Showing papers on "Trace metal published in 2003"

Trace element speciation in poultry litter

Abstract: Trace elements are added to poultry feed for disease prevention and enhanced feed efficiency. High concentrations are found in poultry litter (PL), which raises concerns regarding trace element loading of soils. Trace metal cation solubility from PL may be enhanced by complexation with dissolved organic carbon (DOC). Mineralization of organo-As compounds may result in more toxic species such as As(III) and As(V). Speciation of these elements in PL leachates should assist in predicting their fate in soil. Elemental concentrations of 40 PL samples from the southeastern USA were determined. Water-soluble extractions (WSE) were fractionated into hydrophobic, anionic, and cationic species with solid-phase extraction columns. Arsenic speciation of seven As species, including the main As poultry feed additives, roxarsone (ROX; 3-nitro-4-hydroxyphenylarsonic acid) and p-arsanilic acid (p-ASA; 4-aminophenylarsonic acid), was performed by ion chromatography-inductively coupled plasma-mass spectrometry (IC-ICP-MS). Total As concentrations in the litter varied from 1 to 39 mg kg(-1), averaging 16 mg kg(-1). Mean total Cu, Ni, and Zn concentrations were 479, 11, and 373 mg kg(-1), respectively. Copper and Ni were relatively soluble (49 and 41% respectively) while only 6% of Zn was soluble. Arsenic was highly soluble with an average of 71% WSE. Roxarsone was the major As species in 50% of PL samples. However, the presence of As(V) as the major species in 50% of the PL samples indicates that mineralization of ROX had occurred. The high solubility of As from litter and its apparent ready mineralization to inorganic forms coupled with the large quantity of litter that is annually land-applied in the USA suggests a potential detrimental effect on soil and water quality in the long term.

Accumulation and soluble binding of cadmium, copper, and zinc in the polychaete Hediste diversicolor from coastal sites with different trace metal bioavailabilities.

Abstract: Bioaccumulation of cadmium, copper, and zinc was examined in common ragworms Hediste diversicolor from control (Bay of Somme, Blackwater) and metal-rich (Seine estuary, Boulogne harbor, Restronguet Creek) sites in France and the United Kingdom. The degree of exposure in the field was assessed by considering both total concentrations in superficial sediment and the quantities of metals which may be released in vitro at different pH levels. Among the three contaminated sites, release of the three metals was not detectable in Boulogne harbor, in correlation with limited enhancement of the metal concentrations in the common ragworms from this site. Even at those sites where zinc could be released in vitro from the sediment, zinc concentrations were not enhanced in common ragworms, in agreement with previous findings indicating that the body content of this metal is regulated in H. diversicolor. At all the studied sites, bioaccumulated zinc was mainly in cytosolic form. The distribution of cadmium and copper varied according to the origin of the common ragworms, the insoluble fraction increasing with the degree of contamination (cadmium in the Restronguet Creek, copper in the Seine estuary, and even more in Restronguet Creek). In the cytosolic fraction, metals were partly linked to cytosolic heat-stable thiolic compounds (CHSTC) with molecular masses (5–6 kDa and about 12 kDa) consistent with metallothionein-like proteins (MTLP). Metal-binding to MTLP varied with the degree of contamination and with the metal studied. In contrast to many invertebrates, the presence of metal-binding CHSTC (MM about 2 kDa) other than MTLP seems to be a peculiar feature of H. diversicolor.

In situ growth of Gallionella biofilms and partitioning of lanthanides and actinides between biological material and ferric oxyhydroxides

