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Sample records for heavy metals removal

  1. Process for removing heavy metal compounds from heavy crude oil

    Science.gov (United States)

    Cha, Chang Y. (Golden, CO); Boysen, John E. (Laramie, WY); Branthaver, Jan F. (Laramie, WY)

    1991-01-01

    A process is provided for removing heavy metal compounds from heavy crude oil by mixing the heavy crude oil with tar sand; preheating the mixture to a temperature of about 650.degree. F.; heating said mixture to up to 800.degree. F.; and separating tar sand from the light oils formed during said heating. The heavy metals removed from the heavy oils can be recovered from the spent sand for other uses.

  2. Electrokinetic removal of heavy metals from soil

    Directory of Open Access Journals (Sweden)

    Puvvadi Venkata Sivapullaiah

    2015-03-01

    Full Text Available Removal of heavy metal ions from soils by electrokinetic treatment has several advantages. The extent of removal, however, is both soil specific and ion specific. The conditions to be maintained have to be established based on laboratory studies. With a view to maximize the removal of metal ions the trends of removal of heavy metal ions such as iron, nickel and cadmium form a natural Indian kaolinitic red earth during different conditions maintained in the electrokinetic extraction process are studied. A laboratory electrokinetic extraction apparatus was assembled for this purpose. Attempts are also made to elucidate the mechanism of removal of the metal ions from soil. The composition of the flushing fluid, voltage and duration of extraction are varied. While dilute acetic acid has been used to neutralize the alkalinity that develops at the cathode, EDTA solution has been used to desorb heavy metals from clay surface. Generally the extent of removal was proportional to the osmotic flow. Nickel and Cadmium are more effectively removed than iron. The percentage removal of Ni is generally proportional to the osmotic flow but shows sensitivity to the pH of the system. There is an optimum voltage for removal of metal ions from soil. The removal of iron was negligible under different conditions studied.

  3. Heavy metal removal and recovery using microorganisms

    International Nuclear Information System (INIS)

    Microorganisms -- bacteria, fungi, and microalgae -- can accumulate relatively large amounts of toxic heavy metals and radionuclides from the environment. These organisms often exhibit specificity for particular metals. The metal content of microbial biomass can be a substantial fraction of total dry weight with concentration factors (metal in dry biomass to metal in solution) exceeding one million in some cases. Both living and inert (dead) microbial biomass can be used to reduce heavy metal concentrations in contaminated waters to very low levels -- parts per billion and even lower. In many respects (e.g. specificity, residual metal concentrations, accumulation factors, and economics) microbial bioremoval processes can be superior to conventional processes, such as ion exchange and caustic (lime or hydroxide) precipitation for heavy metals removal from waste and contaminated waters. Thus, bioremoval could be developed to contribute to the clean-up of wastes at the Savannah River Site (SRS) and other DOE facilities. However, the potential advantages of bioremoval processes must still be developed into practical operating systems. A detailed review of the literature suggests that appropriate bioremoval processes could be developed for the SRS. There is great variability from one biomass source to another in bioremoval capabilities. Bioremoval is affected by pH, other ions, temperature, and many other factors. The biological (living vs. dead) and physical (immobilized vs. dispersed) characteristics of the biomass also greatly affect metal binding. Even subtle differences in the microbial biomass, such as the conditions under which it was cultivated, can have major effects on heavy metal binding

  4. 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.

  5. Heavy metal removal using reverse osmosis

    Directory of Open Access Journals (Sweden)

    Lucia Gajdošová

    2009-12-01

    Full Text Available 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 depending on the anions of usedheavy metal salts. The heavy metal concentration also has a significant influence on the membrane separation. There is alsoa significant difference in flux decline depending on the transmembrane pressure.

  6. BIOSORPTIVE REMOVAL OF HEAVY METALS FROM WASTEWATER USING DUCKWEED

    OpenAIRE

    Ankita Suhag; Richa Gupta; Archana Tiwari

    2011-01-01

    Water pollution has been recognized as a problem for decades. The use of heavy metals in industries and their regular mining increases their concentration in water bodies. Unlike organic compounds, metals cannot degrade, and therefore effective cleanup requires their immobilization to reduce or remove toxicity. A few conventional methods employed to remove heavy metals from wastewater are expensive, require skilled labors and maintenance. Therefore, the use of aquatic plants has come up since...

  7. 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

  8. Removal of Heavy Metals from Waste Water Using Water Hyacinth

    OpenAIRE

    Mary Lissy, P. N.; G, Madhu

    2011-01-01

    Water pollution has become one of the most serious problems of today's civilization. In the last few years considerable amount of research has been done on the potential of aquatic macrophytes for pollutant removal or even as bio-indicators for heavy metals in aquatic ecosystems. Water hyacinth is one of the aquatic plant species successfully used for wastewater treatment. It is very efficient in removing pollutants like suspended solids, BOD, organic matter, heavy metals and pathogens. This ...

  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. Magnetic process for removing heavy metals from water employing magnetites

    Science.gov (United States)

    Prenger, F. Coyne; Hill, Dallas D.

    2006-12-26

    A process for removing heavy metals from water is provided. The process includes the steps of introducing magnetite to a quantity of water containing heavy metal. The magnetite is mixed with the water such that at least a portion of, and preferably the majority of, the heavy metal in the water is bound to the magnetite. Once this occurs the magnetite and absorbed metal is removed from the water by application of a magnetic field. In most applications the process is achieved by flowing the water through a solid magnetized matrix, such as steel wool, such that the magnetite magnetically binds to the solid matrix. The magnetized matrix preferably has remnant magnetism, but may also be subject to an externally applied magnetic field. Once the magnetite and associated heavy metal is bound to the matrix, it can be removed and disposed of, such as by reverse water or air and water flow through the matrix. The magnetite may be formed in-situ by the addition of the necessary quantities of Fe(II) and Fe(III) ions, or pre-formed magnetite may be added, or a combination of seed and in-situ formation may be used. The invention also relates to an apparatus for performing the removal of heavy metals from water using the process outlined above.

  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. BIOSORPTIVE REMOVAL OF HEAVY METALS FROM WASTEWATER USING DUCKWEED

    Directory of Open Access Journals (Sweden)

    Ankita Suhag

    2011-09-01

    Full Text Available Water pollution has been recognized as a problem for decades. The use of heavy metals in industries and their regular mining increases their concentration in water bodies. Unlike organic compounds, metals cannot degrade, and therefore effective cleanup requires their immobilization to reduce or remove toxicity. A few conventional methods employed to remove heavy metals from wastewater are expensive, require skilled labors and maintenance. Therefore, the use of aquatic plants has come up since the last few decades. Duckweed is onesuch plant employed as a biosorbent and has been considered a better alternative than any other aquatic plant because of high tolerance to cold than water hyacinth, more easilyharvested than algae, capable of rapid growth (0.1 to 0.5 g g-1 day-1 and small size of plant. This study aims to determine the suitability of this plant for biosorbing toxic heavy metalscommonly found in industrial wastewater, domestic wastewater, and seepage water.

  13. 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...

  14. 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.

  15. Removal of heavy metals from electroplating wastewater by membrane

    Directory of Open Access Journals (Sweden)

    Galaya Srisuwan

    2002-11-01

    Full Text Available This research was to study the treatment of heavy metals in electroplating wastewater using membranes. Two selected membrane types, cellulose acetate microfiltration membrane with pore size 0.2 ?m and polysulfone ultrafiltration membrane with MWCO of 30 kDa were used in this study. Synthetic and factory electroplating wastewater were used as the samples. The experiments were performed by chemical precipitating both synthetic and factory wastewater in the first step and membrane filtrating of supernatant at the pressure of 50, 100 and 200 kPa in the second step. The concentration of chromium, copper, nickel and zinc of treated water were compared with standard values given by the Ministry of Industry (MOI, Thailand. The experimental results showed that flux was highest at the pressure of 200 kPa and decreased as the pressure decreased. The rejection was highest at the pressure of 50 kPa and decreased as pressure increased. The results from synthetic wastewater were better than those from factory wastewater. Thecapability of heavy metal removal of microfiltration and ultrafiltration membrane was the same, but microfiltration gave more flux. The heavy metal removal efficiency of microfiltration of synthetic electroplating wastewater of four processes of chromium, copper, nickel and zinc electroplating , each was higher than that from factory wastewater but slightly lower than the removal efficiency obtained from composite synthetic wastewater. The removal efficiency of chromium, copper, nickel and zinc from composite synthetic wastewater was higher than those from composite factory wastewater for both microfiltration and ultrafiltration processes. The results from the study of membrane surface washing showed little flux increase after washing the membrane by stirring with a propeller at a distance of 2 mm above membrane surface at 400 rpm for 30 minutes.

  16. 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...

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

    Scientific Electronic Library Online (English)

    J, Lin; C, Harichund.

    2011-04-01

    Full Text Available 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

  18. Removal of heavy metals from aqueous solution by sawdust adsorption.

    Science.gov (United States)

    Bulut, Yasemin; Tez, Zeki

    2007-01-01

    The adsorption of lead, cadmium and nicel from aqueous solution by sawdust of walnut was investigated. The effect of contact time, initial metal ion concentration and temperature on metal ions removal has been studied. The equilibrium time was found to be of the order of 60 min. Kinetics fit pseudo first-order, second-order and intraparticle diffusion models, hence adsorption rate constants were calculated. The adsorption data of metal ions at temperatures of 25, 45 and 60 degrees C have been described by the Freundlich and Langmuir isotherm models. The thermodynamic parameters such as energy, entropy and enthalpy changes for the adsorption of heavy metal ions have also been computed and discussed. Ion exchange is probably one of the major adsorption mechanisms for binding divalent metal ions to the walnut sawdust. The selectivity order of the adsorbent is Pb(II) approximately Cd(II)>Ni(II). From these results, it can be concluded that the sawdust of walnut could be a good adsorbent for the metal ions from aqueous solutions. PMID:17915723

  19. Removal of heavy metals using cells of Saccharomyces cerevisiae as a green technology

    OpenAIRE

    Soares, Eduardo V.; Machado, Manuela D.; Soares, Helena M. V. M.

    2012-01-01

    Anthropogenic activities are largely responsible for the release of heavy metals in the environment. Unlike organic pollutants, heavy metals are not degraded and remain indefinitely in the ecosystem, which poses a different kind of challenge for remediation. Municipal sanitary sewers are not designed to treat toxic wastes, such as industrial effluents containing heavy metals. Thus, heavy metals should be removed in a “previous step”, from these metalladen effluents before they ...

  20. Synthesis of hierarchically structured metal oxides and their application in heavy metal ion removal

    Energy Technology Data Exchange (ETDEWEB)

    Hu, Jin-Song; Zhong, Liang-Shu; Song, Wei-Guo; Wan, Li-Jun [Institute of Chemistry, Chinese Academy of Sciences, Beijing (China); Beijing National Laboratory for Molecular Sciences (BNLMS) (China)

    2008-08-04

    Hierarchically structured metal oxides have two or more levels of structure. Their nanometer-sized building blocks provide a high surface area, a high surface-to-bulk ratio, and surface functional groups that can interact with, e.g., heavy metal ions. Their overall micrometer-sized structure provides desirable mechanical properties, such as robustness, facile species transportation, easy recovery, and regeneration. In combination these features are suitable for the removal of heavy metal ions from water. Several general synthesis routes for the fabrication of metal oxides with various morphologies and hierarchical structures are discussed including soft and hard template-assisted routes. These routes are general, reliable, and environmentally friendly methods to prepare transition and rare earth metal oxides, including cobalt oxide, iron oxide, and ceria. As-prepared hierarchically structured metal oxides show excellent adsorption capacities for As{sup V} and Cr{sup VI} ions in water. (Abstract Copyright [2008], Wiley Periodicals, Inc.)

  1. [Removal of heavy metals from extract of Angelica sinensis by EDTA-modified chitosan magnetic adsorbent].

    Science.gov (United States)

    Ren, Yong; Sun, Ming-Hui; Peng, Hong; Huang, Kai-Xun

    2013-11-01

    The concentrations of heavy metals in the extracting solutions of traditional Chinese medicine are usually very low. Furthermore, a vast number of organic components contained in the extracting solutions would be able to coordinate with heavy metals, which might lead to great difficulty in high efficient removal of them from the extracting solutions. This paper was focused on the removal of heavy metals of low concentrations from the extracting solution of Angelica sinensis by applying an EDTA-modified chitosan magnetic adsorbent (EDTA-modified chitosan/SiO2/Fe3O4, abbreviated as EDCMS). The results showed that EDCMS exhibited high efficiency for the removal of heavy metals, such as Cu, Cd and Pb, e.g. the removal percentage of Cd and Pb reached 90% and 94.7%, respectively. Besides, some amounts of other heavy metals like Zn and Mn were also removed by EDCMS. In addition, the total solid contents, the amount of ferulic acid and the HPLC fingerprints of the extracting solution were not changed significantly during the heavy metal removal process. These results indicate that EDCMS may act as an applicable and efficient candidate for the removal of heavy metals from the extracting solution of A. sinensis. PMID:24494559

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

    Directory of Open Access Journals (Sweden)

    M. Ghaedi

    2013-06-01

    Full Text Available 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 affected upon chemical treatment. In this study, the use of some of low cost adsorbents for the removal of heavy metals from wastewater has been reviewed.

  3. Comparison of electrocoagulation and chemical coagulation for heavy metal removal

    Energy Technology Data Exchange (ETDEWEB)

    Akbal, F.; Camci, S. [Ondokuz Mayis University, Engineering Faculty, Environmental Engineering Department, Kurupelit, Samsun (Turkey)

    2010-10-15

    Copper (Cu), chromium (Cr), and nickel (Ni) removal from metal plating wastewater by electrocoagulation and chemical coagulation was investigated. Chemical coagulation was performed using either aluminum sulfate or ferric chloride, whereas electrocoagulation was done in an electrolytic cell using aluminum or iron electrodes. By chemical coagulation, Cu-, Cr-, and Ni-removal of 99.9 % was achieved with aluminum sulfate and ferric chloride dosages of 500, 1000, and 2000 mg L{sup -1}, respectively. Removal of metals by electrocoagulation was affected by the electrode material, wastewater pH, current density, number of electrodes, and electrocoagulation time. Electrocoagulation with iron electrodes at a current density of 10 mA cm{sup -2}, electrocoagulation time of 20 min, and pH 3.0 resulted in 99.9 % Cu-, 99.9 % Cr-, and 98 % Ni-removal. (Abstract Copyright [2010], Wiley Periodicals, Inc.)

  4. An optimised method for electrodialytic removal of heavy metals from harbour sediments

    DEFF Research Database (Denmark)

    Pedersen, Kristine B.; Jensen, Pernille Erland

    2015-01-01

    A 2-compartment electrodialytic cell set-up for treatment of solid materials has in many respects proven superior to other types of cells in removing heavy metals from sediments. Most notably, remediation times were shorter, energy consumption was lower and higher removal efficiencies were observed. By employing m1ultivariate modelling and investigating additional experimental variables, the relative importance of variables effecting remediation was determined and response surfaces for heavy metal removal were calculated. Employing optimal conditions it was possible to remove targeted metals (Pb, Cu, Zn), by 73-96 %, and remediation objectives could be met in a large region of the studied experimental domain.

  5. 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

  6. Heavy metals removal from sewage sludge : Is practical application a feasible option?

    OpenAIRE

    Marchioretto, M.M.; Rulkens, W. H.; Bruning, H.

    2004-01-01

    The present work evaluates some new developments concerning research into the removal of heavy metals from sewage sludge and discusses the significance for practical application. As such, the complete process of sludge treatment as an integral part of a sludge management process is considered. Two conceptual designs of a treatment process that may be applied in practice for heavy metals removal from sewage sludge are discussed. One refers to a physical-chemical treatment and the other to a bi...

  7. 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 ...

  8. 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

  9. Sorption studies on heavy metal removal using chitin/bentonite biocomposite.

    Science.gov (United States)

    Saravanan, D; Gomathi, T; Sudha, P N

    2013-02-01

    Contamination of water by toxic heavy metals due to urbanization is a world-wide environmental problem, which changes chemical and biological properties of both surface and ground water. The heavy metals render the water unsuitable for drinking and are also highly toxic to human beings. Removal of heavy metals is therefore essential. Thus, in my present work batch adsorption studies have been used to remove the Cr(VI) from aqueous solution using chitin composite. The data obtained from batch method at optimized conditions have been subjected to Freundlich and Langmuir isotherm studies. The data were suitable for both models indicating favorability. PMID:23148945

  10. 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

  11. Removal of heavy metals from kaolin using an upward electrokinetic soil remedial (UESR) technology

    International Nuclear Information System (INIS)

    An upward electrokinetic soil remedial (UESR) technology was proposed to remove heavy metals from contaminated kaolin. Unlike conventional electrokinetic treatment that uses boreholes or trenches for horizontal migration of heavy metals, the UESR technology, applying vertical non-uniform electric fields, caused upward transportation of heavy metals to the top surface of the treated soil. The effects of current density, treatment duration, cell diameter, and different cathode chamber influent (distilled water or 0.01 M nitric acid) were studied. The removal efficiencies of heavy metals positively correlated to current density and treatment duration. Higher heavy metals removal efficiency was observed for the reactor cell with smaller diameter. A substantial amount of heavy metals was accumulated in the nearest to cathode 2 cm layer of kaolin when distilled water was continuously supplied to the cathode chamber. Heavy metals accumulated in this layer of kaolin can be easily excavated and disposed off. The main part of the removed heavy metals was dissolved in cathode chamber influent and moved away with cathode chamber effluent when 0.01 M nitric acid was used, instead of distilled water. Energy saving treatment by UESR technology with highest metal removal efficiencies was provided by two regimes: (1) by application of 0.01 M nitric acid as cathode chamber influent, cell diameter of 100 mm, duration of 18 days, and constant voltage of 3.5 V (19.7 kWh/m3 of ktage of 3.5 V (19.7 kWh/m3 of kaolin) and (2) by application of 0.01 M nitric acid as cathode chamber influent, cell diameter of 100 cm, duration of 6 days, and constant current density of 0.191 mA/cm2 (19.1 kWh/m3 of kaolin)

  12. 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).

  13. 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).

  14. Removal of Heavy Metal from Contaminated Water by Biopolymer Crab Shell Chitosan

    OpenAIRE

    Rana, M. S.; Halim, M. A.; Safiullah, S.; Mamun Mollah, M.; Azam, M. S.; Goni, M. A.; Kamal Hossain, M.; Rana, M. M.

    2009-01-01

    The study focuses on potential of using crab shell chitosan as a low-cost biosorbent, for heavy metals removal from aqueous solutions in an adsorption filtration system. Chitosan was synthesized from chitin by the treatment of strong alkali solution under reflux condition and chitin was extracted from crab shell followed by decalcification and deproteinization treatment. Spectrometric (AA and UV) method was employed to detect the heavy metals concentration. Prepared 10 mg L-1 solutions of zin...

  15. 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.

  16. REMOVAL OF HEAVY METALS FROM INDUSTRIAL WASTEWATERS USING INSOLUBLE STARCH XANTHATE

    Science.gov (United States)

    The Northern Regional Research Center developed an effective process to remove heavy metals from wastewaters of two nonferrous metal industries and insoluble starch xanthate (ISX). The study included bench-scale evaluation of wastewaters from two lead battery and one brass mill w...

  17. Heavy metal removal by combining anaerobic upflow packed bed reactors with water hyacinth ponds.

    Science.gov (United States)

    Sekomo, Christian Birame; Kagisha, Vedaste; Rousseau, Diederik; Lens, Piet

    2012-06-01

    The removal of four selected heavy metals (Cu, Cd, Pb and Zn) has been assessed in an upflow anaerobic packed bed reactor filled with porous volcanic rock as an adsorbent and an attachment surface for bacterial growth. Two different feeding regimes were applied using low (5 mg L(-1) of heavy metal each) and high (10 mg L(-1) of heavy metal each) strength wastewater. After a start-up and acclimatization period of 44 days, each regime was operated for a period of 10 days with a hydraulic retention time of one day. Good removal efficiencies of at least 86% were achieved for both the low and high strength wastewater. A subsequent water hyacinth pond with a hydraulic retention time of one day removed an additional 61% Cd, 59% Cu, 49% Pb and 42% Zn, showing its importance as a polishing step. The water hyacinth plant in the post-treatment step accumulated heavy metals mainly in the root system. Overall metal removal efficiencies at the outlet of the integrated system were 98% for Cd, 99% for Cu, 98% for Pb and 84% for Zn. Therefore, the integrated system can be used as an alternative treatment system for metal-polluted wastewater, especially in developing countries. PMID:22856321

  18. 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

  19. 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.

  20. 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.

  1. 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

  2. Elastomeric Nanocomposite Foams for the Removal of Heavy Metal Ions from Water.

    Science.gov (United States)

    Chavan, Asmita A; Li, Hongbo; Scarpellini, Alice; Marras, Sergio; Manna, Liberato; Athanassiou, Athanassia; Fragouli, Despina

    2015-07-15

    We report the fabrication and utilization of elastomeric polymer nanocomposite foams for the efficient removal of Pb(2+) and Hg(2+) heavy metal ions from polluted water. The polydimethylsiloxane (PDMS) foams are properly modified in order to become hydrophilic and allow the polluted water to penetrate in their volume. The ZnSe colloidal nanocrystals (NCs) that decorate the surface of the foams, act as active components able to entrap the metal ions. In this way, after the dipping of the nanocomposite foams in water polluted with Pb(2+) or Hg(2+), a cation exchange reaction takes place, and the heavy metal ions are successfully removed. The removal capacity for the Pb(2+) ions exceeds 98% and the removal of Hg(2+) ions approaches almost 100% in the studied concentrations region of 20-40 ppm. The reaction is concluded after 24 h, but it should be noticed that after the first hour, more than 95% of both the metal ions is removed. The color of the foams changes upon heavy metal ions entrapment, providing thus the opportunity of an easy detection of the presence of the ions in water. Taking into account that the fabricated foams provide good elastic properties and resistance to heat, they can be used in different conditions of water remediation. PMID:26133912

  3. 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)

  4. Effects of pulse current on energy consumption and removal of heavy metals during electrodialytic soil remediation

    DEFF Research Database (Denmark)

    Sun, Tian R.; Ottosen, Lisbeth M.

    2012-01-01

    The aims of this paper were to investigate the possibility for energy saving when using a pulsed electric field during electrodialytic soil remediation (EDR) and the effect of the pulsed current on removal of heavy metals. Eight experiments with constant and pulse current in the different industrially polluted soils were performed. At a current density of 0.1mA/cm2 in soil 1 and 0.2mA/cm2 in soil 2, there was no difference on energy consumption and removal of heavy metals between pulse current and constant current experiments, but at higher current experiments (i.e., 0.2mA/cm2 in soil 1 and 0.8mA/cm2 in soil 2) the energy was saved 67% and 60% and the removal of heavy metals was increased 17–76% and 31–51% by pulse current in soil 1 and soil 2, respectively. When comparing the voltage drop at different parts of EDR cells, it was found that the voltage drop of the area across cation exchange membrane was the major contributor of energy consumption, and the pulse current could decrease the voltage drop of this part effectively. The overall removal of heavy metals in soil 1 (6–54%) was much higher than soil 2 (1–17%) due to the different acidification process and chemical speciation of heavy metals reflected by sequential extraction analysis. Among all experiments, the highest removal efficiency occurred in pulse current experiment of soil 1, where 54% of Cu and 30% of As were removed.

  5. 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

  6. Removal Characteristics of Heavy Metals by Continuous Neutralization of Plating Wastewater with Waste-Oyster Shells

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Hyeong Seok; Song, Dong Keun [Silla University, Pusan (Korea); Sung, Nak Chang [Dong-A University, Pusan (Korea)

    1998-09-30

    Objective of the research is to determine the practical running parameters for neutralization and removal of heavy metals from plating wastewater with waste-oyster shells by the Bohart-Adams equation. Waste-oyster shells discharged from the domestic oyster culturing fields cause a serious ocean environmental pollution. However, it is expected that those are able to be recycled for removal of heavy metals through neutralization of plating wastewater because the shells contain approximate 93% CaCO{sub 3} and have multi-pore voids. By applying the results of the continuous experiments to Bohart-Adams equation, service time decreases in the order of Cr > Fe > Cu, while removal efficiencies of metals become less in the order of Fe > Cr > Cu. (author). 9 refs., 4 tabs., 8 figs.

  7. 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

  8. 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.

