Sedimentation Analysis Research Articles

Dispersion stabilization of carbonyl iron particles and its applications in chemical mechanical planarization

A novel aqueous magnetorheological (MR) slurry is proposed for potential application in the planarization of dielectric substrates, eliminating the need for traditional polishing pads. The preparation of a stable MR slurry hinges on the dispersion properties of abrasives and magnetic responsive particles, particularly high-density carbonyl iron particles (CIP). This study focuses on investigating the dispersion stabilities of CIP and its modified form, SiO2-coated CIP (SiO2@CIP), with the addition of ammonium polyacrylic acid (PAA-NH4) as a dispersant. Experimental measurements, including adsorption isotherms and zeta potential, combined with numerical simulations using density-functional theory, explore the adsorption behavior of PAA-NH4 on CIP and SiO2@CIP. Rheological and sedimentation analyses confirm PAA-NH4’s effectiveness in dispersing both particles. We elucidate the dispersion stabilization mechanism through calculations based on the Derjaguin−Landau−Verwey−Overbeek theory. In MR polishing, SiO2 coating on CIP improves efficiency, reducing surface roughness from over 8 nm (using CIP) to less than 8 Å (using SiO2@CIP). The addition of PAA-NH4 augments dispersion properties, leading to further enhancements in polishing efficiency, resulting in a surface roughness reduction to 2 Å and a simultaneous increase in material removal rate. We thoroughly examine the underlying factors driving these improvements.

Beavers Have Engineered Ecosystems in the Tetons for Millennia

Analysis of lake sediment in Grand Teton National Park is helping piece together ecosystem history, with helpful implications for land managers today.

Identification of Playa Lakes and tracking their evolution pathways using geochemical models in the Great Indian Thar desert

Playa Lakes of the great Indian Thar desert are unique and intricate systems with pronounced scientific and ecological significance. In this study, the combined use of geospatial and field data assisted in depicting and understanding the changes within these natural systems. The purpose of this study is to provide a comprehensive dataset of Playa Lakes, which can help with an overall understanding of playas from a geochemical, ecological, and economic perspective. The 1163 surface depressions were accounted for as possible playas considering the threshold area of >5 km2. A total of 42 representative surface water samples were collected from the selected playas (Sambhar, Didwana, Pachpadra, and Pokhran) and hydrochemical analysis was carried out to identify the geochemical evolution of these playas. The major water types were Na-Cl and Na-Cl-SO4 type. Hardie and Eugster's model was used to explain the possible sequence of evolutionary pathways and brine shifts in the selected playas. Simulated evaporation modeling suggests precipitation of major evaporites (chlorides, carbonates, and sulphates) during progressive evaporation. Surface sediment analysis (X-ray diffraction) confirmed the presence of calcite, halite, and dolomite minerals in the playa sediments. The greatest economic value of these playas may be mineral production and providing food and habitat for migratory birds, though conservation and policy intervention is required for their sustainable utilization.

Sedimentation Analysis of Kabul River by Using HEC-RAS

Sedimentation Analysis of Kabul River by Using HEC-RAS

Studies on the Contamination of Heavy Metals and Their Chemical Speciation in Sediment from Selected Locations of Pune District

The heavy metal speciation analysis in sediments helps us understand and evaluate essential and unavoidable issues in terms of both health and environmental hazards imposed by these metals in our lives. Analyzing the total content of heavy metals enables us to understand only the quantity of the contaminants. To understand the different species or the chemical forms of heavy metals available in the sediments, we must study their speciation. Speciation studies help us determine their possible sources as well as their environmental stability in terms of availability to plants and other organisms. The heavy metals in this study were specified using four-stage sequential extraction, also known as the BCR technique. This study mainly highlights the quantification of metal contamination of Cu, Zn, Pb, Ni, Cd & Cr, and chemical forms as species in sediment samples collected from different Pune District, Maharashtra sites. Heavy metal contamination from the collected samples was analyzed with the use of flame atomic absorption spectrometry. This study indicated that Zn and Ni are among the most abundant metals in the sediment samples; however, Cu and Cd belong to the least abundant category. The oxidizable and residual forms (immobile and cannot be used by the organisms readily) appeared dominant for most heavy metals. Very significant differences were observed in the speciation of heavy metals from sample to sample, which was probably due to differences in water/soil composition and the agrochemicals like pesticides, weedicides, and fertilizers used in agricultural practices; the wastewater generated from different pharmaceuticals, chemical processing and manufacturing industries as well as the improper wastewater treatment methods.