Abstract: Gallionella ferruginea is an iron-oxidizing chemolithotrophic micro-organism that lives in low-oxygen conditions (0.1–1.5 mg L-1 saturation). It produces a stalk structure from the concave side of the cell depending on population development, pH and redox conditions. After Gallionella oxidizes ferrous iron, bacteriogenic iron oxides (BIOS) precipitate on the stalk material and over time the stalks and/or the precipitated BIOS attenuate trace metals from surrounding groundwater. Gallionella ferruginea biofilms were cultured in situ in an artificial channel (2000 × 300 × 250 mm) using groundwater sourced from a borehole 297 m below sea level in the Aspo Hard Rock Laboratory in southern Sweden. The pH of the groundwater in the channels was always between 7.4 and 7.7 with oxygen saturation below 1.5 mg L-1 and Eh between 100 and 200 mV. Oxygen eventually declined to <0.3 mg L-1, terminating prolific biofilm growth. Biofilms formed within 2 weeks and were sampled every 2 weeks over 3 months. Cell number, stalk length and ferric iron concentration were measured for each sample and trace metal concentration was measured by inductively coupled plasma mass spectrometry. Results from well-developed in situ biofilms suggest that Gallionella could concentrate metals at levels up to 1 × 103-fold higher than found within the host rock and more than 1 × 106 times the levels found in the groundwater. These new experiments were used to support the results from the well-developed biofilms and to relate biofilm development and population characteristics to metal attenuation. After 3 months, rare earth element (REE) plots indicated that BIOS can accumulate metals at levels up to 1 × 104-fold higher than found in the groundwater and fractionate heavy rare earth elements over light rare earth elements. Generally the presence of the organic phase promotes the adsorption of all lanthanides and actinides that are not adsorbed by the inorganic phase. The iron oxides are directly correlated with stalk length (R = 0.96), indicating that rapid REE and actinide adsorption requires both iron oxides and a nucleating biological structure for the iron oxides.

Evaluation of the diffusive gradient in a thin film technique for monitoring trace metal concentrations in estuarine waters.

Abstract: Monitoring trace metal concentrations in dynamic estuarine waters is not straightforward. This study demonstrated that important information could be obtained from intensive sampling of physicochemical parameters and trace metal concentrations, in the Gold Coast Broadwater, Australia. A regular pattern of variation in Cu and Ni concentrations was related to the movement of water passed point sources with tidal flows, rather than due to conventional estuarine mixing of end-member waters. However, this approach was logistically demanding and expensive. The diffusive gradients in a thin film (DGT) technique was used as an alternative method due to its continual time-integrated response to changes in trace metal concentrations. Significant correlations were found between 24 h DGT-labile measurements and 0.45-μm filterable measure ments, on time-averaged composite samples (grab samples combined every 4 h for 24 h), for Cu (n = 24, r = 0.965, p < 0.001), Pb (n = 24, r = 0.799, p < 0.001), Zn (n = 17, r = 0.909,...

Uptake and mass balance of trace metals for methane producing bacteria

Abstract: Trace metals play an important role in the growth of methanogens and methane formation. In order to understand the requirement of trace metals for methanogens, the accurate measurement of trace metals inside cells of methanogens was required. In this study, acclimated-methanogens were cultured in batch feed substrate gas (H2/CO2) at 37°C. The balance and uptake of trace metals for cell of acclimated- methanogens were investigated by using inductively coupled plasma mass spectrometer (ICP-MS) and scanning probe microscopy. Cells of the acclimated-methanogens were harvested in the early stationary growth phases and separated by centrifugation and filtration using cellulose membrane under anaerobic condition. In order to remove trace metal ions on the surface of the cells, it was washed with different liquids-distilled water, physiological salt solution, phosphate buffer and EDTA mixture liquid, in different experiments. By using scanning probe microscopy, we found that cell lysis occurred and thus transitional trace metals severely lost when cells were washed with distilled water, while the minimum washing which effect cell lysis was obtained by using phosphate buffer. Washed cells were broken by wet digestion method and analyzed for the content of trace metals by using ICP-MS. The major elements contained in the methanogens cell were obtained, and it was clear that, for conventional method, the shortage of Fe will be created when methanogens grew up to about 1.32 g l −1 , and Zn, Cu, Ni and Co contents will be lacked when methanogens grow up to 1.13, 0.12, 4.8 and 30 g l −1 , respectively. In conclusion, to achieve a high productivity of methane fermentation, Fe, Cu, Ni and Zn contents in the fermentation liquid should be greatly increased.

