Ppm Of Cu2 Research Articles

Lindgrenite as an efficient heterogeneous catalyst to obtain biodiesel

Lindgrenite, Cu3MoO42OH2, presents considerable potential to be used as a catalyst for obtaining biodiesel from soybean oil and methanol. Lindgrenite samples were obtained using conventional coprecipitation and ultrasound-assisted coprecipitation methods. Several catalytic tests were performed to reach the optimal conditions (methanol/oil molar ratio: 45/1, catalyst mass: 1%, reaction time: 4 h, reaction temperature: 180 °C) for obtaining biodiesel, with a 96% yield in the first catalytic cycle and 85% yield in its tenth catalytic cycle. Inductively Coupled Plasma Mass Spectrometry (ICP-MS) of the biodiesel obtained by catalytic method revealed negligible amount of leached metal ions (less than 1 ppm of Cu2+ and less than 3 ppm of Mo6+) with the catalyst obtained by ultrasound-assisted coprecipitation method. The similarity between the FTIR spectra of industrial biodiesel and that obtained in this work confirms the effectiveness of using lindgrenite as an efficient catalyst for the transesterification reaction. Biodiesel synthesis was also confirmed by Nuclear Magnetic Resonance (1H and 13C NMR). The results obtained from Gas Chromatography-Mass Spectrometry (GC-MS) indicate methyl linoleate is the main component of the biodiesel, corresponding to approximately 50.50%. In addition to being easily obtained, lindgrenite is thermally stable and efficient under the applied conditions. The 96% yield after the fifth catalytic cycle is above the catalytic performance commonly observed in the literature. These characteristics indicate that lindgrenite has enormous potential to be used as a new heterogeneous catalyst to obtain biodiesel.

A Facile Method to Fabricate an Enclosed Paper-Based Analytical Device via Double-Sided Patterning for Ionic Contaminant Detection.

Microfluidic paper-based analytical devices (μPADs) have been developed for use in a variety of diagnosis and analysis fields. However, conventional μPADs with an open-channel system have limitations for application as analytical platforms mainly because of the evaporation and contamination of the sample solution. This study demonstrates the design and fabrication of an enclosed three-dimensional(3D)-μPAD and its application as a primary early analysis platform for ionic contaminants. To generate the hydrophobic PDMS barrier, double-sided patterning is carried out using a PDMS blade-coated stamp mold that is fabricated using 3D printing. The selective PDMS patterning can be achieved with controlled PDMS permeation of the cellulose substrate using 3D-designed stamp molds. We find the optimal conditions enabling the formation of enclosed channels, including round shape pattern and inter-pattern distance of 10 mm of stamp design, contact time of 0.5 min, and spacer height of 300 µm of double-sided patterning procedure. As a proof of concept, this enclosed 3D-μPAD is used for the simultaneous colorimetric detection of heavy metal ions in a concentration range of 0.1-2000 ppm, including nickel (Ni2+), copper (Cu2+), mercury (Hg2+), and radioactive isotope cesium-137 ions (Cs+). We confirm that qualitative analysis and image-based quantitative analysis with high reliability are possible through rapid color changes within 3 min. The limits of detection (LOD) for 0.55 ppm of Ni2+, 5.05 ppm of Cu2+, 0.188 ppm of Hg2+, and 0.016 ppm of Cs+ are observed, respectively. In addition, we confirm that the analysis is highly reliable in a wide range of ion concentrations with CV values below 3% for Ni2+ (0.56%), Cu2+ (0.45%), Hg2+ (1.35%), and Cs+ (2.18%). This method could be a promising technique to develop a 3D-μPAD with various applications as a primary early analysis device in the environmental and biological industries.

