Heavy Metals (Cu, Pb and Cd) in Water and Angel Fish (Chelmon rostractus) from Batam Coastal, Indonesia

OpenAIRE

Ismarti Ismarti; Ramses Ramses; Suheryanto Suheryanto; Fitrah Amelia

2017-01-01

Fish play an important role in human nutrition and therefore need to be carefully and routinely monitored to ensure that there are no high levels of heavy metals being transferred to human through their consumption. This study has been carried out to determine level of heavy metals (Cu, Pb, and Cd) in water and angel fish, Chelmon rostractus collected from coast of Batam. We report levels of Cu, Cd and Pb in water and angel fish from Coast Batam using Atomic Absorption Spectroscopy (AAS). Lev...

Graphite furnace analysis of a series of metals (Cu, Mn, Pb, Zn and Cd) in ox kidney

International Nuclear Information System (INIS)

Souza, Vivianne L.B. de; Nascimento, Rizia K. do; Paiva, Ana Claudia de; Silva, Josenilda M. da; Melo, Jessica V. de

2013-01-01

The aim of this study was to create a methodology for animal tissue analysis, with the use of flame atomic absorption spectrophotometry techniques and graphite furnace analysis to determining metal concentrations in ox kidney. The organ of this animal can be considered a great nutritional food, due to the high protein and micronutrient content beyond the ability to absorb and concentrate important metals such as Zn, Fe, Mn and Se. On the other hand, there is a risk when eating this food owing to the capacity to accumulate toxic metals such as Pb and Cd. In accordance with the laboratory analysis, Zn can be analyzed by flame atomic absorption spectrophotometry, but other metals such as Cu, Mn, Pb and Cd, could only be detected by graphite furnace analysis. The results showed that there is more Zn and Cu than other metals. Such metals follows an order reported by the literature (Zn > Cu > Cd > Pb > Mn). The results showed that kidney is actually a rich source of Zn and Cu. The Cd levels in the ox kidney did not exceed the values which cause toxic effects. The adequacy of the results indicates that the proposed methodology can be used for animal tissue analysis.(author)

Graphite furnace analysis of a series of metals (Cu, Mn, Pb, Zn and Cd) in ox kidney

Energy Technology Data Exchange (ETDEWEB)

Souza, Vivianne L.B. de; Nascimento, Rizia K. do; Paiva, Ana Claudia de; Silva, Josenilda M. da, E-mail: vlsouza@cnen.gov.br, E-mail: riziakelia@hotmail.com, E-mail: acpaiva@cnen.gov.br, E-mail: jmnilda@hotmail.com [Centro Regional de Ciencias Nucleares do Nordeste (CRCN-NE/CNEN-PE), Recife, PE (Brazil); Melo, Jessica V. de, E-mail: Jessica_clorofila@hotmail.com [Universidade de Pernambuco, Recife, PE (Brazil)

2013-07-01

The aim of this study was to create a methodology for animal tissue analysis, with the use of flame atomic absorption spectrophotometry techniques and graphite furnace analysis to determining metal concentrations in ox kidney. The organ of this animal can be considered a great nutritional food, due to the high protein and micronutrient content beyond the ability to absorb and concentrate important metals such as Zn, Fe, Mn and Se. On the other hand, there is a risk when eating this food owing to the capacity to accumulate toxic metals such as Pb and Cd. In accordance with the laboratory analysis, Zn can be analyzed by flame atomic absorption spectrophotometry, but other metals such as Cu, Mn, Pb and Cd, could only be detected by graphite furnace analysis. The results showed that there is more Zn and Cu than other metals. Such metals follows an order reported by the literature (Zn > Cu > Cd > Pb > Mn). The results showed that kidney is actually a rich source of Zn and Cu. The Cd levels in the ox kidney did not exceed the values which cause toxic effects. The adequacy of the results indicates that the proposed methodology can be used for animal tissue analysis.(author)

Water Soluble Cationic Porphyrin Sensor for Detection of Hg2+, Pb2+, Cd2+, and Cu2+

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Matibur Zamadar

2016-01-01

Full Text Available Here we report the sensing properties of the aqueous solution of meso-tetra(N-methyl-4-pyridylporphine tetrachloride (1 for simultaneous detection of toxic metal ions by using UV-vis spectroscopy. Cationic porphyrin 1 displayed different electronic absorptions in UV-vis region upon interacting with Hg2+, Pb2+, Cd2+, and Cu2+ ions in neutral water solution at room temperature. Quite interestingly, the porphyrin 1 showed that it can function as a single optical chemical sensor and/or metal ion receptor capable of detecting two or more toxic metal ions, particularly Hg2+, Pb2+, and Cd2+ ions coexisting in a water sample. Porphyrin 1 in an aqueous solution provides a unique UV-vis sensing system for the determination of Cd2+ in the presence of larger metal ions such as Hg2+, or Pb2+. Finally, the examination of the sensing properties of 1 demonstrated that it can operate as a Cu2+ ion selective sensor via metal displacement from the 1-Hg2+, 1-Pb2+, and 1-Cd2+.

Determination of Cu, Cd, Pb and Cr in yogurt by slurry sampling electrothermal atomic absorption spectrometry: A case study for Brazilian yogurt.

Science.gov (United States)

de Andrade, Camila Kulek; de Brito, Patrícia Micaella Klack; Dos Anjos, Vanessa Egéa; Quináia, Sueli Pércio

2018-02-01

A slurry sampling electrothermal atomic absorption spectrometric method is proposed for the determination of trace elements such as Cu, Cr, Cd and Pb in yogurt. The main factors affecting the slurry preparation were optimized: nature and concentration of acid solution and sonication time. The analytical method was validated in-house by calibration, linearity, limits of detection and quantification, precision and accuracy test obtaining satisfactory results in all cases. The proposed method was applied for the determination of Cd, Cr, Cu and Pb in some Brazilian yogurt samples. For these samples, the concentrations ranged from 2.5±0.2 to 12.4±0.2ngg -1 ; 34±3 to 899±7ngg -1 ; <8.3 to 12±1ngg -1 ; and <35.4 to 210±16ngg -1 for Cd, Cu, Cr and Pb, respectively. The daily intake of Cd, Cu, Cr and Pb via consumption of these samples was estimated. Copyright © 2017 Elsevier Ltd. All rights reserved.

The Investigation of Heavy Metal Content (Cu, Cd, Pb in Sapu-Sapu Fish (Hypostomus plecostomus in Bengawan Solo River

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Ristiyana Eko Setyarini

2016-12-01

Full Text Available A study had been carried out to investigate heavy metal (Cu, Cd, Pb content in sapu-sapu fish (hypostomus plecostomus in Bengawan Solo river. The type of this research was observational research, with sapu-sapu fish inhabit Bengawan Solo River as the population. The samples were taken with purposive random sampling. Nine sapu-sapu fishes taken from 3 places, i.e.: Nguter Sukoharjo area, Premulung river outlet and Anyar river, 3 fishes from each palce, and then take examined the content of heavy metal. The result of study showed that the average content of Cu: 0.027 mg/100gr, Cd: 0.005 mg/100gr and Pb: 0.042 mg/100gr. Hence, sapu-sapu fish in Be3ngawan Solo had been contaminated with heavy metal (Cu, Cd, and Pb and should not be consumed.

Electrothermal vaporization inductively coupled plasma-mass spectrometry for the determination of Cr, Cu, Cd, Hg and Pb in rice flour

International Nuclear Information System (INIS)

Li, P.-C.; Jiang, S.-J.

2003-01-01

Ultrasonic slurry sampling (USS)-electrothermal vaporization (ETV) dynamic reaction cell TM (DRC) inductively coupled plasma-mass spectrometry (ICP-MS) has been applied to determine Cr, Cu, Cd, Hg and Pb in rice samples. The influences of instrument operating conditions and slurry preparation on the ion signals were reported. Ascorbic acid was used as a modifier to enhance the ion signals. The background ions at the chromium masses were reduced in intensity significantly by using 0.4 ml min -1 NH 3 as reaction cell gas in the dynamic reaction cell while a q value of 0.6 was used. Since the sensitivities of Cr, Cu, Cd, Hg and Pb in rice flour slurry and aqueous solution were quite different, standard addition and isotope dilution methods were used for the determination of Cr, Cu, Cd, Hg and Pb in these rice samples. This method has been applied to the determination of Cr, Cu, Cd, Hg and Pb in NIST SRM 1568a rice flour reference material and two rice samples purchased from the market. The analytical results for the reference material agreed with the certified values. The results for the rice samples for which no reference values were available were also found to be in good agreement between the isotope dilution and standard addition methods. The method's detection limits estimated from the standard addition plots were about 0.44, 1.7, 0.4, 0.53 and 0.69 ng g -1 for Cr, Cu, Cd, Hg and Pb, respectively, in the original rice flour

Batch adsorption of heavy metals (Cu, Pb, Fe, Cr and Cd) from ...

African Journals Online (AJOL)

cinthia

This study was carried out to evaluate the efficiency of metals (Cu, Fe, Pb, Cr and Cd) removal from mixed metal ions solution using coconut husk as adsorbent. The effects of varying contact time, initial metal ion concentration, adsorbent dose and pH on adsorption process of these metals were studied using synthetically ...

Application of atomic absorption spectrophotometry to determine Cd, Cu, Pb, Zn,...in vegetable samples in Dalat

Energy Technology Data Exchange (ETDEWEB)

Giang, Nguyen; Tam, Nguyen Thanh; Ngoc Trinh, Le Thi; Mai, Truong Phuong; Minh, Nguyen Van [Nuclear Research Institute, Dalat (Viet Nam)

2004-08-01

Nowadays atomic absorption spectrometry has become valuable method for trace element analysis because high specificity; low detection litmus, easy to use; easy sample preparation, low investment and running costs... atomic absorption spectrometry is generally accepted as one the most suitable method for single - element analysis of trace elements in various kinds of materiel. In 2003, we applied flame - atomic absorption spectrometry for analyzing Ca, Cd, Cu, Pb, Zn...in vegetables and their extracted juices were collected form 11 locations of Dalat, including two kinds of vegetables (goods and safety) in both the summer and winter. Average concentration of Ca = 240 mg/kg wet, Cd = 0.035 mg/kg wet, Cu = 0.67 mg/kg wet, Mg = 131 mg/kg wet, Fe = 8.1/kg wet, Mn = 3.1/kg wet, Na = 3266 mg/kg wet, Pb = 0.345 mg/kg wet and Zn = 3.3 mg wet. In their extracted juices: Ca = 89 mg/kg wet, Cd = 0.008 mg/kg wet, Cu = 0.19 mg/kg wet, Mg = 43 mg/kg wet, Fe = 2.3 mg/kg wet, Mn = 0.61 mg/kg wet, Na = 971 mg/kg wet, Pb = 0.107 mg/kg wet and Zn = 0.65 mg/kg wet. (author)

Application of atomic absorption spectrophotometry to determine Cd, Cu, Pb, Zn,...in vegetable samples in Dalat

International Nuclear Information System (INIS)

Nguyen Giang; Nguyen Thanh Tam; Le Thi Ngoc Trinh; Truong Phuong Mai; Nguyen Van Minh

2004-01-01

Nowadays atomic absorption spectrometry has become valuable method for trace element analysis because high specificity; low detection litmus, easy to use; easy sample preparation, low investment and running costs... atomic absorption spectrometry is generally accepted as one the most suitable method for single - element analysis of trace elements in various kinds of materiel. In 2003, we applied flame - atomic absorption spectrometry for analyzing Ca, Cd, Cu, Pb, Zn...in vegetables and their extracted juices were collected form 11 locations of Dalat, including two kinds of vegetables (goods and safety) in both the summer and winter. Average concentration of Ca = 240 mg/kg wet, Cd = 0.035 mg/kg wet, Cu = 0.67 mg/kg wet, Mg = 131 mg/kg wet, Fe = 8.1/kg wet, Mn = 3.1/kg wet, Na = 3266 mg/kg wet, Pb = 0.345 mg/kg wet and Zn = 3.3 mg wet. In their extracted juices: Ca = 89 mg/kg wet, Cd = 0.008 mg/kg wet, Cu = 0.19 mg/kg wet, Mg = 43 mg/kg wet, Fe = 2.3 mg/kg wet, Mn = 0.61 mg/kg wet, Na = 971 mg/kg wet, Pb = 0.107 mg/kg wet and Zn = 0.65 mg/kg wet. (author)

Disponibilidade e fracionamento de Cd, Pb, Cu e Zn em função do pH e tempo de incubação com o solo Availability and fractionation of Cd, Pb, Cu, AND Zn in soil as a function of incubation time and pH

Directory of Open Access Journals (Sweden)

Évio Eduardo Chaves de Melo

2008-06-01

Full Text Available O pH e o tempo de contato influenciam a distribuição dos metais entre frações do solo e a eficiência da fitoextração. Objetivou-se, neste trabalho estudar a disponibilidade dos metais Cd, Pb, Cu e Zn para a fitoextração, bem como suas redistribuições no solo, em função do tempo de incubação em solo com e sem calagem. O solo recebeu Cd, Pb, Cu e Zn nas doses 20, 150, 100 e 150 mg kg-1, respectivamente, na forma de sal solúvel. As amostras foram incubadas por 210, 180, 150, 120, 90, 60, 30 e 0,5 dia. Terminada a incubação, mucuna preta (Stizolobium aterrimum Piper & Tracy foi cultivada por 30 dias. EDTA (10 mmol kg-1 foi aplicado sete dias, antes da coleta das plantas. As amostras de solo foram submetidas à extração química e fracionada. A concentração de metais pesados e a calagem afetaram a produção de matéria seca da parte aérea e da raiz. Em solos sem calagem, o aumento da solubilidade dos metais aumentou a fitoextração de Cd e Zn, mesmo sem aplicação do EDTA. A aplicação do EDTA ao solo com calagem mostrou-se eficiente para a fitoextração de Pb e Cu. A calagem reduziu os teores disponíveis de Cd, Pb, Cu e Zn. A calagem provocou redução nos teores de Cd, Pb, Cu e Zn trocáveis e aumento nas frações matéria orgânica, óxidos de ferro amorfo e cristalino.It is known that pH and incubation time influence the distribution of metals into soil fractions and therefore affect phytoextraction. Taking this in account, the aim of this work was to study the fractionation and availability of heavy metals for phytoextraction, as a function of incubation period in soils with or without liming. The soil samples were applied to Cd, Pb, Cu, and Zn at concentrations of 20, 150, 100, and 150 mg kg-1, respectively, in the form of soluble salt. The samples were kept incubated for high incubation periods: 210, 180, 150, 120, 90, 60, 30, and 0,5 day. After that, velvetbean (Stizolobium aterrimum Piper & Tracy was cultivated

Enriquecimiento, disponibilidad y contaminación de metales traza (Cd, Cu, Pb y Zn en sedimentos de lagunas urbanas de Concepción-Chile Enrichment, availability and contamination of trace metals (Cd, Cu, Pb and Zn in sediments of urban lagoons in Concepción, Chile

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Elizabeth González Sepúlveda

2009-01-01

Full Text Available Trace metals (Cd, Cu, Pb and Zn enrichment, availability and contamination in superficial sediments of three interconnected urban lagoons localized in Concepción-Chile, were evaluated. According to the results of geochemical fracctionation analysis, Cu and Pb are rather associated with oxi-hydroxides, Cd is associated with exchangeable and carbonates fraction, while Zn is mainly associated with organic, oxi-hydroxides and residual fraction. The estimation of the availability percentages indicate that Cu is the most mobile metal and the less mobile is the Cd. An evaluation of the geo-accumulation index and urban industrial pollution allowed to classify the studied zone as moderately to highly contaminated.

Heavy metals (Cd, Pb, Cu, Zn) in mudfish and sediments from three ...

African Journals Online (AJOL)

driniev

2004-04-02

Apr 2, 2004 ... and analysed for Cd and Pb by electro-thermal AAS, and for Cu and Zn by flame AAS. ... measurements and the dolomitic hard water and high pH of the Mooi River water .... Copper and zinc were determined by flame analysis at 324.8 nm ... were placed separately in clean 20 ml glass vials and one ml de-.

Enriquecimiento, disponibilidad y contaminación de metales traza (Cd, Cu, Pb y Zn) en sedimentos de lagunas urbanas de Concepción-Chile Enrichment, availability and contamination of trace metals (Cd, Cu, Pb and Zn) in sediments of urban lagoons in Concepción, Chile

OpenAIRE

Elizabeth González Sepúlveda; María Retamal Cifuentes; Valentina Medina Pedreros; Ramón Ahumada Bermúdez; José Neira Hinojosa

2009-01-01

Trace metals (Cd, Cu, Pb and Zn) enrichment, availability and contamination in superficial sediments of three interconnected urban lagoons localized in Concepción-Chile, were evaluated. According to the results of geochemical fracctionation analysis, Cu and Pb are rather associated with oxi-hydroxides, Cd is associated with exchangeable and carbonates fraction, while Zn is mainly associated with organic, oxi-hydroxides and residual fraction. The estimation of the availability percentages indi...

Population health risk via dietary exposure to trace elements (Cu, Zn, Pb, Cd, Hg, and As) in Qiqihar, Northeastern China.

Science.gov (United States)

Luo, Jinming; Meng, Jia; Ye, Yajie; Wang, Yongjie; Bai, Lin

2018-02-01

The estimated daily intakes (EDIs) of six trace elements (Cu, Zn, Pb, Cd, Hg, and As) in vegetables (leafy vegetable, i.e., bok choy, fruit vegetables, i.e., cucumber and tomato, and other categories, i.e., mushroom, kidney bean, and potato), cereals (rice and wheat flour), and meats (pork, mutton, and beef) most commonly consumed by adult inhabitants of Qiqihar, Northeastern China, were determined to assess the health status of local people. The average EDIs of Cu, Zn, Pb, Cd, Hg, and As were with 20.77 μg (kg bw) -1 day -1 of Cu, 288 μg (kg bw) -1 day -1 of Zn, 2.01 μg (kg bw) -1 day -1 of Pb, 0.41 μg (kg bw) -1 day -1 of Cd, 0.01 μg (kg bw) -1 day -1 of Hg, and 0.52 μg (kg bw) -1 day -1 of As, respectively, which are below the daily allowance recommended by FAO/WHO. However, the maximum EDIs of Pb and Cd were 4.56 μg (kg bw) -1 day -1 and 1.68 μg (kg bw) -1 day -1 , respectively, which are above the recommended levels [i.e., 3.58 μg (kg bw) -1 day -1 for Pb and 1.0 μg (kg bw) -1 day -1 for Cd] by FAO/WHO. This finding indicates that the potential health risk induced by daily ingestion of Pb and Cd for the local residents should receive a significant concern. Similarly, we detected elevated Pb and Cd concentrations, i.e., with average of 13.58 and 0.60 mg kg -1 dw, respectively, in the adult scalp hairs. Consumption of rice, potato, bok choy, and wheat flour contributed to 75 and 82% of Pb and Cd daily intake from foodstuffs. Nevertheless, human scalp hair is inappropriate biological material for determination of the nutritional status of trace elements in this region.

Speciation and behaviour of Cd, Pb and Cu in Zuari Estuary, west coast of India

Digital Repository Service at National Institute of Oceanography (India)

George, M.D.

Dissolved labile and nonlabile forms of Cd, Pb and Cu in Zuari Estuary, Goa, India measured for a period of 14 months showed lowest concentrations during the SW monsoon (June-September) while maximum concentrations were observed during...

Square-wave anodic-stripping voltammetric determination of Cd, Pb and Cu in wine: Set-up and optimization of sample pre-treatment and instrumental parameters

International Nuclear Information System (INIS)

Illuminati, Silvia; Annibaldi, Anna; Truzzi, Cristina; Finale, Carolina; Scarponi, Giuseppe

2013-01-01

For the first time, square-wave anodic-stripping voltammetry (SWASV) was set up and optimized for the determination of Cd, Pb and Cu in white wine after UV photo-oxidative digestion of the sample. The best procedure for the sample pre-treatment consisted in a 6-h UV irradiation of diluted, acidified wine, with the addition of ultrapure H 2 O 2 (three sequential additions during the irradiation). Due to metal concentration differences, separate measurements were carried out for Cd (deposition potential −950 mV vs. Ag/AgCl/3 M KCl deposition time 15 min) and simultaneously for Pb and Cu (E d −750 mV, t d 30 s). The optimum set-up of the main instrumental parameters, evaluated also in terms of the signal-to-noise ratio, were as follows: E SW 20 mV, f 100 Hz, ΔE step 8 mV, t step 100 ms, t wait 60 ms, t delay 2 ms, t meas 3 ms. The electrochemical behaviour was reversible bielectronic for Cd and Pb, and kinetically controlled monoelectronic for Cu. Good accuracy was found both when the recovery procedure was used and when the results were compared with data obtained by differential pulse anodic stripping voltammetry. The linearity of the response was verified up to ∼4 μg L −1 for Cd and Pb and ∼15 μg L −1 for Cu. The detection limits for t d = 5 min in the 10 times diluted, UV digested sample were (ng L −1 ): Cd 7.0, Pb 1.2 and Cu 6.6, which are well below currently applied methods. Application to a Verdicchio dei Castelli di Jesi white wine revealed concentration levels of Cd ∼0.2, Pb ∼10, Cu ∼30 μg L −1 with repeatabilities of (±RSD%) Cd ±6%, Pb ±5%, Cu ±10%

Selective removals of heavy metals (Pb(2+), Cu(2+), and Cd(2+)) from wastewater by gelation with alginate for effective metal recovery.

Science.gov (United States)

Wang, Fei; Lu, Xingwen; Li, Xiao-yan

2016-05-05

A novel method that uses the aqueous sodium alginate solution for direct gelation with metal ions is developed for effective removal and recovery of heavy metals from industrial wastewater. The experimental study was conducted on Pb(2+), Cu(2+), and Cd(2+) as the model heavy metals. The results show that gels can be formed rapidly between the metals and alginate in less than 10 min and the gelation rates fit well with the pseudo second-order kinetic model. The optimum dosing ratio of alginate to the metal ions was found to be between 2:1 and 3:1 for removing Pb(2+) and around 4:1 for removing Cu(2+) and Cd(2+) from wastewater, and the metal removal efficiency by gelation increased as the solution pH increased. Alginate exhibited a higher gelation affinity toward Pb(2+) than Cu(2+) and Cd(2+), which allowed a selective removal of Pb(2+) from the wastewater in the presence of Cu(2+) and Cd(2+) ions. Chemical analysis of the gels suggests that the gelation mainly occurred between the metal ions and the -COO(-) and -OH groups on alginate. By simple calcination of the metal-laden gels at 700 °C for 1 h, the heavy metals can be well recovered as valuable resources. The metals obtained after the thermal treatment are in the form of PbO, CuO, and CdO nanopowders with crystal sizes of around 150, 50, and 100 nm, respectively. Copyright © 2016 Elsevier B.V. All rights reserved.

Heavy metals (Cd, Cu, Ni and Pb) content in two fish species of ...

African Journals Online (AJOL)

GREGORY

2010-09-13

Sep 13, 2010 ... Water pollution and fish physiology. CRC press. Florida, USA, p. 245. Kalay M, Canli M (2000). Elimination of essential (Cu, Zn) and nonessential (Cd, Pb) metals from tissue of a freshwater fish Tilapia zillii following and uptake protocol. Turk. J. Zool. 24: 429-436. Karadede H, Ünlü E (2000). Concentrations ...

Distribution of various forms of Cd, Pb and Cu in the Wadge Bank region (Arabian Sea)

Digital Repository Service at National Institute of Oceanography (India)

George, M.D.

Labile, nonlabile and particulate forms of Cd,Pb and Cu were determined in 29 water samples collected from a depth of 5 m, from the Wadge Bank area. Labile Cd varied from 0.1 to 0.2 mu g.l-1 while nonlabile fraction was in the range 0.1 to 0.3 mu gl...

A study: removal of Cu(II), Cd(II), and Pb(II) ions from real industrial water and contaminated water using activated sludge biomass

Energy Technology Data Exchange (ETDEWEB)

Kusvuran, Erdal; Yildirim, Deniz [Arts and Sciences Faculty, Chemistry Department, Cukurova University, Balcali, Adana (Turkey); Samil, Ali [Arts and Sciences Faculty, Chemistry Department, Sutcu Imam University, Kahramanmaras (Turkey); Gulnaz, Osman [Arts and Sciences Faculty, Biology Department, Cukurova University, Balcali, Adana (Turkey)

2012-11-15

This study aims to remove of Cu{sup 2+}, Cd{sup 2+}, and Pb{sup 2+} ions from solution and to investigate the adsorption isotherms, adsorption kinetics, and ion-exchange affinities of these metals using waste activated sludge (AS) biomass. The adsorptions of the metals on biomass were optimal at an acidic pH value of 6.0 based on its monolayer capacities. Maximum monolayer capacities of AS biomass (q{sub max}) were calculated as 0.478, 0.358, and 0.280 mmol g{sup -1} for Cu{sup 2+}, Cd{sup 2+}, and Pb{sup 2+}, respectively, and the adsorption equilibrium time was found as 60 min for each metal. The adsorbed amount of metal rose with increasing of initial metal ion concentration. The equilibrium adsorption capacity of AS for initial 0.25 mmol L{sup -1} metal concentration was determined as 0.200, 0.167, and 0.155 mmol g{sup -1} for Cu{sup 2+}, Cd{sup 2+}, and Pb{sup 2+} ions, respectively. These relevant values were determined as 0.420, 0.305, and 0.282 mmol g{sup -1} for Cu{sup 2+}, Cd{sup 2+}, and Pb{sup 2+} ions, respectively, when initial metal concentration was 0.50 mmol L{sup -1}. In the multi-metal sorption system, the adsorption capacity of AS biomass was observed in the order of Cu{sup 2+} > Cd{sup 2+} > Pb{sup 2+}. In the presence of 100 mmol L{sup -1} H{sup +} ion, the order of ion-exchange affinity with H{sup +} was found as Cu{sup 2+} > Cd{sup 2+} > Pb{sup 2+}. The adsorption kinetics were also found to be well described by the pseudo-second-order and intraparticle diffusion models. Two different rate constants were obtained as k{sub i1} and k{sub i2} and k{sub i1} (first stage) was found to be higher than k{sub i2} (second stage). (Copyright copyright 2012 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

Highly enhanced photocurrent of novel quantum-dot-co-sensitized PbS-Hg/CdS/Cu:ZnO thin films for photoelectrochemical applications

International Nuclear Information System (INIS)

Gohel, Jignasa V.; Jana, A.K.; Singh, Mohit

2017-01-01

A novel quantum-dot-co-sensitized PbS-Hg/CdS/Cu:ZnO thin films synthesized by low-cost process. The properties of ZnO are also enhanced by doping and co-doping. It is also compared with quantum-dot co-sensitization. Optical properties, crystal structure, morphology, and photocurrent are characterized by UV-Vis spectroscopy, XRD, SEM, and solar simulator, respectively. The bandgap is interestingly reduced highly to 2.6 eV for Ag co-doped Cu:ZnO. It is unprecedentedly reduced to 2.1 eV and even 1.97 eV for CdS and PbS-Hg QD-sensitized thin films, respectively. An exceptionally enhanced photocurrent of 17.1 mA/cm"2 is achieved with PbS-Hg-co-sensitized CdS-sensitized Cu:ZnO thin film. This is an excellent achievement, which highly supports the potential of low-cost solar conversion. (orig.)

Highly enhanced photocurrent of novel quantum-dot-co-sensitized PbS-Hg/CdS/Cu:ZnO thin films for photoelectrochemical applications

Energy Technology Data Exchange (ETDEWEB)

Gohel, Jignasa V.; Jana, A.K.; Singh, Mohit [Sardar Vallabhbhai National Institute of Technology, Chemical Engineering Department, Surat, Gujarat (India)

2017-08-15

A novel quantum-dot-co-sensitized PbS-Hg/CdS/Cu:ZnO thin films synthesized by low-cost process. The properties of ZnO are also enhanced by doping and co-doping. It is also compared with quantum-dot co-sensitization. Optical properties, crystal structure, morphology, and photocurrent are characterized by UV-Vis spectroscopy, XRD, SEM, and solar simulator, respectively. The bandgap is interestingly reduced highly to 2.6 eV for Ag co-doped Cu:ZnO. It is unprecedentedly reduced to 2.1 eV and even 1.97 eV for CdS and PbS-Hg QD-sensitized thin films, respectively. An exceptionally enhanced photocurrent of 17.1 mA/cm{sup 2} is achieved with PbS-Hg-co-sensitized CdS-sensitized Cu:ZnO thin film. This is an excellent achievement, which highly supports the potential of low-cost solar conversion. (orig.)

Influence of Al and the heavy metals Fe, Mn, Zn, Cu, Pb, and Cd on development and efficacy of vesicular-arbuscular mycorrhiza in tropical and subtropical plants. Einfluss von Al und den Schwermetallen Fe, Mn, Zn, Cu, Pb und Cd auf die Effizienz der VA-Mykorrhiza bei tropischen und subtropischen Pflanzen

Energy Technology Data Exchange (ETDEWEB)

Fabig, B.

1982-07-08

In greenhouse experiments the influence of Al and the heavy metals Fe, Mn, Zn, Cu, Pb, and Cd on the efficacy of VA-mycorrhizal fungi was tested with special regard to several soil pH levels and soil water regimes in different combinations. The most important results were: The inoculation led to a significantly better growth of all test plants in the presence of Al, Fe, Mn, Zn, Cu, Pb, and Cd up to a specific amount of the soil-applied element; beyond this specific limit the efficacy of the mycorrhiza was more or less inhibited depending on the element. In correlation with the growth, the nearly always better P uptake of the inoculated plants was impaired only by the highest toxic amounts of the elements. In comparison with the uninoculated plants, all the inoculated plants showed higher P and Pb concentrations. The mycorrhizal plants generally had significantly higher concentrations of the elements Al, Mn, Zn, Cu, and Cd in the roots than the uninoculated plants. Generally even toxic levels of Fe in the soil did not lead to higher Fe concentrations in the plants. Even the highest amounts of Al, Fe, Mn, Zn, and Cu did not cause microscopically visible injuries to the development of the mycorrhiza and did not impede the infection. Only the toxic levels of Pb led to a decrease of the infection rate of about 50%. Pb and Cd were the reason for morphological changes of the different developmental phases of the fungus. High amounts of Pb induced an increased formation of vesicles. The highest amounts of Cd were accompanied by the crowded occurrence of arbuscules.

Distributions of dissolved trace metals (Cd, Cu, Mn, Pb, Ag in the southeastern Atlantic and the Southern Ocean

Directory of Open Access Journals (Sweden)

M. Boye

2012-08-01

Full Text Available Comprehensive synoptic datasets (surface water down to 4000 m of dissolved cadmium (Cd, copper (Cu, manganese (Mn, lead (Pb and silver (Ag are presented along a section between 34° S and 57° S in the southeastern Atlantic Ocean and the Southern Ocean to the south off South Africa. The vertical distributions of Cu and Ag display nutrient-like profiles similar to silicic acid, and of Cd similar to phosphate. The distribution of Mn shows a subsurface maximum in the oxygen minimum zone, whereas Pb concentrations are rather invariable with depth. Dry deposition of aerosols is thought to be an important source of Pb to surface waters close to South Africa, and dry deposition and snowfall may have been significant sources of Cu and Mn at the higher latitudes. Furthermore, the advection of water masses enriched in trace metals following contact with continental margins appeared to be an important source of trace elements to the surface, intermediate and deep waters in the southeastern Atlantic Ocean and the Antarctic Circumpolar Current. Hydrothermal inputs may have formed a source of trace metals to the deep waters over the Bouvet Triple Junction ridge crest, as suggested by relatively enhanced dissolved Mn concentrations. The biological utilization of Cu and Ag was proportional to that of silicic acid across the section, suggesting that diatoms formed an important control over the removal of Cu and Ag from surface waters. However, uptake by dino- and nano-flagellates may have influenced the distribution of Cu and Ag in the surface waters of the subtropical Atlantic domain. Cadmium correlated strongly with phosphate (P, yielding lower Cd / P ratios in the subtropical surface waters where phosphate concentrations were below 0.95 μM. The greater depletion of Cd relative to P observed in the Weddell Gyre compared to the Antarctic Circumpolar Current could be due to increase Cd uptake induced by iron-limiting conditions in these high

Determination of field-based sorption isotherms for Cd, Cu, Pb and Zn in Dutch soils

NARCIS (Netherlands)

Otte JG; Grinsven JJM van; Peijnenburg WJGM; Tiktak A; LBG; ECO

1999-01-01

Sorption isotherms for metals in soil obtained in the laboratory generally underpredict the observed metal content in the solid phase in the field. Isotherms based on in-situ data are therefore required. The aim of this study is to obtain field-based sorption isotherms for Cd, Cu, Pb and Zn as input

Stabilization of Cd-, Pb-, Cu- and Zn-contaminated calcareous agricultural soil using red mud: a field experiment.

Science.gov (United States)

Wang, Yangyang; Li, Fangfang; Song, Jian; Xiao, Ruiyang; Luo, Lin; Yang, Zhihui; Chai, Liyuan

2018-04-12

Red mud (RM) was used to remediate heavy metal-contaminated soils. Experiments with two different dosages of RM added to soils were carried out in this study. It was found that soil pH increased 0.3 and 0.5 unit with the dosage of 3 and 5% (wt%), respectively. At the dosage of 5%, the highest stabilization efficiencies for Cd, Pb, Cu and Zn reached 67.95, 64.21, 43.73 and 63.73%, respectively. The addition of RM obviously transferred Cd from the exchangeable fraction to the residual fraction. Meanwhile, in comparison with the control (no RM added), it reduced 24.38, 49.20, 19.42 and 8.89% of Cd, Pb, Cu and Zn in wheat grains at the RM addition dosage of 5%, respectively. At the same time, the yield of wheat grains increased 17.81 and 24.66% at the RM addition dosage of 3 and 5%, respectively. Finally, the addition of RM did not change the soil bacterial community. These results indicate that RM has a great potential in stabilizing heavy metals in calcareous agricultural soils.

Removal of Pb(II), Cu(II) and Cd(II) from aqueous solution by some fungi and natural adsorbents in single and multiple metal systems

International Nuclear Information System (INIS)

Shoaib, A.; Badar, T.; Aslam, N.

2011-01-01

Six fungal and 10 natural biosorbents were analyzed for their Cu(II), Cd(II) and Pb(II) uptake capacity from single, binary and ternary metal ion system. Preliminary screening biosorption of assays revealed 2 fungi (Aspergillus niger and Cunninghamella echinulata) and three natural [Cicer arietinum husk, Moringa oleifera flower and soil (clay)] adsorbents hold considerable high adsorption efficiency and capacity for 3 meta l ions amongst the adsorbents. Further biosorption trials with five elected adsorbents showed a considerable reduction in metal uptake capability of adsorbents in binary- and ternary systems as compared to singly metal system. Cd(II) manifested the highest inhibitory effect on the biosorption of other metal ions, followed by Pb(II) and Cu(II). On account of metal preference, the selectivity order for metal ion towards the studied biomass matrices was Pb(II) (40-90%) > Cd(II) (2-53%) > Cu(II) (2-30%). (author)

Risk assessment for Cd, Cu, Pb and Zn in urban soils: Chemical availability as the central concept

International Nuclear Information System (INIS)

Rodrigues, S.M.; Cruz, N.; Coelho, C.; Henriques, B.; Carvalho, L.; Duarte, A.C.; Pereira, E.; Römkens, Paul F.A.M.

2013-01-01

To assess the geochemical reactivity and oral bioaccessibility of Cd, Cu, Pb and Zn in urban soils from the Porto area, four extractions were performed including Aqua Regia (AR; pseudototal), 0.43 M HNO 3 (reactive), 0.01 M CaCl 2 (available), and 0.4 M glycine at pH = 1.5, SBET method (oral bioaccessible pool). Oral bioaccessibility in urban soils was higher than in samples from rural, industrial and mining areas which is most likely related to sources of metals and parent materials of corresponding soils. The availability and reactivity were described well by non-linear Freundlich-type equations when considering differences in soil properties. The resulting empirical models are able to predict availability and reactivity and can be used to improve the accuracy of risk assessment. Furthermore, a close 1:1 relationship exists between results from the 0.43 M HNO 3 method and the SBET method which substantially facilitates risk assessment procedures and reduces analytical costs. -- Highlights: ► Availability of PTEs in urban soils is described well by non-linear Freundlich-type equations. ► A 1:1 relationship was obtained between the 0.43 M HNO 3 method and the SBET method. ► A single soil extraction indicates reactivity and bioaccessibility of metals in soils. ► The reactive pool is suitable to assess risks of Cd, Cu, Pb and Zn in urban soils. -- A single analysis of the reactive pool by dilute nitric acid is suitable to assess risks of Cd, Cu, Pb and Zn in urban soils related to leaching to (ground)water and exposure to human beings (bioaccessibility)

Phytoremediation efficiency of pondweed (Potamogeton crispus in removing heavy metals (Cu, Cr, Pb, As and Cd from water of Anzali wetland

Directory of Open Access Journals (Sweden)

Hajar Norouznia

2014-09-01

Full Text Available Plant-based remediation (i.e. phytoremediation is one of the most significant eco-sustainable techniques to cope with devastating consequences of pollutants. In the present study, the potential of a wetland macrophyt (i.e. Potamogeton crispus for the phytoremediation of heavy metals (i.e. Cu, Cr, Pb, As and Cd in the Anzali wetland was evaluated. The results showed that P. crispus tends to accumulate notable amounts of Cu, Cr, Pb, As and Cd according to their assayed concentrations as follows: 8.2 µg g-1 dw, 0.97 µg g-1 dw, 6.04 µg g-1 dw, 2.52 µg g-1 dw and 0.34 µg g-1 dw, respectively. Further accurate perception of the phytoremediation efficiency were conducted using both bioconcentration factor and translocation factor. The average of the highest bioconcentration factors was presented in a descending order as: 2.9×103, 1.9×103, 1.17×103, 0.68×103 and 0.46×103 for the Cu, Cr, Pb, Cd and As, respectively. Based on the results, P. crispus presents high potential to absorb all the alluded metals except for As and partly Cd. Correspondingly, the mean values of translocation factor were reported in the range of 0.41 to 2.24. Eventually, relying on the observed findings, the results support the idea that P. crispus species would be employed as the prospective candidate for the phytoremediation processes in Anzali wetland.

A test of the stability of Cd, Cu, Hg, Pb and Zn profiles over two decades in lake sediments near the Flin Flon Smelter, Manitoba, Canada

Energy Technology Data Exchange (ETDEWEB)

Percival, J.B.; Outridge, P.M., E-mail: outridge@nrcan.gc.ca

2013-06-01

Lake sediments are valuable archives of atmospheric metal deposition, but the stability of some element profiles may possibly be affected by diagenetic changes over time. In this extensive case study, the stability of sedimentary Cd, Cu, Hg, Pb and Zn profiles was assessed in dated sediment cores that were collected in 2004 from four smelter-affected lakes near Flin Flon, Manitoba, which had previously been cored in 1985. Metal profiles determined in 1985 were in most cases clearly reproduced in the corresponding sediment layers in 2004, although small-scale spatial heterogeneity in metal distribution complicated the temporal comparisons. Pre-smelter (i.e. pre-1930) increases in metal profiles were likely the result of long-range atmospheric metal pollution, coupled with particle mixing at the 1930s sediment surface. However, the close agreement between key inflection points in the metal profiles sampled two decades apart suggests that metals in most of the lakes, and Hg and Zn in the most contaminated lake (Meridian), were stable once the sediments were buried below the surface mixed layer. Cadmium, Cu and Pb profiles in Meridian Lake did not agree as well between studies, showing evidence of upward remobilization over time. Profiles of redox-indicator elements (Fe, Mn, Mo and U) suggested that the rate of Mn oxyhydroxide recycling within sediment was more rapid in Meridian Lake, which may have caused the Cd, Cu and Pb redistribution. - Highlights: • Sedimentary Cd, Cu, Hg, Pb and Zn profiles in four lakes were mostly unchanged over 19 years. • In one lake, Cd, Cu and Pb profiles were offset relative to the originals. • The offset could indicate diagenetic upcore dispersal of these metals.

Sorption properties of the activated carbon-zeolite composite prepared from coal fly ash for Ni(2+), Cu(2+), Cd(2+) and Pb(2+).

Science.gov (United States)

Jha, Vinay Kumar; Matsuda, Motohide; Miyake, Michihiro

2008-12-15

Composite materials of activated carbon and zeolite have been prepared successfully by activating coal fly ash (CFA) by fusion with NaOH at 750 degrees C in N(2) followed by hydrothermal treatments under various conditions. Uptake experiments for Ni(2+), Cu(2+), Cd(2+) and Pb(2+) were performed with the materials thus obtained from CFA. Of the various composite materials, that were obtained by hydrothermal treatment with NaOH solution (ca. 4M) at 80 degrees C (a composite of activated carbon and zeolite X/faujasite) proved to be the most suitable for the uptake of toxic metal ions. The relative selectivity of the present sorbents for the various ions was Pb(2+)>Cu(2+)>Cd(2+)>Ni(2+), with equilibrium uptake capacities of 2.65, 1.72, 1.44 and 1.20mmol/g, respectively. The sorption isotherm was a good fit to the Langmuir isotherm and the sorption is thought to progress mainly by ion exchange with Na(+). The overall reaction is pseudo-second order with rate constants of 0.14, 0.17, 0.21 and 0.20Lg/mmol min for the uptake of Pb(2+), Cu(2+), Cd(2+) and Ni(2+), respectively.

Risk assessment for Cd, Cu, Pb, and Zn in urban soils: chemical availability as the central concept

NARCIS (Netherlands)

Rodrigues, S.R.; Cruz, N.; Coelho, C.; Henriques, B.; Carvalho, L.; Duarte, A.C.; Pereira, E.; Römkens, P.F.A.M.

2013-01-01

To assess the geochemical reactivity and oral bioaccessibility of Cd, Cu, Pb and Zn in urban soils from the Porto area, four extractions were performed including Aqua Regia (AR; pseudototal), 0.43 M HNO(3) (reactive), 0.01 M CaCl(2) (available), and 0.4 M glycine at pH = 1.5, SBET method (oral

Distribution and speciation of metals (Cu, Zn, Cd, and Pb) in agricultural and non-agricultural soils near a stream upriver from the Pearl River, China

International Nuclear Information System (INIS)

Yang, Silin; Zhou, Dequn; Yu, Huayong; Wei, Rong; Pan, Bo

2013-01-01

The distribution and chemical speciation of typical metals (Cu, Zn, Cd and Pb) in agricultural and non-agricultural soils were investigated in the area of Nanpan River, upstream of the Pearl River. The investigated four metals showed higher concentrations in agricultural soils than in non-agricultural soils, and the site located in factory district contained metals much higher than the other sampling sites. These observations suggested that human activities, such as water irrigation, fertilizer and pesticide applications might have a major impact on the distribution of metals. Metal speciation analysis presented that Cu, Zn and Cd were dominated by the residual fraction, while Pb was dominated by the reducible fraction. Because of the low mobility of the metals in the investigated area, no remarkable difference could be observed between upstream and downstream separated by the factory site. -- Highlights: ► Agricultural soils contain higher metal concentrations than non-agricultural soils. ► The site located in the factory district has the highest metal concentration. ► Cu, Zn and Cd are dominated by residual fraction, and Pb by reducible fraction. ► Cd pollution should not be overlooked in soils upstream of Pearl River. -- The mobility of four investigated metals is low but Cd pollution should not be overlooked in soils upstream of Pearl River

Characteristics of Heavy Metals Adsorption Cu, Pb and Cd Using Synthetics Zeolite Zsm-5

OpenAIRE

Priyadi,; Iskandar,; Suwardi,; Mukti, Rino Rakhmata

2015-01-01

It is generally known that zeolite has potential for heavy metal adsorption. The objectives of this study were to synthesize and characterize zeolite ZSM-5 and to figure out the adsorption capacity of zeolite ZSM-5 for heavy metals of Cu2+, Pb2+ and Cd2+. Characterization of zeolite ZSM-5 included some variables i.e. crystal structure (XRD), morphology (SEM), specific surface area and total pore volume (N2 physisorption). Adsorption capacity of zeolite ZSM-5 was analysed using a batch system...

The Existence of Heavy Metals such as Pb, Cd, Fe, and Cu in Hair Samples from Gas Station Worker at Yogyakarta Special District

International Nuclear Information System (INIS)

Supriyanto, C.; Zainul Kamal; Samin

2002-01-01

The monitoring of heavy metals existence such as Pb, Cd, Fe, and Cu in hair samples from gas station worker has been carried out with atomic absorption spectrometry method. The initial preparation of sample were done by immersing them in alcohol over night, after they were dried then they were digested using the teflon bomb digester at the temperature at 150 o C for 3 hours. The content of Pb, Cd, Fe, and Cu in were determined with calibration standard curve method. The content of Pb obtained at hair samples in the range of time at 20 years tend to increase. If it was correlated to the worker who has been working, there was no significant different from the worker who has been working for 20 years there was no significant different. While the content of Cu in sample at range time 20 years showed the significant different if it was correlated to the worker who has been working. The validity of method was tested with CRM Human Hair GBW 07601 from IAEA showed that the content of Fe and Cu were in the certified range of CRM. (author)

SWASV speciation of Cd, Pb and Cu for the determination of seawater contamination in the area of the Nicole shipwreck (Ancona coast, Central Adriatic Sea).

Science.gov (United States)

Annibaldi, Anna; Illuminati, Silvia; Truzzi, Cristina; Scarponi, Giuseppe

2011-12-01

The study reports for the first time on the heavy metal contamination of the waters surrounding a shipwreck lying on the sea floor. Square wave anodic stripping voltammetry has been used for a survey of the total and dissolved Cd, Pb and Cu contents of the seawater at the site of the sinking of the Nicole M/V (Coastal Adriatic Sea, Italy). Results show that the hulk has a considerable impact as regards all three metals in the bottom water, especially for the particulate fraction concentrations, which increased by factors of ≈ 9 (Cd), ≈ 3 (Pb) and ≈ 5 (Cu). The contaminated plume extended downstream for about 2 miles. Much lower contamination was observed for dissolved bottom concentrations; nevertheless Pb (0.56 ± 0.03 nmol/L) is higher than the Italian legal limits established for 2015 and Cd (0.23 ± 0.03 nmol/L) is very close the limit of Cd will be exceeded if the hulk is not removed. Copyright © 2011. Published by Elsevier Ltd.

Determination of Cd, Pb, Zn and Cu in Sediment Compartments by Sequential Extraction and Isotope Dilution Inductively Coupled Plasma Mass Spectrometry (ID-ICP-MS

Directory of Open Access Journals (Sweden)

Gardolinski Paulo C. F. C.

2002-01-01

Full Text Available Trace concentrations of Cd, Cu, Pb and Zn in four different sediment fractions extracted in sequence were determined by isotope dilution inductively coupled mass spectrometry (IDICPMS. The metals from each fraction were extracted following the sequential extraction procedure recommended by the Bureau Commun de Référence (BCR of the Commission of the European Communities. As an alternative to external calibration, the elements were quantified by spiking the extracted solutions with 112Cd, 63Cu, 208Pb and 66Zn and application of isotope dilution. The proposed approach was applied to a sample collected from a lake and two standard reference materials, NIST2704 river sediment from the National Institute of Standards & Technology and the BCR-277 estuarine sediment. Detection limits, for each extracted solution, varied from 0.31 to 0.53 mug L¹ for Cd, 0.92 to 2.9 mug L¹ for Cu, 0.22 to 1.1 mug L¹ for Pb and 1.3 to 7.6 mug L¹ for Zn. The sum of the metals concentration in the different fractions was compatible with 95% confidence level found amounts obtained with complete digestion of the samples and with the certified values of the standard reference materials.

Soluble/insoluble (dilute-HCl-extractable fractionation of Cd, Pb and Cu in Antarctic snow and its relationship with metal fractionations in the aerosol

Directory of Open Access Journals (Sweden)

Annibaldi A.

2013-04-01

Full Text Available A chemical fractionation methodology for determination of the (water soluble and the insoluble (dilute-HCl-extractable fractions of Cd, Pb and Cu in Antarctic snow was set-up and verified for the additivity of the two fractions detected. Molten samples were filtrated and the water-insoluble fraction was extracted by dilute ultrapure HCl (pH ~1.5. Metal determinations were carried out in the two fractions by square wave anodic stripping voltammetry. The total metal concentrations in samples collected in the 2000–2001 austral summer in a clean area (Faraglione Camp in the neighbourhood of the Mario Zucchelli Italian Station were of the order of Cd 10-20 pg g−1, Pb 20–40 pg g−1, Cu 60–120 pg g−1 with an approximate equidistribution between soluble and insoluble fractions. These fractionations compare well (and show a quite consistent temporal trend with those observed in the aerosol samples collected in the same area/period and confirm the close relationship between metal distributions in snow/ice and in the aerosol. At the station metal concentrations increase due to anthropic contribution and the distribution changes with Cd predominantly present in the soluble fraction (~80%, while Pb and Cu are more concentrated in the insoluble fraction, 70–80% and ~70%, respectively.

Liquidus surface of the triple reciprocal system PbTe+CdS↔PbS+CdTe

International Nuclear Information System (INIS)

Tomashik, Z.F.; Tomashik, V.N.

1987-01-01

Using differential-thermal and microstructural analyses and mathematical design interaction in PbTe-CdS system is studied. Liquidus surface of the triple reciprocal system PbTe+CdS↔PbS+CdTe is plotted. It is shown that PbTe-CdS system phase diagram is of eutectic type. Maximal solubility of CdS in PbTe attains 13 mol%, and of PbTe in CdS is not over 1 mol%. Projection of liquidus surface of the PbTe+CdS↔PbS+CdTe triple reciprocal system consists of two primary crystallization fields: CdTe x S 1-x and PbTe x S 1-x solid solutions separated by eutectic line

Sub-cellular partitioning of Zn, Cu, Cd and Pb in the digestive gland of native Octopus vulgaris exposed to different metal concentrations (Portugal)

Energy Technology Data Exchange (ETDEWEB)

Raimundo, J. [National Institute for Agronomy and Fisheries Research - IPIMAR, Av. Brasilia, 1449-006 Lisbon (Portugal)], E-mail: jraimundo@ipimar.pt; Vale, C. [National Institute for Agronomy and Fisheries Research - IPIMAR, Av. Brasilia, 1449-006 Lisbon (Portugal); Duarte, R.; Moura, I. [REQUIMTE - CQFB, Department of Chemistry, Faculty of Sciences and Technology, New University of Lisbon, Qta Torre, 2829-516 Monte da Caparica (Portugal)

2008-02-15

Concentrations of Zn, Cu, Cd and Pb and their sub-cellular distributions were determined in composite samples of digestive glands of the common octopus, Octopus vulgaris caught from two areas of the Portuguese coast characterised by contrasting metal contamination. Minor contents of Zn (1%), Cu (2%), Cd (6%) and Pb (7%) were found in the insoluble fraction, consisting of nuclei, mitochondria, lysosomes and microsome operationally separated from the whole digestive gland through a sequential centrifugation. A tendency for linear relationships between metal concentrations in nuclei, mitochondria, lysosomes and whole digestive gland was observed. These relationships suggest that despite low metal content organelles responded to the increasing accumulated metals, which means that detoxifying mechanism in cytosol was incomplete. Poorer correlations between microsome and whole digestive gland did not point to metal toxicity in the analysed compartments. However, the high accumulated Cd indicated that O. vulgaris is an important vehicle of this element to its predators in the coastal environment.

Sub-cellular partitioning of Zn, Cu, Cd and Pb in the digestive gland of native Octopus vulgaris exposed to different metal concentrations (Portugal)

International Nuclear Information System (INIS)

Raimundo, J.; Vale, C.; Duarte, R.; Moura, I.

2008-01-01

Concentrations of Zn, Cu, Cd and Pb and their sub-cellular distributions were determined in composite samples of digestive glands of the common octopus, Octopus vulgaris caught from two areas of the Portuguese coast characterised by contrasting metal contamination. Minor contents of Zn (1%), Cu (2%), Cd (6%) and Pb (7%) were found in the insoluble fraction, consisting of nuclei, mitochondria, lysosomes and microsome operationally separated from the whole digestive gland through a sequential centrifugation. A tendency for linear relationships between metal concentrations in nuclei, mitochondria, lysosomes and whole digestive gland was observed. These relationships suggest that despite low metal content organelles responded to the increasing accumulated metals, which means that detoxifying mechanism in cytosol was incomplete. Poorer correlations between microsome and whole digestive gland did not point to metal toxicity in the analysed compartments. However, the high accumulated Cd indicated that O. vulgaris is an important vehicle of this element to its predators in the coastal environment

Voltametrické stanovení Cu, Pb, Cd, Zn a Tl pomocí stříbrné pevné amalgamové elektrody

Czech Academy of Sciences Publication Activity Database

Josypčuk, Bohdan; Novotný, Ladislav

2002-01-01

Roč. 96, č. 9 (2002), s. 756-760 ISSN 0009-2770 Institutional research plan: CEZ:AV0Z4040901 Keywords : silver solid amalgam electrodes * voltammetry * Cu, Pb, Cd, Zn, Tl Subject RIV: CG - Electrochemistry Impact factor: 0.336, year: 2002

Effects of Cd, Pb, Zn, Cu-resistant endophytic Enterobacter sr CBSB1 and Rhodotorula sp. CBSB79 on the growth and phytoextraction of Brassica plants in multimetal contaminated soils.

Science.gov (United States)

Wang, Wenfeng; Deng, Zujun; Tan, Hongming; Cao, Lixiang

2013-01-01

To survey the effects of endophytic Enterobacter sp. CBSB1 and Rhodotorula sp. CBSB79 resistant to Cd2+, Pb2+, Zn2+, and Cu2+ on the growth and phytoextraction of Brassica, the endophytes were isolated by surface- sterilized methods and characterized. The CBSB1 significantly increased 44.2% of the dry weight of Brassica napus in the multimetal contaminated soil (P Rhodotorula sp CBSB79 showed higher potentials to improve extraction efficacy of Cd, Pb, Zn, and Cu by Brassica seedlings in the field.

The relationships between heavy metal (Cd, Cr, Cu, Fe, Pb, Zn) levels and the size of six Mediterranean fish species

International Nuclear Information System (INIS)

Canli, Mustafa; Atli, Gueluezar

2003-01-01

Significant relationships between metal concentrations and fish size were negative. - Heavy metal (Cd, Cr, Cu, Fe, Pb, Zn) concentrations in the muscle, gill and liver of six fish species (Sparus auratus, Atherina hepsetus, Mugil cephalus, Trigla cuculus, Sardina pilchardus and Scomberesox saurus) from the northeast Mediterranean Sea were measured and the relationships between fish size (length and weight) and metal concentrations in the tissues were investigated by linear regression analysis. Metal concentrations (as μg/g d.w.) were highest in the liver, except for iron in the gill of Scomberesox saurus and lowest in the muscle of all the fish species. Highest concentrations of Cd (4.50), Cr (17.1) and Pb (41.2) were measured in liver tissues of T. cuculus, Sardina pilchardus and A. hepsetus, respectively. The liver of M. cephalus showed strikingly high Cu concentrations (202.8). The gill of Scomberesox saurus was the only tissue that showed highest (885.5) iron concentrations. Results of linear regression analysis showed that, except in a few cases, significant relationships between metal concentrations and fish size were negative. Highly significant (P<0.001) negative relationships were found between fish length and Cr concentrations in the liver of A. hepsetus and M. cephalus, and Cr concentrations in the gill of T. cuculus. Cr and Pb concentrations in the liver and Cu concentrations in all the tissues of Scomberesox saurus also showed very significant (P<0.001) negative relationships. Negative relationships found here were discussed

Responses of different water spinach cultivars and their hybrid to Cd, Pb and Cd-Pb exposures.

