Large Amounts Of Copper Research Articles

Morphophysiological, ultrastructural, and nutritional changes induced by Cu toxicity in young Erythrina fusca plants

ABSTRACTErythrina fusca is an important legume used for shade cover in cacao plantations in Brazil. Cacao plantations receive large quantities of copper (Cu)-containing agrochemicals, mainly for control of diseases. Therefore, Cu toxicity was investigated in seedlings grown in hydroponics with increasing concentrations of Cu (0.005–32 mg L−1) in a greenhouse. Ultrastructural analyses showed cell plasmolysis in the root cortical area and changes in thylakoid membranes at 8 mg Cu L−1 and higher. There were changes in epicuticular wax deposition on the leaf surface at the 16 and 32 mg Cu L−1 treatments. Leaf gas exchanges were highly affected 24 hours after application of treatments beginning at 8 mg Cu L−1 and higher Cu concentrations. Chemical analyses showed that Cu content in E. fusca roots increased as Cu concentration in the nutrient solution increased, whereas the shoot did not show significant changes. It is also observed that excess Cu interfered with Zn, Fe, Mn, Mg, K, P, and Ca content in the different E. fusca organs. Investigation of Cu toxicity symptoms focusing on morphophysiological, ultrastructural, gas exchange, and nutritional changes would be useful to alleviate Cu toxicity in E. fusca under field conditions, an important agroforestry species in cacao plantation.

Urks and the Urban Subsurface as Geosocial Formation

This article investigates “urks,” that is, disconnected parts of urban infrastructure that remain in their subsurface location. The reason for engaging in this topic is resource scarcity concerns, as urks contain large amounts of copper and aluminum that could be “mined” for the benefit of the environment. Our starting point is that there is a certain nonstagnant capacity of waste-like entities such as urks and that their resistance to categorization is crucial to encapsulate their political potential (cf. Hawkins 2006; Moore 2012; Hird 2013). We investigate how this indeterminate capacity has implications in terms of where future trajectories for urk recovery are conceivable. The study is based on interviews with respondents from the infrastructure and waste sectors in Sweden. By stressing the relationship between urks and their geosocial subsurface surroundings, we use the respondents’ exploratory interpretations of urks to outline a spectrum of issues that should be further discussed for urks to become a matter of concern. The negotiation of these issues, we suggest, can be conceived of as a form of navigation along the perceived fault lines between actors and priorities, and they must be resolved for increased urk recovery to occur.

Current Status and Future Perspective of Recycling Copper by Hydrometallurgy from Waste Printed Circuit Boards

The current replacement of electronic products is speeding up, resulting in a growing number of e-waste. Electronic waste, especially waste print circuit boards contain large amounts of copper, which not only bring greater ecological threat, but also cause a serious waste of copper resources. Therefore, the study on clean, effective copper leaching technology has a very important practical significance to reduce environmental hazards of waste print circuit board and resources recycling. Hydrometallurgical is a better technology for recycling copper from waste print circuit boards. In this article, hydrometallurgical copper recovery system is divided into four categories: acid leaching, ammonia - ammonium leaching, chloride leaching, as well as other ways of leaching. The advantages and disadvantages of leaching of copper system are analyzed in the process of copper resource utilization. Studies abound on recycling copper from copper-containing waste with citric acid and other complexing agents as the leaching reagent, but studies on recycling copper from waste print circuit boards are rarely reported, which can be used for reference. The trends of the research are using environmentally friendly reagent as leaching agent, selecting the appropriate leaching solution at a certain temperature and pressure and optimizing the subsequent separation procedure. Recycling of waste gas and waste leachate generated in the hydrometallurgical processcan further reduce chemical costs and meet increasingly exacting environmental requirements.

Social context of the Old Kingdom copper model tools

Copper model tools were usually part of the elite burial equipment during the Old Kingdom in the Ancient Egypt. Definition of tool types is based on the semiotic triangle and a correct reading and interpretation of the artefacts is approached here. Model tools present in the burial equipment were tools for stone- and wood-working, these being materials of conspicuous consumption in the period. Tools are examined as symbols of the patron–craftsman relationship, where the ownership of the copper tools was the patron’s. Copper model tools were standardized and a connection between the size and amount of copper model tools and social status of the buried persons is explored. Persons with higher status had access to larger amounts of copper; however, the rules of the access were changing and access to copper was widening during the Old Kingdom.

