Recycling Of Trace Elements Research Articles

Effect of pH on Trace Elements Removal from Batteries and Compact Disks by Aspergillus terreus Pellets

Background: The aim of this study is the removal of three trace elements (Nickle Ni, Cadmium Cd and Lead Pb) by an environmentally friendly method from Batteries and compact discs. This study aimed to rapidly remove trace elements from E-waste (batteries) by filamentous fungi pellets. Methods: Aspergillus was the best heavy metal tolerated isolate under the following incubation parameters: pH (5), temperature (25°C), ground electronic waste powder doses (0.5, 1 and 1.5 g/L) absorbed by fungal pellets biomass 10 gm/L of wet weight. Result: The results showed the best removal percentage R% of Ni, Cd and Pb removal were (89,91and 96) observed at pH 5. Images from SEM showed accumulations of metal particles on the surface of the fungal hyphae and Fourier Transform Infra-Red Spectroscopy (FT-IR) was used to determine the effective groups in the fungal cell wall responsible of biosorption of trace elements and This study indicates that an application may be possible Aspergillus terreus as a promising candidate for biological sorption and recycling of trace elements and as an ecologically friendly and effective process in terms of time and cost.

Melting of subducted slab dictates trace element recycling in global arcs.

Arc magma acquires continental crust-like trace element signatures through selective recycling of incompatible elements from the subducted slab. The long-standing model of element recycling through aqueous fluid from altered oceanic crust (AOC) and sediment melt has been challenged by the resurgence of mélange diapir (a mix of AOC, sediment, and serpentinite) and saline aqueous fluid models. Here, we present experimental data for near-solidus sediment melts and a framework for calculating trace element concentrations in subduction fluids from metamorphosed sediment and oceanic crust. We observe that variation of element ratios in global primitive arc basalts is comparable with that of sediment and/or oceanic crustal melt, rather than (saline) aqueous fluid or mélange melt. In particular, the systematic correlation of element ratios in arc basalt corresponds to element fractionation in slab melt with temperature and therefore follows a power function. Our findings suggest that slab melt is primarily responsible for element recycling to the arc.

The effect of fluorine and chlorine on trace element partitioning between apatite and sediment melt at subduction zone conditions

The effect of F and Cl on trace element recycling during subduction-related sediment melting has been investigated by performing piston-cylinder experiments with a hydrous experimental pelite starting material (EPSM) with variable Cl (~0, 500, 1000, 2000, or 3000ppm) and F (~0, 700, or 1500ppm) concentrations, at 2.5GPa, 800°C. The variations of trace element concentrations in melt are systematically correlated with the variation of F (0.07–0.39wt%) and Cl (0.07–0.39wt%) contents. Trace elements Zn, V and Pb, and major elements Fe, Mg and Ca, show positive correlations with each other, and also with the Cl content in melt. The concentrations of light and medium rare earth elements (LMREE) increase with the Cl content in melt, whereas both F and Cl cause a decrease in the concentrations of high field strength elements (HFSE, such as Nb, Ta, Zr and Hf). Trace element (REE, Y, Sr, Th, U) concentrations in apatite are found to increase with the mole fraction of chlorapatite (ClAp). The preference for ClAp is stronger for cations with higher charge (e.g., Th4+, U4+>REE3+) and larger ionic radii (e.g., LREE>HREE).Trace element partition coefficients between apatite and melt show up to 4 times variation between experiments, e.g., DLaAp-melt=77–281; DSmAp-melt=176–519; DSrAp-melt=4–12 and DTh,UAp-melt=4–19. The REE partition coefficients between apatite and melt (DREEAp-melt) display a concave pattern with the peak at Sm/Nd and a negative Eu anomaly, and are significantly higher than previously reported values for partitioning experiments conducted at lower pressures and higher temperatures. The high values of DLREEAp-melt demonstrate the importance of apatite in terms of LREE partitioning during sediment melting, while allanite/monazite still dominates the partitioning of Th. In the absence of allanite/monazite, apatite-buffered melt is characterized by a significant enrichment of Th relative to La. Because of the contrasting behavior of LREE and HFSE in melt with the addition of Cl and F, the fractionation of these elements in slab-derived sediment melts will be enhanced by the presence of halogens.

