Hasan Özcan

Investigation of heavy metal mobility and availability by the BCR sequential extraction procedure: relationship between soil properties and heavy metals availability

Abstract In this study, surface soil and corn cob samples were collected from 15 different agricultural fields of Çanakkale, Turkey. These samples were analysed to determine the concentration of Cd, Cu, Mn, Ni, Pb and Zn. BCR sequential extraction was used to extract the binding forms of the metals in the soil samples. At the same time, a wet digestion method was used to determine the total concentration of heavy metals in soil and corn grain samples. The metal concentrations in the extracted phase were measured with flame atomic absorption spectrometer. The accuracy of the methods was confirmed by using BCR-701 and SRM-1570a certified reference materials. The results revealed that the quantity of the mobile fractions (i.e., acid soluble, reducible, and oxidisable) of the Mn, Cd and Pb were higher than that of the immobile fractions (residual). This might be caused by the anthropogenic sources. Pearson’s correlation was applied to determine the correlations between the selected physicochemical properties of soil samples and the amounts of heavy metals in each fraction. The pH, CaCO3 and organic matter contents of soil samples played a dominant role in correlations of heavy metals in various forms and shapes. Hierarchical cluster analysis was applied to examine the relationships between the amount of heavy metal in each fraction of soil samples and the amount of heavy metal in corn grain. As a result, a firm correlation was detected between heavy metals in corn grain and more available (acid soluble and reducible) fractions. Current findings indicate that plants could uptake basically the heavy metals in acid soluble and reducible fractions. BCR sequential extraction not only provides information about potential heavy metal sources in detail and the potential mobility of heavy metals, but also provides information about the interactions between soil characteristics and metal fractions. This provides information on the bonding states of environmentally toxic metals (Cd, Cu, Mn, Ni, Pb and Zn) in the soil matrix, the amounts taken by the plants, and the intrusion means and rates of those metals into the food chain.

Characterization of Heavy Metal Fractions in Agricultural Soils by Sequential Extraction Procedure: The Relationship Between Soil Properties and Heavy Metal Fractions

The present research was conducted to determine heavy metals in agricultural soils from Çanakkale, Turkey, using a sequential extraction procedure (acid soluble, reducible, oxidizable, and residual) as proposed by the Community Bureau of Reference (BCR) of the European Commission. Soil samples were taken from 12 different cultivated sites and analyzed for Cd, Co, Cr, Cu, Mn, Ni, Pb, and Zn concentrations. The results revealed an order of Mn > Cd > Pb > Co > Ni > Cu > Zn > Cr for the heavy metals based on the sum of the first three fractions (acid soluble + reducible + oxidizable). The relationships between soil properties and each metal fraction were identified through Pearsonss correlation analysis. Hierarchical cluster analysis was performed to determine the behaviors and similarities of metals in each fraction. While Mn, Pb, and Zn exhibited subjective behaviors in the acid-soluble fraction, Cd, Co, Cu, Cr, and Ni exhibited similar behaviors with each other.

Determination of heavy metals in sediments of the Ergene River by BCR sequential extraction method

Utilizing the sequential extraction procedure (acid soluble, reducible, oxidizable, and residual) proposed by The European Community Bureau of Reference (BCR), the trace metals present in the sediments of the Ergene River, Turkey, were determined. The sediment samples were collected from 10 sampling sites and analyzed to identify the concentrations of cadmium, cobalt, chromium, copper, manganese, nickel, lead and zinc. The flame atomic absorption spectrometer was used for metal determination. The validation of the results was checked by the analysis of the BCR-701 standard reference material. The relationship existing between the sediment characteristics and metal fractions was identified using the correlation analysis. Hierarchical cluster analysis was performed to find out the grouping of the sampling sites based on the similarities of the heavy metals in the bioavailable fraction. When the extractable amounts of heavy metals are considered, the quantity of the mobile fractions (viz., acid soluble, reducible, and oxidizable) of the heavy metals is observed to be higher when compared with that of the immobile fraction (residual). This might be caused by the anthropogenic sources. Besides, it was statistically discovered that the organic matter, pH and clay contents could influence the bonding of the analyte metals in various forms. The cluster analysis revealed three clusters of the sampling stations, with group I (S5-8) and group II (S3, S4 and S9) showing higher environmental risks. The risk assessment code indicated that the highly mobile soluble fractions of Mn, Zn, Cd and Co created a high environmental risk which could result in negative impacts on the aquatic biota.

Chemometric and geochemical study of the heavy metal accumulation in the soils of a salt marsh area (Kavak Delta, NW Turkey)

PurposeA series of investigations were performed to provide heavy metal signatures of salt marsh soil and to evaluate potential sources in Kavak Delta, NW Turkey.Materials and methodsThe soil samples were collected from 77 sampling sites and analyzed to identify the concentrations of Ba, Cd, Cr, Cu, Fe, Li, Ni, Pb, Se, Sr, and Zn. Inductively coupled plasma atomic emission spectroscopy was used for metal detection. In order to assess the existing pollution, geochemical approaches such as enrichment factor, geo-accumulation index, contamination factor, and pollution load index were applied.Results and discussionThe results indicated that the average values of the analyzed metals (except Ba and Sr) were more than the shale averages. Chemometric analysis was performed, and three main sources with corresponding cluster elements were identified: Pb and Se are mainly derived from anthropogenic sources; Ba, Cd, Cr, Cu, Li, Ni, and Zn have anthropogenic sources combined with lithospheric sources, while Sr comes mainly from lithospheric sources. The resultant pollution load index (1.62) for metals in the salt marsh soils indicated metal pollution in the research site. Geoaccumulation index, enrichment factor, and contamination factor also resulted in supporting outcomes and indicated prominently Cd, Li, Ni, Pb and Se metals in the existing pollution of the site.ConclusionsCombining chemometric and geochemical approaches can be successfully used for natural and anthropogenic sources and pollution assessment of salt marsh soils. It was observed that Cd, Li, Ni, Pb, and Se dominantly accumulated in the research site. These metals may have a negative impact on the existing species in the study area and create an environmental risk.