Efficient stabilization of Cu+ ions in phosphate glasses via reduction of Cu2+ by Sn2+ during ambient atmosphere melting

Glasses containing substantial amounts of well-dispersed luminescent Cu+ ions are attractive materials for applications in solid-state lighting, photonic waveguides, and solar cells. Thus far, coming across a simple yet effective method for the preparation of such has remained elusive given the instability of Cu+ relative to Cu2+, especially for syntheses carried out under the oxidizing air atmosphere. In this work, high concentrations of monovalent copper ions are shown to be successfully incorporated in a high-solubility phosphate glass matrix by a simple melt-quench method. The traditional Cu2+ spectrophotometric analysis commonly utilized for liquid solutions is proposed herein for the solid-state material to estimate the reduction efficiency of Cu2+ during the material preparation process. Reproducibly, the use of relatively large quantities of copper(II) oxide with equal amounts of reducing agent tin(II) oxide (up to 20 mol%), together with the use of sucrose to assist as antioxidant during melting in air atmosphere, yields high-reduction efficiencies estimated at 98 %. Along with the optical absorption analysis, photoluminescence spectroscopy is employed in evaluating the emission properties of the glasses in connection to the Cu+ ions. Further, solid-state 31P nuclear magnetic resonance spectroscopy reveals the structural features of the glasses that support the remarkable stabilization of the Cu+ ions.

Analysis of copper flows in China from 1975 to 2010

By applying substance flow analysis (SFA), the paper attempts to illustrate how copper utilization pattern has changed in the anthroposphere of China from 1975 to 2010. An analytical framework is firstly established and the detailed copper cycles of the specific years 1975, 1985, 1995, 2005 and 2010 are then characterized. Major conclusions include the following: (1) Chinese copper industry has made significant progress driven by large domestic copper demand since 1970s, especially after 1990s. Also the structure of copper industry has shifted from a basic industry to a processing industry. The share of secondary copper production in total refined copper has risen from 20% in 1975 to 38% in 2010; (2) the Chinese society has experienced a rapid copper accumulation since 1990s. The annual input flow to use stage jumped from only 334Gg (that is 0.36kg per capita copper consumption) in 1975 to 7916Gg (5.90kg per capita) in 2010; (3) a large amount of copper has to be imported to meet the huge demand, mainly involving in copper concentrate, refined copper and copper scrap. And the NIR (Net Import Ratio) of the three was 53.0%, 38.7% and 63.0% in 2010, respectively; (4) domestically produced copper scrap increased from 74.5Gg in 1975 to 711.2Gg in 2010. Comparing it with import scrap and domestic new scrap we found that at current stage the in-use stock is still too small to generate high quantities of copper scrap for domestic secondary copper production. (5) Major copper losses occurred through copper Mining, Refining and WM&R, with the Mining exhibited the lowest copper utilization efficiency (CUE) among the three processes, and may have the great potential for increasing copper utilization rate in China.

Effectiveness of ferric salts in removing low levels of dosed copper from NOM-containing natural water

Water utilities dose copper in drinking water systems to inhibit/kill microorganisms including algae. Under conditions observed in the systems, the majority of dosed copper is reported to be in dissolved forms of Cu-NOM and inorganic compounds. High concentrations (40 mg/L) of ferric salts are reported to be able to remove large amounts of copper. However, the fate of dissolved copper when a small amount of ferric salts (< 2 mg/L) is present in natural water or in the distribution pipes when they are released from the corroded iron pipes are not known. The current paper investigates the mechanisms behind the dissolved copper removal in NOM-containing bulk water. When copper was dosed from 250-800 vLg-Cu/L, relatively high solubility was demonstrated in Mundaring water, with dissolved copper increased from 250-720 μg-Cu/L. Both ferric chloride and ferric hydroxide were found to have a considerable ability to remove dissolved copper while the former showed higher capacity. Ferric chloride showed a linear relationship with copper removal (R 2 = 0.99) and the removal by ferric hydroxide showed excellent agreement with either the Freundlich (R 2 = 0.98) or Langmuir (R 2 = 0.99) adsorption isotherm.