Science.gov (United States)

Xin, Junliang; Huang, Baifei; Yang, Zhongyi; Yuan, Jiangang; Dai, Hongwen; Qiu, Qiu

2010-03-15

A pot experiment was conducted to investigate the stability of Cd and/or Pb accumulation in shoot of Cd and Pb pollution-safe cultivars (PSCs), the hereditary pattern of shoot Cd accumulation, and the transfer potentials of Cd and Pb in water spinach (Ipomoea aquatica Forsk.). A typical Cd-PSC, a typical non-Cd-PSC (Cd accumulative cultivar), a hybrid from the former two cultivars, and two typical Cd+Pb-PSCs were grown in seven soils with different concentrations of Cd and Pb. The results showed that concentrations of Cd and Pb in shoot of the PSCs were always lower than the non-PSC and the highest Cd and Pb transfer factors were also always observed in the non-PSC, indicating the stability of the PSCs in Cd and Pb accumulation. Shoot Cd concentration seemed to be controlled by high Cd dominant gene(s) and thus crossbreeding might not minimize Cd accumulation in water spinach. Interaction between Cd and Pb in soils affected the accumulations of the metals in shoot of water spinach. Under middle Cd and Pb treatments, the presence of higher Pb promoted the accumulation of Cd. However, under high Pb treatment, accumulations of Cd and Pb were both restricted. (c) 2009 Elsevier B.V. All rights reserved.

Levels of Cd (II, Mn (II, Pb (II, Cu (II, and Zn (II in Common Buzzard (Buteo buteo from Sicily (Italy by Derivative Stripping Potentiometry

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P. Licata

2010-01-01

Full Text Available The purpose of this study was to determine the concentrations of heavy metals (Cd, Pb, Cu, Mn, and Zn in different organs (liver, kidney, muscle, lung, skin, and feathers of buzzards (Buteo buteo, utilized as a “biological indicator” for environmental contamination, from different areas of Sicily and to investigate the relationships between birds sex, age, and weight and metal levels in these samples. All samples of common buzzards were collected at the “Recovery Center of Wild Fauna” of Palermo, through the Zooprophilactic Institute. Potentiometric stripping analysis (PSA was used to determine the content of Cd(II, Cu(II, Mn(II, Pb(II, and Zn(II in bird tissues. For toxic metals, the highest levels of Pb were in liver and those of Cd in lung; Zn levels were higher than Cu and Mn in all tissues analyzed. The concentrations in liver, lung, kidney, and muscle could be considered as an indicative of chronic exposure to metals while the presence of metals in skin could be consequential to storing and elimination processes. The found concentrations of metals in the studied matrices required a highly sensitive method for their determination and a simple sample preparation procedure, and the proposed method was well suited for this purpose.

Heavy metal (Pb, Cu, Zn and Cd content in wine produced from grape cultivar Mavrud, grown in an industrially polluted region

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Violina Angelova

1999-09-01

Full Text Available The investigation was carried out in the period 1991-1993 with cv. Mavrud, grown in the region with a major industrial pollutant the Non-Ferrous-Metal Works (NFMW and a region with no industrial pollutants (as a control. The heavy metal content in soil, grapes and wine was determined. Most of the heavy metals in the grapes precipitate during fermentation into the sediments, which is the reason for their significantly lower content in the wine. Water washing of grape before processing leads to about 2 time decrease in the Pb, Cu, Zn and Cd contents of wine. The pre-washing of grapes does not lead to any quality deterioration in the wine produced. The amounts of Cu, Zn and Cd in the wine from cv. Mavrud, grown in the region of the NFMW-Plovdiv, are lower than the maximum admissible levels, while the Pb content exceeds them about two times.

Determination of water-soluble and insoluble (dilute-HCl-extractable) fractions of Cd, Pb and Cu in Antarctic aerosol by square wave anodic stripping voltammetry: distribution and summer seasonal evolution at Terra Nova Bay (Victoria Land)

Energy Technology Data Exchange (ETDEWEB)

Annibaldi, A.; Truzzi, C.; Illuminati, S.; Bassotti, E.; Scarponi, G. [Polytechnic University of Marche - Ancona, Department of Marine Science, Ancona (Italy)

2007-02-15

Eight PM10 aerosol samples were collected in the vicinity of the ''Mario Zucchelli'' Italian Antarctic Station (formerly Terra Nova Bay Station) during the 2000-2001 austral summer using a high-volume sampler and precleaned cellulose filters. The aerosol mass was determined by differential weighing of filters carried out in a clean chemistry laboratory under controlled temperature and humidity. A two-step sequential extraction procedure was used to separate the water-soluble and the insoluble (dilute-HCl-extractable) fractions. Cd, Pb and Cu were determined in the two fractions using an ultrasensitive square wave anodic stripping voltammetric (SWASV) procedure set up for and applied to aerosol samples for the first time. Total extractable metals showed maxima at midsummer for Cd and Pb and a less clear trend for Cu. In particular, particulate metal concentrations ranged as follows: Cd 0.84-9.2 {mu}g g{sup -1} (average 4.7 {mu}g g{sup -1}), Pb 13.2-81 {mu}g g{sup -1} (average 33 {mu}g g{sup -1}), Cu 126-628 {mu}g g{sup -1} (average 378 {mu}g g{sup -1}). In terms of atmospheric concentration, the values were: Cd 0.55-6.3 pg m{sup -3} (average 3.4 pg m{sup -3}), Pb 8.7-48 pg m{sup -3} (average 24 pg m{sup -3}), Cu 75-365 pg m{sup -3} (average 266 pg m{sup -3}). At the beginning of the season the three metals appear widely distributed in the insoluble (HCl-extractable) fraction (higher proportions for Cd and Pb, 90-100%, and lower for Cu, 70-90%) with maxima in the second half of December. The soluble fraction then increases, and at the end of the season Cd and Pb are approximately equidistributed between the two fractions, while for Cu the soluble fraction reaches its maximum level of 36%. Practically negligible contributions are estimated for crustal and sea-spray sources. Low but significant volcanic contributions are estimated for Cd and Pb ({proportional_to}10% and {proportional_to}5%, respectively), while there is an evident although not

Cumulation of Cu, Zn, Cd, and Mn in Plants of Gardno Lake

Directory of Open Access Journals (Sweden)

Trojanowski J.

2013-04-01

Full Text Available In the present paper there have been shown the results of research on yhe content of Zn, Cd, Cu, Mn and Pb in chosen plants of Lake Gardno.The biggest concentration of those metals has been observed in Potamogton natans and Elodea canadensis, on average Zn – 34.9, Pb -2.77, Cd – 0.62, Cu – 3.24 and Mn – 257.4 μg g-1. It has been found that the over-ground parts of the plants under analysis cumulate several times less of heavy metals than their roots. The determined enrichment factors enabled the researchers to state that Cu in the examined plants is of natural origin while Mn, Cd and Zn – of anthropogenic origin.

Bioavailability and Variability of Cd, Pb, Zn, and Cu Pollution in Soft Tissues and Shell of Saccostrea cucullata Collected from the Coast of Qeshm Island, Persian Gulf, Iran

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Ali Kazemi

2016-07-01

Full Text Available Background: Marine pollution is a global environmental problem that its monitoring by ideal biomonitors is of great importance. Marine organisms, especially mussels, have the ability to accumulate metals from the environment; they can be considered as a biomonitoring agent. Methods: In this study, concentrations of heavy metals were measured in Saccostrea cucullata collected from seven sites on Qeshm Island's Coast. To achieve a digesting sample, each soft tissue was obtained and each of the shell homogeneous powders, 0.8 g and 1 g, respectively, were mixed with 10 mL HNO3 (69% and poured into a PTFE digestion vessel. The prepared samples were evaluated for Cd, Cu, and Zn by using a flame AAS Model 67OG and for Pb by using a graphite furnace AAS. Results: The distributions of metals between soft tissues and shells were compared in each sampling site. For seven sites, Cd, Zn, and Cu levels in soft tissues were higher than in the shells, but Pb level was higher in the shells than in the soft tissues. In addition, the results indicated the coefficient of variation (CV in the soft tissues was lower than the shells for Cd, and in the shells lower than the soft tissues for Pb, whereas the CV values were different in both the soft tissues and shells for Zn and Cu. Conclusion: The results of this study support using these materials in S. cucullata for biomonitoring. Shells are appropriate for monitoring Pb contamination, and the soft tissues are more apt for monitoring Cd, Zn, and Cu contamination.

Genotypic variations in the accumulation of Cd, Cu, Pb and Zn exhibited by six commonly grown vegetables

International Nuclear Information System (INIS)

Alexander, P.D.; Alloway, B.J.; Dourado, A.M.

2006-01-01

Metal contaminants in garden and allotment soils could possibly affect human health through a variety of pathways. This study focused on the potential pathway of consumption of vegetables grown on contaminated soil. Five cultivars each of six common vegetables were grown in a control and in a soil spiked with Cd, Cu, Pb and Zn. Highly significant differences in metal content were evident between cultivars of a number of vegetables for several of the contaminants. Carrot and pea cultivars exhibited significant differences in accumulated concentrations of Cd and Cu with carrot cultivars also exhibiting significant differences in Zn. Distinctive differences were also identified when comparing one vegetable to another, legumes (Leguminosae) tending to be low accumulators, root vegetables (Umbelliferae and Liliaceae) tending to be moderate accumulators and leafy vegetables (Compositae and Chenopodiaceae) being high accumulators. - Genotypic differences between cultivars of vegetable species can be important in determining the extent of accumulation of metals from contaminated soil

Evaluation of Cd, Cr, Cu, Ni, and Pb in selected cosmetic products from Jordanian, Sudanese, and Syrian markets.

Science.gov (United States)

Massadeh, A M; El-Khateeb, M Y; Ibrahim, S M

2017-08-01

There is no sufficient data that evaluate heavy metal content in cosmetic products in Jordan as well as Sudan and Syria. This study aims to assess metal levels which include Cadmium (Cd), Chromium (Cr), Copper (Cu), Nickel (Ni), and Lead (Pb) in cosmetic products. These elements have draft limits because they are identified as potential impurities and are known to be toxic. This study aims to provide information to the population that may be beneficial to public health. Samples were collected from different brands obtained from markets in Jordan, Sudan, and Syria. Some of the selected cosmetic products were eyeliner, eye pencil, mascara, lipstick, powder, face cream, body cream, sun block, Vaseline, and the traditional eye cosmetic (kohl). The heavy metal content in these samples were determined by atomic absorption spectrometry (AAS). Based on analysis of variance analysis, a significant difference in heavy metal levels was found for samples obtained from Jordanian and Sudanese markets. The acid digestion method used in this study was based on procedures recommended by Nnorom et al. with some modifications as follows. (i) A weight of 2.0 g of cosmetic sample was dissolved in a mixture of 6 mL of high quality concentrated 69% nitric acid (HNO 3 ; Merck, Darmstadt, Germany) and 4 mL of concentrated 37% hydrochloric acid (Scharlau, Spain) in a porcelain crucible and heated on a hotplate to near dryness. (ii) An aliquot of 15 mL HNO 3 (1.00 M) was added to the digested sample and filtered through a Whatman No. 40 filter paper. (iii) The digested sample was transferred quantitatively into a 25 mL volumetric flask and then diluted with deionized water. (iv) Each digested sample was evaporated at 70 °C to about 1 mL and transferred into a polyethylene flask and diluted with 25 mL deionized water. (v) Blank was treated in the same procedure. In Jordan the concentration ranges of heavy metals in the collected samples were: Cd (0.03-0.10 μg/g), Cr (0.0-1.00�

Pb, Cd, Cu and Zn biogeochemical behaviour and biological transfer processes in the Northwestern Mediterranean

International Nuclear Information System (INIS)

Nicolas, E.; Marty, J.C.; Miquel, J.C.; Fowler, S.W.

1999-01-01

Cd, Pb, Cu and Zn concentrations were determined in planktonic organisms (Salps, copepods), their associated faecal pellets and in particles collected at 200 and 2000 m depth in sediment traps moored in the Ligurian Sea. Al and P were also measured and taken as tracers of lithogenic and biogenic components, respectively. The aim of this work was to determine the fluxes of trace metals in the Ligurian Sea and their variations with depth, and to to assess the biogeochemical behaviour of elements having, for some of them, an anthropogenic origin, by the study of biologically-mediated uptake and removal processes

Soil Cd, Cr, Cu, Ni, Pb and Zn sorption and retention models using SVM: Variable selection and competitive model.

Science.gov (United States)

González Costa, J J; Reigosa, M J; Matías, J M; Covelo, E F

2017-09-01

The aim of this study was to model the sorption and retention of Cd, Cu, Ni, Pb and Zn in soils. To that extent, the sorption and retention of these metals were studied and the soil characterization was performed separately. Multiple stepwise regression was used to produce multivariate models with linear techniques and with support vector machines, all of which included 15 explanatory variables characterizing soils. When the R-squared values are represented, two different groups are noticed. Cr, Cu and Pb sorption and retention show a higher R-squared; the most explanatory variables being humified organic matter, Al oxides and, in some cases, cation-exchange capacity (CEC). The other group of metals (Cd, Ni and Zn) shows a lower R-squared, and clays are the most explanatory variables, including a percentage of vermiculite and slime. In some cases, quartz, plagioclase or hematite percentages also show some explanatory capacity. Support Vector Machine (SVM) regression shows that the different models are not as regular as in multiple regression in terms of number of variables, the regression for nickel adsorption being the one with the highest number of variables in its optimal model. On the other hand, there are cases where the most explanatory variables are the same for two metals, as it happens with Cd and Cr adsorption. A similar adsorption mechanism is thus postulated. These patterns of the introduction of variables in the model allow us to create explainability sequences. Those which are the most similar to the selectivity sequences obtained by Covelo (2005) are Mn oxides in multiple regression and change capacity in SVM. Among all the variables, the only one that is explanatory for all the metals after applying the maximum parsimony principle is the percentage of sand in the retention process. In the competitive model arising from the aforementioned sequences, the most intense competitiveness for the adsorption and retention of different metals appears between

CORRELATION OF THE PARTITIONING OF DISSOLVED ORGANIC MATTER FRACTIONS WITH THE DESORPTION OF CD, CU, NI, PB AND ZN FROM 18 DUTCH SOILS

Science.gov (United States)

Eighteen Dutch soils were extracted in aqueous solutions at varying pH. Extracts were analyzed for Cd, Cu, Ni, Pb and Zn by ICP-AES. Extract dissolved organic carbon (DOC) was also concentrated onto a macroreticular resin and fractionation into three operationally defined fract...

Differences in the mobility of Cd, Cu, Pb and Zn during composting of two types of household bio-waste collected in four seasons.

Science.gov (United States)

Hanc, Ales; Szakova, Jirina; Ochecova, Pavla

2014-09-01

The objective of this study was to evaluate the mobility of Cd, Cu, Pb and Zn during 3 different compost aeration rates of household bio-waste, originating in urban settlement (U-bio-waste) and family house buildings (F-bio-waste). The first two weeks, when the thermophilic composting phase became, the highest decline of exchangeable content was recorded. After 12 weeks of composting, lower exchangeable content was found in the case of U-bio-waste composts than F-bio-waste composts, despite higher loss of fresh mass. The order of fractions in both final composts was as follows: residual>oxidizable>reducible>exchangeable. The exchangeable portion of total content in final composts decreased in this order: Zn (17%), Cd (11%), Pb (4%) and Cu (3%). Regarding the low exchangeable content of heavy metals and high-quality organic matter, these types of composts could be used not only as fertilizer, but for remediation of metals contaminated land. Copyright © 2014 Elsevier Ltd. All rights reserved.

Solid Phase Extraction of Trace Al(III), Fe(II), Co(II), Cu(II), Cd(II) and Pb(II) Ions in Beverages on Functionalized Polymer Microspheres Prior to Flame Atomic Absorption Spectrometric Determinations.

Science.gov (United States)

Berber, Hale; Alpdogan, Güzin

2017-01-01

In this study, poly(glycidyl methacrylate-methyl methacrylate-divinylbenzene) was synthesized in the form of microspheres, and then functionalized by 2-aminobenzothiazole ligand. The sorption properties of these functionalized microspheres were investigated for separation, preconcentration and determination of Al(III), Fe(II), Co(II), Cu(II), Cd(II) and Pb(II) ions using flame atomic absorption spectrometry. The optimum pH values for quantitative sorption were 2 - 4, 5 - 8, 6 - 8, 4 - 6, 2 - 6 and 2 - 3 for Al(III), Fe(II), Co(II), Cu(II), Cd(II) and Pb(II), respectively, and also the highest sorption capacity of the functionalized microspheres was found to be for Cu(II) with the value of 1.87 mmol g -1 . The detection limits (3σ; N = 6) obtained for the studied metals in the optimal conditions were observed in the range of 0.26 - 2.20 μg L -1 . The proposed method was successfully applied to different beverage samples for the determination of Al(III), Fe(II), Co(II), Cu(II), Cd(II) and Pb(II) ions, with the relative standard deviation of <3.7%.

Synthesis and characterization of PbO-CdO nanocomposite and its effect on (Bi,Pb)-2223 superconductor

Energy Technology Data Exchange (ETDEWEB)

Yahya, Nabil A.A. [Thamar University, Physics Department, Faculty of Education, Thamar (Yemen); Al-Gaashani, R. [Thamar University, Physics Department, Faculty of Education, Thamar (Yemen); Qatar Environment and Energy Research Institute (QEERI), Hamad Bin Khalifa University (HBKU), Doha (Qatar); Abd-Shukor, R. [Universiti Kebangsaan Malaysia, School of Applied Physics, Bangi, Selangor (Malaysia)

2017-03-15

A PbO-CdO nanocomposite-added Bi{sub 1.6}Pb{sub 0.4}Sr{sub 2}Ca{sub 2}Cu{sub 3}O{sub 10} ((Bi,Pb)-2223) superconductor has been prepared. The effect of the PbO-CdO nanocomposite addition on the transport critical current density (J{sub c}) of (Bi,Pb)-2223 superconductor was investigated. The transition temperature (T{sub c-onset}), zero electrical resistance temperature (T{sub c-R=0}), and J{sub c} of the samples were measured by the four-probe method. Phase formation, structure, and microstructure of samples were investigated. The distribution of nanoparticle size was determined. The results indicated that the PbO-CdO-added samples showed larger grain size and an increased volume fraction of high-T{sub c} phase (Bi-2223) compared to the non-added sample. A slight increase in T{sub c-R=0} of x = 0.15 wt% was observed. J{sub c} of the PbO-CdO nanocomposite-added samples was significantly higher than for the non-added sample. That could be explained by the possibility that the PbO-CdO nanocomposite acts as an effective flux pinning center in (Bi,Pb)-2223. At 77 K, J{sub c} of x = 0.15 wt% added sample was more than 20 times larger than J{sub c} of the non-added sample (x = 0 wt%). A combined effect of enhanced flux pinning, increased fraction of high-T{sub c} phase and improved grain size, which led to increase in the J{sub c} of added samples, is discussed. (orig.)

A transferable force field for CdS-CdSe-PbS-PbSe solid systems

Science.gov (United States)

Fan, Zhaochuan; Koster, Rik S.; Wang, Shuaiwei; Fang, Changming; Yalcin, Anil O.; Tichelaar, Frans D.; Zandbergen, Henny W.; van Huis, Marijn A.; Vlugt, Thijs J. H.

2014-12-01

A transferable force field for the PbSe-CdSe solid system using the partially charged rigid ion model has been successfully developed and was used to study the cation exchange in PbSe-CdSe heteronanocrystals [A. O. Yalcin et al., "Atomic resolution monitoring of cation exchange in CdSe-PbSe heteronanocrystals during epitaxial solid-solid-vapor growth," Nano Lett. 14, 3661-3667 (2014)]. In this work, we extend this force field by including another two important binary semiconductors, PbS and CdS, and provide detailed information on the validation of this force field. The parameterization combines Bader charge analysis, empirical fitting, and ab initio energy surface fitting. When compared with experimental data and density functional theory calculations, it is shown that a wide range of physical properties of bulk PbS, PbSe, CdS, CdSe, and their mixed phases can be accurately reproduced using this force field. The choice of functional forms and parameterization strategy is demonstrated to be rational and effective. This transferable force field can be used in various studies on II-VI and IV-VI semiconductor materials consisting of CdS, CdSe, PbS, and PbSe. Here, we demonstrate the applicability of the force field model by molecular dynamics simulations whereby transformations are initiated by cation exchange.

A transferable force field for CdS-CdSe-PbS-PbSe solid systems

Energy Technology Data Exchange (ETDEWEB)

Fan, Zhaochuan; Vlugt, Thijs J. H., E-mail: t.j.h.vlugt@tudelft.nl [Process and Energy Department, Delft University of Technology, Leeghwaterstraat 39, 2628 CB Delft,The Netherlands (Netherlands); Koster, Rik S.; Fang, Changming; Huis, Marijn A. van [Debye Institute for Nanomaterials Science and Center for Extreme Matter and Emergent Phenomena, Utrecht University, Princetonplein 5, 3584 CC Utrecht (Netherlands); Wang, Shuaiwei [Institute of Nanostructured Functional Materials, Huanghe Science and Technology College, Zhengzhou, Henan 450006 (China); Yalcin, Anil O.; Tichelaar, Frans D.; Zandbergen, Henny W. [Kavli Institute of Nanoscience, Delft University of Technology, Lorentzweg 1, 2628 CJ Delft (Netherlands)

2014-12-28

A transferable force field for the PbSe-CdSe solid system using the partially charged rigid ion model has been successfully developed and was used to study the cation exchange in PbSe-CdSe heteronanocrystals [A. O. Yalcin et al., “Atomic resolution monitoring of cation exchange in CdSe-PbSe heteronanocrystals during epitaxial solid-solid-vapor growth,” Nano Lett. 14, 3661–3667 (2014)]. In this work, we extend this force field by including another two important binary semiconductors, PbS and CdS, and provide detailed information on the validation of this force field. The parameterization combines Bader charge analysis, empirical fitting, and ab initio energy surface fitting. When compared with experimental data and density functional theory calculations, it is shown that a wide range of physical properties of bulk PbS, PbSe, CdS, CdSe, and their mixed phases can be accurately reproduced using this force field. The choice of functional forms and parameterization strategy is demonstrated to be rational and effective. This transferable force field can be used in various studies on II-VI and IV-VI semiconductor materials consisting of CdS, CdSe, PbS, and PbSe. Here, we demonstrate the applicability of the force field model by molecular dynamics simulations whereby transformations are initiated by cation exchange.

Investigation of Pb, Cd, Cu and Mg Concentrations in Groundwater Resources of Razan Plain

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S. Sobhan Ardakani

2015-01-01

Full Text Available Introduction & Objective: Iran is located in the dry and semi dry regions, thus almost 90% of the required fresh water is exploited from groundwater resources. Due to the increasing pol-lution of water resources, the purpose of this study was evaluation of Pb, Cd, Cu and Mg concentrations in groundwater resources of Razan Plain and preparing the zoning map using GIS. Materials & Methods: Groundwater samples were collected from 20 selected stations during two seasons in 2012. The samples were filtered (0.45 ?m and maintained cool in polyethyl-ene bottles. The samples were taken for the analysis of cations, the former was acidified with HNO3 to pH lower than 2. Minor elements were determined using ICP-OES. All statistical analyses were performed using the SPSS statistical package. Also, Kriging Method was used to prepare spatial distribution maps of elements in groundwater samples. Results: The results showed that the mean concentrations of Pb, Cd, Cu and Mg in the groundwater samples during the spring were 5.60±0.66, 0.21±0.04, 32.10±2.21 and 6990.0±302.10 ppb, respectively, and the mean concentrations of these elements in the groundwater samples in the summer were 4.86±0.46, 0.30±0.08, 25.55±3.63 and 3654.05±215.65 ppb, respectively. Comparing the mean concentrations of the evaluated metals with WHO permissible limits showed a significant difference (p<0.05. Thus, the mean concentrations of the metals were significantly lower than the permissible limits. Conclusion: Although the groundwater resources of Razan Plain are not currently polluted with heavy metals, long-term excessive use of agricultural inputs and establishment of pollut-ing industries, can pose a threat to groundwater resources of this area. (Sci J Hamadan Univ Med Sci 2015; 21(4:319-329

Distribution of Cd, Pb and Cu between dissolved fraction, inorganic particulate and phytoplankton in seawater of Terra Nova Bay (Ross Sea, Antarctica) during austral summer 2011-12.

Science.gov (United States)

Illuminati, S; Annibaldi, A; Romagnoli, T; Libani, G; Antonucci, M; Scarponi, G; Totti, C; Truzzi, C

2017-10-01

During the austral summer 2011-2012, the metal quotas of Cd, Pb and Cu in the phytoplankton of Terra Nova Bay (TNB, Antarctica) were measured for the first time. Evolution of all the three metal distributions between dissolved and particulate fractions during the season was also evaluated. Metal concentrations were mainly affected by the dynamic of the pack ice melting and phytoplankton activity. In mid-December when TNB area was covered by a thick pack ice layer and phytoplankton activity was very low, all the three metals were present mainly in their dissolved species. When the pack ice started to melt and the water column characteristics became ideal (i.e. moderate stratification, ice free area), the phytoplankton bloom occurred. Cd showed a nutrient-type behaviour with dissolved and particulate fractions mainly influenced by phytoplankton activity. Cd quota showed a mean value of 0.12 ± 0.07 nmol L -1 (30-100% of the total particulate). Also Cu showed a nutrient-type behaviour, with its quota in phytoplankton varying between 0.08 and 2.1 nmol L -1 (20-100% of the total particulate). Pb features the typical distribution of a scavenged element with very low algal content (0.03 ± 0.02 nmol L -1 , representing 20-50% of the total particulate). The vertical distribution of this element was influenced by several factors (e.g. pack ice melting, atmospheric inputs), the phytoplankton activity affecting Pb behaviour only partially. Metal:C ratios provide valuable information on the biological requirements for Cd, Pb and Cu, leading us to better understand their biogeochemical cycles. Copyright © 2017 Elsevier Ltd. All rights reserved.

Removal of Pb, Cu, Cd, and Zn Present in Aqueous Solution Using Coupled Electrocoagulation-Phytoremediation Treatment

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Francisco Ferniza-García

2017-01-01

Full Text Available This study presents the results of a coupled electrocoagulation-phytoremediation treatment for the reduction of copper, cadmium, lead, and zinc, present in aqueous solution. The electrocoagulation was carried out in a batch reactor using aluminum electrodes in parallel arrangement; the optimal conditions were current density of 8 mA/cm2 and operating time of 180 minutes. For phytoremediation the macrophytes, Typha latifolia L., were used during seven days of treatment. The results indicated that the coupled treatment reduced metal concentrations by 99.2% Cu, 81.3% Cd, and 99.4% Pb, while Zn increased due to the natural concentrations of the plant used.

Experimental Liquidus Studies of the Pb-Cu-Si-O System in Equilibrium with Metallic Pb-Cu Alloys

Science.gov (United States)

Shevchenko, M.; Nicol, S.; Hayes, P. C.; Jak, E.

2018-03-01

Phase equilibria of the Pb-Cu-Si-O system have been investigated in the temperature range from 1073 K to 1673 K (800 °C to 1400 °C) for oxide liquid (slag) in equilibrium with solid Cu metal and/or liquid Pb-Cu alloy, and solid oxide phases: (a) quartz or tridymite (SiO2) and (b) cuprite (Cu2O). High-temperature equilibration on silica or copper substrates was performed, followed by quenching, and direct measurement of Pb, Cu, and Si concentrations in the liquid and solid phases using the electron probe X-ray microanalysis has been employed to accurately characterize the system in equilibrium with Cu or Pb-Cu metal. All results are projected onto the PbO-"CuO0.5"-SiO2 plane for presentation purposes. The present study is the first-ever systematic investigation of this system to describe the slag liquidus temperatures in the silica and cuprite primary phase fields.

Analysis Of Non-Volatile Toxic Heavy Metals (Cd, Pb, Cu,Cr And Zn In ALLIUM SATIVUM (Garlic And Soil Samples ,Collected From Different Locations Of Punjab, Pakistan By Atomic Absorption Spectroscopy

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Ata S.

2013-04-01

Full Text Available Garlic is one of the most widely used medicinal plants. The monitoring of toxic metals such as lead, Cadmium, Chromium, Copper and Zinc in garlic and the soil of garlic fields collected from ten different cities of Punjab is critical for preventing public health against the hazards of metal toxicity. The levels of toxic heavy metals in garlic and soil samples were investigated using Atomic absorption spectrometer. The metal content in garlic samples was found to be in increasing order as Cr> Pb> Cd> Cu> Zn. Infield metal content in the soil also followed the same trend. In garlic samples, Pb, Cd, Cr, Zn and Cu ranged from 0.039mg/L to 0.757mg/L, N.D to 1.211mg/L, 0.03mg/L to 0.451mg/L, 0.02mg/Lto0.42mg/L and 0.451mg/L to 0.893mg/L respectively. In soil samples, Pb, Cd, Cr, Zn and Cu were ranged from 0.459mg/L to 0.797mg/L, 0.205mg/L to1.062mg/L, 0.074mg/L to 2.598mg/L, 0.124mg/L to 0.276mg/L and 0.494mg/L to 0.921mg/L respectively. In our study, the Pb and Cd was found more in garlic from Gujranwala and Jaranwala, Cu and Zn were more in samples from Kasur while Cr was predominant in sample from Sheikhupura. Heavy metal content in soil and garlic samples was within the permissible limits proposed by World Health Organization (WHO.

Experimental and modeling of the electrodialytic and dialytic treatment of a fly ash containing Cd, Cu and Pb

DEFF Research Database (Denmark)

Lima, A.T.; Ribeiro, A.B.; Rodriguez-Maroto, J.M.

2010-01-01

A one-dimensional model is developed for simulating the electrodialytic and dialytic treatment of a fly ash containing cadmium, copper and lead. Two experimental systems have been used, a column of ash and a stirred ash suspension. The movement of Cd, Cu and Pb has been modeled taking into account...... takes into account that OH- generated on the cathode, during the electrodialytic remediation, is periodically neutralized by the addition of nitric acid in the cathode compartment. The anion and cation-exchange membranes are simply represented as ionic filters that preclude the transport of the cations...

Cd, Pb and Cu in spring waters of the Sibylline Mountains National Park (Central Italy, determined by square wave anodic stripping voltammetry

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Truzzi C.

2013-04-01

Full Text Available Square wave anodic stripping voltammetry (SWASV was used to determine Cd, Pb and Cu in spring waters of the Sibylline Mountains National Park, Central Italy. Samples were collected from three different areas of the Park (Mount Bove North, Mount Bove South and Springs of River Nera during the period 2004-2011. Physical-chemical parameters were also determined to obtain a general characterization of the waters. Very low metal concentrations were observed (i.e., Cd 1.3±0.4 ng L-1, Pb 13.8±5.6 ng L-1, Cu 157±95 ng L-1, well below the legal limits and also below the medians of known Italian and European data. Comparing the three areas it was noted that waters from the area of the Nera Springs are the poorest in heavy metals and the richest in minerals, that conversely the waters of Mt. Bove North are the richest in heavy metals and the poorest in mineral salts, and finally that intermediate values both for heavy metals and mineral salts were observed for the waters of Mt. Bove South.

Optimization of simultaneous electrochemical determination of Cd(II), Pb(II), Cu(II) and Hg(II) at carbon nanotube-modified graphite electrodes.

Science.gov (United States)

Pikna, L'ubomír; Heželová, Mária; Kováčová, Zuzana

2015-01-01

The health of the environment is worsening every day. Monitoring of potentially toxic elements and remediation of environmental pollution are necessary. Therefore, the research and development of simple, inexpensive, portable and effective sensors is important. Electrochemistry is a useful component of the field of environment monitoring. The present study focuses on evaluating and comparing three types of electrodes (PIGE, PIGE/MWCNT/HNO3 and PIGE/MWCNT/EDTA/HNO3) employed for the simultaneous electrochemical determination of four potentially toxic elements: Cd(II), Pb(II), Cu(II) and Hg(II). Cyclic voltammograms were measured in an acetate buffer. The LOD, LOQ, the standard and relative precisions of the method and a prediction intervals were calculated (according to the technical procedure DIN 32 645) for the three electrodes and for each measured element. The LOD for PIGE/CNT/HNO3 (the electrode with narrowest calculated prediction intervals) was 2.98 × 10(-7) mol L(-1) for Cd(II), 4.83 × 10(-7) mol L(-1) for Pb(II), 3.81 × 10(-7) mol L(-1) for Cu(II), 6.79 × 10(-7) mol L(-1) for Hg(II). One of the benefits of this study was the determination of the amount of Hg(II) in the mixture of other elements.

Levels of Cd, Cu, Pb and V in marine sediments in the vicinity of the Single Buoy Moorings (SBM3) at Mina Al Fahal in the Sultanate of Oman

International Nuclear Information System (INIS)

Al-Husaini, Issa; Abdul-Wahab, Sabah; Ahamad, Rahmalan; Chan, Keziah

2014-01-01

Highlights: • Assessed metal contamination in the SBM3 marine sediments of Mina Al Fahal, Oman. • Examined heavy metal concentration levels of Cd, Cu, Pb and V. • Mean concentration in the sediments, from highest to lowest, is V > Cu > Pb > Cd. • Highest concentration of V due to waste discharges from nearby heavy tanker traffic. • ICP-OES found low concentrations of all four heavy metals; SMB3 region in good quality. - Abstract: Recently in the Sultanate of Oman, there has been a rapid surge of coastal developments. These developments cause metal contamination, which may affect the habitats and communities at and near the coastal region. As a result, a study was conducted to assess the level of metal contamination and its impact on the marine sediments in the vicinity of the Single Buoy Moorings 3 (SBM3) at Mina Al Fahal in the Sultanate of Oman. Marine subtidal sediment samples were collected from six different stations of the SBM3 for the period ranging from June 2009 to April 2010. These samples were then analyzed for their level and distribution of the heavy metals of cadmium (Cd), copper (Cu), lead (Pb) and vanadium (V). Overall, low concentrations of all four heavy metals were measured from the marine sediments, indicating that the marine at SBM3 is of good quality

Assessing comparative terrestrial ecotoxicity of Cd, Co, Cu, Ni, Pb, and Zn: The influence of aging and emission source

DEFF Research Database (Denmark)

Owsianiak, Mikolaj; Holm, Peter E.; Fantke, Peter

2015-01-01

H or soil organic carbon, emission source occasionally has an effect on reactivity of Cd, Co, Cu, Ni, Pb and Zn emitted from various anthropogenic sources followed by aging in the soil from a few years to two centuries. The uncertainties in estimating the age prevent definitive conclusions about...... the influence of aging time on the reactivity of metals from anthropogenic sources in soils. Thus, for calculating comparative toxicity potentials of man-made metal contaminations in soils, we recommend using time-horizon independent accessibility factors derived from source-specific reactive fractions....

Comparison of trace element contamination levels (Cu, Zn, Fe, Cd ...

African Journals Online (AJOL)

Comparison of trace element contamination levels (Cu, Zn, Fe, Cd and Pb) in the soft tissues of the gastropods Tympanotonus fuscatus fuscatus and Tf radula collected in the Ebrié Lagoon (Côte d'Ivoire): Evidence of the risks linked to linked to lead and.

Distribution and accumulation of Cd, Cu, Hg, Pb and Zn in the surface sediments of El Tobari Lagoon, central-East Gulf of California: An ecosystem associated with agriculture and aquaculture activities.

Science.gov (United States)

Jara-Marini, M E; Tapia-Alcaraz, J N; Dumer-Gutiérrez, J A; García-Rico, L; García-Hernández, J; Páez-Osuna, F

2013-01-01

The purpose of this research is to provide a comprehensive assessment of the concentration levels and spatial variability of cadmium (Cd), copper (Cu), mercury (Hg), lead (Pb) and zinc (Zn) in El Tobari Lagoon in surface sediments during two seasons for several geochemical variables that could explain the observed heavy metal variability. Seventy-two surface sediments samples were collected in 12 different sites of the El Tobari Lagoon. Sediment samples were dried and subjected to acid extraction using a microwave system and five metals (Cd, Cu, Hg, Pb and Zn) were measured using atomic adsorption spectrometry. A certificate sediment material and blanks were used as quality control purposes. The enrichment factor (EF) and the index of geoaccumulation (Igeo) were calculated as index of metals contamination for the sediments, using aluminum as the conservative element. The five metals examined in sediments from El Tobari Lagoon exhibited a linear correlation with Al as result of the large specific surface areas of these sediment components and the chemical affinities between them. The metals contents in sites of the El Tobari Lagoon were variable, and Cd, Cu and Hg presented a seasonal behavior. The enrichment factor and index of geoaccumulation analysis indicated that Cd and Hg exhibited a certain extent (EF for Cd ranged from 4.10 to 10.29; EF for Hg ranged from 2.77 to 12.89) of anthropogenic pollution, while Cu showed sporadic (EF ranged from 0.43 to 2.54) anthropogenic contamination. The highest concentrations of Cd, Cu and Hg were found in the sites that regularly received discharge effluents from agriculture and aquaculture.

Effect of Na, Ca and pH on simultaneous uptake of Cd, Cu, Ni, Pb, and Zn in the water flea Daphnia magna measured using stable isotopes

International Nuclear Information System (INIS)

Komjarova, I.; Blust, R.

2009-01-01

The present study investigates the effects of Na + , Ca 2+ and pH on the kinetics of Cd, Cu, Ni, Pb, and Zn uptake in Daphnia magna at low exposure concentrations measured using a stable isotope technique. Using experimental data the uptake rate constants were calculated for each metal individually on the basis of total metal concentrations. The copper uptake was not significantly affected by variations in chemical composition of the test medium. Calcium had a suppressing effect on the uptake of Cd, Ni, Pb and Zn. Specifically, Cd and Ni uptake rate constants decreased with increases in calcium concentrations from 0.1 to 2.5 mM. The uptake of Zn and Pb was significantly suppressed only at 2.5 mM Ca. The effect of sodium was less clear. There was no effect of varying sodium concentrations on the Ni uptake rate constants. Cd and Pb showed an increase in uptake rate constants at elevated sodium concentrations (2-8 mM Na + for Cd and 8 mM Na + for Pb). A bell-shaped response on increasing Na + concentrations was observed for Zn with a maximum value of uptake rate constant at the middle value (2 mM Na + ). Variation in pH of the medium affected Cd, Ni and Zn uptake processes. When Daphnia were exposed to acidic conditions (pH 6), the Cd and Ni uptake rate constants were the highest, while similarly low values were observed at neutral and basic conditions. In contrast, the uptake rates of Zn were linearly increasing with increasing pH of the medium.

Should legislation regarding maximum Pb and Cd levels in human food also cover large game meat?

Science.gov (United States)

Taggart, Mark A; Reglero, Manuel M; Camarero, Pablo R; Mateo, Rafael

2011-01-01

Game meat may be contaminated with metals and metalloids if animals reside in anthropogenically polluted areas, or if ammunition used to kill the game contaminates the meat. Muscle tissue from red deer and wild boar shot in Ciudad Real province (Spain) in 2005-06 was analysed for As, Pb, Cu, Zn, Se and Cd. Samples were collected from hunting estates within and outside an area that has been historically used for mining, smelting and refining various metals and metalloids. Meat destined for human consumption, contained more Pb, As and Se (red deer) and Pb (boar) when harvested from animals that had resided in mined areas. Age related accumulation of Cd, Zn and As (in deer) and Cd, Cu and Se (in boar) was also observed. Two boar meat samples contained high Pb, at 352 and 2408 μg/g d.w., and these were likely to have been contaminated by Pb ammunition. Likewise, 19-84% of all samples (depending on species and sampling area) had Pb levels > 0.1 μg/g w.w., the EU maximum residue level (MRL) for farm reared meat. Between 9 and 43% of samples exceeded comparable Cd limits. Such data highlight a discrepancy between what is considered safe for human consumption in popular farmed meat (chicken, beef, lamb), and what in game may often exist. A risk assessment is presented which describes the number of meals required to exceed current tolerable weekly intakes (PTWIs) for Pb and Cd, and the potential contribution of large game consumption to such intake limit criteria. Copyright © 2010 Elsevier Ltd. All rights reserved.

Effective removal of heavy metal ions Cd2+, Zn2+, Pb2+, Cu2+ from aqueous solution by polymer-modified magnetic nanoparticles

International Nuclear Information System (INIS)

Ge, Fei; Li, Meng-Meng; Ye, Hui; Zhao, Bao-Xiang

2012-01-01

We prepared novel Fe 3 O 4 magnetic nanoparticles (MNPs) modified with 3-aminopropyltriethoxysilane (APS) and copolymers of acrylic acid (AA) and crotonic acid (CA). The MNPs were characterized by transmission electron microscopy, X-ray diffraction, infra-red spectra and thermogravimetric analysis. We explored the ability of the MNPs for removing heavy metal ions (Cd 2+ , Zn 2+ , Pb 2+ and Cu 2+ ) from aqueous solution. We investigated the adsorption capacity of Fe 3 O 4 -APS-AA-co-CA at different pH in solution and metal ion uptake capacity as a function of contact time and metal ion concentration. Moreover, adsorption isotherms, kinetics and thermodynamics were studied to understand the mechanism of the synthesized MNPs adsorbing metal ions. In addition, we evaluated the effect of background electrolytes on the adsorption. Furthermore, we explored desorption and reuse of MNPs. Fe 3 O 4 -APS-AA-co-CA MNPs are excellent for removal of heavy metal ions such as Cd 2+ , Zn 2+ , Pb 2+ and Cu 2+ from aqueous solution. Furthermore, the MNPs could efficiently remove the metal ions with high maximum adsorption capacity at pH 5.5 and could be used as a reusable adsorbent with convenient conditions.

Adsorption of Pb(II), Cu(II), Cd(II), Zn(II), Ni(II), Fe(II), and As(V) on bacterially produced metal sulfides.

Science.gov (United States)

Jong, Tony; Parry, David L

2004-07-01

The adsorption of Pb(II), Cu(II), Cd(II), Zn(II), Ni(II), Fe(II) and As(V) onto bacterially produced metal sulfide (BPMS) material was investigated using a batch equilibrium method. It was found that the sulfide material had adsorptive properties comparable with those of other adsorbents with respect to the specific uptake of a range of metals and, the levels to which dissolved metal concentrations in solution can be reduced. The percentage of adsorption increased with increasing pH and adsorbent dose, but decreased with increasing initial dissolved metal concentration. The pH of the solution was the most important parameter controlling adsorption of Cd(II), Cu(II), Fe(II), Ni(II), Pb(II), Zn(II), and As(V) by BPMS. The adsorption data were successfully modeled using the Langmuir adsorption isotherm. Desorption experiments showed that the reversibility of adsorption was low, suggesting high-affinity adsorption governed by chemisorption. The mechanism of adsorption for the divalent metals was thought to be the formation of strong, inner-sphere complexes involving surface hydroxyl groups. However, the mechanism for the adsorption of As(V) by BPMS appears to be distinct from that of surface hydroxyl exchange. These results have important implications to the management of metal sulfide sludge produced by bacterial sulfate reduction.

Dynamic adsorption of mixtures of Rhodamine B, Pb (II), Cu (II) and Zn(II) ions on composites chitosan-silica-polyethylene glycol membrane

Science.gov (United States)

Mahatmanti, F. W.; Rengga, W. D. P.; Kusumastuti, E.; Nuryono

2018-04-01

The adsorption of a solution mixture of Rhodamine B, Pb (II), Cu (II) and Zn(II) was studied using dynamic methods employing chitosan-silica-polyethylene glycol (Ch/Si/P) composite membrane as an adsorptive membrane. The composite Ch/Si/P membrane was prepared by mixing a chitosan-based membrane with silica isolated from rice husk ash (ASP) and polyethylene glycol (PEG) as a plasticizer. The resultant composite membrane was a stronger and more flexible membrane than the original chitosan-based membrane as indicated by the maximum percentage of elongation (20.5 %) and minimum Young’s Modulus (80.5 MPa). The composite membrane also showed increased mechanical and hydrophilic properties compared to the chitosan membranes. The membrane was used as adsorption membrane for Pb (II), Cu (II), Cd (II) ions and Rhodamine B dyes in a dynamic system where the permeation and selectivity were determined. The permeation of the components was observed to be in the following order: Rhodamine B > Cd (II) > Pb (II) > Cu (II) whereas the selectivity was shown to decrease the order of Cu (II) > Pb (II) > Cd (II) > Rhodamine B.

Cu(I), Ag(I), Cd(II), and Pb(II) binding to biomolecules studied by perturbed angular correlation of $\\gamma$-rays (PAC) spectroscopy

CERN Multimedia

Metal ions display diverse functions in biological systems and are essential components in both protein and nucleic acid structure and function, and in control of biochemical reaction paths and signalling. Similarly, metal ions may be used to control structure and function of synthetic biomolecules, and thus be a tool in the design of molecules with a desired function. In this project we address a variety of questions concerning both the function of metal ions in natural systems, in synthetic biomolecules, and the toxic effect of some metal ions. All projects involve other experimental techniques such as NMR, EXAFS, UV-Vis, fluorescence, and CD spectroscopies providing complementary data, as well as interpretation of the experimental data by quantum mechanical calculations of spectroscopic properties. The isotopes to be employed in the proposal are the following: $^{111m}$Cd, $^{111}$Ag, $^{199m}$Hg, $^{204m}$Pb, $^{61}$Cu, $^{68m}$Cu

Pine bark as bio-adsorbent for Cd, Cu, Ni, Pb and Zn

DEFF Research Database (Denmark)

Cutillas-Barreiro, L.; Ansias-Manso, L.; Fernandez Calviño, David

2014-01-01

to the added concentrations, with Pb always showing the lowest levels. Stirred flow chamber experiments showed strong hysteresis for Pb and Cu, sorption being mostly irreversible. The differences affecting the studied heavy metals are mainly due to different affinity for the adsorption sites. Pine bark can......The objective of this work was to determine the retention of five metals on pine bark using stirred flow and batch-type experiments. Resulting from batch-type kinetic experiments, adsorption was rapid, with no significant differences for the various contact times. Adsorption was between 98 and 99...

Essential trace (Zn, Cu, Mn and toxic (Cd, Pb, Cr elements in the liver of birds from Eastern Poland

Directory of Open Access Journals (Sweden)

Komosa A.

2012-01-01

Full Text Available We have focused our study on the concentrations of essential heavy metals (Zn, Cu and Mn and non-essential trace metals (Pb, Cd and Cr in the livers of birds from Eastern Poland. The largest mean amount of Zn - as much as 279 mg/kg dry mass (d.m. - was found in mute swans. However, only in one of the analysed buzzard specimens the concentration of Zn, found to be 664 mg/kg d.m., exceeded the level indicative of poisoning for this element. Birds specializing in catching rodents accumulated Mn in their livers in a very narrow range of concentrations, around 5.0 mg/kg d.m. on average. The range of mean Mn concentrations (around 6.5 mg/kg d.m. was also found to be narrow for piscivorous birds. The highest mean levels of Pb were found in mute swans (2.7 mg/kg d.m., and the highest levels of Cd (2.0 mg/kg d.m. for rooks. Concentrations of total Cr above detection level were found in 22 specimens (53.7%, and concentration values were highest for rooks. Analyses showed that the concentrations of biogenic elements did not exceed the levels indicative of poisoning (except in one specimen. The study demonstrated that lead shots remain a hazard to water ecosystems. Pb, Cd and Cr levels in the livers of omnivorous and piscivorous species indicate the permanent presence of these elements in the environment and may confirm the thesis about the growing role of electronic waste, including metallic e-waste, in the emission of the total amount of contamination with these elements.

Effect of bamboo and rice straw biochars on the mobility and redistribution of heavy metals (Cd, Cu, Pb and Zn) in contaminated soil.

Science.gov (United States)

Lu, Kouping; Yang, Xing; Gielen, Gerty; Bolan, Nanthi; Ok, Yong Sik; Niazi, Nabeel Khan; Xu, Song; Yuan, Guodong; Chen, Xin; Zhang, Xiaokai; Liu, Dan; Song, Zhaoliang; Liu, Xingyuan; Wang, Hailong

2017-01-15

Biochar has emerged as an efficient tool to affect bioavailability of heavy metals in contaminated soils. Although partially understood, a carefully designed incubation experiment was performed to examine the effect of biochar on mobility and redistribution of Cd, Cu, Pb and Zn in a sandy loam soil collected from the surroundings of a copper smelter. Bamboo and rice straw biochars with different mesh sizes (Heavy metal concentrations in pore water were determined after extraction with 0.01 M CaCl 2 . Phytoavailable metals were extracted using DTPA/TEA (pH 7.3). The European Union Bureau of Reference (EUBCR) sequential extraction procedure was adopted to determine metal partitioning and redistribution of heavy metals. Results showed that CaCl 2 -and DTPA-extractable Cd, Cu, Pb and Zn concentrations were significantly (p soils, especially at 5% application rate, than those in the unamended soil. Soil pH values were significantly correlated with CaCl 2 -extractable metal concentrations (p metal fractions, and the effect was more pronounced with increasing biochar application rate. The effect of biochar particle size on extractable metal concentrations was not consistent. The 5% rice straw biochar treatment reduced the DTPA-extractable metal concentrations in the order of Cd metals were mainly bound in the soil organic matter fraction. The results demonstrated that the rice straw biochar can effectively immobilize heavy metals, thereby reducing their mobility and bioavailability in contaminated soils. Copyright © 2016 Elsevier Ltd. All rights reserved.

T-x-y diagrams for reciprocal systems PbX + CdI2 = CdX + PbI2 (X=S, Se, Te)

International Nuclear Information System (INIS)

Odin, I.N.

2001-01-01

The present research is undertaken in search of the new complex phases with interesting physical properties. The synthesized samples was analyzed by differential thermal, X-ray diffraction and microstructural methods. The diagonal cross-section CdTe - PbI 2 of the mutual PbTe + CdI 2 = CdTe + PbI 2 system is stable. The T-x phase diagram of the CdTe - PbI 2 system possess eutectic type, the coordinates of eutectic point is 657 ± 2 K, 15 ± 1 mol. % of CdTe. The lead iodide based solid solutions with the mixed structure and the CdTe based solid solutions take place in the equilibria. Solid CdTe dissolves 0.2 mol. % PbI 2 . The fields of the primary crystallization of the CdTe, Pb 1-x Cd x I 2 , PbTe based solid solutions are on the liquidus surface [ru

Removal of Heavy Metals Pb2+, Cu2+, Zn2+, Cd2+, Ni2+, Co2+ and Fe3+ from Aqueous Solutions by using Xanthium Pensylvanicum

Directory of Open Access Journals (Sweden)

Jaber SALEHZADEH

2013-11-01

Full Text Available The hazardous ill effects of heavy metals on the environment and public health is a matter of serious concern. Biosorption is emerging as a sustainable effective technology. Heavy metals in water resources are one of the most important environmental problems of countries. The intensification of industrial activity and environmental stress greatly contributes to the significant rise of heavy metal pollution in water resources making threats on terrestrial and aquatic life. The toxicity of metal pollution is slow and interminable, as these metal ions are non bio-degradable. The adsorption capacity of Xanthium Pensylvanicum towards metal ions such as Pb2+, Cu2+, Zn2+, Cd2+, Ni2+, Co2+ and Fe3+, was studied. The adsorption capacity was performed by batch experiments as a function of process parameters (such as sorption time and pH. Experimental results showed that the removal percentages increasing of metal ions at pH=4, initial concentration of metal ions 10 mg/L, and after 90 min of shaking was: Zn2+ < Cd2+ < Cu2+ < Pb2+ < Ni2+ < Fe3+ < Co2+.

Geographical and pedological drivers of distribution and risks to soil fauna of seven metals (Cd, Cu, Cr, Ni, Pb, V and Zn) in British soils

International Nuclear Information System (INIS)

Spurgeon, David J.; Rowland, Philip; Ainsworth, Gillian; Rothery, Peter; Long, Sara; Black, Helaina I.J.

2008-01-01

Concentrations of seven metals were measured in over 1000 samples as part of an integrated survey. Sixteen metal pairs were significantly positively correlated. Cluster analysis identified two clusters. Metals from the largest (Cr, Cu, Ni, V, Zn), but not the smallest (Cd, Pb) cluster were significantly negatively correlated with spatial location and soil pH and organic matter content. Cd and Pb were not correlated with these parameters, due possibly to the masking effect of recent extensive release. Analysis of trends with soil properties in different habitats indicated that general trends may not necessarily be applicable to all areas. A risk assessment indicated that Zn poses the most widespread direct risk to soil fauna and Cd the least. Any risks associated with high metal concentrations are, however, likely to be greatest in habitats such as arable and horticultural, improved grassland and built up areas where soil metal concentrations are more frequently elevated. - Metal distributions and risks explained by balance of sources and soil property effects on fate

Geographical and pedological drivers of distribution and risks to soil fauna of seven metals (Cd, Cu, Cr, Ni, Pb, V and Zn) in British soils.

Science.gov (United States)

Spurgeon, David J; Rowland, Philip; Ainsworth, Gillian; Rothery, Peter; Long, Sara; Black, Helaina I J

2008-05-01

Concentrations of seven metals were measured in over 1000 samples as part of an integrated survey. Sixteen metal pairs were significantly positively correlated. Cluster analysis identified two clusters. Metals from the largest (Cr, Cu, Ni, V, Zn), but not the smallest (Cd, Pb) cluster were significantly negatively correlated with spatial location and soil pH and organic matter content. Cd and Pb were not correlated with these parameters, due possibly to the masking effect of recent extensive release. Analysis of trends with soil properties in different habitats indicated that general trends may not necessarily be applicable to all areas. A risk assessment indicated that Zn poses the most widespread direct risk to soil fauna and Cd the least. Any risks associated with high metal concentrations are, however, likely to be greatest in habitats such as arable and horticultural, improved grassland and built up areas where soil metal concentrations are more frequently elevated.

Evaluation de la contamination de la chaîne trophique par les éléments traces (Cu, Co, Zn, Pb, Cd, U, V et As dans le bassin de la Lufira supérieure (Katanga/RD Congo

Directory of Open Access Journals (Sweden)

Katemo Manda, B.

2010-01-01

Full Text Available Evaluation of Contamination of the Food Chain by Trace Elements (Cu, Co, Zn, Pb, Cd, U, V and As in the Basin of the Upper Lufira (Katanga/DR Congo. Seven trace elements (Cu, Co, Zn, Cd, Pb, U, V and As were analyzed using a HR ICP-MS in samples of water, plankton, leaves of Phragmites australis, muscle and gills of three fish species (Oreochromis macrochir, Tilapia rendalli, Clarias gariepinus collected in the basin of the upper Lufira. The results indicate a high copper (70.9 ppm and cobalt (32.3 ppm content in the effluent of complex hydrometallurgical Shituru. If contamination of rivers decreases with distance from the pollution source, the values are very high in lake Tshangalele for plankton and leaves of P. australis. For fish, the results indicate that Pb, U, V, Cu, Co and Cd accumulates preferentially in the gills but Zn accumulates more in the muscles. As accumulates in the same order of magnitude in both organs. These results confirm the pollution of the basin by the effluents from Lufira complex hydrometallurgical Shituru.

Comparison of trace element contamination levels (Cu, Zn, Fe, Cd ...

African Journals Online (AJOL)

SERVER

2008-03-18

Mar 18, 2008 ... Chemical analysis of the trace elements in the soft tissues. The trace elements of interest (Cu, Zn, Fe, Pb, Cd) were then determined in the digested solutions, using Thermoelemental type. M6 brand of an atomic absorption Spectrometer equipped with a flame operated atomisation system and a deuterium ...

Distribution of Cd, Ck, Pb and Zn in Soil and Vegetation Compartments in Stands of Five Boreal Tree Species in N.E. Sweden

International Nuclear Information System (INIS)

Alriksson, A.; Eriksson, H. M.

