Chemical Elements In Sediments Research Articles

BENTHIC MACROINVERTEBRATE COMMUNITY IN TWO AMAZONIAN UPLAND LAKES

Studies of biological communities in Amazonian lakes are limited to floodplains of large rivers. However, the high-altitude lakes of the Serra dos Carajás differ from other lakes in the region due to the high natural concentration of iron and manganese. An important component of this biological community are the macroinvertebrates, some of which are sensitive to environmental and chemical variables. However, little is known about the influence of heavy metal concentrations on this community component in Amazonian lakes. In our study, we observed the importance of variables such as water depth and concentration of chemical elements in sediments on the macroinvertebrate community. Through a redundancy analysis, we found that the depth of the lake affects the number of species and the composition of the benthic macroinvertebrate community. We also found a relative importance of the concentration of manganese in the sediment for the community studied. Our results indicate that the macroinvertebrate community is differentiated in the marginal and central regions of the lake, since the deposition of organic matter and heavy metals in the sediment is different in these two regions of the lake. The relationship found has implications for the management and restoration of upland lakes in the Amazon, helping to preserve this unique ecosystem.

Multi-index assessment of sea bottom sediments of the Izmir Gulf, Aegean Sea: A study of interrelation between anthropogenic and hydrodynamic effects

This study aimed to investigate the sediment transport pathways and geochemical parameters in the Izmir Gulf to determine the heavily impacted areas by natural and anthropogenic parameters. The grain size trend analysis was used to determine sediment transport patterns and, statistical methods were employed to identify the sources and distribution of chemical elements in sediments. The main factors that were affecting the area were identified as lithogenic, anthropogenic, maritime traffic, biogenic and shipyard activities. The tannery industry (Cr), maritime traffic and shipyard/dock activities (Cu and Zn), road traffic run-offs (Pb and Zn), and untreated domestic waste discharges (TOC and S) were identified as the sources of metals. Contamination rankings based on metal concentrations indicated higher pollution levels in the Inner Gulf compared to the Central Gulf. Zinc and chromium were found to pose significant risks to benthic organisms. The pollutants tended to accumulate in deposition zones, following sediment transport directions.

Hazardous Elements in Sediments Detected in Former Decommissioned Coal Mining Areas in Colombia: A Need for Environmental Recovery

This study demonstrates an investigation into nanomineralogical and geochemical evolution for the detection of hazardous elements from old, abandoned coal mining deposits capable of causing negative environmental impacts. The general objective of this study is to evaluate the number of nanoparticulate chemical elements in sediments collected during the years 2017 and 2022 from deactivated coal mining areas in the La Guajíra and Cesar regions of Colombia. Sediments were collected and analyzed from areas that experienced spontaneous coal combustion (SCC). The analysis consisted of traditional mineralogical analysis by X-ray diffraction and Raman spectroscopy, nanomineralogy by field emission scanning electron microscope-FE-SEM, and high-resolution transmission electron microscope-HR-TEM (energy dispersive X-ray microanalysis system-EDS). The analyzed sediment samples contained high proportions of amorphous materials containing the chemical elements As, Cl, Hg, Mo, Pb, Sb, and Se. This study emphasizes the need to implement environmental recovery projects at former, now abandoned coal extraction areas located in the investigated region, as they have negative effects on the environment and human health across large regions.

Chemical elements in sediments and in bivalve mollusks from estuarine regions in the south of Bahia State, northeast Brazil

Abstract Estuaries receive daily inputs of chemical elements which can impact the quality of water and sediment, as well as the health of biota. In addition to the sediment, bivalve mollusks have been used in the chemical monitoring of these systems. This study investigated the presence and contents of As, Ba, Cd, Co, Cr, Cu, Fe, Mn, Ni, Pb and Zn in superficial sediment and in bivalves (Crassostrea gasar, C. rhizophorae and Mytella guyanensis) from estuaries in the south / extreme south of Bahia State, northeast Brazil. The samples were evaluated with inductively coupled plasma optical emission spectrometry (ICP-OES, Varian 710). Except for Cd, all other elements were found in the samples, being that Co was exclusive in the sediment. The estuaries equivalent to sampling stations #1 - Valença, #2 - Taperoá, #3 - Ilhéus and #4 - Belmonte showed levels of metals compatibles with those established by the Brazilian legislation, however, the #5 - Santa Cruz Cabrália, in addition to the presence of As, presented a high level of Pb and Cu in C. gasar, which was attributed to the impacts of nautical activities in that locality.