Dietary supplement implicated in fulminant hepatic failure in a well-controlled Wilson disease patient.

We encountered a patient with previously well-controlled Wilson disease who experienced fulminant hepatic failure with hemolytic anemia, possibly caused by the dietary supplement Health Proportion(®) (Jubilant Co., Ltd., Ehime, Japan). A 21-year-old woman was admitted to our hospital with marked liver dysfunction and severe hemolytic anemia. Free serum copper level was elevated at 101μg/dl, and urinary copper excretion was extremely increased (25,600μg/day). Plasma exchange and continuous hemodiafiltration were performed to remove serum copper and to treat the hemolytic anemia. However, liver function did not improve, and she underwent liver transplantation on 28th day after admission. Copper and iron contents in the resected liver were high at 851.9μg and 551.7μg/dry liver weight (g), respectively, despite the patient having regularly taken D-penicillamine since diagnosis and having a well-controlled copper level 1 year before her admission. Two months before admission, the patient had taken a dietary supplement made from soybeans for 1 month. This supplement was labeled as containing large amounts of copper and iron, and we assume that this caused fulminant hepatic failure with hemolytic crisis in this patient. It is important to be mindful of the micronutrient content of dietary supplements, especially for metabolic disorder patients.

Isolation and Biomass Production of a Saccharomyces cerevisiae Strain Binding Copper and Zinc Ions

Copper and zinc are essential trace elements participating in many physiological functions, notably immunity and protection against oxidative stress. Yeasts and the yeast Saccharomyces cerevisiae, in particular, possess in their genome tandem repeats of the CUP1 gene coding for a protein (a metallothionein) capable of capturing and binding toxic elements such as copper ions. The number of copies of this gene in a cell determines its physiological level of resistance to these ions. This paper describes the selection, characterization, and production of a new copper-resistant yeast strain that can bind large quantities of copper and zinc. This approach should lead to increasing the bioavailability of these trace elements and hence to reducing their emission into the environment.

Antimicrobial properties of copper plasma-modified polyethylene

Copper plasma immersion ion implantation is utilized to produce an antibacterial surface on polyethylene. XPS analysis of the plasma-treated materials reveals that a relatively large amount of copper, about 11% relative to carbon, is implanted into the near surface region. At the same time, about 3% copper is found to be also deposited on the surface. The implanted copper is observed to have the zero valence state indicating that the implanted Cu does not bind chemically with the atoms in the polymer. On the other hand, the copper atoms close to the surface are found to have the divalent state due to surface oxidation. Formation of C C bonds is also observed due to dehydrogenation following copper plasma implantation. Based on the results of atomic force microscopy and contact angle measurements, the surface hydrophilicity and roughness are not significantly altered. Our antibacterial experiments indicate that the copper implanted polyethylene exhibits excellent antibacterial effects against Escherichia coli and Staphylococcus aureus, and the effectiveness is 96.2% and 86.1%, respectively.

Finite element method analysis on the stress and strain states in amorphous composites containing crystalline copper during compression

Amorphous composites containing different volume fractions of crystalline copper were synthesized by means of extrusion carried out on the amorphous powders, of which surfaces are coated with crystalline copper. Compression tests were conducted on the amorphous composites to determine the flow behaviors governed by the volume fraction of the ductile copper. Finite element method analyses of the idealized model composites were made to understand the deformation behaviors of the bulk amorphous composites containing different volume fractions of crystalline copper. An extended plastic deformation in copper leads to the ductile fracture of the composite containing a large amount of copper.

