High Concentrations Of Trace Metals Research Articles

The Impact of Penguins on the Content of Trace Elements and Nutrients in Coastal Soils of North Western Chile and the Antarctic Peninsula Area

In isolated areas without direct human impact where several species of seabirds nest, transformations affecting the soil come mainly from natural processes, such as chemical enrichment caused by seabirds. Penguins constitute an important bird biomass in the Southern Hemisphere, where they breed in colonies on different sites from 100 to thousands of individuals. The accumulation of trace elements and nutrients in soils within two perennial colonies of Humboldt penguins (Spheniscus humboldti) located in north western Chile and three colonies of Adelie penguins (Pygoscelis adeliae) in the Antarctic Peninsula area were investigated here. Surface soil samples were collected directly from nesting sites. Control samples were taken outside the colonies within sites adjacent to the nesting areas, but not affected by bird excrement. The contents of Cd, Co, Cr, Cu, Mo, Ni, Sr, V and Zn were determined by inductively coupled plasma optical emission spectrometry. Ammonium (NH4) and nitrate (NO3) ions were determined colorimetrically. Extractable potassium (K) was determined by flame emission spectrometry, and available phosphorus (Olsen-P) was determined by spectrophotometry. The highest concentrations of trace metals (Cd, Co, Cr, Cu, Mo, V and Zn) and macronutrients (available N, K and P), along with an increase in salinity and acidity levels, were found directly below the seabird colony, a situation occurring in northern Chile as well as in the Antarctic Peninsula area, highlighting the role that penguins have as bio-vectors on generating geochemical changes in different ecosystems. Some terrestrial plants and animals that live near those penguin colonies might be affected at a greater level than the organisms that live in sites similar but distant from colonies of birds. New data about the role of these species of seabirds as bio-vectors of chemical contaminants are added.

Urbanization effects on sediment and trace metals distribution in an urban winter pond (Netanya, Israel)

This paper aims to elucidate urban development-induced processes affecting the sediment and the distribution of contaminating metals in a seasonal pond located in the highly populated Israeli Coastal Plain. The paper demonstrates how an integrated approach, including geochemical, sedimentological, geochronological, mathematical, historical, and geographical analyses, may decipher a complicated and dynamic metal pollution history in a sedimentary environment controlled by anthropogenic activity. Three short sediment cores were collected from the margins and center of a small urban pond (Dora, Netanya), located within the Israeli Coastal Plain. Profiles of grain size, organic matter (OM), trace metals (Pb, Zn, V, Ni, Cu, Cr and Co), Pb isotopic ratios, and 210Pb activities (center and southern cores) were determined and a geochemical mixing model was employed (southern core). The watershed contour was calculated, and aerial photos and satellite images were examined. Construction activities in the watershed were chronologically associated with coarse sediment transport and deposition in the margins of the pond. The upper sandy layers were superimposed on layers rich in fine particles and OM, high concentrations of trace metals, and with Pb isotopic composition of more recent petrol. In the 210Pb-dated southern core, deep metal-rich layers with petrol-related Pb isotopic ratios were inconsistent with metal emissions history. These findings point to mobility and migration of recent contamination metals through the coarse upper sediment layers and into deeper denser layers, confirmed also by a geochemical mixing model. Conversely, in the center of the pond, homogeneous fine particles were deposited with metal profiles consistent with regional emissions. A small urban pond was found to provide an important case study for understanding heavy metal pollution records in highly populated regions. The margins of the pond depicted the surrounding urban development and the induced coarse sediment erosion, accompanied with post-depositional metal mobility. Due to the proximate developing residential areas, high metal concentrations accumulated in the margins, overshadowing regional atmospheric pollution levels recorded by sediment at the center of the pond.

Trace metals in sediments and benthic animals from aquaculture ponds near a mangrove wetland in Southern China

In this study, we measured the concentrations of trace metals (Cr, Cu, Zn, As, Cd, Pb and Hg) in typical cultured animals (crabs, clams, and shrimps) and sediments from aquaculture ponds nearby mangrove wetlands in Zhangjiang estuary, China. The contents of Cr, Cu, Cd, and Pb in mangrove sediments were significantly higher than those in pond sediments, while an inverse distribution was observed for Zn, As, and Hg. Significantly higher concentrations of trace metals were found in clams from the mangrove mudflats compared to those from the aquaculture ponds. The sources of trace metals in the clams were primarily from organic fertilizer, whereas those in the shrimp were from contaminated sediment. The results of geo-accumulation index and the ecological risk assessment indicated that the aquaculture ponds near the mangrove wetlands in this subtropical estuary posed a special risk of endogenous and exogenous trace metal pollution to nearby systems.

