Heavy Metals In Bottom Sediments Research Articles

Environmental assessment of toxic heavy metals in bottom sediments of the Sharm Obhur, Jeddah, Saudi Arabia

The concentrations, spatial distributions, pollution level, and health risks of heavy metals in sediments of the Sharm Obhur, Northern Jeddah, Saudi Arabia were evaluated. Average concentrations were found to be: Cr > Zn > Ni > Cu > As>Pb with the highest concentrations found near the head of the sharm, and decreasing towards the mouth. Environmental indices, together with the statistical analyses, showed that the sharm experiences a low to moderate degree of pollution. Sampling sites with heavy metal contamination are concentrated near the head and the southern coast of the sharm, where intensive human activities associated with a boat dock, construction, and recreation are common. The mean carcinogenic risk (CR) values of As, Cr and Ni are at permissible level suggesting unlikely adverse impacts of heavy metals on human health. Despite acceptable CR values; however, serious non-carcinogenic and carcinogenic health threats from metals may yet be an issue particularly for sensitive populations such as children.

Study of the features of determination of heavy metals in bottom sediments

In the work with the application of the atomic absorption method, the peculiarities of the influence of sample preparation on the degree of extraction of heavy metals in samples of bottom sediments were analyzed. Acid, acid-microwave sample preparation and their variations were used in the study. It was found that the greatest influence of the type of sample preparation on the degree of extraction is observed for iron and manganese. For zinc, the smallest dependence of the type of sample preparation on the completeness of its extraction from bottom sediments was noted. There is an ambiguous influence of the type of sample preparation on the degree of extraction for cobalt, copper and nickel, which may be related to the peculiarities of the chemical composition of the bottom sediments.

Content of heavy metals in bottom sediments of drained Kakhovka Reservoir

The article highlights the ecological danger of the destruction of the Kakhovka HPP dam and the draining of the Kakhovka Reservoir. The results of experimental studies of the content of mobile compounds and gross forms of heavy metals in five samples of bottom sediments taken from the bottom of drained reservoirs taken on the territory of the Kushugum community of the Zaporizhia district of the Zaporizhia region. Two samples were taken from the bottom of the former flood zone (Balabyne village), 2 samples — from the bottom of the former limestone quarry, which was connected to the floodplain of the Dnipro (Kushugum village) and 1 sample taken from the open area of the Kakhovka Reservoir (Malokaterynivka village). Based on the results of the research, it was established that the maximum permissible limit (for soil) of mobile compounds of lead (from 2.0 to 4.1 times), zinc (from 2.4 to 5.4 times), cadmium (from 1.9 to 2.5 times) was exceeded. and nickel (from 1.04 to 2.2 times) in all investigated bottom sediment samples. Exceeding the MPC (soil) for the content of gross forms of lead was found in five bottom sediment samples (from 1.1 to 1.5 times). Exceedings of the MPC of the soil by the content of gross forms of cadmium and manganese and mobile compounds of copper, nickel, cobalt and manganese were not detected. The maximum limit for the content of mobile compounds of iron and gross forms of zinc, copper, nickel, cobalt and iron is not regulated. The highest degree of contamination of bottom sediments by the content of: mobile compounds and gross forms of lead and nickel was found in samples taken from the bottom of a former limestone quarry (Kushugum village, Zaporizhzhia region); zinc — in a sample taken from the bottom of the former flood zone in the territory of the town of Balabyne and a sample taken from the open area of the Kakhovka Reservoir in the territory of the town of Malokaterynivka; cadmium — in the samples taken from the bottom of the former limestone quarry in the territory of the town of Balabyne and the sample taken from the open area of the Kakhovka Reservoir in the territory of the town of Malokaterynivka. According to the results of the correlation analysis, an extremely strong dependence was established between the content of mobile compounds of heavy metals and their gross forms — for cobalt (r=0.96), cadmium (r=0.92), nickel (r=0.91), lead (r=0.88) and zinc (r=0.84).