Mesozoic magmatism and copper polymetallic mineralization processes in the Shanghang-Datian region, Fujian Province, Southeast China

Various isotopic ages were reported for four granite plutons in the area studied, i. e., the Tangquan pluton (185-158 Ma); the Zijinshan pluton (157–145 Ma); the Caixi pluton (133 Ma) ; and the Sifang pluton (108–105 Ma). The Tangquan and Zijinshan plutons belong to Early-Middle Jurassic and Late Jurassic of Early-Mesozoic respectively, and the Caixi and Sifang plutons belong to Early-Cretaceous of Late Mesozoic. Both the Tangquan and Sifang plutons, which are the metaluminous granites with A/CNK 1.1, and possesses the geochemical features of crust-derived muddy materials resultant from partial melting with enrichments in K, Rb, Th, Y, HREE and depletions in Sr, Ba, and Ti. The Caixi pluton is a weakly peraluminous granite with A/CNK = 1.0–1.1, and its geochemical characteristics are intermediate between the Zijinshan pluton and the Sifang pluton. The Tangquan pluton with higher Na2O contents, which resulted from partial melting of Proterozoic thick lower-crust derived basic rocks in response to underplating of mantle-derived basic magma, is one of the major host rocks of the metallogenic series of copper, iron and polymetallic deposits. The Sifang pluton with higher K2O contents, which was mixed between middle-lower crust-derived granite magma by partial melting and mantle-derived high-K basic magma, giving rise to the increment of K2O in the melt, and extracted large amounts of copper and other metals, as well as sulphur, is one of the major host rocks of the metallogenic series of porphyry copper, gold and polymetallic deposits. Petrological records have shown that there has occurred lithosphere extension since the Early-Middle Jurassic (180 Ma) in the region, and the formation of Zijinshan peraluminous granite is ascribed to the extension mechanism. With the time passing by, the lithosphere extension-thinning and underplating tend to intensify gradually. The contribution of the mantle to granite formation also increased gradually.

Stability and design criterion for cable-in-conduit-conductors with a broad transition to normal state

Stability criterion in cable-in-conduit conductors (CICC) is often associated with heat removal rate higher than heat generated in the normal zone, which requires low current density in the strands. We show that this criterion is not a mandatory requirement for serviceability of CICC and that CICC may work reliably at higher current densities. In conditions of limited and well defined perturbations, sufficient stability is provided not by a large amount of copper and high transient heat transfer, but by a smooth transition to the normal state and easy current redistribution. A strand parameter space in terms of I c and N-value meeting CICC requirements for stability, limited heat generation, and minimum temperature margin is proposed and discussed. The theory predictions are compared with known experimental data on CICC.

Evaluation of Corrosion Resistance of Multi-Layered Ti/Glass-Ceramic Interfaces by Electrochemical Impedance Spectroscopy

Practical applications of metal/ceramic joints can be found in the biomedical field regarding the encapsulation of implantable telemetric devices, the fabrication of crowns and bridges for dental restoration, or in the production of drug delivery systems, biomedical sensors and electrodes. Most of metal/ceramic joints are produced by the active metal brazing technique, which originates a multi-layered interface which should be able of accommodating the abrupt electronic, crystallographic, chemical, mechanical and thermo-mechanical discontinuity that characterize these systems. Additionally, when considering biomedical applications, corrosion resistance becomes of prime importance. In this work, the corrosion resistance of Ti/glass-ceramic interfaces obtained by active metal brazing was evaluated by electrochemical impedance spectroscopy (EIS) tests. The electrochemical behaviour of the interface was monitored, as a function of time, in a simulated physiological solution at room temperature. In order to evaluate the contribution of each layer and galvanic interactions between them, to the degradation mechanism of the interface, individual samples, representative of reaction layers present at the interface, were fabricated and electrochemically tested. Results show that the corrosion behaviour, of the whole interface was strongly influenced by the chemical composition of its constitutive layers. Thus, layers containing high contents of both titanium and silver showed a polarisation resistance increase with the immersion time, as a result of the formation of a thermodynamically stable passive film. On the other hand, the copper rich layer, appears to be the main responsible for the interface degradation. In fact, for high immersion times, an instable passive film is formed and, as a consequence, large amounts of copper are released. Galvanic interactions between the copper and the silver rich layers where also identified.

