Bottom Sediment Samples Research Articles

Constructing Lithological/Geochemical Time Series in the Cross Sections of Bottom Sediments of Lake Karakel Using Data from Micro-XRF Scanning with a Beam of Synchrotron Radiation on the VEPP-3 Storage Ring

Cores of bottom sediments of Lake Karakel (Northern Caucasus) were obtained in 2010 and 2014 to perform geochemical studies for reconstructing the regional paleoclimate of the late Holocene. Solid samples of bottom sediments were scanned via micro-XRF with a step of 1 mm at the shared resource center of the Siberian Synchrotron and Terahertz Radiation Center. The contents of more than 20 elements were determined. The scan profiles are used to construct a single reference section with correction for a sediment layer dated via radiocarbon analysis, and to create a sediment core age–depth model.

Population, biomass, and production of heterotrophic bacteria in reservoirs of the Upper Volga

Populations, biomasses, and production rates of planktonic, epiphytic, and benthic bacterial communities were defined in two reservoirs of the upper Volga, and their contributions to total numbers of bacteria and productivity were estimated. Populations and production rates of heterotrophic bacteria in 1-cm3 samples of bottom sediments exceed fouling of higher aquatic plants by a factor of 101–102, and in the water layers by a factor of 103–104. In mesotrophic Rybinsk and eutrophic Ivankovskoye reservoirs, benthic bacteria account for 90.4% and 98.8% of the total biomass, and 99.5% and 95.8% of total heterotrophic bacterial products, respectively. In these reservoirs, dissolved organic carbon accounts for 9.55% and 1.19% of the biomass and 4.12% and 0.45% of production, and epiphytic bacteria account for 0.05% and 0.03% of the biomass and 0.03% and 0.02% of production. These findings suggest important roles of benthic bacterial populations in reservoirs of the upper Volga.

Distribution of Mercury in Water and Bottom Sediments of the Estuary Area of the Red River (Vietnam)

The paper determined the content of mercury in water-bottom sediments and the feature of its spatial distribution in the estuary area of the Red River (Vietnam). The studies were conducted at 30 stations during the main hydrological seasons of 2014-2016 (during the flood and low water). Samples of bottom sediments were collected on the surface layer with a depth 0…10 cm. The spatial distribution of mercury was carried out using the Kriging interpolation method in ArcGIS 10.2.2. The concentration of mercury in the water of the Red River varied from 0.05 to 0.08 µg/l in low water and 0.07…0.11 µg/l during the flood. Towards the sea, the concentration of dissolved mercury decreased. The spatial distribution of the suspended form and phases of bottom sediments of mercury in the estuary area of the Red River was characterized by an increase in the concentration in the Delta watercourses towards the sea, the presence of a maximum in the marginal filter and a general decreasing gradient at the coast. The Hg content in the suspended form varied from 0.008 to 0.7 µg/l, and in bottom sediments within 0.1…1.25 mg/(kg dry weight). In river waters, the main forms of mercury were dissolved and suspended, and in the marginal filter – in bottom sediments. Bottom sediments of the estuary area of the Red River were characterized by a higher content of Hg compared to unpolluted soils in temperate and northern latitudes, as well as bottom sediments of water bodies of another region of Vietnam.