2001-01-01

Concentrations and total quantity of cadmium (Cd), cupper (Cu),lead (Pb) and zink (Zn) were determined in biomass and soil compartments in a replicated tree species experiment with 27-yr-old stands growing on former farmland in N.E. Sweden. Sequential extractions of soil samples were performed in order to estimate the exchangeable and an organically bound fraction of each element. The tree species included were Picea abies (L.)H. Karst., Pinus sylvestris L., Pinus contorta Dougl., Larix sibirica Ledeb., and Betula pendula Roth.Tree species influenced the rate of removal of Cu, Pb and Zn in case of stemwood harvesting, and of Cd, Cu and Zn in the case of whole-tree harvesting. B. pendula and P. abies had higher quantities and average concentrations of Zn in the biomass. For all species, >50% of the Zn in the stems was found in the bark. P. abies and L. sibirica had higher quantities of Cu in the biomass than the other species.P. abies and P. contorta had high quantities of Cd in the biomass in relation to the other species. Branches and stembark contained high concentrations of Cd and Pb in relation to foliage and stemwood. Dead branches had especially high concentrations of Pb. The high accumulation rate of Zn in the biomass of B. pendula was related to a low exchangeable amount of Zn in the A horizon. In the superficial centimeters of the A horizon, a depletion similar to that found for Zn was detected for Cu, whereas for Cd and Pb, no correlations were found between quantities of elements in the trees and element pools in the soil

Square-wave anodic-stripping voltammetric determination of Cd, Pb, and Cu in a hydrofluoric acid solution of siliceous spicules of marine sponges (from the Ligurian Sea, Italy, and the Ross Sea, Antarctica)

Energy Technology Data Exchange (ETDEWEB)

Truzzi, C.; Annibaldi, A.; Illuminati, S.; Bassotti, E.; Scarponi, G. [Polytechnic University of Marche, Ancona (Italy). Department of Marine Science

2008-09-15

Square-wave anodic-stripping voltammetry (SWASV) was set up and optimized for simultaneous determination of cadmium, lead, and copper in siliceous spicules of marine sponges, directly in the hydrofluoric acid solution ({proportional_to}0.55 mol L{sup -1} HF, pH {proportional_to}1.9). A thin mercury-film electrode (TMFE) plated on to an HF-resistant epoxy-impregnated graphite rotating-disc support was used. The optimum experimental conditions, evaluated also in terms of the signal-to-noise ratio, were as follows: deposition potential -1100 mV vs. Ag/AgCl, KCl 3 mol L{sup -1}, deposition time 3-10 min, electrode rotation 3000 rpm, SW scan from -1100 mV to +100 mV, SW pulse amplitude 25 mV, frequency 100 Hz, {delta}E{sub step} 8 mV, t{sub step} 100 ms, t{sub wait} 60 ms, t{sub delay} 2 ms, t{sub meas} 3 ms. Under these conditions the metal peak potentials were Cd -654{+-}1 mV, Pb -458 {+-} 1 mV, Cu -198{+-}1 mV. The electrochemical behaviour was reversible for Pb, quasi-reversible for Cd, and kinetically controlled (possibly following chemical reaction) for Cu. The linearity of the response with concentration was verified up to {proportional_to}4 {mu}g L{sup -1} for Cd and Pb and {proportional_to}20 {mu}g L{sup -1} for Cu. The detection limits were 5.8 ng L{sup -1}, 3.6 ng L{sup -1}, and 4.3 ng L{sup -1} for Cd, Pb, and Cu, respectively, with t{sub d}=5 min. The method was applied for determination of the metals in spicules of two specimens of marine sponges (Demosponges) from the Portofino natural reserve (Ligurian Sea, Italy, Petrosia ficiformis) and Terra Nova Bay (Ross Sea, Antarctica, Sphaerotylus antarcticus). The metal contents varied from tens of ng g{sup -1} to {proportional_to}1 {mu}g g{sup -1}, depending on the metal considered and with significant differences between the two sponge species. (orig.)

Extremely High Phosphate Sorption Capacity in Cu-Pb-Zn Mine Tailings.

Science.gov (United States)

Huang, Longbin; Li, Xiaofang; Nguyen, Tuan A H

2015-01-01

Elevated inorganic phosphate (Pi) concentrations in pore water of amended tailings under direct revegetation may cause toxicity in some native woody species but not native forbs or herb species, all of which are key constituents in target native plant communities for phytostabilizing base metal mine tailings. As a result, Pi sorption capacity has been quantified by a conventional batch procedure in three types of base metal mine tailings sampled from two copper (Cu)-lead (Pb)-zinc (Zn) mines, as the basis for Pi-fertiliser addition. It was found that the Pi-sorption capacity in the tailings and local soil was extremely high, far higher than highly weathered agricultural soils in literature, but similar to those of volcanic ash soils. The Langmuir P-sorption maximum was up to 7.72, 4.12, 4.02 and 3.62 mg P g-1 tailings, in the fresh tailings of mixed Cu-Pb-Zn streams (MIMTD7), the weathered tailings of mixed Cu-Pb-Zn streams (MIMTD5), EHM-TD (fresh Cu-stream, high magnetite content) and local soil (weathered shale and schist), respectively. Physicochemical factors highly correlated with the high Pi-sorption in the tailings were fine particle distribution, oxalate and dithionite-citrate-bicarbonate extractable Fe (FeO and Fed), oxalate-extractable Al and Mn, and the levels of soluble Cd and Zn, and total S and Fe. Large amounts of amorphous Fe oxides and oxyhydroxides may have been formed from the oxidation of pyritic materials and redox cycles of Fe-minerals (such as pyrite (FeS2), ankerite (Ca(Fe Mg)(CO3)2 and siderite (FeCO3), as indicated by the extractable FeO values. The likely formation of sparingly soluble Zn-phosphate in the Pb-Zn tailings containing high levels of Zn (from sphalerite ((Zn,Fe)S, ZnS, (Zn,Cd)S)) may substantially lower soluble Zn levels in the tailings through high rates of Pi-fertiliser addition. As a result, the possibility of P-toxicity in native plant species caused by the addition of soluble phosphate fertilizers would be minimal.

Solidified structure of Al-Pb-Cu alloys

International Nuclear Information System (INIS)

Ikeda, Tetsuyuki; Nishi, Seiki; Kumeuchi, Hiroyuki; Tatsuta, Yoshinori.

1986-01-01

Al-Pb-Cu alloys were cast into bars or plates in different two metal mold casting processes in order to suppress gravity segregation of Pb and to achieve homogeneous dispersion of Pb phase in the alloys. Solidified structures were analyzed by a video-pattern-analyzer. Plate castings 15 to 20 mm in thickness of Al-Pb-1 % Cu alloy containing Pb up to 5 % in which Pb phase particles up to 10 μm disperse are achieved through water cooled metal mold casting. The plates up to 5 mm in thickness containing Pb as much as 8 to 10 % cast in this process have dispersed Pb particles up to 5 μm in diameter in the surface layer. Al-8 % Pb-1 % Cu alloy bars 40 mm in diameter and 180 mm in height in which gravity segregation of Pb is prevented can be cast by movable and water sprayed metal mold casting at casting temperature 920 deg C and mold moving speed 1.0 mm/s. Pb phase particles 10 μm in mean size are dispersed in the bars. (author)

EXPLORING POSSIBILITIES OF CULTIVATION A UNPOLLUTED PLANT PRODUCE IN Pb AND Cd CONTAMINATED SITES

Directory of Open Access Journals (Sweden)

Atanas TOMOV

2006-02-01

Full Text Available The control of heavy metals in such way that soil function and product quality are not impeded is a prerequisite to sustainable agriculture. Growing anthropogenic fl uxes of toxic heavy metals in agro-ecosystems affect on purity of farm products and soil fertility. In the article we describe a fi eld experiment – cultivation of potatoes on soil with a medium level of pollution / Zn, Cu, Pb, Cd etc/. We studied the most toxic of them – Pb and Cd; as well as the possibilities for reducing their phytoavailability and accumulation in potatoes tubers, applying soil amendments.

Dynamic modelling of atmospherically-deposited Ni, Cu, Zn, Cd and Pb in Pennine catchments (northern England)

International Nuclear Information System (INIS)

Tipping, E.; Rothwell, J.J.; Shotbolt, L.; Lawlor, A.J.

2010-01-01

Simulation modelling with CHUM-AM was carried out to investigate the accumulation and release of atmospherically-deposited heavy metals (Ni, Cu, Zn, Cd and Pb) in six moorland catchments, five with organic-rich soils, one with calcareous brown earths, in the Pennine chain of northern England. The model considers two soil layers and a third layer of weathering mineral matter, and operates on a yearly timestep, driven by deposition scenarios covering the period 1400-2010. The principal processes controlling heavy metals are competitive solid-solution partitioning of solutes, chemical interactions in solution, and chemical weathering. Agreement between observed and simulated soil metal pools and surface water concentrations for recent years was generally satisfactory, the results confirming that most contemporary soil metal is from atmospheric pollution. Metals in catchments with organic-rich soils show some mobility, especially under more acid conditions, but the calcareous mineral soils have retained nearly all anthropogenic metal inputs. Complexation by dissolved organic matter and co-transport accounts for up to 80% of the Cu in surface waters. - CHUM-AM is applied to six differing moorland catchments to account for the accumulation and leaching of atmospherically-deposited trace metals over the past several centuries.

Dynamic modelling of atmospherically-deposited Ni, Cu, Zn, Cd and Pb in Pennine catchments (northern England)

Energy Technology Data Exchange (ETDEWEB)

Tipping, E., E-mail: et@ceh.ac.u [Centre for Ecology and Hydrology, Lancaster Environment Centre, Library Avenue, Bailrigg, Lancaster LA1 4AP (United Kingdom); Rothwell, J.J. [Upland Environments Research Unit, School of Environment and Development, University of Manchester, Manchester M13 9PL (United Kingdom); Shotbolt, L. [Geography Department, Queen Mary, University of London, Mile End Road, London E1 4NS (United Kingdom); Lawlor, A.J. [Centre for Ecology and Hydrology, Lancaster Environment Centre, Library Avenue, Bailrigg, Lancaster LA1 4AP (United Kingdom)

2010-05-15

Simulation modelling with CHUM-AM was carried out to investigate the accumulation and release of atmospherically-deposited heavy metals (Ni, Cu, Zn, Cd and Pb) in six moorland catchments, five with organic-rich soils, one with calcareous brown earths, in the Pennine chain of northern England. The model considers two soil layers and a third layer of weathering mineral matter, and operates on a yearly timestep, driven by deposition scenarios covering the period 1400-2010. The principal processes controlling heavy metals are competitive solid-solution partitioning of solutes, chemical interactions in solution, and chemical weathering. Agreement between observed and simulated soil metal pools and surface water concentrations for recent years was generally satisfactory, the results confirming that most contemporary soil metal is from atmospheric pollution. Metals in catchments with organic-rich soils show some mobility, especially under more acid conditions, but the calcareous mineral soils have retained nearly all anthropogenic metal inputs. Complexation by dissolved organic matter and co-transport accounts for up to 80% of the Cu in surface waters. - CHUM-AM is applied to six differing moorland catchments to account for the accumulation and leaching of atmospherically-deposited trace metals over the past several centuries.

Stable and metastable phases in reciprocal systems PbSe + Ag2I2 Ag2Se + PbI2 and PbSe + CdI2 = CdSe + PbI2

International Nuclear Information System (INIS)

Odin, I.N.; Grin'ko, V.V.; Kozlovskij, V.F.; Safronov, E.V.

2005-01-01

Mutual system PbSe + Ag 2 I 2 = Ag 2 Se + PbI 2 is investigated. It is shown that diagonal Ag 2 Se-PbI 2 is stable. Liquidus surface and isothermal section at 633 K of phase diagram of PbSe-Ag 2 Se-PbI 2 system are built. Transformations directing to crystallization metastable ternary compound forming in PbSe-PbI 2 system and metastable polytype modifications of lead iodide in PbSe-Ag 2 Se-PbI 2 system at 620-685 K are studied. By hardening from molten state (1150-1220 K) new interstitial metastable phases crystallizing in CdCl 2 structural type are obtained in PbSe-Ag 2 Se-PbI 2 and PbSe + CdI 2 = CdSe + PbI 2 systems [ru

Comprehensive risk assessment and source identification of selected heavy metals (Cu, Cd, Pb, Zn, Hg, As) in tidal saltmarsh sediments of Shuangtai Estuary, China.

Science.gov (United States)

Liu, Chang-Fa; Li, Bing; Wang, Yi-Ting; Liu, Yuan; Cai, Heng-Jiang; Wei, Hai-Feng; Wu, Jia-Wen; Li, Jin

2017-10-06

Heavy metals do not degrade and can remain in the environment for a long time. In this study, we analyzed the effects of Cu, Cd, Pb, Zn, Hg, and As, on environmental quality, pollutant enrichment, ecological hazard, and source identification of elements in sediments using data collected from samples taken from Shuangtai tidal wetland. The comprehensive pollution indices were used to assess environmental quality; fuzzy similarity analysis and geoaccumulation index were used to analyze pollution accumulation; correlation matrix, principal component analysis, and clustering analysis were used to analyze pollution source; environmental risk index and ecological risk index were used to assess ecological risk. The results showed that the environmental quality was either clean or almost clean. Pollutant enrichment analysis showed that the four sub-regions had similar pollution-causing metals to the background values of the soil element of the Liao River Plain, which were ranked according to their similarity. Source identification showed that all the elements were correlated. Ecological hazard analysis showed that the environmental risk index in the study area was less than zero, posing a low ecological risk. Ecological risk of the six elements was as follows: As > Cd > Hg > Cu > Pb > Zn.

Effect of Low-Melting Metals (Pb, Bi, Cd, In) on the Structure, Phase Composition, and Properties of Casting Al-5% Si-4% Cu Alloy

Science.gov (United States)

Yakovleva, A. O.; Belov, N. A.; Bazlova, T. A.; Shkalei, I. V.

2018-01-01

The effect of low-melting metals (Pb, Bi, Cd, In) on the structure, phase composition, and properties of the Al-5% Si-4% Cu alloy was studied using calculations. Polythermal sections have been reported, which show that the considered systems are characterized by the presence of liquid regions and monotectic reactions. The effect of low-melting metals on the microstructure and hardening of base alloy in the cast and heat-treated states has been studied.

Heavy metals (Cd, Pb, Cu, Zn) in mudfish and sediments from three ...

African Journals Online (AJOL)

The percentage of uranium present in sediment samples (analysed by energy dispersive X-ray spectrometry) from the three dams was 9.0 % (SD 2.1%). In sediment it was found that cation exchange capacity measurements and the dolomitic hard water and high pH of the Mooi River water effectively \\'detoxified\\' Cd and Pb, ...

Systems of Rb2I2-CdI2-PbI2 and Cs2I2-CdI2-PbI2

International Nuclear Information System (INIS)

Volchanskaya, V.V.; Il'yasov, I.I.

1979-01-01

The Rb 2 I 2 -CdI 2 -PbI 2 and Cs 2 I 2 -CdI 2 -PbI 2 triple systems have been studied, using the visual-polythermal method. The liquidus of the systems researched consists of the components and compounds crystallization fields: 2RbIxCdI 2 , 2RbIxRbI 2 , RbIxPbI 2 and 2CsIxCdI 2 , 4CsIxPbI 2 , CsIxPbI 2 , respectively. The crystallization fields converge in four non-variant points at 360, 280, 205 and 192 deg C in the Rb 2 I 2 -CdI 2 -PbI 2 system and at 375, 368, 208 and 190 deg C in the CsI 2 -CdI 2 -PbI 2 system

Extremely High Phosphate Sorption Capacity in Cu-Pb-Zn Mine Tailings.

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Longbin Huang

Full Text Available Elevated inorganic phosphate (Pi concentrations in pore water of amended tailings under direct revegetation may cause toxicity in some native woody species but not native forbs or herb species, all of which are key constituents in target native plant communities for phytostabilizing base metal mine tailings. As a result, Pi sorption capacity has been quantified by a conventional batch procedure in three types of base metal mine tailings sampled from two copper (Cu-lead (Pb-zinc (Zn mines, as the basis for Pi-fertiliser addition. It was found that the Pi-sorption capacity in the tailings and local soil was extremely high, far higher than highly weathered agricultural soils in literature, but similar to those of volcanic ash soils. The Langmuir P-sorption maximum was up to 7.72, 4.12, 4.02 and 3.62 mg P g-1 tailings, in the fresh tailings of mixed Cu-Pb-Zn streams (MIMTD7, the weathered tailings of mixed Cu-Pb-Zn streams (MIMTD5, EHM-TD (fresh Cu-stream, high magnetite content and local soil (weathered shale and schist, respectively. Physicochemical factors highly correlated with the high Pi-sorption in the tailings were fine particle distribution, oxalate and dithionite-citrate-bicarbonate extractable Fe (FeO and Fed, oxalate-extractable Al and Mn, and the levels of soluble Cd and Zn, and total S and Fe. Large amounts of amorphous Fe oxides and oxyhydroxides may have been formed from the oxidation of pyritic materials and redox cycles of Fe-minerals (such as pyrite (FeS2, ankerite (Ca(Fe Mg(CO32 and siderite (FeCO3, as indicated by the extractable FeO values. The likely formation of sparingly soluble Zn-phosphate in the Pb-Zn tailings containing high levels of Zn (from sphalerite ((Zn,FeS, ZnS, (Zn,CdS may substantially lower soluble Zn levels in the tailings through high rates of Pi-fertiliser addition. As a result, the possibility of P-toxicity in native plant species caused by the addition of soluble phosphate fertilizers would be minimal.

Determination of mobile form contents of Zn, Cd, Pb and Cu in soil extracts by combined stripping voltammetry

International Nuclear Information System (INIS)

Nedeltcheva, T.; Atanassova, M.; Dimitrov, J.; Stanislavova, L.

2005-01-01

The amount of mobile forms of Zn, Pb, Cd and Cu in extracts obtained by treating soil samples with ammonium nitrate were determined by an appropriate combination of anodic and cathodic stripping voltammetry with hanging mercury drop electrode. Every analysis required three mercury drops: on the first one, zinc was determined; on the second, cadmium and lead; on the third, copper was determined. Zinc, lead and cadmium were determined by conventional differential-pulse anodic stripping voltammetry. For copper determination, adsorptive differential-pulse cathodic stripping voltammetry with amalgamation using chloride ions as a complexing agent was applied. The standard deviation of the results was from 1 to 10% depending on the metal content in the sample. Voltammetric results were in good agreement with the AAS analysis. No microwave digestion of soil extracts was necessary

Determination of mobile form contents of Zn, Cd, Pb and Cu in soil extracts by combined stripping voltammetry

Energy Technology Data Exchange (ETDEWEB)

Nedeltcheva, T. [Department of Analytical Chemistry, University of Chemical Technology and Metallurgy, 8 Kl. Ohridsi Blvd., 1756 Sofia (Bulgaria)]. E-mail: nedel@uctm.edu; Atanassova, M. [Department of Analytical Chemistry, University of Chemical Technology and Metallurgy, 8 Kl. Ohridsi Blvd., 1756 Sofia (Bulgaria); Dimitrov, J. [N. Pushkarov Institute of Soil Science and Agroecology, 7 Shosse Bankya St., 1080 Sofia (Bulgaria); Stanislavova, L. [N. Pushkarov Institute of Soil Science and Agroecology, 7 Shosse Bankya St., 1080 Sofia (Bulgaria)

2005-01-10

The amount of mobile forms of Zn, Pb, Cd and Cu in extracts obtained by treating soil samples with ammonium nitrate were determined by an appropriate combination of anodic and cathodic stripping voltammetry with hanging mercury drop electrode. Every analysis required three mercury drops: on the first one, zinc was determined; on the second, cadmium and lead; on the third, copper was determined. Zinc, lead and cadmium were determined by conventional differential-pulse anodic stripping voltammetry. For copper determination, adsorptive differential-pulse cathodic stripping voltammetry with amalgamation using chloride ions as a complexing agent was applied. The standard deviation of the results was from 1 to 10% depending on the metal content in the sample. Voltammetric results were in good agreement with the AAS analysis. No microwave digestion of soil extracts was necessary.

Spatial and Temporal Distribution of Trace Metals (Cd, Cu, Ni, Pb, and Zn in Coastal Waters off the West Coast of Taiwan

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Kuo-Tung Jiann

2014-01-01

Full Text Available Surface water samples were collected along the west coast of Taiwan during two expedition cruises which represent periods of different regional climatic patterns. Information on hydrochemical parameters such as salinity, nutrients, suspended particulate matter (SPM, and Chlorophyll a concentrations were obtained, and dissolved and particulate trace metal (Cd, Cu, Ni, Pb, and Zn concentrations were determined. Spatial variations were observed and the differences were attributed to (1 influence of varying extents of terrestrial inputs from the mountainous rivers of Taiwan to the coast, and (2 urbanization and industrialization in different parts of the island. Geochemical processes such as desorption (Cd and adsorption to sinking particles (Pb also contributed to the variability of trace metal distributions in coastal waters. Results showed temporal variations in chemical characteristics in coastal waters as a consequence of prevailing monsoons. During the wet season when river discharges were higher, the transport of particulate metals was elevated due to increased sediment loads. During the dry season, lower river discharges resulted in a lesser extent of estuarine dilution effect for chemicals of anthropogenic sources, indicated by higher dissolved concentrations present in coastal waters associated with slightly higher salinity.

Genotoxicity and cytotoxicity response to environmentally relevant complex metal mixture (Zn, Cu, Ni, Cr, Pb, Cd) accumulated in Atlantic salmon (Salmo salar). Part I: importance of exposure time and tissue dependence.

Science.gov (United States)

Stankevičiūtė, Milda; Sauliutė, Gintarė; Svecevičius, Gintaras; Kazlauskienė, Nijolė; Baršienė, Janina

2017-10-01

Health impact of metal mixture at environment realistic concentrations are difficult to predict especially for long-term effects where cause-and-effect relationships may not be directly obvious. This study was aimed to evaluate metal mixture (Zn-0.1, Cu-0.01, Ni-0.01, Cr-0.01, Pb-0.005 and Cd-0.005 mg/L, respectively for 1, 2, 4, 7, 14 and 28 days at concentrations accepted for the inland waters in EU) genotoxicity (micronuclei, nuclear buds, nuclear buds on filament), cytotoxicity (8-shaped nuclei, fragmented-apoptotic erythrocytes), bioaccumulation, steady-state and the reference level of geno-cytotoxicity in hatchery-reared Atlantic salmon tissues. Metals accumulated mostly in gills and kidneys, to the lesser extent in the muscle. Uptake of metals from an entire mixture in the fish for 14 days is sufficient to reach steady-state Cr, Pb concentrations in all tissues; Zn, Cu-in kidneys and muscle, Ni-in liver, kidneys, muscle and Cd-in muscle. Treatment with metal mixture significantly increased summed genotoxicity levels at 7 days of exposure in peripheral blood and liver erythrocytes, at 14 days of exposure in gills and kidney erythrocytes. Significant elevation of cytotoxicity was detected after 2 and 14 days of exposure in gills erythrocytes and after 28 days-in peripheral blood erythrocytes. The amount of Cu, Cr, Pb and Cd accumulated in tissues was dependent upon duration of exposure; nuclear buds, 8-shaped nuclei frequencies also were dependent upon duration of exposure. This study indicates that metals at low levels when existing in mixture causes significant geno-cytotoxicity responses and metals bioaccumulation in salmon.

Associations between standardized school performance tests and mixtures of Pb, Zn, Cd, Ni, Mn, Cu, Cr, Co, and V in community soils of New Orleans

International Nuclear Information System (INIS)

Zahran, Sammy; Mielke, Howard W.; Weiler, Stephan; Hempel, Lynn; Berry, Kenneth J.; Gonzales, Christopher R.

2012-01-01

In New Orleans a strong inverse association was previously identified between community soil lead and 4th grade school performance. This study extends the association to zinc, cadmium, nickel, manganese, copper, chromium, cobalt, and vanadium in community soil and their comparative effects on 4th grade school performance. Adjusting for poverty, food security, racial composition, and teacher-student ratios, regression results show that soil metals variously reduce and compress student scores. Soil metals account for 22%–24% while food insecurity accounts for 29%–37% of variation in school performance. The impact on grade point averages were Ni > Co > Mn > Cu ∼Cr ∼ Cd > Zn > Pb, but metals are mixtures in soils. The quantities of soil metal mixtures vary widely across the city with the largest totals in the inner city and smallest totals in the outer city. School grade point averages are lowest where the soil metal mixtures and food insecurity are highest. - Highlights: ► Mixtures of metals vary; largest totals in the inner city and lowest in the outer city. ► An inverse association between soil Pb and 4th grade school performance is known. ► Assuming the same exposure pathway, multiple metals are compared to performance. ► Soil metals account for 22%–24% of variation in school test performance. ► Soil metal plus food insecurity accounts for 54% of explained variance. - Controlling for potential confounding variables, the accumulation of metals (Pb, Zn, Cd, Ni, Mn, Cu, Cr, and Co) in neighborhood soils is significantly negatively associated with 4th grade school performance on standardized tests in New Orleans.

Dissolved and labile concentrations of Cd, Cu, Pb, and Zn in the South Fork Coeur d'Alene River, Idaho: Comparisons among chemical equilibrium models and implications for biotic ligand models

Science.gov (United States)

Balistrieri, L.S.; Blank, R.G.

2008-01-01

In order to evaluate thermodynamic speciation calculations inherent in biotic ligand models, the speciation of dissolved Cd, Cu, Pb, and Zn in aquatic systems influenced by historical mining activities is examined using equilibrium computer models and the diffusive gradients in thin films (DGT) technique. Several metal/organic-matter complexation models, including WHAM VI, NICA-Donnan, and Stockholm Humic model (SHM), are used in combination with inorganic speciation models to calculate the thermodynamic speciation of dissolved metals and concentrations of metal associated with biotic ligands (e.g., fish gills). Maximum dynamic metal concentrations, determined from total dissolved metal concentrations and thermodynamic speciation calculations, are compared with labile metal concentrations measured by DGT to assess which metal/organic-matter complexation model best describes metal speciation and, thereby, biotic ligand speciation, in the studied systems. Results indicate that the choice of model that defines metal/organic-matter interactions does not affect calculated concentrations of Cd and Zn associated with biotic ligands for geochemical conditions in the study area, whereas concentrations of Cu and Pb associated with biotic ligands depend on whether the speciation calculations use WHAM VI, NICA-Donnan, or SHM. Agreement between labile metal concentrations and dynamic metal concentrations occurs when WHAM VI is used to calculate Cu speciation and SHM is used to calculate Pb speciation. Additional work in systems that contain wide ranges in concentrations of multiple metals should incorporate analytical speciation methods, such as DGT, to constrain the speciation component of biotic ligand models. ?? 2008 Elsevier Ltd.

Photovoltaic properties of sintered CdS/CdTe solar cells doped with Cu

International Nuclear Information System (INIS)

Park, J.W.; Ahn, B.T.; Im, H.B.; Kim, C.S.

1992-01-01

In this paper, all polycrystalline CdS/CdTe solar cells doped with Cu are prepared by a screen printing and sintering method. Cell parameters of the sintered CdS/CdTe solar cells have been investigated in an attempt to find out the optimum doping conditions and concentrations of Cu by adding various amounts of CuCl 2 either into CdTe layer or into back contact carbon layer. Cell parameters of the sintered CdS/CdTe solar cells which contained various amounts of CuCl 2 in the CdTe layers before sintering stay at about the same values as the amount of CuCl 2 increases up to 25 ppm, and then decreases sharply as the amount of CuCl 2 further increases. The Cu added in the CdTe layer diffuses into the CdS layer during the sintering of the CdS-CdTe composite at 625 degrees C to densify the CdTe layer and causes the decrease in the optical transmission of CdS resulting in the degradation of the cell performance. In case the Cu dopant was dispersed in the back carbon paint and was followed by annealing, all cell parameters are improved significantly compared with those fabricated by adding CuCl 2 in the CdTe layer before sintering. A sintered CdS/CdTe solar cell which contained 25 ppm CuCl 2 in the carbon paste and was annealed at 350 degrees C for 10 min shows the highest efficiency. The efficiency of this cell is 12.4% under solar irradiation with an intensity of 80.4 mW/cm 2

Diffusion and influence of Cu on properties of CdTe thin films and CdTe/CdS cells

Energy Technology Data Exchange (ETDEWEB)

Dzhafarov, T.D.; Yesilkaya, S.S.; Yilmaz Canli, N.; Caliskan, M. [Department of Physics, Yildiz Technical University, Davutpasa, 34210 Istanbul (Turkey)

2005-01-31

The effective diffusion coefficients of Cu for thermal and photodiffusion in the CdTe films have been estimated from resistivity versus duration of thermal or photoannealing curves. In the temperature range 60-200{sup o}C the effective coefficient of thermal diffusion (D{sub t}) and photodiffusion (D{sub ph}) are described as D{sub t}=7.3x10{sup -7}exp(-0.33/kT) and D{sub ph}=4.7x10{sup -8}exp(-0.20/kT). It is found that the diffusion doping of CdTe thin films by Cu at 400{sup o}C results in a sharp decrease of resistivity up to 7 orders of magnitude of p-type material, depending on thickness of Cu film. The comparative study of performance of CdTe(Cu)/CdS and CdTe/CdS cells has been studied. It is shown that the diffusion doping of CdTe film by Cu increases efficiency of CdTe(Cu)/CdS cells from 0.9% to 6.8%. The degradation of photovoltaic parameters of CdTe(Cu)/CdS cell, during testing under forward and reverse bias at room temperature, proceeds at a larger rate than those of CdTe/CdS cell without Cu. The degradation of performance of CdTe(Cu)/CdS cells is tentatively assigned to electrodiffusion of Cu in CdTe, resulting in redistribution of concentration of Cu-related centers in CdTe film and heterojunction region.

Optical properties of CuCdTeO thin films sputtered from CdTe-CuO composite targets

Energy Technology Data Exchange (ETDEWEB)

Mendoza-Galván, A., E-mail: amendoza@qro.cinvestav.mx [Cinvestav-IPN, Unidad Querétaro, Libramiento Norponiente 2000, 76230 Querétaro (Mexico); Laboratory of Applied Optics, Department of Physics, Chemistry and Biology, Linköping University, SE-581 83 Linköping (Sweden); Arreola-Jardón, G. [Cinvestav-IPN, Unidad Querétaro, Libramiento Norponiente 2000, 76230 Querétaro (Mexico); Karlsson, L.H.; Persson, P.O.Å. [Thin Film Physics Division, Department of Physics, Chemistry and Biology, Linköping University, SE-581 83 Linköping (Sweden); Jiménez-Sandoval, S. [Cinvestav-IPN, Unidad Querétaro, Libramiento Norponiente 2000, 76230 Querétaro (Mexico)

2014-11-28

The effective complex dielectric function (ε) of Cu and O containing CdTe thin films is reported in the spectral range of 0.05 to 6 eV. The films were fabricated by rf sputtering from targets comprised by a mixture of CdTe and CuO powders with nominal Cu and O concentrations in the range of 2–10 at.%. Low concentration levels improved the crystalline quality of the films. Spectroscopic ellipsometry and transmittance measurements were used to determine ε. The critical point energies E{sub 1}, E{sub 1} + Δ{sub 1}, and E{sub 2} of CdTe are red-shifted with the incorporation of Cu and O. Also, an absorption band is developed in the infrared range which is associated with a mixture of CdTe and low resistivity phases Cu{sub 2−x}Te according to an effective medium analysis. The elemental distribution of the films was mapped by energy dispersive X-ray spectroscopy using scanning transmission electron microscopy. - Highlights: • Incorporation of 2 to 10 at.% of Cu and O atoms in CdTe films • Improved crystalline quality with 2 and 3 at.% of Cu and O • Complex dielectric function of Cu and O containing CdTe thin films • Effective medium modeling of below band-gap absorption.

Trace analysis of Cd, Cu, Pb and Zn in various materials using differential pulse anodic stripping voltammetry

International Nuclear Information System (INIS)

Ahmed, R.; Viqar-un-Nisa; Tanwir, R.

1988-09-01

Sampling and sample preparation methods have been described. Digestion methods for different types of materials and acid purification systems have been developed. For trace analysis purposes cleaning methods for glassware etc. have been described. Differential pulse anodic stripping voltametric (DPASV) method has been worked out for the trace analysis of zn, cd, pb and Cu in different types of materials. Linearity of the method has been checked by drawing concentration versus currents (peak height) curves. Precision of the method has been checked by analysing a number of actual samples. of the method has been verified by analysing standards of U.S.A. Comparative studies have been done between Differential pulse anodic stripping voltammetric method and Atomic Absorption spectroscopic method. Problems of contamination and systematic errors during trace and ultra-trace analysis have been discussed. A variety of samples including soil, spinach, wheat flour, rice flour, dry milk, coriander, kidney stones, bladder stones etc. have been analysed and preliminary results have been reported. (author)

Solvent extraction of Ca2+, Ba2+, Cu2+, Zn2+, Cd2+, Pb2+, UO22+, Mn2+, Co2+ and Ni2+ into nitrobenzene using strontium dicarbol-lylcobaltate and tetra-tert-butyl p-tert-butylcalix[4]arene tetraacetate

Directory of Open Access Journals (Sweden)

E. MAKRLÍK

2008-12-01

Full Text Available The exchange extraction constants corresponding to the general equilibrium M2+(aq + SrL2+(nb D ML2+ (nb + Sr2+ (aq occurring in the two-phase water–nitrobenzene system (M2+ = Ca2+, Ba2+, Cu2+, Zn2+, Cd2+, Pb2+, UO22+, Mn2+, Co2+ or Ni2+; L = tetra-tert-butyl p-tert-butylcalix[4]arene tetraacetate; aq = aqueous phase; nb = nitrobenzene phase were evaluated from extraction experiments and -activity measurements. Furthermore, the stability constants of the ML2+ complexes in water saturated nitrobenzene were calculated; they were found to increase in the cation order Ba2+ < Mn2+ < Pb2+, Co2+ < Cu2+, Zn2+ < Cd2+, Ni2+ < UO22+ < Ca2+.

Proximity effect of Pb on CeCu6 and La0.05Ce0.95Cu6

International Nuclear Information System (INIS)

Chen, T.P.; Tipparachi, U.; Yang, H.D.; Wang, J.T.; Chen, B.; Chen, J.C.J.

1999-01-01

Heavy fermion materials have attracted a great deal of attention since 1979. These materials which contain a rare earth (U, or Ce, etc.) element exhibit unusual behavior at low temperature. The effective mass m* of the Landau quasiparticles is found to be orders of magnitude higher than that of a bare electron. Some of the Heavy Fermion materials become superconductors at low temperature. The pairing of electrons in these superconductors may not be of s symmetry like those in BCS type superconductors. The mismatch in electronic mass and the difference in pairing state between the light conventional superconducting electrons and the heavy fermion electrons have brought the coupling between light electrons (BCS type) and the heavy fermion electrons into question. Proximity effect of Pb on CeCu 6 , Pb on La 0.05 Ce 0.95 Cu 6 , and Pb on Cu was used to investigate the coupling between the conventional superconducting electrons of Pb and the heavy electrons in CeCu 6 or La 0.05 Ce 0.95 Cu 6 . In this experiment proximity effect was found between Pb and CeCu 6 , as well as between Pb and La 0.05 Ce 0.95 Cu 6 . However, the proximity effect is small when compared with that between Pb and Cu. This indicates a much shorter extrapolation length in the heavy fermion materials than in Cu. Such a phenomenon can be explained by the mismatch in effective mass between the superconducting Pb electrons and the heavy fermion electrons

Competition from Cu(II), Zn(II) and Cd(II) in Pb(II) binding to Suwannee River Fulvic Acid

NARCIS (Netherlands)

Chakraborty, P.; Chakrabarti, C.L.

2008-01-01

This is a study of trace metal competition in the complexation of Pb(II) by well-characterized humic substances, namely Suwannee River Fulvic Acid (SRFA) in model solutions. It was found that Cu(II) seems to compete with Pb(II) for strong binding sites of SRFA when present at the same concentration

Measurements of labile Cd, Cu, Ni, Pb, and Zn levels at a northeastern Brazilian coastal area under the influence of oil production with diffusive gradients in thin films technique (DGT).

Science.gov (United States)

de Souza, João M; Menegário, Amauri A; de Araújo Júnior, Marcus A G; Francioni, Eleine

2014-12-01

In this work, the ability of the diffusive gradients in thin films technique (DGT) was evaluated for monitoring the concentrations, and estimating the availability, of metals at a northeastern Brazilian coastal area under the influence of oil production. Three sites with an average distance between 0m (EM-1), 100 m (EM-2), and 1,000 m (EM-3) of a submarine outfall-I (Guamaré-RN, Brazil) and another site (GA-1) with an average distance of 12,000 m east of Outfall I, near the city of Galinhos, were studied. DGT units were deployed at the same sites in three campaigns from July, 2010 to June, 2011. Effects on the accuracy of analytical results regarding the deployment time, gel porosity, and thickness were evaluated. There was no difference between the measurements obtained with two sets of DGT devices, those assembled with open or restrictive pore gel, respectively, showing that organic metallic species are not present near the submarine outlet. After 21 day deployments in a region (near Submarine Outfall I) that receives produced waters that have been treated, there was evidence of biofilm formation on DGT membranes. However, it was demonstrated that the biofilm interference with DGT measurements was negligible. Data found in this work show that total concentrations of Cd, Cu, Pb, Ni, and Zn in seawater samples collected at sites GA-1 and EM-1 in two campaigns were below 0.33, 1.67, 0.47, 0.70, 2.86 ng mL(-1) respectively. For the first time, labile levels of Cd, Cu, Pb, Ni, and Zn in an area under the influence of oil production were determined. DGT measurements allowed the verification of the effects of temporal variation on levels of Zn and Ni. There were no effects of spatial variations on levels of Cd, Cu, Ni, Pb, and Zn at the four studied sites, suggesting no contamination of these metals at the northeastern Brazilian coastal area investigated in this work. Copyright © 2014. Published by Elsevier B.V.

Ostwald ripening of Pb nanocrystalline phase in mechanically milled Al-Pb alloys and the influence of Cu additive

International Nuclear Information System (INIS)

Wu, Z.F.; Zeng, M.Q.; Ouyang, L.Z.; Zhang, X.P.; Zhu, M.

2005-01-01

The coarsening behavior of nanosized Pb phase in both Al-10%Pb and Al-10%Pb-4.5%Cu alloys has been studied by X-ray diffraction and transmission electron microscopy analysis. The coarsening of Pb nanophase in Al-Pb alloys still follows the classical ripening theory (the LSW theory) and the addition of Cu decreases the coarsening rate of Pb nanophase

Leaching of Cu, Cd, Pb, and phosphorus and their availability in the phosphate-amended contaminated soils under simulated acid rain.

Science.gov (United States)

Cui, Hongbiao; Zhang, Shiwen; Li, Ruyan; Yi, Qitao; Zheng, Xuebo; Hu, Youbiao; Zhou, Jing

2017-09-01

Phosphate amendments have been used to immobilize heavy metal-contaminated soils. However, phosphate amendments contain large amounts of phosphorus, which could leach out to potentially contaminate groundwater and surface water. A laboratory column leaching experiment was designed to study the effects of simulated acid rain (SAR) on the potential release of copper (Cu), lead (Pb), cadmium (Cd), and phosphorus (P), and their availability after immobilizing with hydroxyapatite (HAP) and potassium dihydrogen phosphate (PDP). The application of HAP and PDP enhanced the leachate electrical conductivity, total organic carbon, and pH. Higher P was found in the PDP- (>4.29 mg L -1 ) and HAP-treated (>1.69 mg L -1 ) columns than that in untreated (phosphate amendments might promote the leaching of some metals while immobilizing others.

Investigation of the optoelectronic behavior of Pb-doped CdO nanostructures

Science.gov (United States)

Eskandari, Abdollah; Jamali-Sheini, Farid; Cheraghizade, Mohsen; Yousefi, Ramin

2018-03-01

Un- and lead (Pb)-doped cadmium oxide (CdO) semiconductor nanostructures were synthesized by a sonochemical method to study their physical properties. The obtained X-ray diffraction (XRD) patterns indicated cubic CdO crystalline structures for all samples and showed that the crystallite size of CdO increases with Pb addition. Scanning electron microscopy (SEM) images of the nanostructures illustrated agglomerated oak-like particles for the Pb-doped CdO nanostructures. Furthermore, optical studies suggested that the emission band gap energy of the CdO nanostructures lies in the range of 2.27-2.38 eV and crystalline defects increase by incorporation of Pb atoms in the CdO crystalline lattice. In addition, electrical experiments declared that the n-type electrical nature of the un- and Pb-doped CdO nanostructures and the minimum of Pb atoms lead to a high carrier concentration.

PENGARUH LOGAM BERAT Cd, Pb TERHADAP PERUBAHAN WARNA BATANG DAN DAUN SAYURAN

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Hening Widowati

2011-04-01

Full Text Available Cd, Pb heavy metal absorption in aquatic vegetables: Genjer (Limnocharis flava, Kangkung air (Ipomoea aquatica Forsk dan Selada air (Nasturtium officinale R. Br, studied to see the relationship with green figure scale. The research objective was to identify the accumulated Cd, Pb in the consumed organ vegetable, and their impacts to the levels of green figure scale. The research was undertaken by planting three kinds of the aquatic vegetables to the contaminated pure Cd,pure Pb media, mixture of Cd and Pb with factorial randomized block design. Data were analyzed by factorial One-Way Anova and further test of Duncan and HSD to see the difference of Cd, Pb and green figure scale, regression and correlation to know the contribution of Cd, Pb in influencing the green figure scale. Variety of vegetables, media, organ, and the interaction influences the accumulation of Cd, Pb and level of green figure scale. There is a relationship between Cd, Pb metal accumulation to the level of green figure scale of the aquatic vegetables, with negative correlation that Cd, Pb decreased the vegetable green figure scale.

Cu-Doped-CdS/In-Doped-CdS Cosensitized Quantum Dot Solar Cells

Directory of Open Access Journals (Sweden)

Lin Li

2014-01-01

Full Text Available Cu-doped-CdS and In-doped-CdS cosensitized (Cu-doped-CdS/In-doped-CdS quantum dot solar cells (QDSCs are introduced here. Different cosensitized sequences, doping ratios, and the thickness (SILAR cycles of Cu-doped-CdS and In-doped-CdS are discussed. Compared with undoped CdS QDSCs, the short circuit current density, UV-Vis absorption spectra, IPCE (monochromatic incident photon-to-electron conversion, open circuit voltage, and so on are all improved. The photoelectric conversion efficiency has obviously improved from 0.71% to 1.28%.

Analysis of CdS/CdTe devices incorporating a ZnTe:Cu/Ti Contact

International Nuclear Information System (INIS)

Gessert, T.A.; Asher, S.; Johnston, S.; Young, M.; Dippo, P.; Corwine, C.

2007-01-01

High-performance CdS/CdTe photovoltaic devices can be produced using a ZnTe:Cu/Ti back contact deposited onto the CdTe layer. We observe that prolonged exposure of the ZnTe:Cu and Ti sputtering targets to an oxygen-containing plasma significantly reduces device open-circuit voltage and fill factor. High-resolution compositional analysis of these devices reveals that Cu concentration in the CdTe and CdS layers is lower for devices with poor performance. Capacitance-voltage analysis and related numerical simulations indicate that the net acceptor concentration in the CdTe is also lower for devices with poor performance. Photoluminescence analyses of the junction region reveal that the intensity of a luminescent peak associated with a defect complex involving interstitial Cu (Cu i ) and oxygen on Te (O Te ) is reduced in devices with poor performance. Combined with thermodynamic considerations, these results suggest that oxygen incorporation into the ZnTe:Cu sputtering target reduces the ability of sputtered ZnTe:Cu film to diffuse Cu into the CdTe

Assessment Of Heavy Metal Contamination Of Water Sources From Enyigba Pb-Zn District South Eastern Nigeria

Directory of Open Access Journals (Sweden)

Nnabo Paulinus N

2015-08-01

Full Text Available Abstract A total of thirty 30 water samples were collected from the Enyigba PbZn mining district to assess the contamination of the water sources as a result of mining of lead and zinc minerals in the area. This comprises of 12 samples of surface water 14 from mine ponds and 4 from underground borehole water. The samples were acidified to stabilize the metals for periods more than four days without the use of refrigeration. The acidified water samples were analysed by a commercial laboratory at Projects Development Institute PRODA Enugu using Atomic Absorption Spectroscopy AAS. The elements determined by this method are lead Pb zinc Zn copper Cu arsenic As cadmium Cd nickel Ni manganese Mn and cobalt Co. The result and analysis of contamination factor showed that in surface water Cd had the highest concentration followed by As and Pb while Ni had the lowest. In mine ponds Cd also had the highest concentration and followed by Pb and As and Ni the lowest. In borehole water Cd has the highest concentration followed by Pb and As while Ni had the lowest concentration. Compared to WHO permissible limits the contamination of the heavy metals in all water sources are in order CdAsPbNiZnCu. In surface water the order is CdAsPbNiZnCu in mine ponds it is CdPbAsNiZnCu and in borehole water the order is CdAsPbZnNiCu. The calculated contamination factors show very high contamination status for Cd Pb and As. These levels of contamination and values indicate that under the prevailing conditions and environmental regulations in Nigeria the mining district would face major and hazardous discharges of these metals to the water sources.

Determination of trace Cd, Cu, Fe, Pb and Zn in diesel and gasoline by inductively coupled plasma mass spectrometry after sample clean up with hollow fiber solid phase microextraction system

International Nuclear Information System (INIS)

Nomngongo, Philiswa N.; Ngila, J. Catherine

2014-01-01

This study reports a simple and efficient method for the determination of trace Cd, Cu, Fe, Pb and Zn in diesel and gasoline samples by inductively coupled plasma mass spectrometry after matrix removal and analyte pre-concentration using hollow fiber-solid phase microextraction (HF–SPME). The optimization of HF-SPME procedure was carried out using two-level full factorial and central composite designs. Four factors (variables), that are, sample solution pH, acceptor phase amount, extraction time and eluent concentration were optimized. Under the optimized experimental conditions, the precision was ≤ 3% (C = 10 μg L −1 , n = 15), limits of detection and quantification ranged from 0.1 to 0.3 μg L −1 and 0.3–0.9 μg L −1 , respectively, and the maximum preconcentration factor was 30. The HF-SPME method was applied for the determination of trace metals in real gasoline and diesel samples. - Highlights: • Hollow fiber solid phase microextraction of metal ions in diesel and gasoline • Use of hollow fiber-supported sol–gel combined with cation exchange resin • Optimization of HF-SPME using multivariate techniques • Determination of Cd, Cu, Fe, Pb and Zn using ICP–MS • Relatively low LOD and LOQ

Determination of trace Cd, Cu, Fe, Pb and Zn in diesel and gasoline by inductively coupled plasma mass spectrometry after sample clean up with hollow fiber solid phase microextraction system

Energy Technology Data Exchange (ETDEWEB)

Nomngongo, Philiswa N.; Ngila, J. Catherine, E-mail: jcngila@uj.ac.za

2014-08-01

This study reports a simple and efficient method for the determination of trace Cd, Cu, Fe, Pb and Zn in diesel and gasoline samples by inductively coupled plasma mass spectrometry after matrix removal and analyte pre-concentration using hollow fiber-solid phase microextraction (HF–SPME). The optimization of HF-SPME procedure was carried out using two-level full factorial and central composite designs. Four factors (variables), that are, sample solution pH, acceptor phase amount, extraction time and eluent concentration were optimized. Under the optimized experimental conditions, the precision was ≤ 3% (C = 10 μg L{sup −1}, n = 15), limits of detection and quantification ranged from 0.1 to 0.3 μg L{sup −1} and 0.3–0.9 μg L{sup −1}, respectively, and the maximum preconcentration factor was 30. The HF-SPME method was applied for the determination of trace metals in real gasoline and diesel samples. - Highlights: • Hollow fiber solid phase microextraction of metal ions in diesel and gasoline • Use of hollow fiber-supported sol–gel combined with cation exchange resin • Optimization of HF-SPME using multivariate techniques • Determination of Cd, Cu, Fe, Pb and Zn using ICP–MS • Relatively low LOD and LOQ.

Determination of uranium isotopes (235U, 238U) and trace elements (Cd, Pb, Cu and As) in bottled drinking water by Icp-SFMS

International Nuclear Information System (INIS)

Lara A, N.; Hernandez M, H.; Romero G, E. T.; Kuri de la C, A.; Perez B, M. A.

2016-09-01

In the present work we propose an optimized method for the quantification of uranium isotopes ( 235 U, 2 38 U) and the elements Cd, Pb, Cu and As in bottled water for drinking at trace levels of concentration. Based on the multi-element detection capability, the high sensitivity and resolution that the Mass Spectrometry with Magnetic Sector with Inductively Coupled Plasma Source (Icp-SFMS) technique offers; the high, medium and low resolution analysis conditions for the elements under study were established and optimized using and Element 2/Xr equipment and the 23 multi-elemental Certified Reference Material (CRM). The analysis method was validated using the standard reference material Nist 1643d and CRM mono-elemental s as external standards for the quantification of the analytes. Samples, targets and CRM were acidified with 2% of HNO 3 and analyzed without pretreatment under the established analysis conditions. The results obtained show concentrations of 235 U, 238 U, 111 Cd, 208 Pb, 63 Cu and 75 As in the range of μg L -1 , the linearity obtained from the calibration curves for each element has correlation coefficients < 0.99 in all cases, the accuracy of the method in terms of percent relative standard deviation (RSD %) was less than 5%, the mean recovery rate of Nist 1643d ranged from 96.46% to 101.12%. The optimization of the method guarantees the stability and calibration of the equipment throughout the analysis, as well as the ability to resolve interferences. In conclusion, the method proposed using Icp-SFMS offers the advantages of being fast and simple for the multi-elemental analysis in water at trace levels, with low limits of quantification and detection, with good linearity, accuracy, precision and reproducibility to a degree of reliability of 95%. (Author)

Interactions of core–shell quantum dots with metal resistant bacterium Cupriavidus metallidurans: Consequences for Cu and Pb removal

Energy Technology Data Exchange (ETDEWEB)

Slaveykova, Vera I., E-mail: vera.slaveykova@unige.ch [Environmental Biogeochemistry and Ecotoxicology, Institute F.-A. Forel, Earth and Environment Science, Faculty of Sciences, University of Geneva, 10, route de Suisse, 1290 Versoix (Switzerland); Pinheiro, José Paulo [IBB/CBME, Department of Chemistry and Biochemistry, University of the Algarve, Gambelas Campus, 8005-139 Faro (Portugal); Floriani, Magali [IRSN/DEI/SECRE/LRE CEA Cadarache, 13115 Saint-Paul-Lez-Durance (France); Garcia, Miguel [School of Life Sciences, Swiss Federal Institute of Technology (EPFL), Station 15, CH-1015 Lausanne (Switzerland)

2013-10-15

Highlights: • QDs associate with C. metallidurans in time and concentration dependent manner. • 12.9 nm size QDs adhere to the bacterial surface and enter the periplasmic space. • QDs bound significantly Cu and Pb. • QDs increase Cu and Pb content in C. metallidurans during short term exposure. -- Abstract: In the present study we address the interactions of carboxyl-CdSe/ZnS core/shell quantum dots (QDs), as a model of water dispersible engineered nanoparticles, and metal resistant bacteria Cupriavidus metallidurans, largely used in metal decontamination. The results demonstrate that QDs with average hydrodynamic size of 12.9 nm adhere to C. metallidurans. The percentage of bacterial cells displaying QD-fluorescence increased proportionally with contact time and QD concentration in bacterial medium demonstrating the association of QDs with the metal resistant bacteria. No evidence of QD internalization into bacterial cytoplasm was found by transmission electron microscopy with energy dispersive X-ray spectrometry, however QD clusters of sizes between 20 and 50 nm were observed on the bacterial surface and in the bacterial periplasmic compartment; observations consistent with the losses of membrane integrity induced by QDs. The presence of 20 nM QDs induced about 2-fold increase in Cu and Pb uptake fluxes by C. metallidurans exposed to 500 nM Pb or Cu, respectively. Overall, the results of this work suggest that when present in mixture with Cu and Pb, low levels of QDs originating from possible incidental release or QD disposal could increase metal accumulation in metal resistant bacterium.

A two-step leaching method designed based on chemical fraction distribution of the heavy metals for selective leaching of Cd, Zn, Cu, and Pb from metallurgical sludge.

Science.gov (United States)

Wang, Fen; Yu, Junxia; Xiong, Wanli; Xu, Yuanlai; Chi, Ru-An

2018-01-01

For selective leaching and highly effective recovery of heavy metals from a metallurgical sludge, a two-step leaching method was designed based on the distribution analysis of the chemical fractions of the loaded heavy metal. Hydrochloric acid (HCl) was used as a leaching agent in the first step to leach the relatively labile heavy metals and then ethylenediamine tetraacetic acid (EDTA) was applied to leach the residual metals according to their different fractional distribution. Using the two-step leaching method, 82.89% of Cd, 55.73% of Zn, 10.85% of Cu, and 0.25% of Pb were leached in the first step by 0.7 M HCl at a contact time of 240 min, and the leaching efficiencies for Cd, Zn, Cu, and Pb were elevated up to 99.76, 91.41, 71.85, and 94.06%, by subsequent treatment with 0.2 M EDTA at 480 min, respectively. Furthermore, HCl leaching induced fractional redistribution, which might increase the mobility of the remaining metals and then facilitate the following metal removal by EDTA. The facilitation was further confirmed by the comparison to the one-step leaching method with single HCl or single EDTA, respectively. These results suggested that the designed two-step leaching method by HCl and EDTA could be used for selective leaching and effective recovery of heavy metals from the metallurgical sludge or heavy metal-contaminated solid media.

Qualitative analysis of As, Ba, Cd, Cr, Zn, Fe, Mn, K, Hg, Pb y Cu, as constituents of Amatitlan Lake sediment by XRF

International Nuclear Information System (INIS)

Beltran, P.A.E.; Morales, E.A.

1987-10-01

Samples of fifteen sampling points were analyzed. Molybdenum X-ray tube with secondary excitation assembly, SiLi detector and deconvolution software AXIL were employed; self-standardization method based upon incoherent ratio was used for quantitative analysis of some elements. Ca, P, S, Ti, Mn, Fe, Cr, Zn, Cu, Ni, Ga, As, Pb, Ge, Sr and Pb, were found. As, Pb and Cu concentrations lower than 109 mg/lt, 119 mg/lt, and 500mg/lt, respectively, were measured. Hg was not detected. (author)

Certification of trace element contents (As, Cd, Co, Cu, Fe, Mn, Hg, Na, Pb and Zn) in a fly ash obtained from the combustion of pulverised coal

International Nuclear Information System (INIS)

Griepink, B.; Colinet, E.; Guzzi, G.; Haemers, L.; Muntau, H.

1983-01-01

The element contents of As, Cd, Co, Cu, Fe, Mn, Hg, Na, Pb and Zn of a fly ash from pulverised coal are certified. The procedures and their results for the homogenisation, the contamination and homogeneity checks and the analytical campaign are reported. The certified mass fractions and indicative values for Cr, Ni, Th, V and water soluble sulphate are given. The work was carried out within the framework of the activities of the Community Bureau of Reference (BCR) of the Commission of the European Communities. (orig.) [de

Synthesis of the phase with T sub c =110 K in Bi(Pb)-Sr-Ca-Cu-O superconducting ceramics. Sintez fazy T sub c =110 K sverkhprovodyashchej keramiki sostava Bi(Pb)-Sr-Ca-Cu-O

Energy Technology Data Exchange (ETDEWEB)

Dubovitskij, A V; Makarov, E F; Makova, M K; Merzhanov, V A; Topnikov, V N [AN SSSR, Moscow (USSR). Inst. Khimicheskoj Fiziki

1991-05-01

Synthesis of 110 K single-phase bismuth ceramics (BiPb){sub 2}Sr{sub 2}Ca{sub n-1}Cu{sub n}O{sub x} was conducted in narrow temperature and time range. Diffusion of bismuth ions is proposed to be the decisive factor of synthesis of bismuth ceramics. The diffusion depends on prehistory of basic burden preparation and on its dispersivity and homogeneity in particluar. Optimal time of synthesis for lead doped ceramics of 2223 composition, synthesized from initial nitrate components, is equal to 65 h at 850 deg C. The role of Pb{sup 2+} ions is probably reduced to decrease of diffusion mobility of Bi{sup 3+} ions over the bismuth sublattice. Ceramics doping with CdO and CdCl{sub 2} compounds instead of lead stabilizes superconductivity in bismuth ceramics, but with worth superconducting parameters.

