Effects of development time, biomass and ferromanganese oxides on nickel sorption by stream periphyton

Procedurally defined periphyton frequently includes substantial quantities of hydrous iron (Fe) and manganese (Mn) oxides. As these oxides are strong sorbers of heavy metals, their presence may complicate estimation of metal bioaccumulation by periphyton. We examined the relationship between nickel (Ni) sorption and the development time, biomass, and Fe and Mn oxide content of stream periphyton. Development time, the time during which periphyton accrued on submerged tile substrata, was used to provide variation in biomass, Fe and Mn levels. Stream periphyton from four development times was exposed to Ni for 2 h in the laboratory, and then ashed. Development time was significantly associated with ash-free dry mass (AFDM), Fe and Mn levels (ANOVA, P < or = 0.003). Ni extracted by a mild reductant (hydroxylamine hydrochloride) was significantly associated with development time, and with AFDM, Fe and Mn levels (linear models, P < or = 0.0002). A subsequent acid digestion yielded similar associations with the same variables (linear models, P < or = 0.0001). For both extractions, AFDM was significantly and positively correlated with Fe (r = 0.68 and 0.89) and with Mn (r = 0.77 and 0.93) (Spearman rank, P < or = 0.005). These data demonstrate the importance of periphyton development time in influencing both metal sorption and levels of biomass and ferromanganese oxides. The data also suggest that metal contaminant levels in periphyton should not be attributed automatically to biotic sorption. Periphyton metal-accumulation studies conducted where ferromanganese oxide concentrations are elevated should address the potential metal-sorbing roles of Fe and Mn oxides within the periphyton matrix.     

Influence of hydrological regime on pore water metal concentrations in a contaminated sediment-derived soil

Options for wetland creation or restoration might be limited because of the presence of contaminants in the soil. The influence of hydrological management on the pore water concentrations of Cd, Cr, Cu, Fe, Mn, Ni and Zn in the upper soil layer of a contaminated overbank sedimentation zone was investigated in a greenhouse experiment. Flooding conditions led to increased Fe, Mn, Ni and Cr concentrations and decreased Cd, Cu and Zn concentrations in the pore water of the upper soil layer. Keeping the soil at field capacity resulted in a low pore water concentration of Fe, Mn and Ni while the Cd, Cu, Cr and Zn concentrations increased. Alternating hydrological conditions caused metal concentrations in the pore water to fluctuate. Formation and re-oxidation of small amounts of sulphides appeared dominant in determining the mobility of Cd, Cu, and to a lesser extent Zn, while Ni behaviour was consistent with Fe/Mn oxidation and reduction. These effects were strongly dependent on the duration of the flooded periods. The shorter the flooded periods, the better the metal concentrations could be linked to the mobility of Ca in the pore water, which is attributed to a fluctuating CO(2) pressure.     

Relationship between heavy metals concentrations in egret species,their environment and food chain differences from two Headworks of Pakistan

Concentration of ten metals (Cd, Cr, Co, Cu, Fe, Li, Mn, Ni, Pb and Zn) were analyzed in the egg contents, prey and soil samples of little egret (Egretta garzetta) and cattle egret (Bubulcus ibis) from two Headworks to determine habitat and species-specific differences; to assess the importance of prey and habitat contamination as an exposure source for heavy metals. Concentration of Cu, Mn, Cr and Pb in egg contents, Fe, Co, Cu, Mn, Zn in prey and Fe, Co, Cu, Ni, Li in surface soils were significantly different (P < 0.05). Mean metal concentrations of Cr, Pb and Cd were relatively higher in little egret whereas Cu and Mn were higher in the egg contents of cattle egret. The mean concentrations of Cu, Mn and Zn were higher in prey samples of cattle egrets and Cr, Cd and Pb in prey samples of little egrets. In soil samples collected from little egret heronries metal concentrations were higher except Cu and Ni. Correlation Analysis and Hierarchical Agglomerative Cluster Analysis (HACA) identified relatively similar associations of metals and their source identification. Metals such as Fe, Cu, Mn, and Li were related with geochemical origin from parent rock material as well as anthropogenic input whereas Cr, Cd, Pb, Ni, Co and Zn were associated mostly with anthropogenic activities. The study suggested that eggs are useful bio-monitor of local heavy metal contamination.     