Spatial distribution of chemical elements in the surface sediments of a tropical estuary in north-eastern Brazil

The high socioeconomic importance of estuarine environments is contributing to their continuous and increasing settlement by human populations and a growing negative impact on those sensitive habitats. Considering the natural importance of estuarine regions, this study aimed to quantify and spatialize the distribution of the chemical elements iron (Fe), aluminium (Al), manganese (Mn), vanadium (V), barium (Ba), zinc (Zn), copper (Cu), lithium (Li), cobalt (Co), chromium (Cr), nickel (Ni), lead (Pb) and arsenic (As) and produce a potential risk assessment from the surface sediments along the extent of the Serinhaém Estuary, Bahia, Brazil, in order to evaluate the environmental quality of the estuary. The mean concentrations of the chemical elements followed the order: Fe > Al > Mn > Ba > Zn > V > Cr > As > Pb > Co > Li > Cu > Ni. Through analysis using the geo-accumulation index, the concentrations of the chemical elements were determined to reflect the local lithology and not the influence of human activities for all the elements, with the exception of Ba, the enrichment of which came from Camamu Bay. The chemical elements in the sediments do not pose a risk to the local biota or the human population. The distribution maps revealed a tendency for the accumulation of higher concentrations of elements in some sectors of the channel. This study can be used in the future as a complete profile of the background concentrations of the studied elements in the sediments, aiding in the continuity of monitoring actions.

DYNAMICS OF CHEMICALS IN RIVER BOTTOM SEDIMENTS ON THE TERRITORIES IMPACTED BY THE OIL INDUSTRY

Background. Two thirds of all oil reserves of the Russian Federation are concentrated on the territory of Western Siberia. Field work, production and distribution of petroleum products at the oil and gas field are the main reasons for the negative impact on the ecosystems of the northern territories.
 Purpose. The purpose of this study is to evaluate the chemical pollution dynamics of the rivers’ bottom sediments in the Middle Ob region, the region of the Samotlor field.
 Materials and methods. Based on the chemical analysis of the sediment samples, concentrations and total values of the following chemical elements were determined: manganese, copper, nickel, lead, chromium, zinc, iron sulfate ions, chloride ions, petroleum products, mercury. Based on the results of long-term studies of the chemical analysis dynamics of the bottom sediments in the Ob, Agan, and Vakh rivers, a correlation and regression analysis of the studied indicators was carried out.
 Results. The results of the correlation analysis suggest the existence of negative and positive correlations in the studied indicators. Regression analysis of the migration of chemical elements in sediment samples during the study period shows significant fluctuations in the total concentration of chemical elements in sediments, but there is a general tendency to decrease their concentration in sediments.
 Conclusion. Analyzing the ecological state of the studied rivers by the quality of bottom sediments, in general, we can conclude that they are in stable condition. During the study period, there has been a positive dynamics in the concentration of chemical elements in bottom sediments.

First Report of Rare Earth Elements and Other Chemical Elements in Sediments of Rivers throughout Chile

First Report of Rare Earth Elements and Other Chemical Elements in Sediments of Rivers throughout Chile

Preliminary Assessment of Chemical Elements in Sediments and Larvae of Gomphidae (Odonata) from the Blyde River of the Olifants River System, South Africa.

Benthic macroinvertebrates and sediments can act as good indicators of environmental quality. The aim of this study was to assess the accumulation of chemical elements in the Gomphidae (Odonata) collected in the Blyde River. Seven sites were sampled for river sediments assessment and five sites for larvae (naiads) of Gomphidae bioaccumulation analysis. The tissue samples were analysed using inductively coupled plasma optical emission spectrometry (ICP-OES). The results showed high levels of all of the tested elements except Cd in the sediment. The mean concentrations of As, Cu and Cr exceeded the standard guideline values, whereas Pb and Zn were below the standard guideline values. In the insect body tissue, the concentrations of most elements were higher than in the sediments. The elements with the highest concentrations were Mn, Zn, Cu, and As. The bioaccumulation factor (BF) showed a tendency for bioaccumulation for almost all of the selected elements in the insect. The BF value was high for Cu, Mn, Sb, and Zn (BF > 1). The high concentrations of elements in the insect body tissue may pose a risk to fish that consume them, and subsequently to humans when fish from the river are consumed. It is therefore important to monitor the river to reduce pollution to prevent health risks in humans, especially in communities that rely on the river for water and food.