Fluid-related inclusions in Alpine high-pressure peridotite reveal trace element recycling during subduction-zone dehydration of serpentinized mantle (Cima di Gagnone, Swiss Alps)

Serpentinites release at sub-arc depths volatiles and several fluid-mobile trace elements found in arc magmas. Constraining element uptake in these rocks and defining the trace element composition of fluids released upon serpentinite dehydration can improve our understanding of mass transfer across subduction zones and to volcanic arcs. The eclogite-facies garnet metaperidotite and chlorite harzburgite bodies embedded in paragneiss of the subduction melange from Cima di Gagnone derive from serpentinized peridotite protoliths and are unique examples of ultramafic rocks that experienced subduction metasomatism and devolatilization. In these rocks, metamorphic olivine and garnet trap polyphase inclusions representing the fluid released during high-pressure breakdown of antigorite and chlorite. Combining major element mapping and laser-ablation ICP-MS bulk inclusion analysis, we characterize the mineral content of polyphase inclusions and quantify the fluid composition. Silicates, Cl-bearing phases, sulphides, carbonates, and oxides document post-entrapment mineral growth in the inclusions starting immediately after fluid entrapment.Compositional data reveal the presence of two different fluid types. The first (type A) records a fluid prominently enriched in fluid-mobile elements, with Cl, Cs, Pb, As, Sb concentrations up to 103 PM (primitive mantle), ∼102 PM Tl, Ba, while Rb, B, Sr, Li, U concentrations are of the order of 101 PM, and alkalis are ∼2 PM. The second fluid (type B) has considerably lower fluid-mobile element enrichments, but its enrichment patterns are comparable to type A fluid.Our data reveal multistage fluid uptake in these peridotite bodies, including selective element enrichment during seafloor alteration, followed by fluid–rock interaction along with subduction metamorphism in the plate interface melange. Here, infiltration of sediment-equilibrated fluid produced significant enrichment of the serpentinites in As, Sb, B, Pb, an enriched trace element pattern that was then transferred to the fluid released at greater depth upon serpentine dehydration (type A fluid). The type B fluid hosted by garnet may record the composition of the chlorite breakdown fluid released at even greater depth.The Gagnone study-case demonstrates that serpentinized peridotites acquire water and fluid-mobile elements during ocean floor hydration and through exchange with sediment-equilibrated fluids in the early subduction stages. Subsequent antigorite devolatilization at subarc depths delivers aqueous fluids to the mantle wedge that can be prominently enriched in sediment-derived components, potentially triggering arc magmatism without the need of concomitant dehydration/melting of metasediments or altered oceanic crust.

Lawsonite metasomatism and trace element recycling in subduction zones

AbstractAlthough lawsonite‐bearing rocks are rare in exhumed high‐pressure (HP) terranes, they are considered to exert a primary role in subduction dynamics. Recent observations in natural settings have shown that fluid–rock interaction at HP conditions, including metasomatism, may lead to unusually high lawsonite amounts even in rocks that originally contained little or no lawsonite. This process may therefore bear important implications for element recycling in subduction zones. A detailed characterization of the geochemical fingerprints associated with lawsonite metasomatism is presented in this contribution. The studied rocks belong to the HP terranes of Alpine Corsica (France), which is the largest documented exposure for lawsonite metasomatism. Metasomatic lawsonite displays complex compositional zoning, including high trace element, Cr and Ti content. The trace element content is much higher compared with the average of non‐metasomatic lawsonite, and is in line with the re‐incorporation of large amounts of trace elements (e.g. REE, Sr, Pb, Th) in the rock during metasomatism, as shown by mass transfer calculations. Our data suggest that serpentinites represented the main fluid source for the metasomatism, with concurrent contribution of other, possibly Ca‐rich lithologies, such as mafic or meta‐sedimentary rocks. We propose that the breakdown of metasomatic lawsonite may contribute to the genesis of magmas and their characteristic geochemical signatures.

Louisville seamount subduction and its implication on mantle flow beneath the central Tonga–Kermadec arc

Subduction of intraplate seamounts beneath a geochemically depleted mantle wedge provides a seldom opportunity to trace element recycling and mantle flow in subduction zones. Here we present trace element and Sr, Nd and Pb isotopic compositions of lavas from the central Tonga-Kermadec arc, west of the contemporary Louisville-Tonga trench intersection, to provide new insights into the effects of Louisville seamount subduction. Elevated (206)Pb/(204)Pb, (208)Pb/(204)Pb, (86)Sr/(87)Sr in lavas from the central Tonga-Kermadec arc front are consistent with localized input of subducted alkaline Louisville material (lavas and volcaniclastics) into sub-arc partial melts. Furthermore, absolute Pacific Plate motion models indicate an anticlockwise rotation in the subducted Louisville seamount chain that, combined with estimates of the timing of fluid release from the subducting slab, suggests primarily trench-normal mantle flow beneath the central Tonga-Kermadec arc system.