Variations in trace elements in bottom sediments of major rivers in Lake Victoria's basin, Kenya

Abstract: River sediments collected between March 1994 and January 1995 were analysed for iron (Fe), manganese (Mn), zinc (Zn), lead (Pb), copper (Cu), chromium (Cr), aluminium (Al) and cadmium (Cd) in the less than 63 μm grain-size fraction. The river sediments were characterized by a sandy texture, with a relatively low organic matter (as percentage loss on ignition), ranging 3.5–9.6%. The metal mean range values in μg/g dry weight for the river sediments were: Mn (836–2.10 × 104), Fe (1.09 × 104–9.22 × 104), Al (2.86 × 103–7.77 × 103), Zn (34–130), Cu (11–78), Cr (not detected ND–125); Pb (ND–100) and Cd (ND). Temporal variations were significant for Zn, Cr and Pb. There were no significant longitudinal differences in all the elements in rivers Nyando, Nzoia, Yala and Sondu-Miriu, apart from sediment Fe contents. Relatively high sediment Fe, Mn, Zn, Cr and Al were observed in river Kasat. River Kasat was considered polluted with respect to Mn, Zn and Cr, which were comparatively higher than unpolluted sediments and geochemical background values. This supports similar results on surface water trace element levels. Most of the rivers drain an area of relatively similar lithological characteristics. Therefore, apart from the direct waste input into Kasat river from municipal and industrial sources, lack of specific point sources indicate lithological metal origins with localized variations. A final comparative evaluation of the river sediments’ trace metal pollution was made from the study results. The data is vital for pollution management of the lake as information about metal loadings into the lake ecosystem is lacking.

Analysis of Trace Amounts of Metal Ions Using Silica-Based Chelating Resins: A Green Analytical Method

Abstract: This review is concerned mainly with the applications of chelating resins, based on silica gel, for the separation and preconcentration of trace metal ions from various substrates. General methods of preparations of silica-based resins have been discussed. A synthesis of various silica-based chelating resins and their applications in the extraction of trace amounts of metal ions have been reviewed critically and have also been reported in tabular form.

Trace metal accumulation by red clover grown on sewage sludge-amended soils and correlation to mehlich 3 and calcium chloride-extractable metals

Abstract: With the availability of sensitive multielement analytical capability, it is no longer essential to use chemically aggressive soil tests to extract measurable levels of most trace elements. However, the relative abilities of mild and aggressive extractants to assess metal bioavailability in soils have rarely been compared. A greenhouse experiment was carried out to compare a mild soil extractant (hot 0.01 M CaCl(2)) with an aggressive one (Mehlich 3) for predicting accumulation of trace metals by red clover (Trifolium pratense L.). Clover was grown on large columns of nonacid fine-textured and acid coarse-textured soils that had been amended several years earlier by a heavy application of sewage sludge products, and pH was subsequently adjusted using CaCO(3) or H(2)SO(4). The soil extractants (CaCl(2) and Mehlich 3) and clover tissue were analyzed for trace metals (As, Cd, Mo, Cu, Ni, Mn, Pb, and Zn) by axial-view ICP spectrophotometry. Linear regression analyses were performed to relate the concentration of each trace element in the red clover tissue to the concentration extracted from the soil. The results indicate that CaCl(2) extraction is more reliable than Mehlich 3 extraction when evaluating plant availability of trace elements in soils with a wide range of properties (especially pH). The strongly acidic nature of the Mehlich 3 extractant caused large quantities of metals such as Zn, Cd, Cu, and Ni to be extracted from metal-contaminated soils even when the plant availability of these metals was low because of near-neutral soil pH or high clay and organic matter content. Conversely, in coarse-textured and acid soils containing lower total concentrations of metals, plant-available metals were often relatively high, yet Mehlich 3 frequently extracted smaller quantities of metals from these soils than from the near-neutral soils. We conclude that dilute CaCl(2) is preferable to Mehlich 3 as a universal soil extractant for estimating short-term trace metal availability to crops.

Seasonal variations of heavy metals in central Greenland snow deposited from 1991 to 1995.