Chlorophenol compounds in freshwater lakes of subarctic regions

Chlorophenol compounds, representing a group of chlorinated phenols and their derivatives, are ionic compounds with different degree of hydrophobicity, lipophilicity and acidity. As potential anthropogenic sources of pollution of ecosystems by chlorophenol compounds is the regional atmospheric transport of these compounds from the territories of border regions. At the same time, the sources of the diversity of chlorophenol compounds are the natural processes of enzymatic biosynthesis in the components of the environment. These compounds are especially dangerous for the Arctic and subarctic ecosystems, since the conditions of the cold climate contribute to their longterm preservation, which increases their negative impact on living organisms.The research area includes subarctic small thermokarst lakes located in the central part of Vaigach Island and in Bolshezemelskaya tundra.The isolation of chlorophenol compounds from bottom sediment samples was carried out by accelerated liquid flow-through extraction with a hot mixture of organic solvents with extraction of easily and hardly extractable chlorophenol compounds and subsequent analysis on a gas chromatograph with an electron-capture detector. The total content of chlorophenol compounds was determined by summing their concentrations in the easily and hardly extractable fractions.The bottom sediments of the investigated lakes were characterized by a relatively high content of chlorophenol compounds. Toxic pentachlorophenol was found only in the sediments of lake Tundra Bolshezemelskaya. The revealed presence of chlorophenol compounds in the bottom sediments of the investigated lakes suggests their spread in the environment by atmospheric transport from abiogenic sources, as well as natural enzymatic and biochemical processes in these Arctic waters.

The heavy metals/trace elements contents of sediments from Owalla Reservoir, Osun State, Southwest Nigeria

The heavy metals/trace elements contents of sediment samples from Owalla Reservoir were analyzed every three months in two annual cycles (March 2011 – February 2013). The main aim was to measure concentrations of selected elements in sediment samples, their variations in space and seasons and the level of pollution and/or contamination. The bottom sediment samples were collected with a Van Veen Grab and the elemental analysis in the laboratory was based on air-dried samples following standard methods. The overall hierarchy of heavy metals/trace elements in the sediments of the reservoir was in the decreasing order of concentrations: Fe > Mn > As > Zn > Ni > Co > Cr > Cu > Pb > Cd. The concentrations of the heavy metals did not follow any definite pattern from the upstream-downstream basin, although most of them (Cu, Fe, Mn, Zn, and Co) showed significant differences (P<0.05) in their horizontal variations. Mn, Pb, Co, Fe, Ni, and Zn were significantly (P<0.05) higher at the open water region than in the littoral region. All the elements except Ni did not show significant seasonal variations (P>0.05). Most of the elements in the reservoir sediment have concentrations within the background levels and concentrations defined in environmental regulations and guidelines, except for As and Cd. The contamination factors (Cf) for most metals (Co, Cr, Cu, Fe, Mn, Ni, Pb, and Zn) suggested low contamination in the sediments (Cf < 1.0). Conversely, the sediments were moderately contaminated with Cd (Cf = 2.41) and very highly contaminated with As (Cf = 19.33).

Peculiarities of migration of mercury in water and bottom sediments of the estuary area of the Red River (Vietnam)

The paper assessed the content of mercury in water and bottom sediments in the mouth area of the Red River of Vietnam. Given the spatial distribution of mercury in the dissolved, suspended forms and in sediments. The studies were conducted at 30 stations 2 times a year (during the flood and low-water periods) in 2014-2016. Samples of bottom sediments were collected in the surface layer. The spatial distribution of mercury was carried out using the kriging method in ArcGIS 10.2.2. During the study period it was found that the concentration of mercury in the water of the Red River varies from 0,05 to 0,08 μg/l during low-water periods and 0,07 to 0,11 μg/l during the flood period. Towards the sea, the concentration of dissolved mercury decreased. Mercury concentrations in suspended form and bottom sediments increase towards the sea and reach a maximum in the marginal filter. In river waters, the main forms of mercury existence are dissolved and suspended, and in the marginal filter - in bottom sediments. The bottom sediments of the estuary area of the Red River are distinguished by a higher content of Hg compared to uncontaminated soils in reservoirs of temperate and northern latitudes, as well as with bottom sediments of water bodies in another region of Vietnam.

