Occurrence,sources, bioaccumulation,and air–water exchange fluxes of polycyclic aromatic hydrocarbons in Lake Hongze,China

Journal of Soils and Sediments - Compared with deep oligotrophic waters, the distribution and geochemical processes of polycyclic aromatic hydrocarbons (PAHs) in shallow eutrophic waters are more...     

Applying Chemometrics to Determine Dispersion of Mine Tailing-Affected Sediments from Submarine Tailing Disposal in Bøkfjorden,Northern Norway

Mine tailing management is one of the largest environmental issues related to mining operation. This study uses chemometrics to assess the dispersion of iron mine tailing-affected sediments in Bøkfjorden, Northern Norway. Metal concentrations (Al, As, Cd, Cr, Cu, Fe, Mn, Ni, Pb, Zn) and physico-chemical sediment characteristics (conductivity, organic matter, sulphate, chloride, grain size, CaCO₃, pH) were analysed in seven sediment cores collected in a transect out of the fjord along with two reference cores. Results of hierarchical cluster analysis and principal component analysis allowed to distinguish between mine tailing-affected and non-affected sediments. Non-affected sediments were especially characterised by high levels of organic matter whilst mine tailing-affected sediments varied significantly in sediment characteristics depending on location in the fjord. Crucial parameters to reveal mine tailing-affected sediments varied between the target metal Fe along with metals of Cd and Mn, albeit less significant. Variations in mine tailing-affected sediment characteristics could be attributed to other anthropogenic activities in the fjord. Despite potential disturbances, chemometrics made it possible to identify dispersion of mine tailing-affected sediments to cover the inner and middle parts of the fjord. The study demonstrates the advantage of applying chemometrics on complex fjord systems, which in this case was used to distinguish mine tailing-affected sediments from areas with elevated levels of metals not necessarily related to the mine.     

An Evaluation of Fresh Water Sediments Contamination: the Lachine Canal Sediments Case,Montréal,Canada. Part I: Quality Assessment

Due to industrialization over the past 100 years, the sediments at the bottom of the Lachine Canal and Bay have become contaminated. This study investigated the heavy metal accumulation mechanisms within the Lachine Canal sediments and was carried out in three phases. Phase I is covered in the present article, while phases II and III will be discussed in a following paper. During Phase I, 28 parameters were measured on 44 sediment samples collected along the Lachine Canal and Bay. The results revealed the presence of a wide variety of both organic and inorganic contaminants. Heavy metals such as Zn < Pb < Cr < Ni < Cu < Cd (in order of decreasing abundance) in addition to organic contaminants (PAHs < MAHs < PCBs) were found in high concentrations exceeding background concentrations and various quality criteria levels. The total load of both organic and inorganic contaminants was found to be higher in the canal than in the bay zone. Correlation analysis was performed to evaluate sediment assessment values with respect to known adsorptive phases such as % clay fraction, TOC (Total Organic Carbon), and % CaCO₃. Although a positive correlation existed between % clay fraction or TOC and the total cumulative load of heavy metals, the correlation could not be assessed as conclusive. Significant correlations were obtained between Pb, Ni, and Zn and the carbonate content of the sediments. Pollution Indices (PI) were used according to the format proposed by Canadian authorities and as such were evaluated as incomplete.     

Evaluation of Mercury,Lead, Arsenic,and Cadmium in Some Species of Fish in the Atrato River Delta,Gulf of Urabá, Colombian Caribbean

The concentrations of mercury, lead, cadmium, and arsenic were evaluated in 96 samples, 12 by each one of the following eight fish species: snook (Centropomus undecimalis), crevalle jack (Caranx hippos), Serra Spanish mackerel (Scomberomorus brasiliensis), southern red snapper (Lutjanus purpureus), blue runner (Caranx crysos), Atlantic tarpon (Megalops atlanticus), ladyfish (Elops saurus), and Atlantic goliath grouper (Epinephelus itajara), which were collected during 1 year in the Atrato River Delta in the Gulf of Urabá, Colombian Caribbean. Three fish were caught from each of the following sites the community usually uses to catch them (known as fishing grounds): Bahía Candelaria, Bahía Marirrío, Bocas del Roto, and Bocas del Atrato. The quantification of metals was performed by microwave-induced plasma-optical emission spectrometry. The Pb concentration fluctuated from 0.672 to 3.110 mg kg^?1, surpassing the maximum permissible limit (MPL?=?0.3 mg kg^?1) for human consumption for all species. The Hg concentration ranged between < Limit of detection and 6.303 mg kg^?1, and in the crevalle jack and Atlantic tarpon, concentrations exceeded the MPL (0.5 mg kg^?1). The levels of Cd and As were not significant in the studied species and did not exceed the MPL (0.05 mg kg^?1).     