ASSESSMENT OF THE STATE OF WATER, BOTTOM SEDIMENTS AND SOILS OF THE BEZYMYANNY STREAM FLOOD PLAIN (VLADIVOSTOK)

The main parameters of the chemical composition of water, bottom sediments and soils ii monitoring sites have been laid from the headwaters to the mouth of the Bezymyanny stream were determined. The characterization of sanitary and microbiological properties of river water is carried out. An increase in the content of macroelements and heavy metals in bottom sediments and soils. The level of pollution was determined using various geoecological indicators. The consequence of the infl uence of the solid waste landfi ll and the highway is an extremely high level of environmental risk on the Glass Beach.

Speciation of Selected Heavy Metals in Bottom Sediments of River Rwizi, Mbarara City, Uganda

Speciation of Selected Heavy Metals in Bottom Sediments of River Rwizi, Mbarara City, Uganda

Pollution and Potential Ecological Risk Evaluation of Heavy Metals in the Bottom Sediments: A Case Study of Eutrophic Bukwałd Lake Located in an Agricultural Catchment.

Metals are natural components of the earth's crust and are essential elements in the metabolism of fauna and flora. However, some metals at high concentrations may pose an ecological risk. Ecological risk analysis is one of the best methods for detecting potential metal pollution problems and its impact on ecosystems. This study analyzed the potential ecological risk and contamination from heavy metals (Cd, Cu, Pb, Ni, Cr, and Zn) in bottom sediments. It analyzed the spatial variability of heavy metal concentrations in the bottom sediments of Lake Bukwałd. The potential ecological risk index (RI) was used to assess the impact of pollutants accumulated in bottom sediments on the environment. In addition to RI, the geochemical index (Igeo) and contamination factor (CF) were also calculated. The pollutant loading index (PLI) was used to compare the average content of metals in the bottom sediments of lakes. The obtained results indicate that agricultural activity determined the quality of the bottom sediments of the reservoir and the spatial content of trace metals in them. Higher concentrations of elements were found in sediments collected from the agricultural catchment, whereas the lowest concentrations were observed near the outflow from the lake. The calculated RI value was 153.3, representing a moderate ecological threat risk. The concentration of cadmium had the greatest influence on the value of the indicator. The analysis of the scale of pollution of bottom sediments using the geochemical index showed that the bottom sediments in terms of the content of most of the trace metals tested are class II. In Cu and Zn, the Igeo index classified these deposits as class 0 and class I. The highest CF values were determined for Cr, Ni, and Pb and classified as significant contamination. The remaining elements were classified as moderately contaminated. The designated PLI was 2.49, suggesting immediate action to reduce pollution and prevent the degradation of the lake.

КОМПЛЕКСНАЯ ОЦЕНКА ЭКОТОКСИКОЛОГИЧЕСКОГО СОСТОЯНИЯ ВОДОХРАНИЛИЩ СРЕДНЕЙ И НИЖНЕЙ ВОЛГИ МЕТОДАМИ БИОДИАГНОСТИКИ И АНАЛИЗА СОДЕРЖАНИЯ ТЯЖЕЛЫХ МЕТАЛЛОВ В ДОННЫХ ОТЛОЖЕНИЯХ

A comprehensive assessment of the ecotoxicological state of the reservoirs of the Middle and Lower Volga was carried out using the method of biodiagnostics (biomarking, biotesting) and analysis of the content of heavy metals in bottom sediments. The spatial variability of the content of heavy metals in bottom sediments and the values of biomarkers of the state of oxidative stress in the liver of bream from different reservoirs was established. The toxicity of bottom sediments was determined. According to the results of the study, it is possible to arrange the reservoirs according to the degree of deterioration of the ecotoxicological state in the following order: Gorky > Volgograd = Saratov > Kuibyshev > Cheboksary. The Rybinsk reservoir in the area of station 1 can be taken as a background area in terms of anthropogenic load.

