High Concentrations Of Cu Research Articles

Differences in Physiological Metabolism and Antioxidant System of Different Ecotypes of Miscanthus floridulus under Cu Stress

To reveal the similarities and differences in the resistance mechanisms of different ecotypes to Cu stress, a pot experiment was used to systematically compare the physiological responses of non-mining ecotype Miscanthus floridulus (collected from Boluo County, Huizhou City) and mining ecotype Miscanthus floridulus (collected from Dabaoshan mining area) under different Cu concentrations. The results showed that chlorophyll a, chlorophyll b and total chlorophyll in the leaves of the two ecotypes of M. floridulus were negatively correlated with Cu stress concentration (p < 0.01), but the extent of decrease for the ecotypes in the mining area was lower than that for the ecotypes in the non-mining area. The values of chlorophyll a/b for both ecotypes increased with increasing Cu treatment concentration, indicating that Cu is more harmful to chlorophyll b than to chlorophyll a for M. floridulus. Cu stress can lead to the accumulation of malondialdehyde (MDA) in the leaves of M. floridulus with the amount of MDA accumulation observed being greater in the non-mining ecotype than in the mining ecotype (p < 0.05). The content of antioxidant substances (ascorbic acid and reduced glutathione) in the mining ecotype M. floridulus was significantly higher than that in the non-mining ecotype. The activity of SOD in the leaves of non-mining ecotypes was inhibited by Cu stress and the activity of POD was increased by Cu stress. However, the increase in POD in the mining ecotypes was greater than that in the non-mining ecotypes and the activities of the two enzymes in the mining ecotypes were significantly higher than those in the non-mining ecotypes at the highest concentration of Cu. Cu had different effects on PPO activity in the leaves of the two ecotypes of M. floridulus. The plant leaves of the non-mining ecotype at 400 and 800 mg·kg−1 were significantly fewer than those of the control group (p < 0.05), which were 87.1% and 65.2% of the control group, respectively. The PPO activity in the plant leaves of the mining ecotype was higher than that in the leaves of the non-mining ecotype and was significantly higher at 400 and 800 mg·kg−1 than that of the control group (p < 0.05), at 226.5% and 268.1% of the control group, respectively. These results indicate that the mining ecotype M. floridulus is more resistant to copper stress, that resistant ecotypes have been formed, and that small-molecule antioxidant substances play an important role in increasing resistance levels.

Association of Plant and Microorganisms on Textile Wastewater Remediation

Phytoremediation of heavy metals containing textile wastewater using vetiver grass (Chrysopogone zizanioides) associated with Bacillus sp. and Pseudomonas aeruginosa has been performed. Two levels of heavy metal in wastewater (<1 and 100 ppm) in two replication were treated using C. Zizanioides associated with Bacillus sp. and C. Zizanioides associated with Pseudomonas aeruginosa. Assessment of C. zizanioides capability was determined by the efficiency of heavy metals (Cu and Cr) removal and its accumulation in both of leaves and roots of the plants. It was obtained that the experiment of low concentration of Cr was totally eliminated from 0.06 to 0.00 ppm and on the other hand, about 42.6 percent (of 118.65 to 66.06 ppm) for high concentration decreased using C. zizanioides with Bacillus sp. The use of C zizanioides associated with P. aeruginosa was also able to eliminate totally low concentration Cr in textile wastewater (0.08 to 0.00 ppm) and about 69.2 percent (158.76 to 48.9 ppm) of the high Cr concentration. Elimination of Cu from wastewater was 74.4% (0.48 to 0.12) and 55.7% (61.34 to 27.16 ppm) for the treatment using C. zizanioides with Bacillus sp. at a low and high level of concentrations respectively. Meanwhile, combined C. zizanioides with Pseudomonas aeruginosa absorb the Cu 100% (0.36 to 0.00 ppm) and 65% (64.93 to 22.77 ppm) for wastewater with low and high concentrations of Cu respectively. Combination of C. zizanioides, Bacillus sp., and Pseudomonas aeruginosa are fruitful in heavy metals containing wastewater remediation.