Chemical fractionation, mobility and environmental impacts of heavy metals in greenhouse soils from Çanakkale, Turkey

The primary objective of this study was to identify possible heavy metal pollution risks in greenhouse soils. Collected soil samples were subjected to heavy metal analysis to determine Cd, Cr, Cu, Ni, Pb and Zn concentrations. Binding forms of the metals were determined by following a sequential extraction procedure. The wet digestion method with aqua regia procedure was employed to find the pseudo total heavy metal concentrations of soil samples. BCR-701 and NIM-GBW07425 certified reference materials were used to validate the reliability of the methods. Contamination factor, potential ecological risk index and risk assessment code were used to assess the environmental impacts of heavy metals in greenhouse and field samples. Results of extractable amounts of heavy metals from greenhouse samples revealed that mobile fractions of Cd, Pb and Ni were higher than immobile fractions and mobile fractions of Cr and Zn were closer to immobile fractions. Human-induced effects were considered the primary reason for this. Soil pH and organic matter content were found to be highly correlated with heavy metals of soil samples from greenhouses. With regard to environmental impacts of heavy metals, Cd was much more mobile in greenhouse samples than in field samples, retained less in ambient soil and had high environmental risks. It was observed that Cd was highly mobile, less retained and exerted higher environmental risks. With regard to environmental risks, Cd was followed respectively by Pb, Cr and Zn in greenhouse soils. Sequential extraction yielded significant information about mobility, behavior and environmental impacts of heavy metals.

Physico-Chemical Characteristics of Coastal Dunes on the Saros Gulf, Turkey

Abstract In the present paper, several physico-chemical characteristics of dune sands in a rapidly prograding delta environment on the east coast of the Saros Gulf, northwest Turkey, are presented. For accurate characterization and classification of coastal dunes 4 km long and maximum 500 m wide, the pH, CaCO3 content, electrical conductivity, organic matter content, and x-ray fluorescence spectroscopy data were assessed. In terms of dune classification, our results showed the presence of three distinctive coastal dune types: (1) foredune, (2) semistable gray dune, and (3) stationary dark dune. Field observations combining with aerial photo and satellite image interpretations for the period between 1962 and 2007 also revealed dune loss and migration in the dunefield as a consequence of bidirectional effects of south-westerly and northwesterly winds and wind-force rise of lagoon waters.

Investigation of Discharge of Fresh Water in the Canakkale Strait (Dardanelles-Turkey)

The Canakkale Strait (Dardanelles) is a water passage connecting the Aegean Sea and the Marmara Sea. Its NE/SW trend is interrupted by a north-south bend between Eceabat and Canakkale. The width of the Strait varies from 1.35 to 7.73 km, the narrowest part located between Canakkale and Kilitbahir. The average depth of the Strait is approximately 60 m; the deepest part reaches more than 100 m. The aim of this study is to determine the locations of fresh water discharge into the Canakkale Strait. For this purpose, 52 sample points were selected in the study area. The temperature, pH and salinity were measured at different depths of water in the Canakkale Strait (1, 5, 10, 20 and 30 m). A Geographic Information System (GIS) was used to create a tabular and spatial database, with the aim of integrating the physical properties in the Canakkale Strait. The results of this study show that discharge of fresh water is seen in four locations on the southeastern coast between Dardanos and Canakkale, and that the Aegean Sea and Marmara Sea water are mixing between Canakkale and Kilitbahir. In the future, these sources of fresh water may be needed as population increases in the region. However, water pollution in the Canakkale Strait may limit the use of this fresh water.

Ecotourism Potential and Management of Kavak Delta (Northwest Turkey)

Abstract Wetlands are ecosystems where a high level of biodiversity is found. Being a suitable medium for the nourishment, reproduction, and accommodation of many species of living creatures, wetlands are museums of natural riches, not only of the country where they are located but also of the whole world. Kavak Delta, one of the most important wetlands of Turkey, with coastal dunes and halophilic vegetation as well as being on the north–south bird migration route, provides not only opportunities for coastal tourism but also offers substantial potential for ecotourism. During observations, bird species, especially of the orders Anseriformes, Falconiformes, and Charadriiformes, were identified. Some 14 orders, 39 families, and 124 bird species were spotted in the delta. Also, dune and halophilic plants constitute a rich flora in the delta. In this study, the potential for ecotourism and opportunities for coastal tourism in the area are outlined. Within this context, besides ecotourism activities, such as bird observation, botanic tourism, and angling, the use of beaches for coastal tourism is determined. Various recommendations are made for the optimal use of all tourism opportunities detected in the delta and for enabling sustainable coastal use and management.

Solonchaks and Solonchak-Like Soils

Solonchaks are described as soils with a Salic horizon starting within ≤50 cm from the soil surface, and should not have a Thionic horizon starting within the ≤50 cm from the soil surface according to the IUSS Working Group WRB.