Quantifying the impacts of artisanal gold mining on a tropical river system using mercury isotopes

In some locations, artisanal and small-scale gold-mining (ASGM) represents a significant source of anthropogenic Hg to freshwater environments. The Hg released from ASGM can contaminate aquatic fauna and pose health risks to downstream populations. Total Hg (THg) concentrations, speciation, and isotopic compositions were analyzed in water, suspended particulate matter, soil, and bottom sediment samples from pristine areas and in places of active and legacy gold mining along the Oyapock River (French Guiana) and its tributaries.Mass-independent fractionation (MIF) of even Hg isotopes in top soils (Δ200Hg = −0.06 ± 0.02‰, n = 10) implied the uptake of gaseous Hg(0) by plants, rather than wet deposition, as the primary Hg source. Odd isotope MIF was lower in deep soils (Δ199Hg = −0.75 ± 0.03‰, n = 7) than in top soils (Δ199Hg = −0.55 ± 0.15‰, n = 3). This variation could be attributed to differences between the isotopic signatures of modern and pre-industrial atmospheric Hg.Combining a Hg-isotope binary mixing model with a multiple linear regression based on physico-chemical parameters measured in the sediment samples, we determined that active mined creek sediments are contaminated by ASGM activities, with up to 78% of THg being anthropogenic. Of this anthropogenic Hg, more than half (66–74%) originates from liquid Hg(0) that is released during ASGM. The remaining anthropogenic Hg comes from the ASGM-driven erosion of Hg-rich soils into the river. The isotope signatures of anthropogenic Hg in bottom sediments were no longer traceable in formerly mined rivers and creeks.

Secondary dispersion of trace elements in bottom sediments of the High Dam Lake, South Egypt and North Sudan

Thirty-four chemical elements, pH, total nitrogen, and total organic carbon were determined in 49 bottom sediment samples from the whole High Dam Lake in order to improve our understanding of geochemical characteristics of these sediments and geochemical patterns of trace elements and related feeding sources. The present study revealed that the lake were clearly discriminated into three portions in accordance with the sediment geochemistry and geographic position. Likewise, the analyzed elements in the entire lake sediments were classified into six geochemical association patterns that are indicative of the contributing geogenic and anthropogenic sources. As has been noted here, mineralogy, anthropogenic inputs, pH, and organic matter had significant roles in controlling the behavior, concentration, dispersion, and geochemical patterns of the trace elements in the lake sediments. Consequently, the elevated concentration of Bi, Cd, Co, Cr, Cu, Fe, Ga, Mn, Mo, Ni, Sc, V, Y, and Zn posed moderate contamination level in the sediments. At the same time, the enhancement of Ag, Se, and Te levels caused contamination up to very high levels. Admittedly, the contamination levels were generated by natural and human activities that are coming from the Nile basin countries. Despite progressive deterioration of these sediments, they still have economic applications.

ESTIMATION OF SORPTION PROPERTIES OF BOTTOM SEDIMENTS OF THE KUYALNIK ESTUARY

Work is sanctified to research of adsorption descriptions and basic physical and chemical properties and chemical distribution of standards of the ground sedimentations (GS) selected from a superficial layer (0-18 cm) in north part of aquatorium of the Kuyalnik estuary. The sorption of water and methanol vapor, ammonia and sulfur dioxide was determined in the static conditions. Sorption isotherms have been analyzed according to Brunauer-Emmett-Teller theory of polymolecular sorption, the monolayer capacity and the heat of sorption of water molecules and methanol in the first layer have been determined. The essential difference between the values of the specific surface, calculated by different methods (Brunauer-Emmett-Teller theory, Kiselev). The differences in their values are is natural, as for the calculations data are used to measure the sorption of water vapor at different sites of isotherms (for BET - the area at p/ps = 0,01±0,4; Kiselyov at p/ps = 0,55±0,98). Under static conditions the absorption of sulfur dioxide and the ammonia by bottom sediments samples was studied. It is shown the SO2 uptake process, flogoing predominantly through the chemisorption mechanism, occurs only in the presence of «free» water formed after the formation of the monolayer. The maximum sorption capacity on dry samples is 2,6 mg/g. The limiting ammonia sorption capacity (19,1 mg/g at P = 13,3 kPa), unlike sulfur dioxide, in our view, is mainly determined by their organic component, namely the presence in it of humic acids having polyfunctional groups, such as phenolic, hydroxyl groups, carboxylic acid groups that are capable of adsorbing, absorbing and selectively extracting various organic and inorganic substances. The dispersion, organomineral composition, biological, bactericidal activity and sorption characteristics of the samples of bottom sediments (peloids) Kuyalnik estuary in relation to a number of markers of different nature (water vapor, methanol, ammonia, sulfur dioxide) show prospects for use as a cheap natural raw material to expand the range of sorbents for environmental purposes, entero - and vulnerosorbtion (application of sorbents) for medicine, cosmetology.

