WorldWideScience

Sample records for heavy metals removal

  1. Simultaneous removal of nitrate and heavy metals by iron metal*

    OpenAIRE

    Hao, Zhi-wei; Xu, Xin-hua; Jin, Jian; He, Ping; Liu, Yong; Wang, Da-hui

    2005-01-01

    Great attention should be paid now to simultaneously removing common pollutants, especially inorganic pollutants such as nitrate and heavy metals, as individual removal has been investigated extensively. Removing common pollutants simultaneously by iron metal is a very effective alternative method. Near neutral pH, heavy metals, such as copper and nickel, can be removed rapidly by iron metal, while nitrate removal very much slower than that of copper and nickel, and copper can accelerate nitr...

  2. Heavy Metals Removal by Biosorption and Flotation

    OpenAIRE

    Matis, K. A.; ??????, ?. ?.; Zouboulis, A. I.; Lazaridis, N. K.; ???????????, ?. ?.; ??????????, ?. ?.

    2009-01-01

    The removal of a mixture of heavy (toxic) metal cations (copper, nickel and zinc) from liquid effluents was investigated in this study at pilot scale, using counter-current contact mode. The innovative process involved the abstraction of metal ions onto fungal biosorbents, followed by the application of flotation for the subsequent solid/liquid separation of biomass particles. The ability of microorganisms to remove metal ions from aqueous solutions is a well-known phenomenon. Nevertheless, e...

  3. Material Removes Heavy Metal Ions From Water

    Science.gov (United States)

    Philipp, Warren H., Jr.; Street, Kenneth W.; Hill, Carol; Savino, Joseph M.

    1995-01-01

    New high capacity ion-exchange polymer material removes toxic metal cations from contaminated water. Offers several advantages. High sensitivities for such heavy metals as lead, cadmium, and copper and capable of reducing concentrations in aqueous solutions to parts-per-billion range. Removes cations even when calcium present. Material made into variety of forms, such as thin films, coatings, pellets, and fibers. As result, adapted to many applications to purify contaminated water, usually hard wherever found, whether in wastewater-treatment systems, lakes, ponds, industrial plants, or homes. Another important feature that adsorbed metals easily reclaimed by either destructive or nondestructive process. Other tests show ion-exchange polymer made inexpensively; easy to use; strong, flexible, not easily torn; and chemically stable in storage, in aqueous solutions, and in acidic or basic solution.

  4. Removal of heavy metals from biowaste: modelling of heavy metal behaviour and development of removal technologies.

    OpenAIRE

    Veeken, A.

    1998-01-01

    In the Netherlands, recycling of solid organic waste streams as compost only becomes possible if the compost complies with the heavy metals standards of the BOOM decree. This dissertation focuses on the removal of heavy metals from biowaste, i.e. the source separated organic fraction of municipal solid waste. Biowaste is referred to as an organic waste stream but surprisingly it was found that a large part of biowaste is composed of inorganic material, i.e. sand, silt and clay minerals. The i...

  5. Removal of dissolved heavy metals and radionuclides by microbial spores

    International Nuclear Information System (INIS)

    Microbial systems have been shown to remove specific heavy metals from contaminated aqueous waste to levels acceptable to EPA for environmental release. However, systems capable of removing a variety of heavy metals from aqueous waste to environmentally acceptable levels remain to be reported. The present studies were performed to determine the specificity of spores of the bacterium Bacillus megaterium for the adsorption of dissolved metals and radionuclides from aqueous waste. The spores effectively adsorbed eight heavy metals from a prepared metal mix and from a plating rinse waste to EPA acceptable levels for waste water. These results suggest that spores have multiple binding sites for the adsorption of heavy metals. Spores were also effective in adsorbing the radionuclides 85strontium and 197cesium. The presence of multiple sites in spores for the adsorption of heavy metals and radionuclides makes this biosorbent a good candidate for the treatment of aqueous wastes associated with the plating and nuclear industries. 17 refs., 4 tabs

  6. Heavy metals removal from dredged sediments using electro kinetics

    Directory of Open Access Journals (Sweden)

    Ammami M. T.

    2013-04-01

    Full Text Available This study focuses on the use of a remediation process to remove particle-bound recalcitrant pollutants (heavy metals from dredged harbor sediments which must be previously treated before reuse in civil engineering. Electrokinetic (EK remediation is generally accepted as one of the most suitable technologies for extracting cationic heavy metals from fine grained sediments. Many batch tests were performed to better understand the capacity of various additives to improve sediment decontamination (when applying a constant voltage gradient of 1 V.cm-1, and the combination of enhancing agents (acids + surfactants were assessed to obtain an efficient removal of heavy metals. We succeeded in proving that mixing citric acid and a nonionic surfactant (Tween 20, additives which are environmentally friendly, was a good association to enhance heavy metals (Cd, Cr, Cu, Pb and Zn removal.

  7. Heavy metal removal potential of dried Salvinia biomass.

    Science.gov (United States)

    Dhir, Bhupinder; Nasim, Sekh A; Sharmila, P; Saradhi, P Pardha

    2010-02-01

    Investigations were carried out to evaluate heavy metal adsorption capacity of Salvinia. Batch experiments showed that dry plant biomass possess good potential to adsorb heavy metals such as Ni, Co, Cr, Fe, and Cd. The metal adsorption increased with increase in initial metal concentration. The data obtained fitted well with Freundlich equilibrium isotherm. Further characterization of plant biomass showed presence of both acidic and basic surface functionalities that might facilitate binding of metal ions. Fourier transform infrared (FTIR) spectra of plant biomass suggested involvement of carbonyl (C=O), carboxyl (-COO), and hydroxyl (-OH) groups in binding heavy metals to plant biomass. The studies establish S. natans as an effective biosorbent for removing heavy metals from wastewater and further emphasize biomass utilization in wastewater treatment technologies. PMID:20734611

  8. Heavy metals removal from dredged sediments using electro kinetics

    OpenAIRE

    Ammami M. T.; Benamar A.; Koltalo F.; Wang H. Q.; LeDerf F.

    2013-01-01

    This study focuses on the use of a remediation process to remove particle-bound recalcitrant pollutants (heavy metals) from dredged harbor sediments which must be previously treated before reuse in civil engineering. Electrokinetic (EK) remediation is generally accepted as one of the most suitable technologies for extracting cationic heavy metals from fine grained sediments. Many batch tests were performed to better understand the capacity of various additives to improve sediment decontaminat...

  9. Removal of Heavy Metals from Textile Wastewater using Zeolite

    OpenAIRE

    Normala Halimoon

    2010-01-01

    Heavy metals such as lead (Pb), chromium (Cr), cadmium (Cd) and copper (Cu) are widely used for production of colour pigments of textile dyes. Textile dyes pollutants are being released to the environment at various stages of operation therefore it is necessary that the pollutants are treated before discharge using zeolite with and without alum. A study was carried out to compare the effectiveness of treatment using zeolite with and without alum for the removal of heavy metals (Pb, Cu, Cd, Cr...

  10. Heavy metals removal from automobile shredder residues (ASR).

    Science.gov (United States)

    Kurose, Keisuke; Okuda, Tetsuji; Nishijima, Wataru; Okada, Mitsumasa

    2006-10-11

    The fate of heavy metals during a separation process for automobile shredder residues (ASR) was investigated. A washing method to remove heavy metals from the ASR was also investigated. Although the separation process was not designed for removal of heavy metals, but for the recovery of reusable materials, the heavy metal content in the ASR was efficiently decreased. The concentrations of Pb, Cr and Cd in ASR were effectively reduced by a nonferrous metals removal process, and the As concentration was reduced by the removal of light dusts during the separation process. Five heavy metals (As, Se, Pb, Cr, Cd) remaining in the ASR after the separation process satisfied the content criteria of the Environmental Quality Standards for Soil (EQSS), while the concentrations of As, Se, Pb in the leachate from the remaining ASR did not satisfy the elution criteria of the EQSS. After additional washing of the remaining ASR with a pH 1 acid buffer solution, the As, Se, and Pb concentrations satisfied the EQSS for elution. These results indicate that an ASR residue can be safely recycled after a separation process, followed by washing at acidic pH. PMID:16797833

  11. Plasma polymer-functionalized silica particles for heavy metals removal.

    Science.gov (United States)

    Akhavan, Behnam; Jarvis, Karyn; Majewski, Peter

    2015-02-25

    Highly negatively charged particles were fabricated via an innovative plasma-assisted approach for the removal of heavy metal ions. Thiophene plasma polymerization was used to deposit sulfur-rich films onto silica particles followed by the introduction of oxidized sulfur functionalities, such as sulfonate and sulfonic acid, via water-plasma treatments. Surface chemistry analyses were conducted by X-ray photoelectron spectroscopy and time-of-flight secondary ion mass spectroscopy. Electrokinetic measurements quantified the zeta potentials and isoelectric points (IEPs) of modified particles and indicated significant decreases of zeta potentials and IEPs upon plasma modification of particles. Plasma polymerized thiophene-coated particles treated with water plasma for 10 min exhibited an IEP of less than 3.5. The effectiveness of developed surfaces in the adsorption of heavy metal ions was demonstrated through copper (Cu) and zinc (Zn) removal experiments. The removal of metal ions was examined through changing initial pH of solution, removal time, and mass of particles. Increasing the water plasma treatment time to 20 min significantly increased the metal removal efficiency (MRE) of modified particles, whereas further increasing the plasma treatment time reduced the MRE due to the influence of an ablation mechanism. The developed particulate surfaces were capable of removing more than 96.7% of both Cu and Zn ions in 1 h. The combination of plasma polymerization and oxidative plasma treatment is an effective method for the fabrication of new adsorbents for the removal of heavy metals. PMID:25603034

  12. Simultaneous heavy metal removal mechanism by dead macrophytes.

    Science.gov (United States)

    Miretzky, Patricia; Saralegui, Andrea; Fernández Cirelli, Alicia

    2006-01-01

    The use of dead, dried aquatic plants, for water removal of metals derived from industrial activities as a simple biosorbent material has been increasing in the last years. The mechanism of simultaneous metal removal (Cd2+, Ni2+, Cu2+, Zn2+ and Pb2+) by 3 macrophytes biomass (Spirodela intermedia, Lemna minor and Pistia stratiotes) was investigated. L. minor biomass presented the highest mean removal percentage and P. stratiotes the lowest for all metals tested. Pb2+ and Cd2+ were more efficiently removed by the three of them. The simultaneous metal sorption data were analysed according to Langmuir and Freundlich isotherms. Data fitted the Langmuir model only for Ni and Cd, but Freundlich isotherm for all metals tested, as it was expected. The K(F) values showed that Pb was the metal more efficiently removed from water solution. The adsorption process for the three species studied followed first order kinetics. The mechanism involved in biosorption resulted ion exchange between monovalent metals as counter ions present in the macrophytes biomass and heavy metal ions and protons taken up from water. No significant differences were observed in the metal exchange amounts while using multi-metal or individual metal solutions. PMID:15990152

  13. Heavy metal removal from waste waters by ion flotation.

    Science.gov (United States)

    Polat, H; Erdogan, D

    2007-09-01

    Flotation studies were carried out to investigate the removal of heavy metals such as copper (II), zinc (II), chromium (III) and silver (I) from waste waters. Various parameters such as pH, collector and frother concentrations and airflow rate were tested to determine the optimum flotation conditions. Sodium dodecyl sulfate and hexadecyltrimethyl ammonium bromide were used as collectors. Ethanol and methyl isobutyl carbinol (MIBC) were used as frothers. Metal removal reached about 74% under optimum conditions at low pH. At basic pH it became as high as 90%, probably due to the contribution from the flotation of metal precipitates. PMID:17374447

  14. Removing heavy metals by in vitro cultures.

    Science.gov (United States)

    Santos-Díaz, María del Socorro; Barrón-Cruz, María del Carmen

    2012-01-01

    In vitro roots cultures of Typha latifolia and Scirpus americanus aquatic plants have the capacity to remove Pb (II), Mn (II), and Cr (III) from the culture medium. Both species remove Cr and Pb by an absorption process, while Mn is mainly adsorbed to the root surface. This chapter describes a protocol for the establishment of in vitro roots cultures (nontransformed) from T. latifolia and S. americanus, and the procedure for the uptake analysis of Pb (II), Mn (II), and Cr (III) by roots. PMID:22610634

  15. Heavy metal removal using reverse osmosis

    OpenAIRE

    Lucia Gajdošová; Milan Búgel; Tomáš Bakalár

    2009-01-01

    The aim of this work was to study reverse osmosis characteristics for copper, nickel and zinc removal from technological aqueoussolutions. Reverse osmosis (RO) is a separation process that uses pressure to force a solution through a membrane that retainsthe solute on one side and allows the pure solvent to pass to the other side. A polyamide thin-film composite membrane TW30-1812-50was used. The difference in flux decline is significant. There is a significant difference in flux decline depen...

  16. Heavy metal removal from water solutions

    Directory of Open Access Journals (Sweden)

    Barbora Onderková

    2005-11-01

    Full Text Available Equilibrium and kinetic data for copper adsorption on chitosan and Lewatit S100 in batch systems have been obtained. For chitosan particles the best fit isotherm in the concentration range 0 – 8 g.m-3 is the R-P isotherm and for Lewatit S100-G the best fit isotherm in the concentration range 0 – 8 g.m-3 is the Langmuir isotherm. The maximum capacity of chitosan is slightly higher than that of Lewatit; however at aqueous concentrations below about 150 g.m-3 the amount of metal adsorbed on Lewatit is higher.

  17. Heavy metal removal from water solutions

    OpenAIRE

    Barbora Onderková; Milan Búgel; Štefan Schlosser; Tomáš Bakalár

    2005-01-01

    Equilibrium and kinetic data for copper adsorption on chitosan and Lewatit S100 in batch systems have been obtained. For chitosan particles the best fit isotherm in the concentration range 0 – 8 g.m-3 is the R-P isotherm and for Lewatit S100-G the best fit isotherm in the concentration range 0 – 8 g.m-3 is the Langmuir isotherm. The maximum capacity of chitosan is slightly higher than that of Lewatit; however at aqueous concentrations below about 150 g.m-3 the amount of metal adsorbed on ...

  18. Electrodialytic Removal of Heavy Metals from Different Solid Waste Products

    DEFF Research Database (Denmark)

    Ottosen, Lisbeth M.; Christensen, Iben Vernegren

    2003-01-01

    A variety of heavy metal polluted waste products must be handled today. Electrochemical methods have been developed for remediation of polluted soil. One of the methods is the electrodialytic remediation method that is based on electromigration of heavy metal ions and ionic species within the soil matrix, and a separation of the soil and the process solutions, where the heavy metals are concentrated, with ion exchange membranes. For remediation of some soils, such as calcareous soils, it is necessary to add an enhancement solution. It was shown in a laboratory experiment that ammonium citrate could be used when removing Cu and Cr from a soil with 25% carbonates. The final concentrations of the elements were below the target values after the remediation. A question of whether the electrodialytic remediation method can be used for other waste products arose. Preliminary experiments showed that the method could be used for removal of different heavy metals from impregnated wood waste, fly ash from straw combustion, and fly ash from municipal solid waste incineration. The best result was obtained with the wood waste where more than 80% of each of the polluting elements Cu, Cr and As was removed in a 7-day experiment in which oxalic acid was used as enhancement solution. From the straw ash, 66% of the Cd was removed, but 64% of the fly ash dry mass dissolved during the treatment. In this actual experiment, no enhancement solution was used but that will be necessary to avoid dissolution of the ash to such a high extent. For the fly ash from waste incineration, ammonium citrate was tested as enhancement solution and in 14 days 62% Cd, 53% Cu, 6% Pb, and 31% Zn were removed. The preliminary results were thus promising for developing the electrodialytic method to other products than soil, although more research is needed especially in finding the best enhancement solutions for each product.

  19. Removal of Heavy Metal Ions by Blended Periwinkle Shells

    OpenAIRE

    Okuo, James M.

    2006-01-01

    In this study, coconut husk and palm kernel fiber were characterized, blended with periwinkle shells, thiolated and used to remove heavy metal ions-Co2+, Ni2+ and Cd2+ ions from aqueous solution. Periwinkle shells, palm kernel fiber and coco nut husk were obtained from New Benin market, Benin city, Nigeria. These were milled, sieved with a 300ìm mesh sieve, blended in seven different ratios: 1:1:1, 1:1:4, 1:4:1, 4:1:1, 1:3:2, 2:1:3, 3:2:1 and characterized. They were all thiolated and the be...

  20. Removal of heavy metals and radionuclides by seeded magnetic filtration

    International Nuclear Information System (INIS)

    Removal of traces of heavy metal or radionuclide contamination from solution at high flow rate presents a considerable technical challenge. Low flow methods of treatment such as particle gravity settling require expensive large volume equipment, whereas traditional methods of filtration can cause significant energy costs. Magnetic filtration can be used to provide a low cost method of solid-liquid separation at high flow rate, provided contaminants can be selectively bound to a magnetic solid particle. This paper describes the use of such selective magnetic particles made up of inorganic particles coupled with organic polymers

  1. Removal of Heavy Metals and PAH in Highway Detention Ponds

    OpenAIRE

    Bentzen, Thomas Ruby; Larsen, Torben; Thorndahl, Søren Liedtke; Rasmussen, Michael R.

    2010-01-01

    The paper presents some of the first results from a study of the removal of pollutants in highway detention ponds in Denmark. The objective of the study is to set up a procedure for long-term modelling of discharges of pollutants to the environment from the many Danish highway detention ponds, which has been designed according to standard design criteria for several decades. The study will focus on heavy metals (Cd, Cr, Cu, Pb and Zn) and polyaromatic hydrocarbons (PAH). The long-term simulat...

  2. Industrial effluent treatments using heavy-metal removing bacterial bioflocculants

    Scientific Electronic Library Online (English)

    J, Lin; C, Harichund.

    2011-04-01

    Full Text Available SciELO South Africa | Language: English Abstract in english Bioflocculants produced by Herbaspirillium sp. CH7, Paenibacillus sp. CH11, Bacillus sp. CH15 and a Halomonas sp. were preliminarily evaluated as flocculating agents in the treatment of industrial wastewater effluents. Industrial (1 local chemical-industry and 2 textile-industry: Biavin 109-medium b [...] lue dye and Whale dye) effluent (9 m?) containing various heavy metals was vortexed with 1 m? of bioflocculant in a 25 m? test tube. One m? of water (Millipore Elix purification system, 17 mega?) was substituted for the bioflocculant in the control. After 5 min, the heavy metal concentrations, the microbial population and the turbidity of the top layer of the industrial effluent were determined using ICP-OES, spread-plate technique and a turbidity meter respectively. The flocculating activity was calculated based on absorbance at a wavelength of 550 nm. Bioflocculants produced in this study were capable of removing several heavy metals from industrial effluents simultaneously and effectively. This was significant (p

  3. Heavy metal removal from aqueous solutions by activated phosphate rock

    International Nuclear Information System (INIS)

    The use of natural adsorbent such as phosphate rock to replace expensive imported synthetic adsorbent is particularly appropriate for developing countries such as Tunisia. In this study, the removal characteristics of lead, cadmium, copper and zinc ions from aqueous solution by activated phosphate rock were investigated under various operating variables like contact time, solution pH, initial metal concentration and temperature. The kinetic and the sorption process of these metal ions were compared for phosphate rock (PR) and activated phosphate rock (APR). To accomplish this objective we have: (a) characterized both (PR) and (APR) using different techniques (XRD, IR) and analyses (EDAX, BET-N2); and, (b) qualified and quantified the interaction of Pb2+, Cd2+, Cu2+ and Zn2+ with these sorbents through batch experiments. Initial uptake of these metal ions increases with time up to 1 h for (PR) and 2 h for (APR), after then, it reaches equilibrium. The maximum sorption obtained for (PR) and (APR) is between pH 2 and 3 for Pb2+ and 4 and 6 for Cd2+, Cu2+ and Zn2+. The effect of temperature has been carried out at 10, 20 and 40 deg. C. The data obtained from sorption isotherms of metal ions at different temperatures fit to linear form of Langmuir sorption equation. The heat of sorption (?Ho), free energy (?Go) and change in entropy (?So) wnd change in entropy (?So) were calculated. They show that sorption of Pb2+, Cd2+, Cu2+ and Zn2+on (PR) and (APR) an endothermic process. These findings are significant for future using of (APR) for the removal of heavy metal ions from wastewater under realistic competitive conditions in terms of initial heavy metals, concentrations and pH

  4. Heavy metal removal from water/wastewater by nanosized metal oxides: A review

    International Nuclear Information System (INIS)

    Nanosized metal oxides (NMOs), including nanosized ferric oxides, manganese oxides, aluminum oxides, titanium oxides, magnesium oxides and cerium oxides, provide high surface area and specific affinity for heavy metal adsorption from aqueous systems. To date, it has become a hot topic to develop new technologies to synthesize NMOs, to evaluate their removal of heavy metals under varying experimental conditions, to reveal the underlying mechanism responsible for metal removal based on modern analytical techniques (XAS, ATR-FT-IR, NMR, etc.) or mathematical models, and to develop metal oxide-based materials of better applicability for practical use (such as granular oxides or composite materials). The present review mainly focuses on NMOs’ preparation, their physicochemical properties, adsorption characteristics and mechanism, as well as their application in heavy metal removal. In addition, porous host supported NMOs are particularly concerned because of their great advantages for practical application as compared to the original NMOs. Also, some magnetic NMOs were included due to their unique separation performance.

  5. Removal of Heavy Metals and PAH in Highway Detention Ponds

    DEFF Research Database (Denmark)

    Bentzen, Thomas Ruby; Larsen, Torben

    2005-01-01

    The paper presents some of the first results from a study of the removal of pollutants in highway detention ponds in Denmark. The objective of the study is to set up a procedure for long-term modelling of discharges of pollutants to the environment from the many Danish highway detention ponds, which has been designed according to standard design criteria for several decades. The study will focus on heavy metals (Cd, Cr, Cu, Pb and Zn) and polyaromatic hydrocarbons (PAH). The long-term simulation of input of flow and pollution to the ponds will be a hind cast based on time series of historical rainfalls. The modelling will take place in a special version of the MIKE URBAN. The modelling is calibrated and validated on measurements from selected highway catchments. The removal of pollutants in the ponds is studied by local measurements in combination with CFD modelling using the MIKE 21 and MIKE 3 numerical models.

  6. Cyclic electrowinning/precipitation (CEP) system for the removal of heavy metal mixtures from aqueous solutions

    OpenAIRE

    Grimshaw, Pengpeng; Calo, Joseph M.; Hradil, George

    2011-01-01

    The description and operation of a novel cyclic electrowinning/precipitation (CEP) system for the simultaneous removal of mixtures of heavy metals from aqueous solutions are presented. CEP combines the advantages of electrowinning in a spouted particulate electrode (SPE) with that of chemical precipitation and redissolution, to remove heavy metals at low concentrations as solid metal deposits on particulate cathode particles without exporting toxic metal precipitate sludges from the process. ...

  7. Heavy metal removal from copper smelting effluent using electrochemical cylindrical flow reactor

    International Nuclear Information System (INIS)

    The purpose of this study is mainly to evaluate the performance of the continuous recirculation flow cell at low current density and pH (the pH at which the effluents are available) in removing heavy metals from copper smelting effluent by cathodic reduction. During the electrolysis at different pH, % removal of heavy metals removal, energy consumption and heterogeneous reaction rate constants were investigated at given flow rate and current density on the selected industrial effluent. The overall specific energy consumption at the pH 0.64 was observed to be lowest, which is 10.99 kWh/kg of heavy metal removal

  8. Heavy metal removal from water/wastewater by nanosized metal oxides: A review

    Energy Technology Data Exchange (ETDEWEB)

    Hua, Ming; Zhang, Shujuan [State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210046 (China); Pan, Bingcai, E-mail: bcpan@nju.edu.cn [State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210046 (China); Zhang, Weiming; Lv, Lu; Zhang, Quanxing [State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210046 (China)

    2012-04-15

    Nanosized metal oxides (NMOs), including nanosized ferric oxides, manganese oxides, aluminum oxides, titanium oxides, magnesium oxides and cerium oxides, provide high surface area and specific affinity for heavy metal adsorption from aqueous systems. To date, it has become a hot topic to develop new technologies to synthesize NMOs, to evaluate their removal of heavy metals under varying experimental conditions, to reveal the underlying mechanism responsible for metal removal based on modern analytical techniques (XAS, ATR-FT-IR, NMR, etc.) or mathematical models, and to develop metal oxide-based materials of better applicability for practical use (such as granular oxides or composite materials). The present review mainly focuses on NMOs' preparation, their physicochemical properties, adsorption characteristics and mechanism, as well as their application in heavy metal removal. In addition, porous host supported NMOs are particularly concerned because of their great advantages for practical application as compared to the original NMOs. Also, some magnetic NMOs were included due to their unique separation performance.

  9. Mechanisms of heavy metal removal using microorganisms as biosorbent.

    Science.gov (United States)

    Javanbakht, Vahid; Alavi, Seyed Amir; Zilouei, Hamid

    2014-01-01

    Release and distribution of heavy metals through industrial wastewaters has adverse affects on the environment via contamination of surface- and ground-water resources. Biosorption of heavy metals from aqueous solutions has been proved to be very promising, offering significant advantages such as low cost, availability, profitability, ease of operation, and high efficiency, especially when dealing with low concentrations. Residual biomasses of industrial microorganisms including bacteria, algae, fungi, and yeast have been found to be capable of efficiently accumulating heavy metals as biosorbent. This paper presents and investigates major mechanisms of biosorption and most of the functional groups involved. The biosorption process includes the following mechanisms: transport across cell membrane, complexation, ion exchange, precipitation, and physical adsorption. In order to understand how metals bind to the biomass, it is essential to identify the functional groups responsible for metal binding. Most of these groups have been characterized on the cell walls. The biosorbent contains a variety of functional sites including carboxyl, imidazole, sulfydryl, amino, phosphate, sulfate, thioether, phenol, carbonyl, amide, and hydroxyl moieties that are responsible for metal adsorption. These could be helpful to improve biosorbents through modification of surface reactive sites via surface grafting and/or exchange of functional groups. PMID:24804650

  10. Effect of operational parameters on heavy metal removal by electrocoagulation.

    Science.gov (United States)

    Bhagawan, D; Poodari, Saritha; Pothuraju, Tulasiram; Srinivasulu, D; Shankaraiah, G; Yamuna Rani, M; Himabindu, V; Vidyavathi, S

    2014-12-01

    In the present paper, the performance of electrocoagulation (EC) for the treatability of mixed metals (chromium (Cr), copper (Cu), lead (Pb), nickel (Ni), and zinc (Zn)) from metal plating industrial wastewater (EPW) has been investigated. The study mainly focused on the affecting parameters of EC process, such as electrode material, initial pH, distance between electrodes, electrode size, and applied voltage. The pH 8 is observed to be the best for metal removal. Fe-Fe electrode pair with 1-cm inter-electrode distance and electrode surface area of 40 cm(2) at an applied voltage of 8 V is observed to more efficient in the metal removal. Experiments have shown that the maximum removal percentage of the metals like Cr, Ni, Zn, Cu, and Pb are reported to be 96.2, 96.4, 99.9, 98, and 99.5 %, respectively, at a reaction time of 30 min. Under optimum conditions, the energy consumption is observed to be 51.40 kWh/m(3). The method is observed to be very effective in the removal of metals from electroplating effluent. PMID:25056749

  11. Removal of heavy metals from aqueous solution by Carrot residues

    International Nuclear Information System (INIS)

    The removal of Copper(II), Zinc(II), and Chromium (III) from wastewater by carrot residues was investigated to evaluate cation exchange capacity. The effects of solution P H and co-ions were studied in batch experiments. Adsorption equilibria were initially rapidly established, and then decreased markedly after 10 min. Column experiments were carried out in a glass column filled with carrot residues to evaluate the metal removal capacity. The influences of the feed concentration and feed rate were also studied in order to compare the dynamic capacity for metal binding in different feed concentrations

  12. Electrodialytic removal of heavy metals from different fly ashes. Influence of heavy metal speciation in the ashes

    DEFF Research Database (Denmark)

    Pedersen, Anne Juul; Ottosen, Lisbeth M.

    2003-01-01

    Electrodialytic Remediation has recently been suggested as a potential method for removal of heavy metals from fly ashes. In this work electrodialytic remediation of three different fly ashes, i.e. two municipal solid waste incinerator (MSWI) fly ashes and one wood combustion fly ash was studied in lab scale, and the results were discussed in relation to the expected heavy metal speciation in the ashes. In initial leaching experiments the pH-dependent desorption characteristics of the heavy metals Cd, Pb, Zn and Cu were analogous in the two MSWI ashes, and thus it was expected that the speciation of these metals was similar in the two ashes. On the other hand, the leaching behaviour (and concentration) of Cr was diverse. The apparent similar speciation of Cd, Pb, Zn and Cu was only partly confirmed in the following electrodialytic remediation experiments. Significant differences in re-moval efficiencies were observed, especially for Pb and Zn. Cd, the sole heavy metal of environmental concern in the wood ash,was found more tightly bonded in this ash than in the two MSWI ashes. It was suggested that complex Cd-silicates are likely phases in the wood ash whereas more soluble, condensed phases are dominating in the MSWI ashes.

  13. Cyclic electrowinning/precipitation (CEP) system for the removal of heavy metal mixtures from aqueous solutions.

    Science.gov (United States)

    Grimshaw, Pengpeng; Calo, Joseph M; Hradil, George

    2011-11-15

    The description and operation of a novel cyclic electrowinning/precipitation (CEP) system for the simultaneous removal of mixtures of heavy metals from aqueous solutions are presented. CEP combines the advantages of electrowinning in a spouted particulate electrode (SPE) with that of chemical precipitation and redissolution, to remove heavy metals at low concentrations as solid metal deposits on particulate cathode particles without exporting toxic metal precipitate sludges from the process. The overall result is very large volume reduction of the heavy metal contaminants as a solid metal deposit on particles that can either be safely discarded as such, or further processed to recover particular metals. The performance of this system is demonstrated with data on the removal of mixtures of copper, nickel, and cadmium from aqueous solutions. PMID:22102792

  14. Heavy Metal Removal by Chitosan and Chitosan Composite

    International Nuclear Information System (INIS)

    Radiation grafting of diethyl aminoethyl methacrylate (DEAEMA) on chitosan to impart ion exchange properties and to be used for the separation of metal ions from waste water, was carried out. The effect of experimental conditions such as monomer concentration and the radiation dose on grafting were studied. On using chitosan, grafted chitosan and some chitosan composites in metal ion removal they show high up-take capacity for Cu2+ and lower uptake capacities for the other divalent metal ions used (Zn and Co). Competitive study, performed with solutions containing mixture of metal salts, showed high selectivity for Cu2+ than the other metal ion. Limited grafting of DEAEMA polymer -containing specific functional groups-onto the chitosan backbone improves the sorption performance

  15. Removal of Heavy Metal Ions from Polluted Waters by Using of Low Cost Adsorbents: Review

    OpenAIRE

    Ghaedi, M.; Mosallanejad, N.

    2013-01-01

    Adsorption is a fundamental process in the physicochemical treatment of wastewaters which industries employ to reduce hazardous organic and inorganic wastes in effluents. In recent years the use of low-cost adsorbents has been widely investigated as a replacement for the currently costly methods of removing heavy metal ions from wastewater. It is well-known that cellulosic waste materials can be obtained and employed as cheap adsorbents and their performance to remove heavy metal ions can be ...

  16. Investigation of heavy metal removal from motorway stormwater using inorganic ion exchange

    International Nuclear Information System (INIS)

    Stormwater runoff from motorway surfaces contains toxic heavy metals that are not sufficiently removed by current treatment systems. This research has investigated the potential use of inorganic ion exchange materials to further reduce the levels of dissolved heavy metals. Candidate materials (synthetic/natural zeolites, clay/modified clay, hydrotalcite, lignite) were tested by a shaking procedure (mixed 5 mg dm-3 of each heavy metals, shaken for 10 min) and analysed by atomic absorption spectrometry. The synthetic zeolites MAP and Y showed 100% heavy metal removal and were investigated further by a series of batch experiments. The zeolites exhibited a selectivity sequence Pb > Cu > Cd ? Zn. Zeolite MAP has a high capacity for heavy metal uptake (4.5 meq g-1), but is not practical for use in a treatment facility owing to its low particle size (3 ?m). However, large zeolite pellets (? 2 mm) were found to have a low heavy metal uptake (? 44 %) due to diffusion limitations. Selected materials (zeolites MAP, Y, mordenite, and carbon-based lignite) were tested in actual and spiked motorway stormwater. The synthetic zeolites effectively remove heavy metals (? 100 %) but change the environmental chemistry of the stormwater by releasing high concentrations of sodium, removing calcium ions and increasing the solution pH. The presence of other dissolved contaminants in motorway stormwater inhibited the uptake of heavy metals by the natural zeoliteavy metals by the natural zeolite mordenite (34 % less removal). Alkali/alkaline-earth metals (Na, Ca) in solution compete for exchange sites in lignite and mordenite, reducing the heavy metal uptake. Chloride in solution forms complexes with cadmium, severely reducing its uptake by zeolite Y. The presence of dissolved road salt is a potentially serious concern as it causes previously exchanged heavy metals to be re-eluted, especially zinc and cadmium. Zeolite MAP as an exchanger is relatively unaffected by road salt. There is potential for the use of ion exchange materials to remove heavy metals from motorway stormwater, but a balance needs to be achieved between a practical particle size, capacity for heavy metal uptake and the potential environmental impact. (author)

  17. Concurrent removal and accumulation of heavy metals by the three aquatic macrophytes.

    Science.gov (United States)

    Mishra, Virendra Kumar; Tripathi, B D

    2008-10-01

    Under the present investigation effectiveness of three aquatic macrophytes Pistia stratiotes L. (water lettuce), Spirodela polyrrhiza W. Koch (duckweed) and Eichhornia crassipes were tested for the removal of five heavy metals (Fe, Zn, Cu, Cr and Cd). These plants were grown at three different concentrations (1.0, 2.0 and 5.0mgl(-1)) of metals in laboratory experiment. Result revealed high removal (>90%) of different metals during 15 days experiment. Highest removal was observed on 12th day of experiment, thereafter it decreased. Results revealed E. crassipes as the most efficient for the removal of selected heavy metals followed by P. stratiotes and S. polyrrhiza. Results from analysis confirmed the accumulation of different metals within the plant and a corresponding decrease of metals in the water. Significant correlations between metal concentration in final water and macrophytes were obtained. Plants have accumulated heavy metals in its body without the production of any toxicity or reduction in growth. Selected plants shown a wide range of tolerance to all of the selected metals and therefore can be used for large scale removal of heavy metals from waste water. PMID:18296043

  18. Investigation on the emission factors and removal efficiencies of heavy metals from MSW incinerators in Taiwan.

    Science.gov (United States)

    Chang, Moo Been; Jen, Chuan Hsiung; Wu, Hsiu Tung; Lin, Hsin Yi

    2003-06-01

    Two large-scale municipal waste incinerators (MWIs) equipped with different air pollution control devices (APCDs) were selected for conducting flue gas sampling and determination of heavy metals emissions including lead, zinc, cadmium, chromium, copper and mercury. In addition, the emission characteristics and removal efficiencies of heavy metals were evaluated via simultaneous sampling of flue gas upstream and downstream of APCDs. The average removal efficiency of particulate matter was 99.47%, and the removal efficiency of heavy metals could reach 95% or higher (except for Hg) for MWI-A. Preliminary results indicated that the average removal efficiency of particulate matter was 99.94%, and the removal efficiency of heavy metals could reach 98% or higher (except for Hg) for MWI-B. The average removal efficiencies of Hg for MWI-A and MWI-B were 47% and 30% respectively. The removal efficiencies achieved with existing APCDs were close to that reported in the US EPA document (AP-42) for MWIs. The average concentrations of heavy metals and particulate matter emitted from stack could meet current emission standards in Taiwan for both MWIs, but particulate matter, Pb and Cd concentrations of MWI-A were higher than the current emission regulations in Germany and the Netherlands. PMID:12870641

  19. Removal of heavy metals by two free floating aquatic macrophytes.

    Science.gov (United States)

    Mallick, N; Shardendu; Rai, L C

    1996-12-01

    A concentration-dependent decrease in biomass, protein, RNA, DNA, and nutrient (NO3(-) and PO4(3-)) uptake of Lemna minor and Azolla pinnata by Cr, Ni, and Zn was detected. Cr was found to exert maximum toxicity followed by Ni and Zn. Metal uptake was dependent on time and concentration of metal in the external medium. Both the macrophytes, however, showed preference for Zn followed by Ni and Cr. The uptake kinetics also revealed a low Vmax and high Km for Cr. L. minor was more efficient in accumulating Zn and Cr than A. pinnata in Ni. Compared to immobilized algae and bacterial capsules the test macrophytes showed a greater efficiency for metal removal. PMID:8988809

  20. Removal of heavy metals from industrial effluents in the presence of ammonium salts

    International Nuclear Information System (INIS)

    It has been established that heavy metal ions cannot be precipitated by alkaline reagents in the presence of ammonium salts due to the formation of ammonia complexes. A method has been developed for removal of heavy metals from wastewaters in the presence of ammonium salts. The method is based on the precipitation of metal ions by phosphoric acid under specific conditions. The concentration of heavy metals in wastewaters after treatment is below the utmost permissible rates. An electronic system was devised for automatic operation and control of the technological process, which guaranted a high purification effect at a minimum consumption of reagents. (author). 10 refs, 2 figs, 2 tabs

  1. A new material for removing heavy metals from water

    Science.gov (United States)

    Philipp, Warren H., Jr.; Street, Kenneth W., Jr.

    1994-01-01

    The NASA Lewis Research Center developed and is patenting a new high capacity ion exchange material (IEM) that removes toxic metals from contaminated water in laboratory tests. The IEM can be made into many forms, such as thin films, coatings, pellets, and fibers. As a result, it can be adapted to many applications to purify contaminated water wherever it is found, be it in waste water treatment systems, lakes, ponds, industrial plants, or in homes. Laboratory tests have been conducted on aqueous solutions containing only one of the following metal cations: lead, copper, mercury, cadmium, silver, chromium (III), nickel, zinc, and yttrium. Tests were also conducted with: (1) calcium present to determine its effects on the uptake of cadmium and copper, and (2) uranium and lanthanides which are stand-ins for other radioactive elements, (3) drinking water for the removal of copper and lead, and (3) others compositions. The results revealed that the IEM removes all these cations, even in the presence of the calcium. Of particular interest are the results of the tests with the drinking water: the lead concentration was reduced from 142 ppb down to 2.8 ppb (well below the accepted EPA standard).

  2. Ion exchange system design for removal of heavy metals from acid mine drainage wastewater

    Directory of Open Access Journals (Sweden)

    R. S. Sapkal

    2010-11-01

    Full Text Available This paper discusses the methodology used to determine the optimal ion-exchange column size to process all separate batchesof feeds from acid mine drainage wastewater.The optimal design ensures the best utilization of resin material and therefore results in a minimum amount of spent resins.Ion exchanger materials have been studied for removing heavy metals from a metal bearing wastes. For the current treatment,a facility has been designed for the removal of heavy metals from the acid mine drainage (AMD waste by the ion-exchange technology.

  3. Ion exchange system design for removal of heavy metals from acid mine drainage wastewater

    OpenAIRE

    Sapkal, R. S.; Sapkal, V. S.; Gaikwad, R. W.

    2010-01-01

    This paper discusses the methodology used to determine the optimal ion-exchange column size to process all separate batchesof feeds from acid mine drainage wastewater.The optimal design ensures the best utilization of resin material and therefore results in a minimum amount of spent resins.Ion exchanger materials have been studied for removing heavy metals from a metal bearing wastes. For the current treatment,a facility has been designed for the removal of heavy metals from the acid mine dra...

  4. Silica coated magnetite nanoparticles for removal of heavy metal ions from polluted waters

    CERN Document Server

    Dash, Monika

    2013-01-01

    Magnetic removal of Hg2+ and other heavy metal ions like Cd2+, Pb2+ etc. using silica coated magnetite particles from polluted waters is a current topic of active research to provide efficient water recycling and long term high quality water. The technique used to study the bonding characteristics of such kind of nanoparticles with the heavy metal ions is a very sensitive hyperfine specroscopy technique called the perturbed angular correlation technique (PAC).

  5. Removal of Heavy Metals from Liquid Laboratory Waste Using Precipitation and Adsorption Methods

    Directory of Open Access Journals (Sweden)

    Nastiti Siswi Indrasti

    2010-04-01

    Full Text Available Liquid laboratory waste (such as residue of Chemical Oxygen Demand/COD analysis contains high concentration of heavy metals (mercury/Hg, silver/Ag and chrome/Cr and has a high potential to pollute the environment. The liquid waste generated by laboratories is generally in small quantity, but it is extremely toxic. It is urgently in need to find out an appropriate method to reduce the problems according to the liquid waste characteristics. In this research work, precipitation and adsorption methods were evaluated to remove Hg, Ag and Cr from liquid laboratory waste, covering determination of optimum process conditions, levels of removal and achievable treated waste quality. Results showed that a Cr removal of 97% was obtained by pH 10, and Hg and Ag removals of 97-99% were reached by pH 12. Although heavy metals removals using precipitation was very significant, but the concentration of heavy metals in the treated waste was still high (0.73-2.62 mg/L and need for further treatment. Applying activated carbon adsorption for further treatment of the effluent reduced dissolved heavy metals to 0-0.05 mg/L, depending on the type of heavy metals as well as the type and dosing of activated carbon.

  6. Microbial biomass: an economical alternative for removal of heavy metals from waste water.

    Science.gov (United States)

    Gupta, Rani; Mohapatra, Harapriya

    2003-09-01

    Today indiscriminate and uncontrolled discharge of metal contaminated industrial effluents into the environment has become an issue of major concern. Heavy metals, being non-biodegradable and persistent, beyond a permissible concentration form unspecific compounds inside the cells thereby causing cellular toxicity. The only alternative to remove them from the wastewater is by immobilizing them. The conventional methods adopted earlier for this purpose included chemical precipitation, oxidation, reduction, filtration, electrochemical treatment, evaporation, adsorption and ion-exchange resins. These methods require high energy inputs especially when it refers to dilute solutions. Here microbial biomass offers an economical option for removing heavy metals by the phenomenon of biosorption. Non-living or dead biomass sequester metal(s) on their cell surface due to certain reactive groups available like carboxyl, amine, imidazole, phosphate, sulphydryl, sulfate and hydroxyl. The process can be made economical by procuring spent biomass from industry or naturally available bulk biomass. A batch or a continuous process of removal of heavy metals directly from effluents can be developed in a fixed bed reactor using the immobilized biomass. Further biosorption potential of the biomass can be improved by various physical and chemical treatments. The availability of variety of microbial biomass and their metal binding potential makes it a economical and sustainable option for developing effluent treatment process for removal and recovery of heavy metals. PMID:15242288

  7. Comparison of filter media materials for heavy metal removal from urban stormwater runoff using biofiltration systems.

    Science.gov (United States)

    Lim, H S; Lim, W; Hu, J Y; Ziegler, A; Ong, S L

    2015-01-01

    The filter media in biofiltration systems play an important role in removing potentially harmful pollutants from urban stormwater runoff. This study compares the heavy metal removal potential (Cu, Zn, Cd, Pb) of five materials (potting soil, compost, coconut coir, sludge and a commercial mix) using laboratory columns. Total/dissolved organic carbon (TOC/DOC) was also analysed because some of the test materials had high carbon content which affects heavy metal uptake/release. Potting soil and the commercial mix offered the best metal uptake when dosed with low (Cu: 44.78 ?g/L, Zn: 436.4 ?g/L, Cd, 1.82 ?g/L, Pb: 51.32 ?g/L) and high concentrations of heavy metals (Cu: 241 ?g/L, Zn: 1127 ?g/L, Cd: 4.57 ?g/L, Pb: 90.25 ?g/L). Compost and sludge also had high removal efficiencies (>90%). Heavy metal leaching from these materials was negligible. A one-month dry period between dosing experiments did not affect metal removal efficiencies. TOC concentrations from all materials increased after the dry period. Heavy metal removal was not affected by filter media depth (600 mm vs. 300 mm). Heavy metals tended to accumulate at the upper 5 cm of the filter media although potting soil showed bottom-enriched concentrations. We recommend using potting soil as the principal media mixed with compost or sludge since these materials perform well and are readily available. The use of renewable materials commonly found in Singapore supports a sustainable approach to urban water management. PMID:25261749

  8. Investigation of the removal of heavy metals from sediments using rhamnolipid in a continuous flow configuration.

    Science.gov (United States)

    Dahrazma, Behnaz; Mulligan, Catherine N

    2007-10-01

    Heavy metal contamination of sediments is hazardous to benthic organisms and needs more attention in order to prevent entry of these heavy metals into the food chain. Biosurfactants have shown the capability to remove heavy metals from soils and sediments. The objective of this research was to evaluate the performance of rhamnolipid, a glycolipid biosurfactant, in a continuous flow configuration (CFC) for removal of heavy metals (copper, zinc, and nickel) from the sediments taken from Lachine Canal, Canada, to simulate a flow through remediation technique. In this configuration, rhamnolipid solution with a constant rate was passed through the sediment sample within a column. Important parameters such as the concentration of rhamnolipid and the additives, time and the flow rate were investigated. The removal of heavy metals from sediments was up to 37% of Cu, 13% of Zn, and 27% of Ni when rhamnolipid without additives was applied. Adding 1% NaOH to 0.5% rhamnolipid improved the removal of copper by up to 4 times compared with 0.5% rhamnolipid alone. This information is valuable for designing a remediation protocol for sediment washing. PMID:17604818

  9. The removal of heavy metals in urban runoff by sorption on mulch

    International Nuclear Information System (INIS)

    A series of adsorption experiments was conducted in order to assess the ability of three mulches to remove several of the heavy metal ions typically encountered in urban runoff. Three types of mulch, cypress bark (C), hardwood bark (H), and pine bark nugget (P), were selected as potential sorbents to capture heavy metals in urban runoff. The hardwood bark (H) mulch had the best physicochemical properties for adsorption of heavy metal ions. In addition, because of its fast removal rate and acceptably high capacity for all the heavy metal ions, it was concluded that the H mulch is the best of the three adsorbents for treatment of urban runoff containing trace amounts of heavy metals. In order to investigate the sorption isotherm, two equilibrium models, the Freundlich and Langmuir isotherms, were analyzed. The sorption of these metals on H mulch conformed to the linear form of the Langmuir adsorption equation. At pH 5 and 6, the Langmuir constants (Sm) for each metal were found to be 0.324 and 0.359 mmol/g (Cu); 0.306 and 0.350 mmol/g (Pb); and 0.185 and 0.187 mmol/g (Zn) at 25 deg. C. - Capsule: Hardwood bark had the best physicochemical properties for adsorption of metal ions

  10. Method for removal of heavy metal from molten salt in IFR fuel pyroprocessing

    International Nuclear Information System (INIS)

    This report details the pyrometallurgical process for recycling spent metal fuels from the Integral Fast Reactor (IFR) which involves electrorefining spent fuel in a molten salt electrolyte (LiCl-KCI-U/PuCl3) at 500 degree C. The total heavy metal chloride concentration in the salt will be about 2 mol %. At some point, the concentrations of alkali, alkaline earth, and rare earth fission products in the salt must be reduced to lower the amount of heat generated in the electrorefiner. The heavy metal concentration in the salt must be reduced before removing the fission products from the salt. The operation uses a lithium-cadmium alloy anode that is solid at 500 degree C, a solid mandrel cathode with a ceramic catch crucible below to collect heavy metal that falls off it, and a liquid cadmium cathode. The design criteria that had to be met by this equipment included the following: (1) control of the reduction rate by lithium, (2) good separation between heavy metal and rare earths, and (3) the capability to collect heavy metal and rare earths over a wide range of salt compositions. In tests conducted in an engineering-scale electrorefiner (10 kg uranium per cathode), good separation was achieved while removing uranium and rare earths from the salt. Only 13% of the rare earths was removed, while 99.9% of the uranium in the salt was removed; subsequently, the rare earths were also reduced to low concentrations. The uranium concentration in the salt was reduced to 0.05 ppm after uranium and rare earths were transferred from the salt to a solid mandrel cathode with a catch crucible. Rare earth concentrations in the salt were reduced to less than 0.01 wt % in these operations. Similar tests are planned to remove plutonium from the salt in a laboratory-scale (100--300 g heavy metal) electrorefiner

  11. Heavy metal ions affecting the removal of polycyclic aromatic hydrocarbons by fungi with heavy-metal resistance.

    Science.gov (United States)

    Ma, Xiao-Kui; Ling Wu, Ling; Fam, Hala

    2014-12-01

    The co-occurrence of polycyclic aromatic hydrocarbons (PAHs) and heavy metals (HMs) is very common in contaminated environments. It is of paramount importance and great challenge to exploit a bioremediation to remove PAHs in these environments with combined pollution. We approached this question by probing the influence of HMs coexisting with PAHs on the removal of PAHs by Acremonium sp. P0997 possessing metal resistance. A removal capability for naphthalene, fluorene, phenanthrene, anthracene, and fluoranthenepresentalone (98.6, 99.3, 89.9, 60.4, and 70 %, respectively) and in a mixture (96.9, 71.8, 67.0, 85.0, and 87.9 %, respectively) was achieved in mineral culture inoculated with Acremonium sp. P0997, and this strain also displayed high resistance to the individual HMs (Mn(2+), Fe(2+), Zn(2+), Cu(2+), Al(3+), and Pb(2+)). The removal of individual PAHs existing in a mixture was differently affected by the separately tested HMs. Cu(2+)enhanced the partition process of anthracene to dead or alive mycelia and the contribution of the biosorption by this strain but imposed a little negative influence on the contribution of biodegradation to the total removal of anthracene individually in a culture. However, Mn(2+) had an inhibitory effect on the partition process of anthracene to dead or alive mycelia and decreased the contributions of both biosorption and biodegradation to the total anthracene removal. This work showcased the value of fungi in bioremediation for the environments with combined pollution, and the findings have major implications for the bioremediation of organic pollutants in metal-organic mixed contaminated sites. PMID:25077776

  12. Literature review on the use of bioaccumulation for heavy metal removal and recovery. Volume 2

    Energy Technology Data Exchange (ETDEWEB)

    Benemann, J.R. [Benemann (J.R.), Pinole, CA (United States); Wilde, E.W. [Westinghouse Savannah River Co., Aiken, SC (United States)

    1991-02-01

    Bioaccumulation of metals by microbes -- `` bioremoval`` -- is a powerful new technology for the concentration, recovery, and removal of toxic heavy metals and radionuclides from waste streams and contaminated environments. Algae are particularly well suited for metal bioremoval. A recent commercial application of bioremoval utilizes inert (dead) immobilized microalgae biomass as ion exchange materials for the removal of heavy metals from industrial waste waters. Also, living microalgal cultures have been used to remove metals from mine effluents. Microbial cells and biomass can bioaccumulate metals and radionuclides by a large variety of mechanisms, both dependent and independent of cell metabolism. Microbial cell walls can act as ion exchange and metal complexation agents. Heavy metals can precipitate and even crystallize on cell surfaces. Metabolically produced hydrogen sulfide or other metabolic products can bioprecipitate heavy metals. Many microbes produce both intra- and extracellular metal complexing agents which could be considered in practical metal removal processes. Bioremoval processes are greatly affected by the microbial species and even strain used, pH, redox potential, temperature, and other conditions under which the microbes are grown. Development of practical applications of bioremoval requires applies research using the particular waste solutions to be treated, or close simulations thereof. From a practical perspective, the selection of the microbial biomass and the process for contacting the microbial biomass with the metal containing solutions are the key issues. Much of the recent commercial R&D has emphasized commercially available, inert, microbial biomass sources as these can be acquired in sufficient quantities at affordable costs. The fundamental research and practical applications of bioaccumulation by microalgae suggests these organisms warrant a high priority in the development of advanced bioremoval processes.

  13. Literature review on the use of bioaccumulation for heavy metal removal and recovery

    Energy Technology Data Exchange (ETDEWEB)

    Benemann, J.R. (Benemann (J.R.), Pinole, CA (United States)); Wilde, E.W. (Westinghouse Savannah River Co., Aiken, SC (United States))

    1991-02-01

    Bioaccumulation of metals by microbes -- bioremoval'' -- is a powerful new technology for the concentration, recovery, and removal of toxic heavy metals and radionuclides from waste streams and contaminated environments. Algae are particularly well suited for metal bioremoval. A recent commercial application of bioremoval utilizes inert (dead) immobilized microalgae biomass as ion exchange materials for the removal of heavy metals from industrial waste waters. Also, living microalgal cultures have been used to remove metals from mine effluents. Microbial cells and biomass can bioaccumulate metals and radionuclides by a large variety of mechanisms, both dependent and independent of cell metabolism. Microbial cell walls can act as ion exchange and metal complexation agents. Heavy metals can precipitate and even crystallize on cell surfaces. Metabolically produced hydrogen sulfide or other metabolic products can bioprecipitate heavy metals. Many microbes produce both intra- and extracellular metal complexing agents which could be considered in practical metal removal processes. Bioremoval processes are greatly affected by the microbial species and even strain used, pH, redox potential, temperature, and other conditions under which the microbes are grown. Development of practical applications of bioremoval requires applies research using the particular waste solutions to be treated, or close simulations thereof. From a practical perspective, the selection of the microbial biomass and the process for contacting the microbial biomass with the metal containing solutions are the key issues. Much of the recent commercial R D has emphasized commercially available, inert, microbial biomass sources as these can be acquired in sufficient quantities at affordable costs. The fundamental research and practical applications of bioaccumulation by microalgae suggests these organisms warrant a high priority in the development of advanced bioremoval processes.

  14. Literature review on the use of bioaccumulation for heavy metal removal and recovery

    International Nuclear Information System (INIS)

    Bioaccumulation of metals by microbes -- '' bioremoval'' -- is a powerful new technology for the concentration, recovery, and removal of toxic heavy metals and radionuclides from waste streams and contaminated environments. Algae are particularly well suited for metal bioremoval. A recent commercial application of bioremoval utilizes inert (dead) immobilized microalgae biomass as ion exchange materials for the removal of heavy metals from industrial waste waters. Also, living microalgal cultures have been used to remove metals from mine effluents. Microbial cells and biomass can bioaccumulate metals and radionuclides by a large variety of mechanisms, both dependent and independent of cell metabolism. Microbial cell walls can act as ion exchange and metal complexation agents. Heavy metals can precipitate and even crystallize on cell surfaces. Metabolically produced hydrogen sulfide or other metabolic products can bioprecipitate heavy metals. Many microbes produce both intra- and extracellular metal complexing agents which could be considered in practical metal removal processes. Bioremoval processes are greatly affected by the microbial species and even strain used, pH, redox potential, temperature, and other conditions under which the microbes are grown. Development of practical applications of bioremoval requires applies research using the particular waste solutions to be treated, or close simulations thereof. From a practical perspective, the selection of the microbial biomass and the process for contacting the microbial biomass with the metal containing solutions are the key issues. Much of the recent commercial R ampersand D has emphasized commercially available, inert, microbial biomass sources as these can be acquired in sufficient quantities at affordable costs. The fundamental research and practical applications of bioaccumulation by microalgae suggests these organisms warrant a high priority in the development of advanced bioremoval processes

  15. Microbial and plant derived biomass for removal of heavy metals from wastewater.

    Science.gov (United States)

    Ahluwalia, Sarabjeet Singh; Goyal, Dinesh

    2007-09-01

    Discharge of heavy metals from metal processing industries is known to have adverse effects on the environment. Conventional treatment technologies for removal of heavy metals from aqueous solution are not economical and generate huge quantity of toxic chemical sludge. Biosorption of heavy metals by metabolically inactive non-living biomass of microbial or plant origin is an innovative and alternative technology for removal of these pollutants from aqueous solution. Due to unique chemical composition biomass sequesters metal ions by forming metal complexes from solution and obviates the necessity to maintain special growth-supporting conditions. Biomass of Aspergillus niger, Penicillium chrysogenum, Rhizopus nigricans, Ascophyllum nodosum, Sargassum natans, Chlorella fusca, Oscillatoria anguistissima, Bacillus firmus and Streptomyces sp. have highest metal adsorption capacities ranging from 5 to 641 mg g(-1) mainly for Pb, Zn, Cd, Cr, Cu and Ni. Biomass generated as a by-product of fermentative processes offers great potential for adopting an economical metal-recovery system. The purpose of this paper is to review the available information on various attributes of utilization of microbial and plant derived biomass and explores the possibility of exploiting them for heavy metal remediation. PMID:16427277

  16. The removal of heavy metals in urban runoff by sorption on mulch.

    Science.gov (United States)

    Jang, Am; Seo, Youngwoo; Bishop, Paul L

    2005-01-01

    A series of adsorption experiments was conducted in order to assess the ability of three mulches to remove several of the heavy metal ions typically encountered in urban runoff. Three types of mulch, cypress bark (C), hardwood bark (H), and pine bark nugget (P), were selected as potential sorbents to capture heavy metals in urban runoff. The hardwood bark (H) mulch had the best physicochemical properties for adsorption of heavy metal ions. In addition, because of its fast removal rate and acceptably high capacity for all the heavy metal ions, it was concluded that the H mulch is the best of the three adsorbents for treatment of urban runoff containing trace amounts of heavy metals. In order to investigate the sorption isotherm, two equilibrium models, the Freundlich and Langmuir isotherms, were analyzed. The sorption of these metals on H mulch conformed to the linear form of the Langmuir adsorption equation. At pH 5 and 6, the Langmuir constants (S(m)) for each metal were found to be 0.324 and 0.359 mmol/g (Cu); 0.306 and 0.350 mmol/g (Pb); and 0.185 and 0.187 mmol/g (Zn) at 25 degrees C. PMID:15327862

  17. Toxicity, accumulation, and removal of heavy metals by three aquatic macrophytes.

    Science.gov (United States)

    Basile, A; Sorbo, S; Conte, B; Cobianchi, R Castaldo; Trinchella, F; Capasso, C; Carginale, V

    2012-04-01

    A comprehensive understanding of the uptake, tolerance, and transport of heavy metals by plants will be essential for the development of phytoremediation technologies. In the present paper, we investigated accumulation, tissue and intracellular localization, and toxic effects of cadmium (Cd), lead (Pb), zinc (Zn), and copper (Cu) in three aquatic macrophytes (the angiosperms Lemna minor and Elodea canadensis, and the moss Leptodictyum riparium). We also tested and compared their capacity to absorb heavy metal from water under laboratory conditions. Our data showed that all the three species examined could be considered good bioaccumulators for the heavy metals tested. L. riparium was the most resistant species and the most effective in accumulating Cu, Zn, and Pb, whereas L. minor was the most effective in accumulating Cd. Cd was the most toxic metal, followed by Pb, Cu, and Zn. At the ultrastructural level, sublethal concentrations of the heavy metals tested caused induced cell plasmolysis and alterations of the chloroplast arrangement. Heavy metal removal experiments revealed that the three macrophytes showed excellent performance in removing the selected metals from the solutions in which they are maintained, thus suggesting that they could be considered good candidates for wastewaters remediation purpose. PMID:22567718

  18. Performance evaluation of intermediate cover soil barrier for removal of heavy metals in landfill leachate.

    Science.gov (United States)

    Suzuki, Kazuyuki; Anegawa, Aya; Endo, Kazuto; Yamada, Masato; Ono, Yusaku; Ono, Yoshiro

    2008-11-01

    This pilot-scale study evaluated the use of intermediate cover soil barriers for removing heavy metals in leachate generated from test cells for co-disposed fly ash from municipal solid waste incinerators, ash melting plants, and shredder residue. Cover soil barriers were mixtures of Andisol (volcanic ash soil), waste iron powder, (grinder dust waste from iron foundries), and slag fragments. The cover soil barriers were installed in the test cells' bottom layer. Sorption/desorption is an important process in cover soil bottom barrier for removal of heavy metals in landfill leachate. Salt concentrations such as those of Na, K, and Ca in leachate were extremely high (often greater than 30 gL(-1)) because of high salt content in fly ash from ash melting plants. Concentrations of all heavy metals (nickel, manganese, copper, zinc, lead, and cadmium) in test cell leachates with a cover soil barrier were lower than those of the test cell without a cover soil barrier and were mostly below the discharge limit, probably because of dilution caused by the amount of leachate and heavy metal removal by the cover soil barrier. The cover soil barriers' heavy metal removal efficiency was calculated. About 50% of copper, nickel, and manganese were removed. About 20% of the zinc and boron were removed, but lead and cadmium were removed only slightly. Based on results of calculation of the Langelier saturation index and analyses of core samples, the reactivity of the cover soil barrier apparently decreases because of calcium carbonate precipitation on the cover soil barriers' surfaces. PMID:18842283

  19. Parameters for removal of toxic heavy metals by water milfoil (Myriophyllum spicatum)

    Energy Technology Data Exchange (ETDEWEB)

    Wang, T.C.; Ramesh, G. [Harbor Branch Oceanographic Institution, Ft. Pierce, FL (United States); Weissman, J.C.; Varadarajan, R. [Microbial Products, Inc., Vero Beach, FL (United States)] [and others

    1996-12-31

    Due to the increasing awareness of toxic heavy metals contamination to the environment, studies of metal accumulation from the view point of metal removal from contaminated water have been performed. Conventional methods including precipitation, oxidation, reduction, ion exchange, filtration, electrochemical treatment, membrane technologies and evaporation recovery are expensive or ineffective, especially when the metal concentrations are very low in the order of 1 to 100 mg/L. The use of biological systems for removing metals from low metal solution has the potential to achieve greater performance at lower cost. Water milfoil, a rooted aquatic higher plants, has been identified as a potential plant for bioremoval process. The goal of this study was to determine the range of metal adsorptive capabilities by water milfoil under different pH conditions. Five metals, cadmium, zinc, nickel, lead and copper, were used. 9 refs., 4 figs., 2 tabs.

  20. The use of biosorbents for heavy metals removal from aqueous media

    International Nuclear Information System (INIS)

    Biomaterials, which could be adsorbed heavy metals, such bacteria, algae, yeasts, fungi and agricultural waste, is called Biomass. Recently, they are widely used for heavy metal removal from aqueous media, due to their large available quantities, low cost and good performance. The biosorbent, unlike mono functional ion exchange resins, contains variety of functional sites including carboxyl, imidazole, sulphydryl, amino, phosphate, sulfate, thioether, phenol, carbonyl, amide and hydroxyl moieties. In this paper, the biosorbents word widely and nationally used for heavy metal removal were reviewed. Their biosorption performance, their pretreatment and modification, aiming to improve their sorption capacity, and regeneration/reuse was introduced and evaluated. The potential application of biosorption and biosorbents was discussed. (author)

  1. Comparison of Amberlite IR 120 and dolomite's performances for removal of heavy metals

    International Nuclear Information System (INIS)

    The presence of heavy metals in the environment is major concern due to their toxicity. Contamination of heavy metals in water supplies has steadily increased over the last years as a result of over population and expansion of industrial activities. A strong cation-exchange resin, Amberlite IR 120 and a natural zeolite, dolomite were used for the removal of lead(II) and cadmium(II). The optimum conditions were determined in a batch system as concentration range was between 5 and 100 mg/L, pH range between 1 and 8, contact time between 5 and 90 min, and the amount of adsorbent was from 0.1 to 1 g. A constant stirring speed, 2000 rpm, was chosen during all of the experiments. The optimum conditions were found to be a concentration of 20 mg/L, pH of 5, contact time of 60 min and 0.5 g of adsorbent. Also, for investigation of exchange equilibria different amounts of ion exchange resin and dolomite were contacted with a fixed volume and concentration of a heavy metal bearing solutions. Sorption data have been interpreted in terms of Langmuir and Freundlich equations. The effect of adsorption temperature on the heavy metals adsorption onto dolomite was investigated at three different temperatures (20, 40 and 60 deg. C). Thermodynamic parameters were calculated. The results obtained show that the Amberlite IR 120 strong cation-exchange resin and dolomite performed well for the removal of these heavy metals. As a low cost adsorbent, dolomite can preferable for removal of heavolomite can preferable for removal of heavy metals from wastewaters

  2. Removal of heavy metals from fly ash leachate using combined bioelectrochemical systems and electrolysis

    International Nuclear Information System (INIS)

    Highlights: • Heavy metals removal from MSWI fly ash with BES and electrolysis was confirmed. • 98.5% of Cu(II), 95.4% of Zn(II) and 98.1% of Pb(II) removal were achieved in reactors. • BESs can remove some heavy metals in fly ash with energy saving. -- Abstract: Based on environmental and energetic analysis, a novel combined approach using bioelectrochemical systems (BES) followed by electrolysis reactors (ER) was tested for heavy metals removal from fly ash leachate, which contained high detectable levels of Zn, Pb and Cu according to X-ray diffraction analysis. Acetic acid was used as the fly ash leaching agent and tested under various leaching conditions. A favorable condition for the leaching process was identified to be liquid/solid ratio of 14:1 (w/w) and leaching duration 10 h at initial pH 1.0. It was confirmed that the removal of heavy metals from fly ash leachate with the combination of BESs and ER is feasible. The metal removal efficiency was achieved at 98.5%, 95.4% and 98.1% for Cu(II), Zn(II), and Pb(II), respectively. Results of scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDS) indicated that Cu(II) was reduced and recovered mainly as metal Cu on cathodes related to power production, while Zn(II) and Pb(II) were not spontaneously reduced in BESs without applied voltage and basically electrolyzed in the electrolysis reactors

  3. Removal of heavy metals from fly ash leachate using combined bioelectrochemical systems and electrolysis

    Energy Technology Data Exchange (ETDEWEB)

    Tao, Hu-Chun, E-mail: taohc@pkusz.edu.cn [Key Laboratory for Heavy Metal Pollution Control and Reutilization, School of Environment and Energy, Peking University Shenzhen Graduate School, Shenzhen 518055 (China); Lei, Tao; Shi, Gang; Sun, Xiao-Nan; Wei, Xue-Yan; Zhang, Li-Juan [Key Laboratory for Heavy Metal Pollution Control and Reutilization, School of Environment and Energy, Peking University Shenzhen Graduate School, Shenzhen 518055 (China); Wu, Wei-Min [Department of Civil and Environmental Engineering, Center for Sustainable Development and Global Competitiveness, Stanford University, Stanford, CA 94305-4020 (United States)

    2014-01-15

    Highlights: • Heavy metals removal from MSWI fly ash with BES and electrolysis was confirmed. • 98.5% of Cu(II), 95.4% of Zn(II) and 98.1% of Pb(II) removal were achieved in reactors. • BESs can remove some heavy metals in fly ash with energy saving. -- Abstract: Based on environmental and energetic analysis, a novel combined approach using bioelectrochemical systems (BES) followed by electrolysis reactors (ER) was tested for heavy metals removal from fly ash leachate, which contained high detectable levels of Zn, Pb and Cu according to X-ray diffraction analysis. Acetic acid was used as the fly ash leaching agent and tested under various leaching conditions. A favorable condition for the leaching process was identified to be liquid/solid ratio of 14:1 (w/w) and leaching duration 10 h at initial pH 1.0. It was confirmed that the removal of heavy metals from fly ash leachate with the combination of BESs and ER is feasible. The metal removal efficiency was achieved at 98.5%, 95.4% and 98.1% for Cu(II), Zn(II), and Pb(II), respectively. Results of scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDS) indicated that Cu(II) was reduced and recovered mainly as metal Cu on cathodes related to power production, while Zn(II) and Pb(II) were not spontaneously reduced in BESs without applied voltage and basically electrolyzed in the electrolysis reactors.

  4. Study on the Heavy Metals Removal Efficiencies of Constructed Wetlands with Different Substrates

    OpenAIRE

    Yu, Zhaoxiang; Li, Xianpo; Tang, Yingying; Chen, Mengzhi

    2009-01-01

    In this study constructed wetlands (CWs) were used to remove three heavy metals (Zn, Cu and Pb). The two tested substrates were made of coke and gravel, respectively. First order dynamic model was appropriate to describe removing of Zn and Cu. The experimental results showed that first dynamic removal rate constants of Zn in CWs with coke and gravel were 0.2326 h-1 and 0.1222 h-1, respectively. And those of Cu in CWs with coke and gravel were 0.2017 h-1 and 0.3739 h-1. However, removal effici...

  5. Removal of heavy metals from wastewaters by cellulose xanthate chelating exchangers

    International Nuclear Information System (INIS)

    The synthesis of the cellulose xanthate for metal removal has been carried out under conditions different from those currently adopted in the rayon industry. Cheap, stable and water insoluble materials suitable for removing heavy metals from industrial wastewaters have been obtained. The products in sodium and magnesium forms were tested with synthetic and industrial wastewaters containing Cu, Hg, Ag and Cd either in batch or in column operations. Results showed that the cellulose xanthate, in stable at room temperature for at least 1 year; it has a removal capacity of about 0.8 mmol of metal/g and a sparingly water solubility (10%). It can also be used in column operation as ''polishing'' according to its swelling and mechanical properties. The exhausted materials after metal uptake can be successfully post-treated either thermally or by chemical oxidation with sodium hydro chlorite for metals recovery and reuse. (author). 22 refs, 3 figs, 5 tabs

  6. Sorptive removal of technetium from alkaline heavy metals sludge filtrate containing nitrate ion

    International Nuclear Information System (INIS)

    A so-called raffinate waste stream is generated from various uranium recovery and equipment cleaning and decontamination activities at the X-705 facility of the Portsmouth (Ohio) Gaseous Diffusion Plant (PORTS). The day-to-day composition of this waste stream may be variable, but it is generally characterized by high concentrations of nitric acid, toxic heavy metals, and low levels of radioactive nuclides (235U, 99Tc). Some laboratory analysis results for a subsample of typical raffinate from PORTS are given. This paper also lists some regulatory water standards for comparison purposes (note that different standards may be applicable, depending on jurisdiction and intended water usage). Current treatment protocol for the raffinate stream consists of the following: first, dilution and pH adjustment (to a value of about 8.5) to precipitate the hydrolyzable heavy metals; then, filtration to remove the heavy metals sludge (HMS); next, processing of the filtrate with a strong-base anion exchange resin to remove the soluble pertechnetate (TcO4-) ion; next, biodenitrification; and last, sewage disposal. The effectiveness of the heavy metals precipitation unit operation is illustrated; most heavy metals (including uranium) are reduced from very high concentrations in the raffinate to levels in the HMS filtrate which are below regulatory concern

  7. Study on the Heavy Metals Removal Efficiencies of Constructed Wetlands with Different Substrates

    Directory of Open Access Journals (Sweden)

    Zhaoxiang YU

    2009-05-01

    Full Text Available In this study constructed wetlands (CWs were used to remove three heavy metals (Zn, Cu and Pb. The two tested substrates were made of coke and gravel, respectively. First order dynamic model was appropriate to describe removing of Zn and Cu. The experimental results showed that first dynamic removal rate constants of Zn in CWs with coke and gravel were 0.2326 h-1 and 0.1222 h-1, respectively. And those of Cu in CWs with coke and gravel were 0.2017 h-1 and 0.3739 h-1. However, removal efficiencies of Pb in the coke system and the gravel system were within 95-99%, so the first order dynamic model failed to fit the experimental data because the hydraulic resident times of Pb did not affect outlet concentration of Pb. From the removal rate constants, it is found that the coke and gravel system have different absorption efficiencies of heavy metal pollutants. Therefore, it is suggested that the removal efficiencies of heavy metals are influenced by the choice of substrates to some extent.