Environmental Impact of Abattoir Waste Discharge on the Quality of Surface Water and Ground Water in Abeokuta

The problem of getting quality water is increasing as untreated effluents are discharged into water bodies. The study aims at assessing the impact of various abattoirs wastewater on ground and surface water bodies in Abeokuta. Water samples were collected randomly in 9 different locations of Abeokuta (4 stream and 3 groundwater samples as well and 2 around abattoir vicinity as controls of surface and groundwater). All the samples were collected on the same day in the morning and were analysed for physical, chemical and microbiological load. The water quality parameters measured includes; Colour, Odour, pH, EC, Temperature, TDS, Cl2, DO, BOD, COD, TS, TSS, NO3, PO4, Heavy Metals (Pb, Zn, Cu, Cd, Fe), microbiological analysis. The parameters were analysed using standard procedures and the results were analysed using descriptive and inferential statistics. The ranges of the means values of all the parameters measured for pH, Temperature, Hardness, TDS, Cl2, NO3, PO4, BOD5, DO, COD, TS and TSS were 7.23-7.36, 27.3°C-28.0°C, 164- 323 mg/L, 102-518 mg/L, 20-70 mg/L, 0.005-0.706 mg/L, 0.212-0.850 mg/L, 0.570-7.400 mg/L, 1.0-6.8 mg/L, 72-504 mg/L, 0.260-0.520 mg/L, 15.4-16.1 mg/L and that of heavy metal were; 0.03-0.19 mg/L, 0.020-0.090 mg/L, 0.010-0.030 mg/L, 0.0-0.700 mg/L, 0.040-4.960 mg/L for Pb, Zn, Cu, Cd, Fe respectively while that of the Faecal Coliform was 100- 300 cfu/ml respectively. The results of the study revealed that all of the measured parameters show significant difference in their mean except Cl2, EC, PO4 TDS and Temperature. From the results, it was discovered that the concentration of Hardness, Pb, Cu, Pb, Zn, Cd, Fe and Faecal Coliform exceeded the permissible limits of both the WHO and FEPA standard for drinking and wastewater effluent. Pollution of ground and surface water through discharge of waste is an evidenced by the high concentrations of pollution indicators, nutrients and trace metals above the acceptable limits.

Does the harvest of logging residues and wood ash application affect the mobilization and bioavailability of trace metals?

Residue biomass from conventional forestry, such as slash (i.e., tree tops and branches) and stumps, are used at an increasing rate for energy purposes in Sweden. This review examined current knowledge on how extraction of forest biomass for large-scale energy production, including the practice of ash application for nutrient recycling, influences the mobility and stocks of trace metals in the forest environment at different time scales. The study focussed on Swedish energy production systems and contemporary forest management practices, as well as the heavy metals lead (Pb), cadmium (Cd) and mercury (Hg). The historic accumulation of these elements in forest soils has mainly originated from diffuse, long-term atmospheric deposition.There is little conclusive evidence that slash harvest generally increases the risk for mobilization of trace metals from soils during the regeneration phase, compared with stem-only harvesting. However, microbial transformation of mercury into the highly toxic methyl mercury (MeHg) species is facilitated in suboxic soil conditions that may increase during the regeneration phase. Therefore it has been hypothesized that stump harvest could result in increased mercury methylation and transport to surface waters, owing to stump harvest effects on soil physical conditions and hydrological pathways. The few studies available on the stump harvest effects of Hg showed no consistent difference in runoff from clear-felled and stump harvested catchments compared to clear-felled and soil-scarified catchments in terms of concentrations or fluxes of MeHg.Assuming that the highest trace metal concentrations in wood ash recommended by the Swedish Forest Authority are not exceeded, wood ash application does not currently increase metal loads at the national scale, because trace metal export in harvested biomass is much larger than that returned in wood ash. The net load of Pb, Cd, and Cu will not increase at the local scale if ash doses do not greatly exceed the compensation for nutrients exported in harvested biomass. Biomass harvest and ash application have negligible effects on the load of mercury to forest soils.A large number of studies have examined the effects of wood ash on trace metal content in soil, water and biota. Most studies showed no effect of wood ash application. When increased concentrations were found (Cd, Cr, Cu, Zn), this was in soils where concentrations remained well below harmful levels. Relatively fewer reports of increased concentrations are reported for soil water and plants, and no effects were reported for edible berries or fungi.