Sediment-associated organopollutants, metals and nutrients in the Nechako River, British Columbia: a current study with a synthesis of historical data

The flow-diverted Nechako River is the second largest tributary of the Fraser River which drains 25% of mainland British Columbia, Canada. The watershed provides critical reproductive habitats for anadromous chinook salmon (Oncorhynchus tshawytscha) and sockeye salmon (O. nerka) and year-round habitat for the endangered Nechako white sturgeon (Acipenser transmontanus) population. In this study, the chemical quality of sediment in the upper Nechako River and its major tributaries was examined for polychlorinated biphenyls (PCBs), polybrominated diphenyl ethers (PBDEs), legacy organochlorine (OC) pesticides, polycyclic aromatic hydrocarbons (PAHs), organophosphorus and phenoxy acid herbicides, polychlorinated dibenzo-p-dioxins (PCDDs) and furans (PCDFs), labile (exchangeable) metals/metalloids, and major nutrients (N and P). ΣPCB and ΣPBDE were detected in channel bottom sediments at all Nechako River and tributary sites; hexachlorobenzene (HCB) and 4,4′-DDE (dichlorodiphenyldichloroethylene) were also detected at most sites. Organophosphorus and phenoxy acid herbicides were not detected in any samples. While ΣPCB, ΣPBDE, HCB, and 4,4′-DDE concentrations in bottom sediments were always well below provincial and federal guidelines for the protection of aquatic life, concentrations of total labile As (AsT), CrT, CuT, FeT, MnT, NiT, and ZnT in suspended and/or bottom sediments often exceeded provincial threshold effect levels (TEL) and, in some cases, approached or exceeded probable effect levels. Distinct CuT, NiT, PbT and ZnT concentration maxima in suspended sediments were linked to road and urban densities. Historical PCDD, PCDF and PAH data show that concentrations in bottom sediment samples were highest at a site in the lower Nechako River between Miworth and the City of Prince George where PCDD and PCDF concentrations exceeded the interim federal TEL. Nitrogen and P concentrations in bottom sediments were negatively correlated with water velocity and sediment texture; the evidence suggests that reductions in velocity resulting from the 1952 diversion of the Nechako River have increased the nutrient content of bottom substrates.

Pollution of Small Kaunas Rivers with Biogenic Compounds and Heavy Metals

The pollution of surface water bodies with biogenic compounds and heavy metals is a serious global concern for environment as well as for human health. Therefore, the aim of this study was to investigate the pollution of secondary rivers of Nemunas, flowing in Kaunas city, with respect to concentrations of biogenic nitric and phosphorus compounds as well as heavy metals in water and bottom sediments of the rivers. The samples of water and bottom sediments were taken in the influxes of Sėmena, Girstupis, Marvelė, Vėžpienis and Versvas. It was investigated the concentrations of inorganic nitric compounds (ammonium, nitrites and nitrates), and phosphates as well as heavy metals (Zn and Cu) in water and bottom sediments. Sėmena was found to be the cleanest river, as it’s ecological state varied from very good (with respect to phosphates) till average (with respect to ammonium). Girstupis was highly polluted with phosphates; however, it has shown relatively good ecological state with respect to nitric compounds. High concentration of phosphates was also found in Versvas, however, contrary to Girstupis, this river contained exceptionally high concentration of reduced nitric compounds (ammonium). Vėžpienis and Marvelė were the most polluted rivers, most of the nitric and phosphorus compounds exceeded the limit values set in the wastewater management regulations. These rivers were attributed to bad or very bad ecological state with respect to ammonium and good or average ecological state with respect to nitrates and/or phosphates. The concentrations of Zn was relatively low in investigated Kaunas rivers, however, the concentration of Cu was found to be almost 3-times higher than the limit value in Sėmena, Girstupis and Versvas.DOI: http://dx.doi.org/10.5755/j01.erem.74.2.20615