  8. Equilibrium analysis for heavy metal cation removal using cement kiln dust.

    Science.gov (United States)

    El Zayat, Mohamed; Elagroudy, Sherien; El Haggar, Salah

    2014-01-01

    Ion exchange, reverse osmosis, and chemical precipitation have been investigated extensively for heavy metal uptake. However, they are deemed too expensive to meet stringent effluent characteristics. In this study, cement kiln dust (CKD) was examined for the removal of target heavy metals. Adsorption studies in completely mixed batch reactors were used to generate equilibrium pH adsorption edges. Studies showed the ability of CKD to remove the target heavy metals in a pH range below that of precipitation after an equilibrium reaction time of 24 h. A surface titration experiment indicated negative surface charge of the CKD at pH below 10, meaning that electrostatic attraction of the divalent metals can occur below the pH required for precipitation. However, surface complexation was also important due to the substantive metal removal. Accordingly, a surface complexation model approach that utilizes an electrostatic term in the double-layer description was used to estimate equilibrium constants for the protolysis interactions of the CKD surface as well as equilibria between background ions and the sorbent surface. It was concluded that the removal strength of adsorption is in the order: Pb > Cu > Cd. The experiments were also supported by Fourier transform infrared spectroscopy (FTIR). PMID:25259489

  9. Biological removal and recovery of trace heavy metals

    Energy Technology Data Exchange (ETDEWEB)

    Hatch, R.T.; Menawat, A.

    1978-01-01

    Sphaerotilus natans have been shown to insolubilize a number of metal sulfates including iron, magnesium, copper, cobalt, and cadmium. The metal precipitates in the form of a finely divided deposit outside the cell surface. The insolubilization process continues according to first-order reaction kinetics at mineral concentrations below 1 ppM and results in the production of less than 0.1 g cell mass/g metal insolubilized. Analysis of the data indicates that the insolubilization process is mass transfer limited. 10 figures, 2 tables.

  10. Removal of Some Heavy Metals from Wastewater using Radiation- Adsorption Method

    International Nuclear Information System (INIS)

    Wastewater containing toxic materials poses a serious environmental problem. Many of the pollutants are not readily biodegradable and complete removal in many cases is a relatively expensive process. On the other hand, incomplete removal is a serious health hazard. In the present study, a try was made to explain the degradation kinetics due to gamma-irradiation and adsorption of some heavy metals: Uranium, Molybdenum, Zirconium, and Vanadium. Factors affecting the process such as concentration, irradiation dose and ph of the solution was studied. Gamma-radiation doses up to 50 kGy did not result in the degradation of the heavy metals. However, as expected gamma radiation resulted in a change in the valency of these heavy metal ions to other oxidation states which may have resulted in less toxicity. Adsorption and ion-exchange purification of the heavy metals onto GAC,Merck Ion Exchangers I, and IV and polymeric membranes showed that GAC has the highest adsorption capacity for all pollutants compared with the ion-exchangers and polymeric membranes which may be due to its very high surface area and high porous nature which causes internal and external distribution within the carbon particle more than it dose in the case of polymeric membranes and ion-exchangers. GAC was followed by the cation exchanger with different percent adsorption according to the type of pollutant and the least removal percent was shown by the polymeric membranes. Also, a study of the affinity of the pollutants towards the different adsorbents was carried out

  11. Natural Jordanian zeolite: removal of heavy metal ions from water samples using column and batch methods.

    Science.gov (United States)

    Baker, Hutaf M; Massadeh, Adnan M; Younes, Hammad A

    2009-10-01

    The adsorption behavior of natural Jordanian zeolites with respect to Cd(2 + ), Cu(2 + ), Pb(2 + ), and Zn(2 + ) was studied in order to consider its application to purity metal finishing drinking and waste water samples under different conditions such as zeolite particle size, ionic strength and initial metal ion concentration. In the present work, a new method was developed to remove the heavy metal by using a glass column as the one that used in column chromatography and to make a comparative between the batch experiment and column experiment by using natural Jordanian zeolite as adsorbent and some heavy metals as adsorbate. The column method was used using different metal ions concentrations ranged from 5 to 20 mg/L with average particle size of zeolite ranged between 90 and 350 mum, and ionic strength ranged from 0.01 to 0.05. Atomic absorption spectrometry was used for analysis of these heavy metal ions, the results obtained in this study indicated that zeolitic tuff is an efficient ion exchanger for removing heavy metals, in particular the fine particle sizes of zeolite at pH 6, whereas, no clear effect of low ionic strength values is noticed on the removal process. Equilibrium modeling of the removal showed that the adsorption of Cd(2 + ), Cu(2 + ), Pb(2 + ), and Zn(2 + ) were fitted to Langmuir, Freundlich and Dubinin-Kaganer-Radushkevich (DKR). The sorption energy E determined in the DKR equation (9.129, 10.000, 10.541, and 11.180 kJ/mol for Zn(2 + ), Cu(2 + ), Cd(2 + ) and Pb(2 + ) respectively) which revealed the nature of the ion-exchange mechanism. PMID:18830802

  12. Method for removing heavy metal and nitrogen oxides from flue gas, device for removing heavy metal and nitrogen oxides from flue gas

    Energy Technology Data Exchange (ETDEWEB)

    Huang, Hann-Sheng; Livengood, Charles David

    1997-12-01

    A method for the simultaneous removal of oxides and heavy metals from a fluid is provided comprising combining the fluid with compounds containing alkali and sulfur to create a mixture; spray drying the mixture to create a vapor phase and a solid phase; and isolating the vapor phase from the solid phase. A device is also provided comprising a means for spray-drying flue gas with alkali-sulfide containing liquor at a temperature sufficient to cause the flue gas to react with the compounds so as to create a gaseous fraction and a solid fraction and a means for directing the gaseous fraction to a fabric filter.

  13. Removal of heavy metals from aqueous solution by biochars derived from anaerobically digested biomass.

    Science.gov (United States)

    Inyang, Mandu; Gao, Bin; Yao, Ying; Xue, Yingwen; Zimmerman, Andrew R; Pullammanappallil, Pratap; Cao, Xinde

    2012-04-01

    This study examined the ability of two biochars converted from anaerobically digested biomass to sorb heavy metals using a range of laboratory sorption and characterization experiments. Initial evaluation of DAWC (digested dairy waste biochar) and DWSBC (digested whole sugar beet biochar) showed that both biochars were effective in removing a mixture of four heavy metals (Pb(2 +), Cu(2+), Ni(2+), and Cd(2+)) from aqueous solutions. Compared to DAWC, DWSBC demonstrated a better ability to remove Ni and Cd. Further investigations of lead sorption by the two biochars indicated that the removal was mainly through a surface precipitation mechanism, which was confirmed by batch sorption experiments, mathematical modeling, and examinations of lead-laden biochars samples using SEM-EDS, XRD, and FTIR. The lead sorption capacity of the two biochars was close to or higher than 200mmol/kg, which is comparable to that of commercial activated carbons. PMID:22325901

  14. Efficiency of lipopeptide biosurfactants in removal of petroleum hydrocarbons and heavy metals from contaminated soil.

    Science.gov (United States)

    Singh, Anil Kumar; Cameotra, Swaranjit Singh

    2013-10-01

    This study describes the potential application of lipopeptide biosurfactants in removal of petroleum hydrocarbons and heavy metals from the soil samples collected from industrial dumping site. High concentrations of heavy metals (like iron, lead, nickel, cadmium, copper, cobalt and zinc) and petroleum hydrocarbons were present in the contaminated soil samples. Lipopeptide biosurfactant, consisting of surfactin and fengycin was obtained from Bacillus subtilis A21. Soil washing with biosurfactant solution removed significant amount of petroleum hydrocarbon (64.5 %) and metals namely cadmium (44.2 %), cobalt (35.4 %), lead (40.3 %), nickel (32.2 %), copper (26.2 %) and zinc (32.07 %). Parameters like surfactant concentration, temperature, agitation condition and pH of the washing solution influenced the pollutant removing ability of biosurfactant mixture. Biosurfactant exhibited substantial hydrocarbon solubility above its critical micelle concentration. During washing, 50 % of biosurfactant was sorbed to the soil particles decreasing effective concentration during washing process. Biosurfactant washed soil exhibited 100 % mustard seed germination contradictory to water washed soil where no germination was observed. The results indicate that the soil washing with mixture of lipopeptide biosurfactants at concentrations above its critical micelle concentration can be an efficient and environment friendly approach for removing pollutants (petroleum hydrocarbon and heavy metals) from contaminated soil. PMID:23681773

  15. Removal of Heavy Metal from Contaminated Soil with Chelating Agents

    OpenAIRE

    Wei Jiang; Tao Tao; Zhi-Ming Liao

    2011-01-01

    Removal of copper and nickel by the addition of the biodegradable chelating agent, chitosan and ethylenediamine tetraacetic acid (EDTA), was investigated, alongside the reaction of a reference compound sodium citrate for comparison. The artificial-contaminated soils were used in this study. The experiments showed that the extraction ability for copper and nickel from the contaminated soil decreased as follows: chitosan > EDTA > sodium citrate. The pH value of the eluents is the key to c...

  16. USING BIOPOLYMERS TO REMOVE HEAVY METALS FROM SOIL AND WATER

    Science.gov (United States)

    Chemical remediation of soils may involve the use of harsh chemicals that generate waste streams and may adversely affect the soil's integrity and ability to support vegetation. his paper reviews the promise of benign reagents such as biopolymers to extract metals. he biopolymers...

  17. Heavy metal ion removal by adsorption on to biological materials

    International Nuclear Information System (INIS)

    The development of regulations constraints in the industrial waste-waters management leads to the study of new treatment processes, using raw or functionalized biological materials. These processes show competitive performances in metal ion sorption efficiency for the low metal content effluents. Uptake capacities of Uranium as high as 400 mg.g-1 chitosan, equivalent to the double of the uptake capacity of fungal origin biomass, can be reached. The application of these processes to real mine wastewaters gives efficiency coefficient upper to 90%, the residual concentrations are compatible to a direct injection into the environment. The grafting of functional groups onto the chitosan scales up the sorption performances to uptake capacity upper than 600 mg.g-1 polymer. pH, metal concentration are cited as major parameters, particle size influences both uptake kinetics and sorption equilibrium, in the case of the uranium accumulation by chitosan. The desorption of uranium from the sorbent allows the valorization of uranium and the re-use of the sorbent. (authors). 21 refs., 10 figs

  18. Removal of heavy metals using different polymer matrixes as support for bacterial immobilisation.

    Science.gov (United States)

    Pires, Carlos; Marques, Ana P G C; Guerreiro, António; Magan, Naresh; Castro, Paula M L

    2011-07-15

    Great attention is focused on the microbial treatment of metal contaminated environments. Three bacterial strains, 1C2, 1ZP4 and EC30, belonging to genera Cupriavidus, Sphingobacterium and Alcaligenes, respectively, showing high tolerance to Zn and Cd, up to concentrations of 1000ppm, were isolated from a contaminated area in Northern Portugal. Their contribution to Zn and Cd removal from aqueous streams using immobilised alginate, pectate and a synthetic cross-linked polymer was assessed. In most cases, matrices with immobilised bacteria showed better metal removal than the non-inoculated material alone. For the immobilisation with all the polymers, 1C2 was the strain that increased the removal of Zn the most, whereas EC30 was the most promising for Cd removal, especially when combined with the synthetic polymer with up to a ca. 11-fold increase in metal removal when compared to the polymer alone. Removal of individual metals from binary mixtures showed that there was differential immobilisation. There was greater removal of Cd than Zn (removals up to 40% higher than those showed for Zn). The results show that metal contaminated environments constitute a reservoir of microorganisms resistant/tolerant to heavy metals that have the capacity to be exploited in bioremediation strategies. Capsule immobilisation of bacteria in the naturally occurring alginate and pectate and in a synthetic cross-linked polymer increased the Zn and Cd removal abilities from single and binary contaminated waters; the applications with the synthetic polymer were the most promising for Cd and Zn removal in single and binary mixtures. PMID:21592655

  19. Preparation and characterisation of biodegradable pollen-chitosan microcapsules and its application in heavy metal removal.

    Science.gov (United States)

    Sarg?n, ?dris; Kaya, Murat; Arslan, Gulsin; Baran, Talat; Ceter, Talip

    2015-02-01

    Biosorbents have been widely used in heavy metal removal. New resources should be exploited to develop more efficient biosorbents. This study reports the preparation of three novel chitosan microcapsules from pollens of three common, wind-pollinated plants (Acer negundo, Cupressus sempervirens and Populus nigra). The microcapsules were characterized (Fourier transform infrared spectroscopy, thermogravimetric analysis, scanning electron microscopy and elemental analysis) and used in removal of heavy metal ions: Cd(II), Cr(III), Cu(II), Ni(II) and Zn(II). Their sorption capacities were compared to those of cross-linked chitosan beads without pollen grains. C. sempervirens-chitosan microcapsules exhibited better performance (Cd(II): 65.98; Cu(II): 67.10 and Zn(II): 49.55 mg g(-1)) than the other microcapsules and the cross-linked beads. A. negundo-chitosan microcapsules were more efficient in Cr(III) (70.40 mg g(-1)) removal. P. nigra-chitosan microcapsules were found to be less efficient. Chitosan-pollen microcapsules (except P. nigra-chitosan microcapsules) can be used in heavy metal removal. PMID:25479387

  20. The Predisposition of Iraqi Rice Husk to Remove Heavy Metals from Aqueous Solutions and Capitalized from Waste Residue

    OpenAIRE

    Mohammed Nsaif; Firas Saeed

    2013-01-01

    This study is deal with study the potential of Iraqi Rice Husk (IRH) on the removal of three heavy metals pollutant which were (Mg, Mn and Mo) ions from industrial wastewater using different design parameters by adsorption process. Results show that the removal efficiency were (93.95, 97.18 and 95.26) % for heavy metal (Mg, Mn and Mo) respectively from aquatic solution decreased with increasing of initial concentration and flow rate while the removal efficiency increased with increasing absor...

  1. Chitosan membrane development and design of equipment for the removal of heavy metals from water

    International Nuclear Information System (INIS)

    A filtration technique has compared with 1,75% m/v chitosan membranes, crosslinked with glutaraldehyde (0,08% m/v) and without cross link, to quantify the removal capacity of chromium, copper and cadmium ions of model solutions. In addition, a simple and low cost equipment was developed to use with prepared membranes. The main goal has been to use biodegradable materials for removing heavy metals from water, through a low energy consumption, cheap, and applicable to specific problems. Two data sheets were prepared for the membranes and was found that chromium was the metal with the highest removal from water, by using a crosslinked membrane. Metal adsorption was best adjusted to the Freundlich isotherm model, better than Langmuir isotherm model. However, no correlation has been found between pore size of the membranes and crosslinking degree. (author)

  2. Acidification of Harbour sediment and removal of heavy metals induced by water splitting in electrodialytic remediation.

    DEFF Research Database (Denmark)

    NystrØm, Gunvor Marie; Ottosen, Lisbeth M.

    2005-01-01

    Harbor sediments are often contaminated with heavy metals, which can be removed by electrodialytic remediation. Water splitting at the anion exchange membrane in contact with the contaminated material in electrodialytic remediation is highly important for the removal of heavy metals. Here it was investigated how acidification caused by water splitting at the anion exchange membrane during electrodialytic remediation of contaminated harbor sediment and hence the metal removal, was influenced by different experimental conditions. Two different experimental cells were tested, where the number of compartments and ion exchange membranes differed. Totally, 14 electrodialytic experiments were made, with varying remediation time, current densities, and liquid to solid ratio (L/S). pH in the sediment decreased slightly after 1 day of remediation, even if the sediment had a high buffering capacity, suggesting that water splitting at the anion exchange membrane started early in the remediation process. An increase in the voltage over the cell and a decrease in the electrical conductivity in the sediment suspension also indicated that the water splitting started within 1 day of remediation. When the sediment was acidified, the voltage decreased and electrical conductivity increased. After 5 days of remediation the sediment was acidified at the chosen current density (1 mA/cm(2)) and the main metal removal was observed shortly after. Thus it was crucial for the metal removal that the sediment was fully acidified. Lower metal removal was seen in an experimental cell with three compartments compared to five compartments, due to increased sensitivity of pH changes in the cell.

  3. Characterization of natural adsorbent material for heavy metal removal in a petrochemical site contamination

    Directory of Open Access Journals (Sweden)

    Bianchi F.

    2013-04-01

    Full Text Available Despite of over 25 years of intensive technological efforts, sub-surface environment cleanup still remains a challenge, especially in case of highly contaminated sites. In this context, ion exchanger technologies could provide simple and effective solutions for heavy metal removal in water treatment. The challenge is finding exchanger able to operate in extreme natural environments or in situations involving natural interfering species such as inorganic ions. In this paper we exam the use of natural zeolites as versatile exchanger for environmental protection of coastal refinery's groundwater against pollution of Ni, Cd, Pb. The influence of particle diameter on clinoptilolite performances toward heavy metal removal is studied. Also, we evaluate the exchanger activities in condition of high ionic strength, commonly present in groundwater located under coastal petrol industries. The obtained results confirmed that ion exchangers could provide an effective solutions for remediation in complex environmental conditions.

  4. Efficiency of Phragmites australis and Typha latifolia for heavy metal removal from wastewater.

    Science.gov (United States)

    Kumari, Menka; Tripathi, B D

    2015-02-01

    A cost-effective and promising technology has been demonstrated for the removal of copper (Cu), cadmium (Cd), chromium (Cr), nickel (Ni), iron (Fe), lead (Pb) and zinc (Zn) from urban sewage mixed with industrial effluents within 14 days. With the help of P. australis and T. latifolia grown alone and in combination batch experiments were designed to assess the removal of heavy metals from the wastewater collected from 5 sampling stations. The results revealed that P. australis performed better than T. latifolia for Cu, Cd, Cr, Ni, Fe, Pb and Zn removal, while mixing of the plant species further enhanced the removal of Cu to 78.0±1.2%, Cd to 60.0±1.2%, Cr to 68.1±0.4%, Ni to 73.8±0.6%, Fe to 80.1±0.3%, Pb to 61.0±1.2% and Zn to 61.0±1.2% for wastewater samples from Raj Ghat. Negative correlation coefficients of Cu, Cd, Cr, Ni, Fe, Pb and Zn concentrations in wastewater with the retention time revealed that there was an increase in the heavy metal removal rate with retention time. P. australis showed higher accumulative capacities for Cu, Cd, Cr, Ni and Fe than T. latifolia. P. australis and T. latifolia grown in combination can be used for the removal of Cu, Cd, Cr, Ni, Fe, Pb and Zn from the urban sewage mixed with industrial effluents within 14 days. PMID:25463857

  5. Molecular Characterization and Phylogenetic Analyses of Heavy Metal Removal Bacteria from the Persian Gulf

    OpenAIRE

    Zolgharnein, H.; Karami, K.; Mazaheri Assadi, M.; Dadolahi Sohrab, A.

    2010-01-01

    A total of 35 heavy metals resistance and removal bacterial strains were isolated from samples of marine environment and enclosed industrial areas. All isolates were characterized by molecular method. The diversity of isolated bacteria was examined by the phylogenetic analysis of 16S rRNA gene sequences. The phylogenetic analysis of the sequences revealed seven main taxonomic lineages. The phylogenetic tree illustrated discrimination between isolated bacteria from wastewater, industrials area...

  6. EVALUATION OF HEAVY METAL REMOVAL BY OXIDISED LIGNINS IN ACID MEDIA FROM VARIOUS SOURCES

    OpenAIRE

    Quintana, Germa?n C.; Rocha, George J. M.; Gonc?alves, Adilson R.; Vela?squez, Jorge A.

    2008-01-01

    The capacity for removal of heavy metals from liquid streams by formation of complexes with lignins oxidized by acid treatment was studied. Lignins were obtained from different sources: sulfuric acid pretreated cane bagasse, soda pulping bagasse, eucalypt Kraft lignin, and commercial Kraft lignin. These lignins were characterized using different techniques to determine Klason lignin, carbohydrates, total acids, ashes, and their main functional groups: phenolic-OH, carbonyls, etc. The studi...

  7. Removal of radioactive materials and heavy metals from water using magnetic resin

    Science.gov (United States)

    Kochen, Robert L. (Boulder, CO); Navratil, James D. (Simi Valley, CA)

    1997-01-21

    Magnetic polymer resins capable of efficient removal of actinides and heavy metals from contaminated water are disclosed together with methods for making, using, and regenerating them. The resins comprise polyamine-epichlorohydrin resin beads with ferrites attached to the surfaces of the beads. Markedly improved water decontamination is demonstrated using these magnetic polymer resins of the invention in the presence of a magnetic field, as compared with water decontamination methods employing ordinary ion exchange resins or ferrites taken separately.

  8. Characterization of natural adsorbent material for heavy metal removal in a petrochemical site contamination

    OpenAIRE

    Bianchi F.; Farao C.; Maretto M.; Petrangeli Papini M.; Vignola R.

    2013-01-01

    Despite of over 25 years of intensive technological efforts, sub-surface environment cleanup still remains a challenge, especially in case of highly contaminated sites. In this context, ion exchanger technologies could provide simple and effective solutions for heavy metal removal in water treatment. The challenge is finding exchanger able to operate in extreme natural environments or in situations involving natural interfering species such as inorganic ions. In this paper we exam the use of ...

  9. Teawaste as An Adsorbent for Heavy Metal Removal from Industrial Wastewaters

    OpenAIRE

    Mahvi, Amir H. A.; Dariush Naghipour; Forugh Vaezi; Shahrokh Nazmara

    2005-01-01

    Water used in industries creates a wastewater that has a potential hazard for our environment because of introducing various contaminants such as heavy metals into soil and water resources. In this study, removal of cadmium, lead and nickel from industrial wastewaters has been investigated by using teawaste as a natural adsorbent. The research is a bench scale experimental type and analyses have performed by using different amounts of adsorbent in solutions with 5 differen...

  10. Removal of Heavy Metal Ions with Acid Activated Carbons Derived from Oil Palm and Coconut Shells

    OpenAIRE

    Rahman, Mokhlesur M.; Mohd Adil; Yusof, Alias M.; Kamaruzzaman, Yunus B.; Ansary, Rezaul H.

    2014-01-01

    In this work, batch adsorption experiments were carried out to investigate the suitability of prepared acid activated carbons in removing heavy metal ions such as nickel(II), lead(II) and chromium(VI). Acid activated carbons were obtained from oil palm and coconut shells using phosphoric acid under similar activation process while the differences lie either in impregnation condition or in both pretreatment and impregnation conditions. Prepared activated carbons were modified by dispersing hy...

  11. Iron oxide nanoparticles: applicability for heavy metal removal from contaminated water

    International Nuclear Information System (INIS)

    Due to the infinite size of nanoparticles, the surface area is relatively large and, as a result, they usually have high reactivity and sorption to various heavy metals. In this work, we investigated the sorption behavior of the iron oxide (?-Fe2O3) nanoparticles and its applicability to purify water from the aluminum (Al III), arsenic (As III), cadmium (Cd II), cobalt (Cd II), copper (Cu II), and nickel (Ni II). A batch experiment was performed, in which aqueous solutions of the metallic ions were prepared. The adsorption behaviors of the ?-Fe2O3 nanoparticles towards the metallic ions were studied under different conditions of contact time, ph, temperature, ?-Fe2O3 dosage and metal concentration. 10 ml of aqueous solutions contaminated with each metal were artificially prepared and treated with the nanoparticles. The adsorption behaviors study was performed by changing one of the conditions while keeping the others fixed. The fixed conditions were: metal concentration = 1 ppm; ?-Fe2O3 dosage=0.35 g; contact time = 30 minutes; temperature=21± 1 degree C; and ph ? 7. According to the results, maximum percent removals (%) for all metals tested were reached within a short period of time (5 minutes). The maximum percent removal (%) of both Cu (II) and As (II) reached more than 95%, while the other metal had percent removal between 35% and 65%. Increasing the ph of solution led Increasing the ph of solution led to increase of the percent removal for all metals except Al which had plateau shape with ph, reaching a maximum percent removal at ph 5 and decreasing back at higher ph

  12. Biological removal of heavy metals from printed circuit board and electroplating waste waters in Metex process systems

    Energy Technology Data Exchange (ETDEWEB)

    Morper, M.; Fuerst, P.

    1991-01-01

    Systems designed for biological removal of heavy metals from industrial wastewaters are marketed by Linde under the tradename Metex. The patented process utilizing the high heavy metal uptake capacity of biologically active anaerobic biomass in sepecially developed sludge-bed reactors normally does not require addition of chemicals and enables the recently tightened German effluent limits for heavy metals to be met even in the presence of interfering secondary substances. Industrial systems for removal of copper, lead and tin from wastewaters in the manufacture of printed circuit boards have been in operation for periods up to two years and longer with a single charge of biomass. Pilot tests conducted on numerous industrial effluents confirm that nearly all environmentally relevant heavy metals commonly occurring in wastewaters can be removed, resulting in metal-rich sludges which lend themselves to convenient disposal or can be processed for recovery of the metals. (orig.).

  13. Nitrogen removal and heavy metals in leachate treatment using SBR technology

    International Nuclear Information System (INIS)

    Biological nitrogen removal by the use of Sequencing Batch Reactors (SBRs) is today an accepted and well proven model. The results of SBR performance on nitrogen removal have encouraged consultants, engineering companies and landfill operators to develop and build full scale SBR plants at a number of sites in Sweden. Two of these plants, Isaetra and Norsa, have been studied closely. The Norsa plant treats leachate at a controlled water temperature, while the Isaetra plant is exposed to temperature variation throughout the year. Both plants have very well proven nitrogen removal capacities, although winter conditions have an adverse impact on their performance. Typical nitrification efficiency is close to 100%, while the total nitrogen removal is about 90-95% under stable operation conditions. A good relationship between the nitrogen load and the nitrification rate has been observed at the Norsa SBR plant. The heavy metal content in the leachate is very low thanks to anaerobic precipitation inside the landfill into metal sulphides. The heavy metal content in the biological sludge is consequently also very low.

  14. Use of a glass residue in the removal of heavy metals from wastewater.

    Science.gov (United States)

    Catalfamo, Paola; Primerano, Patrizia; Arrigo, Ileana; Corigliano, Francesco

    2006-01-01

    The extraction of silica from powdered glass cullet with an aqueous solution of sodium hydroxide has been proposed as an alternative to glass recycling aimed to the low temperature production of sodium silicates. The unextracted residue obtained after a counter current two-step extractive process at approximately 100 degrees C and room pressure is mainly made of calcium and sodium silicate and shows high porosity and a large surface area. We thought that it could be active as an agent for the removal of heavy metals from wastewater. In this paper the capacity of the unextracted residue of removing six metal ions (i.e., Cu2+, Ni2+, Zn2+, Cd2+, Pb2+ e Cr3+) was studied in a stirred batch reactor. The data obtained demonstrate that the removal of metal ions from wastewater is achieved with high capacity in a short time and their concentration is lowered under the legal limits without any appreciable influence from changes of physical and chemical conditions. Sodium and calcium ions take the place of heavy metals in water while pH keeps almost neutral. The exchange mechanism was identified. PMID:16948437

  15. Polyaza macroligands as potential agents for heavy metal removal from wastewater

    Directory of Open Access Journals (Sweden)

    Elizondo Martínez Perla

    2013-01-01

    Full Text Available Two polyaza macroligands N,N´-bis(2-aminobenzyl-1,2- ethanediamine (L1 and 3,6,9,12-tetraaza-4(1,2,11(1,2-dibenzo-1(1,3- piridinaciclotridecafano (L2 were characterized and investigated for their metal ion extraction capabilities. The nature of all complexes was established by spectroscopic techniques. The equilibrium constants were determined by spectrophotometric and potentiometric techniques and the residual concentration of metals in the solutions by Atomic Absorption Spectrometry (AAS. The capacity of the ligands to remove heavy metals such as Cu(II, Ni(II, Cd(II, Zn(II and Pb(II as insoluble complexes was evaluated in wastewater from industrial effluents. These agents showed high affinity for the studied metals. The values of equilibrium constants of the isolated complexes (between 1 x 104 and 2 x 107 demonstrated the feasibility of applying these chelating agents as an alternative to remove heavy metals from industrial effluents.

  16. Physical Characterization of Prepared and Spent CFA/PFA/RHA Sorbents in Removing Heavy Metals and Dyes

    OpenAIRE

    Ismail, S.; Dahlan, I.

    2012-01-01

    High concentration of heavy metals and dyes creates health and environmental problems. Different types of treatment have been applied to remove these pollutants. In this study, physical characterization of CFA/PFA/RHA sorbent has been investigated to obtain a better understanding of adsorption process in removing heavy metals and dye. The sorbents from Coal Fly Ash (CFA), Palm oil Fuel Ash (PFA) and Rice Husk Ash (RHA) were prepared using water hydration method, sol-gel method and activation ...

  17. Hydrothermally modified fly ash for heavy metals and dyes removal in advanced wastewater treatment

    International Nuclear Information System (INIS)

    Fly ash resulted from coal burning is a waste that can be used in wastewater treatment for removal of dyes and heavy metals by adsorption. Class “F” fly ash (FA), collected from the Central Heat and Power (CHP) Plant Brasov (Romania), with oxides composition SiO2/Al2O3 over 2.4 was used for obtaining a new substrate with good adsorption capacity for dyes and heavy metals from wastewater. A new material was obtained from modified fly ash with NaOH and hexadecyltrimethylammonium bromide (HTAB) a cationic surfactant. Contact time, optimum amount of substrate and the pH corresponding to 50 mL solution of pollutants were the parameters optimized for obtaining the maximum efficiency in the adsorption process. The optimized adsorption parameters were further used in thermodynamic and kinetic studies of the adsorption processes. The adsorption kinetic mechanisms, and the substrate capacities are further discussed correlated with the surface structure (XRD), composition (EDS, FTIR), and morphology (SEM, AFM). The results indicate that the novel nano-substrate composite with fly ash modified can be used as an efficient and low cost adsorbent for simultaneous removal of dyes and heavy metals, the resulted water respects the discharge regulations.

  18. Hydrothermally modified fly ash for heavy metals and dyes removal in advanced wastewater treatment

    Science.gov (United States)

    Visa, Maria; Chelaru, Andreea-Maria

    2014-06-01

    Fly ash resulted from coal burning is a waste that can be used in wastewater treatment for removal of dyes and heavy metals by adsorption. Class “F” fly ash (FA), collected from the Central Heat and Power (CHP) Plant Brasov (Romania), with oxides composition SiO2/Al2O3 over 2.4 was used for obtaining a new substrate with good adsorption capacity for dyes and heavy metals from wastewater. A new material was obtained from modified fly ash with NaOH and hexadecyltrimethylammonium bromide (HTAB) a cationic surfactant. Contact time, optimum amount of substrate and the pH corresponding to 50 mL solution of pollutants were the parameters optimized for obtaining the maximum efficiency in the adsorption process. The optimized adsorption parameters were further used in thermodynamic and kinetic studies of the adsorption processes. The adsorption kinetic mechanisms, and the substrate capacities are further discussed correlated with the surface structure (XRD), composition (EDS, FTIR), and morphology (SEM, AFM). The results indicate that the novel nano-substrate composite with fly ash modified can be used as an efficient and low cost adsorbent for simultaneous removal of dyes and heavy metals, the resulted water respects the discharge regulations.

  19. Hydrothermally modified fly ash for heavy metals and dyes removal in advanced wastewater treatment

    Energy Technology Data Exchange (ETDEWEB)

    Visa, Maria, E-mail: maria.visa@unitbv.ro; Chelaru, Andreea-Maria, E-mail: andreea.chelaru1@yahoo.com

    2014-06-01

    Fly ash resulted from coal burning is a waste that can be used in wastewater treatment for removal of dyes and heavy metals by adsorption. Class “F” fly ash (FA), collected from the Central Heat and Power (CHP) Plant Brasov (Romania), with oxides composition SiO{sub 2}/Al{sub 2}O{sub 3} over 2.4 was used for obtaining a new substrate with good adsorption capacity for dyes and heavy metals from wastewater. A new material was obtained from modified fly ash with NaOH and hexadecyltrimethylammonium bromide (HTAB) a cationic surfactant. Contact time, optimum amount of substrate and the pH corresponding to 50 mL solution of pollutants were the parameters optimized for obtaining the maximum efficiency in the adsorption process. The optimized adsorption parameters were further used in thermodynamic and kinetic studies of the adsorption processes. The adsorption kinetic mechanisms, and the substrate capacities are further discussed correlated with the surface structure (XRD), composition (EDS, FTIR), and morphology (SEM, AFM). The results indicate that the novel nano-substrate composite with fly ash modified can be used as an efficient and low cost adsorbent for simultaneous removal of dyes and heavy metals, the resulted water respects the discharge regulations.

  20. Montmorillonite surface properties and sorption characteristics for heavy metal removal from aqueous solutions

    International Nuclear Information System (INIS)

    Surface properties of montmorillonite (MMT) and its adsorption characteristics for heavy metals have been investigated with nickel and copper as sorbate from aqueous solutions. Employing the potentiometric and mass titration techniques in batch experimental methods, the point of zero charge (PZC) and point of zero net proton charge (PZNPC) of MMT edges at different ionic strengths present pHPZC and pHPZNPC to be 3.4 ± 0.2. A crossing point was observed for the proton adsorption vs. pH curves at different ionic strengths of KCl electrolyte and in investigating MMT remediation potentialities as sorbent for heavy metals polluted waters, the effects of heavy metal concentration, pH, MMT dosage, reaction time and temperature for Cu2+ and Ni2+ uptake were studied. The sorption of metal ions by MMT was pH dependent and the adsorption kinetics revealed sorption rate could be well fitted by the pseudo-second-order rate model. The data according to mass transfer and intraparticle diffusion models confirmed diffusion of solutes inside the clay particles as the rate-controlling step and more important for the adsorption rate than the external mass transfer. Adsorption isotherms showed that the uptake of Cu2+ and Ni2+ could be described by the Langmuir model and from calculations on thermodynamic parameters, the positive ?Go values at different temperatures suggest that the sorption of both metal ions wt that the sorption of both metal ions were non-spontaneous. Change in enthalpy (?Ho) for Ni2+ and Cu2+ were 28.9 and 13.27 kJ/mol K respectively, hence an endothermic diffusion process, as ion uptake increased with increase in temperature. Values of ?So indicate low randomness at the solid/solution interface during the uptake of both Cu2+ and Ni2+ by MMT. Montmorillonite has a considerable potential for the removal of heavy metal cationic species from aqueous solution and wastewater.

  1. Copper removal using a heavy-metal resistant microbial consortium in a fixed-bed reactor.

    Science.gov (United States)

    Carpio, Isis E Mejias; Machado-Santelli, Glaucia; Sakata, Solange Kazumi; Ferreira Filho, Sidney Seckler; Rodrigues, Debora Frigi

    2014-10-01

    A heavy-metal resistant bacterial consortium was obtained from a contaminated river in São Paulo, Brazil and utilized for the design of a fixed-bed column for the removal of copper. Prior to the design of the fixed-bed bioreactor, the copper removal capacity by the live consortium and the effects of copper in the consortium biofilm formation were investigated. The Langmuir model indicated that the sorption capacity of the consortium for copper was 450.0 mg/g dry cells. The biosorption of copper into the microbial biomass was attributed to carboxyl and hydroxyl groups present in the microbial biomass. The effect of copper in planktonic cells to form biofilm under copper rich conditions was investigated with confocal microscopy. The results revealed that biofilm formed after 72 h exposure to copper presented a reduced thickness by 57% when compared to the control; however 84% of the total cells were still alive. The fixed-bed bioreactor was set up by growing the consortium biofilm on granular activated carbon (GAC) and analyzed for copper removal. The biofilm-GAC (BGAC) column retained 45% of the copper mass present in the influent, as opposed to 17% in the control column that contained GAC only. These findings suggest that native microbial communities in sites contaminated with heavy metals can be immobilized in fixed-bed bioreactors and used to treat metal contaminated water. PMID:24952346

  2. EVALUATION OF HEAVY METAL REMOVAL BY OXIDISED LIGNINS IN ACID MEDIA FROM VARIOUS SOURCES

    Directory of Open Access Journals (Sweden)

    Germán C. Quintana

    2008-11-01

    Full Text Available The capacity for removal of heavy metals from liquid streams by formation of complexes with lignins oxidized by acid treatment was studied. Lignins were obtained from different sources: sulfuric acid pretreated cane bagasse, soda pulping bagasse, eucalypt Kraft lignin, and commercial Kraft lignin. These lignins were characterized using different techniques to determine Klason lignin, carbohydrates, total acids, ashes, and their main functional groups: phenolic-OH, carbonyls, etc. The studied lignins were determined spectroscopically using FTIR. In order to increase the metal adsorption capacity, lignins were oxidized at 100°C during 2 h, using aqueous solutions of H2O2 in distilled water solvent and HCl catalyst. Some lignin adsorption isotherms were constructed before and after the oxidation process to define Cd(II ion removal capacity.

  3. Modeling of heavy metals removal from aqueous solution using activated carbon produced from cotton stalk.

    Science.gov (United States)

    El Zayat, Mohamed; Smith, Edward

    2013-01-01

    Activated carbon produced from cotton stalks was examined for the removal of heavy metal contaminants. Adsorption studies in completely mixed batch reactors were used to generate equilibrium pH adsorption edges. Continuous flow experiments using the activated carbon in fixed beds were conducted to determine heavy metal breakthrough versus bed volumes treated. At given pH value in the range 5-7, the adsorption capacity was similar for copper and lead and clearly greater than for cadmium. A surface titration experiment indicated negative surface charge of the activated carbon at pH > 6, meaning that electrostatic attraction of the divalent heavy metals can occur below the pH required for precipitation. Substantive metal removal below the pH of zero charge might be due to surface complexation. Accordingly, a surface complexation model approach that utilizes an electrostatic term in the double-layer description was used to estimate equilibrium constants for the protolysis interactions of the activated carbon surface as well as equilibria between background ions used to establish ionic strength and the sorbent surface. Pb(II) adsorption edges were best modeled using inner-layer surface complexation of Pb(2+), while Cd(II) and Cu(II) data were best fit by outer-layer complexes with Me(2+). The full set of equilibrium constants were used as input in a dual-rate dynamic model to simulate the breakthrough curves of the target metals (Pb, Cu and Cd) from fixed bed experiments and to estimate external (or film) diffusion and internal (surface) diffusion coefficients. PMID:23552252

  4. Teawaste as An Adsorbent for Heavy Metal Removal from Industrial Wastewaters

    Directory of Open Access Journals (Sweden)

    Amir H.A. Mahvi

    2005-01-01

    Full Text Available Water used in industries creates a wastewater that has a potential hazard for our environment because of introducing various contaminants such as heavy metals into soil and water resources. In this study, removal of cadmium, lead and nickel from industrial wastewaters has been investigated by using teawaste as a natural adsorbent. The research is a bench scale experimental type and analyses have performed by using different amounts of adsorbent in solutions with 5 different concentrations of each metal and also in a mixed combination. Besides, the effect of various amounts of teawaste used in adsorption efficiency experiments has been investigated. Results indicate that the removal efficiency is highest for lead and is minimum for cadmium. About 94 and 100% lead removal were achieved by using 0.5 and 1.5g adsorbent for solutions having concentrations of 5 and 10 mg/L Pb. Whereas, 1.5g teawaste can treat nickel solution of 5 mg/L concentration with an efficiency of not more that 85.7%. For cadmium, the efficiency was only 77.2% in the same conditions. On the other hand, for mixtures of metals and by applying 0.5 g teawaste, we considered a 3.5% decrease in lead removal efficiency and a 13.2% decrease in nickel adsorption for a mixed solution of 5 mg/L.

  5. Removal of heavy metals using a microbial active, continuously operated sand filter

    International Nuclear Information System (INIS)

    Heavy metals play an important role within the spectrum of the various pollutants, emitted into the environment via human activities. In contrast to most organic pollutants, heavy metal can not be degraded. Many soils, lakes and rivers show a high contamination with heavy metals due to the enrichment of these pollutants. In addition to existing chemical-physical and biological technologies for the treatment of heavy metal containing waste waters a demand for new, efficient and low-cost cleaning technologies exists, particularly for high volumes of weakly contaminated waters. Such a technology was developed within the framework of a scientific project of the European Union. The approach makes use of a continuously operated, moving-bed Astrasand filter, which has been operated as a continuous biofilm reactor. By inoculation of the reactor with bacteria providing different, defined mechanisms of metal immobilization, and by continuous supply of suitable nutrients, a metal-immobilizing biofilm is built up and regenerated continuously. Metal-enriched biomass is removed continuously from the system, and the contained metals can be recycled by pyrometallurgical treatment of the biomass. The subjects of the present work were the optimization of the nutrient supply for the process of metal removal, the investigation of the toxicity of different waste waters, the optimization of inoculation and biofilm formation, set-up and operation of a lab scale sand filter and the operation a lab scale sand filter and the operation of a pilot scale sand filter treating rinsing water of a chemical nickel plating plant. First, basic parameters like toxicity of heavy metal-containing waste waters and the influence of the nutrition of bacteria on biosorption and total metal removal were examined, using freely suspended bacteria in batch culture. Concerning toxicity great differences could be found within the spectrum of heavy metal-containing waste waters tested. Some waters completely inhibited growth, while others did not influence the bacterial biomass production. A sand column system with partial circulation of the waste water was constructed for the treatment of toxic waste waters. Using this experimental set-up a resistant biofilm was built up by continuous increase of waste water concentration. With this biofilm-system it is possible to treat waste waters, which completely inhibit bacterial growth with freely suspended cells in batch culture. The selection of suitable nutrients for the bacteria turned out to be crucial for the efficiency of the metal removal process too. From all essential macro- and micro-elements only C, N and P had to be added to the waste waters, in some cases the addition of a carbon source was sufficient. All other nutrients were already present in the waste waters. In order to optimize the nutrient supplementation, various carbon and nitrogen sources were checked concerning biomass production and metal removal. Some nutrient sources strongly supported bacterial growth, but simultaneously reduced metal removal by unfavorable chemical interactions with heavy metals. From all nutrient sources tested, Na-acetate turned out to be the best choice for carbon supply of the bacteria. If the addition of nitrogen to the waste water is necessary, nitrate, ammonia or urea are suitable sources for bacterial growth and metal removal. In experiments with single fixed bed columns (100 cm3 sand) and subsequent tests in the lab-scale (10 dm3 sand) and pilot scale sand filter (1,7 m3 sand), a suitable procedure for the inoculation of the sand filter and the formation of biofilm on the sand grains was developed. The maintenance of stock cultures was carried out on agar plates made of waste water, enriched with missing nutrients. Production of the biomass for inoculation was realized in liquid culture using waste water, enriched with nutrients too. The formation of a biofilm on the sand grains was achieved by addition of the liquid culture to the sand filter, supply of nutrients and distribution of the formed biomass by internal circulati

  6. Microbiological treatment for removal of heavy metals and nutrients in FGD wastewater

    Energy Technology Data Exchange (ETDEWEB)

    Shulder, Stephen J. [Structural Integrity Associates, Annapolis, MD (United States); Riffe, Michael R. [Siemens Water Technologies, General Industry Solutions, Warrendale, PA (United States); Walp, Richard J. [URS Corporation, Princeton, NJ (United States)

    2010-12-15

    In efforts to comply with the Clean Air Act many coal-fired fossil plants are installing wet flue gas desulfurization (WFGD) systems, also known as scrubbers, to remove sulfur dioxide (SO{sub 2}). Limestone slurry is injected into an absorber to promote the formation of calcium sulfate (CaSO{sub 4}) or gypsum. Chloride (chlorine in the fuel) becomes dissolved and increases in the absorber loop, which can lead to a more corrosive environment. Inert matter in the limestone also enters the absorber and must be reduced to meet the gypsum quality specification. To control the buildup of chloride and fines in the flue gas desulfurization (FGD) system a continuous blowdown or purge stream is utilized. Environmental regulations on the discharge of treated FGD wastewater are becoming increasingly more stringent to control impacts on the receiving body of water (stream, lake, river, or ocean). These new limitations often focus on heavy metals such as selenium and nutrients including nitrogen and phosphorus compounds. The FGD chloride purge stream is typically treated by chemical addition and clarification to remove excess calcium and heavy metals with pH adjustment prior to discharge. However this process is not efficient at selenium or nutrient removal. Information on a new approach using biological reactor systems or sequencing batch reactors (SBRs) to achieve reductions in selenium and nitrogen compounds (ammonia, nitrite, and nitrate) is discussed. A brief discussion on the physical/chemical pretreatment is also provided. (orig.)

  7. Removal mechanisms of heavy metal pollution from urban runoff in wetlands

    Science.gov (United States)

    Zhang, Zhiming; Cui, Baoshan; Fan, Xiaoyun

    2012-12-01

    Solid particles, particularly urban surface dust in urban environments contain large quantities of pollutants. It is considered that urban surface dust is a major pollution source of urban stormwater runoff. The stormwater runoff washes away urban surface dust and dissolves pollutants adsorbed onto the dust and finally discharges into receiving water bodies. The quality of receiving water bodies can be deteriorated by the dust and pollutants in it. Polluted waters can be purified by wetlands with various physical, chemical, and biologic processes. These processes have been employed to treat pollutants in urban stormwater runoff for many years because purification of treatment wetlands is a natural process and a low-cost method. In this paper, we reviewed the processes involved during pollutants transport in urban environments. Particularly, when the urban stormwater runoff enters into wetlands, their removal mechanisms involving various physical, chemical and biologic processes should been understood. Wetlands can remove heavy metals by absorbing and binding them and make them form a part of sediment. However, heavy metals can be released into water when the conditions changed. This information is important for the use of wetlands for removing of pollutants and reusing stormwater.

  8. Removal of Selected Heavy Metals from Green Mussel via Catalytic Oxidation

    International Nuclear Information System (INIS)

    Perna viridis or green mussel is a potentially an important aquaculture product along the South Coast of Peninsular Malaysia especially Johor Straits. As the coastal population increases at tremendous rate, there was significant effect of land use changes on marine communities especially green mussel, as the heavy metals input to the coastal area also increase because of anthropogenic activities. Heavy metals content in the green mussel exceeded the Malaysian Food Regulations (1985) and EU Food Regulations (EC No: 1881/ 2006). Sampling was done at Johor Straits from Danga to Pendas coastal area for green mussel samples. This research introduces a catalytic oxidative technique for demetallisation in green mussel using edible oxidants such as peracetic acid (PAA) enhanced with alumina beads supported CuO, Fe2O3, and ZnO catalysts. The lethal dose of LD50 to rats of PAA is 1540 mg kg-1 was verified by National Institute of Safety and Health, United State of America. The best calcination temperature for the catalysts was at 1000 degree Celsius as shown in the X-Ray Diffraction (XRD), Nitrogen Adsorption (BET surface area) and Field Emission Scanning Electron Microscopy (FESEM) analyses. The demetallisation process in green mussel was done successfully using only 100 mgL-1 PAA and catalyzed with Fe2O3/ Al2O3 for up to 90 % mercury (Hg) removal. Using PAA with only 1 hour of reaction time, at room temperature (30-35 degree Celsius), pH 5-6 and salinity of 25-28 ppt, 90 % lead (Pb) was removed from life mussel without catalyst. These findings have a great prospect for developing an efficient and practical method for post-harvesting heavy metals removal in green mussel. (author)

  9. Effective heavy metal removal from aqueous systems by thiol functionalized magnetic mesoporous silica

    International Nuclear Information System (INIS)

    A thiol-functionalized magnetic mesoporous silica material (called SH-mSi-Fe3O4), synthesized by a modified Stoeber method, has been investigated as a convenient and effective adsorbent for heavy metal ions. Structural characterization by powder X-ray diffraction, N2 adsorption-desorption isotherm, Fourier transform infrared spectroscopy and elemental analyses confirms the mesoporous structure and the organic moiety content of this adsorbent. The high saturation magnetization (38.4 emu/g) make it easier and faster to be separated from water under a moderate magnetic field. Adsorption kinetics was elucidated by pseudo-second-order kinetic equation and exhibited 3-stage intraparticle diffusion mode. Adsorption isotherms of Hg and Pb fitted well with Langmuir model, exhibiting high adsorption capacity of 260 and 91.5 mg of metal/g of adsorbent, respectively. The distribution coefficients of the tested metal ions between SH-mSi-Fe3O4 and different natural water sources (groundwater, lake water, tap water and river water) were above the level of 105 mL/g. The material was very stable in different water matrices, even in strong acid and alkaline solutions. Metal-loaded SH-mSi-Fe3O4 was able to regenerate in acid solution under ultrasonication. This novel SH-mSi-Fe3O4 is suitable for repeated use in heavy metal removal from different water matrices.ifferent water matrices.

  10. Effective heavy metal removal from aqueous systems by thiol functionalized magnetic mesoporous silica

    Energy Technology Data Exchange (ETDEWEB)

    Li Guoliang [State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, P.O. Box 2871, Beijing 100085 (China); Zhao Zongshan [Key Laboratory of Marine Chemistry Theory and Technology, Ministry of Education, College of Chemistry and Chemical Engineering, Ocean University of China, 238 Songling Road, Qingdao 266100 (China); Liu Jiyan, E-mail: liujy@rcees.ac.cn [State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, P.O. Box 2871, Beijing 100085 (China); Jiang Guibin [State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, P.O. Box 2871, Beijing 100085 (China)

    2011-08-15

    A thiol-functionalized magnetic mesoporous silica material (called SH-mSi-Fe{sub 3}O{sub 4}), synthesized by a modified Stoeber method, has been investigated as a convenient and effective adsorbent for heavy metal ions. Structural characterization by powder X-ray diffraction, N{sub 2} adsorption-desorption isotherm, Fourier transform infrared spectroscopy and elemental analyses confirms the mesoporous structure and the organic moiety content of this adsorbent. The high saturation magnetization (38.4 emu/g) make it easier and faster to be separated from water under a moderate magnetic field. Adsorption kinetics was elucidated by pseudo-second-order kinetic equation and exhibited 3-stage intraparticle diffusion mode. Adsorption isotherms of Hg and Pb fitted well with Langmuir model, exhibiting high adsorption capacity of 260 and 91.5 mg of metal/g of adsorbent, respectively. The distribution coefficients of the tested metal ions between SH-mSi-Fe{sub 3}O{sub 4} and different natural water sources (groundwater, lake water, tap water and river water) were above the level of 10{sup 5} mL/g. The material was very stable in different water matrices, even in strong acid and alkaline solutions. Metal-loaded SH-mSi-Fe{sub 3}O{sub 4} was able to regenerate in acid solution under ultrasonication. This novel SH-mSi-Fe{sub 3}O{sub 4} is suitable for repeated use in heavy metal removal from different water matrices.

  11. The effect of weak chelating agents on the removal of heavy metals by precipitation processes

    International Nuclear Information System (INIS)

    Particle size distributions and heavy metal removals are presented for hydroxide precipitation and sulfide precipitation of zinc and cadmium in the presence of several weak complexing agents, namely citrate, tartrate, and ammonia. The pH was held constant at pH 10.0 in these experiments. The presence of these weak complexing agents had little effect on the chemical equilibrium for both the hydroxide and sulfide systems due to their weak complexing ability with metal ions. The presence of the complexing agents does affect the particle size distribution, generally forming smaller particles. Particle size distributions are presented for the Zn(OH)/sub 2/, ZnS, Cd(OH)/sub 2/, and CdS systems (at pH 10.0) in the presence of the chelating agents citrate, tartrate, and ammonia. Sulfide precipitation exhibits a better particle size distribution and settling characteristics than the corresponding metal hydroxide precipitation for both zinc and cadmium

  12. Removal of Some Heavy Metals from Wastewater by Using of Fava Beans

    Directory of Open Access Journals (Sweden)

    Abdunnaser Mohamed Etorki

    2014-03-01

    Full Text Available The Fava Beans were used in this work as low cost adsorbent material for removal of Pb(II, Cd(II and Zn(II ions from aqueous solutions. The samples were prepared without farther treatment and sorted according to the particles diameter by standard sieves 250 - 500 ?m. Batch adsorption experiments were carried out to study the adsorption process, several parameters such as Initial pH of adsorbent, effect of contact time, effect of adsorbent amount and effect of metal concentration were conducted in these experiments. The effects of any one of those previously mentioned parameters on the adsorption capacity were studied while the other parameters were kept constant. It was found that the obtained maximum adsorption capacities of Fave beans for the removal of selected heavy metals were very high. This provide us to use Fava beans as a low coast adsorbent material to clean up the water in the environment from toxic heavy metals such as Pb(II, Cd(II and Zn(II ions.

  13. Nonlinear modelisation of heavy metal removal from aqueous solution using Ulva lactuca algae.

    Science.gov (United States)

    Zakhama, S; Dhaouadi, H; M'Henni, F

    2011-01-01

    After extensive analysis, Ulva lactuca dried algae, collected from the Monastir coastal zone, was proven to be successful as an adsorbent for the removal of certain inorganic pollutants. The main objective of this study was the nonlinear modeling of heavy metal removal from an aqueous solution, using a freely available and well analyzed biomaterial, as well as the evaluation of its efficacy on various metal ion sorptions. Although relatively low specific surface area, compared to more conventional adsorbents, the selected biomaterial displays very interesting retention capacities when used with aqueous inorganic pollutants. The pseudo, first and second-order kinetic models were used to investigate the kinetic retention mechanism. Assuming the nonlinear form, the results indicate that the retention mechanism is diffusion controlled. Concerning the heavy metal uptake capacity, it was found that the selected biomaterial has a retention capacity of 67 mg g(-1) of Ni(II), 112 mg g(-1) of Cu(II), 127 mg g(-1) of Cd(II) and 230 mg g(-1) of Pb(II). PMID:20855200

  14. UV-radiation curing of simultaneous interpenetrating polymer network hydrogels for enhanced heavy metal ion removal

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Jingjing, E-mail: jjwang1@hotmail.com [Department of Polymer Materials and Engineering, School of Material Engineering, Key Laboratory for Advanced Technology in Environmental Protection of Jiangsu Province, Yancheng Institute of Technology, Yancheng 224051 (China); Liu, Fang [Department of Polymer Materials and Engineering, School of Material Engineering, Key Laboratory for Advanced Technology in Environmental Protection of Jiangsu Province, Yancheng Institute of Technology, Yancheng 224051 (China)

    2012-11-01

    Highlights: Black-Right-Pointing-Pointer Simultaneous IPN hydrogels were prepared by hybrid photopolymerization of AM and DVE-3. Black-Right-Pointing-Pointer The synergistic complexation was found in the adsorption studies. Black-Right-Pointing-Pointer The simultaneous IPN hydrogels could be used as fast-responsive and renewable sorbent materials. - Abstract: Simultaneous interpenetrating polymer network (IPN) hydrogels have been prepared by UV-initiated polymerization of a mixture of acrylamide (AM) and triethylene glycol divinyl ether (DVE-3). The consumption of each monomer upon UV-irradiation was monitored in situ by real-time infrared (RTIR) spectroscopy. The acrylamide monomer AM was shown to polymerize faster and more extensively than the vinyl ether monomer DVE-3, which was further consumed upon storage of the sample in the dark, due to the living character of the cationic polymerization. The IPN hydrogels were used to remove heavy metal ions from aqueous solution under the non-competitive condition. The effects of pH values of the feed solution and the DVE-3 content in the formulation on the adsorption capacity were investigated. The results indicated that the adsorption capacity of the IPN hydrogels increased with the pH values and DVE-3 content in the formulation. Furthermore, the synergistic complexation of metal ions with two polymer networks in the IPN was found in the adsorption studies. Adsorption kinetics and regeneration studies suggested that the IPN hydrogels could be used as fast-responsive and renewable sorbent materials in heavy metal removing processes.

  15. Separation of heavy metals: Removal from industrial wastewaters and contaminated soil

    Energy Technology Data Exchange (ETDEWEB)

    Peters, R.W.; Shem, L.

    1993-01-01

    This paper reviews the applicable separation technologies relating to removal of heavy metals from solution and from soils in order to present the state-of-the-art in the field. Each technology is briefly described and typical operating conditions and technology performance are presented. Technologies described include chemical precipitation (including hydroxide, carbonate, or sulfide reagents), coagulation/flocculation, ion exchange, solvent extraction, extraction with chelating agents, complexation, electrochemical operation, cementation, membrane operations, evaporation, adsorption, solidification/stabilization, and vitrification. Several case histories are described, with a focus on waste reduction techniques and remediation of lead-contaminated soils. The paper concludes with a short discussion of important research needs in the field.

  16. Separation of heavy metals: Removal from industrial wastewaters and contaminated soil

    Energy Technology Data Exchange (ETDEWEB)

    Peters, R.W.; Shem, L.

    1993-03-01

    This paper reviews the applicable separation technologies relating to removal of heavy metals from solution and from soils in order to present the state-of-the-art in the field. Each technology is briefly described and typical operating conditions and technology performance are presented. Technologies described include chemical precipitation (including hydroxide, carbonate, or sulfide reagents), coagulation/flocculation, ion exchange, solvent extraction, extraction with chelating agents, complexation, electrochemical operation, cementation, membrane operations, evaporation, adsorption, solidification/stabilization, and vitrification. Several case histories are described, with a focus on waste reduction techniques and remediation of lead-contaminated soils. The paper concludes with a short discussion of important research needs in the field.

  17. Poly(ethylene glycol dimethacrylate-n-vinyl imidazole) beads for heavy metal removal

    International Nuclear Information System (INIS)

    Poly(ethylene glycol dimethacrylate-n-vinyl imidazole) [poly(EGDMA-VIM)] hydrogel (average diameter 150-200 ?m) was prepared by copolymerizing ethylene glycol dimethacrylate (EGDMA) with n-vinyl imidazole (VIM). The copolymer hydrogel bead composition was characterized by elemental analysis and found to contain 5 EGDMA monomer units each VIM monomer unit. Poly(EGDMA-VIM) beads had a specific surface area of 59.8 m2/g. Poly(EGDMA-VIM) beads were characterized by swelling studies and scanning electron microscopy (SEM). These poly(EGDMA-VIM) beads with a swelling ratio of 78% were used for the heavy metal removal studies. Chelation capacity of the beads for the selected metal ions, i.e., Cd(II), Hg(II) and Pb(II) were investigated in aqueous media containing different amounts of these ions (10-750 mg/l) and at different pH values (3.0-7.0). Chelation rate was very fast. The maximum chelation capacities of the poly(EGDMA-VIM) beads were 69.4 mg/g for Cd(II), 114.8 mg/g for Pb(II) and 163.5 mg/g for Hg(II). The affinity order on molar basis was observed as follows: Hg(II)>Cd(II)>Pb(II). Chelation behavior of heavy metal ions could be modelled using both the Langmuir and Freundlich isotherms. pH significantly affected the chelation capacity of VIM incorporated beads. Chelation of heavy metal ions from synthetic wastewater was also studied. The chelation capacities are 45.6 mg/g for Cd(II), 74.2 mg/g for Hg(II) and 92.5 mg/g for Pb(II) at 0.5 mmol/l initial metal/g for Pb(II) at 0.5 mmol/l initial metal concentration. Regeneration of the chelating-beads was easily performed with 0.1 M HNO3. These features make poly(EGDMA-VIM) beads potential candidate adsorbent for heavy metal removal

  18. Procion Green H-4G immobilized poly(hydroxyethylmethacrylate/chitosan) composite membranes for heavy metal removal

    International Nuclear Information System (INIS)

    The effective removal of toxic heavy metals from environmental samples still remains a major topic of present research. Metal-chelating membranes are very promising materials as adsorbents when compared with conventional beads because they are not compressible, and they eliminate internal diffusion limitations. The purpose of this study was to evaluate the performance of a novel adsorbent, Procion Green H-4G immobilized poly(hydroxyethylmethacrylate (HEMA)/chitosan) composite membranes, for the removal of three toxic heavy metal ions, namely, Cd(II), Pb(II) and Hg(II) from aquatic systems. The Procion Green H-4G immobilized poly(hydroxyethylmethacrylate/chitosan) composite membranes were characterized by elemental analysis, scanning electron microscopy and Fourier transform infrared (FTIR) spectroscopy. The immobilized amount of the Procion Green H-4G was calculated as 0.018±0.003 ?mol/cm2 from the nitrogen and sulphur stoichiometry. The adsorption capacity of Procion Green H-4G immobilized poly(hydroxyethylmethacrylate/chitosan) composite membranes for selected heavy metal ions from aqueous media containing different amounts of these ions (30-400 mg/l) and at different pH values (2.0-6.0) was investigated. The amount of Cd(II), Pb(II) and Hg(II) adsorbed onto the membranes measured at equilibrium, increased with time during the first 45 min and then remained unchanged toward the equilibrium adsorption. The maximum amounts of heavy metal ions adsorbed weramounts of heavy metal ions adsorbed were 43.60±1.74, 68.81±2.75 and 48.22±1.92 mg/g for Cd(II), Pb(II) and Hg(II), respectively. The heavy metal ion adsorption on the pHEMA/chitosan membranes (carrying no dye) were relatively low, 6.31±0.13 mg/g for Cd(II), 18.73±0.37 mg/g for Pb(II) and 18.82±0.38 mg/g for Hg(II). Competitive adsorption of the metal ions was also studied. When the metal ions competed with each other, the adsorbed amounts were 12.74±0.38 mg Cd(II)/g, 28.80±0.86 mg Pb(II)/g and 18.41±0.54 mg Hg(II)/g. Procion Green H-4G immobilized poly(hydroxyethylmethacrylate/chitosan) membranes can be regenerated by washing with a solution of nitric acid (0.01 M). The percent desorption achieved was as high as 95%. These novel membranes are suitable for repeated use for more than five adsorption/desorption cycles without any considerable loss in adsorption capacity. Adsorption equilibria were well described by Langmuir equation. It can be concluded that Procion Green H-4G immobilized poly(hydroxyethylmethacrylate/chitosan) membranes may effectively be used for the removal of Cd(II), Pb(II) and Hg(II) ions from aqueous solutions

  19. Comparative evaluation of microbial and chemical leaching processes for heavy metal removal from dewatered metal plating sludge

    International Nuclear Information System (INIS)

    The purpose of the study described in this paper was to evaluate the application of bioleaching technique involving Acidithiobacillus ferrooxidans to recover heavy metals (Zn, Cu, Ni, Pb, Cd and Cr) in dewatered metal plating sludge (with no sulfide or sulfate compounds). The effect of some conditional parameters (i.e. pH, oxidation-reduction potential (ORP), sulfate production) and operational parameters (i.e. pulp density of the sludge and agitation time) were investigated in a 3 l completely mixed batch (CMB) reactor. The metal recovery yields in bioleaching were also compared with chemical leaching of the sludge waste using commercial inorganic acids (sulfuric acids and ferric chloride). The leaching of heavy metals increased with decreasing of pH and increasing of ORP and sulfate production during the bioleaching experiment. Optimum pulp density for bioleaching was observed at 2% (w/v), and leaching efficiency decreased with increasing pulp density in bioleaching experiments. Maximum metal solubilization (97% of Zn, 96% of Cu, 93% of Ni, 84% of Pb, 67% of Cd and 34% of Cr) was achieved at pH 2, solids contents of 2% (w/v), and a reaction temperature of 25 ± 2 deg. C during the bioleaching process. The maximum removal efficiencies of 72% and 79% Zn, 70% and 75% Cu, 69% and 73% Ni, 57% and 70% Pb, 55% and 65% Cd, and 11% and 22% Cr were also attained with the chemical leaching using sulfuric acids and ferric chloride, respectively, at pH 2, solids contents of 2% (ctively, at pH 2, solids contents of 2% (w/v), and a reaction temperature of 25 ± 2 deg. C during the acid leaching processes. The rates of metal leaching for bioleaching and chemical leaching are well described by a kinetic equation related to time. Although bioleaching generally requires a longer period of operation compared to chemical leaching, it achieves higher removal efficiency for heavy metals. The efficiency of leaching processes can be arranged in descending order as follows: bioleaching > ferric chloride leaching > sulfuric acid leaching. These results suggest that bioleaching may be an alternative or adjunct to conventional physicochemical treatment of dewatered metal plating sludge for the removal hazardous heavy metals.

  20. Poly(ethylene glycol dimethacrylate-n-vinyl imidazole) beads for heavy metal removal

    Energy Technology Data Exchange (ETDEWEB)

    Kara, Ali; Uzun, Lokman; Besirli, Necati; Denizli, Adil

    2004-01-30

    Poly(ethylene glycol dimethacrylate-n-vinyl imidazole) [poly(EGDMA-VIM)] hydrogel (average diameter 150-200 {mu}m) was prepared by copolymerizing ethylene glycol dimethacrylate (EGDMA) with n-vinyl imidazole (VIM). The copolymer hydrogel bead composition was characterized by elemental analysis and found to contain 5 EGDMA monomer units each VIM monomer unit. Poly(EGDMA-VIM) beads had a specific surface area of 59.8 m{sup 2}/g. Poly(EGDMA-VIM) beads were characterized by swelling studies and scanning electron microscopy (SEM). These poly(EGDMA-VIM) beads with a swelling ratio of 78% were used for the heavy metal removal studies. Chelation capacity of the beads for the selected metal ions, i.e., Cd(II), Hg(II) and Pb(II) were investigated in aqueous media containing different amounts of these ions (10-750 mg/l) and at different pH values (3.0-7.0). Chelation rate was very fast. The maximum chelation capacities of the poly(EGDMA-VIM) beads were 69.4 mg/g for Cd(II), 114.8 mg/g for Pb(II) and 163.5 mg/g for Hg(II). The affinity order on molar basis was observed as follows: Hg(II)>Cd(II)>Pb(II). Chelation behavior of heavy metal ions could be modelled using both the Langmuir and Freundlich isotherms. pH significantly affected the chelation capacity of VIM incorporated beads. Chelation of heavy metal ions from synthetic wastewater was also studied. The chelation capacities are 45.6 mg/g for Cd(II), 74.2 mg/g for Hg(II) and 92.5 mg/g for Pb(II) at 0.5 mmol/l initial metal concentration. Regeneration of the chelating-beads was easily performed with 0.1 M HNO{sub 3}. These features make poly(EGDMA-VIM) beads potential candidate adsorbent for heavy metal removal.

  1. Optimization of heavy metal and suspended solids removal using groundwater treatment plant sludge (GWTPS)

    International Nuclear Information System (INIS)

    Full text: A groundwater treatment plant located in Chicha, Kelantan, produced 5 tons of sludge daily that require offsite disposal. The sludge was found to contain high concentration of iron and manganese. An attempt was made to reuse the Groundwater Treatment Plant Sludge (GWTPS) for wastewater treatment purposes. This study is focusing on the effectiveness of GWTPS as an adsorbent in removing Zn and Cu, as well as coagulant in removing suspended solids. The characteristic of the freshly prepared GWTPS was analyzed by measuring its pH in distilled water and total Fe concentration. Adsorption study was conducted using GWTPS. Using batch test method, parameters such as pH, contact time, adsorbent dosage and initial concentration of sorbent was varied in order to find the optimum in removing Zn and Cu. The ability of GWTPS in removing Zn and Cu was further analyzed based on its removal efficiency. Recycled Ferric Chloride (RFC) and Recycled Ferrous Sulphate (RFS) are generated from GWTPS through a digestion process using Environmental Express Hot Block. The optimization of RFC and RFS was determined by varying the GWTPS dosage and contact time during digestion. Both RFC and RFS was tested for its efficiency as a coagulant in removing Zn, Cu and suspended solids by jar test method. It was found that GWTPS was effective in removing Zn and Cu. From the study it can be concluded that RFC and RFS, a coagulant derived from groundwater sludge, is effective in removing suspendr sludge, is effective in removing suspended solids that contain heavy metals such as Zn and Cu. (author)

  2. Removal of Heavy Metal Ions by using Calcium Carbonate Extracted from Starfish Treated by Protease and Amylase

    Directory of Open Access Journals (Sweden)

    Kyong-Soo Hong

    2011-10-01

    Full Text Available CaCO3 extracted from starfish by using the commercial protein lyase having ?-amylase, ?-amylase, and protease is applied to remove heavy metal ions. The extracted CaCO3 shows excellent characteristics in removing heavy metal ions such as Cu2+, Cd2+, Pb2+, and Cr6+ compared with conventional materials such as crab shells, sawdust, and activated carbon except for removing Zn2+. SEM images reveal that the extracted CaCO33 has a good morphology and porosity. We characterize the removal efficiencies of the extracted CaCO3 for the heavy metal ions according to the concentrations, pH, temperatures, and conditions of empty bed contact times.

  3. Removal of heavy metal species from industrial sludge with the aid of biodegradable iminodisuccinic acid as the chelating ligand.