Determination of uranium isotopes ({sup 235}U, {sup 238}U) and trace elements (Cd, Pb, Cu and As) in bottled drinking water by Icp-SFMS; Determinacion de isotopos de uranio ({sup 235}U, {sup 238}U) y elementos traza (Cd, Pb, Cu y As) en agua embotellada para beber por ICP-SFMS

Energy Technology Data Exchange (ETDEWEB)

Lara A, N.; Hernandez M, H.; Romero G, E. T.; Kuri de la C, A.; Perez B, M. A., E-mail: nancy.lara@inin.gob.mx [ININ, Carretera Mexico-Toluca s/n, 52750 Ocoyoacac, Estado de Mexico (Mexico)

2016-09-15

In the present work we propose an optimized method for the quantification of uranium isotopes ({sup 235}U, 2{sup 38}U) and the elements Cd, Pb, Cu and As in bottled water for drinking at trace levels of concentration. Based on the multi-element detection capability, the high sensitivity and resolution that the Mass Spectrometry with Magnetic Sector with Inductively Coupled Plasma Source (Icp-SFMS) technique offers; the high, medium and low resolution analysis conditions for the elements under study were established and optimized using and Element 2/Xr equipment and the 23 multi-elemental Certified Reference Material (CRM). The analysis method was validated using the standard reference material Nist 1643d and CRM mono-elemental s as external standards for the quantification of the analytes. Samples, targets and CRM were acidified with 2% of HNO{sub 3} and analyzed without pretreatment under the established analysis conditions. The results obtained show concentrations of {sup 235}U, {sup 238}U, {sup 111}Cd, {sup 208}Pb, {sup 63}Cu and {sup 75}As in the range of μg L{sup -1}, the linearity obtained from the calibration curves for each element has correlation coefficients < 0.99 in all cases, the accuracy of the method in terms of percent relative standard deviation (RSD %) was less than 5%, the mean recovery rate of Nist 1643d ranged from 96.46% to 101.12%. The optimization of the method guarantees the stability and calibration of the equipment throughout the analysis, as well as the ability to resolve interferences. In conclusion, the method proposed using Icp-SFMS offers the advantages of being fast and simple for the multi-elemental analysis in water at trace levels, with low limits of quantification and detection, with good linearity, accuracy, precision and reproducibility to a degree of reliability of 95%. (Author)

Does Biochar Alter the Speciation of Cd and Pb in Aqueous Solution?

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Liqiang Cui

2014-11-01

Full Text Available Cadmium and lead contamination in bodies of water has been a serious concern because of risk to the environment. A laboratory experiment was initiated to investigate the efficacy of biochar (BC in removing cadmium and lead (Cd and Pb, respectively from solution. After absorption by BC, the fractions of Cd and Pb at different solution temperatures were measured. The adsorption data were described by Langmuir isotherm with maximum adsorption capacities of 6.36, 6.47, and 6.74 mg Cd g-1 and 50.05, 55.86, and 63.09 mg Pb g-1 at 25, 35, and 45 °C, respectively. The adsorption capacities were affected by Cd/Pb initial concentration, pH, BC particle size, BC dosage, and reaction time. Biochar adsorbed the Cd and Pb mainly as species bound with carbonate (> 50% and organic compounds (~40%. Exchangeable and residual fractions of Cd and Pb were less than 10%. Results from this study indicate that BC is highly effective in the adsorption of the heavy metals Cd and Pb through binding with carbonates.

Phytoextraction of Pb and Cu contaminated soil with maize and microencapsulated EDTA.

Science.gov (United States)

Xie, Zhiyi; Wu, Longhua; Chen, Nengchang; Liu, Chengshuai; Zheng, Yuji; Xu, Shengguang; Li, Fangbai; Xu, Yanling

2012-09-01

Chelate-assisted phytoextraction using agricultural crops has been widely investigated as a remediation technique for soils contaminated with low mobility potentially toxic elements. Here, we report the use of a controlled-release microencapsulated EDTA (Cap-EDTA) by emulsion solvent evaporation to phytoremediate soil contaminated with Pb and Cu. Incubation experiments were carried out to assess the effect of Cap- and non-microencapsulated EDTA (Ncap-EDTA) on the mobility of soil metals. Results showed EDTA effectively increased the mobility of Pb and Cu in the soil solution and Cap-EDTA application provided lower and more constant water-soluble concentrations of Pb and Cu in comparison with. Phytotoxicity may be alleviated and plant uptake of Pb and Cu may be increased after the incorporation of Cap-EDTA. In addition phytoextraction efficiencies of maize after Cap- and Ncap-EDTA application were tested in a pot experiment. Maize shoot concentrations of Pb and Cu were lower with Cap-EDTA application than with Ncap-EDTA. However, shoot dry weight was significantly higher with Cap-EDTA application. Consequently, the Pb and Cu phytoextraction potential of maize significantly increased with Cap-EDTA application compared with the control and Ncap-EDTA application.

Metastable phases freezing from melts of reciprocal systems PbX + CdI2=CdX + PbI2 (X=S, Se, Te)

International Nuclear Information System (INIS)

Odin, I.N.; Chukichev, M.V.

2001-01-01

The transformations in the mutual PbX + CdI 2 =CdX + PbI 2 (X=S, Se, Te) systems leading to the crystallization of metastable polytypical modifications of lead iodide in metastable ternary compounds are studied for the first time. Microstructural and X-ray diffraction analyses were conducted. Their phase diagrams were constructed. The luminescence properties of the stable and metastable modifications of the lead iodide and the metastable compound Pb 4 SeI 6 were investigated. The lines 504 and 512 nm are noted in the 2H-PbI 2 cathodoluminescence spectra. The close lines - 508 and 516 nm provide for the 6R-PbI 2 modification. The metastable compound Pb 4 SeI 6 is characterized by the 769 and 868 nm lines [ru

Study of Cu and Pb partitioning in mine tailings using the Tessier sequential extraction scheme

Energy Technology Data Exchange (ETDEWEB)

Andrei, Mariana Lucia, E-mail: marianaluciaandrei@yahoo.com [National Institute for Research and Development of Isotopic and Molecular Technologies, 65-103 Donath, 400293 Cluj-Napoca (Romania); Babes-Bolyai University, Environmental Science and Engineering Faculty, 30 Fantanele, 400294, Cluj-Napoca (Romania); Senila, Marin; Hoaghia, Maria Alexandra; Levei, Erika-Andrea [INCDO-INOE 2000, Research Institute for Analytical Instrumentation, 67 Donath, 400293, Cluj-Napoca (Romania); Borodi, Gheorghe [National Institute for Research and Development of Isotopic and Molecular Technologies, 65-103 Donath, 400293 Cluj-Napoca (Romania)

2015-12-23

The Cu and Pb partitioning in nonferrous mine tailings was investigated using the Tessier sequential extraction scheme. The contents of Cu and Pb found in the five operationally defined fractions were determined by inductively coupled plasma optical emission spectrometry. The results showed different partitioning patterns for Cu and Pb in the studied tailings. The total Cu and Pb contents were higher in tailings from Brazesti than in those from Saliste, while the Cu contents in the first two fractions considered as mobile were comparable and the content of mobile Pb was the highest in Brazesti tailings. In the tailings from Saliste about 30% of Cu and 3% of Pb were found in exchangeable fraction, while in those from Brazesti no metals were found in the exchangeable fraction, but the percent of Cu and Pb found in the bound to carbonate fraction were high (20% and 26%, respectively). The highest Pb content was found in the residual fraction in Saliste tailings and in bound to Fe and Mn oxides fraction in Brazesti tailings, while the highest Cu content was found in the fraction bound to organic matter in Saliste tailings and in the residual fraction in Brazesti tailings. In case of tailings of Brazesti medium environmental risk was found both for Pb and Cu, while in case of Saliste tailings low risk for Pb and high risk for Cu were found.

Study of Cu and Pb partitioning in mine tailings using the Tessier sequential extraction scheme

International Nuclear Information System (INIS)

Andrei, Mariana Lucia; Senila, Marin; Hoaghia, Maria Alexandra; Levei, Erika-Andrea; Borodi, Gheorghe

2015-01-01

The Cu and Pb partitioning in nonferrous mine tailings was investigated using the Tessier sequential extraction scheme. The contents of Cu and Pb found in the five operationally defined fractions were determined by inductively coupled plasma optical emission spectrometry. The results showed different partitioning patterns for Cu and Pb in the studied tailings. The total Cu and Pb contents were higher in tailings from Brazesti than in those from Saliste, while the Cu contents in the first two fractions considered as mobile were comparable and the content of mobile Pb was the highest in Brazesti tailings. In the tailings from Saliste about 30% of Cu and 3% of Pb were found in exchangeable fraction, while in those from Brazesti no metals were found in the exchangeable fraction, but the percent of Cu and Pb found in the bound to carbonate fraction were high (20% and 26%, respectively). The highest Pb content was found in the residual fraction in Saliste tailings and in bound to Fe and Mn oxides fraction in Brazesti tailings, while the highest Cu content was found in the fraction bound to organic matter in Saliste tailings and in the residual fraction in Brazesti tailings. In case of tailings of Brazesti medium environmental risk was found both for Pb and Cu, while in case of Saliste tailings low risk for Pb and high risk for Cu were found

河川水, 海水のCu, Pb, Cd, Znの分布と, その河口域における挙動の予察的研究

OpenAIRE

佐藤, 修; Sato, Osamu

1980-01-01

This report describes the distribution and speciation of Cu, Pb, Cd and Zn in natural waters and the laboratory experiments to examine the effects on river water of NaCl. Samples were collected from Tenpaku River, Kiso River, Toyo River and Atsumi Bay. The distribution of labile and total metales were determined by differential pulse anodic stripping voltammetry (DPASV) before and after u. v. irradiation. CornpIexing capacity was determined by the method proposed by CHAU (1974). Analysis of T...

Effects of Crop Straw Returning with Lime on Activity of Cu, Zn, Pb and Cd in Paddy Soil

Directory of Open Access Journals (Sweden)

NI Zhong-ying

2017-05-01

Full Text Available Crop straw returning is an important measure for increasing soil carbon fixation and soil fertility in China, but it also may result in some risk of raising activity of heavy metals in the soil. In order to understand the effects of different sources of crop straw on heavy metals activity in soil with different pollution levels, and to take appropriate measures to prevent the activation of heavy metals in the soil, both pot and field experiments were carried out to study the effects of crop straw returning with lime on activity of Cu, Zn, Pb and Cd in paddy soil. The experiments were carried out in the soils with both light and heavy pollution of heavy metals. In the pot experiment, three straws, including rice straw with heavy pollution of heavy metals, rice straw with light pollution of heavy metals, and rape straw with light pollution of heavy metals, were tested. Two dosages of lime(0 kg·hm-2 and 750 kg·hm-2were applied. Field experiment had three treatments, ie., control without application of straw and lime, straw returning and straw returning + lime. Soil available heavy metals, accumulation of heavy metals in rice grain, and chemical forms of soil heavy metals were dynamical monitored. The results showed that crop straw returning increased significantly the concentrations of dissolved organic carbon and water soluble heavy metals in paddy soils at the early stage of experiment (in first 20 days. The increase in water soluble heavy metals in the soil with heavy pollution of heavy metals was most obvious as compared with the control treatment. After 60th day of the experiment, the effects of straw returning on the activity of heavy metals in the soil decreased gradually with the time, and became no obvious. The concentrations of water soluble heavy metals in the soil treated with rape straw was generally lower than that of rice straw, while those in the soil treated with heavy pollution of rice straw was higher than low pollution of rice

Biosorption of Cu2+ and Pb2+ using sophora alopecuroides residue

Science.gov (United States)

Feng, N.; Fan, W.; Zhu, M.; Zhang, Y.

2016-08-01

Sophora alopecuroides residue (SAP), a kind of traditional Chinese herbal medicine residue, was developed in an alternative biosorbent for the removal Cu2+ and Pb2+ in simulated wastewater. The morphology and surface texture of SAP were characterized by scanning electron microscopy, which showed a loose and porous structure. The biosorption experiments of Cu2+ and Pb2+ onto SAP were investigated by using batch techniques. High biosorption percentage appeared at pH values of 4.5-6.0. The experimental data followed the second-order kinetic model well. Equilibrium fit with the Langmuir isotherm model well. The maximum biosorption capacity of an adsorbent at 25 °C was respectively 60.6 mg/g Cu2+ and 128.1 mg/g Pb2+. The findings of the present study show that SAP is an attractive and effective biosorbent for Cu2+ and Pb2+.

Study of Fe, Zn, Cu, Cd, Pb concentrations in liver, kidney and muscle tissue of cow and sheep marketed in Hamedan in 2011

Directory of Open Access Journals (Sweden)

S Sobhanardakani

2012-11-01

Full Text Available Importance of heavy metals in food safety and detrimental effects of their high concentrations in food stuff is well documented. In this study, concentrations of Fe, Zn, Cu, Cd and Pb in kidney, liver and muscle tissues of cow and sheep at Hamedan retails were evaluated. A total number of 180 samples was assessed for the amount of heavy metals as ppb in wet weight. For this, wet-digestion method was used to determine the concentration of given elements by ICP (Varian ES-710. Results showed that the highest concentration of heavy metals was determined in the liver and kidney samples, while the lowest concentration was found in muscle tissue. Among the heavy metals, Fe in cow’s liver had the highest concentration (25507±879 ppb and Cd in muscle tissue of sheep has the lowest concentration (192±54 ppb. In overall, accumulation of heavy metals in tissues of cows was higher than sheep. Statistical comparison of accumulated metals concentration in various tissues of these two animal groups showed significant difference (P

Heavy metals pollution and pb isotopic signatures in surface sediments collected from Bohai Bay, North China.

Science.gov (United States)

Gao, Bo; Lu, Jin; Hao, Hong; Yin, Shuhua; Yu, Xiao; Wang, Qiwen; Sun, Ke

2014-01-01

To investigate the characteristics and potential sources of heavy metals pollution, surface sediments collected from Bohai Bay, North China, were analyzed for the selected metals (Cd, Cr, Cu, Ni, Pb, and Zn). The Geoaccumulation Index was used to assess the level of heavy metal pollution. Pb isotopic compositions in sediments were also measured to effectively identify the potential Pb sources. The results showed that the average concentrations of Cd, Cr, Cu, Ni, Pb, and Zn were 0.15, 79.73, 28.70, 36.56, 25.63, and 72.83 mg/kg, respectively. The mean concentrations of the studied metals were slightly higher than the background values. However, the heavy metals concentrations in surface sediments in Bohai Bay were below the other important bays or estuaries in China. The assessment by Geoaccumulation Index indicated that Cr, Zn, and Cd were classified as "the unpolluted" level, while Ni, Cu, and Pb were ranked as "unpolluted to moderately polluted" level. The order of pollution level of heavy metals was: Pb > Ni > Cu > Cr > Zn > Cd. The Pb isotopic ratios in surface sediments varied from 1.159 to 1.185 for (206)Pb/(207)Pb and from 2.456 to 2.482 for (208)Pb/(207)Pb. Compared with Pb isotopic radios in other sources, Pb contaminations in the surface sediments of Bohai Bay may be controlled by the mix process of coal combustion, aerosol particles deposition, and natural sources.

Glomus mosseae enhances root growth and Cu and Pb acquisition of upland rice (Oryza sativa L.) in contaminated soils.

Science.gov (United States)

Lin, Aijun; Zhang, Xuhong; Yang, Xiaojin

2014-12-01

A pot culture experiment was carried out to investigate the roles of Glomus mosseae in Cu and Pb acquisition by upland rice (Oryza sativa L.) and the interactions between Cu and Pb. The soil was treated with three Cu levels (0, 100 and 200 mg kg(-1)) and three Pb levels (0, 300, and 600 mg kg(-1)). All treatments were designed with (+M) or without (-M) G. mosseae inoculation in a randomized block design. The addition of Cu and Pb significantly decreased root mycorrhizal colonization. Compared with -M, +M significantly increased root biomass in almost all treatments, and also significantly increased shoot biomass in the Pb(0)Cu(200), Pb(300)Cu(0), and all Pb(600) treatments. AM fungi enhanced plant Cu acquisition, but decreased plant Cu concentrations with all Cu plus Pb treatments, except for shoot in the Cu(200)Pb(600) treatment. Irrespective of Cu and Pb levels, +M plants had higher Pb uptakes than -M plants, but had lower root Pb and higher shoot Pb concentrations than those of -M plants. Another interpretation for the higher shoot Pb concentration in +M plants relied on Cu-Pb interactions. The study provided further evidences for the protective effects of AM fungi on upland rice against Cu and Pb contamination, and uncovered the phenomenon that Cu addition could promote Pb uptake and Pb partitioning to shoot. The possible mechanisms by which AM fungi can alleviate the toxicity induced by Cu and Pb are also discussed.

Contamination and Health Risks from Heavy Metals (Cd and Pb and Trace Elements (Cu and Zn in Dairy Products

Directory of Open Access Journals (Sweden)

Hamid Reza Ghafari

2017-08-01

Conclusion: Considering the serious contamination of some brands of butter and cheese by Cu and Pb, a control of heavy metals and trace elements levels during the whole production processing of dairy products must be applied.

Modulation-free bismuth-lead cuprate superconductors: BiPbSr1+xL1-xCuO6 and BiPbSr2Y1-xCaxCu2O8

International Nuclear Information System (INIS)

Manivannan, V.; Gopalakrishnan, J.; Rao, C.N.R.

1991-01-01

Modulation-free BiPbSrLCuO 6 (L=La, Pr, Nd) and BiPbSr 2 YCu 2 O 8 , which are isotypic with the n=1 and 2 members of the Bi 2 Sr 2 Ca n-1 Cu n O 2n+4 family, have been prepared and characterized. These parent compounds are nonsuperconducting, but when doped with holes by substitution chemistry give modulation-free superconducting cuprates of the general formulas BiPbSr 1+xL1-x CuO 6 and BiPbSr 2 Y 1-x Ca x Cu 2 O 8 , exhibiting maximum T c 's of 24 and 85 K, respectively. Significantly, the hole concentration at the maximum T c is 0.12 in the cuprate family with a single Cu-O layer and 0.22 in that with two Cu-O layers

Sem-EDAX'S Application For Characterization Of Superconductor Material Of (Bi,Pb)-Sr-Ca-Cu-O

International Nuclear Information System (INIS)

Handayani, Ari; Wuryanto; Prambudi, Bambang

1996-01-01

The microstructure and composition analysis of superconductor material of (Bi,Pb)-Sr-Ca-Cu-O which were synthesized by two different processes (CA and CD Process) by varying the sintering time, i.e. 20,60 and 100 hours were done by using SEM-EDAX method. The standard sample of superconductor material of Bi-Sr-Ca-Cu-O with 1112, 2212 and 2223 phase from Stream has been used for comparison, At 25 kV, the composition analysis showed that, at 20 and 60 hours of sintering, a mixture of phases existed while 100 hours of sintering resulted in a phase close to phase 2223. The result of microstructure observation showed significant differences. At synthesized CA process, 100 hours of sintering gives bigger and clearer platelet microstructure shape than that given by 20 and 60 hours of sintering. Also from the synthesized CD process, the 60 and 100 hours of sintering gives bigger and clearer platelet microstructure shape than that given by the 20 hours of sintering

Distribution of POC, PON and particulate Al, Cd, Cr, Cu, Pb, Ti, Zn and δ13C in the English Channel and adjacent areas

International Nuclear Information System (INIS)

Dauby, P.; Frankignoulle, M.; Gobert, S.; Bouquegneau, J.M.

1994-01-01

A study of the spatial distribution of the total suspended matter and of its elemental composition (C, N and trace metals) has been performed in the English Channel. The Celtic Sea, and the Southern Bight of the North Sea in June and October 1991. South-west to north-east gradients of suspended matter mass and of lithogenic components (Ti an Al) linked to riverine inputs and to depth shallowing, are observed; organic carbon and nitrogen display an opposite distribution pattern and reach a maximum in the Biscay oceanic waters. Cu, Pb and Zn concentrations are highest near industrialized areas and large estuaries, showing the importance of river inputs. In contrast, Cd, Cu and Cr concentrations are markedly elevated in organic-rich suspended matter from waters in which suspended matter loadings are low, suggesting a significant biological uptake. Finally, 13 C/ 12 C analyses reveal the relative importance of coastal or continental inputs in the north-eastern Channel and in the North Sea. (authors). 56 refs., 12 figs., 3 tabs

Genesis of the Bangbule Pb-Zn-Cu polymetallic deposit in Tibet, western China: Evidence from zircon U-Pb geochronology and S-Pb isotopes

Science.gov (United States)

Kan, Tian; Zheng, Youye; Gao, Shunbao

2016-04-01

The Banbule Pb-Zn-Cu skarn deposit is located in the Longger-Gongbujiangda volcanic magma arc in the Gangdese-Nyainqentanglha Plate. It is the only lead-zinc polymetallic deposit discovered in the westernmost Nyainqentanglha metallogenic belt. The measured and indicated resources include 0.9 Mt of Pb+Zn (4.77% Pb and 4.74% Zn, respectively), 6499 t of Cu, and 178 t of Ag (18.75g/t Ag). The orebodies mainly occur as lenses, veins and irregular shapes in the contact zone between the quartz-porphyry and limestone of the Upper Permian Xiala Formation, or in the boundaries between limestone and sandstone. Pb-Zn-Cu mineralization in the Banbule deposit is closely associated with skarns. The ore minerals are dominated by galena, sphalerite, chalcopyrite, bornite, and magnetite, with subordinate pyrite, malachite, and azurite. The gangue minerals are mainly garnet, actinolite, diopside, quartz, and calcite. The ore-related quartz-porphyry displays LA-ICP-MS zircon U-Pb age of 77.31±0.74 Ma. The δ34S values of sulfides define a narrow range of -0.8 to 4.7‰ indicating a magmatic source for the ore-forming materials. Lead isotopic systematics yield 206Pb/204Pb of 18.698 to 18.752, 207Pb/204Pb of 15.696 to 15.760, and 208Pb/204Pb of 39.097 to 39.320. The data points are constrained around the growth curves of upper crust and orogenic belt according to the tectonic discrimination diagrams. The calculated Δβ - Δγ values plot within the magmatic field according to the discrimination diagram of Zhu et al. (1995). The S-Pb isotopic data suggest that Bangbule is a typical skarn deposit, and the Pb-Zn-Cu mineralization is genetically related to the quartz-porphyry in the mining district. The discovery of the Bangbule deposit indicates that there is metallogenic potential in the westernmost Nyainqentanglha belt, which is of great importance for the exploration work in this area.

Flux flow and proximity effects in aligned Pb--Cd eutectic lamellar structures

International Nuclear Information System (INIS)

Spencer, C.R.

1977-09-01

A high speed directional solidification technique was used to fabricate lamellar Pb-Cd and (Pb-Mg)--(Cd-Mg) superconductor-normal metal composites in which all the lamellae are oriented perpendicular to the broad surface of the sample. These lamellar composites are found to behave like a large number (approximately 1000) of superconducting-normal-superconducting junctions. For the Pb-Cd eutectic system, the critical current densities and critical fields have shown no dependence upon the lamellar periods between 1.0 and 3.1 microns. The critical current density of the aligned lamellar Pb-Cd structures was enhanced approximately 50% when compared to quenched eutectic alloy and to pure Pb. The superconducting transition temperature, T/sub c/, varies inversely with the square of the thickness of the superconducting material as expected from Ginzburg-Landau theory. Upon annealing, the Pb lamellae change from type II to type I superconductivity

Flux flow and proximity effects in aligned Pb--Cd eutectic lamellar structures

Energy Technology Data Exchange (ETDEWEB)

Spencer, C. R.

1977-09-01

A high speed directional solidification technique was used to fabricate lamellar Pb-Cd and (Pb-Mg)--(Cd-Mg) superconductor-normal metal composites in which all the lamellae are oriented perpendicular to the broad surface of the sample. These lamellar composites are found to behave like a large number (approximately 1000) of superconducting-normal-superconducting junctions. For the Pb-Cd eutectic system, the critical current densities and critical fields have shown no dependence upon the lamellar periods between 1.0 and 3.1 microns. The critical current density of the aligned lamellar Pb-Cd structures was enhanced approximately 50% when compared to quenched eutectic alloy and to pure Pb. The superconducting transition temperature, T/sub c/, varies inversely with the square of the thickness of the superconducting material as expected from Ginzburg-Landau theory. Upon annealing, the Pb lamellae change from type II to type I superconductivity.

Prediction of phase equilibria and thermal analysis in the Bi-Cu-Pb ternary system

Energy Technology Data Exchange (ETDEWEB)

Manasijevic, Dragan [University of Belgrade, Technical Faculty, VJ 12, 19210 Bor (Serbia); Mitovski, Aleksandra, E-mail: amitovski@tf.bor.ac.rs [University of Belgrade, Technical Faculty, VJ 12, 19210 Bor (Serbia); Minic, Dusko [University of Pristina, Faculty of Technical Sciences, 38220 Kosovska Mitrovica (Serbia); Zivkovic, Dragana; Marjanovic, Sasa [University of Belgrade, Technical Faculty, VJ 12, 19210 Bor (Serbia); Todorovic, Radisa [Institute of Mining and Metallurgy, Zeleni Bulevar 35, 19210 Bor (Serbia); Balanovic, Ljubisa [University of Belgrade, Technical Faculty, VJ 12, 19210 Bor (Serbia)

2010-05-20

The knowledge about phase diagram of the Bi-Cu-Pb ternary system is of importance in development of copper-lead based bearing materials, soldering and in refining of copper and lead. In this work, the phase diagram of the Bi-Cu-Pb ternary system was calculated by the CALPHAD method using binary thermodynamic parameters included in the COST 531 database. The results include liquidus projection, invariant equilibria and three vertical sections with molar ratio Cu:Pb = 1, Cu:Pb = 1:3 and Bi:Cu = 1. Alloys, with compositions along three predicted vertical sections, were measured using differential scanning calorimetry (DSC). The experimentally determined phase transition temperatures were compared with calculated results and good mutual agreement was noticed.

Prediction of phase equilibria and thermal analysis in the Bi-Cu-Pb ternary system

International Nuclear Information System (INIS)

Manasijevic, Dragan; Mitovski, Aleksandra; Minic, Dusko; Zivkovic, Dragana; Marjanovic, Sasa; Todorovic, Radisa; Balanovic, Ljubisa

2010-01-01

The knowledge about phase diagram of the Bi-Cu-Pb ternary system is of importance in development of copper-lead based bearing materials, soldering and in refining of copper and lead. In this work, the phase diagram of the Bi-Cu-Pb ternary system was calculated by the CALPHAD method using binary thermodynamic parameters included in the COST 531 database. The results include liquidus projection, invariant equilibria and three vertical sections with molar ratio Cu:Pb = 1, Cu:Pb = 1:3 and Bi:Cu = 1. Alloys, with compositions along three predicted vertical sections, were measured using differential scanning calorimetry (DSC). The experimentally determined phase transition temperatures were compared with calculated results and good mutual agreement was noticed.

RF properties of superconducting Pb electroplated onto Cu

International Nuclear Information System (INIS)

Delayen, J.R.

1988-01-01

The properties of Pb as a superconducting material for high power rf applications are reviewed. The most common method of producing Pb superconducting resonators, which is by electrodeposition of a thin layer on a Cu substrate, is described, and some suggestions for further development are presented. 56 references, 11 figures, 1 table

Succulent species differ substantially in their tolerance and phytoextraction potential when grown in the presence of Cd, Cr, Cu, Mn, Ni, Pb, and Zn.

Science.gov (United States)

Zhang, Chengjun; Sale, Peter W G; Clark, Gary J; Liu, Wuxing; Doronila, Augustine I; Kolev, Spas D; Tang, Caixian

2015-12-01

Plants for the phytoextraction of heavy metals should have the ability to accumulate high concentrations of such metals and exhibit multiple tolerance traits to cope with adverse conditions such as coexistence of multiple heavy metals, high salinity, and drought which are the characteristics of many contaminated soils. This study compared 14 succulent species for their phytoextraction potential of Cd, Cr, Cu, Mn, Ni, Pb, and Zn. There were species variations in metal tolerance and accumulation. Among the 14 succulent species, an Australian native halophyte Carpobrotus rossii exhibited the highest relative growth rate (20.6-26.6 mg plant(-1) day(-1)) and highest tolerance index (78-93%), whilst Sedum "Autumn Joy" had the lowest relative growth rate (8.3-13.6 mg plant(-1) day(-1)), and Crassula multicava showed the lowest tolerance indices (phytoextraction of these heavy metals than other species. These findings suggest that Carpobrotus rossii is a promising candidate for phytoextraction of multiple heavy metals, and the aquatic or semiterrestrial Crassula helmsii is suitable for phytoextraction of Cd and Zn from polluted waters or wetlands.

Photovoltaic properties of Cu-doped CH3NH3PbI3 with perovskite structure

Science.gov (United States)

Shirahata, Yasuhiro; Oku, Takeo

2017-01-01

Photovoltaic properties of copper (Cu)-doped perovskite (CH3NH3PbCuxI3+x) photovoltaic devices with different Cu content were investigated. The CH3NH3PbCuxI3+x films were polycrystalline with a tetragonal system, and their lattice constants and crystallite size varied with Cu doping. Compared to conversion efficiencies of non-doped CH3NH3PbI3 photovoltaic device, those of CH3NH3PbCuxI3+x photovoltaic devises increased. The improvement of photovoltaic properties was attributed to partial substitution of Cu at the Pb sites.

The effect of Cu on the properties of CdO/Cu/CdO multilayer films for transparent conductive electrode applications

Energy Technology Data Exchange (ETDEWEB)

Raaif, M.; Mohamed, S.H. [Sohag University, Physics Department, Faculty of Science, Sohag (Egypt)

2017-06-15

Transparent conductive CdO/Cu/CdO multilayer films were prepared using rf plasma magnetron sputtering and electron beam evaporation techniques. The CdO layers were prepared using rf plasma magnetron sputtering, while the Cu interlayer was prepared by electron beam evaporation technique. The Cu layer thickness was varied between 1 and 10 nm. The structural and optical properties as well as the sheet resistance of the multilayer films were studied. X-ray diffraction measurements revealed the presence of cubic CdO structure and the Cu peak was only observed for the multilayers prepared with 10 nm of Cu. It has been observed that the Cu interlayer thickness has a great influence on the optical and electrical properties of the multilayers. The transmittance of the multilayer films decreased while the reflectance increased with increasing Cu interlayer thickness. The refractive index and the extinction coefficient of the multilayer films were calculated. The estimated optical band gap values were found to be decreased from 2.75 ± 0.02 to 2.40 ± 0.02 eV as the Cu interlayer thickness increased from 1 to 10 nm. The sheet resistance was sensitive to the Cu interlayer thickness and it decreased with increasing Cu interlayer thickness. A sheet resistSSance of 21.7 Ω/sq, an average transmittance (between 700 and 1000 nm) of 77%, and an optical band gap of 2.5 ± 0.02 eV were estimated for the multilayer film with 2 nm Cu layer. The multilayer film with 2 nm Cu layer has the highest figure of merit value of 3.2 x 10{sup -3} Ω{sup -1}. This indicates that the properties of this multilayer film are suitable for transparent conductive electrode applications. (orig.)

Effects of Cu, Zn and Pb Combined Pollution on Soil Hydrolase Activities

Directory of Open Access Journals (Sweden)

FENG Dan

2015-08-01

Full Text Available To study the relations between soil enzyme activities and heavy metal pollution, the combined effects of Cu, Zn and Pb on the three hydrolase activities, including invertase(IN, urease(Uand alkaline phosphatase(ALPwere investigated via an orthogonal experiment. Results showed as the following: When the concentration of Cu was 400 mg·kg-1, the U and ALP activities were decreased 51% and 44%, separately; When Zn was at 500 mg·kg-1, IN and ALP activities were only decreased 3% and 9%, while U activity was increased; When Pb was at 500 mg·kg-1, IN and U activities were increased, while ALP activity was decreased 13%. As a whole, Cu was considered as the most remarkable influence factor for IN, U and ALP activity regardless of interactions among the heavy metals, Zn came second, and Pb mainly showed activation. Considering interactions, Cu×Zn could significantly influence U activity(P<0.05, effects of Cu×Pb and Cu×Zn on ALP activity were remarkable(95% confidence interval. The response of ALP activity was more sensitive than the other two enzymes. Soil ALP activity might be a sensitive tool for assessing the pollution degree of Cu.

Remediation of Biological Organic Fertilizer and Biochar in Paddy Soil Contaminated by Cd and Pb

Directory of Open Access Journals (Sweden)

MA Tie-zheng

2015-02-01

Full Text Available The effect of application of biological organic fertilizer and biochar on the immobilized remediation of paddy soil contaminated by Cd and Pb was studied under the field experiment. The results showed that biological organic fertilizer and biochar increased the soil pH and soil nutrient contents, and reduced the soil available Cd and Pb concentrations significantly. The soil pH had significantly negative correla-tion with the soil available Cd and Pb contents. The application of biological organic fertilizer and biochar decreased Cd and Pb concentration in all parts of the rice plant, with Cd concentration in brown rice decrease by 22.00% and 18.34% and Pb decease in brown rice by 33.46% and 12.31%. The concentration of Cd and Pb in brown rice had significant positive correlation with the soil available Cd and Pb concentra-tions. It was observed that both biological organic fertilizer and biochar had a positive effect on the remediation of paddy soil contaminated by Cd and Pb.

First-principles-based analysis of the influence of Cu on CdTe electronic properties

International Nuclear Information System (INIS)

Krasikov, D.; Knizhnik, A.; Potapkin, B.; Selezneva, S.; Sommerer, T.

2013-01-01

The maximum voltage of CdTe solar cells is limited by low majority carrier concentration and doping difficulty. Copper that enters from the back contact can form both donors and acceptors in CdTe. It is empirically known that the free carrier concentration is several orders lower than the total Cu concentration. Simplified thermodynamic models of defect compensation after Cu introduction can be found in literature. We present a first-principles-based analysis of kinetics of defect formation upon Cu introduction, and show that Cu i is mobile at room temperature. Calculations of properties of Cu i –V Cd and Cu i –Cu Cd complexes show that the neutral Cu i –Cu Cd complex is mobile at elevated temperatures, while formation of the V Cd –Cu i complex is unlikely because it transforms into the Cu Cd defect. - Highlights: ► First-principles calculations of copper defects in CdTe are performed. ► Formation of Cd vacancy + Cu interstitial(Cu i ) complex is unlikely. ► Cu i defect is mobile at room temperature. ► Cu i + Cu on Cd-site (Cu Cd ) complex is mobile at elevated temperature. ► Cu Cd defect forms by kicking-out of the regular lattice Cd by Cu i

Cu-Doping Effects in CdI(2) Nanocrystals: The Role of Cu-Agglomerates.

Science.gov (United States)

Miah, M Idrish

2008-11-22

Cu-doping effects in CdI(2) nanocrystals are studied experimentally. We use the photostimulated second harmonic generation (PSSHG) as a tool to investigate the effects. It is found that the PSSHG increases with increasing Cu content up to 0.6% and then decreases due to the formation of the Cu-agglomerates. The PSSHG for the crystal with Cu content higher than 1% reduces to that for the undoped CdI(2) crystal. The results suggest that a crucial role of the Cu-metallic agglomerates is involved in the processes as responsible for the observed effects.

Cu-Doping Effects in CdI2Nanocrystals: The Role of Cu-Agglomerates

Directory of Open Access Journals (Sweden)

Miah M

2008-01-01

Full Text Available Abstract Cu-doping effects in CdI2nanocrystals are studied experimentally. We use the photostimulated second harmonic generation (PSSHG as a tool to investigate the effects. It is found that the PSSHG increases with increasing Cu content up to 0.6% and then decreases due to the formation of the Cu-agglomerates. The PSSHG for the crystal with Cu content higher than 1% reduces to that for the undoped CdI2crystal. The results suggest that a crucial role of the Cu-metallic agglomerates is involved in the processes as responsible for the observed effects.

[Effects of soil properties on the stabilization process of cadmium in Cd alone and Cd-Pb contaminated soils].

Science.gov (United States)

Wu, Man; Xu, Ming-Gang; Zhang, Wen-Ju; Wu, Hai-Wen

2012-07-01

In order to clarify the effects of soil properties on the stabilization process of the cadmium (Cd) added, 11 different soils were collected and incubated under a moisture content of 65%-70% at 25 degrees C. The changes of available Cd contents with incubation time (in 360 days) in Cd and Cd-Pb contaminated treatments were determined. The stabilization process was simulated using dynamic equations. The results showed that after 1.0 mg x kg(-1) Cd or 500 mg x kg(-1) Pb + 1.0 mg x kg(-1) Cd were added into the soil, the available Cd content decreased rapidly during the first 15 days, and then the decreasing rate slowed down, with an equilibrium content reached after 60 days' incubation. In Cd-Pb contaminated soils, the presence of Pb increased the content of available Cd. The stabilization process of Cd could be well described by the second-order equation and the first order exponential decay; meanwhile, dynamic parameters including equilibrium content and stabilization velocity were used to characterize the stabilization process of Cd. These two key dynamic parameters were significantly affected by soil properties. Correlation analysis and stepwise regression suggested that high pH and high cation exchange capacity (CEC) significantly retarded the availability of Cd. High pH had the paramount effect on the equilibrium content. The stabilization velocity of Cd was influenced by the soil texture. It took shorter time for Cd to get stabilized in sandy soil than in the clay.

Investigation of Cu-poor and Cu-rich Cu(In,Ga)Se{sub 2}/CdS interfaces using hard X-ray photoelectron spectroscopy

Energy Technology Data Exchange (ETDEWEB)

Ümsür, B., E-mail: buenyamin.uemsuer@helmholtz-berlin.de [Helmholtz-Zentrum-Berlin, Hahn-Meitner-Platz 1, D-14109 Berlin (Germany); Calvet, W.; Höpfner, B.; Steigert, A.; Lauermann, I.; Gorgoi, M.; Prietzel, K.; Navirian, H.A.; Kaufmann, C.A.; Unold, T. [Helmholtz-Zentrum-Berlin, Hahn-Meitner-Platz 1, D-14109 Berlin (Germany); Lux-Steiner, M. Ch. [Helmholtz-Zentrum-Berlin, Hahn-Meitner-Platz 1, D-14109 Berlin (Germany); Freie Universität Berlin, Department of Physics, Arnimallee 14, D-14195 Berlin (Germany)

2015-05-01

Cu-poor and Cu-rich Cu(In,Ga)Se{sub 2} (CIGSe) absorbers were used as substrates for the chemical bath deposition of ultrathin CdS buffer layers in the thickness range of a few nanometers in order to make the CIGSe/CdS interface accessible by hard X-ray photo-emission spectroscopy. The composition of both, the absorber and the buffer layer as well as the energetics of the interface was investigated at room temperature and after heating the samples to elevated temperatures (200 °C, 300 °C and 400 °C). It was found that the amount of Cd after the heating treatment depends on the near surface composition of the CIGSe absorber. No Cd was detected on the Cu-poor surface after the 400 °C treatment due to its diffusion into the CIGSe layer. In contrast, Cd was still present on the Cu-rich surface after the same treatment at 400 °C. - Highlights: • Cd diffusion into Cu(In,Ga)Se{sub 2} (CIGSe) absorber is investigated. • Cu-poor and Cu-rich CIGSe samples are compared. • Cd diffusion into CIGSe is found to be dependent on the surface composition of CIGSe.

Content Heavy Metal Pb, Cd In Perna viridis And Sediments In Semarang Bay

Science.gov (United States)

Suprapto, D.; Suryanti, S.; Latifah, N.

2018-02-01

Waste disposal from human activities, generally contain heavy metals such as Pb and Cd which derived from industrial activities. The aims of the study were to know the concentration of Pb and Cd heavy metals contained in Perna viridis tissue, sediment and water at Semarang Bay. This study was conducted in May 2017 at Semarang Bay. - Samples were collected using purposive sampling method. The heavy metal content in the water and clam was observed using- APHA method and was analyzed using AAS (Atomic Absorption Spectrophotometer). The results showed that concentration of heavy metal of Pb in the water was 0.00-50.5mg/L and the Cd content was of 26.9-51.7 mg/L, whereas the concentration of Pb in the sediment is 445.5-2.053.0mg/L and Cd 963.3-2,150.0 mg/L. Pb content in soft tissue of Perna viridis - is 67.1-1.933.9 mg/L and the concentration of Cd was 203.5-5.787.3 mg/L. The analysis of Pb and Cd in seawater, sediment and soft tissue of Perna viridis according to Enviroment Ministerial decree (KepMenLH ) number 51 of 2004 and applied by NOAA 1999 does not exceed the quality standard, that meant that the Perna viridis has been contaminated by metal Pb it is controversial with the above sentence and Cd. It concluded that the metal content of Pb and Cd in Perna viridis tissue exceeds the quality standard, so it is not suitable to be consumed, especially in high quantity

Determination of Ca, Cu, Fe and Pb in sugarcane raw spirits by atomic absorption spectrophotometry

International Nuclear Information System (INIS)

Lorenzo, Magdalena; Reyes, Arlyn; Blanco, Idania; Vasallo, Maria C

2010-01-01

The determination of Ca, Cu, Fe and Pb in sugarcane raw spirits by atomic absorption spectrophotometry was carried out. For 20 μL injected sample, calibration within the 0,5-25,0 mg. L -1 Ca; 0,25-5,0 mg. L -1 Cu, Pb and Cu intervals were established using the ratios Cu, Ca, Fe and Pb absorbance versus analyte concentration, respectively. Typical linear correlations of r = 0,999 were obtained. The proposed method was applied for the direct determination of Ca, Cu, Fe and Pb in sugar cane spirits, and in samples. The results obtained were in accordance to those obtained at 95% confidence level

Proficiency test Plant 6 - determination of As, Cd, Cu, Hg, Pb, Se and Zn in dry mushroom powder (Suillus bovinus)

International Nuclear Information System (INIS)

Polkowska-Motrenko, H.; Dudek, J.; Chajduk, E.; Sypula, M.; Sadowska-Bratek, M.

2006-01-01

Proficiency testing scheme PLANT 6: Determination of As, Cd, Cu, Hg, Pb, Se and Zn in dry mushroom powder (Suillus bovinus) has been described. The proficiency test has been provided by the Institute of Nuclear Chemistry and Technology (Warsaw) with cooperation with POLLAB-CHEM/EURACHEM-PL and REFMAT Society. Wild mushrooms were collected in the forest in north-west Poland, cleaned, i.e. dust, soil and attached mosses were removed. Mushrooms were cut into smaller parts and air dried in a dryer. Dried mushrooms were milled in a centrifugal mill and sieved. Particles of fraction below 1 mm diameter were collected. Analytical samples of 20 g mass were prepared. The material were then characterized by homogeneity testing and determination of assigned values for concentration of elements in question. The testing samples were sent to the laboratories participating in the proficiency test. The results supplied by the participants were statistically evaluated and the calculated values of z-score and En numbers were used for the evaluation of the participating laboratory competency. (author)

Study of the potential of barnyard grass for the remediation of Cd- and Pb-contaminated soil.

Science.gov (United States)

Xu, Jianling; Cai, Qiongyao; Wang, Hanxi; Liu, Xuejun; Lv, Jing; Yao, Difu; Lu, Yue; Li, Wei; Liu, Yuanyuan

2017-05-01

In this study, the microwave digestion method was used to determine total cadmium (Cd) and lead (Pb) concentrations, the BCR method was used to determine different states of Cd and Pb, and atomic absorption spectroscopy (AAS) and inductively coupled plasma optical emission spectrometry (ICP-OES) were used to determine Cd and Pb concentrations in simulated soil and barnyard grass before and after planting barnyard grass to provide a theoretical basis for the remediation of Cd- and Pb-contaminated soil. The results showed that the bioconcentration factor changes with different Cd concentrations are relatively complex and that the removal rate increases regularly. The 100 mg kg -1 Cd treatment had the highest removal rate, which reached 36.66%. For Pb, the bioconcentration factor decreased and tended to reach equilibrium as the Pb concentration increased. The highest removal rate was 41.72% and occurred in the 500 mg kg -1 Pb treatment; however, this removal rate was generally lower than that of Cd. In addition, the reduction state had the highest change rate, followed by the residual, acid soluble and oxidation states. For Pb, the residual state has the highest change rate, followed by the acid soluble state, reduction state and oxidation state. In addition, a significant correlation was observed between the soil Pb and Cd concentrations and the concentrations of Pb and Cd that accumulated in the belowground biomass of the barnyard grass, but no significant correlation was observed between the soil Pb and Cd concentrations and the amounts of Pb and Cd that accumulated in the aboveground biomass of the barnyard grass. The highest transfer factor of Cd was 0.49, which occurred in the 5 mg kg -1 Cd treatment. The higher transfer factor of Pb was 0.48 in the 100 mg kg -1 Pb treatment. All of these factors indicate that the belowground biomass of barnyard grass plays a more important role in the remediation of Cd- and Pb-contaminated soils than the aboveground

Availability of heavy metals (Cd, Pb, And Cr) in agriculture from commercial fertilizers.

Science.gov (United States)

Nacke, H; Gonçalves, A C; Schwantes, D; Nava, I A; Strey, L; Coelho, G F

2013-05-01

The purpose of this study was to investigate the availability of the heavy metals cadmium (Cd), lead (Pb), and chromium (Cr) to soil and maize plants fertilized with different sources and doses of zinc (Zn) in a Rhodic Eutrudox soil. For that purpose, concentrations of Cd, Pb, and Cr were evaluated in leaf tissue and grains of maize plants and in 0-20 and 20-40 cm soil layers after fertilization with four doses of Zn from eight different sources of fertilizer. There was no accumulation of Cd, Pb, and Cr in maize grain and Cd and Cr in leaf tissue of the plants; nevertheless, there was accumulation of Pb in leaf tissue, showing its availability throughout different sources of Zn and consequent uptake by plants. Regarding the soil, it was observed that fertilizer from the different sources made Cd, Pb, and Cr available at increasing amounts proportional to increased Zn doses. Under experimental conditions, fertilization with Zn increased concentrations of heavy metals Cd, Pb and Cr in soil, further highlighting the importance of conducting more studies related to the application of mineral fertilizers for micronutrient supply and the availability of heavy metals.

Preliminary study of CdTe and CdTe:Cu thin films nanostructures deposited by using DC magnetron sputtering

Energy Technology Data Exchange (ETDEWEB)

Marwoto, Putut; Made, D. P. Ngurah; Sugianto [Departement of Physics, Faculty of Mathematics and Natural Sciences, Universitas Negeri Semarang, Gunungpati, Semarang 50229 Jawa Tengah (Indonesia); Wibowo, Edy; Astuti, Santi Yuli; Aryani, Nila Prasetya [Materials Research Group, Laboratory of Thin Film, Department of Physics, Universitas Negeri Semarang, Gunungpati, Semarang 50229 Jawa Tengah (Indonesia); Othaman, Zulkafli [Departement of Physics, Universiti Teknologi Malaysia (UTM), Skudai, Johor Bahru (Malaysia)

2013-09-03

Growth and properties of CdTe and CdTe:Cu thin films nanostrucures deposited by using dc magnetron sputtering are reported. Scanning electron microscope (SEM) was used to observe the surface morphologies of the thin films. At growth conditions of 250 °C and 14 W, CdTe films did not yet evenly deposited. However, at growth temperature and plasma power of 325 °C and 43 W, both CdTe and CdTe:Cu(2%) have deposited on the substrates. In this condition, the morphology of the films indicate that the films have a grain-like nanostructures. Grain size diameter of about 200 nm begin to appear on top of the films. Energy Dispersive X-rays spectroscopy (EDX) was used to investigate chemical elements of the Cu doped CdTe film deposited. It was found that the film deposited consist of Cd, Te and Cu elements. XRD was used to investigate the full width at half maximum (FWHM) values of the thin films deposited. The results show that CdTe:Cu(2%) thin film has better crystallographic properties than CdTe thin film. The UV-Vis spectrometer was used to investigate the optical properties of thin films deposited. The transmittance spectra showed that transmittance of CdTe:Cu(2%) film is lower than CdTe film. It was found that the bandgap energy of CdTe and CdTe:Cu(2%) thin films of about 1.48 eV.

Noise properties of Pb/Cd-free thick film resistors

International Nuclear Information System (INIS)

Stadler, Adam Witold; Kolek, Andrzej; Zawislak, Zbigniew; Mleczko, Krzysztof; Jakubowska, Malgorzata; Kielbasinski, Konrad Rafal; Mlozniak, Anna

2010-01-01

Low-frequency noise spectroscopy has been used to examine noise properties of Pb/Cd-free RuO 2 - and CaRuO 3 -based thick films screen printed on alumina substrates. Experiments were performed in the temperature range 77-300 K and the frequency range 0.5-5000 Hz with multiterminal devices. The measured noise has been recognized as resistance noise that consists of background 1/f noise and components generated by several thermally activated noise sources (TANSs) of different activation energies. The total noise has been composed of the contributions generated in the resistive layer and in the resistive/conductive layers interface. These noise sources are non-uniformly distributed in the resistor volume. Noise intensity of new-resistive layers has been described by the noise parameter C bulk . Pb/Cd-free layers turned out to be noisier than their Pb-containing counterparts; however, the removal of Pb and Cd from resistive composition is hardly responsible for the increase in the noise. In the case of RuO 2 layers noise increases most likely due to larger grain size of RuO 2 powder used to prepare resistive pastes. Information on the quality of the resistive-to-conductive layers interface occurred to be stored in the values of noise parameter C int . Pb/Cd-free RuO 2 -based resistive pastes form well-behaved interfaces with various Ag-based conductive pastes. In contrast, CaRuO 3 -based paste forms bad contacts with AgPd terminations because the density of TANSs increases in the interface area.

Improved performance of CdSe/CdS/PbS co-sensitized solar cell with double-layered TiO2 films as photoanode

Science.gov (United States)

Zhang, Xiaolong; Lin, Yu; Wu, Jihuai; Jing, Jing; Fang, Biaopeng

2017-07-01

Improving the photovoltaic performance of CdSe/CdS/PbS co-sensitized double-layered TiO2 solar cells is reported. Double-layered TiO2 films with TiO2 microspheres as the light blocking layers were prepared. PbS, CdS and CdSe quantum dots (QDs) were assembled onto TiO2 photoanodes by simple successive ionic layer absorption and reaction (SILAR) to fabricate CdSe/CdS/PbS co-sensitized solar cells. An improved power conversion efficiency (PCE) of 5.11% was achieved for CdSe/CdS/PbS co-sensitized solar cells at one sun illumination (AM 1.5 G, 100 mW cm-2), which had an improvement of 22.6% over that of the CdSe/CdS co-sensitized solar cells (4.17%). This enhancement is mainly attributed to their better ability of the absorption of solar light with the existence of PbS QDs, the reduction of charge recombination of the excited electron and longer lifetime of electrons, which have been proved with the photovoltaic studies and electrochemical impedance spectroscopy (EIS).

Accumulation of Trace Metal Elements (Cu, Zn, Cd, and Pb in Surface Sediment via Decomposed Seagrass Leaves: A Mesocosm Experiment Using Zostera marina L.

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Shinya Hosokawa

Full Text Available Accumulation of Cu, Zn, Cd, and Pb in the sediment of seagrass ecosystems was examined using mesocosm experiments containing Zostera marina (eelgrass and reference pools. Lead was approximately 20-fold higher in the surface sediment in the eelgrass pool than in eelgrass leaves and epiphytes on the eelgrass leaves, whereas zinc and cadmium were significantly lower in the surface sediment than in the leaves, with intermediate concentrations in epiphytes. Copper concentrations were similar in both the surface sediment and leaves but significantly lower in epiphytes. Carbon and nitrogen contents increased significantly with increasing δ13C in surface sediments of both the eelgrass and reference pools. Copper, Zn, Cd, and Pb also increased significantly with increasing δ13C in the surface sediment in the eelgrass pool but not in the reference pool. By decomposition of eelgrass leaves with epiphytes, which was examined in the eelgrass pool, copper and lead concentrations increased more than 2-fold and approximately a 10-fold, whereas zinc and cadmium concentrations decreased. The high copper and lead concentrations in the surface sediment result from accumulation in decomposed, shed leaves, whereas zinc and cadmium remobilized from decomposed shed leaves but may remain at higher concentrations in the leaves than in the original sediments. The results of our mesocosm study demonstrate that whether the accumulation or remobilization of trace metals during the decomposition of seagrass leaves is trace metal dependent, and that the decomposed seagrass leaves can cause copper and lead accumulation in sediments in seagrass ecosystems.

Stabilization of As-, Pb-, and Cu-contaminated soil using calcined oyster shells and steel slag.

Science.gov (United States)

Moon, Deok Hyun; Wazne, Mahmoud; Cheong, Kyung Hoon; Chang, Yoon-Young; Baek, Kitae; Ok, Yong Sik; Park, Jeong-Hun

2015-07-01

In this study, As-, Pb-, and Cu-contaminated soil was stabilized using calcined oyster shells (COS) and steel slag (SS). The As-contaminated soil was obtained from a timber mill site where chromate copper arsenate (CCA) was used as a preservative. On the other hand, Pb- and Cu-contaminated soil was obtained from a firing range. These two soils were thoroughly mixed to represent As-, Pb-, and Cu-contaminated soil. Calcined oyster shells were obtained by treating waste oyster shells at a high temperature using the calcination process. The effectiveness of stabilization was evaluated by 1-N HCl extraction for As and 0.1-N HCl extraction for Pb and Cu. The treatment results showed that As, Pb, and Cu leachability were significantly reduced upon the combination treatment of COS and SS. The sole treatment of SS (10 wt%) did not show effective stabilization. However, the combination treatment of COS and SS showed a significant reduction in As, Pb, and Cu leachability. The best stabilization results were obtained from the combination treatment of 15 wt% COS and 10 wt% SS. The SEM-EDX results suggested that the effective stabilization of As was most probably achieved by the formation of Ca-As and Fe-As precipitates. In the case of Pb and Cu, stabilization was most probably associated with the formation of pozzolanic reaction products such as CSHs and CAHs.

Development, validation and accreditation of a method for the determination of Pb, Cd, Cu and As in seafood and fish feed samples.

Science.gov (United States)

Psoma, A K; Pasias, I N; Rousis, N I; Barkonikos, K A; Thomaidis, N S

2014-05-15

A rapid, sensitive, accurate and precise method for the determination of Pb, Cd, As and Cu in seafood and fish feed samples by Simultaneous Electrothermal Atomic Absorption Spectrometry was developed in regard to Council Directive 333/2007EC and ISO/IEC 17025 (2005). Different approaches were investigated in order to shorten the analysis time, always taking into account the sensitivity. For method validation, precision (repeatability and reproducibility) and accuracy by addition recovery tests have been assessed as performance criteria. The expanded uncertainties based on the Eurachem/Citac Guidelines were calculated. The method was accredited by the Hellenic Accreditation System and it was applied for an 8 years study in seafood (n=202) and fish feeds (n=275) from the Greek market. The annual and seasonal variation of the elemental content and correlation among the elemental content in fish feeds and the respective fish samples were also accomplished. Copyright © 2013 Elsevier Ltd. All rights reserved.