Long‐Term Landscape Evolution in Response to Climate Change, Ecosystem Dynamics, and Fire in a Basaltic Catchment on the Colorado Plateau

AbstractPredicting responses of semi‐arid to montane landscapes in southwestern North America to ongoing anthropogenic changes requires understanding of past interplay among geomorphic, ecologic, and climatic factors. This study utilizes modern weathering and sediment transport processes to inform the interpretation of a 250‐kyr lacustrine sediment record of paleoecology, hydrology, and erosion from a small, closed basin, basaltic catchment on the southwestern edge of the Colorado Plateau. Geochemical and mineralogical analyses of bedrock, colluvium, and lake sediments indicate that clastic sediments in the basin are a mixture of local physical weathering products (albite and ilmenite) and eolian dust (quartz, illite, and zircon). Dust fractions increase during glacial periods coincident with lower overall sedimentation rates, suggesting this pattern results from decreased local erosion rates and not increased dust deposition. Titanium counts from X‐ray fluorescence core scanning, a proxy for ilmenite content, traces past local erosion rates. The highest erosion rates, inferred from the highest Ti counts, follow climatic transitions toward interglacial conditions (Marine Isotope Stage 5e, 3a, and the Holocene), periods characterized by vegetation changeover (observed in the core's palynology), higher temperatures (piñon‐juniper‐oak pollen abundance), lower effective precipitation (shallow lake facies), and increased wildfire activity (microscopic charcoal particle counts and sizes). While brief inferred episodes of erosion occur following abrupt transitions to cooler and wetter conditions, indicated by the abundance of subalpine tree (spruce and fir) pollen and deeper lake facies, landscapes appear more stable during glacial periods. This long‐term perspective suggests that aridification and resulting vegetation succession and increased wildfires will increase erosion rates in similar settings regionwide.

Mineral composition of the Sumer Formation sediments near the village of Sumer (Northwestern Bulgaria)

Previous analyses of the Sumer Formation sediments have been limited to samples up to 400 m deep near the village of Varbitsa. This study extends the investigation, exploring the mineral composition and carbonate content of the sediments near the village of Sumer. Samples were collected from two outcrops at the Montana-Vratsa Road junction (C-1) and the Shugavitsa river basin (C-2). Both outcrops revealed a quartz and calcite content of approximately 75–80%, with a significant variance in calcite levels: 11.4% at C-1 and 31.3% at C-2. Illite (4.5%) and kaolinite (2%), these clay minerals essential for the marls’ sorption properties, were only detected in C-1 samples. The C-2 outcrop exhibits a higher carbonate content (17.65%) compared to C-1 (10.85%). These findings mirror the mineral composition trends observed near Varbitsa, where the content of illite and kaolinite increases with depth. The results provide valuable data for future geochemical and geotechnical evaluations pertinent to the development of geological repositories.

Coralline algae and bryozoans as major carbonate sediment components of shallow and mesophotic reefs on the Abrolhos Bank, Brazil, SW Atlantic

