scholarly journals Geochemical Features of Redox-Sensitive Trace Metals in Sediments under Oxygen-Depleted Marine Environments

Minerals ◽  
2020 ◽  
Vol 10 (11) ◽  
pp. 1021
Author(s):  
Moei Yano ◽  
Kazutaka Yasukawa ◽  
Kentaro Nakamura ◽  
Minoru Ikehara ◽  
Yasuhiro Kato
Keyword(s):  
Sedimentary Environment ◽  
Organic Matter Content ◽  
Oxygen Depletion ◽  
Major And Trace Elements ◽  
Matter Content ◽  
Open Ocean ◽  
Chemical Compositions ◽  
Marine Environments ◽  
High Productivity ◽  
Sedimentary Environments

Organic- and sulfide-rich sediments have formed in oxygen-depleted environments throughout Earth’s history. The fact that they are generally enriched in redox-sensitive elements reflects the sedimentary environment at the time of deposition. Although the modern ocean is well oxidized, oxygen depletion occurs in certain areas such as restricted basins and high-productivity zones. We measured bulk chemical compositions (major and trace elements, total organic carbon, and total sulfur) of organic- and sulfide-rich sediments collected from eight areas having oxygen-depleted water to discuss relationships between geochemical features and sedimentary environments. Major elemental compositions generally show mixtures of terrigenous detritus and biogenic carbonate. Some redox-sensitive elements might be controlled by organic matter content, whereas others could be contained in sulfide minerals in sediments. In particular, Mo and U show a characteristic trend; areas with higher Mo and U—at least partially owing to a depositional process called the “particulate shuttle”—generally correspond to regions influenced by the open ocean. In contrast, areas with lower Mo and U are more restricted marine environments. This suggests that the degree of Mo and U enrichment reflects the geography in terms of proximity to the open ocean, or the degree of the supply of these elements from the open ocean.

scholarly journals The Relationship between Mollusks and Oxygen Concentrations in Todos Santos Bay, Baja California, Mexico

2016 ◽  
Vol 2016 ◽  
pp. 1-10 ◽  
Author(s):  
J. Gabriel Kuk-Dzul ◽  
Victoria Díaz-Castañeda
Keyword(s):  
Organic Matter ◽  
Dissolved Oxygen ◽  
Bottom Water ◽  
Organic Matter Content ◽  
Oxygen Depletion ◽  
Matter Content ◽  
The Other ◽  
Natural Conditions ◽  
The Relationship ◽  
Oxygen Concentrations

This study describes the relationship between mollusks, physicochemical properties of seawater, and sediments under natural conditions of low impact. Thirty-nine stations were sampled in October 1994 using a Van Veen grab (0.1 m−2). Temperature, salinity, and dissolved oxygen (DO) concentrations of bottom water were obtained with a CTD. Organic matter content and sediment grain analysis were determined. A total of 836 mollusks were collected. Gastropoda was the most abundant (52%) and diverse class with 27 genera, followed by Bivalvia with eight genera and Scaphopoda with only one genus. According to CCA analysis, dominant mollusks were significantly related with high DO concentrations.Donax,Natica,Acteocina,Bulla,Anachis,Odostomia, andCrucibulumcan be classified as sensitive genera because they were found mainly in high oxygen concentrations (3.1–5.6 mL L−1); on the other hand,Cardiomya,Nuculana,Laevicardium,Chione,Truncatella, andDentaliumcan be classified as tolerant genera (1.0–5.6 mL L−1). Todos Santos Bay hosts a diverse malacological fauna (36 genera); our results show that the dominant genera were mainly related to high dissolved oxygen concentrations. Mollusks can be a useful tool in environmental monitoring programs related with oxygen depletion in coastal areas.

scholarly journals Vliv sedimentačního prostředí na magnetickou susceptibilitu přelivových sedimentů nivy Moravy ve Strážnickém Pomoraví

2020 ◽  
Vol 27 (1-2) ◽  
Author(s):  
Jaroslava Ježková ◽  
Zdeněk Máčka
Keyword(s):  
Magnetic Particles ◽  
Organic Matter Content ◽  
Matter Content ◽  
River Channel ◽  
Oxbow Lake ◽  
Magnetic Signal ◽  
Sedimentary Environments ◽  
Direct Dependence ◽  
19Th And 20Th Century ◽  
Floodplain Sediments