Toxicological health risk analysis of hazardous trace elements accumulation in the edible fish species of the Black Sea in Türkiye using multivariate statistical and spatial assessment

In the current study, the levels of eleven hazardous trace elements (HTEs) were measured in five different fish species frequently consumed in eleven cities along the Black Sea coast of Türkiye. And also the maximum permissible limits (MPLs) specified by international standards are compared to 11 HTEs levels. In addition, human health risk levels from fish consumption were assessed using multiple approaches. The highest metal concentrations of Fe, Mn, Co, Cr, Ni, Cd and Hg were detected in the fish sampled from Samsun city. It was determined that Cu, Zn, Pb and As metal concentrations were the highest in fish sampled from Düzce city. In the demersal Mullus barbatus (MB), the highest quantities of As, Cr, Mn, Fe, Co, Ni, Hg, and Pb were discovered. The highest concentrations of Zn and Cd were found in Engraulis encrasicolus (EE), which is a topminnow fish. The highest concentrations of Cu were found in Sarda sarda (SS), which is a topminnow fish. For all HTEs, the metal hazard index (MPI) and target hazard quotients (THQ) from metal intake by ingesting fish species were less than 1, indicating no risk from consumption. All investigated fish species were acceptable (10-4 to 10-6) in terms of carcinogenic risks (CR) from exposure to inorganic arsenic (iAs). Additionally, because the hazard index (HI) is less than 1, it has been determined that consuming certain fish species will not pose a risk to public health. The predicted daily intakes of HTEs in each fish species were far lower than their corresponding acceptable daily intakes, indicating that consuming fish would not put consumers at risk for health problems from daily intakes of HTEs. In addition, the multivariate statistical analysis justified that HTEs were from anthropogenic and lithogenic origin.

Contamination, Source Apportionment, and Health Risk Assessment of Heavy Metals in Farmland Soils Surrounding a Typical Copper Tailings Pond.

Tailings resulting from mining and smelting activities may cause soil heavy-metal pollution and harm human health. To evaluate the environmental impact of heavy metals from tailings on farmland soils in the surrounding area, heavy metals (As, Cd, Cr, Cu, Ni, Pb, and Zn) in tailings and farmland soils in the vicinity of a typical copper tailings pond were analyzed. Contamination status, potential sources, and health risks for farmland soils were investigated. The results showed that the tailings contained a high concentration of Cu (1136.23 mg/kg). The concentrations of Cd and Cu in the farmland soils exceeded the soil quality standard. The geoaccumulation index (Igeo) indicated that the soils were moderately polluted by Cu and Cd, and slightly polluted by Ni, Cr, and Zn. The absolute principal component scores-multiple linear regression (APCS-MLR) model was applied for source apportionment. The results showed that tailings release is the main source of soil heavy-metals contamination, accounting for 35.81%, followed by agricultural activities (19.41%) and traffic emission (16.31%). The health risk assessment suggested that the children in the study region were exposed to non-carcinogenic risks caused by As, while the non-carcinogenic risk to adults and the carcinogenic risk to both adults and children were at acceptable levels. It is necessary to take effective measures to control heavy-metal contamination from tailings releases to protect humans, especially children, from adverse health risks.

Effects of different levels of metal exposure and precipitation regimes on chlorophyll a fluorescence parameters in a coastal Brazilian restinga species

This work aimed to investigate whether there was a relationship between precipitation regimes and concentrations of trace elements (Cu, Mn, Fe and Zn) deposited on the coast from ore tailings released in the Mariana disaster (Minas Gerais, Brazil) in 2015. We also sought to answer if there would be a synergistic effect of increased precipitation and trace element levels affecting photosynthesis. The combination of these factors was evaluated using the dynamics of chlorophyll a fluorescence in plants of Byrsonima sericea, a shrub species, used as a model in restinga studies. In situ studies showed that, throughout the year, the photosynthetic performance of B. sericea exhibited seasonal variability. The combination of both trace elements in soil and leaves and precipitation regimes drives the variability of the chlorophyll fluorescence parameters on restinga vegetation. Significant negative correlations were observed between the high concentrations of metals (mainly Cu and Fe) and photosynthetic performance indices and the oxygen evolving complex (OEC) activity in PSII. Combined effects of high concentrations of Cu, Fe, Mn and Zn and different rainfall regimes were manifested in the alteration of Chlorophyll a Fluorescence parameters related to quantum efficiency, specific energy fluxes and performance indices. Data presented in this study conclusively proved that Byrsonima sericea respond to different environmental conditions and that the dry season was more damaging to plants than the rainy season in terms of the impacts of both the rain regime and metal availability; metal availability also varied according to rainfall patterns and transport via marine aerosols.