Transport of trace metals (Mn, Fe, Ni, Zn and Cd) in the western Arctic Ocean (Chukchi Sea and Canada Basin) in late summer 2012

Distributions of trace metals (Mn, Fe, Ni, Zn and Cd) in the western Arctic Ocean (Chukchi Sea and Canada Basin) in September 2012 were investigated to elucidate the mechanisms behind the transport of these metals from the Chukchi Shelf to the Canada Basin. Filtered (<0.22µm) and unfiltered seawater samples were analyzed to determine dissolved (D) and total dissolvable (TD) trace metal concentrations, respectively. We identified maxima in vertical profiles for the concentrations of D-Fe and TD-Fe, as well as for the other four analyzed trace metals, which occurred in the halocline and/or near-bottom waters. Concentration profiles of all trace metals except for Cd also tended to show peaks near the surface, which suggest that the inflow of low-salinity Pacific-origin water from the Bering Strait, as well as local fresh water inputs such as river water and melting sea-ice, influenced trace metal concentrations. The distribution patterns and concentration ranges were generally similar between the D and TD fractions for Ni, Zn and Cd, which indicate that Ni, Zn and Cd were present mainly in their dissolved forms, whereas the concentrations of TD-Fe and TD-Mn were generally higher than those of D-Fe and D-Mn, respectively. These results are consistent with the results of previous studies of this region. For both Fe and Mn, labile particulate (LP) concentrations (the difference between the TD and D fractions, which is acid-leachable fraction in the particles during storage at pH 1.5–1.6) were highest in the near-bottom waters of the Chukchi Shelf region. The relationships between the distance from the shelf break and the concentrations of trace metals revealed that Fe and Mn concentrations in halocline waters tended to decrease logarithmically with distance, whereas changes in the concentrations of Ni, Zn, Cd and phosphate with distance were small. These results suggest that the distributions of Fe and Mn were controlled mainly by input from shelf sediment and removal through scavenging processes. Based on the phase distributions of Fe and Mn, which were calculated as ratios between the LP and D fractions, different behaviors between Fe and Mn were expressed during lateral transportation. The concentration of TD-Fe declined rapidly via removal of LP-Fe from the water column, whereas the concentration of TD-Mn declined more slowly through the transformation of D-Mn into LP-Mn. In contrast, the concentrations of D-Cd, D-Zn and D-Ni were more strongly correlated with phosphate levels, which suggest that, like phosphate, the distributions of Cd, Zn and Ni were generally controlled by the internal biogeochemical cycles of the ocean interior. Based on the findings of studies that have previously evaluated the concentration maxima of Ni, Zn and Cd within the halocline layer in the Canada Basin near the Canadian Arctic Archipelago, the elevated Ni, Zn and Cd concentrations in the halocline layer may extend across the Canada Basin from the Chukchi Sea shelf-break area. The determination coefficients for correlations with phosphate concentration varied between the concentrations of Ni, Zn and Cd, which suggest that the sources of these trace metals, such as sediments and sea-ice melting, affected their patterns of distributions differently. Our findings reveal the importance and impact of the halocline layer for the transport of trace metals in the western Arctic Ocean during the late summer. The existence of rich and various sources likely sustained the high concentrations of trace metals and their unique profiles in this region.

Assessment of trace metal and rare earth elements contamination in rivers around abandoned and active mine areas. The case of Lubumbashi River and Tshamilemba Canal, Katanga, Democratic Republic of the Congo