Etude d’impact des métaux traces (Hg, Cd, Pb, Cu et Zn) dans les cystes et la biomasse "d’Artemia" exploités dans la saline de Sfax

OpenAIRE

Aloui, N.; Amorri, M.; Choub., L.

2010-01-01

RESUME La saline de Sfax constitue un site potentiel pour l’exploitation et la production de l’Artemia locale. Des quantités importantes d’Artemia sont exploitées chaque année (60 kg de cystes poids sec) et sont utilisées en alimentation larvaire. Afin de démontrer l’impact de divers rejets industriels, agricoles dans cette saline, nous avons procédé à la détermination de quelques métaux traces toxiques : le mercure (Hg), le cadmium (Cd), le plomb (Pb), le cuivre (Cu) et le zinc (Zn) p...

Determination of Cu, Zn, Pb and Cd by Atomic Emission Spectrometry with Inductively Coupled Plasma in Organs of the Specie Gambusia punctata (Poeciliidae)

International Nuclear Information System (INIS)

Argota Perez, George; Argota Coello, Humberto; Rodriguez Amado, Jesus; Fernandez Heredia, Angel

2013-01-01

The aim of this research was to adequate the ICP-AES method to the quantification of Cu, Zn, Pb and Cd in brain, liver and gills of the specie Gambusia punctata, in order to know the level of exposure of the ecosystems San Juan and File in Santiago de Cuba province. To achieve the fitness for purpose of the method, limits of detection, reproducibility and accuracy were evaluated using reference certificated materials of fishes. The biological samples were classified according the ecosystem, length, sex and organ. It were dried, digested with mix of acids and the metals measured in the spectrometer. The results demonstrated that factors as length and sex have not influence in the bioaccumulation, whereas the gill was the organ where all the elements were bioaccumulated. Finally, due that the smallest concentrations of metals were in the File ecosystem, it could be used as an environmental reference

Evaluation of the air quality regarding total suspended particles and heavy metals (Pb, Cd, Ni, Cu, Cr) in the Hermosillo city, Sonora, Mexico, during a yearly period; Evaluacion de la calidad del aire respecto de particulas suspendidas totales y metales pesados (Pb, Cd, Ni, Cu, Cr) en la Ciudad de Hermosillo, Sonora, Mexico, durante un periodo anual

Energy Technology Data Exchange (ETDEWEB)

Cruz C, M. E.; Quintero N, M. [Universidad Autonoma de Baja California, Instituto de Ingenieria, Campus Mexicali, Calle de la Normal s/n, y Blvd. Benito Juarez, Col. Insurgentes Este, Mexicali, Baja California (Mexico); Gomez A, A.; Varela S, J., E-mail: martincruzcampas@hotmail.com [Universidad de Sonora, Departamento de Ingenieria Quimica y Metalurgia, Blvd. Rosales y Luis Ensina s/n, Edificio 5B, Col. Centro, 83000 Hermosillo, Sonora (Mexico)

2013-07-01

In the present study, the air quality of the city of Hermosillo, Sonora, Mexico was assessed considering total suspended particulates (tsp) and heavy metals (Pb, Cd, Ni, Cu, Cr) from June 2001 through May 2002 in three monitoring sites Centro (Mazon), Nor este (CESUES) and Noroeste (CBTIS). The filter-samples used for that purpose were provided by the Air Quality Evaluation and Improvement Program (PEMCA) of the municipality of Hermosillo. The sampling method was based on high volume sampling frequency set every 6 days with non-simultaneous sampling among the three sampling sites. Filters were dissolved for metal determination by acidic-extraction, and then analyzed by flame atomic absorption spectrophotometry. Results indicate that tsp concentrations at Centro and Noroeste sites were frequently higher than the maximum daily permissible level (260 {mu}g/m{sup 3}), while in the three sites the annual average was higher than the maximum annual permissible level (75 {mu}g/m{sup 3}) both established in the standard NOM-024-Ssa-1993 (Ssa 1994a). According to the Air Quality Standard Index (US EPA 1992a), used in Mexico by Air Quality Metropolitan Index (IMECA) the results indicate that the air quality in the city of Hermosillo regarding tsp was placed between no satisfactory and poor. In regard to heavy metals (Pb, Cd, Ni, Cu, Cr), concentrations detected were below the maximum permissible levels and/or criteria taking into account the standard NOM-026-Ssa-1993 (Ssa 1994b), the Who criterion (2000), the European Union criterion (Cec 2003), and the European Environmental Agency criteria (EEA 2004). Such findings would mean that airborne metals are of no concern; however, air quality is still classified as no satisfactory due to high particulate matter concentrations. Keeping air quality parameters monitoring is recommended in order to get extensive data for use in risk studies of air quality and health (morbidity/mortality), as well as topographic conditions

Bioaccessibility of Ba, Cu, Pb, and Zn in urban garden and orchard soils

International Nuclear Information System (INIS)

Cai, Meifang; McBride, Murray B.; Li, Kaiming

2016-01-01

Exposure of young children to toxic metals in urban environments is largely due to soil and dust ingestion. Soil particle size distribution and concentrations of toxic metals in different particle sizes are important risk factors in addition to bioaccessibility of these metals in the particles. Analysis of particle size distribution and metals concentrations for 13 soils, 12 sampled from urban gardens and 1 from orchard found that fine particles (<105 μm) comprised from 22 to 66% by weight of the tested soils, with Ba, Cu, Pb and Zn generally at higher concentrations in the finer particles. However, metal bioaccessibility was generally lower in finer particles, a trend most pronounced for Ba and Pb. Gastric was higher than gastrointestinal bioaccessibility for all metals except Cu. The lower bioaccessibility of Pb in urban garden soils compared to orchard soil is attributable to the higher organic matter content of the garden soils. - Highlights: • The bioaccessibility of metals in urban garden and orchard soils was measured. • Ba, Cu, Pb, Zn were concentrated in fine particles of the soils. • Bioaccessibilities of Ba and Pb were generally lower in fine particles of soils. • Pb bioaccessibility was generally lower in soils with higher organic matter content. • Pb bioaccessibility was lower in urban garden soils than in an orchard soil. - Pb and other trace metals (Ba, Cu, Zn) were concentrated in fine particles of urban and orchard soils, but the bioaccessibility of Ba and Pb was generally lower in finer particles.

Study on accumulation of Fe, Pb, Zn, Ni and Cd in Nerita lineata and Thais bitubercularis from Tanjung Harapan and Teluk Kemang, Malaysia.

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Tengku

2017-01-01

Full Text Available The presence of Cd, Cu, Zn, Ni, Fe, Al, Zn, Mn, Cr, and Sn were attributed to metal industries. Cu contamination was associated with piggery industry. Shipping activities contribute to elevated levels of Pb, Cu and As. Elevated levels of metals in the sediments are attributed to anthropogenic activities. Samples were collected in April 2012 and analysed using inductively coupled plasma mass spectrometry (ICP-MS. Fe is the most abundant metal in the tissue and shell compared to the rest of the metals. The concentrations of heavy metals in the soft tissues of Nerita lineata taken from Tanjung Harapan follow this order: Fe > Zn > Ni > Cu > Cd while in Thais bitubercularis, the metal concentrations were higher following the order of Fe > Zn > Cu > Ni > Cd. The samples taken from Teluk Kemang were higher and exhibited different trend for both organisms. Results from this study are useful for further exploration of Thais bitubercularis as accumulators of Cu, Cd, and Zn. For recommendation, more studies on monitoring the concentration level of heavy metals in marine environment should be done regularly and increase numbers of samples use to biomonitor the heavy metals in marine environment as it is important to have information or data regarding the quality of marine environment in order to control pollution such as water pollution from being contaminated with heavy metals. This is essential as the pollutants emit in the marine environment may affect marine lives as well as human’s health

Forest Soil Pollution with Heavy Metals (Pb, Zn, Cd, and Cu in the Area of the “French Mines” on the Medvednica Mountain, Republic of Croatia

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Ivan Perković

2017-01-01

Full Text Available Background and Purpose: This paper deals with the results of the investigation of the selected heavy metal contents in forest soil in the region of an abandoned mine. The analysis of the forest ecosystem soil on the Medvednica Mountain was conducted in the region of the so-called “French Mines” (FM. The elements selected for analyses were cadmium (Cd, copper (Cu, lead (Pb, and zinc (Zn because of their toxicological characteristics. Material and Methods: In the investigated area - five entrances of the FM - composite topsoil samples (0–5 cm were taken. Those samples were compared to the control samples which were taken outside the area affected by mines. The soil samples were analysed for the following parameters: pH, particle size distribution, organic C content and pseudo-total mass fractions of the selected heavy metals. The heavy metals were determined by atomic emission spectrometry with inductively coupled plasma (ICP-MS. Results and Conclusion: The results reveal that the soil is locally polluted, i.e. the highest mass fraction values of these four heavy metals were found in the area of the FM. Average pseudo-total fraction of Cd in the analysed topsoil samples was in the range of 0.17–4.41 mg·kg−1 (median: 0.97 mg·kg−1. Cu was found in the range of 4.54–1260 mg·kg−1 (median: 45.7 mg·kg−1. In the case of Zn, mass fraction values were found in the range of 36.8–865 mg·kg−1 (median: 137 mg·kg−1. Finally, average values of the pseudo-total fraction of Pb were found in the range of 58.4–12000 mg·kg−1 (median: 238 mg·kg−1. The results reveal that mining activities leave consequences on soil for a long time.

Deposition of Cu-doped PbS thin films with low resistivity using DC sputtering

Science.gov (United States)

Soetedjo, Hariyadi; Siswanto, Bambang; Aziz, Ihwanul; Sudjatmoko

2018-03-01

Investigation of the electrical resistivity of Cu-doped PbS thin films has been carried out. The films were prepared using a DC sputtering technique. The doping was achieved by introducing the Cu dopant plate material directly on the surface of the PbS sputtering target plate. SEM-EDX data shows the Cu concentration in the PbS film to be proportional to the Cu plate diameter. The XRD pattern indicates the film is in crystalline cubic form. The Hall effect measurement shows that Cu doping yields an increase in the carrier concentration to 3.55 × 1019 cm-3 and a significant decrease in electrical resistivity. The lowest resistivity obtained was 0.13 Ωcm for a Cu concentration of 18.5%. Preferential orientation of (1 1 1) and (2 0 0) occurs during deposition.

Whisker and Hillock formation on Sn, Sn-Cu and Sn-Pb electrodeposits

International Nuclear Information System (INIS)

Boettinger, W.J.; Johnson, C.E.; Bendersky, L.A.; Moon, K.-W.; Williams, M.E.; Stafford, G.R.

2005-01-01

High purity bright Sn, Sn-Cu and Sn-Pb layers, 3, 7 and 16 μm thick were electrodeposited on phosphor bronze cantilever beams in a rotating disk apparatus. Beam deflection measurements within 15 min of plating proved that all electrodeposits had in-plane compressive stress. In several days, the surfaces of the Sn-Cu deposits, which have the highest compressive stress, develop 50 μm contorted hillocks and 200 μm whiskers, pure Sn deposits develop 20 μm compact conical hillocks, and Sn-Pb deposits, which have the lowest compressive stress, remain unchanged. The differences between the initial compressive stresses for each alloy and pure Sn is due to the rapid precipitation of Cu 6 Sn 5 or Pb particles, respectively, within supersaturated Sn grains produced by electrodeposition. Over longer time, analysis of beam deflection measurements indicates that the compressive stress is augmented by the formation of Cu 6 Sn 5 on the bronze/Sn interface, while creep of the electrodeposit tends to decrease the compressive stress. Uniform creep occurs for Sn-Pb because it has an equi-axed grain structure. Localized creep in the form of hillocks and whiskers occurs for Sn and Sn-Cu because both have columnar structures. Compact hillocks form for the Sn deposits because the columnar grain boundaries are mobile. Contorted hillocks and whiskers form for the Sn-Cu deposits because the columnar grain boundary motion is impeded

Contact angle study on the activation mechanisms of sphalerite with Cu(II) and Pb(II); Estudio de los mecanismos de activacion de la esfalerita con Cu(II) y Pb(II)

Energy Technology Data Exchange (ETDEWEB)

Davila Pulido, G. I.; Uribe Salas, A.

2011-07-01

This article presents results of an experimental study on the sphalerite activation with Cu(II) and Pb(II), whose main objective was to investigate the activation mechanisms and to evaluate the magnitude of the hydrophobization achieved with both chemical species. The hydrophobicity acquired by the mineral due to the interaction with the activator and collector (sodium isopropyl xanthate) is characterized making use of the contact angle technique. The results show that Cu(II) replaces the Zn of the external layers of the mineral, promoting the sulfide (S{sup 2}-) oxidation to produce a mixture of CuS, Cu{sub 2}S and S{sup o}, of hydrophobic nature. The subsequent interaction with xanthate increases the hydrophobicity of the mineral surface. In turn, Pb(II) activation of sphalerite is due to the formation of a PbS layer that reacts with xanthate to produce hydrophobic species (e.g., PbX{sub 2}). It is also observed that the hydrophobicity of sphalerite activated with Pb(II) is favored under air atmospheres, as compared to that obtained under nitrogen atmospheres. It is concluded that the hydrophobicity achieved by lead activation may be of the same order of magnitude to that deliverately induced by copper activation. (Author) 11 refs.

Assessing comparative terrestrial ecotoxicity of Cd, Co, Cu, Ni, Pb, and Zn: The influence of aging and emission source

International Nuclear Information System (INIS)

Owsianiak, Mikołaj; Holm, Peter E.; Fantke, Peter; Christiansen, Karen S.; Borggaard, Ole K.; Hauschild, Michael Z.

2015-01-01

Metal exposure to terrestrial organisms is influenced by the reactivity of the solid-phase metal pool. This reactivity is thought to depend on the type of emission source, on aging mechanisms that are active in the soil, and on ambient conditions. Our work shows, that when controlling for soil pH or soil organic carbon, emission source occasionally has an effect on reactivity of Cd, Co, Cu, Ni, Pb and Zn emitted from various anthropogenic sources followed by aging in the soil from a few years to two centuries. The uncertainties in estimating the age prevent definitive conclusions about the influence of aging time on the reactivity of metals from anthropogenic sources in soils. Thus, for calculating comparative toxicity potentials of man-made metal contaminations in soils, we recommend using time-horizon independent accessibility factors derived from source-specific reactive fractions. - Highlights: • We found an effect of source on reactivity of anthropogenic metals in soils. • The influence of aging on reactivity of anthropogenic metals was not consistent. • We recommend including source and disregarding aging in calculation of CTPs values. - Improving current life cycle inventory (LCI) and life cycle impact assessment (LCIA) practice in terrestrial ecotoxicity assessment of metals.

Pollution of soils (Pb, Cd, Cr, Zn, Cu, Ni) along the ring road of Wrocław (Poland)

Science.gov (United States)

Hołtra, Anna; Zamorska-Wojdyła, Dorota

2017-11-01

The concentrations of metallic pollution in soils and plants along the ring road of Wrocław, Poland, have been determined. Environmental samples were collected from the surface layer of the profile within 2-3 m from the edge of the road. The analysis of metals (Pb, Cd, Cr, Zn, Cu and Ni) has been carried out through FAAS and GFAAS methods. The mineralizates of soils and plants were prepared in HNO3, 65% supra pure, using the Microwave Digestion System. The pH and conductivity of the soil solutions were measured to evaluate their active and exchangeable acidity and the salinity of the soils. The index of the enrichment of soils in metals (Wn) and the bioaccumulation coefficient (WB) have been determined. Also, histograms of the frequency of the occurrence of metals in the environmental samples and the Pearson's correlation coefficients were presented. The results of metal concentrations in soils were compared to the geochemical background in uncontaminated soils of Poland. The assessment of the results in the soils was also made relative to the standard, according to the Polish Ministry of Environment Regulation from September 1st, 2016. During the assessment of the bioaccumulation coefficients of metals in plants a reference was made to the content of undesirable substances in feed in agreement with the Polish Ministry of Agriculture and Rural Development Regulation from January 23rd, 2007.

Effect of heavy metals (Cu, Cd and Pb) on aspartate and alanine aminotransferase in Ruditapes philippinarum (Mollusca: Bivalvia)

International Nuclear Information System (INIS)

Blasco, J.; Puppo, J.

1999-01-01

The accumulation of cadmium, copper and lead and their effects on aspartate and alanine aminotransferases in digestive gland, gills, foot and soft body in the clam Ruditapes philippinarum were examined. The animals were exposed to different concentrations: Cd (200-600 μg·l -1 ), Pb (350-700 μg·l -1 ) and Cu (10-20 μg·l -1 ) for 7 days. The highest concentrations were found in digestive gland for cadmium and copper, and in gills for lead, and the lowest values were observed in the foot. Aspartate aminotransferase activity (AST), in general, was not inhibited by cadmium, lead or copper during the exposure. Only in clams exposed to cadmium (600 μg·l -1 , 7 days) and copper (20 μg·l -1 , 5 days) were observed significant differences (P -1 . A significant correlation (P<0.05) was observed between ALT and metal accumulation for cadmium, copper and lead in gills. In the case of soft body, only cadmium and lead showed a significant correlation. In summary, R. philippinarum can be considered a bioindicator species for cadmium and lead accumulation and ALT could be useful as biomarker of sublethal stress for these metals in soft tissues and gills. Only gills can be considered an adequate target tissue for copper. (Copyright (c) 1999 Elsevier Science B.V., Amsterdam. All rights reserved.)

Deposition of Cu-doped PbS thin films with low resistivity using DC sputtering

Directory of Open Access Journals (Sweden)

Hariyadi Soetedjo

2018-03-01

Full Text Available Investigation of the electrical resistivity of Cu-doped PbS thin films has been carried out. The films were prepared using a DC sputtering technique. The doping was achieved by introducing the Cu dopant plate material directly on the surface of the PbS sputtering target plate. SEM-EDX data shows the Cu concentration in the PbS film to be proportional to the Cu plate diameter. The XRD pattern indicates the film is in crystalline cubic form. The Hall effect measurement shows that Cu doping yields an increase in the carrier concentration to 3.55 × 1019 cm−3 and a significant decrease in electrical resistivity. The lowest resistivity obtained was 0.13 Ωcm for a Cu concentration of 18.5%. Preferential orientation of (1 1 1 and (2 0 0 occurs during deposition. Keywords: Thin films, Lead sulfide, Sputtering, Resistivity, Semiconductor, Infrared

Evaluation of the air quality regarding total suspended particles and heavy metals (Pb, Cd, Ni, Cu, Cr) in the Hermosillo city, Sonora, Mexico, during a yearly period

International Nuclear Information System (INIS)

Cruz C, M. E.; Quintero N, M.; Gomez A, A.; Varela S, J.

2013-01-01

In the present study, the air quality of the city of Hermosillo, Sonora, Mexico was assessed considering total suspended particulates (tsp) and heavy metals (Pb, Cd, Ni, Cu, Cr) from June 2001 through May 2002 in three monitoring sites Centro (Mazon), Nor este (CESUES) and Noroeste (CBTIS). The filter-samples used for that purpose were provided by the Air Quality Evaluation and Improvement Program (PEMCA) of the municipality of Hermosillo. The sampling method was based on high volume sampling frequency set every 6 days with non-simultaneous sampling among the three sampling sites. Filters were dissolved for metal determination by acidic-extraction, and then analyzed by flame atomic absorption spectrophotometry. Results indicate that tsp concentrations at Centro and Noroeste sites were frequently higher than the maximum daily permissible level (260 μg/m 3 ), while in the three sites the annual average was higher than the maximum annual permissible level (75 μg/m 3 ) both established in the standard NOM-024-Ssa-1993 (Ssa 1994a). According to the Air Quality Standard Index (US EPA 1992a), used in Mexico by Air Quality Metropolitan Index (IMECA) the results indicate that the air quality in the city of Hermosillo regarding tsp was placed between no satisfactory and poor. In regard to heavy metals (Pb, Cd, Ni, Cu, Cr), concentrations detected were below the maximum permissible levels and/or criteria taking into account the standard NOM-026-Ssa-1993 (Ssa 1994b), the Who criterion (2000), the European Union criterion (Cec 2003), and the European Environmental Agency criteria (EEA 2004). Such findings would mean that airborne metals are of no concern; however, air quality is still classified as no satisfactory due to high particulate matter concentrations. Keeping air quality parameters monitoring is recommended in order to get extensive data for use in risk studies of air quality and health (morbidity/mortality), as well as topographic conditions, meteorological and

Co-contamination of Cu and Cd in paddy fields: Using periphyton to entrap heavy metals

Energy Technology Data Exchange (ETDEWEB)

Yang, Jiali [State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Sciences, Chinese Academy of Sciences, 71 East Beijing Road, Nanjing 210008 (China); College of Resource and Environment, University of Chinese Academy of Sciences, Beijing 100049 (China); Tang, Cilai [Department of Environmental Engineering, College of Hydraulic & Environmental Engineering, China Three Gorges University, Yichang 443002 (China); Wang, Fengwu [State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Sciences, Chinese Academy of Sciences, 71 East Beijing Road, Nanjing 210008 (China); School of Civil Engineering, East China Jiaotong University, 808 Shuang Gang East Road, Nanchang, Jiangxi 330013 (China); Wu, Yonghong, E-mail: yhwu@issas.ac.cn [State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Sciences, Chinese Academy of Sciences, 71 East Beijing Road, Nanjing 210008 (China)

2016-03-05

Highlights: • Periphyton was capable of simultaneously entrapping Cu and Cd from paddy fields. • Cu and Cd bioavailability decreased with time after exposure to periphyton. • Periodic adsorption–desorption was the main mechanism used to remove Cd and Cu. • Periphyton was able to adapt to steady accumulation of Cu and Cd. • The inclusion of periphyton will help entrap heavy metals in paddy fields. - Abstract: The ubiquitous native periphyton was used to entrap Cu and Cd from paddy fields. Results showed that Cu- and Cd-hydrate species such as CuOH{sup +}, Cu{sub 2}(OH){sub 2}{sup 2+}, CdOH{sup +}, and Cu{sub 3}(OH){sub 4}{sup 2+} decreased with time in the presence of periphyton. When the initial concentrations of Cu and Cd were 10 mg/L, the heavy metal content in the periphyton fluctuated from 145.20 mg/kg to 342.42 mg/kg for Cu and from 101.75 mg/kg to 236.29 mg/kg for Cd after 2 h exposure. The concentration of Cd in periphytic cells varied from 42.93 mg/kg to 174 mg/kg after 2 h. The dominant periphyton microorganism species shifted from photoautotrophs to heterotrophs during the exposure of periphyton to Cu and Cd co-contamination. Although Cu and Cd could inhibit periphyton photosynthesis and carbon utilization, the periphyton was able to adapt to the test conditions. Cu and Cd accumulation in rice markedly decreased in the presence of periphyton while the number of rice seeds germinating was higher in the periphyton treatments. These results suggest that the inclusion of native periphyton in paddy fields provides a promising buffer to minimize the effects of Cu and Cd pollution on rice growth and food safety.

Adsorption of Cu, As, Pb and Zn by Banana Trunk

International Nuclear Information System (INIS)

Nurzulaifa Shaheera Erne Mohd Yasim; Zitty Sarah Ismail; Suhanom Mohd Zaki; Mohd Fahmi Abd Azis

2016-01-01

The purpose of this study is to investigate the effectiveness of banana trunk as an adsorbent in removal of heavy metals in aqueous solution. Functional groups of adsorbent were determined using Fourier Transform Infrared spectroscopy (FTIR). Batch experiments were conducted to determine the adsorption percentage of heavy metals (Cu, As, Pb and Zn). The optimum adsorption using banana trunk was based on pH difference, contact time and dosage. Adsorption percentage was found to be proportional to pH, contact time and dosage. Maximum adsorption percentage of Cu, As, Pb and Zn at pH 6, 100 minutes and 8 gram of dosage are 95.80 %, 75.40 %, 99.36 % and 97.24 %, respectively. Langmuir and Freundlich isotherms were used to determine the equilibrium state for heavy metals ion adsorption experiments. All equilibrium heavy metals were well explained by the Freundlich isotherm model with R"2= 0.9441, R"2= 0.8671, R"2= 0.9489 and R"2= 0.9375 for Cu, As, Pb and Zn respectively. It is concluded that banana trunk has considerable potential for the removal of heavy metals from aqueous solution. (author)

The effect of intermetallic compound morphology on Cu diffusion in Sn-Ag and Sn-Pb solder bump on the Ni/Cu Under-bump metallization

Science.gov (United States)

Jang, Guh-Yaw; Duh, Jenq-Gong

2005-01-01

The eutectic Sn-Ag solder alloy is one of the candidates for the Pb-free solder, and Sn-Pb solder alloys are still widely used in today’s electronic packages. In this tudy, the interfacial reaction in the eutectic Sn-Ag and Sn-Pb solder joints was investigated with an assembly of a solder/Ni/Cu/Ti/Si3N4/Si multilayer structures. In the Sn-3.5Ag solder joints reflowed at 260°C, only the (Ni1-x,Cux)3Sn4 intermetallic compound (IMC) formed at the solder/Ni interface. For the Sn-37Pb solder reflowed at 225°C for one to ten cycles, only the (Ni1-x,Cux)3Sn4 IMC formed between the solder and the Ni/Cu under-bump metallization (UBM). Nevertheless, the (Cu1-y,Niy)6Sn5 IMC was observed in joints reflowed at 245°C after five cycles and at 265°C after three cycles. With the aid of microstructure evolution, quantitative analysis, and elemental distribution between the solder and Ni/Cu UBM, it was revealed that Cu content in the solder near the solder/IMC interface played an important role in the formation of the (Cu1-y,Niy)6Sn5 IMC. In addition, the diffusion behavior of Cu in eutectic Sn-Ag and Sn-Pb solders with the Ni/Cu UBM were probed and discussed. The atomic flux of Cu diffused through Ni was evaluated by detailed quantitative analysis in an electron probe microanalyzer (EPMA). During reflow, the atomic flux of Cu was on the order of 1016-1017 atoms/cm2sec in both the eutectic Sn-Ag and Sn-Pb systems.

The effect of Cu addition and milling contaminations on the microstructure evolution of ball milled Al-Pb alloy during sintering

International Nuclear Information System (INIS)

Zhu, M.; Ouyang, L.Z.; Wu, Z.F.; Zeng, M.Q.; Li, Y.Y.; Zou, J.

2006-01-01

Al-10 wt.%Pb and Al-10 wt.%Pb-x wt.%Cu (x = 0-7.0) bulk alloys were prepared by sintering the mechanically alloyed powders at various temperatures. The microstructure changes of the as consolidated powders in the course of sintering were analyzed by differential scanning calorimetry, scanning electron microscopy, X-ray diffraction analysis and transmission electron microscopy. It has been found that, with respect to the Al-10 wt.%Pb-x wt.%Cu alloy, CuAl 2 and Cu 9 Al 4 phases formed in the milling process, and the amount of CuAl 2 phase increased while the Cu 9 Al 4 phase disappeared gradually in the sintering process. In both Al-10 wt.%Pb and Al-10 wt.%Pb-x wt.%Cu alloys, the sintering process results in the coarsening of Pb phase and the growth rate of Pb phase fulfills the Lifshitz-Slyozov-Wagner equation even though the size of the Pb phase was in nanometer range. The Pb particle exhibits cuboctahedral morphology and has a cubic to cubic orientation relationship with the Al matrix. The addition of Cu strongly depressed the growth rate of Pb. Contamination induced by milling has apparent influence on the microstructure of the sintered alloys. Al 7 Cu 2 Fe and aluminium oxide phases were identified in the sintered alloys. The cuboctahedral morphology of Pb particles was broken up by the presence of the oxide phase

Radionuclide X-ray fluorescence determination of Mn, Fe, Cu, Zn and Pb in wastewaters and sludges from wastewater treatment plants in Bratislava (SR)

International Nuclear Information System (INIS)

Harangozo, M.; Toelgyessy, J.

1997-01-01

Radiometric X-ray fluorescence analysis was used for the determination of Mn, Fe, Cu, Zn and Pb in wastewater and sludges from three wastewater treatment plants in Bratislava (SR). Metals were determined in wastewaters after preconcentration by 8-hydroxyquinoline and in sludges by drying and pressing to pellets. 238 Pu and 109 Cd was used for excitation of fluorescence radiation. (author)

VALIDACIÓN DE LA METODOLOGÍA PARA LA DETERMINACIÓN DE SB, AS, CD, CU, CR, HG, NI, PB Y ZN EN SEDIMENTOS POR ICO-MS

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Hermógenes Rosas Rodríguez

2004-01-01

Full Text Available En este trabajo se presentan los resultados obtenidos en la validación de la técnica ICP-MS utilizada para la determinación de nueve elementos en sedimentos: Sb, As, Cd, Cu, Cr, Hg, Ni, Pb y Zn. Para ello se llevó a cabo el estudio de los siguientes parámetros de fiabilidad: precisión, exactitud y límites de detección y cuantificación. Para el análisis de estos elementos se utilizó un ICP-MS ELAN 6000 de Perkin Elmer®. El estudio de los distintos parámetros de validación fue muy satisfactorio para la mayoría de los analitos, alcanzándose límites de detección y de cuantificación muy bajos (inferiores a 1microg/l e incluso de 1 ng/l para el Cd. El método ICP-MS es exacto y preciso, obteniéndose para la mayoría de los elementos coeficientes de variación en torno al 2% y porcentajes de recuperación del 100%.

Biosorption of Pb2+ and Cu2+ in aqueous solutions using agricultural wastes

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Nieva Aileen D.

2017-01-01

Full Text Available This study aimed to determine and compare the adsorptive capacity of Pb2+ and Cu2+ in simulated wastewater onto three agricultural wastes The adsorption capacities of Pb2+ onto the agricultural wastes can be arranged as Litchi chinensis (4.30 mg of sorbate per g of sorbent (mg g-1, 85.68% adsorption > Bambusa vulgaris (3.83 mg g-1, 76.19% adsorption > Annona squamosa (2.70 mg g-1, 53.66% adsorption while the adsorption capacities of Cu2+ onto the same agricultural wastes can be arranged in the order: Bambusa vulgaris (3.86 mg g-1, 77.17% adsorption > Annona squamosal (3.58 mg g-1, 71.58% adsorption > Litchi chinensis (3.42 mg g-1, 68.32% adsorption. The biosorbents had relatively higher adsorptive capacities with Cu2+ as compared to that of Pb2+ except for Litchi chinensis. Although the results show lower adsorptive capacity as compared to a number of treated agricultural wastes showing 80% up to almost 100% adsorption of Pb2+ and Cu2+, the results show that Annona squamosa, Bamubusa vulgaris, and Litchi chinensis are potential biosorbents and promote sustainable treatment process.

Synthesis and application of a novel Cu/RGO@Pb alloy for lead-acid batteries

International Nuclear Information System (INIS)

Wu, Yumeng; Zhao, Ruirui; Zhou, Huawen; Zhang, Dejing; Zhao, Wei; Chen, Hongyu

2016-01-01

In this work, a novel Cu/RGO@Pb alloy was prepared successfully and tested in the simulated lead-acid battery environment. In preparing the novel alloy, Cu/RGO composite was firstly synthesized in order to increase the wettability of RGO to Pb, and then the composite was added to the molten lead to obtain the target alloy. Scanning electron microscope, energy dispersive spectrometer, X-ray diffraction as well as electrochemical measurements were employed to evaluate the performance of the obtained composite and alloy. Results show that the prepared Cu/RGO@Pb possessed higher oxygen evolution over-potential and lower hydrogen evolution over-potential than the contrast alloy, indicating this novel alloy was more suitable for using as positive grids in lead acid batteries. Moreover, the RGO additive could inhibit the formation of Pb(II) and Pb(IV) film on the surface of the alloy, which could enhance the deep-charge/discharge performance of the grids and improve the corrosion resistance.

A Diffusive Gradient-in-Thin-Film Technique for Evaluation of the Bioavailability of Cd in Soil Contaminated with Cd and Pb

Science.gov (United States)

Wang, Peifang; Wang, Teng; Yao, Yu; Wang, Chao; Liu, Cui; Yuan, Ye

2016-01-01

Management of heavy metal contamination requires accurate information about the distribution of bioavailable fractions, and about exchange between the solid and solution phases. In this study, we employed diffusive gradients in thin-films (DGT) and traditional chemical extraction methods (soil solution, HOAc, EDTA, CaCl2, and NaOAc) to determine the Cd bioavailability in Cd-contaminated soil with the addition of Pb. Two typical terrestrial species (wheat, Bainong AK58; maize, Zhengdan 958) were selected as the accumulation plants. The results showed that the added Pb may enhance the efficiency of Cd phytoextraction which is indicated by the increasing concentration of Cd accumulating in the plant tissues. The DGT-measured Cd concentrations and all the selected traditional extractants measured Cd concentrations all increased with increasing concentration of the addition Pb which were similar to the change trends of the accumulated Cd concentrations in plant tissues. Moreover, the Pearson regression coefficients between the different indicators obtained Cd concentrations and plants uptake Cd concentrations were further indicated significant correlations (p < 0.01). However, the values of Pearson regression coefficients showed the merits of DGT, CaCl2, and Csol over the other three methods. Consequently, the in situ measurement of DGT and the ex situ traditional methods could all reflect the inhibition effects between Cd and Pb. Due to the feature of dynamic measurements of DGT, it could be a robust tool to predict Cd bioavaiability in complex contaminated soil. PMID:27271644

A Diffusive Gradient-in-Thin-Film Technique for Evaluation of the Bioavailability of Cd in Soil Contaminated with Cd and Pb

Directory of Open Access Journals (Sweden)

Peifang Wang

2016-06-01

Full Text Available Management of heavy metal contamination requires accurate information about the distribution of bioavailable fractions, and about exchange between the solid and solution phases. In this study, we employed diffusive gradients in thin-films (DGT and traditional chemical extraction methods (soil solution, HOAc, EDTA, CaCl2, and NaOAc to determine the Cd bioavailability in Cd-contaminated soil with the addition of Pb. Two typical terrestrial species (wheat, Bainong AK58; maize, Zhengdan 958 were selected as the accumulation plants. The results showed that the added Pb may enhance the efficiency of Cd phytoextraction which is indicated by the increasing concentration of Cd accumulating in the plant tissues. The DGT-measured Cd concentrations and all the selected traditional extractants measured Cd concentrations all increased with increasing concentration of the addition Pb which were similar to the change trends of the accumulated Cd concentrations in plant tissues. Moreover, the Pearson regression coefficients between the different indicators obtained Cd concentrations and plants uptake Cd concentrations were further indicated significant correlations (p < 0.01. However, the values of Pearson regression coefficients showed the merits of DGT, CaCl2, and Csol over the other three methods. Consequently, the in situ measurement of DGT and the ex situ traditional methods could all reflect the inhibition effects between Cd and Pb. Due to the feature of dynamic measurements of DGT, it could be a robust tool to predict Cd bioavaiability in complex contaminated soil.

Electroluminescent Cu-doped CdS quantum dots

NARCIS (Netherlands)

Stouwdam, J.W.; Janssen, R.A.J.

2009-01-01

Incorporating Cu-doped CdS quantum dots into a polymer host produces efficient light-emitting diodes. The Cu dopant creates a trap level that aligns with the valence band of the host, enabling the direct injection of holes into the quantum dots, which act as emitters. At low current densities, the

Determination of Cd, Pb and As in sediments of the Sava River by electrothermal atomic absorption spectrometry

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SIMONA MURKO

2010-01-01

Full Text Available The applicability of nitric acid, palladium nitrate and a mixture of palladium and magnesium nitrate as matrix modifiers were estimated for the accurate and reproducible determination of cadmium (Cd, lead (Pb and arsenic (As in sediments of the Sava River by electrothermal atomic absorption spectrometry, ETAAS. Decomposition of the samples was done in a closed vessel microwave-assisted digestion system using nitric, hydrochloric and hydrofluoric acids, followed by the addition of boric acid to convert the fluorides into soluble complexes. The parameters for the determination of Cd, Pb and As in sediments were optimised for each individual element and for each matrix modifier. In addition, two sediment reference materials were also analysed. In determination of Cd and Pb, nitric acid was found to be the most appropriate matrix modifier. The accurate and reliable determination of Cd and Pb in sediments was possible also in the presence of boric acid. The use of a mixture of palladium and magnesium nitrate efficiently compensated for matrix effects and enabled the accurate and reliable determination of As in the sediments. Quantification of Cd and As was performed by calibration using acid matched standard solutions, while the standard addition method was applied for the quantification of Pb. The repeatability of the analytical procedure for the determination of Cd, Pb and As in sediments was ±5 % for Cd, ±4 % for Pb and ±2 % for As. The LOD values of the analytical procedure were found to be 0.05 mg/kg for Cd and 0.25 mg/kg for Pb and As, while the LOQ values were 0.16 mg/kg for Cd and 0.83 mg/kg for Pb and As. Finally, Cd, Pb and As were successfully determined in sediments of the Sava River in Slovenia.

PbS/Cd3P2 quantum heterojunction colloidal quantum dot solar cells

International Nuclear Information System (INIS)

Cao, Hefeng; Xu, Songman; Liu, Huan; Liu, Zeke; Zhu, Xiangxiang; Peng, Jun; Ma, Wanli; Hu, Long; Luo, Miao; Tang, Jiang

2015-01-01

Here, we demonstrated the quantum heterojunction colloidal quantum dot (CQD) solar cells employing the PbS CQDs/Cd 3 P 2 CQDs architecture in which both the p-type PbS and n-type Cd 3 P 2 CQD layers are quantum-tunable and solution-processed light absorbers. We synthesized well-crystallized and nearly monodispersed tetragonal Cd 3 P 2 CQDs and then engineered their energy band alignment with the p-type PbS by tuning the dot size and hence the bandgap to achieve efficient light absorbing and charge separation. We further optimized the device through the Ag-doping strategy of PbS CQDs that may leverage an expanded depletion region in the n-layer, which greatly enhances the photocurrent. The resulting devices showed an efficiency of 1.5%. (paper)

Lattice parameter values and phase transitions for the Cu2Cd1-zMnzSnSe4 and Cu2Cd1-zFezSnSe4 alloys

International Nuclear Information System (INIS)

Moreno, E.; Quintero, M.; Morocoima, M.; Quintero, E.; Grima, P.; Tovar, R.; Bocaranda, P.; Delgado, G.E.; Contreras, J.E.; Mora, A.E.; Briceno, J.M.; Avila Godoy, R.; Fernandez, J.L.; Henao, J.A.; Macias, M.A.

2009-01-01

X-ray powder diffraction measurements and differential thermal analysis (DTA) were made on polycrystalline samples of the Cu 2 Cd 1-z Mn z SnSe 4 and Cu 2 Cd 1-z Fe z SnSe 4 alloy systems. The diffraction patterns were used to show the equilibrium conditions and to derive lattice parameter values. For Cu 2 Cd 0.8 Fe 0.2 SnSe 4 as well as for Cu 2 Cd 0.2 Fe 0.8 SnSe 4 the crystal structures were refined using the Rietveld method. It was found that the internal distortion parameter σ decreases as Cd is replaced by either Mn and/or Fe. For the Cu 2 Cd 1-z Mn z SnSe 4 and Cu 2 Cd 1-z Fe z SnSe 4 alloy systems, only two single solid phase fields, the tetragonal stannite α(I4-bar2m) and the wurtz-stannite δ (Pmn2 1 ) structures were found to occur in the diagram. In addition to the tetragonal stannite α phase extra X-ray diffraction lines due to MnSe and/or FeSe 2 were observed for as grown samples in the range 0.7 < z < 1.0. However, it was found that the amount of the extra phase decreased for the compressed samples.

The Changes of Elements Composition in Aspergillus niger and Aspergillus terreus at Different Co2+, Cd2+ and Pb2+ Concentrations Using X-rays Microanalysis

International Nuclear Information System (INIS)

Ouda, S.M.

2010-01-01

X-ray microanalysis in electron microscope allows simultaneous detection and quantitative analysis of several elements so it contributes to understand the role of ions in physiological processes. Energy dispersive X-ray (EDX) analysis used to detect the changes in elements levels in Aspergillus niger and Aspergillus terreus when allowing to grow on Czapek's Dox liquid media amended with different Co 2+ , Cd 2+ and Pb 2+ concentrations and these changes may play a role in fungal uptake for these heavy metal ions. Results showed that Ca, Zn and Cu levels in both fungal isolates significantly decreased (P<0.05) when concentrations of used metal ions increased, also O, Na, Cl and K levels for A. niger and C and P for A. terreus recorded significant reduction (P<0.05) in their percentages. Also, the results revealed that, C and P for A. niger and O, Na, Mg, Cl and K levels for A. terreus significantly increased (P<0.05) as a result of increasing metal ions concentrations. Lack of Cd and Pb peaks in X-ray spectrum for A. terreus led this work to conclude that, A. niger was more effective than A. terreus in Co, Cd, Pb uptake into fungal biomass. The increase or decrease of levels of detected elements could be related to the difference between two fungal isolates in uptake certain heavy metal ion (Co, Cd, Pb)

Assessment of soil contamination by potentially toxic trace elements (PTSD) (As, Cd, Cu, Hg, Pb, Zn) in a lower plain of the Hron River according to Law no. 219/2008 Coll., by geo-accumulation index, anthropogenic factor and Tomlinson index; Zhodnotenie kontaminacie pod potencialne toxickymi stopovymi prvkami (PTSP) (As, Cd, Cu, Hg, Pb, Zn) v dolnej casti nivy Hrona podla zakona c. 219/2008 Z.z., indexu geoakumulacie, antropogenneho faktora a Tomlinsonovho indexu

Energy Technology Data Exchange (ETDEWEB)

Hlodak, M [Univerzita Komenskeho v Bratislave, Prirodovedecka fakulta, Ustav laboratorneho vyskumu geomaterialov, 84215 Bratislava (Slovakia)

2012-04-25

Soil contamination by different PTSD may have different geogenic and anthropogenic origin and occurs in all countries of the world. The aim of this paper is to evaluate the soils contamination of a lower plain of the Hron River. This paper used the results of the thesis Soil contamination of the Hron River floodplain by trace elements (As, Cd, Cu, Hg, Pb, Zn) [1]. Soil contamination was evaluated by: Act. 219/2008 Coll. on the protection and use of agricultural land, by anthropogenic factor (AF), geo-accumulation index (IgeoE) and Tomlinson index - the index of the pollution load (PLI). (author)

Evaluation of heavy metals (Cr, Fe, Ni, Cu, Zn, Cd, Pb and Hg) in water, sediments and water lily (Eichornia crassipes) from Jose Antonio Alzate dam; Evaluacion de metales pesados Cr, Fe, Ni, Cu, Zn, Cd, Pb y Hg en agua, sedimento y lirio acuatico (Eichhornia crassipes) de la Presa Jose Antonio Alzate, Estado de Mexico

Energy Technology Data Exchange (ETDEWEB)

Avila P, P

1996-12-31

Water, sediments and water lily (Eichornia crassipes) from the Jose Antonio Alzate Dam were analyzed in order to determine concentrations of chromium, iron, nickel, copper, zinc, cadmium, lead and mercury. Mercury, lead, chromium and iron were found in concentrations above permissible limits in water, and in high concentrations in sediments. Cadmium, nickel, copper and zinc never were found in concentrations above permissible limits in water. The highest concentrations of heavy metals in water lily were found in the root. Accumulation factors decreased in the following order: Zn> Cr> Fe> Ni> Cu> Pb> Hg and Cd. Statistical differences ({alpha} < 0.5) between the collection samples dates was observed. High correlations between metals concentrations in superficial water, sediment and water hyacinth were also observed. These correlations could indicate that the heavy metals studied here, are originated from a natural source such as sediments or from an industrial source. (Author).

The Survey and Measurement of Ni, Pb, Cu, Mn, Zn, Cd and V Content in Green Vegetables of South Area of Tehran Refinery

International Nuclear Information System (INIS)

Kazemzadeh Khoyi, J.; Noori, A. S.; Pourang, N.; Alizadeh, M.; Ghoreishi, H.; Padash, A.

2013-01-01

Oil pollution is one of the most critical soil and water pollutant. Areas which are subjected to oil industry may have this kind of pollution by different ways such as extraction, transformation and refining. The example of these areas is south east of Tehran refinery which is surrounded by agricultural fields and are subjected by pollution via Tehran refinery, oil transforming lines, waste water and industrial activities. Since the crops from this area is providing the needs of neighbor cities like Tehran, to realize their oil pollution, the content of some heavy metals like Ni, V, Cu, Cd, Zn, Pb and Mn has been measured. The results analyzed by analytical method include SPSS and MVSP. Finally the relation between elements and pollution has been recognized. The result of this survey showed the high heavy metal content in most plants which were higher than similar research. Onion had the highest amount of most heavy metals. Ni and Pd content were high in plants which are indicator of oil pollution.

Behaviours of MeCl2 (Me: Pb and Cd) during thermal treatment of ...

African Journals Online (AJOL)

hope&shola

electrostatic precipitators, bag-filters are generally used in incinerator ... often used to prepare various ceramic products like bricks and tiles ... ceramics. The chloride salts of Cd and Pb are considered because chloride is one of the major anionic constituents of MSWI fly ash. Finally the leaching behaviours of Pb and Cd ...

Antifriction coating of Cu-Fe-Al-Pb system for plain bearings

Science.gov (United States)

Kotenkov, Pavel; Kontsevoi, Yurii; Mejlakh, Anna; Pastukhov, Eduard; Shubin, Alexey; Goyda, Eduard; Sipatov, Ivan

2017-09-01

Aluminium, copper and their compounds are used in common as basis for antifriction coatings of plain bearings. Antifriction testing of plain bearings (based on Al and Cu) made by leading automotive manufacturers from Germany, Japan, USA, United Kingdom and Russia were carried out to make judicious selection of basis for development of new antifriction material. Testing was carried out using friction machine. It was defined that materials based on Cu provide better durability and robustness of plain bearings in comparison with Al based ones. The new antifriction composite coatings based on copper were developed taking into account the requirements specified for plain bearings of internal-combustion engine. Pilot samples of plain bearings with antifriction coatings of Cu-Fe-Al-Pb system were produced. The antifriction composite having Cu-5Fe-5Al5Fe2-10Pb (mass %) composition has demonstrated low friction factor and high wear-resistance. Metallographic analysis of pilot samples was carried out by means of optical and scanning electron microscopy.

Kandungan Tembaga (Cu dan Timbal (Pb pada Lamun Enhalus accoroides dari Perairan Batam, Kepulauan Riau, Indonesia

Directory of Open Access Journals (Sweden)

Ismarti Ismarti

2017-02-01

Full Text Available The objective of the present study was to analyze the metal content of copper and lead in Enhalus accoroides seagrass in Batam Island waters. Samples of seagrass (E. accoroides were collected from six locations along the western region of Batam Island then dried and performed with acid destruction. The measurements of Cu and Pb in the samples were conducted by Atomic Absorption Spectrophotometer. The result showed that there was an increasing of copper and lead contaminant level on sample E accoroides during two periods in a year.  The Cu level ranged from 0.63 to 46.1 mg/kg, meanwhile, lead level ranged from  2.14 to 10.52mg/kg respectively. The highest accumulation of copper and lead were recorded on leaves, it was reached 10.81 mg/kg and 5.98mg/kg, respectively. Penelitian ini bertujuan menganalisis kandungan logam tembaga (Cu dan timbal (Pb pada lamun Enhalus accoroides di sepanjang perairan barat Pulau Batam. Sampel lamun dikumpulkan dari enam lokasi  kemudian dikeringkan dan dilakukan destruksi dengan asam. Penentuan kadar logam tembaga dan timbal dalam sampel dilakukan dengan spektrometri serapan atom. Hasil penelitian menunjukan adanya peningkatan kadar logam Cu dan Pb pada sampel lamun E. accoroides selama 2 periode sampling dalam 1 tahun. Kadar logam Cu dan Pb pada lamun secara berturut berada pada rentang 0.63-46.1 mg/kg dan 2.14-10.52mg/kg. Akumulasi logam Cu dan Pb dalam lamun E. accoroides tertinggi pada bagian daun sebanyak 10.81 mg/kg Cu dan 5.98 mg/kg Pb.

Bioaccumulation of toxic metals (Cd and Cu) by Groenlandia densa (L.) Fourr.

Science.gov (United States)

Kara, Yesim; Zeytunluoglu, Ali

2007-12-01

In this study, Groenlandia densa (L.) Fourr. (opposite-leaved pondweed), was exposed to prepared stock solution of cadmium and copper with 1.0, 3.0, 5.0 and 7.0 mg L(-1) concentration in certain periods (24, 48, 72 and 96 h) and changing amount of accumulation of plants in depending on time and concentration was measured by atomic absorption spectrophotometer. The results show that under experimental conditions, G. densa (L.) Fourr. proved to be a good accumulator of Cd and Cu. Removal of the metals from solution was fast in the first 4 days. The accumulation of Cd and Cu increased with the initial concentration and also with time. The highest concentrations of each trace element accumulated in opposite-leaved pondweed tissues were 1,955 mug Cd g(-1), 6,135 microg Cu g(-1) after 4 days. The maximum values of bioconcentration factor (BCF) were found for Cd and Cu 724 and 1,669, respectively. BCF values for Cd and Cu increased with time.

Accumulation of Heavy Metals (Pb, Cd, V) in Sediment, roots and ...

African Journals Online (AJOL)

Michael Horsfall

info and www.bioline.org.br/ja. Accumulation of Heavy Metals (Pb, Cd, V) in Sediment, roots and leaves of ... ABSTRACT: Sirik mangrove forests harbour two species, Avicennia marina and .... Based on the soil critical concentration value of Pb.

Low-temperature thermoelectric properties of Pb doped Cu2SnSe3

Science.gov (United States)

Prasad K, Shyam; Rao, Ashok; Gahtori, Bhasker; Bathula, Sivaiah; Dhar, Ajay; Chang, Chia-Chi; Kuo, Yung-Kang

2017-09-01

A series of Cu2Sn1-xPbxSe3 (0 ≤ x ≤ 0.04) compounds was prepared by solid state synthesis technique. The electrical resistivity (ρ) decreased with increase in Pb content up to x = 0.01, thereafter it increased with further increase in x (till x = 0.03). However, the lowest value of electrical resistivity is observed for Cu2Sn0.96Pb0.04Se3. Analysis of electrical resistivity of all the samples suggests that small poloron hoping model is operative in the high temperature regime while variable range hopping is effective in the low temperature regime. The positive Seebeck coefficient (S) for pristine and doped samples in the entire temperature range indicates that the majority charge carriers are holes. The electronic thermal conductivity (κe) of the Cu2Sn1-xPbxSe3 compounds was estimated by the Wiedemann-Franz law and found that the contribution from κe is less than 1% of the total thermal conductivity (κ). The highest ZT 0.013 was achieved at 400 K for the sample Cu2Sn0.98Pb0.02Se3, about 30% enhancement as compared to the pristine sample.

TiO2 flower-like nanostructures decorated with CdS/PbS nanoparticles

International Nuclear Information System (INIS)

Trenczek-Zajac, Anita; Kusior, Anna; Lacz, Agnieszka; Radecka, Marta; Zakrzewska, Katarzyna

2014-01-01

Highlights: • TiO 2 flower-like nanostructures were prepared with the use of Ti foil and 30% H 2 O 2 . • QDs of CdS and PbS were deposited using the SILAR method. • The SILAR method makes it possible to control the size of QDs. • Band gap energy of CdS was found to be 2.35 eV. • Sensitization of TiO 2 with CdS or PbS improves the photoelectrochemical properties. - Abstract: Flower-like nanostructures of TiO 2 were prepared by immersing Ti foil in 30% H 2 O 2 at 80 °C for times varying from 15 to 240 min. Upon annealing at 450 °C in an Ar atmosphere, the received amorphous samples crystallized in an anatase structure with rutile as a minority phase. SEM images revealed that partially formed flowers were present at the surface of the prepared samples as early as after 15 min of immersion. The size of the individual flowers increased from 400–800 nm after 15 min of reaction to 2.5–6.0 μm after 240 min. It was also found that surface is very rough and surface development is considerable. After 45 min of immersion, the nanoflowers were sensitized with CdS and PbS quantum dots (QDs-CdS/QDs-PbS) deposited using the SILAR method from water- and methanol-based precursor solutions at different concentrations (0.001–0.1 M). QDs-CdS crystallized in the hawleyite structure, while QDs-PbS in the galena form. SEM analysis showed the tendency of quantum dots to agglomerate at high concentrations of the precursor in water-based solutions. QDs obtained from methanol-based solutions were uniformly distributed. The produced QDs-PbS were smaller than QDs-CdS. Based on the optical reflectance spectra, the band-gap energies of TiO 2 nanostructures with and without QDs were calculated to be 3.32 eV for flower-like TiO 2 nanostructures and 2.35 eV for QDs-CdS. The photoelectrochemical behaviour of nanoflowers was found to improve significantly after the deposition of QDs-CdS

Study on Characteristics of CdS/Cu2S Photovoltaic Cell

International Nuclear Information System (INIS)

Nwe Nwe Htun

2011-12-01

In this paper the CdS-Cu2S photovoltaic cell has been prepared and characteristiced by using evaporation method on glass substrate. CdS film was deposited on the Pyrex glass substrate by evaporation and Cu2S layer was obtained by electroplating in a dilute acqueous solution of CusO4 at room temperature. Silver electrode was applied to the electroplated surface. The results of electrical and optical characteristics of the CdS-Cu2S hetrojunction were investigated. The photovoltaic response has been observed under various illuminated intensity for different wavelengths in visible region. It was found to be the photovoltage and photocurrent varying with different light intensities. It can be concluded that formation of a low resistivity CdS film and Cu2S layer play a big role in obtaining a high efficiency cell.

Pb and Cd on growth, leaf ultrastructure and essential oil yield mint (Mentha arvensis L.

Directory of Open Access Journals (Sweden)

Caroline Nery Jezler

2015-03-01

Full Text Available Contamination of medicinal plants with heavy metals as Pb and Cd can affect the growth and the essential oil production of the plants and represent a risk to those who consume as medicine. This study aimed to evaluate the effects of absorption and localization of Pb and Cd on growth, ultrastructural aspects of leaves and essential oil yield and composition of Mentha arvensis, applied on the soil with increasing concentrations (8, 16, 32, 64 and 128mg kg-1. There was a differential absorption of Pb and Cd by M. arvensis mainly concentrated in the roots. Pb was found in small amounts in the leaves while Cd largely exceeded the safety limit without symptoms of toxicity. The ultrastructural analysis revealed the metal accumulation on vesicles surrounding the mitochondria and the presence of electron dense deposits surrounding the mitochondria, nucleus and chloroplasts. Little changes caused by Pb and Cd application were not enough to affect the growth and essential oil yield and composition of M. arvensis

Half-metallic antiferromagnetism in double perovskite BiPbCrCuO6

International Nuclear Information System (INIS)

Weng, Ke-Chuan; Wang, Y. K.

2015-01-01

The electronic structure and magnetic properties of BiPbCrCuO 6 double perovskite are investigated based on first-principles density functional calculations with generalized gradient approximation (GGA) and GGA incorporated with Coulomb correlation interaction U (GGA + U). The results suggest the half-metallic (HM) and antiferromagnetic (AFM) properties of BiPbCrCuO 6 double perovskite. The HM-AFM property of the double perovskite is caused by the double-exchange mechanism between neighboring Cr 5+ (t 2g 1 ↓) and Cu 2+ (t 2g 3 ↑t 2g 3 ↓e g 2 ↑e g ↓) via the intermediate O 2− (2s 2 2p 6 ) ion

Evaluation of heavy metals (Cr, Fe, Ni, Cu, Zn, Cd, Pb and Hg) in water, sediments and water lily (Eichornia crassipes) from Jose Antonio Alzate dam

International Nuclear Information System (INIS)

Avila P, P.