Heavy metals in coastal soils and sediments of the ponds in Samara

The total contents of Mn, Cr, Ni, Cu, Zn, Pb and Cd in foreshore soils and bottom sediments of 20 ponds have been investigated for the first time in Samara by the method of spectrometry with inductively coupled plasma. It is shown that polymetallic pollution of coastal soils and bottom sediments of 16 ponds out of 20 considered is acceptable; 3 ponds, located in the 13th microdistrict (small pond) and on the Solnechnaya street (large and small ponds), are characterized by moderately hazardous pollution with heavy metals; 1 pond, located in the area of the former Hippodrome, has a high level of pollution of coastal soils. Cu, Zn and Pb should be considered to be the main elements that significantly affected the ecological state of coastal soils and bottom sediments of the studied ponds. Their content in selected samples ranged: from 0,3 to 20,3 for Cu, from 0,2 to 14,9 units for Zn, from 0,2 to 25,2 units of background concentrations to Pb. The analysis of heavy metals average levels in coastal soils and bottom sediments of Samara ponds showed, that bottom sediments were enriched with all analyzed metals except Mn in comparison with coastal soils, whereas Mn was accumulated to upper levels in coastal soils. The location of water bodies in various parts of the urban area relief caused differences between the levels of heavy metals accumulation. For instance, the coastal soils of the ponds located on the watershed between the Saratov reservoir and the Samara River accumulated heavy metals more actively than the coastal soils of the ponds on the Volga slope. The accumulation of heavy metals in bottom sediments on the watershed was more active for Mn, Cr, Zn and Cd whereas in the ponds on the Volga slope it was shown for Ni, Cu and Pb.

Accumulation of Heavy Metals in Bottom Sediment and Their Migration in the Water Ecosystem of Kapshagay Reservoir in Kazakhstan

The bottom sediment of reservoirs has many functions. Among them, matter sorption is a very important one, and results in many side-effects on the reservoir sediment forming the water–bottom sediment system. As a result, bottom sediment can also be an indicator of anthropogenic water pollution. There is only very little knowledge of this situation in the study area. The main objective was the analysis of heavy metal accumulation in bottom sediment, as well as their ability to migrate throughout the water–bottom sediment system and their spatial distribution in the Kapshagay Reservoir in Kazakhstan. Heavy metal concentrations, in the both water samples and the bottom sediment, were determined using the atomic absorption spectrophotometric method. Surfer software was used to visualize the processes of migration and accumulation. Another objective was the development of model maps of the spatial distribution of metals in the reservoir water area, which indicated significant anthropogenic loads. It is obvious that both the transboundary inflow of the Ili River and the inflow from small rivers in the territory of Kazakhstan are the reasons for the anthropogenic water and sediment load. The results of the spectrometric analysis verify the water pollution in the reservoir, revealing increased concentrations of zinc reaching up to 10.8 µg/L and lead up to 32.7 µg/L, transported by the transboundary runoff of the Ili River and by the small rivers on the left bank into the Kapshagay Reservoir. Sediment concentrations close to the central part and dam zone of the reservoir reached the following values: zinc up to 37.0 mg/kg and lead up to 8.8 mg/kg. The results of this study indicate a significant anthropogenic load of the ecological conditions of the Kapshagay Reservoir. This is discussed and compared with other relevant studies.

Assessment of heavy metals distribution and environmental risk parameters in bottom sediments of the Pechora River estuary (Arctic Ocean Basin)

The article is devoted to the study of the content of heavy metals in the bottom sediments of the estuary of the Pechora River, which is the largest river in the European Arctic of Russia. In addition to metals, the particle size distribution and physicochemical parameters of river sediments were analyzed, such as the content of carbonates, organics and ash components. Average concentrations of heavy metals in the sediments of the Pechora Delta sediment have been found to be significantly lower than terrestrial values. The assessment of pollution and toxicity of sediments in the Pechora delta, made using various parameters Igeo, Cf, Cd, EF and ERI, showed a low level of heavy metals in bottom sediments, coupled with a low level of environmental risk. Despite the fact that high concentrations of heavy metals of anthropogenic origin are continuously recorded in the water of the Pechora River, (almost throughout the entire length), there is no accumulation of pollutants in the sediments of the delta. Thus, the estuary of the Pechora River, unlike other large estuary systems, does not act as a filter or sediment trap, which contributes to the penetration of heavy metals deep into the Barents Sea and the widespread distribution of pollutants in the ecosystems of the Arctic.