    Science.gov (United States)

    Wu, Qing; Duan, Gaoqi; Cui, Yanrui; Sun, Jianhui

    2015-01-01

    High level of heavy metals in industrial sludge was the obstacle of sludge disposal and resource recycling. In this study, iminodisuccinic acid (IDS), a biodegradable chelating ligand, was used to remove heavy metals from industrial sludge generated from battery industry. The extraction of cadmium, copper, nickel, and zinc from battery sludge with aqueous solution of IDS was studied under various conditions. It was found that removal efficiency greatly depends on pH, chelating agent's concentration, as well as species distribution of metals. The results showed that mildly acidic and neutral systems were not beneficial to remove cadmium. About 68 % of cadmium in the sample was extracted at the molar ratio of IDS to heavy metals 7:1 without pH adjustment (pH 11.5). Copper of 91.3 % and nickel of 90.7 % could be removed by IDS (molar ratio, IDS: metals?=?1:1) with 1.2 % phosphoric acid effectively. Removal efficiency of zinc was very low throughout the experiment. Based on the experimental results, IDS could be a potentially useful chelant for heavy metal removal from battery industry sludge. PMID:25115899

  4. Magnetite–hematite nanoparticles prepared by green methods for heavy metal ions removal from water

    International Nuclear Information System (INIS)

    Graphical abstract: The negatively charged cubic magnetite nanoparticles, prepared by the coprecipitation method in N2 atmosphere, can adsorb up to 99% of the positively charged toxic heavy metal ions at a proper pH value. -- Highlights: • Mixed magnetite–hematite nanoparticles were synthesized via different routes. • Prepared samples were characterized by XRD, HRTEM, BET and magnetic hysteresis. • The material was employed as a sorbent for removal of some heavy metal ions from water. • The effects of pH and the contact time on the adsorption process were studied and optimized. -- Abstract: Mixed magnetite–hematite nanoparticles were synthesized via different routes such as, coprecipitation in air and N2 atmosphere, citrate–nitrate, glycine–nitrate and microwave-assisted citrate methods. The prepared samples were characterized by X-ray diffraction (XRD), high resolution transmission electron microscope (HRTEM), BET measurements and magnetic hysteresis. XRD data showed the formation of magnetite–hematite mixture with different compositions according to the synthesis method. The particle size was in the range of 4–52 nm for all the prepared samples. From HRTEM micrographs, it was found that, the synthesis method affects the moropholgy of the prepared samples in terms of crystallinity and porosity. The magnetite–hematite mixture was employed as a sorbent material for removal of some heavy metal ions from water such as lead(II), cadmium(II) and chromium(III). The effects of pH value and the contact time on the adsorption process were studied and optimized in order to obtain the highest possible adsorption efficiency of the magnetite–hematite mixture. The effect of the synthesis method of the magnetite–hematite mixture on the adsorption process was also investigated. It was found that samples prepared by the coprecipitation method had better adsorption efficiency than those prepared by other combustion methods

  5. Magnetite–hematite nanoparticles prepared by green methods for heavy metal ions removal from water

    Energy Technology Data Exchange (ETDEWEB)

    Ahmed, M.A. [Physics Department, Faculty of Science, Cairo University, Postal Code 12613, Giza (Egypt); Ali, S.M. [Chemistry Department, Faculty of Science, Cairo University, Postal Code 12613, Giza (Egypt); El-Dek, S.I. [Physics Department, Faculty of Science, Cairo University, Postal Code 12613, Giza (Egypt); Galal, A., E-mail: galal@sci.cu.edu.eg [Chemistry Department, Faculty of Science, Cairo University, Postal Code 12613, Giza (Egypt)

    2013-06-01

    Graphical abstract: The negatively charged cubic magnetite nanoparticles, prepared by the coprecipitation method in N{sub 2} atmosphere, can adsorb up to 99% of the positively charged toxic heavy metal ions at a proper pH value. -- Highlights: • Mixed magnetite–hematite nanoparticles were synthesized via different routes. • Prepared samples were characterized by XRD, HRTEM, BET and magnetic hysteresis. • The material was employed as a sorbent for removal of some heavy metal ions from water. • The effects of pH and the contact time on the adsorption process were studied and optimized. -- Abstract: Mixed magnetite–hematite nanoparticles were synthesized via different routes such as, coprecipitation in air and N{sub 2} atmosphere, citrate–nitrate, glycine–nitrate and microwave-assisted citrate methods. The prepared samples were characterized by X-ray diffraction (XRD), high resolution transmission electron microscope (HRTEM), BET measurements and magnetic hysteresis. XRD data showed the formation of magnetite–hematite mixture with different compositions according to the synthesis method. The particle size was in the range of 4–52 nm for all the prepared samples. From HRTEM micrographs, it was found that, the synthesis method affects the moropholgy of the prepared samples in terms of crystallinity and porosity. The magnetite–hematite mixture was employed as a sorbent material for removal of some heavy metal ions from water such as lead(II), cadmium(II) and chromium(III). The effects of pH value and the contact time on the adsorption process were studied and optimized in order to obtain the highest possible adsorption efficiency of the magnetite–hematite mixture. The effect of the synthesis method of the magnetite–hematite mixture on the adsorption process was also investigated. It was found that samples prepared by the coprecipitation method had better adsorption efficiency than those prepared by other combustion methods.

  6. Synthesis of Mesoporous Adsorbent and its Application for Heavy Metal Ions Removal from Aqueous Solution

    International Nuclear Information System (INIS)

    The mesoporous silicas were synthesized via the evaporation-induced self-assembly (EISA) in the experiment. Cetyltrimethyl ammonium bromide (CTAB) was used as the template, and the silicon source was tetraethoxyorthosilicate (TEOS). The mesoporous silicas were characterized by nitrogen adsorption-desorption analysis, FTIR, TEM and SEM. The mesoporous silicas (adsorbent) exhibited higher pore diameter (centered at 5.57 nm), BET surface area (457.3 m2·g-1) and pore volume (0.563 cm2·g-1). The mesoporous silicas were used as the adsorbent to remove the heavy metal ions from aqueous solution. The following order of equilibrium adsorption capacity for Cu2+, Co2+, Ag+ and As3+ on adsorbent was: Ag+>Cu2+>Co2+>As3+. Analysis of adsorption kinetics showed that Cu2+, Co2+, Ag+ and As3+ adsorption fit the pseudo-second-order nonlinear model significantly. The removal rate for heavy metal ions was high, and the adsorbent can be regenerated by acid treatment without altering its properties.

  7. Evaluation of single and multilayered reactive zones for heavy metals removal from stormwater.

    Science.gov (United States)

    Pawluk, Katarzyna; Fronczyk, Joanna

    2015-06-01

    In this paper, the ability of granular activated carbon (GAC), silica spongolite (SS) and zeolite (Z) to remove heavy metals from aqueous solutions has been investigated through column tests. The breakthrough times for a mobile tracer that does not sorb to the material for SS, GAC and layered SS, Z and GAC were as follows: 2.54×10(4)?s, 2.38×10(4)?s and 3.02×10(4) s. The breakthrough time (tbR) for Ni was in the range from tbR?=?1.70×10(6)?s for SS, through tbR?=?3.98×10(5)?s for the layered bed, to tbR?=?8.75×10(5)?s for GAC. The breakthrough time for Cd was in the range from tbR?=?1.83×10(5)?s for GAC to tbR?=?1.30×10(6)?s for SS, Z, GAC. During the experiment, the concentration of Cd, Cu, Pb and Zn in the solution from a column filled with construction aggregate and the concentration of Pb, and Cu in a filtrate from the column filled with several materials was close to zero. The reduction in metal ions removal was due to high pH values of the solution (above 8.00). In addition, during the testing period, an increase in Cd and Zn concentrations in the filtrate from the column filled with the layered bed was observed, but at the end of the experiment the concentrations did not reach the maximum values. The test results suggest that the multilayered permeable reactive barrier is the most effective technology for long time effective removal of heavy metals. PMID:25496055

  8. Influence of the civil construction debris layer in heavy metals removal of the leachate submitted to recirculation in landfill

    OpenAIRE

    Maike Rossmann; Katia Gonçalves Gutierrez; Antônio Teixeira Matos

    2010-01-01

    Little is known about the ability of stabilized organic matter (old MSW) and construction waste (RCC) to retain heavy metals from leachate generated in landfills. The objective of this study was to assess the potential of MSW to remove old heavy metals in MSW leachate produced by freshly collected, and the effect of RCC in the concentration of heavy metals in effluents from MSW old. In three columns (CR), put a layer of RCC and then MSW old and, on the other three (SR), only MSW old. Analyzed...

  9. The Predisposition of Iraqi Rice Husk to Remove Heavy Metals from Aqueous Solutions and Capitalized from Waste Residue

    Directory of Open Access Journals (Sweden)

    Mohammed Nsaif

    2013-12-01

    Full Text Available This study is deal with study the potential of Iraqi Rice Husk (IRH on the removal of three heavy metals pollutant which were (Mg, Mn and Mo ions from industrial wastewater using different design parameters by adsorption process. Results show that the removal efficiency were (93.95, 97.18 and 95.26 % for heavy metal (Mg, Mn and Mo respectively from aquatic solution decreased with increasing of initial concentration and flow rate while the removal efficiency increased with increasing absorbance material bed height, pH and feeding temperature. Statistical model is achieved to find an expression relates the overall operating parameters with the removal efficiency for each metal ions used in this investigation in a general equation (each one alone. The samples of (IRH remaining after using it in the removal of (Mg, Mn and Mo heavy metal ions above from Simulated Synthetic Aqueous Solutions (SSAS to investigate the capitalized of it in different methods. Different benefits possess which are: remove the three toxic heavy metals ions contaminated the water, get rid of agricultural waste (IRH, in the same time, produce light and more benefit hydrocarbons from n-heptane isomerization using a type Y-zeolite catalyst synthesis from remaining (IRH and prepare a cheap and active rodenticide.

  10. USE OF CLAY TO REMOVE HEAVY METALS FROM JEBEL CHAKIR LANDFILL LEACHATE

    Directory of Open Access Journals (Sweden)

    ISLEM CHAARI

    2011-06-01

    Full Text Available Adsorptive removal of copper and nickel from Jebel Chakir landfill leachate onto smectite-rich clayey rock were carried out by both batch and column methods. The raw AYD clay was sampled in El Hamma area (Tunisia. The adsorbent employed was characterized by X-ray diffraction, specific surface area, cation exchange capacity and point of zero charge. Results showed that raw AYD clay possesses a high surface area owing to its mineralogical composition. An increase in the clay quantity from 0.5 to 5.5g generates a reduction in the quantity of metals adsorbed in the solid phase. The adsorption of heavy metals increases with a decrease in the pH leachate from 8.11 to 5.0. The column experiments showed that the addition of sand to the J. Aïdoudi clay can be useful for leachate depollution, but for a few volume due to the fine fraction of this clay (< 2µm = 89.6%. the comparison study of the heavy metals adsorption on raw AYD clay by the two modes of adsorption (batch and column showed that column test are better than that obtained by batch test.

  11. Electrochemical technology for removing heavy metals present in synthetic produced water

    Scientific Electronic Library Online (English)

    K. R., Souza; D. R., Silva; W., Mata; C. A., Martínez-Huitle; A. L. M. L., Mata.

    2012-04-01

    Full Text Available The performance of an electrocoagulation (EC) system with aluminium and iron electrodes for removing heavy metal ions (Cd2+, Cu2+, Cr3+, Sr2+ and Zn2+) present in synthetic produced water on laboratory scale was studied systematically. Experimental parameters such as applied current, flow effluent a [...] nd sacrificial electrodes were investigated in order to understand their influence on the EC process. Increasing the current density accelerated the electrocoagulation process, but made it less efficient. Cd2+, Cu2+, Sr2+ and Zn2+ showed similar removal rates, under similar conditions, indicating a uniform electrochemical behavior. The study gave indications on the removal mechanisms of the investigated metals. Cd2+, Cu2+ and Zn2+ ions are hydrolyzed and co-precipitated as hydroxides. Cr4+, was proposed to be reduced first to Cr3+ at the cathode before precipitating as hydroxide. The process expenditure was estimated and reported showing the viability of this process as a green alternative, obtaining modest costs using Fe electrodes.

  12. Method of removal of heavy metal from molten salt in IFR fuel pyroprocessing

    Science.gov (United States)

    Gay, Eddie C. (Park Forest, IL)

    1995-01-01

    An electrochemical method of separating heavy metal values from a radioactive molten salt including Li halide at temperatures of about 500.degree. C. The method comprises positioning a solid Li--Cd alloy anode in the molten salt containing the heavy metal values, positioning a Cd-containing cathode or a solid cathode positioned above a catch crucible in the molten salt to recover the heavy metal values, establishing a voltage drop between the anode and the cathode to deposit material at the cathode to reduce the concentration of heavy metals in the salt, and controlling the deposition rate at the cathode by controlling the current between the anode and cathode.

  13. Chitosan/sporopollenin microcapsules: Preparation, characterisation and application in heavy metal removal.

    Science.gov (United States)

    Sarg?n, ?dris; Arslan, Gulsin

    2015-04-01

    Use of natural polymers as biosorbents for heavy metal removal is advantageous. This paper reports a study aiming to design a novel biosorbent from two biomacromolecules; chitosan, a versatile derivative of chitin, and sporopollenin, a biopolymer with excellent mechanical properties and great resistance to chemical and biological attack. Chitosan/sporopollenin microcapsules were prepared via cross-linking and characterised by employing scanning electron microscopy, Fourier transform infrared spectroscopy and thermogravimetric analysis. Sorption performance of the microcapsules and the plain chitosan beads were tested for Cu(II), Cd(II), Cr(III), Ni(II) and Zn(II) ions at different metal ion concentration, pH, amount of sorbent, temperature and sorption time. The adsorption pattern followed Langmuir isotherm model and the sorption capacity of the chitosan/sporopollenin microcapsules was found to be Cu(II): 1.34, Cd(II): 0.77, Cr(III): 0.99, Ni(II): 0.58 and Zn(II): 0.71mmolg(-1). Plain chitosan beads showed higher affinity for the ions; Cu(II): 1.46, Cr(III): 1.16 and Ni(II): 0.81mmolg(-1) but lower for Cd(II): 0.15 and Zn(II): 0.25mmolg(-1). Sporopollenin enhanced Cd(II) and Zn(II) ions sorption capacity of the chitosan microcapsules. Chitosan/sporopollenin microcapsules can be used in Cd(II) and Zn(II) metal removal. PMID:25660654

  14. Removal and bioaccumulation of heavy metals from aqueous solutions using freshwater algae.

    Science.gov (United States)

    Shamshad, Isha; Khan, Sardar; Waqas, Muhammad; Ahmad, Nadeem; -Ur-Rehman, Khushnood; Khan, Kifayatullah

    2015-01-01

    Four freshwater algae, including Cladophora glomerata, Oedogonium westii, Vaucheria debaryana and Zygnema insigne, were tested for their bioaccumulation capacity for cadmium (Cd), chromium (Cr) and lead (Pb) in a controlled environment with an average temperature of 18 °C, and light/dark duration of 12:12 h. Experiments were performed in aqueous solutions containing selected heavy metals (HM) (ranging from 0.05 to 1.5 mg L(-1)) with 0.5 g of living algae at 18 °C and pH 6.8. The results indicated that C. glomerata was observed to be the most competent species for the removal of Cr, Cd and Pb from aqueous solutions. HM removal trends were in the order of Cd>Cr>Pb while the removal efficiency of selected algae species was in the order of C. glomerata, O. westii, V. debaryana and Z. insigne. The bioaccumulation capacity of C. glomerata, V. debaryana and Z. insigne was observed for different HM. Removal of HM was higher with low levels of HM in aqueous solutions. The results indicated that C. glomerata, O. westii, V. debaryana and Z. insigne had significant (P ?0.01) diverse bioaccumulation capacity for Cr, Cd and Pb. PMID:25607667

  15. Development of the removal technology for toxic heavy metal ions by surface-modified activated carbon

    Energy Technology Data Exchange (ETDEWEB)

    Park, Geun Il; Song, Kee Chan; Kim, Kwang Wook; Kim, In Tae; Cho, Il Hoon; Kim, Joon Hyung

    2001-01-01

    Adsorption capacities of both radionuclides(uranium, cobalt) and toxic heavy metals (lead, cadmium and chromium) using double surface-modified activated carbon in wide pH ranges are extensively evaluated. Surface-modified activated carbons are classified as AC(as-received carbon), OAC(single surface-modified carbon with nitric acid solution) and OAC-Na(double surface-modified carbon with various alkali solutions). It is established that optimal condition for the second surface modification of OAC is to use the mixed solution of both NaOH and NaCl with total concentration of 0.1 N based on adsorption efficiencies of uranium and cobalt. Variations of adsorption efficiencies in pH ranges of 2{approx}10 and the adsorption capacities in batch adsorber and fixed bed for removal of both radionuclides and toxic heavy metals using OAC-Na were shown to be superior to that of the AC and OAC even in a low pH range. Capacity factors of OAC-Na for the removal of various metal ions are also excellent to that of AC or OAC. Quantitative analysis of capacity factors for each ions showed that adsorption capacity of OAC-Na increased by 30 times for uranium, 60 times for cobalt, 9 times for lead, 30 times for cadmium, 3 times for chromium compared to that of AC at pH 5, respectively. Adsorption capacity of OAC-Na is comparable to that of XAD-16-TAR used as commercial ion exchange resin.

  16. Development of the removal technology for toxic heavy metal ions by surface-modified activated carbon

    International Nuclear Information System (INIS)

    Adsorption capacities of both radionuclides(uranium, cobalt) and toxic heavy metals (lead, cadmium and chromium) using double surface-modified activated carbon in wide pH ranges are extensively evaluated. Surface-modified activated carbons are classified as AC(as-received carbon), OAC(single surface-modified carbon with nitric acid solution) and OAC-Na(double surface-modified carbon with various alkali solutions). It is established that optimal condition for the second surface modification of OAC is to use the mixed solution of both NaOH and NaCl with total concentration of 0.1 N based on adsorption efficiencies of uranium and cobalt. Variations of adsorption efficiencies in pH ranges of 2?10 and the adsorption capacities in batch adsorber and fixed bed for removal of both radionuclides and toxic heavy metals using OAC-Na were shown to be superior to that of the AC and OAC even in a low pH range. Capacity factors of OAC-Na for the removal of various metal ions are also excellent to that of AC or OAC. Quantitative analysis of capacity factors for each ions showed that adsorption capacity of OAC-Na increased by 30 times for uranium, 60 times for cobalt, 9 times for lead, 30 times for cadmium, 3 times for chromium compared to that of AC at pH 5, respectively. Adsorption capacity of OAC-Na is comparable to that of XAD-16-TAR used as commercial ion exchange resin

  17. Removal and treatment of radioactive, organochlorine and heavy metal contaminants from solid surfaces

    International Nuclear Information System (INIS)

    The U.S. Department of Energy (DOE) is defining decontamination and decommissioning (D ampersand D) obligations at its sites. Current D ampersand D activities are Generally labor intensive, use chemical reagents that are difficult to treat, and may expose workers to radioactive and hazardous chemicals. Therefore, new technologies are desired that minimize waste, allow much of the decommissioned materials to be reused rather than disposed of as waste, and produce wastes that will meet disposal criteria The O'Brien ampersand Gere Companies tested a scouring decontamination system on concrete and steel surfaces contaminated with radioactive and hazardous wastes under the sponsorship of Martin Marietta Energy Systems, Inc. (MMES) at DOE's K-25 former gaseous diffusion plant in Oak Ridge, Tennessee. The scouring system that O'Brien ampersand Gere Companies developed removes fixed radioactive and hazardous surface contamination, while leaving the surface intact. Blasting residuals are dissolved and treated using physical/chemical processes. Bench- and pilot-scale testing of the soda blasting system was conducted between December 1993 and September 1994 on surfaces contaminated with uranium, technetium, heavy metals, and PCBs. Areas of concrete and metal surfaces were blasted. Blasting residuals were dissolved in tap water and treated for radioactive, hazardous, and organochlorine constituents. The treatment system comprised pH adjustment, aeration, solids settling, filtratitment, aeration, solids settling, filtration, carbon adsorption, and ion exchange. This system produced treated water and residual solid waste. Testing demonstrated that the system is capable of removing greater than 95% of radioactive and PCB surface contamination to below DOE's unrestricted use release limits; aqueous radionuclides, heavy metals, and PCBs were below DOE and USEPA treatment objectives after blasting residuals treatment. Waste residuals volume was decreased by 71%

  18. Heavy metal removal and speciation transformation through the calcination treatment of phosphorus-enriched sewage sludge ash.

    Science.gov (United States)

    Li, Rundong; Zhao, Weiwei; Li, Yanlong; Wang, Weiyun; Zhu, Xuan

    2015-02-11

    On the basis of the heavy metal (Cd, As, Pb, Zn, Cu, Cr, and Ni) control problem during the thermochemical recovery of phosphorus (P) from sewage sludge (SS), P-enriched sewage sludge ash (PSSA) was calcined at 1100°C. The effect of organic chlorinating agent (PVC) and inorganic chlorinating agent (MgCl2) on the fixed rate of P removal and the speciation transformation of heavy metal was studied. The removal of heavy metals Cd, Pb, As, Zn, and Cr exhibited an increasing tendency with the addition of chlorinating agent (PVC). However, an obvious peak under 100gCl/kg of PSSA appeared for Cu, owing to the presence of carbon and hydrogen in PVC. MgCl2 was found to be more effective than PVC in the removal of most heavy metals, such that up to 98.9% of Cu and 97.3% of Zn was effectively removed. Analyses of heavy metal forms showed that Pb and Zn occurred in the residue fraction after calcination. Meanwhile, the residue fraction of Cr, Ni, Cd, and Cu exhibited a decreasing tendency with the increase in the added chlorinating agent (MgCl2). Losses of P from PSSA were around 16.6% without the addition of chlorinating agent, which were greatly reduced to around 7.7% (PVC) and to only 1.7% (MgCl2). PMID:25464279

  19. Removing Adsorbed Heavy Metal Ions from Sand Surfaces via Applying Interfacial Properties of Rhamnolipid.

    Science.gov (United States)

    Haryanto, Bode; Chang, Chien-Hsiang

    2015-02-01

    In this study, the interfacial properties of biosurfactant rhamnolipid were investigated and were applied to remove adsorbed heavy metal ions from sand surfaces with flushing operations. The surface tension-lowering activity, micelle charge characteristic, and foaming ability of rhamnolipid were identified first. For rhamnolipid in water, the negatively charged characteristic of micelles or aggregates was confirmed and the foaming ability at concentrations higher than 40 mg/L was evaluated. By using the rhamnolipid solutions in a batch washing approach, the potential of applying the interfacial properties of rhamnolipid to remove adsorbed copper ions from sand surfaces was then demonstrated. In rhamnolipid solution flushing operations for sand-packed medium, higher efficiency was found for the removal of adsorbed copper ions with residual type than with inner-sphere interaction type, implying the important role of interaction type between the copper ion and the sand surface in the removal efficiency. In addition, the channeling effect of rhamnolipid solution flow in the sand-packed medium was clearly observed in the solution flushing operations and was responsible for the low removal efficiency with low contact areas between solution and sand. By using rhamnolipid solution with foam to flush the sand-packed medium, one could find that the channeling effect of the solution flow was reduced and became less pronounced with the increase in the rhamnolipid concentration, or with the enhanced foaming ability. With the reduced channeling effect in the flushing operations, the removal efficiency for adsorbed copper ions was significantly improved. The results suggested that the foam-enhanced rhamnolipid solution flushing operation was efficient in terms of surfactant usage and operation time. PMID:25748376

  20. Multivariate methods for evaluating the efficiency of electrodialytic removal of heavy metals from polluted harbour sediments

    DEFF Research Database (Denmark)

    Pedersen, Kristine Bondo; Kirkelund, Gunvor Marie

    2015-01-01

    Chemometrics was used to develop a multivariate model based on 46 previously reported electrodialytic remediation experiments (EDR) of five different harbour sediments. The model predicted final concentrations of Cd, Cu, Pb and Zn as a function of current density, remediation time, stirring rate, dry/wet sediment, cell set-up as well as sediment properties. Evaluation of the model showed that remediation time and current density had the highest comparative influence on the clean-up levels. Individual models for each heavy metal showed variance in the variable importance, indicating that the targeted heavy,metals were bound to different sediment fractions. Based on the results, a PLS model was used to design five new EDR experiments of a sixth sediment to achieve specified clean-up levels of Cu and Pb. The removal efficiencies were up to 82% for Cu and 87% for Pb and the targeted clean-up levels were met in four out of five experiments. The clean-up levels were better than predicted by the model, which could hence be used for predicting an approximate remediation strategy; the modelling power will however improve with more data included. (C) 2014 Elsevier B.V. All rights reserved.

  1. Multivariate methods for evaluating the efficiency of electrodialytic removal of heavy metals from polluted harbour sediments.

    Science.gov (United States)

    Pedersen, Kristine Bondo; Kirkelund, Gunvor M; Ottosen, Lisbeth M; Jensen, Pernille E; Lejon, Tore

    2015-02-11

    Chemometrics was used to develop a multivariate model based on 46 previously reported electrodialytic remediation experiments (EDR) of five different harbour sediments. The model predicted final concentrations of Cd, Cu, Pb and Zn as a function of current density, remediation time, stirring rate, dry/wet sediment, cell set-up as well as sediment properties. Evaluation of the model showed that remediation time and current density had the highest comparative influence on the clean-up levels. Individual models for each heavy metal showed variance in the variable importance, indicating that the targeted heavy metals were bound to different sediment fractions. Based on the results, a PLS model was used to design five new EDR experiments of a sixth sediment to achieve specified clean-up levels of Cu and Pb. The removal efficiencies were up to 82% for Cu and 87% for Pb and the targeted clean-up levels were met in four out of five experiments. The clean-up levels were better than predicted by the model, which could hence be used for predicting an approximate remediation strategy; the modelling power will however improve with more data included. PMID:25464314

  2. Impact of vertical electrokinetic-flushing technology to remove heavy metals and polycyclic aromatic hydrocarbons from contaminated soil

    International Nuclear Information System (INIS)

    Highlights: ? Heavy metals and PAHs were removed from contaminated soils by UESR. ? The treatment duration, initial soil water content and soil type was examined. ? Cadmium has the higher removal efficiency followed by zinc and lead. ? The removal efficiency of PAHs was poor compared to heavy metals. - Abstract: This study presents the feasibility of using the vertical electrokinetic-flushing technology for the simultaneous removal of cadmium (Cd), lead (Pb), zinc (Zn), as well as phenanthrene and pyrene from contaminated soils. Eight vertical bench-scale electrokinetic-flushing experiments were conducted analyzing the effect of treatment duration, initial soil water content and soil type. The highest removal efficiency was achieved for Cd (82%), followed by Zn (73%) and Pb (37%) from natural soil after 8 days of treatment with water content 60%. The study demonstrated that the metals were extracted from the soil mainly due to the dominated low pH conditions and vertically migrated from anode towards the cathode. Besides, it was found that the removal efficiency was increased in the experiments with higher treatment duration, while the higher soil water content further enhances metals removal. In terms of the organic pollutants, under the conditions conducted the electrokinetic-flushing treatment, low removal efficiency for phenanthrene (29%) and pyrene (19%) was achieved. However, it is noticeable that without the use of any solubilizing agent the organic polsolubilizing agent the organic pollutants could be removed following the movement of the pore fluid.

  3. Molecular Characterization and Phylogenetic Analyses of Heavy Metal Removal Bacteria from the Persian Gulf

    Directory of Open Access Journals (Sweden)

    H. Zolgharnein

    2010-01-01

    Full Text Available A total of 35 heavy metals resistance and removal bacterial strains were isolated from samples of marine environment and enclosed industrial areas. All isolates were characterized by molecular method. The diversity of isolated bacteria was examined by the phylogenetic analysis of 16S rRNA gene sequences. The phylogenetic analysis of the sequences revealed seven main taxonomic lineages. The phylogenetic tree illustrated discrimination between isolated bacteria from wastewater, industrials area and marine environment. Results showed new genetic differences and relationship between marine and industrial strains. Some Pseudomonas strains isolated from marine environment were well differentiated from those of industrial wastewater. Members of the genera Delftia and Bacterium formed a monophyletic group within the subdivision of the class. There was a clear differentiation between two groups of Pseudomonas and other groups of bacteria in the phylogenetic tree.

  4. Long Term Estimates of Removal of Heavy Metals and PAH in Retention Basins

    DEFF Research Database (Denmark)

    Larsen, Torben; Neerup-Jensen, O.

    2004-01-01

    The paper describes a method for the long-term simulation of the discharge of pollutants to the environment from storm sewer overflows in combined sewer systems, which have a connected retention basins. This study covers heavy metals (Cd, Cu, Ni, Pb, Zn) and PAH. The method includes both the influence of the flow-dependant sedimentation and the variation of the settling velocity of the particles. The results show that including these effects lead to significant lower discharges of pollutants compared to conventional methods of estimation. As an example computations with a spectrum of basins which cover realistic sizes show that the long-term discharges of PAH are about half of the expected values without removal.

  5. Enhancing the removal of arsenic, boron and heavy metals in subsurface flow constructed wetlands using different supporting media.

    Science.gov (United States)

    Allende, K Lizama; Fletcher, T D; Sun, G

    2011-01-01

    The presence of arsenic and heavy metals in drinking water sources poses a serious health risk due to chronic toxicological effects. Constructed wetlands have the potential to remove arsenic and heavy metals, but little is known about pollutant removal efficiency and reliability of wetlands for this task. This lab-scale study investigated the use of vertical subsurface flow constructed wetlands for removing arsenic, boron, copper, zinc, iron and manganese from synthetic wastewater. Gravel, limestone, zeolite and cocopeat were employed as wetland media. Conventional gravel media only showed limited capability in removing arsenic, iron, copper and zinc; and it showed virtually no capability in removing manganese and boron. In contrast, alternative wetland media: cocopeat, zeolite and limestone, demonstrated significant efficiencies--in terms of percentage removal and mass rate per m3 of wetland volume--for removing arsenic, iron, manganese, copper and zinc; their ability to remove boron, in terms of mass removal rate, was also higher than that of the gravel media. The overall results demonstrated the potential of using vertical flow wetlands to remove arsenic and metals from contaminated water, having cocopeat, zeolite or limestone as supporting media. PMID:22049756

  6. Crayfish Carapace Micro-powder (CCM): A Novel and Efficient Adsorbent for Heavy Metal Ion Removal from Wastewater

    OpenAIRE

    Xiaodong Zheng; Bin Li; Bo Zhu; Rui Kuang; Xuan Kuang; Baoli Xu; Meihu Ma

    2010-01-01

    Crayfish carapace, a plentiful waste in China, was applied to remove divalent heavy metal ions—copper (Cu), cadmium (Cd), zinc (Zn), and lead (Pb)—from wastewater. The adsorption capacities of crayfish carapace micro-powder (CCM) for heavy metal ions were studied with adsorbent dosages ranging from 0.5–2.5 g/L and with initial metal concentrations ranging from 50–250 mg/L. CCM particle size, initial solution pH (from 2.5–6.5), temperature (from 25–65 °C) and calcium level (from 3...

  7. Removal turbidity and separation of heavy metals using electrocoagulation-electroflotation technique A case study.

    Science.gov (United States)

    Merzouk, B; Gourich, B; Sekki, A; Madani, K; Chibane, M

    2009-05-15

    The electrocoagulation (EC) process was developed to overcome the drawbacks of conventional wastewater treatment technologies. This process is very effective in removing organic pollutants including dyestuff wastewater and allows for the reduction of sludge generation. The purposes of this study were to investigate the effects of the operating parameters, such as pH, initial concentration (C(0)), duration of treatment (t), current density (j), interelectrode distance (d) and conductivity (kappa) on a synthetic wastewater in the batch electrocoagulation-electroflotation (EF) process. The optimal operating conditions were determined and applied to a textile wastewater and separation of some heavy metals. Initially a batch-type EC-EF reactor was operated at various current densities (11.55, 18.6, 35.94, 56.64, 74.07 and 91.5mA/cm(2)) and various interelectrode distance (1, 2 and 3cm). For solutions with 300mg/L of silica gel, high turbidity removal (89.54%) was obtained without any coagulants when the current density was 11.55mA/cm(2), initial pH was 7.6, conductivity was 2.1mS/cm, duration of treatment was 10min and interelectrode distance was 1cm. The application of the optimal operating parameters on a textile wastewater showed a high removal efficiency for various items: suspended solid (SS) 86.5%, turbidity 81.56%, biological oxygen demand (BOD(5)) 83%, chemical oxygen demand (COD) 68%, and color over 92.5%. During the EC process under these conditions, we have studied the separation of some heavy metal ions such as iron (Fe), nickel (Ni), copper (Cu), zinc (Zn), lead (Pb) and cadmium (Cd) with different initial concentrations in the range of 50-600mg/L and initial pH between 7.5 and 7.8. This allowed us to show that the kinetics of electrocoagulation-electroflotation is very quick (<15min), and the removal rate reaches 95%. PMID:18799259

  8. Removal turbidity and separation of heavy metals using electrocoagulation-electroflotation technique

    International Nuclear Information System (INIS)

    The electrocoagulation (EC) process was developed to overcome the drawbacks of conventional wastewater treatment technologies. This process is very effective in removing organic pollutants including dyestuff wastewater and allows for the reduction of sludge generation. The purposes of this study were to investigate the effects of the operating parameters, such as pH, initial concentration (C0), duration of treatment (t), current density (j), interelectrode distance (d) and conductivity (?) on a synthetic wastewater in the batch electrocoagulation-electroflotation (EF) process. The optimal operating conditions were determined and applied to a textile wastewater and separation of some heavy metals. Initially a batch-type EC-EF reactor was operated at various current densities (11.55, 18.6, 35.94, 56.64, 74.07 and 91.5 mA/cm2) and various interelectrode distance (1, 2 and 3 cm). For solutions with 300 mg/L of silica gel, high turbidity removal (89.54%) was obtained without any coagulants when the current density was 11.55 mA/cm2, initial pH was 7.6, conductivity was 2.1 mS/cm, duration of treatment was 10 min and interelectrode distance was 1 cm. The application of the optimal operating parameters on a textile wastewater showed a high removal efficiency for various items: suspended solid (SS) 86.5%, turbidity 81.56%, biological oxygen demand (BOD5) 83%, chemical oxygen demand (COD) 68%, and color over 92.5%. During the EC proc and color over 92.5%. During the EC process under these conditions, we have studied the separation of some heavy metal ions such as iron (Fe), nickel (Ni), copper (Cu), zinc (Zn), lead (Pb) and cadmium (Cd) with different initial concentrations in the range of 50-600 mg/L and initial pH between 7.5 and 7.8. This allowed us to show that the kinetics of electrocoagulation-electroflotation is very quick (<15 min), and the removal rate reaches 95%

  9. Removal turbidity and separation of heavy metals using electrocoagulation-electroflotation technique

    Energy Technology Data Exchange (ETDEWEB)

    Merzouk, B. [Departement d' Hydraulique, Universite Mohamed Boudiaf de M' sila (Algeria)], E-mail: mbelkov@yahoo.fr; Gourich, B. [Laboratoire de Genie des Procedes, Ecole Superieure de Technologie de Casablanca, B.P. 8012, Oasis (Morocco); Sekki, A. [Departement de Genie des Procedes, Universite Ferhat Abbas de Setif (Algeria); Madani, K.; Chibane, M. [Faculte des Sciences de la Nature et de la Vie, Universite A - Mira de Bejaia (Algeria)

    2009-05-15

    The electrocoagulation (EC) process was developed to overcome the drawbacks of conventional wastewater treatment technologies. This process is very effective in removing organic pollutants including dyestuff wastewater and allows for the reduction of sludge generation. The purposes of this study were to investigate the effects of the operating parameters, such as pH, initial concentration (C{sub 0}), duration of treatment (t), current density (j), interelectrode distance (d) and conductivity ({kappa}) on a synthetic wastewater in the batch electrocoagulation-electroflotation (EF) process. The optimal operating conditions were determined and applied to a textile wastewater and separation of some heavy metals. Initially a batch-type EC-EF reactor was operated at various current densities (11.55, 18.6, 35.94, 56.64, 74.07 and 91.5 mA/cm{sup 2}) and various interelectrode distance (1, 2 and 3 cm). For solutions with 300 mg/L of silica gel, high turbidity removal (89.54%) was obtained without any coagulants when the current density was 11.55 mA/cm{sup 2}, initial pH was 7.6, conductivity was 2.1 mS/cm, duration of treatment was 10 min and interelectrode distance was 1 cm. The application of the optimal operating parameters on a textile wastewater showed a high removal efficiency for various items: suspended solid (SS) 86.5%, turbidity 81.56%, biological oxygen demand (BOD{sub 5}) 83%, chemical oxygen demand (COD) 68%, and color over 92.5%. During the EC process under these conditions, we have studied the separation of some heavy metal ions such as iron (Fe), nickel (Ni), copper (Cu), zinc (Zn), lead (Pb) and cadmium (Cd) with different initial concentrations in the range of 50-600 mg/L and initial pH between 7.5 and 7.8. This allowed us to show that the kinetics of electrocoagulation-electroflotation is very quick (<15 min), and the removal rate reaches 95%.

  10. Comparative Study for Removal of Some Heavy Metals from Liquid Wastes Using Natural Resources and Bacteria

    International Nuclear Information System (INIS)

    Twenty three bacterial strains have been isolated from polluted water and soil samples of Ismailia Canal in Egypt. The polluted sites were at Abu Zabal Factory (fertilizer factory), Elshaba factory (Aluminum sulfate factory) and Oil-pipes Company (petrochemical materials). By screening the abilities of these isolates to tolerate heavy metals, it has been found that isolate MAM-4was the most potent isolate. This isolate was identified as Providencia rettgeri. As the concentration of Al3+ increased the ability of P. rettgeri to uptake Al3+ decreased. P. rettgeri could remove 97.2% of Al3+ from 25 mg/L. Bacillus cereus ATCC 11778 (American Type Culture Collection, U.S.A) gave the same trend for Al3+ uptake but P. rettgeri was more tolerant to Al3+ than B. cereus ATCC 11778.With increasing Co2+ concentration, abilities of P. rettgeri and B. cereus ATCC 11778 to uptake decreased. P. rettgeri could uptake 59 mg/L Co2+ from 200 mg/L (29.5%), while B. cereus ATCC 11778 uptake 68.3 mg/L (34.1%). Also, as the concentration of Cu2+ increased the abilities of P. rettgeri and B. cereus ATCC 11778 to uptake Cu2+ decreased. P. rettgeri removed 11.5 mg/Cu2+ from 25 mg/L (47.0%), while B. cereus ATCC 11778 removed 13.5 mg/L from the some concentration (54.%). Combined treatment of 1.0% untreated clay with P. rettgeri could remove 471.8 mg/L Al3+ from 500 mg/L (94.4%), 82.4 mg/L Co2+ from 200 mg/L (41.2%) and 150 mg/L Cu2+ from 300 mg/L (50%). However, 1.0 % treated clay combined with P. rettgeri adsorbed 207.8 mg/L Al3+from 500 mg/L (41.5%), 52.0 mg/L Co2+ from 200 mg/L (26.0%) and 185 mg/L Cu2+ from 300 mg/L (61.6%). The combined treatment adsorbed more heavy metals than clay only or bacterial cells only. Three KGy gamma radiations reduced the viable count of P. rettgeri by 7.4 log cycles. P. rettegri mutant MI was able to tolerate more Al3+ than the parent strain

  11. Adsorption materials for removal of heavy metals and petroleum hydrocarbons from contaminated leachates

    International Nuclear Information System (INIS)

    Adsorption function and capacities, for heavy metals and selected hydrocarbons, of several low-cost and alternative bio-sorption materials have been investigated. The materials studied were residual products from the forest industry (saw dust, pine bark and fiber ash) and natural materials (peat moss, shrimp shells and seaweed). Batch tests and column experiments were carried out with both artificial solutions and highly contaminated leachate from an industrial landfill. Fiber ashes and peat showed the highest sorption capacity for metals among the materials studied in comparative batch tests. In these tests, artificial single metal solutions in concentration ranges of 1?10 mg/l, and liquid to solid ratios of 20 and 200 were used. The fiber ash removed lead by 99%, copper by 100%, zinc by 99% and chromium by 82%. Peat removed lead by 98%, copper by 94%, zinc by 73% and chromium by 88%. Metal removal from the landfill leachates was also studied in batch tests, where lead was reduced by ash and peat by 99% and 96% respectively, copper by 100% and 92%, zinc by 95% and 33%, cadmium by 88% and 40%. A net release of Al, Cr, Ca, Ba and K from ash was observed, whereas the peat removed chromium by 66% and aluminium by 85%. The lower performance of the adsorbents for complex solutions as real leachates, suggests competitive sorption of ions although the mechanisms of sorption are not yet fully understood. In initial batch studies for organic pollutants, the adsorption for diesrganic pollutants, the adsorption for diesel oil by ash and peat was 98% and 97% respectively, 97% and 92 % for the n-alkane C16, and 91% for n-C12 for both materials. Bark adsorbed diesel oil by 83%, and the lower value could be explained by the larger particle size of the bark. Several column tests with peat, a peat-ash mixture and bark have been carried out to investigate the adsorbents' behavior and sorption capacity under flowing conditions. Both simulated contaminated groundwater and real landfill leachates were used as eluents. Sorption capacities for the metals and break-through volumes of the solutions were obtained. For most of the metals studied (Cd, Pb, Zn, Cu, Ni) ground peat appeared to be the best adsorbent, both in degree of sorption and service time. The column with peat-ash mixture adsorbed Cd, Ni and Pb to a lower degree, but retained the metals for a longer time than the peat column. The adsorption rate was significantly higher when artificial solutions were used and the metals were adsorbed for a longer time: Cu and Ni for approximately 20% and Zn for 50% longer time. These results point out that laboratory tests can overestimate adsorbent's performance and experiments should be specific and using real leachates. High iron content showed no effect on the sorption capacity of Cd and Cu, but other metals as Ni, Pb, Zn were sorbed for a shorter time. To better understand the basic mechanisms and processes, column tests need to be complemented with batch tests for basic studies of adsorption and competitive mechanisms. (authors)

  12. Adsorption materials for removal of heavy metals and petroleum hydrocarbons from contaminated leachates

    Energy Technology Data Exchange (ETDEWEB)

    Kalmykova, Y.; Steenari, B.M. [Chalmers Univ. of Technology, Environmental Inorganic Chemistry, Goeteborg (Sweden); Stromvall, A.M. [Chalmers Univ. of Technology, Water Environment Transport, Department of Civil and Environmental Engineering, SE Goteborg (Sweden)

    2005-07-01

    Adsorption function and capacities, for heavy metals and selected hydrocarbons, of several low-cost and alternative bio-sorption materials have been investigated. The materials studied were residual products from the forest industry (saw dust, pine bark and fiber ash) and natural materials (peat moss, shrimp shells and seaweed). Batch tests and column experiments were carried out with both artificial solutions and highly contaminated leachate from an industrial landfill. Fiber ashes and peat showed the highest sorption capacity for metals among the materials studied in comparative batch tests. In these tests, artificial single metal solutions in concentration ranges of 1?10 mg/l, and liquid to solid ratios of 20 and 200 were used. The fiber ash removed lead by 99%, copper by 100%, zinc by 99% and chromium by 82%. Peat removed lead by 98%, copper by 94%, zinc by 73% and chromium by 88%. Metal removal from the landfill leachates was also studied in batch tests, where lead was reduced by ash and peat by 99% and 96% respectively, copper by 100% and 92%, zinc by 95% and 33%, cadmium by 88% and 40%. A net release of Al, Cr, Ca, Ba and K from ash was observed, whereas the peat removed chromium by 66% and aluminium by 85%. The lower performance of the adsorbents for complex solutions as real leachates, suggests competitive sorption of ions although the mechanisms of sorption are not yet fully understood. In initial batch studies for organic pollutants, the adsorption for diesel oil by ash and peat was 98% and 97% respectively, 97% and 92 % for the n-alkane C16, and 91% for n-C{sub 12} for both materials. Bark adsorbed diesel oil by 83%, and the lower value could be explained by the larger particle size of the bark. Several column tests with peat, a peat-ash mixture and bark have been carried out to investigate the adsorbents' behavior and sorption capacity under flowing conditions. Both simulated contaminated groundwater and real landfill leachates were used as eluents. Sorption capacities for the metals and break-through volumes of the solutions were obtained. For most of the metals studied (Cd, Pb, Zn, Cu, Ni) ground peat appeared to be the best adsorbent, both in degree of sorption and service time. The column with peat-ash mixture adsorbed Cd, Ni and Pb to a lower degree, but retained the metals for a longer time than the peat column. The adsorption rate was significantly higher when artificial solutions were used and the metals were adsorbed for a longer time: Cu and Ni for approximately 20% and Zn for 50% longer time. These results point out that laboratory tests can overestimate adsorbent's performance and experiments should be specific and using real leachates. High iron content showed no effect on the sorption capacity of Cd and Cu, but other metals as Ni, Pb, Zn were sorbed for a shorter time. To better understand the basic mechanisms and processes, column tests need to be complemented with batch tests for basic studies of adsorption and competitive mechanisms. (authors)

  13. Influence of the civil construction debris layer in heavy metals removal of the leachate submitted to recirculation in landfill

    Directory of Open Access Journals (Sweden)

    Maike Rossmann

    2010-08-01

    Full Text Available Little is known about the ability of stabilized organic matter (old MSW and construction waste (RCC to retain heavy metals from leachate generated in landfills. The objective of this study was to assess the potential of MSW to remove old heavy metals in MSW leachate produced by freshly collected, and the effect of RCC in the concentration of heavy metals in effluents from MSW old. In three columns (CR, put a layer of RCC and then MSW old and, on the other three (SR, only MSW old. Analyzed in the leachate and effluent pH, EC, BOD and metals Zn, Cd, Cu and Pb. There were similar and efficient removal of BOD and heavy metals in both treatments. The presence of the layer of RCC was considered important to the overall improvement in effluent quality, but did not influence the concentration of metals in the effluent. The order of retention of metals in the columns was: Cu ~ Pb> Cd> Zn. With the exception of Cd and Zn, all other variables assessed in the effluent were below the maximum standards set in DN 01.08 COPAM / CERH for release effluent into water bodies.

  14. Hybrid flotation--membrane filtration process for the removal of heavy metal ions from wastewater.

    Science.gov (United States)

    Blöcher, C; Dorda, J; Mavrov, V; Chmiel, H; Lazaridis, N K; Matis, K A

    2003-09-01

    A promising process for the removal of heavy metal ions from aqueous solutions involves bonding the metals firstly to a special bonding agent and then separating the loaded bonding agents from the wastewater stream by separation processes. For the separation stage, a new hybrid process of flotation and membrane separation has been developed in this work by integrating specially designed submerged microfiltration modules directly into a flotation reactor. This made it possible to combine the advantages of both flotation and membrane separation while overcoming the limitations. The feasibility of this hybrid process was proven using powdered synthetic zeolites as bonding agents. Stable fluxes of up to 80l m(-2)h(-1) were achieved with the ceramic flat-sheet multi-channel membranes applied at low transmembrane pressure (copper, nickel and zinc, were reduced from initial concentrations of 474, 3.3 and 167mg x l(-1), respectively, to below 0.05 mg x l(-1), consistently meeting the discharge limits. PMID:12909122

  15. Removal of heavy metals in a wet detention pond in Reykjavik

    OpenAIRE

    Vollertsen, Guðbjo?rg Esther G.

    2009-01-01

    Studying wet detention ponds is relevant because they are mainly built to protect salmon rivers. More knowledge is needed on wet detention ponds for Icelandic conditions. The goals of this study are to gather information about the time variability in heavy metal concentration in surface water entering a wet detention pond. In addition, estimate the treatment efficiency for heavy metals in a wet detention pond during different runoff events. Lastly, to evaluate the impact of a detention pond o...

  16. Functionalized Nanoporous Silica for the Removal of Heavy Metals from Biological Systems: Adsorption and Application

    OpenAIRE

    Yantasee, Wassana; Rutledge, Ryan D.; Chouyyok, Wilaiwan; Sukwarotwat, Vichaya; Orr, Galya; Warner, Cynthia L.; Warner, Marvin G.; Fryxell, Glen E.; Wiacek, Robert J.; Timchalk, Charles; Addleman, R. Shane

    2010-01-01

    Surface-functionalized nanoporous silica, often referred to as self-assembled monolayers on mesoporous supports (SAMMS), has previously demonstrated the ability to serve as very effective heavy metal sorbents in a range of aquatic and environmental systems, suggesting that they may be advantageously utilized for biomedical applications such as chelation therapy. Herein we evaluate surface chemistries for heavy metal capture from biological fluids, various facets of the materials’ biocompati...

  17. Adsorptive removal of heavy metals from water using sodium titanate nanofibres loaded onto GAC in fixed-bed columns.

    Science.gov (United States)

    Sounthararajah, D P; Loganathan, P; Kandasamy, J; Vigneswaran, S

    2015-04-28

    Heavy metals are serious pollutants in aquatic environments. A study was undertaken to remove Cu, Cd, Ni, Pb and Zn individually (single metal system) and together (mixed metals system) from water by adsorption onto a sodium titanate nanofibrous material. Langmuir adsorption capacities (mg/g) at 10(-3)M NaNO3 ionic strength in the single metal system were 60, 83, 115 and 149 for Ni, Zn, Cu, and Cd, respectively, at pH 6.5 and 250 for Pb at pH 4.0. In the mixed metals system they decreased at high metals concentrations. In column experiments with 4% titanate material and 96% granular activated carbon (w/w) mixture at pH 5.0, the metals breakthrough times and adsorption capacities (for both single and mixed metals systems) decreased in the order Pb>Cd, Cu>Zn>Ni within 266 bed volumes. The amounts adsorbed were up to 82 times higher depending on the metal in the granular activated carbon+titanate column than in the granular activated carbon column. The study showed that the titanate material has high potential for removing heavy metals from polluted water when used with granular activated carbon at a very low proportion in fixed-bed columns. PMID:25668299

  18. Heavy Metal Removal from Multicomponent System by the Cyanobacterium Nostoc muscorum: Kinetics and Interaction Study.

    Science.gov (United States)

    Roy, Arindam Sinha; Hazarika, Jayeeta; Manikandan, N Arul; Pakshirajan, Kannan; Syiem, Mayashree B

    2015-04-01

    In this study, Nostoc muscorum, a native cyanobacterial species isolated from a coal mining site, was employed to remove Cu(II), Zn(II), Pb(II) and Cd(II) from aqueous solution containing these metals in the mixture. In this multicomponent study, carried out as per the statistically valid Plackett-Burman design of experiments, the results revealed a maximum removal of both Pb(II) (96.3 %) and Cu(II) (96.42 %) followed by Cd(II) (80.04 %) and Zn(II) (71.3 %) at the end of the 60-h culture period. Further, the removal of these metals was attributed to both passive biosorption and accumulation by the actively growing N. muscorum biomass. Besides, the specific removal rate of these metals by N. muscorum was negatively correlated to its specific growth rate. For a better understanding of the effect of these metals on each other's removal by the cyanobacteria, the results were statistically analyzed in the form of analysis of variance (ANOVA) and Student's t test. ANOVA of the metal bioremoval revealed that the main (individual) effect due to the metals was highly significant (P value cyanobacteria in the bioremoval of these metals but also the effect of individual metals on each other's removal in the multicomponent system. PMID:25725800

  19. Immobilization of Thiadiazole Derivatives on Magnetite Mesoporous Silica Shell Nanoparticles in Application to Heavy Metal Removal from Biological Samples

    International Nuclear Information System (INIS)

    In this report magnetite was synthesized by a coprecipitation method, then coated with a layer of silica. Another layer of mesoporous silica was added by a sol-gel method, then 5-amino-1,3,4-thiadiazole-thiol (ATT) was immobilized onto the synthesized nanoparticles with a simple procedure. This was followed by a series of characterizations, including transmission electron microscopy (TEM), FT-IR spectrum, elemental analysis and XRD. Heavy metal uptake of the modified nanoparticles was examined by atomic absorption spectroscopy. For further investigation we chose Cu2+ as the preferred heavy metal to evaluate the amount of adsorption, as well as the kinetics and mechanism of adsorption. Finally, the capacity of our nanoparticles for the heavy metal removal from blood was shown. We found that the kinetic rate of Cu2+ adsorption was 0.05 g/mg/min, and the best binding model was the Freundlich isotherm.

  20. Immobilization of Thiadiazole Derivatives on Magnetite Mesoporous Silica Shell Nanoparticles in Application to Heavy Metal Removal from Biological Samples

    Science.gov (United States)

    Emadi, Masoomeh; Shams, Esmaeil

    2010-12-01

    In this report magnetite was synthesized by a coprecipitation method, then coated with a layer of silica. Another layer of mesoporous silica was added by a sol-gel method, then 5-amino-1,3,4-thiadiazole-thiol (ATT) was immobilized onto the synthesized nanoparticles with a simple procedure. This was followed by a series of characterizations, including transmission electron microscopy (TEM), FT-IR spectrum, elemental analysis and XRD. Heavy metal uptake of the modified nanoparticles was examined by atomic absorption spectroscopy. For further investigation we chose Cu2+ as the preferred heavy metal to evaluate the amount of adsorption, as well as the kinetics and mechanism of adsorption. Finally, the capacity of our nanoparticles for the heavy metal removal from blood was shown. We found that the kinetic rate of Cu2+ adsorption was 0.05 g/mg/min, and the best binding model was the Freundlich isotherm.

  1. The Use of Microwave Derived Activated Carbon for Removal of Heavy Metal in Aqueous Solution

    Directory of Open Access Journals (Sweden)

    Rafeah Wahi

    2011-09-01

    Full Text Available Palm oil processing waste which is palm oil kernel shell (POKS was converted to activated carbon (POKS AC through 7 min microwave pyrolysis at temperature 270 °C followed by chemical activation using NaOH and HCl. The adsorption study on Ni(II, Cu(II and Cr(IV was conducted to evaluate the efficiency of the prepared activated carbon to remove heavy metal. The adsorption capacity was determined as a function of adsorbate initial concentration and adsorbent dosage. Based on Langmuir isotherm, Ni(II showed highest adsorption capacity of 40.98 mg/g, followed by Cr(IV and Cu(II with adsorption capacity of 40.60 mg/g and 13.69 mg/g, respectively. Cr(IV and Cu(II showed better fitting to Freundlich isotherm model with high correlation regression indicating the applicability of heterogeneous adsorption. Ni(II show better fitting with Langmuir isotherm that indicate monolayer coverage. The use of POKS AC is not only effective for adsorption of Cr(IV, Ni(II and Cu(II in aqueous solution but also helps to overcome the over abundance of POKS waste problem.

  2. Characterization and application of dried plants to remove heavy metals, nitrate, and phosphate ions from industrial wastewaters

    Energy Technology Data Exchange (ETDEWEB)

    Chiban, Mohamed; Soudani, Amina; Sinan, Fouad [Department of Chemistry, Faculty of Sciences, Agadir (Morocco); Tahrouch, Saida [Department of Biology, Faculty of Sciences, Agadir (Morocco); Persin, Michel [European Membrane Institute, CRNS, Montpellier (France)

    2011-04-15

    Low cost adsorbents were prepared from dried plants for the removal of heavy metals, nitrate, and phosphate ions from industrial wastewaters. The efficiency of these adsorbents was investigated using batch adsorption technique at room temperature. The dried plant particles were characterized by N{sub 2} at 77 K adsorption, scanning electron microscopy, energy dispersive X-ray spectroscopy, Fourier transform infrared spectroscopy, and phytochemical screening. The adsorption experiments showed that the microparticles of the dried plants presented a good adsorption of heavy metals, phosphate, and nitrate ions from real wastewaters. This adsorption increased with increasing contact time. The equilibrium time was found to be 30 min for heavy metals and nitrate ions and 240 min for phosphate ions. After the adsorption process, the Pb(II) concentrations, as well as those of Cd(II), Cu(II), and Zn(II) were below the European drinking water norms concentrations. The percentage removal of heavy metals, nitrates, and phosphates from industrial wastewaters by dried plants was {proportional_to}94% for Cd{sup 2+}, {proportional_to}92% for Cu{sup 2+}, {proportional_to}99% for Pb{sup 2+}, {proportional_to}97% for Zn{sup 2+}, {proportional_to}100% for NO{sub 3}{sup -} and {proportional_to}77% for PO{sub 4}{sup 3-} ions. It is proved that dried plants can be one alternative source for low cost absorbents to remove heavy metals, nitrate, and phosphate ions from municipal and industrial wastewaters. (Copyright copyright 2011 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  3. Removal of Heavy Metal Ions (Pb2+, Cu2+ in Aqueous Solutions by Pterygota macrocarpa Sawdust

    Directory of Open Access Journals (Sweden)

    K. Adouby

    2007-01-01

    Full Text Available The purpose of this study is the use of Pterygota macrocarpa sawdust as adsorbent for lead and copper removal into aqueous acid solutions. The results showed that the rate of removal is better for particle sizes lower than 0.5 mm, in the metal solutions at pH 3. The Langmuir, Freundlich and Temkin isotherms studies were allowed to determine the maximum capacity of adsorption of the sawdust; it is 115.61 and 24.02 mg g-1 for the lead and cooper removal, respectively. This study also showed that the metal ions removal is accompanied by a releasing of K+, Ca2+ and Mg2+ in the metal solutions. This use could constitute a way of valorisation of the sawdust, a main waste of the wood industry.

  4. Removal of some heavy metals from industrial waste water using polyacrylamide ferric antimonate as new ion exchange material

    International Nuclear Information System (INIS)

    Composite ion exchangers consist of one or more ion exchangers combined with another material, which can be inorganic or organic and may it be an ion exchanger. The reason for manufacturing a composite material is to produce a granular material, with sufficient strength for column use, from ion exchangers that do not form, or only form weak, granules themselves. Attempts in this study are focused to prepare composite ion exchangers for treatment of wastewater. Heavy metals when present in water in concentrations exceeding the permitted limits are injurious to the health. Hence, it is very important to treat such waters to remove the metal ions present before it is supplied for any useful purpose. Therefore, many investigations have studied to develop more effective process to treat such waste stream. Ion-exchange has been widely adopted in heavy metal containing wastewater and most of the ion-exchangers (i.e. ion-exchange media) currently being used are commercially mass-produced organic resins.Therefore, the main aim of this work is directed to find the optimum conditions for removal of some heavy metals from industrial waste water.1-Preparation of polyacrylamide ferric antimonate composite.2-Characterization of the prepared exchanger using IR spectra, X-ray diffraction pattern, DTA and TG analyses.3-Chemical stability, capacity and equilibrium measurements will be determined on the materials using at different conditions (ph heating temperature and reaction temperature).4-Kinetic studies of some heavy metals.5-Ion exchange isotherm.6-Breakthrough curves for removal of the investigated metal ions on the prepared exchanger under certain condition.

  5. Studies on sorption, desorption, regeneration and reuse of sugar-beet pectin gels for heavy metal removal

    Energy Technology Data Exchange (ETDEWEB)

    Mata, Y.N. [Department of Materials Science and Metallurgical Engineering, Complutense University of Madrid, Ciudad Universitaria s/n 28040 Madrid (Spain); Blazquez, M.L., E-mail: mlblazquez@quim.ucm.es [Department of Materials Science and Metallurgical Engineering, Complutense University of Madrid, Ciudad Universitaria s/n 28040 Madrid (Spain); Ballester, A.; Gonzalez, F.; Munoz, J.A. [Department of Materials Science and Metallurgical Engineering, Complutense University of Madrid, Ciudad Universitaria s/n 28040 Madrid (Spain)

    2010-06-15

    This work reports the effectiveness of sugar-beet pectin xerogels for the removal of heavy metals (cadmium, lead and copper) after multiple batch sorption-desorption cycles, with and without a gels regeneration step. Metals were recovered from xerogel beads without destroying their sorption capability and the beads were successfully reused (nine cycles) without significant loss in both biosorption capacity and biosorbent mass. Metals uptake levelled off or increased after using a 1 M CaCl{sub 2} regeneration step after each desorption. Calcium, as a regenerating agent, increased the stability and reusability of the gels repairing the damage caused by the acid and removing the excess protons after each elution providing new binding sites. Because of their excellent reusability, pectin xerogels are suitable for metal remediation technologies.

  6. Studies on sorption, desorption, regeneration and reuse of sugar-beet pectin gels for heavy metal removal

    International Nuclear Information System (INIS)

    This work reports the effectiveness of sugar-beet pectin xerogels for the removal of heavy metals (cadmium, lead and copper) after multiple batch sorption-desorption cycles, with and without a gels regeneration step. Metals were recovered from xerogel beads without destroying their sorption capability and the beads were successfully reused (nine cycles) without significant loss in both biosorption capacity and biosorbent mass. Metals uptake levelled off or increased after using a 1 M CaCl2 regeneration step after each desorption. Calcium, as a regenerating agent, increased the stability and reusability of the gels repairing the damage caused by the acid and removing the excess protons after each elution providing new binding sites. Because of their excellent reusability, pectin xerogels are suitable for metal remediation technologies.

  7. Electrodialytic removal of heavy metals from municipal solid waste incineration fly ash using ammonium citrate as assisting agent

    DEFF Research Database (Denmark)

    Pedersen, Anne Juul; Ottosen, Lisbeth M.

    2005-01-01

    Electrodialytic remediation, an electrochemically assisted separation method, has previ-ously shown potential for removal of heavy metals from municipal solid waste incineration (MSWI) fly ashes. In this work electrodialytic remediation of MSWI fly ash using ammonium citrate as assisting agent was studied, and the results were compared with traditional batch extraction experiments. The application of electric current was found to increase the heavy metal release significantly compared to batch extraction experiments at comparable conditions (same liquid-to-solid ratio, same assisting agent, and same extraction time). Up to 86 % Cd, 20 % Pb, 62 % Zn, 81 % Cu and 44 % Cr was removed from 75 g of MSWI fly ash in electrodialytic remediation experiments using ammonium citrate as assisting agent. The time range for the experiments varied between 5 and 70 days.

  8. Heavy Metals Removal in Aqueous Solution by Activated Carbons Prepared from Coconut Shell and Seed Shell of the Palm Tree

    OpenAIRE

    Gueu, S.; Yao, B.; Adouby, K.; Ado, G.

    2006-01-01

    The purpose of this study is to convert locally vegetal materials such as coconut shell and seed shell of palm tree, which are low-cost, renewable and widely available into inexpensive adsorbent materials for heavy metal copper, lead and zinc removal from wastewater. Both raw materials were chemically activated by phosphoric acid (H3PO4). Various parameters such as adsorbent dose, pH and activation temperature of carbon were studied to establish optimum adsorption conditions. The results show...

  9. Removal of dissolved heavy metals from pre-settled stormwater runoff by iron-oxide coated sand (IOCS)

    OpenAIRE

    Møller, J.; Ledin, Anna; Mikkelsen, Peter Steen

    2006-01-01

    Sorption to iron-oxide coated sand (IOCS) is a promosing technology for removal of the dissolved heavy metal fraction in stormwater runoff. The development of a new technology is necessary since studies of stormwater runoff from traffic areas indicate that an oil separator and detention pond may not guarantee that emission limit values set by the Danish EPA are satisfied. Runoff water was sampled from an urban highway, allowed to settle for 24 hours to simulate the effect of a detention pond,...

  10. Removal of heavy metals from acid mine drainage (AMD) using coal fly ash, natural clinker and synthetic zeolites.

    Science.gov (United States)

    Ríos, C A; Williams, C D; Roberts, C L

    2008-08-15

    Acid mine drainage (AMD) is a widespread environmental problem associated with both working and abandoned mining operations, resulting from the microbial oxidation of pyrite in presence of water and air, affording an acidic solution that contains toxic metal ions. The generation of AMD and release of dissolved heavy metals is an important concern facing the mining industry. The present study aimed at evaluating the use of low-cost sorbents like coal fly ash, natural clinker and synthetic zeolites to clean-up AMD generated at the Parys Mountain copper-lead-zinc deposit, Anglesey (North Wales), and to remove heavy metals and ammonium from AMD. pH played a very important role in the sorption/removal of the contaminants and a higher adsorbent ratio in the treatment of AMD promoted the increase of the pH, particularly using natural clinker-based faujasite (7.70-9.43) and the reduction of metal concentration. Na-phillipsite showed a lower efficiency as compared to that of faujasite. Selectivity of faujasite for metal removal was, in decreasing order, Fe>As>Pb>Zn>Cu>Ni>Cr. Based on these results, the use of these materials has the potential to provide improved methods for the treatment of AMD. PMID:18221835

  11. Validity of manganese as a surrogate of heavy metals removal in constructed wetlands treating acidic mine water

    International Nuclear Information System (INIS)

    The evaluation of manganese as a surrogate for heavy metal behavior in two wetland treatment systems receiving acidic coal mine drainage in central Pennsylvania was investigated. The use of manganese as an indicator is based on physical/chemical treatment processes quite different from wetland treatment. The treatment systems represented one anoxic, subsurface flow system and one oxic surface flow system. Water quality parameters measured included pH, alkalinity, acidity, and a suite of metals. Correlation and linear regression analysis were used to evaluate the ability of a candidate predictor variable (indicator) to predict heavy metal concentrations and removal. The use of manganese as a predictor of effluent quality proved to be poor in both wetland treatment systems, as evidenced by low linear R2 values and negative correlations. Zinc emerged as the best predictor of the detectable heavy metals at the anoxic wetland. Zinc exhibited positive strong linear correlations with copper, cobalt, and nickel (R2 values of 0.843, 0.881, and 0.970, respectively). Effluent pH was a slightly better predictor of effluent copper levels in the anoxic wetland. Iron and cobalt effluent concentrations showed the only strong relationship (R2 value = 0.778) in the oxic system. The lack of good correlations with manganese strongly challenges its appropriateness as a surrogate for heavy metals in these systems

  12. Physical Characterization of Prepared and Spent CFA/PFA/RHA Sorbents in Removing Heavy Metals and Dyes

    Directory of Open Access Journals (Sweden)

    S. Ismail

    2012-01-01

    Full Text Available High concentration of heavy metals and dyes creates health and environmental problems. Different types of treatment have been applied to remove these pollutants. In this study, physical characterization of CFA/PFA/RHA sorbent has been investigated to obtain a better understanding of adsorption process in removing heavy metals and dye. The sorbents from Coal Fly Ash (CFA, Palm oil Fuel Ash (PFA and Rice Husk Ash (RHA were prepared using water hydration method, sol-gel method and activation by NaOH method. The prepared sorbents were used to remove single components of zinc (Zn2+, nickel (Ni2+, iron (Fe2+ and brilliant green dye from synthetic wastewater. The CFA/PFA/RHA sorbent prepared from sol-gel method showed high adsorption efficiency. From the particle size distribution analysis it was shown that the sorbents have a variation as a result of the reaction during the preparation of sorbent and treatment processes. Higher BET specific surface area was obtained for sorbent prepared from water hydration method. The surface morphology of the sorbents revealed the structure of CFA/PFA/RHA sorbent before and after the adsorption processes. This study shows that physical characteristics of CFA/PFA/RHA sorbent affecting the adsorption of heavy metals and dye.

  13. Poly(vinyl pyridine-poly ethylene glycol methacrylate-ethylene glycol dimethacrylate) beads for heavy metal removal

    Energy Technology Data Exchange (ETDEWEB)

    Duran, Ali [Department of Chemical Engineering, Faculty of Engineering, Hacettepe University, 06532 Ankara (Turkey)], E-mail: ali.duran@kosgeb.gov.tr; Soylak, Mustafa [Department of Chemistry, Faculty of Arts and Sciences, Erciyes University, 38039 Kayseri (Turkey); Tuncel, S. Ali [Department of Chemical Engineering, Faculty of Engineering, Hacettepe University, 06532 Ankara (Turkey)

    2008-06-30

    Poly(vinyl pyridine-poly ethylene glycol methacrylate-ethylene glycol dimethacrylate) [poly(VP-PEGMA-EGDMA)] beads with an average size of 30-100 {mu}m were prepared by suspension polymerization. Poly(VP-PEGMA-EGDMA) beads were characterized by swelling studies, scanning electron microscopy (SEM), elemental analysis, Fourier Transform Infrared Spectroscopy (FTIR). The beads with a swelling ratio of 65% were used for the heavy metal removal studies. Chelation capacity of the beads for the selected metal ions, i.e., Pb(II), Cd(II), Cr(III) and Cu(II) were investigated in aqueous media containing different amounts of these ions (5-80 mg/l) and at different pH values (2.0-10.0). The maximum chelation capacities of the poly(VP-PEGMA-EGDMA) beads were 18.23 mg/g for Pb(II), 16.50 mg/g for Cd(II), 17.38 mg/g for Cr(III) and 18.25 mg/g for Cu(II). The affinity order on mass basis was observed as follows: Cu(II) > Pb(II) > Cr(III) > Cd(II). pH significantly affected the chelation capacity of VP incorporated beads. Heavy metal adsorption on the poly(PEGMA-EGDMA) control microspheres was negligible. Regeneration of the chelating beads was easily performed with 0.1 M HNO{sub 3}. It was shown that these beads can be used effectively for heavy metal removal from aqueous solutions with repeatedly adsorption-desorption operations. These features show that poly(VP-PEGMA-EGDMA) beads are potential candidate sorbent for heavy metal removal.

  14. Novel biopolymer-coated hydroxyapatite foams for removing heavy-metals from polluted water

    Energy Technology Data Exchange (ETDEWEB)

    Vila, M.; Sanchez-Salcedo, S.; Cicuendez, M.; Izquierdo-Barba, I. [Inorganic and BioInorganic Chemistry Department, Pharmacy Faculty, Universidad Complutense de Madrid, Plaza de Ramon y Cajal s/n, 28040 Madrid (Spain); Biomedical Research Networking Center in Bioengineering, Biomaterials and Nanomedicine, CIBER-BBN (Spain); Vallet-Regi, Maria, E-mail: vallet@farm.ucm.es [Inorganic and BioInorganic Chemistry Department, Pharmacy Faculty, Universidad Complutense de Madrid, Plaza de Ramon y Cajal s/n, 28040 Madrid (Spain); Biomedical Research Networking Center in Bioengineering, Biomaterials and Nanomedicine, CIBER-BBN (Spain)

    2011-08-15

    Highlights: {yields} 3D-macroporous biopolymer-coated hydroxyapatite (HA) foams as potential devices for the treatment of heavy metal ions. {yields} HA stable foams coated with biopolymers. {yields} Feasible advance in development of new, easy to handle and low cost water purifying methods. - Abstract: 3D-macroporous biopolymer-coated hydroxyapatite (HA) foams have been developed as potential devices for the treatment of lead, cadmium and copper contamination of consumable waters. These foams have exhibited a fast and effective ion metal immobilization into the HA structure after an in vitro treatment mimicking a serious water contamination case. To improve HA foam stability at contaminated aqueous solutions pH, as well as its handling and shape integrity the 3D-macroporous foams have been coated with biopolymers polycaprolactone (PCL) and gelatine cross-linked with glutaraldehyde (G/Glu). Metal ion immobilization tests have shown higher and fast heavy metals captured as function of hydrophilicity rate of biopolymer used. After an in vitro treatment, foam morphology integrity is guaranteed and the uptake of heavy metal ions rises up to 405 {mu}mol/g in the case of Pb{sup 2+}, 378 {mu}mol/g of Cu{sup 2+} and 316 {mu}mol/g of Cd{sup 2+}. These novel materials promise a feasible advance in development of new, easy to handle and low cost water purifying methods.

  15. Novel biopolymer-coated hydroxyapatite foams for removing heavy-metals from polluted water

    International Nuclear Information System (INIS)

    Highlights: ? 3D-macroporous biopolymer-coated hydroxyapatite (HA) foams as potential devices for the treatment of heavy metal ions. ? HA stable foams coated with biopolymers. ? Feasible advance in development of new, easy to handle and low cost water purifying methods. - Abstract: 3D-macroporous biopolymer-coated hydroxyapatite (HA) foams have been developed as potential devices for the treatment of lead, cadmium and copper contamination of consumable waters. These foams have exhibited a fast and effective ion metal immobilization into the HA structure after an in vitro treatment mimicking a serious water contamination case. To improve HA foam stability at contaminated aqueous solutions pH, as well as its handling and shape integrity the 3D-macroporous foams have been coated with biopolymers polycaprolactone (PCL) and gelatine cross-linked with glutaraldehyde (G/Glu). Metal ion immobilization tests have shown higher and fast heavy metals captured as function of hydrophilicity rate of biopolymer used. After an in vitro treatment, foam morphology integrity is guaranteed and the uptake of heavy metal ions rises up to 405 ?mol/g in the case of Pb2+, 378 ?mol/g of Cu2+ and 316 ?mol/g of Cd2+. These novel materials promise a feasible advance in development of new, easy to handle and low cost water purifying methods.