An Evaluation of Fresh Water Sediments Contamination: The Lachine Canal Sediments Case,Montréal,Canade. Part II: Heavy Metal Particulate Speciation Study

Over the last century, discharge of industrial effluents and municipal wastewater have contaminated the Lachine Canal sediments. This study investigated the associations between heavy metals and natural sediment constituents. X-ray Diffraction, Transmission Electron Microscopy and geochemical analysis revealed that the sediments consisted mainly of silt and clay size fractions composed of: feldspar, illite, kaolinite, chlorite, calcite and dolomite as well as minor amounts of Fe minerals. Organic matter and amorphous metal oxides were also identified. Each of these constituents bound heavy metals at varying degrees as assessed by a sequential chemical extraction (SCE) protocol. The associations with each geochemical phase were (in order of decreasing significance): 1) residual phase, 2) oxide phase, 3) carbonate phase, 4) organic phase and 5) exchangeable phase. According to the cation exchange capacity (CEC), carbonate and oxide content measurements, the heavy metals occupied a minor fraction of the total capacity of the sediments to retain metals by these mechanisms. The SCE results revealed that the partition patterns varied with pH. The phases associated to the carbonate and the exchangeable phases were the most sensitive to a change in pH with the residual phase being almost unchanged. The Zn and Cd were sensitive to release when the conditions drifted to acidic conditions. The partition patterns for various grain size fractions (<53 µm, 53–75 µm, 75–175 µm and <175 µm) revealed that no particular fraction accumulated a certain heavy metal. Finally, from protocols, techniques and results interpretation in this study, various engineering applications such as the technical choice of clean-up scenarios, screening of remediation techniques and the development of remediation quality criteria were proposed within the framework of the management of contaminated sediments.     

Evaluation of Soil Tests for Plant‐available Mercury in a Soil–Crop Rotation System

A reliable soil test is needed for estimating mercury (Hg) availability to crop plants. In this study, four extraction procedures including 0.1 M hydrochloric acid (HCl), 1 M ammonium acetate (NH₄OAc) (pH 7.0), 0.005 M diethylenetriaminepentaacetic acid (DTPA), and 0.1 M calcium chloride (CaCl₂) (pH5.0) were compared for their adequacy in predicting soil Hg availability to crop plants of a rice–cabbage–radish rotation system. The amounts of Hg extracted by each of the four procedures increased with increasing equilibrium time. The optimal time required for extraction of soil Hg was approximately 30 min, though it varied slightly among the four extractants. The amounts of Hg extracted decreased with increasing soil/solution ratio, and a soil/solution ratio of 1:5 appeared to be adequate for soil Hg availability tests. The amounts of Hg extracted increased in the order of NH₄OAc < CaCl₂ < DTPA < HCl in silty loam soil (SLS) soil, and the order was NH₄OAc < CaCl₂ ≈ DTPA < HCl in yellowish red soil (YRS) soil. Significant positive correlations among the four extractants were obtained in SLS soil. In contrast, the correlations were poor in YRS soil, especially for HCl. There were significant correlations between concentrations of Hg in edible tissue of three plants and the amounts of soil Hg extractable to the four extractants for soil–rice system and soil–radish system, but not for soil–Chinese cabbage system. The 0.1M HCl extraction overall provided the best estimation of soil‐available Hg and could be used to predict phytoavailability of Hg in soil–crop systems.     