Innovative in vivo and in vitro bioassays for the establishment of toxicity thresholds of pollutants in sediment quality assessment using polychaetes and their immune cells

Sediment toxicity testing has become a crucial component for assessing the risks posed by contaminated sediments and for the development of sediment quality assessment strategies. Commonly used organisms for bioassays with estuarine sediments include amphipods, Arenicola marina polychaetes and echinoids. Among the latter, the Sea Urchin Embryo test (SET) is the most widely used. However, one relevant limitation of this bioassay is the unavailability of gametes all year-round, particularly outside the natural spawning seasons. Consequently, the establishment of an appropriate and complementary model organism for a continuous assessment of sediment quality is recommended. A reliable assessment of the hazards resulting from pollutants in sediments or pore water, can be achieved with ecologically relevant species of sediment such as the polychaete Hediste diversicolor, which is widespread in estuaries and has the capacity to accumulate pollutants. The aim of this work was to develop reliable in vivo and in vitro bioassays with H. diversicolor and its coelomocytes (immune cells) to determine the toxicity thresholds of different contaminants bounded to sediments or resuspended into water. Polychaetes were exposed to sublethal concentrations of CuCl2 (in vivo) and a non-invasive method for collection of polychaetes coelomocytes was applied for the in vitro bioassay, exposing cells to a series of CuCl2 and AgNPs concentrations. Same reference toxicants were used to expose Paracentrotus lividus following the SET (ICES Nº 51; Beiras et al., 2012) and obtained toxicity thresholds were compared between the two species. In vivo exposure of polychaetes to high concentrations of Cu produced weight loss and histopathological alterations. After in vitro approaches, a significant decrease in coelomocytes viability was recorded for both toxicants, in a monotonic dose-response curve, at very short-exposure times (2 h). The toxicity thresholds obtained with polychaetes were in line with the ones obtained with the SET, concluding that their sensitivity is similar. In conclusion, in vivo and in vitro bioassays developed with H. diversicolor are accurate toxicity screenings of pollutants that could be bounded to sediments or dissolved in the pore water, and may complement the SET outside the spawning period of the echinoderms. The bioassays herein developed could be applied not only to establish the toxicity thresholds of individual compounds or mixtures, but also to assess the toxicity of field collected sediments.

Metallothionein Expression as a Physiological Response against Metal Toxicity in the Striped Rockcod Trematomus hansoni.

Metal bioaccumulation and metallothionein (MT) expression were investigated in the gills and liver of the red-blooded Antarctic teleost Trematomus hansoni to evaluate the possibility for this species to face, with adequate physiological responses, an increase of copper and cadmium concentrations in its tissues. Specimens of this Antarctic fish were collected from Terra Nova Bay (Ross Sea) and used for a metal exposure experiment in controlled laboratory conditions. The two treatments led to a significant accumulation of both metals and increased gene transcription only for the MT-1. The biosynthesis of MTs was verified especially in specimens exposed to Cd, but most of these proteins were soon oxidized, probably because they were involved in cell protection against oxidative stress risk by scavenging reactive oxygen species. The obtained data highlighted the phenotypic plasticity of T. hansoni, a species that evolved in an environment characterized by naturally high concentrations of Cu and Cd, and maybe the possibility for the Antarctic fish to face the challenges of a world that is becoming more toxic every day.