The Abrolhos Bank is the largest reef complex in the South Atlantic, harboring unique pinnacle formations (“chapeirões”) and the world's most extensive rhodolith bed. Building organisms (e.g., bryozoans, crustose coralline algae, and corals) interplay with bioeroding groups (e.g., sponges, fishes, echinoderms, and polychaetes) in the carbonate production and erosion processes controlling the reef structure. Many physical, chemical, and biological erosion processes break down these calcareous organisms in several sediment grain sizes. The present study aims to characterize the superficial sediments of three Abrolhos Bank carbonate reefs with increasing depth (6–33 m) and distance from the coast (14–75 km). Surface sediments (∼5 cm surface layer) were analyzed to determine their biological source, mineralogical compositions, and grain size distribution. In the site closer to the coast (Pedra de Leste), values of organic matter and finer terrigenous sediments were higher, while offshore sites (Parcel dos Abrolhos and California Reef) were composed mainly of carbonate bioclastics. The analyzed fragments were composed of 11 large groups, comprising eight invertebrates: Annelida, Ascidiacea, Bryozoa, Cnidaria, Crustacea, Echinodermata, Mollusca, and Porifera, plus Foraminifera, Osteichthyes, and one macroalgae(Rhodophyta). Within these large groups, a total of 61 taxa were identified, including five new records for the Abrolhos Bank (two Bryozoa and three Mollusca). In shallower reefs (Pedra de Leste and Parcel dos Abrolhos), the main bioclastic component was crustose coralline algae, CCA (45 and 49%, respectively), while in the mesophotic reef (California Reef) it was Bryozoa (42%). The sponge chips' contribution to the sediment composition varied from 0.3% to 3% in Pedra de Leste and Parcel dos Abrolhos, respectively. However, it could be underestimated due to the formation of peloids or fine sediment aggregates, which mask the visualization of some fine-grained particles. The main results from sediment analyses highlight the importance of calcifying organisms (CCA and Bryozoa) and bioeroding ones (sponges) to sediment formation on different cross-shelf reefs on the Abrolhos Bank.

Investigating the association between intestinal parasite infection and cribra orbitalia in the medieval population of Cambridge, UK

ObjectiveCribra orbitalia is believed to be a skeletal indicator of chronic anaemia, scurvy, rickets or related metabolic diseases. It has been suggested that it may be used as a proxy indicator for intestinal parasite infection, as parasites often cause anaemia today. Our aim is to investigate this association in the medieval population of Cambridge, UK. MaterialsIndividuals excavated from the cemeteries of the Augustinian friary and All Saints by the Castle parish church, and aged from 7 to adulthood. MethodsWe undertook parasite analysis of the pelvic sediment and control samples of 46 burials with intact orbital roofs. ResultsHuman roundworm (Ascaris lumbricoides) and/or whipworm (Trichuris trichiura) were identified in the pelvic sediment of 22 individuals, and cribra orbitalia noted in 11 individuals. Barnards test showed no association between parasite infection and cribra orbitalia (p = .882). ConclusionWe found no association between infection and cribra orbitalia infection in this medieval adult population, calling into question this hypothesis, at least for adults. SignificanceHigh or low cribra orbitalia prevalence in adults should not be used to infer rates of intestinal parasite infection. LimitationsThe individuals in the study were over the age of 7, with no younger children. It is possible that only parasites which cause marked anaemia (such as hookworm, schistosomiasis or malaria) may cause cribra orbitalia, while less marked anaemia from roundworm and whipworm may not do so. Suggestions for Further ResearchRepeating this study in younger children, when most cribra orbitalia appears to form.

Sedimentary evolution and lake level fluctuations of Urmia Lake (north‐west Iran) over the past 50 000 years; insights from Artemia faecal pellet records

AbstractA 25 m long sediment core from hypersaline Urmia Lake (north‐west Iran) was studied for the Late Quaternary depositional history and palaeoclimate variations using the abundance and compositional characteristics of Artemia faecal pellets. Sediment analysis is supported by scanning electron microscopy – energy dispersive X‐ray spectroscopy, organic and inorganic carbon content measurements, and stable isotopes (δ13C and δ18O) from faecal pellet carbonates. The imprecise chronology of the core back to 50 kyr bp is supported by ten radiocarbon ages from faecal pellets and bulk sediments. The palaeoenvironmental record is subdivided into four periods: (i) During much of Marine Isotope Stage 3, a period of lake level lowering is characterized by a decreasing amount of faecal pellets, and an increasing amount of coated grains, sulphate minerals and reworked shell fragments. (ii) During late Marine Isotope Stage 3 and early Marine Isotope Stage 2 a lake level lowstand and a lake floor exposure is interpreted based on the relatively low abundance of pellets, which are multicoloured and appear together with volcanic lithics and rounded sulphate minerals. (iii) During late Marine Isotope Stage 2 the record is devoid of pellets but dominated by large sulphate crystals suggesting a prolonged low lake level. (iv) During Marine Isotope Stage 1 a relative lake level highstand is rapidly established with sediments that are highly abundant in fresh pellets. The modern lake level lowstand is represented by a salt crust. The δ13C and δ18O records measured from faecal pellet carbonates suggest a link with the precipitation versus evaporation balance in the lake over time. From bottom to top the linear trend towards more negative delta values illustrates the increasing amount of precipitation arriving at the lake from the Late Pleistocene to the Holocene. Two prominent isotope minima during the Late Pleistocene and one prominent minimum in the early Holocene mark relative high lake levels, which can also be linked to Lake Van in Turkey.