Concentrations,spatial distribution,and pollution assessment of heavy metals in surficial sediments from upstream of Yellow River,China

Surface sediments were collected from 122 sites in the upstream of the Yellow River, China. The concentration of Fe, Mn, Cu, Ni, Zn, Cr, Pb, and Cd in sediments was investigated to explore the spatial distribution based on statistics and interpolation method. The results suggested that the concentrations of heavy metals were lower than potential effect levels (PEL). The samples above threshold effect level (TEL) for Pb and Zn were less than 10%, while almost 50% of samples for Ni exceeded PEL. Pb and Zn in sediments performed little or no adverse effects on the aquatic ecosystems. Higher concentrations of all heavy metals occurred in Qinghai and Gansu sections; the concentrations of Cu, Ni, and Zn were significantly higher than the Inner Mongolia section. Lower concentration of Fe, Mn, Cu, Ni, and Zn appeared in Qinghai section; the concentrations of Fe, Mn, Cr, and Pb manifested relatively steady and similar distributions and approximately decreasing tendency along the upstream of Yellow River.

     

The influence of body size, condition index and tidal exposure on the variability in metal bioaccumulation in Mytilus edulis

Mussels are commonly used to monitor metal pollution despite high inter-individual variability in tissue concentrations. In this study, influences of body size, condition index and tidal height on concentrations of As, Cd, Co, Cr, Cu, Fe, Mn, Ni, Pb and Zn were investigated. Body weight was inversely related to metal concentrations and for Cd, Mn, Pb and Zn the regression was affected by tidal height. Except for As, Fe and Mn metal concentrations were inversely related to physiological status though no differences between essential and non-essential metals were obvious. After correcting for body size, tidal height was related positively to As, Cd and Zn, negatively related to Cu, Fe and Mn while Co, Cr, Ni and Pb were independent of tidal height. The study recommends stringent measures during sampling for biomonitoring or metal concentrations at each location must be normalized to a common body size, CI and tidal height.     

Airborne heavy metal pollution and its effects on foliar elemental composition of Empetrum hermaphroditum and Vaccinium myrtillus in Sør-Varanger, northern Norway

Uptake of Al, Cu, Fe, Mn, Ni, Ca, K, Mg, P, and S in Empetrum nigrum L. ssp. hermaphroditum Hagerup and Vaccinium myrtillus L. from Ni, Cu and SO2 contaminated sites in S?r-Varanger, northern Norway, were investigated. The primary objective was to study the effect of airborne heavy metal pollution on foliar element composition of these two dwarf shrubs. Ni distribution and availability in soils clearly indicate atmospheric deposition of Ni particulates in S?r-Varanger. Foliar Ni concentrations in E. hermaphroditum and V. myrtillus increased in relation to plant available Ni in corresponding soils. Leaves of E. hermaphroditum generally contained higher concentrations of Ni than leaves of V. myrtillus. Emissions influenced some features of leaf elemental composition of the two species in very different ways. In leaves of V. myrtillus, S increased in proportion to Ni and Cu, while levels of Mn decreased. In leaves of E. hermaphroditum, Fe increased in proportion to Ni and Cu, while levels of Ca decreased.     

Trace metals in the Mexican shrimp Penaeus vannamei from estuarine and marine environments

Trace-metal concentrations (Fe, Mn, Ni, Cu, Co, Cd, Cr, and Zn) were measured in estuarine postlarvae, juveniles, and marine adults of the shrimp Penaeus vannamei collected along the Pacific coast of Mexico. With the exception of Fe, the trace-metal concentrations fell within the ranges of similar organisms collected elsewhere. Size-dependent relationships were observed only for Ni, Fe, and Zn and varied depending on the element considered. Small individuals had higher concentrations of Fe and Ni than larger individuals. For Zn, the opposite tendency occurred. This may reflect different metabolic requirements of young and old shrimps.     

Evaluation of heavy metal concentrations of edible wild-grown mushrooms from China

ABSTRACT

The heavy metal contents (Co, Cu, Fe, Mn, Ni, and Zn) of eight species of wild edible mushrooms from China were determined. The analyses were performed using inductively coupled plasma atomic emission spectrophotometry after microwave digestion. The contents of Co, Cu, Fe, Mn, Ni, and Zn in caps of mushroom samples were 0.7–7.2, 16.2–70.4, 371–1315, 12.5–29.8, 7.1–58.5, and 77.8–187.4 mg kg^?1 dry matter (dm), respectively, while considerable differences were found to be 1.8–25.9, 9.8–36.3, 288–6762, 13.3–103.9, 5.9–78.7, and 38.7–118 mg kg^?1 dm for stipes. The results indicated that higher levels of Co, Fe, and Ni were found in the mushrooms samples analyzed. Zinc and manganese levels were similar to previous reports, whereas Cu was lower than literature values. Correlation analysis suggested that significant correlations were found between the minerals determined and the greatest amount of contamination is associated with Co, Mn, Ni, and Fe. The results of this study indicate that heavy metal contents in mushroom species are mainly related to the mineral resources of sampling sites.     