Heavy Metals in Alcoholic Beverages Consumed in Awka, South-East Nigeria: Carcinogenic and Non-carcinogenic Health Risk Assessments

Consumption of alcoholic beverages has been a long-standing tradition that dates back to the use of fruit-based cereals and vegetable substrates. Selected international, national, and local-based alcoholic beverages (herbal gin, imported red wine, Heineken, imported dry gin, local dry gin, palm wine, Guinness stout, and whisky) were purchased from popular drinking joints in Awka metropolis, Anambra state, Nigeria, where questionnaires were administered to respondents in order to get the actual consumption rate. Using Atomic Absorption Spectrophotometer (AAS), heavy metals (Cd, Cr, Cu, Fe, Pb, Mn, Ni and Zn) were analysed quantitatively. Background references from the World Health Organization (WHO) and the International Organization of Grapes and Wines (IOGW) were used to assess contamination and pollution potential in heavy metals. After determining the average daily intake (ADI) for non-carcinogenesis and carcinogenesis, the hazard index and overall cancer risk were calculated using reference dosage and cancer slope factor. Heavy metal analysis showed that Cu and Zn were found to be the most prevalent in all alcoholic beverages. Imported dry gin was highest for Cr, whereas Guinness stout was lowest. Local dry gin (0.936 mg/l) and imported red wine (0.075 mg/l) had the highest concentrations of Cu and Fe whereas Heineken (0.024 mg/l) and herbal gin (0.01 mg/l) had the lowest respectively. Local dry gin (0.078 mg/l), imported red wine (0.048 mg/l), Heineken (0.009 mg/l), and Guinness stout (0.33 mg/l) had the highest Pb, Mn, Ni, and Zn concentrations respectively, whereas Guinness stout (0.022 mg/l), Whisky (0.00 mg/l), imported dry gin (0.001 mg/l), and palm wine (0.027 mg/l) had the lowest concentrations respectively. There are no known health risks as a result of the contamination and pollution potential. Heineken and palm wine were both above 1 on the hazard index, indicating that there were potential health issues. However, cancer risk analysis revealed that all beverages were above the US EPA’s recommended range of 1.00E06–1.00E04, implying that cancer-related illness is likely in a population of 1 in 1000 to 10,000 people. As a result, alcoholic beverage manufacturers should strive for continuous improvement in order to avoid public health issues.

Effect of acute Cu exposure on immune response mechanisms of golden cuttlefish (Sepia esculenta)

Sepia esculenta is a common economic cephalopod that has received extensive attention due to the tender meat, rich protein content and certain medicinal value thereof. Over the past decade, multiple industries have discharged waste into the ocean in large quantities, thereby significantly increasing the concentration of heavy metals in the ocean. Copper (Cu) is a common heavy metal in the ocean. The increase of Cu content will affect numerous biological processes such as immunity and metabolism of marine organisms. High concentrations of Cu may inhibit S. esculenta growth, development, swimming, and other processes, which would significantly affect its culture. In this research, transcriptome analysis is used to initially explore Cu-exposed S. esculenta larval immune response mechanisms. And compared to control group with normally growing larvae, 2056 differentially expressed genes (DEGs) are identified in experimental group with Cu-exposed larvae. The results of DEGs functional enrichment analyses including GO and KEGG indicate that Cu exposure might promote inflammatory and innate immune responses in cuttlefish larvae. Then, 10 key genes that might regulate larval immunity are identified using a comprehensive analysis that combines protein-protein interaction (PPI) network and KEGG functional enrichment analyses, of which three genes with the highest number of protein interactions or involve in more KEGG signaling pathways are identified as hub genes that might significantly affect larval immune response processes. Comprehensive analysis of PPI network and KEGG signaling pathway are used for the first time to explore Cu-exposed S. esculenta larval immune response mechanisms. Our results preliminarily reveal immune response mechanisms of cephalopods exposed to heavy metals and provide valuable resources for further understanding mollusk immunity.