Four profiles in different sedimentary environments - natural levee, proximal floodplain, distal floodplain, oxbow lake - were sampled to obtain magnetic susceptibility (MS), grain size, organic matter content (LOI) and pH. Relationships between selected parameters (χlf, D50, LOI, pH) were analysed by means of statistical analysis (linear regression, PCA, factor analysis). Principal goal was to investigate how character of individual sedimentary environments and their distance from the active river channel is reflected in the magnetic signal of overbank deposits. A decrease in the magnetic signal with increasing distance from the river channel was shown, confirming that fluvial deposition is a major factor of contamination of floodplain sediments by anthropogenic magnetic particles. The base of elevated values of MS (levee: 80 cm, proximal floodplain: 30 cm) probably corresponds to the turn of the 19th and 20th century and the strongest magnetic signal (levee: 32,5 cm, proximal floodplain: 5 cm) belongs to the 1980s. Statistically significant relationships were found between: χlf and LOI (direct dependence), LOI and D50 (indirect dependence), pH and D50 (direct dependence) when data from all profiles were analysed together.

scholarly journals Post-depositional evolution over a time scale of 1 million years of eastern Mediterranean organic-rich and organic-poor sediments: new insights on the debromination and layer-silicate markers

2017 ◽  
Vol 188 (4) ◽  
pp. 21 ◽  
Author(s):  
Anne Murat ◽  
Daniel Beaufort ◽  
Benoît Hébert ◽  
François Baudin ◽  
Stefano Michele Bernasconi ◽  
...  
Keyword(s):  
Organic Matter ◽  
Clay Minerals ◽  
Manganese Oxides ◽  
Eastern Mediterranean ◽  
Organic Matter Content ◽  
Matter Content ◽  
Core Material ◽  
Physical Parameters ◽  
Chemical Compositions ◽  
Burial Depth

Organic matter degradation is the engine behind the biogeochemical evolution of sediments during burial. Previous research has shown that eogenesis is the seat of a complex interplay between organic matter, microbes and the most reactive part of inorganic compounds, such as clay minerals. To explore the variability and stability of bromine and clay minerals as geochemical and mineral tracers, we selected an eastern Mediterranean core that has a high degree of stability in the quality and quantity of organic matter through time at a one-million-year scale and great variability in organic matter content at a 10 ky scale. According to the very low maximal burial depth reached by these sediments (the core length is only 36.5 m), physical parameters, such as temperature and pressure, did not significantly influence the evolution of the studied parameters during the burial history. The bulk clay mineralogy of organic-rich and organic-poor sediments is similar all along the investigated core material; smectite predominates over kaolinite. The only identified authigenic minerals are biogenetic framboidal pyrite and manganese oxides. The X-ray data and the chemical compositions of the smectite are characteristic of a montmorillonite which is representative of a detrital Nile source. At a one-million-year scale, the organic matter content has no significant influence on clay eogenesis, and detrital smectite and kaolinite remain unchanged. Bromine is present in marine organic matter as organobromine compounds. During eogenesis, bromine is released from organic matter as bromide ion, resulting in an increase in the bromide concentration in the pore water with depth. Dissolved bromide can be used as a conservative tracer of the debromination of sedimentary organic matter. For the first time, we established that solid-phase BrOrg is a reliable tracer of debromination rates in marine sediments. The rate of debromination depends on the organic matter content. The rate increases from less than 2.3 × 10−4 μmolBrOrg mol.C−1.y−1 to 6.3 × 10−4 μmolBrOrg mol.C−1.y−1 when TOC varies from 0.17 to 3%. This increase is related to the development of the bacterial population and provides the basis for further investigation of other oceanic basins. For TOC values  >4%, the rate of debromination decreases. We propose that the bioavailability of organic matter is another factor of variability in the debromination rate.