  9. 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

  10. 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

  11. Heavy metal removal from municipal solid waste fly ash by chlorination and thermal treatment

    International Nuclear Information System (INIS)

    Municipal solid waste (MSW) fly ash is classified as a hazardous material because it contains high amounts of heavy metals. For decontamination, MSW fly ash is first mixed with alkali or alkaline earth metal chlorides (e.g. calcium chloride) and water, and then the mixture is pelletized and treated in a rotary reactor at about 1000deg. C. Volatile heavy metal compounds are formed and evaporate. In this paper, the effect of calcium chloride addition, gas velocity, temperature and residence time on the separation of heavy metals are studied. The fly ash was sampled at the waste-to-energy plant Fernwaerme Wien/Spittelau (Vienna, Austria). The results were obtained from batch tests performed in an indirectly heated laboratory-scale rotary reactor. More than 90% of Cd and Pb and about 60% of Cu and 80% of Zn could be removed in the experiments.

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

    Science.gov (United States)

    Kocaoba, Sevgi

    2007-08-17

    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 1g. 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 degrees 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 heavy metals from wastewaters. PMID:17335969

  13. Plasmid Mediated Tolerance and Removal of Heavy Metals by Enterobacter sp

    Directory of Open Access Journals (Sweden)

    Bahig El-Deeb

    2009-01-01

    Full Text Available Problem statement: The role of plasmid in the heavy metal resistance and accumulation by endophytic bacteria was investigated. Approach: The experimental results showed that high level plasmid mediated Cd2+ and Zn2+ resistance in this strain is due to decreased Cd2+ and/or Zn2+ uptake/accumulation by resistance strain. Results: Based on the fact that subsequent plasmid curing experiments demonstrated that the ability to grow in presence of Cd2+and Zn2+ was encoded by the 98 kb plasmid, whereas the ability to grow in presence of Pb2+ appeared to be encoded by the chromosome. The Cd2+ and Zn2+ removal capacity of the respective metal resistant strain (pBN4 were about 36 and 45 µg g-1 DW respectively, while the removal capacity of the both metal by sensitive variant showed a significant high Cd2+ and Zn2+ removal capacity of 153 and 228 µg g-1 DW respectively. Conclusion: The isolated endophytic Enterobacter was not only tolerant to heavy metals, but also bound considerable amount of heavy metals from the growth medium. The biosorbed order of the metals by parental strain and its cured derivatives strain based on the cell dry weight was found to be in the order of Pb2+> Zn2+>Cd2+.

  14. Removal and treatment of radioactive, organochlorine, and heavy metal

    International Nuclear Information System (INIS)

    A decontamination system was tested on concrete and steel surfaces contaminated with radioactive (238U and 99Tc) and hazardous (PCBs and lead) waste in Oak Ridge, TN. The principal objectives of this on-site soda blasting demonstration project were to evaluate the effectiveness of decontamination by blasting with sodium bicarbonate and to minimize waste volume by dissolving and treating blasting residuals through a wastewater treatment system. Areas of concrete floors and columns and steel and aluminum surfaces were selected to evaluate the soda blasting process. Testing evaluated six operating variables: air pressure, water pressure, nozzle orifice diameter, nozzle orifice design, media type, and media flow rate. Spent blasting media was mixed with water for treatment. The treatment system comprised pH adjustment, chemical precipitation, solids removal, carbon adsorption, and ion exchange. Removal rates from blasting averaged between 95 and 100% beta/gamma and non-quantifiable to 100% alpha for surfaces tested using selected blasing parameters. The non-quantifiable percent removals for alpha resulted from initial readings which approached background levels. In each test, the post blast alpha readings were below the release limit of 5000 dpm. The waste volume reduction system effectively removed more than 97% of uranium and more than 99 percent of lead and PCBs. Ion exchange column testing results demonstrated technetium removal to below the 100 rated technetium removal to below the 100 pCi/l treatment objective for both resins. Testing results demonstrated that this soda blasting/waste residuals treatment system provided a 70% reduction in waste volume as compared to blasting without treatment. The system removed fixed radioactive and hazardous surface contamination, while leaving the surface intact, and produced water meeting stringent water quality criteria and residual solid waste requiring off-site management

  15. 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

  16. 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

  17. Removal of Heavy Metal from Contaminated Water by Biopolymer Crab Shell Chitosan

    Directory of Open Access Journals (Sweden)

    M.S. Rana

    2009-01-01

    Full Text Available The study focuses on potential of using crab shell chitosan as a low-cost biosorbent, for heavy metals removal from aqueous solutions in an adsorption filtration system. Chitosan was synthesized from chitin by the treatment of strong alkali solution under reflux condition and chitin was extracted from crab shell followed by decalcification and deproteinization treatment. Spectrometric (AA and UV method was employed to detect the heavy metals concentration. Prepared 10 mg L-1 solutions of zinc, lead, cadmium, cobalt, nickel, chromium, manganese and iron were passed through the 5 g of chitosan separately and it was found that chitosan was excellent adsorbent in removing mentioned heavy metals. The removal efficiency of chitosan was in the following order Mn>Cd>Zn>Co>Ni>Fe>Pb>Cr. The result also showed that the time required for 100% breakthrough of prepared chitosan for Mn and Zn was approximately 27 and 23 h whereas it was only 16 h for both Cr and Pb, respectively. The research revealed that prepared chitosan showed better removal performance for Mn, Cd, Zn whereas the removal efficiency was satisfactory for Co, Ni and Fe but it exhibited relatively least performance for Pb and Cr.

  18. 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...

  19. Removal of heavy metals in wastewater by membrane bioreactor: effects of flux and suction period

    International Nuclear Information System (INIS)

    The effects of flux and suction period on the removal of selected heavy metals including nickel, arsenic, cadmium, antimony and lead by membrane bioreactor was investigated. The sludge-age was arranged as 25 days and MLSS concentration was about 13 g/L. The flux was increased from 13 to 26 L/m2-h to understand the effects of flux on the removals. Moreover, to understand the effect of bio-film formation on the membrane plate surfaces, different samples were taken at different periods of the suction cycle. COD removal during the study was over 95%. Influent concentration of each of the heavy metals spiked directly to the wastewater was about 100 meu g/L. Effluent concentrations of cadmium and lead were under the limit of detection in all samples meaning that all the cadmium and lead were removed. Removals of over 50, 96, and 95% for arsenic, nickel and antimony were achieved, respectively. The highest removal was achieved in the first minute of the suction where the metals were accumulated in the surface biomass. (author)

  20. 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

  1. Sewage sludge ash to phosphorus fertiliser: Variables influencing heavy metal removal during thermochemical treatment

    International Nuclear Information System (INIS)

    The aim of this study was to improve the removal of heavy metals from sewage sludge ash by a thermochemical process. The resulting detoxified ash was intended for use as a raw material rich in phosphorus (P) for inorganic fertiliser production. The thermochemical treatment was performed in a rotary kiln where the evaporation of relevant heavy metals was enhanced by additives. The four variables investigated for process optimisation were treatment temperature, type of additive (KCl, MgCl2) and its amount, as well as type of reactor (directly or indirectly heated rotary kiln). The removal rates of Cd, Cr, Cu, Ni, Pb, Zn and of Ca, P and Cl were investigated. The best overall removal efficiency for Cd, Cu, Pb and Zn could be found for the indirectly heated system. The type of additive was critical, since MgCl2 favours Zn- over Cu-removal, while KCl acts conversely. The use of MgCl2 caused less particle abrasion from the pellets in the kiln than KCl. In the case of the additive KCl, liquid KCl - temporarily formed in the pellets - acted as a barrier to heavy metal evaporation as long as treatment temperatures were not sufficiently high to enhance its reaction or evaporation

  2. Removal of Heavy Metals from Solid Wastes Leachates Coagulation-Flocculation Process

    Directory of Open Access Journals (Sweden)

    Z. Yousefi

    2008-01-01

    Full Text Available The main objectives of present research were to determine heavy metals (Ni, Cd, Cr, Zn and Cu and COD concentration in raw leachate in Esfahan (Iran composting plant and to examine the application of coagulation-flocculation process for the treatment of raw leachates. Jar-test experiments were employed in order to determine the optimum conditions (effective dosage and optimum pH for the removal of COD and heavy metals. Alum (aluminum sulphate and Ferric chloride were tested as conventional coagulants. Ten times had taken sampling from leachates as standard methods in the composting plant prior to composting process. The results showed that Leachate pH was 4.3-5.9 and the average was 4.98±0.62. The concentration of Leachate pollutants were more than effluent standard limits (Environment protection Agency. And also the results indicated, Cd and Zn with concentration 0.46±0.41 and 5.81±3.69 mg L-1, had minimum and maximum levels, respectively. The results of coagulation and flocculation tests showed that in optimum conditions, the removal efficiency of heavy metals and COD by using alum were 77-91 and 21%, respectively. While removal of heavy metals and COD by ferric chloride were 68-85.5% and 28%, respectively. Also the residues of heavy metals after treatment get to under of standard limits of Iran EPA. The results have indicated optimum pH of two coagulants for leachate treatment was 6.5 and 10 and also effective coagulant dosages were 1400 and 1000 mg L-1 for alum and ferric chloride, respectively. In view of economical, ferric chloride is cost benefit. The physico-chemical process may be used as a useful pretreatment step, especially for fresh leachates.

  3. 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)

  4. Silver-modified clinoptilolite for the removal of Escherichia coli and heavy metals from aqueous solutions.

    Science.gov (United States)

    Akhigbe, Lulu; Ouki, Sabeha; Saroj, Devendra; Lim, Xiang Min

    2014-09-01

    This paper investigates the potential of using the silver antibacterial properties combined with the metal ion exchange characteristics of silver-modified clinoptilolite to produce a treatment system capable of removing both contaminants from aqueous streams. The results have shown that silver-modified clinoptilolite is capable of completely eliminating Escherichia coli after 30-min contact time demonstrating its effectiveness as a disinfectant. Systems containing both E. coli and metals exhibited 100 % E. coli reduction after 15-min contact time and maximum metal adsorption removal efficiencies of 97, 98, and 99 % for Pb(2+), Cd(2+), and Zn(2+) respectively after 60 min; 0.182-0.266 mg/g of metal ions were adsorbed by the zeolites in the single- and mixed-metal-containing solutions. Nonmodified clinoptilolite showed no antibacterial properties. This study demonstrated that silver-modified clinoptilolite exhibited high disinfection and heavy metal removal efficiencies and consequently could provide an effective combined treatment system for the removal of E. coli and metals from contaminated water streams. PMID:24756684

  5. 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.

  6. Potential immobilized Saccharomyces cerevisiae as heavy metal removal

    Science.gov (United States)

    Raffar, Nur Izzati Abdul; Rahman, Nadhratul Nur Ain Abdul; Alrozi, Rasyidah; Senusi, Faraziehan; Chang, Siu Hua

    2015-05-01

    Biosorption of copper ion using treated and untreated immobilized Saccharomyces cerevisiae from aqueous solution was investigate in this study. S.cerevisiae has been choosing as biosorbent due to low cost, easy and continuously available from various industries. In this study, the ability of treated and untreated immobilized S.cerevisiae in removing copper ion influence by the effect of pH solution, and initial concentration of copper ion with contact time. Besides, adsorption isotherm and kinetic model also studied. The result indicated that the copper ion uptake on treated and untreated immobilized S.cerevisiae was increased with increasing of contact time and initial concentration of copper ion. The optimum pH for copper ion uptake on untreated and treated immobilized S.cerevisiae at 4 and 6. From the data obtained of copper ion uptake, the adsorption isotherm was fitted well by Freundlich model for treated immobilized S.cerevisiae and Langmuir model for untreated immobilized S.cerevisiae according to high correlation coefficient. Meanwhile, the pseudo second order was described as suitable model present according to high correlation coefficient. Since the application of biosorption process has been received more attention from numerous researchers as a potential process to be applied in the industry, future study will be conducted to investigate the potential of immobilized S.cerevisiae in continuous process.

  7. 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

  8. Polyrhodanine modified anodic aluminum oxide membrane for heavy metal ions removal.

    Science.gov (United States)

    Song, Jooyoung; Oh, Hyuntaek; Kong, Hyeyoung; Jang, Jyongsik

    2011-03-15

    Polyrhodanine was immobilized onto the inner surface of anodic aluminum oxide (AAO) membrane via vapor deposition polymerization method. The polyrhodanine modified membrane was applied to remove heavy metal ions from aqueous solution because polyrhodanine could be coordinated with specific metal ions. Several parameters such as initial metal concentration, contact time and metal species were evaluated systematically for uptake efficiencies of the fabricated membrane under continuous flow condition. Adsorption isotherms of Hg(II) ion on the AAO-polyrhodanine membrane were analyzed with Langmuir and Freundlich isotherm models. The adsorption rate of Hg(II) ion on the membrane was obeyed by a pseudo-second order equation, indicating the chemical adsorption. The maximum removal capacity of Hg(II) ion onto the fabricated membrane was measured to be 4.2 mmol/g polymer. The AAO-polyrhodanine membrane had also remarkable uptake performance toward Ag(I) and Pb(II) ions. Furthermore, the polyrhodanine modified membrane could be recycled after recovery process. These results demonstrated that the polyrhodanine modified AAO membrane provided potential applications for removing the hazardous heavy metal ions from wastewater. PMID:21295909

  9. Removal heavy metals and sulphate from waste waters by sulphate-reducing bacteria

    OpenAIRE

    Ku?nierová Mária; Luptáková Alena

    2000-01-01

    This article is devoted to the process of bacterial sulphate reduction, which is used to removal of heavy metals and sulphate ions from waste waters.The life of animals and plants depends on the existence of microscopic organisms ? microorganisms (MO), which play an important role in cycle changes of biogenic elements on the earth. The sulphur cycle in the nature is considered as one of the oldest and most significant biological systems (Fig. 1). The sulphate-reducing bacteria (SRB) miss the...

  10. The role of algae in heavy metals removal from mining wastewater

    OpenAIRE

    Benchraka, Chouaib

    2010-01-01

    Nature is the key solution for human need and problems emerging from man-made structures. Inefficiently purified industrial and municipal wastewater discharges cause so far many prominent pollution cases. In this work experimental scale algae turf scrubbers (ATS) have been used to remove excess amounts of nutrients and heavy metals from mineral wastewaters. ATS are mechanical systems designed for growing algae under controlled conditions to absorb the excess nutrients or/and pollutant...

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

    OpenAIRE

    Germán C. Quintana; George J. M. Rocha; Adilson R. Gonçalves; Jorge A. Velásquez

    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...

  12. A study on removal of heavy metal ions in waste water by foam fractionation

    International Nuclear Information System (INIS)

    The purpose of this study is to remove the Cd2+, Cu2+, Hg2+, Pb2+ and Zn2+ ions in the waste water efficiently by sulfide precipitation and foam fractionation using the cationic surfactant (cetyl trimethly ammomium bromide, CTAB). In this study, the effects of pH, Na2S dose for sulfide precipitation and removal efficiency, removal rate of heavy metal ions by varying the pH range, Na2S dose and CTAB concentration were investigated. The optimum concentration of Na2S for sulfide precipitation was 1.0-1.5 equivalents to metal ions and pH range was 6.0-10.0 in coexistence of several metals. Coagulation by means of CTAB showed the best result at pH 8 and optimum CTAB concentration for foam fractionation was 40-5 mg/l at the entire pH range. Removal rate by means of form fractionation showed the following order; HgS>CdS>PbS>ZnS>CuS. Removal efficiencies of Cd2+, Cu2+, Hg2+ and Pb2+ were more than 99% at pH3-8, but Zn2+ showed more than 92% at above pH 10. When several metalions were coexisted, the optimum pH range for upmost removal efficiency showed pH 6-10 and more than 97% of them could be removed within 9 minutes.(Author)

  13. A feasibility study on bioelectrokinetics for the removal of heavy metals from tailing soil.

    Science.gov (United States)

    Lee, Keun-Young; Kim, Hyun-A; Lee, Byung-Tae; Kim, Soon-Oh; Kwon, Young-Ho; Kim, Kyoung-Woong

    2011-01-01

    The combination of bioremediation and electrokinetics, termed bioelectrokinetics, has been studied constantly to enhance the removal of organic and inorganic contaminants from soil. The use of the bioleaching process originating from Fe- and/or S-oxidizing bacteria may be a feasible technology for the remediation of heavy metal-contaminated soils. In this study, the bioleaching process driven by injection of S-oxidizing bacteria, Acidithiobacillus thiooxidans, was evaluated as a pre-treatment step. The bioleaching process was sequentially integrated with the electrokinetic soil process, and the final removal efficiency of the combined process was compared with those of individual processes. Tailing soil, heavily contaminated with Cd, Cu, Pb, Zn, Co, and As, was collected from an abandoned mine area in Korea. The results of geochemical studies supported that this tailing soil contains the reduced forms of sulfur that can be an energy source for A. thiooxidans. From the result of the combined process, we could conclude that the bioleaching process might be a good pre-treatment step to mobilize heavy metals in tailing soil. Additionally, the electrokinetic process can be an effective technology for the removal of heavy metals from tailing soil. For the sake of generalizing the proposed bioelectrokinetic process, however, the site-specific differences in soil should be taken into account in future studies. PMID:21046430

  14. Investigation of Media Effects on Removal of Heavy Metals in Bioretention Cells

    Science.gov (United States)

    Gülbaz, Sezar; Melek Kazezyilmaz-Alhan, Cevza; Copty, Nadim K.

    2015-04-01

    Heavy metals are the most toxic elements at high concentrations, although some of them such as Cu and Zn are essential to plants, humans, and animals within a limited value. However, some heavy metals, such as Pb, have adverse effects even at low concentrations. Therefore, it is known that the toxic metals such as Zn, Cu and Pb in storm water runoff are serious threat for aquatic organisms. It is very important to control and reduce heavy metal concentration in urban storm water runoff. There are several methods to remove the aforementioned toxic metals such as electrolyte extraction, chemical precipitation, ion-exchange, reverse osmosis, membrane filtration, adsorption, cementation, and electrochemical treatment technologies. However, these methods are highly expensive and hard to implement for treatment of big volumes of water such as storm water. For this purpose, Low Impact Development (LID) Best Management Practices (BMPs) have become popular to collect, infiltrate, and treat toxic metals in storm water runoff in recent years. LID-BMP is a land planning method which is used to manage storm water runoff and improve water quality by reducing contaminant in storm water runoff. Bioretention is an example of LID-BMP application of which usage has recently been started in storm water treatment. Researchers have been investigating the advantages of bioretention systems and this study contributes to these research efforts by seeking for the media effects of bioretention on heavy metal removal. For this purpose, batch sorption experiments were performed to determine the distribution coefficients and retardation factor of copper (Cu), lead (Pb), and zinc (Zn) for bioretention media such as mulch, turf, local or vegetative soil, sand and gravel. Furthermore, sorption reaction kinetics of Cu, Pb and Zn are tested in order to assess the sorption equilibrium time of these metals for 5 bioretention media. The results of sorption test show that turf has higher sorption capacity than mulch and local soil for heavy metals used in the experiment. On the other hand, sand and gravel have relatively lower sorption capacities. Linear equilibrium isotherm represents sorption of these metals for all bioretention media. The highest sorption is observed for Pb followed by Cu and Zn for all bioretention media. The time required for reaching equilibrium conditions for bioretention column media is ranged from 1 to 6 hours for each metal investigated.

  15. 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.

  16. A novel biodegradable ?-cyclodextrin-based hydrogel for the removal of heavy metal ions.

    Science.gov (United States)

    Huang, Zhanhua; Wu, Qinglin; Liu, Shouxin; Liu, Tian; Zhang, Bin

    2013-09-12

    A novel biodegradable ?-cyclodextrin-based gel (CAM) was prepared and applied to the removal of Cd(2+), Pb(2+) and Cu(2+) ions from aqueous solutions. CAM hydrogel has a typical three-dimensional network structure, and showed excellent capability for the removal of heavy metal ions. The effect of different experimental parameters, such as initial pH, adsorbent dosage and initial metal ion concentration, were investigated. The adsorption isotherm data fitted well to the Freundlich model. The adsorption capacity was in the order Pb(2+)>Cu(2+)>Cd(2+) under the same experimental conditions. The maximum adsorption capacities for the metal ions in terms of mg/g of dry gel were 210.6 for Pb(2+), 116.41 for Cu(2+), and 98.88 for Cd(2+). The biodegradation efficiency of the resin reached 79.4% for Gloeophyllum trabeum. The high adsorption capacity and kinetics results indicate that CAM can be used as an alternative adsorbent to remove heavy metals from aqueous solution. PMID:23911476

  17. Novel nanofiltration membranes consisting of a sulfonated pentablock copolymer rejection layer for heavy metal removal.

    Science.gov (United States)

    Thong, Zhiwei; Han, Gang; Cui, Yue; Gao, Jie; Chung, Tai-Shung; Chan, Sui Yung; Wei, Shawn

    2014-12-01

    Facing stringent regulations on wastewater discharge containing heavy metal ions, various industries are demanding more efficient and effective treatment methods. Among the methods available, nanofiltration (NF) is a feasible and promising option. However, the development of new membrane materials is constantly required for the advancement of this technology. This is a report of the first attempt to develop a composite NF membrane comprising a molecularly designed pentablock copolymer selective layer for the removal of heavy metal ions. The resultant NF membrane has a mean effective pore diameter of 0.50 nm, a molecular weight cutoff of 255 Da, and a reasonably high pure water permeability (A) of 2.4 LMH/bar. The newly developed NF membrane can effectively remove heavy metal cations such as Pb(2+), Cd(2+), Zn(2+), and Ni(2+) with a rejection of >98.0%. On the other hand, the membrane also shows reasonably high rejections toward anions such as HAsO4(2-) (99.9%) and HCrO4(-) (92.3%). This performance can be attributed to (1) the pentablock copolymer's unique ability to form a continuous water transport passageway with a defined pore size and (2) the incorporation of polyethylenimine as a gutter layer between the selective layer and the substrate. To the best of our knowledge, this is the first reported NF membrane comprising this pentablock copolymer as the selective material. The promising preliminary results achieved in this study provide a useful platform for the development of new NF membranes for heavy metal removal. PMID:25369240

  18. 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.

  19. 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 ...

  20. Removal of heavy metals from wastewater using functionalized coal fly ashes

    International Nuclear Information System (INIS)

    Complete text of publication follows. Among inorganic pollutants, heavy metal ions are very toxic and carcinogenic in nature. The presence of heavy metals in the aquatic environment has been of the greatest concern because of their toxicity even at very low concentrations. Therefore, the removal of the toxic metal ions prior to supplying water for drinking, bathing, etc is very important. Nonetheless, the removal of the toxic metal ions from water is a very difficult task due to the high cost of treatment methods. Adsorption is by far the most versatile and widely used method for this purpose. In this study, attempts have been made to develop a low-cost adsorbent using coal fly ashes, a waste byproduct of the coal fire industry, for the removal of arsenic, aluminium, cadmium, zinc, copper, iron, lead, manganese and nickel from wastewater. After applying a washing step to the coal fly ashes, functionalized fly ash surfaces were accomplished by using several organic compounds. The effect of several parameters (contact time, temperature, time that the ashes remain functionalized, concentration of the heavy metals, solution pH) on the adsorption process was stated. Several equilibrium and kinetics treatments were also carried out, also resulting that the adsorption process was found to be exothermic in nature. Retention studies were characterised by SEM/ED-XRS, FT-IR, Raman spectrometry and electrothermal atomic absorption spectrometry (ETAAS). The optimised retention sysmetry (ETAAS). The optimised retention system was applied to develop an analytical procedure for the retention of low concentrations of lead in wastewater and determination by ETAAS.

  1. 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.

  2. 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.

  3. 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.

  4. 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.

  5. Removal of Heavy Metals from Industrial Wastewaters Using Local Alum and Other Conventional Coagulants-A Comparative Study

    Directory of Open Access Journals (Sweden)

    A.O. Ogunfowokan

    2007-01-01

    Full Text Available The present study aimed at effective management and purification of industrial wastewaters using cheaper and locally available local alum for removal of heavy metals as a substitute to convectional coagulants. The effect of local alum, aluminum sulphate and ferric chloride on the metal contents of industrial wastewaters was investigated in the pH range of 5.9-7.5. Wastewater samples from battery, paint and textile industries were treated with different doses of locally available alum, aluminum sulphate and ferric chloride in order to determine and compare their effectiveness in removing heavy metal contents of the wastewaters. The percentage removal of the metals from the industrial wastewaters increased with mg L-l dosage of the coagulants used with optimal performance generally at a slightly alkaline pH. Local alum proved to be equally effective in removing heavy metals from the industrial wastewater samples compared with the conventional aluminum sulphate and ferric chloride.