ENVIRONMENTAL STATE OF SURFACE WATERS AND BOTTOM SEDIMENTS IN WATER BODIES OF THE SOUTHWESTERN PART OF THE ALTAI TERRITORY

Ecological research findings on surface waters and bottom sediments in water bodies of the southwestern part of the Altai Territory are presented. Samples were collected and analyzed between 2020 and 2021. Activities of natural (40К, 226Ra, 232Th) and artificial (241Am, 239+240Pu, 137Cs and 90Sr) radionuclides were determined in bottom sediments, research into the content of heavy metals (copper, zinc, lead and cadmium) in surface waters and bottom sediments was undertaken. As a result, it was found that radiation parameters of bottom sediments in water bodies of the southwestern part of the Altai Territory did not exceed the regulatory level. No residual nuclear plumes at the Semipalatinsk Test Site are currently detected in water of water bodies of interest. The content of heavy metals in bottom sediments does not correspond to the regulatory level. Ground water contamination with heavy metals was not detected.

Spatial Distribution and Ecotoxicological Assessment of Heavy Metals in Bottom Sediments of Yellow River from Inner Mongolia, China

Spatial Distribution and Ecotoxicological Assessment of Heavy Metals in Bottom Sediments of Yellow River from Inner Mongolia, China

Accumulation of oil products and heavy metals in bottom sediments at Temryuk harbor (the Sea of Azov, 2006-2020)

The paper presents the results attained on the rate of accumulation as well as seasonal and inter-annual time profiles of oil products and some heavy metals (Cu, Zn, Pb, Fe) in the bottom sediments within the Temryuk harbor area (Gazovikov Bay) in the period from 2006 to 2020 when concentrations of oil products (OP) were recorded to vary from 88 to 413, copper – 13.6-116.0, zinc – 58.2-415.0, lead – 14.0-55.3 and iron – 8.4-41.0 g/kg, with median values of 211, 39, 122, 20 mg/kg and 30 g/kg, respectively. There is a trend for a higher rate of accumulation of oil products and lead. The paper specifies some geochemical features of bottom sediments at the seaport of Temryuk against the sediments in the Azov Sea. It delineates statistically significant relationships between levels of the pollutants under consideration, which decrease (as the correlation coefficient decreases) in the following sequence Cu-Zn> Cu-Pb> Zn-Pb >> Cu-Fe> Zn-OP> Zn-Fe, Cu-OP.

Assessment Of Water Quality And Bottom Supplies In The Bottom Of The Mekong River

The article presents the results of studies of the content of heavy metals in bottom sediments in the lower reaches of the Mekong River (3 estuaries in Ben Tre). The results of the content of heavy metals for 20 research sites were analyzed and compared with the national standards of Vietnam, which are used to assess the level of adverse effects on aquatic animals and river ecosystems, as well as with similar standards adopted in various countries of the world. When compared with the standards, the content of heavy metals in the study area (Ben Tre province) was quite high. The tributaries flowing into the main river also have a relatively high content of heavy metals, which proves that, in addition to pollution from the upper reaches of the river, socio-economic activities in the catchment, including land reclamation, also have a strong effect on the accumulation of heavy metals in channel sediments. In addition, the authors, comparing the content of heavy metals, both with the established standards of Vietnam and with the standards of some countries of the world, creating a basis for rational agriculture and sustainable development.