Features of bitumoids composition of bottom sediments of the coastal zone of the East Siberian Sea

An anthropogenic influence, in particular, oil contamination on the Arctic ecosystems is studied. For this composition of the chloroform bitumoids extracted from the samples of bottom sediments is explored. The samples were taken near seaport Kolyma River and a coastal zone of the East Siberian Sea. In bottom sediments of the seaport the yeild of bitumoid reached 25500 mkg g-1. As appeared, their samples were oil contaminated. Hydrocarbons prevailed significantly over the sum of resinous components in their composition as aliphatic compounds dominated over oxygen groups in chemical structure. N-alkanes maked up 28% of the sum of the identified hydrocarbons with a distribution maximum in the area nC15,16. CPI is typical for oil and oil products. The values of ratio of isoprenoids to n-alkanes and the distribution of isoprenoids point to processes of biodegradation of oil hydrocarbons. In the sea samples the yield of bitumoid much less 193-1577 mkg g-1 and oil contamination traces aren’t found. The future of chemical structure and distribution of individual saturated hydrocarbons reveal a strong relationship with terrigenous organic matter of recent deposits. The prevalence of odd hydrocarbons nC23-nC35 and high concentrations nC27, nC29, nC31 is characteristic for lipids of highest land plants.

Monitoring of polychlorinated biphenyls (PCBs) in environmental objects of the city Ust-Kamenogorsk in Kazakhstan

This work devoted to the assessment of the current level of the contamination with polychlorinated biphenyls (PCBs) in environmental objects of the city Ust-Kamenogorsk in Kazakhstan. Particularly, the territory of former Capacitor Plant in Ust-Kamenogorsk and surrounding area were explored and samples of soil, bottom sediments, water, vegetation and fish were sampled from these places. The chemical-analytical studies of PCB contamination were carried out using gas chromatography-mass spectrometry, electrochemical impedance spectroscopy.

Heavy metals risk assessment in water and bottom sediments of ICOLLs in Northern Poland

<p>Natural diversity of intermittently closed and open lakes and lagoons (ICOLLs) depends on mutual interactions of several factors: (i) an impact of sea water and land background; (ii) temporary meteorological situation; (iii) hydrological conditions; and (iv) the shape of lake basin. However, some regional, local or even sudden impacts including anthropogenic ones create their final ecological status. To identify heavy metals risk assessment in ICOLLs located in Polish coastline wide range of them were determined in water and bottom sediment samples collected in 10 water reservoirs. Multidimensional data set of 20 variables was explored by the use of chemometrics according to seasonality (Spring, Summer, Autumn), sample type (water, sediment) and level of isolation (fully isolated, partially and fully connected lakes). The results showed that 70.5% and 77% of the data variance can be explained by the use of principal component analysis for waters and sediments, respectively. Waters of fully isolated or partially connected lakes are more abundant with Ir, Nd and Sm, while less abundant with Pr and Sr. Bottom sediments taken from Jamno lake show significant contamination by heavy metals of the highest environmental concern (Al, Cr, Cu, Ni, Ti and Zn).</p>

The Presence of Toxic and Non-Toxic Cyanobacteria in the Sediments of the Limpopo River Basin: Implications for Human Health.