  6. Removal of Heavy Metals from Industrial Wastewaters Using Local Alum and Other Conventional Coagulants-A Comparative Study

    Science.gov (United States)

    Ogunfowokan, A. O.; Durosinmi, L. M.; Oyekunle, J. A. O.; Ogunkunle, O. A.; Igbafe, I. T.

    The present study aimed at effective management and purification of industrial wastewaters using cheaper and locally available local alum for removal of heavy metals as a substitute to convectional coagulants. The effect of local alum, aluminum sulphate and ferric chloride on the metal contents of industrial wastewaters was investigated in the pH range of 5.9-7.5. Wastewater samples from battery, paint and textile industries were treated with different doses of locally available alum, aluminum sulphate and ferric chloride in order to determine and compare their effectiveness in removing heavy metal contents of the wastewaters. The percentage removal of the metals from the industrial wastewaters increased with mg L-l dosage of the coagulants used with optimal performance generally at a slightly alkaline pH. Local alum proved to be equally effective in removing heavy metals from the industrial wastewater samples compared with the conventional aluminum sulphate and ferric chloride.

  7. Heavy metal removal from synthetics wastes by natural and acid-activated bentonite s

    International Nuclear Information System (INIS)

    This paper examines heavy metals removal from synthetics wastes by the use of natural and sulfuric acid-activated bentonite so that a cheap adsorbent can be attained for removing these metals from the wastes. Bentonite is a 2: 1 layer alurninnisilicate whose dominant mineral is montmorillonite which is a nano-structure and nano porous material. Montmorillonite affects all the properties of bentonite. In the next step, the effect of acid activation on the adsorption of both of lead (Pb) and thallium (Tl) is studied. In this research, after the mineralogical and chemical composition analyses by X-ray diffraction and fluorescence (XRD and X-ray fluorescence) methods, granulometric analysis is carried out on five samples namely, S 2-Raw, S 3-Raw, Es 3-Raw, G 1-Raw and GH 1-Raw to remove the heavy metals such as Cr, Co, Cu, Fe, Pb, Tl, Ni, and Zn accompanying atomic absorption spectroscopy. Then, the effect of four factors including concentration, liquid to solid ratio (L/S), time, and activation temperature in acid activation process were studied. This process is done by a mineral acid, sulfuric acid, to promote the absorbability of lead and thallium in both natural and activated types of Es 3-Raw and GH 1-Raw. In all case, due to the presence of dominant mineral of nano-montmorillonite and its unique structure, montmorillonite has a higher absorbability in comparison with that of the other clay minerals.

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

    Science.gov (United States)

    Ijagbemi, Christianah Olakitan; Baek, Mi-Hwa; Kim, Dong-Su

    2009-07-15

    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 pH(PZC) and pH(PZNPC) 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 Cu(2+) and Ni(2+) 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 Cu(2+) and Ni(2+) could be described by the Langmuir model and from calculations on thermodynamic parameters, the positive Delta G degrees values at different temperatures suggest that the sorption of both metal ions were non-spontaneous. Change in enthalpy (Delta H degrees) for Ni(2+) and Cu(2+) 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 DeltaS degrees indicate low randomness at the solid/solution interface during the uptake of both Cu(2+) and Ni(2+) by MMT. Montmorillonite has a considerable potential for the removal of heavy metal cationic species from aqueous solution and wastewater. PMID:19131158

  9. 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.

  10. Untreated coffee husks as biosorbents for the removal of heavy metals from aqueous solutions.

    Science.gov (United States)

    Oliveira, Waleska E; Franca, Adriana S; Oliveira, Leandro S; Rocha, Sonia D

    2008-04-15

    The objective of this work was to propose an alternative use for coffee husks (CH), a coffee processing residue, as untreated sorbents for the removal of heavy metal ions from aqueous solutions. Biosorption studies were conducted in a batch system as a function of contact time, initial metal ion concentration, biosorbent concentration and pH of the solution. A contact time of 72 h assured attainment of equilibrium for Cu(II), Cd(II) and Zn(II). The sorption efficiency after equilibrium was higher for Cu(II) (89-98% adsorption), followed by Cd(II) (65-85%) and Zn(II) (48-79%). Even though equilibrium was not attained in the case of Cr(VI) ions, sorption efficiency ranged from 79 to 86%. Sorption performance improved as metal ions concentrations were lowered. The experimental sorption equilibrium data were fitted by both Langmuir and Freundlich sorption models, with Langmuir providing the best fit (R2>0.95). The biosorption kinetics was determined by fitting first and second-order kinetic models to the experimental data, being better described by the pseudo-second-order model (R2>0.99). The amount of metal ions sorbed increased with the biosorbent concentration in the case of Cu(II) and Cr(VI) and did not present significant variations for the other metal ions. The effect of the initial pH in the biosorption efficiency was verified in the pH range of 4-7, and the results showed that the highest adsorption capacity occurred at distinct pH values for each metal ion. A comparison of the maximum sorption capacity of several untreated biomaterial-based residues showed that coffee husks are suitable candidates for use as biosorbents in the removal of heavy metals from aqueous solutions. PMID:17804159

  11. 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.

  12. 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

  13. Effect of pulse current on energy consumption and removal of heavy metals during electrodialytic soil remediation

    DEFF Research Database (Denmark)

    Sun, Tian Ran

    2013-01-01

    Contamination of soils and groundwater keep attracting attention of worldwide. The contaminants of concern include a wide range of toxic pollutants such as heavy metals, radionuclides, and organic compounds. The environment and humans are exposed to these pollutants through different exposure pathways to unacceptable dosages, leading to intolerable adverse effects on both public health and the environment. In the last decades, soil and water remediation have gained growing awareness, as the necessity becomes clearer for development of such techniques for elimination of the negative impact from the contamination on human health and land use. Electrochemical remediation has been recognized as a promising group of technologies forremediation of contaminated sites, leading to several research programs worldwide for the development. Electrochemical remediation is also synonymously referred to as electrokinetics, electrokinetic remediation, electroremediation or electroreclamation. Electrochemical remediation technologies are part of a broader class of technologies known as direct current technologies. The techniques utilize the transport processes obtained by application of the electric DC field: transport of water (electroosmosis) and ions (electromigration), with electromigration being the most important transport process when treating heavy metal contaminated soils. Electrodialytic remediation (EDR), one of the enhanced electrochemical remediation techniques, is developed at the Technical University of Denmark in the early 1990s and aims at removal of heavy metals from contaminated soils. The electrodialytic remediation method differs from the electrokinetic remediation methods in the use of ion exchange membranes for separation of the soil and the processing solutions in the electrode compartments. Therefore no current is wasted for carrying ions from one electrode compartment to the other. The EDR technique has been tested for decontamination of a variety of different heavy metal polluted particulate materials: mine tailings, soil, different types of fly ashes, sewage sludge, freshwater sediments and harbor sediments. In previous works including both lab and pilot scaleexperiments, this technique has demonstrated effective removal of heavy metals from all the contaminated materials. In the PhD project, the focus turns to energy saving aspect of EDR which influencing costs and thus the applicability for remediation beyond bench and pilot scale. The overall aim of the present PhD study is to clarify and understand the underlying mechanisms of the effect of pulse current on energy consumption and removal of heavy metals during electrodialytic soil remediation. Series of experiments with constant and pulse current in twodifferent industrially polluted soils were conducted. Results showed that the pulse current gave positive effect in relation to energy saving and improvement of removal of heavy metals during EDR. The positive effect was related toenhancement of the acidification process, increasing the electric conductivity in soil pore fluid, and diminishing the polarization process of membranes and soil particles. The efficacy of pulse current was found dependent on applied current density, soil buffering capacity, and applied pulse frequency. In stationary EDR, the efficacy of pulse current was more significant at higher current densities, higher buffering capacities, and lower pulse frequencies (i.e. adequate relaxation time with respect to the current “ON” time). On the contrary in suspended EDR, higher pulse frequency was preferred, and the difference was due to the different transport process of ions between stationary and suspended EDR. The major energy was consumed by the fouling of cation exchange membrane in stationary EDR, whereas major energy consumption was found in soil suspension in suspended EDR. Compared with stationary EDR (maximum 70% energy saving), less energy was saved (maximum 33%) in suspended EDR, even with higher applied current densities. Although it was demonstrated that the pulse current is

  14. 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.

  15. 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)

  16. The application of fish scales in removing heavy metals from energy-produced waste streams: the role of microbes

    International Nuclear Information System (INIS)

    In energy production, heavy metals pose significant contamination hazards. For example, the petroleum industry generates wastes that are often high in heavy metal concentrations. Heavy metals are very toxic and extremely deleterious to humans, plants, and animals. Application of fish scale to remove heavy metals is a very recent innovation. It is an environmentally appealing and economically attractive alternative to current heavy metal adsorbing materials. Previously, the adsorption phenomenon on this exotic waste material was explained by only physical-chemical reactions. Biological effects on adsorption of heavy metals such as lead, arsenic, and chromium were studied using Atlantic Cod scale. The difference in results between nonsterilized and sterilized experiments shows the microbial contribution to heavy metal removal. Results show a wide range of microbial contribution in removing chromium cations. For lead and arsenic cations, the effect is less. Measurement of pH gives some indication of the microbial role in the biosorption process and of the presence of possible microbial species. (author)

  17. 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.

  18. 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.

  19. GENERIC ADSORPTION COEFFICIENTS AND NATURAL REMOVAL OF HEAVY METALS IN MUDDY RIVER WATER

    Directory of Open Access Journals (Sweden)

    Amini Rad H1, A Hasannattaj1*, M Scholz2, B Navayineya1 and L Weekes2

    2013-09-01

    Full Text Available In this study a possible natural flocculating capacity of River's is experimentally investigated. For this purpose, Chalus River in northern part of IRAN due to its heavy metal pollution, high flows and high suspended and bed sediments fluctuation level is selected. In this investigation heavy metals content of water, suspended and bed sediments of the Chalus River, is experimentally evaluated. The samples were obtained during the wet season (mud flow from three existing observing sampling station. In this experimental study the effect of suspended particle concentration, bed sediment and contact time on the removal capacity and determination of generic adsorption coefficient by WASP model is computed. The result of analysis showed that the adsorption capacity of the heavy metals is indirectly proportional with an increase in concentration of suspended particles. Also the behavior of adsorption in this investigation follows by Freundlich isotherm as a liner isotherm.  From this analysis also can be said that the self-purification capacity of river is also greatly affected by this novelty of rivers.

  20. 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

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

    Science.gov (United States)

    Bayat, Belgin; Sari, Bulent

    2010-02-15

    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 3l 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 degrees 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% (w/v), and a reaction temperature of 25+/-2 degrees 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. PMID:19880247

  2. 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.

  3. 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.

  4. Kinetic study on removal of heavy metal ions from aqueous solution by using soil.

    Science.gov (United States)

    Lim, Soh-Fong; Lee, Agnes Yung Weng

    2015-07-01

    In the present study, the feasibility of soil used as a low-cost adsorbent for the removal of Cu(2+), Zn(2+), and Pb(2+) ions from aqueous solution was investigated. The kinetics for adsorption of the heavy metal ions from aqueous solution by soil was examined under batch mode. The influence of the contact time and initial concentration for the adsorption process at pH of 4.5, under a constant room temperature of 25?±?1 °C were studied. The adsorption capacity of the three heavy metal ions from aqueous solution was decreased in order of Pb(2+)?>?Cu(2+)?>?Zn(2+). The soil was characterized by Fourier transform infrared (FTIR) spectroscopy, scanning electron microscopic-energy dispersive X-ray (SEM-EDX), and Brunauer, Emmett, and Teller (BET) surface area analyzer. From the FTIR analysis, the experimental data was corresponded to the peak changes of the spectra obtained before and after adsorption process. Studies on SEM-EDX showed distinct adsorption of the heavy metal ions and the mineral composition in the study areas were determined to be silica (SiO2), alumina (Al2O3), and iron(III) oxide (FeO3). A distinct decrease of the specific surface area and total pore volumes of the soil after adsorption was found from the BET analysis. The experimental results obtained were analyzed using four adsorption kinetic models, namely pseudo-first-order, pseudo-second-order, Elovich, and intraparticle diffusion. Evaluating the linear correlation coefficients, the kinetic studies showed that pseudo-second-order equation described the data appropriable than others. It was concluded that soil can be used as an effective adsorbent for removing Cu(2+), Zn(2+), and Pb(2+) ions from aqueous solution. PMID:25854202

  5. 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

  6. Potencialidades de un biosorbente algal para la remoción de metales pesados / Potentiality of a Seaweed Biosorbent for Heavy Metals Removal

    Scientific Electronic Library Online (English)

    Omar, Gutiérrez-Benítez; Julia, González-Álvarez; María Sonia, Freire-Leira; Iván Leandro, Rodríguez-Rico; Ángel Ramón, Moreira-González.

    2014-04-01

    Full Text Available La biosorción es considerada una tecnología alternativa para la remoción de metales pesados de aguas residuales y la utilización de algas marinas como adsorbentes incentiva el interés científico, teniendo en cuenta la variedad, abundancia y disponibilidad de diferentes especies nativas y arribantes [...] a los litorales costeros cubanos. El objetivo del trabajo es caracterizar un biosorbente algal, preparado a partir del alga marina Sargassum, para conocer sus potencialidades para la remoción de metales pesados en soluciones acuosas. Se realizó la caracterización físico-química, morfológica y estructural del biosorbente utilizando avanzadas técnicas de microanálisis y análisis superficial. Se confirma presencia de los principales grupos funcionales presentes en el ácido algínico, alginatos, polisacáridos y proteínas que contiene este tipo de biomasa algal, biopolímeros que aportan sitios activos que facilitan los mecanismos de biosorción y por consiguiente le pueden aportar a este tipo de biosorbente una alta capacidad de biosorción de metales pesados. Abstract in english The biosorption is considered an alternative technology for removal of heavy metals from wastewater and the use of seaweeds as adsorbents encourages scientific interest, considering the variety, abundance and availability of different species growing or arriving at the coastal shoreline. The aim of [...] the research was to characterize a seaweed biosorbent prepared from marine algae Sargassum, to know their potentialities for heavy metals removal from aqueous solutions. A characterization physico-chemical, morphological and structural of a seaweed bioadsorbent was performed using microanalysis and surface anaytical advanced techiques. Was confirmed of major functional groups present in the alginic acid, alginates, polysaccharides and proteins containing this type of seaweed biomass, biopolymers that facilitate the biosorption mechanisms and consequently they can contribute a high capacity of biosorption of heavy metals of this biosorbente.

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

    Science.gov (United States)

    Wu, Shengju; Wu, Cuirong; Li, Fengting; Xu, Ran

    2010-11-01

    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.

  8. Phase-controlled preparation of iron (oxyhydr)oxide nanocrystallines for heavy metal removal

    International Nuclear Information System (INIS)

    Obtaining cost-effective iron (oxyhydr)oxide nanocrystallines is the essential prerequisite for their future extensive applications in environmental remediation, such as the removal of heavy metals from contaminated waters. Here, various phases of iron (oxyhydr)oxide nanocrystallines were simply synthesized from the phase-controlled transformation of amorphous hydrous ferric- or ferrous-oxide in thermal solution with a certain ethanol/water ratio and with the presence of oleic acid. According to this method, goethite nanorods in diameter of 3–4 nm, hematite nanocubes sized 20–30 nm, and magnetite nanoparticles in diameter of 6–7 nm were successfully obtained. The final products of this transformation can be conveniently controlled by adjusting the reaction parameters, such as pH, temperature, and ethanol/water ratio. Due to the enhanced specific surface area and probably the modifications of the surface structure of nanocrystallines, the as-synthesized goethite nanorods and magnetite nanoparticles demonstrated extremely strong As(III) affinity, with 5.8 and 54 times of As(III) adsorption, respectively, higher than the micron-sized relatives. The cost-effective feature of as-synthesized nanocrystallines and their remarkably enhanced affinity toward arsenic made them potentially applicable for the removal of arsenic and such like heavy metals from the contaminated environment.

  9. 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

  10. Removal of Heavy Metal Ions from Wastewater by Carbon Nanotubes (CNTs

    Directory of Open Access Journals (Sweden)

    Ashish Gadhave

    2014-07-01

    Full Text Available Advent of nanotechnology has introduced us with new generation of adsorbents such as carbon nanotubes (CNTs which have aroused widespread attention due to their outstanding ability for the removal of various inorganic and organic pollutants from large volumes of water. This article reviews the practical feasibility of various kinds of raw and surface modified carbon nanotubes for adsorption of heavy metal ions from wastewater. Further, properties of CNTs (adsorption sites, characterization of CNTs (pore volume, BET surface area, surface total acidity, surface total basicity and solution properties (ionic strength, effect of pH are explained very well. The adsorption mechanisms are mainly attributable to chemical interactions between metal ions and surface functional groups of the CNTs. The adsorption capacity increases to greater extend after functionalization i.e. surface oxidation of CNTs. Future work on developing cost effective ways of production of CNTs and analyzing its toxicity are recommended.

  11. Simultaneous removal of organic contaminants and heavy metals from kaolin using an upward electrokinetic soil remediation process

    International Nuclear Information System (INIS)

    Kaolins contaminated with heavy metals, Cu and Pb, and organic compounds, p-xylene and phenanthrene, were treated with an upward electrokinetic soil remediation (UESR) process. The effects of current density, cathode chamber flushing fluid, treatment duration, reactor size, and the type of contaminants under the vertical non-uniform electric field of UESR on the simultaneous removal of the heavy metals and organic contaminants were studied. The removal efficiencies of p-xylene and phenanthrene were higher in the experiments with cells of smaller diameter or larger height, and with distilled water flow in the cathode chamber. The removal efficiency of Cu and Pb were higher in the experiments with smaller diameter or shorter height cells and 0.01 M HNO3 solution as cathode chamber flow. In spite of different conditions for removal of heavy metals and organics, it is possible to use the upward electrokinetic soil remediation process for their simultaneous removal. Thus, in the experiments with duration of 6 days removal efficiencies of phenanthrene, p-xylene, Cu and Pb were 67%, 93%, 62% and 35%, respectively. The experiment demonstrated the feasibility of simultaneous removal of organic contaminants and heavy metals from kaolin using the upward electrokinetic soil remediation process

  12. 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.

  13. Removing heavy metals from wastewaters with use of shales accompanying the coal beds.

    Science.gov (United States)

    Jab?o?ska, Beata; Siedlecka, Ewa

    2015-05-15

    A possibility of using clay waste rocks (shales) from coal mines in the removal of heavy metals from industrial wastewaters is considered in this paper. Raw and calcined (600 °C) shales accompanying the coal beds in two Polish coal mines were examined with respect to their adsorptive capabilities for Pb, Ni and Cu ions. The mineralogical composition of the shales was determined and the TG/DTG analysis was carried out. The granulometric compositions of raw and calcined shales were compared. Tests of adsorption for various Pb(II), Ni(II) and Cu(II) concentrations were conducted and the pH before and after adsorption was analyzed. The results indicate that the shales from both coal mines differ in adsorptive capabilities for particular metal ions. The calcination improved the adsorptive capabilities for lead, but worsened them for nickel. The examined shales have good adsorptive capabilities, and could be used as inexpensive adsorbents of heavy metal ions, especially in the regions where resources of shale are easy accessible in the form of spoil tips. PMID:25770963

  14. 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.

  15. Hydrogen sulfide removal from coal gas by the metal-ferrite sorbents made from the heavy metal wastewater sludge

    International Nuclear Information System (INIS)

    The metal-ferrite (chromium-ferrite and zinc-ferrite) sorbents made from the heavy metal wastewater sludge have been developed for the hydrogen sulfide removal from coal gas. The high temperature absorption of hydrogen sulfide from coal gas with the metal-ferrite sorbent in a fixed bed reactor was conducted in this study. The metal-ferrite powders were the products of the ferrite process for the heavy metal wastewater treatment. The porosity analysis results show that the number of micropores of the sorbents after sulfidation and regeneration process decreases and the average pore size increases due to the acute endothermic and exothermic reactions during the sulfidation-regeneration process. The FeS, ZnS, and MnS peaks are observed on the sulfided sorbents, and the chromium extraction of the CFR6 can fulfill the emission standard of Taiwan EPA. The suitable sulfidation temperature range for chromium-ferrite sorbent is at 500-600 deg. C. In addition, effects of various concentrations of H2 and CO were also conducted in the present work at different temperatures. By increasing the H2 concentration, the sulfur sorption capacity of the sorbent decreases and an adverse result is observed in the case of increasing CO concentration. This can be explained via water-shift reaction

  16. 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

  17. 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

  18. 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 removes fixed radioactive and hazardous contamination yet leaves the surface intact. Blasting residuals are treated using physical/chemical processes. Bench- and pilot-scale testing of the system was conducted on surfaces contaminated with uranium, technetium, heavy metals, and PCBs. Areas of concrete and metal surfaces were blasted. Residuals were dissolved in tap water and treated for radioactive, hazardous, and organochlorine constituents. The treatment system comprised pH adjustment, aeration, solids settling, filtration, carbon adsorption, and ion exchange. This system produced treated water and residual solid waste. Testing demonstrated that the systewaste. 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 treatment. Waste residuals volume was decreased by 71 %. Preliminary analyses suggest that this system provides significant waste volume reduction and is more economical than alternative surface decontamination techniques that are commercially available or under development

  19. 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.

  20. 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%

  1. 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.

  2. Soil heavy metals

    Energy Technology Data Exchange (ETDEWEB)

    Sherameti, Irena [Jena Univ. (Germany). Inst. fuer Allgemeine Botanik und Pflanzenphysiologie; Varma, Ajit (eds.) [Amity Univ., Uttar Pradesh (India). Amity Inst. of Microbial Technology; Amity Science, Technology and Innovation Foundation, Noida, UP (India)

    2010-07-01

    Human activities have dramatically changed the composition and organisation of soils. Industrial and urban wastes, agricultural application and also mining activities resulted in an increased concentration of heavy metals in soils. How plants and soil microorganisms cope with this situation and the sophisticated techniques developed for survival in contaminated soils is discussed in this volume. The topics presented include: the general role of heavy metals in biological soil systems; the relation of inorganic and organic pollutions; heavy metal, salt tolerance and combined effects with salinity; effects on abuscular mycorrhizal and on saprophytic soil fungi; heavy metal resistance by streptomycetes; trace element determination of environmental samples; the use of microbiological communities as indicators; phytostabilization of lead polluted sites by native plants; effects of soil earthworms on removal of heavy metals and the remediation of heavy metal contaminated tropical land. (orig.)

  3. Removal of heavy metals from aqueous solution by an efficient low cost biosorbent (abstract)

    International Nuclear Information System (INIS)

    The aim of this work was to assess the possibility of removing some heavy metals from water by a low-cost bio sorbent. Removal of lead and cadmium which differ in toxicity, as well as in some other characteristics were examined. Sawdust of Morus alba wood modified with 0.5N NaOH was applied as low cost bio sorbent. The sample was characterized by BET surface area, EDX, FTIR and Zeta potential technique. The removal of Cd(II) and Pb(II) by treated sawdust has been found to be concentration, contact time, adsorbate dose and temperature dependent. The adsorption parameters were determined using Freundlich, Langmuir and Tempkin isotherm models. The applicability of kinetic models i.e. pseudo first order, Elovich and parabolic diffusion has also been investigated. Thermodynamic parameters like delta H, delta S and delta G were calculated from the kinetic data. The equilibrium adsorption was achieved in 100 min. The result shows that the adsorbent examined was found to have good adsorption capacity. Surface complexation and ion exchange are the major removal mechanisms involved. The correlation coefficient for Langmuir, Freundlich and Tempkin equation were well fitted. The adsorption follows first-order kinetics. The rate of adsorption was high at high temperature. The positive values of delta S reflect some structural exchange among the active site of the adsorbent and metal ion. The negative value of Gibbs free energy (delta G) shows the spontaneous nature of the process.ows the spontaneous nature of the process. The findings of the data reveal that the modified Sawdust is a low-cost, easily available bio sorbent and can be use as alternative to other commercial adsorbents as well as for effluent treatment in industries. (author)

  4. Waste Conversion into Activated Carbon for Heavy Metal Removal from Waste Water

    Science.gov (United States)

    Lyubchik, Svetlana; Khodorkovskij, M.; Makarova, T.; Tikhonova, Liliya; Mota, José Paulo; Fonseca, Isabel

    Activated carbons were prepared from co-mingled natural organic waste, comprising 25% sunflower husks, 50% petroleum waste and 25% low-grade bituminous coal. The porous carbon materials were obtained either by direct activation with steam at 1,123 K, or through pre-oxidation stages with binary eutectic Na/K carbonates, followed by carbonization at 623 K in an inert atmosphere, and then steam activation at 1,123 K. The activated carbons prepared from the co-mingled natural organic wastes were used as adsorbents to remove copper (II), cobalt (III), nickel (II), iron (II), and manganese (II) from real multi-component solutions. Batch experiments were carried out to study the kinetics of multi-component, competitive adsorption. The mechanisms of heavy-metal adsorption on activated carbon are discussed.