The Impact of Coal Combustion Residue Effluent on Water Resources: A North Carolina Example

The combustion of coal to generate electricity produces about 130 million tons of coal combustion residues (CCRs) each year in the United States; yet their environmental implications are not well constrained. This study systematically documents the quality of effluents discharged from CCR settling ponds or cooling water at ten sites and the impact on associated waterways in North Carolina, compared to a reference lake. We measured the concentrations of major and trace elements in over 300 samples from CCR effluents, surface water from lakes and rivers at different downstream and upstream points, and pore water extracted from lake sediments. The data show that CCR effluents contain high levels of contaminants that in several cases exceed the U.S. EPA guidelines for drinking water and ecological effects. This investigation demonstrates the quality of receiving waters in North Carolina depends on (1) the ratio between effluent flux and freshwater resource volumes and (2) recycling of trace elements through adsorption on suspended particles and release to deep surface water or pore water in bottom sediments during periods of thermal water stratification and anoxic conditions. The impact of CCRs is long-term, which influences contaminant accumulation and the health of aquatic life in water associated with coal-fired power plants.

Silicate and carbonate melt inclusions associated with diamonds in deeply subducted carbonate rocks

Abstract Deeply subducted carbonate rocks from the Kokchetav massif (Northern Kazakhstan) recrystallised within the diamond stability field ( P = 4.5–6.0 GPa; T ≈ 1000 °C) and preserve evidence for ultra high-pressure carbonate and silicate melts. The carbonate rocks consist of garnet and K-bearing clinopyroxene embedded in a dolomite or magnesian calcite matrix. Polycrystalline magnesian calcite and polyphase carbonate–silicate inclusions occurring in garnet and clinopyroxene show textural features of former melt inclusions. The trace element composition of such carbonate inclusions is enriched in Ba and light rare earth elements and depleted in heavy rare earth elements with respect to the matrix carbonates providing further evidence that the inclusions represent trapped carbonate melt. Polyphase inclusions in garnet and clinopyroxene within a magnesian calcite marble, consisting mainly of a tight intergrowth of biotite + K-feldspar and biotite + zoisite + titanite, are interpreted to represent two different types of K-rich silicate melts. Both melt types show high contents of large ion lithophile elements but contrasting contents of rare earth elements. The Ca-rich inclusions display high REE contents similar to the carbonate inclusions and show a general trace element characteristic compatible with a hydrous granitic origin. Low SiO 2 content in the silicate melts indicates that they represent residual melts after extensive interaction with carbonates. These observations suggest that hydrous granitic melts derived from the adjacent metapelites reacted with dolomite at ultra high-pressure conditions to form garnet, clinopyroxene – a hydrous carbonate melt – and residual silicate melts. Silicate and carbonate melt inclusions contain diamond, providing evidence that such an interaction promotes diamond growth. The finding of carbonate melts in deeply subducted crust might have important consequences for recycling of trace elements and especially C from the slab to the mantle wedge.

Serpentinite Subduction: Implications for Fluid Processes and Trace-Element Recycling

Serpentinites are important components of the oceanic lithosphere and are viewed as major water sources in subduction zones. Study of a set of ultramafic rocks equilibrated at increasing subduction depths (oceanic and high-pressure antigorite serpentinites, olivine-orthopyroxene rocks), shows that these rocks can act as carriers of Cl, B, Sr, Rb, Cs, and alkalis. Serpentinization of the oceanic mantle produces enrichment in Sr, Cl, B, and alkalis. The subduction path within the stability field of antigorite serpentine is accompanied recycling of oceanic Cl, B, Sr, and alkalis into variably saline fluids (4-8 wt% NaClequiv based on mass balance calculations; 10 to 50 wt% NaClequiv based on fluid inclusion analysis). Fluids are produced during a first (olivine-in) dehydration reaction releasing a maximum amount of 2 wt% H2O. The oxygen isotope compositions of the high-pressure antigorite serpentinites largely mirror those of the pre-subduction protoliths. This is interpreted as a lack of re-equilibration due to limited fluid production and mobility during high-pressure metamorphism Breakdown of the antigorite serpentinites to olivine-orthopyroxene rocks releases 6.5 wt% H2O with formation of a low salinity fluid (0.4-2 wt% NaClequiv based on mass balance calculations). The salt contents of subduction fluids appear to decrease with increasing depth: a "differentiation" in the Cl content of fluids can thus be expected, with shallower saline fluids being followed by deeper, less saline, solutions. Primary fluid inclusions in olivine-orthopyroxene rocks represent remnants of the antigorite-breakdown fluid. Their trace-element compositions are enriched in several LILE (Rb, Sr, Cs, Pb), Li, B, and alkalis and are depleted in HFSE; their trace-element patterns are similar to those of many present-day arc lavas. Oxygen isotope compositions of olivine-orthopyroxene rocks are rather homogeneous, and are suggestive of larger fluid mobility during dehydration. The antigorite breakdown reaction appears to produce a mobile fluid that can play a role in the metasomatism of sub-arc mantle. Serpentinized oceanic mantle thus represents a valuable candidate reservoir for fluids and incompatible elements: consequently, its role in the overall element cycle in subduction settings should be re-evaluated.