Active and abandoned mine activities constitute the sources of deterioration of water and soil quality in many parts of the world, particularly in the African Copperbelt regions. The accumulation in soils and the release of toxic substances into the aquatic ecosystem can lead to water resources pollution and may place aquatic organisms and human health at risk. In this study, the impact of past mining activity (i.e., abandoned mine) on aquatic ecosystems has been studied using ICP-MS analysis for trace metals and Rare Earth Elements (REE) in sediment samples from Lubumbashi River (RL) and Tshamilemba Canal (CT), Katanga, Democratic Republic of the Congo (DRC). Soil samples from surrounding CT were collected to evaluate trace metal and REE concentrations and their spatial distribution. The extent of trace metal contamination compared to the background area was assessed by Enrichment Factor (EF) and Geoaccumulation Index (Igeo). Additionally, the trace metal concentrations probable effect levels (PELs) for their potential environmental impact was achieved by comparing the trace metal concentrations in the sediment/soil samples with the Sediment Quality Guidelines (SQGs). Spearman's Rank-order correlation was used to identify the source and origin of contaminants. The results highlighted high concentrations of trace metals in surface sediments of CT reaching the values of 40152, 15586, 610, 10322, 60704 and 15152mgkg−1 for Cu, Co, Zn, Pb, Fe and Mn, respectively. In the RL, the concentrations reached the values of 24093, 2046, 5463, 3340, 68290 and 769mgkg−1 for Cu, Co, Zn, Pb, Fe and Mn, respectively. The ΣREE varied from 66 to 218 and 142–331mgkg−1 for CT and RL, respectively. The soil samples are characterized by variable levels of trace metals. The EF analysis showed “extremely severe enrichment” for Cu and Co. However, no enrichment was observed for REE. Except for Mo, Th, U, Eu, Mo, Ho and Tm for which Igeo is classified as “moderately polluted and/or unpolluted”, all elements in different sites are classified in the class 6, “extremely polluted”. The trace metal concentrations in all sampling sites largely exceeded the SQGs and the PELs for the Protection of Aquatic Life recommendation. Cu and Co had positive correlation coefficient values (r=0.741, P<0.05, n=14). This research presents useful tools for the evaluation of water contamination in abandoned and active mining areas.

Growth and toxin production of Azadinium poporum strains in batch cultures under different nutrient conditions

Azaspiracid-2 (AZA2) is the dominant toxin produced by Azadinium poporum strains AZDY06 and AZFC22 isolated from the South China Sea. Biomass and AZA2-production were examined within batch cultures with variation in experimental concentrations of nitrate (0, 88, 882, and 2647µM) or phosphate (0, 3.6, 36, and 109µM), different nitrogen sources (nitrate and urea) and media (f/2-Si, L1-Si, and K-Si) in the present study. Growth of both strains positively responded to nitrate or phosphate nutrients, but the growth status was significantly repressed by the highest additional level of phosphate (109µM). Both AZDY06 and AZFC22 grew well with higher specific growth rates, but with shorter growth periods, within f/2-Si medium spiked with urea than that within media spiked with nitrate. L1-Si medium with relatively high concentrations of trace metals was relatively favorable to both strains of A. poporum tested here. No obvious change within the toxin profile occurred in all cultures of both strains under the various nutrient conditions, although trace amounts of some suspicious derivatives of AZA2 occurred in some cultures. AZA2 cell quotas within both strains significantly (p<0.05) increased at the stationary phase under lower additional phosphate (0 and 3.6µM). Significant differences were not found within AZA2 cell quotas in cultures with additional nitrate ranging from 0 to 2647µM. The highest AZA2 cell quota and maximum AZA2 quantity per culture volume occurred in batch culture at the stationary phase under phosphate concentrations at 3.6µM. Neither A. poporum strain exhibited significant changes in AZA2 cell quotas within f/2-Si media spiked with urea or nitrate as nitrogen sources. The AZA2 cell quota of strain AZDY06 also did not change remarkably within f/2-Si, L1-Si, and K-Si media, however the AZA2 cell quota of strain AZFC22 within L1-Si medium was significantly (p<0.05) higher than that within f/2-Si medium.

Changes in soil organic carbon fractions after remediation of a coastal floodplain soil