  5. 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.

  6. 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.

  7. Removal of heavy metals from aqueous solution by adsorption on biomass based adsorbent

    Energy Technology Data Exchange (ETDEWEB)

    Alam, Sultan; Azmatullah, M. [Malakand Univ., Chakdara, Dir (Pakistan). Dept. of Chemistry; Bangash, Fazlullah Khan [Peshawar Univ. (Pakistan). Inst. of Chemical Sciences; Amin, Noor-ul [Abdul Wali Khan Univ., Mardan (Pakistan). Dept. of Chemistry

    2013-09-15

    Removal of heavy metals i.e. Zn{sup 2+} and Cd{sup 2+} from aqueous solution by adsorption onto biomass based adsorbent was investigated as a function of time and different concentrations. The sample was characterized by FTIR, EDS, BET surface area and Zeta potential technique, which was reported earlier. Adsorption kinetics of Zn{sup 2+} and Cd{sup 2+} was tested by first order kinetics, 'Elovich and parabolic diffusion kinetic equations which show that the process of adsorption is diffusion controlled process. The rate of adsorption was high at high adsorption temperature. Thermodynamic parameters like {Delta}H , {Delta}S and {Delta}G were calculated from the kinetic data. The negative value of Gibbs free energy ({Delta}G ) shows the spontaneous nature of the process. Freundlich, Langmuir, Temkin isotherms and distribution coefficient were found fit to the adsorption isotherm data. (orig.)

  8. 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%.

  9. 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

  10. 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%

  11. 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

  12. 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)

  13. Simultaneous removal of oil and grease, and heavy metals from artificial bilge water using electro-coagulation/flotation.

    Science.gov (United States)

    Rincón, Guillermo J; La Motta, Enrique J

    2014-11-01

    US and international regulations pertaining to the control of bilge water discharges from ships have concentrated their attention to the levels of oil and grease rather than to the heavy metal concentrations. The consensus is that any discharge of bilge water (and oily water emulsion within 12 nautical miles from the nearest land cannot exceed 15 parts per million (ppm). Since there is no specific regulation for metal pollutants under the bilge water section, reference standards regulating heavy metal concentrations are taken from the ambient water quality criteria to protect aquatic life. The research herein presented discusses electro-coagulation (EC) as a method to treat bilge water, with a focus on oily emulsions and heavy metals (copper, nickel and zinc) removal efficiency. Experiments were run using a continuous flow reactor, manufactured by Ecolotron, Inc., and a synthetic emulsion as artificial bilge water. The synthetic emulsion contained 5000 mg/L of oil and grease, 5 mg/L of copper, 1.5 mg/L of nickel, and 2.5 mg/l of zinc. The experimental results demonstrate that EC is very efficient in removing oil and grease. For oil and grease removal, the best treatment and cost efficiency was obtained when using a combination of carbon steel and aluminum electrodes, at a detention time less than one minute, a flow rate of 1 L/min and 0.6 A/cm(2) of current density. The final effluent oil and grease concentration, before filtration, was always less than 10 mg/L. For heavy metal removal, the combination of aluminum and carbon steel electrodes, flow rate of 1 L/min, effluent recycling, and 7.5 amps produced 99% zinc removal efficiency. Copper and nickel are harder to remove, and a removal efficiency of 70% was achieved. PMID:24908614

  14. 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.

  15. Removal of Heavy Metals Ions from Wastewater with Conventional Activated Sludge Process: Case study in Isfahan (Iran

    Directory of Open Access Journals (Sweden)

    Ali Jalilzadeh

    2007-01-01

    Full Text Available The pollution of industrial and municipal wastewater, which mixes with the toxic metal ions, is an environmental important matter. The discharge of industrial wastewater, which contains heavy metals, is toxic for the life of aquatic organisms although it makes water supplies undesirable for drinking. Due to these materials is accumulative, so determination and removal these materials are necessary. This study was done in WWTP of Isfahan (Iran. The data were compared with the standards of US-EPA and Environmental Agency of Iran. In this comparison, some metal concentration of effluent was higher according to standard limits of Iran. Results of research illustrate, conventional activated sludge process only cannot remove heavy metal sufficiently.

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

    Directory of Open Access Journals (Sweden)

    Mokhlesur M. Rahman

    2014-05-01

    Full Text Available 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 hydrated iron oxide. The adsorption equilibrium data for nickel(II and lead(II were obtained from adsorption by the prepared and commercial activated carbons. Langmuir and Freundlich models fit the data well. Prepared activated carbons showed higher adsorption capacity for nickel(II and lead(II. The removal of chromium(VI was studied by the prepared acid activated, modified and commercial activated carbons at different pH. The isotherms studies reveal that the prepared activated carbon performs better in low concentration region while the commercial ones in the high concentration region. Thus, a complete adsorption is expected in low concentration by the prepared activated carbon. The kinetics data for Ni(II, Pb(II and Cr(VI by the best selected activated carbon fitted very well to the pseudo-second-order kinetic model.

  17. Removal heavy metals and sulphate from waste waters by sulphate-reducing bacteria

    Directory of Open Access Journals (Sweden)

    Ku?nierová Mária

    2000-09-01

    Full Text Available This article is devoted to the process of bacterial sulphate reduction, which is used to removal of heavy metals and sulphate ions from waste waters.The life of animals and plants depends on the existence of microscopic organisms ? microorganisms (MO, which play an important role in cycle changes of biogenic elements on the earth. The sulphur cycle in the nature is considered as one of the oldest and most significant biological systems (Fig. 1. The sulphate-reducing bacteria (SRB miss the assimilatory part of the cycle and produce sulphides. The microbial population of this dissimilatory part is called ?sulfuretum?. The SRB can be found in anaerobic mud and sediments of freshwater, thermal or non-thermal sulphur springs, mining waters from sulphide deposits, oil deposits, sea and ocean beds, and in the gastrointestinal tract of man and animals. The SRB represent a group of chemoorganotrophic, strictly anaerobic and gramnegative bacteria, which exhibit a great morphological and physiological diversity. Despite of their considerable morphological variety, they have one property in common, which is the ability to utilise preferentially sulphates (occasionally sulphites, thiosulphates, tetrathionates as electron acceptors, which are reduced to sulphides, during anaerobic respiration. The electron donors in these processes are simple organic compounds as lactate, malate, etc.,(heterotrophically reduction or gaseous hydrogen (autotrophically reduction. SRB can produce a considerable amount of hydrogen sulphide, which reacts easily in aqueous solution with the cations of heavy metals, forming metal sulphides that have low solubility. The bacterial sulphate reduction can be used for the treatment of acid mine drainage waters, which is considered to be the major problem associated with mining activities.In order to remove heavy metals from waste waters, e.g., from galvanizing plants, mine waters (Smolnik, ?obov locality and metallurgic plants (works Krompachy by use of the activity of SRB, mixed strains were isolated, cultivated, and their production of hydrogen sulphide was assessed. The cultures were then tested for the ability to precipitate copper and sulphates from a model solution.The bacteria were isolated from water samples from two localities: Východoslovenské ?eleziarne (works ? VS? and spring Gajdovka ? Gj. Isolation, cultivation and eliminating Cu2+ and SO42- was carried out under following conditions: statically, temperature 30 oC, pH 7,5, nutrient medium by J. Postgate (medium B, C and D and anaerobic conditions. Residual copper in the solution was measured by atomic absorption photometry. The concentracion of sulphates in the solution was measured by the nefelometric method.Our findings from the isolation of SRB from two Slovak water samples and testing the cultures for their ability to remove copper permit the following conclusions: SRB occur in sufficient numbers in sulphur mineral water from natural sources and in industrial waste waters reservoirs, the sulphate-reducing activity can be harnessed for the purification of some industrial waste waters.The nature possesses a great biological potential that can be exploited under certain conditions in the cleanup of environmental pollution resulting from the industrial activity in the past and present.

  18. Effectiveness of commercial reagents for heavy metal removal from water with new insights for future chelate designs.

    Science.gov (United States)

    Matlock, Matthew M; Henke, Kevin R; Atwood, David A

    2002-05-27

    Toxic heavy metals in air, soil, and water are global problems that are a growing threat to the environment. To meet the federal and state guidelines for heavy metal discharge, companies often use chemical precipitation or chelating agents. In order to be competitive economically, many of these chelating ligands are simple, easy to obtain, and, generally offer weak bonding for heavy metals. Laboratory testing of three commercial reagents, trimercaptotriazine (TMT), Thio-Red potassium/sodium thiocarbonate (STC), and HMP-2000 sodium dimethyldithiocarbamate (SDTC) has shown that the compounds were unable to reduce independent solutions containing 50.00 ppm of divalent cadmium, copper, iron, lead, or mercury to meet EPA standards. Additionally, the compounds displayed high leaching rates and in some cases decomposed to produce toxic substances. In contrast, the studies demonstrate that a recently reported sulfur-containing multidentate ligand is both safe and effective for the removal of these metals. PMID:11992699

  19. GENERIC ADSORPTION COEFFICIENTS AND NATURAL REMOVAL OF HEAVY METALS IN MUDDY RIVER WATER

    OpenAIRE

    Amini Rad H, A. Hasannattaj

    2013-01-01

    In this study a possible natural flocculating capacity of River's is experimentally investigated. For this purpose, Chalus River in northern part of IRAN due to its heavy metal pollution, high flows and high suspended and bed sediments fluctuation level is selected. In this investigation heavy metals content of water, suspended and bed sediments of the Chalus River, is experimentally evaluated. The samples were obtained during the wet season (mud flow) from three existing observing sampling s...

  20. 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.

  1. Sewage sludge ash to phosphate fertilizer by chlorination and thermal treatment: residence time requirements for heavy metal removal.

    Science.gov (United States)

    Nowak, Benedikt; Wegerer, Harald; Aschenbrenner, Philipp; Rechberger, Helmut; Winter, Franz

    2012-01-01

    Heavy metal removal from sewage sludge ash can be performed by mixing the ash with environmentally compatible chlorides (e.g. CaCl2 or MgCl2) and water, pelletizing the mixture and treating the pellets in a rotary reactor at about 1000 degrees C. Thermogravimetry-mass spectroscopy, muffle oven tests (500-1150 degrees C) and investigations in a laboratory-scale rotary reactor (950-1050 degrees C, residence time 1-25 min) were carried out. In the rotary reactor, up to 97% of Cu, 95% Pb and 95% Zn can be removed at 1050 degrees C. As Cl release starts from 400 degrees C (obtained from thermogravimetry-mass spectrometry experiments), heavy metals are already removed partially within the heating period. This heavy metal removal can be described as being similar to a first-order rate law. To meet the limit values specified in the Austrian and German fertilizer ordinances, residence times of the order of minutes are sufficient at 950 degrees C. PMID:23393980

  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 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.

  4. 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.

  5. Enzyme-based glucose delivery: a possible tool for biosorbent preparation for heavy metal removal from polluted environments.

    Science.gov (United States)

    Palela, Mihaela; Bahrim, Gabriela Elena; Glazyrina, Julia; Brand, Eva; Neubauer, Peter

    2013-11-01

    This study was performed to examine the influence of the controlled glucose supply technology, EnBase(®) Flo, on growth and heavy metals uptake capacity of two Bacillus strains isolated from food industry wastewater. Bacillus sp. growth on EnBase Flo (mineral salt complex medium containing starch-derived polymer as substrate) was examined in 24 deep well plates, controlling the glucose amount release by adding two amyloglucosidase concentrations (3 and 6 UL(-1)). Adsorption of the heavy metals Zn(2+), Cd(2+) and Pb(2+) was assessed in a single component system using synthetic metal solutions and as a function of the initial concentration of adsorbate, equilibrium time and removal efficiency. The Langmuir and Freundlich adsorption models were used for the mathematical description of the biosorption equilibrium and isotherm constants. A pseudo second-order model was applied to describe the uptake rate for two isolates. The EnBase(®) Flo technology improved the cells growth over ten times after 24 h of fed-batch cultivation. The EnBase(®) Flo technology improved the Cd(2+) and Pb(2+) uptake capacity of the bacterial strains by approximately 55 and 44 %, respectively. The biosorption of each metal was fairly rapid (within 30 min), which could be an advantage for large scale treatment of contaminated sites. This initial study may be a basis for future developments to apply EnBase Flo for the biomass production used further as biosorbent for heavy metal removal from aqueous solutions. PMID:23456253

  6. 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.

  7. 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,...

  8. Design and simulation of an activated sludge unit associated to a continuous reactor to remove heavy metals

    Energy Technology Data Exchange (ETDEWEB)

    D`Avila, J.S.; Nascimento, R.R. [Ambientec Consultoria Ltda., Aracaju, SE (Brazil)

    1993-12-31

    A software was developed to design and simulate an activated sludge unit associated to a new technology to remove heavy metals from wastewater. In this process, a continuous high efficiency biphasic reactor operates by using particles of activated peat in conjugation with the sludge unit. The results obtained may be useful to increase the efficiency or to reduce the design and operational costs involved in a activated sludge unit. (author). 5 refs., 2 tabs.

  9. 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

  10. 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.

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

    International Nuclear Information System (INIS)

    Poly(vinyl pyridine-poly ethylene glycol methacrylate-ethylene glycol dimethacrylate) [poly(VP-PEGMA-EGDMA)] beads with an average size of 30-100 ?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 HNO3. 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

  12. Removal of heavy metals from tannery effluents of Ambur industrial area, Tamilnadu by Arthrospira (Spirulina) platensis.

    Science.gov (United States)

    Balaji, S; Kalaivani, T; Rajasekaran, C; Shalini, M; Vinodhini, S; Priyadharshini, S Sunitha; Vidya, A G

    2015-06-01

    The present study was carried out with the tannery effluent contaminated with heavy metals collected from Ambur industrial area to determine the phycoremediation potential of Arthrospira (Spirulina) platensis. Two different concentrations (50 and 100 %) of heavy metals containing tannery effluent treated with A. platensis were analysed for growth, absorption spectra, biochemical properties and antioxidant enzyme activity levels. The effluent treatments revealed dose-dependent decrease in the levels of A. platensis growth (65.37 % for 50 % effluent and 49.32 % for 100 % effluent), chlorophyll content (97.43 % for 50 % effluent and 71.05 % for 100 % effluent) and total protein content (82.63 % for 50 % effluent and 62.10 % for 100 % effluent) that leads to the reduction of total solids, total dissolved solids and total suspended solids. A. platensis with lower effluent concentration was effective than at higher concentration. Treatment with the effluent also resulted in increased activity levels of antioxidant enzymes, such as superoxide dismutase (14.58 units/g fresh weight for 50 % and 24.57 units/g fresh weight for 100 %) and catalase (0.963 units/g fresh weight for 50 % and 1.263 units/g fresh weight for 100 %). Furthermore, heavy metal content was determined using atomic absorption spectrometry. These results indicated that A. platensis has the ability to combat heavy metal stress by the induction of antioxidant enzymes demonstrating its potential usefulness in phycoremediation of tannery effluent. PMID:25944749

  13. MECHANISMS OF HEAVY METAL REMOVAL FROM ACID MINE DRAINAGE USING CHITIN

    Science.gov (United States)

    Acid Mine Drainage (AMD) emanating from inactive or active mine sites contains elevated levels of toxic heavy metals, which can have an adverse impact to the surrounding environment. The major pathway involved in generation of AMD is weathering of pyritic mineral ores, where in s...

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

    OpenAIRE

    Nur Azreen Fuadi; Ahmmed Saadi Ibrahem; Kamariah Noor Ismail

    2014-01-01

    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 tre...

  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. Novel kinetic model of the removal of divalent heavy metal ions from aqueous solutions by natural clinoptilolite.

    Science.gov (United States)

    Jovanovic, Mina; Rajic, Nevenka; Obradovic, Bojana

    2012-09-30

    Removal of heavy metal ions from aqueous solutions using zeolites is widely described by pseudo-second order kinetics although this model may not be valid under all conditions. In this work, we have extended approaches used for derivation of this model in order to develop a novel kinetic model that is related to the ion exchange mechanism underlying sorption of metal ions in zeolites. The novel model assumed two reversible steps, i.e. release of sodium ions from the zeolite lattice followed by bonding of the metal ion. The model was applied to experimental results of Cu(II) sorption by natural clinoptilolite-rich zeolitic tuff at different initial concentrations and temperatures and then validated by predictions of ion exchange kinetics of other divalent heavy metal ions (i.e. Mn(II), Zn(II) and Pb(II)). Model predictions were in excellent agreements with experimental data for all investigated systems. In regard to the proposed mechanism, modeling results implied that the sodium ion release rate was constant for all investigated metals while the overall rate was mainly determined by the rate of heavy metal ion bonding to the lattice. In addition, prediction capabilities of the novel model were demonstrated requiring one experimentally determined parameter, only. PMID:22818175

  17. 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

  18. Growth and heavy metals removal efficiency of Nostoc muscorum and Anabaena subcylindrica in sewage and industrial wastewater effluents.

    Science.gov (United States)

    El-Sheekh, Mostafa M; El-Shouny, Wagieh A; Osman, Mohamed E H; El-Gammal, Eman W E

    2005-02-01

    The growth of Nostoc muscorum and Anabaena subcylindrica in sterilized sewage wastewater and N. muscorum in sterilized wastewater of El-Soda Company was higher than those grown in Allen synthetic medium. Whereas, the growth of A. subcylindrica in El-Soda Company sterilized wastewater and N. muscorum as well as A. subcylindrica grown in Verta Company sterilized wastewater was slightly lower than that grown in the standard synthetic medium. The contents of chlorophyll a, carotenoids and protein of N. muscorum and A. subcylindrica grown in sterilized sewage wastewater were higher than those grown in the standard medium. Similarly, N. muscorum and the bio-mixture of N. muscorum and A. subcylindrica grown in the sterilized wastewater of El-Soda Company showed high pigments and protein contents more than those reared in Allen medium. On the other hand, the bio-mixture of N. muscorum and A. subcylindrica grown in the sterilized sewage wastewater, A. subcylindrica grown in El-Soda Company and Verta Company sterilized wastewater showed lower contents of pigments and protein compared to synthetic medium. Heavy metals, copper, cobalt, lead and manganese were removed by 12.5-81.8, 11.8-33.7, 26.4-100 and 32.7-100%, respectively, from wastewater by using cyanobacterial cultures. The metal sorption efficiency depended on the type of biosorbent, the physiological state of the cells, availability of heavy metal, concentration of heavy metal and chemical composition of wastewater. It was observed also that the single cultures in most cases was better than the mixed cultures in heavy metal removal, this may be due to the cyanobacterial competition for nutrients in mixed cultures. PMID:21783496

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

    OpenAIRE

    Veeken, A.; Hamelers, B.

    1998-01-01

    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...

  1. Comparison of 2-compartment, 3-compartment and stack designs for electrodialytic removal of heavy metals from harbour sediments

    DEFF Research Database (Denmark)

    Pedersen, Kristine B.; Ottosen, Lisbeth M.

    2014-01-01

    Comparisons of cell and stack designs for the electrodialytic removal of heavy metals from two harbour sediments, were made. Multivariate modelling showed that sediment properties and experimental set-ups had the highest influence on the heavy metal removal indicating that they should be modelled and analysed separately. Clean-up levels of Cu, Pb and Zn were significantly higher for the cell designs, implying that longer time and relatively more electric charge and energy would be necessary to achieve similar clean-up levels in the stack design experiments.In the studied experimental domain, the optimal current density for the 2- and 3-compartment cells was 0.12mA/cm2 (center value) removing the highest quantity of Cu, Pb and Zn per Wh. The highest percentages removed were 82% Cu, 81% Pb and 92% Zn were however achieved at higher current density. For the stack experiments conducted at same electric charge per unit sediment, energy consumption was a magnitude higher and the highest clean-up levels were 21% Cu,42% Pb and 73% Zn.

  2. 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

  3. 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.

  4. 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.

  5. Removal of heavy metals from contaminated water using ethylenediamine-modified green seaweed (Caulerpa serrulata)

    Science.gov (United States)

    Mwangi, Isaac W.; Ngila, J. Catherine

    The demand for clean water is on the increase as the population increases. One of the ways to address the water shortage is to treat the polluted water through removal of the contaminants. The use of adsorbents for pollutant removal is one of the promising methods. Seaweed is an aquatic plant and its sorption ability for selected metals in water was investigated in this study. We report the performance of the seaweed (Caulerpa serrulata) before and after modification with ethylenediamine (EDA), on adsorption of copper, lead and cadmium in aqueous solution. The adsorption capacities for Cu, Cd and Pb were 5.27 mg g-1, 2.12 mg g-1 and 2.16 mg g-1, respectively, with the EDA-modified seaweed, and 3.29 mg g-1, 4.57 mg g-1 and 1.06 mg g-1, with the unmodified weed, respectively. The pH for maximum adsorption was found to be within the range of pH 4-pH 6. In a separate investigation, it was found that 0.1 g of dried seaweed leached 20 mg of dissolved organic carbon (DOC) using 100 ml of distilled-deionised water. The resulting solution was green. The leaching phenomenon contributes to secondary pollution. Modification of the seaweed with EDA reduced the DOC content by half (50%) and also removed the green colouration. Kinetic studies showed that the adsorbent was able to take up to 95% of the metals (in synthetic standard solutions) in less than 10 min. The adsorbed metals were then stripped using a solution of 0.5 M HNO3 indicating that the adsorbent can be regenerated. In addition, the study revealed that modification improved the thermal stability of the adsorbent such that even when the temperature was raised to 1000 °C, more than 80% (compared to weed) of the modified adsorbent was not degraded, indicating that modification had a significant influence on the thermal stability of seaweed. The modified seaweed has been shown to have great potential for the removal of metals and DOC in polluted water. The modified adsorbent can therefore be applied for the removal of metals in polluted waters hence suitable for treatment of water for domestic consumption at a point of use.

  6. 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.

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

    Directory of Open Access Journals (Sweden)

    B. Gajda

    2012-12-01

    Full Text Available 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 acetate as a matrix, orto-nitrophenyl octyl ether (ONPOE as a plasticizer and 1-decylimidazole as a carrier were used in investigations. The membrane processes were carried out in a membrane module for 24 hours.Findings: The results obtained point out a significant influence of chloride anions concentration on separation process of certain metal ions. It was observed that zinc(II ions are isolated most effectively from the solution containing 2M of chloride anions. About 88% of Zn(II, 5.5% of Co(II, 6.5% of Cd(II and below 1% of Ni(II were separated from such a solution.Research limitations/implications: The obtained results show that it is possibility of the selective extraction of heavy metal ions from polymetallic chloride solutions in membrane processes. The aqueous solution containing 2M of chloride ions was used in the investigation.Practical implications: The results show that Zn(II can be effectively recovered from solutions containing Co(II, Cd(II and Ni(II. This process would allow the utilization of waste solutions containing the heavy metal ions. The results of the study presented in the paper can be used in the utilization process of the spent batteries and accumulators.Originality/value: The innovative issue shown in this paper concerns the usage of 1-decylimidazole in selective separation of nickel(II, cobalt(II, cadmium(II and zinc(II ions in membrane process using PIM.

  8. 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.

  9. 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.

  10. 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.

  11. Removal of heavy metal from industrial wastewater using chitosan coated oil palm shell charcoal

    Scientific Electronic Library Online (English)

    Nomanbhay, Saifuddin M; Palanisamy, Kumaran.