Recycling of trace elements required for humans in CELSS

Recycle of complete nourishment necessary for human should be constructed in CELSS (Controlled Ecological Life Support Systems). Essential elements necessary for human support are categorized as major elements, semi-major elements and trace elements. Recently, trace elements have been identified from considerations of local diseases, food additive problems, pollution problems and adult diseases, consisting of Fe, Zn, Cu, Se, Co, F, Si, Mn, Cr, I, As, Mo, Ni, V, Sn, Li, Br, Cd, Pb, B. A review of the biogeochemical history of the earth's biosphere and the physiological nature of humans and plants explains some of the requirements. A possible route for intake of trace elements is considered that trace elements are dissolved in some chemical form in water, absorbed by plants through their roots and then transfered to human as foods. There may be a posibility that living things absorb some trace elements from atmosphere. Management and recycling of trace elements in CELSS is discussed.

Trace element distribution and isotopic composition of Archean Greenstones

Trace element abundances and Sr isotopic compositions in Archean and modern volcanic rocks are reviewed. K, Rb, Ba and perhaps Sr are more mobile than rare earth and some transition elements in alteration and low-grade metamorphism. Data of K, Rb, Sr and Ba from individual greenstone samples usually show significant variations. However, average values of these elements from a large set of samples tend to show a rather consistent feature. Geochemical arguments derived from these elements are also in general agreement with those from more refractory REE. Alteration effects on REE patterns are observed, but most Archean volcanic rocks appear to possess their original magmatic patterns. Archean low-K tholeiites and high-Mg komatiites are characterized by their generally flat REE patterns of about 2.5 to 15 times chondritic abundances. Their ( La Sm ) N ratios range from 0.7 to 1.3 and are significantly higher than those of typical MORB (0.4 to 0.7). The data of peridotitic komatiites have been used to estimate the REE abundances in the Archean upper mantle. The two times chondritic abundances thus derived is similar to those estimated for the modern upper mantle. For andesitic rocks, most Archean REE patterns can find their modern analogues, but in some cases Archean patterns (with severe HREE depletion) have rare modern analogues. Archean siliceous volcanic rocks commonly show severe HREE depletion. This cannot be explained as due to fractional crystallization of basaltic magmas, rather, it suggests a separate melting event in which garnet plays an important role in the source region. The source is hence likely an eclogite or garnet amphibolite in the mantle due to lithosphere subduction or that converted from a thick pile of basaltic rocks of the same greenstone belt. The application of trace element abundances to identification of the tectonic settings for Archean volcanic rocks is not very successful. This is mainly due to the following factors: (1) insufficient understanding of geochemical characteristics of trace elements or simply due to indiscriminate LIL and REE patterns in modern volcanic rocks from different tectonic settings, (2) insufficient understanding of geochemical behaviors of some transition elements during partial melting and crystal fractionation under different P, T, X conditions, (3) evolutionary change of the upper mantle composition through time, (4) existence of heterogeneities in both the Archean and the modern upper mantle, and finally, (5) insufficient understanding in tectonic styles during the Archean. Available Sr isotopic data for Archean volcanic rocks show that they are essentially evolved along a path with Rb Sr ratio = 0.026–0.034 . Most modern oceanic island volcanic rocks and continental basalts also have Sr isotopic composition evolved along the same path. Some Archean basalts, e.g. 2.7 b.y. Minnesota, show an early depletion of Rb relative to Sr. Likewise, the modern ocean ridge basalts show a significant depletion of Rb relative to Sr. This depletion probably took place about 2 b.y.ago. Evidence from both Nd and Sr isotopes suggests that, counting MORB sources apart, the upper mantle has evolved essentially with a constant Rb Sr and Sm Nd ratios. Trace element abundances also show a gross constancy in Archean and modern volcanic rocks. This seems to militate against the consequences of partial melting processes operating in the upper mantle of non-infinite trace element reservoir. It may, however, be explained as due to the interplay of (1) replenishment of trace elements from lower part of the mantle, and (2) recycling of trace elements in the crust-upper mantle system.