history of terrestrial planets. We report on the nucleosynthetic Fe isotope composition (μ54Fe) of various meteorites and show that the only material matching the terrestrial composition is CI (Ivuna-type) carbonaceous chondrites, which represent the bulk solar system composition. All other meteorites, including carbonaceous, ordinary, and enstatite chondrites, record excesses in μ54Fe. This observation is inconsistent with protracted growth of Earth by stochastic collisional accretion, which predicts a μ54Fe value reflecting a mixture of the various meteorite parent bodies. Instead, our results suggest a rapid accretion and differentiation of Earth during the ~5–million year disk lifetime, when the volatile-rich CI-like material is accreted to the proto-Sun via the inner disk.

scholarly journals Low Dose Coagulant and Local Soil Ballast Effectively Remove Cyanobacteria (Microcystis) from Tropical Lake Water without Cell Damage

Water ◽  
2021 ◽  
Vol 13 (2) ◽  
pp. 111
Author(s):  
Somjate Thongdam ◽  
Anthony C. Kuster ◽  
Brian J. Huser ◽  
Anootnara T. Kuster
Keyword(s):  
Zeta Potential ◽  
Lake Water ◽  
Cellular Structure ◽  
Lake Restoration ◽  
Low Dose ◽  
Morphological Changes ◽  
Cell Damage ◽  
Tropical Lake ◽  
Chl A ◽  
Local Soil

The combination of a low dose of coagulant with a ballast, also known as “flock and sink,” has been proposed as a lake restoration and cyanobacteria bloom management strategy. The effectiveness of this technique using aluminum sulfate (alum) as a coagulant and a local soil (LS) from Thailand as a ballast in eutrophic water dominated by positively buoyant Microcystis colonies collected from a tropical lake was investigated by measuring changes in chlorophyll-a (chl-a), pH, and zeta potential. Cell integrity was also evaluated using scanning electron microscopy. Results showed that alum alone could reduce chl-a (up to 60% to 83%) at doses (higher than 3 to 6 mg Al/L) dependent on the initial pH (7.6 to 8.2) and initial chl-a concentration (138 to 615 µg/L) of the lake water but resulted in morphological changes to cellular structure and generally required a dose that reduced pH to <7. LS ballast alone was able to reduce chl-a concentrations (up to 26% at highest dose of 400 mg/L) and caused no significant changes to pH or zeta potential. Combining a low dose of alum (2 mg Al/L) with some amount of LS ballast (50 to 400 mg/L) created an interaction effect that resulted in 81 to 88% reduction in chl-a without changes to zeta potential or morphological changes to cellular structure. Flock and sink may serve a niche role in lake restoration when positively buoyant cyanobacteria are present in the water column during time of treatment. This research showed that an 800% increase in ballast dose resulted in about an 8% reduction in chl-a when combined with 2 mg Al/L of alum. Therefore, it is recommended that ballast dose should be determined by considering its phosphorus sorption capacity and the potentially releasable phosphorus in the lake sediment in order to realize long-term reductions in sediment nutrient release.

Iron oxide mineralogy and stable iron isotope composition in a Gleysol with petrogleyic properties

2011 ◽  
Vol 12 (1) ◽  
pp. 97-114 ◽  
Author(s):  
Tim Mansfeldt ◽  
Stephan Schuth ◽  
Werner Häusler ◽  
Friedrich E. Wagner ◽  
Stephan Kaufhold ◽  
...  
Keyword(s):  
Iron Oxide ◽  
Isotope Composition ◽  
Iron Isotope

Sediment–Water Distribution Coefficients and Speciation of Cadmium in a Canadian Shield Lake

1994 ◽  
Vol 51 (9) ◽  
pp. 1951-1958 ◽  
Author(s):  
R. Wagemann ◽  
M. J. Capel ◽  
R. Hesslein ◽  
M. Stephenson
Keyword(s):  
Bottom Sediments ◽  
Water Distribution ◽  
Suspended Particles ◽  
Distribution Coefficients ◽  
Canadian Shield ◽  
Exponential Equation ◽  
Suspended Particulate ◽  
Dissolved Sulfide ◽  
Nonequilibrium Conditions ◽  
Calculated Fraction

Sediment–water distribution coefficients for Cd were strongly pH dependent at pH > 6.5 for three surficial bottom sediments and suspended particles from a Canadian Shield lake (Lake 382). A single exponential equation in terms of pH fitted the distribution coefficients of all sediments. In the range 6.5 ≤ pH ≤ 8 the distribution coefficients were 109 × 10−3 to 1579 × 10−3 L/mg for suspended particulate matter and 0.6 × 10−3 to 129 × 10−3 L/mg for the bottom sediments. Speciation calculations performed using the computer program MACS80 and measured Cd fractions associated with suspended particles agreed well down to 7 m. In deeper water the measured fraction exceeded the calculated fraction, hypothetically because of CdS formation, differing sediment compositions, or nonequilibrium conditions. In September, H2S was 100–300 μg/L in the lower hypolimnion. Even at only 5 μg dissolved sulfide/L, some of the added Cd would precipitate as CdS at pH > 6, and the dissolved Cd, under anoxic conditions, would be largely Cd(HS)+ and Cd(HS)2. Under aerobic conditions at pH ≥ 7.5, approximately 85% of the Cd was on suspended particles and complexed with dissolved organic matter. The solids Cd(OH)2, CdCO3, and Cd3(PO4)2 played no role in the control of dissolved Cd.

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