Vliyaniye fiziko-khimicheskikh kharakteristik donnykh otlozheniy na raspredeleniye mikroelementov v pribrezhnykh akvatoriyakh Krymskogo poluostrova

The paper presents the results of studies of the Kalamitsky Bay bottom sediments pollution level with microelements and heavy metals (Pb, Zn, Cu, Ni, Co, Cr, V, As, Sr, Ti, Fe, Mn) in comparison with the content of these microelements and heavy metals in the Balaklava Bay sediments. The paper analyzes data obtained during expeditions on the R/V Professor Vodyanitsky in the Kalamitsky Gulf in August 2011 (seaward part) and on the R/V Rioni in September 2012 (coastal area) as well as in the Balaklava Bay in October 2018. Content of microelements and heavy metals in bottom sediments of the studied water areas was determined by the X-ray fluorescence method using Spectroscan MAX-G device. For the water area of the Kalamitsky Gulf, the features of the studied trace element spatial distribution are considered, groups of trace elements with different spatial distribution patterns are identified. The correlation analysis determined influence of physicochemical characteristics of the sediments on distribution and accumulation of trace elements. In the water area of the Kalamitsky Gulf, a statistically significant correlation was observed of nickel, iron and zinc content with the clay fraction; dependance of increased concentrations of zinc, nickel and chrome on the content of organic carbon and predominance of lead in highcarbonate sediments. For the Balaklava Bay, the maximum positive values of correlations with the pelitic-silty fraction were noted for iron, manganese, vanadium and chrome; organic carbon correlates with chrome, iron, nickel and copper, whereas carbonates correlate with strontium. Similar patterns were observed earlier in the Sevastopol region bays, Feodosiya Gulf and Kerch Strait.

Основные критерии оценок содержания тяжелых металлов в донных отложениях водных объектов

The main criteria for assessing the content of heavy metals in sediments of water bodies. At present, the methodology for rationing pollutants in bottom sediments of surface watercourses is clearly not sufficiently developed. There are various and significantly different approaches to the assessment of soil contamination with heavy metals. The maximum permissible concentration (MAC), which is the main criterion for assessing the levels of pollution, is not perfect and needs to be significantly adjusted. A number of methodological assessments of contamination of bottom sediments with heavy metals with comparative characteristics are considered, of which a method for estimating the anthropogenic load on a reservoir according to its geo-classes has been proposed as one of the best. The gross content of heavy metals in bottom sediments of water bodies does not give a sufficient idea of the possibility of secondary pollution of water masses and, as a result, subsequent toxic effects. A much more important indicator is their content and distribution by forms of existence in the solid phase and pore solution of bottom sediments. As a consequence, this article develops a topic for estimating possible secondary pollution of water bodies by determining the content and distribution of TM by forms of existence in the solid phase and pore sediment solution.

Temporal and spatial variability of heavy metals in bottom sediments and the aquatic macrophyte Paspalum repens of the Orinoco River floodplain lagoons impacted by industrial activities.

This study investigated the water parameters and the levels of several heavy metals in leaves and roots of the aquatic macrophyte Paspalum repens and in bed sediments of one unpolluted lagoon and two polluted lagoons of the Orinoco River floodplain to know the impact of the alumina refining wastes on these ecosystems. The sampling was performed during four hydrological periods, covering one hydrological year. Chemical parameters in water (pH, conductivity, and total dissolved solids) and the levels of Al, Pb, Cr, and Cu in sediments were the highest in Macanillal (LMaca) lagoon, whereas sediments of Punta Cuchillo (LPC) lagoon also had elevated concentrations of Al and Fe in comparison with Las Aruhacas (LArh) lagoon (unpolluted lagoon). Chemical parameters in waters returned almost to natural values during high water stage because of the huge inundation of the Orinoco River during the high discharge periods. The solid/liquid discharges of industrial effluents over these systems also affected the grain size distribution of sediments in the lagoons. In all the studied lagoons, the distribution of elements in leaves of P. repens was in the order K ≥ Cr > Ca > Mg > Al > Fe > Mn > Cu > Pb, whereas Al was found to be the more abundant element in roots. The high abundance of Cr in P. repens was related with the high Cr accumulation potential shown by aquatic macrophytes. Despite this, the concentration of elements in P. repens did not show differences between the plants collected in the polluted lagoons versus the plants collected in the unpolluted lagoon. This suggests that P. repens is unsuitable for bio-monitoring studies of heavy metals in these aquatic environments impacted by alkaline residues.