  16. Removal effectiveness and mechanisms of naphthalene and heavy metals from artificially contaminated soil by iron chelate-activated persulfate

    International Nuclear Information System (INIS)

    The effectiveness and mechanisms of naphthalene and metal removal from artificially contaminated soil by FeEDTA/FeEDDS-activated persulfate were investigated through batch experiments. Using FeEDTA-activated persulfate, higher naphthalene removal from the soil at 7 h was achieved (89%), compared with FeEDDS-activated persulfate (75%). The removal was mainly via the dissolution of naphthalene partitioned on mineral surfaces, followed by activated persulfate oxidation. Although EDDS is advantageous over EDTA in terms of biodegradability, it is not preferable for iron chelate-activated persulfate oxidation since persulfate was consumed to oxidize EDDS, resulting in persulfate inadequacy for naphthalene oxidation. Besides, 55 and 40% of naphthalene were removed by FeEDTA and FeEDDS alone, respectively. Particularly, 21 and 9% of naphthalene were degraded in the presence of FeEDTA and FeEDDS alone, respectively, which caused by electrons transfer among dissolved organic matter, Fe2+/Fe3+ and naphthalene. Over 35, 36 and 45% of Cu, Pb and Zn were removed using FeEDTA/FeEDDS-activated persulfate. -- Highlights: ? FeEDTA/FeEDDS-activated persulfate oxidation removed PAH and heavy metal from soil. ? More naphthalene was removed by FeEDTA-activated persulfate compared to FeEDDS. ? Persulfate was consumed to oxidize EDDS in FeEDDS-activated persulfate oxidation. ? Metals can be extracted from soil by free EDTA/EDDS dissociated from FeEDTA/FeEDDS. Naphthalene oxidation can be induced by e? transfer among Fe2+, DOM and naphthalene. -- This study focuses on the potencies and mechanisms of naphthalene and metal removal from contaminated soil by FeEDTA/FeEDDS-activated persulfate

  17. Effects of liquefaction time and temperature on heavy metal removal and distribution in liquefied CCA-treated wood sludge.

    Science.gov (United States)

    Pan, Hui

    2010-06-01

    Wood liquefaction was studied as a recycling method for chromated copper arsenate (CCA)-treated wood waste. The effects of liquefaction temperature and time on the removal of the heavy metals and their distribution in liquefied CCA-treated wood sludge were investigated. The residue content decreased as the temperature increased from 120 to 180 degrees C regardless of the reaction time. It decreased gradually with the increase of reaction time under liquefaction temperatures 120 and 150 degrees C. But it decreased as the reaction time increased from 30 to 60min then increased when the reaction time increased to 90min under liquefaction temperature 180 degrees C due to the re-condensation of decomposed wood components. The total concentrations of arsenic, chromium, and copper in the sludge samples increased, while the percentage of the removed metals decreased, with increasing liquefaction temperature, which could be related to the changes of wood residue content and the fate of the heavy metals under different liquefaction conditions. The exchangeable/acid extractable fraction of all three heavy metals decreased as the liquefaction temperature increased. At the same time, Cr and As increased in both oxidizable and reducible fractions. The amount of Cr in the oxidizable fraction increased 40% as the liquefaction temperature increased from 120 to 180 degrees C. The major change of Cu distribution was the increase in reducible fraction with the increase of liquefaction time. The results of this study suggested that high liquefaction temperature tends to inhibit the heavy metal recovery when liquefaction is used as a recycling method for CCA-treated wood waste. PMID:20462629

  18. Synthesis and characterization of radiation grafted films for removal of arsenic and some heavy metals from contaminated water

    International Nuclear Information System (INIS)

    Grafting of styrene/maleic anhydride and methyl methacrylate/maleic anhydride binary monomers onto the low density polyethylene film was performed using the ?-ray irradiation technique. Then, the synthesized grafted films were treated with different ammonia derivatives for developing chelating functionalization. These chelating products were characterized by the gravimetric method as well as by the Fourier transformed infrared spectroscopic method, and were used for removal of arsenic and some heavy metals from aqueous solutions. The optimum absorbed dose of 30 kGy reveals the graft yielding of about 325% in the films. Uptake of arsenic and some heavy-metal ions (Cr(III), Mn(II), Fe(III), Ni(II), Cu(II) and Pb(II)) from contaminated water by the chelating functionalized films (CFF) was examined by an atomic absorption spectrophotometer. The maximum arsenic removal capacity of 5062 mg/kg has been observed for the film treated with hydroxylamine hydrochloride. The CFF prepared by semicarbazide and thiol analogs show affinity toward the metal ions with an order: Cu(II)>Fe(III)>Mn(II) etc. The results obtained from this study indicate that the functionalized films show good chelating and ion-exchange property for metal ions. - Highlights: ? Optimization of radiation dose for grafting reaction of polyethylene with binary monomers. ? Chelating functionalization of grafted film with various amine compounds. ? Characterization of both grafted and chelating functionaliz grafted and chelating functionalized films. ? Proposed mechanism for both grafting and chelating functionalization reaction. ? Application of the synthesized films for the removal of arsenic and some heavy metals from contaminated water.

  19. Removal of heavy metal from polluted river water using aquatic macrophytes Salvinia sp

    Scientific Electronic Library Online (English)

    F. R., Espinoza-Quiñones; C. E., Zacarkim; S. M., Palacio; C. L., Obregón; D. C., Zenatti; R. M., Galante; N., Rossi; F. L., Rossi; I. R. A., Pereira; R. A., Welter; M. A., Rizzutto.

    2005-09-01

    Full Text Available Concentrations of trace metallic element as well as macronutrients were measured in water and plants from pond water. The aquatic macrophyte Salvinia sp. was evaluated for its trace metals removal potential in river water under laboratory conditions. The experiment were performed using several healt [...] hy acclimatized plants Salvinia sp. The water and grown plants were collected from ponds. For the trace element removal´s test, 30-35 grams of fresh aquatic plants were grown in river water into a greenhouse for ten weeks. Control plants were also grown during the experiment. Every two weeks, both plants and water samples were collected. After the end of each experiment, the growth rate was calculated. Trace element concentrations in plants and pond water were obtained using TXRF techniques. Values for the elements (K, Ca, Ti, Fe, Cr, Mn, Cu, Zn and Sr) concentrations in plant dry weight have been obtained after deducting metal contents of control plants. For each trace element, the aquatic Salvinia sp. plant showed to possess different affinity for the incorporation of the metals in its biomass. Results suggest the use of aquatic macrophytes Salvinia sp. for metal abatement in dilute wastewaters.

  20. Metals removal from resids

    Energy Technology Data Exchange (ETDEWEB)

    Miller, J.W.; Skripek, M.; Baron, K.; Lindsay, D.A.

    1983-05-01

    Many refiners today are asking how they should process heavy oil and resid. That is a difficult question, which must be faced as supplies of light crudes continue to decline and the markets for low-sulfur fuel oil disappear. This paper discusses the deep demetallation of resid conversion. Examples are given to illustrate the advantages of using a new demetallation, or metals-removal, catalyst upstream of a proven residuum-upgrading catalyst. This two-catalyst combination gives the unicracking/hydrodesulfurization (UK/HDS) technology the increased flexibility to process tougher, higher-metals-residua feedstocks and to operate longer at lower hydrogen pressures.

  1. Heavy metal removal in phytofiltration and phycoremediation: the need to differentiate between bioadsorption and bioaccumulation.

    Science.gov (United States)

    Olguín, Eugenia J; Sánchez-Galván, Gloria

    2012-11-15

    Phytoremediation and phycoremediation are cost-effective and environmentally sound technologies for the treatment of polluted streams and wastewaters contaminated with metals. Currently, the most commonly used parameter to assess the metal uptake of biomass is (q) expressed as mg metal g dry weight(-1). By contrast, the bioconcentration factor (BCF) is one of the most widely used factors to evaluate the metal uptake capacity of macrophytes. However, both parameters the metal uptake (q) and the BCF cannot be applied to differentiate between the ability of live plants or photosynthetic microorganisms to adsorb the metal onto their surface through passive mechanisms or to accumulate the contaminant at intracellular level through metabolically active mechanisms. This mini review has the objective of discussing the need to differentiate between bioadsorption and bioaccumulation of metals in live plants and photosynthetic microorganisms used in phytofiltration and phycoremediation processes, respectively. The use of two specific factors, the bioadsorption factor (BAF) and the intracellular accumulation factor (IAF) that have been previously reported in order to make a clear differentiation between these two metal removal mechanisms in Salvinia minima and Leptolyngbya crossbyana is highlighted. It is suggested that the BAF and the IAF can be used in phytofiltration wetlands and phycoremediation lagoons, where there is the need of specific information indicating the fate of the metal in order to gain information about possible removal mechanisms. These factors could also provide a tool to decide whether it is possible to harvest the biomass and to recover a fair amount of metal adsorbed onto the surface by means of desorbent agents. A critical assessment of the use of EDTA as desorbent agent is also included. PMID:22673055

  2. Removal of heavy metals from sewage sludge by extraction with organic acids

    OpenAIRE

    Veeken, A.; Hamelers, B.

    1999-01-01

    Waste water treatment in activated sludge plants results in the production of large amounts of surplus sludge. After composting the sludge can be reused as fertiliser and soil conditioner in agriculture. Compared to landfilling and incineration, utilisation of sludge-compost is a more sustainable treatment because it recycles both nutrients and organic matter. However the high levels of heavy metals in sludge frequently prevent the reuse of sludge compost in agriculture. The extraction of hea...

  3. The removal of heavy metals from contaminated soil by a combination of sulfidisation and flotation.

    Science.gov (United States)

    Vanthuyne, Mathias; Maes, André

    2002-05-01

    The possibility of removing cadmium, copper, lead and zinc from Belgian loamy soil by a combination of sulfidisation pre-treatment and Denver flotation was investigated. The potentially available--sulfide convertible--metal content of the metal polluted soil was estimated by EDTA (0.1 M, pH 4.65) extraction and BCR sequential extraction. EDTA extraction is better at approximating the metal percentage that is expected to be convertible into a metal sulfide phase, in contrast to the sequential extraction procedure of 'Int. J. Environ. Anal. Chem. 51 (1993) pp. 135-151' in which transition metals present as iron oxide co-precipitates are dissolved by hydroxylammoniumchloride in the second extraction step. To compare the surface characteristics of metal sulfides formed by sulfidisation with those of crystalline metal sulfides, two types of synthetic sediments were prepared and extracted with 0.1 M EDTA (pH 4.65) in anoxic conditions. Separate metal sulfides or co-precipitates with iron sulfide were formed by sulfide conditioning. The Denver flotation of both types of synthetic sediments (kerosene as collector at high background electrolyte concentrations) resulted in similar concentrating factors for freshly formed metal sulfides as for fine-grained crystalline metal sulfides. The selective flotation of metal sulfides after sulfide conditioning of a polluted soil, using kerosene or potassium ethyl xanthate as collectors and MIBC as frother, was studied at high background electrolyte concentrations. The sulfidisations were made in ambient air and inside an anoxic glove box. The concentrating factors corrected by the potentially available metal percentage, determined by 0.1 M EDTA extraction, lie between 2 and 3. The selective flotation of these finely dispersed, amorphous, metal sulfides can possibly be improved by optimising the bubble-particle interaction. PMID:12083717

  4. Optimization of pH and Retention Time on the Removal of Nutrients and Heavy Metal (Zinc Using Immobilized Marine Microalga Chlorella marina

    Directory of Open Access Journals (Sweden)

    A. Shenbaga Devi

    2013-01-01

    Full Text Available The interaction of phosphorus and nitrogen on their removal by microalgae can be of great concern during their role as bioremediant of waste water. Microalgae play an imperative role in nutrient and heavy metal removal in wastewater by their biosorption mechanisms. The study was attempted to optimize the pH and retention time for nutrient and heavy metal (zinc removal from aqueous solutions using immobilized marine microalga Chlorella marina as beads and powder. The study inferred that pH 6 was found to optimum for removal of all nutrients except nitrite. However, for heavy metal removal, the pH 8 was found to be suitable for biosorbent studies. Further, the present experiment inferred that the 24 h incubation was enough for nutrients and zinc removal while using immobilized microalga C. marina beads.

  5. An intelligent displacement pumping film system: A new concept for enhancing heavy metal ion removal efficiency from liquid waste

    International Nuclear Information System (INIS)

    Highlights: • A new concept for design of an intelligent displacement pumping film was proposed. • As-prepared ESIX hybrid film system showed excellent Ni2+ uptake/exclude rate. • Piston-like proton pumping effect existed in the prepared ESIX hybrid film. • The mechanism of the ion pumping effect was proved by XPS analysis. - Abstract: A concept of electrochemically switched ion exchange (ESIX) hybrid film system with piston-like proton pumping effect for the removal of heavy metal ions was proposed. Based on this concept, a novel ESIX hybrid film composed of layered alpha zirconium phosphate (?-Zr(HPO4)2; ?-ZrP) nanosheets intercalated with a potential-responsive conducting polyaniline (PANI) was developed for the removal of Ni2+ ions from wastewater. It is expected that the space between ?-ZrP nanosheets acts as the reservoir for the functional ions while the intercalated PANI works as the potential-sensitive function element for piston-like proton pumping in such ESIX hybrid films. The prepared ESIX hybrid film showed an excellent property of rapid removal of Ni2+ ions from wastewater with a high selectivity. The used film was simply regenerated by only altering the applied potential. The ion pumping effect for the ESIX of Ni2+ ions using this kind of film was proved via XPS analysis. The proposed ESIX hybrid film should have high potential for the removal of Ni2+ ions and/or other heavy metal ions from wastewater in various industrial processes

  6. Changes in nutrient profile of soil subjected to bioleaching for removal of heavy metals using Acidithiobacillus thiooxidans

    Energy Technology Data Exchange (ETDEWEB)

    NareshKumar, R. [Centre for Environmental Studies, Anna University, Chennai 600025 (India)], E-mail: nareshkrish@hotmail.com; Nagendran, R. [Centre for Environmental Studies, Anna University, Chennai 600025 (India)

    2008-08-15

    Studies were carried out to assess changes in nitrogen, phosphorus and potassium contents in soil during bioleaching of heavy metals from soil contaminated by tannery effluents. Indigenous sulfur oxidizing bacteria Acidithiobacillus thiooxidans isolated from the contaminated soil were used for bioremediation. Solubilization efficiency of chromium, cadmium, copper and zinc from soil was 88, 93, 92 and 97%, respectively. However, loss of nitrogen, phosphorus and potassium from the soil was 30, 70 and 68%, respectively. These findings indicate that despite its high potential for removal of heavy metals from contaminated soils, bioleaching results in undesirable dissolution/loss of essential plant nutrients. This aspect warrants urgent attention and detailed studies to evaluate the appropriateness of the technique for field application.

  7. Determination of Heavy Metal Removal Efficiency of Chrysopogon zizanioides (Vetiver using Textile Wastewater Contaminated Soil

    Directory of Open Access Journals (Sweden)

    P. Lakshmanaperumalsamy

    2011-01-01

    Full Text Available A pot culture study was conducted using textile wastewater contaminated soil which was amended with Vermicompost (VC in various proportions for a period of two months. The plant used for the study was Chrysopogon zizanioides (Vetiver to investigate the accumulation of heavy metals in their roots. Physico-chemical parameters like pH, EC, TKN, P, K, TOC and metals like Pb, Cd and Cu and microbial population of the textile wastewater contaminated soil were analyzed initially (0 day and finally (60th day. The growth parameters of vetiver like root length, shoot length, fresh weight and dry weight were also recorded initially and finally. Based on the data C. zizanioides (Vetiver tolerated and accumulated the greatest amount of heavy metals. C. zizanioides could uptake more lead than the other metals. The effect of vermicompost on the growth of C. zizanioides showed that the biomass was increased when the vermicompost concentration was increased. The microbial population like bacteria, actinomycetes and fungi was more in the rhizosphere soil than in non-rhizosphere soil.

  8. Fabrication of chelating diethylenetriaminated pan micro and nano fibers for heavy metal removal

    Directory of Open Access Journals (Sweden)

    Abdouss Majid

    2012-01-01

    Full Text Available In this study, commercial acrylic fibers were modified with diethylenetriamine to prepare metal chelating fibers. The effects of process parameters on the efficiency of the reaction were investigated. FTIR spectroscopy and TGA analysis were used to confirm the chemical changes made to the fibers during the reaction. The ability of the modified fibers for removal of Pb (II, Cu (II and Ce (IV ions from aqueous media was determined. The modified fibers showed a slight decrease in mechanical properties compared to raw ones. Furthermore, the acrylic micro fibers were electrospun to nanofibers and the ability of modified nanofibers for the adsorption of the metal ions was studied.

  9. Influences of thermal decontamination on mercury removal, soil properties, and repartitioning of coexisting heavy metals.

    Science.gov (United States)

    Huang, Yu-Tuan; Hseu, Zeng-Yei; Hsi, Hsing-Cheng

    2011-08-01

    Thermal treatment is a useful tool to remove Hg from contaminated soils. However, thermal treatment may greatly alter the soil properties and cause the coexisting contaminants, especially trace metals, to transform and repartition. The metal repartitioning may increase the difficulty in the subsequent process of a treatment train approach. In this study, three Hg-contaminated soils were thermally treated to evaluate the effects of treating temperature and duration on Hg removal. Thermogravimetric analysis was performed to project the suitable heating parameters for subsequent bench-scale fixed-bed operation. Results showed that thermal decontamination at temperature>400°C successfully lowered the Hg content toextractable, organic-matter bound, and residual forms from the Fe/Mn oxide bound form. These results suggest that thermal treatment may markedly influence the effectiveness of subsequent decontamination methods, such as acid washing or solvent extraction. PMID:21624629

  10. Accumulation of Heavy Metal Ions from Tanneries Wastes: An Approach For Chromium Removal Using Activated Charcoal

    Directory of Open Access Journals (Sweden)

    H. Tahir

    2012-09-01

    Full Text Available The environment is under increasing pressure from solid and liquid wastes emanating from the leather industry. These are inevitable by-products of the leather manufacturing process and causes significant pollution unless treated in some way prior to discharge. The tanneries wastes samples were collected from Lahore Pakistan. The samples were digested by wet oxidation method and the concentrations of metals: Cr, Co, Cu, Cd, Mn, Zn, Ni and Pb were estimated in sediments and liquid waste samples by atomic absorption spectrophotometer. The results show that the concentrations of these metals were higher than the values given by the national environmental quality standards. Selective separation of Cr ion from other metals was investigated in sediment sample TS2 by adsorption method using low cost natural adsorbent activated charcoal. The adsorption studies were carried out under the optimized conditions of adsorption like pH, shaking time and amount of adsorbent. The concentration of Cr after removal was determined by atomic absorption spectrophotometer. The adsorption equilibrium data were fitted in adsorption isotherm equations like: Freundlich, and Dubinin-Radushkevich equations at temperatures ranges from 303 to 318 K. Thermodynamic parameters ?H, ?S and ?G were also calculated. The values of sorption free energy were estimated by employing D-R equation. The percent removal data show that about 99% removal was achieved by employing low cost adsorbent. This method can be employed on industrial scale for the treatment of solid and liquid waste before discharge into the main streams.

  11. Removal of heavy metals from a chelated solution with electrolytic foam separation

    Energy Technology Data Exchange (ETDEWEB)

    Min-Her Leu; Juu-En Chang; Ming-Sheng Ko [National Cheng Kung Univ., Taiwan (China)

    1994-11-01

    An experimental study was conducted on the chelation and electrolytic foam separation of trace amounts of copper, nickel, zinc, and cadmium from a synthetic chelated metal wastewater. Sodium ethylenediaminetetraacetate (EDTA), citrate, sodium diethyldithiocarbamate (NDDTC), and potassium ethyl xanthate (KEtX) were used with sodium dodecylsulfate (NaDS) as a foam-producing agent. Experimental results from an electrolytic foam separation process showed that chelating agents NDDTC and KEtX, due to their higher chelating strength and hydrophobic property, can efficiently separate Cu and Ni from chelated compounds (Cu, Ni/EDTA, and Cu, Ni/citrate). In a Cu-EDTA-NDDTC system with a chelating agent/metal ratio of 4, the residual Cu(II) concentration is 0.7 mg/L. The effects of chelating agent types and different chelating agents concentrations on the removal of metal ions were studied. The effect of NaDS dosage on flotation behavior and the efficiency of metal removal were also investigated.

  12. Modification of Salix americana willow bark for removal of heavy metal ions from aqueous solutions

    Directory of Open Access Journals (Sweden)

    Rypi?ska Iwona

    2014-12-01

    Full Text Available Salix americana willow bark is a waste arising in the process of wicker decortication that so far has not found any practical application. The bark can adsorb metal ions, because in its composition among others are phenolic groups which may be involved in the removal of metal ions from water solutions. The results of sorption of copper(II and zinc(II on modified willow bark of Salix americana were presented. The bark was modified with nitric and sulfuric acids at concentrations ranging from 5 to 15%. The best adsorption results were obtained using 15% nitric acid for modification. Adsorption of metal ions from aqueous solutions at concentrations raging from 20 to 100 mg/dm3 was studied. It was found that an increase in the initial concentration of copper(II and zinc(II resulted in an increase in their adsorption on the modified cortex.

  13. The use of ionizing radiation and ion exchange resins in the removal of heavy metals from waste water

    International Nuclear Information System (INIS)

    The removal of heavy metal ions from waste water using gamma-radiation and a polymeric membrane prepared by radiation graft copolymerization of vinyl acetate (VAc) onto low density polyethylene films was investigated for the cases of zinc and iron ions. These metal ions were reduced by the hydrated electrons and hydrogen atoms to lower or zero valence state and eventually precipitate out of solution. parameter analysis includes the effect metal ion concentration, Ph, degree of grafting and irradiation dose. The maximum precipitation of the unirradiated metal ions was achieved at Ph 10, while the least precipitation occurred at Ph 3. Irradiation at Ph 5.5 resulted in more precipitation of iron than zinc. Both elements were adsorbed by different adsorbents granular activated carbon (GAC), powdered activated carbon (PAC), amberlite IR-120 plus, dowex-1- exchangers and grafted membranes). The combined treatment by irradiation plus adsorption showed more removal percent, especially for powdered activated carbon (PAC). Also, the grafted membranes showed a removal percent of 98% at high degree of grafting

  14. Molecular Characterization of Some Novel Marine Alicyclobacillus Strains, Capable of Removing Lead from a Heavy Metal Contaminated Sea Spot

    Directory of Open Access Journals (Sweden)

    Eman A.H. Mohamed

    2009-01-01

    Full Text Available Sea water from heavy metal contaminated area in the Mediterranean, was analyzed for its heavy metal contents and their concentrations. It was observed that lead has the highest concentration (0.48 ppm among the remaining heavy metal concentrations. Four different Gram-positive, rod-shaped and spore forming Alicyclobacillus (formally Bacillus isolates were isolated from the same sea spot. Phenotypic characterization of pure cultures were examined for motility, Gram reaction, spore morphology, catalase and oxidase production. Scanning electron micrograph showed that cells of both strains were occurring singly or in short chains. Randomly Amplified Polymorphic DNA (RAPD analysis showed a great deal of differentiation among the isolates, revealing that each of them has its own DNA fingerprint. A dendrogram showing the genetic similarity among the sea isolates, clustered them into two main groups at 30% of genetic similarity. Partial sequencing of the 16S rDNA of 2, representative isolates revealed that both of them are novel Alicyclobacillus strains S2 and S4. The isolates had the ability to remove lead from contaminated solutions. A promising strain, S4, showed a valuable uptake levels, 64 and 65.3% at 0.5 and 0.9 ppm of pb2+, respectively, after only 2 h of exposure to lead. This strain can be later used efficiently for the bioremediation of lead in contaminated water bodies.

  15. REMOVAL OF HEAVY METALS FROM DYE EFFLUENT USING ACTIVATED CARBON PRODUCED FROM COCONUT SHELL

    Directory of Open Access Journals (Sweden)

    Onyeji, L. I.

    2011-12-01

    Full Text Available The ability of activated carbon produced from coconut shell to remoe mercury Hg (II, Lead Pb (II and Copper Cu (II from dye effluent was investigated. The activated carbon was produced through chemical activation processes by using zinc chloride (ZnCl2. The adsorption capacity was determined as a function of adsorbent dosage. The adsorption Isotherms of the studied metals on adsorbent were also determined and compared with the Langmair models. The activated carbon produced showed excellent effecency in removing Hg (II and Pb(II with percentage removal up to 80 % at low adsorbent dosage of 2 g. In contrast, only about 29 % removal of Cu (II was achieved at adsorbent dosage of 2 g. The study also showed that the adsorption of Hg (II, Pb (II and Cu (II by the activated carbon is dependent on the dosage of the adsorbent and the initial metal concentration. The use of cocnut shell for activated carbon also helps in solving the problem of over abundance of cocnut shell as agricultural waste.

  16. Removal of Heavy Metals from Simulated Wastewater Using Physically and Chemically Modified Palm Shell Activated Carbon

    Directory of Open Access Journals (Sweden)

    Nur Azreen Fuadi

    2014-01-01

    Full Text Available The purpose of the present study is to investigate the adsorption efficiency of Activated Carbons (AC derived from oil palm shell in an adsorption column for removal of beryllium, calcium, cadmium, cobalt, chromium, copper, iron, lithium, magnesium, manganese, molybdenum, nickel, lead, antimony, strontium, titanium, vanadium and zinc ions from aqueous solution. Three types of adsorbent were used for the metal removal, which undergoes physical and/or chemical treatment. In physical treatment, raw palm shell was burned at 600°C for 5 h. All the adsorbents undergo physical treatment, with only the first adsorbent unblended, while the second adsorbent was blended. The third adsorbent underwent physical and chemical treatments where the physically treated AC was mixed with solvents for 24 h, then washed and dried. The solvent used for the third adsorbent were acetone and benzene. The results indicated that removal of metal ions by adsorption spawned different activities for different adsorbents. It is indicated that for overall adsorption efficiency, AC derived by combining physical and chemical treatment showed a maximum adsorption capacity with the least area under graph; 1371, calculated using trapezoidal equation. The physical treatment produced high carbon content by carbonization and high surface area by size reduction, while the chemical treatment enhanced the development of carbon surface by generating more pores, thus increasing the number of adsorption sites.

  17. Removal of heteroatoms and metals from heavy oils by bioconversion processes

    Energy Technology Data Exchange (ETDEWEB)

    Kaufman, E.N.

    1996-06-01

    Biocatalysts, either appropriate microorganisms or isolated enzymes, will be used in an aqueous phase in contact with the heavy oil phase to extract heteroatoms such as sulfur from the oil phase by bioconversion processes. Somewhat similar work on coal processing will be adapted and extended for this application. Bacteria such as Desulfovibrio desulfuricans will be studied for the reductive removal of organically-bound sulfur and bacteria such as Rhodococcus rhodochrum will be investigated for the oxidative removal of sulfur. Isolated bacteria from either oil field co-produced sour water or from soil contaminated by oil spills will also be tested. At a later time, bacteria that interact with organic nitrogen may also be studied. This type of interaction will be carried out in advanced bioreactor systems where organic and aqueous phases are contacted. One new concept of emulsion-phase contacting, which will be investigated, disperses the aqueous phase in the organic phase and is then recoalesced for removal of the contaminants and recycled back to the reactor. This program is a cooperative research and development program with the following companies: Baker Performance Chemicals, Chevron, Energy BioSystems, Exxon, Texaco, and UNOCAL. After verification of the bioprocessing concepts on a laboratory-scale, the end-product will be a demonstration of the technology at an industrial site. This should result in rapid transfer of the technology to industry.

  18. Application of chemically modified rice husk for the removal of heavy metals from aqueous solution.

    Science.gov (United States)

    Kayal, N; Sinhia, P K; Kundu, D

    2010-01-01

    The removal efficiency of lead, cadmium and zinc from aqueous solution on adsorption by using rice husk, a non-conventional material in its natural and chemically modified form has been presented in this paper. It has been observed that rate of adsorption is dependent on the nature of the adsorbent, adsorbent dose, particle size of the adsorbent, concentration, pH, contact time, temperature, etc. Under identical experimental condition chemically modified rice husk was found to possess greater adsorption capacity for all metals than untreated rice husk and chemically modified rice husk ash. Chemically modified rice husk could remove 99.8% Pb, 95% Cd and 97% Zn from aqueous solution at room temperature. PMID:21114100

  19. Chestnut shell as heavy metal adsorbent: Optimization study of lead, copper and zinc cations removal

    International Nuclear Information System (INIS)

    The influence of initial cation concentration, temperature and pH was investigated to optimize Pb2+, Cu2+ and Zn2+ removal from aqueous solutions using acid formaldehyde pre-treated chestnut shell as adsorbent. Experiments were planned according to an incomplete 33 factorial experimental design. Under the optimal conditions selected, the metal ion adsorption equilibrium was satisfactorily described by the Langmuir isotherm model. The maximum pre-treated chestnut shell adsorption capacity was obtained for Pb2+ ions, 8.5 mg g-1, and the order of cation affinity was Pb2+ > Cu2+ > Zn2+. A model that considered the effect of axial dispersion was successfully used to describe the fixed-bed adsorption behaviour of Pb2+, Cu2+ and Zn2+ ions at the flow rates essayed. Fourier transform infrared (FTIR) and X-ray photoelectron (XPS) spectroscopies showed that the functional groups involved in metal ions binding included carboxyl, hydroxyl, ether, alcoholic and amino groups.

  20. Comparison of rice husk- and dairy manure-derived biochars for simultaneously removing heavy metals from aqueous solutions: role of mineral components in biochars.

    Science.gov (United States)

    Xu, Xiaoyun; Cao, Xinde; Zhao, Ling

    2013-08-01

    Rice husk biochar (RHBC) and dairy manure biochar (DMBC) were prepared as sorbents for simultaneously removing Pb, Cu, Zn, and Cd from aqueous solutions. DMBC was more effective in removing all the four heavy metals than RHBC, with the removal capacities of above 486 mmol kg(-1) for each metal, much higher than those of RHBC (65.5-140 mmol kg(-1)). RHBC showed stronger competition for metal removal than DMBC when the four metals coexisted, with Pb the least affected and Cd the most inhibited. When each metal was 1mM in the multi-metal system, the metal removal by RHBC was reduced by 38.4-100%, much higher than that reduced by 2-40.9% for DMBC. The stronger competition for metals removal by RHBC was due to the fact that all metals competed only for the ionized phenolic-O(-) groups, while the removal of metals by DMBC resulted not only from the complexation with ionized hydroxyl-O(-) groups but also from the precipitation of metals with CO3(2-) and/or PO4(3-) that were rich in DMBC, resulting in less competition. The different mechanisms for the removal of metals by the two biochars were evidenced by the instrumental analysis of XRD, FTIR, and SEM as well as chemical modeling of Visual MINTEQ. Results indicated the waste biomass can be converted into value-added biochar as sorbents for removal of heavy metals and the removal ability varies with different biochar feedstock sources where the mineral components such as CO3(2-), PO4(3-) originated from the feedstock play an important role in the sorption nature of biochar. PMID:23591132

  1. Graft copolymerization of polystyrene onto chitosan congress as an adsorbent for the removal of heavy metal ions

    International Nuclear Information System (INIS)

    Chitosan is primarily composed of glucosamine, 2-amino-2-deoxy-?-D-glucose. Chitosan has different types of reactive functional groups. Both hydroxyl and amino groups are possible sites for the reaction to incorporate new and desired functional groups. By modification of these groups various materials for different field of application can be achieved. Chitosan has been used as adsorbent for the removal of heavy metal ions from aqueous solution through adsorption process. Properties of chitosan, such as solubility, mechanical stability and adsorption compatibility, are enhanced by grafting. In this study, chitosan was graft copolymerized with polystyrene for wastewater treatment and evaluated its effectiveness in removing toxic heavy metals by adsorption. Chitosan-graft-polystyrene was characterized by FTIR spectroscopy, and SEM. Adsorption study of the copolymer is carried out as a function of adsorbent dose, pH, and contact time. Residual concentration was measured by Atomic Absorption Spectroscopy. To get an insight of the rate of adsorption and the rate limiting step of the transport mechanism, kinetic analysis was utilized. Langmuir equation/isotherm was used for proper quantification of the sorption equilibrium in the bio sorption process (author)

  2. High-Density Three-Dimension Graphene Macroscopic Objects for High-Capacity Removal of Heavy Metal Ions

    Science.gov (United States)

    Li, Weiwei; Gao, Song; Wu, Liqiong; Qiu, Shengqiang; Guo, Yufen; Geng, Xiumei; Chen, Mingliang; Liao, Shutian; Zhu, Chao; Gong, Youpin; Long, Mingsheng; Xu, Jianbao; Wei, Xiangfei; Sun, Mengtao; Liu, Liwei

    2013-07-01

    The chemical vapor deposition (CVD) fabrication of high-density three-dimension graphene macroscopic objects (3D-GMOs) with a relatively low porosity has not yet been realized, although they are desirable for applications in which high mechanical and electrical properties are required. Here, we explore a method to rapidly prepare the high-density 3D-GMOs using nickel chloride hexahydrate (NiCl2.6H2O) as a catalyst precursor by CVD process at atmospheric pressure. Further, the free-standing 3D-GMOs are employed as electrolytic electrodes to remove various heavy metal ions. The robust 3D structure, high conductivity (~12 S/cm) and large specific surface area (~560 m2/g) enable ultra-high electrical adsorption capacities (Cd2+ ~ 434 mg/g, Pb2+ ~ 882 mg/g, Ni2+ ~ 1,683 mg/g, Cu2+ ~ 3,820 mg/g) from aqueous solutions and fast desorption. The current work has significance in the studies of both the fabrication of high-density 3D-GMOs and the removal of heavy metal ions.

  3. Removal of Heavy Metals and Organic Contaminants from Wwater by Novel Filtration Methods. Final report

    International Nuclear Information System (INIS)

    The removal of hazardous waste, generated by the dismantling of nuclear weapons is a problem that requires urgent attention by the US Department of Energy. Low levels of radioactive contaminants combined with organic solvent residues have leaked from aging containers into the soil and underground water in the surrounding area. Due to the complexity of the problem, it is evident that traditional adsorption methods are ineffective, since the adsorbent tends to saturate with the aqueous component. It has become apparent that a much more aggressive approach is required which involves the use of specially designed materials. We have investigated the potential of solids that combine high surface area/high pore volume and high electrical conductivity, a rare combination of properties found in a single material. In this program we examined the potential of newly developed materials for the trapping of organic solvents within specially engineered cavities without allowing the material to become saturated with water. Catalytically grown carbon nanofibers are a set of novel structures that are produced by the decomposition of selected carbon-containing gases over metal particles. These materials consist of extremely small graphite platelets stacked in various orientations with respect to the fiber axis. Such an arrangement results in a unique structure that is composed of an infinite number of extremely short and narrow pores, suitable for sequestering small molecules. In addition, when the graphene layers are aligned parallel to the fiber axis, an unusual combination of high surface area and low electrical resistivity solids are attained. We have attempted to capitalize on this blend of properties by using such structures for the selective removal of organic contaminants from aqueous streams. Experimental results indicate that nanofibers possessing a structure in which the graphite platelets are aligned perpendicular to the fiber axis and possessing a high degree of structural perfection exhibit superior selective adsorption properties with respect to removal of alcohols from aqueous medial over that displayed by active carbon. Furthermore, we have attempted to take advantage of the high electrical conductivity as well as the high availability of edges, and we have used these materials for the removal of metal ions from solution. Preliminary results indicate that graphite nanofibers can, in the presence or absence of an applied electric field, capture metal ions from solution. In addition, it has been found that certain types of nanofibers can absorb substantial amounts of water both in the vapor and liquid phase

  4. Heavy metal sorption by microalgae

    International Nuclear Information System (INIS)

    Viable microalgae are known to be able to accumulate heavy metals (bioaccumulation). Against a background of the increasing environmental risks caused by heavy metals, the microalgae Chlorella vulgaris and Spirulina platensis and their potential for the biological removal of heavy metals from aqueous solutions were taken as an example for investigation. Small-scale cultivation tests (50 l) with Cd-resistant cells of Chlorella vulgaris have shown that approx. 40% of the added 10 mg Cd/l was removed from the solution within seven days. At this heavy metal concentration sensitive cells died. Non-viable microalgae are able to eliminate heavy metal ions in a short time by biosorption in uncomplicated systems, without any toxicity problems. Compared with original biomasses, the sorption capacity of microalgal by-products changes only insignificantly. Their low price makes them economical. (orig.)

  5. Synthesis of monodisperse Fe3O4 - silica core-shell microspheres and their application for removal of heavy metal ions from water

    International Nuclear Information System (INIS)

    Monodisperse Fe3O4 - silica core-shell microspheres have been successfully prepared by using a two step method. Due to their exceptional properties, these composite microspheres can be removed conveniently from water via an external magnet. These composite microspheres can be applied to remove heavy metal ions from industrial wastewater because the surface of the microspheres is covered with SiO2, and the SiO2 is inactive and can adsorb heavy metal ions (such as Hg2+, Pb2+). Furthermore, the interaction between SiO2 and heavy metal ions is reversible, which means that the adsorbed ions can be removed from SiO2 in weak acidic deionized water with the assistance of ultrasound radiation. It is noteworthy that the adsorption ability of the composite microspheres is so strong that any further modification of the composite microspheres is unnecessary. On the basis of the above points, we consider that the synthesized Fe3O4 - silica composite microspheres can be used as a useful recyclable tool for heavy metal ion removal. This work provides a potential and unique technique for heavy metal ion removal from industrial wastewater.

  6. Removal of heavy metals from aqueous solutions using Fe3O4, ZnO, and CuO nanoparticles

    International Nuclear Information System (INIS)

    This study investigated the removal of Cd2+, Cu2+, Ni2+, and Pb2+ from aqueous solutions with novel nanoparticle sorbents (Fe3O4, ZnO, and CuO) using a range of experimental approaches, including, pH, competing ions, sorbent masses, contact time, scanning electron microscopy, transmission electron microscopy, and X-ray diffraction. The images showed that Fe3O4, ZnO, and CuO particles had mean diameters of about 50 nm (spheroid), 25 nm (rod shape), and 75 nm (spheroid), respectively. Tests were performed under batch conditions to determine the adsorption rate and uptake at equilibrium from single and multiple component solutions. The maximum uptake values (sum of four metals) in multiple component solutions were 360.6, 114.5, and 73.0 mg g?1, for ZnO, CuO, and Fe3O4, respectively. Based on the average metal removal by the three nanoparticles, the following order was determined for single component solutions: Cd2+ > Pb2+ > Cu2+ > Ni2+, while the following order was determined in multiple component solutions: Pb2+ > Cu2+ > Cd2+ > Ni2+. Sorption equilibrium isotherms could be described using the Freundlich model in some cases, whereas other isotherms did not follow this model. Furthermore, a pseudo-second order kinetic model was found to correctly describe the expewas found to correctly describe the experimental data for all nanoparticles. Scanning electron microscopy, energy dispersive X-ray before and after metal sorption, and soil solution saturation indices showed that the main mechanism of sorption for Cd2+ and Pb2+ was adsorption, whereas both Cu2+ and Ni2+ sorption were due to adsorption and precipitation. These nanoparticles have potential for use as efficient sorbents for the removal of heavy metals from aqueous solutions and ZnO nanoparticles were identified as the most promising sorbent due to their high metal uptake.

  7. Heavy metal removal from produced water using retorted shale; Remocao de metais pesados em aguas produzidas utilizando xisto retortado

    Energy Technology Data Exchange (ETDEWEB)

    Pimentel, Patricia M.; Melo, Marcos A.F.; Melo, Dulce M.A.; Silva Junior, Carlos N.; Assuncao, Ary L.C. [Universidade Federal do Rio Grande do Norte (UFRN), Natal, RN (Brazil); Anjos, Marcelino J. [Universidade Federal, Rio de Janeiro, RJ (Brazil). Coordenacao dos Programas de Pos-graduacao de Engenharia

    2004-07-01

    The Production of oil and gas is usually accompanied by the production of large volume of water that can have significant environmental effects if not properly treated. In this work, the use of retort shale was investigated as adsorbent agent to remove heavy metals in produced water. Batch adsorption studies in synthetic solution were performed for several metal ions. The efficiency removal was controlled by solution pH, adsorbent dosage, and initial ion concentration and agitation times. Two simple kinetic models were used, pseudo-first- and second-order, were tested to investigate the adsorption mechanisms. The equilibrium data fitted well with Langmuir and Freundlich models. The produced water samples were treated by retorted shale under optimum adsorption conditions. Synchrotron radiation total reflection X-ray fluorescence was used to analyze the elements present in produced water samples from oil field in Rio Grande do Norte, Brazil. The removal was found to be approximately 20-50% for Co, Ni, Sr and above 80% for Cr, Ba, Hg and Pb. (author)

  8. Application of the artificial intelligence to estimate the constructed wetland response to heavy metal removal

    International Nuclear Information System (INIS)

    Current design approaches lack essential parameters necessary to evaluate the removal of metals contained in wastewater which is discharged to constructed wetlands. As a result, there is no guideline for an accurate design of constructed wetlands. An artificial intelligence approach was used to assess constructed wetland design. For this purpose concentrations of bioavailable mercury were evaluated in conditions where initial concentrations of inorganic mercury, chloride concentrations and pH values changed. Fuzzy knowledge base was built based on results obtained from previous investigations performed in a greenhouse for floating plants, and from computations for mercury speciation. The Fuzzy Decision Support System (FDSS) used the knowledge base to find parameters that permit to generate the highest amount of mercury available for plants. The findings of this research can be applied to wetlands and all natural processes where correlations between them are uncertain. (author)

  9. Preparation and characterization of bentonite clays mixture destined to the removal of heavy metals

    International Nuclear Information System (INIS)

    In this work a mixture was prepared with 50% wt. of the Bofe and Verde-lodo clays. The characterization methods used they were: thermal analyses (TG and DTG), X-ray diffraction, fisissorption of N2, scanning electron microscopy and X-ray energy dispersive spectroscopy. The rehearsals of adsorption we accomplished in system of finite bath using as adsorbent the mixture loamy in natura or it mixes calcined. Starting from TG and DTG a thermal treatment was accomplished to 500 deg C of the loamy mixture. Through the results of the copper adsorption, it was verified that mixes loamy it provokes chemical precipitation of the copper while the calcined sample presents amount metal adsorbed around 7.31 mg of copper/g of adsorbent. The value of removal percentage obtained by the calcined sample it was of 63.02%. (author)

  10. Effective removal of heavy metals from industrial sludge with the aid of a biodegradable chelating ligand GLDA.

    Science.gov (United States)

    Wu, Qing; Cui, Yanrui; Li, Qilu; Sun, Jianhui

    2015-02-11

    Tetrasodium of N,N-bis(carboxymethyl) glutamic acid (GLDA), a novel readily biodegradable chelating ligand, was employed for the first time to remove heavy metals from industrial sludge generated from a local battery company. The extraction of cadmium, nickel, copper, and zinc from battery sludge with the presence of GLDA was studied under different experimental conditions such as contact times, pH values, as well as GLDA concentrations. Species distribution of metals in the sludge sample before and after extraction with GLDA was also analyzed. Current investigation showed that (i) GLDA was effective for Cd extraction from sludge samples under various conditions. (ii) About 89% cadmium, 82% nickel and 84% copper content could be effectively extracted at the molar ratio of GLDA:M(II)=3:1 and at pH=4, whereas the removal efficiency of zinc was quite low throughout the experiment. (iii) A variety of parameters, such as contact time, pH values, the concentration of chelating agent, stability constant, as well as species distribution of metals could affect the chelating properties of GLDA. PMID:25464318

  11. Adsorptive removal of heavy metals from aqueous solution by treated sawdust (Acacia arabica)

    International Nuclear Information System (INIS)

    The removal of Cr(VI), Pb(II), Hg(II) and Cu(II), by treated sawdust has been found to be concentration, pH, contact time, adsorbent dose and temperature dependent. The adsorption parameters were determined using both Langmuir and Freundlich isotherm models. Adsorption capacity for treated sawdust, i.e. Cr(VI) (111.61 mg/g), Pb(II) (52.38 mg/g), Hg(II) (20.62 mg/g), and Cu(II) (5.64 mg/g), respectively. Surface complexation and ion exchange are the major removal mechanisms involved. The adsorption isotherm studies clearly indicated that the adsorptive behaviour of metal ions on treated sawdust satisfies not only the Langmuir assumptions but also the Freundlich assumptions. The applicability of Lagergren kinetic model has also been investigated. The adsorption follows first-order kinetics. Thermodynamic constant (kad), standard free energy (?Go), enthalpy (?Ho) and entropy (?So) were calculated for predicting the nature of adsorption. The percentage adsorption increases with pH to attain a maximum at pH 6 and thereafter it decreases with further increase in pH. The results indicate the potential application of this method for effluent treatment in industries and also provide strong evidence to support the adsorption mechanism proposed

  12. Enhancement of heavy metals removal efficiency from liquid wastes by using potential-triggered proton self-exchange effects

    International Nuclear Information System (INIS)

    Highlights: • A mechanism of potential-triggered proton self-exchange effect was proposed. • An electroactive film was fabricated using a facile and controllable method. • The electroactive film showed a high selectivity to Cu2+ ion removal. • The electroactive film exhibited an excellent cycling stability. - Abstract: A concept of electrochemically switched ion exchange (ESIX) film with potential-triggered proton self-exchange effect (PTPS) for removal of Cu2+ ions was proposed. Based on this concept, a novel ESIX film made of poly (2,6- pyridinedicarboxylic acid) (PPDA) was successfully fabricated, and applied to remove Cu2+ ions from aqueous solution. It is found that Cu2+ ions were rapidly removed with a high selectivity and this film was reproducible by simple changing the applied potential. Herein, the mechanism of the potential-triggered proton self-exchange (PTPS) effect on the ion-exchange process using this kind of film was proposed. Electrochemical quartz crystal microbalance, IR spectroscopy and X-ray photoelectron spectra methods were used to characterize and attest the proposed mechanism. This PPDA film showed high potential for the Cu2+ detection and the treatment of wastewater containing heavy metal ions in various industrial processes

  13. New biodegradable organic-soluble chelating agents for simultaneous removal of heavy metals and organic pollutants from contaminated media

    Energy Technology Data Exchange (ETDEWEB)

    Ullmann, Amos, E-mail: Ullmann@eng.tau.ac.il [Faculty of Engineering, School of Mechanical Engineering, Tel Aviv University, Tel Aviv 69978 (Israel); Brauner, Neima; Vazana, Shlomi; Katz, Zhanna [Faculty of Engineering, School of Mechanical Engineering, Tel Aviv University, Tel Aviv 69978 (Israel); Goikhman, Roman [The Hebrew University of Jerusalem, The Robert H. Smith, Faculty of Agriculture, Food and Environment, Rehovot (Israel); Seemann, Boaz; Marom, Hanit [School of Chemistry, Faculty of Exact Sciences, Tel Aviv University, Tel Aviv 69978 (Israel); Gozin, Michael, E-mail: cogozin@gmail.com [School of Chemistry, Faculty of Exact Sciences, Tel Aviv University, Tel Aviv 69978 (Israel)

    2013-09-15

    Highlights: • New soil remediation process using phase transition of partially miscible solvents. • Design and synthesis of new bio-degradable, organic soluble chelating agents. • Feasibility tests of the process on authentically polluted sediments and sludge. • Simultaneous removal of toxic metals and organic pollutants was demonstrated. -- Abstract: Advanced biodegradable and non-toxic organic chelators, which are soluble in organic media, were synthesized on the basis of the S,S-ethylenediamine-disuccinate (S,S-EDDS) ligand. The modifications suggested in this work include attachment of a lipophilic hydrocarbon chain (“tail”) to one or both nitrogen atoms of the S,S-EDDS. The new ligands were designed and evaluated for application in the Sediments Remediation Phase Transition Extraction (SR-PTE) process. This novel process is being developed for the simultaneous removal of both heavy metals and organic pollutants from contaminated soils, sediments or sludge. The new chelators were designed to bind various target metal ions, to promote extraction of these ions into organic solvents. Several variations of attached tails were synthesized and tested. The results for one of them, N,N?-bis-dodecyl-S,S-EDDS (C24-EDDS), showed that the metal-ligand complexes are concentrated in the organic-rich phase in the Phase Transition Extraction process (more than 80%). Preliminary applications of the SR-PTE process with the C24-EDDS ligand were conducted also on actually contaminated sludge (field samples). The extraction of five toxic metals, namely, Cd, Cu, Ni, Pb and Zn was examined. In general, the extraction performance of the new ligand was not less than that of S,S-EDDS when a sufficient ligand-to-extracted ion ratio (about 4:1 was applied.

  14. New biodegradable organic-soluble chelating agents for simultaneous removal of heavy metals and organic pollutants from contaminated media

    International Nuclear Information System (INIS)

    Highlights: • New soil remediation process using phase transition of partially miscible solvents. • Design and synthesis of new bio-degradable, organic soluble chelating agents. • Feasibility tests of the process on authentically polluted sediments and sludge. • Simultaneous removal of toxic metals and organic pollutants was demonstrated. -- Abstract: Advanced biodegradable and non-toxic organic chelators, which are soluble in organic media, were synthesized on the basis of the S,S-ethylenediamine-disuccinate (S,S-EDDS) ligand. The modifications suggested in this work include attachment of a lipophilic hydrocarbon chain (“tail”) to one or both nitrogen atoms of the S,S-EDDS. The new ligands were designed and evaluated for application in the Sediments Remediation Phase Transition Extraction (SR-PTE) process. This novel process is being developed for the simultaneous removal of both heavy metals and organic pollutants from contaminated soils, sediments or sludge. The new chelators were designed to bind various target metal ions, to promote extraction of these ions into organic solvents. Several variations of attached tails were synthesized and tested. The results for one of them, N,N?-bis-dodecyl-S,S-EDDS (C24-EDDS), showed that the metal-ligand complexes are concentrated in the organic-rich phase in the Phase Transition Extraction process (more than 80%). Preliminary applications of the SR-PTE process with the C24-EDDS ligand were conducted also on actually contaminated sludge (field samples). The extraction of five toxic metals, namely, Cd, Cu, Ni, Pb and Zn was examined. In general, the extraction performance of the new ligand was not less than that of S,S-EDDS when a sufficient ligand-to-extracted ion ratio (about 4:1 was applied

  15. Microbial methods versus ion exchangers for the removal of heavy metals from aqueous solutions

    International Nuclear Information System (INIS)

    In the first part of the work examples from literature were studied and experiments were performed to compare the elimination of heavy metals in aqueous solutions using biomass (biosorption) with that using ion exchangers. The disadvantages of biosorption lie in the mechanical and chemical instability of biomass. To date it has not been possible to considerably improve on the selectivity of ion-exchange resins. The capacity of some biomass types, related to dry weight, can reach and even surpass that of ion exchangers. In the second part of the work a method was developed for the selective eliminiation of mercury in aqueous solutions using an active bioadsorber. This process is based on the biotransformation of Hg2+ to Hg0 effected by the reductase system of mercury-resistent microorganisms. The developing elemental mercury accumulates in the fixed bed. Kinetic studies on intact cells and fixed-bed experiments upto the 1-liter scale using organisms fixed on parous support materials were performed. Input concentrations of upto 10 mg Hg/l were decreased to residual levels in the range of 30-100 ?g Hg/l. (orig.)

  16. New biodegradable organic-soluble chelating agents for simultaneous removal of heavy metals and organic pollutants from contaminated media.

    Science.gov (United States)

    Ullmann, Amos; Brauner, Neima; Vazana, Shlomi; Katz, Zhanna; Goikhman, Roman; Seemann, Boaz; Marom, Hanit; Gozin, Michael

    2013-09-15

    Advanced biodegradable and non-toxic organic chelators, which are soluble in organic media, were synthesized on the basis of the S,S-ethylenediamine-disuccinate (S,S-EDDS) ligand. The modifications suggested in this work include attachment of a lipophilic hydrocarbon chain ("tail") to one or both nitrogen atoms of the S,S-EDDS. The new ligands were designed and evaluated for application in the Sediments Remediation Phase Transition Extraction (SR-PTE) process. This novel process is being developed for the simultaneous removal of both heavy metals and organic pollutants from contaminated soils, sediments or sludge. The new chelators were designed to bind various target metal ions, to promote extraction of these ions into organic solvents. Several variations of attached tails were synthesized and tested. The results for one of them, N,N'-bis-dodecyl-S,S-EDDS (C24-EDDS), showed that the metal-ligand complexes are concentrated in the organic-rich phase in the Phase Transition Extraction process (more than 80%). Preliminary applications of the SR-PTE process with the C24-EDDS ligand were conducted also on actually contaminated sludge (field samples). The extraction of five toxic metals, namely, Cd, Cu, Ni, Pb and Zn was examined. In general, the extraction performance of the new ligand was not less than that of S,S-EDDS when a sufficient ligand-to-extracted ion ratio (about 4:1 was applied. PMID:23832060

  17. Role of Organic Matter in the Removal of Heavy Metals in Stormwater Runoff

    Science.gov (United States)

    Barrett, M.; Ingenloff, C.; Katz, L.

    2011-12-01

    Heavy metals (copper, zinc, and lead) are common constituents in highway runoff and concentrations in runoff from highway facilities are particularly high. These concentrations are also generally higher than observed in natural water bodies and several studies have demonstrated acute and chronic toxicity to aquatic ecosystems. One focus of this project is to assess the potential of sorption to reduce the concentration of metals in runoff. The difficulty evaluating adsorption in multi-component systems is to capture the impacts of background organic matter and other complexing ions on adsorption behavior. Very few studies have evaluated the ability of surface complexation models to predict adsorption in systems that contain organic matter from highway runoff. Moreover, the composition of the organic matter in stormwater runoff can be significantly different from natural organic matter typically used to assess the impact of background organics on metal ion adsorption. This research project specifically addresses these concerns and examines the impact of highway runoff on the adsorption behavior to determine whether existing surface complexation and chemical speciation models and parameter databases can be used to predict adsorption of target metal ions in these waters. Previous research has employed both actual storm water that has been obtained from actual field highway runoff sites as well as synthetic storm water compositions that have attempted to mimic the major components of natural storm water. Researchers and practitioners in the field generally agree on the importance of capturing the background water matrix; however, concerns associated with required volumes, holding times, aging, consistency and temporal and spatial variability often favor the use of synthetic formulations. While synthetic storm water can achieve the required consistency, numerous artifacts can be introduced due to the high reactivity of trace metal ions with background inorganic and organic ligands. Of particular concern, is the background organic matrix associated with stormwater. While most of the inorganic composition of natural stormwater can be adequately characterized using routine analytical procedures, characterization of organic matter to the same level of detail is not possible. Indeed, methods for characterization of natural organic matter typically only provide operational definitions of the composition. A compromise between using natural and synthetic storm water was therefore made by recognizing the importance of capturing the organic matter from natural storm water, but adding the flexibility of using synthetic storm water to provide the ionic composition. To alleviate concerns associated with storing large volumes and aging of organic solutions, the storm water was concentrated within twenty-four hours of collection using reverse osmosis and then freeze-dried. The freeze-dried organic matter will be reconstituted as needed at concentrations that mimic the initial total organic concentration of the stormwater when it was collected. This paper provides detailed guidance for the preparation of a synthetic water that can be used to simulate stormwater composition.

  18. Coupled Electrokinetics-Adsorption Technique for Simultaneous Removal of Heavy Metals and Organics from Saline-Sodic Soil

    Science.gov (United States)

    Lukman, Salihu; Essa, Mohammed Hussain; Mu'azu, Nuhu Dalhat; Bukhari, Alaadin

    2013-01-01

    In situ remediation technologies for contaminated soils are faced with significant technical challenges when the contaminated soil has low permeability. Popular traditional technologies are rendered ineffective due to the difficulty encountered in accessing the contaminants as well as when employed in settings where the soil contains mixed contaminants such as petroleum hydrocarbons, heavy metals, and polar organics. In this study, an integrated in situ remediation technique that couples electrokinetics with adsorption, using locally produced granular activated carbon from date palm pits in the treatment zones that are installed directly to bracket the contaminated soils at bench-scale, is investigated. Natural saline-sodic soil, spiked with contaminant mixture (kerosene, phenol, Cr, Cd, Cu, Zn, Pb, and Hg), was used in this study to investigate the efficiency of contaminant removal. For the 21-day period of continuous electrokinetics-adsorption experimental run, efficiency for the removal of Zn, Pb, Cu, Cd, Cr, Hg, phenol, and kerosene was found to reach 26.8, 55.8, 41.0, 34.4, 75.9, 92.49, 100.0, and 49.8%, respectively. The results obtained suggest that integrating adsorption into electrokinetic technology is a promising solution for removal of contaminant mixture from saline-sodic soils. PMID:24235885

  19. Influence of the composition and removal characteristics of organic matter on heavy metal distribution in compost leachates.

    Science.gov (United States)

    He, Xiao-Song; Xi, Bei-Dou; Li, Dan; Guo, Xu-Jing; Cui, Dong-Yu; Pan, Hong-Wei; Ma, Yan

    2014-06-01

    Compost leachates were collected to investigate the influence of the composition and removal of volatile fatty acids (VFAs), humic-like substances (HSs), and dissolved organic nitrogen (DON) on heavy metal distribution during the leachate treatment process. The results showed that acetic and propionic acids accounted for 81.3 to 93.84% of VFAs, and that these acids were removed by the anaerobic-aerobic process. Humic- and fulvic-like substances were detected by excitation-emission matrix spectroscopy coupled with parallel factor analysis, and their content significantly decreased after the anaerobic and membrane treatments. DON in compost leachates ranged from 26.53 mg L(-1) to 919.46 mg L(-1), comprised of dissolved free amino acids and the protein-like matter bound to humic- and fulvic-like substances, and was removed by the aerobic process. Correlation analysis showed that Mn, Ni, and Pb were bound to VFAs and protein-, fulvic-, and humic-like substances in the leachates. Co was primarily bound to fulvic- and humic-like matter and inorganic sulfurs, whereas Cu, Zn, and Cd interacted with inorganic sulfur. PMID:24595753

  20. Kinetics and equilibrium studies for the removal of heavy metals in both single and binary systems using hydroxyapatite

    Science.gov (United States)

    Ramesh, S. T.; Rameshbabu, N.; Gandhimathi, R.; Nidheesh, P. V.; Srikanth Kumar, M.

    2012-09-01

    Removal of heavy metals is very important with respect to environmental considerations. This study investigated the sorption of copper (Cu) and zinc (Zn) in single and binary aqueous systems onto laboratory prepared hydroxyapatite (HA) surfaces. Batch experiments were carried out using synthetic HA at 30 °C. Parameters that influence the adsorption such as contact time, adsorbent dosage and pH of solution were investigated. The maximum adsorption was found at contact time of 12 and 9 h, HA dosage of 0.4 and 0.7 g/l and pH of 6 and 8 for Cu and Zn, respectively, in single system. Adsorption kinetics data were analyzed using the pseudofirst-, pseudosecond-order and intraparticle diffusion models. The results indicated that the adsorption kinetic data were best described by pseudosecond-order model. Langmuir and Freundlich isotherm models were applied to analyze adsorption data, and Langmuir isotherm was found to be applicable to this adsorption system, in terms of relatively high regression values. The removal capacity of HA was found to be 125 mg of Cu/g, 30.3 mg of Zn/g in single system and 50 mg of Cu/g, 15.16 mg of Zn/g in binary system. The results indicated that the HA used in this work proved to be effective material for removing Cu and Zn from aqueous solutions.

  1. Impact of carbonate on the efficiency of heavy metal removal from kaolinite soil by the electrokinetic soil remediation method

    International Nuclear Information System (INIS)

    While the feasibility of using electrokinetics to decontaminate soils has been studied by several authors, the effects of soil composition on the efficiency of this method of decontamination has yet to be fully studied. This study focuses its attention on the effect of 'calcite or carbonate' (CaCO3) on removal efficiency in electrokinetic soil remediation. Bench scale experiments were conducted on two soils: kaolinite and natural-soil of a landfill in Hamedan, Iran. Prescribed quantities of carbonates were mixed with these soils which were subsequently contaminated with zinc nitrate. After that, electrokinetic experiments were conducted to determine the efficiency of electrokinetic remediation. The results showed that an increase in the quantity of carbonate caused a noticeable increase on the contaminant retention of soil and on the resistance of soil to the contaminant removal by electrokinetic method. Because the presence of carbonates in the soil increases its buffering capacity, acidification is reduced, resulting in a decrease in the rate of heavy metal removed from the contaminant soil. This conclusion was validated by the evaluation of efficiency of electrokinetic method on a soil sample from the liner of a waste disposal site, with 28% carbonates.

  2. Comparative studies on the removal of heavy metals ions onto cross linked chitosan-g-acrylonitrile copolymer.

    Science.gov (United States)

    Shankar, P; Gomathi, Thandapani; Vijayalakshmi, K; Sudha, P N

    2014-06-01

    The graft copolymerization of acrylonitrile onto cross linked chitosan was carried out using ceric ammonium nitrate as an initiator. The prepared cross linked chitosan-g-acrylonitrile copolymer was characterized using FT-IR and XRD studies. The adsorption behavior of chromium(VI), copper(II) and nickel(II) ions from aqueous solution onto cross linked chitosan graft acrylonitrile copolymer was investigated through batch method. The efficiency of the adsorbent was identified from the varying the contact time, adsorbent dose and pH. The results evident that the adsorption of metal ions increases with the increase of shaking time and metal ion concentration. An optimum pH was found to be 5.0 for both Cr(VI) and Cu(II), whereas the optimum pH is 5.5 for the adsorption of Ni(II) onto cross linked chitosan-g-acrylonitrile copolymer. The Langmuir and Freundlich adsorption models were applied to describe the isotherms and isotherm constants. Adsorption isothermal data could be well interpreted by the Freundlich model. The kinetic experimental data properly correlated with the second-order kinetic model. From the above results it was concluded that the cross linked chitosan graft acrylonitrile copolymer was found to be the efficient adsorbent for removing the heavy metals under optimum conditions. PMID:24680901

  3. Electrodialytic remediation of harbour sediment in suspension - Evaluation of effects induced by changes in stirring velocity and current density on heavy metal removal and pH

    DEFF Research Database (Denmark)

    Kirkelund, Gunvor Marie; Ottosen, Lisbeth M.

    2009-01-01

    Electrodialytic remediation was used to remove heavy metals from a suspension of dredged harbour sediment. The studied metals Cu, Pb, Zn and Cd are normally strongly bound in anoxic sediment. Six electrodialytic laboratory remediation experiments were made, lasting 14 days and under oxic conditions. The influence on the metal removal was investigated by changing current densities and stirring velocity of the sediment suspension. Using a current density of 1.0 mA/cm2 gave the highest metal removal. The sediment suspension was partly oxidised when mixed into a suspension for the electrodialytic remediation experiments and was further oxidised during the experiments. Even at low stirring velocities, oxic conditions were obtained. The metal removal was dependent on the achieved pH in the sediment and the highest metal removal and corresponding low pH was obtained by using a current density of 1.0 mA/cm2 and a stirring velocity of the sediment suspension of 1000 rpm. The highest removal obtained was 98% Cd, 78% Zn, 65% Pb and 44% Cu after 14 days of remediation. The metal removal was more dependent on the stirring velocity than on the current density. When manually stirring the sediment suspension or using a stirring velocity of 60 rpm the sediment deposited, which led to a slightly higher pH in the sediment and keeping all the sediment in suspension is essential for a successful remediation.

  4. OPTIMIZATION OF MOTOR VEHICLE INDUSTRIES WASTEWATER TREATMENT METHODS WITH THE AIM OF HEAVY METALS REMOVAL AND WATER REUSE IN PILOT SCALE

    Directory of Open Access Journals (Sweden)

    S. A. Mirbagheri, M. Salehi M

    2006-10-01

    Full Text Available The waste of motor vehicle industries is mainly the result of washing, coloring and various stages of chassis manufacturing, which include oil, grease, dyestuff, chromium, phosphate and other pollutants. In the present research, extended aeration activated sludge biological treatment plant is being considered and evaluated, for the removal of heavy metals and pollution load from industrial wastes and sanitary wastewaters, and on the pilot scale for optimization of waste treatment method for motor vehicle industries. To accomplish the pilot experiments, the natural waste of Bahman motor vehicle factory is used. Effective factors on efficient removal of heavy metals and pollution load such as concentration of biological mass (MLVSS, COD, BOD, pH in the extended aeration activated sludge biological treatment system, in different ratios of the mixing of industrial waste to sanitary wastewater have been experimented and evaluated. The performance of the above system, in the best of conditions, removes about 90% of pollution load and 65% of heavy metals existing in the industrial wastes. After analyzing the experiments, it is concluded that the removal of heavy metals through biological methods is possible and moreover it is feasible to biologically treat the mixing of motor vehicle industries effluent and sanitary wastewater up to the ratio of one to one, if guided exactly and scientifically.

  5. Highly effective removal of heavy metals by polymer-based zirconium phosphate: a case study of lead ion.

    Science.gov (United States)

    Pan, B C; Zhang, Q R; Zhang, W M; Pan, B J; Du, W; Lv, L; Zhang, Q J; Xu, Z W; Zhang, Q X

    2007-06-01

    Zirconium phosphate (ZrP) has recently been demonstrated as an excellent sorbent for heavy metals due to its high selectivity, high thermal stability, and absolute insolubility in water. However, it cannot be readily adopted in fixed beds or any other flowthrough system due to the excessive pressure drop and poor mechanical strength resulting from its fine submicrometer particle sizes. In the present study a hybrid sorbent, i.e., polymer-supported ZrP, was prepared by dispersing ZrP within a strongly acidic cation exchanger D-001 and used for enhanced lead removal from contaminated waters. D-001 was selected as a host material for sorbent preparation mainly because of the Donnan membrane effect resulting from the nondiffusible negatively charged sulfonic acid group on the exchanger surface, which would enhance permeation of the targeted metal ions. The hybrid sorbent (hereafter denoted ZrP-001) was characterized using a nitrogen adsorption technique, scanning electron microscope (SEM), and X-ray diffraction (XRD). Lead sorption onto ZrP-001 was found to be pH dependent due to the ion-exchange mechanism, and its sorption kinetics onto ZrP-001 followed the pseudo-first-order model. Compared to D-001, ZrP-001 exhibited more favorable lead sorption particularly in terms of high selectivity, as indicated by its substantially larger distribution coefficients when other competing cations Na(+), Ca(2+), and Mg(2+) coexisted at a high level in solution. Fixed-bed column runs showed that lead sorption on ZrP-001 resulted in a conspicuous decrease of this toxic metal from 40 mg/L to below 0.05 mg/L. By comparison with D-001 and ZrP-CP (ZrP dispersion within a neutrally charged polymer CP), enhanced removal efficiency of ZrP-001 resulted from the Donnan membrane effect of the host material D-001. Moreover, its feasible regeneration by diluted acid solution and negligible ZrP loss during operation also helps ZrP-001 to be a potential candidate for lead removal from water. Thus, all the results suggested that ZrP-001 offers excellent potential for lead removal from contaminated water. PMID:17336317

  6. Removal of heavy metals by exopolymeric substances produced by resistant purple nonsulfur bacteria isolated from contaminated shrimp ponds

    Scientific Electronic Library Online (English)

    Saijai, Panwichian; Duangporn, Kantachote; Banjong, Wittayaweerasak; Megharaj, Mallavarapu.

    2011-07-15

    Full Text Available Two purple nonsulfur bacteria (PNSB) strains, Rhodobium marinum NW16 and Rhodobacter sphaeroides KMS24 were investigated for their potential to remove heavy metals (HMs) from contaminated shrimp pond water. Tolerance of both PNSB strains growing with both microaerobic-light and aerobic-dark conditio [...] ns, based on their minimum inhibitory concentrations, was in the order of Cu2+ > Zn2+ > Cd2+ (Pb precipitation occurred at 0.34 mM). Results from a scanning electron microscope equipped with an energy dispersive X-ray spectrometer (SEM-EDX) indicated that Cu2+ and Zn2+ altered the cellular morphology of both strains and accumulated HMs were found in their cells. The highest amounts of both cations were found in their cell walls followed by the cytoplasm and cell membrane. Using the highest concentrations (mM) of HMs found in shrimp pond of 0.0067 Cd2+, 0.54 Cu2+, 0.30 Pb2+, 0.89 Zn2+ and 3% NaCl under both incubating conditions exopolymeric substances (EPS) produced by both strains showed a greater removal of all HMs (average percentages; 90.52-97.29) than their cells (average percentages; 14.02-75.03).

  7. Colorimetric detection of copper and efficient removal of heavy metal ions from water by diamine-functionalized SBA-15.

    Science.gov (United States)

    Wang, Zhuqing; Wang, Min; Wu, Genhua; Wu, Dayu; Wu, Aiguo

    2014-06-14

    SBA-15 functionalized with N-[3-(trimethoxysilyl)propyl]ethylene-diamine (TPED) was synthesized and used for the colorimetric detection of Cu(2+) and removal of heavy metal ions in aqueous solutions. Compared to free SBA-15, the adsorption ability of diamine-functionalized SBA-15 (depicted as SBA-TPED) increased remarkably, the maximum adsorption capacity of SBA-TPED for Cu(2+), Pb(2+) and Zn(2+) was 27.22, 96.43 and 12.16 mg g(-1), respectively. Furthermore, SBA-TPED exhibits high selectivity for Cu(2+) with the relative selectivity coefficient of SBA-TPED for Cu(2+)/Pb(2+) being over 10 and for Cu(2+)/Zn(2+) being over 60. The naked-eye detection limit of SBA-TPED for Cu(2+) is 0.95 ppm, and the determination of Cu(2+) in real water samples also displays satisfactory results. Moreover, SBA-TPED possesses fast kinetics for removing Cu(2+) with a saturation time of less than 30 min, and can be regenerated by simple acid treatment. PMID:24745033

  8. The potential of melt-mixed polypropylene-zeolite blends in the removal of heavy metals from aqueous media

    Science.gov (United States)

    Motsa, Machawe M.; Thwala, Justice M.; Msagati, Titus A. M.; Mamba, Bhekie B.

    The continued deterioration of the water quality in natural water sources such as rivers and lakes has led to tensions amongst relevant stakeholders to such an extent that cooperative water resource management is being regarded as an ideal solution to culminate conflicts and maximise the benefits. The desire to develop technologies that combine the three most important aspects of integrated water resource management (namely social, economic and environmental) has been encouraged by relevant authorities. This paper therefore reports the application of clinoptilolite-polypropylene (CLI-PP) blends/composites for the removal of lead from aqueous media. Just like many other heavy metals, lead poses a threat to water and soil quality as well as to plant and animal health. The findings on the adsorption behaviour of clinoptilolite-polypropylene composites with respect to Pb 2+ are also reported here, with the aim of extending its application to wastewater and environmental water purification. The batch equilibrium adsorption method was employed and the influence of contact time, pH, initial metal-ion concentration, temperature and pretreatment was determined. The optimum pH was found to be between pH 6 and pH 8 while the maximum sorption of lead at optimal pH was 95%. No big difference was observed between the adsorption behaviour of composites functionalised with 20% and 30% clinoptilolite, respectively. The pretreatment with HCl and NaCl made a slight difference to the adsorption capacity of composites.