Effect of dissolved metal species on arsenic precipitation and stability during the pressure oxidation of arsenopyrite

This work investigated the influence of dissolved Al3+, Ca2+, Cu2+ and Mg2+ cations on the behaviour of As during the acid pressure oxidation of arsenopyrite at 210˚C. Basic ferric arsenate sulfate was the major As-bearing product in the baseline after 1 h, and a similar result and degree of As precipitation was observed at up to 5,000 ppm of Al3+ and up to 500 ppm of Ca2+, Cu2+, and Mg2+. At 5,000 ppm of Cu2+, basic copper ferric arsenate was formed as a co-product along with improved As precipitation, while 5,000 ppm of Mg2+ resulted in scorodite as a minor product, potentially formed during cooling due to As co-precipitation following the dissolution and oxidation of Fe(II). All samples exhibited similar As stabilities, with As leachability near 10 ppm compared to the recommended limit of 5 ppm. The experimental and thermodynamic modelling results suggest that the dissolved cations at the studied concentrations have a beneficial impact on the removal of As under the investigated conditions. Subsequently, density functional theory calculations on doped scorodite indicated that ionic substitution of Fe with Al, Ca or Mg enhanced the stability of the crystal structure, while the opposite was observed with Cu due to increased reactivity of the Cu in the crystal.

Copper-Doped Biphasic Calcium Phosphate Powders: Dopant Release, Cytotoxicity and Antibacterial Properties.

Cytotoxicity and antibacterial properties associated with the dopant release of Cu-doped Biphasic Calcium Phosphate (BCP) powders, mainly composed of hydroxyapatite mixed with β-tricalcium phosphate powders, were investigated. Twelve BCP ceramics were synthesized at three different sintering temperatures (600 °C, 900 °C and 1200 °C) and four copper doping rates (x = 0.0, 0.05, 0.10 and 0.20, corresponding to the stoichiometric amount of copper in Ca10Cux(PO4)6(OH)2-2xO2x). Cytotoxicity assessments of Cu-doped BCP powders, using MTT assay with human-Mesenchymal Stem Cells (h-MSCs), indicated no cytotoxicity and the release of less than 12 ppm of copper into the biological medium. The antibacterial activity of the powders was determined against both Gram-positive (methicillin-sensitive (MS) and methicillin resistant (MR) Staphylococcus aureus) and Gram-negative (Escherichia coli and Pseudomonas aeruginosa) bacteria. The Cu-doped biomaterials exhibited a strong antibacterial activity against MSSA, MRSA and E. coli, releasing approximatively 2.5 ppm after 24 h, whereas 10 ppm were required to induce an antibacterial effect against P. aeruginosa. This study also demonstrated that the culture medium used during experiments can directly impact the antibacterial effect observed; only 4 ppm of Cu2+ were effective for killing all the bacteria in a 1:500 diluted TS medium, whereas 20 ppm were necessary to achieve the same result in a rich, non-diluted standard marrow cell culture medium.

Real‐Time Probe for the Efficient Sensing of Inorganic Fluoride and Copper Ions in Aqueous Media

AbstractA highly sensitive and efficient rhodamine 6G based probe (P3) was synthesized for the real‐time sensing of F− and Cu2+ ions. The probe P3 was able to show significant color change from brown to pink in the presence of F− and yellow to orange in presence of Cu2+ ions. The UV‐vis studies confirm that the probe P3 was able to detect F− and Cu2+ ions over other ions. Further, UV‐vis titration studies were carried out to understand the detection mechanism and stoichiometry between P3: F− and P3: Cu2+ ions. 1H‐NMR titration was performed to confirm the F− ion binding to probe P3, where, deprotonation of hydrazone proton (‐C=N‐NH‐) was observed. In addition, the limit of detection for P3:F− and P3:Cu2+ ions were found to be 4.02 μM and 1.64 μM respectively which is useful for practical applications. Lastly, probe P3 was used to detect and quantify the F− ions present in a commercially available mouthwash product. Furthermore, P3 was adsorbed on the surface of silica microsphere to detect Cu2+ ions. Interestingly, the material could visually detect 1 ppm of Cu2+ ions which is lower than the permissible limit.

DNA damage induced by copper on erythrocytes of gilthead sea bream Sparus aurata and mollusk Scapharca inaequivalvis.