The presence of harmful algal blooms (HABs) and cyanotoxins in drinking water sources poses a great threat to human health. The current study employed molecular techniques to determine the occurrence of non-toxic and toxic cyanobacteria species in the Limpopo River basin based on the phylogenetic analysis of the 16S rRNA gene. Bottom sediment samples were collected from selected rivers: Limpopo, Crocodile, Mokolo, Mogalakwena, Nzhelele, Lephalale, Sand Rivers (South Africa); Notwane (Botswana); and Shashe River and Mzingwane River (Zimbabwe). A physical-chemical analysis of the bottom sediments showed the availability of nutrients, nitrates and phosphates, in excess of 0.5 mg/L, in most of the river sediments, while alkalinity, pH and salinity were in excess of 500 mg/L. The FlowCam showed the dominant cyanobacteria species that were identified from the sediment samples, and these were the Microcystis species, followed by Raphidiopsis raciborskii, Phormidium and Planktothrix species. The latter species were also confirmed by molecular techniques. Nevertheless, two samples showed an amplification of the cylindrospermopsin polyketide synthetase gene (S3 and S9), while the other two samples showed an amplification for the microcystin/nodularin synthetase genes (S8 and S13). Thus, these findings may imply the presence of toxic cyanobacteria species in the studied river sediments. The presence of cyanobacteria may be hazardous to humans because rural communities and farmers abstract water from the Limpopo river catchment for human consumption, livestock and wildlife watering and irrigation.

Trace elements in soils of oases of Enderby Land (on an example of Vecherny oasis)

The content of trace elements in the soils of the Vecherny Oasis (Enderby Land, East Antarctica), where the construction of the Belarusian Antarctic Station started in December 2015, is considered. The results of the research are based on data collected during four Belarusian Antarctic expeditions in the period from 2011 to 2017, and analytical testing of soil samples taken from impacted and non-impacted sites. A total of 22 soil samples were analyzed for the content of trace elements; to compare the levels of accumulation and possible migration pathways, 7 samples of bottom sediments were also analyzed. Determination of trace elements was carried out using the AAS method (Cd, Cr, Cu, Pb, Ni, Zn, Fe, Mn) and emission spectral analysis (about 40 elements). The average values and range of concentrations of trace elements in soils and bottom sediments of the oasis are presented. The possible dependence of the trace elements content on the location positions in the landscape and on the sources of impact is discussed. It is shown, that the variability of metals content in soil profile for background site is low. In comparison with other oases of Antarctica no hotspots have been revealed and no significant areas of soil contamination have been identified yet, which is largely due to the fragmentation of the soil cover and lack of significant sources of pollution.

Beach Erosion in the Gulf of Castellammare di Stabia in Response to the Trapping of Longshore Drifting Sediments of the Gulf of Napoli (Southern Italy)

The results of this study have allowed verification that longshore sediment transport along the coast of Napoli Gulf (southern Italy) takes place from Northwest to Southeast. The current analysis describes the results of an integrated sedimentological and geomorphological study of the Neapolitan coastal area. A sedimentological and morphosedimentary study was carried out by bathymetric survey and sampling of bottom sediments. The analysis of modal isodensity curves shows that all the sediments are moved from NW to SE by longshore currents parallel to the coastline. The morphological evolution of the Castellammare di Stabia Gulf coastal area, based on historical coastline changes, starts from 1865, when the sandy littoral was wide and in its natural state. Since the construction of the Torre Annunziata harbor in 1871, sediments transported by a NW-SE longshore drift have become trapped, inducing the genesis of a new wide triangular-shaped beach on the updrift side (NW) of the harbor breakwall. This process induced a significant shoreline retreat of the south-east sector of the littoral. Widespread beach erosion of the coastal physiographic unit of Castellammare di Stabia Gulf (delimited by two ports) is more developed in the southern portion. This study highlights a slight rotation of the shoreline toward the East and a general trend of regression, with typical overall accentuation of shoreline concavity, and significant widening of the triangular-shaped beaches at the end of the falcate. This reduced sediment input removed from the sedimentary budget a large amount of deposits, which are hardly restorable due to the scarce supply of sediment load by the Sarno river and its tributaries. In addition to this new and important derived morphologic feature, other recent human interventions have contributed to further modifications of morphologic characteristics of emerged and submerged beach. The intense use of the territory caused modifications on both the fluvial course and river mouth with direct and indirect effects on the shoreline and the drainage network of the Sarno River.