  9. Removal of metal ions from aqueous solution

    Science.gov (United States)

    Jackson, Paul J. (both Los Alamos, NM); Delhaize, Emmanuel (both Los Alamos, NM); Robinson, Nigel J. (Durham, GB2); Unkefer, Clifford J. (Los Alamos, NM); Furlong, Clement (Seattle, WA)

    1990-11-13

    A method of removing heavy metals from aqueous solution, a composition of matter used in effecting said removal, and apparatus used in effecting said removal. One or more of the polypeptides, poly (.gamma.-glutamylcysteinyl)glycines, is immobilized on an inert material in particulate form. Upon contact with an aqueous solution containing heavy metals, the polypeptides sequester the metals, removing them from the solution. There is selectivity of poly (.gamma.-glutamylcysteinyl)glycines having a particular number of monomer repeat unit for particular metals. The polypeptides are easily regenerated by contact with a small amount of an organic acid, so that they can be used again to remove heayv metals from solution. This also results in the removal of the metals from the column in a concentrated form.

  10. Removal of selected heavy metals from MSW fly ash by the electrodialytic process

    DEFF Research Database (Denmark)

    Ferreira, Célia Maria Dias; Jensen, Pernille Erland

    2005-01-01

    This paper aims to assess the applicability of the electrodialytic remediation technique for the removal of zinc, lead, copper and cadmium from municipal solid waste (MSW) incinerator fly ash. A broad range of experimental conditions were studied including current densities, remediation times, use of assisting agents and cell design. Several operational problems were identified during the electrodialytic experiments, among which are formation of precipitates, dryness of sample and partial dissolution of sample creating preferential pathways for the electric current. These problems may explain the low remediation efficiencies obtained. Comparison between experiments showed that generally the use of Na-gluconate as assisting agent leads to better results than distilled water. Increasing the concentration of the assisting agent also results in higher removals.

  11. REMOVAL OF HEAVY METALS AND ORGANIC CONTAMINANTS FROM AQUEOUS STREAMS BY NOVEL FILTRATION METHODS

    Science.gov (United States)

    Catalytically grown carbon nanofibers are a novel material that is produced by the decomposition of selected hydrocarbons over metal particles. The material consists of graphite platelets perfectly aligned and stacked in various directions with respect to the fiber axis. Such an ...

  12. Design of high efficiency fibers for ion exchange and heavy metal removal

    Science.gov (United States)

    Dominguez, Lourdes

    Ion exchange materials coated on glass fiber substrates have a number of advantages over the conventional ion exchange beads. These include simplification of the overall synthesis including faster more efficient functionalization and elimination of toxic solvents. Other benefits include the ability to be fabricated in the form of felts, papers, or fabrics, improving media contact efficiency and enhancing both the rates of reaction and regeneration. In addition, physical and mechanical requirements of strength and dimensional stability are achieved by use of glass fiber substrates. Investigations were focused on design of: (1) polymeric cationic exchange fibers and their application for lead and mercury removal, (2) polymeric anionic exchange fibers and their application for arsenate removal, (3) enhancement of anionic fiber selectivity for monovalent ions over divalent ions through bulkier triaklylamine functional groups, and (4) polymeric mercaptyl fibers for the application of arsenite removal. The design and characterization of a cationic exchange fiber is described. Dynamic mode (breakthrough) experiments for calcium, lead, and mercury ion solutions are also presented. The second system consists of the preparation and characterization of anionic exchange fibers with equilibrium adsorption isotherms and dynamic mode kinetic experiments for arsenate removal. Modification of the resin with bulkier functional groups (trimethylamine, triethylamine, tripropylamine, tributylanmine), thereby effecting a change in the selectivity from divalent species to monovalent species, is considered in the separation of nitrates from sulfates. The ability of a thiol group to bind to the highly toxic arsenite ion (as is done in proteins and enzymes) provided the model used to chemically modify and characterize a polyvinyl alcohol mercaptyl fibrous system, coated on a fiberglass substrate, for the purpose of arsenite (As3+) removal from water. Physical/chemical aspects of naturally occurring thiols and disulfides was used to draw parallels to observations found with the polyvinyl alcohol mercaptyl system and its reactivity towards arsenite. The ability of these systems to chelate arsenite was presented through equilibrium adsorption isotherms. All fibrous systems were characterized through a variety of techniques such as scanning electron microscopy, diffuse reflectance infrared spectroscopy, elemental analysis, analytical analysis, and thermal analysis of the copolymer.

  13. REMOVAL OF HEAVY METALS FROM DYE EFFLUENT USING ACTIVATED CARBON PRODUCED FROM COCONUT SHELL

    OpenAIRE

    Onyeji, L. I.; Aboje, A. A.

    2011-01-01

    The ability of activated carbon produced from coconut shell to remoe mercury Hg (II), Lead Pb (II) and Copper Cu (II) from dye effluent was investigated. The activated carbon was produced through chemical activation processes by using zinc chloride (ZnCl2). The adsorption capacity was determined as a function of adsorbent dosage. The adsorption Isotherms of the studied metals on adsorbent were also determined and compared with the Langmair models. The activated carbon produced showed excellen...

  14. The application of polymer inclusive membranes for removal of heavy metal ions from waste solutions

    OpenAIRE

    Gajda, B.; Bogacki, M. B.

    2012-01-01

    Purpose: The aim of the conducted studies was to determine the possibility of selective separation and precipitation of metal ions from polimetalic solution containing nickel(II), cobalt(II), cadmium(II) and zinc(II) cations using polymer inclusive membranes. 1-decylimidazole was used in membrane as a carrier of ions. The influence of chloride anions concentration on the process has also been investigated.Design/methodology/approach: Polymer inclusive membranes (PIM) containing cellulose acet...

  15. Estimation and removal of selected heavy metal ions from tanneries liquid waste and sediments

    International Nuclear Information System (INIS)

    Concentration of potentially toxic and general metals Cu, Co, Cr, Cd, Mn, Zn, Ni and Pb in sediments and liquid waste samples of selected tanneries ware measured by atomic absorption spectrophotometer, after digestion with nitric acid. The corresponding analytical data revealed elevated concentrations of above mentioned metals compared to the permissible levels including chromium which steels into the sediments. Selective separation of chromium in sediment from other metal ions has been investigated using activated charcoal and employing batch technique. The effects of adsorbent concentration, pH, shaking time and percentage reduction in chromium concentration (93 - 99 %) with temperature have been studied. The adsorption equilibrium data were fitted in Freundlich, Dubinin, Redushkevich and Virial isotherms equations at temperatures 303K to 318K. Thermodynamic parameters delta H-zero degree, delta S- zero degree and delta G zero degree were calculated using Virial isotherm expression. The values of free energy of adsorption delta G decrease with increase in temperature and show endothermic nature of adsorption of Chromium on activated charcoal. (authors)

  16. Arsenic removal via electrocoagulation from heavy metal contaminated groundwater in La Comarca Lagunera Mexico

    International Nuclear Information System (INIS)

    Arsenic contamination is an enormous worldwide problem. A large number of people dwelling in Comarca Lagunera, situated in the central part of northern Mexico, use well water with arsenic in excess of the water standard regulated by the Secretary of Environment and Natural Resources of Mexico (SEMARNAT), to be suitable for human health. Individuals with lifetime exposure to arsenic develop the classic symptoms of arsenic poisoning. Among several options available for removal of arsenic from well water, electrocoagulation (EC) is a very promising electrochemical treatment technique that does not require the addition of chemicals or regeneration. First, this study will provide an introduction to the fundamental concepts of the EC method. In this study, powder X-ray diffraction, scanning electron microscopy, transmission Moessbauer spectroscopy and Fourier transform infrared spectroscopy were used to characterize the solid products formed at iron electrodes during the EC process. The results suggest that magnetite particles and amorphous iron oxyhydroxides present in the EC products remove arsenic(III) and arsenic(V) with an efficiency of more than 99% from groundwater in a field pilot scale study

  17. Heavy Metals Removal in Aqueous Solution by two Delta-diketones

    Directory of Open Access Journals (Sweden)

    D. Fanou

    2007-01-01

    Full Text Available This research presents the elimination of lead, coppers, zinc and iron by complexation with ?-diketones particularly, 1, 3, 5-triphenylpentane-1,5-dione and 3-furyl-1,5-diphenylpentane-1, 5-dione in liquid biphasic system (water/dichloromethane. Various factors (pH, nature and concentration in metal ions, time of contact, chelating capacity and temperature influencing this interaction were examined. The use of these molecules in the complexation optimal conditions (Temperature = 35°C, Mass ratio Cmetal/Cextractant = 4, Contact time = 30 min and pH 4, led to the elimination of more than 70% of lead, iron, coppers and zinc.

  18. Removal of heteroatoms and metals from heavy oils by bioconversion processes. CRADA final report

    Energy Technology Data Exchange (ETDEWEB)

    Kaufman, E N; Borole, A P

    1999-03-01

    The objective of this Cooperative research and Development Agreement project between Oak Ridge National Laboratory ( O W ) and Baker Performance Chemicals (BPC), Chevron, Energy BioSystems, Exxon, UNOCAL and Texaco is to investigate the biological desukrization of crude oil. Biological removal of organic s&%r fiom crude oil offers an attractive alternative to conventional thermochemical treatment due to the mild operating conditions afforded by the biocatalyst. In order for biodesulfbrization to realize commercial success, reactors must be designed which allow for sufficient liquid / liquid and gas / liquid mass transfer while simultaneously reducing operating costs. To this end we have been developing advanced bioreactors for biodesufirization and have been studying their performance using both actual crude oil as well as more easily characterized model systems.

  19. Isolation of purple nonsulfur bacteria for the removal of heavy metals and sodium from contaminated shrimp ponds

    Scientific Electronic Library Online (English)

    Saijai, Panwichian; Duangporn, Kantachote; Banjong, Wittayaweerasak; Megharaj, Mallavarapu.

    2010-07-15

    Full Text Available In order to determine whether waters used for the shrimp cultivation contained toxic levels of heavy metals (HMs) and sodium (Na), analysis was carried out on 31 shrimp ponds in areas of southern Thailand. Purple nonsulfur bacteria (PNB) were also isolated from the same ponds to investigate if they [...] could be used for bioremediation of the above contaminants. The highest HMs concentrations of the sediment samples in mg/kg dry weight were found as follows: 0.75 cadmium (Cd), 62.63 lead (Pb), 34.60 copper (Cu) and 58.50 zinc (Zn). However, all sediment samples met Hong Kong standards for dredged sediment. In contrast, contamination of Cu (9-30 µg/L) and Zn (140-530 µg/L) exceeding the standard guidelines for marine aquatic animal set by the Pollution Control Department, Thailand, were found in 32 and 61% of water samples, respectively. Two metal resistant PNB isolates, NW16 and KMS24, were selected from the 120 PNB isolates obtained. Both isolates reduced the levels of HMs by up to 39% for Pb, 20% for Cu, 7% for Cd, 5% for Zn and 31% for Na from water that contained the highest levels of HMs found and 3% NaCl when cultured with either microaerobic-light or aerobic-dark conditions. The isolate NW16 removed a greater percentage of the HMs than the isolate KMS24, but the isolate KMS24 was able to survive better under a greater variety of environmental conditions. Both strains were therefore suitable to use for further investigating their abilities to remediate water contaminated with HMs and Na.

  20. Post-annealing treatment for Cu-TiO2 nanotubes and their use in photocatalytic methyl orange degradation and Pb(II) heavy metal ions removal

    Science.gov (United States)

    Sreekantan, Srimala; Mohd Zaki, Syazwani; Lai, Chin Wei; Tzu, Teoh Wah

    2014-07-01

    TiO2 nanotubes were synthesized via electrochemical anodization of Ti foil at 60 V for 1 h in a bath with electrolytes composed of ethylene glycol containing 5 wt.% of NH4F and 1 vol.% of H2O2. The incorporation of optimum Cu2+ ions (1.30 at.%) into TiO2 nanotubes were prepared by using wet impregnation method to improve their photocatalytic methyl orange degradation and Pb(II) heavy metal removal. The small Cu2+ ions were successfully diffused into lattice of TiO2 nanotubes by conducting post-annealing treatment at 400 °C for 4 h in argon atmosphere after wet impregnation. In this manner, optimum Cu2+ ions played a crucial role in suppressing the recombination of charge carriers by forming inter-band states (mismatch of the band energies) within the lattice of Cu-TiO2. The experimental results showed that a maximum of 80% methyl orange removal and 97.3% Pb(II) heavy metal removal at pH 11 under UV irradiation for 5 h. Besides, it was noticed that photocatalytic Pb(II) heavy metal removal was strong dependence on pH of the solution because of the amphoteric character of Cu-TiO2 in an aqueous medium.

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

    International Nuclear Information System (INIS)

    We prepared novel Fe3O4 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 (Cd2+, Zn2+, Pb2+ and Cu2+) from aqueous solution. We investigated the adsorption capacity of Fe3O4-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. Fe3O4-APS-AA-co-CA MNPs are excellent for removal of heavy metal ions such as Cd2+, Zn2+, Pb2+ and Cu2+ 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.

  2. Removal of heavy metals from water by zeolite mineral chemically modified. Mercury as a particular case

    International Nuclear Information System (INIS)

    Research works on the removal of mercury from water by zeolite minerals show that a small quantity of this element is sorbed. In this work the mercury sorption from aqueous solutions in the presence and absence of Cu(l l), Ni(l l) and/or Zn(l l) by a Mexican zeolite mineral, natural and modified by cisteaminium chloride or cistaminium dichloride, was investigated in acidic p H. The zeolite minerals were characterized by X- Ray diffraction Ftir, scanning electron microscopy and semiquantitative elemental analysis (EDS), surface area analysis (BET) and thermogravimetric analysis (TGA). Mercury from aqueous solutions was quantified by Atomic absorption spectroscopy. The amount of sulphur on the zeolite samples treated with Na CI and modified with cisteaminium chloride (0.375 mmol/g) or cistaminium dichloride(0.475 mmol/g) was found to be higher than that of the zeolite minerals modified with cisteaminium chloride and cistaminium dichloride without treating them with Na CI. The amount of sulphur on the zeolite minerals modified with thiourea was the lowest. The diffusion coefficients and sorption isotherms for mercury were determined in the natural, treated with Na CI and, treated with Na CI and then modified with the cisteaminium chloride or cistaminium dichloride zeolite samples. The retention of mercury was the highest for the zeolite minerals treated Na CI and then modified with cisteaminium chloride or cistaminium dichloride, with adsorption capacity of 0.0511 and 0.0525 mmol Hg/g, respectively. In this research work, it was found that the retention of mercury by the modified minerals was not affected by the presence of Cu (Il), Zn(l l) y Ni (I l) under the experimental conditions. (Author)

  3. Potential application of activated carbon from maize tassel for the removal of heavy metals in water

    Science.gov (United States)

    Olorundare, O. F.; Krause, R. W. M.; Okonkwo, J. O.; Mamba, B. B.

    Water-pollution problems worldwide have led to an acute shortage of clean and pure water for both domestic and human consumption. Various technologies and techniques are available for water treatment which includes the use of activated carbon. In this study activated carbons used for the removal of lead (II) ions from water samples were prepared from maize tassels (an agricultural waste residue) which were modified using physical and chemical activation. In the physical activation CO2 was used as the activating agent, while in chemical activation H3PO4 with an impregnation ratio ranging from 1 to 4 was employed. The maize tassel was pyrolysed at different temperatures ranging from 300 °C to 700 °C in an inert atmosphere for a period of 60 min and activated at 700 °C for 30 min. The effects of activation temperature, impregnation ratio and duration were examined. The resultant modified tassels were characterised by measuring their particle-size distribution, porosities, pore volume, and pore-size distribution using scanning electron microscopy (SEM). The activated carbon produced by chemical activation had the highest BET surface area ranging from 623 m2 g-1 to 1 262 m2 g-1. The surface chemistry characteristics of the modified tassels were determined by FT-IR spectroscopy and Boehm’s titration method. The experimental data proved that properties of activated carbon depend on final temperature of the process, impregnation ratio and duration of the treatment at final temperature. The adsorption studies showed that chemically prepared activated carbon performed better than physically prepared activated carbon.

  4. The simulation of condensation removal of a heavy metal from exhaust gases onto sorbent particles

    International Nuclear Information System (INIS)

    A numerical model BAEROSOL for solving the general dynamic equation (GDE) of aerosols is presented. The goal was to model the capture of volatilized metals by sorbents under incinerator-like conditions. The model is based on algorithms presented by Jacobson and Turco [Aerosol Science and Technology 22 (1995) 73]. A hybrid size bin was used to model growth and formation of particles from the continuum phase and the coagulation of existing particles. Condensation and evaporation growth were calculated in a moving size bin approach, where coagulation and nucleation was modeled in the fixed size bin model of the hybrid grid. To account for the thermodynamic equilibrium in the gas phase, a thermodynamic equilibrium code CET89 was implemented. The particle size distribution (PSD) calculated with the model was then compared to analytical solutions provided for growth, coagulation and both combined. Finally, experimental findings by Rodriguez and Hall [Waste Management 21 (2001) 589-607] were compared to the PSD predicted by the developed model and the applicability of the model under incineration conditions is discussed

  5. Determination of Heavy Metal Removal Efficiency of Chrysopogon zizanioides (Vetiver) using Textile Wastewater Contaminated Soil

    OpenAIRE

    Lakshmanaperumalsamy, P.; Rathinamala, J.; Jayashree, S.

    2011-01-01

    A pot culture study was conducted using textile wastewater contaminated soil which was amended with Vermicompost (VC) in various proportions for a period of two months. The plant used for the study was Chrysopogon zizanioides (Vetiver) to investigate the accumulation of heavy metals in their roots. Physico-chemical parameters like pH, EC, TKN, P, K, TOC and metals like Pb, Cd and Cu and microbial population of the textile wastewater contaminated soil were analyzed initially (0 day) and finall...

  6. OPTIMIZATION OF MOTOR VEHICLE INDUSTRIES WASTEWATER TREATMENT METHODS WITH THE AIM OF HEAVY METALS REMOVAL AND WATER REUSE IN PILOT SCALE

    OpenAIRE

    S A Mirbagheri, M. Salehi M.

    2006-01-01

    The waste of motor vehicle industries is mainly the result of washing, coloring and various stages of chassis manufacturing, which include oil, grease, dyestuff, chromium, phosphate and other pollutants. In the present research, extended aeration activated sludge biological treatment plant is being considered and evaluated, for the removal of heavy metals and pollution load from industrial wastes and sanitary wastewaters, and on the pilot scale for optimization of waste treatment method for m...

  7. A novel reusable nanocomposite for complete removal of dyes, heavy metals and microbial load from water based on nanocellulose and silver nano-embedded pebbles.

    Science.gov (United States)

    Suman; Kardam, Abhishek; Gera, Meeta; Jain, V K

    2015-03-01

    The present work proposed a nanocellulose (NC)-silver nanoparticles (AgNPs) embedded pebbles-based composite material as a novel reusable cost-effective water purification device for complete removal of dyes, heavy metals and microbes. NC was prepared using acid hydrolysis of cellulose. The AgNPs were generated in situ using glucose and embedded within the porous concrete pebbles by the technique of inter-diffusion of ion, providing a very strong binding of nanoparticles within the porous pebbles and thus preventing any nanomaterials leaching. Fabrication of a continual running water purifier was achieved by making different layering of NC and Ag nano-embedded pebbles in a glass column. The water purifier exhibited not only excellent dye and heavy metal adsorption capacity, but also long-term antibacterial activity against pathogenic and non-pathogenic bacterial strains. The adsorption mainly occurred through electrostatic interaction and pore diffusion also contributed to the process. The bed column purifier has shown 99.48% Pb(II) and 98.30% Cr(III) removal efficiency along with 99% decontamination of microbial load at an optimum working pH of 6.0. The high adsorption capacity and reusability, with complete removal of dyes, heavy metals and Escherichia coli from the simulated contaminated water of composite material, will provide new opportunities to develop a cost-effective and eco-friendly water purifier for commercial application. PMID:25243917

  8. Simultaneous removal of coexistent heavy metals from simulated urban stormwater using four sorbents: a porous iron sorbent and its mixtures with zeolite and crystal gravel.

    Science.gov (United States)

    Wu, Peng; Zhou, Yu-shan

    2009-09-15

    The selectivity sequence and removal of coexistent heavy metals (namely As, Cd, Cr, Cu, Ni and Zn) in synthetic urban stormwater runoff were investigated by adsorption onto a porous iron sorbent (namely P1) and its mixtures with zeolite and crystal gravel, respectively (namely P2, P3, and P4). A batch method was employed to simulate the sorption processes. The geochemical model PHREEQC was used to calculate the metals' species and saturation data for elucidating the sorption data. The equilibrium data demonstrated a good fit with the Freundlich model and showed affinity in the orders: Cd>Zn>Ni>Cu>As>Cr (sorbents P1, P3 and P4) and Cd>Zn>Ni>As>Cu>Cr (sorbent P2). In addition to this, Calculated Distribution Coefficient (K(d)) values were used to compare the overall heavy metal removal efficiencies of the sorbents, which, in decreasing order, was found to be P4>P1>P2>P3. In comparing these four commercial sorbents, sorbent P4 represents a promising material for treatment of urban stormwater runoff containing mixed heavy metals. PMID:19303211

  9. Porous Ca-based bead sorbents for simultaneous removal of SO?, fine particulate matters, and heavy metals from pilot plant sewage sludge incineration.

    Science.gov (United States)

    Han, Yosep; Hwang, Gukhwa; Kim, Donghyun; Park, Soyeon; Kim, Hyunjung

    2015-02-11

    In this study, a porous calcium-based sorbent was prepared for simultaneous removal of SO2, particulate matter (PM), and heavy metals generated during incineration of sewage sludge. The prepared sorbent was confirmed to have a 3-dimensional-network pore structure, a high specific surface area of 68.5m(2)/g, and gas permeability of 1.12 × 10(-10)m(2). Laboratory-scale tests indicated that there was an improvement in the performance of SO2 removal as the porosity and the specific surface area of the sorbent increased. Additionally, increasing reaction temperature led to greater SO2 removal. Meanwhile, the SL-4 and LS-3 sorbents prepared in this study were installed for operation during pilot tests treating the sewage sludge combustion gas generated by a fluidized incinerator in order to compare and evaluate their feasibility for use in industrial applications. The results showed that the reactivity between SO2 and the starting material of the sorbent (Ca(OH)2>CaCO3), as well as the high specific surface area of the sorbent, were confirmed to be critical factors that improved the performance of SO2 removal. Notably, the results confirmed that both fine PM (? 1 ?m) and heavy metals were simultaneously removed with increasing efficiency over the time of operation. PMID:25261759

  10. Removal of heavy metals from aqueous solutions containing complexing agents by precipitation with acylthioreas; Abtrennung von Schwermetallen aus komplexbildnerhaltigen waessrigen Loesungen durch Faellung mit Acylthioharnstoffen

    Energy Technology Data Exchange (ETDEWEB)

    Ringmann, S.; Schuster, M. [Technische Univ. Muenchen (Germany). Inst. fuer Anorganische Chemie

    1997-09-01

    Several N`-acyl-N,N-dialkylthiourea derivatives have been applied as precipitants for the removal of Co(II), Ni(II), Cu(II), Zn(II), Cd(II) and Pb(II) from aqueous solutions. A general optimization of the experimental conditions was followed by studies concerning the pH dependence of complex formation as well as the influence of competing ligands (such as citric acid, tartaric acid, ammonia, glycine) on the residual concentration of heavy metal ions. After the treatment of model solutions (with initial metal concentrations ranging from 1 to 100 mg/l) with acylthioureas, a decrease of the metal content can be achieved in most cases, often meeting the requirements for indirect delivery of waste water. The selective separation of Cu from solutions containing the above mentioned heavy metals and additionally Fe, alkaline and alkaline earth metals can be achieved by appropriate selection of the pH range. Digestion of the metal chelates with diluted H{sub 2}SO{sub 4} yields (with the exception of lead and cobalt) solutions of the metal sulfates which can be subjected to electrolysis aiming at the recovery of elemental metals, and the ligand. Comparing to solutions having initial concentrations of 100 mg/l enrichment factors up to 100 can be achieved. (orig.)

  11. Removal of heavy metal ions from wastewater by a novel HEA/AMPS copolymer hydrogel: preparation, characterization, and mechanism.

    Science.gov (United States)

    Li, Zhengkui; Wang, Yueming; Wu, Ningmei; Chen, Qichun; Wu, Kai

    2013-03-01

    This study aims to synthesize 2-hydroxyethyl acrylate (HEA) and 2-acrylamido-2-methylpropane sulfonic (AMPS) acid-based hydrogels by gamma radiation and to investigate their swelling behavior and heavy metal ion adsorption capabilities. The copolymer hydrogels prepared were characterized via scanning electron microscopy, Fourier transformed infrared spectra, thermal gravimetric analysis, and X-ray photoelectron spectroscopy. The research showed that the copolymer hydrogel was beneficial for permeation due to its porous structure. In addition, the experimental group A-2-d [70 % water volume ratio and (n (AMPS)/n (HEA))?=1:1] was an optimal adsorbent. The optimal pH was 6.0 and the optimal temperature was 15 °C. Pb(2+), Cd(2+), Cu(2+), and Fe(3)+ achieved adsorption equilibriums within 24 h, whereas Cr(3+) reached equilibrium in 5 h. Pb(2)+, Cd(2+), Cr(3+), and Fe(3+) maximum load capacity was 1,000 mg L(-1), whereas the Cu(2+) maximum capacity was 500 mg L(-1). The priority order in the multicomponent adsorption was Cr(3+)>Fe(3+)>Cu(2+)>Cd(2+)>Pb(2+). The adsorption process of the HEA/AMPS copolymer hydrogel for the heavy metal ions was mainly due to chemisorption, and was only partly due to physisorption, according to the pseudo-second-order equation and Langmuir adsorption isotherm analyses. The HEA/AMPS copolymer hydrogel was confirmed to be an effective adsorbent for heavy metal ion adsorption. PMID:22614052

  12. Heavy metals removal from acid mine drainage water using biogenic hydrogen sulphide and effluent from anaerobic treatment: Effect of pH

    International Nuclear Information System (INIS)

    Four alternatives (runs A, B, C and D) for heavy metals removal (Fe, Cu, Zn and Al) from acid mine drainage water (AMDW) produced in the mining areas of the Huelva Province, Spain, were evaluated. In run A, the anaerobic effluent from the treatment of acid mine drainage water (cheese whey added as a source of carbon) was mixed with the raw AMDW. The pH increased to 3.5 with the addition of KOH. In run B, biogas with around 30% of hydrogen sulphide obtained in the anaerobic reactor was sparged to the mixture obtained in run A, but in this case at a pH of 5.5. In run C, the pH of the raw AMDW was increased to 3.5 by the addition of KOH solution. Finally, in run D, the pH of the raw AMDW was increased to 5.5 by the addition of KOH solution and further biogas was sparged under the same conditions as in run A. It was found that heavy metal removal was a function of pH. At a pH of 3.5 most of the iron was removed while Zn and Cu were partially removed. At a pH of 5.5 the removal of all metals increased considerably. The best results were obtained in run B where the percentages of removal of Fe, Cu, Zn and Al achieved values of 91.3, 96.1, 79.0 and 99.0%, respectively. According to the experimental results obtained tentative schemas of the flow diagram of the processes were proposed.

  13. Recycling of agricultural solid waste, coir pith: Removal of anions, heavy metals, organics and dyes from water by adsorption onto ZnCl2 activated coir pith carbon

    International Nuclear Information System (INIS)

    The abundant lignocellulosic agricultural waste, coir pith is used to develop ZnCl2 activated carbon and applied to the removal of toxic anions, heavy metals, organic compounds and dyes from water. Sorption of inorganic anions such as nitrate, thiocyanate, selenite, chromium(VI), vanadium(V), sulfate, molybdate, phosphate and heavy metals such as nickel(II) and mercury(II) has been studied. Removal of organics such as resorcinol, 4-nitrophenol, catechol, bisphenol A, 2-aminophenol, quinol, O-cresol, phenol and 2-chlorophenol has also been investigated. Uptake of acidic dyes such as acid brilliant blue, acid violet, basic dyes such as methylene blue, rhodamine B, direct dyes such as direct red 12B, congo red and reactive dyes such as procion red, procion orange were also examined to assess the possible use of the adsorbent for the treatment of contaminated ground water. Favorable conditions for maximum removal of all adsorbates at the adsorbate concentration of 20 mg/L were used. Results show that ZnCl2 activated coir pith carbon is effective for the removal of toxic pollutants from water

  14. Capacidade da Lemna aequinoctialis para acumular metais pesados de água contaminada / Ability of Lemna aequinoctialis for removing heavy metals from wastewater

    Scientific Electronic Library Online (English)

    Mauro Célio da Silveira, Pio; Katiuscia dos Santos de, Souza; Genilson Pereira, Santana.

    2013-06-01

    Full Text Available SciELO Brazil | Language: Portuguese Abstract in portuguese A capacidade das plantas em tolerar e absorver quantidades elevadas de metais pesados é usada como uma tecnologia promissora para limpeza de resíduos perigosos em ambientes altamente contaminados. O desempenho da macrófita L. aequinoctialis em absorver metais pesados foi estudado durante sua floraçã [...] o em dois períodos de amostragem diferentes. As amostras de L. aequinoctialis e água foram coletadas por 800 horas em intervalos de 48 horas. A quantidade de Ni, Cu, Co, Cr, Mn, Zn e Fe presente na L. aequinoctialis e água foram determinados por espectrometria de absorção atômica com chama (FAAS). Os resultados foram avaliados pelas técnicas de estatística de componentes principais (PCA), análise de agrupamento hierárquico (HCA) e boxplot. Os resultados mostram que a rizofiltração da L. aequinoctialis remove altas quantidades de metais pesados na seguinte ordem Cr > Ni > Cu > Fe > Zn > Mn. No entanto, observou-se que mudanças significativas na composição química, pH e condutividade elétrica da água alteram a capacidade de absorção da L. aequinoctialis. Abstract in english Plant ability for tolerating and accumulating high amount of heavy metal is used as a promissory technology for removing contaminants from highly polluted environments. The ability of the macrophyte L. aequinoctialis to remove heavy metal was studied in two different sampling times during its flower [...] ing. Samples of plant tissue L. aequinoctialis and water were collected for 800 hours at 48 hour intervals. Concentrations of Ni, Cu, Co, Cr, Mn, Zn, and Fe present in L. aequinoctialis and water were determined by flame atomic absorption spectrometry (FAAS). Data were subjected to the techniques of principal components analysis (PCA), hierarchical cluster analysis (HCA) and boxplot. We found that rhizofiltration of L. aequinoctialis removes high amount of heavy metal in this order: Cr >Ni>Cu> Fe > Zn >Mn. Only significant changes in chemical composition of the water, pH and electrical conductivity alter the absorption capacity of L. aequinoctialis.

  15. Capacidade da Lemna aequinoctialis para acumular metais pesados de água contaminada Ability of Lemna aequinoctialis for removing heavy metals from wastewater

    Directory of Open Access Journals (Sweden)

    Mauro Célio da Silveira Pio

    2013-06-01

    Full Text Available A capacidade das plantas em tolerar e absorver quantidades elevadas de metais pesados é usada como uma tecnologia promissora para limpeza de resíduos perigosos em ambientes altamente contaminados. O desempenho da macrófita L. aequinoctialis em absorver metais pesados foi estudado durante sua floração em dois períodos de amostragem diferentes. As amostras de L. aequinoctialis e água foram coletadas por 800 horas em intervalos de 48 horas. A quantidade de Ni, Cu, Co, Cr, Mn, Zn e Fe presente na L. aequinoctialis e água foram determinados por espectrometria de absorção atômica com chama (FAAS. Os resultados foram avaliados pelas técnicas de estatística de componentes principais (PCA, análise de agrupamento hierárquico (HCA e boxplot. Os resultados mostram que a rizofiltração da L. aequinoctialis remove altas quantidades de metais pesados na seguinte ordem Cr > Ni > Cu > Fe > Zn > Mn. No entanto, observou-se que mudanças significativas na composição química, pH e condutividade elétrica da água alteram a capacidade de absorção da L. aequinoctialis.Plant ability for tolerating and accumulating high amount of heavy metal is used as a promissory technology for removing contaminants from highly polluted environments. The ability of the macrophyte L. aequinoctialis to remove heavy metal was studied in two different sampling times during its flowering. Samples of plant tissue L. aequinoctialis and water were collected for 800 hours at 48 hour intervals. Concentrations of Ni, Cu, Co, Cr, Mn, Zn, and Fe present in L. aequinoctialis and water were determined by flame atomic absorption spectrometry (FAAS. Data were subjected to the techniques of principal components analysis (PCA, hierarchical cluster analysis (HCA and boxplot. We found that rhizofiltration of L. aequinoctialis removes high amount of heavy metal in this order: Cr >Ni>Cu> Fe > Zn >Mn. Only significant changes in chemical composition of the water, pH and electrical conductivity alter the absorption capacity of L. aequinoctialis.

  16. Self-assembled 3D flower-like ?-Fe2O3 microstructures and their superior capability for heavy metal ion removal

    International Nuclear Information System (INIS)

    Hierarchically 3D flower-like ?-Fe2O3 microstructures have been synthesized through a urea-assisted hydrothermal synthetic route. The product was characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The as-prepared product was consisted of hierarchically flow-like microstructures assembled from nanopetal subunits. The effects of the urea and NaOH on the morphology of the products were systematically studied, and a possible formation mechanism of the ?-Fe2O3 microflowers was proposed based on the experimental results. These flower-like ?-Fe2O3 microstructures were used as adsorbent for water treatment, and the results revealed excellent performance for heavy metal ion removal. With maximum capacities of 41.46 and 33.82 mg g?1 for As(V) and Cr(VI), respectively, such flower-like ?-Fe2O3 microstructures are expected to be an attractive adsorbent for the removal of heavy metal ions from water. - Graphical abstract: Display Omitted - Highlights: • 3D flower-like hematite microstructures were synthesized by a hydrothermal method. • The formation mechanism of flower-like microstructures was proposed. • Effective removal of As(V) and Cr(VI) from aqueous solution

  17. Self-assembled 3D flower-like ?-Fe{sub 2}O{sub 3} microstructures and their superior capability for heavy metal ion removal

    Energy Technology Data Exchange (ETDEWEB)

    Liang, Hanfeng; Xu, Binbin; Wang, Zhoucheng, E-mail: zcwang@xmu.edu.cn

    2013-09-16

    Hierarchically 3D flower-like ?-Fe{sub 2}O{sub 3} microstructures have been synthesized through a urea-assisted hydrothermal synthetic route. The product was characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The as-prepared product was consisted of hierarchically flow-like microstructures assembled from nanopetal subunits. The effects of the urea and NaOH on the morphology of the products were systematically studied, and a possible formation mechanism of the ?-Fe{sub 2}O{sub 3} microflowers was proposed based on the experimental results. These flower-like ?-Fe{sub 2}O{sub 3} microstructures were used as adsorbent for water treatment, and the results revealed excellent performance for heavy metal ion removal. With maximum capacities of 41.46 and 33.82 mg g{sup ?1} for As(V) and Cr(VI), respectively, such flower-like ?-Fe{sub 2}O{sub 3} microstructures are expected to be an attractive adsorbent for the removal of heavy metal ions from water. - Graphical abstract: Display Omitted - Highlights: • 3D flower-like hematite microstructures were synthesized by a hydrothermal method. • The formation mechanism of flower-like microstructures was proposed. • Effective removal of As(V) and Cr(VI) from aqueous solution.

  18. One step solvothermal synthesis of functional hybrid ?-Fe2O3/carbon hollow spheres with superior capacities for heavy metal removal.

    Science.gov (United States)

    Cui, Hao-Jie; Cai, Jie-Kui; Zhao, Huan; Yuan, Baoling; Ai, Cuiling; Fu, Ming-Lai

    2014-07-01

    One-step hydrothermal method was developed to prepare hybrid ?-Fe2O3/carbon hollow spheres with a predominant orientation (111) plane of ?-Fe2O3 and rich oxygen-containing functional groups on carbon. The resulting functional hybrid exhibited extremely high adsorption capacities for toxic Pb(II) and Cr(VI) ions in solutions with easy magnetic separation. The ease of synthesis and low cost, coupled with the efficient and rapid removal of toxic heavy metal ions, make hybrid ?-Fe2O3/carbon hollow spheres an attractive adsorbent for the purification of waste and contaminated water. PMID:24776674

  19. Studies on the Use of Supported Liquid Membrane Technique for Removal of Heavy Metals from Water Effluents

    International Nuclear Information System (INIS)

    The present work is directed to develop, assess and establish different systems for the removal and recovery of Co, Ni, Zn and Cd from aqueous solutions using supported liquid membrane (SLM) technique. The individual permeation of Co(II) and Ni(II) from aqueous chloride solutions through SLM using CYANEX 301 in kerosene supported on cellulose acetate membrane was studied based on the optimum conditions for separation obtained by liquid-liquid extraction experiments. Application studies of the investigated system were carried out on the permeation of four heavy elements (Co(II), Ni(II), Zn(II) and Cd(II) ) of equal concentrations when mixed together in real water samples from different origins. For this purpose, samples from Ismailia canal, El-Manzala lake, sea water and drinking water were selected for these experiments. The results obtained show that complete removal of Zn(II) from aqueous chloride medium of ph 3 from El-Manzala lake water is obtained at different temperature degrees and the removal of a large amounts of Co(II), Cd(II) and Ni(II) from drinking water is also possible.

  20. Heavy metals removal in wastewater by activated carbon adsorption and clays of cationic interchange; Eliminacion de metales pesados en disolucion mediante adsorcion en carbon activo y arcillas de intercambio cationico

    Energy Technology Data Exchange (ETDEWEB)

    Montes, M. A.; Medialdea, J. M.; Garcia Mediavilla, B.; Moron, M. J.; Arnaiz, M. C.; Garcia Martinez de Simon, I.; Lopez, C. M.; Escot, E.; Lebrato, J. [Universidad de Sevilla. Sevilla (Spain)

    1999-11-01

    Among the different treatment systems assessed for the purification of the wastewaters poured from Aznalcollar quarry the last April 25, 1998, physical and chemical adsorption proved highly efficient for the removal of refractory heavy metals. In laboratory experiments, 99% of dissolved Mn and Zn was removed when wastewater passed through a packedbed column filled with a cationic exchange clay. In the same way, activated-carbon adsorption removed more than 80% of dissolved Zn and 11-16% of Mn. Results confirm the feasibility of these processes and contribute knowledge on their operational characteristics so that in any other similar situation we can consider all treatment possibilities. 8 refs.

  1. Heavy metal removal from wastewater using phragmites australis-voltammetric study of the interaction between heavy metals and the chemical constituents of phragmites australis

    International Nuclear Information System (INIS)

    This is the first study of the complexation between metal ions and compounds isolated from a plant used in constructed wetlands. The relation between the chemical constituents of phragmites australis and the ability of the plant to uptake metal ions from wastewater has been investigated. Eighteen compounds were separated and identified from the butanolic extract of Phragmites australis. Seven of which are flavonoid glycosides. The main flavone glycoside isolated was tricin-7-O-beta-D-glucopyranoside. Complexes of Pb(II), Cd(II), Ni(II) and Zn(II) with the butanolic extract, tricin-7-O-beta-D-glucopyranoside and tricin were studied by different pulse polarography, under the optimum conditions of complex formation of each metal. It was found that Pb(II) and Cd(II) from 1:2 complex with each of the three ligands only in basic media. The conditional formation constants and the coordination numbers of the complexes formed between Pb(II) and the butanolic extract, tricin-7-O-beta-D-glucopyranoside and tricin were of comparable values indicating that the compounds in the butanolic extract that formed complexes with lead are most likely flavonoids. The same was observed in the case of Cd(II) ion. Nickel(II) ion formed a 1:2 complex with the crude butanolic extract and 1:1 complex with tricin-7-O-beta-D-glucopyranoside in basic media. Overlapping signals prevented the detection of complexes with higher coordination numbers. Complex formation between Ni(II) and tricin was indicmation between Ni(II) and tricin was indicated by the shifts in the peak potential of Ni(II) induced by ligand addition, but the presence of overlapping peaks prevented further studies. For Zinc(II) ion, complexation with the three ligands in basic media was indicated by the shifts in the peak potential of Zn(II). The presence of overlapping peaks prevented the determination of the formation constant and the coordination number. Nevertheless, the formation constant of a 1:2 complex between Zn(II) and butanolic extract was determined in acidic medium, pH=5.4. No complexation with tricin-7-O-beta-D-glucopyranoside or with tricin was detected under acidic conditions, confirming the need of a basic medium, and hence deprotonated phenolic groups of the flavonids in order to chelate metals. A preliminary study of adsorption of the metal ions on the dry ground plant material was found to be a favorable process, which obeys Langmuir isotherm of monolayer adsorption. This phenomenon needs further investigation. (author)

  2. Inorganic particulates in removal of toxic heavy metal ions. Pt. 8 Removal of zinc, cadmium and mercury ions from aqueous solution by hydrous titanium oxide

    International Nuclear Information System (INIS)

    Adsorption behavior of zinc, cadmium and mercury ions on hydrous titanium oxide in aqueous solution has been studied as a function of concentration of the metal ion (10-2 - 10-7 M), temperature (303-333 K) and pH 3-10 by applying radiotracer technique. The kinetics of adsorption follows the first order rate law and agrees well with the classical Freundlich isotherm. The removal was found to increase with increasing pH but was suppressed in the presence of EDTA. The overall process is endothermic and irreversible in nature. (author)

  3. Application of Gamma Radiation to Enhance Heavy Metals Removal Efficiency to Bacteria Isolated from Ronpiboon District, Nakhon Sri Thamarat Province, Thailand

    International Nuclear Information System (INIS)

    The objective of this study was to isolate soil bacteria capable to te move 4 heavy metals, namely, arsenic (As(III)), lead Pb(II) and cadmium f ron old tin mine in Ronpiboon district, Nakhon Sri Thamarat. It was found that there were bacteria which capable to resist arsenic, lead and copper 11, 15, 8 and 2 ileitis, respectively[evacuate;y. The arsenic removal efficiency of these bacteria was evaluated at the low concentration of 1 u g/l. with the results of 7-61%. The lead and copper removal efficiencies at 10 mg/l were found at the range pf 9-98% and 8-40%, respectively. Six isolates of bacteria (KRD, KRH, KRM, KCD13 and KCD14) were selected to be irradiated by gamma radiation at the levels of 2-10 kGy. The heavy metals resistance was found increase in the range of of 125-16% for arsenic, 0-50% for copper, 0-18% for lead and 0-17% for cadmium, respectively. Also ut was found that the low temperature at 4 and -40 degree Celsius can prolong the bacterial survival up to 6 months. Later the arsenic removal experiment in liquid medium was conducted and it was found that the mutants can perform slightly better than wild type only >17%. It was due to the initial concentration of arsenic was too high (10 mg/l). The preliminary study of arsenic removal in soil was also conducted using pack-bed reactor. We found the proper ratio of pack material (soil and gravel) was 1:1 to promote the liquid and air circulation. The suitable medium was found to be acidified mo lass solution which were found promote the growth of tested bacterial isolates.

  4. Synthesis of LTA zeolite on corundum supports: Preliminary assessment for heavy metal removal from waste water; Sintesis de zeolita LTA sobre soportes de corindon: Evaluacion preliminar para la eliminacion de metales pesados de efluentes acuosos

    Energy Technology Data Exchange (ETDEWEB)

    Jacas, A.; Ortega, P.; Velasco, M. J.; Camblor, M. A.; Rodriguez, M. A.

    2012-11-01

    The effectiveness of materials based on LTA Zeolite as active phase, for their incorporation into systems aimed at the removal of heavy metals on waste water is evaluated in a preliminary way. This type of Zeolite with the main channel of a minimum free diameter of 0,41 nm and a low SiO{sub 2}/Al{sub 2}O{sub 3} ratio is an interesting molecular sieve, which in turn display a high ion exchange capacity. From this point of view, LTA Zeolite crystals were obtained in situ by hydrothermal synthesis and characterized by x ray diffraction (XRD) and scanning electron microscopy (SEM). We have studied the effect of hydrothermal synthesis time at 378 K. Likewise, the removal capacity of heavy metal from the active phase was evaluated in as a first step on diluted solutions of cooper salts at slightly acidic pH ({approx} 4,7). (Author) 28 refs.

  5. Molecular Characterization of Some Novel Marine Alicyclobacillus Strains, Capable of Removing Lead from a Heavy Metal Contaminated Sea Spot

    OpenAIRE

    Mohamed, Eman A. H.; Elsersy, Nermeen A.

    2009-01-01

    Sea water from heavy metal contaminated area in the Mediterranean, was analyzed for its heavy metal contents and their concentrations. It was observed that lead has the highest concentration (0.48 ppm) among the remaining heavy metal concentrations. Four different Gram-positive, rod-shaped and spore forming Alicyclobacillus (formally Bacillus) isolates were isolated from the same sea spot. Phenotypic characterization of pure cultures were examined for motility, Gram reaction, spore morp...

  6. Synthesis of MnFe2O4@Mn-Co oxide core-shell nanoparticles and their excellent performance for heavy metal removal.

    Science.gov (United States)

    Ma, Zichuan; Zhao, Dongyuan; Chang, Yongfang; Xing, Shengtao; Wu, Yinsu; Gao, Yuanzhe

    2013-10-21

    Magnetic nanomaterials that can be easily separated and recycled due to their magnetic properties have received considerable attention in the field of water treatment. However, these nanomaterials usually tend to aggregate and alter their properties. Herein, we report an economical and environmentally friendly method for the synthesis of magnetic nanoparticles with core-shell structure. MnFe2O4 nanoparticles have been successfully coated with amorphous Mn-Co oxide shells. The synthesized MnFe2O4@Mn-Co oxide nanoparticles have highly negatively charged surface in aqueous solution over a wide pH range, thus preventing their aggregation and enhancing their performance for heavy metal cation removal. The adsorption isotherms are well fitted to a Langmuir adsorption model, and the maximal adsorption capacities of Pb(II), Cu(II) and Cd(II) on MnFe2O4@Mn-Co oxide are 481.2, 386.2 and 345.5 mg g(-1), respectively. All the metal ions can be completely removed from the mixed metal ion solutions in a short time. Desorption studies confirm that the adsorbent can be effectively regenerated and reused. PMID:23945878

  7. Removal of some heavy metals ions from wastewater by copolymer of iron and aluminum impregnated with active silica derived from rice husk ash.

    Science.gov (United States)

    Abo-El-Enein, S A; Eissa, M A; Diafullah, A A; Rizk, M A; Mohamed, F M

    2009-12-30

    Recently because of increasing of the environmental awareness and demands, several attempts were carried out for the conversion of by-products of natural materials, especially agricultural wastes, to highly sorption capacity materials. In recent years, attention has been focused on the utilization of unmodified or modified agro-residues as sorbents for removal of pollutants. Various modifications have been reported to enhance sorption capacities for heavy metals. The present study deals with the adsorption equilibrium of iron, manganese, lead and arsenic ions from aqueous solutions on copolymer of Al(+3), Si(+4) and Fe(+3) using batch techniques. The influence of various parameters, such as agitation time, sorbent mass and pH of sorbate solution were investigated. Under this study the maximum adsorption capacity of iron and aluminum copolymer impregnated with silica (PAlFeClSi) for lead, iron, manganese and arsenic are found to be 416, 222, 158, 146 mg/g, respectively. PMID:19709808

  8. Synthesis of a novel silica-supported dithiocarbamate adsorbent and its properties for the removal of heavy metal ions

    International Nuclear Information System (INIS)

    Highlights: ? A new silica-supported dithiocarbamate adsorbent (Si-DTC) was synthesized following a novel synthesis route by anchoring the chelating agent of macromolecular dithiocarbamate (MDTC) to the chloro-functionalized silica matrix(SiCl). ? By adopting this method, it could make more efforts to increase the nucleophilic reactivity of polyamine with carbon disulfide under strong alkaline condition and avoid the degradation of silica matrix. ? The new adsorbent were used to absorb Pb(II), Cd(II), Cu(II) and Hg(II) which are known to be common heavy metal ions from polluted aqueous solutions. ? The dithiocarbamate groups and the amino groups in Si-DTC both take part in the adsorption process for M(II) from aqueous solutions but the adsorption mechanism of Hg(II) onto Si-DTC is quite different from that of Pb(II), Cd(II) or Cu(II) onto Si-DTC, which is testified by the XPS and FT-IR results. - Abstract: Silica-supported dithiocarbamate adsorbent (Si-DTC) was synthesized by anchoring the chelating agent of macromolecular dithiocarbamate (MDTC) to the chloro-functionalized silica matrix (SiCl), as a new adsorbent for adsorption of Pb(II), Cd(II), Cu(II) and Hg(II) from aqueous solution. The surface characterization was performed by FT-IR, XPS, SEM and elemental analysis indicating that the modification of the silica surface was successfully performed. The effects of media pH, adsorption time, initial metal ion concentration and adsorption temperature on adsornd adsorption temperature on adsorption capacity of the adsorbent had been investigated. Experimental data were exploited for kinetic and thermodynamic evaluations related to the adsorption processes. The characteristics of the adsorption process were evaluated by using the Langmuir, Freundlich and Dubinin-Radushkevich (D-R) adsorption isotherms and adsorption capacities were found to be 0.34 mmol g-1, 0.36 mmol g-1, 0.32 mmol g-1 and 0.40 mmol g-1 for Pb(II), Cd(II), Cu(II) and Hg(II), respectively. The adsorption mechanism of Hg(II) onto Si-DTC is quite different from that of Pb(II), Cd(II) or Cu(II) onto Si-DTC, which is demonstrated by the XPS and FT-IR results.

  9. Synthesis of a novel silica-supported dithiocarbamate adsorbent and its properties for the removal of heavy metal ions

    Energy Technology Data Exchange (ETDEWEB)

    Bai, Lan [School of Chemistry and Chemical Engineering, Central South University, Changsha 410083 (China); Hu, Huiping, E-mail: phuhuiping@126.com [School of Chemistry and Chemical Engineering, Central South University, Changsha 410083 (China); Fu, Weng; Wan, Jia [School of Chemistry and Chemical Engineering, Central South University, Changsha 410083 (China); Cheng, Xiliang; Zhuge, Lei; Xiong, Lei [School of Metallurgical Science and Engineering, Central South University, Changsha 410083 (China); Chen, Qiyuan [School of Chemistry and Chemical Engineering, Central South University, Changsha 410083 (China)

    2011-11-15

    Highlights: {yields} A new silica-supported dithiocarbamate adsorbent (Si-DTC) was synthesized following a novel synthesis route by anchoring the chelating agent of macromolecular dithiocarbamate (MDTC) to the chloro-functionalized silica matrix(SiCl). {yields} By adopting this method, it could make more efforts to increase the nucleophilic reactivity of polyamine with carbon disulfide under strong alkaline condition and avoid the degradation of silica matrix. {yields} The new adsorbent were used to absorb Pb(II), Cd(II), Cu(II) and Hg(II) which are known to be common heavy metal ions from polluted aqueous solutions. {yields} The dithiocarbamate groups and the amino groups in Si-DTC both take part in the adsorption process for M(II) from aqueous solutions but the adsorption mechanism of Hg(II) onto Si-DTC is quite different from that of Pb(II), Cd(II) or Cu(II) onto Si-DTC, which is testified by the XPS and FT-IR results. - Abstract: Silica-supported dithiocarbamate adsorbent (Si-DTC) was synthesized by anchoring the chelating agent of macromolecular dithiocarbamate (MDTC) to the chloro-functionalized silica matrix (SiCl), as a new adsorbent for adsorption of Pb(II), Cd(II), Cu(II) and Hg(II) from aqueous solution. The surface characterization was performed by FT-IR, XPS, SEM and elemental analysis indicating that the modification of the silica surface was successfully performed. The effects of media pH, adsorption time, initial metal ion concentration and adsorption temperature on adsorption capacity of the adsorbent had been investigated. Experimental data were exploited for kinetic and thermodynamic evaluations related to the adsorption processes. The characteristics of the adsorption process were evaluated by using the Langmuir, Freundlich and Dubinin-Radushkevich (D-R) adsorption isotherms and adsorption capacities were found to be 0.34 mmol g{sup -1}, 0.36 mmol g{sup -1}, 0.32 mmol g{sup -1} and 0.40 mmol g{sup -1} for Pb(II), Cd(II), Cu(II) and Hg(II), respectively. The adsorption mechanism of Hg(II) onto Si-DTC is quite different from that of Pb(II), Cd(II) or Cu(II) onto Si-DTC, which is demonstrated by the XPS and FT-IR results.

  10. Removal of Heavy Metal Ions by Using Composite of Cement Kiln Dust/Ethylene Glycol co Acrylic Acid Prepared by y-Irradiation

    International Nuclear Information System (INIS)

    Various composites of cement kiln dust (CKD) and poly(ethylene glycol co acrylic acid) using y-irradiation was investigated. The samples were prepared using three percentages of cement kiln dust namely, 20, 50 and 75 by wt % and mixed with an equimolar ratio (1:1) of ethylene glycol and acrylic acid then irradiated at doses; 10,20 and 30 kGy of gamma-irradiation. The results showed that (CKD) and poly(ethylene glycol co acrylic acid) composites were formed only at 30 kGy. In addition, CKD alone has the lowest degree of removal of heavy metal ions compared with the prepared composites. A composite containing 75% cement kiln dust by weight percentage, showed the highest degree of removal of cobalt ions, whereas, a composite of 20% CKD showed the highest degree for cadmium ion removal. While the composite of 75% CKD showed a higher selectivity of cobalt ion than cadmium ion in their mixed solution.

  11. Decay heat removal analyses on the heavy liquid metal cooled fast breeding reactor. Comparisons of the decay heat removal characteristics on lead, lead-bismuth and sodium cooled reactors

    International Nuclear Information System (INIS)

    The feasibility study on several concepts for the commercial fast breeder reactor(FBR) in future has been conducted in JNC for the kinds of possible coolants and fuel types to confirm the direction of the FBR developments in Japan. In this report, Lead and Lead-Bismuth eutectic coolants were estimated for the decay heat removal characteristics by the comparison with sodium coolant that has excellent features for the heat transfer and heat transport performance. Heavy liquid metal coolants, such as Lead and Lead-Bismuth, have desirable chemical inertness for water and atmosphere. Therefore, there are many economical plant proposals without an intermediate heat transport system that prevents the direct effect on a reactor core by the chemical reaction between water and the liquid metal coolant at the hypocritical tube failure accidents in a steam generator. In this study, transient analyses on the thermal-hydraulics have been performed for the decay heat removal events in Equivalent plant' with the Lead, Lead-Bismuth and Sodium coolant by using Super-COPD code. And a resulted optimized lead cooled plant in feasibility study was also analyzed for the comparison. In conclusion, it is become clear that the natural circulation performance, that has an important roll in passive safety characteristic of the reactor, is more excellent in heavy liquid metals than sodium coolant during the decay heat removal transients. However, we need to confirm the heat transfer reduction by to confirm the heat transfer reduction by the oxidized film or the corrosion products expected to appear on the heat transfer surface in the Lead and Lead-Bismuth circumstance. (author)

  12. Transfer of heavy metals through terrestrial food webs: a review.

    Science.gov (United States)

    Gall, Jillian E; Boyd, Robert S; Rajakaruna, Nishanta

    2015-04-01

    Heavy metals are released into the environment by both anthropogenic and natural sources. Highly reactive and often toxic at low concentrations, they may enter soils and groundwater, bioaccumulate in food webs, and adversely affect biota. Heavy metals also may remain in the environment for years, posing long-term risks to life well after point sources of heavy metal pollution have been removed. In this review, we compile studies of the community-level effects of heavy metal pollution, including heavy metal transfer from soils to plants, microbes, invertebrates, and to both small and large mammals (including humans). Many factors contribute to heavy metal accumulation in animals including behavior, physiology, and diet. Biotic effects of heavy metals are often quite different for essential and non-essential heavy metals, and vary depending on the specific metal involved. They also differ for adapted organisms, including metallophyte plants and heavy metal-tolerant insects, which occur in naturally high-metal habitats (such as serpentine soils) and have adaptations that allow them to tolerate exposure to relatively high concentrations of some heavy metals. Some metallophyte plants are hyperaccumulators of certain heavy metals and new technologies using them to clean metal-contaminated soil (phytoextraction) may offer economically attractive solutions to some metal pollution challenges. These new technologies provide incentive to catalog and protect the unique biodiversity of habitats that have naturally high levels of heavy metals. PMID:25800370

  13. Removal of heavy metals from aqueous solutions using Fe{sub 3}O{sub 4}, ZnO, and CuO nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Mahdavi, Shahriar, E-mail: smahdaviha@yahoo.com; Jalali, Mohsen, E-mail: jalali@basu.ac.ir [College of Agriculture, Bu-Ali Sina University, Department of Soil Science (Iran, Islamic Republic of); Afkhami, Abbas, E-mail: afkhami@basu.ac.ir [College of Chemistry, Bu-Ali Sina University, Department of Analytical Chemistry (Iran, Islamic Republic of)

    2012-08-15

    This study investigated the removal of Cd{sup 2+}, Cu{sup 2+}, Ni{sup 2+}, and Pb{sup 2+} from aqueous solutions with novel nanoparticle sorbents (Fe{sub 3}O{sub 4}, ZnO, and CuO) using a range of experimental approaches, including, pH, competing ions, sorbent masses, contact time, scanning electron microscopy, transmission electron microscopy, and X-ray diffraction. The images showed that Fe{sub 3}O{sub 4}, ZnO, and CuO particles had mean diameters of about 50 nm (spheroid), 25 nm (rod shape), and 75 nm (spheroid), respectively. Tests were performed under batch conditions to determine the adsorption rate and uptake at equilibrium from single and multiple component solutions. The maximum uptake values (sum of four metals) in multiple component solutions were 360.6, 114.5, and 73.0 mg g{sup -1}, for ZnO, CuO, and Fe{sub 3}O{sub 4}, respectively. Based on the average metal removal by the three nanoparticles, the following order was determined for single component solutions: Cd{sup 2+} > Pb{sup 2+} > Cu{sup 2+} > Ni{sup 2+}, while the following order was determined in multiple component solutions: Pb{sup 2+} > Cu{sup 2+} > Cd{sup 2+} > Ni{sup 2+}. Sorption equilibrium isotherms could be described using the Freundlich model in some cases, whereas other isotherms did not follow this model. Furthermore, a pseudo-second order kinetic model was found to correctly describe the experimental data for all nanoparticles. Scanning electron microscopy, energy dispersive X-ray before and after metal sorption, and soil solution saturation indices showed that the main mechanism of sorption for Cd{sup 2+} and Pb{sup 2+} was adsorption, whereas both Cu{sup 2+} and Ni{sup 2+} sorption were due to adsorption and precipitation. These nanoparticles have potential for use as efficient sorbents for the removal of heavy metals from aqueous solutions and ZnO nanoparticles were identified as the most promising sorbent due to their high metal uptake.

  14. Ion exchange extraction of heavy metals from wastewater sludges.

    Science.gov (United States)

    Al-Enezi, G; Hamoda, M F; Fawzi, N

    2004-01-01

    Heavy metals are common contaminants of some industrial wastewater. They find their way to municipal wastewaters due to industrial discharges into the sewerage system or through household chemicals. The most common heavy metals found in wastewaters are lead, copper, nickel, cadmium, zinc, mercury, arsenic, and chromium. Such metals are toxic and pose serious threats to the environment and public health. In recent years, the ion exchange process has been increasingly used for the removal of heavy metals or the recovery of precious metals. It is a versatile separation process with the potential for broad applications in the water and wastewater treatment field. This article summarizes the results obtained from a laboratory study on the removal of heavy metals from municipal wastewater sludges obtained from Ardhiya plant in Kuwait. Data on heavy metal content of the wastewater and sludge samples collected from the plant are presented. The results obtained from laboratory experiments using a commercially available ion exchange resin to remove heavy metals from sludge were discussed. A technique was developed to solubilize such heavy metals from the sludge for subsequent treatment by the ion exchange process. The results showed high efficiency of extraction, almost 99.9%, of heavy metals in the concentration range bound in wastewater effluents and sludges. Selective removal of heavy metals from a contaminated wastewater/sludge combines the benefits of being economically prudent and providing the possibility of reuse/recycle of the treated wastewater effluents and sludges. PMID:15027828

  15. Efficient removal of dyes by a novel magnetic Fe3O4/ZnCr-layered double hydroxide adsorbent from heavy metal wastewater

    International Nuclear Information System (INIS)

    Graphical abstract: To purify heavy metal wastewater (pickling waste liquor (PWLA and PWLB) and electroplating wastewater (EPWC and EPWD)), a novel magnetic Fe3O4/ZnCr–LDH material was formed via two-step microwave hydrothermal method (Step 1 and Step 2) and applicable for organic dyes wastewater treatment. Highlights: ? Fe3O4/ZnCr-layered double hydroxide adsorbent was produced from wastewater. ? RSM was successfully applied to the optimization of the preparation conditions. ? The maximum adsorption capacity of MO was found to be 240.16 mg/g. ? The MO adsorption mechanism on MFLA was certified. ? MFLA could be recycled after catalytic regeneration by the oxidation technology. - Abstract: A novel magnetic Fe3O4/ZnCr-layered double hydroxide adsorbent was produced from electroplating wastewater and pickling waste liquor via a two-step microwave hydrothermal method. Adsorption of methyl orange (MO) from water was studied using this material. The effects of three variables have been investigated by a single-factor method. The response surface methodology (RSM) based on Box–Behnken design was successfully applied to the optimization of the preparation conditions. The maximum adsorption capacity of MO was found to be 240.16 mg/g, indicating that this material may be an effective adsorbent. It was shown that 99% of heavy metal ions (Fe2+, Feal ions (Fe2+, Fe3+, Cr3+, and Zn2+) can be effectively removed into precipitates and released far less in the adsorption process. In addition, this material with adsorbed dye can be easily separated by a magnetic field and recycled after catalytic regeneration with advanced oxidation technology. Meanwhile, kinetic models, FTIR spectra and X-ray diffraction pattern were applied to the experimental data to examine uptake mechanism. The boundary layer and intra-particle diffusion played important roles in the adsorption mechanisms.

  16. Metals removal from spent salts

    Science.gov (United States)

    Hsu, Peter C. (Pleasanton, CA); Von Holtz, Erica H. (Livermore, CA); Hipple, David L. (Livermore, CA); Summers, Leslie J. (Livermore, CA); Brummond, William A. (Livermore, CA); Adamson, Martyn G. (Danville, CA)

    2002-01-01

    A method and apparatus for removing metal contaminants from the spent salt of a molten salt oxidation (MSO) reactor is described. Spent salt is removed from the reactor and analyzed to determine the contaminants present and the carbonate concentration. The salt is dissolved in water, and one or more reagents may be added to precipitate the metal oxide and/or the metal as either metal oxide, metal hydroxide, or as a salt. The precipitated materials are filtered, dried and packaged for disposal as waste or can be immobilized as ceramic pellets. More than about 90% of the metals and mineral residues (ashes) present are removed by filtration. After filtration, salt solutions having a carbonate concentration >20% can be spray-dried and returned to the reactor for re-use. Salt solutions containing a carbonate concentration salt solutions that contain less than 1.0 ppm of contaminants.

  17. Radiation induced copolymerization of binary monomers system(styrene/acrylic acid) and its application in removal of some heavy metals and dyes from aquatic solutions

    International Nuclear Information System (INIS)

    Radiation-induced coploymerization of binary monomer system styrene/acrylic acid (Sty/AAc) using direct radiation technique has been investigated. The appropriate reaction conditions such as solvent, commonomer concentration, commonomer composition and irradiation dose at which the coplymerization process was carried out successfully were selected. The effect of different parameters on the conversion percent of the commonmer into coplomer was studied by gravimetric method. It was found that, using methanol/distilled water as a cosolvent with composition 80/20 wt% enhanced the copolymerization process. The conversion (%) of the commonomer was increased with increasing radiation dose. Some properties of the coplymer such as wate uptake, thermal stability, surface topography were investigated. The improvement in such properties of the prepared coplymers was observed which makes possible uses in some practical applications such as in the removal of some heavy metals and dyes from wastewater. the prepared copolymer has good chemical and thermal stability where as the styrene content lead to increase the swelling behaviour. It was found that the maximum metal uptake by the coplymer is ordered in the sequence of Bp2+>Cu2+>Ni2+. The possibility of the removal of three classes of dyes from aqueous solutions; namely wegocet yellow 4GL (direct yellow 44), congo red (diect red 28). Remacryl blue 3G (basic blue3) and xylene blue *acid blue 7 was stblue3) and xylene blue *acid blue 7 was studied. It could be concluded that the Sty/AAc copolymer with composition 20/80 wt % can be used as a contrilled water retainer for carrying of some substance in aquatic fields involving environmental treatments. Also, it could be concluded that the most important parameter affecting the swelling behaviour and characteristic of the prepared copolymer are the type of conversion due to chemical treatment, the pH of the medium and coonstituents of the prepared copolymer

  18. Desarrollo de membranas de quitosano y diseño de un equipo para la eliminación de metales pesados del agua Chitosan membrane development and design of equipment for the removal of heavy metals from water

    Directory of Open Access Journals (Sweden)

    Jesús Mora Molina

    2012-11-01

    Full Text Available El presente estudio comparó la eficiencia de la filtración con membranas de quitosano 1,75% m/v, entrecruzadas con glutaraldehído (0,08% m/v y sin entrecruzar, para estimar la capacidad de remoción de iones de cadmio, cromo y cobre de disoluciones modelo. Además, se diseñó un equipo de bajo costo para la experimentación con las membranas elaboradas. La finalidad de la investigación era emplear materiales biodegradables para remover metales pesados de aguas, mediante una técnica de bajo consumo energético y, por otra parte, generar soluciones baratas, efectivas y aplicables a problemas específicos. Se elaboraron dos fichas técnicas con información sobre las membranas y se encontró que el cromo fue el metal removido en mayor medida por las membranas entrecruzadas, ajustándose al modelo de isoterma de Freundlich. Sin embargo, no se encontró relación entre el tamaño de poro de las membranas y el grado de entrecruzamiento.A filtration technique with 1,75% m/v chitosan membranes crosslinked with glutaraldehyde (0,08% v/v was used to quantify the removal capacity of chromium, copper and cadmium ions from water. A simple and low cost filtration system was developed to use with prepared membranes.The main goal was to use biodegradable materials for removing heavy metals from water, through a low energy consumption, cheap, and specific method.As a result, two data sheets were prepared for the membranes. It was found out that chromium was the metal with the highest removal from water, by using a crosslinked membrane. Metal adsorption was best adjusted to the Freundlich isotherm model, better than Langmuir isotherm model.However, it was found no correlation between pore size and crosslinking degree.

  19. Modelling of the acid-base properties of natural and synthetic adsorbent materials used for heavy metal removal from aqueous solutions.

    Science.gov (United States)

    Pagnanelli, Francesca; Vegliò, Francesco; Toro, Luigi

    2004-02-01

    In this paper a comparison about kinetic behaviour, acid-base properties and copper removal capacities was carried out between two different adsorbent materials used for heavy metal removal from aqueous solutions: an aminodiacetic chelating resin as commercial product (Lewatit TP207) and a lyophilised bacterial biomass of Sphaerotilus natans. The acid-base properties of a S. natans cell suspension were well described by simplified mechanistic models without electrostatic corrections considering two kinds of weakly acidic active sites. In particular the introduction of two-peak distribution function for the proton affinity constants allows a better representation of the experimental data reproducing the site heterogeneity. A priori knowledge about resin functional groups (aminodiacetic groups) is the base for preliminary simulations of titration curve assuming a Donnan gel structure for the resin phase considered as a concentrated aqueous solution of aminodiacetic acid (ADA). Departures from experimental and simulated data can be interpreted by considering the heterogeneity of the functional groups and the effect of ionic concentration in the resin phase. Two-site continuous model describes adequately the experimental data. Moreover the values of apparent protonation constants (as adjustable parameters found by non-linear regression) are very near to the apparent constants evaluated by a Donnan model assuming the intrinsic constants in resin phase equal to the equilibrium constants in aqueous solution of ADA and considering the amphoteric nature of active sites for the evaluation of counter-ion concentration in the resin phase. Copper removal outlined the strong affinity of the active groups of the resin for this ion in solution compared to the S. natans biomass according to the complexation constants between aminodiacetic and mono-carboxylic groups and copper ions. PMID:14637348

  20. Metal Removal in Wastewater

    OpenAIRE

    Sanchez Roldan, Laura

    2014-01-01

    The aim of this work was to study Copper removal capacity of different algae species and their mixtures from the municipal wastewater. This project was implemented in the greenhouse in the laboratories of Tampere University of Applied Sciences and the wastewater used was the one from the Tampere municipal wastewater treatment plant. Five algae species and three mixtures of them were tested for their Copper removal potential in wastewater in one batch test run. The most efficient algae mixture...

  1. Assessing fly ash treatment: Remediation and stabilization of heavy metals

    OpenAIRE

    Lima, A. T.; Ottosen, Lisbeth M.; Ribeiro, Alexandra B.

    2012-01-01

    Fly ashes from Municipal Solid Waste (MSW), straw (ST) and co-combustion of wood (CW) are here analyzed with the intent of reusing them. Two techniques are assessed, a remediation technique and a solidification/stabilization one. The removal of heavy metals from fly ashes through the electrodialytic process (EDR) has been tried out before. The goal of removing heavy metals has always been the reuse of fly ash, for instance in agricultural fields (BEK). The best removal rates are here summariz...

  2. Plant rhamnogalacturonan II complexation of heavy metal cations

    Science.gov (United States)

    O`Neill, M.A.; Pellerin, P.J.M.; Warrenfeltz, D.; Vidal, S.; Darvill, A.G.; Albersheim, P.

    1999-03-02

    The present invention provides rhamnogalacturonan-II (RG-II) and relates to its ability to complex specific multivalent heavy metal cations. In the presence of boric acid, RG-II monomers form dimers that are cross-linked by a borate ester. The yield of such borate ester cross-linked dimers of RG-II is enhanced in the presence of specific heavy metal cations. The present invention further relates to the utility of RG-II in assays for the detection of specific heavy metal contamination; as a reagent useful in the removal of specific heavy metal cations contaminating foods and liquids, for example, fish, wines, etc.; as a pharmaceutical composition useful as an antidote in specific heavy metal cation poisoning; as a treatment for the detoxification of specific heavy metal cations from blood and/or tissues; and in a method of remediation of waters and soils contaminated with specific heavy metal cations. 15 figs.