Effects of aqueous extracts of wildfire ashes on tadpoles of Pelophylax perezi: Influence of plant coverage

Wildfires have been pointed out as an important source of diffuse contamination to aquatic ecosystems, namely through the input of toxic compounds such as polycyclic aromatic hydrocarbons and metals. However, amphibians' responses to this disturbance have been largely ignored. Hence, this study intended to assess how ashes from Pinus sp. and Eucalyptus sp. plantation forests affect tadpoles of Pelophylax perezi. Tadpoles were exposed 14 days to serial concentrations (26.9 %–100 %) of aqueous extracts of ashes (AEA, with 10 g L−1 of ashes) containing Eucalypt (ELS) and Pine (PLS) ashes. The following endpoints were measured: mortality, malformations, developmental stage, body length and weight. Effects at sub-individual level were also monitored for oxidative stress, neurotoxicity, and energetic metabolism. Chemical characterization of the AEA of ELS showed higher concentrations of As, Cd, Co, Cr, Pb and V, while PLS showed higher concentrations of Cu, Mn, Ni and Zn. Concerning the lethal effects of AEAs on tadpoles, both extracts were able to induce mortality at high concentrations (76.9 and/or 100 % of AEA), although a high variability in the response was found. A significant mortality in tadpoles exposed to ELS was observed at the concentration of 76.9 %. For organisms exposed to PLS, though a mortality above 20 % was registered at the two highest tested concentrations, it was not significantly different from the control. No significant sub-lethal effects were observed in the ELS treatments. Contrasting, exposure to PLS induced a decrease in body length, weight, glutathione-S-transferase activity and an increase in oxygen consumption. Overall, the distinct effects of ELS and PLS suggest an influence of vegetation cover in ash toxicity. In conclusion, exposure to both ash extracts negatively affected sublethal responses of tadpoles of P. perezi. Future research is needed to assess how these effects at individual level may translate into effects at population level.

Pollution index assessment of surface water and sediment quality with reference to heavy metals in Teesta River in Eastern Himalayan range, India

Assessment of heavy metals in water and sediment samples were done from six locations during monsoon and winter seasons in Teesta River in Eastern Himalayas. Three-way ANOVA was used to analyze seasonal, temporal and spatial variations in metals concentration in both water and sediment samples. Downstream sites exceeded the Indian River System prescribed concentration limits for cadmium, chromium, lead and zinc. Risk assessment of heavy metal pollution using heavy metal pollution index (HPI) and degree of contamination (Cdeg) indices revealed the upstream site S1 having the lowest HPI. Downstream site S3 showed the highest HPI of 68.24 and 44.82 during monsoon and winter respectively. Good water quality was indicated at site S1 compared to high to medium range pollution in downstream sites. Cdeg for sediments signalled sites S3 and S6 as moderately polluted. Correlation analysis of heavy metals exhibited a strong correlation among all heavy metals except Cd (water) and Cd and Pb (sediment) indicating a possible common origin. Cluster analysis based on metal concentrations identified two groups each for water and sediment sites. For water, group 1 comprised of S1 and S2 and the other group comprised of S3, S4, S5 and S6. For sediment samples, S1 was separated from the remaining five sites. Principal Component Analysis evinced high concentrations of Cu, Co and Zn at S3; Cd, Cu and Pb at S5; and Cu and Co at S6. S1 seemed devoid of heavy metals indicating anthropogenic input at downstream sites. The study indicated the river being vulnerable to various point and non-point sources of pollution, exacerbated by expanding small and large-scale industries. This study offers potential for extrapolation to design effective management policies to minimize pollution load in the Teesta River in order to improve the ecological health of the river.

Co-precipitation of gold and base metal sulfides during fluid boiling triggered by fault-valve processes in orogenic gold deposits