Coastal floodplain soils and wetland sediments can store large amounts of soil organic carbon (SOC). These environments are also commonly underlain by sulfidic sediments which can oxidise to form coastal acid sulfate soils (CASS) and contain high concentrations of acidity and trace metals. CASS are found on every continent globally except Antarctica. When sulfidic sediments are oxidised, scalds can form, which are large bare patches without vegetation. However, SOC stocks and fractions have not been quantified in these coastal floodplain environments. We studied the changes in soil geochemistry and SOC stocks and fractions three years after remediation of a CASS scald. Remediation treatments included raising water levels, and addition of either lime (LO) or lime and mulch (LM) relative to a control (C) site. We found SOC concentrations in the remediated sites (LO and LM) were more than double than that found at site C, reflected in the higher SOC stocks to a depth of 1.6 m (426 Mg C/ha, 478 Mg C/ha and 473 Mg C/ha at sites C, LO and LM, respectively). The particulate organic C (POC) fraction was higher at sites LO and LM due to increased vegetation and biomass inputs, compared to site C. Reformation of acid volatile sulfide (AVS) occurred throughout the profile at site LM, whereas only limited AVS reformation occurred at sites LO and C. Higher AVS at site LM may be linked to the additional source of organic matter provided by the mulch. POC can also potentially contribute to decreasing acidity as a labile SOC source for Fe3+ and SO42− reduction. Therefore, coastal floodplains and wetlands are a large store of SOC and can potentially increase SOC following remediation due to i) reduced decomposition rates with higher water levels and waterlogging, and ii) high C inputs due to rapid revegetation of scalded areas and high rates of biomass production. These results highlight the importance of maintaining vegetation cover in coastal floodplains and wetlands for sequestering SOC.

Trace Metals Levels in African Giant Land Snails (Achatina achatina) from Selected Local Government Areas in Akwa Ibom State, Nigeria

Trace metals (As, Cd, Cr, Hg, Pb and Se) in African giant land snails from selected Local Government Areas (LGA) in Akwa Ibom State of Nigeria were analysed using atomic absorption spectrophotometric (AAS) technique. Results showed that the mean levels of Cr (399 ± 195 mg/kg) and Se (51.6 ± 31.3 mg/kg) were significantly higher (P Se > Pb > Cd > As > Hg. The results showed that As and Hg fell within their permissible safe levels; but Cd, Cr, Pb and Se were significantly above safe levels for human consumption. The high concentration of trace metals in the snail samples may be related to anthropogenic activities taking place in the areas studied.

Ecotoxicological assessment of diamondback terrapin (Malaclemys terrapin) pond habitat, prey and eggs in Bermuda

Total petroleum hydrocarbons, PAH and various trace metal residues were extracted and analyzed from fresh whole diamondback terrapin (Malaclemys terrapin) eggs, whole brackish-water gastropods (terrapin prey) and benthic sediment from anchialine pond environments in Bermuda inhabited by terrapins. Gastropods and terrapin eggs showed higher concentrations of trace metals and organic contaminants than sediments. Conversely, PAHs were mostly found within the sediment and smaller amounts detected in gastropods and terrapin eggs. Results indicated that contaminants in prey were transferred to terrapin eggs, and that concentrations of several contaminants exceeded potentially toxic concentrations for aquatic vertebrates. Necropsy of unhatched eggs from nests that had yielded viable hatchlings showed significantly compromised embryonic development. Bermudian diamondback terrapins reside and feed in brackish wetland habitats characterized by widespread, multifactorial contamination. This study suggests that environmental contamination plays a role in the recorded low hatching success in terrapin eggs in Bermuda.

Reactive transport modeling of early diagenesis in a reservoir lake affected by acid mine drainage: Trace metals, lake overturn, benthic fluxes and remediation

The Sancho Reservoir in SW Spain has been impacted by acid mine drainage (AMD) since the Tharsis mine stopped activity in 1998. As a result, the reservoir exhibits low pH (~3.5) and high aqueous concentrations of sulfate, aluminum, iron and trace metals. Thus far, removal of contaminants by sediment burial has not been as effective as expected in improving water quality within the reservoir. To inform potential remediation strategies, a 1-D, non-steady-state reactive transport model with a comprehensive set of equilibrium and kinetic biogeochemical reactions is used to simulate the fate of trace metals and acidity in sediments affected by AMD. Two realizations of the model account for the spatial heterogeneity of bottom water oxygenation. A “permanently oxic” model represents shallow sediments above the thermocline, while a “holomictic” model represents the deeper sediments where bottom water oxygen levels oscillate between completely anoxic and oxic as a result of water-column overturn. The model is calibrated against an extensive dataset on the depth distributions of pore water and solid phase species. Model results imply that, under permanently oxic conditions, the sediments act as a sink for acidity (H+) and aqueous Al, Zn, Cu, Co and Ni, but act as a source of aqueous Mn, Fe and As. The latter are released to the overlying water as a result of Mn and Fe (oxy)hydroxide reductive dissolution in the sediments. Below the thermocline, when bottom waters become anoxic, metal sulfides precipitate in the sediment. When the bottom waters subsequently become oxic, the metal sulfides are oxidized along the downward-penetrating oxygen front and the associated metals are released to the overlying water. On the order of 35% of the sediment pools of sulfide-bound Zn, Cu, Co and Ni, and ~25% of FeS are thus reoxidized. However, overall the sediments act as a net sink for the pollutants considered in the model. On an annual basis, about 10% of the total elemental masses of S, Al, Zn and Cu present in the water column of the reservoir are removed by burial in the sediments, but only ~2% for Co and Ni. For Fe, Mn and As, the corresponding values are 80, 70 and 98% respectively. The model predicts that, if AMD input to the reservoir were to completely cease, the sediments would reach a new steady state with negligible release of aqueous contaminants to the overlying water column within a few years.