1995-01-01

Water, sediments and water lily (Eichornia crassipes) from the Jose Antonio Alzate Dam were analyzed in order to determine concentrations of chromium, iron, nickel, copper, zinc, cadmium, lead and mercury. Mercury, lead, chromium and iron were found in concentrations above permissible limits in water, and in high concentrations in sediments. Cadmium, nickel, copper and zinc never were found in concentrations above permissible limits in water. The highest concentrations of heavy metals in water lily were found in the root. Accumulation factors decreased in the following order: Zn> Cr> Fe> Ni> Cu> Pb> Hg and Cd. Statistical differences (α < 0.5) between the collection samples dates was observed. High correlations between metals concentrations in superficial water, sediment and water hyacinth were also observed. These correlations could indicate that the heavy metals studied here, are originated from a natural source such as sediments or from an industrial source. (Author)

Spatial distribution of Cd and Cu in soils in Shenyang Zhangshi Irrigation Area (SZIA), China*

Science.gov (United States)

Sun, Li-na; Yang, Xiao-bo; Wang, Wen-qing; Ma, Li; Chen, Su

2008-01-01

Heavy metal contamination of soils, derived from sewage irrigation, mining and inappropriate utilization of various agrochemicals and pesticides, and so on, has been of wide concern in the last several decades. The Shenyang Zhangshi Irrigation Area (SZIA) in China is a representative area of heavy metal contamination of soils resulting from sewage irrigation for about 30 years. This study investigated the spatial distribution and temporal variation of soil cadmium (Cd) and copper (Cu) contamination in the SZIA. The soil samples were collected from the SZIA in 1990 and 2004; Cd and Cu in soils was analyzed and then the spatial distribution and temporal variation of Cd and Cu in soils were modeled using Kriging methods. The results show that long-term sewage irrigation had caused serious Cd and Cu contamination in soils. The mean and the maximum of soil Cd are markedly higher than the levels in second grade standard soil (LSGSS) in China, and the maximum of soil Cu is close to the LSGSS in China in 2004 and is more than the LSGSS in China in 1990. The contamination magnitude of soil Cd and the soil extent of Cd contamination had evidently increased since sewage irrigation ceased in 1992. The contamination magnitude of soil Cu and the soil extent of Cu contamination had evidently increased in topsoil, but obviously decresed in subsoil. The soil contamination of Cd and Cu was mainly related to Cd and Cu reactivation of contaminated sediments in Shenyang Xi River and the import of Cd and Cu during irrigation. The eluviation of Cd and Cu in contaminated topsoil with rainfall and irrigation water was another factor of temporal-spatial variability of Cd and Cu contamination in soils. PMID:18357631

[Remediation Pb, Cd contaminated soil in lead-zinc mining areas by hydroxyapatite and potassium chloride composites].

Science.gov (United States)

Wang, Li; Li, Yong-Hua; Ji, Yan-Fang; Yang, Lin-Sheng; Li, Hai-Rong; Zhang, Xiu-Wu; Yu, Jiang-Ping

2011-07-01

The composite agents containing potassium chloride (KCl) and Hydroxyapatite (HA) were used to remediate the lead and cadmium contaminated soil in Fenghuang lead-zinc mining-smelting areas, Hunan province. The objective of this study was to identify and evaluate the influence of Cl- to the fixing efficiency of Pb and Cd by HA. Two types of contaminated soil (HF-1, HF-2) were chosen and forty treatments were set by five different Hydroxyapatite (HA) dosages and four different Cl- dosages. The toxicity characteristic leaching procedure (TCLP) was used to evaluate the results. It showed that HA could efficiently fix the Pb and Cd from TCLP form. The maximum Pb-fixing efficiency and Cd-fixing efficiency of two types of soil were 83.3%, 97.27% and 35.96%, 57.82% when the HA: Pb: KCl molar ratio was 8: 1: 2. Compared to the fixing efficiency without KCl, KCl at the KCl: Pb molar ratio of 2 improved Pb-fixing efficiency and Cd-fixing efficiency by 6.26%, 0.33% and 7.74%, 0.83% respectively when the HA: Pb molar ratio was 8. Generally, Cl- can improve the Pb/Cd-fixing efficiency in heavy metal contaminated soil by Hydroxyapatite.

Effects of CuBr addition to CH3NH3PbI3(Cl) perovskite photovoltaic devices

Science.gov (United States)

Oku, Takeo; Ohishi, Yuya; Tanaka, Hiroki

2018-01-01

Effects of CuBr addition to perovskite CH3NH3PbI3(Cl) precursor solutions on photovoltaic properties were investigated. The CH3NH3Pb(Cu)I3(Cl,Br)-based photovoltaic devices were fabricated by a spin-coating technique, and the microstructures of the devices were investigated by X-ray diffraction, optical microscopy and scanning electron microscopy. Current density-voltage characteristics were improved by a small amount of CuBr addition, which resulted in improvement of the conversion efficiencies of the devices. The structure analysis showed decrease of unit cell volume and increase of Cu/Br composition by the CuBr addition, which would indicate the Cu/Br substitution at the Pb/I sites in the perovskite crystal, respectively.

Comparative adsorption of Pb2+ and Cd2+ by cow manure and its vermicompost

International Nuclear Information System (INIS)

Zhu, Weiqin; Du, Wenhui; Shen, Xuyang; Zhang, Hangjun; Ding, Ying

2017-01-01

Organic waste has great potential for use as an amendment to immobilize heavy metals in the environment. Therefore, this study investigates various properties of cow manure (CM) and its derived vermicompost (CV), including the pH, cationic exchangeable capacity (CEC), elemental composition and surface structure, to determine the potential of these waste products to remove Pb 2+ and Cd 2+ from solution. The results demonstrate that CV has a much higher pH, CEC and more irregular pores than CM and is enriched with minerals and ash content but has a lower C, H, O and N content. Adsorption isotherms studies shows that the adsorption of Pb 2+ and Cd 2+ onto either CM or CV follows a Langmuir model and presents maximum Pb 2+ and Cd 2+ adsorption capacities of 102.77 mg g −1 and 38.11 mg g −1 onto CM and 170.65 and 43.01 mg g −1 onto CV, respectively. Kinetic studies show that the adsorption of Pb 2+ onto CM and CV fits an Elovich model, whereas the adsorption of Cd 2+ onto CM and CV fits a pseudo-second-order model. Desorption studies indicate that CV is more effective than CM in removing Pb 2+ and Cd 2+ . FTIR analysis demonstrates that the adsorption of Pb 2+ and Cd 2+ onto CM mainly depends on existed aliphatic alcohol, aromatic acid as well as new produced carbonates, whereas that onto CV may be contributed by the existed aliphatic alcohol, aromatic acids as well as some carbonates and phosphates. Thus, vermicomposting disposal of cow manure with destination mineral addition may broaden the way of its recycle and environmental usage. - Graphical abstract: The existed aliphatic alcohol, aromatic acids and its only carbonates and phosphates may underlie much higher efficiency of vermicompost (CV) on Pb 2+ and Cd 2+ removal than cow manure (CM). - Highlights: • Less irregular pores in cow manure (CM) than its vermicompost (CV). • More Pb 2+ or Cd 2+ could be removed from solution by vermicompost (CV) than by cow manure (CM). • The existed aliphatic

The matrix effect study in the spectrographic analysis of rare earth elements. Pt. 1. The influence of Sn, Pb, Sb, Bi, Cu, Ag, Zn and Cd on the spectral lines intensity of Y, La, Ce, Pr, Nd and Sm in the current arc exciting between C-electrodes

International Nuclear Information System (INIS)

Wysocka-Lisek, J.; Paszkowska, B.; Mularczyk, K.

1976-01-01

In the beginning the influence of Sn, Pb, Sb, Bi, Cu, Ag, Zn and Cd on the light rare earth spectral lines using Ni as the internal standard, during the intermittent current arc excitation between C-electrodes was studied. On the basis of the spectral lines intensity measurements, it was stated that one may apply the addition of Ni as the internal standard by the quantitative determination of Sn, Pb, Sb, Bi, Zn and Cd in the light rare earth mixtures with one of the above. Also a great influence of the presence of the individually studied metal was observed on the spectral line intensity of rare earth elements and nickel. The differences of the thermo-chemical reactions nature between excited elements and the carbon of the electrodes may cause that influence. (author)

Distribution and evolution of Zn, Cd, and Pb in Apollo 16 regolith samples and the average U-Pb ages of the parent rocks

Science.gov (United States)

Cirlin, E. H.; Housley, R. M.

1982-01-01

The concentration of surface (low temperature site) and interior (high temperature site) Cd, Zn, and Pb in 13 Apollo 16 highland fines samples, pristine rock 65325, and mare fines sample 75081 were analyzed directly from the thermal release profiles obtained by flameless atomic absorption technique (FLAA). Cd and Zn in pristine ferroan anothosite 65325, anorthositic grains of the most mature fines 65701, and basaltic rock fragments of mare fines 75081 were almost all surface Cd and Zn indicating that most volatiles were deposited on the surfaces of vugs, vesicles and microcracks during the initial cooling process. A considerable amount of interior Cd and Zn was observed in agglutinates. This result suggests that high temperature site interior volatiles originate from entrapment during the lunar maturation processes. Interior Cd found in the most mature fines sample 65701 was only about 15% of the total Cd in the sample. Interior Pb present in Apollo 16 fines samples went up to 60%. From our Cd studies we can assume that this interior Pb in highland fines samples is largely due to the radiogenic decay which occurred after the redistribution of the volatiles took place. We obtained an average age of 4.0 b.y. for the parent rocks of Apollo 16 highland regolith from our interior Pb analyses.

TELAAHAN LOGAM BERAT Pb DAN Cd PADA SEDIMEN DI PERAIRAN BARAT LAUT DUMAI – RIAU

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Syahminan Syahminan

2015-08-01

Full Text Available This research was conducted in Dumai sea western waters, Riau Province. Dumai marine waters are part of the territorial waters of Riau that relate directly to the Strait of Malacca, and are at Rupat Strait region, and has a high accessibility of the region, both locally and internationally. Dumai waters is also an estuary waters affected by the activities of the land, and the waters that receive input from various types of waste from various activities in Dumai city and surrounding areas. The research was aimed to knowing the general condition of the Dumai sea western waters, analyzing the content of Pb and Cd in sediments, observing the correlation between organic matter and heavy metal of Pb and Cd, and find out the status of pollution Dumai Sea Western Waters by comparing the results of the analysis with some quality standard countries, The method used is a survey method. Based on the Decree of The Minister of Environment No. 51 of 2004, that the general condition of the Dumai sea western waters still can support the life activities of marine organisms in the waters. The results showed that the concentrations of Pb and Cd in sediments of Dumai is below the threshold value. The results of simple linear regression analysis of heavy metals Pb and Cd with organic matter content showed that the concentration of heavy metals Pb and Cd is not influenced by organic matter content or have a very weak correlation with linear regression equation consecutive y = 0,0834x + 7,7866 and y = -0,001x + 0,0559. The status of pollution of Dumai sea western waters for Pb 8,76 µg/g and Cd 0,04 µg/g still under quality standardsKeywords: Dumai Sea Western Waters, Sediments, Heavy Metal Pb and Cd

Bio-remediation of Pb and Cd polluted soils by switchgrass: A case study in India.

Science.gov (United States)

Arora, Kalpana; Sharma, Satyawati; Monti, Andrea

2016-01-01

In the present study bioremediation potential of a high biomass yielding grass, Panicum virgatum (switchgrass), along with plant associated microbes (AM fungi and Azospirillum), was tested against lead and cadmium in pot trials. A pot trial was set up in order to evaluate bioremediation efficiency of P. virgatum in association with PAMs (Plant Associated Microbes). Growth parameters and bioremediation potential of endomycorrhizal fungi (AMF) and Azospirillum against different concentrations of Pb and Cd were compared. AM fungi and Azospirillum increased the root length, branches, surface area, and root and shoot biomass. The soil pH was found towards neutral with AMF and Azospirillum inoculations. The bioconcentration factor (BCF) for Pb (12 mg kg(-1)) and Cd (10 mg kg(-1)) were found to be 0.25 and 0.23 respectively and translocation index (Ti) was 17.8 and 16.7 respectively (approx 45% higher than control). The lower values of BCF and Ti, even at highest concentration of Pb and Cd, revealed the capability of switchgrass of accumulating high concentration of Pb and Cd in the roots, while preventing the translocation of Pb and Cd to aerial biomass.

PM2.5 particulates and metallic elements (Ni, Cu, Zn, Cd and Pb) study in a mixed area of summer season in Shalu, Taiwan.

Science.gov (United States)

Fang, Guor-Cheng; Xiao, You-Fu; Zhuang, Yuan-Jie; Cho, Meng-Hsien; Huang, Chao-Yang; Tsai, Kai-Hsiang

2017-08-01

PM 2.5 has become an important environmental issue in Taiwan during the past few years. Moreover, electricity increased significantly during the summertime and TTPP generated by coal burning base is the main electricity provider in central Taiwan. Therefore, summer season has become the main research target in this study. The ambient air concentrations of particulate matter PM 2.5 and PM 10 collected by using VAPS at a mixed characteristic sampling site were studied in central Taiwan. The results indicated that the average daytime PM 2.5 and PM 10 particulate concentrations were occurred in May and they were 44.75 and 57.77 µg/m 3 in this study. The results also indicated that the average nighttime PM 2.5 and PM 10 particulate concentrations were occurred in June and they were 38.19 and 45.79 µg/m 3 in this study. The average PM 2.5 /PM 10 ratios were 0.7 for daytime, nighttime and 24-h sampling periods in the summer for this study. This value was ranked as the lowest ratios when compared to the other seasons in previous study. Noteworthy, the results further indicated that the metallic element Pb has the mean highest concentrations for 24-h, daytime and nighttime sampling periods when compared to those of the other metallic elements (Ni, Cu, Zn and Cd). The average mean highest metallic Pb concentrations in PM10 were 110.7, 203.0 and 207.2 ng/m 3 for 24-h, daytime and nighttime sampling periods in this study. And there were 59.53, 105.2 and 106.6 ng/m 3 for Pb in PM2.5 for 24-h, daytime and nighttime sampling periods, respectively. Moreover, the results further indicated that mean metallic element Pb concentrations on PM 2.5 and PM 10 were all higher than those of the other elements for 24 h, day and nighttime.

Optical phonons in PbTe/CdTe multilayer heterostructures

Energy Technology Data Exchange (ETDEWEB)

Novikova, N. N.; Yakovlev, V. A. [Russian Academy of Sciences, Institute for Spectroscopy (Russian Federation); Kucherenko, I. V., E-mail: kucheren@sci.lebedev.ru [Russian Academy of Sciences, Lebedev Physical Institute (Russian Federation); Karczewski, G. [Polish Academy of Sciences, Institute of Physics (Poland); Aleshchenko, Yu. A.; Muratov, A. V.; Zavaritskaya, T. N.; Melnik, N. N. [Russian Academy of Sciences, Lebedev Physical Institute (Russian Federation)

2015-05-15

The infrared reflection spectra of PbTe/CdTe multilayer nanostructures grown by molecular-beam epitaxy are measured in the frequency range of 20–5000 cm{sup −1} at room temperature. The thicknesses and high-frequency dielectric constants of the PbTe and CdTe layers and the frequencies of the transverse optical (TO) phonons in these structures are determined from dispersion analysis of the spectra. It is found that the samples under study are characterized by two TO phonon frequencies, equal to 28 and 47 cm{sup −1}. The first frequency is close to that of TO phonons in bulk PbTe, and the second is assigned to the optical mode in structurally distorted interface layers. The Raman-scattering spectra upon excitation with the radiation of an Ar{sup +} laser at 514.5 nm are measured at room and liquid-nitrogen temperatures. The weak line at 106 cm{sup −1} observed in these spectra is attributed to longitudinal optical phonons in the interface layers.

Enhanced removal of Cd(II) and Pb(II) by composites of mesoporous carbon stabilized alumina

Energy Technology Data Exchange (ETDEWEB)

Yang, Weichun [Department of Environmental Engineering, School of Metallurgy and Environment, Central South University, Lushan South Road 932, Changsha 410017 (China); Chinese National Engineering Research Center for Control & Treatment of Heavy Metal Pollution, Lushan South Road 932, Changsha 410017 (China); Tang, Qiongzhi; Wei, Jingmiao; Ran, Yajun [Department of Environmental Engineering, School of Metallurgy and Environment, Central South University, Lushan South Road 932, Changsha 410017 (China); Chai, Liyuan [Department of Environmental Engineering, School of Metallurgy and Environment, Central South University, Lushan South Road 932, Changsha 410017 (China); Chinese National Engineering Research Center for Control & Treatment of Heavy Metal Pollution, Lushan South Road 932, Changsha 410017 (China); Wang, Haiying, E-mail: haiyw25@163.com [Department of Environmental Engineering, School of Metallurgy and Environment, Central South University, Lushan South Road 932, Changsha 410017 (China); Chinese National Engineering Research Center for Control & Treatment of Heavy Metal Pollution, Lushan South Road 932, Changsha 410017 (China)

2016-04-30

Graphical abstract: - Highlights: • Mesoporous carbon stabilized alumina was prepared by one-pot hard-templating method. • MC/Al{sub 2}O{sub 3} showed excellent performance for Cd(II) and Pb(II) adsorption. • Enhanced adsorption was due to the high surface area and special functional groups. - Abstract: A novel adsorbent of mesoporous carbon stabilized alumina (MC/Al{sub 2}O{sub 3}) was synthesized through one-pot hard-templating method. The adsorption potential of MC/Al{sub 2}O{sub 3} for Cd(II) and Pb(II) from aqueous solution was investigated compared with the mesoporous carbon. The results indicated the MC/Al{sub 2}O{sub 3} showed excellent performance for Cd(II) and Pb(II) removal, the adsorption capacity reached 49.98 mg g{sup −1} for Cd(II) with initial concentration of 50 mg L{sup −1} and reached 235.57 mg g{sup −1} for Pb(II) with initial concentration of 250 mg L{sup −1}, respectively. The kinetics data of Cd(II) adsorption demonstrated that the Cd(II) adsorption rate was fast, and the removal efficiencies with initial concentration of 10 and 50 mg L{sup −1} can reach up 99% within 5 and 20 min, respectively. The pseudo-second-order kinetic model could describe the kinetics of Cd(II) adsorption well, indicating the chemical reaction was the rate-controlling step. The mechanism for Cd(II) and Pb(II) adsorption by MC/Al{sub 2}O{sub 3} was investigated by X-ray photoelectron spectroscopy (XPS) and Fourier transformed infrared spectroscopy (FTIR), and the results indicated that the excellent performance for Cd(II) and Pb(II) adsorption of MC/Al{sub 2}O{sub 3} was mainly attributed to its high surface area and the special functional groups of hydroxy-aluminum, hydroxyl, carboxylic through the formation of strong surface complexation or ion-exchange. It was concluded that MC/Al{sub 2}O{sub 3} can be recognized as an effective adsorbent for removal of Cd(II) and Pb(II) in aqueous solution.

Facile fabrication of CuO-Pb2O3 nanophotocatalyst for efficient degradation of Rose Bengal dye under visible light irradiation

Science.gov (United States)

Kamaraj, Eswaran; Somasundaram, Sivaraman; Balasubramani, Kavitha; Eswaran, Muthu Prema; Muthuramalingam, Rajarajan; Park, Sanghyuk

2018-03-01

A p-type CuO/n-type Pb2O3 heterojunction photocatalyst was prepared by a simple wet chemical process and the photocatalytic ability was evaluated for the degradation of Rose Bengal (RB) under visible light irradiation. Synthesized nanocatalysts were characterized by X-ray diffraction (XRD), UV-vis diffuse reflectance spectroscopy (DRS), scanning electron microscopy (SEM), transmission electron microscopy (TEM), Energy-dispersive X-ray spectroscopy (EDS), Brunauer-Emmett-Teller (BET) surface area analysis, and X-ray photoelectron spectroscopy (XPS). The p-n heterojunction of CuO-Pb2O3 nanostructures can promote the light absorption capability of photocatalyst and charge separation of electron-hole pairs. Photodegradation assays showed that the addition of CuO effectively enhanced the photocatalytic activity of CuO-Pb2O3 under visible light irradiation (λmax > 420 nm). Compared with pure Pb2O3 and CuO, the CuO-Pb2O3 exhibited significantly enhanced photocatalytic degradation activity. The reaction rate constant of CuO-Pb2O3 is 0.092 min-1, which is much higher than those of CuO (0.073 min-1) and Pb2O3 (0.045 min-1).

Adsorption characteristics of Pb(II) and Cu(II) ions by domestic clays

International Nuclear Information System (INIS)

Kwon, Ee Yol; Noh, Hea Ran

1990-01-01

This investigation was carried out to study the adsorption characteristics of Pb(II) and Cu(II) ions in aqueous solution by using clays of Gampo 35, Bentonite (chulwon) and Mangwoon 95 which were dug in the country. As the results, the adsorption of metal ions clays were reached equilibrium by shaking for about 40-60 minutes. In acidic solution, the adsorptivity of clays was increased as pH increased, however, Gampo 35 showed the high adsorptivity over 90% even at pH2-3. Pb(II) ion showed better removal efficiency than Cu(II) ion. The adsorptivities of adsorbents showed following order: Gampo 35>Bentonite> Mangwoon 95. The adsorption isotherms of Pb(II) ion on clays were well fitted in Freundlich's equation. Freundlich constantstion isotherms of Pb(II) ion on clays were well fitted in Freundlich's equation. Freundlich constants (1/n) of Gampo 35, Bentonite and Mangwoon 95 were 0.195, 0.271 and 0.314, respectively.(Author)

Position annihilation study on the (Bi,Pb)-Sr-Ca-Cu-(O,F) superconductor

International Nuclear Information System (INIS)

Wang Xiaogang; Gao Xiaohui; Wang Ruidan; Hu Pingya

1993-01-01

In this note, we report the results of positron lifetime measurements in heat-treated (Bi, Pb)-Sr-Ca-Cu-(O, F), and discuss the possible location of the doped fluorine in the (Bi, Pb)-system superconductors. (orig.)

Directional solidification of filamentary shapes of Pb--Cd and Pb--Sn eutectic alloys

International Nuclear Information System (INIS)

Dhindaw, B.K.; Verhoeven, J.D.; Spencer, C.R.; Gibson, E.D.

1978-01-01

Eutectic alloys of Pb--Cd and Pb--Sn were directionally solidified as thin filamentary strips contained in stainless steel and quartz capillaries. As the solidification rate increased the filament width, w, had to be reduced to maintain complete alignment of the lamellae clear across the filament. It was determined that in order to achieve complete alignment the ratio of filament width to lamellar spacing, w/lambda had to be less than about 30. Experiments were carried out at rates of 2-400 μm/s and at temperature gradients of 130 and 320 0 C/cm

PbO-SiO_2-CuO及びPbO-SiO_2-K_2O-Na_2O-CuO系ガラス中のCu^<2+>イオンの光吸収スペクトル及びガラスの屈折率

OpenAIRE

小山田, 了三; 古賀, 秀人; 星野, 朝則

1984-01-01

PbO-SiO2-CuO及びPbO-SiO2-K2O-Na2O-CuO系ガラス中のCu2+イオンの光吸収スペクトルを測定し、ガラス組成と吸収ピーク波数との関係を調べた。その結果、PbO-SiO2-CuO系ガラス中のCu2+の吸収ピーク波数は[PbO]/[SiO2]比の増加とともに高波数側へシフトすることが分かった。PbO-SiO2-K2O-Na2O-CuO系ガラス中のCu2+の吸収ピーク波数の混合アルカリ効果は[PbO]/[SiO2]比により現れ方が異なる。[PbO]/[SiO2]=0.64の場合、ピーク波数は[K2O]/[K2O+Na2O]比の増加とともに低波数側へシフトする。[PbO]/[SiO2]=1.0の場合もピーク波数は[K2O]/[K2O+Na2O]比の増加とともに低波数側へシフトし、[K2O]/[K2O+Na2O]=0.7付近に極小が存在する。[PbO]/[SiO2]=1.5の場合、極小が[K2O]/[K2O+Na2O]=0.35付近に存在し、このとき混合アルカリ効果が最も顕著に現れる。次に、PbO-SiO2-K2O-Na2O-CuO系ガラスの組成と屈折率の関係を調...

Failure analysis of PB-1 (EBTS Be/Cu mockup)

International Nuclear Information System (INIS)

Odegard, B.C. Jr.; Cadden, C.H.

1996-11-01

Failure analysis was done on PB-1 (series of Be tiles joined to Cu alloy) following a tile failure during a high heat flux experiment in EBTS (electron beam test system). This heat flux load simulated ambient conditions inside ITER; the Be tiles were bonded to the Cu alloy using low-temperature diffusion bonding, which is being considered for fabricating plasma facing components in ITER. Results showed differences between the EBTS failure and a failure during a room temperature tensile test. The latter occurred at the Cu-Be interface in an intermetallic phase formed by reaction of the two metals at the bonding temperature. Fracture strengths measured by these tests were over 300 MPa. The high heat flux specimens failed at the Cu-Cu diffusion bond. Fracture morphology in both cases was a mixed mode of dimple rupture and transgranular cleavage. Several explanations for this difference in failure mechanism are suggested

TiO{sub 2} flower-like nanostructures decorated with CdS/PbS nanoparticles

Energy Technology Data Exchange (ETDEWEB)

Trenczek-Zajac, Anita, E-mail: anita.trenczek-zajac@agh.edu.pl [AGH University of Science and Technology, Faculty of Materials Science and Ceramics, al. A. Mickiewicza 30, 30-059 Krakow (Poland); Kusior, Anna; Lacz, Agnieszka; Radecka, Marta [AGH University of Science and Technology, Faculty of Materials Science and Ceramics, al. A. Mickiewicza 30, 30-059 Krakow (Poland); Zakrzewska, Katarzyna [AGH University of Science and Technology, Faculty of Computer Science, Electronics and Telecommunications, al. A. Mickiewicza 30, 30-059 Krakow (Poland)

2014-12-15

Highlights: • TiO{sub 2} flower-like nanostructures were prepared with the use of Ti foil and 30% H{sub 2}O{sub 2}. • QDs of CdS and PbS were deposited using the SILAR method. • The SILAR method makes it possible to control the size of QDs. • Band gap energy of CdS was found to be 2.35 eV. • Sensitization of TiO{sub 2} with CdS or PbS improves the photoelectrochemical properties. - Abstract: Flower-like nanostructures of TiO{sub 2} were prepared by immersing Ti foil in 30% H{sub 2}O{sub 2} at 80 °C for times varying from 15 to 240 min. Upon annealing at 450 °C in an Ar atmosphere, the received amorphous samples crystallized in an anatase structure with rutile as a minority phase. SEM images revealed that partially formed flowers were present at the surface of the prepared samples as early as after 15 min of immersion. The size of the individual flowers increased from 400–800 nm after 15 min of reaction to 2.5–6.0 μm after 240 min. It was also found that surface is very rough and surface development is considerable. After 45 min of immersion, the nanoflowers were sensitized with CdS and PbS quantum dots (QDs-CdS/QDs-PbS) deposited using the SILAR method from water- and methanol-based precursor solutions at different concentrations (0.001–0.1 M). QDs-CdS crystallized in the hawleyite structure, while QDs-PbS in the galena form. SEM analysis showed the tendency of quantum dots to agglomerate at high concentrations of the precursor in water-based solutions. QDs obtained from methanol-based solutions were uniformly distributed. The produced QDs-PbS were smaller than QDs-CdS. Based on the optical reflectance spectra, the band-gap energies of TiO{sub 2} nanostructures with and without QDs were calculated to be 3.32 eV for flower-like TiO{sub 2} nanostructures and 2.35 eV for QDs-CdS. The photoelectrochemical behaviour of nanoflowers was found to improve significantly after the deposition of QDs-CdS.

Comparative adsorption of Pb2+ and Cd2+ by cow manure and its vermicompost.

Science.gov (United States)

Zhu, Weiqin; Du, Wenhui; Shen, Xuyang; Zhang, Hangjun; Ding, Ying

2017-08-01

Organic waste has great potential for use as an amendment to immobilize heavy metals in the environment. Therefore, this study investigates various properties of cow manure (CM) and its derived vermicompost (CV), including the pH, cationic exchangeable capacity (CEC), elemental composition and surface structure, to determine the potential of these waste products to remove Pb 2+ and Cd 2+ from solution. The results demonstrate that CV has a much higher pH, CEC and more irregular pores than CM and is enriched with minerals and ash content but has a lower C, H, O and N content. Adsorption isotherms studies shows that the adsorption of Pb 2+ and Cd 2+ onto either CM or CV follows a Langmuir model and presents maximum Pb 2+ and Cd 2+ adsorption capacities of 102.77 mg g -1 and 38.11 mg g -1 onto CM and 170.65 and 43.01 mg g -1 onto CV, respectively. Kinetic studies show that the adsorption of Pb 2+ onto CM and CV fits an Elovich model, whereas the adsorption of Cd 2+ onto CM and CV fits a pseudo-second-order model. Desorption studies indicate that CV is more effective than CM in removing Pb 2+ and Cd 2+ . FTIR analysis demonstrates that the adsorption of Pb 2+ and Cd 2+ onto CM mainly depends on existed aliphatic alcohol, aromatic acid as well as new produced carbonates, whereas that onto CV may be contributed by the existed aliphatic alcohol, aromatic acids as well as some carbonates and phosphates. Thus, vermicomposting disposal of cow manure with destination mineral addition may broaden the way of its recycle and environmental usage. Copyright © 2017 Elsevier Ltd. All rights reserved.

Modelling the leaching of Pb, Cd, As, and Cr from cementitious waste using PHREEQC

International Nuclear Information System (INIS)

Halim, Cheryl E.; Short, Stephen A.; Scott, Jason A.; Amal, Rose; Low, Gary

2005-01-01

A leaching model was developed using the United States Geological Survey public domain PHREEQC geochemical package to simulate the leaching of Pb, Cd, As, and Cr from cementitious wastes. The model utilises both kinetic terms and equilibrium thermodynamics of key compounds and provides information on leachate and precipitate speciation. The model was able to predict the leaching of Pb, Cd, As, and Cr from cement in the presence of both simple (0.1 and 0.6 M acetic acid) and complex municipal landfill leachates. Heavy metal complexation by the municipal landfill leachate was accounted for by the introduction of a monoprotic organic species into the model. The model indicated Pb and As were predominantly incorporated within the calcium silicate hydrate matrix while a greater portion of Cd was seen to exist as discrete particles in the cement pores and Cr (VI) existed mostly as free CrO 4 2- ions. Precipitation was found to be the dominant mechanism controlling heavy metal solubility with carbonate and silicate species governing the solubility of Pb and carbonate, silicate and hydroxide species governing the solubility of Cd. In the presence of acetic acid, at low pH values Pb and Cd acetate complexes were predominant whereas, at high pH values, hydroxide species dominated. At high pH values, the concentration of As in the leachate was governed by the solubility of Ca 3 (AsO 4 ) 2 with the presence of carbonate alkalinity competing with arsenate for Ca ions. In the presence of municipal landfill leachate, Pb and Cd organic complexes dominated the heavy metal species in solution. The reduction of As and Cr in municipal landfill leachate was crucial for determining aqueous speciation, with typical municipal landfill conditions providing the reduced forms of As and Cr

Assessment of Cd, Cr and Pb Pollution in Sediment and Water of Gheshlagh River, Iran, in September 2013

Directory of Open Access Journals (Sweden)

Farshid Majnoni

2015-03-01

Full Text Available Background: This study aimed to evaluate the pollution levels of surface water with heavy metals including Pb, Cd and Cr in Gheshlagh River, western Iran. Methods: Water and sediment were sampled in five monitoring stations with three replicates in time along the river. The concentration of Cr, Pb and Cd in both water and sediment samples were measured with graphite furnace atomic absorption spectrometer (Australia, Varian 220. The Geoaccumulation Index and Pollution Load Index were employed to assess the pollution level of sediments with heavy metals. Results: The mean value of Cd, Cr, Pb in sediment samples were 0.69, 17.19 and 10.69 µgg-1 per dry weight, respectively. Water samples contained Cd, Cr and Pb concentration of 1.99, 1.45 and 12.92 µgL-1, respectively. The Geoaccumulation Index and Pollution Load Index indicates that the sediments were not polluted with Pb and Cr, and unpolluted to moderately contaminated with Cd in Gheshlagh River. Conclusion: This study concludes that the Gheshlagh River is threatened by heavy metals particularly Cd and Pb.

Biomonitoring potential of five sympatric Tillandsia species for evaluating urban metal pollution (Cd, Hg and Pb)

Science.gov (United States)

Sánchez-Chardi, Alejandro

2016-04-01

The present study quantifies non essential heavy metals highly toxic for biological systems (Pb, Hg and Cd) in five autochthonous epiphytic plants from Tillandsia genus (T. recurvata, T. meridionalis, T. duratii, T. tricholepis, T. loliacea) according to different traffic levels (reference, low, medium and high polluted sites) in Asunción (Paraguay). The three metals increased in polluted sites following Pb (till 62.99 ppm in T. tricholepis) > Cd (till 1.35 ppm in T. recurvata) > Hg (till 0.36 ppm in T. recurvata) and Pb and Cd levels were directly related to traffic flow. Although the species showed similar bioaccumulation pattern (namely, higher levels of metals in polluted sites), enrichment factors (maximum EF values 37.00, 18.16, and 11.90 for Pb, Hg, and Cd, respectively) reported T. tricholepis as the most relevant bioindicator due to its wide distribution and abundance in study sites, low metal content in control site and high metal contents in polluted sites, and significant correlations with traffic density of Pb and Cd. This study emphasizes the necessity of biomonitoring air pollution in areas out of air monitoring control such as Asunción, where the high levels of metal pollution especially Pb, may represent an increment of risk for the human population inhabiting this urban area.

Lime and Phosphate Amendment Can Significantly Reduce Uptake of Cd and Pb by Field-Grown Rice

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Rongbo Xiao

2017-03-01

Full Text Available Agricultural soils are suffering from increasing heavy metal pollution, among which, paddy soil polluted by heavy metals is frequently reported and has elicited great public concern. In this study, we carried out field experiments on paddy soil around a Pb-Zn mine to study amelioration effects of four soil amendments on uptake of Cd and Pb by rice, and to make recommendations for paddy soil heavy metal remediation, particularly for combined pollution of Cd and Pb. The results showed that all the four treatments can significantly reduce the Cd and Pb content in the late rice grain compared with the early rice, among which, the combination amendment of lime and phosphate had the best remediation effects where rice grain Cd content was reduced by 85% and 61%, respectively, for the late rice and the early rice, and by 30% in the late rice grain for Pb. The high reduction effects under the Ca + P treatment might be attributed to increase of soil pH from 5.5 to 6.7. We also found that influence of the Ca + P treatment on rice production was insignificant, while the available Cd and Pb content in soil was reduced by 16.5% and 11.7%, respectively.

Fast and direct analysis of Cr, Cd and Pb in brown sugar by GF AAS.

Science.gov (United States)

Dos Santos, Jeferson M; Quináia, Sueli P; Felsner, Maria L

2018-09-15

A simple and fast analytical method for the determination of Cr, Pb and Cd in brown sugar by GF AAS using slurry sampling was developed and in house validated for the first time. Analytical curves were prepared by external standardization for Cr, and by matrix simulation for Pb and Cd and they were linear. Low limits of quantification for Cr (32.8 ng g -1 ), Pb (49.3 ng g -1 ) and Cd (4.5 ng g -1 ) were found. Repeatability and intermediate precision estimates (brown sugar samples ranged from <32.8 to 160 ng g -1 for Cr, from <49.3 to 211.0 ng g -1 for Pb and from <4.5 to 7.0 ng g -1 for Cd and they may be assigned to anthropogenic activities and the adoption of inadequate practices of production and processing. Copyright © 2018 Elsevier Ltd. All rights reserved.

Phytoextraction of initial cutting of Salix matsudana for Cd and Cu.

Science.gov (United States)

Wang, Wen-Wen; Cheng, Liu Ke; Hao, Jie Wei; Guan, Xin; Tian, Xing-Jun

2016-06-27

Salix species are widely used as vegetation filters because of their flourishing root system and fast growth rate. However, studies have yet to determine whether the root system functions in vegetable filters with mixed heavy metal (HM) pollution or whether initial cutting participates in the phytoextraction of HMs. This study aims to determine the function of the root system and initial cutting as vegetation filters in the absorption and accumulation of Cd and Cu. Thick (>1 cm in diameter) and fine (phytoextraction capacity of plants. The initial cuttings could also absorb and accumulate HMs in the early growth stages of willow without roots. Cu inhibited the plant absorption and accumulation of Cd and promoted Cd transport to shoots. Cd inhibited the Cu absorption of the root system. Our study provided essential data regarding woody species as vegetation filters of HM pollution.

Metal pollution (Cd, Pb, Zn, and As) in agricultural soils and soybean, Glycine max, in southern China.

Science.gov (United States)

Zhao, Yunyun; Fang, Xiaolong; Mu, Yinghui; Cheng, Yanbo; Ma, Qibin; Nian, Hai; Yang, Cunyi

2014-04-01

Crops produced on metal-polluted agricultural soils may lead to chronic toxicity to humans via the food chain. To assess metal pollution in agricultural soils and soybean in southern China, 30 soybean grain samples and 17 soybean-field soil samples were collected from 17 sites in southern China, and metal concentrations of samples were analyzed by graphite furnace atomic absorption spectrophotometer. The integrated pollution index was used to evaluate if the samples were contaminated by Cd, Pb, Zn and As. Results showed that Cd concentration of 12 samples, Pb concentration of 2 samples, Zn concentration of 2 samples, and As concentrations of 2 samples were above the maximum permissible levels in soils. The integrated pollution index indicated that 11 of 17 soil samples were polluted by metals. Metal concentrations in soybean grain samples ranged from 0.11 to 0.91 mg kg(-1) for Cd; 0.34 to 2.83 mg kg(-1) for Pb; 42 to 88 mg kg(-1) for Zn; and 0.26 to 5.07 mg kg(-1) for As, which means all 30 soybean grain samples were polluted by Pb, Pb/Cd, Cd/Pb/As or Pb/As. Taken together, our study provides evidence that metal pollution is an important concern in agricultural soils and soybeans in southern China.

Chemical speciation of Pb(II, Cd(II, Hg(II, Co(II, Ni(II, Cu(II and Zn(II binary complexes of l-methionine in 1,2-propanediol-water mixtures

Directory of Open Access Journals (Sweden)

M. Padma Latha

2007-04-01

Full Text Available Chemical speciation of Pb(II, Cd(II, Hg(II, Co(II, Ni(II, Cu(II and Zn(II complexes of L-methionine in 0.0-60 % v/v 1,2-propanediol-water mixtures maintaining an ionic strength of 0.16 M at 303 K has been studied pH metrically. The active forms of ligand are LH2+, LH and L-. The predominant species detected are ML, MLH, ML2, ML2H, ML2H2 and MLOH. Models containing different numbers of species were refined by using the computer program MINIQUAD 75. The best-fit chemical models were arrived at based on statistical parameters. The trend in variation of complex stability constants with change in the dielectric constant of the medium is explained on the basis of electrostatic and non-electrostatic forces.

Relationships among DNA hypomethylation, Cd, and Pb exposure and risk of cigarette smoking-related urothelial carcinoma

Energy Technology Data Exchange (ETDEWEB)

Chung, Chi-Jung [Department of Health Risk Management, College of Public Health, China Medical University, Taichung, Taiwan (China); Department of Medical Research, China Medical University and Hospital, Taichung, Taiwan (China); Chang, Chao-Hsiang [Department of Urology, China Medical University and Hospital, Taichung, Taiwan (China); Department of Medicine, College of Medicine, China Medical University and Hospital, Taichung, Taiwan (China); Liou, Saou-Hsing [Division of Environmental Health and Occupational Medicine, National Health Research Institutes, Zhunan, Miaoli County, Taiwan (China); Liu, Chiu-Shong [Department of Family Medicine, China Medical University and Hospital, Taichung, Taiwan (China); Liu, Huei-Ju [Division of Environmental Health and Occupational Medicine, National Health Research Institutes, Zhunan, Miaoli County, Taiwan (China); Hsu, Li-Ching [Department of Health Risk Management, College of Public Health, China Medical University, Taichung, Taiwan (China); Chen, Jhih-Sheng [Department of Chemistry, Fu Jen Catholic University, New Taipei City, Taiwan (China); Lee, Hui-Ling, E-mail: 076308@mail.fju.edu.tw [Department of Chemistry, Fu Jen Catholic University, New Taipei City, Taiwan (China)

2017-02-01

Cigarette smoking and environmental exposure to heavy metals are important global health issues, especially for urothelial carcinoma (UC). However, the effects of cadmium and lead exposure, as well as the levels of DNA hypomethylation, on UC risk are limited. We evaluated the possible exposure sources of Cd and Pb and the relationship among DNA hypomethylation, urinary Cd and Pb levels, and UC risk. We recruited 209 patients with UC and 417 control patients for a hospital-based case–control study between June 2011 and August 2014. We collected environmental exposure-related information with questionnaires. Blood and urine samples were analyzed to measure the Cd and Pb exposure and 5-methyl-2′-deoxycytidine levels as a proxy for DNA methylation. Multivariate logistic regression and 95% confidence intervals were applied to estimate the risk for UC. Study participants with high Cd and Pb exposure in blood or urine had significantly increased risk of UC, especially among the smokers. After adjusting for age and gender, the possible connections of individual cumulative cigarette smoking or herb medicine exposure with the increased levels of Cd and Pb were observed in the controls. Participants with 8.66%–12.39% of DNA hypomethylation had significantly increased risk of UC compared with those with ≥ 12.39% of DNA hypomethylation. Environmental factors including cigarette smoking and herb medicine may contribute to the internal dose of heavy metals levels. Repeat measurements of heavy metals with different study design, detailed dietary information, and types of herb medicine should be recommended for exploring UC carcinogenesis in future studies. - Highlights: • Smoking and herb medicine ingestion is associated with increased urinary Cd and Pb levels. • Urinary levels of Cd and Pb are associated with increased risk of UC. • UC carcinogenesis might have partially resulted from DNA hypomethylation.

Relationships among DNA hypomethylation, Cd, and Pb exposure and risk of cigarette smoking-related urothelial carcinoma

International Nuclear Information System (INIS)

Chung, Chi-Jung; Chang, Chao-Hsiang; Liou, Saou-Hsing; Liu, Chiu-Shong; Liu, Huei-Ju; Hsu, Li-Ching; Chen, Jhih-Sheng; Lee, Hui-Ling

2017-01-01

Cigarette smoking and environmental exposure to heavy metals are important global health issues, especially for urothelial carcinoma (UC). However, the effects of cadmium and lead exposure, as well as the levels of DNA hypomethylation, on UC risk are limited. We evaluated the possible exposure sources of Cd and Pb and the relationship among DNA hypomethylation, urinary Cd and Pb levels, and UC risk. We recruited 209 patients with UC and 417 control patients for a hospital-based case–control study between June 2011 and August 2014. We collected environmental exposure-related information with questionnaires. Blood and urine samples were analyzed to measure the Cd and Pb exposure and 5-methyl-2′-deoxycytidine levels as a proxy for DNA methylation. Multivariate logistic regression and 95% confidence intervals were applied to estimate the risk for UC. Study participants with high Cd and Pb exposure in blood or urine had significantly increased risk of UC, especially among the smokers. After adjusting for age and gender, the possible connections of individual cumulative cigarette smoking or herb medicine exposure with the increased levels of Cd and Pb were observed in the controls. Participants with 8.66%–12.39% of DNA hypomethylation had significantly increased risk of UC compared with those with ≥ 12.39% of DNA hypomethylation. Environmental factors including cigarette smoking and herb medicine may contribute to the internal dose of heavy metals levels. Repeat measurements of heavy metals with different study design, detailed dietary information, and types of herb medicine should be recommended for exploring UC carcinogenesis in future studies. - Highlights: • Smoking and herb medicine ingestion is associated with increased urinary Cd and Pb levels. • Urinary levels of Cd and Pb are associated with increased risk of UC. • UC carcinogenesis might have partially resulted from DNA hypomethylation.

A new colorimetric chemosensors for Cu{sup 2+} and Cd{sup 2+} ions detection: Application in environmental water samples and analytical method validation

Energy Technology Data Exchange (ETDEWEB)

Tekuri, Venkatadri; Trivedi, Darshak R., E-mail: darshak_rtrivedi@yahoo.co.in

2017-06-15

A new heterocyclic thiophene-2-caboxylic acid hydrazide based chemosensor R1 to R4 were designed, synthesized and characterized by various spectroscopic techniques like FT-IR, UV-Vis, {sup 1}H NMR, {sup 13}C NMR, Mass and SC-XRD. The chemosensor R3 showed a significant color change from colorless to yellow in the presence of Cu{sup 2+} ions and chemosensor R4 showed a significant color change from colorless to yellow in the presence of Cd{sup 2+} ions over the other tested cations such as Cr{sup 3+}, Mn{sup 2+}, Fe{sup 2+}, Fe{sup 3+}, Co{sup 2+}, Ni{sup 2+}, Zn{sup 2+}, Ag{sup 2+}, Al{sup 3+}, Pb{sup 2+}, Hg{sup 2+}, K{sup +}, Ca{sup 2+} and Mg{sup 2+}. The high selective and sensitivity of R3 towards Cu{sup 2+} and R4 towards Cd{sup 2+} ions was confirmed by UV-Vis spectroscopic study. The R3 showed a red shift in the presence of Cu{sup 2+} ions by Δλ{sub max} 67 nm and R4 showed a red shift in the presence of Cd{sup 2+} ions by Δλ{sub max} 105 nm in the absorption spectrum. The binding stoichiometric ratio of the complex between R3 - Cu{sup 2+} and R4 - Cd{sup 2+} ions have been found to be 1:1 using the B-H plot. Under optimized experimental conditions, the R3 and R4 exhibits a dynamic linear absorption response range, from 0 to 50 μM for Cu{sup 2+} ions and 0 to 30 μM for Cd{sup 2+} ions, with the detection limit of 2.8 × 10{sup −6} M for Cu{sup 2+} and 2.0 × 10{sup −7} M for Cd{sup 2+} ions. The proposed analytical method for the quantitative determination of Cu{sup 2+} and Cd{sup 2+} ions was validated and successfully applied for the environmental samples with good precision and accuracy. - Highlights: • Detection of Cu{sup 2+} and Cd{sup 2+} ions has gained significance by virtue of its key role in biological and environmental science. • The R3 and R4 showed instantaneous color change from colorless to yellow in the presence of Cu{sup 2+} and Cd{sup 2+} ions respectively. • The proposed detection methods were validated and

Sorption Potentials of Waste Tyre for Some Heavy Metals (Pb Cd in Aqueous Solution

Directory of Open Access Journals (Sweden)

Austin Kanayo ASIAGWU

2009-07-01

Full Text Available An investigation into the adsorption potential of activated and inactivated waste tyre powders for some heavy metals (Pb2+ and Cd2+ in their aqueous solution has been studied. The result indicated that inactivated waste tyre is a good non-conventional adsorbent for the removal of Cd from aqueous solution. A total of 93.3% of Cadmium contents was removed. The inactivated waste type proved a good adsorbent for the removal of Pb2+ 5g of 500mm activated tyre removed over 86.66% of Pb2+ from solution.

Solid-phase extraction of Mn(II), Co(II), Ni(II), Cu(II), Cd(II) and Pb(II) ions from environmental samples by flame atomic absorption spectrometry (FAAS)

Energy Technology Data Exchange (ETDEWEB)

Duran, Celal [Department of Chemistry, Faculty of Art and Science, Karadeniz Technical University, 61080 Trabzon (Turkey); Gundogdu, Ali [Department of Chemistry, Faculty of Art and Science, Karadeniz Technical University, 61080 Trabzon (Turkey); Bulut, Volkan Numan [Department of Chemistry, Giresun Faculty of Art and Science, Karadeniz Technical University, 28049 Giresun (Turkey); Soylak, Mustafa [Department of Chemistry, Faculty of Art and Science, Erciyes University, 38039 Kayseri (Turkey)]. E-mail: soylak@erciyes.edu.tr; Elci, Latif [Department of Chemistry, Faculty of Art and Science, Pamukkale University, 20020 Denizli (Turkey); Sentuerk, Hasan Basri [Department of Chemistry, Faculty of Art and Science, Karadeniz Technical University, 61080 Trabzon (Turkey); Tuefekci, Mehmet [Department of Chemistry, Faculty of Art and Science, Karadeniz Technical University, 61080 Trabzon (Turkey)

2007-07-19

A new method using a column packed with Amberlite XAD-2010 resin as a solid-phase extractant has been developed for the multi-element preconcentration of Mn(II), Co(II), Ni(II), Cu(II), Cd(II), and Pb(II) ions based on their complex formation with the sodium diethyldithiocarbamate (Na-DDTC) prior to flame atomic absorption spectrometric (FAAS) determinations. Metal complexes sorbed on the resin were eluted by 1 mol L{sup -1} HNO{sub 3} in acetone. Effects of the analytical conditions over the preconcentration yields of the metal ions, such as pH, quantity of Na-DDTC, eluent type, sample volume and flow rate, foreign ions etc. have been investigated. The limits of detection (LOD) of the analytes were found in the range 0.08-0.26 {mu}g L{sup -1}. The method was validated by analyzing three certified reference materials. The method has been applied for the determination of trace elements in some environmental samples.

Microstructural discovery of Al addition on Sn–0.5Cu-based Pb-free solder design

International Nuclear Information System (INIS)

Koo, Jahyun; Lee, Changsoo; Hong, Sung Jea; Kim, Keun-Soo; Lee, Hyuck Mo

2015-01-01

It is important to develop Pb-free solder alloys suitable for automotive use instead of traditional Sn–Pb solder due to environmental regulations (e.g., Restriction of Hazardous Substances (RoHS)). Al addition has been spotlighted to enhance solder properties. In this study, we investigated the microstructural change of Sn–0.5Cu wt.% based Pb-free solder alloys with Al addition (0.01–0.05 wt.%). The small amount of Al addition caused a remarkable microstructural change. The Al was favored to form Cu–Al intermetallic compounds inside the solder matrix. We identified the Cu–Al intermetallic compound as Cu_3_3Al_1_7, which has a rhombohedral structure, using EPMA and TEM analyses. This resulted in refined Cu_6Sn_5 networks in the Sn–0.5Cu based solder alloy. In addition, we conducted thermal analysis to confirm its stability at a high temperature of approximately 230 °C, which is the necessary temperature range for automotive applications. The solidification results were substantiated thermodynamically using the Scheil solidification model. We can provide criteria for the minimum aluminum content to modify the microstructure of Pb-free solder alloys. - Graphical abstract: The minor Al additions refined eutectic Cu_6Sn_5 IMC networks on the Sn–0.5Cu based solder alloys. The microstructure was dramatically changed with the minor Al addition. - Highlights: • We observed dramatic microstructure-change with Al additions. • We defined Cu_3_3Al_1_7 IMC with Al additions using TEM analysis. • We investigated grain refinement with Al additions using EBSD. • We discussed the refinement based on Scheil solidification model.

Microstructural discovery of Al addition on Sn–0.5Cu-based Pb-free solder design

Energy Technology Data Exchange (ETDEWEB)

Koo, Jahyun; Lee, Changsoo [Department of Materials Science and Engineering, KAIST, Daejeon 305-701 (Korea, Republic of); Hong, Sung Jea [MK Electron Co., Ltd., Yongin Cheoin-gu 316-2 (Korea, Republic of); Kim, Keun-Soo, E-mail: keunsookim@hoseo.edu [Department of Display Engineering, Hoseo University, Asan 336-795 (Korea, Republic of); Lee, Hyuck Mo, E-mail: hmlee@kaist.ac.kr [Department of Materials Science and Engineering, KAIST, Daejeon 305-701 (Korea, Republic of)

2015-11-25

It is important to develop Pb-free solder alloys suitable for automotive use instead of traditional Sn–Pb solder due to environmental regulations (e.g., Restriction of Hazardous Substances (RoHS)). Al addition has been spotlighted to enhance solder properties. In this study, we investigated the microstructural change of Sn–0.5Cu wt.% based Pb-free solder alloys with Al addition (0.01–0.05 wt.%). The small amount of Al addition caused a remarkable microstructural change. The Al was favored to form Cu–Al intermetallic compounds inside the solder matrix. We identified the Cu–Al intermetallic compound as Cu{sub 33}Al{sub 17}, which has a rhombohedral structure, using EPMA and TEM analyses. This resulted in refined Cu{sub 6}Sn{sub 5} networks in the Sn–0.5Cu based solder alloy. In addition, we conducted thermal analysis to confirm its stability at a high temperature of approximately 230 °C, which is the necessary temperature range for automotive applications. The solidification results were substantiated thermodynamically using the Scheil solidification model. We can provide criteria for the minimum aluminum content to modify the microstructure of Pb-free solder alloys. - Graphical abstract: The minor Al additions refined eutectic Cu{sub 6}Sn{sub 5} IMC networks on the Sn–0.5Cu based solder alloys. The microstructure was dramatically changed with the minor Al addition. - Highlights: • We observed dramatic microstructure-change with Al additions. • We defined Cu{sub 33}Al{sub 17} IMC with Al additions using TEM analysis. • We investigated grain refinement with Al additions using EBSD. • We discussed the refinement based on Scheil solidification model.

The role of Cd and Ga in the Cu(In,Ga)S2/CdS heterojunction studied with X-ray spectroscopic methods

International Nuclear Information System (INIS)

Johnson, Benjamin E.

2010-01-01

Photovoltaic cells with the structure Glass/Mo/Cu(In,Ga)S 2 /CdS/i-ZnO/n+-ZnO are currently among the most successful and promising thin-layer solar cells. In this system, the Cu(In,Ga)S 2 (CIS) acts as the absorber, the CdS as the buffer layer and the ZnO as the window layer. The goal of this work is the investigation of the Cu(In,Ga)S 2 /CdS semiconductor heterojunction both as a component of the solar cell and as a separate material system. The characteristics of this junction were investigated both during junction formation through chemical bath deposition (CBD) and after the junction was completed. It is currently thought that the Cu(In,Ga)S 2 /CdS junction is responsible for several different properties of the solar cell: lattice matching and band offset optimization between the absorber and window layer and chemical passivation of the absorber surface by the CBD-CdS process on CIS which acts to reduce the surface defect density. The Cd may also pin the Fermi Level on the CIS surface or cause a type inversion of the absorber surface from p-type to n-type. In order to investigate the junction several new methods were used along side the conventional methods of X-ray, Ultraviolet and Inverse Photoelectron Spectroscopy. These were Near-UV Constant Final State Yield Spectroscopy for the measurement of the valence band offset at the interface between CIS and CdS and Near Edge X-ray Absorption Fine Structure to follow the development of the Cu(In,Ga)S 2 conduction band edge with increasing Ga concentration. Additionally, the advantages and disadvantages of the established and new methods were compared and discussed. It was discovered that the deposition of CdS neither pins the Fermi Level on the CIS surface at a position important for the solar cell, nor does it dope the absorber surface, although the deposition does lead to the formation of a Cd-containing CIS surface layer (CIS:Cd). Because this surface layer is not soluble in HCl it cannot be CdS as this is

A review of Pb-Sb(As-S, Cu(Ag-Fe(Zn-Sb(As-S, Ag(Pb-Bi(Sb-S and Pb-Bi-S(Te sulfosalt systems from the Boranja orefield, West Serbia

Directory of Open Access Journals (Sweden)

Radosavljević Slobodan A.