The extreme fluctuations in pressure during earthquakes are widely regarded as responsible for gold mineralization in quartz-vein-hosted gold deposits. However, it is barely noticed that base metal sulfides can precipitate together with gold during these processes. Here we present the phenomenon and unravel the mechanism of the co-precipitation of Au and base metal sulfides during the fluid boiling via geological study and thermodynamic modeling, respectively. The Bangbu deposit, a lode-type orogenic gold deposit in Tibet shows two mineralization substages of pyrite. The pyrite formed in the later substage is hosted in the wall rock selvages of laminated crack-seal quartz veins formed by the fault-valve processes. The pyrite grains are characterized by anhedral small crystals with porous textures and abundant native gold, chalcopyrite, galena, and sphalerite inclusions. They also contain higher concentrations of Cu, Pb, Ag, Sb, and Au, and lower concentrations of Co and Ni, compared to the euhedral large-grained pyrite formed in the initial substage. The textural and trace element characteristics of the pyrite indicate that vigorous boiling occurred during fault-valve behavior, which decreased the solubilities of Au, Cu, Pb, and Zn in the ore fluid in Bangbu. The co-precipitation of Au and base metal sulfides triggered by fluid boiling has also been reported in other orogenic gold deposits worldwide.Thermodynamic models are designed to acquire the predominant species and solubility of Au, Cu, Pb, and Zn in orogenic ore fluids under varied chemical conditions. The results show that Au, Cu, Pb, and Zn are dominantly transported as hydrosulfide complexes under lower mesozonal to epizonal deposit conditions. At temperatures of about above 350 °C, Au hydrosulfide species still predominates, but the predominant Cu, Pb, and Zn species change from hydrosulfide to chloride complexes. A sudden decrease in the reduced sulfur concentration during fluid boiling may be the most important mechanism controlling the precipitation of Au, Cu, Pb, and Zn in lower mesozonal to epizonal deposits. The decrease of logfS2 during fluid boiling can increase the fluid pH, resulting in the decrease of solubilities of base metal chloride complexes and thus explain the co-precipitation of Au and base metal sulfides in hypozonal deposits.

Phytoextraction of Cu, Cd, Zn and As in four shrubs and trees growing on soil contaminated with mining waste

Mining activity has degraded large extensions of soil and its waste is composed of metals, anthropogenic chemicals, and sterile rocks. The use of native species in the recovery of polluted soils improves the conditions for the emergence of other species, tending to a process of ecosystem restoration. The objective of this study was to evaluate the bioaccumulation of metal(loid)s in four species of native plants and the effect of their distribution and bioavailability in soil with waste from an abandoned gold mine. Soil samples were taken from two sites in La Planta, San Juan, Argentina: Site 1 and Site 2 (mining waste and reference soil, respectively). In Site 1, vegetative organ samples were taken from Larrea cuneifolia, Bulnesia retama, Plectrocarpa tetracantha, and Prosopis flexuosa. The concentration of metal(loid)s in soil from Site 1 were Zn > As > Cu > Cd, reaching values of 7123, 6516, 240 and 76 mg kg−1, respectively. The contamination indices were among the highest categories of contamination for all four metal(loid)s. The spatial interpolation analysis showed the effect of the vegetation as the lowest concentration of metal(loid)s were found in rhizospheric soil. The maximum concentrations of As, Cu, Cd and Zn found in vegetative organs were 371, 461, 28, and 1331 mg kg−1, respectively. L. cuneifolia and B. retama presented high concentrations of Cu and Zn. The most concentrated metal(loid)s in P. tetracantha and P. flexuosa were Zn, As and Cu. Cd was the least concentrated metal in all four species. The values of BAF and TF were greater than one for all four species. In conclusion, the different phytoextraction capacities and the adaptations to arid environments of these four species are an advantage for future phytoremediation strategies. Their application contributes to the ecological restoration and risk reduction, allowing the recovery of ecosystem services.

Simultaneous removal of Cr(VI) and Cu(II) from acid wastewater by electrocoagulation using sacrificial metal anodes

• In MP-P mode, EC with Al-Al-Al-Al combination outperformed other Fe and/or Al combinations. • Al EC was highly efficient for simultaneous removal of Cr(VI) and Cu(II) from acid wastewater. • Appropriate concentration of Cu(II) promoted removal of Cr(VI) and total Cr, and vice versa. • Removal mechanisms were elucidated via characterization of scums, precipitates, and cathode deposits. Removal of heavy metals from acid wastewater is an important concern in the field of water treatment. Here, electrocoagulation (EC) technology with Fe and/or Al anode was investigated for the simultaneous elimination of Cr(VI) and Cu(II) from wastewater (initial pH: 3.5–4.0). In the energy-efficient monopolar parallel mode, the EC with Al-Al-Al-Al combination (anode–cathode-anode–cathode) showed the highest removal efficiency among different electrode combination modes, whereas the EC with Fe-Fe-Fe-Fe combination showed the lowest removal efficiency. The main electrochemical parameters of Al EC were further optimized based on cost-effectiveness analysis. Operating cost, including energy consumption, sludge treatment, and anode loss was estimated. The sludge treatment cost accounted for the largest percentage of the operating cost (82.4%) whereas energy consumption cost was the lowest (4.8%). At the initial pH of 3–6, Al EC displayed desirable removal efficiency towards Cu(II) (77.6%–97.9%), Cr(VI) (84.2%–96.4%), and total Cr (83.1%–94.9%). At the conductivity of 899–2300 μS/cm, excellent pollutant removal efficiency was maintained (90.2%–99.8%). Appropriate concentration of Cu(II) promoted the removal of Cr(VI) and total Cr, whereas too high concentration of Cu(II) inhibited their removal and vice versa. Through SEM-EDS and XRD analyses of the scums, precipitates, and cathode deposits, possible mechanisms of Cr(VI) and Cu(II) removal were proposed.