Spatial distribution and ecological risk assessment of trace metals in urban soils in Wuhan, central China.

Surface soil samples from 467 sample sites were collected in urban area of Wuhan City in 2013, and total concentrations of five trace metals (Pb, Zn, Cu, Cr, and Cd) were measured. Multivariate and geostatistical analyses showed that concentrations of Pb, Zn, and Cu are higher along Yangtze River in the northern area of Wuhan, gradually decrease from city center to suburbs, and are mainly controlled by anthropogenic activities, while those of Cr and Cd are relatively spatially homogenous and mainly controlled by soil parent materials. Pb, Zn, Cu, and Cd have generally higher concentrations in roadsides, industrial areas, and residential areas than in school areas, greenbelts, and agricultural areas. Areas with higher road and population densities and longer urban construction history usually have higher trace metal concentrations. According to estimated results of the potential ecological risk index and Nemero synthesis pollution index, almost the whole urban area of Wuhan is facing considerable potential ecological risk caused by soil trace metals. These results reveal obvious trends of trace metal pollution, and an important impact of anthropogenic activities on the accumulation of trace metals in soil in Wuhan. Vehicular emission, industrial activities, and household wastes may be the three main sources for trace metal accumulation. Increasing vegetation cover may reduce this threat. It should be pointed out that Cd, which is strongly accumulated in soil, could be the largest soil pollution factor in Wuhan. Effective measures should be taken as soon as possible to deal with Cd enrichment, and other trace metals in soil should also be reduced, so as to protect human health in this important large city.

Biochemical indicators and biomarkers in chub (Squalius cephalus L.) from the Sava River

Biochemical indicators and biomarkers were analyzed in the liver and gills of chub caught in three localities along the Sava River exposed to different environmental impacts. Sampling sites were: downstream from Zagreb (Zgd), downstream Sremska Mitrovica (SM) and downstream from Belgrade (Bgd). We observed that the relative amounts and levels of activity of Cu, Zn containing superoxide dismutase and glutathione in both the liver and gills, and the relative amounts of heat shock protein (HSP90) and metallothioneins in the gills were highest in the Zgd locality, suggesting a higher impact of metal pollution. The Zgd locality had higher concentrations of trace metals in the water, especially iron. In the SM and Bgd localities, higher relative levels of glutathione peroxidase and catalase were recorded (especially in SM) as compared to the Zgd locality, pointing to the presence of hydrogen peroxide and different classes of organic peroxides. Low water oxygen and high temperature levels in the Bgd locality suggesting different metabolic activity between examined locations. Our results suggest that different presence and concentrations of individual environmental factors (total environment) influence the way how fish establish homeostasis.

Geochemical and mineralogical characteristics of beach sediments along the coast between Alanya and Silifke (southern Turkey)