2016-01-01

Full Text Available Recent mineralogical, chemical, physical, and crystallographic investigations of the Boranja orefield showed very complex mineral associations and assemblages where sulfosalts have significant role. The sulfosalts of the Boranja orefield can be divided in four main groups: (i Pb-Sb(As-S system with ±Fe and ±Cu; (ii Cu(Ag-Fe(Zn-Sb(As-S system; (iii Ag(Pb-Bi(Sb-S; (iv and Pb-Bi-S(Te system. Spatially, these sulfosalts are widely spread, however, they are the most abundant in the following polymetallic deposits and ore zones: Cu(Bi-FeS Kram-Mlakva; Pb(Ag-Zn-FeS2 Veliki Majdan (Kolarica-Centralni revir-Kojići; Sb-Zn-Pb-As Rujevac; and Pb-Zn-FeS2-BaSO4 Bobija. The multi stage formation of minerals, from skarnhydrothermal to complex hydrothermal with various stages and sub-stages has been determined. All hydrothermal stages and sub-stages of various polymetallic deposits and ore zones within the Boranja orefield are followed by a variety of sulfosalts. [Projekat Ministarstva nauke Republike Srbije, br. OI-176016: Magmatism and geodynamics of the Balkan Peninsula from Mesozoic to present day: Significance for the formation of metallic and non-metallic mineral deposits

NaCl protects against Cd and Cu-induced toxicity in the halophyte Atriplex halimus

Energy Technology Data Exchange (ETDEWEB)

Bankaji, I.; Sleimi, N.; Gómez-Cadenas, A.; Pérez-Clemente, R.M.

2016-07-01

The objective of the present work was to evaluate the extent of Cd- and Cu-induced oxidative stress and the antioxidant response triggered in the halophyte species Atriplex halimus after metallic trace elements exposure. Plants were treated for one month with Cd2+ or Cu2+ (400 µM) in the absence or presence of 200 mM NaCl in the irrigation solution. The interaction between salinity and heavy metal stress was analyzed in relation to plant growth, tissue ion contents (Na+, K+ and Mg2+), oxidative damage and antioxidative metabolism. Data indicate that shoot and root weight significantly decreased as a consequence of Cd2+- or Cu2+-induced stress. Metallic stress leads to unbalanced nutrient uptake by reducing the translocation of K+ and Mg2+ from the root to the shoot. The levels of malondialdehyde increased in root tissue when Cd, and especially Cu, were added to the irrigation solution, indicating that oxidative damage occurred. Results showed that NaCl gave a partial protection against Cd and Cu induced toxicity, although these contaminants had distinct influence on plant physiology. It can be concluded that salinity drastically modified heavy metal absorption and improved plant growth. Salinity also decreased oxidative damage, but differently in plants exposed to Cd or Cu stress.

Study on accumulation mechanism of Cu and Pb in moss, Scopelophila cataractae, by micro-XRF imaging and XAFS analysis

International Nuclear Information System (INIS)

Yoshii, Yuichi; Nakai, Izumi; Hokura, Akiko; Abe, Tomoko; Itouga, Misao; Sakakibara, Hitoshi; Terada, Yasuko

2011-01-01

Scopelophila cataractae is known as a 'copper moss'. It is known as a peculiar moss which can accumulate high level of metals (Cu, Pb, etc.) in its plant body. This moss is expected as a material to collect metals from water. In this study, gametophyte's leaf of the moss was examined by μ-XRF imaging, and Cu K-edge and Pb L 1 -, L 3 -edge XAFS analyses to reveal the accumulation behavior of Cu and Pb. μ-XRF imaging was carried out utilizing X-ray microbeam at BL37XU, SPring-8 from the undulator source, and at BL-4A, Photon Factory KEK from the bending magnet. The results have revealed that Cu and Pb were accumulated on the cell wall of the leaf, and especially at the stereid cells of midrib. It was found that Cu-XANES spectra of the leaf were similar to that of copper(II) acetate, a reference substance. On the other hand, Pb XANES spectra of the leaf were similar to that of a reference, lead(II) stearate. These results suggested that these metals were bound to oxygen of carboxyl group in the plant. Consequently, it is assumed that Cu and Pb could be bound to acidic sugar which is a component of its cell wall such as pectic acid, polygalacturonic acid and others. Furthermore, to compare with other heavy-metal accumulating moss (Scopelophila ligulata and Sphagnum palustre), their gametophyte's leaves were also examined by μ-XRF imaging. S. ligulata accumulated Pb in its stereid cells of midlib, while S. palustre accumulated Pb in its hyaline cells. (author)

Spin-coating deposition of PbS and CdS thin films for solar cell application

Energy Technology Data Exchange (ETDEWEB)

Patel, Jayesh; Mighri, Frej [Laval University, CREPEC, Department of Chemical Engineering, Quebec, QC (Canada); Ajji, Abdellah [Ecole Polytechnique, CREPEC, Chemical Engineering Department, Montreal, QC (Canada); Tiwari, Devendra; Chaudhuri, Tapas K. [Charotar University of Science and Technology (CHARUSAT), Dr. K.C. Patel Research and Development Centre, Anand District, Gujarat (India)

2014-12-15

In this work, we describe a simple spin-coating deposition technique for lead sulphide (PbS) and cadmium sulphide (CdS) films from a methanolic metal-thiourea complex. The characterization of the films by X-ray diffraction and X-ray photoelectron spectroscopy techniques revealed that pure cubic phase PbS and CdS layers were formed via this method. As shown by atomic force microscopy and scanning electron microscopy results, both films were homogeneous and presented a smooth surface. Optical properties showed that the energy band gap of PbS and CdS films were around 1.65 and 2.5 eV, respectively. The PbS film is p-type in nature with an electrical conductivity of around 0.8 S/cm. The hole concentration and mobility were 2.35 x 10{sup 18} cm{sup -3} and 2.16 x 10{sup -3} cm{sup 2}/V/s, respectively, as determined from Hall measurement. Both films were used to develop a thin film solar cell device of graphite/PbS/CdS/ITO/glass. Device characterization showed the power conversion efficiency of around 0.24 %. The corresponding open circuit voltage, short circuit current and fill factor were 0.570 V, 1.32 mA/cm{sup 2} and 0.32, respectively. (orig.)

Modelling equilibrium adsorption of single, binary, and ternary combinations of Cu, Pb, and Zn onto granular activated carbon.

Science.gov (United States)

Loganathan, Paripurnanda; Shim, Wang Geun; Sounthararajah, Danious Pratheep; Kalaruban, Mahatheva; Nur, Tanjina; Vigneswaran, Saravanamuthu

2018-03-30

Elevated concentrations of heavy metals in water can be toxic to humans, animals, and aquatic organisms. A study was conducted on the removal of Cu, Pb, and Zn by a commonly used water treatment adsorbent, granular activated carbon (GAC), from three single, three binary (Cu-Pb, Cu-Zn, Pb-Zn), and one ternary (Cu-Pb-Zn) combination of metals. It also investigated seven mathematical models on their suitability to predict the metals adsorption capacities. Adsorption of Cu, Pb, and Zn increased with pH with an abrupt increase in adsorption at around pH 5.5, 4.5, and 6.0, respectively. At all pHs tested (2.5-7.0), the adsorption capacity followed the order Pb > Cu > Zn. The Langmuir and Sips models fitted better than the Freundlich model to the data in the single-metal system at pH 5. The Langmuir maximum adsorption capacities of Pb, Cu, and Zn (mmol/g) obtained from the model's fits were 0.142, 0.094, and 0.058, respectively. The adsorption capacities (mmol/g) for these metals at 0.01 mmol/L equilibrium liquid concentration were 0.130, 0.085, and 0.040, respectively. Ideal Adsorbed Solution (IAS)-Langmuir and IAS-Sips models fitted well to the binary and ternary metals adsorption data, whereas the Extended Langmuir and Extended Sips models' fits to the data were poor. The selectivity of adsorption followed the same order as the metals' capacities and affinities of adsorption in the single-metal systems.

Structural, optical and electrical characterization of Mn2+ and Cd2+ doped/co-doped PbS nanocrystals

International Nuclear Information System (INIS)

Sakthi Sudar Saravanan, R.; Meena, M.; Pukazhselvan, D.; Mahadevan, C.K.

2015-01-01

Highlights: • Mn and Cd doped/codoped nano PbS was synthesized by SMI method. • The observed stress is ∼90% lower, and the strain is only in the order of 10 −6 . • Band gap value can be enhanced from 0.5 eV to 2.025–2.235 eV (±0.012 eV). • Role of two conduction activation barriers was observed. - Abstract: The strain and stress minimized nanoparticles of PbS, Pb 0.95 Mn 0.05 S, Pb 0.95 Cd 0.05 S and Pb 0.90 Mn 0.05 Cd 0.05 S were successfully synthesized using solvothermal microwave irradiation (SMI) method. The quality/performance of the materials was found to be in the series Pb 0.90 Mn 0.05 Cd 0.05 S > Pb 0.95 Cd 0.05 S > Pb 0.95 Mn 0.05 S > PbS. The average crystallite size in the best material Pb 0.90 Mn 0.05 Cd 0.05 S was found to be ∼18 nm where the particles are distributed within the range 20–60 nm. Optical studies reveals the existence of direct band gap in the range of 2.025–2.235 eV (±0.012 eV). This is one of the widest E g values reported for this system. Electrical measurements were performed on compacts of nanoparticles in the temperature range 313–433 K and frequency range 100 Hz–1 MHz. The conductivity profile exhibits two components; in which the activation energy (ΔE) values obtained for the temperature range 373–433 K is almost twice as compared to the ΔE value obtained for 313–373 K. Nonetheless, the conductivity at the higher temperatures was always higher than at the low temperatures and interestingly, the nanoparticles exhibits higher conductivity than their bulk counterpart. The feasible mechanism of conduction is discussed

Formation pathways in the synthesis and properties of (Tl0.5Pb0.5)(Sr0.9Ba0.1)2Ca2Cu3Oz and (Tl0.5Pb0.5)(Sr0.8Ba0.2)2Ca2Cu3Oz-1223 superconductors

International Nuclear Information System (INIS)

Auinger, M; Gritzner, G; Bertrand, Ch; Galez, Ph; Soubeyroux, J-L

2007-01-01

The formation pathway of (Tl 0.5 Pb 0.5 )(Sr 0.9 Ba 0.1 ) 2 Ca 2 Cu 3 O z and (Tl 0.5 Pb 0.5 )(Sr 0.8 Ba 0.2 ) 2 Ca 2 Cu 3 O z was studied by neutron and x-ray diffraction. The following reaction pathway was proposed: thallium oxide and lead oxide react with Sr-rich (Sr 1-x Ca x )CuO 2 and Ca-rich (Ca x Sr 1-x )O to form Sr 4 Tl 2 O 7 and (Ca x Sr 1-x )PbO 3 , respectively. The thallate and the plumbate compounds then form the (Tl 0.5 Pb 0.5 )-1212 phase starting at a temperature of 600 deg. C. Finally, between 850 and 900 deg. C, the 1223 phase is formed from (Tl 0.5 Pb 0.5 )-1212 (Ca x Sr 1-x ) 2 CuO 3 and CuO. Parallel experiments to fabricate the (Tl, Pb)-1223 superconductor resulted in specimens with critical temperatures of 117.5 K and 116 K, respectively, and transition widths of 2 K. Differences between the pathways for the formation of Pb-doped, Sr-rich and Pb-free, Ba-rich Tl-1223 superconductors are discussed

Cd, Zn, Ni and Cu in the Indian Ocean

NARCIS (Netherlands)

Saager, Paul M.; Baar, Hein J.W. de; Howland, Robin J.

1992-01-01

Vertical profiles of dissolved Cd, Zn, Ni and Cu in the Northwest Indian Ocean (Arabian Sea) exhibit a nutrient type distribution also observed in other oceans. The area is characterized by strong seasonal upwelling and a broad oxygen minimum zone in intermediate waters. However, neither Cd, Zn, Ni

Wave Function Engineering in CdSe/PbS Core/Shell Quantum Dots.

Science.gov (United States)

Wieliczka, Brian M; Kaledin, Alexey L; Buhro, William E; Loomis, Richard A

2018-05-25

The synthesis of epitaxial CdSe/PbS core/shell quantum dots (QDs) is reported. The PbS shell grows in a rock salt structure on the zinc blende CdSe core, thereby creating a crystal structure mismatch through additive growth. Absorption and photoluminescence (PL) band edge features shift to lower energies with increasing shell thickness, but remain above the CdSe bulk band gap. Nevertheless, the profiles of the absorption spectra vary with shell growth, indicating that the overlap of the electron and hole wave functions is changing significantly. This leads to over an order of magnitude reduction of absorption near the band gap and a large, tunable energy shift, of up to 550 meV, between the onset of strong absorption and the band edge PL. While the bulk valence and conduction bands adopt an inverse type-I alignment, the observed spectroscopic behavior is consistent with a transition between quasi-type-I and quasi-type-II behavior depending on shell thickness. Three effective mass approximation models support this hypothesis and suggest that the large difference in effective masses between the core and shell results in hole localization in the CdSe core and a delocalization of the electron across the entire QD. These results show the tuning of wave functions and transition energies in CdSe/PbS nanoheterostructures with prospects for use in optoelectronic devices for luminescent solar concentration or multiexciton generation.

Relation Between pH and Desorption of Cu, Cr, Zn, and Pb from Industrially Polluted Soils

DEFF Research Database (Denmark)

Ottosen, Lisbeth M.; Hansen, Henrik K.; Jensen, Pernille Erland

2009-01-01

Desorption of Cu, Cr, Pb, and Zn from industrially polluted soils as a result of acidification is in focus. The eight soils of the investigation vary greatly in composition and heavy metal concentration/combination. Three soils had elevated concentrations of Cu, Pb, and Zn; regardless of pollution...... level, pollution origin, and soil type, the order for desorption as pH decreased was Zn > Cu > Pb. Turning to a single heavy metal in different soils, there was a huge difference in the pH at which the major desorption started. The variation was most significant for Pb where, e.g., less than 10......% was desorbed at pH 2.5 from one soil, whereas in another soil 60% Pb was desorbed at this pH. Sequential extraction was made and the soils in which a high percentage of Pb was found in the residual phase (adsorbed strongest) was also the soils where less Pb was desorbed at low pH in the desorption experiments...

CdO necklace like nanobeads decorated with PbS nanoparticles: Room temperature LPG sensor

Energy Technology Data Exchange (ETDEWEB)

Sonawane, N.B. [Department of Physics, School of Physical Sciences, North Maharashtra University, Jalgaon, 425001 M.S. (India); K.A.M.P. & N.K.P. Science College, Pimpalner, Sakri, Dhule, M.S. (India); Baviskar, P.K. [Department of Physics, School of Physical Sciences, North Maharashtra University, Jalgaon, 425001 M.S. (India); Ahire, R.R. [S.G. Patil Science, Sakri, Dhule, M.S. (India); Sankapal, B.R., E-mail: brsankapal@gmail.com [Nano Materials and Device Laboratory, Department of Applied Physics, Visvesvaraya National Institute of Technology, South Ambazari Road, Nagpur, 440010 M.S. (India)

2017-04-15

Simple chemical route has been employed to grow interconnected nanobeads of CdO having necklace like structure through air annealing of cadmium hydroxide nanowires. This nanobeads of n-CdO with high surface area has been decorated with p-PbS nanoparticles resulting in the formation of nano-heterojunction which has been utilized effectively as room temperature liquefied petroleum gas (LPG) sensor. The room temperature gas response towards C{sub 2}H{sub 5}OH, Cl{sub 2}, NH{sub 3}, CO{sub 2} and LPG was investigated, among which LPG exhibits significant response. The maximum gas response of 51.10% is achieved with 94.54% stability upon exposure of 1176 ppm concentration of LPG at room temperature (27 °C). The resulting parameters like gas response, response and recovery time along with stability studies has been studied and results are discussed herein. - Highlights: • Conversion of Cd(OH){sub 2} nanowires to CdO nanonecklace by air annealing at 290 °C. • Decoration of PbS nanoparticles over CdO nanobeads by SILAR method. • Formation of n-CdO/p-PbS nano-heterojunction as room temperature LPG sensor. • Maximum gas response of 51.10% with 94.54% stability.

Estudio de los mecanismos de activación de la esfalerita con Cu(II y Pb(II

Directory of Open Access Journals (Sweden)

Dávila Pulido, G. I.

2011-08-01

Full Text Available This article presents results of an experimental study on the sphalerite activation with Cu(II and Pb(II, whose main objective was to investigate the activation mechanisms and to evaluate the magnitude of the hydrophobization achieved with both chemical species. The hydrophobicity acquired by the mineral due to the interaction with the activator and collector (sodium isopropyl xanthate is characterized making use of the contact angle technique. The results show that Cu(II replaces the Zn of the external layers of the mineral, promoting the sulfide (S^2– oxidation to produce a mixture of CuS, Cu₂S and S°, of hydrophobic nature. The subsequent interaction with xanthate increases the hydrophobicity of the mineral surface. In turn, Pb(II activation of sphalerite is due to the formation of a PbS layer that reacts with xanthate to produce hydrophobic species (e.g., PbX₂. It is also observed that the hydrophobicity of sphalerite activated with Pb(II is favored under air atmospheres, as compared to that obtained under nitrogen atmospheres. It is concluded that the hydrophobicity achieved by lead activation may be of the same order of magnitude to that deliverately induced by copper activation.

Este artículo presenta los resultados de un estudio experimental sobre la activación de esfalerita (ZnS con Cu(II y Pb(II, cuyo objetivo principal consistió en investigar los mecanismos de activación y en evaluar la magnitud relativa de la hidrofobización alcanzada con ambas especies químicas. La hidrofobicidad que la superficie mineral adquiere como resultado de la interacción con los activadores y colectores tipo xantato (ditiocarbonatos alquílicos, R-O-CS₂ –, se caracteriza mediante la técnica del ángulo de contacto. Los resultados muestran que el Cu(II es intercambiado por el Zn de las capas exteriores del cristal, promoviendo la oxidación de sulfuro (S^2– para producir una mezcla de

Lattice parameter values and phase transitions for the Cu2Cd1-zMn zGeSe4 and Cu2Cd1-zFe zGeSe4 alloys

International Nuclear Information System (INIS)

Quintero, E.; Tovar, R.; Quintero, M.; Delgado, G.E.; Morocoima, M.; Caldera, D.; Ruiz, J.; Mora, A.E.; Briceno, M.; Fernandez, J.L.

2007-01-01

X-ray powder diffraction measurements and differential thermal analysis (DTA) were made on polycrystalline samples of the Cu 2 Cd 1-z Mn z GeSe 4 and Cu 2 Cd 1-z Fe z GeSe 4 alloy systems. The diffraction patterns were used to show the equilibrium conditions and to derive lattice parameter values. The effect of the annealing temperature and cooling rate to room temperature are discussed. For the Cu 2 Cd 1-z Fe z GeSe 4 system, only two single solid phase fields, the tetragonal stannite α and the wurtz-stannite δ structures were found to occur in the diagram. For the Cu 2 Cd 1-z Mn z GeSe 4 system, in addition to the tetragonal stannite α and the wurtz-stannite δ phases, MnSe was found to exist in the diagram. The DTA experiments showed that the cooling curves for both systems exhibited effects of undercooling

Prosopis juliflora--a green solution to decontaminate heavy metal (Cu and Cd) contaminated soils.

Science.gov (United States)

Senthilkumar, P; Prince, W S P M; Sivakumar, S; Subbhuraam, C V

2005-09-01

Soil and plant samples (root and shoot) of Prosopis juliflora were collected in the vicinity of metal based foundry units in Coimbatore and assessed for their heavy metal content (Cu and Cd) to ascertain the use of P. juliflora as a green solution to decontaminate soils contaminated with Cu and Cd. The results showed that Cu and Cd content was much higher in plant components compared to their extractable level in the soil. Furthermore, there exist a strong correlation between the distance of the sources of industrial units and accumulation of heavy metals in plants. Accumulation of Cd in roots is comparatively higher than that of shoots. However, in case of Cu no such clear trend is seen. Considering the accumulation efficiency and tolerance of P. juliflora to Cd and Cu, this plant can be explored further for the decontamination of metal polluted soils. On the other hand, in view of heavy metal accumulate the practice of providing foliage and pods as fodder for live stock should be avoided.

Physical properties of nanostructured (PbSx(CuS1−x composite thin films grown by successive ionic layer adsorption and reaction method

Directory of Open Access Journals (Sweden)

A.U. Ubale

2016-03-01

Full Text Available Nanostructured ternary semiconducting (PbSx(CuS1−x thin films were grown on glass substrates by successive ionic layer adsorption and reaction (SILAR technique at room temperature. The structural, morphological and optical characterizations of the films were carried out by X-ray diffraction, scanning electron microscopy and UV–Vis spectrophotometer respectively. The structural studies revealed that, (PbSx(CuS1−x films are nanocrystalline in nature and have mixed phase of cubic PbS and hexagonal CuS. The optical absorption measurements showed that band gap energy of (PbSx(CuS1−x can be engineered between 2.57 and 2.28 eV by varying compositional parameter ‘x’. The room temperature dc dark electrical resistivity of PbS film is found to be 28.85 Ωcm and it decreases when content of Cu in composite increases and becomes 0.05 Ωcm for pure CuS. The thermo-emf measurements showed that the as deposited (PbSx(CuS1−x films are of n-type. The water angle contact measurements of (PbSx(CuS1−x, revealed that, films are hydrophilic in nature and it could be advantageous in electrochemical application.

Effect of Sintering Time on Superconducting Wire Bi-Pb-Sr-Ca-Cu-O With Dopant MgO Sheated Ag Using Powder in Tube Method

Directory of Open Access Journals (Sweden)

Hariyati Lubis

2018-01-01

  DAFTAR PUSTAKA Abbas M.M., Abass L.K and Salman U., (2012, Influences of Sintering Time on the Tc of Bi2-xCuxPb0.3Sr2Ca2Cu3010+ High Temperature Superconductors, Energy Procedia 18, 215-224  Abbas, M.M., Abbas, L.K., Bahedh, H.S. 2015. Superconducting Properties of Bi2-SbxPb0,3Sr1,9Ba0,1Ca2Cu3O10+δ Compounds. Journal of Applied Science Research. 11. 22: 164-172 Darsono, N., Imaduddin, A., Raju, K., Yoon, D.H., (2015, Synthesis and Characterization of Bi1.6Pb0.4Sr2Ca2Cu3O7 Superconducting Oxide by High-Energy Milling, J Supercond Nov Magn. E. Chew,. (2010, Superconducting Transformer Design And Construction, University of Canterbury, Christchurch, New Zealand. March Hamadneh, I., Halim, S. A., dan Lee, C. K., (2006,  Characterization of Bi1.6Pb0.4Sr2Ca2Cu3Oy Ceramic Superconductor Prepared Via Coprecipitation Method at Different Sintering Time, J. Mater. Sci, 41: 5526-5530. Hermiz G.Y., Aljurani B.A., Beayaty M.A., (2014, Effect of Mn Substitution on the Superconducting Properties of Bi1.7Pb0,3Sr2Ca2-xMnxCu3O10+, International Journal Of Engineering and Advanced Technology (IJEAT. 3. 4: 213-217 John R Hull, (2003, Applications of high-temperature superconductors in power technology, Reports on Progress in Physics, Volume 66, Number 11 Lu, X.Y., Yi, D., Chen, H., Nagata, A. 2016. Effect of Sn, MgO and Ag2O mix-doping on the formation and superconducting properties of Bi-2223 Ag/tapes. Physics Procedia. 81: 129-132 Meretliev Sh., Sadykov K.B., Berkeliev A., (2000, Doping of High Temperature Superconductors, Turk J Phy.24: 39-48 Mohammed, N. H., Ramadhan A., Ali I. A., Ibrahim, I. H., dan Hassan, M. S, (2012, Optimizing the Preparation Conditions of Bi-2223 Superconducting Phase Using PbO and PbO2, Materials Sciences and Applications, 3: 224-233. Roumie, M., Marhaba, S., Awad R., Kork M., Hassan I., Mawassi R., (2014, Effect of Fe2O3 Nano-Oxide Addition on the Superconducting Properties of the (Bi,Pb-2223 Phase, Journal of Supercond Nov Magn, 27: 143-153 Serkan

Simultaneous preconcentration of Cu, Fe and Pb as methylthymol blue complexes on naphthalene adsorbent and flame atomic absorption determination

International Nuclear Information System (INIS)

Pourreza, Nahid; Hoveizavi, Reza

2005-01-01

A simultaneous preconcentration method was developed for determination of trace amounts of Cu, Fe and Pb by atomic absorption spectrometry. The method is based on the retention of their methylthymol blue complexes by naphthalene methyltrioctyl ammonium chloride adsorbent in a column. The adsorbed metal complexes were eluted from the column with nitric acid and Cu, Fe and Pb were determined by flame atomic absorption spectrometry. Several parameters such as pH of the sample solution, ligand concentration, volume of the sample and the amount of methyltrioctyl ammonium chloride loaded on naphthalene were evaluated. The effect of diverse ions on the preconcentration was also investigated. A preconcentration factor of up to 100 or more can easily be achieved depending on the volume of the sample taken. The calibration graphs were obtained in the range of 5-40, 10-100 and 10-200 ng ml -1 for Cu, Fe and Pb in the initial solution, respectively, when using 500 ml of the solution. The detection limit based on three standard deviations of the blank was 0.54, 3.1, and 4.5 ng ml -1 for Cu, Fe and Pb, respectively. The relative standard deviations (R.S.D.) of 0.62-1.4% for Cu, 1.9-3.4% for Fe and 1.0-2.2% for Pb were obtained. The method was applied to the determination of Cu, Fe and Pb in river and wastewater samples

Determination of toxicity limiting values of Zn, Cu, and Pb for oat and red clover

Energy Technology Data Exchange (ETDEWEB)

Hodenberg, A V; Finck, A

1975-01-01

Toxicity limiting values of Zn, Cu and Pb are determined in order to investigate the causes of growth damages in certain fields. Since the true toxicity limit is difficult to estimate, a somewhat higher content is called the toxicity limiting value resulting after the subtraction of a significant yield difference. The pot experiments with increasing fertilization of Zn, Cu and Pb in soil cultures gave the following results. For Zn, the toxicity limit is 410 ppm in oats at the beginning of tilling. In red clover six weeks of age, it is only 290 ppm of Zn and therefore much lower. For Cu, the toxicity limit is 20 ppm in oats at the beginning of tilling and 18 ppm in six weeks old red clover. For Pb, a toxic effect could be observed above 50 ppm, but this does not seem to be the true limit because of disturbing salt effects.

Specific heat (1-330K), magnetic susceptiblity and Meissner effect Bi-(Pb)-Sr-Ca-Cu-O samples

International Nuclear Information System (INIS)

Junod, A.; Eckert, D.; Triscone, G.; Brunner, O.; Muller, J.; Zhao, Z.

1989-01-01

Five samples in the Bi 2 - y Pb y Sr 2 CaCu 2 O 8 + x system selected for their sharp diamagnetic transitions are characterized with particular emphasis on the specific heat. The behavior of the magnetic susceptibility upon doping with holes (Pb) is similar to that of the La 1 - y Sr y CuO 4 system

CuO nanostructures grown by the SILAR method: Influence of Pb-doping on the morphological, structural and optical properties

Energy Technology Data Exchange (ETDEWEB)

Bayansal, F., E-mail: fbayansal@gmail.com [Department of Metallurgical and Materials Engineering, Faculty of Technology, Mustafa Kemal University, Hatay (Turkey); Department of Physics, Faculty of Arts and Sciences, Mustafa Kemal University, Hatay (Turkey); Gülen, Y. [Department of Physics, Faculty of Arts and Sciences, Marmara University, İstanbul (Turkey); Şahin, B. [Department of Physics, Faculty of Arts and Sciences, Mustafa Kemal University, Hatay (Turkey); Kahraman, S. [Department of Metallurgical and Materials Engineering, Faculty of Technology, Mustafa Kemal University, Hatay (Turkey); Department of Physics, Faculty of Arts and Sciences, Mustafa Kemal University, Hatay (Turkey); Çetinkara, H.A. [Department of Physics, Faculty of Arts and Sciences, Mustafa Kemal University, Hatay (Turkey)

2015-01-15

Highlights: • CuO nanostructures with Pb-doping by the SILAR method is reported for the first time. • CuO nanostructures of different morphologies were grown by different Pb ratios. • E{sub g} values of the films can be altered by changing Pb doping concentrations. - Abstract: CuO nanostructures with and without Pb were synthesized by the Successive Ionic Layer Adsorption and Reaction method. The films were characterized by scanning electron microscopy, energy dispersive X-ray spectroscopy, X-ray diffraction and ultraviolet–visible spectrophotometry. Scanning electron microscopy results showed that the morphology of the film surface was changed from plate-like to coral-like nanostructures with increasing Pb concentration. The X-ray diffraction patterns showed the monoclinic crystal structure with preferential planes of (1{sup ¯}11) and (1 1 1). Furthermore, ultraviolet–visible spectra showed that the band gap of the films was tailored by Pb doping.

CuO nanostructures grown by the SILAR method: Influence of Pb-doping on the morphological, structural and optical properties

International Nuclear Information System (INIS)

Bayansal, F.; Gülen, Y.; Şahin, B.; Kahraman, S.; Çetinkara, H.A.

2015-01-01

Highlights: • CuO nanostructures with Pb-doping by the SILAR method is reported for the first time. • CuO nanostructures of different morphologies were grown by different Pb ratios. • E g values of the films can be altered by changing Pb doping concentrations. - Abstract: CuO nanostructures with and without Pb were synthesized by the Successive Ionic Layer Adsorption and Reaction method. The films were characterized by scanning electron microscopy, energy dispersive X-ray spectroscopy, X-ray diffraction and ultraviolet–visible spectrophotometry. Scanning electron microscopy results showed that the morphology of the film surface was changed from plate-like to coral-like nanostructures with increasing Pb concentration. The X-ray diffraction patterns showed the monoclinic crystal structure with preferential planes of (1 ¯ 11) and (1 1 1). Furthermore, ultraviolet–visible spectra showed that the band gap of the films was tailored by Pb doping

An experimental and thermodynamic equilibrium investigation of the Pb, Zn, Cr, Cu, Mn and Ni partitioning during sewage sludge incineration.

Science.gov (United States)

Liu, Jingyong; Fu, Jiewen; Ning, Xun'an; Sun, Shuiyu; Wang, Yujie; Xie, Wuming; Huang, Shaosong; Zhong, Sheng

2015-09-01

The effects of different chlorides and operational conditions on the distribution and speciation of six heavy metals (Pb, Zn, Cr, Cu, Mn and Ni) during sludge incineration were investigated using a simulated laboratory tubular-furnace reactor. A thermodynamic equilibrium investigation using the FactSage software was performed to compare the experimental results. The results indicate that the volatility of the target metals was enhanced as the chlorine concentration increased. Inorganic-Cl influenced the volatilization of heavy metals in the order of Pb>Zn>Cr>Cu>Mn>Ni. However, the effects of organic-Cl on the volatility of Mn, Pb and Cu were greater than the effects on Zn, Cr and Ni. With increasing combustion temperature, the presence of organic-Cl (PVC) and inorganic-Cl (NaCl) improved the transfer of Pb and Zn from bottom ash to fly ash or fuse gas. However, the presence of chloride had no obvious influence on Mn, Cu and Ni. Increased retention time could increase the volatilization rate of heavy metals; however, this effect was insignificant. During the incineration process, Pb readily formed PbSiO4 and remained in the bottom ash. Different Pb compounds, primarily the volatile PbCl2, were found in the gas phase after the addition of NaCl; the dominant Pb compounds in the gas phase after the addition of PVC were PbCl2, Pb(ClO4)2 and PbCl2O4. Copyright © 2015. Published by Elsevier B.V.

The resistivity measurements of Pb-based 1212 superconductors under pressure

International Nuclear Information System (INIS)

Sampath Kumar, T.S.; Subba Raman, T.S.; Gokulnath, K.; Latha, B.; Natarajan, S.

1995-01-01

High pressure resistivity study of (Pb 0.5 Cd 0.5 )Sr 2 (Y 0.7 Ca 0.3 )Cu 2 O 7 compounds, annealed in air and oxygen, has been carried out at room temperature. Both the samples show an initial drop in resistivity up to 20 kb followed by a steady value up to 80 kb. But the rate of drop of resistivity with pressure is sharp for the oxygen annealed 1212-sample, and has the lowest resistivity value above 20 kb. The high pressure results suggest that the (Pb,Cd)-1212 samples are under-doped. (author)

The role of Cd and Ga in the Cu(In,Ga)S{sub 2}/CdS heterojunction studied with X-ray spectroscopic methods

Energy Technology Data Exchange (ETDEWEB)

Johnson, Benjamin E.

2010-08-15

Photovoltaic cells with the structure Glass/Mo/Cu(In,Ga)S{sub 2}/CdS/i-ZnO/n+-ZnO are currently among the most successful and promising thin-layer solar cells. In this system, the Cu(In,Ga)S{sub 2} (CIS) acts as the absorber, the CdS as the buffer layer and the ZnO as the window layer. The goal of this work is the investigation of the Cu(In,Ga)S{sub 2}/CdS semiconductor heterojunction both as a component of the solar cell and as a separate material system. The characteristics of this junction were investigated both during junction formation through chemical bath deposition (CBD) and after the junction was completed. It is currently thought that the Cu(In,Ga)S{sub 2}/CdS junction is responsible for several different properties of the solar cell: lattice matching and band offset optimization between the absorber and window layer and chemical passivation of the absorber surface by the CBD-CdS process on CIS which acts to reduce the surface defect density. The Cd may also pin the Fermi Level on the CIS surface or cause a type inversion of the absorber surface from p-type to n-type. In order to investigate the junction several new methods were used along side the conventional methods of X-ray, Ultraviolet and Inverse Photoelectron Spectroscopy. These were Near-UV Constant Final State Yield Spectroscopy for the measurement of the valence band offset at the interface between CIS and CdS and Near Edge X-ray Absorption Fine Structure to follow the development of the Cu(In,Ga)S{sub 2} conduction band edge with increasing Ga concentration. Additionally, the advantages and disadvantages of the established and new methods were compared and discussed. It was discovered that the deposition of CdS neither pins the Fermi Level on the CIS surface at a position important for the solar cell, nor does it dope the absorber surface, although the deposition does lead to the formation of a Cd-containing CIS surface layer (CIS:Cd). Because this surface layer is not soluble in HCl it cannot

Enhanced charge collection and photocatalysis performance of CdS and PbS nanoclusters co-sensitized TiO{sub 2} porous film

Energy Technology Data Exchange (ETDEWEB)

Zhang, Miao; Xu, Yanyan; Gong, Zezhou; Tao, Jiajia [School of Physics & Material Science, Anhui University, Hefei 230601 (China); Sun, Zhaoqi, E-mail: szq@ahu.edu.cn [School of Physics & Material Science, Anhui University, Hefei 230601 (China); Lv, Jianguo [School of Electronic & Information Engineering, Hefei Normal University, Hefei, 230601 (China); National Laboratory for Infrared Physics, Shanghai Institute of Technical Physics, Chinese Academy of Sciences, Shanghai 200083 (China); Chen, Xiaoshuang [National Laboratory for Infrared Physics, Shanghai Institute of Technical Physics, Chinese Academy of Sciences, Shanghai 200083 (China); Jiang, Xishun [School of Physics & Material Science, Anhui University, Hefei 230601 (China); School of Mechanical & Electronic Engineering, Chuzhou University, Chuzhou, 239000 (China); He, Gang; Wang, Peihong; Meng, Fanming [School of Physics & Material Science, Anhui University, Hefei 230601 (China)

2015-11-15

A novel translucent TiO{sub 2} porous film was prepared through etched method. The CdS, PbS and CdS/PbS nanoclusters were imbedded on TiO{sub 2} porous film by successive ionic layer adsorption and reaction method. Microstructure, morphology, optical and photoelectron-chemical properties of the as-synthesized thin films were investigated systematically. XRD and morphology analysis showed that PbS or CdS nanoclusters have been attached to the TiO{sub 2} porous films. It was found that the energy band gap of TiO{sub 2} porous film decreased from 3.46 to 3.2 eV after sensitized with nanoclusters. The photocurrent density of ITO/TiO{sub 2} photoelectrode increased from 0.017 to 0.28 mA/cm{sup 2} after co-sensitized with CdS and PbS nanoclusters. Besides, the photoelectrode sensitized with two sorts of nanoclusters showed evident higher photocurrent density than which sensitized just one sort of nanoclusters. The photocurrent density of ITO/TiO{sub 2}/PbS and TO/TiO{sub 2}/CdS photoelectrode was 0.11 mA/cm{sup 2} and 0.22 mA/cm{sup 2} respectively. 0.28 mA/cm{sup 2} can be obtained by ITO/TiO{sub 2}/CdS/PbS photoelectrode. The results showed that the optical and photoelectrochemistry properties and phtotcatalysis performance of TiO{sub 2} porous film were greatly improved by co-sensitized with CdS and PbS nanoclusters. - Graphical abstract: When CdS and PbS were brought in the cascade structure, such a Fermi level alignment causes upward and downward shifts of the band edges for PbS and CdS, respectively. Therefore the resulting band edges for the ITO/TiO{sub 2}/CdS/PbS devices are inferred to have a stepwise structure. The elevated conduction band edge of PbS provides a higher driving force for the injection of photogenerated electrons from PbS to CdS as well as the injection of excited holes from CdS to PbS. Such a structure offers efficient separation and transport of the excited electrons and holes. - Highlights: • Ti films were obtained from direct current

Metal and metalloid contamination in roadside soil and wild rats around a Pb-Zn mine in Kabwe, Zambia

Energy Technology Data Exchange (ETDEWEB)

Nakayama, Shouta M.M.; Ikenaka, Yoshinori; Hamada, Kyohei [Laboratory of Toxicology, Department of Environmental Veterinary Sciences, Graduate School of Veterinary Medicine, Hokkaido University, Kita 18, Nishi 9, Kita-ku, Sapporo 060-0818 (Japan); Muzandu, Kaampwe; Choongo, Kennedy [Department of Biomedical Studies, School of Veterinary Medicine, University of Zambia, P.O. Box 32379, Lusaka (Zambia); Teraoka, Hiroki; Mizuno, Naoharu [Department of Toxicology, School of Veterinary Medicine, Rakuno Gakuen University, Ebetsu 069-8501 (Japan); Ishizuka, Mayumi, E-mail: ishizum@vetmed.hokudai.ac.j [Laboratory of Toxicology, Department of Environmental Veterinary Sciences, Graduate School of Veterinary Medicine, Hokkaido University, Kita 18, Nishi 9, Kita-ku, Sapporo 060-0818 (Japan)

2011-01-15

Metal (Cr, Co, Cu, Zn, Cd, Pb, Ni) and metalloid (As) accumulation was studied in roadside soil and wild rat (Rattus sp.) samples from near a Pb-Zn mine (Kabwe, Zambia) and the capital city of Zambia (Lusaka). The concentrations of the seven metals and As in the soil samples and Pb in the rat tissue samples were quantified using atomic absorption spectroscopy. The concentrations of Pb, Zn, Cu, Cd, and As in Kabwe soil were much higher than benchmark values. Geographic Information System analysis indicated the source of metal pollution was mining and smelting activity. Interestingly, the area south of the mine was more highly contaminated even though the prevailing wind flow was westward. Wild rats from Kabwe had much higher tissue concentrations of Pb than those from Lusaka. Their body weight and renal Pb levels were negatively correlated, which suggests that mining activity might affect terrestrial animals in Kabwe. - The area around Kabwe, Zambia is highly polluted with metals and As. Wild rats from this area had high tissue concentrations of Pb and decreased body weight.

Two new 3-D cadmium bromoplumbates: the only example of heterometallic bromoplumbate based on crown [Cd(Pb4O4)Br2] clusters.

Science.gov (United States)

Xiao, Hong; Zhou, Jian; Liu, Xing

2018-04-03

Two new cadmium bromoplumbates [CdPb2Br2L2]n (1, L = ethylene glycol) and [CdPb6Br6L4]n (2) have been solvothermally synthesized and structurally characterized. 1 contains 1-D neutral heterometallic chains [CdPb2Br2L2]n, which are further connected via weak Pb-Br bonds, resulting in a 3-D network structure. The 3-D framework of 2 is constructed by the interconnection of a 2-D neutral layer [CdPb6Br6L4]nvia weak Pb-Br bonds. The [CdPb6Br6L4]n layer is based on the linkages of dimeric [Pb2Br4] units and heterometallic crown [Cd(Pb4O4)Br2] clusters containing a rare eight-membered [Pb4O4] ring. Although a few heterometallic bromoplumbate clusters have been reported, they usually exhibit molecular moieties. 2 represents the only example of 3-D heterometallic bromoplumbate based on the combination of heterometallic crown [Cd(Pb4O4)Br2] clusters and dimeric [Pb2Br4] units. Their optical properties are studied and density functional theory calculations for 1 and 2 have also been performed.

Leaching potential of pervious concrete and immobilization of Cu, Pb and Zn using pervious concrete.

Science.gov (United States)

Solpuker, U; Sheets, J; Kim, Y; Schwartz, F W

2014-06-01

This paper investigates the leaching potential of pervious concrete and its capacity for immobilizing Cu, Pb and Zn, which are common contaminants in urban runoff. Batch experiments showed that the leachability of Cu, Pb and Zn increased when pHconcrete might function to attenuate contaminant migration. A porous concrete block was sprayed with low pH water (pH=4.3±0.1) for 190 h. The effluent was highly alkaline (pH~10 to 12). In the first 50 h, specific conductance and trace-metal were high but declined towards steady state values. PHREEQC modeling showed that mixing of interstitial alkaline matrix waters with capillary pore water was required in order to produce the observed water chemistry. The interstitial pore solutions seem responsible for the high pH values and relatively high concentrations of trace metals and major cations in the early stages of the experiment. Finally, pervious concrete was sprayed with a synthetic contaminated urban runoff (10 ppb Cu, Pb and Zn) with a pH of 4.3±0.1 for 135 h. It was found that Pb immobilization was greater than either Cu or Zn. Zn is the most mobile among three and also has the highest variation in the observed degree of immobilization. Copyright © 2014 Elsevier B.V. All rights reserved.

1D chain formation by coadsorption of Pb and Bi on Cu(001): Determination using low energy electron diffraction

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Kabiruzzaman, Md; Ahmed, Rezwan; Nakagawa, Takeshi; Mizuno, Seigi

2017-10-01

Coadsorption of two heavy metals, Pb and Bi, on Cu(001) at room temperature has been studied using low energy electron diffraction (LEED). c(4 × 4), c(2 × 2), and c(9√{ 2}×√{ 2}) phases are obtained at different coverages; here, we have determined the best-fit structure of c(4 × 4) phase. This structure can be described as a 1D substitutional chain arrangement of Pb and Bi atoms between the Cu rows along the [110] direction. The unit cell in the two-dimensional (2D) surface consists of one Bi atom, two Pb atoms, and four Cu atoms with one vacancy at the center. The optimal structure parameters demonstrate that Bi atoms are located at fourfold-hollow sites and that Pb atoms are laterally displaced by 0.78 Å from the fourfold-hollow site toward the vacancy. The reasons for the formation of the c(4 × 4) structure upon deposition of Pb and Bi on Cu(001) are discussed in comparison with a similar structure formed by the individual adsorption of Pb on the same substrate.

The effect of Pb addition on the morphology of CdSe quantum dot

Science.gov (United States)

Kim, Young-Kuk; Cho, Young-Sang; Chung, Kookchae; Choi, Chul-Jin

2010-08-01

CdSe quantum dots had been synthesized with a hot injection method. It was shown that the addition of Pb ions in the initial precursor solution changed the morphology of CdSe nanocrystals from slightly prolate ellipsoid to branched rod. Photoluminescence (PL) of the branched nanocrystals showed rapid depression of emission intensity due to the morphological development to the branched nanocrystal induced by Pb addition. Low temperature PL spectrum indicated that the surface recombination of charge carrier resulted in the large depression of emission from the branched nanocrystal.

Effect of dissolved organic matter (DOM) of contrasting origins on Cu and Pb speciation and toxicity to Paracentrotus lividus larvae.

Science.gov (United States)

Sánchez-Marín, Paula; Santos-Echeandía, Juan; Nieto-Cid, Mar; Alvarez-Salgado, Xosé Antón; Beiras, Ricardo

2010-01-31

Water samples of contrasting origin, including natural seawater, two sediment elutriates and sewage-influenced seawater, were collected and obtained to examine the effect of the dissolved organic matter (DOM) present on metal bioavailability. The carbon content (DOC) and the optical properties (absorbance and fluorescence) of the coloured DOM fraction (CDOM) of these materials were determined. Cu and Pb complexation properties were measured by anodic stripping voltammetry (ASV) and the effect of DOM on Cu and Pb bioavailability was studied by means of the Paracentrotus lividus embryo-larval bioassay. Sediment elutriates and sewage-influenced water (1) were enriched 1.4-1.7 times in DOC; (2) absorbed and reemitted more light; and (3) presented higher Cu complexation capacities (L(Cu)) than the natural seawater used for their preparation. L(Cu) varied from 0.08 microM in natural seawater to 0.3 and 0.5 microM in sediment elutriates and sewage-influenced water, respectively. Differences in DOC, CDOM and Cu complexation capacities were reflected in Cu toxicity. DOM enriched samples presented a Cu EC(50) of 0.64 microM, significantly higher than the Cu EC(50) of natural and artificial seawater, which was 0.38 microM. The protecting effect of DOM on Cu toxicity greatly disappeared when the samples were irradiated with high intensity UV-light. Cu toxicity could be successfully predicted considering ASV-labile Cu concentrations in the samples. Pb complexation by DOM was only detected in the DOM-enriched samples and caused little effect on Pb EC(50). This effect was contrary for both elutriates: one elutriate reduced Pb toxicity in comparison with the control artificial seawater, while the other increased it. UV irradiation of the samples caused a marked increase in Pb toxicity, which correlated with the remaining DOC concentration. DOM parameters were related to Cu speciation and toxicity: good correlations were found between DOC and Cu EC(50), while L(Cu) correlated

Effect of dissolved organic matter (DOM) of contrasting origins on Cu and Pb speciation and toxicity to Paracentrotus lividus larvae

International Nuclear Information System (INIS)

Sanchez-Marin, Paula; Santos-Echeandia, Juan; Nieto-Cid, Mar; Alvarez-Salgado, Xose Anton; Beiras, Ricardo

2010-01-01

Water samples of contrasting origin, including natural seawater, two sediment elutriates and sewage-influenced seawater, were collected and obtained to examine the effect of the dissolved organic matter (DOM) present on metal bioavailability. The carbon content (DOC) and the optical properties (absorbance and fluorescence) of the coloured DOM fraction (CDOM) of these materials were determined. Cu and Pb complexation properties were measured by anodic stripping voltammetry (ASV) and the effect of DOM on Cu and Pb bioavailability was studied by means of the Paracentrotus lividus embryo-larval bioassay. Sediment elutriates and sewage-influenced water (1) were enriched 1.4-1.7 times in DOC; (2) absorbed and reemitted more light; and (3) presented higher Cu complexation capacities (L Cu ) than the natural seawater used for their preparation. L Cu varied from 0.08 μM in natural seawater to 0.3 and 0.5 μM in sediment elutriates and sewage-influenced water, respectively. Differences in DOC, CDOM and Cu complexation capacities were reflected in Cu toxicity. DOM enriched samples presented a Cu EC 50 of 0.64 μM, significantly higher than the Cu EC 50 of natural and artificial seawater, which was 0.38 μM. The protecting effect of DOM on Cu toxicity greatly disappeared when the samples were irradiated with high intensity UV-light. Cu toxicity could be successfully predicted considering ASV-labile Cu concentrations in the samples. Pb complexation by DOM was only detected in the DOM-enriched samples and caused little effect on Pb EC 50 . This effect was contrary for both elutriates: one elutriate reduced Pb toxicity in comparison with the control artificial seawater, while the other increased it. UV irradiation of the samples caused a marked increase in Pb toxicity, which correlated with the remaining DOC concentration. DOM parameters were related to Cu speciation and toxicity: good correlations were found between DOC and Cu EC 50 , while L Cu correlated better with the

Effect of dissolved organic matter (DOM) of contrasting origins on Cu and Pb speciation and toxicity to Paracentrotus lividus larvae

Energy Technology Data Exchange (ETDEWEB)

Sanchez-Marin, Paula, E-mail: paulasanchez@uvigo.es [Laboratorio de Ecoloxia Marina (LEM), Universidade de Vigo, Campus Universitario, 36310 Vigo, Galicia (Spain); Santos-Echeandia, Juan; Nieto-Cid, Mar; Alvarez-Salgado, Xose Anton [Instituto de Investigacions Marinas, Consejo Superior de Investigaciones Cientificas (CSIC), Eduardo Cabello 6, 36208 Vigo, Galicia (Spain); Beiras, Ricardo [Laboratorio de Ecoloxia Marina (LEM), Universidade de Vigo, Campus Universitario, 36310 Vigo, Galicia (Spain)

2010-01-31

Water samples of contrasting origin, including natural seawater, two sediment elutriates and sewage-influenced seawater, were collected and obtained to examine the effect of the dissolved organic matter (DOM) present on metal bioavailability. The carbon content (DOC) and the optical properties (absorbance and fluorescence) of the coloured DOM fraction (CDOM) of these materials were determined. Cu and Pb complexation properties were measured by anodic stripping voltammetry (ASV) and the effect of DOM on Cu and Pb bioavailability was studied by means of the Paracentrotus lividus embryo-larval bioassay. Sediment elutriates and sewage-influenced water (1) were enriched 1.4-1.7 times in DOC; (2) absorbed and reemitted more light; and (3) presented higher Cu complexation capacities (L{sub Cu}) than the natural seawater used for their preparation. L{sub Cu} varied from 0.08 {mu}M in natural seawater to 0.3 and 0.5 {mu}M in sediment elutriates and sewage-influenced water, respectively. Differences in DOC, CDOM and Cu complexation capacities were reflected in Cu toxicity. DOM enriched samples presented a Cu EC{sub 50} of 0.64 {mu}M, significantly higher than the Cu EC{sub 50} of natural and artificial seawater, which was 0.38 {mu}M. The protecting effect of DOM on Cu toxicity greatly disappeared when the samples were irradiated with high intensity UV-light. Cu toxicity could be successfully predicted considering ASV-labile Cu concentrations in the samples. Pb complexation by DOM was only detected in the DOM-enriched samples and caused little effect on Pb EC{sub 50}. This effect was contrary for both elutriates: one elutriate reduced Pb toxicity in comparison with the control artificial seawater, while the other increased it. UV irradiation of the samples caused a marked increase in Pb toxicity, which correlated with the remaining DOC concentration. DOM parameters were related to Cu speciation and toxicity: good correlations were found between DOC and Cu EC{sub 50}, while L

Effects of Different Doping Ratio of Cu Doped CdS on QDSCs Performance

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Xiaojun Zhu

2015-01-01

Full Text Available We use the successive ionic layer adsorption and reaction (SILAR method for the preparation of quantum dot sensitized solar cells, to improve the performance of solar cells by doping quantum dots. We tested the UV-Vis absorption spectrum of undoped CdS QDSCs and Cu doped CdS QDSCs with different doping ratios. The doping ratios of copper were 1 : 100, 1 : 500, and 1 : 1000, respectively. The experimental results show that, under the same SILAR cycle number, Cu doped CdS quantum dot sensitized solar cells have higher open circuit voltage, short circuit current density photoelectric conversion efficiency than undoped CdS quantum dots sensitized solar cells. Refinement of Cu doping ratio are 1 : 10, 1 : 100, 1 : 200, 1 : 500, and 1 : 1000. When the proportion of Cu and CdS is 1 : 10, all the parameters of the QDSCs reach the minimum value, and, with the decrease of the proportion, the short circuit current density, open circuit voltage, and the photoelectric conversion efficiency are all increased. When proportion is 1 : 500, all parameters reach the maximum values. While with further reduction of the doping ratio of Cu, the parameters of QDSCs have a decline tendency. The results showed that, in a certain range, the lower the doping ratio of Cu, the better the performance of quantum dot sensitized solar cell.

Tolerance and hyperaccumulation of a mixture of heavy metals (Cu, Pb, Hg, and Zn) by four aquatic macrophytes.

Science.gov (United States)

Romero-Hernández, Jorge Alberto; Amaya-Chávez, Araceli; Balderas-Hernández, Patricia; Roa-Morales, Gabriela; González-Rivas, Nelly; Balderas-Plata, Miguel Ángel

2017-03-04

In the present investigation, four macrophytes, namely Typha latifolia (L.), Lemna minor (L.), Eichhornia crassipes (Mart.) Solms-Laubach, and Myriophyllum aquaticum (Vell.) Verdc, were evaluated for their heavy metal (Cu, Pb, Hg, and Zn) hyperaccumulation potential under laboratory conditions. Tolerance analyses were performed for 7 days of exposure at five different treatments of the metals mixture (Cu +2 , Hg +2 , Pb +2 , and Zn +2 ). The production of chlorophyll and carotenoids was determined at the end of each treatment. L. minor revealed to be sensitive, because it did not survive in all the tested concentrations after 72 hours of exposure. E. crassipes and M. aquaticum displayed the highest tolerance to the metals mixture. For the most tolerant species of aquatic macrophytes, The removal kinetics of E. crassipes and M. aquaticum was carried out, using the following mixture of metals: Cu (0.5 mg/L) and Hg, Pb, and Zn 0.25 mg/L. The obtained results revealed that E. crassipes can remove 99.80% of Cu, 97.88% of Pb, 99.53% of Hg, and 94.37% of Zn. M. aquaticum withdraws 95.2% of Cu, 94.28% of Pb, 99.19% of Hg, and 91.91% of Zn. The obtained results suggest that these two species of macrophytes could be used for the phytoremediation of this mixture of heavy metals from the polluted water bodies.

Stabilization of Pb²⁺ and Cu²⁺ contaminated firing range soil using calcined oyster shells and waste cow bones.

Science.gov (United States)

Moon, Deok Hyun; Cheong, Kyung Hoon; Khim, Jeehyeong; Wazne, Mahmoud; Hyun, Seunghun; Park, Jeong-Hun; Chang, Yoon-Young; Ok, Yong Sik

2013-05-01

Pb(2+) and Cu(2+) contamination at army firing ranges poses serious environmental and health risks to nearby communities necessitating an immediate and prompt remedial action. In this study, a novel mixture of calcined oyster shells (COSs) and waste cow bones (WCBs) was utilized to immobilize Pb(2+) and Cu(2+) in army firing range soils. The effectiveness of the treatment was evaluated based on the Korean Standard leaching test. The treatment results showed that Pb(2+) and Cu(2+) immobilization in the army firing range soil was effective in significantly reducing Pb(2+) and Cu(2+) leachability upon the combined treatment with COS and WCB. A drastic reduction in Pb(2+) (99%) and Cu(2+) leachability (95%) was obtained as compared to the control sample, upon treatment with 5 wt.% COS and 5 wt.% WCB. The combination treatment of COS and WCB was more effective for Pb immobilization, than the treatment with COS or WCB alone. The 5 wt.% COS alone treatment resulted in 95% reduction in Cu(2+) leachability. The SEM-EDX results suggested that Pb(2+) and Cu(2+) immobilization was most probably associated with the formation of ettringite, pozzolanic reaction products and pyromorphite-like phases at the same time. Copyright © 2013 Elsevier Ltd. All rights reserved.

KINETIC AND EQUILIBRIUM STUDY FOR THE SORPTION OF Pb(II ...

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passive process for adsorption of the metal ions by metabolically inactive biomass. ..... split in the concentration gradient between solute concentration in the .... binding capacity of Cd(II), Cr(III), Cu(II), Ni(II), Pb(II) and Sn(II) ions increased with ...