    2005-04-15

    Full Text Available This research focuses on understanding biosorption process and developing a cost effective technology for treatment of heavy metals-contaminated industrial wastewater. A new composite biosorbent has been prepared by coating chitosan onto acid treated oil palm shell charcoal (AOPSC). Chitosan loading [...] on the AOPSC support is about 21% by weight. The shape of the adsorbent is nearly spherical with particle diameter ranging 100~150 µm. The adsorption capacity of the composite biosorbent was evaluated by measuring the extent of adsorption of chromium metal ions from water under equilibrium conditions at 25ºC. Using Langmuir isotherm model, the equilibrium data yielded the following ultimate capacity values for the coated biosorbent on a per gram basis of chitosan: 154 mg Cr/g. Bioconversion of Cr (VI) to Cr (III) by chitosan was also observed and had been shown previously in other studies using plant tissues and mineral surfaces. After the biosorbent was saturated with the metal ions, the adsorbent was regenerated with 0.1 M sodium hydroxide. Maximum desorption of the metal takes place within 5 bed volumes while complete desorption occurs within 10 bed volumes. Details of preparation of the biosorbent, characterization, and adsorption studies are presented. Dominant sorption mechanisms are ionic interactions and complexation.

  12. 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

  13. 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.

  14. Chemical modification of cellulosic biopolymer and its use in removal of heavy metal ions from wastewater.

    Science.gov (United States)

    Singha, A S; Guleria, Ashish

    2014-06-01

    Use of biological macromolecules for wastewater remediation process has become the topic of intense research mostly driven by growing concerns about the depletion of petroleum oil reserves and environmental problems. So in view of technological significance of cellulosic biopolymers in various fields, the present study is an attempt to synthesize cellulosic biopolymers based graft copolymers using free radical polymerization. The resulting cellulosic polymers were characterized by Fourier transform infrared spectroscopy (FT-IR), Scanning electron microscopy (SEM), X-ray diffraction (XRD) and thermogravimetric (TGA) analysis. Furthermore, modified cellulosic biopolymer was used in removal of Cu(2+), Zn(2+), Cd(2+) and Pb(2+) toxic metal ions from wastewater. The effects of pH, contact time, temperature and metal ions concentration were studied in batch mode experiments. Langmuir and Dubinin-Radushkevich (D-R) models were used to show the adsorption isotherm. The maximum monolayer capacity qm calculated using Langmuir isotherm for Cu(2+), Zn(2+), Cd(2+), Pb(2+) metal ions were 1.209, 0.9623, 1.2609 and 1.295mmol/g, respectively. The thermodynamic parameters ?H° and ?G° values for metal ions adsorption on modified cellulosic biopolymer showed that adsorption process was spontaneous as well as exothermic in nature. PMID:24704540

  15. 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

  16. Removal of Heavy Metals and Organic Contaminants from Aqueous Streams by Novel Filtration Methods

    Energy Technology Data Exchange (ETDEWEB)

    Rodriguez, N.M.

    2000-08-01

    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.

  17. 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.)

  18. 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.

  19. Removal of heavy metals from wastewater using CFB-coal fly ash zeolitic materials

    International Nuclear Information System (INIS)

    Polish bituminous (PB) and South African (SA) coal fly ash (FA) samples, derived from pilot-scale circulated fluidized bed (CFB) combustion facilities, were utilized as raw materials for the synthesis of zeolitic products. The two FAs underwent a hydrothermal activation with 1 M NaOH solution. Two different FA/NaOH solution/ratios (50, 100 g/L) were applied for each sample and several zeolitic materials were formed. The experimental products were characterized by means of X-ray diffraction (XRD) and energy dispersive X-ray coupled-scanning electron microscope (EDX/SEM), while X-ray fluorescence (XRF) was applied for the determination of their chemical composition. The zeolitic products were also evaluated in terms of their cation exchange capacity (CEC), specific surface area (SSA), specific gravity (SG), particle size distribution (PSD), pH and the range of their micro- and macroporosity. Afterwards the hybrid materials were tested for their ability of adsorbing Cr, Pb, Ni, Cu, Cd and Zn from contaminated liquids. Main parameters for the precipitation of the heavy metals, as it was concluded from the experimental results, are the mineralogical composition of the initial fly ashes, as well as the type and the amount of the produced zeolite and specifically the mechanism by which the metals ions are hold on the substrate.

  20. 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)

  1. 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)

  2. 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

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

    Science.gov (United States)

    Meena, Ajay Kumar; Kadirvelu, K; Mishra, G K; Rajagopal, Chitra; Nagar, P N

    2008-02-11

    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 (k(ad)), standard free energy (DeltaG degrees ), enthalpy (DeltaH degrees ) and entropy (DeltaS degrees ) 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. PMID:17600619

  4. Removal of heavy metal ions from aqueous solutions using carbon aerogel as an adsorbent.

    Science.gov (United States)

    Meena, Ajay Kumar; Mishra, G K; Rai, P K; Rajagopal, Chitra; Nagar, P N

    2005-06-30

    The removal of Cd(II), Pb(II), Hg(II), Cu(II), Ni(II), Mn(II) and Zn(II) by carbon aerogel 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. 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 carbon aerogel satisfies not only the Langmuir assumptions but also the Freundlich assumptions, i.e. multilayer formation on the surface of the adsorbent with an exponential distribution of site energy. The applicability of the Lagergren kinetic model has also been investigated. Thermodynamic constant (K(ad)), standard free energy (DeltaG(0)), enthalpy (DeltaH(0)) and entropy (DeltaS(0)) were calculated for predicting the nature of adsorption. 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. PMID:15878798

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

    Energy Technology Data Exchange (ETDEWEB)

    Meena, Ajay Kumar [Centre for Fire, Explosive and Environment Safety (CFEES), Defence R and D Organisation (DRDO), Brig. S.K. Mazumdar Road, Timarpur, Delhi 110054 (India); Kadirvelu, K. [Centre for Fire, Explosive and Environment Safety (CFEES), Defence R and D Organisation (DRDO), Brig. S.K. Mazumdar Road, Timarpur, Delhi 110054 (India)], E-mail: kadirvelu@lycos.com; Mishra, G.K.; Rajagopal, Chitra [Centre for Fire, Explosive and Environment Safety (CFEES), Defence R and D Organisation (DRDO), Brig. S.K. Mazumdar Road, Timarpur, Delhi 110054 (India); Nagar, P.N. [Centre for Fire, Explosive and Environment Safety (CFEES), Defence R and D Organisation (DRDO), Brig. S.K. Mazumdar Road, Timarpur, Delhi 110054 (India); Department of Chemistry, University of Rajasthan, Jaipur 302004 (India)

    2008-02-11

    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 (k{sub ad}), standard free energy ({delta}G{sup o}), enthalpy ({delta}H{sup o}) and entropy ({delta}S{sup o}) 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.

  6. 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

  7. 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.)

  8. Agricultural by-products as low-cost sorbents for the removal of heavy metals from dilute wastewaters.

    Science.gov (United States)

    Humelnicu, D; Ignat, M; Doroftei, F

    2015-05-01

    n the last years, much attention has been focused on the use of low-cost adsorbents for the removal of Cu(II) and Zn(II) from contaminated waters. In this context, we studied the sorption performances of two kinds of by-products resulted from the agriculture: soy bran and mustard husk. The effects of contact time, the initial metal ion concentration, pH, sorbent mass, and temperature on the adsorption capacity of the agricultural by-products as sorbents were investigated. The thermodynamic parameters associated with the adsorption process indicated that the process is spontaneous and endothermic. Modeling of experimental adsorption isotherm data showed that non-linear Langmuir isotherm fits better than other isotherms. The obtained values for the separation factor, R L were less than one which supports that the adsorption process was favorable. The obtained results indicated that the soy bran has a higher sorption capacity toward zinc ions (74.02 mg g(-1)) than mustard husk (63.69 mg g(-1)). Therefore, there is a great requirement for the search of biomaterials that are cheap and easily available for the removal of heavy metal ions from wastewater. The studied sorbents have the advantage of very low cost and great availability for simple operational experiments. PMID:25832011

  9. 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.

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

    DEFF Research Database (Denmark)

    MØller, J.; Ledin, Anna

    2002-01-01

    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, and finally spiked with metals to ensure concentration levels similar to high levels reported in the leterature (Pb=20, Cu=40, Zn=110, and Cr=15 ppb). Column experiments were conducted to test the influence of the infiltration rate (1 or 3 m/h) and the type of iron(hydr)oxide mineral (amorphous ferrihydrite and goethite coated sand). The results show that at least 90% of lead, copper and zinc can be removed by IOCS after 480 pore volumes. Control columns with uncoated filter sand show that lead, copper and zinc were removed with >95%, 35% and 5%, respectively. The removal of the negative metaloxy-ion, CrO4-3 was insignificant in both IOCS and sand columns at pH=7.7. Destruction of the columns after the experiments showed, that Pb, Cu and Zn penetrated to different depths in the columns. No saturation of lead was found in the first cm of the column after 1696 pore volumes of teated water. Copper showed a curved adsorption front, indicating that an infiltration speed of 3 m/h is sligtly too fast for the equilibrium between water phase and IOCS to be reached. The column with ferrihydrite was fully saturated with regard to zinc after 1696 pore volumes. In general the coating of goethite is found to be at least twice as effective as ferrihydrite with respect to the adsorption capacity of copper and zinc. Furthermore, desorption of metals from the IOCS by soaking in weak acid (pH=2.25) showed that 20%, 58% and 75% of the adsorbed Pb, Cu and Zn was recovered. Reuse of the IOCS after soaking in weak acis is possible, but it is likely to lower the adsorption capacities found in this study.

  11. 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

  12. Sequential removal of heavy metals ions and organic pollutants using an algal-bacterial consortium.

    Science.gov (United States)

    Muñoz, Raul; Alvarez, Maria Teresa; Muñoz, Adriana; Terrazas, Enrique; Guieysse, Benoit; Mattiasson, Bo

    2006-05-01

    The residual algal-bacterial biomass from photosynthetically supported, organic pollutant biodegradation processes, in enclosed photobioreactors, was tested for its ability to accumulate Cu(II), Ni(II), Cd(II), and Zn(II). Salicylate was chosen as a model contaminant. The algal-bacterial biomass combined the high adsorption capacity of microalgae with the low cost of the residual biomass, which makes it an attractive biosorbent for environmental applications. Cu(II) was preferentially taken-up from the medium when the metals were present both separately and in combination. There was no observed competition for adsorption sites, which suggested that Cu(II), Ni(II), Cd(II), and Zn(II) bind to different sites and that active Ni(II), Cd(II) and Zn(II) binding groups were present at very low concentrations. Therefore, special focus was given to Cu(II) biosorption. Cu(II) biosorption by the algal-bacterial biomass was characterized by an initial fast cell surface adsorption followed by a slower metabolically driven uptake. pH, Cu(II), and algal-bacterial concentration significantly affected the biosorption capacity for Cu(II). Maximum Cu(II) adsorption capacities of 8.5+/-0.4 mg g-1 were achieved at an initial Cu(II) concentration of 20 mg l-1 and at pH 5 for the tested algal-bacterial biomass. These are consistent with values reported for other microbial sorbents under similar conditions. The desorption of Cu(II) from saturated biomass was feasible by elution with a 0.0125 M HCl solution. Simultaneous Cu(II) and salicylate removal in a continuous stirred tank photobioreactor was not feasible due to the high toxicity of Cu(II) towards the microbial culture. The introduction of an adsorption column, packed with the algal-bacterial biomass, prior to the photobioreactor reduced Cu(II) concentration, thereby allowing the subsequent salicylate biodegradation in the photobioreactor. PMID:16307789

  13. 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).

  14. A study on removal of heavy metals and pH increasing effects in plating wastewater using oyster shells

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Eun Ho; Kim, Jung Kwon; Sung, Nak Chang [Dong-A University, Pusan (Korea, Republic of)

    1997-08-31

    In the present, batch test was conducted to evaluate the neutralization and adsorption of heavy metals from the plating wastewater using oyster shells. The smaller particle size of oyster shells, the higher neutralization and adsorption efficiencies of heavy metals with increasing time. It seemed that adsorption efficiencies of heavy metals were influenced by competitive reaction within a same pH range rather than solubility. As a result on the experiments of Freundlich isotherm, the adsorption capacities(k) were Fe 3.66 and Cr 1.24, respectively and the adsorption intensities(1/n) were Fe 3.3 and Cr 2.55, respectively. In view of these results, it showed that ocean wastes containing the similar compositions as oyster shells could utilize the neutralization and adsorption of heavy metals in plating wastewater. (author). 14 refs., 1 tab., 7 figs.

  15. Electrodialytic treatment of municipal wastewater and sludge for the removal of heavy metals and recovery of phosphorus

    DEFF Research Database (Denmark)

    Ebbers, Benjamin; Ottosen, Lisbeth M.

    2015-01-01

    Municipal wastewater and sewage sludge is an abundant source of phosphorus (P), but its usage is often limited due to wastewater treatment methods and contaminants, mostly heavy metals (HM's). Three compartment (3C) electrodialysis (ED) was used to simultaneously extract HM's (Cd, Cr, Cu, Ni, Pb and Zn) and recover P from municipal sludge samples obtained at different stages during wastewater treatment involving biological and chemical treatment as well as polymer addition for thickening of sludge and anaerobic digestion of excess sludge. Direct P recovery was investigated for high P reject water stream using the 3C ED cell setup and a two-compartment (2C) where the cathode in direct contact with the wastewater while P was extracted to and concentrated in the anolyte. Simultaneous extraction of HM's and recovery of P from wastewater or raw sludge using 3C ED was be most effective at a low pH using anaerobically digested sludge. The hydrolysis of OM during anaerobic digestion and the anaerobic conditions allowed for easier extraction of HM's such as Cd, Ni and Zn as they had fewer adsorption places, and improved P availability and extractability. Extraction of P from high concentration P streams was most effective using a 3C ED cell setup, with the electrodes separated from the sample by ion-exchange membranes. Extraction with the 2C ED cell setup was less effective due to a rise in pH, caused by half reactions at the cathode and subsequent precipitation of P. For either removal of heavy metals or recovery of phosphorus using ED, the end-products in wastewater treatment, like anaerobically digested sludge and reject-water streams, are therefore best to be treated.

  16. Heavy Metals Removal from Swine Wastewater Using Constructed Wetlands with Horizontal Sub-Surface Flow

    Directory of Open Access Journals (Sweden)

    María C. Ponce-Caballero

    2012-08-01

    Full Text Available The removal efficiency of Cu and Zn from swine wastewater was evaluated as effected by three variables: the hydraulic retention time (HRT (24, 48, 72 and 96 hours, two different plant species (Typha domingensis Pers. and Eleocharis cellulosa and two different sizes of filter media (5 and 15 mm using a horizontal sub-surface flow constructed wetland. From the results, a significant difference was observed in the removal efficiency of Cu and Zn with respect to different hydraulic retention times. The best results were obtained in the HRT of 96 hours for Zn where 96% removal of Zn with Typha domingensis Pers. specie with gravel of 15 mm (experimental unit 6 was achieved. For Cu, at 72 hours of HRT, the efficiency was nearly 100% in five of the six study units (1, 2, 3, 5 and 6. In contrast, in experimental unit 4 with gravel of 15 mm and without plants, only 86% Cu removal was achieved.

  17. Heavy Metals Removal from Swine Wastewater Using Constructed Wetlands with Horizontal Sub-Surface Flow

    OpenAIRE

    Ponce-caballero, Mari?a C.; Roger Méndez-Novelo; Barcelo?-quintal, Icela D.; Germán Giácoman-Vallejos; Cortes-esquivel, Jorge A.

    2012-01-01

    The removal efficiency of Cu and Zn from swine wastewater was evaluated as effected by three variables: the hydraulic retention time (HRT) (24, 48, 72 and 96 hours), two different plant species (Typha domingensis Pers. and Eleocharis cellulosa) and two different sizes of filter media (5 and 15 mm) using a horizontal sub-surface flow constructed wetland. From the results, a significant difference was observed in the removal efficiency of Cu and Zn with respect to different hydraulic retention ...

  18. Heavy metals precipitation in sewage sludge

    OpenAIRE

    Marchioretto, M.M.; Rulkens, W. H.; Bruning, H

    2005-01-01

    There is a great need for heavy metal removal from strongly metal-polluted sewage sludges. One of the advantages of heavy metal removal from this type of sludge is the possibility of the sludge disposal to landfill with reduced risk of metals being leached to the surface and groundwater. Another advantage is the application of the sludge as soil improver. The use of chemical precipitation to remove dissolved heavy metals from sewage sludge implies a high cost for chemicals. This work shows, f...

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

    International Nuclear Information System (INIS)

    We have found that cross-linked polyvinylpyridine (PVP) resin is more efficient than strongly basic anion-exchange resin for removal of technetium in wastes containing high concentrations of nitrate ion. Resin loading by nitrate is greatly reduced, and PVP resins are very stable with respect to chemical and radiological degradation. We have also found that the inexpensive inorganic reagents, elemental iron and ferrous sulfide, are very efficient for the removal of technetium and soluble mercury from aqueous nitrate wastes. The spent reactant and sorbent occupies a much smaller volume (per unit of technetium removed) than does organic resin, and the spent reactant can be immobilized into grout, with a very low leach rate for technetium. 30 refs., 5 figs., 13 tabs

  20. Removal of organic pollutants and heavy metals in soils by electrokinetic remediation.

    Science.gov (United States)

    Ricart, M T; Pazos, M; Gouveia, S; Cameselle, C; Sanroman, M A

    2008-07-01

    In this work, the feasibility of electrokinetic remediation for the restoration of polluted soil with organic and inorganic compounds had been development and evaluated using a model soil sample. The model soil was prepared with kaolinite clay artificially polluted in the laboratory with chromium and an azo dye: Reactive Black 5 (RB5). The electromigration of Cr in a spiked kaolinite sample was studied in alkaline conditions. Despite of the high pH registered in the kaolinite sample (around pH 9.5), Cr migrated towards the cathode and it was accumulated in the cathode chamber forming a white precipitate. The removal was not complete, and 23% of the initial Cr was retained into the kaolinite sample close to the cathode side. The azo dye RB5 could be effectively removed from kaolinite by electrokinetics and the complete cleanup of the kaolinite could be achieved in alkaline environment. In this condition, RB5 formed an anion that migrated towards the anode where it was accumulated and quickly degraded upon the electrode surface. The electrokinetic treatment of a kaolinite sample polluted with both Cr and RB5 yielded very good results. The removal of Cr was improved compared to the experiment where Cr was the only pollutant, and RB5 reached a removal as high as 95%. RB5 was removed by electromigration towards the anode, where the dye was degraded upon the surface of the electrode by electrochemical oxidation. Cr was transported towards the cathode by electromigration and electroosmosis. It is supposed that the interaction among RB5 and Cr into the kaolinite sample prevented premature precipitation and allow Cr to migrate and concentrate in the cathode chamber. PMID:18569297

  1. 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.

  2. 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.

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

    OpenAIRE

    Tahir, H.; Yasmeen, G.; Akhtar, N.; Sultan, M.; Qadri, M.

    2012-01-01

    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...

  4. 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...

  5. 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)

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

    Energy Technology Data Exchange (ETDEWEB)

    Parga, Jose R. [Institute Technology of Saltillo, Department of Metallurgy and Materials Science, V. Carranza 2400, C.P. 25280, Saltillo, Coahuila, Mexico (Mexico)]. E-mail: drjrparga@hotmail.com; Cocke, David L. [Lamar University, Gill Chair of Chemistry and Chemical Engineering, Beaumont, TX 77710 (United States); Valenzuela, Jesus L. [University of Sonora, Hermosillo, Sonora, Mexico (Mexico); Gomes, Jewel A. [Lamar University, Gill Chair of Chemistry and Chemical Engineering, Beaumont, TX 77710 (United States); Kesmez, Mehmet [Lamar University, Gill Chair of Chemistry and Chemical Engineering, Beaumont, TX 77710 (United States); Irwin, George [Lamar University, Department of Chemistry and Physics, Beaumont, TX 77710 (United States); Moreno, Hector [Lamar University, Gill Chair of Chemistry and Chemical Engineering, Beaumont, TX 77710 (United States); Weir, Michael [Lamar University, Gill Chair of Chemistry and Chemical Engineering, Beaumont, TX 77710 (United States)

    2005-09-30

    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.

  7. 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

  8. 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.

  9. 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.

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

    Directory of Open Access Journals (Sweden)

    Jaber SALEHZADEH

    2013-11-01

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

  11. Organic-Inorganic Hybrid Polymers as Adsorbents for Removal of Heavy Metal Ions from Solutions: A Review

    Directory of Open Access Journals (Sweden)

    Babak Samiey

    2014-01-01

    Full Text Available Over the past decades, organic-inorganic hybrid polymers have been applied in different fields, including the adsorption of pollutants from wastewater and solid-state separations. In this review, firstly, these compounds are classified. These compounds are prepared by sol-gel method, self-assembly process (mesopores, assembling of nanobuilding blocks (e.g., layered or core-shell compounds and as interpenetrating networks and hierarchically structures. Lastly, the adsorption characteristics of heavy metals of these materials, including different kinds of functional groups, selectivity of them for heavy metals, effect of pH and synthesis conditions on adsorption capacity, are studied.

  12. Zeolite formation from coal fly ash and heavy metal ion removal characteristics of thus-obtained Zeolite X in multi-metal systems.

    Science.gov (United States)

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

    2009-06-01

    Zeolitic materials have been prepared from coal fly ash as well as from a SiO(2)-Al(2)O(3) system upon NaOH fusion treatment, followed by subsequent hydrothermal processing at various NaOH concentrations and reaction times. During the preparation process, the starting material initially decomposed to an amorphous form, and the nucleation process of the zeolite began. The carbon content of the starting material influenced the formation of the zeolite by providing an active surface for nucleation. Zeolite A (Na-A) was transformed into zeolite X (Na-X) with increasing NaOH concentration and reaction time. The adsorption isotherms of the obtained Na-X based on the characteristics required to remove heavy ions such as Ni(2+), Cu(2+), Cd(2+) and Pb(2+) were examined in multi-metal systems. Thus obtained experimental data suggests that the Langmuir and Freundlich models are more accurate compared to the Dubinin-Kaganer-Radushkevich (DKR) model. However, the sorption energy obtained from the DKR model was helpful in elucidating the mechanism of the sorption process. Further, in going from a single- to multi-metal system, the degree of fitting for the Freundlich model compared with the Langmuir model was favored due to its basic assumption of a heterogeneity factor. The Extended-Langmuir model may be used in multi-metal systems, but gives a lower value for equilibrium sorption compared with the Langmuir model. PMID:19233542

  13. 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.

  14. 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)

  15. Hybrid surfactant-templated mesoporous silica formed in ethanol and its application for heavy metal removal.

    Science.gov (United States)

    Yang, Hong; Xu, Ran; Xue, Xiaoming; Li, Fengting; Li, Guangtao

    2008-04-01

    With cetyltrimethylammonium (CTAB) and tetramethylammonium hydroxide (TMAOH) as hybrid surfactant templates, a mesoporous adsorbent (adsorbent C) was synthesized in ethanol via the integration of "One-step" procedure and "Evaporation-Induced Self-Assembly" procedure. During the synthesis, TMAOH served as the subsidiary structure-directing agent. Adsorbent C exhibited higher pore diameter (centered at 6.1 nm), BET surface area (421.9 m(2)/g) and pore volume (0.556 cm(3)/g) than the other two adsorbents only using P123 (adsorbent A) or CTAB (adsorbent B) as the surfactant. The adsorbents were also characterized by XRD and FTIR spectroscopy. The adsorption of copper, zinc, lead, iron, silver and manganese ions on adsorbent C was investigated by contrast tests with adsorbent A and B. The experimental data showed that adsorbent C possessed better adsorption properties than the counterparts. The order of adsorption capacity for six metal ions was Mn(2+)

  16. 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...

  17. 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

  18. A study on stack configuration of continuous electrodeionization for removal of heavy metal ions from the primary coolant of a nuclear power plant.

    Science.gov (United States)

    Yeon, Kyeong-Ho; Song, Jung-Hoon; Moon, Seung-Hyeon

    2004-04-01

    This study investigated the production of high-purity water in the primary coolant of a nuclear power plant via the continuous electrodeionization (CEDI) process, using ion exchange resins as ion-conducting media between ion exchange membranes. The effectiveness of this method was examined with respect to the removal of heavy metals. The study was carried out on a laboratory scale with an effective area of 20 cm(2). The CEDI system was operated with a layered bed of cation exchange resins, anion exchange resins, and mixed-bed ion exchange resins. The stack configuration was designed to prevent a reaction between metal ions and hydroxide ions. The CEDI operation with the layered bed removed more than 99% of the ions at 30% of the current efficiency. The results showed that, with an inlet conductivity of 40 microScm(-1), a linear velocity of 4.17 cms(-1), and an applied current density of 17 mAcm(-2), the CEDI process yielded an outlet conductivity of 0.5 microScm(-1), thereby preventing the precipitation of metal ions. This study therefore successfully demonstrated the feasibility of the CEDI operation for the removal of heavy metals at a very low concentration. PMID:15026246

  19. Photoactivated metal removal

    Energy Technology Data Exchange (ETDEWEB)

    Nimlos, M.R.; Filley, J.; Ibrahim, M.A.; Watt, A.S.; Blake, D.M.