Reply to comments on: Mao et al. (2018) “Bibliometric analysis of insights into soil remediation” Journal of Soils and Sediments, 18(7):2520–2534

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Evaluation of Water Quality from the Perspective of Eutrophication in Lake Eğirdir,Turkey

Water, Air, &; Soil Pollution - Lake E?irdir is one of the most important freshwater resources in Turkey. The lake is located at the border of Isparta province in South West Turkey, an area...     

White-tailed sea eagle Haliaeetus albicilla reintroduction to the Isle of Rhum,Scotland, 1975–1977

An attempt to reintroduce the white-tailed sea eagle to the west of Scotland was initiated by the Nature Conservancy Council in 1975, on the Isle of Rhum. Four eaglets were obtained from Norway that year; one of them died in captivity and the other three (all females) were released. Ten more were acquired in 1976 and a further four in 1977. Of these a total of 13 (8♀ and 5♂) had been released into the wild by May 1977. Two have since been recovered dead, but the others apparently adapted readily to a free-living existence. Eight more are to be released during 1978. The first nesting attempts can be expected once the young birds reach sexual maturity at 5 years of age (possibly in 1980 or 1981).     

Tolerance mechanisms of Leymus chinensis to salt–alkaline stress

The salinization–alkalization of soil is an increasing environmental problem and a limiting factor for plant growth and productivity. This paper studied the morphological and physiological response of rhizomes of Leymus chinensis, which grows rapidly and is highly tolerant to arid and saline–alkaline soils, to different levels of saline–alkali stress. Biomass and density of rhizomes showed a variation along with the increase in saline–alkali stress; they show the maximum level in a saline–alkali medium. Rhizome internode length and specific root length gradually increased, while root biomass indicated a contrary tendency towards increase in saline–alkali stress. Under different saline–alkali stress, the root–shoot ratio showed no significant differences among groups. The variation in Na⁺ content was increased with the increase in saline–alkali stress. The contents of K⁺ and proline were the highest in a saline–alkali medium; under different levels of salt–alkali stress, the presence of organic acids (OAs) showed different changes. Citrate, malate and succinate were the dominant OAs accumulated in rhizomes. The activity of superoxide dismutase, catalase and peroxidase increased with incrementing salt–alkaline stress. In summary, L. chinensis is likely to exert a series of adaptable response on its physiology and morphology under different levels of salt-alkaline stress. Further study on large-scale cultivation of the L. chinensis would be beneficial for the ecological recovery and exploitation of the salt-alkalinized soil.     

Aquatic Gastropods as Mercury Indicatorsin the Pantanal of Poconé Region (Mato Grosso, Brasil)

Gold mining is the principal polluting activity in themunicipality of Poconé at the northern limit ofthe Pantanal of Mato Grosso, Brasil and ischaracterized by the inadequate use of mercury in thegold extraction process. A way to contribute to theassessment of the environmental impact of mercuryrelease in the Pantanal is to make use of bioaccumulation. Thus, determinations of total mercuryin 188 Gastropods of three different species were madein seven different sampling sites during the dry andwet periods. Increase of mercury levels in the snailswas restricted to the gold mining area and adjacentsedimentation areas. The largest mercuryconcentrations were found at the Tanque dos Padressite, reaching 2.04 g g^-1 in individuals ofPomacea scalaris. In the other sampling sites,molluscs collected in the Araras/Piuval Bay complex,a mercury retention area, showed the largest mercuryconcentration, reaching up to 1.12 g g^-1.     

Metal Status of Soils and Plants Irrigated with Water from Lake İznik,Turkey

Lake ?znik, located in the southeast part of the Marmara region in Turkey, is considered the largest lake in the region. Soil pollution from irrigation with lake water has become an important concern for arable lands surrounding the lake. Therefore, a study was conducted to investigate trace element contamination of soils and plants irrigated with water from the lake, which has been polluted with industrial and municipal wastes. Eleven different crops grown in 30 different horticultural fields, consistently irrigated with lake water, were studied. To determine pollutant concentrations, soils, plants, and water were sampled and analyzed for both total and extractable iron (Fe), manganese (Mn), zinc (Zn), copper (Cu), cobalt (Co), nickel (Ni), chromium (Cr), lead (Pb), and cadmium (Cd). Iron, Cu, and Ni in destructively sampled soils were found to be excessive in soils. The results were subjected to statistical analysis using simple correlations and t‐test. There were no statistically significant relationships among the total and extractable metals in soils and extractable plant metals. Because of lack of standard concentrations indicating excessive concentration of extractable elements, statuses of extractable elements in the soils were not evaluated. Cobalt, Pb, Cr, and Cu concentrations were greater than the normal range in leaves. The accumulation of metals differed greatly among the various plant species, but irrigation with lake water did not increase metals in soils. The appearance of metals in soils might be due to agricultural activities and parent material. Continuous monitoring and future studies of the area are recommended to ascertain long‐term impacts of pollution on plants.     