Enrichment and speciation changes of Cu and Cd in black soldier fly (Hermetia illucens) larval compost and their effects on larval growth performance

Municipal sludge (MS), rainwater sludge (RS), and kitchen waste (KW) were used as nutritional supplements for black soldier fly larvae (BSFL). Cd (52.3 %) was more easily assimilated in the BSFL body than Cu (34.8 %). After biotransformation in BSFL, the weak acid-soluble fraction (F1) of Cu and Cd increased by an average of 29.0 % and 42.7 %, respectively, whereas the reducible fraction (F2) of Cu and Cd decreased by an average of 13.8 % and 56.4 %, respectively, in the BSFL sand (BSFL feces and waste residues). A significant correlation (P < 0.01) was found between pH and the speciation of Cu and Cd. The abundance of Bacteroides had a positive correlation (P < 0.05) with the F1 of Cu, an extremely significant negative correlation (P < 0.001) with the F2 of Cd, and an extremely significant positive correlation with the F1 of Cd (P < 0.001). In addition, Cu and Cd exposures significantly (P < 0.01) reduced larval weight by 67.7 % and 45.3 %, respectively, pupation rate by 46.3 % and 26.5 %, respectively, and eclosion rate by 35.5 % and 33.4 %, respectively. Exposure to high concentrations of Cu and Cd also prolonged the development cycle (1–12 days) of BSFL and led to the failure of BSFL to complete their metamorphosis.

Modelling and experimental investigations of composition-dependent heat and mass transfer during Cu–Ni alloy nanoparticle synthesis in a transferred arc helium plasma

In the synthesis of alloy nanoparticles (NPs) via arc evaporation and fast quenching, the composition of the synthesized NPs differs significantly from that of the precursor. The properties of the NPs formed following evaporation of a copper–nickel anode by a helium arc are investigated using a nucleation model coupled to the thermal and flow fields derived from a magneto-hydrodynamic simulation of the arc, and experimentally. Results are obtained for three different Cu:Ni precursor compositions, 10:90, 50:50 and 90:10 at%. The synthesized particles are spherical with different size distributions and have a higher concentration of Cu than the precursor in all three cases, in contrast to previous observations, but in accordance with the predictions of the model. Emission spectroscopic measurements of copper and nickel lines indicate that the concentration of atomic copper in the plasma region near the anode is much higher than that of the nickel, in accordance with the predictions of the model. The higher vapour pressure of copper compared to nickel, and its higher activity in the alloy precursor (anode), immersed in a self-consistent thermal and flow field maintained by the transferred arc are found to play a critical role. The thermodynamic, radiative and transport properties of the helium plasma contaminated with evaporated precursor are important in determining the thermal and flow fields.

Performance of chlorophyll a fluorescence parameters in Lemna minor under heavy metal stress induced by various concentration of copper

The objective of the present investigation was to understand the efficacy of chlorophyll fluorescence analysis and to identify the specific photosynthetic parameters for early and rapid detection of Cu-induced HM-stress in plants. Aquatic angiosperm Lemna minor was exposed to various concentrations (0–40 µM) of Cu. We observed that the FV/FO (Efficiency of the water-splitting complex on the donor side of PSII), quantum yield for electron transport, and quantum yield of primary photochemistry were decreased however, dissipated quantum yield was increased with Cu concentration. ABS/CSM, TRO/CSM, ETO/CSM and maximum quantum yield were displayed the dose–response relationship under Cu stress. Performance indexes were increased initially due to the beneficial effects of Cu at lower concentration while decreased significantly (p ≤ 0.05) at highest concentration of Cu. The outcomes of the present research revealed that the ChlF analysis is very sensitive tool that can be used to determine the toxicity of heavy metals in plants.