Effect of composition on the fabrication and properties of Ag-Cu alloy sheathed (Bi,Pb)2223 tapes

International Nuclear Information System (INIS)

Nakamura, Yuichi; Nakashima, Sohei; Inada, Ryoji; Oota, Akio

2004-01-01

To achieve high J c values as well as high mechanical strength, the effects of Ag-Cu alloy sheath and initial composition of precursor on the microstructure and J c properties of Ag-Cu alloy sheathed tapes were investigated. The alkaline-earth cuprate particles were found to form preferentially near the interface between superconducting core and sheath. Although the worse (Bi,Pb)2223 purity and microstructure of alloy sheathed tapes, the reduction of J c values of the tapes was small especially in 7-filaments tapes. This might be explained by the well grain alignment of (Bi,Pb)2223 into the middle region of the filament due to the high strength of alloy sheath. The usage of the Cu deficient composition was effective to reduce the total amount of 14:24 particle while the filament thickness should be thin to maintain J c values for Ag-Cu alloy sheathed tapes due to the lack of Cu diffusion from the sheath to convert 2212 into (Bi,Pb) in the middle region of the filament

Assessment of the Bioavailability of Cu, Pb, and Zn through Petunia axillaris in Contaminated Soils

Directory of Open Access Journals (Sweden)

Lydia Bondareva

2014-01-01

Full Text Available Heavy metals are potentially toxic to human life and the environment. Metal toxicity depends on chemical associations in soils. For this reason, determining the chemical form of a metal in soils is important to evaluate its mobility and the potential accumulation. The aim of this examination is to evaluate the accumulation potential of Petunia x hybrida as a flower crop for three metals, namely, copper (Cu, lead (Pb, and nickel (Ni. Trace metals (Zn, Cu, and Pb in the soils were partitioned by a sequential extraction procedure into H2O extractable (F1, 1 M CH3COONa extractable (F2. Chemical fractionation showed that F1 and F2 fraction of the metals were near 1% and residue was the dominant form for Zn, Cu, and Pb in all samples. Using fluorescence method allowed us to estimate condition of the plants by adding metals. As result of plant and soil analysis, we can conclude that Petunia has Cu, Zn, and Ni tolerance and accumulation. Therefore, Petunia has the potential to serve as a model species for developing herbaceous, ornamental plants for phytoremediation.

Assessment of Pb, Zn, Cu, Ni and Cr in vegetables grown around Zanjan

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A. Afshari

2017-05-01

Full Text Available This study was conducted aimed to assess the potential risk of heavy metals on human health resulting from consumption of vegetables. To this end, the vegetables grown around town and industrial center of Zanjan were sampled randomly. Plant samples were digested using hydrochloric acid (HCL 2 M and concentration of elements (Pb, Zn, Cu, Ni and Cr were recorded by atomic absorption. Obtained means of heavy metals in all vegetables (N= 32 for Zn, Pb, Cu, Ni and Cr is 98.8, 31.9, 19.3, 4.4 and 2.3 mg/kg, respectively. The highest amount of metal pollution index (MPI in the basil and the lowest was observed in the garden cress (respectively 16.46 and 4.88. Daily intake (EDI for zinc, copper and chromium in all age groups was lower than the provisional tolerable daily intake (PTDI. This amount for nickel was 2, 1.6 and 1.3 %, and for Pb 28.1, 22 and 19 % higher than PTDI in children, adults and seniors, respectively. The potential risk (THQ was calculated in all age groups as Pb>>Cu>Zn>Ni>Cr. The potential risks (THQ of chromium, nickel and zinc were calculated lower than 1, for copper a bit more of 1 and for lead much higher than 1. Health index (HI for children, adults and the elderly was estimated 31.331, 24.58 and 21.14, respectively, with the largest contribution of the lead (89.7%.

Influence of mechanical activation on the leaching of non-ferrous metals from a CuPbZn complex concentrate

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Godoèíková Erika

2000-09-01

Full Text Available The aim of study was to research the procedures of copper, lead and zinc leaching from CuPbZn complex sulphide concentrate during the intervention of mechanical activation.Mechanical activation belongs to innovative procedures, which intensifies technological processes by means of creation of new surfaces and making defective structure of solid phase. Mechanical impact on the solid phase is a suitable procedure to ensure the mobility of its structure elements and to accumulate the mechanical energy that is later used in following processes of leaching.This paper deals with the intensification of the chloride and thiourea leaching of copper, lead and zinc from a CuPbZn complex concentrate of Hodruša-Hámre (Slovak deposit by using the mechanical activation in an attritor. Ferric chloride and thiourea were used as leaching reagents. The leaching of the concentrate with ferric chloride solution afforded 23 % recovery of Cu, 99 % of Pb and 28 % of Zn. 9 % recovery of Cu, 17 % of Pb and 3 % of Zn were achieved by the leaching with thiourea. Thus results showed that the extraction of Cu, Zn and also Pb in the case of thiourea leaching was low. The use of milling in the attritor as an innovation method of pretreatment leads to the structural degradation and increasing the surface area of the investigated concentrate from the original value of 0.18 m2g-1 to the maximum value of 4.67 m2g-1. This fact manifested itself in the subsequent process of extraction of Cu, Pb and Zn into the chloride and thiourea solutions. Our results indicate more effective leaching of pretreated concentrate in the chloride medium with recoveries of 84 % Zn and 100 % Pb. In thiourea, the recoveries for Zn and Pb were low, however 99 % Cu can be recovered. In regard to the economy, the extraction of Cu, Pb and Zn was studied in this work with the aspect of minimal energy consumption during milling. The maximum recoveries of non-ferrous metals in the solutions of ferric chloride

A theoretical study of perovskite CsXCl3 (X=Pb, Cd) within first principles calculations

Energy Technology Data Exchange (ETDEWEB)

Ilyas, Bahaa M., E-mail: bahaastring@gmail.com [Department of Physics, University Of Dohuk (Iraq); Elias, Badal H. [Laboratory of Theoretical Physics, Department of Physics, Faculty of Sciences, University of Dohuk (Iraq)

2017-04-01

The structural, elastic, electronic, optical acoustic and thermodynamic properties of the cubic perovskite CsPbCl{sub 3} and CsCdCl{sub 3} unit cell, were studied using an ultra-soft pseudopotential plane wave, the Trouiller-Martins-Functional was utilized to perform these calculations. The study was implemented within both the Local Density Approximation (LDA) and the Generalized Gradient Approximation (GGA). the Generalized Gradient Approximation (GGA) scheme proposed by van Leeuwen-Baerends which is the same as the Perdew-Wang 92 functional have been carried out to preform our calculations. As for the Local Density Approximation (LDA) the Teter-Pade parametrization (4/93) was implemented which is the same as Perdew-Wang that in its turn reproduces the Ceperley-Alder-Functional. The computed GGA/LDA-lattice parameter for both CsCdCl{sub 3} and CsPbCl{sub 3} is in an exquisite agreement with the experimental and theoretical results. The energy band structure shows that CsCdCl{sub 3} is Γ–R indirect band gap insulator, while CsPbCl{sub 3} is an insulator with a direct band gap Γ–Γ separating the valence bands from the conduction bands, which shows metallic nature after pressure 30 GPa. A hybridization exists between Pb-p states and Cl-p states for CsPbCl{sub 3}, and Cd-p states and Cs-p states for the CsCdCl{sub 3} in the valence bonding region. Optimization of both cell shape (geometry) volume were investigated as pressure of 0–20 GPa and 0–40 GPa for the CsCdCl{sub 3} and CsPbCl{sub 3} respectively. The Pressure dependence of cubic perovskite elastic constants, Young modulus, bulk and shear moduli, Lame’s constants, elastic anisotropy factor, elastic wave velocities, phonon dispersion, Debye temperature and the density of states of CsXCl{sub 3} (X=Pb, Cd) were theoretically calculated and compared with the other available theoretical results. The above elastic constants reveal the fact that both compounds are stable and show nature of ductility. For

Investigation and thermodynamic calculation of phase diagram of CdI2-PbI2-NaI system

International Nuclear Information System (INIS)

Storonkin, A.V.; Vasil'kova, I.V.; Korobkov, S.V.

1976-01-01

Using the thermographic and X-ray phase analyses binary CdI 2 -PbI 2 , PI 2 -NaI, CdI 2 -NaI systems and a triple CdI 2 -PbI 2 -NaI system are investigated and their melting diagrams are plotted. A method of thermodynamic calculation has been proposed and tested of the shape of the eutectic lines for the system CdI 2 -PbI 2 -NaI, taking into account the non-ideality of the liquid phase. The method uses data obtained for the binary systems. The liquidus surface of the triple system has been constructed on the basis of the calculation. The results of the calculation of the triple eutectics are in good agreement with the experimental data

Levels of Cd, Cu, Pb and V in marine sediments in the vicinity of the Single Buoy Moorings (SBM3) at Mina Al Fahal in the Sultanate of Oman.

Science.gov (United States)

Al-Husaini, Issa; Abdul-Wahab, Sabah; Ahamad, Rahmalan; Chan, Keziah

2014-06-15

Recently in the Sultanate of Oman, there has been a rapid surge of coastal developments. These developments cause metal contamination, which may affect the habitats and communities at and near the coastal region. As a result, a study was conducted to assess the level of metal contamination and its impact on the marine sediments in the vicinity of the Single Buoy Moorings 3 (SBM3) at Mina Al Fahal in the Sultanate of Oman. Marine subtidal sediment samples were collected from six different stations of the SBM3 for the period ranging from June 2009 to April 2010. These samples were then analyzed for their level and distribution of the heavy metals of cadmium (Cd), copper (Cu), lead (Pb) and vanadium (V). Overall, low concentrations of all four heavy metals were measured from the marine sediments, indicating that the marine at SBM3 is of good quality. Copyright © 2014 Elsevier Ltd. All rights reserved.

One pot synthesis of Pb S/Cu2S core-shell nanoparticles and their optical properties

International Nuclear Information System (INIS)

Serrano, T.; Gomez, I.

2014-01-01

The synthesis of Pb S/Cu 2 S core-shell nanoparticles with emission on the visible range and with improved luminescence properties was carried out by the colloidal solution-phase growth method by using simple stabilizers such as trisodium citrate and 3-mercaptopropionic acid. The core shell arrangement for particles with different crystalline structure was achieved, in addition this is the first report related to the synthesis Pb S/C 2 S core-shell system. The data obtained from absorption spectra, Pl spectra, and HRTEM image provided direct proof of the formation of Pb S core with size around 11 nm and Cu 2 S shell of 5 nm thickness. According to the UV-vis absorption and Pl spectrum the optical characteristics observed in the synthesized material correspond to a Pb S/Cu 2 S system that has a higher confinement effect than the pure Pb S nanoparticles. The Q Y was improved in 15% from Pb S/C 2 S nanoparticles. The estimated band (Homo-Lumo) alignment determined by C V measurements corresponds to a type-I core shell arrangement. The synthesized material was studied with different techniques. The size and dispersion of the particles were determined by ultraviolet-visible (UV-Vis), photoluminescence and quantum yield, Dynamic Light Scattering method and X-ray diffraction with copper radiation (λ = 0.15418 nm). (Author)

Growth of nucleation sites on Pb-doped Bi2Sr2Ca1Cu2O8+δ

International Nuclear Information System (INIS)

Finnemore, D.K.; Xu, M.; Kouzoudis, D.; Bloomer, T.; Kramer, M.J.; McKernan, S.; Balachandran, U.; Haldar, P.

1996-01-01

In the growth of Bi 2 Sr 2 Ca 2 Cu 3 O 10+δ from mixed powders of Pb-doped Bi 2 Sr 2 Ca 1 Cu 2 O 8+δ and other oxides, it has been discovered that a dense array of hillocks or mesas grow at the interface between a Ag overlay and Pb-doped Bi 2 Sr 2 Ca 1 Cu 2 O 8+δ grains during the ramp up to the reaction temperature. As viewed in an environmental scanning electron microscope, the Ag coated grains develop a texture that looks like open-quote open-quote chicken pox close-quote close-quote growing on the grains at about 700 degree C. These hillocks are about 100 nm across and are spaced at about 500 to 1000 nm. If there is no Ag, this texture does not develop. Preliminary measurements indicate that the hillocks are a recrystallization of (Bi,Pb) 2 Sr 2 Ca 1 Cu 2 O 8+δ , and are definitely not a Pb rich phase. copyright 1996 American Institute of Physics

Determination of As, Cd, Cu, Hg and Pb in biological samples by modern electrothermal atomic absorption spectrometry

International Nuclear Information System (INIS)

Sardans, Jordi; Montes, Fernando; Penuelas, Josep

2010-01-01

this technique that reaches figures of merit equivalent to Inductively coupled plasma mass spectrometry (ICP-MS). Herein is presented an overview of recent advances and applications of (ETAAS) for the determination of As, Cd, Cu, Hg and Pb in biological samples drawn from studies over the last decade.

Determination of As, Cd, Cu, Hg and Pb in biological samples by modern electrothermal atomic absorption spectrometry

Energy Technology Data Exchange (ETDEWEB)

Sardans, Jordi, E-mail: j.sardans@creaf.uab.ca [Ecophysiological and Global Change Unit CSIC-CREAF, Edifici C, Universitat Autonoma de Barcelona, Bellaterra 08193, Barcelona (Spain); Montes, Fernando [Departamento de Ciencias Analiticas, Facultad de Ciencias, Universidad Nacional de Educacion a Distancia (UNED), C/ Senda del Rey 9. 28040 Madrid (Spain); Penuelas, Josep [Ecophysiological and Global Change Unit CSIC-CREAF, Edifici C, Universitat Autonoma de Barcelona, Bellaterra 08193, Barcelona (Spain)

2010-02-15

of this technique that reaches figures of merit equivalent to Inductively coupled plasma mass spectrometry (ICP-MS). Herein is presented an overview of recent advances and applications of (ETAAS) for the determination of As, Cd, Cu, Hg and Pb in biological samples drawn from studies over the last decade.

Chemical speciation of Pb, Ni Cr, Cu, Co and V in two natural soils and in an antropic agricultural soil contaminated by irrigation with the polluted Rio Bogota waters in its High Basin

International Nuclear Information System (INIS)

Matamoros, Adriana; Vargas, O; Mejia, L

1999-01-01

Traditional and continuous irrigation with the highly polluted waters of Rio Bogota in its upper basin has induced in soils, grasses and crops grown next to the river, a gradually increasing accumulation of highly toxic elements like Pb, Ni, Cr, Cu, Cd, Co, V and some others, which represents a real and very high risk for public health whenever grasses and edible crops growing on them absorb these elements above critical or permissible limits. To evaluate the magnitude of this problem three different soils of the Sabana were subjected to the chemical speciation procedure proposed by Tessier (1979) in order to determine: 1) the total content of essential and/or structural elements like Al, Fe, Ca, K, P, Mn and Ti, and the trace elements Pb, Ni, Cr, Cu, Cd, Co and V accumulated through time in the soils; 2) the relative proportion on which each one of them are linked to the different components or fractions of soils (ex. exchangeable, CO 3 , Fe/Mn oxides, O.M. and sulfides, and residual fraction) and 3) the bioavailability or amount of each that could be really absorbed by plants or able to go down to the underground water. Results showed in general for all soils normal values for the essential and/or structural elements and high to very high levels of Pb, Ni, Cu, Cd, Cr, Co y V, higher in Jardines de Colombia and Las Parcelas farms soils than in el Recreo farm soils. This situation is aggravated by the relatively high mobility and high concentration and bioavailability of some of these elements, which increase the risk for public health and the possibility of its migration down to the underground waters

Phenazine containing indeno-furan based colorimetric and “on–off” fluorescent sensor for the detection of Cu2+ and Pb2+

International Nuclear Information System (INIS)

Aggarwal, Komal; Khurana, Jitender M.

2015-01-01

A new fluorescent sensor 10a,15a-dihydroxy-10aH-benzo[a]indeno[2′,1′:4,5]furo[2,3-c]phenazin-15 (15aH)-one (1) based on the combination of phenazine and indenofuran moieties was designed and synthesized. Structure of the synthesized sensor has been confirmed by X-ray crystallographic analysis. Absorption and emission spectra of 1 has been studied in solvents of different polarity. The solvent effect on the spectral properties of 1 has been investigated by using the Lippert–Mataga and Reichardt–Dimroth methods. It exhibits high sensitivity and selectivity towards Cu 2+ and Pb 2+ ions over other metal ions by fluorescence quenching. Sensor 1 exhibited a visible color change from light orange to pink, and yellow in the presence of Cu 2+ and Pb 2+ , respectively. The fluorescence of the 1-Cu 2+ /Pb 2+ complexes can be reversibly restored to that of the uncomplexed ligand by using EDTA. Binding stoichiometry and mechanism of Cu 2+ and Pb 2+ ions detection have been investigated. The linear range for the synthesized sensor was found to be 1×10 −6 –6.31×10 −5 M with detection limit of 1.3×10 −6 M. Theoretical calculations were employed to understand the sensing mechanism of the sensors towards Cu 2+ . - Highlights: • A new indeno-furan based “on–off” sensor for detection of Cu 2+ and Pb 2+ has been synthesized. • 1 shows naked-eye visible color changes upon interaction with Cu 2+ and Pb 2+ . • The complex formation of 1 with Cu 2+ and Pb 2+ could be reversed by addition of EDTA

PROFIL LOGAM BERAT Cd, Cr (VI DAN Pb PADA LOKASI BERBEDA DI PROVINSI LAMPUNG SERTA BIOAKUMULASINYA PADA TANAMAN PANGAN

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Hening Widowati

2015-11-01

Full Text Available The heavy metal profile analysis of Cd, Cr(VI and Pb in the different location in Lampung Province and their bioaccumulation to crops has been conducted. The aims were finding out the difference of metal accumulation in the different pollutant area and determining how it happened to the vegetables surrounding, which were kangkoong and spinach. The research methods were purposive sampling in the different location in Lampung Province, namely 1 highlands, 2 paddy fields, 3 road sides and 4industrial areas. Based on the results, it is found that the highest metal concentration of Cd, Cr(VI and Pb are in the industrial area. Commonly, the value of BCFo-w (0,12-2,00 is higher than BCF¬o-s (0,01-0,18 which shows that there is low metal accumulation of Cd, Cr(VI and Pb in kangkoong and spinach. Furthermore, the BCF value of Cd and Cr(VI are higher compared to Pb.  Keywords: Logam berat, Cd, Cr(VI, Pb,bioakumulasi.

Mode-locked Er-doped fiber laser based on PbS/CdS core/shell quantum dots as saturable absorber.

Science.gov (United States)

Ming, Na; Tao, Shina; Yang, Wenqing; Chen, Qingyun; Sun, Ruyi; Wang, Chang; Wang, Shuyun; Man, Baoyuan; Zhang, Huanian

2018-04-02

Previously, PbS/CdS core/shell quantum dots with excellent optical properties have been widely used as light-harvesting materials in solar cell and biomarkers in bio-medicine. However, the nonlinear absorption characteristics of PbS/CdS core/shell quantum dots have been rarely investigated. In this work, PbS/CdS core/shell quantum dots were successfully employed as nonlinear saturable absorber (SA) for demonstrating a mode-locked Er-doped fiber laser. Based on a film-type SA, which was prepared by incorporating the quantum dots with the polyvinyl alcohol (PVA), mode-locked Er-doped operation with a pulse width of 54 ps and a maximum average output power of 2.71 mW at the repetition rate of 3.302 MHz was obtained. Our long-time stable results indicate that the CdS shell can effectively protect the PbS core from the effect of photo-oxidation and PbS/CdS core/shell quantum dots were efficient SA candidates for demonstrating pulse fiber lasers due to its tunable absorption peak and excellent saturable absorption properties.

Synthesis of Pb(II Imprinted Carboxymethyl Chitosan and the Application as Sorbent for Pb(II Ion

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Abu Masykur

2014-07-01

Full Text Available The aims of this research is to synthesize Pb(II imprinted polymers with carboxymethyl chitosan (CMC as polymers and bisphenol A diglycidyl ether (BADGE as cross-linker (Pb-IIP. Chitosan (CTS, non imprinted polymer (NIP and Pb-IIP were characterized using infrared (IR spectroscopy, X-ray diffraction (XRD, surface area analyzer (SAA, scanning electron microscopy (SEM, and energy dispersive X-ray (EDX spectroscopy. The result showed that the adsorption was optimum at pH 5 and contact time of 250 min. Adsorption of Pb(II ion with all of adsorbents followed pseudo-second order kinetic equation. Adsorption of Pb(II ion on CTS followed Freundlich isotherm while that on NIP and Pb-IIP followed the Langmuir adsorption isotherm. The adsorbent of Pb-IIP give higher capacity than the NIP and CTS. Adsorption capacity of Pb-IIP, NIP and CTS were 167.1, 128.9 and 76.1 mg/g, respectively. NIP gave higher adsorption selectivity for Pb(II/Ni(II and Pb(II/Cu(II, whereas Pb-IIP showed higher adsorption selectivity for Pb(II/Cd(II.The hydrogen bonding dominated interaction between Pb(II ion on NIP and Pb-IIP.

Photoelectric properties by interface effect of organic/inorganic(CuPc/PbTe) multilayer prepared by pulsed laser deposition and thermal evaporation

CERN Document Server

Lee, H Y; Choi, B C; Jeong, J H; Tabata, H; Kawai, T

1999-01-01

Highly crystallized CuPc/PbTe multilayer are prepared at substrate temperature from room temperature to 300 .deg. C by pulsed laser deposition and thermal evaporation method. From the measurement of AFM image, these all film exhibits composed of round grains and flat matrix. For observation the interface effect of multilayer, we measured the transverse current-voltage characteristics in the dark and under illumination. The photocarrier is generated in the CuPc layer and the electron-hole pairs are separated by the steep incline of the potential near the CuPc/PbTe interface. The CuPc/PbTe multilayers in the in-plane current-voltage curve exhibit larger photoconduction effect than that of CuPc single layer.

Study of surfaces and interfaces in CdS-Cu2S and (Cd sub(x) Zn sub(1-x))S-Cu2S solar cells

International Nuclear Information System (INIS)

Dhere, N.G.; Dhere, R.G.; Bloss, W.H.; Schock, H.W.; Bauer, E.; Cyris, P.

1983-01-01

Auger microprobe was used for the analysis of interfaces and surfaces in several stages involved in the preparation of solar cells, in order to study the origin of adhesion problems and to study the formation of CdS-Cu 2 S barrier by the wet method. The detachment of the first CdS and (Cd sub(x) Zn sub(1-x))S films, during the dip process, was attributed to the contamination of Cr-Ag metallic substrates by existing chlorine from the environment next to the sea, due to long film stocking, by degasified species from the evaporating material and by the ejection of particles together with CdS vapour during deposition. The formation of conical mounds on the surface and of the CdS-Cu 2 S barrier at aproximatelly 3000 A depth in the dipped samples were observed. The migration of copper towards surface direction and the formation of a superficial thin layer of copper oxide after treatment in H 2 plasma and air heating, were also verified. (C.L.B.) [pt

Distribution characteristics of Cd, Pb and their influencing factors after earthquake-with example of a disater area named xinhuang village

International Nuclear Information System (INIS)

Cai Yan; Zhang Yi; Zhang Shirong; Song Xu; Wang Jibing; Huang Aiping

2010-01-01

Using hydrochloric acid, nitric acid, hydrofluoric acid and perchloric acid digestion, ICP determination method, combined with geostatistics and GIS, this paper studied the distribution characteristics and influencing factors of Cd, Pb of the soil samples in a typical 5.12 earthquake-stricken area named Xinhuang village as an example. The results showed that the average Cd content of the soil samples was 0.36 ± 0.20 mg /kg, 23.08% of which exceeded the national soil environmental quality standard II, but didn't exceed the standard III. The average Pb content of the soil samples was 28.97 ± 6.82 mg /kg and did not exceed the national standard II. The spatial distribution of Cd, Pb content appeared as belt-shaped and group shape respectively. Cd content took the mid-eastern part as a center, whose concentration was low, and gradually increased to north, to mid-west and to south, respectively; Pb content decreased first and increased afterward from north to south and from east to west. However, Cd, Pb contents in the soil under tent settlements after the earthquake, living garbage dumps and the housing collapse were significantly higher than the soil where were not affected by the earthquake. Cd content in the paddy field soil of 40 ∼ 60 cm depth under tent settlements was the highest, which was 0.46 mg /kg, the highest was 0.57 mg /kg; in the natural paddy field soil of 0 ∼ 20 cm, which. Pb content in the paddy field soil of 0 ∼ 20 cm depth under tent settlements and the natural paddy field soil, were 25.22 mg /kg and 26.16 mg /kg respectively. The influencing factors indicated that: Cd content of paddy fields, dry land and wasteland had not significant difference; Pb content of paddy fields were significantly higher than that of wasteland; The correlation coefficient of organic matter content and the Pb content was 0.616, which took a highly significant positive correlation; Cd content and pH or Cd content and organic matter content did not take significant

Pb, Cu, and Zn distributions at humic acid-coated metal-oxide surfaces

Science.gov (United States)

Wang, Yingge; Michel, F. Marc; Choi, Yongseong; Eng, Peter J.; Levard, Clement; Siebner, Hagar; Gu, Baohua; Bargar, John R.; Brown, Gordon E.

2016-09-01

Mineral surfaces are often coated by natural organic matter (NOM), which has a major influence on metal-ion sorption and sequestration because of the abundance of binding sites in such coatings and the changes they cause in local nanoscale environments. The effects of NOM coatings on mineral surfaces are, however, still poorly understood at the molecular level due to the complexity of these systems. In this study, we have applied long-period X-ray standing wave-fluorescence yield (LP-XSW-FY) spectroscopy to measure the partitioning of naturally present Cu(II) (0.0226%), Zn(II) (0.009%), and Pb(II) (∼0.0004%) between Elliott Soil Humic Acid (ESHA) coatings and three model single-crystal metal-oxide substrates: α-Al2O3 (0 0 0 1), α-Al2O3 (1 -1 0 2), and α-Fe2O3 (0 0 0 1). The competitive sorption effects among these metal ions for binding sites in the ESHA coatings and on the metal-oxide surfaces were investigated as a function of reaction time, calcium content, and solution pH. Pb(II) ions present in the ESHA coatings were found to redistribute to reactive α-Al2O3 (1 -1 0 2) and α-Fe2O3 (0 0 0 1) surfaces after 3 h of reaction (pH = 6.0, [Ca(II)] = 2 mM). Pb(II) partitioning onto these reactive metal-oxide surfaces increased with increasing reaction time (up to 7 d). In addition, the partitioning of Cu(II) and Zn(II) from the ESHA coating to the α-Fe2O3 (0 0 0 1) substrate increased slightly with reaction time (2.4% and 3.7% for Cu(II) and Zn(II), respectively, after 3 h and 6.4% and 7.7% for Cu(II) and Zn(II), respectively, after 72 h of reaction time). However, no changes in the partitioning of Cu(II) and Zn(II) onto the α-Al2O3 (1 -1 0 2) surface were observed with increasing reaction time, suggesting that these ions strongly complex with functional groups in the ESHA coatings. Similar results were obtained for Cu(II) and Zn(II) on the ESHA-coated α-Al2O3 (1 -1 0 2) surfaces in samples without the addition of calcium. However, the amounts of Pb

The effect of morphology and surface composition on radiation resistance of heterogeneous material CdS-PbS

Energy Technology Data Exchange (ETDEWEB)

Malyar, I. V., E-mail: imalyar@yandex.ru; Stetsyura, S. V., E-mail: stetsyurasv@info.sgu.ru [Chernyshevsky Saratov State University (Russian Federation)

2011-07-15

As a result of a complex study of the heterophase photosensitive material CdS-PbS by the methods of scanning electron microscopy and Auger spectrometry, it has been found that the radiation resistance of this material depends on the morphology and phase composition at its surface. It is shown that, as the temperature of annealing is increased, aggregations with predominant content of PbS grow; simultaneously, the composition of these aggregations varies as a consequence of the reaction of substitution of sulfur atoms with oxygen atoms. The latter of the aforementioned processes brings about a decrease in the radiation resistance of the heterophase photosensitive material CdS-PbS, which is accounted for by a decrease in the gettering due to appearance of an intermediate oxidized layer between PbS and CdS. An increase in the sizes and number of spherical aggregations at the surface, which consist of crystallites with predominant content of PbS, brings about an increase in the radiation resistance.

UV-Induced Anisotropy In CdBr2-CdBr2: Cu Nanostructures

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El-Naggar A. M.

2015-09-01

Full Text Available We have found an occurrence of anisotropy in the nanostructure CdBr2-CdBr2: Cu nanocrystalline films. The film thickness was varied from 4 nm up to 80 nm. The films were prepared by successive deposition of the novel layers onto the basic nanocrystals. The detection of anisotropy was performed by occurrence of anisotropy in the polarized light at 633 nm He-Ne laser wavelength. The occurrence of anisotropy was substantially dependent on the film thickness and the photoinduced power density. Possible mechanisms of the observed phenomena are discussed.

Content of Pb, Cd and Cl in forest trees caused by the traffic of motor vehicles

Energy Technology Data Exchange (ETDEWEB)

Mankovska, B

1977-01-01

The contents of Pb, Cd in spruce trees and soil polluted by the traffic of motor vehicles was determined by the method of atomic absorption, that of Cl by the mercurometric method. In general the raised level of Pb, Cd and Cl was found in the soils and assimilation organs close to the roadway. The most important factors influencing this raise are mentioned: the age of needles, season of year, character of surface of plant organs, tree species, both horizontal and vertical distance from the road. There is a statistically very high significant relation (at 95% level of significance) between the amount of Pb and Cd in mg in mg.kg/sup -1/ and horizontal distance from the road; that of Cl is lower.

The Adsorption of Pb, Zn, Cu, Ni, and Cd by Modified Ligand in a Single Component Aqueous Solution: Equilibrium, Kinetic, Thermodynamic, and Desorption Studies

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E. Igberase

2017-01-01

Full Text Available In this investigation, an amino functionalized adsorbent was developed by grafting 4-aminobenzoic acid onto the backbone of cross-linked chitosan beads. The 3 sets of beads including chitosan (CX, glutaraldehyde cross-linked chitosan (CCX, and 4-aminobenzoic acid grafted cross-linked chitosan (FGCX were characterized by FTIR, XRD, SEM, and TGA. The water content and amine concentration of FGCX were determined. The effect of adsorption parameters was studied and the optimum was used for further studies. Equilibrium data was obtained from the adsorption experiment carried out at different initial concentration; the data were applied in isotherm, thermodynamics, and kinetic studies. The Langmuir and Dubinin-Kaganer-Radushkevich (DKR models were successful in describing the isotherm data for the considered metal ions while the Freundlich and Temkin model fit some of the considered metal ions. Pseudo-second-order and intraparticle model described the kinetic data quite well. Thermodynamic parameters such as Gibb’s free energy change (ΔGo, enthalpy change (ΔHo, and entropy change (ΔSo were calculated and the results showed that the adsorption of Pb, Cu, Ni, Zn, and Cd ions onto FGCX is spontaneous and endothermic in nature. Regeneration of the spent adsorbent was efficient for the considered metal ions.

Study on the application of electrothermal atomization atomic absorption spectrometry for the determination of metallic Cu, Pb, Zn, Cd traces in sea water samples

International Nuclear Information System (INIS)

Nguyen Thi Kim Dung; Doan Thanh Son; Tran Thi Ngoc Diep

2004-01-01

The trace amount of some heavy metallic elements (Cu, Zn, Pb, Cd) in sea water samples were determined directly (without separation) and quantitatively by using Electro-Thermal Atomization Atomic Absorption Spectrometry (ETA-AAS). The effect of mainly major constituents such as Na, Mg, Ca, K, and the mutual effect of the trace elements, which were present in the matrix on the absorption intensity of each analyzed element was studied. The adding of a certain chemical modification for each trace element was also investigated in order to eliminate the overall effect of the background during the pyrolysis and atomization. The sea water sample after fitrating through a membrane with 0.45 μm-hole size was injected in to the graphite tube via an autosampler (MPE50). The absorption intensity of each element was then measured on the VARIO-6 under the optimum parameters for spectrometer such as: maximum wavelength, current of hollow cathode lamp, and that for graphite furnace such as dry temperature, pyrolysis temperature, atomization temperature, ect. The analytical procedures were set-up and applied for the determination of these above mentioned elements in the synthesized sea water sample and in the real sea water samples with high precision and accuracy. (author)

Monitoring for Pb and Cd pollution using feral pigeons in rural, urban, and industrial environments of Korea

International Nuclear Information System (INIS)

Nam, Dong-Ha; Lee, Doo-Pyo

2006-01-01

This study was aimed at evaluating the lead (Pb) and cadmium (Cd) contamination status using resident pigeons from rural (island), central urban (Seoul), and four industrial complex areas in Korea with varying traffic density as well as atmospheric metal pollution records. We also discussed the results with respect to metal exposure trends in urban area after introduction of lead-free gasoline in Korea. Mean concentrations of Pb and Cd in bone and kidney of pigeons from Seoul were comparable to those from industrial complex areas and were about 15-20 times those at the reference site. This suggests that exposure to metals in the urban environment is as high as in the industrial areas. Lead and Cd concentrations in lungs of pigeons from Seoul were significantly higher by more than three times in 2000 than in 1991 (p < 0.01), whereas the residues in liver, kidney, and bone remained at a similar level, despite the introduction of unleaded gasoline in 1993. The Pb and Cd concentrations in tissues of pigeons did not decrease as atmospheric metal levels decreased. Ingestion may be more important than inhalation in exposing pigeons to Pb and Cd in this study

Monitoring for Pb and Cd pollution using feral pigeons in rural, urban, and industrial environments of Korea

Energy Technology Data Exchange (ETDEWEB)

Nam, Dong-Ha [Laboratory for Animal Ecology, School of Environment and Applied Chemistry, Kyunghee University (Korea, Republic of); Lee, Doo-Pyo [Science of Biology, Department of Biological Science, Honam University (Korea, Republic of)]. E-mail: dplee@honam.ac.kr

2006-03-15

This study was aimed at evaluating the lead (Pb) and cadmium (Cd) contamination status using resident pigeons from rural (island), central urban (Seoul), and four industrial complex areas in Korea with varying traffic density as well as atmospheric metal pollution records. We also discussed the results with respect to metal exposure trends in urban area after introduction of lead-free gasoline in Korea. Mean concentrations of Pb and Cd in bone and kidney of pigeons from Seoul were comparable to those from industrial complex areas and were about 15-20 times those at the reference site. This suggests that exposure to metals in the urban environment is as high as in the industrial areas. Lead and Cd concentrations in lungs of pigeons from Seoul were significantly higher by more than three times in 2000 than in 1991 (p < 0.01), whereas the residues in liver, kidney, and bone remained at a similar level, despite the introduction of unleaded gasoline in 1993. The Pb and Cd concentrations in tissues of pigeons did not decrease as atmospheric metal levels decreased. Ingestion may be more important than inhalation in exposing pigeons to Pb and Cd in this study.

Effect of TEA on characteristics of CdS/PbS thin film solar cells prepared by CBD

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Sattarian H.

2016-09-01

Full Text Available In this study, a solar cell with a glass/ITO/CdS/PbS/Al structure was constructed. Both window (CdS and absorption (PbS layers were deposited by chemical bath deposition (CBD method. The CdS window layer was deposited on ITO-glass. The PbS nanocrystalline thin film was prepared with and without triethanolamine on CdS films at bath temperature of 25 °C. CdS and PbS nanocrystals were identified using XRD and SEM. The cells are photosensitive in a large spectral range (at visible and near infrared regions. The cell with absorbing layer obtained from the bath without TEA has higher efficiency with the following parameters: the open circuit voltage (Voc is 275 mV, short circuit current (Jsc is 12.24 mA/cm2, maximum voltage (Vmax is 165 mV and maximum current (Jmax is 7.11 mA/cm2 with the efficiency η = 1.31 %, fill factor FF is 32 % under the illumination intensity of 90 mW/cm2. The cells have an area of 0.15 cm2.

Assessment of Individual and Combined Toxicities of Four Non-Essential Metals (As, Cd, Hg and Pb in the Microtox Assay

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Paul B. Tchounwou

2006-03-01

Full Text Available Although most researches with non-essential metals (NEMs have been done with single or individual metals, in reality, organisms are often exposed to multiple contaminants at the same time through the air, food and water. In this study, we tested the toxicity of four NEMs, As, Cd, Pb, and Hg, individually and as a composite mixture using the microtox bioassay. This assay uses the reduction of bioluminescence of the bacterium Vibrio fischeri as a measure of toxicity. The concentrations of each chemical in the mixture were based on multiples of their maximum contaminant levels (MCLs set by the U.S. EPA. The highest concentration of exposure was 20 times the MCL, which translated into 200, 100, 40 and 300 ppb for As, Cd, Hg and Pb, respectively. The ratio for the mixture from these concentrations was 10:5:2:15 for As, Cd, Hg and Pb, respectively. Among the individual metals tested, the ranking of toxicity was Hg>Pb>Cd>As based on the EC50 values of 109, 455, 508 and 768 ppb for Hg, Pb, Cd and As, respectively. The EC50 for the composite mixture was 495% MCL which translated into nominal concentrations of 49, 25, 10 and 74 ppb for As, Cd, Hg, and Pb, respectively. Overall, the EC50 value of each NEM within the mixture was lower than the EC50 of the individual chemical; an evidence of synergism for the mixture. The individual toxic units (TU were 0.06, 0.05, 0.09, and 0.16 for As, Cd Hg, and Pb, respectively and the summed toxic unit (TU was 0.37 (less than 1. This study provides needed scientific data necessary for carrying out complete risk assessment of As, Cd, Hg, and Pb mixtures of some priority compounds.

Effects of Exposion to Fine Particles of Pb and Cd on Early Growth of Rice and Potatoes

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YANG Fan

2017-08-01

Full Text Available Heavy metal-containing particles in the atmosphere have negative impacts on the seedling growth and early stage growth of terrestrial plants. Exposure scenarios were established to simulate the ambient conditions with different pollution levels of airborne heavy metals. Under these scenarios, hazardous impacts of fine particles containing lead(Pb and cadmium(Cd on the emergence, seedling growth, and fresh weight(including both above ground stem leaf of rice and underground stem tuber of potato were evaluated. The results showed that, for exposure treatment groups, the concentrations of Pb and Cd in the artificial soil increased at the end of the test. Compared with the background value in soil, the Cd level elevated about 8.8 times while no significant increase was observed for Pb concentration. The accumulation values of Pb and Cd were 0.002 0, 0.054 mg·kg-1 in the stem leaf of rice and 0.185 0, 0.074 mg·kg-1 in the stem tuber of potato. The exposure had no significant inhibition effect on all the biomass endpoints of rice, but had an inhibition rate of 27% on the fresh weight of potato underground stem tuber. Thus, under the simulation exposure, larger impact was projected to the Cd concentration in the artificial soil, and the Cd accumulative effect was more obvious in the underground stem tuber of potatoes. Compared with the control groups, the combined pollution of Pb and Cd in the exposure treatment groups indicated remarkable inhibition and stress effects. Moreover, aboveground stem leaf of rice showed better adaption and low sensitivity when exposed to pollutants at certain concentrations.

Spatial distribution and risk assessment of heavy metals in soil near a Pb/Zn smelter in Feng County, China.

Science.gov (United States)

Shen, Feng; Liao, Renmei; Ali, Amjad; Mahar, Amanullah; Guo, Di; Li, Ronghua; Xining, Sun; Awasthi, Mukesh Kumar; Wang, Quan; Zhang, Zengqiang

2017-05-01

A large scale survey and a small scale continuous monitoring was conducted to evaluate the impact of Pb/Zn smelting on soil heavy metals (HMs) accumulation and potential ecological risk in Feng County, Shaanxi province of China. Soil parameters including pH, texture, CEC, spatial and temporal distribution of HMs (Cd, Cu, Ni, Pb and Zn), and BCR fractionation were monitored accordingly. The results showed the topsoil in the proximity of smelter, especially the smelter area and county seat, were highly polluted by HMs in contrast to the river basins. Fractionation of Cd and Zn in soil samples revealed higher proportion of mobile fractions than other HMs. The soil Cd and Zn contents decreased vertically, but still exceeded the second level limits of Environmental Quality Standard for Soils of China (EQSS) within 80cm. The dominated soil pollutant (Cd) had higher ecological risk than Cu, Ni, Zn and Pb. The potential ecological risk (PER) factor of Cd were 65.7% and 100% in surrounding county and smelter area, respectively. The long-term smelter dust emission mainly contributed to the HMs pollution and posed serious environment risk to living beings. Copyright © 2017 Elsevier Inc. All rights reserved.

[Immobilization remediation of Cd and Pb contaminated soil: remediation potential and soil environmental quality].

Science.gov (United States)

Sun, Yue-Bing; Wang, Peng-Chao; Xu, Ying-Ming; Sun, Yang; Qin, Xu; Zhao, Li-Jie; Wang, Lin; Liang, Xue-Feng

2014-12-01

A pot experiment was conducted to investigate the immobilization remediation effects of sepiolite on soils artificially combined contamination by Cd and Pb using a set of various pH and speciation of Cd and Pb in soil, heavy metal concentration in Oryza sativa L., and soil enzyme activity and microbial quantity. Results showed that the addition of sepiolite increased the soil pH, and the exchangeable fraction of heavy metals was converted into Fe-Mn oxide, organic and residual forms, the concentration of exchangeable form of Cd and Pb reduced by 1.4% - 72.9% and 11.8% - 51.4%, respectively, when compared with the control. The contents of heavy metals decreased with increasing sepiolite, with the maximal Cd reduction of 39.8%, 36.4%, 55.2% and 32.4%, respectively, and 22.1%, 54.6%, 43.5% and 17.8% for Pb, respectively, in the stems, leaves, brown rice and husk in contrast to CK. The addition of sepiolite could improve the soil environmental quality, the catalase and urease activities and the amount of bacteria and actinomycete were increased to some extents. Although the fungi number and invertase activity were inhibited compared with the control group, it was not significantly different (P > 0.05). The significant correlation between pH, available heavy metal content, urease and invertase activities and heavy metal concentration in the plants indicated that these parameters could be used to evaluate the effectiveness of stabilization remediation of heavy metal contaminated soil.

Bioaccumulation of metals (Cd, Cu, Ni, Pb and Zn) in suspended cultures of blue mussels exposed to different environmental conditions

DEFF Research Database (Denmark)

Maar, Marie; Larsen, Martin Mørk; Tørring, Ditte Bruunshøj

2015-01-01

corresponding to Good Ecological Status (GES) in the European Union Water Framework Directive (WFD) and in future climate change scenarios (higher metal concentrations and higher temperatures). For this purpose, GES is interpreted as good chemical status for the metals using the Environmental Quality Standards...... targets for Cd, Ni and Pb are not protective with respect to marine mussel production and probably should be reduced for marine waters. Climate changes may increase the metal contamination of mussels, but not to any critical level at the relatively unpolluted study sites. In conclusion, WFD targets should...

Influence of hydrology on heavy metal speciation and mobility in a Pb-Zn mine tailing

International Nuclear Information System (INIS)

Kovacs, Elza; Dubbin, William E.; Tamas, Janos

2006-01-01

Among the inorganic toxicants of greatest concern in mine tailings, Pb, Zn, Cu, Cd and As figure prominently due to their abundance and potential toxicity. Here we report on their biolability and solid-phase speciation in two sediment cores subject to variable hydrological regimes at an abandoned pyritic mine tailing. The oxic conditions of well-drained sediments induced pyrite oxidation and the subsequent liberation of H + , SO 4 2- and considerable quantities of Fe(III), which precipitated as goethite. Solubility of Pb, Zn, Cu and Cd was closely coupled to pH and goethite presence. Metal lability was particularly low in zones of neutralization, formed by the accumulation of calcite, first carried then deposited by percolating waters in both saturated and unsaturated cores. We conclude that differential hydrology induces variable heavy metal speciation and biolability in Pb-Zn mine tailings, and suggest that site-specific risk assessments must account for past and present hydrological regimes. - Variable hydrology influences heavy metal speciation and mobility, and the formation of neutralization zones, in a Pb-Zn mine tailing

Bournonite PbCuSbS3 : Stereochemically Active Lone-Pair Electrons that Induce Low Thermal Conductivity.

Science.gov (United States)

Dong, Yongkwan; Khabibullin, Artem R; Wei, Kaya; Salvador, James R; Nolas, George S; Woods, Lilia M

2015-10-26

An understanding of the structural features and bonding of a particular material, and the properties these features impart on its physical characteristics, is essential in the search for new systems that are of technological interest. For several relevant applications, the design or discovery of low thermal conductivity materials is of great importance. We report on the synthesis, crystal structure, thermal conductivity, and electronic-structure calculations of one such material, PbCuSbS3 . Our analysis is presented in terms of a comparative study with Sb2 S3 , from which PbCuSbS3 can be derived through cation substitution. The measured low thermal conductivity of PbCuSbS3 is explained by the distortive environment of the Pb and Sb atoms from the stereochemically active lone-pair s(2) electrons and their pronounced repulsive interaction. Our investigation suggests a general approach for the design of materials for phase-change-memory, thermal-barrier, thermal-rectification and thermoelectric applications, as well as other functions for which low thermal conductivity is purposefully sought. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Determination of Cr, Cd, Sn, and Pb in Selected Herbal Products Available in Philippine Markets

Directory of Open Access Journals (Sweden)

Joan S. De Vera

2017-12-01

Full Text Available The growing popularity of herbal products in the Philippines makes it imperative to monitor and ensure safety of consumers from metal contaminants. In this study, trace concentrations of Cr, Cd, Sn, and Pb in herbal products were simultaneously measured using a microwaveassisted digestion as sample pre-treatment and inductively coupled plasma mass spectrometry (ICP-MS for elemental detection. Using the optimized method, recoveries of ERM CD281, the primary cer t i f ied reference material (CRM used, were found to be between 80-89%, and the method detection limits (MDL for Cr, Cd, Sn, and Pb were 0.15, 0.07, 0.3, and 0.14 μg/L, respectively. The linear ranges for Cr and other elements (Cd, Sn, and Pb were 0.01-500 and 0.01-50 μg/L, respectively. All correlation coeff icients were 0.9999 or better. Most of the products tested had measurable trace metal concentrations, which were below the suggested maximum limits in herbal products. However, one product derived from mangosteen exceeded the limit for Cd (0.42 mg/kg. Subsequent analysis of metal content in tea infusions showed that only a small fraction of metals may leach out, suggesting that consumption of tea infusions pose lesser risks. The order of abundance of metals found in herbal products was Cr>Pb>Cd>Sn. The variability of metal concentrations in herbal products underlines the fact that many plant ingredients are susceptible to contamination, and quality control during processing must be improved to minimize the possibility of contamination. The results of this study suggest that vigilant monitoring of herbal products is imperative to avoid exposure to trace metal contamination.

Distribution of toxic metals, Hg, Cd and Pb in zooplankton along the Indian coasts

Digital Repository Service at National Institute of Oceanography (India)

Sengupta, R.; Kureishy, T.W.

Distribution of toxic metals such as Hg, Cd and Pb in zooplankton is assessed with a view to correlate it with the prevalent environmental conditions along the Indian coast. While Hg could not be detected in zooplankton the concentrations of Cd...

Elevated CO2 increases glomalin-related soil protein (GRSP) in the rhizosphere of Robinia pseudoacacia L. seedlings in Pb- and Cd-contaminated soils.

Science.gov (United States)

Jia, Xia; Zhao, Yonghua; Liu, Tuo; Huang, Shuping; Chang, Yafei

2016-11-01

Glomalin-related soil protein (GRSP), which contains glycoproteins produced by arbuscular mycorrhizal fungi (AMF), as well as non-mycorrhizal-related heat-stable proteins, lipids, and humic materials, is generally categorized into two fractions: easily extractable GRSP (EE-GRSP) and total GRSP (T-GRSP). GRSP plays an important role in soil carbon (C) sequestration and can stabilize heavy metals such as lead (Pb), cadmium (Cd), and manganese (Mn). Soil contamination by heavy metals is occurring in conjunction with rising atmospheric CO 2 in natural ecosystems due to human activities. However, the response of GRSP to elevated CO 2 combined with heavy metal contamination has not been widely reported. Here, we investigated the response of GRSP to elevated CO 2 in the rhizosphere of Robinia pseudoacacia L. seedlings in Pb- and Cd-contaminated soils. Elevated CO 2 (700 μmol mol -1 ) significantly increased T- and EE- GRSP concentrations in soils contaminated with Cd, Pb or Cd + Pb. GRSP contributed more carbon to the rhizosphere soil organic carbon pool under elevated CO 2  + heavy metals than under ambient CO 2 . The amount of Cd and Pb bound to GRSP was significantly higher under elevated (compared to ambient) CO 2 ; and elevated CO 2 increased the ratio of GRSP-bound Cd and Pb to total Cd and Pb. However, available Cd and Pb in rhizosphere soil under increased elevated CO 2 compared to ambient CO 2 . The combination of both metals and elevated CO 2 led to a significant increase in available Pb in rhizosphere soil compared to the Pb treatment alone. In conclusion, increased GRSP produced under elevated CO 2 could contribute to sequestration of soil pollutants by adsorption of Cd and Pb. Copyright © 2016 Elsevier Ltd. All rights reserved.

Bioleaching mechanism of Zn, Pb, In, Ag, Cd and As from Pb/Zn smelting slag by autotrophic bacteria.

Science.gov (United States)

Wang, Jia; Huang, Qifei; Li, Ting; Xin, Baoping; Chen, Shi; Guo, Xingming; Liu, Changhao; Li, Yuping

2015-08-15

A few studies have focused on release of valuable/toxic metals from Pb/Zn smelting slag by heterotrophic bioleaching using expensive yeast extract as an energy source. The high leaching cost greatly limits the practical potential of the method. In this work, autotrophic bioleaching using cheap sulfur or/and pyrite as energy matter was firstly applied to tackle the smelting slag and the bioleaching mechanisms were explained. The results indicated autotrophic bioleaching can solubilize valuable/toxic metals from slag, yielding maximum extraction efficiencies of 90% for Zn, 86% for Cd and 71% for In, although the extraction efficiencies of Pb, As and Ag were poor. The bioleaching performance of Zn, Cd and Pb was independent of leaching system, and leaching mechanism was acid dissolution. A maximum efficiency of 25% for As was achieved by acid dissolution in sulfursulfur oxidizing bacteria (S-SOB), but the formation of FeAsO4 reduced extraction efficiency in mixed energy source - mixed culture (MS-MC). Combined works of acid dissolution and Fe(3+) oxidation in MS-MC was responsible for the highest extraction efficiency of 71% for In. Ag was present in the slag as refractory AgPb4(AsO4)3 and AgFe2S3, so extraction did not occur. Copyright © 2015 Elsevier Ltd. All rights reserved.

Determination of Cd, Cr and Pb in phosphate fertilizers by laser-induced breakdown spectroscopy

Energy Technology Data Exchange (ETDEWEB)

Nunes, Lidiane Cristina; Gustinelli Arantes de Carvalho, Gabriel [NAPTISA Research Support Center “Technology and Innovation for a Sustainable Agriculture”, Center for Nuclear Energy in Agriculture, University of São Paulo, Av. Centenário 303, 13416-000, Piracicaba SP (Brazil); Santos, Dario [Federal University of São Paulo, R. Prof. Artur Riedel 275, 09972-270, Diadema SP (Brazil); Krug, Francisco José, E-mail: fjkrug@cena.usp.br [NAPTISA Research Support Center “Technology and Innovation for a Sustainable Agriculture”, Center for Nuclear Energy in Agriculture, University of São Paulo, Av. Centenário 303, 13416-000, Piracicaba SP (Brazil)

2014-07-01

A validated method for quantitative determination of Cd, Cr, and Pb in phosphate fertilizers by laser-induced breakdown spectroscopy (LIBS) is presented. Laboratory samples were comminuted and homogenized by cryogenic or planetary ball milling, pressed into pellets and analyzed by LIBS. The experimental setup was designed by using a Q-switched Nd:YAG at 1064 nm with 10 Hz repetition rate, and the intensity signals from Cd II 214.441 nm, Cr II 267.716 nm and Pb II 220.353 nm emission lines were measured by using a spectrometer furnished with an intensified charge-coupled device. LIBS parameters (laser fluence, lens-to-sample distance, delay time, integration time gate, number of sites and number of laser pulses per site) were chosen after univariate experiments with a pellet of NIST SRM 695 (Trace Elements in Multi-Nutrient Fertilizer). Calibration and validation were carried out with 30 fertilizer samples from single superphosphate, triple superphosphate, monoammonium phosphate, and NPK mixtures. Good results were obtained by using 30 pulses of 50 J cm{sup −2} (750 μm spot size), 2.0 μs delay time and 5.0 μs integration time gate. No significant differences between Cd, Cr, and Pb mass fractions determined by the proposed LIBS method and by ICP OES after microwave-assisted acid digestion (AOAC 2006.03 Official Method) were found at 95% confidence level. The limits of detection of 1 mg kg{sup −1} Cd, 2 mg kg{sup −1} Cr and 15 mg kg{sup −1} Pb and the precision (coefficients of variation of results ranging from 2% to 15%) indicate that the proposed LIBS method can be recommended for the determination of these analytes in phosphate fertilizers. - Highlights: • First LIBS application for quantitative Cd, Cr and Pb determination in fertilizers. • LIBS method was validated for analysis of phosphate fertilizers pressed pellets. • LIBS sample throughput is remarkably better than already existing methods.

On The Utilization of (1-X)Cu-X Pb) Alloys for Gamma-Rays Shielding

International Nuclear Information System (INIS)

Abd El-Latif, A.A.; Saeid, Kh.S.; Abd El-Latif, A.A.

2011-01-01

The present work deals with the study of the attenuation properties of gamma rays for [(1-X) Cu -X Pb] alloys where, x=10%, 20%, 30%, and 40% Pb waste by weight. Investigation has been performed by measuring the transmitted gamma ray spectra behind cylindrical samples of [(1-X) Cu - X Pb] alloys of different thicknesses. A collimated beam of gamma ray measured by using γ - ray spectrometer NaI(Tl) Scintillation detector with multichannel analyzer (MCA) cassy. Total mass attenuation coefficients (μ/ρ) of γ-ray have been evaluated and calculated using measured results and XCOM code respectively . Comparison between measured and calculated results shows a reasonable divergence at 0.511 MeV ,and 0.662 MeV γ-ray energies, in addition there is a convergence at 1.17 MeV, 1.274 MeV, and 1.3 MeV γ-ray energies

Quantifying the signature of the industrial revolution from Pb and Cd isotopes in the Susquehanna Shale Hills Critical Zone Observatory

Science.gov (United States)

Ma, L.; Herndon, E.; Jin, L.; Sanchez, D.; Brantley, S. L.

2013-12-01

Anthropogenic forcings have dominated metal cycling in many environments. During the period of the industrial revolution, mining and smelting of ores and combustion of fossil fuels released non-negligible amounts of potentially toxic metals such as Pb, Cd, Mn, and Zn into the environment. The extent and fate of these metal depositions in soils during that period however, have not been adequately evaluated. Here, we combine Pb isotopes with Cd isotopes to trace the sources of metal pollutants in a small temperate watershed (Shale Hills) in Pennsylvania. Previous work has shown that Mn additions to soils in central PA was caused by early iron production, as well as coal burning and steel making upwind. Comparison of the Pb and Cd concentrations in the bedrock and soils from this watershed show that Pb and Cd in soils at Shale Hills are best characterized by addition profiles, consistent with atmospheric additions. Three soil profiles at Shale Hills on the same hillslope have very similar anthropogenic Pb inventories. Pb isotope results further reveal that the extensive use of local coals during iron production in early 19th century in Pennsylvania is most likely the anthropogenic Pb source for the surface soils at Shale Hills. Pb concentrations and isotope ratios were used to calculate mass balance and diffusive transport models in soil profiles. The model results further reveal that during the 1850s to 1920s, coal burning in local iron blasting furnaces significantly increased the Pb deposition rates to 8-14 μg cm-2 yr-1, even more than modern Pb deposition rates derived from the use of leaded gasoline in the 1940s to 1980s. Furthermore, Cd has a low boiling point (~760 °C) and easily evaporates and condenses. The evaporation and condensation processes could generate systematic mass-dependent isotope fractionation between Cd in coal burning products and the naturally occurring Cd in the sulfide minerals of coals. This fractionation indicates that Cd isotopes can

One pot synthesis of Pb S/Cu{sub 2}S core-shell nanoparticles and their optical properties