Abstract: To better assess the seasonality in the fallout of heavy metals to central Greenland, a continuous series of 68 snow samples has been collected at a remote site in the Summit area from a 2.7 m pit using ultraclean sampling procedures. This covers a continuous four year time period from spring 1991 to spring 1995. Co, Cu, Zn, Mo, Rh, Pd, Ag, Cd, Sb, Pt, Pb, Bi and U were determined using ultrasensitive inductively coupled plasma sector field mass spectrometry under clean room conditions. In addition we also determined Al by graphite furnace atomic absorption spectrometry and Na+, Ca2+, SO42−, MSA and oxalate by ion chromatography, species that will assist in the interpretation of the trace metal data. The data show pronounced inter- and intra-annual variations, with large differences in the amplitude of these variations for the element studied, with few clear seasonality patterns. Generally, high concentrations are observed in the spring snow layers, while much lower concentrations are typical of summer snow layers. Significant correlations are observed between Co, Cu, Zn, Ag and Sb, while Pt, Pd and Rh show no correlation with the other metals. Crustal enrichment factors show that while the crustal dust contribution is probably important for some metals for part of the year (spring), anthropogenic inputs are as important in many instances. Pronounced intra-annual variations are observed for some metals, in particular Pt. The variations observed for this metal parallel fairly closely changes in Russian Pt production, which points to emissions from smelters in the Russian Arctic as likely sources for Pt.

Trace Heavy Metal Levels in Street Dust Samples from Yozgat City Center, Turkey

Abstract: The copper, cadmium, chromium, nickel, lead, manganese and cobalt contents of dust samples taken from Yozgat city center, Turkey were determined by flame atomic absorption spectrometry after digestion with aqua regia. The highest levels of the trace metal ions in the streets with heavy traffic were noted. The lowest levels of the metal concentrations were found in the samples from hospital and health centers. The results found in the present study were compared with some cities around the world. The levels of the metal ions found were generally below the mean world-wide contents of the street dust samples. Correlations between heavy trace metal levels of the dust samples were also evaluated.

Effects of trace element addition on volatile fatty acid conversions in anaerobic granular sludge reactors

Abstract: The effect of the addition of trace elements on the conversion of a mixture of volatile fatty acids (Acetate, Propionate, Butyrate, in a ratio 3:1:1) by anaerobic granular sludge was investigated. Two Upflow Anaerobic Sludge Bed reactors (pH 7, 30°C) were operated for 140 days at an organic loading rate ranging from 2 g COD l−1 d−1 up to 10 g COD 1−1 d−1 and a hydraulic retention time of 12 hours. One reactor (Rl) was supplied with a trace metal cocktail in the basal medium, whereas trace metals were omitted from the influent of the second reactor (R2). As a result, the trace metal concentration in the granules from R2 steadily decreased at a rate of 48 μg metal g−1 TS d−1 down to 35% of their initial value. In contrast, trace metals accumulated in granules present in Rl. At the end of the experiment, the COD removal efficiencies were 99 and 77% for, respectively, the control (R1) and deprived (R2) reactors. This difference was due to lack of propionate conversion by sludge from R2. No difference...

Biomonitoring of trace metal contamination in mangrove-lined Brazilian coastal systems using the oyster Crassostrea rhizophorae : comparative study of regions affected by oil, salt pond and shrimp farming activities

Abstract: The oyster Crassostrea rhizophorae has been used as a biomonitor of trace metal contamination in two Brazilian coastal systems. C. rhizophorae were collected in January 1998 from 15 stations (from 4 coastal inlets (including 1 estuary) and 1 coastal beach) near Macau, Rio Grande do Norte (RN), Brazil, a region affected by the activities of the oil industry and salt manufacture in coastal salt ponds; oysters were also collected in September 1999 from 8 stations in the Curimatau estuary (RN), an estuary becoming increasingly affected by shrimp farming activities. C. rhizophorae is a net accumulator of trace metals and can be used as a biomonitor, the accumulated soft tissue concentrations representing integrated records of bioavailable metal over the life of the oyster. At Macau, significant differences in oyster accumulated concentrations (and hence bioavailabilities to the oyster) of Fe, Zn, Cu, and Mn were found between stations; raised zinc availabilities at the coastal site are in close proximity to oil industry activities but the very high availabilities of Fe, Cu and Mn in the Rio dos Cavalos estuary originate from an unknown source. In the Curimatau estuary, bioavailabilities of Mn, Pb and Cd, but particularly of Cu and Zn, to the oysters are raised at the two most downstream sites, the only sites below the effluent of a large shrimp farming enterprise. The oysters also act as a local food source, and concentrations of Zn, Cu and Pb of some of the oysters are above typical public health recommended limits.