AbstractThe aim of this work was to determine the distribution of trace metals in the coastal sediments from the area between Silifke and Alanya (Turkey) and to investigate the sources of these elements, based on their mineralogical, petrographical and geochemical characteristics. Forty three samples were analysed for the determination of their water content, grain-size distribution, petrographical features and their chemical and mineralogical compositions. The samples had low water content, in agreement with the large sand grain size.The mineralogical composition reflects the complex geological setting of the area. The most abundant mineral phases are represented by calcite and dolomite, followed by quartz and mica. Chlorite, feldspar and other carbonates are present in lesser amounts, while kaolinite was detected in one sample only. All samples contain hematite, chromite, magnetite and goethite and one sample contained pyrite. Samples with high concentrations of trace metals, contained fragments of metamorphic rocks with pyroxene, amphibole, quartz and feldspar, whereas carbonates and opaque minerals were subordinate. Compared to literature data, the average concentrations of several elements and trace metals were great enough to be considered as possibly toxic, exceeding the Turkish higher acceptable limits. Geochemical data were treated statistically using Principal Component Analysis (PCA) to obtain evidence of their distribution and to identify any correlations.Based on the distribution of mineral phases, the area investigated was divided into different provinces, each characterized by the abundance of one, or more, tracer minerals. In the westernmost areas, between Alanya and Demirtas, the sediments indicate a provenance from dolomites or marbles. In the area between Demirtas and Gazipasa the provenance was from quartzites, clastic and metamorphic rocks and in the sector between Guney and Anamur, the sediments were derived mostly from low-grade metamorphic rocks, in particular metaschists and metabasites. The sediments in the area between Anamur and Ovacik, display variable source rocks and those between Ovacik and Silifke, were derived from limestones and, subordinately, clastic rocks.The trace-metal concentrations in beach sands appear to be related to the abundance of silicate minerals derived from weathering of the metamorphic-rock outcrops in the inland mountainous regions. In contrast, the trace-metal contents of the limestone- and dolomite-bearing beach sands were small.

Modeling the impact of carbon dioxide leakage into an unconfined, oxidizing carbonate aquifer

Multiphase, reactive transport modeling was used to identify the mechanisms controlling trace metal release under elevated CO2 conditions from a well-characterized carbonate aquifer. Modeling was conducted for both batch and column experiments. The column experiments resulted in higher trace metal concentrations because the rock to water ratio was higher. A kinetic desorption model fits the overall trends in release for seven trace metals observed in batch and column experiments exposing Edwards Aquifer material to elevated concentrations of CO2. Observed and predicted trace metal concentrations are compared to groundwater concentrations from this aquifer to determine the potential for leaking CO2 to adversely impact drinking water quality. Finally, a three-dimensional multiphase flow and reactive-transport simulation of CO2 leakage from an abandoned wellbore into a generalized model of the shallow, unconfined portion of the aquifer is used to determine potential impacts on groundwater quality. As a measure of adverse impacts on groundwater quality, both the EPA’s regulatory limits and the maximum trace metal concentration observed in the aquifer were used as threshold values. Results of the field-scale simulations indicate that CO2 leakage into a carbonate aquifer is likely to cause decreases in pH and increases in TDS beyond observed ranges in the aquifer and beyond regulatory limits. However, trace metal concentrations are not predicted to exceed either the observed maximums or the regulatory limits.

Seawater inundation of coastal floodplain sediments: Short-term changes in surface water and sediment geochemistry

Coastal floodplains are highly vulnerable to seawater inundation as a result of storm surge and sea-level rise due to their low elevation and proximity to the coastline. Intact soil cores from a levee, acid-sulfate soil scald and four backswamp sites on a coastal floodplain in eastern Australia were inundated with artificial seawater treatments (0%, 50% and 100%) for 14days to examine the short term consequences for surface water and floodplain sediment geochemistry. All sites displayed an initial decrease in surface water pH following inundation with 50% and 100% seawater. In addition, higher concentrations of trace metals (Al, Fe, Mn, Ni and Zn) were observed in most sites inundated with 50% or 100% seawater. This was generally attributed to competitive exchange and desorption of trace metals from sediments due to the higher ionic strength of the seawater solutions and upward diffusive flux of metals from the sediments to surface waters. At one backswamp site, reductive processes had established by day 7, which also resulted in elevated Fe2+ concentrations in the overlying surface waters. Transmission electron microscopy (TEM) identified the presence of poorly crystalline ferrihydrite and schwertmannite, and goethite and jarosite. These meta-stable Fe(III) minerals can act as a source of metals for desorption and can also be readily reduced and act as a source of Fe2+ to surface waters. Importantly, inundation with either 50% or 100% seawater resulted in a similar magnitude of acidity and trace metal mobilisation. The data suggest that an inundation event of ~0.2m depth with either 50% or 100% seawater could cause a pulse mobilisation of up to 64.8 and 9.1kgha−1 of Fe and Al, respectively — quantities of similar magnitude to previous estimates of annual drainage fluxes from similar backswamps. This study suggests that the short term inundation of coastal floodplain sediments by either brackish water or seawater will result in rapid declines in surface water quality as a result of increased liberation of acidity and trace metals.