A comparison of Cu, Pb, As, Cd, Zn, Fe, Ni and Mn determined by acid extraction/ICP-OES and ex situ field portable X-ray fluorescence analyses

Total concentrations of Cu, Pb, As, Cd, Zn, Fe, Ni and Mn were determined for 81 soil samples using two types of field portable X-ray fluorescence (FPXRF) system; dual isotope and X-ray tube. FPXRF metal concentrations were statistically compared with analytical results from aqua regia extractions followed by Inductively Coupled Plasma-Optical Emission Spectrometry (ICP-OES) analysis. The ability of each FPXRF instrument to produce analytical results comparable to the reference method was assessed by linear regression. A high degree of linearity was found for Fe and Pb with the X-ray tube instrument and for Fe, Cu, Pb, Zn, Cd and Mn with the dual source instrument. FPXRF analyser performance improved with increased analysis time for Cu, Mn and Pb, whilst Fe, Zn, Cd, Ni and As showed no significant improvement. Particle size did not influence FPXRF analyser performance. Both the dual isotope and the X-ray tube FPXRF instruments are effective tools for rapid, quantitative assessment of soil metal contamination and for monitoring the efficacy of remediation strategies.     

Estimation of metal uptake efficiencies from precipitation in mosses in Lithuania

The main sources contributing to heavy metal content in mosses in Lithuania were examined by a comparison of heavy metal concentrations in moss and corresponding deposition levels calculated from bulk deposition analysis. Bulk deposition was collected in open areas as well as under the canopy of trees. Uptake efficiencies in moss were calculated for Cd, Cr, Cu, Fe, Mn, Ni, V and Zn. All elements in moss except Pb and Cd appeared to be more or less influenced by sources other than air pollution. The general order of this influence on the heavy metal content in moss was observed as follows: Ni < V < Cr < Zn < Fe < Mn. The contents of Mn and Zn in moss were greatly influenced by leaching from the canopy while Pb was the only element which showed a net metal retention by the canopy. Concentrations of Fe and Cr in moss were dominating due to contribution from soil dust.     

Mobility of heavy metals from polluted sediments of a semi-enclosed basin: in situ benthic chamber experiments in Taranto’s Mar Piccolo (Ionian Sea,Southern Italy)

In situ benthic flux experiments were conducted at two stations in the Mar Piccolo of Taranto (Italy), one of the most industrialised and contaminated coastal areas of the Mediterranean. Sediments of the two stations are notably different in their trace metal content, with a station closer to a Navy harbour showing higher mean concentrations of almost all investigated metals (Al, As, Cd, Cr, Cu, Fe, Hg, Mn, Ni, Pb, V and Zn). Conversely, both stations are characterised by significant Hg contamination, compared to the local baseline. Results of a sequential extraction scheme on surface sediments suggest a relatively scarce mobility of the examined metals (Zn > Ni > Cr > As > Cu > Pb). A Hg-specific extraction procedure showed that most of the element (93.1 %) occurs in a fraction comprising Hg bound to Fe/Mn oxi-hydroxides. Reduction of these oxides may affect Hg remobilisation and redistribution. Porewater profiles of dissolved trace metals were quite similar in the two sites, although significant differences could be observed for Al, Cu, Fe and Hg. The highest diffusive fluxes were observed for As, Fe and Mn. Mobility rates of several trace elements (Al, As, Cd, Cr, Cu, Fe, Hg, Mn, Ni, Pb, V and Zn) were directly measured at the sediment–water interface. Results from benthic in situ incubation experiments showed increasing dissolved metal concentrations with time, resulting in higher fluxes for Cu, Fe, Hg, V and Zn in the most contaminated site. Conversely, fluxes of Mn, Ni and Pb were comparable between the two stations. The estimated flux of Hg (97 μg m^?2 day^?1) was the highest observed among similar experiments conducted in other highly contaminated Mediterranean coastal environments. Benthic fluxes could be partially explained by considering rates of organic matter remineralisation, dissolution of Fe/Mn oxy-hydroxides and metal speciation in sediments. Seasonal and spatial variation of biogeochemical parameters can influence metal remobilisation in the Mar Piccolo area. In particular, metals could be promptly remobilised as a consequence of oxygen depletion, posing a serious concern for the widespread fishing and mussel farming activities in the area.     