Anthropogenic Influences on Annual Flux of Cations and Anions at Meio Stream Basin, São Paulo State, Brazil

The chemical dynamics at Meio Stream Basin, São Paulo State, Brazil were evaluated using major elements as natural tracers. The surface water samples from Meio Stream were collected near the mouth of Meio Stream at the confluence with the Mogi-Guaçu River on February 25, 2005, April 20, 2005, and July 8, 2005. Rainwater samples were collected (using a “bulk” collector) for 1 year at one sampling point located about 4 km from downtown Leme city and other possible sources of contamination. The analyses were performed by pH, temperature, dissolved oxygen, electrical conductivity, total solids, sulfate, nitrate, phosphate, alkalinity, chloride, sodium, calcium, potassium, and magnesium. This basin has serious environmental problems in terms of rainwater and surface water quality, which result in the negative annual flux of cations and anions at Meio Stream Basin, with the exception of chlorine. The Meio Stream, downstream from Leme city, receives several elements/compounds through anthropogenic activities, mainly related to the discharge of domestic effluents. Anthropogenic inputs (mining, fossil fuel burning, and agricultural activities) are responsible for the higher concentrations of cations and anions in the rainwater from this basin.     

Evaluating the Absorption of Boron by Plants��A Potential Tool to Remediate Contaminated Sediments from Cecina River Basin in Italy

Assessment of native plants and laboratory-scale phytoextraction tests are fundamental and preliminary steps in checking the feasibility and practice of low-cost and low-impact phytoremediation. In this study, we investigated the absorption of B by plants as a tool to remove boron in sediments from different areas of the Cecina River basin in Tuscany, Italy. The investigation was performed analyzing total and available B fraction in sediment samples as well as the B content in different tissues of native plants colonizing the contaminated areas. In laboratory scale, a phytoextraction screening test was performed. Selected high biomass crops (Brassica juncea, Zea mays, and Helianthus annuus) were evaluated in the most contaminated sample in two consecutive growing cycles. Results from field survey showed no hyperaccumulator native plant was present in the investigated areas although, high accumulation levels were found in native species from Bulera dump (Rumex crispus??259 mg?kg^?1 and Poa spp??203 mg?kg^?1). Results from laboratory phytoextraction tests showed a higher ability of B. juncea which removed about 18.5 mg?B?kg^?1 sediment in after the two consecutive growing cycles, representing on the whole 45% of the initial available B fraction. The sediment characteristics affected by the phytoextraction processes were also discussed.     

Bean Plant Production of Dry Matter and Grain Related to Soil Citric Acid–Extractable Copper,Zinc, Cadmium,and Lead

Some knowledge concerning soil heavy‐metal content and its availability to plants is essential to evaluate the risk of potentially toxic elements in the alimentary chain. Assessment of heavy‐metal availability to plants was achieved by a simple extraction method. The goal of this work was to determine the contents of copper (Cu), zinc (Zn), cadmium (Cd), and lead (Pb), soluble in 2% citric acid solution (chelating agent), in dystrophic red latosol soil (RL_d) and humic red‐yellow latosol soil (RYL_h). We focused on relating the contents of Cu, Zn, Cd, and Pb to the production of dry matter and grains by bean plants cultivated in a glasshouse. Heavy‐metal contents extracted by citric acid increased with increasing dosage increments, mainly in RL_d; production of dry matter by bean plant was negatively affected by the studied metals. However, in some cases, grain production was increased.     