  3. Biosurfactant of marine origin exhibiting heavy metal remediation properties.

    Science.gov (United States)

    Das, Palashpriya; Mukherjee, Soumen; Sen, Ramkrishna

    2009-10-01

    The present study was aimed at elucidating the role of biosurfactant product isolated from a marine bacterium in removing heavy metals from heavy metal containing solutions. In this study, metal removal was biosurfactant-mediated. Efficiency of metal removal depended on the concentration of the metal as well as that of the biosurfactant. At a concentration 5x, the critical micelle concentration (CMC), almost complete removal of 100 ppm of lead and cadmium occurred. Atomic absorption spectroscopy (AAS) studies also showed metal removal at a concentration less than the CMC in contrast to earlier findings that only micelles are involved in metal removal. Fourier transform infrared spectroscopy (FTIR) and transmission electron microscopy (TEM) equipped with energy dispersive X-ray spectroscopy (EDS) further substantiated these findings. PMID:19505818

  4. Assessment of Phytoextraction Potential of Fenugreek (Trigonellafoenum-graecum L. to Remove Heavy Metals (Pb and Ni from Contaminated Soil

    Directory of Open Access Journals (Sweden)

    Leela Kaur

    2015-02-01

    Full Text Available The objective of the present study was to evaluate the effect of metal mobilizing agents, ethelynediaminetetraacetic acid (EDTA and salicylic acid (SA, on the accumulation and translocation of lead (Pb and nickel (Ni by fenugreek (Trigonellafoenum-graecumL. plants in contaminated soil. EDTA and SA were amended at 100 mM and 1.0 mM respectively. Pb and Ni content were estimated using ICP-OES. Plant samples were prepared for scanning electron microscope (SEM analysis to investigate metals distribution in different tissues (root, stem and leaf of plant. The results showed that EDTA increased Pb and Ni uptake as compared to SA. SEM analysis revealed that in the presence of EDTA, the deposition of Pb particles was predominantly in vascular tissues of the stem and leaf.    

  5. Screening the possibility for removing cadmium and other heavy metals from wastewater sludge and bio-ashes by an electrodialytic method

    International Nuclear Information System (INIS)

    Both wastewater sludge and fly ash from combustion of biomass (bio-ash) have traditionally been applied to agricultural land in Denmark. However, Cd concentrations often exceed limiting values. The present study is a preliminary investigation of the possibility for reducing the Cd concentration in wastewater sludge and bio-ashes (straw and wood) using an electrodialytic method. The waste products were treated as stirred suspensions. During the remediation the suspension was acidified from water splitting at the anion exchange membrane and the acidification mobilized Cd that was removed to the electrode compartments. Even though the matrices were very different the remediation was successful in all cases. After treatment the Cd concentration in the ashes allowed for spreading at agricultural land and the limiting concentration of 0.8 mg Cd/kg for the wastewater sludge was almost reached (0.84 and 0.88 mg Cd/kg). The main differences of the waste products influencing the remediation process were: the sludges had a high content of organic particles that were mobilized by electrophoresis and fouled the anion exchange membrane; the straw-ash contained a lot of chloride, which formed anionic complexes with Cd, and the wood ash had a high initial pH (13.3). The mass of wastewater sludge and bio-ashes decreased during treatment but the concentration of other heavy metals (Pb, Ni, Cu and Zn) was not increased to exceed limiting values in remediated matrixin remediated matrix

  6. Electrospun Fe2O3-Al2O3 nanocomposite fibers as efficient adsorbent for removal of heavy metal ions from aqueous solution.

    Science.gov (United States)

    Mahapatra, A; Mishra, B G; Hota, G

    2013-08-15

    In this study, Iron oxide-alumina mixed nanocomposite fiber was prepared by electrospinning method and its performance was evaluated as a heavy metal ion adsorbent. Here boehmite nanoparticle was synthesized by sol-gel method and was impregnated in PVP-iron acetylacetonate solution in a ratio of 1:1:2. These boehmite impregnated polymer solution was electrospun to form nanocomposite polymer fiber. The electrospun nanofiber was sintered at 1000°C for converting it to pure oxide form for further application as adsorbent. Iron oxide-alumina mixed nanocomposite fiber was characterized by UV-vis-DRS, IR, SEM-EDX, TEM, BET and TGA-DTA analytical techniques. Batch adsorption experiments were carried out to study the sorption behavior of Cu(2+), Pb(2+), Ni(2+) and Hg(2+) ions as a function of initial concentration, contact time and pH. The removal percentage was in the order of Cu(2+)

  7. Chemically modified olive stone: A low-cost sorbent for heavy metals and basic dyes removal from aqueous solutions

    International Nuclear Information System (INIS)

    In the present work, we have investigated the sorption efficiency of treated olive stones (TOS) towards cadmium and safranine removal from their respective aqueous solutions. TOS material was prepared by treatment of olive stones with concentrated sulfuric acid at room temperature followed up by a subsequent neutralization with 0.1 M NaOH aqueous solution. The resulting material has been thoroughly characterized by SEM, energy-dispersive X-ray (EDX), MAS 13C NMR, FTIR and physicochemical parameters were calculated. The sorption study of TOS at the solid-liquid interface was investigated using kinetics, sorption isotherms, pH effect and thermodynamic parameters. The preliminary results indicate that TOS exhibit a better efficiency in terms of sorption capacities toward the two pollutants (128.2 and 526.3 mg/g for cadmium and safranine, respectively) than those reported so far in the literature. Moreover, the sorption process is ascertained to occur fast enough so that the equilibrium is reached in less than 15 min of contact time. The results found in the course of this study suggest that ion exchange mechanism is the most appropriate mechanism involved in cadmium and safranine removal. Finally, the sorption efficiency of TOS is compared to those of other low-cost sorbents materials yet described in the literature

  8. Chemically modified olive stone: A low-cost sorbent for heavy metals and basic dyes removal from aqueous solutions

    Energy Technology Data Exchange (ETDEWEB)

    Aziz, Abdellah [Laboratoire de Valorisation des Materiaux, University of Mostaganem, B.P. 227, Mostaganem R.P. (Algeria)], E-mail: abyoucef_aziz@yahoo.fr; Ouali, Mohand Said [Laboratoire de Valorisation des Materiaux, University of Mostaganem, B.P. 227, Mostaganem R.P. (Algeria)], E-mail: ouali@univ-mosta.dz; Elandaloussi, El Hadj [Laboratoire de Valorisation des Materiaux, University of Mostaganem, B.P. 227, Mostaganem R.P. (Algeria); De Menorval, Louis Charles; Lindheimer, Marc [LAMMI (ICGm-UMR CNRS 5253), Universite Montpellier II, 2 Place Eugene Bataillon, Case Courrier 015 34095, Montpellier Cedex 5 (France)

    2009-04-15

    In the present work, we have investigated the sorption efficiency of treated olive stones (TOS) towards cadmium and safranine removal from their respective aqueous solutions. TOS material was prepared by treatment of olive stones with concentrated sulfuric acid at room temperature followed up by a subsequent neutralization with 0.1 M NaOH aqueous solution. The resulting material has been thoroughly characterized by SEM, energy-dispersive X-ray (EDX), MAS {sup 13}C NMR, FTIR and physicochemical parameters were calculated. The sorption study of TOS at the solid-liquid interface was investigated using kinetics, sorption isotherms, pH effect and thermodynamic parameters. The preliminary results indicate that TOS exhibit a better efficiency in terms of sorption capacities toward the two pollutants (128.2 and 526.3 mg/g for cadmium and safranine, respectively) than those reported so far in the literature. Moreover, the sorption process is ascertained to occur fast enough so that the equilibrium is reached in less than 15 min of contact time. The results found in the course of this study suggest that ion exchange mechanism is the most appropriate mechanism involved in cadmium and safranine removal. Finally, the sorption efficiency of TOS is compared to those of other low-cost sorbents materials yet described in the literature.

  9. Rapid synthesis of titania-silica nanoparticles photocatalyst by a modified sol-gel method for cyanide degradation and heavy metals removal

    Energy Technology Data Exchange (ETDEWEB)

    Harraz, Farid A., E-mail: fharraz@cmrdi.sci.eg [Nanostructured Materials and Nanotechnology Division, Central Metallurgical Research and Development Institute (CMRDI), P.O. Box 87 Helwan, Cairo 11421 (Egypt); Abdel-Salam, Omar E. [Faculty of Engineering, Cairo University, Giza (Egypt); Mostafa, Ahlam A. [Aircraft Factory, Helwan (Egypt); Mohamed, Reda M. [Nanostructured Materials and Nanotechnology Division, Central Metallurgical Research and Development Institute (CMRDI), P.O. Box 87 Helwan, Cairo 11421 (Egypt); Faculty of Science, King Abdulaziz University (Saudi Arabia); Hanafy, M. [Faculty of Engineering, Cairo University, Giza (Egypt)

    2013-02-25

    Highlights: Black-Right-Pointing-Pointer TiO{sub 2}-SiO{sub 2} photocatalyst was prepared by a modified sol-gel technique. Black-Right-Pointing-Pointer The modified TiO{sub 2}-SiO{sub 2} catalyst shows remarkable photocatalytic activity. Black-Right-Pointing-Pointer Complete degradation of cyanide and removal of Cr, Co, Pb were achieved. Black-Right-Pointing-Pointer Catalytic performance depends essentially on catalyst, target and reaction time. - Abstract: Titania-silica (TiO{sub 2}-SiO{sub 2}) photocatalyst was prepared by a modified sol-gel technique. Titania sol was firstly synthesized by acid hydrolysis of a TiCl{sub 4} precursor instead of titanium alkoxides. The titania sol was further modified with SiO{sub 2} to obtain a modified catalyst. The as-prepared TiO{sub 2}-SiO{sub 2} catalyst demonstrated a remarkable photocatalytic activity toward degradation of cyanide and heavy metals removal (Cr(III), Co(II) and Pb(II)). The influence of the preparation parameters; the reaction time, the calcination temperature and time, the [H{sup +}]/[Ti] ratio, the pH value and the acid concentration on the structural and chemical properties of the catalyst was investigated in details. The catalytic performance was found to depend essentially on the catalyst and target concentrations and the reaction time. The as-synthesized catalyst was characterized by a variety of techniques including surface area measurement, X-ray diffraction analysis (XRD), scanning electron microscopy (SEM) transmission electron microscopy (TEM) and ultraviolet-visible (UV-vis) spectroscopy measurements. Results of the synthesis and characterization of TiO{sub 2}-SiO{sub 2} catalyst and its photocatalytic performance are presented and thoroughly discussed.

  10. Rapid synthesis of titania–silica nanoparticles photocatalyst by a modified sol–gel method for cyanide degradation and heavy metals removal

    International Nuclear Information System (INIS)

    Highlights: ? TiO2–SiO2 photocatalyst was prepared by a modified sol–gel technique. ? The modified TiO2–SiO2 catalyst shows remarkable photocatalytic activity. ? Complete degradation of cyanide and removal of Cr, Co, Pb were achieved. ? Catalytic performance depends essentially on catalyst, target and reaction time. - Abstract: Titania–silica (TiO2–SiO2) photocatalyst was prepared by a modified sol–gel technique. Titania sol was firstly synthesized by acid hydrolysis of a TiCl4 precursor instead of titanium alkoxides. The titania sol was further modified with SiO2 to obtain a modified catalyst. The as-prepared TiO2–SiO2 catalyst demonstrated a remarkable photocatalytic activity toward degradation of cyanide and heavy metals removal (Cr(III), Co(II) and Pb(II)). The influence of the preparation parameters; the reaction time, the calcination temperature and time, the [H+]/[Ti] ratio, the pH value and the acid concentration on the structural and chemical properties of the catalyst was investigated in details. The catalytic performance was found to depend essentially on the catalyst and target concentrations and the reaction time. The as-synthesized catalyst was characterized by a variety of techniques including surface area measurement, X-ray diffraction analysis (XRD), scanning electron microscopy (SEM) transmission electron micrission electron microscopy (TEM) and ultraviolet–visible (UV–vis) spectroscopy measurements. Results of the synthesis and characterization of TiO2–SiO2 catalyst and its photocatalytic performance are presented and thoroughly discussed.

  11. Separation of heavy metals from aqueous solutions using ''biosorbents''--development of contacting devices for uranium removal

    International Nuclear Information System (INIS)

    The objective of this work is to evaluate the utility of a mixed culture of denitrifying bacteria for the separation of uranium from process wastewaters. The selection of this culture was based upon the knowledge that wastewaters generated in a number of nuclear-materials processing operations require treatment to remove both nitrate and uranium. The effects of process variables on the rate of uranium accumulation and equilibrium distribution were studied. Several methods for contacting the biosorbent with aqueous uranium solutions were examined. These included suspended cells or flocs in stirred-tank reactors and films of cells or inert particles in columnar reactors. Results indicating the equilibrium distribution of uranium between the biosorbent and liquid phases are presented as a sorption isotherm. Saturation of the biosorbent with uranium was attained at a biosorbent-phase uranium concentration of about 0.14g uranium/g dry cells. 11 refs

  12. Effective removal of heavy metal ions Cd{sup 2+}, Zn{sup 2+}, Pb{sup 2+}, Cu{sup 2+} from aqueous solution by polymer-modified magnetic nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Ge, Fei; Li, Meng-Meng; Ye, Hui [Institute of Organic Chemistry, School of Chemistry and Chemical Engineering, Shandong University, Jinan 250100 (China); Zhao, Bao-Xiang, E-mail: bxzhao@sdu.edu.cn [Institute of Organic Chemistry, School of Chemistry and Chemical Engineering, Shandong University, Jinan 250100 (China)

    2012-04-15

    We prepared novel Fe{sub 3}O{sub 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{sup 2+}, Zn{sup 2+}, Pb{sup 2+} and Cu{sup 2+}) from aqueous solution. We investigated the adsorption capacity of Fe{sub 3}O{sub 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{sub 3}O{sub 4}-APS-AA-co-CA MNPs are excellent for removal of heavy metal ions such as Cd{sup 2+}, Zn{sup 2+}, Pb{sup 2+} and Cu{sup 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.

  13. Efficient removal of dyes by a novel magnetic Fe{sub 3}O{sub 4}/ZnCr-layered double hydroxide adsorbent from heavy metal wastewater

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Dan; Li, Yang; Zhang, Jia [School of Environmental and Chemical Engineering, Shanghai University, No. 99 Shangda Road, Shanghai 200444 (China); Li, Wenhui [Department of Chemistry, East China University of Science and Technology, 130 Meilong Road, Shanghai 200237 (China); Zhou, Jizhi; Shao, Li [School of Environmental and Chemical Engineering, Shanghai University, No. 99 Shangda Road, Shanghai 200444 (China); Qian, Guangren, E-mail: grqian@shu.edu.cn [School of Environmental and Chemical Engineering, Shanghai University, No. 99 Shangda Road, Shanghai 200444 (China)

    2012-12-15

    Graphical abstract: To purify heavy metal wastewater (pickling waste liquor (PWL{sub A} and PWL{sub B}) and electroplating wastewater (EPW{sub C} and EPW{sub D})), a novel magnetic Fe{sub 3}O{sub 4}/ZnCr-LDH material was formed via two-step microwave hydrothermal method (Step 1 and Step 2) and applicable for organic dyes wastewater treatment. Highlights: Black-Right-Pointing-Pointer Fe{sub 3}O{sub 4}/ZnCr-layered double hydroxide adsorbent was produced from wastewater. Black-Right-Pointing-Pointer RSM was successfully applied to the optimization of the preparation conditions. Black-Right-Pointing-Pointer The maximum adsorption capacity of MO was found to be 240.16 mg/g. Black-Right-Pointing-Pointer The MO adsorption mechanism on MFLA was certified. Black-Right-Pointing-Pointer MFLA could be recycled after catalytic regeneration by the oxidation technology. - Abstract: A novel magnetic Fe{sub 3}O{sub 4}/ZnCr-layered double hydroxide adsorbent was produced from electroplating wastewater and pickling waste liquor via a two-step microwave hydrothermal method. Adsorption of methyl orange (MO) from water was studied using this material. The effects of three variables have been investigated by a single-factor method. The response surface methodology (RSM) based on Box-Behnken design was successfully applied to the optimization of the preparation conditions. The maximum adsorption capacity of MO was found to be 240.16 mg/g, indicating that this material may be an effective adsorbent. It was shown that 99% of heavy metal ions (Fe{sup 2+}, Fe{sup 3+}, Cr{sup 3+}, and Zn{sup 2+}) can be effectively removed into precipitates and released far less in the adsorption process. In addition, this material with adsorbed dye can be easily separated by a magnetic field and recycled after catalytic regeneration with advanced oxidation technology. Meanwhile, kinetic models, FTIR spectra and X-ray diffraction pattern were applied to the experimental data to examine uptake mechanism. The boundary layer and intra-particle diffusion played important roles in the adsorption mechanisms.

  14. Metals Removal from Recovered base Oil using Chitosan Biopolymers

    Directory of Open Access Journals (Sweden)

    A. Ahmad

    2010-01-01

    Full Text Available It was common to use solvent extraction to recover base oil from used lubricants. Although, significant amount of contaminants removal was achieved by using solvent extraction, some problems arised which need to be resolved. The recovered base oil from solvent extraction was still in the darkish color with stink odor and only minimum heavy metals were removed. As an alternative, an adsorption method which used chitosan to remove metals and contaminants was being investigated. This paper presents the application of experimental design on the study of metals removal from the recovered base oil using adsorption process. Four parameters namely temperature, contact time, chitosan grain size and chitosan dosage on the performance of chitosan to adsorb metals were studied. It was found that the most influential parameter effecting the metals removal was the chitosan grain size. The metals removals also greatly depended on the temperature of the process and chitosan dosage. The performance of these parameters will be further investigated.

  15. Preparation and characterization of sodium iron titanate ion exchanger and its application in heavy metal removal from waste waters

    International Nuclear Information System (INIS)

    The ion exchange properties of sodium iron titanates, namely, NaFeTiO4, Na2Fe2Ti6O16 and iron-doped sodium nonatitanate were investigated. Conventional solid state and sol-gel methods were used in the synthesis of the sodium iron titanates. Structural characterization of the materials was performed with powder X-ray diffraction (XRD), thermogravimetry (TG), scanning electron microscopy (SEM) equipped with energy dispersive spectrometer (EDS) and with inductively coupled plasma optical emission spectrometry (ICP-OES). Based on TG analyses, the novel iron-doped sodium nonatitanate was proven to be a member of the layered titanate family. The different sodium iron titanates were compared based on the efficiency in separating Ni from aqueous streams by conducting batch experiments with a batch factor of 1000 ml/g. Iron-doped sodium nonatitanate exhibited the best ion exchange performance compared to the other sodium iron titanates studied. It was found to be selective for nickel over potassium and showed 99% removal efficiency for Ni

  16. Heavy Metal Pumps in Plants

    Energy Technology Data Exchange (ETDEWEB)

    Harper, J.F.

    2000-10-01

    The long term goal of the funded research is to understand how heavy metals are taken up from the soil and translocated throughout the plant. The potential application of this research is to create plants with better heavy metal uptake systems and thereby improve the ability of these plants to help clean up toxic metals from soils. A rate limiting step is using plant for bioremediation is the normally poor capacity of plants to concentrate toxic metals. Our interest in metal ion transport systems includes those for essential mineral nutrients such as molybdenum, copper, iron, manganese, as well as toxic metals such as cerium, mercury, cesium, cadmium, arsenic and selenium. Understanding the pathways by which toxic metals accumulate in plants will enable the engineering of plants to exclude toxic metals and create healthier food sources, or to extract toxic metals from the soil as a strategy to clean up polluted lands and water.

  17. Removal of Heavy Metals (Fe3+, Cu2+, Zn2+, Pb2+, Cr3+ and Cd2+) from Aqueous Solutions by Using Hebba Clay and Activated Carbon

    Scientific Electronic Library Online (English)

    S.A., Shama; M.A., Gad.

    Full Text Available SciELO Portugal | Language: English Abstract in english The adsorption capacity of hebba clay and activated carbon towards (Fe3+, Cu2+, Zn2+, Pb2+, Cr3+, Cd2+) metal ions was studied. The adsorption capacity was investigated by batch experiment. The effect of weight of hebba was studied and the results showed that the removal percentages increased as the [...] weight of sorbent increased. The effect of contact time was also studied and the results showed that the removal percentages increased as the contact time increased. The effect of pH of the solution was also studied and the removal percentages for (Cu2+, Zn2+ and Cd2+) were affected slightly by changing the pH value, but for (Fe3+, Pb2+ and Cr3+) the effect was higher. Also, the effect of initial concentration of metal ions was studied at four different concentrations (5, 10, 30, 50 mg/L); in case of metal ions (Cu2+, Zn2+ and Cd2+), the removal percentages increased by increasing initial concentration. But for the other metal ions it decreased. The order of increasing removal percentages of metal ions at pH=4.86, concentration of metal ions 30 mg/L, and after four hours of shaking, was (Pb2+

  18. Removal of Heavy Metals (Fe3+, Cu2+, Zn2+, Pb2+, Cr3+ and Cd2+ from Aqueous Solutions by Using Hebba Clay and Activated Carbon

    Directory of Open Access Journals (Sweden)

    S.A. Shama

    2010-01-01

    Full Text Available The adsorption capacity of hebba clay and activated carbon towards (Fe3+, Cu2+, Zn2+, Pb2+, Cr3+, Cd2+ metal ions was studied. The adsorption capacity was investigated by batch experiment. The effect of weight of hebba was studied and the results showed that the removal percentages increased as the weight of sorbent increased. The effect of contact time was also studied and the results showed that the removal percentages increased as the contact time increased. The effect of pH of the solution was also studied and the removal percentages for (Cu2+, Zn2+ and Cd2+ were affected slightly by changing the pH value, but for (Fe3+, Pb2+ and Cr3+ the effect was higher. Also, the effect of initial concentration of metal ions was studied at four different concentrations (5, 10, 30, 50 mg/L; in case of metal ions (Cu2+, Zn2+ and Cd2+, the removal percentages increased by increasing initial concentration. But for the other metal ions it decreased. The order of increasing removal percentages of metal ions at pH=4.86, concentration of metal ions 30 mg/L, and after four hours of shaking, was (Pb2+ < Cu2+ < Cd2+ < Cr3+ < Zn2+ < Fe3+. But in the case of activated carbon, the order was Cd2+ < Zn2+ < Cu2+ < Pb2+ < Cr6+ < Fe3+.

  19. Inorganic particulates in removal of toxic heavy metal ions: efficient removal of cadmium ions from aqueous solutions by hydrous manganese oxide

    International Nuclear Information System (INIS)

    Adsorption of cadmium ions from aqueous solutions of Cd(NO3)2 on hydrous manganese oxide (HMO) has been studied as a function of the contact time, concentration (10-2-10-7 M), temperature (303-333 K) and pH (2.80-11.80) of the Cd(II) solution employing 'radiotracer technique'. The results on adsorption of Cd(II) on HMO show that the removal process is essentially complete in ca. 2 h and the steady state values of adsorption at various concentrations agree well with the classical Freundlich adsorption isotherm. The temperature and pH of the bulk solution markedly affect the extent of adsorption and the process is thermodynamically irreversible. The exposure of HMO to neutrons and ?-radiations from a 11.1 GBq (Ra-Be) neutron source having 1.72 Gy/h dose rate or to a high radiation ?-cell (having mean dose rate 4.66 kGy/h) has practically no significant effect on the adsorption capacity of HMO. (orig.)

  20. CONSTRUCTED WETLANDS FOR TREATMENT OF HEAVY METALS IN URBAN STORMWATER RUNOFF: CHEMICAL SPECIATION OF WETLAND SEDIMENTS

    Science.gov (United States)

    Heavy metals in urban stormwater runoff are primarily removed by sedimentation in stormwater best management practices (BMPs) such as constructed wetlands. Heavy metals accumulated in wetland sediments may be potentially toxic to benthic invertebrates and aquatic microorganisms, ...

  1. Application of mechanosynthesized azine-decorated zinc(II) metal-organic frameworks for highly efficient removal and extraction of some heavy-metal ions from aqueous samples: a comparative study.

    Science.gov (United States)

    Tahmasebi, Elham; Masoomi, Mohammad Yaser; Yamini, Yadollah; Morsali, Ali

    2015-01-20

    The three zinc(II) metal-organic frameworks [Zn2(oba)2(4-bpdb)]·(DMF)x (TMU-4), [Zn(oba)(4-bpdh)0.5]n·(DMF)y (TMU-5), and [Zn(oba)(4-bpmb)0.5]n·(DMF)z (TMU-6) [DMF = dimethylformamide, H2oba = 4,4'-oxybisbenzoic acid, 4-bpdb = 1,4-bis(4-pyridyl)-2,3-diaza-1,3-butadiene, 4-bpdh = 2,5-bis(4-pyridyl)-3,4-diaza-2,4-hexadiene, and 4-bpmb = N(1),N(4)-bis((pyridin-4-yl)methylene)benzene-1,4-diamine], which contain azine-functionalized pores, have been successfully synthesized by mechanosynthesis as a convenient, rapid, low-cost, solventless, and green process. These MOFs were studied for the removal and extraction of some heavy-metal ions from aqueous samples, and the effects of the basicity and void space of these MOFs on adsorption efficiency were evaluated. The results showed that, for trace amounts of metal ions, the basicity of the N-donor ligands in the MOFs determines the adsorption efficiency of the MOFs for the metal ions. In contrast, at high concentrations of metal ions, the void space of the MOFs plays a main role in the adsorption process. The studies conducted revealed that, among the three MOFs, TMU-6 had a lower adsorption efficiency for metal ions than the other two MOFs. This result can be attributed to the greater basicity of the azine groups on the TMU-4 and TMU-5 pore walls as compared to the imine groups on the N-donor ligands on the TMU-6 pore walls. Subsequently, TMU-5 was chosen as an efficient sorbent for the extraction and preconcentration of trace amounts of some heavy-metal ions including Cd(II), Co(II), Cr(III), Cu(II), and Pb(II), followed by their determination by flow injection inductively coupled plasma optical emission spectrometry. Several variables affecting the extraction efficiency of the analytes were investigated and optimized. The optimized methodology exhibits a good linearity between 0.05 and 100 ?g L(-1) (R(2) > 0.9935) and detection limits in the range of 0.01-1.0 ?g L(-1). The method has enhancement factors between 42 and 225 and relative standard deviations (RSDs) of 2.9-6.2%. Subsequently, the potential applicability of the proposed method was evaluated for the extraction and determination of target metal ions in some environmental water samples. PMID:25548873

  2. Biosorption of heavy metals and uranium from dilute solutions

    International Nuclear Information System (INIS)

    Eichhornia crassipes approaches being a scourge in many parts of the world, choking waterways and hindering transport upon them. At the same time it is known to readily abstract heavy metal ions from water and, thus, aids in the removal of heavy metals found in such waters. This paper considers the possibility of using specific parts of the plant as an inexpensive adsorbent for the removal of heavy metals from contaminated chemical and mining industry waste waters. In particular the root of the plant was found to be an excellent accumulator of heavy metal ions including uranium from solution. It is also suggested that dried roots of the plant might be placed in simple bags and used in a very low cost metal ion removal system

  3. Enhancement of Heavy Metals Phyroextraction on an Industrial Contaminated soil using EDTA and NTA

    International Nuclear Information System (INIS)

    Large areas of agricultural soils from Romania are contaminated by heavy metals that mainly originate from industrial emissions. To achieve high heavy metals removal rates, the concentrations of soluble heavy metals in the soils must be enhanced. Several chelating agents can effectively increase the solubility of metallic contaminants in soils and subsequently enhance their uptake by crops. (Author)

  4. Removal of Heavy Metal Ions (Pb2+, Cu2+) in Aqueous Solutions by Pterygota macrocarpa Sawdust

    OpenAIRE

    Adouby, K.; Koffi Akissi, L. C.; Eboua Wandan, N.; Yao, B.

    2007-01-01

    The purpose of this study is the use of Pterygota macrocarpa sawdust as adsorbent for lead and copper removal into aqueous acid solutions. The results showed that the rate of removal is better for particle sizes lower than 0.5 mm, in the metal solutions at pH 3. The Langmuir, Freundlich and Temkin isotherms studies were allowed to determine the maximum capacity of adsorption of the sawdust; it is 115.61 and 24.02 mg g-1 for the lead and cooper removal, respectively. This study also showed tha...

  5. Heavy metals extraction from anaerobically digested sludge.

    OpenAIRE

    Marchioretto, M. M.; Bruning, H.; Loan, N. T. P.; Rulkens, W. H.

    2001-01-01

    This paper reports on the chemical extraction efficiency in the removal of heavy metals from sludge from an activated-sludge system, which receives as influent both industrial and municipal wastewater. Utilizing a series of chemical extractants in a sequential order comprised the first phase of the research, called sequential chemical extraction (SCE). The work started with the well-known Tessier method followed by Veeken and by Sims and Kline SCE schemes. Afterwards, modified versions of Tes...

  6. Optimización del Proceso de Remoción de Metales Pesados de Agua Residual de la Industria Galvánica por Precipitación Química / Optimization of the Removal Processs of Heavy Metals from Raw Water of Galvanic Industry by Chemical Precipitation

    Scientific Electronic Library Online (English)

    Eduardo, Soto; Rosa del C, Miranda; César A, Sosa; José A, Loredo.

    Full Text Available Se han estudiado las condiciones óptimas requeridas para remover metales pesados del agua residual de una industria galvánica, que contiene cromo (435 mg/L), zinc (720 mg/L), hierro (168 mg/L) y níquel (24 mg/L). Se usó agua preparada en el laboratorio (agua sintética) y agua de la industria misma ( [...] agua cruda). El tratamiento se hizo mediante precipitación química, usando sosa para ajustar el pH y cloruro férrico como aditivo coagulante en un equipo de prueba de jarras. Las condiciones óptimas encontradas usando el agua sintética fueron: 7 minutos para el tiempo de floculación, 18 rpm para la velocidad de agitación y 11.8 mL para la dosis de coagulante. Para el agua cruda fueron: 9.5 minutos para el tiempo de floculación, 30 rpm para la velocidad de agitación y 5.2 mL para la dosis de coagulante. Las condiciones de tratamiento fueron diferentes para el agua residual cruda, ya que el agua residual cruda contiene otros contaminantes, los cuales sobrecargan la superficie coloidal, esto afecta el proceso de floculación Abstract in english The aim of this research was to obtain the optimum conditions to remove heavy metals from wastewaters of the galvanic industry, which contain chromium (435 mg/L), zinc (720 mg/L), iron (168 mg/L) and nickel (24 mg/L). The treatment was made by chemical precipitation using caustic soda to set pH and [...] ferric chloride like coagulant aid in jar test. The responses to optimize are: flocculation time, stirring speed and coagulant dose. The optimum conditions to remove heavy metals from synthetic wastewater was, flocculation time: 7 minutes, stirring speed: 18 rpm, coagulant dose: 11.8 mL and flocculation time: 9.5 minutes,stirring speed: 30 rpm, coagulant dose: 5.2 mL for raw wastewater. The treatment conditions were different for the raw wastewater because the raw wastewater contains other pollutants which over charge the colloidal surface and affects the flocculation processes

  7. Optimización del Proceso de Remoción de Metales Pesados de Agua Residual de la Industria Galvánica por Precipitación Química Optimization of the Removal Processs of Heavy Metals from Raw Water of Galvanic Industry by Chemical Precipitation

    Directory of Open Access Journals (Sweden)

    Eduardo Soto

    2006-01-01

    Full Text Available Se han estudiado las condiciones óptimas requeridas para remover metales pesados del agua residual de una industria galvánica, que contiene cromo (435 mg/L, zinc (720 mg/L, hierro (168 mg/L y níquel (24 mg/L. Se usó agua preparada en el laboratorio (agua sintética y agua de la industria misma (agua cruda. El tratamiento se hizo mediante precipitación química, usando sosa para ajustar el pH y cloruro férrico como aditivo coagulante en un equipo de prueba de jarras. Las condiciones óptimas encontradas usando el agua sintética fueron: 7 minutos para el tiempo de floculación, 18 rpm para la velocidad de agitación y 11.8 mL para la dosis de coagulante. Para el agua cruda fueron: 9.5 minutos para el tiempo de floculación, 30 rpm para la velocidad de agitación y 5.2 mL para la dosis de coagulante. Las condiciones de tratamiento fueron diferentes para el agua residual cruda, ya que el agua residual cruda contiene otros contaminantes, los cuales sobrecargan la superficie coloidal, esto afecta el proceso de floculaciónThe aim of this research was to obtain the optimum conditions to remove heavy metals from wastewaters of the galvanic industry, which contain chromium (435 mg/L, zinc (720 mg/L, iron (168 mg/L and nickel (24 mg/L. The treatment was made by chemical precipitation using caustic soda to set pH and ferric chloride like coagulant aid in jar test. The responses to optimize are: flocculation time, stirring speed and coagulant dose. The optimum conditions to remove heavy metals from synthetic wastewater was, flocculation time: 7 minutes, stirring speed: 18 rpm, coagulant dose: 11.8 mL and flocculation time: 9.5 minutes,stirring speed: 30 rpm, coagulant dose: 5.2 mL for raw wastewater. The treatment conditions were different for the raw wastewater because the raw wastewater contains other pollutants which over charge the colloidal surface and affects the flocculation processes

  8. Customizable Biopolymers for Heavy Metal Remediation

    International Nuclear Information System (INIS)

    Nanoscale materials have been gaining increasing interest in the area of environmental remediation because of their unique physical, chemical and biological properties. One emerging area of research has been the development of novel materials with increased affinity, capacity, and selectivity for heavy metals because conventional technologies are often inadequate to reduce concentrations in wastewater to acceptable regulatory standards. Genetic and protein engineering have emerged as the latest tools for the construction of nanoscale materials that can be controlled precisely at the molecular level. With the advent of recombinant DNA techniques, it is now possible to create 'artificial' protein polymers with fundamentally new molecular organization. The most significant feature of these nanoscale biopolymers is that they are specifically pre-programmed within a synthetic gene template and can be controlled precisely in terms of sizes, compositions and functions at the molecular level. In this review, the use of specifically designed protein-based nano-biomaterials with both metal-binding and tunable properties for heavy metal removal is summarized. Several different strategies for the selective removal of heavy metals such as cadmium and mercury are highlighted

  9. Recycling of agricultural solid waste, coir pith: Removal of anions, heavy metals, organics and dyes from water by adsorption onto ZnCl{sub 2} activated coir pith carbon

    Energy Technology Data Exchange (ETDEWEB)

    Namasivayam, C. [Environmental Chemistry Division, Department of Environmental Sciences, Bharathiar University, Coimbatore 641 046 (India)]. E-mail: cnamasi@yahoo.com; Sangeetha, D. [Environmental Chemistry Division, Department of Environmental Sciences, Bharathiar University, Coimbatore 641 046 (India)

    2006-07-31

    The abundant lignocellulosic agricultural waste, coir pith is used to develop ZnCl{sub 2} activated carbon and applied to the removal of toxic anions, heavy metals, organic compounds and dyes from water. Sorption of inorganic anions such as nitrate, thiocyanate, selenite, chromium(VI), vanadium(V), sulfate, molybdate, phosphate and heavy metals such as nickel(II) and mercury(II) has been studied. Removal of organics such as resorcinol, 4-nitrophenol, catechol, bisphenol A, 2-aminophenol, quinol, O-cresol, phenol and 2-chlorophenol has also been investigated. Uptake of acidic dyes such as acid brilliant blue, acid violet, basic dyes such as methylene blue, rhodamine B, direct dyes such as direct red 12B, congo red and reactive dyes such as procion red, procion orange were also examined to assess the possible use of the adsorbent for the treatment of contaminated ground water. Favorable conditions for maximum removal of all adsorbates at the adsorbate concentration of 20 mg/L were used. Results show that ZnCl{sub 2} activated coir pith carbon is effective for the removal of toxic pollutants from water.

  10. Development and evaluation of Mn oxide-coated composite adsorbent for the removal and recovery of heavy metals from coal processing wastewater. Final report, December 1995

    Energy Technology Data Exchange (ETDEWEB)

    Fan, Huan Jung; Anderson, P.R.

    1995-12-31

    The overall objective of this research was to evaluate a Mn oxide-coated granular activated carbon (MnGAC) for the removal and recovery of metals from wastewaters. The composite adsorbent was prepared by coating M-n-oxide onto granular activated carbon. Three coating methods (adsorption, precipitation, and dry oxidation) were developed and studied in this research. The adsorbent (MnTOG) prepared by a dry oxidation method had the highest Cu(II) adsorption capacity of the three synthesis methods. In multiple adsorption/regeneration cycle tests, MnTOG had better Cu(II) removal relative to those adsorbents prepared by other methods. MnTOG had the ability to remove Cu(II) and Cd(II) to trace level (< 4 ug/L) in a column process at least through 3000 and 1400 BV, respectively. Cd(II) removal was hindered by the presence of Cu(II). However, Cu(II) removal was only slightly reduced by the presence of Cd(II). Cu(II) adsorption in batch and fixed-bed processes onto MnTOG was successfully modeled with a homogeneous surface diffusion model (HSDM). However, the HSDM could only successfully describe the adsorption of Cd(II) onto MnTOG in the batch process, but not the fixed-bed process. M-n oxide can be deposited on GAC to create a composite adsorbent with an increased Cu(II) or Cd(II) adsorption capacity. Composite adsorbent (MnGAC) has the potential to become an efficient way to remove metals from metal contaminated wastewater.

  11. The ability of Azolla caroliniana to remove heavy metals (Hg(II), Cr(III), Cr(VI)) from municipal waste water.

    Science.gov (United States)

    Bennicelli, R; Stepniewska, Z; Banach, A; Szajnocha, K; Ostrowski, J

    2004-04-01

    The aim of this paper was to investigate the capacity of a small water fern, Azolla caroliniana Willd. (Azollaceae), to purify waters polluted by Hg and Cr. Many plants are capable of accumulating heavy metals (called hyperaccumulators) and one of them is the water fern A. caroliniana. During 12 days of the experiment the fern was grown on the nutrient solution containing Hg2+, Cr3+ and CrO4(2-) ions, each in a concentration 0.1, 0.5 and 1.0 mg dm(-3). The presence of these ions caused a 20-31% inhibition of A. caroliniana growth, the highest in the presence of Hg(II) ions, in comparison to the control. After day 12 of the experiment, metal contents the solution decreased to 0-0.25 mg dm(-3), and this decrease comprised between 74 (Cr3+ 1.0 mg dm(-3) treatment) and 100% (CrO4(2-) 0.1 mg dm(-3) treatment). The fern took a lesser quantity of the metals from 0.1 mg dm(-3) treatments compared to 0.5 and 1.0 mg dm(-3) treatments. In the A. caroliniana tissues the concentration of heavy metals under investigation ranged from 71 to 964 mg kg(-1) dm; the highest level being found for Cr(III) containing nutrient solution. PMID:14720557

  12. Heavy metals in edible mushrooms

    International Nuclear Information System (INIS)

    It has been reported that edible mushrooms are able to enrich the concentrations of several heavy metals. The Cd has especially drawn attention due to its high toxicity. By using particle induced X-ray emission (PIXE) analysis for the determination of the heavy metals it is possible to obtain a screening of the content of a wide number of elements. By analysing different species it is shown that one or a few elements may be characteristic for a single species. It is especially remarkable that several species of the family Agaricaceae are enriching Ag to a very high degree (up to 200 ppm). (author)

  13. Preparation and characterization of multi-walled carbon nanotubes/chitosan nanocomposite and its application for the removal of heavy metals from aqueous solution

    International Nuclear Information System (INIS)

    Research highlights: ? Nanocomposite made of multi-walled carbon nanotubes and chitosan was prepared and characterized. ? The characterization confirmed the homogenous and well distribution of the MWCNTs within the chitosan matrix. ? MWCNTs/chitosan nanocomposite was used for the removal of copper, zinc, cadmium and nickel ions from aqueous solution. ? The results showed that nanocomposite could remove successfully most of the metal ions from solution with high efficiency. - Abstract: Multi-walled carbon nanotubes (MWCNTs) were modified with chitosan, and a homogenous nanocomposite was obtained. The morphological properties of the MWCNTs/chitosan nanocomposite were studied with scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FT-IR), and thermal gravimetric analysis (TGA). The morphological results indicate the successful modification and the formation of MWCNTs/chitosan nanocomposites. The MWCNTs/chitosan nanocomposite was packed inside a glass column and used for the removal of copper, zinc, cadmium, and nickel ions from aqueous solution. The MWCNTs/chitosan nanocomposite showed a great efficiency for the removal of the target metal ions from the aqueous solution. The results suggested that this novel MWCNTs/chitosan nanocomposite could be used for different environmental applications.

  14. REMOVAL OF METALS IN COMBINED TREATMENT SYSTEMS

    Science.gov (United States)

    This project assessed the variables influencing the removal of eight metals through combined industrial-municipal treatment plants. The eight metals investigated were: aluminum, cadmium, chromium, copper, iron, lead, nickel, and zinc. The metals were studied at subtoxic influent ...

  15. Phytoremediation of Heavy Metals in Aqueous Solutions

    Directory of Open Access Journals (Sweden)

    Felix Aibuedefe AISIEN

    2010-12-01

    Full Text Available One of the major environmental problems is the pollution of water and soil by toxic heavy metals. This study investigated the phytoremediation potential of water hyacinth, for the removal of cadmium (Cd, lead (Pb and zinc (Zn. Water hyacinths were cultured in bore-hole water, supplemented with 5mg/l of Zn and Pb and 1mg/l of Cd at pH 4.5, 6.8 and 8.5. The plants were separately harvested each week for six weeks. The results showed that removal of these metals from solution was fast especially in the first two weeks, after which it became gradual till saturation point was reached. The accumulation of Cd and Zn in leaves and roots increased with increase in pH. The highest accumulation was in the roots with metal concentration of 4870mg/kg, 4150mg/kg and 710mg/kg for Zn, Pb and Cd respectively at pH 8.5. The maximum values of bioconcentration factor (BCF for Zn, Pb and Cd were 1674, 1531 and 1479 respectively, suggesting that water hyacinth was good accumulator of Zn, Pb and Cd, and could be used to treat industrial wastewater contaminated with heavy metals such as Zn, Pb and Cd.

  16. Heavy Metal Concentrations in Predator Fish

    OpenAIRE

    Srebrenka Nejedli; Visnja Orescanin; Marko Ivanusic; Zeljka Matasin; Ivana Tlak Gajger

    2011-01-01

    Waters can be polluted by heavy metals which are accumulated and concentrated by fish therefore they show the degree of environmental pollution. The aim of this study was to determine concentrations of heavy metals in water, mud and fish organs to determine whether these concentrations are allowed and in accordance with normative provisions and considering the pollution by heavy metals if the fish meat is hygienically safe food of animal origin. Concentrations of heavy metals (lead, chromium,...

  17. Heavy metals in trees and energy crops - a literature review

    International Nuclear Information System (INIS)

    This literature review deals with the use of energy crops for cleaning of soils from heavy metals. It also deals with the use of low accumulating energy crops to be used on strongly contaminated soils where a low uptake of heavy metals is preferred, for example on mining deposits. In addition to the efforts to reduce the sources for heavy metal contamination of soils (for example commercial fertilizers and atmospheric deposition) the uptake and removal of heavy metals from the soils by the use of energy crops have recently been discussed as a method for cleaning of soils. Species from the Salix family (willow) have a greater potential for accumulating heavy metals than cereals which makes them interesting for this purpose. The Salix family consists of species with a great genetic variation. This will probably make it possible to find or develop clones with different characteristics suitable for cleaning of contaminated soils as well as for plant covering of soils that are extremely contaminated by heavy metals. In the former case an accumulation of heavy metals in the harvested parts, the shoots, is preferred. In the later case clones that do not accumulate heavy metals and maybe also clones with only root accumulation are preferred. There are also Salix clones with a specific accumulation of heavy metals which makes it possible to clean soils from a toxic metal and at the same time avoid the risk for deficiency of essential metals, for example Zn. The greatest potential to clean soils by the use of energy crops, is when the contamination levels in the soils are low, the areas to clean are large and when the time needed for cleaning is of minor importance. The most suitable soils are those where the metal contamination is located in the top soil layer and where the heavy metal concentrations in the sub soil layer are still low. 58 refs, 8 tabs, 1 fig

  18. Phytoextraction of heavy metals from mine soils using hyperaccumulator plants.

    OpenAIRE

    Pe?rez Esteban, Javier; Escola?stico, Consuelo; Ruiz Ferna?ndez, Juan; Masaguer Rodri?guez, Alberto; Moliner Aramendia, Ana Mari?a

    2010-01-01

    Phytoextraction is an environmental-friendly and cost-effective technology that uses metal hyperaccumulator plants to remove heavy metals from soils. The metals are absorbed by the roots, transported and accumulated in the aerial parts of the plants, which can be harvested and eliminated. The aim of this work was to study some hyperaccumulator species that could be useful to decontaminate mine soils and also to investigate the bioavailability and uptake of these metals by plants with the addi...

  19. Actividad emulsificante y de remoción de metales pesados del ramnolípido producido por Pseudomonas aeruginosa PB 25 / Oil emulsifying activity and removal of heavy metals by Pseudomonas aeruginosa PB 25 rhamnolipid

    Scientific Electronic Library Online (English)

    J. Daniel, Giraldo; Susana, Gutiérrez; Fernando, Merino.

    2014-01-01

    Full Text Available SciELO Peru | Language: Spanish Abstract in spanish El avance científico-tecnológico realizado desde la revolución industrial, ha aumentado la capacidad del ser humano para explotar los recursos naturales causando una constante perturbación en los ecosistemas. En este contexto, el uso de los biosurfactantes, representa una prometedora alternativa de [...] aplicación para procesos de remediación de ambientes naturales. El objetivo del presente trabajo fue evaluar la actividad emulsificante y de remoción de metales pesados de un biosurfactante de naturaleza ramnolipídica producido por Pseudomonas aeruginosa PB25. Esta creció con una velocidad específica (µ) de 0,0285 h-1 y un tiempo generacional (t g) de 24,321 h; registrándose a su vez una concentración máxima de 2,47 g/L de ramnolípidos en la fase estacionaria de crecimiento, con valores de rendimiento (Y) de 0,13 gramos de ramnolípido por gramo de glicerol y de productividad de 0,082 g/L-h. El ramnolípido alcanzó 5,257 Unidades de Actividad Emulsificante /mL frente a crudo de petróleo e índices de emulsificación E24 de 53, 64, 62 y 84 % para crudo de petróleo, petróleo diesel 2, gasolina y kerosene, respectivamente. Logró remover 98% de plomo y 99% de cadmio en soluciones acuosas a pH 11. Por lo cual, este biosurfactante puede ser empleado en procesos de biorremediación. Abstract in english Since the industrial revolution, the science and technology advances have increased the human ability to exploit natural resources causing pollution in ecosystems. In this context, the use of biosurfactants represents a promising alternative application for any technological process of remediation o [...] f natural environments. The objective of this work was the evaluation of the emulsifying activity and the ability to remove heavy metals with a rhamnolipidic biosurfactant produced by Pseudomonas aeruginosa PB25. This strain had a specific growth rate (?) of 0.0285 h-1 and a generational time (td) of 24.321 h. It produced 2.47 g/L rhamnolipid, with yields (Y) of 0.13 g/g and productivity of 0.082 g/L-h. The rhamnolipid had 5.257 emulsifying activity units/mL and E24 emulsification index of 53, 64, 62 and 84% for crude oil, diesel oil 2, gasoline and kerosene, respectively. It got to remove 98% of lead and 99% of cadmium in aqueous solutions at pH 11. In conclusion, it can be used in biotechnological processes.

  20. Heavy Metal Stars

    Science.gov (United States)

    2001-08-01

    La Silla Telescope Detects Lots of Lead in Three Distant Binaries Summary Very high abundances of the heavy element Lead have been discovered in three distant stars in the Milky Way Galaxy . This finding strongly supports the long-held view that roughly half of the stable elements heavier than Iron are produced in common stars during a phase towards the end of their life when they burn their Helium - the other half results from supernova explosions. All the Lead contained in each of the three stars weighs about as much as our Moon. The observations show that these "Lead stars" - all members of binary stellar systems - have been more enriched with Lead than with any other chemical element heavier than Iron. This new result is in excellent agreement with predictions by current stellar models about the build-up of heavy elements in stellar interiors. The new observations are reported by a team of Belgian and French astronomers [1] who used the Coude Echelle Spectrometer on the ESO 3.6-m telescope at the La Silla Observatory (Chile). PR Photo 26a/01 : A photo of HD 196944 , one of the "Lead stars". PR Photo 26b/01 : A CES spectrum of HD 196944 . The build-up of heavy elements Astronomers and physicists denote the build-up of heavier elements from lighter ones as " nucleosynthesis ". Only the very lightest elements (Hydrogen, Helium and Lithium [2]) were created at the time of the Big Bang and therefore present in the early universe. All the other heavier elements we now see around us were produced at a later time by nucleosynthesis inside stars. In those "element factories", nuclei of the lighter elements are smashed together whereby they become the nuclei of heavier ones - this process is known as nuclear fusion . In our Sun and similar stars, Hydrogen is being fused into Helium. At some stage, Helium is fused into Carbon, then Oxygen, etc. The fusion process requires positively charged nuclei to move very close to each other before they can unite. But with increasing atomic mass and hence, increasing positive charge of the nuclei, the electric repulsion between the nuclei becomes stronger and stronger. In fact, the fusion process only works up to a certain mass limit, corresponding to the element Iron [2]. All elements that are heavier than Iron cannot be produced via this path. But then, how were those heavy elements we now find on the Earth produced in the first place? From where comes the Zirconium in artificial diamonds, the Barium that colours fireworks, the Tungsten in the filaments in electric bulbs? Which process made the Lead in your car battery? Beyond iron The production of elements heavier than Iron takes place by adding neutrons to the atomic nuclei . These neutral particles do not feel any electrical repulsion from the charged nuclei. They can therefore easily approach them and thereby create heavier nuclei. This is indeed the way the heaviest chemical elements are built up. There are actually two different stellar environments where this process of "neutron capture" can happen. One place where this process occurs is inside very massive stars when they explode as supernovae . In such a dramatic event, the build-up proceeds very rapidly, via the so-called "r-process" ( "r" for rapid ). The AGB stars But not all heavy elements are created in such an explosive way. A second possibility follows a more "peaceful" road. It takes place in rather normal stars, when they burn their Helium towards the end of their lives. In the so-called "s-process" ( "s" for slow ), heavier elements are then produced by a rather gentle addition of neutral neutrons to atomic nuclei. In fact, roughly half of all the elements heavier than Iron are believed to be synthesized by this process during the late evolutionary phases of stars. This process takes place during a specific stage of stellar evolution, known as the "AGB" phase [3]. It occurs just before an old star expels its gaseous envelope into the surrounding interstellar s

  1. Coupling bioleaching and electrokinetics to remediate heavy metal contaminated soils.

    Science.gov (United States)

    Huang, Qingyun; Yu, Zhen; Pang, Ya; Wang, Yueqiang; Cai, Zhihong

    2015-04-01

    In this study, bioleaching was coupled with electrokinetics (BE) to remove heavy metals (Cu, Zn, Cr and Pb) from contaminated soil. For comparison, bioleaching (BL), electrokinetics (EK), and the chemical extraction method were also applied alone to remove the metals. The results showed that the BE method removed more heavy metals from the contaminated soil than the BL method or the EK method alone. The BE method was able to achieve metal solubilization rates of more than 70 % for Cu, Zn and Cr and of more than 40 % for Pb. Within the range of low current densities (metal removal. However, the metal solubilization rates did not increase with increasing current density when the current density was higher than 1 mA cm(-2). Therefore, it is suggested that bioleaching coupled with electrokinetics can effectively remediate heavy metal-contaminated soils and that preliminary tests should be conducted before field operation to detect the lowest current density for the greatest metal removal. PMID:25680933

  2. [Study on the disposal process for removing heavy metal ions from wastewater by composite biosorbent of nano Fe3O4/Sphaerotilus natans].

    Science.gov (United States)

    Guan, Xiao-Hui; Qin, Yu-Chun; Wang, Li-Wen; Yin, Rong; Lu, Min; Yang, Ying-Jun

    2007-02-01

    Composite biosorbent nano Fe3O4/Sphaerotilus natans was prepared when nano Fe3O4 was used as carrier, then the composite biosorbent characterized by infrared instrument and investigated on adsorbing heavy metal ions from wastewater. Infrared spectrum analysis shows that--CONH--and--OH are principal activated groups of composite biosorbent. The experiment of adsorption shows that biomass concentration and flow velocity are main influencing factors. The composite biosorbent has best effect on the adsorption of Cu2+ under the conditions of biomass 1.5 g/L (Sphaerotilus natans/Fe3O4 = 3:2), flow velocity 0.96 L/h and initial concentration of Cu2+ was less than 20 mg/L. Composite biosorbent can be used for more 10 times when biosorbent was regenerated by HCl solution, and HCl solution can be used 3 times repeatedly. The selective sequence was Ph2+ > Cu2+ > Zn2+ > Cd2+. PMID:17489213

  3. A study on the preparation of organic-inoganic composite bead and the properties of adsorption for the removal of radionuclides and heavy metal ions

    International Nuclear Information System (INIS)

    PAN-inorganic ion exchanger (Ni2Fe(CN)6, K2Ti4O9) composite beads were prepared in the range of 0.5 ? 3.5mm in size. The control of polymer(PAN) viscosity in the range of 900 ? 1200cP was important to make a spherical composite bead. The dispersion of inorganic particle and bead morphology were observed by SEM. Bead porosity and pore size distribution were also measured by porosieter. The effect of pH and uptake rates of heavy metal ions (Ag, Sr, Cs and Co) were measured with the composite bead containing inorganic ion exhangers. Langmuir and Freundlich isotherm were successful to describe the equilibrium isotherms of Ag ion with inorganic ion exchanger

  4. Mechanisms of bacterial metals removal from solids

    International Nuclear Information System (INIS)

    The Great Lakes area sediments are contaminated with varying amounts of heavy metals and polychlorinated organic matter. With respect to the bioremediation of metallic contents of these sediments, it was shown that a number of microorganisms exist which can effectively solubilize heavy metals. The basic reaction mechanisms of bioleaching processes were discussed and the effects of semiconductor character of the sulfide substrate explained. A special emphasis was made to comment on INEL's bioremediation capability. 37 refs

  5. Detoxification of Heavy Metal Contaminated Soils

    OpenAIRE

    Floarea Damian; Gheorghe Damian

    2007-01-01

    The concentration of the heavy metals in the soils from the strong affected zones because of the mining and metallurgical industry, Baia Mare and Zlatna (Romania), is significant due to the high values of the contents and association of the four metals Pb, Cu, Zn, Cd. The efficacy of the natural zeolites in heavy metals immobilization from the studied soils was evaluated in experiments in which the plant growth was observed. Heavy metals contaminated soils have been treated with a mixture of ...

  6. Microalgae - A promising tool for heavy metal remediation.

    Science.gov (United States)

    Suresh Kumar, K; Dahms, Hans-Uwe; Won, Eun-Ji; Lee, Jae-Seong; Shin, Kyung-Hoon

    2015-03-01

    Biotechnology of microalgae has gained popularity due to the growing need for novel environmental technologies and the development of innovative mass-production. Inexpensive growth requirements (solar light and CO2), and, the advantage of being utilized simultaneously for multiple technologies (e.g. carbon mitigation, biofuel production, and bioremediation) make microalgae suitable candidates for several ecofriendly technologies. Microalgae have developed an extensive spectrum of mechanisms (extracellular and intracellular) to cope with heavy metal toxicity. Their wide-spread occurrence along with their ability to grow and concentrate heavy metals, ascertains their suitability in practical applications of waste-water bioremediation. Heavy metal uptake by microalgae is affirmed to be superior to the prevalent physicochemical processes employed in the removal of toxic heavy metals. In order to evaluate their potential and to fill in the loopholes, it is essential to carry out a critical assessment of the existing microalgal technologies, and realize the need for development of commercially viable technologies involving strategic multidisciplinary approaches. This review summarizes several areas of heavy metal remediation from a microalgal perspective and provides an overview of various practical avenues of this technology. It particularly details heavy metals and microalgae which have been extensively studied, and provides a schematic representation of the mechanisms of heavy metal remediation in microalgae. PMID:25528489

  7. Radiation synthesis of inter polymer polyelectrolyte complex chitosan/ acrylic acid hydrogel and its application for removal of some heavy metals and phenolic compounds

    International Nuclear Information System (INIS)

    Copolymer hydrogels composed of chitosan and acrylic acid (AAc) were synthesized by using gamma- irradiation and their swelling behaviour, thermal property, were investigated. Chitosan/AAc copolymer hydrogel exhibited relatively high equilibrium water content and also showed reasonable sensitivity to ph. The removal of Cu(II). Co(II) and Cr(III), from aqueous solution by the prepared chitosan/AAc (0.6/4) copolymer composition was examined by batch equilibrium technique. The adsorption capacities of the chitosan/AAc (0.8/ 2, wt/wt) copolymer towards phenol, and 2,6-dimethylphenol were 26.7, 12.5 mg/ g polymer, respectively. The effect of treatment time, initial feed concentration and temperature on the metal and phenolic compound uptake were investigated at different ph values

  8. Effect of ultrasonic treatment on heavy metal decontamination in milk.

    Science.gov (United States)

    Porova, Nataliya; Botvinnikova, Valentina; Krasulya, Olga; Cherepanov, Pavel; Potoroko, Irina

    2014-11-01

    Ultrasound has been found useful in increasing the efficiency and consumer safety in food processing. Removal of heavy metal (lead, mercury, and arsenic) contamination in milk is extremely important in regions of poor ecological environment - urban areas with heavy motor traffic or well established metallurgical/cement industry. In this communication, we report on the preliminary studies on the application of low frequency (20kHz) ultrasound for heavy metal decontamination of milk without affecting its physical, chemical, and microbiological properties. PMID:24746508

  9. Dissymmetrical tunnelling in heavy fermion metals

    CERN Document Server

    Shaginyan, V R

    2005-01-01

    A tunnelling conductivity between a heavy fermion metal and a simple metallic point is considered. We show that at low temperatures this conductivity can be noticeably dissymmetrical with respect to the change of voltage bias. The dissymmetry can be observed in experiments on the heavy fermion metals whose electronic system has undergone the fermion condensation quantum phase transition.

  10. Sorption of heavy metal ions on new metal-ligand complexes chemically derived from Lycopodium clavatum

    Energy Technology Data Exchange (ETDEWEB)

    Pehlivan, E.; Ersoz, M.; Yildiz, S. [Univ. of Selcuk, Konya (Turkey); Duncan, H.J. [Univ. of Glasgow, Scotland (United Kingdom)

    1994-08-01

    Sorption of heavy metal ions from aqueous solution has been investigated as a function of pH using a novel exchanger system whereby Lycopodium clavatum is functionalized with carboxylate and glyoxime metal-ligand complexes. The new ligand exchangers were prepared using a reaction of diaminosporopollenin with various metal-ligand complexes of glyoxime and monocarboxylic acid. The sorptive behavior of these metal-ligand exchangers and the possibilities to remove and to recover selectively heavy metal cations using these systems are discussed on the basis of their chemical natures and their complexing properties.

  11. Factorial experimental design for recovering heavy metals from sludge with ion-exchange resin.

    Science.gov (United States)

    Lee, I Hsien; Kuan, Yu-Chung; Chern, Jia-Ming

    2006-12-01

    Wastewaters containing heavy metals are usually treated by chemical precipitation method in Taiwan. This method can remove heavy metals form wastewaters efficiently, but the resultant heavy metal sludge is classified as hazardous solid waste and becomes another environmental problem. If we can remove heavy metals from sludge, it becomes non-hazardous waste and the treatment cost can be greatly reduced. This study aims at using ion-exchange resin to remove heavy metals such as copper, zinc, cadmium, and chromium from sludge generated by a PCB manufacturing plant. Factorial experimental design methodology was used to study the heavy metal removal efficiency. The total metal concentrations in the sludge, resin, and solution phases were measured respectively after 30 min reaction with varying leaching agents (citric acid and nitric acid); ion-exchange resins (Amberlite IRC-718 and IR-120), and temperatures (50 and 70 degrees C). The experimental results and statistical analysis show that a stronger leaching acid and a higher temperature both favor lower heavy metal residues in the sludge. Two-factors and even three-factor interaction effects on the heavy metal sorption in the resin phase are not negligible. The ion-exchange resin plays an important role in the sludge extraction or metal recovery. Empirical regression models were also obtained and used to predict the heavy metal profiles with satisfactory results. PMID:16843592

  12. Factorial experimental design for recovering heavy metals from sludge with ion-exchange resin

    International Nuclear Information System (INIS)

    Wastewaters containing heavy metals are usually treated by chemical precipitation method in Taiwan. This method can remove heavy metals form wastewaters efficiently, but the resultant heavy metal sludge is classified as hazardous solid waste and becomes another environmental problem. If we can remove heavy metals from sludge, it becomes non-hazardous waste and the treatment cost can be greatly reduced. This study aims at using ion-exchange resin to remove heavy metals such as copper, zinc, cadmium, and chromium from sludge generated by a PCB manufacturing plant. Factorial experimental design methodology was used to study the heavy metal removal efficiency. The total metal concentrations in the sludge, resin, and solution phases were measured respectively after 30 min reaction with varying leaching agents (citric acid and nitric acid); ion-exchange resins (Amberlite IRC-718 and IR-120), and temperatures (50 and 70 deg. C). The experimental results and statistical analysis show that a stronger leaching acid and a higher temperature both favor lower heavy metal residues in the sludge. Two-factors and even three-factor interaction effects on the heavy metal sorption in the resin phase are not negligible. The ion-exchange resin plays an important role in the sludge extraction or metal recovery. Empirical regression models were also obtained and used to predict the heavy metal profiles with satisfactory results

  13. Poisoning of domestic animals with heavy metals

    Directory of Open Access Journals (Sweden)

    Velev Romel

    2009-01-01

    Full Text Available The term heavy metal refers to a metal that has a relatively high density and is toxic for animal and human organism at low concentrations. Heavy metals are natural components of the Earth's crust. They cannot be degraded or destroyed. To a small extent they enter animal organism via food, drinking water and air. Some heavy metals (e.g cooper, iron, chromium, zinc are essential in very low concentrations for the survival of all forms of life. These are described as essential trace elements. However, when they are present in greater quantities, like the heavy metals lead, cadmium and mercury which are already toxic in very low concentrations, they can cause metabolic anomalies or poisoning. Heavy metal poisoning of domestic animals could result, for instance, from drinking-water contamination, high ambient air concentrations near emission sources, or intake via the food chain. Heavy metals are dangerous because they tend to bioaccumulate in a biological organism over time. Manifestation of toxicity of individual heavy metals varies considerably, depending on dose and time of exposure, species, gender and environmental and nutritional factors. Large differences exist between the effects of a single exposure to a high concentration, and chronic exposures to lower doses. The aim of this work is to present the source of poisoning and toxicity of some heavy metals (lead, mercury, cadmium, thallium, arsenic, as well as new data about effects of those heavy metals on the health of domestic animals. .

  14. Heavy Metal Risk Management: Case Analysis

    OpenAIRE

    Kim, Ji Ae; Lee, Seung Ha; Choi, Seung Hyun; Jung, Ki Kyung; Park, Mi Sun; Jeong, Ji Yoon; Hwang, Myung Sil; Yoon, Hae Jung; Choi, Dal Woong

    2012-01-01

    To prepare measures for practical policy utilization and the control of heavy metals, hazard control related institutions by country, present states of control by country, and present states of control by heavy metals were examined. Hazard control cases by heavy metals in various countries were compared and analyzed. In certain countries (e.g., the U.S., the U.K., and Japan), hazardous substances found in foods (e.g., arsenic, lead, cadmium, and mercury) are controlled. In addition, the Joint...

  15. Mosses accumulate heavy metals from the substrata of coal ash

    Directory of Open Access Journals (Sweden)

    Vukojevi? Vanja

    2005-01-01

    Full Text Available Plants that are able to accumulate and tolerate extraordinarily high concentrations of heavy metals (hyperaccumulators can be used for phytoremediation (removal of contaminants from soils or phytomining (growing a crop of plants to harvest the metals. Two moss species, Bryum capillare Hedw. and Ceratodon purpureus Hedw., were tested as potential phytoremedies under in vivo conditions on a coal ash disposal site in the surroundings of Obrenovac (NW Serbia. The content of various heavy metals (iron, manganese zinc, lead, nickel, cadmium, and copper in the mosses and substrata were investigated over a period of three years. Iron and zinc were found to have the highest concentration in the mosses.

  16. Elaboration, characterization and application of polysulfone and polyacrylic acid blends as ultrafiltration membranes for removal of some heavy metals from water

    Energy Technology Data Exchange (ETDEWEB)

    Mbareck, Chamekh, E-mail: chamec1@yahoo.fr [Universite de Nouakchott, Faculte des Sciences et Techniques, B.P. 5026, Nouakchott (Mauritania, Islamic Republic of); Nguyen, Quang Trong; Alaoui, Ouafa Tahiri [P.B.S. Universite de Rouen, 76821 Mont-Saint-Aignan (France); Barillier, Daniel [ERPCB, EA3914, IUT-UFR Sciences, Universite de Caen, 14032 Caen Cedex (France)

    2009-11-15

    Polysulfone (PSf)/polyacrylic acid ultrafiltration (PSf/PAA) membranes were prepared from a polymer blend in dimethylformamide by coagulation in water according to the wet phase inversion method. Immobilization of water-soluble PAA within the non-soluble PSf matrix was proven by the increase of ion exchange capacity and the intensity of the carboxyl groups' peak with the increase of PAA content as shown by Fourier transform infrared spectra. These results lead to consider that PSf and PAA form a semi-interpenetrating polymer networks. The obtained membranes showed a decrease of mean surface-pore sizes, the overall porosity and the hydraulic permeability with the increase in PAA content. Such results were imputed to the morphologic modifications of PSf film with the immobilization of increasing PAA amount. PSf/PAA membranes showed high lead, cadmium and chromium rejection which reaches 100% at pH superior to 5.7 and a low rejection at low pH. Moreover, the heavy metal rejection decreases with feed solution concentration and applied pressure increases. These behaviors were attributed to the role of carboxylic groups in ion exchange or complexation. As a matter of fact, the strong lead ion-PAA interactions were revealed by the scanning electron microscopy with energy dispersive X-rays (SEM-EDX).

  17. Elaboration, characterization and application of polysulfone and polyacrylic acid blends as ultrafiltration membranes for removal of some heavy metals from water

    International Nuclear Information System (INIS)

    Polysulfone (PSf)/polyacrylic acid ultrafiltration (PSf/PAA) membranes were prepared from a polymer blend in dimethylformamide by coagulation in water according to the wet phase inversion method. Immobilization of water-soluble PAA within the non-soluble PSf matrix was proven by the increase of ion exchange capacity and the intensity of the carboxyl groups' peak with the increase of PAA content as shown by Fourier transform infrared spectra. These results lead to consider that PSf and PAA form a semi-interpenetrating polymer networks. The obtained membranes showed a decrease of mean surface-pore sizes, the overall porosity and the hydraulic permeability with the increase in PAA content. Such results were imputed to the morphologic modifications of PSf film with the immobilization of increasing PAA amount. PSf/PAA membranes showed high lead, cadmium and chromium rejection which reaches 100% at pH superior to 5.7 and a low rejection at low pH. Moreover, the heavy metal rejection decreases with feed solution concentration and applied pressure increases. These behaviors were attributed to the role of carboxylic groups in ion exchange or complexation. As a matter of fact, the strong lead ion-PAA interactions were revealed by the scanning electron microscopy with energy dispersive X-rays (SEM-EDX).

  18. Oil palm biomass as an adsorbent for heavy metals.

    Science.gov (United States)

    Vakili, Mohammadtaghi; Rafatullah, Mohd; Ibrahim, Mahamad Hakimi; Abdullah, Ahmad Zuhairi; Salamatinia, Babak; Gholami, Zahra

    2014-01-01

    Many industries discharge untreated wastewater into the environment. Heavy metals from many industrial processes end up as hazardous pollutants of wastewaters.Heavy metal pollution has increased in recent decades and there is a growing concern for the public health risk they may pose. To remove heavy metal ions from polluted waste streams, adsorption processes are among the most common and effective treatment methods. The adsorbents that are used to remove heavy metal ions from aqueous media have both advantages and disadvantages. Cost and effectiveness are two of the most prominent criteria for choosing adsorbents. Because cost is so important, great effort has been extended to study and find effective lower cost adsorbents.One class of adsorbents that is gaining considerable attention is agricultural wastes. Among many alternatives, palm oil biomasses have shown promise as effective adsorbents for removing heavy metals from wastewater. The palm oil industry has rapidly expanded in recent years, and a large amount of palm oil biomass is available. This biomass is a low-cost agricultural waste that exhibits, either in its raw form or after being processed, the potential for eliminating heavy metal ions from wastewater. In this article, we provide background information on oil palm biomass and describe studies that indicate its potential as an alternative adsorbent for removing heavy metal ions from wastewater. From having reviewed the cogent literature on this topic we are encouraged that low-cost oil-palm-related adsorbents have already demonstrated outstanding removal capabilities for various pollutants.Because cost is so important to those who choose to clean waste streams by using adsorbents, the use of cheap sources of unconventional adsorbents is increasingly being investigated. An adsorbent is considered to be inexpensive when it is readily available, is environmentally friendly, is cost-effective and be effectively used in economical processes. The advantages that oil palm biomass has includes the following:available and exists in abundance, appears to be effective technically, and can be integrated into existing processes. Despite these advantages, oil palm biomasses have disadvantages such as low adsorption capacity, increased COD, BOD and TOC. These disadvantages can be overcome by modifying the biomass either chemically or thermally. Such modification creates a charged surface and increases the heavy metal ion binding capacity of the adsorbent. PMID:24984835

  19. Phytoremediation of heavy metal contaminated soil by Jatropha curcas.

    Science.gov (United States)

    Chang, Fang-Chih; Ko, Chun-Han; Tsai, Ming-Jer; Wang, Ya-Nang; Chung, Chin-Yi

    2014-12-01

    This study employed Jatropha curcas (bioenergy crop plant) to assist in the removal of heavy metals from contaminated field soils. Analyses were conducted on the concentrations of the individual metals in the soil and in the plants, and their differences over the growth periods of the plants were determined. The calculation of plant biomass after 2 years yielded the total amount of each metal that was removed from the soil. In terms of the absorption of heavy metal contaminants by the roots and their transfer to aerial plant parts, Cd, Ni, and Zn exhibited the greatest ease of absorption, whereas Cu, Cr, and Pb interacted strongly with the root cells and remained in the roots of the plants. J. curcas showed the best absorption capability for Cd, Cr, Ni, and Zn. This study pioneered the concept of combining both bioremediation and afforestation by J. curcas, demonstrated at a field scale. PMID:25236867

  20. Ecological risk and pollution history of heavy metals in Nansha mangrove, South China.

    Science.gov (United States)

    Wu, Qihang; Tam, Nora F Y; Leung, Jonathan Y S; Zhou, Xizhen; Fu, Jie; Yao, Bo; Huang, Xuexia; Xia, Lihua

    2014-06-01

    Owing to the Industrial Revolution in the late 1970s, heavy metal pollution has been regarded as a serious threat to mangrove ecosystems in the region of the Pearl River Estuary, potentially affecting human health. The present study attempted to characterize the ecological risk of heavy metals (Cd, Cr, Cu, Mn, Ni, Pb and Zn) in Nansha mangrove, South China, by estimating their concentrations in the surface sediment. In addition, the pollution history of heavy metals was examined by determining the concentrations of heavy metals along the depth gradient. The phytoremediation potential of heavy metals by the dominant plants in Nansha mangrove, namely Sonneratia apetala and Cyperus malaccensis, was also studied. Results found that the surface sediment was severely contaminated with heavy metals, probably due to the discharge of industrial sewage into the Pearl River Estuary. Spatial variation of heavy metals was generally unobvious. The ecological risk of heavy metals was very high, largely due to Cd contamination. All heavy metals, except Mn, decreased with depth, indicating that heavy metal pollution has been deteriorating since 1979. Worse still, the dominant plants in Nansha mangrove had limited capability to remove the heavy metals from sediment. Therefore, we propose that immediate actions, such as regulation of discharge standards of industrial sewage, should be taken by the authorities concerned to mitigate the ecological risk posed by heavy metals. PMID:24675443

  1. Heavy Metal Music and Adolescent Suicidal Risk.

    Science.gov (United States)

    Lacourse, Eric; Claes, Michel; Villeneuve, Martine

    2001-01-01

    Studied differentiating characteristics of youth who prefer heavy metal music, worship music, and use music for vicarious release. Data for 275 secondary school students suggest that heavy metal music preference and worshipping is not related to suicidal risk when controlling for other suicide factors. Discusses findings in the context of…

  2. Growth and Heavy Metals Accumulation Potential of Microalgae Grown in Sewage Wastewater and Petrochemical Effluents

    OpenAIRE

    Thirugnanamoorthy, K.; Selvaraju, M.; Ajayan, K. V.