    1999-07-01

    The authors propose the use of photochromic dyes as light activated switches to bind and release metal ions. This process, which can be driven by solar energy, can be used in environmental and industrial processes to remove metals from organic and aqueous solutions. Because the metals can be released from the ligands when irradiated with visible light, regeneration of the ligands and concentration of the metals may be easier than with conventional ion exchange resins. Thus, the process has the potential to be less expensive than currently used metal extraction techniques. In this paper, the authors report on their studies of the metal binding of spirogyran dyes and the hydrolytic stability of these dyes. They have prepared a number of spirogyrans and measured their binding constants for calcium and magnesium. They discuss the relationship of the structure of the dyes to their binding strengths. These studies are necessary towards determining the viability of this technique.

  20. Microbial treatment of heavy metal leachates

    International Nuclear Information System (INIS)

    Ore-mining metallurgy and other industrial activities represent the source of heavy metal and radionuclide contamination in terrestrial and aquatic environments. Physico-chemical processes are employed for heavy metal removal from industrial wastewaters. However, limitations due to the cost-effectiveness and use of contaminating reagents make these processes not environmentally friendly. (Author)

  1. Biosorption of Heavy Metals by Biomass

    OpenAIRE

    Akc?i?n, Go?ksel

    2001-01-01

    Wetland plants are successfully used in the biosorption of heavy metals in natural and constructed wetlands. In this study, the removal of heavy metals by water hyacinth [ Eichhornia crassipes (Mart.)Solms)] were investigated. The plants were grown under control in the Turkish climate. The biosorption was dependent on factors such as metal concentration, constant temperature, pH and relative moisture. The plants were exposed to different metal concentrations of Chromium(III), Chromi...

  2. Zeolite formation from coal fly ash and heavy metal ion removal characteristics of thus-obtained Zeolite X in multi-metal systems

    Energy Technology Data Exchange (ETDEWEB)

    Jha, V.K.; Nagae, M.; Matsuda, M.; Miyake, M. [Okayama University, Okayama (Japan). Dept. of Material & Energy Science

    2009-06-15

    Zeolitic materials have been prepared from coal fly ash as well as from a SiO{sub 2}-Al{sub 2}O{sub 3} system upon NaOH fusion treatment, followed by subsequent hydrothermal processing at various NaOH concentrations and reaction times. During the preparation process, the starting material initially decomposed to an amorphous form, and the nucleation process of the zeolite began. The carbon content of the starting material influenced the formation of the zeolite by providing an active surface for nucleation. Zeolite A (Na-A) was transformed into zeolite X (Na-X) with increasing NaOH concentration and reaction time. The adsorption isotherms of the obtained Na-X based on the characteristics required to remove heavy ions such as Ni{sup 2+}, Cu{sup 2+}, Cd{sup 2+} and Pb{sup 2+} were examined in multi-metal systems. Thus obtained experimental data suggests that the Langmuir and Freundlich models are more accurate compared to the Dubinin-Kaganer-Radushkevich (DKR) model. However, the sorption energy obtained from the DKR model was helpful in elucidating the mechanism of the sorption process. Further, in going from a single- to multi-metal system, the degree of fitting for the Freundlich model compared with the Langmuir model was favored due to its basic assumption of a heterogeneity factor. The Extended-Langmuir model may be used in multi-metal systems, but gives a lower value for equilibrium sorption compared with the Langmuir model.

  3. 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.

  4. Biofilm establishment and heavy metal removal capacity of an indigenous mining algal-microbial consortium in a photo-rotating biological contactor.

    Science.gov (United States)

    Orandi, S; Lewis, D M; Moheimani, N R

    2012-09-01

    An indigenous mining algal-microbial consortium was immobilised within a laboratory-scale photo-rotating biological contactor (PRBC) that was used to investigate the potential for heavy metal removal from acid mine drainage (AMD). The microbial consortium, dominated by Ulothrix sp., was collected from the AMD at the Sar Cheshmeh copper mine in Iran. This paper discusses the parameters required to establish an algal-microbial biofilm used for heavy metal removal, including nutrient requirements and rotational speed. The PRBC was tested using synthesised AMD with the multi-ion and acidic composition of wastewater (containing 18 elements, and with a pH of 3.5 ± 0.5), from which the microbial consortium was collected. The biofilm was successfully developed on the PRBC's disc consortium over 60 days of batch-mode operation. The PRBC was then run continuously with a 24 h hydraulic residence time (HRT) over a ten-week period. Water analysis, performed on a weekly basis, demonstrated the ability of the algal-microbial biofilm to remove 20-50 % of the various metals in the order Cu > Ni > Mn > Zn > Sb > Se > Co > Al. These results clearly indicate the significant potential for indigenous AMD microorganisms to be exploited within a PRBC for AMD treatment. PMID:22644382

  5. 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 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.

  6. 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.

  7. Removal of heavy metals and organic contaminants from aqueous streams by novel filtration methods. 1998 annual progress report

    International Nuclear Information System (INIS)

    'Graphite nanofibers are a new type of material consisting of nanosized graphite platelets where only edges are exposed. Taking advantage of this unique configuration the authors objective is: (1) To produce graphite nanofibers with structural properties suitable for the removal of contaminants from water. (2) To test the suitability of the material in the removal of organic from aqueous solutions. (3) To determine the ability of the nanofibers to function as an electrochemical separation medium the selective removal of metal contaminants from solutions. This report summarizes work after 1.5 of a 3-year project. During this period, efforts have been concentrated on the production, characterization and optimization of graphite nanofibers (GNF). This novel material has been developed in the laboratory from the metal catalyzed decomposition of certain hydrocarbons (1). The structures possess a cross-sectional area that varies between 5 to 100 nm and have lengths ranging from 5 to 100 mm (2). High-resolution transmission electron microscopy studies have revealed that the nanofibers consist of extremely well-ordered graphite platelets, which are oriented in various directions with respect to the fiber axis (3). The arrangement of the graphene layers can be tailored to a desired geometry by choice of the correct catalyst system and reaction conditions, and it is therefore possible to generate structures where the layers are stacked in a ribbon, herring-bone, or stacked orientation. The research has been directed on two fronts: (a) the use of the material for the removal of organic contaminants, and (b) taking advantage of the high electrical conductivity as well as high surface area of the material to use it as electrode for the electrochemical removal of metal pollutants from aqueous streams.'

  8. In situ growth of monodispersed Fe3O4 nanoparticles on graphene for the removal of heavy metals and aromatic compounds.

    Science.gov (United States)

    Wu, Hai-Xia; Wu, Jia-Wei; Niu, Zhi-Gang; Shang, Xiu-Li; Jin, Jun

    2013-01-01

    We report on the efficient removal of heavy metal ions and aromatic compounds from simulated wastewater with a nanocomposite. The nanocomposite was obtained via thermal decomposition of the precursor Fe(acac)3 onto the surface of graphene, modified by diethylenetriamine pentaacetic anhydride through dopamine. It was found that the maximum adsorption capacity of the nanocomposite toward Cu(2+) and naphthalene was 207.9 and 72.2 mg g(-1) respectively, displaying a high efficiency for the removal of heavy metal ions as well as aromatic compounds at pH 7.0 and 293 K. The Langmuir for naphthalene and the Freundlich for the Cu(2+) adsorption isotherms were applicable for describing the removal processes. Furthermore, the nanocomposite was carefully examined by transmission electron microscopy, Fourier transform infrared spectroscopy, X-ray diffraction, Raman spectra, and UV-vis spectroscopy. This work provides a very efficient, fast and convenient approach to exploring a promising nanocomposite for water treatment. PMID:24334882

  9. 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

  10. New Adsorbents from Ti(OPrn)4 by the Sol-Gel Process: Synthesis, Characterization and Application for Removing Some Heavy Metal Ions from Aqueous Solution

    OpenAIRE

    Sayilkan, Funda; Sayilkan, Hikmet

    2004-01-01

    New adsorbents were synthesized by the sol-gel process from the product of a hydrolysis reaction and its coated form of titanium(IV)-n-propoxide for removing some heavy metal ions from aqueous solution. Titanium(IV)-n-propoxide was uncatalyst hydrolyzed with different amounts of water at room temperature and was found to react in a 1:1.6 ratio (mole of Ti:mole of H2O). It was found that the condensation following the hydrolysis reaction was alcohol condensation. The hydrolysis-conde...

  11. 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)

  12. 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.

  13. Use of low cost dead biomasses in the removal of heavy metal toxic/radiotoxic ions from aqueous wastes- a radiotracer study

    International Nuclear Information System (INIS)

    In an environmental context, accelerating pollution by toxic metal ions, metalloids, radionuclides and organometal (loid)s has provided the impetus for the research to look into the biotechnological potential of utilizing several low cost dead biomasses/agricultural byproducts to replace existing expensive technologies. Unlike organic pollutants which are biodegradable, these metallic contaminants tend to persist rather indefinitely in the environment, and are eventually accumulated through the food chain thus posing a serious threat to plants, animal and man. The use of radiotracer technique by several workers and ourselves in the study of adsorption uptake or ions (cations and anions) from aqueous solutions by metals/metals oxide surfaces at micro down to tracer level concentrations had been quite rewarding. In continuation of this work the present studies were directed to assess the uptake behaviour of abundantly available low cost dead biomasses [e.g. Rice hulls (oryza sativa L),] Mango (mangifera indica) and Neem (azadirachta indica)barks] towards some heavy metal (Hg2+, Cd2+, Cr2+, Zn2+ and Ce3+) toxic and radiotoxic (Sr2+ and Csl+)ions from aqueous solutions at low ionic concentrations (10-2-10-8 mol dm-3). In all these studies the adsorptive solution was labeled by a suitable radiotracer of the metal ion and the uptake of ions by the three biosorbents e uptake of ions by the three biosorbents was assessed through monitoring of the decrease in radioactivity of the bulk. A parametric study through change of temperature, pH and addition of other co-ions/complexing agents has helped in deducing the thermodynamic parameters and mechanism of the uptake of the ions. The extent of removal of metal ions by these dead biomasses is quite high in most cases and the nature of the uptake appears to be exchange type. These findings show that the agricultural byproducts (dead biomasses) can be utilized in the development of waste water treatment technology for removal of heavy metal toxic and radiotoxic ions. (author)

  14. 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...

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

    OpenAIRE

    Salehzadeh, Jaber

    2013-01-01

    The hazardous ill effects of heavy metals on the environment and public health is a matter of serious concern. Biosorption is emerging as a sustainable effective technology. Heavy metals in water resources are one of the most important environmental problems of countries. The intensification of industrial activity and environmental stress greatly contributes to the significant rise of heavy metal pollution in water resources making threats on terrestrial and aquatic life. The toxicity of meta...

  16. Potato peels as solid waste for the removal of heavy metal copper(II) from waste water/industrial effluent.

    Science.gov (United States)

    Aman, Tehseen; Kazi, Asrar Ahmad; Sabri, Muhammad Usman; Bano, Qudsia

    2008-05-01

    A new sorbent potato peels, which are normally discarded as solid waste for removing toxic metal ion Cu(II) from water/industrial waste water have been studied. Potato peels charcoal (PPC) was investigated as an adsorbent of Cu(II) from aqueous solutions. Kinetic and isotherm studies were carried out by studying the effects of various parameters such as temperature, pH and solid liquid ratios. The optimum pH value for Cu(II) adsorption onto potato peels charcoal (PPC) was found to be 6.0. The thermodynamic parameters such as standard Gibb's free energy (Delta G degrees ), standard enthalpy (Delta H degrees ) and standard entropy (DeltaS degrees ) were evaluated by applying the Van't Hoff equation. The thermodynamics of Cu(II) adsorption onto PPC indicates its spontaneous and exothermic nature. The equilibrium data at different temperatures were analyzed by Langmuir and Freundlich isotherms. PMID:18215510

  17. 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

  18. Sonochemical synthesis and characterization of CdS/ZnS core-shell nanoparticles and application in removal of heavy metals from aqueous solution

    Science.gov (United States)

    Amiri, O.; Hosseinpour-Mashkani, S. M.; Mohammadi Rad, M.; Abdvali, F.

    2014-02-01

    In the present work, CdS/ZnS core-shell nanoparticles have been successfully synthesized with the aid of Cd(NO3)2 and Zn(NO3)2?6H2O as the starting reagents in presence of ultrasonic irradiation. Besides, the effects of preparation parameters such as ultrasonic power, irradiation time and precursor concentration on the morphology CdS/ZnS core-shell nanoparticles and removal of heavy metals (Hg2+, Pb2+) were studied by SEM images and batch adsorption mode. The as-synthesized products were characterized by powder X-ray diffraction (XRD), transmission electron microscopy (TEM), high-resolution field-emission transmission electron microscope (HRTEM), photoluminescence spectroscopy (PL), scanning electronic microscopy (SEM), spectra energy dispersive analysis of X-ray (EDS) and ultraviolet-visible (UV-Vis) techniques.

  19. Marine macroalga Sargassum horneri as biosorbent for heavy metal removal: roles of calcium in ion exchange mechanism.

    Science.gov (United States)

    Southichak, B; Nakano, K; Nomura, M; Chiba, N; Nishimura, O

    2008-01-01

    Brown seaweed Sargassum horneri, a troublesome biomass scattered along the seashore, was utilized as a biosorbent for Pb(II) removal from aqueous solutions. The Pb(II) adsorption by brown seaweed was enhanced by pretreatment with CaCl(2), and the Langmuir adsorption isotherm equation showed a maximum capacity of a Q(max) of 0.696 mmol/g and a b value of 94.33 L/mmol. Results obtained from the mass-balance equation derived from the simulation model of the Langmuir adsorption isotherm suggested that the adsorption performance of brown seaweed biosorbent was sufficient to reduce the concentration of Pb(II) to meet the range of WHO guideline. The mechanism, as elucidated using pH monitoring, adsorption rate and ion exchange model, involved the rapid pH change of metal solutions that led to high reaction rate and Pb(II) uptake in the first 30 min of the biosorption process. The energy X-ray analysis's result confirmed the sharp reduction of calcium content in the biosorbent after Pb(II) adsorption. The amount of calcium ions released from the biosorbent was about 1.5 times the amount of Pb(II) adsorbed and proved the role of calcium in the ion exchange mechanism. These adsorption equilibrium and mechanistic studies provide useful information for system design and performance prediction of biosorption processes. PMID:18725741

  20. New concept to remove heavy metals from liquid waste based on electrochemical pH-switchable immobilized ligands

    Science.gov (United States)

    Pascal, Viel; Laetitia, Dubois; Joël, Lyskawa; Marc, Sallé; Serge, Palacin

    2007-01-01

    Absorption on resins is often used as secondary step in the treatment of water-based effluents, in order to reach very low concentrations. The separation of the trapped effluents from the resins and the regeneration of the resins for further use create wide volumes of secondary effluents coming from the washings of the resins with chemical reagents. We propose an alternative solution based on a "surface strategy" through adsorption phenomena and electrical control of the expulsion stage. The final goal is to limit or ideally to avoid the use of chemical reagents at the expulsion (or regeneration) stage of the depolluting process. Heavy metal ions were captured on active filters composed by a conducting surface covered by poly-4-vinylpyridine (P 4VP). Due to pyridine groups those polymer films have chelating properties for copper ions. Our strategy for electrical triggering of the copper expulsion in aqueous medium is based on pH sensitive chelating groups. Applying moderate electro-oxidizing conditions generates acidic conditions in the vicinity of the electrode, i.e. "inside" the polymer film. This allows a "switch-off" of the complexing properties of the film from the basic form of pyridine to pyridinium. Interestingly, no buffer washing is necessary to restore (or "switch-on") the complexing properties of the polymer film because the pH of the external medium is left unchanged by the electrochemical effect that affects only the vicinity of the electrode. Switch-on/switch-off cycles are followed and attested by IR spectroscopy and EQCM method.

  1. Development of a low-cost alternative for metal removal from textile wastewater:

    OpenAIRE

    Sekomo Birame, C.

    2012-01-01

    Heavy metals (Cd, Cr, Cu, Pb and Zn) found in textile wastewater are removed by a combination of adsorption using volcanic rock as adsorbent, sulfide precipitation and phytoremediation techniques. The integrated system for metal removal combining anaerobic bioreactor as main treatment step and a polishing step composed by algae, duckweed and water hyacinth ponds for heavy metal removal from industrial wastewater. The maximum of the metal removal was achieved in the bioreactor where metal sulp...

  2. Removal of Some Heavy Metals from their Aqueous Solutions using 2- Acrylamido-2-Methyl-1-Propane Sulfonic Acid/Polyvinyl Alcohol Copolymer Hydrogels Prepared by Gamma Irradiation

    International Nuclear Information System (INIS)

    2-acrylamido-2-methyl-1- propane sulfonic acid (AMPS) and Poly vinyl alcohol (PVA) were used to synthesis a series of functional copolymer hydrogels by means of gamma-radiations induced copolymerization and crosslinking. Factors affecting the hydrogel preparation were optimized. The prepared hydrogels were characterized by studying their swelling characteristics. The possibility of using the prepared hydrogel in the field of water treatment was evaluated by investigating their ability to recover some heavy me tal ions from their aqueous solutions. The prepared hydrogel showed a promising capability to chelate metal ions such as: Cu+2, Mn+2 and Ni+2 from their aqueous solutions. The obtained data show that the chelating ability of the prepared hydrogels increases by increasing the AMPS content in the hydrogel as well as the increment in the ph of the solution and the metal ion concentration. The prepared hydrogel was able to remove as much as 230 mg of Ni, 160 mg of Mn and 140 mg of Cu per gram of dry gel at the optimum conditions. The prepared PVA/AMPS copolymer hydrogels are chemically stable enough to be reused for at least 5 times with the same efficiency.

  3. 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.

  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. Removal of Heavy Metals Fe3+, Cu2+, Zn2+, Pb2+, Cr3+ and Cd2+ from Aqueous Solutions by Using Eichhornia Crassipes

    Scientific Electronic Library Online (English)

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

    Full Text Available The adsorption capacity of Eichhornia Crassipes towards metal ions such as Fe3+, Cu2+, Zn2+, Pb2+, Cr3+ and Cd2+, was studied. The adsorption capacity was investigated by batch experiments. The results showed that the removal percentages increased as the weight of sorbent increased, except for Fe3+ [...] and Zn2+. The effect of contact time was also studied and the results showed that the removal percentages increased as the contact time increased for Cr3+, Zn2+ and Pb2+, but for Fe3+, Cu2+ and Cd2+ the removal decreased. The effect of pH of the solution was also studied and the removal percentages increased as pH increased. Also the effect of the 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 by increasing initial concentration over 30 mg/L. The order of increasing removal percentages of metal ions at pH=4.86, initial concentration of metal ions 30 mg/L, and after four hours of shaking was: Cu2+

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

    DEFF Research Database (Denmark)

    Ottosen, Lisbeth M.; Pedersen, Anne Juul

    2007-01-01

    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 0.8mgCd/kg for the wastewater sludge was almost reached (0.84 and 0.88mgCd/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 matrix.

  7. Application of a new generation of complexing agents in removal of heavy metal ions from different wastes

    OpenAIRE

    Ko?ody?ska, Dorota

    2013-01-01

    Complexing agents are extensively applied in many fields of industry. They are used to provide effective controlling trace metal ions in cleaning industries, textile, pulp and paper production, water treatment, agriculture, food industries, etc. Recently, the low biodegradability of these ligands and their accumulation in the environment has become a cause for concern. Therefore, replacement of ethylenediaminetetraacetic acid and diethylenetriaminepentaacetic acid by more environmentally frie...

  8. Aqueous heavy metals removal on amine-functionalized Si-MCM-41 and Si-MCM-48

    International Nuclear Information System (INIS)

    Ordered mesoporous silica with hexagonal and cubic structure, type MCM-41 and MCM-48 respectively, were synthesized under basic media using pure silica, cetyltrimethylammonium bromide and tetramethylammonium hydroxide, for MCM-41 and tetraethylorthosilica, cetyltrimethylammonium and NaOH for MCM-48. The expanded materials were prepared by post-synthesis method with N-N dimethyldodecylamine (DMDDA) and dodecylamine (DDA). Small angle X-ray diffraction, nitrogen adsorption-desorption measurements, FT-IR and thermogravimetry were used to characterize the samples. The expanded materials were tested for adsorption of Cd2+, Co2+, Cu2+ and Pb2+ in aqueous solution. Aminated materials were found to be fast adsorbents for metallic ions cation with affinity for Cu2+, Pb2+, than for Cd2+ and Co2+ from single solution. In mixed metallic ions cation solutions, competition by the adsorption sites is likely to occur, the adsorption preference is for Cu2+and Pb2+. The kinetic of the reaction is very rapid and follow pseudo-second order and clearly indicated that Langmuir model describe better the for metal ions adsorption on aminated mesoporous material than Freundlich model.

  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. Phytoremediation of Heavy Metals in Aqueous Solutions

    OpenAIRE

    Aisien, Felix Aibuedefe; Faleye, Oluwole; Aisien, Eki Tina

    2010-01-01

    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 especia...

  11. 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 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+

  12. 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+.

  13. Inorganic particulates in removal of toxic heavy metal ions. Part 10. Removal behavior of aluminum hydroxide for Hg(II). A radiotracer study

    International Nuclear Information System (INIS)

    The removal behavior of amorphous aluminum hydroxide for Hg(II) ions from aqueous solutions was investigated by employing a radiotracer technique at micro down to trace level concentrations. The batch type experiments were performed to obtain various physico-chemical parameters, viz., effect of sorptive concentration, temperature and pH. It was observed that the increase in sorptive concentration (from 1 x 10-8 to 1 x 10-2 mol x dm-3), temperature (from 303 to 333 K) and pH (from 3.4 to 10.3) apparently favored the uptake of Hg(II) by this solid. Similarly, the presence of anions (six fold) viz., oxalate, phosphate, glycine and EDTA also enhanced the uptake behavior of aluminum hydroxide for Hg(II). Whereas, the added cations viz., Na+, K+, Ba2+, Sr2+, Mg2+, Cd2+ and Fe3+ more or less suppressed the removal behavior of the adsorbent. Further, the adsorption process followed the classical Freundlich adsorption isotherm and deductions of various thermodynamic data revealed that the uptake of Hg(II) on aluminum hydroxide followed the ion-exchange type mechanism and thermodynamically it was found to be endothermic in nature. (author)

  14. 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

  15. Inorganic particulates for removal of heavy toxic metal ions: removal behaviour of tungsten oxide for Hg(II) ions from aqueous solution- radiotracer study

    International Nuclear Information System (INIS)

    A radiotracer technique has been used in the study of the removal for Hg(II) ions from aqueous solutions by synthesised tungsten oxide at different adsorptive concentrations (10-4 - 10-8 M), pH (ca 3.41 - 8.54) and temperature (303 -333 K). The uptake of Hg(II) ions, which fitted Freundlich isotherm, increased with increase in the studied temperature range and no significant desorption of adsorbed ions took place in the equilibrium bulk solution. Pre-irradiation of tungsten oxide using a 11.1 GBq (Ra-Be) neutron source having a neutron flux of 3.9 x 1(16 cm-2s-1 associated with gamma-dose rate of 1.7 Gyh-1 did not significantly influence adsorption of Hg (II) by the adsorbent. (author)

  16. 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, ...

  17. 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

  18. 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

  19. 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

  20. Cell surface engineering of microorganisms towards adsorption of heavy metals.

    Science.gov (United States)

    Li, Peng-Song; Tao, Hu-Chun

    2015-06-01

    Heavy metal contamination has become a worldwide environmental concern due to its toxicity, non-degradability and food-chain bioaccumulation. Conventional physical and chemical treatment methods for heavy metal removal have disadvantages such as cost-intensiveness, incomplete removal, secondary pollution and the lack of metal specificity. Microbial biomass-based biosorption is one of the approaches gaining increasing attention because it is effective, cheap, and environmental friendly and can work well at low concentrations. To enhance the adsorption properties of microbial cells to heavy metal ions, the cell surface display of various metal-binding proteins/peptides have been performed using a cell surface engineering approach. The surface engineering of Gram-negative bacteria, Gram-positive bacteria and yeast towards the adsorption of heavy metals are reviewed in this article. The problems and future perspectives of this technology are discussed. PMID:23915280

  1. 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

    Energy Technology Data Exchange (ETDEWEB)

    Obuseng, Veronica; Nareetsile, Florence [Department of Chemistry, University of Botswana, Private Bag UB 00704, Gaborone (Botswana); Kwaambwa, Habauka M., E-mail: hmkwaambwa@yahoo.com [Department of Chemistry, University of Botswana, Private Bag UB 00704, Gaborone (Botswana)

    2012-06-12

    Highlights: Black-Right-Pointing-Pointer Materials are effective and selective in simultaneous removal of heavy metal ions. Black-Right-Pointing-Pointer Use of composite adsorbent of both materials may result in more effective material. Black-Right-Pointing-Pointer Seeds biomass has various functional groups involves in metal removal. Black-Right-Pointing-Pointer Attainment of sorption equilibrium is rapid for the seeds biomass. Black-Right-Pointing-Pointer Seeds biomass effectiveness is not affected over wide effective pH range. - Abstract: 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.