Trace metal behaviour in the Conwy estuary,North Wales

The distribution of trace metals Zn, Ni, Mn, Fe, Cu, Pb, Cd and Cr between suspended particulate matter (SPM) and water in the Conwy estuary, North Wales, has been studied in three surveys in 1998. Dissolved Cu and Mn showed some monthly variations. Most of the dissolved trace metals displayed a negative association with salinity, indicating rivers as a major source of inputs for them. Particulate Zn, Mn and Fe showed a decreasing concentration seaward, whilst the levels of Ni, Cu, Cr and Pb increased with salinity. SPM concentration was the most important variable significantly related to trace metal concentrations in SPM, with an inverse relationship between the two parameters. This was explained by the relative enrichment of trace metals in fine particles at low SPM concentrations and relative depletion of trace metals in coarse particles at high SPM concentrations. Particulate Zn, Mn and Pb were dominated by the fraction available to acetic acid (non-detrital), whilst particulate Ni, Fe and Cr were dominated by the fraction available to nitric acid (detrital). The partition coefficient of trace metals between SPM and water declined with increasing SPM concentration, consistent with the so-called "particle concentration effect". Such a phenomenon may be explained by the presence of fine particles (including colloids) enriched with trace metals at low SPM concentrations, and the salinity-induced desorption.     

Nickel and other metal uptake and accumulation by species of Alyssum (Brassicaceae) from the ultramafics of Iran

Some plants growing on serpentine (ultramafic) soils are able to hyperaccumulate nickel in their above-ground parts. The genus Alyssum L. contains the greatest number of Ni-hyperaccumulator plants so far reported. There are substantial areas of serpentine soils at many locations in Iran. This paper presents the analyses for Ni, Cr, Mn, Fe, Mg and Ca in soils and Alyssum species from the ultramafics of west and northwest Iran. Soil analysis for total elements in these areas indicates that typical concentrations of Ni, Cr, Mn, Fe, Mg and Ca are up to about 1240, 365, 800, 51,150, 152,390 and 11,790 microg g(-1), respectively. During this study, seven Alyssum species were collected. Analysis of leaf dry matter shows that Alyssum bracteatum can contain up to 2300 microg Nig(-1), while the other species contain much lower concentrations of Ni and other elements. A. bracteatum is endemic to Iran and the first Ni hyperaccumulator reported from this species.     

Heavy metals incidence in the application of inorganic fertilizers and pesticides to rice farming soils

The concentrations of Cd, Co, Cu, Ni, Pb, Zn, Fe and Mn in different inorganic fertilizers (urea, calcium superphosphate, iron sulphate and copper sulphate) and in pesticides (two herbicides and one fungicide) are evaluated together with the contribution of these metals in soils from their use. The study was made in rice farming areas to the north of Albufera Natural Park (Valencia, Spain). The results obtained show that superphosphate is the fertilizer that contains the highest concentrations of Cd, Co, Cu and Zn as impurities. Copper sulphate and iron sulphate have the most significant concentrations of Pb, and are the only fertilizers in which Ni was detected. The three pesticides analysed show similar Cd contents and the highest levels of Fe, Mn, Zn, Pb and Ni are found in the herbicides. The most significant additions of heavy metals as impurities that soil receives from agricultural practices, are Mn, Zn, Co and Pb. Three contamination indexes have been applied to provide a basis for comparison of potential heavy metal toxicity. These results denote the potential toxicity of heavy metals in the studied soils.     

The wet deposition of trace metals to the western atlantic ocean at the mid-atlantic coast and on Bermuda

The concentration of the trace metals Cd, Cu, Fe, Mn, Ni, Pb, V and Zn has been measured in atmospheric precipitation events at the middle Atlantic coast (Lewes, DE) and on the western Atlantic island of Bermuda. The purpose is to assess the sources, transport, and wet deposition of trace metals to the western Atlantic during non-summer months when trace metals are likely to be transported by westerly air mass flow from N America to the open Atlantic. The concentrations, and wet deposition of trace metals are greater at the coast than on Bermuda, and the other at both sites (Fe > Zn > Pb > Cu, Mn, Ni > V > Cd) is similar. The trace metal enrichment factors for all metals but Mn, based on crustal Fe, are significantly greater than unity, and the order (Cd > Pb > Zn > Cu > Ni > V) is also the same at the coast as on Bermuda. This evidence suggests common sources from North America for trace metals in western Atlantic precipitation and important atmospheric transport of trace metals to the Atlantic Ocean. Calculations using enrichment factors from sea salt aerosol (Na based) indicate recycling of trace metals from the sea surface, while generally considered not to be important, could be a potentially significant process contributing to Mn and V enrichments in open western Atlantic precipitation.     