    2011-01-01

    Microalgae exhibit a number of heavy metal uptake process by different metabolism. In this study, the ability of microalgae for removal of heavy metal from wastewater was studied. Growth and biochemical contents of microalgae were determined by spectrophotometer. Heavy metal analysis of wastewater effluents were performed by atomic absorption spectrophotometer before and after treatment at laboratory scale. The growth of Scenedesmus bijuga and Oscillatoria quadripunctulata in sewage wastewate...

  3. Evaluación de la eficiencia de una batería de filtros empacados en zeolita en la remoción de metales pesados presentes en un licor mixto bajo condiciones de laboratorio / Evaluation of efficiency of a filter battery packaging zeolite in the removal of heavy metals in a mixed liquor under laboratory conditions

    Scientific Electronic Library Online (English)

    Diana Rocío, Acevedo Cifuentes; Sandra Milena, Builes Felizzola; Carlos Andrés, Ordóñez Ante; Idalia Jacqueline, López Sánchez.

    2011-01-01

    Full Text Available En este artículo se muestran resultados de investigación obtenidos en la remoción de los metales pesados, plomo, níquel, cromo, cadmio y mercurio, presentes en una solución compuesta por licor mixto proveniente de la planta de tratamiento de aguas residuales de San Fernando y una solución preparada [...] con metales pesados con una concentración conocida, mediante el uso de una batería de filtros empacados en zeolita clinoptilolita. La experimentación se desarrolló bajo condiciones controladas de caudal y pH, a temperatura ambiente. Se encontró que la eficiencia de los filtros bajo las condiciones específicas de diseño es significativamente alta en la remoción de los metales pesados evaluados en la solución acuosa. Se encontró, además, que sin importar el valor de la concentración inicial, se obtuvo una remoción importante en los contaminantes luego de pasar por los filtros con una mayor eficiencia en la remoción del mercurio. Abstract in english This article shows the research results on the removal of five heavy metals (lead, nickel, chromium, cadmium and mercury) present in a liquor made of a mixture of wastewater from San Fernando wastewater treatment plant and a solution prepared with known concentrations of heavy metals, using a series [...] of batery filters packed with zeolita clinoptilolita. The experiments were run under controlled conditions of flow and pH, at room temperature. It was found that the removal efficiency was significantly high under the specified design conditions; also, it was found an important removal of the contaminants after passing through the filters, independently of the initial concentration, with the highest observed removal for mercury.

  4. Evaluación de la eficiencia de una batería de filtros empacados en zeolita en la remoción de metales pesados presentes en un licor mixto bajo condiciones de laboratorio Evaluation of efficiency of a filter battery packaging zeolite in the removal of heavy metals in a mixed liquor under laboratory conditions

    Directory of Open Access Journals (Sweden)

    Diana Rocío Acevedo Cifuentes

    2011-01-01

    Full Text Available En este artículo se muestran resultados de investigación obtenidos en la remoción de los metales pesados, plomo, níquel, cromo, cadmio y mercurio, presentes en una solución compuesta por licor mixto proveniente de la planta de tratamiento de aguas residuales de San Fernando y una solución preparada con metales pesados con una concentración conocida, mediante el uso de una batería de filtros empacados en zeolita clinoptilolita. La experimentación se desarrolló bajo condiciones controladas de caudal y pH, a temperatura ambiente. Se encontró que la eficiencia de los filtros bajo las condiciones específicas de diseño es significativamente alta en la remoción de los metales pesados evaluados en la solución acuosa. Se encontró, además, que sin importar el valor de la concentración inicial, se obtuvo una remoción importante en los contaminantes luego de pasar por los filtros con una mayor eficiencia en la remoción del mercurio.This article shows the research results on the removal of five heavy metals (lead, nickel, chromium, cadmium and mercury present in a liquor made of a mixture of wastewater from San Fernando wastewater treatment plant and a solution prepared with known concentrations of heavy metals, using a series of batery filters packed with zeolita clinoptilolita. The experiments were run under controlled conditions of flow and pH, at room temperature. It was found that the removal efficiency was significantly high under the specified design conditions; also, it was found an important removal of the contaminants after passing through the filters, independently of the initial concentration, with the highest observed removal for mercury.

  5. Plant transporters involved in heavy metal homeostasis

    OpenAIRE

    Dorina Podar

    2010-01-01

    Transition metal ions (predominately manganese, iron, cobalt, nickel, copper and zinc) havean array of catalytic and regulatory roles in the growth and development of all living organisms.However, an excess of these metal ions can also be toxic to any life form and therefore every cell andwhole organism needs to maintain the concentration of these essential nutrient metals within a narrowrange: a process known as metal homeostasis. Heavy metal ions are taken up into cells by selectivetranspor...

  6. Method for removing metal ions from solution with titanate sorbents

    Science.gov (United States)

    Lundquist, Susan H. (White Bear Township, MN); White, Lloyd R. (Minneapolis, MN)

    1999-01-01

    A method for removing metal ions from solution comprises the steps of providing titanate particles by spray-drying a solution or slurry comprising sorbent titanates having a particle size up to 20 micrometers, optionally in the presence of polymer free of cellulose functionality as binder, said sorbent being active towards heavy metals from Periodic Table (CAS version) Groups IA, IIA, IB, IIB, IIIB, and VIII, to provide monodisperse, substantially spherical particles in a yield of at least 70 percent of theoretical yield and having a particle size distribution in the range of 1 to 500 micrometers. The particles can be used free flowing in columns or beds, or entrapped in a nonwoven, fibrous web or matrix or a cast porous membrane, to selectively remove metal ions from aqueous or organic liquid.

  7. Heavy metals in municipal solid waste deposits

    Energy Technology Data Exchange (ETDEWEB)

    Flyhammar, P.

    1997-12-01

    Extensive use of heavy metals in modern society influences routes followed by fluxes on the surface of the Earth. The changed flow paths may be harmful for the balance of biological systems at different levels, micro-organisms, human beings and whole ecosystems, since the toxicity of heavy metals is determined by their concentrations and chemical forms. Despite the low mobility of heavy metals (Zn, Cu, Pb, Cr, Ni and Cd) in municipal landfills, it was found that extensive transformations of the binding forms of heavy metal take place within the waste mass during the degradation of the waste. These changes appear to be closely related to the development of early diagenetic solid phases, i.e. new secondary solid phases formed in the waste. The heavy metals often constitute a minor part of these phases and the bindings include several forms such as adsorption, complexation, coprecipitation, precipitation, etc. It was also found that the associations between heavy metals and solid phases are dominated by several binding forms to one specific substrate rather than bindings to various solid phases. The mobility of iron and manganese seems to increase during the processes involved in waste degradation due to the solution of oxide/hydroxide phases, while the heavy metals appear to become less mobile due to their binding to organic compounds and sulphides. However, one exception in this case may be nickel. Another aspect of the transformation of heavy metals is the accumulation of pools of heavy metals which can become susceptible to environmental changes, such as oxidation or acidification. However, the risk of increased mobilization caused by lower pH values seem to be limited since municipal solid waste has a large buffer capacity. 66 refs, 9 figs, 3 tabs 66 refs, 9 figs, 3 tabs

  8. Determination of heavy metals in sludge

    International Nuclear Information System (INIS)

    The determination of heavy metals in sludge has been investigated. The sludge was separated from waste water sewage by precipitation. The heavy metals analysis has been done using neutron activation (NAA) and x-ray fluorescence. The existence of some metals (Cu, Fe, Ca, K, and Ti) is very important for plants. Otherwise, Pb and Cr had polluted the environment. The results are compared with sheep dung, rubbish and cow dung that are used as natural fertilizer. It is found that the sludge has a low concentration of heavy metals than other. Tow standard samples derived from IAEA have been analyzed with our samples. It is found that our sludge contains some concentration of heavy metals less than the standard. It is found that the increase of Cu and Zn concentration due to uses of pesticides. (author)

  9. Experimental research on heavy metal wastewater treatment with dipropyl dithiophosphate

    International Nuclear Information System (INIS)

    In view of the existing technical problems about treatment of heavy metal pollution, a new organic heavy metal chelator-dipropyl dithiophosphate has been developed. This paper focuses on the mechanism about the laboratory synthesis of dipropyl dithiophosphate and chelate heavy metal, discusses the effects of pH value, added quantity of chelator, reactive time and coexistence of several heavy metal ions on the treatment effectiveness, and compares the stability of chelate complex with conventional neutral precipitation method. The results of the experiment show that, within the scope of pH 3-6, for the wastewater with the concentration of lead, cadmium, copper and mercury being 200 mg/L, dipropyl dithiophosphate enjoys a removal rate about these elements up to over 99.9%, and the concentrations of the lead, cadmium, copper and mercury in the wastewater after treatment are less than 1, 0.1, 0.5 and 0.05 mg/L, respectively, which meet the limit value of concentration stipulated in the Integrated Wastewater Discharge Standard (GB8978-1996). And the treatment effectiveness are not affected by pH value and coexistent heavy metal ions, which makes up the deficiency that neutral precipitation must be used under the condition of high alkalinity. The optimum quantity of dipropyl dithiophosphate chelator added is 1.2 times as much as stoichiometric amount and the optimum reactive time is 20 min for lead, cadmium and copper, and 30 min for mercury. Within the scope of pH 3-9, eacr mercury. Within the scope of pH 3-9, each heavy metal ion release of chelate complex will decrease along with increased pH value. But under any pH conditions, the release of heavy metal ions in hydroxide is far higher than that in chelate complex, therefore reducing the risk of polluting the environment again

  10. Biosorption and Metal Removal Through Living Cells.

    Czech Academy of Sciences Publication Activity Database

    Kotrba, P.; Macková, M.; Fišer, J.; Macek, Tomáš

    Dordrecht : Springer, 2011 - (Kotrba, P.; Macková, M.; Macek, T.), s. 197-233 ISBN 978-94-007-0442-8 R&D Projects: GA MŠk 1M06030 Grant ostatní: GA MŠk(CZ) 1M0520 Institutional research plan: CEZ:AV0Z40550506 Keywords : heavy metal * bioprecipitation * biotransformation * activated sludge * phytoremediation Subject RIV: EI - Biotechnology ; Bionics

  11. Development of a treatment process for the removal of heavy metals from raw water for drinking water supply using chelating ion exchange resins. Subproject 1. Final report; Entwicklung der Verfahrenstechnik zur Eliminierung von Schwermetallen aus Rohwaessern zur Trinkwassergewinnung mit chelatbildenden Kationenaustauscherharzen zur technischen Reife. Teilprojekt 1. Abschlussbericht

    Energy Technology Data Exchange (ETDEWEB)

    Overath, H.; Stetter, D.; Doerdelmann, O.

    2002-07-01

    Chelating cation exchange resins with iminodiacetic acid group (Lewatit TP 207 and Amberlite IRC 748) were tested for the removal of heavy metals in a drinking water treatment plant. The pilot scale filtration experiments were conducted by varying the operating conditions, such as flow rate and feed concentrations. Heavy metal concentrations (nickel, lead, cadmium, zinc) in the feed were adjusted between 20 and 200 {mu}g/L. Different methods for regeneration and conditioning of the resins were developed and investigated. Finally the ion exchange resins were tested according to German health regulations for ion exchangers in drinking water treatment. (orig.)

  12. Heavy metal extraction from PCB wastewater treatment sludge by sulfuric acid

    International Nuclear Information System (INIS)

    Heavy metals contaminated wastewater sludge is classified as hazardous solid waste and needs to be properly treated to prevent releasing heavy metals to the environment. In this study, the wastewater treatment sludge from a printed circuit board manufacturing plant was treated in a batch reactor by sulfuric acid to remove the contained heavy metals. The effects of sulfuric acid concentration and solid to liquid ratio on the heavy metal removal efficiencies were investigated. The experimental results showed that the total and individual heavy metal removal efficiencies increased with increasing sulfuric acid concentration, but decreased with increasing solid to liquid ratio. A mathematical model was developed to predict the residual sludge weights at varying sulfuric concentrations and solid to liquid ratios. The trivalent heavy metal ions, iron and chromium were more difficult to be removed than the divalent ions, copper, zinc, nickel, and cadmium. For 5 g/L solid to liquid ratio, more than 99.9% of heavy metals can be removed from the sludge by treating with 0.5 M sulfuric acid in 2 h.

  13. Bioaccumulation of heavy metals in fauna from wet detention ponds for stormwater runoff

    DEFF Research Database (Denmark)

    Stephansen, Diana; Nielsen, AsbjØrn Haaning

    2012-01-01

    Stormwater detention ponds remove pollutants e.g. heavy metals and nutrients from stormwater runoff. These pollutants accumulate in the pond sediment and thereby become available for bioaccumulation in fauna living in the ponds. In this study the bioaccumulation was investigated by fauna samples from 5 wet detention ponds for analyses of heavy metal contents. Five rural shallow lakes were included in the study to survey the natural occurrence of heavy metals in water-dwelling fauna. Heavy metal concentrations in water-dwelling fauna were generally found higher in wet detention ponds compared to rural shallow lakes.

  14. Heavy Metal Poisoning and Cardiovascular Disease

    OpenAIRE

    Ferns, Gordon A.; Alissa, Eman M.

    2011-01-01

    Cardiovascular disease (CVD) is an increasing world health problem. Traditional risk factors fail to account for all deaths from CVD. It is mainly the environmental, dietary and lifestyle behavioral factors that are the control keys in the progress of this disease. The potential association between chronic heavy metal exposure, like arsenic, lead, cadmium, mercury, and CVD has been less well defined. The mechanism through which heavy metals act to increase cardiovascular risk factors may act ...

  15. Heavy Metal Compositions in Gaborone Industrial Effluent

    OpenAIRE

    Nkegbe, E.; Koorapetse, I.

    2005-01-01

    This study assessed the compositions of five heavy metals in Gaborone Industrial effluent from five industrial premises; a brewery, pharmaceutical company, paints and chemical industry (commercial photography studios and a soap manufacturing company).The heavy metals monitored were Lead (Pb), Cadmium (Cd), Iron (Fe), Nickel (Ni) and Zinc (Zn). All the industries discharged during the study period a certain amount of Nickel although in very minute concentrations in relation to the Gaborone Cit...

  16. Heavy metals anthropogenic pollutants in Austria

    International Nuclear Information System (INIS)

    Several heavy metals from anthropogenic sources are emitted in the atmosphere damaging the air quality and the human health, besides they accumulate on the soil and lately are transmitted into the human food chain. Therefore at international level there is a concern to reduce them. Austrian heavy metals emissions (cadmium, mercury and lead) during 1990-2002 are given including an analysis of causes and sources. Lead is the main pollutant and the main sector responsible is the industry. 5 figs. (nevyjel)

  17. Quantification of uncertainty in modelled partitioning and removal of heavy metals (Cu, Zn) in a stormwater retention pond and a biofilter

    DEFF Research Database (Denmark)

    Vezzaro, Luca; Eriksson, Eva

    2012-01-01

    Strategies for reduction of micropollutant (MP) discharges from stormwater drainage systems require accurate estimation of the potential MP removal in stormwater treatment systems. However, the high uncertainty commonly affecting stormwater runoff quality modelling also influences stormwater treatment models. This study identified the major sources of uncertainty when estimating the removal of copper and zinc in a retention pond and a biofilter by using a conceptual dynamic model which estimates MP partitioning between the dissolved and particulate phases as well as environmental fate based on substance-inherent properties. The two systems differ in their main removal processes (settling and filtration/sorption, respectively) and in the time resolution of the available measurements (composite samples and pollutographs). The most sensitive model factors, identified by using Global Sensitivity Analysis (GSA), were related to the physical characteristics of the simulated systems (flow and water losses) and to the fate processes related to Total Suspended Solids (TSS). The model prediction bounds were estimated by using the Generalized Likelihood Uncertainty Estimation (GLUE) technique. Composite samples and pollutographs produced similar prediction bounds for the pond and the biofilter, suggesting a limited influence of the temporal resolution of samples on the model prediction bounds. GLUE highlighted model structural uncertainty when modelling the biofilter, due to disregard of plant-driven evapotranspiration, underestimation of sorption and neglect of oversaturation with respect to minerals/salts. The results of this study however illustrate the potential for the application of conceptual dynamic fate models base on substanceinherent properties, in combination with available datasets and statistical methods, to estimate the MP removal in different stormwater treatment systems and compare with environmental quality standards targeting the dissolved MP fraction.

  18. Heavy metal uptake by fast growing willow species

    International Nuclear Information System (INIS)

    Bioremediation is a general term used to describe the use of biological systems for renovating contaminated soil. The technique can be divided into two categories: the use of microbiological processes, and the use of vegetation, to immobilize, transform or remove contaminants from the soil. It has been suggested that the rapid biomass accumulation of Salix species grown intensively as in short-rotation forestry systems, may be used to remove heavy metal contamination from soil. Many potentially toxic heavy metals are also essential plant nutrients, hence the mechanisms exist for the absorption by plants of these and similar ions and their translocation through the plant structure. A limited number of deciduous species have been found to translocate metals to the leaves immediately before senescence, however, the principal site of metal accumulation in higher plants is the roots. A small number of species endemic to metalliferous soils are capable of accumulating unusually high concentrations of potentially toxic metals in their above ground biomass. These have been termed hyperaccumulators. This paper reports on the level and location of heavy metal accumulation by four varieties of Salix growing in soils with elevated levels of heavy metals. A trial was established in 1991 on land with a long history of sewage sludge application. Further applications have been made each year and the first harvest taken in January 1994. Significant differences have been found between icant differences have been found between the take-up of individual metals, between willow varieties and across differing sludge applications. 7 refs, 1 fig, 6 tabs

  19. The removal of actinide metals from solution

    International Nuclear Information System (INIS)

    A process is specified for removing actinide metals (e.g. uranium) from solutions. The solution is contacted with a substrate comprising the product obtained by reacting an inorganic solid containing surface hydroxyl groups (e.g. silica gel) with a compound containing a silane grouping, a nitrogen-containing group (e.g. an amine) and other specified radicals. After treatment, the actinide metal is recovered from the substrate. (U.K.)

  20. Aplicação da zeólita natural escolecita na remoção de metais pesados de efluentes industriais: competição entre os cátions e processo de dessorção / Removal of heavy metals from industrial effluents by scolecite: competition and desorption processes

    Scientific Electronic Library Online (English)

    S. M., Dal Bosco; R. S., Jimenez; W. A., Carvalho.

    Full Text Available SciELO Brazil | Language: Portuguese Abstract in portuguese Efluentes aquosos industriais são a principal causa de contaminação das águas com metais pesados. Diante de uma legislação cada vez mais rígida para o descarte desses metais, o desenvolvimento de procedimentos eficientes e de baixo custo para o tratamento de efluentes contendo metais pesados torna-s [...] e de grande interesse. Um estudo sobre a capacidade de retenção de metais pesados pela zeólita natural escolecita foi realizado, de modo a se avaliar a viabilidade desta aplicação. Os cátions utilizados foram Mn(II), Cd(II), Ni(II) e Cr(III). Nesta etapa do trabalho, foi avaliado o comportamento da zeólita na adsorção seletiva de cátions presentes nos pares Cd/Mn, Cr/Ni, Cr/Cd e Ni/Mn, bem como a possibilidade de dessorção dos cátions metálicos adsorvidos em sua estrutura. A escolecita apresentou uma seletividade que pode ser relacionada, na maioria dos casos, à valência e ao raio iônico das espécies hidratadas. Os cátions Cr(III) e Ni(II) foram fortemente adsorvidos, não podendo ser substancialmente removidos por troca com cátions sódio ou cálcio. Dos cátions testados, apenas o Cd(II) apresentou comportamento de adsorção e de dessorção atípicos, demonstrando uma elevada labilidade no processo de troca iônica. Abstract in english During recent years stringent regulations of wastewater discharge into aquatic bodies have been imposed. Removal of contaminants, as heavy metals, is one of the fundamental goal in waste treatment. In order to achieve efficient cost effective technology, natural materials as zeolites are generally b [...] een applied is wastewater treatment to remove pollutants. We investigated the ability of scolecite, a natural zeolite from the top of the basaltic flows of Serra Geral Formation in Paraná Basin, Brazil, to retain chromium(III), nickel(II), cadmium(II) and manganese(II) in synthetic aqueous effluents. We evaluated the ion selectivity by batch experiments in a binary combination solution. The scolecite showed high efficiency retaining the tested metals, even when they are in competition. The zeolite preference for one cation could be related to cations with high charge density (e.g., Cr(III)) and lower hydration energies (e.g., Cd(II)). The unusual Cd(II) exchange behavior observed can be related to its lability. Cr(III) and Ni(II) were efficiently adsorbed, so they could not be substantially removed from scolecite structure by sodium or calcium cations.

  1. Plant transporters involved in heavy metal homeostasis

    Directory of Open Access Journals (Sweden)

    Dorina Podar

    2010-12-01

    Full Text Available Transition metal ions (predominately manganese, iron, cobalt, nickel, copper and zinc havean array of catalytic and regulatory roles in the growth and development of all living organisms.However, an excess of these metal ions can also be toxic to any life form and therefore every cell andwhole organism needs to maintain the concentration of these essential nutrient metals within a narrowrange: a process known as metal homeostasis. Heavy metal ions are taken up into cells by selectivetransporters and as they cannot be degraded, the “desired” levels of metal ions are achieved by anumber of strategies that involve: chelation, sequestration and export out of the cell. Cation DiffusionFacilitators (CDF is a large family of transporters involved in maintaining the cytosolic metalconcentration. They transport different heavy metal divalent ions, but exhibit main affinity for zinc, ironand manganese. Metal Tolerance Proteins (MTPs are a subfamily of the Cation Diffusion Facilitator (CDFfamily found in plants. There has been much interest in these heavy metal transporters in order toprovide an insight into plant metal homeostasis, which has significant implications in human health andphytoremediation. Although data regarding the CDFs/MTPs mechanism is gathering there is still littleinformation with respect to metal selectivity determinants.

  2. EXTRACTION, RECOVERY, AND BIOSTABILITY OF EDTA FOR REMEDIATION OF HEAVY METAL-CONTAMINATED SOIL. (R825549C052)

    Science.gov (United States)

    Chelation removal of heavy metals from contaminated soil is seen as a viable remediation technique. A useful chelating agent should be strong, reusable, and biostable during metal extraction and recovery operations. This work tested the extraction, recovery, and biostability o...

  3. Surfactant biocatalyst for remediation of recalcitrant organics and heavy metals

    Science.gov (United States)

    Brigmon, Robin L. (North Augusta, SC); Story, Sandra (Greenville, SC); Altman, Denis J. (Evans, GA); Berry, Christopher J. (Aiken, SC)

    2011-05-03

    Novel strains of isolated and purified bacteria have been identified which have the ability to degrade petroleum hydrocarbons including a variety of PAHs. Several isolates also exhibit the ability to produce a biosurfactant. The combination of the biosurfactant-producing ability along with the ability to degrade PAHs enhances the efficiency with which PAHs may be degraded. Additionally, the biosurfactant also provides an additional ability to bind heavy metal ions for removal from a soil or aquatic environment.

  4. Regenerative process for removal of mercury and other heavy metals from gases containing H.sub.2 and/or CO

    Science.gov (United States)

    Jadhav, Raja A. (Naperville, IL)

    2009-07-07

    A method for removal of mercury from a gaseous stream containing the mercury, hydrogen and/or CO, and hydrogen sulfide and/or carbonyl sulfide in which a dispersed Cu-containing sorbent is contacted with the gaseous stream at a temperature in the range of about 25.degree. C. to about 300.degree. C. until the sorbent is spent. The spent sorbent is contacted with a desorbing gaseous stream at a temperature equal to or higher than the temperature at which the mercury adsorption is carried out, producing a regenerated sorbent and an exhaust gas comprising released mercury. The released mercury in the exhaust gas is captured using a high-capacity sorbent, such as sulfur-impregnated activated carbon, at a temperature less than about 100.degree. C. The regenerated sorbent may then be used to capture additional mercury from the mercury-containing gaseous stream.

  5. Remoção de metais pesados de efluentes aquosos pela zeólita natural escolecita - influência da temperatura e do pH na adsorção em sistemas monoelementares / Heavy metals removal from wastewater by the natural zeolite scolecite - temperature and pH influence in single-metal solutions

    Scientific Electronic Library Online (English)

    Ricardo Sarti, Jimenez; Sandra Maria, Dal Bosco; Wagner Alves, Carvalho.

    2004-10-01

    Full Text Available SciELO Brazil | Language: Portuguese Abstract in portuguese [...] Abstract in english Cation exchange capabilities of a Brazilian natural zeolite, identified as scolecite, were evaluated for application in wastewater control. We investigated the process of sorption of chromium(III), nickel(II), cadmium(II) and manganese(II) in synthetic aqueous effluents, including adsorption isother [...] ms of single-metal solutions. The natural zeolite showed the ability to take up the tested heavy metals in the order Cr(III) > Cd(II) > Ni(II) > Mn(II), and this could be related to the valence and the hydration radius of the metal cations. The influence of temperature (25, 40 and 60 ºC) and initial pH value (from 4 to 6) was also evaluated. It was found that the adsorption increased substantially when the temperature was raised to 60 ºC and that maximum adsorption capacity was observed at pH 6. These results demonstrate that scolecite can be used for removal of heavy metals from aqueous effluents, under optimized conditions.

  6. Remoção de metais pesados de efluentes aquosos pela zeólita natural escolecita - influência da temperatura e do pH na adsorção em sistemas monoelementares Heavy metals removal from wastewater by the natural zeolite scolecite - temperature and pH influence in single-metal solutions

    Directory of Open Access Journals (Sweden)

    Ricardo Sarti Jimenez

    2004-10-01

    Full Text Available Cation exchange capabilities of a Brazilian natural zeolite, identified as scolecite, were evaluated for application in wastewater control. We investigated the process of sorption of chromium(III, nickel(II, cadmium(II and manganese(II in synthetic aqueous effluents, including adsorption isotherms of single-metal solutions. The natural zeolite showed the ability to take up the tested heavy metals in the order Cr(III > Cd(II > Ni(II > Mn(II, and this could be related to the valence and the hydration radius of the metal cations. The influence of temperature (25, 40 and 60 ºC and initial pH value (from 4 to 6 was also evaluated. It was found that the adsorption increased substantially when the temperature was raised to 60 ºC and that maximum adsorption capacity was observed at pH 6. These results demonstrate that scolecite can be used for removal of heavy metals from aqueous effluents, under optimized conditions.

  7. Dendroremediation of heavy metal polluted soils.

    Science.gov (United States)

    González-Oreja, J A; Rozas, M A; Alkorta, I; Garbisu, C

    2008-01-01

    Heavy metals are among the most common and harmful pollutants reaching the soil ecosystem all over the world. Phytoextraction is an effective, non-intrusive, inexpensive, aesthetically pleasing, socially accepted, highly promising phytotechnology for the remediation of soils polluted with heavy metals. To overcome the so-called 'Achilles' heel' of phytoextraction, namely, the long time needed for effective remediation, this phytotechnology should be combined with other profit-making activities such as forestry or bioenergy production. Dendroremediation, or the use of trees to clean up polluted soil and water, appears of great potential for metal phytoextraction, especially when using fast-growing tree species, for example, willows (Salix sp. pl.) and poplars (Populus sp. pl.). Most important, the ecologic and environmental risks of dispersing heavy metals into the ecosystems by dendroremediation strategies should be minimized by selecting the right tree species, properly managing/disposing the polluted plant material, or a combination of both options. PMID:19119687

  8. Removal of gadolinium nitrate from heavy water

    Energy Technology Data Exchange (ETDEWEB)

    Wilde, E.W.

    2000-03-22

    Work was conducted to develop a cost-effective process to purify 181 55-gallon drums containing spent heavy water moderator (D2O) contaminated with high concentrations of gadolinium nitrate, a chemical used as a neutron poison during former nuclear reactor operations at the Savannah River Site (SRS). These drums also contain low level radioactive contamination, including tritium, which complicates treatment options. Presently, the drums of degraded moderator are being stored on site. It was suggested that a process utilizing biological mechanisms could potentially lower the total cost of heavy water purification by allowing the use of smaller equipment with less product loss and a reduction in the quantity of secondary waste materials produced by the current baseline process (ion exchange).

  9. Biomass-derived materials in the remediation of heavy-metal contaminated water: removal of Cadmium(II) and copper(II) from aqueous solutions.

    Science.gov (United States)

    Tiwari, Diwakar; Lee, Seung Mok

    2011-09-01

    Manganese-coated activated carbon (MCAC) and activated carbon were used in batch experiments for the removal of cadmium(II) and copper(II). Results showed that uptake of Cd(II) and Cu(II) was unaffected by increases in pH (3.0 to 8.5) or concentration (1 to 20 mg/L). Increased ionic strength (from 0.001 to 1 M NaNO3), however, significantly affected the uptake of Cd(II); adsorption of Cu(II) was not affected. Freundlich adsorption isotherm results indicated that MCAC possessed higher sorption capacity than activated carbon. Second-order rate constants were found to be 0.0386 for activated carbon and 0.0633 g/mg x min for MCAC for Cd(II) and 0.0774 for AC and 0.1223 g/mg x min for MCAC for Cu(II). Column experiments showed that maximum sorption capacity of MCAC was 39.48 mg/g for Cu(II) and 12.21 mg/g for Cd(II). PMID:22073735

  10. Competitive adsorption of dyes and heavy metals on zeolitic structures.

    Science.gov (United States)

    Hernández-Montoya, V; Pérez-Cruz, M A; Mendoza-Castillo, D I; Moreno-Virgen, M R; Bonilla-Petriciolet, A

    2013-02-15

    The adsorption of Acid blue 25, basic blue 9, basic violet 3, Pb(2+), Ni(2+), Zn(2+) and Cd(2+) ions has been studied in single and dye-metal binary solutions using two mineral materials: Clinoptilolite (CL) and ER (Erionite). These zeolites were characterized by FT-IR spectroscopy; potentiometric titration and nitrogen adsorption isotherms at 77 K to obtain their textural parameters. Results indicated that ER has an acidic character and a high specific surface (401 m(2) g(-1)) in contrast with the zeolite CL (21 m(2) g(-1)). Surprisingly, the removal of dyes was very similar for the two zeolites and they showed a considerable selectivity by the basic dyes in comparison with the acid dyes. In the case of heavy metals, ER was more effective in the adsorption process showing a selectivity of: Pb(2+) > Ni(2+) > Zn(2+) > Cd(2+). In the multicomponent adsorption experiments an antagonistic effect was observed in the removal of basic dyes and heavy metals. Particularly, the adsorbed amount of basic violet 3 decreased more significantly when the heavy metals are presents in contrast with the basic blue 9. PMID:23321372

  11. Heavy metal contaminants in yerberia shop products.

    Science.gov (United States)

    Levine, Michael; Mihalic, Jason; Ruha, Anne-Michelle; French, Robert N E; Brooks, Daniel E

    2013-03-01

    Complementary and alternative medications, including the use of herbal medications, have become quite popular in the USA. Yerberias are found throughout the southwest and specialize in selling Hispanic herbal products. The products sold in these stores are not regulated by any governmental agency. Previous reports have found Ayurvedic medications contain high levels of lead, mercury, and arsenic. The primary purpose of this study is to examine the prevalence of heavy metal contaminants sold at Yerberia stores in the southwest. Yerberias in the Phoenix, Arizona area were identified via search of an on-line search engine using the words "Yerberia Phoenix." Every second store was selected, and products were purchased using a standard script. The products were subsequently analyzed for mercury, lead, and arsenic. The main outcome is the prevalence of heavy metal content in over-the-counter "cold" medications purchased at a Yerberia. Twenty-two samples were purchased. One product contained pure camphor (2-camphone) and was subsequently not further analyzed. Of the 21 samples analyzed, lead was found in 4/21 (19.4 %). Arsenic and mercury were in 1/21 (4.8 %) each. Because two samples contained two heavy metals, the total prevalence of heavy metals was 4/21 (19.4). Heavy metal contaminants are commonly encountered in over-the-counter herbal "cold" medications purchased at Yerberias in the southwest. PMID:22562238

  12. Use of cestodes as indicator of heavy-metal pollution.

    Science.gov (United States)

    Yen Nhi, Tran Thi; Mohd Shazili, Noor Azhar; Shaharom-Harrison, Faizah

    2013-01-01

    Thirty snakehead fish, Channa micropeltes (Cuvier, 1831) were collected at Lake Kenyir, Malaysia. Muscle, liver, intestine and kidney tissues were removed from each fish and the intestine was opened to reveal cestodes. In order to assess the concentration of heavy metal in the environment, samples of water in the surface layer and sediment were also collected. Tissues were digested and the concentrations of manganese (Mn), zinc (Zn), copper (Cu), cadmium (Cd) and lead (Pb) were analysed by using inductively-coupled plasma mass-spectrometry (ICP-MS) equipment. The results demonstrated that the cestode Senga parva (Fernando and Furtado, 1964) from fish hosts accumulated some heavy metals to a greater extent than the water and some fish tissues, but less than the sediment. In three (Pb, Zn and Mn) of the five elements measured, cestodes accumulated the highest metal concentrations, and in remaining two (Cu and Cd), the second highest metal accumulation was recorded in the cestodes when compared to host tissues. Therefore, the present study indicated that Senga parva accumulated metals and might have potential as a bioindicator of heavy-metal pollution. PMID:23146722

  13. Natural removal of added N-nutrients, reactive phosphorus, crude oil, and heavy metals from the water phase in a simulated water/sediment system

    Energy Technology Data Exchange (ETDEWEB)

    Lam-Leung, S.Y.; Cheung, M.T. [Hong Kong Baptist Univ., Kowloon (Hong Kong); He, Y.Q. [South China Sea Institute of Oceanology, Guangzhou (China)] [and others

    1996-08-01

    Water/sediment simulation systems were constructed by using an aquarium (0.45 x 0.29 x 0.35 m{sup 3}), filled with suitable amounts of water and sediment collected from three selected locations: Lan Hau Shan (LHS), Tai Hu (TH), and Loong Yu Tao (LYT) of the Zhujiang (Pearl River) Estuary of China in November 1992 at low-tide period. The salinities of the water samples collected form LHS, TH, LYT were found to be 0.2, 4.6, 16.2 g L{sup -1}, respectively. Known amounts of ammonium, nitrate, nitrite, reactive phosphorous, crude oil, arsenate(III), cadmium (II), copper(II), and zinc(II) were added as pollutants into each of the water/sediment simulation systems. The rates of the natural removal of each added pollutant in all water/sediment simulation systems were studied by monitoring their concentrations at various intrevals in the investigation period. Except for Cr(III) and reactive phosphorous in the water/sediment systems of the LHS, TH, and LYT sites, and nitrate in the TH and LYT sites, the concentrations of the added pollutants in the water phase of the studied systems under a flow-condition simulation were reduced to 8% or less of the corresponding added amount on or before the 12th day by natural processes. The rate of self-purification and the estimated assimulative capacity of each added pollutant in all water/sediment simulation systems is discussed. 30 refs., 11 figs., 4 tabs.

  14. Recovery of heavy metals from contaminated groundwaters using immobilized algae

    International Nuclear Information System (INIS)

    A biosorption process has been developed for removing toxic metal ions from water and is based upon the natural, strong affinity of biological materials, such as the cell walls of plants and microorganisms, for heavy metal ions. Non-living algae have been immobilized in a polymer to produce a open-quotes biologicalclose quotes ion exchange resin, AlgaSORB reg-sign. The material is selective for heavy metal ions (over calcium and magnesium), functions well with solutions with high dissolved solid content and is capable of removing metal ions to ppB levels. The process has been demonstrated to be effective for mercury and uranium removal from contaminated groundwaters from US Department of Energy sites at Hanford, Oak Ridge and Savannah River. Groundwaters from Hanford, initially with uranium at concentrations of 160 ug/L, were treated by passage through columns containing AlgaSORB reg-sign, and effluents showed uranium concentrations to be below 10 ug/L levels. Likewise, mercury-contaminated groundwaters from Oak Ridge and Savannah River, initially with mercury concentrations of 30 ug/L and 10 ug/L, respectively were treated so that effluents contained mercury at concentrations less than 2.0 ug/L

  15. Heavy metals and woody plants - biotechnologies for phytoremediation

    Directory of Open Access Journals (Sweden)

    Capuana M

    2011-01-01

    Full Text Available Soil contamination by heavy metals is among the most serious danger for the environment, and new methods for its containment and removal are claimed, in particular for agricultural soils. Phytoremediation is an emerging, potentially effective technology applicable to restoration of contaminated soils and waters. Besides hyperaccumulator herbaceous plants, several woody species are now considered of interest to this aim. Many woody plants are fast growing, have deep roots, produce abundant biomass, are easy to harvest, and several species revealed some capacity to tolerate and accumulate heavy metals. Biotechnologies are now available for investigating this potential and enlarge the possibilities of exploitation of trees for remediation. The use of in vitro cultures, the role of bacteria and mychorrhizas, the powerful tool of genetic engineering, are some of the aspects focused in this paper that open prospects of global relevance for a better understanding of the processes related to the uptake of heavy metals by woody plants. In recent years significant progress has been made in identifying native plants and developing genetically modified tree plants for the remediation of heavy-metal polluted environment. Despite the intensive research developed in the last years, few field trials demonstrated the feasibility of the approach described, therefore much efforts should be addressed to this goal.

  16. Community Heavy Metal Exposure, San Francisco, California

    Science.gov (United States)

    Chavez, A.; Devine, M.; Ho, T.; Zapata, I.; Bissell, M.; Neiss, J.

    2008-12-01

    Heavy metals are natural elements that generally occur in minute concentrations in the earth's crust. While some of these elements, in small quantities, are vital to life, most are harmful in larger doses. Various industrial and agricultural processes can result in dangerously high concentrations of heavy metals in our environment. Consequently, humans can be exposed to unsafe levels of these elements via the air we breathe, the water and food we consume, and the many products we use. During a two week study we collected numerous samples of sediments, water, food, and household items from around the San Francisco Bay Area that represent industrial, agricultural, and urban/residential settings. We analyzed these samples for Mercury (Hg), Lead (Pb), and Arsenic (As). Our goal was to examine the extent of our exposure to heavy metals in our daily lives. We discovered that many of the common foods and materials in our lives have become contaminated with unhealthy concentrations of these metals. Of our food samples, many exceeded the EPA's Maximum Contaminant Levels (MCL) set for each metal. Meats (fish, chicken, and beef) had higher amounts of each metal than did non-meat items. Heavy metals were also prevalent in varying concentrations in the environment. While many of our samples exceeded the EPA's Sediment Screening Level (SSL) for As, only two other samples surpassed the SSL set for Pb, and zero of our samples exceeded the SSL for Hg. Because of the serious health effects that can result from over-exposure to heavy metals, the information obtained in this study should be used to influence our future dietary and recreational habits.

  17. Chitosan-based biosorbents: modification and application for biosorption of heavy metals and radionuclides.

    Science.gov (United States)

    Wang, Jianlong; Chen, Can

    2014-05-01

    Heavy metal pollution is a serious environmental problem in the world, especially in developing countries. Among different treatment technologies, biosorption seems a promising alternative method. Chitosan-based biosorbents are potential and effective for heavy metal removal from aqueous solution. The preparation and characterization of the natural polymer chitosan, modified chitosan and chitosan composites, and their application for the removal or recovery of toxic heavy metals, precious metals and radionuclides from wastewater were introduced. Chitosan structures and their properties, chitosan modifications (physical conditioning and chemical modification), blends and composites as well as the metal sorption by chitosan-based biosorbents were briefly presented. The metal sorption capacities, influence of intrinsic nature of metal ions, pH and contact time, desorbing agents, isotherm and kinetics models, biosorption mechanisms were discussed. PMID:24461334

  18. Removal of actinide metals from solution

    International Nuclear Information System (INIS)

    Uranium or other actinide metals may be removed from solution by contacting the solution with a substrate comprising the product obtained by reacting an inorganic solid containing surface hydroxyl groups (silica, silica gel, alumina, titania, zirconia, glass, sepiolite, or zeolite) with a complex silicone compound. The actinide metal may be in an aqueous or organic solution. The solution and substrate are contacted at temperatures between 0deg and 200deg, at atmospheric or higher pressures. When the substrate loses its activity it may be disposed of, or the actinide may be recovered

  19. Heavy metals in water, sediments and submerged macrophytes in ponds around the Dianchi Lake, China.

    Science.gov (United States)

    Wang, Zhixiu; Yao, Lu; Liu, Guihua; Liu, Wenzhi

    2014-09-01

    Through retaining runoff and pollutants such as heavy metals from surrounding landscapes, ponds around a lake play an important role in mitigating the impacts of human activities on lake ecosystems. In order to determine the potential for heavy metal accumulation of submerged macrophytes, we investigated the concentrations of 10 heavy metals (i.e., As, Cd, Co, Cr, Cu, Fe, Mn, Ni, Pb, and Zn) in water, sediments, and submerged macrophytes collected from 37 ponds around the Dianchi Lake in China. Our results showed that both water and sediments of these ponds were polluted by Pb. Water and sediments heavy metal concentrations in ponds received urban and agricultural runoff were not significantly higher than those in ponds received forest runoff. This result indicates that a large portion of heavy metals in these ponds may originate from atmospheric deposition and weathering of background soils. Positive relationships were found among heavy metal concentrations in submerged macrophytes, probably due to the coaccumulation of heavy metals. For most heavy metals, no significant relationships were found between submerged macrophytes and their water and sediment environments. The maximum concentrations of Cr, Fe and Ni in Ceratophyllum demersum were 4242, 16,429 and 2662mgkg(-1), respectively. The result suggests that C. demersum is a good candidate species for removing heavy metals from polluted aquatic environments. PMID:25011115

  20. Effects of HIP on heavy metal samples

    International Nuclear Information System (INIS)

    Since heavy metal is a liquid phase sintered material, containerless HIPing at temperatures beween 12000C and 15000C can be applied to reduce porosity and improve tensile properties. Optimum HIPing-temperatures for W-Ni/Fe and W-Ni/Cu heavy metal samples were found to be around 13000C - 14000C. At highest HIPing-temperatures property values decreased again. Fractographic evaluation of tensile test specimen has been carried out by SEM and LM. The changes in microstructure by HIPing have been investigated and their relation to mechanical property changes is discussed. 5 refs., 14 figs., 1 tab. (Author)

  1. Superhydrogels of nanotubes capable of capturing heavy-metal ions.

    Science.gov (United States)

    Song, Shasha; Wang, Haiqiao; Song, Aixin; Hao, Jingcheng

    2014-01-01

    Self-assembly regulated by hydrogen bonds was successfully achieved in the system of lithocholic acid (LCA) mixed with three organic amines, ethanolamine (EA), diethanolamine (DEA), and triethanolamine (TEA), in aqueous solutions. The mixtures of DEA/LCA exhibit supergelation capability and the hydrogels consist of plenty of network nanotubes with uniform diameters of about 60 nm determined by cryogenic TEM. Interestingly, the sample with the same concentration in a system of EA and LCA is a birefringent solution, in which spherical vesicles and can be transformed into nanotubes as the amount of LCA increases. The formation of hydrogels could be driven by the delicate balance of diverse noncovalent interactions, including electrostatic interactions, hydrophobic interactions, steric effects, van der Waals forces, and mainly hydrogen bonds. The mechanism of self-assembly from spherical bilayer vesicles into nanotubes was proposed. The dried hydrogels with nanotubes were explored to exhibit the excellent capability for capturing heavy-metal ions, for example, Cu(2+), Co(2+), Ni(2+), Pb(2+), and Hg(2+). The superhydrogels of nanotubes from the self-assembly of low-molecular-weight gelators mainly regulated by hydrogen bonds used for the removal of heavy-metal ions is simple, green, and high efficiency, and provide a strategic approach to removing heavy-metal ions from industrial sewage. PMID:24136830

  2. Heavy Metal Stress and Some Mechanisms of Plant Defense Response

    Science.gov (United States)

    Emamverdian, Abolghassem; Ding, Yulong; Mokhberdoran, Farzad; Xie, Yinfeng

    2015-01-01

    Unprecedented bioaccumulation and biomagnification of heavy metals (HMs) in the environment have become a dilemma for all living organisms including plants. HMs at toxic levels have the capability to interact with several vital cellular biomolecules such as nuclear proteins and DNA, leading to excessive augmentation of reactive oxygen species (ROS). This would inflict serious morphological, metabolic, and physiological anomalies in plants ranging from chlorosis of shoot to lipid peroxidation and protein degradation. In response, plants are equipped with a repertoire of mechanisms to counteract heavy metal (HM) toxicity. The key elements of these are chelating metals by forming phytochelatins (PCs) or metallothioneins (MTs) metal complex at the intra- and intercellular level, which is followed by the removal of HM ions from sensitive sites or vacuolar sequestration of ligand-metal complex. Nonenzymatically synthesized compounds such as proline (Pro) are able to strengthen metal-detoxification capacity of intracellular antioxidant enzymes. Another important additive component of plant defense system is symbiotic association with arbuscular mycorrhizal (AM) fungi. AM can effectively immobilize HMs and reduce their uptake by host plants via binding metal ions to hyphal cell wall and excreting several extracellular biomolecules. Additionally, AM fungi can enhance activities of antioxidant defense machinery of plants. PMID:25688377

  3. Heavy metal stress and some mechanisms of plant defense response.

    Science.gov (United States)

    Emamverdian, Abolghassem; Ding, Yulong; Mokhberdoran, Farzad; Xie, Yinfeng

    2015-01-01

    Unprecedented bioaccumulation and biomagnification of heavy metals (HMs) in the environment have become a dilemma for all living organisms including plants. HMs at toxic levels have the capability to interact with several vital cellular biomolecules such as nuclear proteins and DNA, leading to excessive augmentation of reactive oxygen species (ROS). This would inflict serious morphological, metabolic, and physiological anomalies in plants ranging from chlorosis of shoot to lipid peroxidation and protein degradation. In response, plants are equipped with a repertoire of mechanisms to counteract heavy metal (HM) toxicity. The key elements of these are chelating metals by forming phytochelatins (PCs) or metallothioneins (MTs) metal complex at the intra- and intercellular level, which is followed by the removal of HM ions from sensitive sites or vacuolar sequestration of ligand-metal complex. Nonenzymatically synthesized compounds such as proline (Pro) are able to strengthen metal-detoxification capacity of intracellular antioxidant enzymes. Another important additive component of plant defense system is symbiotic association with arbuscular mycorrhizal (AM) fungi. AM can effectively immobilize HMs and reduce their uptake by host plants via binding metal ions to hyphal cell wall and excreting several extracellular biomolecules. Additionally, AM fungi can enhance activities of antioxidant defense machinery of plants. PMID:25688377

  4. Heavy metal pollutant tolerance of Azolla pinnata

    Energy Technology Data Exchange (ETDEWEB)

    Sarkar, A.; Jana, S.

    1986-01-01

    The effects of Hg, As, Pb, Cu, Cd, and Cr (1,2 and 5 mg L/sup -1/ each) on Azolla pinnata R. Br. were analyzed. The treatments (2 and 5 mg L/sup -1/) of the heavy metal pollutants decreased Hill activity, chlorophyll, protein and dry wt, and increased tissue permeability over control values. The effects were most pronounced with the treatment of 5 mg L/sup -1/. The harmful effects of the metals were, in general, found by the treatments in the order: Cd > Hg > Cu > As > Pb > Cr. There was no significant change in these parameters at 1 mg L/sup -1/ of the metals over control. Thus Azolla pinnata shows tolerance to the heavy metals tested up to 1 mg L/sup -1/ each.

  5. Determination of heavy metals in sediments

    International Nuclear Information System (INIS)

    This work is an approach to study the determination of heavy metals in sediments. It analyzer the different ways by means of which heavy metals are introduced into the river sediments, as well as their toxicity in the total concentration and in each of the species of the system. This study presents the main operation methods in sediments. One of the most relevant and suitable method to identify the way in which metals are joined in the different stages (phases) of sediments is the sequential extraction proposed by the MS and T from the Buorean of Certified Reference (European Community). Its also discussed the possible ways to determine if the presence of metals is caused by the anthropogenic action or by lithogenic cause

  6. Removal of Metallic Iron on Oxide Slags

    Science.gov (United States)

    Shannon, George N.; Fruehan, R. J.; Sridhar, Seetharaman

    2009-10-01

    It is possible, in some cases, for ground coal particles to react with gasifier gas during combustion, allowing the ash material in the coal to form phases besides the expected slag phase. One of these phases is metallic iron, because some gasifiers are designed to operate under a reducing atmosphere ({p_{O2}} of approximately 10-4 atm). Metallic iron can become entrained in the gas stream and deposit on, and foul, downstream equipment. To improve the understanding of the reaction between different metallic iron particles and gas, which eventually oxidizes them, and the slag that the resulting oxide dissolves in, the kinetics of iron reaction on slag were predicted using gas-phase mass-transfer limitations for the reaction and were compared with diffusion in the slag; the reaction itself was observed under confocal scanning laser microscopy. The expected rates for iron droplet removal are provided based on the size and effective partial pressure of oxygen, and it is found that decarburization occurs before iron reaction, leading to an extra 30- to 100-second delay for carbon-saturated particles vs pure iron particles. A pure metallic iron particle of 0.5 mg should be removed in about 220 seconds at 1400 °C and in 160 seconds at 1600 °C.

  7. Separation processes: Heavy metals, ions and minerals

    International Nuclear Information System (INIS)

    This volume contains the proceedings of a symposium which was held February 12--16, 1995 in Las Vegas, Nevada. The symposium was sponsored by EPD Aqueous Processing Committee, EPD Precious Metals Committee, and jointly by EPD/LMD Recycling Committee. The purpose of this meeting was to provide a forum for exchange of state-of-the-art information on the separation processes for heavy metals, ions, and minerals. Individual papers have been processed separately for inclusion in the appropriate data bases

  8. Irradiation of Liquid Fungi Isolated Media from Contaminated Sources with Heavy Metals Additive

    International Nuclear Information System (INIS)

    Occupational lead exposure is an important health issue in Egyptian workers, employees of paint factories, workers of copying centres, drivers, and tile making factories are in higher risk of lead toxicity. Wastewater, particularly from electroplating, paint, leather, metal and tanning industries, contain enormous amount of heavy metals. Microorganisms including fungi have been reported to exclude heavy metals from wastewater through bioaccumulation and bio sorption at low cost and in eco-friendly way. Low level lead exposure can significantly induce motor dis functions and cognitive impairment in children. Seventy six fungal isolates tolerant to heavy metals like Pb, Cd, Cr and Ni were isolated from sewage, sludge and industrial effluents containing heavy metals. Four fungi (Phanerochaete chrysosporium, Aspergillus awamori, Aspergillus flavus, Trichoderma viride) were included in this study. The majority of the fungal isolates were able to tolerate up to 400 ppm concentration of Pb, Cd, Cr and Ni. The most heavy metal tolerant fungi were studied for removal of heavy metals from liquid media at 50 ppm concentration. Results indicated removal of substantial amount of heavy metals by some of the fungi with respect to Pb, Cd, Cr and Ni with maximum uptake of 59.67, 16.25, 0.55 and 0.55 mg/g by fungi Pb3 (Aspergillus terreus), Trichoderma viride, Cr8 (Trichoderma longibrachiatum), and isolate Ni27 (A. niger), respectively. This indicated t(A. niger), respectively. This indicated the potential of these fungi as bio sorbent for removal of heavy metals from wastewater and industrial effluents containing higher concentration of heavy metals. The F-ratio was 0.55 and gives non-significant as irradiated

  9. Heavy metals and related trace elements

    International Nuclear Information System (INIS)

    A review is given of heavy metals and related trace elements in the aquatic environment. Other reviews and bibliographies are cited, dealing with the metabolism and transport of metal ions and with the toxic effects of stable and radioactive trace metals on aquatic organisms. The sources of trace elements in natural waters are discussed. It is suggested that atmospheric inputs of several trace metals comprise sizable fractions of total inputs to the Great Lakes and continental shelf waters. Information on stack emissions of trace elements from a coal-fired steam plant was used to estimate the likely range of air concentrations and inputs to a forested watershed in Tennessee. Some basic concepts of cycling of elements through aquatic communities were examined, such as the Pb, Mn and Zn concentrations in sediment and estuarine plants and animals colonizing dredge-spoil disposal areas. The use of plants as biological indicators of trace element contamination was outlined, as well as bioaccumulation in aquatic fauna. The effects of environmental factors on the kinetics of element exchange were noted, for example the influx rates of Cs 137 in tubificid worms, and Co 60 and Zn 65 in shrimp were shown to be temperature dependent. The toxicity of heavy metals on aquatic fauna was discussed, such as the histopathological lesions in the kidney and liver of fishes caused by heavy metals, and the effects of Hg and Cu on the olfactory response of rainbow troutonse of rainbow trout

  10. Microwave enhanced stabilization of heavy metal sludge

    International Nuclear Information System (INIS)

    A microwave process can be utilized to stabilize the copper ions in heavy metal sludge. The effects of microwave processing on stabilization of heavy metal sludge were studied as a function of additive, power, process time, reaction atmosphere, cooling gas, organic substance, and temperature. Copper leach resistance increased with addition of aluminum metal powder, with increased microwave power, increased processing time, and using a gaseous environment of nitrogen for processing and air for cooling [N2/air]. The organic in the sludge affected stabilization, whether or not the organic smoldered. During heating in conventional ovens, exothermic oxidation of the organic resulted in sludge temperatures of about 500 deg. C for oven control temperatures of 200-500 deg. C. After microwave heating dried the sludge, the sludge temperature rose to 500 deg. C. The reaction between copper ions and metal aluminum in the dried sludge should be regarded as a solid phase reaction. Adding aluminum metal powder and reaction temperature were the key parameters in stabilizing copper in the heavy metal sludge, whether heated by microwave radiation or conventional oven. The mass balance indicates insignificant volatization of the copper during heating

  11. Assessing the resistance and bioremediation ability of selected bacterial and protozoan species to heavy metals in metal-rich industrial wastewater

    OpenAIRE

    Kamika Ilunga; Nb, Momba Maggy

    2013-01-01

    Abstract Background Heavy-metals exert considerable stress on the environment worldwide. This study assessed the resistance to and bioremediation of heavy-metals by selected protozoan and bacterial species in highly polluted industrial-wastewater. Specific variables (i.e. chemical oxygen demand, pH, dissolved oxygen) and the growth/die-off-rates of test organisms were measured using standard methods. Heavy-metal removals were determined in biomass and supernatant by the Inductively Couple Pla...

  12. Heavy metal accumulation by bacteria and other microorganisms

    International Nuclear Information System (INIS)

    Bacteria, and other microorganisms, exhibit a number of metabolism-dependent and -independent processes for the uptake and accumulation of heavy metals and radionuclides. The removal of such harmful substances from effluents and waste waters by micro-based technologies may provide an alternative or additional means of metal/radionuclide recovery for economic reasons and/or environmental protection. Both living and dead cells as well as products derived from or produced by microorganisms can be effective metal accumulators and there is evidence that some biomass-based clean-up processes are economically viable. However, many aspects of metal-microbe interactions remain unexploited in biotechnology and further development and application is necessary, particularly to the problem of radionuclide release into the environment. (author) 1 fig., 1 tab., 39 refs

  13. Effects of remediation train sequence on decontamination of heavy metal-contaminated soil containing mercury.

    Science.gov (United States)

    Hseu, Zeng-Yei; Huang, Yu-Tuan; Hsi, Hsing-Cheng

    2014-09-01

    When a contaminated site contains pollutants including both nonvolatile metals and Hg, one single remediation technology may not satisfactorily remove all contaminants. Therefore, in this study, chemical extraction and thermal treatment were combined as a remediation train to remove heavy metals, including Hg, from contaminated soil. A 0.2 M solution of ethylenediamine tetraacetic acid (EDTA) was shown to be the most effective reagent for extraction of considerable amounts of Cu, Pb, and Zn (> 50%). Hg removal was ineffective using 0.2 M EDTA, but thermogravimetric analysis suggested that heating to 550 degrees C with a heating rate of 5 degrees C/min for a duration of 1 hr appeared to be an effective approach for Hg removal. With the employment of thermal treatment, up to 99% of Hg could be removed. However executing thermal treatment prior to chemical extraction reduced the effectiveness of the subsequent EDTA extraction because nonvolatile heavy metals were immobilized in soil aggregates after the 550 degrees C treatment. The remediation train of chemical extraction followed by thermal treatment appears to remediate soils that have been contaminated by many nonvolatile heavy metals and Hg. Implications: A remediation train conjoining two or more techniques has been initialized to remove multiple metals. Better understandings of the impacts of treatment sequences, namely, which technique should be employed first on the soil properties and the decontamination efficiency, are in high demand. This study provides a strategy to remove multiple heavy metals including Hg from a contaminated soil. The interactions between thermal treatment and chemical extraction on repartitioning of heavy metals was revealed. The obtained results could offer an integrating strategy to remediate the soil contaminated with both heavy metals and volatile contaminants. PMID:25282998

  14. Bioleaching of heavy metal from woody biochar using Acidithiobacillus ferrooxidans and activation for adsorption.

    Science.gov (United States)

    Wang, Buyun; Li, Cuiping; Liang, Hui

    2013-10-01

    A woody biochar which was the byproduct of gasification of sawdust was treated with bioleaching by Acidithiobacillus ferrooxidans. After bioleaching, most heavy metal was removed from biochar. Leaching efficiency of heavy metal was efficient in a wide pulp density range from 1% to 10% (w/v) and decreased only a little with the increase in pulp density. It made application of biochar free of heavy metal risk. Benefitting from the improvement in functional group composition and pore structure after bioleaching, adsorption capacity of biochar to methylene blue and heavy metal was enhanced greatly. Adsorption of methylene blue could be described by pseudo-second-order model and Langmuir equation and the enhancement was mainly caused by the modification of physical character of biochar. Adsorption of heavy metal could be described by Freundlich equation and was mainly determined by chemical character of biochar. PMID:23978608

  15. Situ formation of apatite for sequestering radionuclides and heavy metals

    Science.gov (United States)

    Moore, Robert C. (Edgewood, NM)

    2003-07-15

    Methods for in situ formation in soil of a permeable reactive barrier or zone comprising a phosphate precipitate, such as apatite or hydroxyapatite, which is capable of selectively trapping and removing radionuclides and heavy metal contaminants from the soil, while allowing water or other compounds to pass through. A preparation of a phosphate reagent and a chelated calcium reagent is mixed aboveground and injected into the soil. Subsequently, the chelated calcium reagent biodegrades and slowly releases free calcium. The free calcium reacts with the phosphate reagent to form a phosphate precipitate. Under the proper chemical conditions, apatite or hydroxyapatite can form. Radionuclide and heavy metal contaminants, including lead, strontium, lanthanides, and uranium are then selectively sequestered by sorbing them onto the phosphate precipitate. A reducing agent can be added for reduction and selective sequestration of technetium or selenium contaminants.

  16. Separately removable tubes in heavy duty heat exchanger assemblies

    International Nuclear Information System (INIS)

    The invention is directed to removable heat exchanger tube assemblies in heavy duty equipment radiators in which the tubes are each separately removable if they become defective in service. An inwardly facing annular ledge or abutment is molded into the inside diameter of each upper and lower sealing member to receive the respective ends of the tubes and prevent vertical movement of the tubes in service. A flange or shoulder is also provided on the lower portions of each tube and engages the inside of the lower sealing member to further restrain downward movement of the tubes in service. Each tube may be removed by pushing the tube upwardly to overcome the upper ledge abutment and thereby lift the tube free of the lower seal. Each tube may then be removed sidewise from the radiator. Variations of the removable sealing arrangement can be made and are described herein

  17. Investigation of Heavy Metals in Groundwater

    Directory of Open Access Journals (Sweden)

    J. Nouri

    2006-01-01

    Full Text Available The objective of this study was to evaluate and map regional patterns of heavy metals (Cu, Cd, Ni and Zn occurrence in south of Iran. The study was performed in Shush and Andimeshk plains in the south part of Iran, with high agricultural activities that cover an area of 1100 km2 between the Dez and Karkhe rivers. This region was divided into four sub-regions A, B, C and D. Additionally 168 groundwater samples were collected from 42 water wells during the months April, May, August and September of 2004. The Flame Atomic Absorption Spectrometry (AAS-Flame was used to measure the heavy metals concentration in water samples. The results demonstrated that all of the samples, Cu, Zn and Ni concentrations have been shown below the EPA MCLG, EPA secondary standard and EPA MCL, respectively, but Cd, contents of 4.8% of all samples was higher than EPA MCL. The heavy metals concentration is more pronounced in south part than northern part of the studied area. Absent confining layers, proximity to land surface, excess agricultural and industrial activities in south part and groundwater flow direction that is generally from north to south parts in this area makes south region of Shush plain especially vulnerable to heavy metals pollution and other contaminants.

  18. ANALYSIS OF HEAVY METALS IN STORMWATER

    Science.gov (United States)

    Sampling has been undertaken to determine the concentrations of heavy metals, both particle-associated and dissolved, in stormwater from several storm sewer outfalls in Monmouth County, NJ. This project is ongoing in concert with coordinated studies of pathogen and nutrient input...

  19. Erratum - Intracellular heavy metal nanoparticle storage

    OpenAIRE

    Iannitti T; Capone S; Gatti A; et al.

    2011-01-01

    Iannitti T, Capone S, Gatti A, Capitani F, Cetta F, Palmieri BIntracellular heavy metal nanoparticle storage: progressive accumulation within lymph nodes with transformation from chronic inflammation to malignancy. Int J Nanomedicine. 2010;5:955–960.Dr Federico Capitani’s name was spelt incorrectly as "Frederico Capitani" in the published paper.

  20. Environmental migrations of radionuclides and heavy metals

    International Nuclear Information System (INIS)

    The environmental local and distant migrations of radium 226, lead 210, uranium, thorium and heavy metals such as cadmium, lead, mercury and vanadium were studied. Their vertical migration in atmosphere as well as cumulation in soil, plants and human tissues are discussed. (A.S.)

  1. Atmospheric heavy metal deposition in Europe

    Energy Technology Data Exchange (ETDEWEB)

    Ruehling, Aa. (ed.)

    1994-03-01

    Atmospheric heavy metal deposition in Europe including 21 countries was monitored by the moss technique. The objectives of the project were to characterise qualitatively and quantitatively the regional atmospheric deposition pattern of heavy metals in background areas in Europe, to indicat the location of important heavy metal pollution sources. Samples of mainly the moss species Pleurozium schreberi, Hylocomium splendens and Hypnum cupresiforme were collected during the summertime 1990. The total concentrations of arsenic, cadmium, chromium, copper, iron, lead, nickel, vanadium and zinc were determined and the results presented in the form of coloured contour maps of Europe. In the Nordic countries and adjacent areas the regional deposition pattern of all the metals shows a decreasing gradient from relatively high values in the southern parts of Scandinavia to low values towards the North. A significant decreas. in the concentrations of most elements was found in this area during the last 10-20 years. Important local enhancements of the concentrations in moss were found superimposed on the regional background pattern, especially at the great smelting combinates in Nikel, Zapolyarnyj and Monchegorsk in Russia in the western part of the Kola Peninsula. Higher levels of metals are found at Mazeikiai (oil refinery) in Lithuania, close to Liepaja (steel mill) and Riga in Latvia and in the industrial north-eastern area of Estonia and adjacent area of Russia. Higher levels of metals were found in the metropolitan area of St. Petersburg. In Central Europe, Poland, and the Czech Republic have numerous sources of air pollution, as well as area in Germany. The Netherlands is particularly affected by pollution from Belgium and western Germany. The Environmental Monitoring and Data Group in the Nordic Countries would like the next survey of heavy metals, including mercury, in moss to take place in 1995. (EG) (45 refs.)

  2. Removal of metal ions from simulated wastewater by saccharomyces yeast biomass : combining biosorption and flotation processes

    OpenAIRE

    Zouboulis, A. I.; ???????????, ?. ?.; Matis, K. A.; Lazaridis, N. K.; ??????, ?. ?.; ??????????, ?. ?.

    2009-01-01

    Aqueous solutions containing heavy metals can be successfully treated by a combination of biosorption and flotation, in order to remove (or recover) the contained metals. Nonliving biomass of yeast Saccharomyces, which is a solid industrial by-product, was found to be a suitable biosorbent of metal ions (zinc, copper, and nickel). It was found also possible to reuse it after the appropriate desorption treatment. Electrokinetic behavior of biomass as well as elution and multiple-cycles operati...

  3. Biochar-attenuated desorption of heavy metals in small arms range soils

    Science.gov (United States)

    Stabilization (capping/solidification) and dilution (e.g., washing, chelate-assisted phytoremediation) represent non-removal and removal remediation technologies for heavy metal contaminated soils. Biochar is stable in soil, and contains carboxyl and other surface ligands; these properties are usef...

  4. Heavy metal vaporization and abatement during thermal treatment of modified wastes

    International Nuclear Information System (INIS)

    This study examines the vaporization percentage and partitioning of heavy metals Cd, Pb and Zn during thermal treatment of wastes with added PVC, heavy metals or phosphate, and the efficiency of sorbents for removal of these metallic compounds in flue gas of an industrial solid waste incinerator. Firstly, vaporization experiments were carried out to determine the behavior of heavy metals during combustion under various conditions (type of waste, temperature, presence of chloride or phosphate ...). The experimental results show relatively high vaporization percentage of metallic compounds within fly ash and limestone matrix while heavy metals within sediments treated with phosphoric acid are less volatile. Vaporization of metals increases with increasing temperature and with chloride addition. The thermal behavior of the selected heavy metals and their removal by sorbents (sodium bicarbonate, activated carbon) was also studied in an industrial solid waste incinerator. These pilot scale experiments confirm that heavy metals are concentrated in fly ashes and cyclone residues, thus effectively controlling their release to the atmosphere

  5. Minor heavy metal: A review on occupational and environmental intoxication

    OpenAIRE

    Wiwanitkit Viroj

    2008-01-01

    Heavy metal is widely used in industries and presents as a problematic environmental pollution. Some heavy metals, especially lead and mercury, are well described for their occupational and environmental intoxication whereas the other minor heavy metals are less concerned. In this article, the author will present the details of occupational and environmental minor heavy metal intoxication. This review focuses mainly on aluminum, tin, copper, manganese, chromium, cadmium and nickel.

  6. Heavy metal tolerance in metal hyperaccumulator plant, Salvinia natans.

    Science.gov (United States)

    Dhir, B; Srivastava, S

    2013-06-01

    Metal tolerance capacity of Salvinia natans, a metal hyperaccumulator, was evaluated. Plants were exposed to 10, 30 and 50 mg L?¹ of Zn, Cd, Co, Cr, Fe, Cu, Pb, and Ni. Plant biomass, photosynthetic efficiency, quantum yield, photochemical quenching, electron transport rate and elemental (%C, H and N) constitution remained unaffected in Salvinia exposed to 30 mg L?¹ of heavy metals, except for Cu and Zn exposed plants, where significant reductions were noted in some of the measured parameters. However, a significant decline was noted in most of the measured parameters in plants exposed to 50 mg L?¹ of metal concentration. Results suggest that Salvinia has fairly high levels of tolerance to all the metals tested, but the level of tolerance varied from metal to metal. PMID:23553503

  7. Evaluation of uptake rate of heavy metals by Eichhornia crassipes and Hydrilla verticillata.

    Science.gov (United States)

    Dixit, Savita; Dhote, Sangeeta

    2010-10-01

    Lakes, ponds, and streams are the sources of surface water, which anchorage the survival of aquatic life flora and fauna and maintain ecological balance. Due to urbanization, population explosion, and industrialization, these natural sources are getting polluted. Present paper is an attempt to evaluate the uptake rate of heavy metals namely lead (Pb), zinc (Zn), iron (Fe), and chromium (Cr) by the macrophytes. The two macrophytes taken for the study are Eichhornia crassipes and Hydrilla verticillata. Both macrophytes have the capacity to absorb heavy metals from contaminated water. The present experimental study was conducted to compare and identify their potential to improve the water quality by removing the heavy metals. The paper critically evaluates the water-purifying capacity of submerged macrophyte (H. verticillata) and free-floating macrophyte (E. crassipes). It also evaluates the extent up to which heavy metal can be removed by macrophyte in a given period of time. PMID:19890730

  8. Interaction of natural complexing agents with soil bound heavy metals -geochemical and environmental technical aspects

    International Nuclear Information System (INIS)

    The sanitation of heavy metal polluted soils requires the application of an adequate technology, which should be consistent in its ecological aims and methodology. Therefore a research programme has been developed at the 'Institute of Ecological Chemistry' of the 'GSF-Research Center', Neuherberg, which has its starting point in the study of influences of natural organic complexing agents on the chemical activity and dynamic of heavy metals in soils. The groundlaying idea is to elevate the concentration of complexing agents in the soil solution by additional application and possible stimulation of their microbial production to such an extent, that heavy metals will be enhanced solubilized, mobilized and removed together with the seepage water. Batch experiments in order to extract heavy metals from typical soil components (bentonite, peat) by amino acids demonstrate, that removal rates up to 95% can be obtained. (orig.)