Pollutant bioaccumulation in sentinel fish chronically exposed in Iguaçu river reservoirs (Southern Brazil) and human health risk of fish consumption

Bioaccumulation studies in fish mark the initial phase of assessing the risk of chemical exposure to biota and human populations. The Iguaçu River boasting a diverse endemic ichthyofauna, is grappling with the repercussions of human activities. This study delved into the bioaccumulation of micropollutants, the early-warning effects on Rhamdia quelen and Oreochomis niloticus in the Segredo Reservoir (HRS) and the potential risk of human exposure. Two groups of caged fish in three sites of the reservoir were exposed during the autumn-winter and spring-summer, while a third group (O. niloticus) underwent a twelve-month exposure, and inorganic and organic chemicals analysis in water, sediment, and biota. Additionally, metallothionein expression and genotoxicity were employed as biomarkers. PAHs, PCBs, Al, Cu, Fe, and As in water and DDTs, Cu, Zn, and As in sediment surpassed the thresholds set by Brazilian regulations, where DDT exhibited bioaccumulation in muscle, alongside metals in liver, kidney, gills, and muscle tissues. R. quelen showed metallothionein expression whereas DNA damage and NMA frequencies were elevated in target organs and in brain and erythrocytes of O. niloticus during summer. In this species the DNA damage in liver was remarkable after twelve months. Target Hazard Quotients and Cancer Risk values shedding light on the vulnerability of both children and adults. The reservoir's conditions led to heightened sensitivity to micropollutants for R. quelen species. The data presented herein provides decision-makers with pertinent insights to facilitate effective management and conservation initiatives within the Iguaçu Basin.

Distribution of Heavy Metals in Surface Sediments of a Tropical Mangrove Wetlands in Hainan, China, and Their Biological Effectiveness

The distribution and ecological risk of heavy metals in sediments were studied through the systematic collection and analysis of mangrove wetland sediments in Dongzhai Harbor, Hainan. The main insights obtained were as follows: (1) The distribution characteristics and influencing factors of heavy metals in wetland sediments were analyzed by using the inverse-distance weight interpolation method. In terms of spatial distribution, the contents of heavy metals As, Ba, Cd, Co, Cr, Cu, Hg, Mn, Ni, Pb, Sr, Ti, and Zn in the western part of the wetland were significantly higher than in the eastern part. The contents of heavy metals Cd, Co, Cr, Cu, Hg, Mn, Ni, Zn, and Ti near the anthropogenic area were significantly higher than at other points. (2) The pollution sources and ecological risks of heavy metals in wetland sediments were explored by using correlation analysis, cluster analysis, and potential ecological risk index analysis. The results showed that As, Ba, Pb, and Sr mainly originated from natural processes; Co, Cr, Cu, Mn, Ni, Ti, and Zn mainly originated from industry; and agricultural heavy metals mainly originated from Cd and Hg. The ecological risk analysis showed that there were obvious ecological risks of heavy metals in the western and southeastern corners of the wetland, which were both located in the vicinity of land far away from the coastline and near the human activities, and featured mangrove forests with dense vegetation characteristics.

Direct recycling of carbon black and graphite from an aqueous anode slurry of lithium-ion batteries by centrifugal fractionation

Centrifugation is a promising method for direct recycling of lithium-ion battery materials from an aqueous slurry. The present work investigates the continuous fractionation of an aqueous anode slurry into the active material graphite and the conductive carbon black in a decanter centrifuge. To evaluate the separation success, two analytical methods utilizing the different particle sizes and sedimentation velocities of the materials were developed and tested. Both methods can detect graphite separation efficiencies up to 90 % based on centrate samples. The detectability of carbon black in sediment samples is more sensitive for the sedimentation analysis, which can measure carbon black separation efficiencies down to 1 %, in contrast to the particle size analysis, allowing the detection of separation efficiencies down to 10 %. Both methods provide similar results in terms of assessing the separation process in the lab-scale decanter centrifuge. At a centrifugal acceleration of 352 g and a volume flow of 66 l/h, more than 90 % graphite can be separated with a low carbon black deposition between 10 % and 20 %. Thus, a high recovery of graphite and carbon black from an aqueous anode slurry by using a decanter centrifuge is basically possible.