  2. 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

    International Nuclear Information System (INIS)

    Highlights: ? Materials are effective and selective in simultaneous removal of heavy metal ions. ? Use of composite adsorbent of both materials may result in more effective material. ? Seeds biomass has various functional groups involves in metal removal. ? Attainment of sorption equilibrium is rapid for the seeds biomass. ? Seeds biomass effectiveness is not affected over wide effective pH range. - Abstract: 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.

  3. Bioremediation of Heavy Metals in Liquid Media Through Fungi Isolated from Contaminated Sources

    OpenAIRE

    Joshi, P. K.; Swarup, Anand; Maheshwari, Sonu; Kumar, Raman; Singh, Namita

    2011-01-01

    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 biosorption at low cost and in eco-friendly way. An attempt was, therefore, made to isolate fungi from sites contaminated with heavy metals for higher tolerance and removal of heavy metals from wastewater. Seventy-six fungal isolates tolerant to he...

  4. 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.

  5. Removal of Heavy Metals Fe3+, Cu2+, Zn2+, Pb2+, Cr3+ and Cd2+ from Aqueous Solutions by Using Eichhornia Crassipes

    OpenAIRE

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

    2010-01-01

    The adsorption capacity of Eichhornia Crassipes towards metal ions such as Fe3+, Cu2+, Zn2+, Pb2+, Cr3+ and Cd2+, was studied. The adsorption capacity was investigated by batch experiments. The results showed that the removal percentages increased as the weight of sorbent increased, except for Fe3+ and Zn2+. The effect of contact time was also studied and the results showed that the removal percentages increased as the contact time increased for Cr3+, Zn2+ and Pb2+, but for Fe3+, Cu2+ and Cd2...

  6. A Novel Permeable Reactive Barrier (PRB) for Simultaneous and Rapid Removal of Heavy Metal and Organic Matter - A Systematic Chemical Speciation Approach on Sustainable Technique for Pallikarani Marshland Remediation

    Science.gov (United States)

    Selvaraj, A.; Nambi, I. M.

    2014-12-01

    In this study, an innovative technique of ZVI mediated 'coupling of Fenton like oxidation of phenol and Cr(VI) reduction technique' was attempted. The hypothesis is that Fe3+ generated from Cr(VI) reduction process acts as electron acceptor and catalyst for Fenton's Phenol oxidation process. The Fe2+ formed from Fenton reactions can be reused for Cr(VI) reduction. Thus iron can be made to recycle between two reactions, changing back and forth between Fe2+ and Fe3+ forms, makes treatment sustainable.(Fig 1) This approach advances current Fenton like oxidation process by (i)single system removal of heavy metal and organic matter (ii)recycling of iron species; hence no additional iron required (iii)more contaminant removal to ZVI ratio (iv)eliminating sludge related issues. Preliminary batch studies were conducted at different modes i) concurrent removal ii) sequential removal. The sequential removal was found better for in-situ PRB applications. PRB was designed based on kinetic rate slope and half-life time, obtained from primary column study. This PRB has two segments (i)ZVI segment[Cr(VI)] (ii)iron species segment[phenol]. This makes treatment sustainable by (i) having no iron ions in outlet stream (ii)meeting hypothesis and elongates the life span of PRB. Sequential removal of contaminates were tested in pilot scale PRB(Fig 2) and its life span was calculated based on the exhaustion of filling material. Aqueous, sand and iron aliquots were collected at various segments of PRB and analyzed for precipitation and chemical speciation thoroughly (UV spectrometer, XRD, FTIR, electron microscope). Chemical speciation profile eliminates the uncertainties over in-situ PRB's long term performance. Based on the pilot scale PRB study, 'field level PRB wall construction' was suggested to remove heavy metal and organic compounds from Pallikaranai marshland(Fig 3)., which is contaminated with leachate coming from nearby Perungudi dumpsite. This research provides (i)deeper insight into the environmental friendly, accelerated, sustainable technique for combined removal of organic matter and heavy metal (ii)evaluation of the novel technique in PRB, which resulted in PRB's increased life span (iii)designing of PRB to remediate the marshland and its ecosystem, thus save the habitats related to it.

  7. 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.

  8. 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.

  9. 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

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

    OpenAIRE

    Pérez Esteban, Javier; Escolástico, Consuelo; Ruiz Fernández, Juan; Masaguer Rodríguez, Alberto; Moliner Aramendia, Ana María

    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...

  11. Bioremediation of heavy metals in liquid media through fungi isolated from contaminated sources.

    Science.gov (United States)

    Joshi, P K; Swarup, Anand; Maheshwari, Sonu; Kumar, Raman; Singh, Namita

    2011-10-01

    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 biosorption at low cost and in eco-friendly way. An attempt was, therefore, made to isolate fungi from sites contaminated with heavy metals for higher tolerance and removal of heavy metals from wastewater. 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, Aspegillus awamori, Aspergillus flavus, Trichoderma viride) also 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, maximum uptake of 59.67, 16.25, 0.55, and 0.55 mg/g was observed by fungi Pb3 (Aspergillus terreus), Trichoderma viride, Cr8 (Trichoderma longibrachiatum), and isolate Ni27 (A. niger) respectively. This indicated the potential of these fungi as biosorbent for removal of heavy metals from wastewater and industrial effluents containing higher concentration of heavy metals. PMID:23024411

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

    OpenAIRE

    Vukojevi? Vanja; Sabovljevi? Marko; Jovanovi? S.

    2005-01-01

    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 meta...

  13. Heavy metal uptake by agro based waste materials

    Scientific Electronic Library Online (English)

    Suleman, Qaiser; Anwar R, Saleemi; Muhammad, Mahmood Ahmad.

    2007-07-15

    Full Text Available Presence of heavy metals in the aquatic systems has become a serious problem. As a result, there has been a great deal of attention given to new technologies for removal of heavy metal ions from contaminated waters. Biosorption is one such emerging technology which utilized naturally occurring waste [...] materials to sequester heavy metals from industrial wastewater. The aim of the present study was to utilize the locally available agricultural waste materials for heavy metal removal from industrial wastewater. The wastewater containing lead and hexavalent chromium was treated with biomass prepared from ficus religiosa leaves. It was fund that a time of one hr was sufficient for sorption to attain equilibrium. The equilibrium sorption capacity after one hr was 16.95 ± 0.75 mg g-1 and 5.66 ± 0.43 mg g-1 for lead and chromium respectively. The optimum pH was 4 for lead and 1 for chromium. Temperature has strong influence on biosorption process. The removal of lead decreased with increase in temperature. On the other hand chromium removal increased with increase in temperature up to 40ºC and then started decreasing. Ion exchange was the major removal mechanism along with physical sorption and precipitation. The biosorption data was well fitted to Langmuir adsorption model. The kinetics of biosorption process was well described by the pseudo 2nd order kinetics model. It was concluded that adsorbent prepared from ficus religiosa leaves can be utilized for the treatment of heavy metals in wastewater

  14. 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 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.

  15. 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 (current density led to more 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

  16. Adsorption of Heavy Metal from Recovered base Oil using Zeolite

    OpenAIRE

    Ahmad, A.; Ripin, A.; Ali, S. M. W.

    2010-01-01

    Recovery of used lubricating oil by extraction produced organic sludge and recovered base oil, but this oil has metallic content such as magnesium and zinc. In this study, purification of recovered base oil by using adsorption process to remove heavy metals was performed. Zeolite was used as an adsorbent. The parameters studied were contact time, amount of zeolite, temperature and their interactions. The results showed that zinc removal was higher than that of the magnesium. The optimum magne...

  17. Phycoremediation of heavy metals using transgenic microalgae.

    Science.gov (United States)

    Rajamani, Sathish; Siripornadulsil, Surasak; Falcao, Vanessa; Torres, Moacir; Colepicolo, Pio; Sayre, Richard

    2007-01-01

    Microalgae account for most of the biologically sequestered trace metals in aquatic environments. Their ability to adsorb and metabolize trace metals is associated with their large surface:volume ratios, the presence of high-affinity, metal-binding groups on their cell surfaces, and efficient metal uptake and storage systems. Microalgae may bind up to 10% of their biomass as metals. In addition to essential trace metals required for metabolism, microalgae can efficiently sequester toxic heavy metals. Toxic heavy metals often compete with essential trace metals for binding to and uptake into cells. Recently, transgenic approaches have been developed to further enhance the heavy metal specificity and binding capacity of microalgae with the objective of using these microalgae for the treatment of heavy metal contaminated wastewaters and sediments. These transgenic strategies have included the over expression of enzymes whose metabolic products ameliorate the effects of heavy metal-induced stress, and the expression of high-affinity, heavy metal binding proteins on the surface and in the cytoplasm of transgenic cells. The most effective strategies have substantially reduced the toxicity of heavy metals allowing transgenic cells to grow at wild-type rates in the presence of lethal concentrations of heavy metals. In addition, the metal binding capacity of transgenic algae has been increased five-fold relative to wild-type cells. Recently, fluorescent heavy metal biosensors have been developed for expression in transgenic Chlamydomonas. These fluorescent biosensor strains can be used for the detection and quantification of bioavailable heavy metals in aquatic environments. The use of transgenic microalgae to monitor and remediate heavy metals in aquatic environments is not without risk, however. Strategies to prevent the release of live microalgae having enhanced metal binding properties are described. PMID:18161494

  18. Induction of in vitro roots cultures of Thypha latifolia and Scirpus americanus and study of their capacity to remove heavy metals

    Scientific Electronic Library Online (English)

    María del Socorro, Santos-Díaz; María del Carmen, Barrón-Cruz; María Catalina, Alfaro-De la Torre.

    2007-07-15

    Full Text Available We have established the conditions to obtain in vitro root cultures of Thypha latifolia and Scirpus americanus and have investigated their capacity to remove Pb(II), Mn(II) and Cr(III) from the culture medium. The best conditions for the in vitro culture growth were: an inoculum of 0.2 g of T. latif [...] olia roots and 0.05 g of S. americanus roots (fresh weight), Murashige-Skoog medium and 2 mg L-1of indolacetic acid. The T. latifolia and S. americanus root cultures were cultivated onto media containing Cr (15 µg L-1), Pb (60 µg L-1) or Mn (1.8 mg L-1). Both species were able to remove Pb and Cr near to 100% and 71-100% of Mn from the medium solution during the 6-8 days of experimentation. According to metal concentrations removed from the medium containing the growing root mass, the in vitro root culture of S. americanus can be considered as an accumulator for Pb (157.73 µg g-1), Cr (55.6 µg g-1) and Mn (5000 µg g-1).

  19. Biosolids and heavy metals in soils

    Directory of Open Access Journals (Sweden)

    Silveira Maria Lucia Azevedo

    2003-01-01

    Full Text Available The application of sewage sludge or biosolids on soils has been widespread in agricultural areas. However, depending on their characteristics, they may cause increase in heavy metal concentration of treated soils. In general, domestic biosolids have lower heavy metal contents than industrial ones. Origin and treatment method of biosolids may markedly influence their characteristics. The legislation that controls the levels of heavy metal contents in biosolids and the maximum concentrations in soils is still controversial. In the long-term, heavy metal behavior after the and of biosolid application is still unknown. In soils, heavy metals may be adsorbed via specific or non-specific adsorption reactions. Iron oxides and organic matter are the most important soil constituents retaining heavy metals. The pH, CEC and the presence of competing ions also affect heavy metal adsorption and speciation in soils. In solution, heavy metals can be present either as free-ions or complexed with organic and inorganic ligands. Generally, free-ions are more relevant in environmental pollution studies since they are readily bioavailable. Some computer models can estimate heavy metal activity in solution and their ionic speciation. Thermodynamic data (thermodynamic stability constant, total metal and ligand concentrations are used by the GEOCHEM-PC program. This program allows studying heavy metal behavior in solution and the effect of changes in the conditions, such as pH and ionic strength and the application of organic and inorganic ligands caused by soil fertilization.

  20. 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

  1. 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

  2. Preparation and characterization of bentonite clays mixture destined to the removal of heavy metals; Preparacao e caracterizacao da mistura de argilas bentoniticas destinadas a remocao de metais pesados

    Energy Technology Data Exchange (ETDEWEB)

    Almeida Neto, A.F. de; Silva, M.G.C. da, E-mail: ambrosio@feq.unicamp.b [Universidade Estadual de Campinas (UNICAMP), SP (Brazil). Fac. de Engenharia Quimica. Dept. de Termofluidodinamica

    2009-07-01

    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 N{sub 2}, 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)

  3. The Heavy Metal Subculture and Suicide.

    Science.gov (United States)

    Stack, Steven; And Others

    1994-01-01

    Assessed relationship between heavy metal music and suicide with data on heavy metal magazine subscriptions and youth suicide in 50 states. Found that, controlling for other predictors of suicide, greater strength of metal subculture, higher youth suicide rate, suggests that music perhaps nurtures suicidal tendencies already present in subculture.…

  4. 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. .

  5. Electrodialytic removal of heavy metals and chloride from municipal solid waste incineration fly ash and air pollution control residue in suspension - test of a new two compartment experimental cell

    DEFF Research Database (Denmark)

    Kirkelund, Gunvor Marie; Magro, Cátia

    2015-01-01

    Municipal solid waste incineration (MSWI) residues such as fly ash and air pollution control (APC) residues are classified as hazardous waste and disposed of, although they contain potential resources. The most problematic elements in MSWI residues are leachable heavy metals and salts. For reuse of MSWI residues in for instance concrete, the aim of remediation should be reduction of the heavy metal leaching, while at the same time keeping the alkaline pH, so the residue can replace cement. In this study a MSWI residues were subjected to electrodialytic remediation under various experimental conditions. Also a newly developed 2 compartment experimental cell was tested. The results show that the pH development in the MSWI residue suspension depended on the type of MSWI residue and the experimental cell type. The acidification of the suspension occurred earlier when using the 2 compartment setup and the acidification of the fly ash occurred earlier than for the APC residue but the highest removal was seen with the 3 compartment cell. The lowest final pH for the fly ash and APC residue was 6.4 and 10.9, respectively. The results showed that the leaching of Cd, Cu, Pb and Zn was reduced compared to the initial heavy metal leaching except when the pH was reduced to a level below 8 for the fly ash. On the other hand, Cr leaching increased by the electrodialytic treatment. Cl leaching from the MSWI residues was less dependent on experimental conditions and was reduced in all experiments compared to the initial levels.

  6. 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.

  7. Removal of heavy metal ions from aqueous solution using Fe3O4-SiO2-poly(1,2-diaminobenzene) core-shell sub-micron particles.

    Science.gov (United States)

    Zhang, Fan; Lan, Jing; Zhao, Zongshan; Yang, Ye; Tan, Ruiqin; Song, Weijie

    2012-12-01

    In this work, Fe(3)O(4)-SiO(2)-poly(1,2-diaminobenzene) sub-micron particles (FSPs) with high saturated magnetization of ?60-70 emu/g were developed and utilized for the removal of As(III), Cu(II), and Cr(III) ions from aqueous solution. The isothermal results fitted well with the Freundlich model and the kinetic results fitted well with the two-site pseudo-second-order model, which indicated that multilayer adsorption of As(III), Cu(II), and Cr(III) ions on FSPs occurred at two sites with different energy of adsorption. The maximum adsorption capacities followed the order of As(III) (84±5 mg/g, pH=6.0)>Cr(III) (77±3 mg/g, pH=5.3)>Cu(II) (65±3 mg/g, pH=6.0). And the chelating interaction was considered as the main adsorption mechanism. The as-prepared materials were chemically stable with low leaching of Fe (?1.7 wt.%) and poly(1,2-diaminobenzene) (?4.9 wt.%) in tap water, sea water, and acidic/basic solutions. These metal-loaded FSPs could be easily recovered from aqueous solutions using a permanent magnet within 20s. They could also be easily regenerated with acid. The present work indicates that the FSPs are promising for removal of heavy metal ions in field application. PMID:22939254

  8. The reactive surface of Castor leaf [Ricinus communis L.] powder as a green adsorbent for the removal of heavy metals from natural river water

    Science.gov (United States)

    Martins, Amanda E.; Pereira, Milene S.; Jorgetto, Alexandre O.; Martines, Marco A. U.; Silva, Rafael I. V.; Saeki, Margarida J.; Castro, Gustavo R.

    2013-07-01

    In this study, a green adsorbent was successfully applied to remove toxic metals from aqueous solutions. Dried minced castor leaves were fractionated into 63-?m particles to perform characterization and extraction experiments. Absorption bands in FTIR (Fourier Transform Infrared Spectroscopy) spectra at 1544, 1232 and 1350 cm-1 were assigned to nitrogen-containing groups. Elemental analysis showed high nitrogen and sulfur content: 5.76 and 1.93%, respectively. The adsorption kinetics for Cd(II) and Pb(II) followed a pseudo-second-order model, and no difference between the experimental and calculated Nf values (0.094 and 0.05 mmol g-1 for Cd(II) and Pb(II), respectively) was observed. The Ns values calculated using the modified Langmuir equation, 0.340 and 0.327 mmol g-1 for Cd(II) and Pb(II), respectively, were superior to the results obtained for several materials in the literature. The method proposed in this study was applied to pre-concentrate (45-fold enrichment factor) and used to measure Cd(II) and Pb(II) in freshwater samples from the Paraná River. The method was validated through a comparative analysis with a standard reference material (1643e).

  9. Decay heat removal analyses in heavy-liquid-metal-cooled fast breeding reactors. Development of the thermal-hydraulic analysis method for lead-bismuth-cooled, natural-circulation reactors

    International Nuclear Information System (INIS)

    The feasibility study on future commercial fast breeder reactors in Japan has been conducted at JNC, in which various plant design options with all the possible coolant and fuel types are investigated to determine the conditions for the future detailed study. Lead-bismuth eutectic coolant has been selected as one of the possible coolant options. During the phase-I activity of the feasibility study in FY1999 and FY2000, several plant concepts, which were cooled by the heavy liquid metal coolant, were examined to evaluate the feasibility mainly with respect to economical competitiveness with other coolant reactors. A medium-scale (300 - 550 MWe) plant, cooled by a lead-bismuth natural circulation flow in a pool type vessel, was selected as the most possible plant concept for the heavy liquid metal coolant. Thus, a conceptual design study for a lead-bismuth-cooled, natural-circulation reactor of 400 MWe has been performed at JNC to identify remaining difficulties in technological aspect and its construction cost evaluation. In this report, a thermal-hydraulic analysis method for lead-bismuth-cooled, natural-circulation reactors is described. A Multi-dimensional Steam Generator analysis code (MSG) was applied to evaluate the natural circulation plant by combination with a flow-network-type, plant dynamics code (Super-COPD). By using this combined multi-dimensional plant dynamics code, decay heat removals, ULOHS and UTOP accidents were evaluated for the 100 MWe STAR-LM conwere evaluated for the 100 MWe STAR-LM concept designed by ANL. In addition, decay heat removal by the Primary Reactor Auxiliary Cooling System (PRACS) in the 400 MWe lead-bismuth-cooled, natural-circulation reactor, being studied at JNC, was analyzed. In conclusion, it becomes clear that the combined multi-dimensional plant dynamics code is suitably applicable to analyses of lead-bismuth-cooled, natural-circulation reactors to evaluate thermal-hydraulic phenomena during steady-state and transient conditions. (author)

  10. MOLECULAR CHARACTERIZATION OF A NOVEL HEAVY METAL UPTAKE TRANSPORTER FROM HIGHER PLANTS & ITS POTENTIAL FOR USE IN PHYTOREMEDIATION

    Science.gov (United States)

    Soils with high levels of heavy metals such as Cd, Cr and Pb are detrimental to human and animal health. Many human disorders have been attributed to environmental contamination by heavy metals. Removal of heavy metals from highly contaminated soils is therefore a very costly but...

  11. Heavy Metal Concentrations in Predator Fish

    Directory of Open Access Journals (Sweden)

    Srebrenka Nejedli

    2011-01-01

    Full Text Available 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, manganese, iron, copper and zinc were determined in water, mud and different organs (liver, kidney, intestine, milt and skin+muscle of pike (Esox lucius and European catfish (Silurus glanis by Energy Dispersive X-Ray Fluorescence method (EDXRF. Statistically significant difference was determined between the concentrations of heavy metals in mud and water (p<0.05 as well as in fish organs (p<0.05. The obtained results show that the highest concentrations of heavy metals were determined in liver and the lowest ones in skin and muscle i.e., in edible fish parts. In accordance with normative regulations of the European Union and the Republic of Croatia, the determined values are lower than the maximally allowed concentrations of heavy metals in fish muscle. When the pollution by heavy metals is taken into account, it indicates that the researched fish meat is hygienically safe food of animal origin.

  12. LIMING EFFECT ON SOIL HEAVY METALS AVAILABILITY

    Directory of Open Access Journals (Sweden)

    Krunoslav Karali?

    2013-06-01

    Full Text Available The aim of this paper was to determine the influence of acid soils liming and initial soil acidity as well as organic matter content on availability of four heavy metals m(Zn, Pb, Cr and Cd. Liming experiment was conducted in laboratory conditions with six soils of different acidity according to rapid incubation method which was conducted in sealed containers for three days at a constant temperature of 60°C. Liming treatments resulted in trend of heavy metals availability decrement in all soils, but intensity of decrement differed considering initial soil acidity and initial heavy metals availability. According to relative heavy metals availability decrement, liming resulted in the strongest effect in extremely acid soils with the highest initial concentrations of available Zn, Pb, Cr and Cd. On the other side, the weakest relative liming effect on heavy metals availability decrement was recorded in moderately acid soils with the lowest initial concentrations of available heavy metals. Considering impact of initial humus content in soil, higher relative liming efficiency of heavy metals availability decrement was determined in soils with higher soil organic matter content and with lower initial concentrations of available heavy metals.

  13. Study of hybrid membrane processes for separation of heavy metals from water and wastewater

    OpenAIRE

    Erwe, Torsten

    2010-01-01

    The removal of heavy metals from industrial waste water or from groundwater is a big challenge for the industry. It';s not possible to discharge industrial wastewater contaminated with heavy metals directly into rivers, water reservoirs or into the sea, because the heavy metals present a considerable danger to the ecosystem. Indirect discharge of this wastewater into municipal sewage treatment plants may have a major effect on the activated sludge and hinder the efficiency of the plants. The ...

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

    OpenAIRE

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

    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...

  15. 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.

  16. 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.