Assessment of sediment quality using different pollution indicators and statistical analyses, Hurghada area, Red Sea coast, Egypt

Thirty bottom sediment samples were collected from northern Hurghada coast, Red Sea, Egypt to evaluate the level of anthropogenic pollutants, using enrichment factor (EF), potential ecological risk index (PERI), soil pollution index (SPI), potential contamination index (Cp) and multivariate statistical analysis (correlation analysis, principal component analysis, and hierarchical cluster analysis). Fe, Mn, Zn, Pb, Ni, Cu, Co and Cd were analyzed by Atomic Absorption Spectrophotometer. Results indicated that the average values of Pb and Cd were greater than the ones recorded from many other worldwide coastal areas. The studied sediments are extremely severe enrichment with Pb and Cd (EF > 50), severe enrichment with Zn (EF = 10–25), very high risk with Cd (PERI ≥ 320), high risk with Pb (160 ≤ PERI ˂ 320), highly contaminated with Pb (SPI > 3), a severe contamination with Pb (Cp > 3). The accumulation of pollutants is associated with the muddy and fine sediment; especially the studied area is a semi-closed bay, characterized by long time of water retention. Possible sources of metals pollution in the studied area are shipment operations and anticorrosive and antifouling paints, dredging and land filling, municipal wastewater from tourist centers and fishermen cargo boats.

Surfactants in Klodnica River (Katowice, Poland). Part II. Quaternary Ammonium Compounds

Abstract The paper presents methods of determination of analytes of the cation group (alkyl benzyl dimethyl ammonium (BDDA-C12-C16), alkyl trimethyl ammonium (TMA), hexadecyl piridinium (HP)) in surface water and bottom sediment samples. In the sample preparation phase the solid phase extraction (SPE) or accelerated solvent extraction/ultrasound assisted extraction (ASE/UAE)-SPE technique was used and in the identification phase and quantitative determination of analytes phase - ion chromatography technique (combined with a conductivity detector (CD)). The determined concentrations were in the range below the determined method detection limit (MDL) or method quantification limit (MQL) figures up to 0.142 ±0.023 mg/dm3 or 2014 ±10 μg/kg (liquid and solid samples, respectively). Comparing concentrations of individual analytes found in liquid and solid environmental samples we may notice that surfactants containing a shorter alkyl chain in their molecules were found in higher concentrations in liquid samples (hydrophobicity increasing with the chain length).

Hidrodinâmica e transporte de sedimentos na bacia do rio Branco, afluente do rio Paraguai, Pantanal Mato-grossensse

Estudos sobre a hidrodinâmica e o transporte de sedimentos possibilitam compreender como ocorrem as pressões no meio e a relação entre os elementos ambientais. O objetivo da pesquisa foi analisar as variáveis hidrodinâmicas e transporte de sedimentos na bacia hidrográfica do Rio Branco, afluente do Pantanal mato-grossense. Foram selecionadas dezesseis seções para obtenção de informações da hidrodinâmica e do transporte de sedimentos. Com o intuito de obter a batimetria, utilizou-se o ecobatímetro. A verificação da velocidade do fluxo foi realizada com o uso do molinete fluviométrico. A fim de coletar os sedimentos suspensos, usou-se a garrafa de Van Dorn; para os sedimentos de fundo, utilizou-se a draga Van Veen. O fracionamento das amostras de sedimentos de fundo foi realizado através do método da pipeta, com dispersão total e peneiramento. A vazão dos canais variou entre 0,005 e 4,861m³/s no período de estiagem e de 0,11 a 126,42 m³/s no período chuvoso. Os sedimentos transportados em suspensão mantiveram-se entre 12 e 288mg/L-1. A carga sólida em suspensão ficou entre 0,02 e 3.146 t/dia-1. Na composição granulométrica de sedimentos de fundo, predominaram as frações de areia fina. Através desse estudo foi possível observar o comportamento hídrico e a disposição de sedimentos entre os períodos de cheia e estiagem.