Revision of the Quaternary calcareous nannofossil biochronology of Arctic Ocean sediments

Despite extensive chronological studies, the relationship between the age and sub-seafloor depth of Arctic Ocean sediments remains ambiguous. This prevents confident identification of paleoceanographic changes in the Arctic during the Quaternary. Currently, age-depth models derived from uranium-series decay in Arctic sediments diverge by hundreds of thousands of years compared to those built on known evolutionary appearances and extinctions of calcareous nannoplankton, a group of globally valuable age-markers. Here we report on high-resolution biostratigraphic analysis of late Quaternary sediments in six cores from the central Arctic Ocean (CAO). We applied paired light microscope (LM) and scanning electron microscope (SEM) imaging to improve nannofossil diagnosis. We argue that low abundances and poor preservation have led to misidentification of the true stratigraphic depth of the critical Pleistocene nannofossil bio-events that have underpinned age models for many Arctic sedimentary records for decades. The revised calcareous nannofossil biochronology provides a radically different geochronological framework for CAO sediments – indicating that what had previously been identified as Marine Isotope Stage (MIS) 7 (191–243 ka) in many sedimentary records is older than MIS 12 (424–478 ka). Furthermore, it suggests that previously inferred sub-stages of MIS 5 could represent full interglacial periods rather than interstadials. The results help reconcile the different dating approaches and provide a transformative step towards resolving the disparity in Quaternary Arctic age-depth models, bringing us one step closer to accurate paleoceanographic reconstructions based on sediment cores.

Impact of iron addition on phosphorus dynamics in sediments of a shallow peat lake 10 years after treatment

Internal phosphorus (P) loading is a key water quality challenge for shallow lakes. Addition of iron (Fe) salts has been used to enhance P retention in lake sediments. However, its effects on sediment geochemistry are poorly studied, albeit pivotal for remediation success. Here, we assess the factors controlling the retention of P and long-term effects following application of FeCl3 (0.5–1 mol Fe/m2, 2010) in the eutrophic, shallow peat lake Terra Nova (the Netherlands). Treatment reduced P levels in the lake for two years, but afterwards summer release of P intensified, resulting in higher surface water P concentrations than before treatment. Porewater and sediment analyses indicate that the majority of the added Fe is still undergoing redox cycling within the top 10 cm of sediment accounting for the binding of up to 70 % of sedimentary P. Sequential extractions further suggest that organic matter (OM) plays a key role in the resulting P and Fe dynamics: While reduction of P binding Fe(III) phases results in P release to porewaters, the produced Fe2+ remains bound to the solid phase presumably stabilized by OM. This causes P release from the sediments in excess to Fe during temporary low oxygen conditions in summer months, as confirmed by whole core flux incubation experiments. Quantitative coprecipitation of P with Fe upon reoxygenation of the water body is then impossible, leading to a gradual increase in surface water P. This first long-term study on a shallow peat lake underpins the role of OM for Fe cycling and the need to carefully consider the sediment properties and diagenetic pathways in the planning of Fe-amendments.

El sur de Collasuyu: Abordaje territorial espacial y análisis múltiple de microfósiles en sedimentos de sitios incas en el noroeste argentino

Throughout the Andean region, a type of architectural structure, known as an orthogonal structure or “cell,” has been recorded, which is related to the Inca presence and has an interesting representation in the south sector of Collasuyu (northwestern Argentina). Since research on this type of structure includes few and superficial analyses, we propose an exploratory study of multiple analyses of microfossils and sediments from two sites – Corral Negro and Urbina – integrated with a GIS spatial study of 32 structures in 14 site samples to provide new information for a discussion of their functionality and participation in the landscapes of Collasuyu.