Quantification of Soil Macropores at Different Slope Positions under Alpine Meadow Using Computed Tomography in the Qinghai Lake Watershed,NE Qinghai–Tibet

Eurasian Soil Science - Soil macropores largely control fluid and solute transport and the runoff processes on the slopes. However, the characterization of soil macropores for different slope...     

Tripartite symbiosis of Pisum–Glomus–Rhizobium leads to enhanced productivity,nitrogen and phosphorus economy,quality, and biofortification in garden pea in a Himalayan acid Alfisol

The present study was carried out to assess nitrogen (N) and phosphorus (P) economy, quality, and productivity of garden pea (Pisum sativum L.) through dual-inoculation of arbuscular mycorrhizal fungi (AMF) and Rhizobium in an acid Alfisol. Experiment was laid out in randomized block design replicated thrice comprising 13 treatments viz. Rhizobium along with three graded N levels (25%, 50%, and 75% soil-test-based recommended N), AMF along with three graded P levels (25%, 50%, and 75% soil-test-based recommended P), dual-inoculation of AMF and Rhizobium conjoint with four graded N and P levels (25%, 50%, 75%, and 100% soil-test-based recommended N and P), and three other treatments viz. generalized recommended NP potassium (K) dose (GRD), farmers' practice, and absolute control. The results revealed that dual-inoculation of AMF and Rhizobium enhanced the pea productivity, macronutrient (NPK) and micronutrient iron, copper, zinc, and manganese (Fe, Cu, Zn, and Mn) concentrations, and their uptake besides enhancing garden pea quality. Also, dual-inoculation of both symbionts at 75% and 100% soil-test-based N and P dose behaved statistically alike with respect to pea pod yield, NPK uptake, and quality parameters like total soluble solids (TSS) and crude protein (CP), thus indicating an economy of about 25% soil-test-based N and P dose through co-inoculation. AMF and Rhizobium dual-inoculated treatments led to enhanced TSS and CP in pea pods by 4.2% and 6.2%, respectively, over GRD, while sole application of AMF- or Rhizobium-imbedded treatments could enhance these quality parameters by 2.1% only in each case. Similarly, the highest N and P response ratio was registered in dual-inoculated treatments. Overall, dual-inoculation of AMF and Rhizobium with 75% soil-test-based N and P dose in pea can save up to 25% fertilizer N and P dose in acid Alfisol.Also, this tripartite symbiosis besides enhancing pea quality led to better bio-fortified pea seeds with micronutrients especially Fe and Zn, which can greatly curtail the widespread anemia and Zn deficiency in humans living in Himalayan acid Alfisol.     

Sediments in urban river basins: a review of sediment–contaminant dynamics in an environmental system conditioned by human activities

Background, aim and scope  Over 50% of the global population live in urban centres and, therefore, an understanding of the processes acting upon urban systems is a global issue. The nature of human-made, often impervious, land surfaces and heavily engineered waterways results in hydrological and sedimentological systems in urbanised basins which contrast significantly to those within more natural (i.e. pristine, forested, agricultural) aquatic systems. In addition, the abundance of contamination sources in urban systems results in chemical pressures often manifested as high pollution concentrations or loadings, which in turn have detrimental impacts on human and ecosystem health. These lead to management and sustainability issues not generally encountered in more natural environments. The purpose of this review is to provide a state-of-the-art assessment of sediment sources, pathways and storage within urban river systems, to consider sediment management within urban systems and river basins, and examine the role of local and global environmental changes on sediment processes and management. Inevitably, much of the sediment that is transported within urbanised basins is contaminated, so this review also considers sediment–contaminant sources and interactions. Conclusions and recommendations  We reach a number of conclusions and recommendations for future research. There is a need for better sampling and monitoring of sediment and sediment-associated contaminant fluxes and cycling in urban river channels and basins. This should include better techniques and studies to identify sources and transfers of road-deposited sediment (RDS), airborne particulate matter and sediments in the river system. Greater interdisciplinary research, combining sedimentologists, hydrologists, urban planners, urban archaeologists, chemists and biologists, is needed. More attention needs to focus on upscaling and connecting urban areas to the rest of the river basin, both upstream and downstream. Finally, there is a need to balance multiple needs (urban population, water resources) with likely trends in both urban development and global environmental change.