Residual metal concentrations in soils and leaf accumulations in tobacco a decade following farmland application of municipal sludge

The objectives of this investigation were to examine the long-term residual effects of metal loading through sewage sludge applications on the total vs. diethylene triamine pentacetic acid (DTPA) extractable metal concentrations in soil and leaf accumulations in tobacco. Maryland tobacco (Nicotiana tabacum L.), cv. 'MD 609', was grown in 1983 and 1984 at two sites in Maryland that had been amended in 1972 with dewatered, digested sewage sludge from washington, DC, at rates equal to 0, 56, 112 and 224 mg ha(-1). The metal concentrations in the sludge, in mg kg(-1) dry weight, were: 1300 Zn, 570 Cu, 280 Pb, 45 Ni and 13 Cd. Soil samples collected from the surface horizon and composite leaf samples of cured tobacco were analyzed for total Zn, Cu, Mn, Fe, Pb, Ni and Cd concentrations. The soil samples were also examined for soil pH and DTPA extractable metals. Equations were generated using polynomic and stepwise regression analyses which described the relationships between total vs. DTPA extractable soil metals, and between DTPA soil and soil pH vs. plant metal concentrations, respectively. Significant increases were observed for both total and DTPA extractable metal concentrations for all metals, with all but total Mn and Ni being significant for linear and quadratic effects regarding sludge rates. However, linear relationships were found between DTPA extractable vs. total soil concentrations for all elements except Pb and Ni which were quadratic. Significant increases in plant Zn, Cu, Mn, Ni and Cd and decreases in Fe were observed with increased sludge rates. Plant Pb levels were unaffected by sludge applied Pb. Linear relationships were observed between plant Zn and Cd and DTPA soil metal levels: however, Mn and Cu levels were described by quadratic and cubic relationship, respectively. Relationships between plant Fe and Pb and DTPA extractable concentrations were nonsignificant. Additional safeguards to protect crop contamination from heavy metals such as Cd were discussed.     

Seasonal variation and background levels of heavy metals in two green seaweeds

Seasonal variation in the contents of different metals (Al, Cr, Cu, Fe, Mn, Ni and Zn) in two genera of macroalgae, Ulva and Enteromorpha was studied at 22 sites on the northwest coast of Spain. The seasonal variation in the different metals followed a similar pattern in both seaweeds and appeared to be caused by dilution during the period of maximum growth and concentration during periods of slow growth. Fluvial inputs of Al, Fe and Mn in autumn and winter appeared to accentuate the latter effect: the concentrations of these three metals in both macroalgae and of Cr in Enteromorpha were highest at those sites most influenced by inputs from rivers. The background levels of Cr, Cu, Ni and Zn in the algae in summer and winter were established.     

Evaluation of diffusive gradients in thin film (DGT) samplers for measuring contaminants in the Antarctic marine environment

This work has been the first application of DGT samplers for measuring metals in water and sediment porewater in the Antarctic environment, and whilst DGT water sampling was restricted to quantification of Cd, Fe and Ni, preconcentration using Empore chelating disks provided results for an additional nine elements (Sn, Pb, Al, Cr, Mn, Co, Cu, Zn, As). Although higher concentrations were measured for some metals (Cd, Ni, Pb) using the Empore technique, most likely due to particulate-bound or colloidal species becoming entrapped in the Empore chelating disks, heavy metal concentrations in the impacted Brown Bay were found to be comparable with the non-impacted O'Brien Bay. Sediment porewater sampling using DGT also indicated little difference between Brown Bay and O'Brien Bay for many metals (Cd, Al, Cr, Co, Ni, Cu), however, greater amounts of Pb, Mn, Fe and As were accumulated in DGT probes deployed in Brown Bay compared with O'Brien Bay, and a higher accumulation of Sn was observed in Brown Bay inner than any of the other three sites sampled. Comparison of DGT derived porewater concentrations with actual porewater concentrations showed limited resupply of Cd, Pb, Al, Cr, Mn, Co, Ni, Cu, Zn and As from the solid phase to porewater, with these metals appearing to be strongly bound to the sediment, however, resupply of Fe and Sn was apparent. Based upon our observations here, we suggest that Sn, and to a lesser extent Pb, are critical contaminants.     

Evaluation of ecological risk,source, and spatial distribution of some heavy metals in marine sediments in the Middle and Eastern Black Sea region,Turkey

Environmental Science and Pollution Research - In the present study, the concentration levels of heavy metals such as Mn, Fe, Ni, Cu, Zn, Cr, and Pb in sediment samples collected from 16 sampling...