Speciation of Heavy Metals by Modified BCR Sequential Extraction in Soils Contaminated by Phosphogypsum in Sfax, Tunisia

The accumulation of trace metals in soil is a serious environmental problem that creates a hazard when metals are transferred to water or plants. To understand the mobility and bioavailability of trace metals, the concentrations and distributions of trace metals must be established for different physical and chemical phases of the soil. We determined the concentrations of trace metals (Zn, Pb, Cu, Cr, Co, Ni, Mn, and Fe) in soil using the sequential extraction method recommended by Community Bureau of Reference (BCR) and analysed chemical properties, such as the pH, cation exchange capacity, total organic carbon, electrical conductivity, and calcium carbonate. Our results revealed higher concentrations of trace metals in topsoil samples (0–20 cm) than in subsoil samples (20–40 cm and 40–60 cm) for most metals at four sites. Zn in the topsoil was mostly associated with the non-resistant fraction at all sites. Approximately 60% more Pb was bound to the non-residual, exchangeable and reducible fractions at all sites, and soil depths. Cr, Cu, Ni and Fe were mainly in the residual fraction, whereas Mn was largely present in the non-resistant fraction. The global contamination factor of trace metals decreased with soil depth. The mobility and bioavailability were greatest for Zn, followed by Cu and Pb. DOI: http://dx.doi.org/10.5755/j01.erem.70.4.7807

Plume characterization of a typical South African braai

To braai is part of the South African heritage that transcends ethnic barriers and socio-economic groups. In this paper, a comprehensive analysis of atmospheric gaseous and aerosol species within a plume originating from a typical South African braai is presented. Braai experiments were conducted at Welgegund – a comprehensively equipped regional background atmospheric air quality and climate change monitoring station. Five distinct phases were identified during the braai. Sulphur dioxide (SO 2 ), nitrogen oxides(NO x ) and carbonmonoxide (CO) increased significantly, while ozone (O 3 ) did not increase notably. Aromatic and alkane volatile organic compounds were determined, with benzene exceeding the 2015 South African one-year ambient air quality limit. A comparison of atmospheric PM 10 (particulate matter of an aerodynamic diameter ≤10 μm) concentrations with the 24-hour ambient limit indicated that PM 10 is problematic during the meat grilling phase. From a climatic point of view, relatively high single scattering albedo (ω o ) indicated a cooling aerosol direct effect, while periods with lowerω o coincided with peak black carbon (BC) emissions. The highest trace metal concentrations were associated with species typically present in ash. The lead (Pb) concentration was higher than the annual ambient air quality limit. Sulphate (SO 4 2– ), calcium (Ca 2+ ) and magnesium (Mg 2+ ) were the dominant water-soluble species present in the aerosols. The largest number of organic aerosol compounds was in the PM 2.5–1 fraction, which also had the highest semi-quantified concentration. The results indicated that a recreational braai does not pose significant health risks. However, the longer exposure periods that are experienced by occupational vendors, will significantly increase health risks. KEYWORDS Braai (barbeque), atmospheric gaseous species, aerosols, atmospheric organic compounds, optical properties, chemical properties.

Physicochemical Characterization and Determination of Trace Metals in Sugar Manufactured from Sugar Cane

The current study is interested in determination of trace metals in sugar originated from different sources such as soil, water. The analytical technique used in the study was atomic absorption spectroscopy and the results revealed that concentration of metals found in soil sample was; 51 mg/kg Fe, 6 mg/kg Mn, 2.5 mg/kg Cu, 0.36 mg/kg Cd, 8.32 mg/kg Zn, 3.92mg/kg Cr, 5.4 mg/kg Ni, 4.08 mg/kg Co and 0.28 mg/kg Ag. Concentration of metals found in sugar sample was 0.89 mg/kg Fe, 0.28 mg/kg Mn, 0.79 mg/kg Zn, 0.88 mg/kg Cr, 0.61 mg/kg Ni, and 0.33 mg/kg Co. Concentration of copper, silver and cadmium was not detected. Concentration of metals found in effluent sample was 19.3 mg/kg Fe, 2.5 mg/kg Mn, 1.1 mg/kg Zn, 1.39 mg/kg Cr, 2.84 mg/kg Ni, 1.6 mg/kg Co and 0.05 mg/kg Cd. The physicochemical characters such as biological oxygen demand, chemical oxygen demand, temperature, electrical conductivity and pH are determined to be significant. High concentration of trace metals was determined in soil in relative to other sample and sugar sample studied is safe for consumption.