  9. Leaching of heavy metals from steelmaking slags

    International Nuclear Information System (INIS)

    Leaching tests with EAF and Ladle slags were performed, using a flow through tests and the standard batch test DIN 38414-S4. The previous method was used to simulate the leaching behaviour of steel slags under landfill. the chemical analysis of the leachates during this period shows, in general, for both types of slag, and increase of heavy metal releases with ageing. Standard test method DIN 38414-S4 was used to evaluate leachability of heavy metals by water in unprocessed slags. After more than one year of trials, slang samples submitted to these trials presented very low total leaching levels. The most extracted elements are calcium and magnesium. Nevertheless, in flow-though test, calcium and magnesium leached from solid slags are below 0.5% and all other metals below 0.1%. Leachates obtained with DIN 38414-S4 present, as expected, higher leaching values; however, these are inferior to 5% (Ca) and 1% (other elements). (Author) 12 refs

  10. Heavy metal fates in laboratory bioretention systems.

    Science.gov (United States)

    Sun, Xueli; Davis, Allen P

    2007-01-01

    Key to managing heavy metals in bioretention is to understand their fates in bioretention facilities. In this study, pot prototypes filled with bioretention media were built to simulate the conditions of natural growth of plants. Synthetic runoff with different heavy metal loadings (copper, cadmium, lead, and zinc) was periodically applied. Metal accumulations in tissues of grasses -Panicum virgatum, Kentucky-31, and Bromus ciliatus, were investigated after 230d of growth and multiple runoff treatment events. After 183d of periodic runoff application, the concentrations of Zn, Cu, Pb and Cd with low and high loadings had the same trends in the plant tissues, Zn>Cu>Pb>Cd, following the trend of the input metal concentrations. The fates of input metals were 88-97% captured in soil media, 2.0-11.6% not captured by bioretention media, and 0.5-3.3% accumulated in plants. Compared to the metals retained by the soil, the percentages of input metals taken up by plants were relatively low due to the low plant biomass produced in this study. Greater biomass density would be required for the vegetation to have a valuable impact in prolonging the lifetime of a bioretention cell. PMID:17005239

  11. Arbuscular Mycorrhizal Fungi Can Benefit Heavy Metal Tolerance and Phytoremediation

    Science.gov (United States)

    Forgy, David

    2012-01-01

    Sites contaminated by heavy metals, such as industrial waste sites, create unwelcoming environments for plant growth. Heavy metals can have a wide range of toxic effects such as replacing essential elements or disrupting enzyme function. While some heavy metals are essential to plant nutrition at low concentrations, high concentrations of any…

  12. Phytoremediation of water bodies contaminated with radioactive heavy metal

    International Nuclear Information System (INIS)

    The sources of the radioactive heavy metal in the water bodies were analyzed. The factors that affect phyto remediation of water contaminated with radioactive heavy metal were discussed. The plant species, mechanism and major technology of phyto remediation of water contaminated with radioactive heavy metal were particularly introduced. The prospective study was remarked. (authors)

  13. Accumulation of heavy metals in plants

    Energy Technology Data Exchange (ETDEWEB)

    Nakagawa, Y.; Mitsugi, H.; Takata, N.; Watanabe, H.

    1973-10-01

    Accumulation of toxic metals in plants caused by air pollution was investigated in the vicinities of a steel industry and non-ferrous metal industries. The tree leaves were sampled, cleansed, burned to ashes at a low temperature, dissolved in dilute nitric acid, and measured by atomic absorption spectrophotometry. The trees examined were Paulonia, cherry, plane, and gingko, and the metals extracted were iron, manganese, zinc, cadmium, and lead. All heavy metals were accumulated in leaves approximately in direct proportion to the amount of metals in the air. The Fe concentration in leaves decreased in proportion to the distance from the emission source, but Mn tends to increase with the distance. The relationship between these accumulations and Fe and Mn in the soil was not clear. All Cd, Pb, and Zn concentrations in leaves decreased in proportion to the distance from the emission sources. Cadmium in soil showed the same tendency as leaves, but Pb and Zn content in the soil fluctuated.

  14. Application of 1-(2-pyridylazo)-2-naphthol-modified nanoporous silica as a technique in simultaneous trace monitoring and removal of toxic heavy metals in food and water samples.

    Science.gov (United States)

    Abolhasani, Jafar; Behbahani, Mohammad

    2015-01-01

    Solid-phase extraction is one the most useful and efficient techniques for sample preparation, purification, cleanup, preconcentration, and determination of heavy metals at trace levels. In this paper, functionalized MCM-48 nanoporous silica with 1-(2-pyridylazo)-2-naphthol was applied for trace determination of copper, lead, cadmium, and nickel in water and seafood samples. The experimental conditions such as pH, sample and eluent flow rate, type, concentration and volume of the eluent, breakthrough volume, and effect of coexisting ions were optimized for efficient solid-phase extraction of trace heavy metals in different water and seafood samples. The content of solutions containing the mentioned heavy metals was determined by flame atomic absorption spectrometry (FAAS), and the limits of detection were 0.3, 0.4, 0.6, and 0.9 ng mL(-1) for cadmium, copper, nickel, and lead, respectively. Recoveries and precisions were >98.0 and <4%, respectively. The adsorption capacity of the modified nanoporous silica was 178 mg g(-1) for cadmium, 110 mg g(-1) for copper, 98 mg g(-1) for nickel, and 210 mg g(-1) for lead, respectively. The functionalized MCM-48 nanoporous silica with 1-(2-pyridylazo)-2-naphthol was characterized by thermogravimetry analysis (TGA), differential thermal analysis (DTA), transmission electron microscopy (TEM), Fourier transform infrared spectrometry (FT-IR), X-ray diffraction (XRD), elemental analysis (CHN), and N2 adsorption surface area measurement. PMID:25504188

  15. Chelant extraction of heavy metals from contaminated soils

    International Nuclear Information System (INIS)

    The current state of the art regarding the use of chelating agents to extract heavy metal contaminants has been addressed. Results are presented for treatability studies conducted as worst-case and representative soils from Aberdeen Proving Ground's J-Field for extraction of copper (Cu), lead (Pb), and zinc (Zn). The particle size distribution characteristics of the soils determined from hydrometer tests are approximately 60% sand, 30% silt, and 10% clay. Sequential extractions were performed on the 'as-received' soils (worst case and representative) to determine the speciation of the metal forms. The technique speciates the heavy metal distribution into an easily extractable (exchangeable) form, carbonates, reducible oxides, organically-bound, and residual forms. The results indicated that most of the metals are in forms that are amenable to soil washing (i.e. exchangeable+carbonate+reducible oxides). The metals Cu, Pb, Zn, and Cr have greater than 70% of their distribution in forms amenable to soil washing techniques, while Cd, Mn, and Fe are somewhat less amenable to soil washing using chelant extraction. However, the concentrations of Cd and Mn are low in the contaminated soil. From the batch chelant extraction studies, ethylenediaminetetraacetic acid (EDTA), citric acid, and nitrilotriacetic acid (NTA) were all effective in removing copper, lead, and zinc from the J-Field soils. Due to NTA being a Class II carcinogen, it is not recommended for use in remediating is not recommended for use in remediating contaminated soils. EDTA and citric acid appear to offer the greatest potential as chelating agents to use in soil washing the Aberdeen Proving Ground soils. The other chelating agents studied (gluconate, oxalate, Citranox, ammonium acetate, and phosphoric acid, along with pH-adjusted water) were generally ineffective in mobilizing the heavy metals from the soils. The chelant solution removes the heavy metals (Cd, Cu, Pb, Zn, Fe, Cr, As, and Hg) simultaneously. Using a multiple-stage batch extraction, the soil was successfully treated passing both the Toxicity Characteristics Leaching Procedure (TCLP) and EPA Total Extractable Metal Limit. The final residual Pb concentration was about 300 mg/kg, with a corresponding TCLP of 1.5 mg/l. Removal of the exchangeable and carbonate fractions for Cu and Zn was achieved during the first extraction stage, whereas it required two extraction stages for the same fractions for Pb. Removal of Pb, Cu, and Zn present as exchangeable, carbonates, and reducible oxides occurred between the fourth- and fifth-stage extractions. The overall removal of copper, lead, and zinc from the multiple-stage washing were 98.9%, 98.9%, and 97.2%, respectively. The concentration and operating conditions for the soil washing extractions were not necessarily optimized. If the conditions had been optimized and using a more representative Pb concentration (?12000 mg/kg), it is likely that the TCLP and residual heavy metal soil concentrations could be achieved within two to three extractions. The results indicate that the J-Field contaminated soils can be successfully treated using a soil washing technique. (Copyright (c) 1999 Elsevier Science B.V., Amsterdam. All rights reserved.)

  16. Surface binding of toxins and heavy metals by probiotics.

    Science.gov (United States)

    Zoghi, Alaleh; Khosravi-Darani, Kianoush; Sohrabvandi, Sara

    2014-01-01

    Removal of toxic metals and toxins using microbial biomass has been introduced as an inexpensive, new promising method on top of conventional methods for decontamination of food, raw material and concentrated. In this article the potential application of lactic acid bacteria and yeasts as the most familiar probiotics to eliminate, inactivate or reduce bioavailability of contamination in foods and feed has been reviewed. After fast glance to beneficial health effects and preservative properties of lactic acid bacteria, the mechanisms which explain antibacterial and antifungal efficiency as well as their antifungal metabolites are mentioned. Then the article has been focused on potential application of single strain or combination of lactic acid bacteria for removal of heavy metals (copper, lead, cadmium, chromium, arsenic), cyanotoxins (microcystin-LR, -RR, -LF) and mycotoxins (aflatoxin B1, B2, B2a, M1, M2, G1, G2, patulin, ochratoxin A, deoxynivalenol, fumonisin B1 and B2, 3-acetyldeoxynivalenol, deoxynivalenol, fusarenon, nivalenol, diacetoxyscirpenol, HT-2 and T-2 toxin, zearalenone and its derivative, etc) from aqueous solutions in vitro. Wherever possible the mechanism of decontamination and the factors influencing yield of removal are discussed. Some factors which can facilitate metal removal capacity of lactic acid bacteria including the strains, surface charge, pH, temperature, presence of other cations are introduced. The cell wall structure of lactic acid bacteria and yeasts are also introduced for further explanation of mechanism of action in complex binding of probiotic to contaminants and strength of mycotoxin- bacterium interaction. PMID:24329992

  17. Compost as a source of microbial isolates for the bioremediation of heavy metals: In vitro selection

    Energy Technology Data Exchange (ETDEWEB)

    Vargas-Garcia, Maria del Carmen, E-mail: mcvargas@ual.es; Lopez, Maria Jose, E-mail: mllopez@ual.es; Suarez-Estrella, Francisca, E-mail: fsuarez@ual.es; Moreno, Joaquin, E-mail: jcasco@ual.es

    2012-08-01

    Heavy metal pollution has become a major environmental concern nowadays and the bioremediation of polluted habitats is an increasingly popular strategy due to both its efficiency and safety. A screening and selection protocol based on different composting processes was designed in order to isolate heavy metal-resistant microorganisms. A collection of 51 microorganisms was obtained and most of them showed the capability to tolerate heavy metals in multi-polluted aqueous systems (Cd(II), Cr(VI), Ni, Pb, Zn(II)), as well as to remove them. The highest detoxification ratios were observed for Pb. Some of the isolates detoxifying more than a 90% of this metal, while the other metals were removed in a range between 20% and 60%. The best isolates (Graphium putredinis, Fusarium solani, Fusarium sp. and Penicillium chrysogenum) were further assayed in order to determine the predominant removal mechanism and the potential use of their dead biomass as a biosorbent. Intracellular accumulation was the prevalent mechanism for most isolates and metals, with the exception of Ni. In this case, the proportion removed by extracellular adsorption was similar or even higher than that removed by intracellular accumulation. Thus, the efficiency of living cells was higher than that of dead biomass except in the case of Ni. - Highlights: Black-Right-Pointing-Pointer Composting is a good reservoir for the isolation of HM-resistant microorganisms. Black-Right-Pointing-Pointer Pb was the most removed heavy metal in multi-polluted aqueous systems. Black-Right-Pointing-Pointer Intracellular accumulation was the predominant mechanism for heavy metal removal. Black-Right-Pointing-Pointer Graphium putredinis, which detoxifies organic pollutants, was the most efficient isolate.

  18. Detoxification of Heavy Metal Contaminated Soils

    Directory of Open Access Journals (Sweden)

    Floarea Damian

    2007-01-01

    Full Text Available The concentration of the heavy metals in the soils from the strong affected zones because of the mining and metallurgical industry, Baia Mare and Zlatna (Romania, is significant due to the high values of the contents and association of the four metals Pb, Cu, Zn, Cd. The efficacy of the natural zeolites in heavy metals immobilization from the studied soils was evaluated in experiments in which the plant growth was observed. Heavy metals contaminated soils have been treated with a mixture of organic substance and zeolites (organo ? zeolitic material. Zeolitic tuffs were roll-crushed and ground in small grains with dimensions between 0.05 and 2.0 mm. Clinoptilolite is the predominant zeolite and appears as compact masses of tabular and prismatic micron ? sized crystals that are evident in SEM images. In the mixture, the polluted soil represents 83% and the organo ? zeolitic material represents 17%. The soils used in the experiment are excessive contaminated with Pb (40375-1054ppm in association with Zn (1175-490ppm, Cd (24.2-13.2ppm and Cu (409.5-37.6ppm in Baia Mare zone and with Cu (7000-360ppm in association with Zn (3100-1900ppm, Cd (80-40ppm and Pb (2000-50ppm in Zlatna zone. The original soil and the treated soil have been planted with Lolium perenne. The growth of the plants has demonstrated that the soil treated with organo?zeolitic material allows the growth of vegetation much faster than the original soil. These results show that growth of the plants was possible because the organo?zeolitic material mixed with the soil provides the substances necessary for the plants to develop (ammonium, humus, potassium, calcium. At the same time, heavy metals that inhibit the plant development are blocked through the cationic exchange mechanism that makes them enter the zeolites structure and they no longer directly have access to the plant roots.

  19. Assessing fly ash treatment: Remediation and stabilization of heavy metals

    DEFF Research Database (Denmark)

    Lima, A.T.; Ottosen, Lisbeth M.

    2012-01-01

    Fly ashes from Municipal Solid Waste (MSW), straw (ST) and co-combustion of wood (CW) are here analyzed with the intent of reusing them. Two techniques are assessed, a remediation technique and a solidification/stabilization one. The removal of heavy metals from fly ashes through the electrodialytic process (EDR) has been tried out before. The goal of removing heavy metals has always been the reuse of fly ash, for instance in agricultural fields (BEK). The best removal rates are here summarized and some new results have been added. MSW fly ashes are still too hazardous after treatment to even consider application to the soil. ST ash is the only residue that gets concentrations low enough to be reused, but its fertilizing value might be questioned. An alternative reuse for the three ashes is here preliminary tested, the combination of fly ash with mortar. Fly ashes have been substituted by cement fraction or aggregate fraction. Surprisingly, better compressive strengths were obtained by replacing the aggregatefraction. CW ashes presented promising results for the substitution of aggregate in mortar and possibly in concrete.

  20. [Designing metal frame removable partial dentures].

    Science.gov (United States)

    Witter, D; Barèl, J C; Keltjens, H M A M; Creugers, N H J

    2011-02-01

    Oral health care providers have the full responsibility for designing metal frame removable partial dentures and making all of the necessary preparations. Important principles of design are that the denture should hamper natural cleaning and daily oral hygiene as little as possible and that it should have good stability and retention. The designing process follows several phases without a strict chronological sequence. If it is necessary to return to a previous phase, the process follows a circular sequence. The usual phases are evaluating dental arch study casts, examining diagnostic set-ups, selecting abutment teeth, surveying dental arch study casts, selecting the major connector, selecting minor connector and clasp types, selecting artificial teeth, modifying the denture design from theoretically ideal towards practically optimal, and carrying out the intended tooth preparations in a dental arch study cast. Tooth preparations in the working cast together with a denture design prescription will provide the dental technician with the information needed for manufacturing the metal frame removable partial denture. PMID:21438358

  1. HEAVY METALS IN PRODUCTIVE PARTS OF AGRICULTURAL PLANTS

    OpenAIRE

    Július Árvay; Ján Tomáš; Tomáš Tóth

    2012-01-01

    The contents of heavy metals in plants were not in relation to contents of heavy metals in soil. Increased content of heavy metals in soils was not in consistency with content in plants. Usually content of heavy metals in plants according to our results were lower than their content in soil. Only the over limit contents of copper and cadmium were assessed in grain of barley and oat. The results of heavy metals content showed that dominant part on content of elements in plants have their mobil...

  2. Fungal biotrap for retrieval of heavy metals from industrial wastewaters

    International Nuclear Information System (INIS)

    Biotraps are living cells or specific cell components capable of removing or stabilizing toxic substances form waste streams. The fungus Penicillium ochro-chloron was discovered growing in an electroplating wastewater stream in Japan. It is not only tolerant to very high concentrations of divalent metal ions, but it can effectively remove heavy metals (such as uranium cadmium, nickel, etc.) from almost any aqueous waste stream. This paper discussed P. ochro-chloron biotrap which was prepared by growing spores in a glucose-minimal salts medium supplemented with 0.5 percent Tween 80 for 5 days with constant gentle agitation. The while mycelia beads 4-6 mm dia. were treated in a Buchner funnel with 80% ethanol to kill the cells, 15 percent sodium carbonate/bicarbonate pH 9.5, and then resuspended in an aqueous slurry at pH 4.0. The mycelia beads were used as an adsorbent in a batch experiment to determine copper-to-mycelia binding. This system should be capable of heavy metal uptake and recovery from both electroplating wastewaters and contaminated aqueous environments. The use of this fungus biotrap will rival synthetic cation environments. The use of this fungus biotrap will rival synthetic cation exchange resins because of lower cost, lower weight per unit of exchange capacity and ease of application

  3. Electroremediation of heavy metals in sewage sludge

    Scientific Electronic Library Online (English)

    C., Elicker; P. J., Sanches Filho; K. R. L., Castagno.

    2014-06-01

    Full Text Available SciELO Brazil | Language: English Abstract in english This paper presents the application of electrokinetic remediation in the treatment of sludge in a sewage treatment station. The study consisted of, in a first step, the characterization of physicochemical parameters of sludge and, in a second step, the implementation of the electrokinetic remediatio [...] n technique. The concentrations of Cu, Cr, Pb and Zn in sludge samples, before and after the experiment, were determined by atomic absorption spectroscopy. After 40 hours of experiment, considering an electrolyte flow-rate of 1.34 L.h-1 at a voltage of 20 V, the removal rate of all the metals accompanied was over 50%; the highest removal efficiency was for Pb, with 72.49%. The results show the feasibility of using the electrochemical technique of electrokinetic remediation for metal removal from a sludge sewage treatment station.

  4. Modification of Heavy metal uptake efficiency by modified chitosan/anionic surfactant systems

    Energy Technology Data Exchange (ETDEWEB)

    Negm, Nabel A.; Ali, Hanan Elsharkawy [Applied Surfactant Laboratory, Petrochemicals Department, Egyptian Petroleum Research Institute, Nasr City, Cairo (Egypt)

    2010-06-15

    The presence of toxic heavy metals in natural environments entails a potential health hazard for humans. Metal contaminants in these environments are usually tightly bound to colloidal particles and organic matter. On the other hand, the potential of these metals towards chelation by different chelating agents presents a good characteristic for their removal from the environment. On this basis, two chitosan/anionic surfactant complexes were prepared and evaluated for their ability to remove heavy metals from aqueous solutions. The experimental results of the uptake of metal ions including Cu{sup 2+}, Sn{sup 2+}, Co{sup 2+} and Ni{sup 2+} are reported in this study. The results show that modified chitosan with short-spacer group cross-linkers has a higher potential for heavy metal uptake than long-chain cross-linker-modified chitosan. Also, increasing the electronegativity of the heavy metals increases their uptake from the medium. Increasing the time of exposure of the heavy metals to the modified polymer increases the efficiency of the metal uptake process. (Abstract Copyright [2010], Wiley Periodicals, Inc.)

  5. A study of the removal of heavy metals from aqueous solutions by Moringa oleifera seeds and amine-based ligand 1,4-bis[N,N-bis(2-picoyl)amino]butane.

    Science.gov (United States)

    Obuseng, Veronica; Nareetsile, Florence; Kwaambwa, Habauka M

    2012-06-12

    Uptake for lead, copper, cadmium, nickel and manganese from aqueous solution using the Moringa oleifera seeds biomass (MOSB) and amine-based ligand (ABL) was investigated. Experiments on two synthetic multi-solute systems revealed that MOSB performed well in the biosorption and followed the decreasing orders Pb(II)>Cu(II)>Cd(II)>Ni(II)>Mn(II) and Zn(II)>Cu(II)>Ni(II). The general trend of the heavy metal ions uptake by the amine-based ligand followed decreased in the order Mn>Cd>Cu>Ni>Pb, which is the reverse trend for what was observed for MOSB. Comparing the single- and multi-metal solutions, there was no clear effect in the biosorption capacity of MOSB suggesting the presence of sufficient active binding sites for all metal ions studied. The MOSB performance is also not affected by pH in the range 3.5-8. PMID:22632049

  6. Heavy Metal Contents in Tea and Herb Leaves

    Directory of Open Access Journals (Sweden)

    Saud S. AL-Oud

    2003-01-01

    Full Text Available The quality of tea brands and herbs available in the retail market in the Kingdom of Saudi Arabia were assessed based on contents of heavy metals in their tissues. All tested brands of tea and herbs possess considerable amounts of the eight tested heavy metals, Mn, Fe, Zn, Cu, Ni, Co, Pb and Cd. The tested nine brands of tea as well as five herbs proved high variability (P < 0.01 in their contents of heavy metals. Among tested heavy metals, Mn was the most abundant one in tea leaves (390-900 ?g g?1 whereas Fe was the predominance one in herb leaves (326-1755 ?g g?1. Fortunately, toxic heavy metals, Pb and Cd, had the lowest contents in both tea and herb leaves. Among tested tea brands, Chinese green tea possesses the highest contents of heavy metals. Concentrations of tested heavy metals in tea and herb beverage were markedly lower than their total contents. The concentrations of toxic heavy metals, Pb and Cd were too low to be detected in beverage using the available analytical techniques. The solubility of studied heavy metals in both brew and infusion extracts varied widely and ranged from 0.0-48%. The lowest rates of solubility were listed for toxic heavy metals Pb and Cd. The amounts of heavy metals that one may take up through consumption of tea and herb beverages were found to match the acceptable daily intake that takes into account exposure from air, food and drinking water.

  7. Heavy metal transfer from atmosphere to plants

    Science.gov (United States)

    Asta, J.; Guillard, E.; Tissut, M.; Gaude, T.; Ravanel, P.

    2003-05-01

    Heavy metal contamination due to traffic was studied in the water basin of the Aiguebelette lake (Savoie, France) in the alpine chain. It is surrounded by mountains and crossed by a highway on a 6-km-distance. Contamination of lichens, mosses, barks and dead leaves litters were submitted to a comparative study. The quantities of six metals (Pb, Al, Cd, Zn, Mn, Ni) were estimated in each of these materials. Except for Al which was highly concentrated in Xanthoria parietina and to a lesser extent in mosses, all the matrices accumulated the metals in a relatively similar way. The hyperaccumulation factor varied from 2 to 258, depending on the sampling point on the studied metal and on the matrix. Bark represented a long-term accumulator and contained more lead than the other matrices. In the studied water basin, a specific atmospheric movement allowed to distribute the contaminants far away from the highway, especially on the west slope of the highest mountain.

  8. Dynamic tensile testing of heavy metals

    International Nuclear Information System (INIS)

    For some applications of heavy metals it is most valuable to have material properties data obtained with high strain rates. The parameters from this kind of testing can then be used for materials selection. At FFV Materials Technology an apparatus for high speed tensile testing was developed. Test specimens can be fractured at strain rates from 1.103 - 1.104 strain/second. This strain rate is about seven to eight orders of magnitude higher than strain rate used in conventional tensile testing. Ultimate tensile strength and elongation date are obtained from the tests. The apparatus and the interpretation of the results are presented. The results of different kinds of heavy metals with varying Ni/Fe ratios, the effect of additions (Mo, Cr and Co) and the effects of deformation (swaging) and annealing prior to testing were investigated and are discussed. 1 ref., 3 tabs., 3 figs. (Author)

  9. Quantum Criticality in Heavy Fermion Metals

    CERN Document Server

    Gegenwart, Philipp; Steglich, Frank; 10.1038/nphys892

    2009-01-01

    Quantum criticality describes the collective fluctuations of matter undergoing a second-order phase transition at zero temperature. Heavy fermion metals have in recent years emerged as prototypical systems to study quantum critical points. There have been considerable efforts, both experimental and theoretical, which use these magnetic systems to address problems that are central to the broad understanding of strongly correlated quantum matter. Here, we summarize some of the basic issues, including i) the extent to which the quantum criticality in heavy fermion metals goes beyond the standard theory of order-parameter fluctuations, ii) the nature of the Kondo effect in the quantum critical regime, iii) the non-Fermi liquid phenomena that accompany quantum criticality, and iv) the interplay between quantum criticality and unconventional superconductivity.

  10. Removal, recovery and enrichment of metals from aqueous solutions using carbon nanotubes

    International Nuclear Information System (INIS)

    Environmental pollution caused by toxic metals (heavy metals, radioactive metals, etc.) is one of the major global issues, thus removal of toxic metals from contaminated water seems to be particularly important. On the other hand, the recovery and enrichment of metals, especially noble metals, from waste water is also crucial. To address these issues, nanotechnology plays an essential role in environmental monitoring and pollution control. To remove metals from contaminated water, or enrich metals from waste water, carbon nanotubes (CNTs) and their composites have attracted great attention due to their excellent adsorption performance. The removal efficiency for metal ions by CNTs was observed around 10-80 %, which could be improved to approach 100 % by selectively functionalizing CNTs with organic ligands. Herein, we review the applications of CNTs in treatment of toxic metal-containing wastewater for environmental monitoring and metals recovery. Due to their higher sensitivity and selectivity towards the enrichment of metals or detection of toxic metal pollution of the environment, and the latest research progress of using CNT composites for metal treatment is also discussed. (author)

  11. Assays of heavy metal accumulation in lichens

    International Nuclear Information System (INIS)

    In a biomonitoring investigation in Rome (Central Italy) a series of laboratory tests has been carried out to evaluate accumulation and release of heavy metals on lichen thalli taken from live plants and thalli, used as transplants. The thalli were whole, ground, viable, and dead. The results show that a) the dead thalli accumulate as much as the viable ones; b) distilled waterwashing does not induce the release of metals, especially of led, which does instead happen in acid solutions. This would seem to confirm the hypothesis of the lixiviating effect of acid rains; c) lastly, to a greater accumulation seems to correspond a lesser release

  12. Polymers contamination by heavy metal compounds

    OpenAIRE

    Jovani? Saša; Stoiljkovi? Dragoslav M.; Popovi? Ivanka G.

    2002-01-01

    The contamination of important synthetic (surface unmodified) polymers by various heavy metal compounds (such as copper, manganese and lead) in aqueous medium was investigated in this study. The influence of the pH of the aqueous medium, temperature and metal type on contamination was investigated during a 10 day period. It was found that increasing pH contributed to higher polymer contamination (at higher pH 100 times for copper and up to 400 times for lead), as well as contact with easily p...

  13. Heavy metal burden of the Pinnau river

    International Nuclear Information System (INIS)

    The water phase and sediment of the Pinnau river were investigated for their heavy-metal pollution. Tests for the elements chromium, mercury, nickel, arsenic, lead, copper, cadmium, zinc and iron were carried through with sediment samples in 1984 and 1989 and with water samples in 1987 and 1989. Whereas no significant changes in the levels of these metals were found in the water phase during the two-year period of invetigation, slightly reduced levels of zinc, cadmium and mercury were established in the sediment in 1989 as compared to 1984. (orig.)

  14. Phytoremediation of heavy metal from contaminated soil.

    Czech Academy of Sciences Publication Activity Database

    Soudek, Petr; Kališová, Ivana; Van?k, Tomáš

    Praha : ÚOCHB AV ?R, 2003 - (Van?k, T.; Schwitzguébel, J.), s. 65 ISBN 80-86241-19-X R&D Projects: GA MŠk OC 837.10; GA AV ?R IBS4055014; GA AV ?R IAA6055902 Institutional research plan: CEZ:AV0Z4055905 Keywords : heavy metals * phytoremediation * corn Subject RIV: DK - Soil Contamination ; De-contamination incl. Pesticides

  15. Heavy metals in carabids (Coleoptera, Carabidae)

    OpenAIRE

    Ruslan Butovsky

    2011-01-01

    Carabid beetles (Coleoptera, Carabidae) are one of the most studied soil groups in relation to heavy metal (HM) accumulation and use for bioindication of environmental pollution. Accumulation of Zn and Cu in carabid beetles was species-, sex- and trophic group-specific. No differences were found in HM contents between omnivorous and carnivorous species. The use of carabid beetles as indicators of HM accumulation appears to be rather limited.

  16. Black Hole Thermodynamics and Heavy Fermion Metals

    CERN Document Server

    Brynjolfsson, E J; Thorlacius, L; Zingg, T

    2010-01-01

    Heavy fermion metals typically exhibit non-Fermi-liquid behavior at low temperatures, including a logarithmic or power law rise in the ratio of specific heat to temperature as the temperature is lowered. This anomalous specific heat can be qualitatively reproduced in a simple class of gravitational dual models with dynamical critical exponent z > 1, whereas their conformal counterparts at z = 1 exhibit conventional Fermi liquid behavior in the low-temperature specific heat.

  17. Heavy Metal Contaminants in Yerberia Shop Products

    OpenAIRE

    Levine, Michael; Mihalic, Jason; Ruha, Anne-michelle; French, Robert N. E.; Brooks, Daniel E.

    2012-01-01

    Complementary and alternative medications, including the use of herbal medications, have become quite popular in the USA. Yerberias are found throughout the southwest and specialize in selling Hispanic herbal products. The products sold in these stores are not regulated by any governmental agency. Previous reports have found Ayurvedic medications contain high levels of lead, mercury, and arsenic. The primary purpose of this study is to examine the prevalence of heavy metal contaminants sold a...

  18. Heavy metals in the hydrological cycle

    International Nuclear Information System (INIS)

    An integrated approach to the problems associated with heavy metals in the hydrological cycle is presented. Research and practical experience from a broad spectrum of disciplines are drawn together concentrating on the following themes: water quality, domestic and industrial wastes, sludge and dredge materials, soil interactions, effects on aquatic ecosystems, organometallics (with particular reference to tin compounds), speciation, the marine environment and health effects. One paper is within INIS scope and is processed separately. (U.K.)

  19. Heavy metal glasses for optical devices

    International Nuclear Information System (INIS)

    Optical communication devices based on non-linear phenomena have been calling attention, according literature shows. Among the various materials studied, glasses are detached. It was found a co-relation between the refractive index and the non-linear optical coefficients; bigger linear refractive indexes will have more probability of application of vitreous matrix in the field of optical devices. Among the compositions which present these characteristics are the heavy metal glasses. (author)

  20. Heavy metal movement in metal-contaminated soil profiles

    Energy Technology Data Exchange (ETDEWEB)

    Li, Zhenbin; Shuman, L.M. [Univ. of Georgia, Griffin, GA (United States)

    1996-10-01

    Heavy metal movement in soil profiles is a major environmental concern because even slow transport through the soil may eventually lead to deterioration of groundwater quality. In this study, three metal-contaminated soil (Fuquay, Dothan, and Clarendon) were selected from cropland were a high-metal flue dust had been applied annually for 6 years to raise soil pH, with application ending 4 years before sampling. One uncontaminated soil (Tifton) from the same physiographic area was also sampled as a control. Soil samples were collected in 15-cm increments from the surface to 105 cm in depth. Total contents of Zn, Cd, and Pb in the soils samples were determined. To better understand metal movement in relation to metal fractions in the soil profile, soil samples were also extracted sequentially for exchangeable (EXC), organic matter (OM), Mn oxide (MNO), amorphous Fe oxide (AFEO), crystalline Fe oxide (CFEO), and residual (RES) fractions. 35 refs., 6 figs., 2 tabs.

  1. Heavy metal emissions for Danish road transport

    Energy Technology Data Exchange (ETDEWEB)

    Winther, M.; Slentoe, E.

    2010-04-15

    This report presents new heavy metal emission factors for cars, vans, trucks, buses, mopeds and motorcycles for each of the emission sources fuel consumption, engine oil, tyre wear, brake wear and road abrasion. The emission components covered are Arsenic (As), Cadmium (Cd), Chromium (Cr), Copper (Cu), Mercury (Hg), Nickel (Ni), Lead (Pb), Selenium (Se) and Zinc (Zn), all of them relevant for emission reporting to the UNECE CLRTAP (United Nations Economic Commission for Europe Convention on Long Range Transboundary Pollutants) convention. The report also presents a new Danish inventory for the year 2007. The following emissions in total TSP (in brackets) are calculated for the year 2007: As (8 kg), Cd (48 kg), Cr (197 kg), Cu (51 779 kg), Hg (28 kg), Ni (158 kg), Pb (6 989 kg), Se (33 kg) and Zn (28 556 kg). Per vehicle type cars are the most important source of emission for all heavy metal species, followed by vans, trucks, buses and 2-wheelers. By using the detailed emission factors and inventory calculation methods established in the present project, estimates of heavy metal emissions can be made for other years than 2007. (author)

  2. Reduction of dioxin and heavy metals by semi-dry scrubber and baghouse from MSW incinerator

    International Nuclear Information System (INIS)

    This paper presents the result of investigations about PCDDs/PCDFs and heavy metals discharged from MSW incineration plants. As to the PCDDs/PCDFs, inlet temperature of the baghouse appeared to be most important parameter. To control the PCDDs/PCDFs lower temperature is better. And dust load on the fabric filter is important parameter too. The heavier dust load on the fabric filter, the better the removal of the PCDDs/PCDFs. As to the heavy metals, Pb, Cn, Zn, are removed well at the baghouse and the removal of them depends on the dust load on the fabric filter same as PCDDs and PCDFs. However, it is difficult to remove Hg at baghouse in spite of low temperature and heavy dust load on the fabric filter

  3. Broom fibre PRB for heavy metals groundwater remediation

    Science.gov (United States)

    Molinari, A.; Troisi, S.; Fallico, C.; Paparella, A.; Straface, S.

    2009-04-01

    Soil contamination by heavy metal and, though it, of groundwater represent a serious alteration of original geochemical levels owing to various human activities as: particular industrial processes and their non-correct treatment emission, urban traffic, use of phytosanitary product and mineral fertilizer. Heavy metals are genotoxic contaminants who can be found by environmental matrix analysis or by examination of the genetic damage inducted, after exposition, to sentry organism. In this last case we use a relative quantitation of the gene expression monitoring the mitochondrial oxidative metabolism hepatopancreas's gene of the organism used by bioindicator. This test is based on consideration that the hepatopancreas is the first internal organ affected by heavy metals or any other pollutant that the organism is exposed. In this work, the organism used by bioindicator to evalutate the pollutant contamination of waste water is Danio rerio (Zebrafish) that is a little tropical fish of 2-3 cm, native on asiatic south-east rivers. This organism has a large use in scientific field because its genoma is almost completely mapped and, above all, because the congenital gene cause in human, if it was mutated in zebrafish, similar damage or almost similar mutation that happens in human being so you can develop a dose - response curve. To do this, after prepared a cadmium solution with a concentration 10 times the Italian normative limit, the organisms have been put in the aquarium to recreate the optimal condition to survival of zebrafish observed by continuous monitoring by web-cam. After one month exposition, that we took little by little sample fish to analyzing, for different exposition time, the hepatopancreas's fish. First results shows considerable variation of the gene expression by interested gene in mitochondrial oxidative metabolism compared to control, highlighting the mutagenity caused by heavy metals on Danio rerio's hepatopancreas and, mutatis mutandis, also in human being. One of the most interesting techniques applied in contaminated aquifer by heavy metals is the PRBs (Troisi et al., 2002; Calvin et al., 2006), in particular broom fibers PRB (Troisi et al., 2008). The first results highlight an optimum removal capacity for contaminants underlined from following removal percentage: 98.01% (Cd), 99.95% (Cu), 97.35% (Pb) and 99.53% (Zn). A fundamental parameter for PRB design is the decay coefficient who indicates the removal capacity (degradation, transformation, adsorption/absorption, mass transport, etc.). This parameter has been determined for four heavy metals: Cadmium (Cd), Copper (Cu), Lead (Pb) and Zinc (Zn) carrying out column tests. Besides, for real use of broom fibers PRB same tests have been performed, using flow cells, to estimate a relation between hydraulic conductivity of fiber and its density. References Chien C. C., H. I. Inyang and L.G. Everett (2006). Barrier Systems for Environmental Contaminant Containment and Treatment. Taylor and Francis Group eds. Troisi S., C. Fallico, S. Straface S. e L. Mazzuca. (2008). Biodreni per la bonifica di siti contaminati realizzati con fibre naturali liberiane ad elevato sviluppo superficiale. CS2008A00018. Università della Calabria. Troisi S, E. Migliari and S. Straface (2002). Soil and groundwater contamination by heavy metals in the industrial area of Crotone. Third International Conference Risk Analysis III. Sintra, Ed. by C.A. Brebbia. WIT Press.

  4. Improvement Bio sorption of Heavy Metals from Industrial Wastewater Using Azolla

    International Nuclear Information System (INIS)

    This study aims to improve the removal process which is vital for some heavy metals and natural radionuclides from industrial wastewater by bio sorption using living organisms with rapid growth as a trial to increase the efficient use of those organisms in the removal process is vital for the toxic elements. Bio sorption of heavy metal (Copper, Manganese, Iron, Zinc, Lead and Strontium) from industrial waste water (contaminated) with six different time periods for Azolla growth. The results indicate that Azolla plant able to on the absorption of ions of heavy elements and Sr and was up to the maximum absorption of most of the elements at a concentration of 50% of polluted water + 50% fresh water so we recommend using the plant Azolla as bio sorbent in the disposal and collection of heavy metals and radionuclides from industrial waste water and deal with it safely to humans and the environment. The results obtained confirm the ability of the fern to grow and absorb ion of heavy metal when mixed with industrial waste water and other sources of polluted water and act as bio filter. The optimum conditions for maximum removal of heavy metals were also determined. Study was conducted on recycling municipal wastewaters for cultivation of Azollamicrophylla biomass, which is used for inoculation into paddy fields as N bio fertilizer and has other applications as green manure,animal feed and bio filter.

  5. [Characteristics of speciation and evaluation of ecological risk of heavy metals in sewage sludge of Guangzhou].

    Science.gov (United States)

    Guo, Peng-Ran; Lei, Yong-Qian; Cai, Da-Chuan; Zhang, Tao; Wu, Rui; Pan, Jia-Chuan

    2014-02-01

    Contents of heavy metals in different sewage sludges were analyzed and the speciation distribution and bioavailability of heavy metals were investigated, and the risk assessment code (RAC) and toxicity characteristic leaching procedure for solid waste were used to evaluate the potential ecological risk and leaching toxicity risk of heavy metals in sludge samples, respectively. The results showed that contents of Cu, Cr, Pb and Zn were high and presented a great difference by different sources in sewage sludges. Most of heavy metals existed in non-residual fractions and percentages of the mobile fraction (acid soluble fraction) of heavy metals in acidic sludge were higher. According to the results of single extraction, 1 mol x L(-1) NaOAc solution (pH 5.0) and 0.02 mol x L(-1) EDTA + 0.5 mol x L(-1) NH4OAc solution (pH 4.6) were suitable for evaluating bioavailable heavy metals in acidic and alkaline sludge, respectively. Percentages of bioavailable heavy metals were higher with the stronger of sludge acidity. The mobile ability of heavy metals resulted in the high ecological risk of sludge samples, and the bioavailability of heavy metals caused acidic sludges with a very high ecological risk but alkaline sludges with the middle ecological risk. Leaching toxicity risk was very high in sludge samples except domestic sewage sludge. After the removal of bioavailable heavy metals, leaching toxicity risk of sludge samples was still high in spite of its decrease; however, part type of sludges could be implemented landfill disposal. PMID:24812965

  6. Neutron removal in peripheral relativistic heavy ion collisions

    International Nuclear Information System (INIS)

    We investigate the relativistic Coulomb fragmentation of 197Au by heavy ions, leading to one-, two- and three-neutron removal. To resolve the ambiguity connected with the choice of a specific minimum impact parameter in a semiclassical calculation, a microscopic approach is developed based on nucleon-nucleon collisions ('soft-spheres' model). This approach is compared with experimental data for 197Au at 1 GeV/nucleon and with a calculation using the 'sharp-cutoff' approximation. We find that the harmonic-oscillator model predicting a Poisson distribution of the excitation probabilities of multiphonon states gives a good agreement with one-neutron removal cross sections but is unable to reach an equally good agreement with three-neutron removal cross sections. (orig.)

  7. Growth and Heavy Metals Accumulation Potential of Microalgae Grown in Sewage Wastewater and Petrochemical Effluents

    Directory of Open Access Journals (Sweden)

    K. Thirugnanamoorthy

    2011-01-01

    Full Text Available Microalgae exhibit a number of heavy metal uptake process by different metabolism. In this study, the ability of microalgae for removal of heavy metal from wastewater was studied. Growth and biochemical contents of microalgae were determined by spectrophotometer. Heavy metal analysis of wastewater effluents were performed by atomic absorption spectrophotometer before and after treatment at laboratory scale. The growth of Scenedesmus bijuga and Oscillatoria quadripunctulata in sewage wastewater was higher than those grown in synthetic medium. Whereas, the growth of S. bijuga and O. quadripunctulata in sterilized petrochemical effluents was slightly lower than that grown in the standard synthetic medium. The chlorophyll, carotenoid and protein content of S. bijuga and O. quadripunctulata grown in sterilized sewage wastewater were higher than those grown in the standard medium. Similarly S. bijuga and O. quadripunctulata grown in sterilized petrochemical effluents showed lower contents of pigments and protein than those grown in sewage and synthetic medium. Heavy metals copper, cobalt, lead and zinc were removed by 37-50, 20.3-33.3, 34.6-100 and 32.1-100%, respectively from sewage wastewater and petrochemical effluent using Ocillatoria culture. The metal absorption by S. bijuga were (Cu, Co, Pb, Zn 60-50, 29.6-66, 15.4-25 and 42.9-50%, respectively from sewage and petrochemical effluents. Both species showed high level of heavy metal removal efficiency and metal sorption efficiency of both microalgae depended on the type of biosorbent, the physiological status of the cells, availability of heavy metal, concentration of heavy metal and chemical composition of wastewater.

  8. Metallic artifact in MRI after removal of orthopedic implants

    International Nuclear Information System (INIS)

    Objective: The aim of the present study was to evaluate the metallic artifacts in MRI of the orthopedic patients after removal of metallic implants. Subjects and methods: From March to August 2009, 40 orthopedic patients operated for removal of orthopedic metallic implants were studied by post-operative MRI from the site of removal of implants. A grading scale of 0–3 was assigned for artifact in MR images whereby 0 was considered no artifact; and I–III were considered mild, moderate, and severe metallic artifacts, respectively. These grading records were correlated with other variables including the type, size, number, and composition of metallic devices; and the site and duration of orthopedic devices stay in the body. Results: Metallic susceptibly artifacts were detected in MRI of 18 of 40 cases (45%). Screws and pins in removed hardware were the most important factors for causing artifacts in MRI. The artifacts were found more frequently in the patients who had more screws and pins in the removed implants. Gender, age, site of implantation of the device, length of the hardware, composition of the metallic implants (stainless steel versus titanium), and duration of implantation of the hardware exerted no effect in producing metallic artifacts after removal of implants. Short TE sequences of MRI (such as T1 weighted) showed fewer artifacts. Conclusion: Susceptibility of metallic artifacts is a frequent phenomenon in MRI of patients upon removal of metallic orthoptients upon removal of metallic orthopedic implants.

  9. Magnetic filtration of heavy metals containing waters

    International Nuclear Information System (INIS)

    The high-intensity magnetic separation is applied above all in the beneficiation of fine-grained weakly magnetic ores, but also in the treatment of industrial, especially metallurgical and mining waters as well as of wastewaters from nuclear power stations. Similarly, it can be used in the field of geothermal energy supply and gases filtration. The magnetic separation or filtration respectively, directly enables the treatment of waters contaminated by solid ferromagnetic and paramagnetic particles. The magnetic filtration can remove heavy metals ions and even the oil substances by means of magnetic sorbents or special additives. The filtration of solid magnetic particles can be carried out in matrix-less and matrix separators. On the basis of mathematical description of particles dynamics and hydrodynamic conditions of suspension flow which resulted in the determination of geometrical parameters of separating zone the design of matrix-less magnetic separator was carried out. A strong, high-intensity magnetic field was created by means of a superconductive magnetic circuit. It was found out that for the achievement of optimal technological parameters during the magnetic separation of solid particles with grain size under 40 mm, the maximal solids concentration is to be 200 g/L. The design of matrix parameters and selection of inductive filling resides in theoretical considerations as well as in experimental works. Under laboratory condition the influence of following parameters on magnetic filtration process have been observed: the diameter of inductive ferromagnetic balls, the thickness of filtration layer, the intensity of magnetic field, the flow velocity of suspension, the density of suspension, the grain size of solids and the temperature of suspension. It was found that a spatial arrangement of inductive bodies in filtration layer influences not only the velocity of suspension flow but also a room size for catching of magnetic particles. The acting of magnetic field expresses itself in a rearrangement of inductive bodies or their secularisation's, respectively. Such rearrangement results in the room size decreasing in comparison with the one at the arrangement without the magnetic field acting. For instance, if an volume of filtration chamber is loosely filled by globe-shaped inductive bodies a coefficient of fill equals 0.60. But under acting of magnetic field its value falls to the range of 0.55 - 0.56. (authors)

  10. Sediment, water pollution indicators for heavy metals

    International Nuclear Information System (INIS)

    The complexity of an aquatic system requires consideration of its dynamics: spatial and temporal variations of physical, chemical and biological. Heavy metals have peculiar behavior in the aquatic system and may not be available in the waters, but on sediments.The sub-basin of the Sarandi stream is responsible for the contamination of Pampulha Lake. The Instituto Mineiro das Águas – IGAM - uses tool for monitoring the quality of surface water for developing strategies for conservation, restoration and rational use of water resources. So through the indices: IQA ( Indice de qualidade de águas) Index of water quality, and TC- toxic contamination, reduces conflicts, implements the disciplining of the environmental economy.This study determined the monitoring of sediment and water of Sarandi Stream, so in the samples collected during dry and rainy seasons (2007- 2008) were analyzed heavy metals (Cu, Cd, Cr, Co, Ni, Zn, Pb) and physical-chemical factors (conductivity, solids dissolved, temperature, turbidity). This allowed the determination of Hackanson factors of contamination and Muller Index geoaccumulation, indicating very high contamination in sediments regarding the elements Cr, Cu, and Cd, and high contamination for Pb, Zn, and Mn. The comparison with the indices of water quality- IQA (IGAM - 2006, 2007 and 2008), combined with exploratory data analysis and graphs of correlation between the variables indicated favorable conditions for metals contamination on water and sediment for these metals, besides allowing the identification of its source

  11. Process for Separating Heavy Metals from Industrial Residues by Using an Ultrasound Flotation and Eucalyptus as Sequestering Agent

    OpenAIRE

    Abrego Lopez Jose

    2006-01-01

    The disclosed method relates to the process for the removal of heavy or toxic metals from residual, industrial or municipal waters and sludges to such an extent that the waters processed by flotation comply with the ecological standards. Tests were carried out in order to remove heavy metals in samples of residual industrial waters from electroplating plants. The methodology used is the ultrasound flotation in two steps, using in the first step a collector (which is generally heteropolar orga...

  12. Determination of the levels of heavy metals in cocoa products

    International Nuclear Information System (INIS)

    Fermented and dried cocoa beans from all the major cocoa-producing regions in Ghana were analyzed for levels of the following heavy metals: arsenic, cadmium, chromium, cobalt, copper, iron, lead, manganese, nickel and zinc. The shells of the beans which usually do not form a part of the edible portion of the beans were removed and analyzed separately from the cocoa nibs (de-shelled beans) for all the elements above. To determine the distribution of metals during processing of the beans soxhlet extractions of fat from pulverised cocoa nibs was performed and cocoa powders obtained analyzed for their levels of heavy metals. Three commercial brands of 'natural' cocoa powders on the local market were also analyzed to determine the levels of these metals. The analyses were performed using an inductively coupled plasma - optical emission spectrophotometer (ICP-OES) following a microwave-assisted digestion process. The levels of toxic metals lead, cadmium and arsenic were found to be low (? 0.020 ?g/g, ? 0.087 ?g/g, < 0.001 ?g/g, respectively) and well within the acceptable limits set by the WHO (0.100 ?g/g, 0.100 ?g/g, and 0.010 ?g/g respectively). However, the levels of zinc copper, iron and manganese were however quite high. With a high fat content of the cocoa beans (approximately 50%) and greater portioning of metals into the non-fat portions of the beans, metals levels were considerably higher (almost double) in processed cocoa than in the cocoa itself. (au)than in the cocoa itself. (au)

  13. Natural Bioremediation of Heavy Metals Through Nematode Parasite of Fish

    Directory of Open Access Journals (Sweden)

    Rafia Azmat

    2008-01-01

    Full Text Available Parallel analysis of heavy metals (Pb, Cd, Hg, As, Zn and Fe in muscles and guts of fishes, seawater and fish parasites were detected by atomic absorption Spectrophotometry. The bioaccumulation potential of heavy toxic metals was assessed in the Echinocephalus sp. and Ascaris sp. which is, reported as natural bioremediator of heavy metals in Liza vaigiensis from Karachi coast. Investigation suggests that infected fish contain low concentration of heavy metals in their muscle as compared to non - infected one. The high level of toxic metals in Echinocephalus sp. and Ascaris sp. within its host suggests that these nematode parasites are sensitive indicator of heavy metals in aquatic ecosystem showing sharing of more burden of environmental pollution of sea and also act as bioremediator of heavy metals in fish.

  14. Magnetic susceptibility as an indicator of heavy metal contamination in compost.

    Science.gov (United States)

    Paradelo, Remigio; Moldes, Ana Belén; Barral, María Teresa

    2009-02-01

    One of the main restrictions to the agronomic use of compost is the excess of heavy metals, which are often present due to inadequate separation of biodegradable fractions from non-degradable or inert materials. Magnetic susceptibility (MS) measurements are a simple technique that has been reported as a useful tool for assessing anthropogenic pollution, especially heavy metal pollution on soil and sediment samples. The close relationship of MS with heavy metal contamination has been proved by combined analyses of chemical and magnetic data. In this study, the MS and total heavy metal concentrations of eight composts from different origins were determined; all composts were passed under a magnet to remove the magnetic material, and total heavy metals were determined again. In our work, high correlations were found between magnetic susceptibility and total Cd, Zn, Pb, Cr and Ni, thus confirming the applicability of MS measurement as a proxy for heavy metal contamination in compost quality assessments. The application of a magnet over the composts reduced the MS as well as the heavy metal content, the reduction of Fe and MS being the most significantly correlated. Thus, the inclusion of an additional magnetic separation step in the post-process compost finishing could be envisaged. PMID:19220992

  15. The possible use of soluble humic substances for remediation of heavy metal polluted soils

    DEFF Research Database (Denmark)

    Borggaard, Ole K.; Jensen, Julie Katrine

    2008-01-01

    Polluted soil is a common and serious environmental problem. While reliable methods exist for cleaning soil contaminated by organic compounds through degradation, remediation of heavy metal polluted soils awaits an appropriate solution. This is because heavy metals are nondegradable and generally strongly bonded in soils. Consequently, removal of heavy metals by extraction is difficult and requires harsh chemicals such as ethylenediaminetetraacetic acid (EDTA) and acids. However, use of EDTA is environmentally problematic because of persistence, toxicity and deterioration of soil structure. Therefore, the potential of soluble natural humic substances (HS) to extract heavy metals from contaminated soils is tested as an environmental friendly substitute for EDTA. A strongly polluted urban soil and a moderately polluted agricultural soil were extracted at neutral pH in batch mode by three HS solutions from beech and Norway spruce litter and processed cow slurry, all containing 25 mM dissolved organic carbon (DOC). After 10 weeks, 8 % to 39 % of the total Cd, Cu, Ni and Pb soil contents were extracted. Increasing the DOC concentration to 100 mM resulted in markedly increased heavy metals extraction. Heavy metal extraction with dissolved HS is compared with EDTA at the same concentration and sequential extraction has been performed to identify extracted pools. The results indicate a clear potential of using HS solutions for remediation of heavy metal polluted soils, which is fortunate, especially if organic waste products such as sewage sludge and animal slurry after proper processing can be turned into soluble HS as preliminary investigations indicate.

  16. Comparison of Heavy Metals Extraction Efficiency in Contaminated Soils by Various Concentrations of EDTA

    Directory of Open Access Journals (Sweden)

    A.H. Mahvi

    2005-01-01

    Full Text Available This study aimed to establish an optimized concentration and application of Na2-EDTA in heavy metals removal from contaminated soils. Laboratory experiments were conducted to evaluate the interaction of metals (Cd, Zn and Pb in soil. Thus, the feasibility of soil washing for the decontaminated silt, clay and loam with single and several metals were evaluated in laboratory-scale batch experiments. Extraction of Cd, Zn and Pb in experimental soils was determined by several different concentrations of extraction solutions. Batch washing of the contaminated soil with deionised water was used as a control. Of the washing reagent test, Na2-EDTA 0.1 M solutions were generally more effective for removing heavy metals from soils. Na2-EDTA 0.1M preferentially extracted lead over Cd and Zn. However, Na2-EDTA 0.005 M solution indicated higher removal efficiency for Cd and Zn.

  17. Phytoremediation of Heavy-Metal-Contaminated Soil in a Reclaimed Dredging Area Using Alnus Species

    Directory of Open Access Journals (Sweden)

    Deok Beom Lee

    2009-11-01

    Full Text Available To investigate the possible applications of plants to remediate heavy-metal-contaminated soil, a pilot experiment was performed for four years in a reclaimed dredging area using two Alnus species, i.e., Alnus firma and Alnus hirsuta. In a comparison of phytomass of the two species at two different planting densities, the phytomass of Alnus planted at low density was twice as high as that of Alnus planted at high density after four years. The Alnus species showed active acclimation to the heavy-metal-contaminated soil in a reclaimed dredging area. A. hirsuta showed greater accumulation of phytomass than A. firma, indicating that it is the better candidate for the phytoremediation of heavy-metal-contaminated soils. In the pilot system, Alnus plants took metals up from the soil in the following order; Pb > Zn > Cu > Cr > As > Cd. Uptake rates of heavy metals per individual phytomass was higher for Alnus spp. planted at low density than those planted at high density in the pilot system. Low plant density resulted in higher heavy metal uptake per plant, but the total heavy metal concentration was not different for plants planted at low and high density, suggesting that the plant density effect might not be important with regard to total uptake by plants. The quantity of leached heavy metals below ground was far in excess of that taken up by plants, indicating that an alternative measurement is required for the removal of heavy metals that have leached into ground water and deeper soil. We conclude that Alnus species are potential candidates for phytoremediation of heavy-metal- contaminated surface soil in a reclaimed dredging area

  18. Use of heavy ions to model radiation damage of metals

    International Nuclear Information System (INIS)

    The methods for modeling radiation damage of metals using heavy ions are reviewed and the results obtained are analyzed. It is shown that irradiation of metals with heavy ion can simulate neutron exposure with the equivalent dose with adequate accuracy and permits a detailed analysis of radiation damage of metals

  19. Filter materials for metal removal from mine drainage--a review.

    Science.gov (United States)

    Westholm, Lena Johansson; Repo, Eveliina; Sillanpää, Mika

    2014-08-01

    A large number of filter materials, organic and inorganic, for removal of heavy metals in mine drainage have been reviewed. Bark, chitin, chitosan, commercial ion exchangers, dairy manure compost, lignite, peat, rice husks, vegetal compost, and yeast are examples of organic materials, while bio-carbons, calcareous shale, dolomite, fly ash, limestone, olivine, steel slag materials and zeolites are examples of inorganic materials. The majority of these filter materials have been investigated in laboratory studies, based on various experimental set-ups (batch and/or column tests) and different conditions. A few materials, for instance steel slag materials, have also been subjects to field investigations under real-life conditions. The results from these investigations show that steel slag materials have the potential to remove heavy metals under different conditions. Ion exchange has been suggested as the major metal removal mechanisms not only for steel slag but also for lignite. Other suggested removal mechanisms have also been identified. Adsorption has been suggested important for activated carbon, precipitation for chitosan and sulphate reduction for olivine. General findings indicate that the results with regard to metal removal vary due to experimental set ups, composition of mine drainage and properties of filter materials and the discrepancies between studies renders normalisation of data difficult. However, the literature reveals that Fe, Zn, Pb, Hg and Al are removed to a large extent. Further investigations, especially under real-life conditions, are however necessary in order to find suitable filter materials for treatment of mine drainage. PMID:24781327

  20. Heavy metals in MSW incineration fly ashes

    DEFF Research Database (Denmark)

    Ferreira, Celia; Ribeiro, Alexandra B.

    2003-01-01

    Incineration is a common solution for dealing with the increasing amount of municipal solid waste (MSW). During the process, the heavy metals initially present in the waste go through several transformations, ending up in combustion products, such as fly ash. This article deals with some issues related to the combustion of MSW and the formation of fly ash, especially in what concerns heavy metals. Treatment of the flue gas in air pollution control equipment plays an important role and the basic processes to accomplish this are explained. Fly ash from a semi-dry flue gas treatment system is characterized regarding its physical-chemical properties: pH, solubility, chemical composition, and leaching, amongst others. Results indicate a high alkalinity and the presence of large amounts of calcium, chlorides, sulfates, carbonates, sodium and potassium. Metal concentrations in fly ash are: 6,2 g/kg for zinc, 2,4 g/kg for lead, 1,7 g/kg for iron, and 7,9 g/kg for magnesium. Copper, manganese, chromium and cadmium arealso present with 546, 338, 104 and 91 mg/kg of fly ash, respectively. These results are extremely important in subsequent studies on the treatment of fly ash.

  1. Peltier effect in normal metal-insulator-heavy fermion metal junctions

    OpenAIRE

    Goltsev, A. V.; Rowe, D. M.; Kuznetsov, V. L.; Kuznetsova, L. A.; Min, Gao

    2003-01-01

    A theoretical study has been undertaken of the Peltier effect in normal metal - insulator - heavy fermion metal junctions. The results indicate that, at temperatures below the Kondo temperature, such junctions can be used as electronic microrefrigerators to cool the normal metal electrode and are several times more efficient in cooling than the normal metal - heavy fermion metal junctions.

  2. Atmospheric heavy metal deposition in Europe estimated by moss analysis

    Energy Technology Data Exchange (ETDEWEB)

    Ruehling, Aa. [Swedish Environmental Research Inst., Lund (Sweden). Dept. of Ecology

    1995-12-31

    Atmospheric heavy metal deposition in Europe including 21 countries was monitored in 1990-1992 by the moss technique. This technique is based on the fact that the concentrations of heavy metals in moss are closely correlated to atmospheric deposition. This was the first attempt to map heavy metal deposition in this large area. The objectives of the project were to characterise qualitatively and quantitatively the regional atmospheric deposition pattern of heavy metals in background areas in Europe, to indicate the location of important heavy metal pollution sources and to allow retrospective comparisons with similar studies. The present survey is a follow-up of a joint Danish and Swedish project in 1980 and an extended survey in 1985 within the framework of the Nordic Council of Ministers. In Sweden, heavy-metal deposition was first mapped on a nation-wide scale in 1968-1971 and 1975. (author)

  3. Heavy metal ions are potent inhibitors of protein folding

    International Nuclear Information System (INIS)

    Environmental and occupational exposure to heavy metals such as cadmium, mercury and lead results in severe health hazards including prenatal and developmental defects. The deleterious effects of heavy metal ions have hitherto been attributed to their interactions with specific, particularly susceptible native proteins. Here, we report an as yet undescribed mode of heavy metal toxicity. Cd2+, Hg2+ and Pb2+ proved to inhibit very efficiently the spontaneous refolding of chemically denatured proteins by forming high-affinity multidentate complexes with thiol and other functional groups (IC50 in the nanomolar range). With similar efficacy, the heavy metal ions inhibited the chaperone-assisted refolding of chemically denatured and heat-denatured proteins. Thus, the toxic effects of heavy metal ions may result as well from their interaction with the more readily accessible functional groups of proteins in nascent and other non-native form. The toxic scope of heavy metals seems to be substantially larger than assumed so far

  4. The potential for heavy metal decontamination

    Energy Technology Data Exchange (ETDEWEB)

    Baker, A.J.M. [Univ. of Sheffield (United Kingdom); McGrath, S.P.; Sidoli, C.M.D. [AFRC Institute of Arable Crops Research, Harpenden (United Kingdom); Reeves, R.D. [Massey Univ., Palmerston North (New Zealand)

    1996-12-31

    Preliminary trials to assess the ability of plant species to extract metals are presented. A range of zinc and nickel hyperaccumulator plants from the Brassicaceae family, collected from diverse populations in Europe, were grown on plots along with nonaccumulating crop plants from the same family. Extraction efficiencies and the number of croppings required to reduce the total zinc in the soil to a concentration of 300 mg/kg are tabulated. Zinc accumulation remained high over a wide range of soil metal concentration. However, the concentration of nickel in the hyperaccumulators increased in accordance with increasing total nickel concentrations in the soil. Calculations suggest that there is an excellent potential for using hyperaccumulator species to remove metals from the rhizosphere where remediation can be considered over a period of years and multiple cropping is a viable option.

  5. Metal plating removal from insulator substrate using pulsed arc discharge

    Science.gov (United States)

    Imasaka, K.; Gnapowski, S.; Akiyama, H.

    2014-06-01

    Removal technique of metal materials from a metal plating insulator substrate using a pulsed arc discharge was proposed and its fundamental characteristics were investigated. The metal plating substrate with three metal-layers structure (cupper, nickel and gold layers) is used as the sample substrate. Repetitive pulsed arc discharge plasma is generated using three types of electrode systems. Effects of the electrode systems on the metal plating removal from the insulator substrate were investigated. The metal plating was removed by the pulsed arc discharge between the electrode and substrate surface. A part of the gold layer, which is the topmost metal layer on the insulator substrate is vaporized and removed by the repetitive pulsed arc discharges.

  6. Phytoremediation of Heavy Metals in Contaminated Water and Soil Using Miscanthus sp. Goedae-Uksae 1.

    Science.gov (United States)

    Bang, Jihye; Kamala-Kannan, Seralathan; Lee, Kui-Jae; Cho, Min; Kim, Chang-Hwan; Kim, Young-Jin; Bae, Jong-Hyang; Kim, Kyong-Ho; Myung, Hyun; Oh, Byung-Taek

    2015-01-01

    The aim of this study is to characterize the heavy metal phytoremediation potential of Miscanthus sp. Goedae-Uksae 1, a hybrid, perennial, bio-energy crop developed in South Korea. Six different metals (As, Cu, Pb, Ni, Cd, and Zn) were used for the study. The hybrid grass effectively absorbed all the metals from contaminated soil. The maximum removal was observed for As (97.7%), and minimum removal was observed for Zn (42.9%). Similarly, Goedae-Uksae 1 absorbed all the metals from contaminated water except As. Cd, Pb, and Zn were completely (100%) removed from contaminated water samples. Generally, the concentration of metals in roots was several folds higher than in shoots. Initial concentration of metals highly influenced the phytoremediation rate. The results of the bioconcentration factor, translocation factor, and enrichment coefficient tests indicate that Goedae-Uksae 1 could be used for phytoremediation in a marginally contaminated ecosystem. PMID:25747237

  7. [Reactions of cyanobacteria to certain heavy metals].

    Science.gov (United States)

    Kostiaev, V Ia

    1980-01-01

    The effect of zinc and cobalt chlorides on cellular growth, N2 fixation, photosynthesis and changes in the content of Na+ and K+ ions in cells was studied with the blue-green alga (cyanobacterium) Anabaena spheroides. The cells were most susceptible to the action of cobalt ions at the beginning of the logarithmic growth phase, and least sensitive by the end of the phase. Cobalt ions were more toxic than zinc ions. The salts of heavy metals inhibited active transport of ions into the algal cells. PMID:6777649

  8. Investigation of Heavy Metals in Groundwater

    OpenAIRE

    Nouri, J.; Mahvi, A. H.; Babaei, A. A.; Jahed, G. R.; Ahmadpour, E.

    2006-01-01

    The objective of this study was to evaluate and map regional patterns of heavy metals (Cu, Cd, Ni and Zn) occurrence in south of Iran. The study was performed in Shush and Andimeshk plains in the south part of Iran, with high agricultural activities that cover an area of 1100 km2 between the Dez and Karkhe rivers. This region was divided into four sub-regions A, B, C and D. Additionally 168 groundwater samples were collected from 42 water wells during the months April, May, August and Septemb...

  9. Heavy Metal Resistance Patterns of Frankia Strains†

    OpenAIRE

    Richards, Joel W.; Krumholz, Glenn D.; Chval, Matthew S.; Tisa, Louis S.

    2002-01-01

    The sensitivity of 12 Frankia strains to heavy metals was determined by a growth inhibition assay. In general, all of the strains were sensitive to low concentrations (50 mM), and SeO22? (1.5 to 3.5 mM). While most strains were sensitive to 0.1 mM Cu2+, four strains were resistant to elevated levels of Cu2+ (2 to 5 mM and concentrations as high as 20 mM). The mechanism of SeO22? resistance seems to involve reduction of the selenite oxyanion to insoluble elemental selenium, whereas Pb2+ re...

  10. Heavy metal retention of different embankments

    Science.gov (United States)

    Werkenthin, Moritz; Kluge, Bjoern; Wessolek, Gerd

    2013-04-01

    The accumulation and retention of heavy metals in roadside soils has been studied for at least over forty years, but it is still subject of major interest. The continuously increasing road traffic induces high heavy metal loadings in runoff and seepage water. Elevated concentrations of heavy metals are a potential environmental risk. Especially in the long term development there is an increasing problem of soil contamination and groundwater pollution. A significant rate of road runoff infiltrates into the hard and soft shoulder. They are usually built during road construction and located directly along the road edge. According to valid german law, newly constructed hard shoulders have to provide a specific bearing capacity to enable trafficability in emergency cases. Therefore the applicable materials consist of defined gravel-soil mixtures, which can fulfill this requirement. To determine and compare the concentration of Pb, Cd, Zn, Cu, Ni, Cr in the road runoff and seepage water of different hard shoulder substrates, we installed 6 lysimeters along the edge of the german highway A115. Three lysimeters were filled with different materials wich are commonly used for road construction in Germany and compacted afterwards. Surface runoff is sampled, as is seepage water in two depths in the three lysimeters. Furthermore three lysimeters where installed and filled with plain gravel, to observe the distribution, quantity and quality of road runoff. Additionally soil column experiments were carried out with the same construction material. Both, the measured seepage water concentrations from field and column experiments of Pb, Cd, Zn, Cu, Ni, Cr do not yet exceed the trigger values of the German Federal Soil Protection and Contamination Ordinance (BBodSchV). No significant differences in heavy metal concentrations of the three artificial hard shoulder lysimeters were determined so far. First analytical results of the road runoff show concentrations of up to 12.9 µg/l Pb, 0.1 µg/l Cd, 19.8 µg/l Cu, 3.9 µg/l Cr, and 49.6 µg/l Zn. They are in the same order of magnitude as literature values.

  11. Role of mycorrhiza to reduce heavy metal stress

    OpenAIRE

    Syeda Asma Bano; Darima Ashfaq

    2013-01-01

    Plants have a system of antioxidant enzymes, which helps to alleviate the effects of various types of stresses. Heavy metals like Cadmium and lead are tolerable for plants to certain extent. The antioxidant enzymes do not function properly at higher concentrations of Cadmium, lead and some other heavy metals. The activities of antioxidant enzymes are reduced due to reactive oxygen species produced as a result of heavy metal stress. The catalase activity was directly inhibited by O2- (Kon...

  12. Effect of heavy metals on enzymes production by Hebeloma crustuliniforme

    OpenAIRE

    Hanna Dahm; Edmund Strzelczyk

    1996-01-01

    Studies were carried out in order to d?termine the effect of some heavy metals (Cu, Cd, Pb, Zn) on the production of enzymes (cellulases, peetinases. proteases) by ectomycorrhizal fungus Hebeloma crusliliniforme (Buli.: Fr.) Quél. All the heavy metals inhibited the general enzymatic activity regardless of the source of carbon used. The metals reduced the egzocellulolytic activity more in media with cellulose powder than with CMC (carboxymethylocellulosc). Among pectolytic enzymes heavy meta...

  13. Measurement of Heavy Metals in Fish from the Tajan River

    OpenAIRE

    Zare, S.; Ebadi, A. G.

    2005-01-01

    In this study samples of three commonly consumed fish ( Sefid, Kafal and Koli ) were analysed for concentrations of heavy metals (Pb, Cd and Cu). Fish were captured using electric fishing on four sites along the Tajan River (Mazandaran province). The concentrations of heavy metals were determined by atomic absorption spectrophotometer. Samples contained detectable concentrations of heavy metals but at concentrations below the Maximum Residue Limit (MRL). Cadmium concentrations were below the ...

  14. Leaching of heavy metals from dredged bottom sediments

    OpenAIRE

    Baran A.; Tarnawski M.

    2013-01-01

    Deposition of sediments on land in atmospheric conditions causes many risks connected with environmental protection. Particularly dangerous is leaching of heavy metals from sediments deposited on land The research aimed at assessment of leaching of heavy metals from dredged bottom sediments potentially disposed on land. In this research it has been shown that the leaching of heavy metals during disposal of polluted and unpolluted bottom sediments does not pose threat to the environment. Leach...

  15. Heavy metal mobility in paper sludge-amended soil columns

    OpenAIRE

    Burgos, Pilar; Madejo?n, Engracia; Lo?pez Nu?n?ez, Rafael; Cabrera, Francisco

    2001-01-01

    The land application of sludge from pulp mills could be one of the most useful and ecological approaches to solving two problems: waste disposal and soil organic matrer reduction. However, the use of this product can imply several risks derived from the high content of heavy metals. Heavy metal content is a limiting factor for the continual and generalised agronomic utilisation of some organic residues. Therefore, a study of the mobility of heavy metals in soil and of hea...

  16. Coal burning leaves toxic heavy metal legacy in the Arctic

    OpenAIRE

    Mcconnell, Joseph R.; Edwards, Ross

    2008-01-01

    Toxic heavy metals emitted by industrial activities in the midlatitudes are transported through the atmosphere and deposited in the polar regions; bioconcentration and biomagnification in the food chain mean that even low levels of atmospheric deposition may threaten human health and Arctic ecosystems. Little is known about sources and long-term trends of most heavy metals before ?1980, when modern measurements began, although heavy-metal pollution in the Arctic was widespread during recent...

  17. Heavy metals occurrence in Italian food supplements

    Directory of Open Access Journals (Sweden)

    Brizio P.

    2013-04-01

    Full Text Available In recent years a significant increase in food supplements consumption has been observed, maybe in the belief that they couldn’t be dangerous for consumers health, even if they don’t achieved medical effects. However, environmental pollution can cause heavy metals contamination that could exceed maximum levels established by European legislation. Aim of this work was to evaluate arsenic, cadmium, chromium, lead and mercury content in 12 food supplements seized in a Piedmont shop by the Italian authority against food adulteration. All metals were analysed after mineralization and dilution step