Multiple Evaluation of Typical Heavy Metals Pollution in Surface Soil and Road Dust from Beijing and Hebei Province, China.

Soil and road dust are important receptors of heavy metals in the environment. Meanwhile, heavy metal could transfer to the atmosphere through resuspension. Due to the serious consequences and atmospheric haze in Jing-Jin-Ji area, it's important to evaluate the pollution level, particle size distribution and sources of heavy metals. For heavy metals in soil samples, similar concentrations to the background values and no obvious pollution or low-level pollution was presented. Higher concentration of Cu (78.9mg/kg) and Zn (261mg/kg) were found in road dust. The source appointment results showed that Mn, Co, Cr, Ni, Zn and Pb in soils and Cr, Co and Mn in road dust were mainly from the natural sources, while traffic source contributed to most of Cu, Zn and Pb in road dust. Different particle size distribution patterns were found in soils and road dusts, and the finest particles presented the highest heavy metal concentrations.

NBMI Exerts Protection Against Copper Overload in HepG2 and SH‐SY5Y Cell Lines

Copper (Cu) is a naturally occurring essential element required for many biological processes. At low concentrations, Cu plays a vital role by getting incorporated into various metalloenzymes and at higher concentrations can be harmful to hepatic, central, and renal systems. Chronic toxicity with high concentrations of Cu have been characterized in Wilsons’s disease patients, and chelation has been the mainstay of therapy. As the currently approved chelator D‐pencillamine is associated with many adverse effects, the search for other therapeutic interventions is ongoing. N,N′bis‐(2‐mercaptoethyl) isophthalamide (NBMI) is a novel metal chelator and thiol redox antioxidant. NBMI has been shown to chelate harmful heavy metals such as mercury and lead in vitro. We explored whether NBMI displayed cytoprotective effects in HepG2 and SH‐SY5Y cells exposed to copper sulfate (CuSO4). Both the cell types were treated with either vehicle or NBMI (0 ‐ 100 μM) for 24 hours followed by CuSO4 (750 μM) for an additional 24 hours. Cell viability (CellTiter‐Glo® Assay) and degree of oxidative stress (ROS Assay) were determined. Comparisons between multiple groups were performed using analysis of variance (ANOVA) followed by a post hoc Tukey’s test. Results with p‐value &lt;0.05 were considered statistically significant. Exposure of HepG2 and SH‐SY5Y cells to CuSO4 decreased cell viability in a concentration‐dependent manner. In addition, CuSO4 exposure led to an increase in ROS levels in HepG2 cells indicating oxidative stress. Pretreatment with NBMI diminished CuSO4‐induced cell death in both cell types and decreased ROS levels in HepG2 cells. The results imply that NBMI is a new and promising chelator for treating Cu‐overload genetic disorders.

HIGHLY LUMINESCENT CU DOPED SNO2 NANOCOMPOSITES AND THEIR PHOTOCATALYTIC APPLICATION AS EXCELLENT METHYLENE DYE REMOVAL

Cu doped SnO2 nanostructures were grown using hydrothermal method. The solution was obtained by dissolving stannous chloride in distilled water (DW) with ammonium as surfactant followed by irradiation with ultrasonic vibrations. Obtained samples were characterized by structural, morphological and optical studies. All the peaks in the Xray diffractograms are identified and indexed as structure. In pure form of Cu nanoparticles shows crystalline structures and in high concentration of Cu in SnO2 nanoparticles shows the disappearing of peaks occurring as the pH increases. Negative slope of Williamson–Hall plots indicates compressive strain. Particle size of Cu doped SnO2 nanostructures decreases with increasingthe doping concentration. An optical study shows good luminescence in visible region. A strong quantum effect was evident from the far blue shifted optical direct and indirect band gap. 80% of MO dye removed from waste water.