HEAVY METAL SPECIATION IN BOTTOM SEDIMENTS OF THE VYSHNEVOLOTSKY RESERVOIR

2018 ◽  
pp. 46-54
Author(s):  
O. A. Lipatnikova
Keyword(s):  
Heavy Metal ◽  
Organic Matter ◽  
Bottom Sediments ◽  
Metal Speciation ◽  
Organic Matter Content ◽  
Water Reservoir ◽  
Matter Content ◽  
Heavy Metal Speciation ◽  
Mobile Forms ◽  
Manganese Hydroxides

The study of heavy metal speciation in bottom sediments of the Vyshnevolotsky water reservoir is presented in this paper. Sequential selective procedure was used to determine the heavy metal speciation in bottom sediments and thermodynamic calculation — to determine ones in interstitial water. It has been shown that Mn are mainly presented in exchangeable and carbonate forms; for Fe, Zn, Pb и Co the forms are related to iron and manganese hydroxides is played an important role; and Cu and Ni are mainly associated with organic matter. In interstitial waters the main forms of heavy metal speciation are free ions for Zn, Ni, Co and Cd, carbonate complexes for Pb, fulvate complexes for Cu. Effects of particle size and organic matter content in sediments on distribution of mobile and potentially mobile forms of toxic elements have been revealed.

Physico-Chemical Properties of Soil Collected from Chandrabhaga River in Kalmeshwar, Nagpur, Maharashtra

2020 ◽  
Vol 07 (02) ◽  
pp. 1-3
Author(s):  
Amita M Watkar ◽  
Keyword(s):  
Organic Matter ◽  
Soil Quality ◽  
Agricultural Land ◽  
Organic Matter Content ◽  
Chemical Properties ◽  
Matter Content ◽  
Soil Attributes ◽  
Essential Components ◽  
Agricultural Land Management ◽  
Physical And Chemical

Soil, itself means Soul of Infinite Life. Soil is the naturally occurring unconsolidated or loose covering on the earth’s surface. Physical properties depend upon the amount, size, shape, arrangement, and mineral composition of soil particles. It also depends on the organic matter content and pore spaces. Chemical properties depend on the Inorganic and organic matter present in the soil. Soils are the essential components of the environment and foundation resources for nearly all types of land use, besides being the most important component of sustainable agriculture. Therefore, assessment of soil quality and its direction of change with time is an ideal and primary indicator of sustainable agricultural land management. Soil quality indicators refer to measurable soil attributes that influence the capacity of a soil to function, within the limits imposed by the ecosystem, to preserve biological productivity and environmental quality and promote plant, animal and human health. The present study is to assess these soil attributes such as physical and chemical properties season-wise.

UPAYA MEMPERTAHANKAN BUNGA DAN FRUIT SET TANAMAN CABAI (Capsicum annum L.) PADA LAHAN ULTISOL MELALUI PEMBERIAN LUMPUR LAUT DAN PUPUK KANDANG

2017 ◽  
Vol 13 (2) ◽  
pp. 74-77
Author(s):  
Imelda J Lawalatta ◽  
Francina Matulessy ◽  
Meitty L Hehanussa
Keyword(s):  
Fruit Set ◽  
Agricultural Land ◽  
Mineral Soil ◽  
Organic Matter Content ◽  
Nutrient Deficiency ◽  
Matter Content ◽  
Infrastructure Development ◽  
Capsicum Annum ◽  
Factor Effect ◽  
Marine Mud

Chili (Capsicum annum L.) often experience the highest price fluctuations in Indonesia. This is caused by the production that is often disrupted in certain months, especially in the months in the rainy season due to flowers and fruits that fall before the harvest. Since agricultural land has changed its function for infrastructure development, marginal land (Ultisol) is used. The ultisol problem is: high acidity, low organic matter content, nutrient deficiency important for plants (eg N, P, Ca, Mg and Mo) and high solubility of Al, Fe and Mn. The provision of organic materials such as manure and marine mud will overcome the problem of acid-rich mineral soil and play an important role in improving, increased and maintaining sustainable land productivity. Research results for chili flower significantly. the highest number of flowers found in the treatment of L0P3, L1P2, L1P3 and L2P3 that is > 60 flower/plant. There was a single factor effect for the amount of fruit, mostly found in L3 treatment (600 ton/ha marine mud) that is 22.36 fruit/plant. The treatment of manure significantly influenced the formation of the most fruit set in the treatment of P0 and P2 (without manure and manure 20 ton/ha) that is 77.60% and 70.,45%. Keywords: Ultisol, Marine mud, Manure, Flowers and Fruit sets   ABSTRAK Tanaman cabai besar (Capsicum annum L.) sering mengalami fluktuasi harga paling tinggi di Indonesia. Hal tersebut disebabkan oleh produksi yang sering terganggu pada bulan tertentu terutama pada bulan-bulan di musim penghujan dikarenakan bunga dan buah yang rontok sebelum panen. Karena lahan pertanian banyak beralih fungsinya untuk pembangunan infrastuktur, maka digunakan lahan marginal (Ultisol). Masalah ultisol ialah: kemasaman tinggi, kadar bahan organik yang rendah, kekurangan unsur hara penting bagi tanaman (contoh: N, P, Ca, Mg dan Mo) serta tingginya kelarutan Al, Fe dan Mn. Pemberian bahan organik seperti pupuk kandang dan Lumpur laut akan mengatasi persoalan tanah mineral masam berkadar Al tinggi dan berperan penting dalam memperbaiki, meningkatkan serta mempertahankan produktifitas lahan secara berkelanjutan Hasil Penelitian untuk jumlah bunga cabai berpengaruh signifikan. jumlah bunga terbanyak terdapat pada perlakuan L0P3, L1P2, L1P3 dan L2P3 yaitu > 60 bunga/tanaman. Terjadi pengaruh faktor tunggal untuk jumlah buah, terbanyak terdapat pada perlakuan L3 ( 600 ton/ha lumpur laut) yaitu 22,36 buah/tanaman. Perlakuan pupuk kandang berpengaruh signifikan Pembentukan fruit set terbanyak pada perlakuan P0 dan P2 (tanpa pupuk kandang dan pupuk kandang 20 ton/ha) yaitu 77,60% dan 70,45%. Kata kunci: Ultisol, Lumpur Laut, Pupuk Kandang, Bunga dan Fruit set