Оценка окислительно–восстановительных реакций донных отложений пруда Угольчик методом автографии на фотобумаге

The article considers the analysis of bottom sediments selected on the territory of the Central Forest State Natural Biosphere Reserve of the Tver region, in the Ugolchik Pond for the assessment of redox reactions by autography on photo paper, which is an indicator of the state and number of anaerobic microorganisms at the bottom of the reservoir according to autography. Keywords: BOTTOM SEDIMENTS, AUTOGRAPH ON PHOTO PAPER, AQUATIC ECOSYSTEMS, ECOLOGICAL ASSESSMENT OF WATER BODIES

Morphometric Changes between Peroba and Redonda Beaches, Icapuí-Ceará Region, Brazil, Applying High Resolution Remotely Piloted Aircraft Images from 2020 to 2021

Beaches are regions of the coastal zone where the effects of interaction between marine, terrestrial and atmospheric ecosystems are often seen. Natural and anthropic agents act together in coastal processes, which may result in erosion or accretion. If the erosion is intense and continuous, it will represent a severe problem, especially in densely occupied and economically significant beaches, such as the beaches of Peroba and Redonda that have registered erosive events. Thus, this work aimed to analyze the variation of the coastline and the volume of beach sediments through a historical series of one year employing a remotely piloted aircraft, conjugated with the analysis of sediments collected in fields. At Peroba beach, the shoreline was stable, having varied by about 0,87 m/year, and the volume indicated a positive sediment balance of about 18.815 m3. At Redonda beach, the coastline degraded by about 1,27 m/year. The volume indicated a negative sediment balance of -1.230 m3. The beaches were mainly characterized by sediments of very fine and fine sand fractions. The volume variation indicated similar trends to the shoreline, with more significant deposition in the west and erosion in the east.

Digital Tool for Sedimentation Analysis of Pig Manure Without Bedding

Existing digital tools for sedimentation analysis are reviewed. It has been established that solutions that allow taking into account the specifics of organic livestock waste, in particular pig liquid manure, are currently missing. Experimental studies were carried out to determine the mass of sedimented particles of pig litterless manure over time. A mathematical model has been developed that describes this dependence. Based on the research conducted, a digital tool for sedimentation analysis of pig liquid manure was developed and patented.

Spatial and temporal distributions of clay minerals in the central Andaman Sea: Provenances and sedimentary processes over the last 42 kyr

The uplift of the Tibetan Plateau has led to the formation of the world’s largest sediment “source–sink” system in the northeastern Indian Ocean, and seafloor sediments record rich environmental and climatic information during the accumulation process, making it an ideal area to reconstruct past sedimentary processes. To reveal fine sediment provenance and climatic implications, we present a sedimentary reconstruction during the past 42 kyr based on clay mineral analyses of sediments from core ADM-159 retrieved from the central Andaman Sea. The clay minerals mainly consist of illite (I, 27%–47%) and kaolinite (K, 8%–37%) with minor smectite (S, 11%–37%) and chlorite (C, 11%–37%). Provenance analyses show that the illite-dominated clay minerals are mainly derived from terrestrial sources of detrital material input from the Irrawaddy River, indicating a primary supply of fine sediment from Myanmar terrestrial material. Considering the stable sediment provenance, S/K, S/(I+C), and the illite chemical index were chosen to reconstruct the transport pattern of the fine fraction sediment over the last 42 kyr. S/K and S/(I+C) showed relatively consistent trends over time with relatively high values at 32–25 and 15–6 ka BP, indicating a strong supply and transport capacity of fine particulate matter. In contrast, relatively low values of S/K and S/(I+C) occurred at 25–15 ka BP, indicating a relatively weak deposition process of fine sediments in the study area. The trends in S/K and S/(I+C) are roughly consistent with the variations in solar radiation. Together with the illite chemical index, these trends indicate that solar activity controlled the weathering and sedimentation of fine-grained sediments. We also found significant periodicities in our clay mineral records at 25.05 and 0.473–0.477 kyr, suggesting that the parameters of the Earth’s orbit and solar radiation were potential driving mechanisms of the changes in regional climate. Moreover, monsoon precipitation triggered by the movement of the intertropical convergence zone was another important factor controlling the supply and transport of fine particulate matter in the study area, especially the weak precipitation during the last deglacial period and the relatively strong precipitation during the Holocene, so we could draw a conclusion that precipitation during these periods had significant effects on the weathering, erosion, and transport of fine particulate terrestrial materials over the last 42 kyr.