Accumulation of selected chemical elements in sediments of kettle hole lakes on rural areas

Accumulation of selected chemical elements in sediments of kettle hole lakes on rural areas

Variation of the chemical composition of sediments under middle- and low-temperature hydrothermal conditions in the southern trough of Guaymas Basin, Gulf of California: Communication 1. results of the study of bulk sediment samples

The paper presents the results of the study of variations in the content of macro- and microelements (rare earth elements included) in the Upper Pleistocene sediments from DSDP Hole 477. The variations took place at the depth interval 110–191 m in the course of temperature drop to about 100°C in the upper part of the hydrothermal system. Variations in the content of most chemical elements in sediments from DSDP Hole 477 are manifested more weakly than in the underlying sediments of the interval 191–267 m of DSDP Hole 477A that were altered at a temperature of about 300°C. For many chemical elements, influence of the sedimentary cover on the compositional transformation of solutions during their interaction with sediments attenuates with the cooling of its upper part to the point of its complete termination.

Erratum to: An assessment study in the determination of chemical elements in sediments and fish in the Zarka River and King Talal Dam, Jordan

Concentrations of several trace elements were detected in the sediments at King Talal Dam and at different locations along the Zarka River, Jordan. Chemical elements were also detected in the edible part of common fish types existing at the dam. Elemental concentrations were determined using neutron activation analysis (NAA). The results showed that the concentration of chemical elements in the sediments decreases as one moves away from the Khirbet Al Samra waste water treatment plant. The results also revealed that most of the elements had higher concentrations in Tilapia fish compared to the Catfish.

An assessment study in the determination of chemical elements in sediments and fish in the Zarka River and King Talal Dam, Jordan

An assessment study in the determination of chemical elements in sediments and fish in the Zarka River and King Talal Dam, Jordan

Distribution, source and enrichment of some chemical elements in sediments of the Pearl River Estuary, China

Chemical elements (Al2O3, Fe2O3, CaO, TiO2, Cu, Pb, Cr, Zn, Co, Ni, V, Ba, Sr and Y) and grain size of sediment cores (25–45cm long), taken at 12 stations in the Pearl River estuary by an undisturbed multicorer in the summer of 1999, were analyzed. Sediments in the Pearl River estuary were characterized as having a relatively coarse grain size. Frequent resuspension, transportation and redistribution of settled sediment on the estuary floor could be deduced from the spatial and depth distribution of chemical elements, combined with the survey data of suspended particle matter in the water column. The grain size and heavy minerals are factors controlling the distribution of chemical elements in the estuary. Except for CaO and Sr, the chemical elements were always enriched on the western side, in the middle and at the northern side of the estuary. Three main patterns (complex, top enrichment and uniform distribution) of heavy metals in depth profiles reflected the sedimentary and preservation conditions in Pearl River estuary. Fe2O3, Al2O3, TiO2, V, Cr, Ni, Zn, Cu and Y in the Pearl River estuary sediments mainly originated from terrestrial (rock and soil) weathering, however, Cr, Ni, Zn, Cu, TiO2, V and Y may have had some anthropogenic sources. CaO and Sr in sediments originate from marine sources. TiO2 and V might be related to ilmenite. Although both Co and Pb are mainly derived from anthropogenic sources, Pb in the Pearl River estuary sediments may be supplied by precipitation of aerosols and Co may originate from industrial drainage in the region. Concentrations of heavy metals in the Pearl River estuary sediments are higher than those from the Yellow River estuary and Changjiang River estuary sediments. The input of heavy metals into the Pearl River estuary has been increasing during recent decades and is becoming a serious pollution problem. As a reference element, Fe2O3 has proved to be a good predictor of naturally occurring concentrations for TiO2, V, Ni, Cr, Zn and Cu in the Pearl River estuary. The maximum gap between observed concentration and predicted concentration for these elements reached 0.105% (i.e. 36.07, 18.76, 82.67, 67.3 and 16.28mgkg-1, respectively). Two zones were identified to be seriously contaminated by heavy metals in the estuary. One was nearby the Humen mouth and the other was near the western and mid-western part of the Pearl River estuary.