scholarly journals Soil nitrogen supply of peat grasslands estimated by degree days and soil organic matter content

2020 ◽  
Vol 117 (3) ◽  
pp. 351-365
Author(s):  
J. Pijlman ◽  
G. Holshof ◽  
W. van den Berg ◽  
G. H. Ros ◽  
J. W. Erisman ◽  
...  
Keyword(s):  
Organic Matter ◽  
Soil Organic Matter ◽  
Soil Nitrogen ◽  
Organic Matter Content ◽  
Matter Content ◽  
Nitrogen Supply ◽  
Degree Days ◽  
Soil Organic Matter Content ◽  
Soil Nitrogen Supply

scholarly journals Microbial Respiration and Enzyme Activity Downstream from a Phosphorus Source in the Everglades, Florida, USA

Land ◽  
2021 ◽  
Vol 10 (7) ◽  
pp. 696
Author(s):  
Sanku Dattamudi ◽  
Saoli Chanda ◽  
Leonard J. Scinto
Keyword(s):  
Nutrient Dynamics ◽  
Microbial Respiration ◽  
Organic Matter Content ◽  
Physicochemical Analysis ◽  
Matter Content ◽  
Enzyme Assays ◽  
Co2 Efflux ◽  
Soil Organic Matter Content ◽  
Phosphorus Source ◽  
P Distribution

Northeast Shark River Slough (NESS), lying at the northeastern perimeter of Everglades National Park (ENP), Florida, USA, has been subjected to years of hydrologic modifications. Construction of the Tamiami Trail (US 41) in 1928 connected the east and west coasts of SE Florida and essentially created a hydrological barrier to southern sheet flow into ENP. Recently, a series of bridges were constructed to elevate a portion of Tamiami Trail, allow more water to flow under the bridges, and attempt to restore the ecological balance in the NESS and ENP. This project was conducted to determine aspects of soil physiochemistry and microbial dynamics in the NESS. We evaluated microbial respiration and enzyme assays as indicators of nutrient dynamics in NESS soils. Soil cores were collected from sites at certain distances from the inflow (near canal, NC (0–150 m); midway, M (150–600 m); and far from canal, FC (600–1200 m)). Soil slurries were incubated and assayed for CO2 emission and β-glucoside (MUFC) or phosphatase (MUFP) activity in concert with physicochemical analysis. Significantly higher TP contents at NC (2.45 times) and M (1.52 times) sites than FC sites indicated an uneven P distribution downstream from the source canal. The highest soil organic matter content (84%) contents were observed at M sites, which was due to higher vegetation biomass observed at those sites. Consequently, CO2 efflux was greater at M sites (average 2.72 µmoles g dw−1 h−1) than the other two sites. We also found that amendments of glucose increased CO2 efflux from all soils, whereas the addition of phosphorus did not. The results indicate that microbial respiration downstream of inflows in the NESS is not limited by P, but more so by the availability of labile C.

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