Heavy metal pollution in rivers and its impact on aquatic ecosystems is a dynamic process. Fish are ideal indicators of heavy metal contamination in aquatic systems because they occupy different trophic levels and are of different sizes and ages. In particular, copper is an essential trace metal for living organisms and it is present in all natural waters and sediments. In this paper, we report data on the effect of copper on DNA erythrocytes from the teleost gilthead sea bream Sparus aurata and the bivalve mollusk Scapharca inaequivalvis. In particular, the effect of 0.1 ppm of Cu2+ on the nucleated erythrocytes was analyzed using the "comet assay." This test is a promising tool for estimation of DNA damage at the single cell level. The data obtained show that the in vivo treatment with 0.1 ppm of copper increased the susceptibility of DNA to be damaged. Exposure to Cu2+ produces a more evident effect on Sparus aurata, as all three comet parameters significantly increased (tail length, tail intensity, and tail moment). The higher comet parameters measured in Scapharca inaequivalvis compared to Sparus aurata could be due to the difference in stability of the respective hemoglobins. The comet assay could represent a useful test to evaluate the biological consequences of environmental contamination by metals on marine organisms.

Acute Toxicity of Mercury, Copper and Zinc to a Freshwater Pulmonate Snail, Lymnaea luteola (LAMARCK)

AbstractThe short‐term toxicity of mercury, copper and zinc was studied using a freshwater pulmonate snail, Lymnaea luteola (LAMARCK). The median period of survival increases with decreasing the toxicant concentration. The 96 h LC50 values and their confidence limits were 0.135 (0.112 … 0.186) ppm of Hg2+; 0.172 (0.118 … 0.355) ppm of Cu2+; and 6.13 (5.73 to 7.19) ppm of Zn2+. The relative potency ratio indicates that the Hg2+ ions were most toxic, followed by Cu2+ and Zn2+ ions.

Fundamental Studies on Utilization of Micro Green Algae for Treatment of Industrial Wastes or Polluted Water. III. : Resistance of Live Chlorella in Polluted Water against Toxicity of Some Heavy Metals

Resistance of some chlorella in "algae water" against some heavy metals was examined. Cultivation of planktonic alga, chlorella, in heavily polluted river water in Nagoya city resulted in the increase of chlorella cells to 105-106/ml and water containing amount of chlorella is designated in this paper as "algae water." Addition of heavy metals to such a water hardly affected the live chlorella, up to 2 ppm of Cu2+ (as CuSO4) or 3 ppm each of Ni2+ (as NiSO4), Zn2+ (as ZnSO4), and Cr6+ (as K2CrO4), at pH 6-9. After several days, the amount of the dissolved metals present was 0.3-0.8 ppm of copper, and 0.8-2.0 ppm each of nickel, zinc, and chromium. These values of copper and zinc were higher than their theoretical solubility in water. The chlorella cells collected by centrifugation from the algae water after 1 week in such a water added with 20mg/liter of Cu2+ or 10mg/liter of Ni2+, Zn2+, or Cr6+, proliferated when cultured again in polluted river water. The polluted river water used for the experiments showed the values of ca. 30 ppm COD, ca. 50 ppm BOD, and no dissolved oxygen. From these results, it was considered that the toxicity of these heavy metals for the alga was buffered by the components in the heavily polluted water or in the algae water.

Fundamental Studies on Utilization of Micro Green Algae at Treatments of Iudustrial Wastes or Polluted Waters. II. : Resistance of Living Micro Algae against Toxicity of Industrial Wastes

In the cultivation of green algae Chlorella with hard polluted river water in Nagoya City cell numbers became 105-6/ml. This cultivated water is called asalgae waterby the author. This Chlorella inalgae waterwas able to live until pH 3 in a low pH zone, and until 0.5 ppm of Cu2+, until 1.0 ppm of Pb2+, Zn2+, Ni2+ and Cr6+ for more than two days without any influence. These metals are contained in a plating waste. Limits of added waste volume to thealgae waterfor living of green algae was 1/10 volume at the gas work, 1/20 volume at the plating factory, and 1/5 volume at the milling factory. These Facts show a part of information about the resistance of micro planktonic green algae against wastewaters.