Speciation of heavy metals in bottom sediments of drinking water reservoir for Gdańsk, Poland – changes over the 14 years

There was conducted a comparative study of the concentrations of heavy metals (Zn, Cu, Pb, and Cd) in the surface layer of sediments collected in two investigation periods: 1999–2000 and 2013. The results demonstrated that the degree of metals pollution decreased over time. The contamination factors (Cf) calculated for Zn, Cu, Pb, and Cd were respectively 3.63, 3.86, 3.23, and 3.25 in the first period of research and 1.35, 3.42, 1.98, and 1.43 in the second one. The metal speciation analysis indicated that Zn was mainly associated with the Fe–Mn oxides fraction and the residual fraction, and Cu – with the residual fraction and the organic fraction in both periods of investigation, while the percentage of geochemical fractions in binding of Pb and Cd changed in time. The share of fractions Fe–Mn oxides/carbonate increased in the case of Pb, and carbonate/exchangeable fractions in the case of Cd. The risk assessment code (RAC) decreased in the following order: Cd > Zn > Pb > Cu and was higher in 2013 - achieved the very high-risk category in the case of Cd. Thus, despite the decrease of sediment pollution, RAC for Cd increased due to changed geochemical speciation.

Метод нечеткого определения концентрации тяжелых металлов при атомно-абсорбционном спектральном анализе донных отложений

Due to the technogenic impact on the biosphere and its components, a significant amount of heavy metals and radionuclides ends up in the environment. One of the main directions for improving the ecological components of environmental safety is the biotransformation of bottom sediments of reservoirs containing heavy metals, with the help of vermiculture, into biologically safe organic fertilizer. Assessment of the concentration of heavy metals in bottom sediments is an urgent task, the solution of which will allow preserving the natural environment, improving the condition of soils and, as a result, human health. The problem of using bottom deposits in this case is the accuracy of determining the content of various heavy metals in them, which affect the vital activity of earthworms. The gross and mobile forms of heavy metals in experimental substrates can be most accurately determined by atomic absorption spectral analysis. Atomic absorption analysis is a method of analytical chemistry based on the selective absorption of electromagnetic radiation of a certain wavelength by neutral atoms of the element being determined free of all molecular bonds. In the process of absorption, an electron moves from the main energy level to a higher one as a result of photon excitation. In this case, the intensity of the exciting light of a given frequency decreases. Accurate quantification is often hampered by significant matrix interference and non-uniform analyte distribution. To achieve the accuracy and reliability of the method required for vermicultivation, this work proposes a modification of the analysis method by applying fuzzy modeling of the experimental results. From a mathematical point of view, the process of constructing a calibration graph can be implemented using the procedure for constructing a fuzzy scale in the method for decoding the weight of proteins during electrophoresis. An algorithm is described for determining the fuzzy concentration of a metal from the atomic absorption signal data, followed by defuzzification of the obtained fuzzy concentration for analysis and practical use. Keywords: fuzzy modeling, spectral analysis, heavy metals.

Condition of bottom sediment in the area of artificial islands of the Kashagan field, Kazakhstan

Aim.The aim of the research was to determine the pollution of bottom sediment with heavy metals around artificial islands A and D, where hydrocarbon raw materials from the subsalt stratum are being extracted from island D, and where production has not begun from island A. Investigations were carried out to compare the content of heavy metals in bottom sediments around these artificial islands. Material and Methods.The content of heavy metals Cd, Cr, Cu, Fe, Ni, Pb and Zn in the bottom sediment in the region of artificial islands A and D was studied. Samples were processed under laboratory conditions by standard methods. Measurement of the content of heavy metals Cd, Cr, Cu, Fe, Ni and Zn was made using an ICP‐MS spectrometer, and of Pb was made using a ContAA‐600 atomic absorption spectrometer with electrometric atomization (with a HydrEA System Batch Mode HS 55 modular hydride attachment). Results. In 2017, the average concentration of all studied elements in the region of island D was found to be higher than in the region of island A. Conclusion. In all seasons of the research, values in excess of the Maximum Permissible Concentration (MPC) of all pollutants was not found.