Friction layers and friction films on PMC brake pads

A rather new tool, the focused ion beam (FIB) technique, was used to characterise superficial layers at micro-contact areas of a commercial brake pad. The friction material was a polymer matrix composite (PMC) with approximately 50% metal content (semi-metallic) and the counter part was a cast iron rotor. Though the contact areas were not visible as topographic features, they could be identified with the aid of their increased secondary electron emission during FIB-scanning of the surface after tribological activation. Target preparation of micron-sized cross-sections with the FIB enabled the study of superficial layers at predetermined sites at high magnification. Depending on the constituent of the pad, one, two or three layers were identified. The three layer structure comprised: (i) a 100 nm thick friction film containing nanocrystalline metal oxides and an amorphous phase which was enriched with sulphur, (ii) a nanocrystalline friction layer of compacted wear debris accommodating surface roughness and (iii) a severely deformed layer if the supporting constituent was a metal particle. Though the majority of loose wear particles was iron oxide, the friction film which adhered tightly to the pad surface contained a large amount of copper and sulphur, whereas zinc was transferred to the cast iron rotor.

Some aspects of water quality in a polluted lowland river in relation to the intracellular chemical levels in planktonic and epilithic diatoms

Changes in elemental concentrations of diatoms and river water from the river Erh-Jen were determined using scanning electron microscopy energy-dispersive X-ray microanalysis and inductively coupled plasma mass spectrometry. Relatively large amounts of copper and lead found in both planktonic and epilithic diatoms implied these algae might play an important role in biogeochemical cycles and in the transfer of those elements to higher trophic levels in the aquatic environment. Changes in elemental concentrations within diatom cells were found to vary with other elements within cells and the same or different elements in water. Planktonic and epilithic cells showed different correlation patterns. For epilithic diatoms, negative correlations were found between concentrations of total phosphorus and phosphate in water and those of phosphorus within cells, and between concentrations of lead in water and in cells. Concentrations of chromium and mercury within planktonic cells and those of phosphorus, manganese and lead within epilithic ones were found to be easily influenced by other elements in river water, indicating appearance of the competitive manner on uptake of such elements by algal cells. Relatively high concentration factors (CFs) for cadmium, mercury and lead by diatoms in this study suggested they are good accumulators for these heavy metals. Significant negative corrections were found between the CFs of diatoms and the concentrations of elements in river water.

Nutritional analysis of the edible pit of Sclerocarya birrea in the Republic of Niger ( daniya, Hausa)

Wild plant foods in the Sahel region of West Africa play an important role in the diets of local residents. During periods of grain shortage, people in rural Niger increase their reliance on wild plant foods to supplement their diets. We report the partial nutrient content of the pit of the seed Sclerocarya birrea, a snack food eaten by children in rural Niger. The pit contained relatively large amounts of copper (24.8 μg/g dry wt), magnesium (4210 μg/g dry wt), and zinc (62.4 μg/g dry wt). The protein content of the pit was high (36.4% of dry wt); however, the protein fraction contained relatively low proportions of leucine, phenylalanine, lysine, and threonine. Fatty acids accounted for 47 mg/g dry wt of the pit, two-thirds of which was due to oleic acid. The essential fatty acid linoleic acid was present (24.5 mg/g dry wt), but the other essential fatty acid, α-linolenic acid, was absent. Such data are useful for health and nutrition program planning by governmental and non-governmental organizations in Niger. The consumption of daniya pits by just children highlights the need to better understand the cultural context of how wild plant foods are used in a particular local context.

Thermodynamic evaluation of gold oxidation and reduction mechanisms in ammonium thiosulfate solution

The copper-catalyzed gold oxidation and reduction mechanisms in ammonium thiosulfate solution were investigated by Eh-pH diagram based on the optimum reagent combination for a 60% (by weight) -75-μm silicate ore containing 16-g/t Au with the maximum gold extraction of 92% and the minimum ammonium thiosulfate consumption of 23 kg/t for 24-hours of leaching at ambient temperature. The gold recovery by cementation was nearly 100% using Zn and Al powders at metal/Au mass ratios of 30 and was around 95% using Cu powder at a Cu/Au + mass ratio of 50. To oxidize the gold efficiently with less thiosulfate consumption, the stable region of [Cu(NH 3 ) 4 ] 2 + should be as wide as possible in the region where [Cu(S 2 O 3 ) 2 ] 3 - is more stable than [Cu(NH 3 ) 2 ] + in the Eh-pH diagram. To recover gold using Zn, Cu or Al powder efficiently, the solubility of [Cu(S 2 O 3 ) 2 ] 3 - should be higher than [Cu(NH 3 ) 2 ] + on copper precipitation. Zinc powder may recover gold more efficiently than copper powder with a similar trend on the effect of ammonia, copper and thiosulfate. However, the large amount of copper will be co-precipitated along with gold because the stability of zine ammine and thiosulfate complexes are higher than that of copper's. Aluminum may reduce gold efficiently at higher thiosulfate concentration and pH. These results were confirmed and compared to the optimum reagent combination for a finer-ground, 100% (by weight) - 75-μm, sample. It was concluded that the optimum reagent combination was 0.5-mol/dm 3 NH 4 OH, 0.0001-mol/dm 3 CuSO 4 .5H 2 O and 0.05-mol/dm 3 (NH 4 ) 2 S 2 O 3 , which resulted in 94% gold extraction and an ammonium thiosulfate consumption of 3 kg/t. Gold and copper stabilities agreed with the thermodynamic rule found on a coarser ground ore (60% by weight -75 μm). The lower reagent combination will reduce gold oxidation power, but significantly minimizes reagent consumption. From this pregnant solution, nearly 100% of the gold was successfully recovered by zinc precipitation at a Zn/Au + mass ratio of 30. Aluminum and copper precipitations resulted in less than 40% gold recoveries at metal/gold mass ratios of 30. The thiosulfate oxidation mechanism is believed to be in agreement with the Belousov-Zhavotinsky reaction.

Selective Ordered Mesoporous Silica Adsorbents

ABSTRACTOrdered mesoporous silica (OMS) adsorbents were prepared by grafting amino, carboxylic and thiol-containing functional groups onto MCM-41 for the selective removal of dye and metal pollutants from wastewater. The amino containing OMS-NH2 adsorbent has a large adsorption capacity and a strong affinity for the Acid blue 25. It can selectively remove Acid blue 25 from a mixture of dyes (i.e., Acid blue 25 and Methylene blue). The OMS-COOH is a good adsorbent for Methylene blue displaying excellent adsorption capacity and selectivity for the dye. The chemically modified OMS adsorbents were also tested for the selective removal and recovery of metals (i.e., lead and copper). The OMS-SH adsorbent can selectively remove lead from solutions containing Pb2+ and Cu2+ ions, whereas the OMS-NH2 selectively adsorbed a large quantity of copper. The selectivity of the adsorbents for lead and copper is strongly influenced by pH. Indeed, by simply adjusting the pH, OMS-NH2 can adsorb mainly lead or copper from a mixture containing both metals.

Oxygen demand, nitrogen and copper removal by free-water-surface and subsurface-flow constructed wetlands under tropical conditions

This study was conducted to: (1) assess the role of wetland vegetation in the removal of oxygen demand and nitrogen under tropical conditions, (2) estimate the uptake of nitrogen and copper by wetland plants and (3) investigate the speciation of Cu in wetland media among four operationally defined host fractions, namely exchangeable, carbonate, reducible and organically bound. Four laboratory-scale wetland units, two free-water-surface (FWS) and two subsurface-flow (SF) with one of each planted with cattails ( Typha augustifolia), were fed with primary-treated sewage and operated at nominal retention times of 0.6–7 days. The influent and effluent BOD/COD and nitrogen concentrations were monitored to assess the performance of the wetland units for various mass loading rates. At the end of the study, all cattail plants were harvested and analyzed for total Kjeldahl nitrogen (TKN). Four other wetland units, which were identical to the first four, were fed with domestic wastewater spiked with copper in increasing concentrations. Copper speciation patterns in the sand layer were determined at the end of the study. The results showed that wetland vegetation did not play an important role in oxygen demand removal but were capable of removing about 22% and 26% of the nitrogen input in the FWS and SF wetland units, respectively. Mass balance analysis indicated that less than 1% of copper introduced was taken up by the cattails. Copper speciation patterns in the sand media showed that the exchangeable fraction contributed 30–57% and 63–80% of the nonresidual copper in the planted and unplanted FWS wetlands, respectively. For SF units, the percentages were 52–62% and 59–67%, respectively. This indicates that large amount of copper in the media were potentially remobilizable.