  17. Heavy metal adsorption by modified oak sawdust: thermodynamics and kinetics.

    Science.gov (United States)

    Argun, Mehmet Emin; Dursun, Sukru; Ozdemir, Celalettin; Karatas, Mustafa

    2007-03-01

    This paper describes the adsorption of heavy metal ions from aqueous solutions by oak (Quercus coccifera) sawdust modified by means of HCl treatment. Our study tested the removal of three heavy metals: Cu, Ni, and Cr. The optimum shaking speed, adsorbent mass, contact time, and pH were determined, and adsorption isotherms were obtained using concentrations of the metal ions ranging from 0.1 to 100mgL(-1). The adsorption process follows pseudo-second-order reaction kinetics, as well as Langmuir and D-R adsorption isotherms. The paper discusses the thermodynamic parameters of the adsorption (the Gibbs free energy, entropy, and enthalpy). Our results demonstrate that the adsorption process was spontaneous and endothermic under natural conditions. The maximum removal efficiencies were 93% for Cu(II) at pH 4, 82% for Ni(II) at pH 8, and 84% for Cr(VI) at pH 3. PMID:16879919

  18. Heavy metal adsorption by modified oak sawdust: Thermodynamics and kinetics

    International Nuclear Information System (INIS)

    This paper describes the adsorption of heavy metal ions from aqueous solutions by oak (Quercus coccifera) sawdust modified by means of HCl treatment. Our study tested the removal of three heavy metals: Cu, Ni, and Cr. The optimum shaking speed, adsorbent mass, contact time, and pH were determined, and adsorption isotherms were obtained using concentrations of the metal ions ranging from 0.1 to 100 mg L-1. The adsorption process follows pseudo-second-order reaction kinetics, as well as Langmuir and D-R adsorption isotherms. The paper discusses the thermodynamic parameters of the adsorption (the Gibbs free energy, entropy, and enthalpy). Our results demonstrate that the adsorption process was spontaneous and endothermic under natural conditions. The maximum removal efficiencies were 93% for Cu(II) at pH 4, 82% for Ni(II) at pH 8, and 84% for Cr(VI) at pH 3

  19. Gamma radiation-polymerized methacrylates used as heavy metals adsorbents

    International Nuclear Information System (INIS)

    Heavy metal removal from aqueous solution is a priority research area since the actual methods are costly and a major drawback is the large amounts of sludge generated when applying traditional techniques. Adsorption is a physiochemical wastewater treatment process, which is gaining prominence as a means of producing high quality effluents, which are low in metal ion concentrations. The development of inexpensive adsorbents for the treatment of wastewater is an important area in environmental sciences. In this work we describe some of the physical and chemical phenomena that take place in the polymerization of methacrylates when gamma radiation is used. We explain how polymeric material characterization equipment are used for obtaining information regarding the material properties. Then we explain how the new polymeric material obtained can be use for the wastewater treatment. Finally, a comparison in the heavy metal removal from aqueous solution with other sorbent materials is presented. (Author)

  20. Study on Biosorption of Heavy Metals by Modified Lignocellulosic Waste

    Directory of Open Access Journals (Sweden)

    Usama Eldemerdash

    2011-01-01

    Full Text Available Heavy metal laden effluent coming out of various industries is posing a huge pressure on the environment. This in turn, necessitates the development of a noble low cost and efficient technology for the removal of such wastes from industrial effluents. In this particular research, the heavy metal (lead (II biosorption capacity of modified agri-waste (rice husk and sugarcane bagasse has been studied, taking the two biosorbents as abundant and low cost biosorbents with promising potential to remove hazardous heavy metal wastes from effluent streams. In the study, options to enhance metal sorption capacity by chemical and thermal modification of the sorbents have been investigated. Impact of modifier chemicals used include sodium hydroxide, sulfuric acid, nitric acid, citrc acid, acrylic acid and glutamic acid in case of rice husk and modifiers like Sodium Dodecyl Sulfate (SDS, Sodium bicarbonate, Cetyl trimethyl diammonium bromide (CTAB, sodium methylate and urea, in case of sugar cane bagasse in addition to those used with rice husk. Characterization of the sorbents surfaces has been made before and after chemical and thermal modification and after sorption of heavy metals using Fourrier Transform Infra-Red Spectroscopy (FTIR and Scanning Electron Microscope (SEM. Some studies have also been done on mechanism of sorption. In addition impact of concentration of sodium hydroxide and citric acid as effective chemical modifier has been studied. Tests to understand impact of particle size have also been conducted and results for the two biosorbents have been compared.

  1. 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

  2. Adsorptive Removal of Arsenite as (III) and Arsenate as (V) Heavy Metals from Waste Water using Nigella sativa L.

    OpenAIRE

    El-said, S. M.; Alamri, M. B. S.; Ali-Bin Saleh El-Barak; Alsogair, O.

    2009-01-01

    This study was focused on Nigella sativa Linn. as an alternative absorbent in order to remove As (III) and arsenate As (V) from synthetic waste water. As such, Nigella sativa L. was collected from Burydah A-Qassim. Batch experiments were conducted to determine the adsorptive efficiency of Nigella sativa L. to remove As (III) and arsenate As (V) from waste water. The preliminary experiments were revealed that alkaline solutions (pH>9) without Nigella sativa L. caused homogeneous oxidation o...

  3. 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

  4. 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

  5. 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.)

  6. 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.

  7. 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.

  8. Remediating sites contaminated with heavy metals

    International Nuclear Information System (INIS)

    This article is intended to serve as a reference for decision makers who must choose an approach to remediate sites contaminated with heavy metals. Its purpose is to explain pertinent chemical and physical characteristics of heavy metals, how to use these characteristics to select remedial technologies, and how to interpret and use data from field investigations. Different metal species are typically associated with different industrial processes. The contaminant species behave differently in various media (i.e., groundwater, soils, air), and require different technologies for containment and treatment. We focus on the metals that are used in industries that generate regulated waste. These include steelmaking, paint and pigment manufacturing, metal finishing, leather tanning, papermaking, aluminum anodizing, and battery manufacturing. Heavy metals are also present in refinery wastes as well as in smelting wastes and drilling muds

  9. 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 ...

  10. 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

  11. Heavy metals in equine biological components

    Scientific Electronic Library Online (English)

    Maria Verônica de, Souza; Maurício Paulo Ferreira, Fontes; Raphael Bragança Alves, Fernandes.

    2014-02-01

    Full Text Available The objective of this research was to determine the concentration of heavy metals in the blood (Pb, Ni and Cd), serum (Cu and Zn) and hair (Pb, Ni, Cd, Cu and Zn) of horses raised in non-industrial and industrial areas (with steel mill), and to verify the possibility to use these data as indicators [...] of environmental pollution. The samples were collected during summer and winter, aiming to verify animal contamination related to environment and season of the year. Copper and Zn contents determined in the serum and Cd and Ni contents obtained in the blood indicated no contamination effects of industries. For some animals, contents of Pb in the blood were higher than those considered acceptable for the species, but without relationship with industrialization and without clinical signs of Pb intoxication. The heavy metals evaluated on the hair of horses in this study were not increased with the presence of industries, but Cu and Cd contents were influenced by the season. The contents of some heavy metals in biological components analyzed were influenced by season sampling; however, serum, blood and hair may not be suitable to indicate differences in environmental contamination between the two contrasting areas. Most part of the heavy metal contents was lower or close to the reference values for horses. Serum, blood and hair components from horses may not be effective as indicators of environmental pollution with heavy metals. Industrialization and seasons have no effects on most part of heavy metals contents from those components.

  12. 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.

  13. 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 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.

  14. 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.

  15. 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.

  16. Surfactant biocatalyst for remediation of recalcitrant organics and heavy metals

    Energy Technology Data Exchange (ETDEWEB)

    Brigmon, Robin L. (North Augusta, SC); Story, Sandra (Greenville, SC); Altman; Denis J. (Evans, GA); Berry, Christopher J. (Aiken, SC)

    2011-03-29

    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.

  17. Surfactant biocatalyst for remediation of recalcitrant organics and heavy metals

    Energy Technology Data Exchange (ETDEWEB)

    Brigmon, Robin L. (North Augusta, SC); Story, Sandra (Greenville, SC); Altman, Denis J. (Evans, GA); Berry, Christopher J. (Aiken, SC)

    2011-03-15

    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.

  18. Surfactant biocatalyst for remediation of recalcitrant organics and heavy metals

    Energy Technology Data Exchange (ETDEWEB)

    Brigmon, Robin L. (North Augusta, SC); Story, Sandra (Greenville, SC); Altman, Denis (Evans, GA); Berry, Christopher J. (Aiken, SC)

    2009-01-06

    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.

  19. Removal of Retired Alkali Metal Test Systems

    Energy Technology Data Exchange (ETDEWEB)

    Brehm, W. F.; Church, W. R.; Biglin, J. W.

    2003-02-26

    This paper describes the successful effort to remove alkali metals, alkali metal residues, and piping and structures from retired non-radioactive test systems on the Hanford Site. These test systems were used between 1965 and 1982 to support the Fast Flux Test Facility and the Liquid Metal Fast Breeder Reactor Program. A considerable volume of sodium and sodium-potassium alloy (NaK) was successfully recycled to the commercial sector; structural material and electrical material such as wiring was also recycled. Innovative techniques were used to safely remove NaK and its residues from a test system that could not be gravity-drained. The work was done safely, with no environmental issues or significant schedule delays.

  20. The fate of the discharged heavy metals

    International Nuclear Information System (INIS)

    Measurements were made in order to deduce the fate of heavy pollutants which were discharged during milling operations. The extent to which these metals have accumulated in the Finniss River floodplains and the significance of the accumulation with respect to the pastoral use of the plains are discussed. The metals investigated were copper, manganese, zinc and radium. (author)

  1. ACTINOMYCETES: TOLERANCE AGAINST HEAVY METALS AND ANTIBIOTICS

    Directory of Open Access Journals (Sweden)

    Smriti Singh, Shruti Pandey and Hotam Singh Chaudhary*

    2014-09-01

    Full Text Available Heavy metals can be both, essential as well as toxic for living beings. Micronutrients such as, Co, Fe, Mn have important role to play in living systems whereas, Pb Cd etc. pose harmful effects even at low concentrations. When these heavy metals get accumulated within the tissues of the organisms at various levels of the ecological chain, they cause decrease in the biomass and biological diversity by affecting the growth, morphology and activity of the organisms. Accumulation of heavy metals in soil also causes soil contamination, which can be overcome with the help of bioremediation. A large group of soil bacteria belonging to the Actinomycetes species are exposed to heavy metals in a variety of ways; although, they show resistance to heavy metals. The species of actinomycetes possess resistance for antibiotic synthesis as well. This makes the actinomycetes suitable agents for bioremediation. In this experiment, a total of 20 isolates from Shivpuri region of Madhya Pradesh were tested for the metal tolerance against selected heavy metals. After this, the most tolerant strains were tested to check their antibiotic susceptibility. Metal tolerance was tested by agar well diffusion method and tube dilution method. Out of the 20 isolates, Ash1, Ash 2, Ash 4,Ash 6, Ash 7, Ash 8, Ash 9, Ash 10, Ash 11, Ash 12, Ash 13, Ash 15 were resistant at 10 mM conc. of CuSo4, but their growth was inhibited at higher concentrations of metal salts. Isolates Ash 10, Ash 11, Ash 12, Ash 13, Ash 19, Ash 20 were found to be resistant at 10mM conc. of ZnSO4, but they were also inhibited at higher concentrations. For different concentrations of Pb(CH3COO2 most of the isolates showed same level of tolerance.

  2. 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.

  3. 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 [...] 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.

  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. Preparation of silica-supported porous sorbent for heavy metal ions removal in wastewater treatment by organic-inorganic hybridization combined with sucrose and polyethylene glycol imprinting

    International Nuclear Information System (INIS)

    A new porous sorbent for wastewater treatment of metal ions was synthesized by covalent grafting of molecularly imprinted organic-inorganic hybrid on silica gel. With sucrose and polyethylene glycol 4000 (PEG 4000) being synergic imprinting molecules, covalent surface coating on silica gel was achieved by using polysaccharide-incorporated sol-gel process starting from the functional biopolymer, chitosan and an inorganic epoxy-precursor, gamma-glycidoxypropyltrimethoxysiloxane (GPTMS) at room temperature. The prepared porous sorbent was characterized by using simultaneous thermogravimetry and differential scanning calorimeter (TG/DSC), scanning electron microscopy (SEM), nitrogen adsorption porosimetry measurement and X-ray diffraction (XRD). Copper ion, Cu2+, was chosen as the model metal ion to evaluate the effectiveness of the new biosorbent in wastewater treatment. The influence of epoxy-siloxane dose, buffer pH and co-existed ions on Cu2+ adsorption was assessed through batch experiments. The imprinted composite sorbent offered a fast kinetics for the adsorption of Cu2+. The uptake capacity of the sorbent imprinted by two pore-building components was higher than those imprinted with only a single component. The dynamic adsorption in column underwent a good elimination of Cu2+ in treating electric plating wastewater. The prepared composite sorbent exhibited high reusability. Easy preparation of the described porous compospreparation of the described porous composite sorbent, absence of organic solvents, cost-effectiveness and high stability make this approach attractive in biosorption

  6. Biosorption of heavy metal and dyes : a promising technology leather wastewater treatment

    OpenAIRE

    Rosales, E.; Pazos, M.; Sanroma?n, M. A.; Tavares, M. T.

    2011-01-01

    The presence of dyes and heavy metals is usual in industrial processes like chrome tanning in tannery industry and their removal may be an environmental problem. Different techniques were developed and applied for the treatment of dyes and heavy metals in effluents. Among them, adsorption showed to be an economic, simple operation and an effective technique. Zeolites have a strong affinity for cations of transition metals, but only little affinity for anions and non-polar organic molecules. T...

  7. BIOSORPTION AND RECOVERY OF HEAVY METALS FROM AQUEOUS SOLUTIONS BY EICHHORNIA CRASSIPES (WATER HYACINTH) ASH

    OpenAIRE

    Tariq Mahmood; Salman Akbar Malik; Syed Tajammul Hussain

    2010-01-01

    Heavy metal’s release without treatment poses a significant threat to the environment. Heavy metals are non-biodegradable and persistent. In the present study the ash of water hyacinth (Eichhornia crassipes), was used to remove six metals from aqueous solutions through biosorption. Results of batch and column experiments showed excellent adsorption capacity. Removal of lead, chromium, zinc, cadmium, copper, and nickel was 29.83, 1.263, 1.575, 3.323, 2.984 and 1.978 µgg-1, respectively. The...

  8. 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

  9. 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

  10. 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

  11. Heavy metal hazards of Nigerian herbal remedies

    International Nuclear Information System (INIS)

    The uses of herbal products are not regulated in Nigeria and in many low-income countries and are freely available to everyone. The safety of these herbal medicines is poorly understood. This study characterizes the content of cadmium, copper, iron, nickel, selenium, zinc, lead and mercury in a random sample of Nigerian traditional products. Ready-to-use herbal products were purchased from the open market and digested using HNO3.The heavy metal content of the digested filtrate was determined by atomic absorption spectrometry Uni-cam Model 929. The result showed that 100% of the samples contained elevated amounts of heavy metals. These data alert us to the possibility of heavy metal toxicity from herbal products in Nigeria. The public health hazards from ingestion of herbal medicines should be identified and disclosed by in-depth risk assessment studies

  12. Uso de biomassa seca de aguapé (Eichornia crassipes visando à remoção de metais pesados de soluções contaminadas - DOI: 10.4025/actascitechnol.v31i1.3166 Use of water hyacinth (Eichornia crassipes dry biomass for removing heavy metals from contaminated solutions - DOI: 10.4025/actascitechnol.v31i1.3166

    Directory of Open Access Journals (Sweden)

    Claudemir Selzlein

    2009-04-01

    Full Text Available O presente trabalho avaliou a eficiência da biomassa seca de aguapé (Eichornia crassipes na remoção dos metais pesados cádmio (Cd, chumbo (Pb, cromo (Cr, cobre (Cu, zinco (Zn e níquel (Ni de soluções preparadas com estes metais. O delineamento utilizado foi inteiramente casualizado, com cinco tratamentos (soluções com diferentes concentrações dos metais pesados e quatro repetições. A biomassa seca permaneceu nas soluções dos tratamentos por um período de 48h, e nos intervalos de 1; 2; 3; 6; 12; 24; 36 e 48h após a instalação do experimento, coletaram-se alíquotas de cada tratamento, determinando-se a maior remoção de cada metal pesado pela biomassa seca do aguapé. Foi realizada digestão nitroperclórica na biomassa seca e determinação dos teores dos metais na biomassa e nas alíquotas por espectrometria de absorção atômica, modalidade chama. Para os metais Cd, Pb, Cr, Cu e Zn ocorreu remoção significativa pela massa seca do aguapé nos diferentes tratamentos, enquanto para o Ni não foi encontrada diferença significativa. Dessa forma, conclui-se que a biomassa seca produzida, a partir do aguapé Eichornia crassipes, é um excelente material para a remoção, tanto em pequena como em grande escala, de corpos hídricos contaminados com metais pesados.The present work evaluated the efficiency of the dry biomass of water hyacinth (Eichornia crassipes in the removal of heavy metals cadmium (Cd, lead (Pb, chromium (Cr, cupper (Cu, zinc (Zn and nickel (Ni from solutions prepared with these metals. The delineation used was entirely randomized, with five treatments (solutions with different concentrations of heavy metals and four repetitions. The dry biomass remained in the treatment solutions for a period of 48h. In the intervals of 1; 2; 3; 6; 12; 24; 36 and 48h after experiment installation, samples were collected of each treatment, determining the greater removal for each heavy metal by water hyacinth dry biomass. Nitro-perchloric digestion was conducted in the dry biomass, and metal levels were determined in the dry biomass and in the samples by atomic absorption spectrometry, flame modality. The metals Cd, Pb, Cr, Cu e Zn were removed by water hyacinth dry biomass in the different treatments, whereas for Ni removal did not occur. The water hyacinth Eichornia crassipes is an excellent material for removal, in small and larger scales, of water bodies contaminated with heavy metals

  13. Mushrooms pollution by radioactivity and heavy metals

    International Nuclear Information System (INIS)

    Some basic notions of radioactivity are recalled first (definition, origin, measurement units, long- and short-term effects..). Then, the pedology of soils and the properties and toxicity of 3 heavy metals (lead, cadmium, mercury) are presented to better understand the influence of some factors (genre, age, ecological type, pollution, conservation..) on the contamination of macro-mycetes by radioactivity and heavy metals. The role of chemists is to inform the consumers about these chemical and radioactive pollutions and to give some advices about the picking up (quantities, species and places to avoid) and the cooking of mushrooms. (J.S.)

  14. 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

  15. 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...

  16. Some Case Studies on Metal-Microbe Interactions to Remediate Heavy Metals- Contaminated Soils in Korea

    Science.gov (United States)

    Chon, Hyo-Taek

    2015-04-01

    Conventional physicochemical technologies to remediate heavy metals-contaminated soil have many problems such as low efficiency, high cost and occurrence of byproducts. Recently bioremediation technology is getting more and more attention. Bioremediation is defined as the use of biological methods to remediate and/or restore the contaminated land. The objectives of bioremediation are to degrade hazardous organic contaminants and to convert hazardous inorganic contaminants to less toxic compounds of safe levels. The use of bioremediation in the treatment of heavy metals in soils is a relatively new concept. Bioremediation using microbes has been developed to remove toxic heavy metals from contaminated soils in laboratory scale to the contaminated field sites. Recently the application of cost-effective and environment-friendly bioremediation technology to the heavy metals-contaminated sites has been gradually realized in Korea. The merits of bioremediation include low cost, natural process, minimal exposure to the contaminants, and minimum amount of equipment. The limitations of bioremediation are length of remediation, long monitoring time, and, sometimes, toxicity of byproducts for especially organic contaminants. From now on, it is necessary to prove applicability of the technologies to contaminated sites and to establish highly effective, low-cost and easy bioremediation technology. Four categories of metal-microbe interactions are generally biosorption, bioreduction, biomineralization and bioleaching. In this paper, some case studies of the above metal-microbe interactions in author's lab which were published recently in domestic and international journals will be introduced and summarized.

  17. 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

  18. Heavy metal detoxification in eukaryotic microalgae.

    Science.gov (United States)

    Perales-Vela, Hugo Virgilio; Peña-Castro, Julián Mario; Cañizares-Villanueva, Rosa Olivia

    2006-06-01

    Microalgae are aquatic organisms possessing molecular mechanisms that allow them to discriminate non-essential heavy metals from those essential ones for their growth. The different detoxification processes executed by algae are reviewed with special emphasis on those involving the peptides metallothioneins, mainly the post transcriptionally synthesized class III metallothioneins or phytochelatins. Also, the features that make microalgae suitable organisms technologies specially to treat water that is heavily polluted with metals is discussed. PMID:16405948

  19. 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

  20. 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

  1. Solvent extraction for heavy crude oil removal from contaminated soils.

    Science.gov (United States)

    Li, Xingang; Du, Yongliang; Wu, Guozhong; Li, Zhongyuan; Li, Hong; Sui, Hong

    2012-06-01

    A new strategy of heavy crude oil removal from contaminated soils was studied. The hexane-acetone solvent mixture was used to investigate the ability of solvent extraction technique for cleaning up soils under various extraction conditions. The mixtures of hexane and acetone (25 vol%) were demonstrated to be the most effective in removing petroleum hydrocarbons from contaminated soils and approx 90% of saturates, naphthene aromatics, polar aromatics, and 60% of nC(7)-asphaltenes were removed. Kinetic experiments demonstrated that the equilibrium was reached in 5 min and the majority of the oil pollutants were removed within 0.5 min. The effect of the ratio between solvent and soil on the extraction efficiency was also studied and results showed that the efficiency would increase following the higher solvent soil ratio. Then the multistage continuous extraction was considered to enhance the removal efficiency of oil pollutants. Three stages crosscurrent and countercurrent solvent extraction with the solvent soil ratio 6:1 removed 97% oil contaminants from soil. Clearly the results showed that the mixed-solvent of hexane and acetone (25 vol%) with character of low-toxic, acceptable cost and high efficiency was promising in solvent extraction to remove heavy oil fractions as well as petroleum hydrocarbons from contaminated soils. PMID:22483725

  2. 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

  3. 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.

  4. 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

  5. THEORETICAL STUDIES CONCERNING RESIDUAL SOIL POLLUTION BY HEAVY METALS

    OpenAIRE

    CRISTIAN RADU; VALENTIN NEDEFF; ALEXANDRA-DANA CHITIMUS

    2013-01-01

    The paper describes a series of theoretical aspects concerning residual soil pollution by heavy metals. Heavy metals, unlike organic and radionuclide pollutants, are considered to be the most persistent/resistant polluting substances in the soil, displaying a tendency for accumulation. The behavior of heavy metals in the soil depends on the physical and chemical properties of the soil, as well as on their origin and source. Knowledge of the properties of heavy metals is very important, having...

  6. 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.

  7. Heavy Metals Bioaccumulation of Several Bradyrhizobium japonicum Strains

    OpenAIRE

    ADE NOOR SYAMSUDIN; TEDJA-IMAS; SUMINAR SETIATI ACHMADI

    2005-01-01

    Heavy metal utilization in industry and agriculture have caused an environmental problem to existing life. Bioaccumulation is made up by a concentration of certain chemical compounds in living tissues. The objective of this research was to reveal the ability of lipopolysaccharides (LPSs) of heavy metal Bradyrhizobium japonicum tolerant strains in accumulating heavy metals. The strains used were BDG 10, KDR 10, and KDR 15. The ability of each strains on heavy metal accumulation of Cu, Pb, Zn, ...

  8. Phytoextraction of heavy metals by canola (Brassica napus) and radish (Raphanus sativus) grown on multicontaminated soil

    Energy Technology Data Exchange (ETDEWEB)

    Marchiol, L.; Assolari, S.; Sacco, P.; Zerbi, G

    2004-11-01

    Phytoextraction can provide an effective in situ technique for removing heavy metals from polluted soils. The experiment reported in this paper was undertaken to study the basic potential of phytoextraction of Brassica napus (canola) and Raphanus sativus (radish) grown on a multi-metal contaminated soil in the framework of a pot-experiment. Chlorophyll contents and gas exchanges were measured during the experiment; the heavy metal phytoextraction efficiency of canola and radish were also determined and the phytoextraction coefficient for each metal calculated. Data indicated that both species are moderately tolerant to heavy metals and that radish is more so than canola. These species showed relatively low phytoremediation potential of multicontaminated soils. They could possibly be used with success in marginally polluted soils where their growth would not be impaired and the extraction of heavy metals could be maintained at satisfying levels.

  9. Phytoextraction of heavy metals by canola (Brassica napus) and radish (Raphanus sativus) grown on multicontaminated soil

    International Nuclear Information System (INIS)

    Phytoextraction can provide an effective in situ technique for removing heavy metals from polluted soils. The experiment reported in this paper was undertaken to study the basic potential of phytoextraction of Brassica napus (canola) and Raphanus sativus (radish) grown on a multi-metal contaminated soil in the framework of a pot-experiment. Chlorophyll contents and gas exchanges were measured during the experiment; the heavy metal phytoextraction efficiency of canola and radish were also determined and the phytoextraction coefficient for each metal calculated. Data indicated that both species are moderately tolerant to heavy metals and that radish is more so than canola. These species showed relatively low phytoremediation potential of multicontaminated soils. They could possibly be used with success in marginally polluted soils where their growth would not be impaired and the extraction of heavy metals could be maintained at satisfying levels

  10. Evaluation of alternative removal methods for decommissioning of heavy components in nuclear power plants

    International Nuclear Information System (INIS)

    Highlights: • This paper is to evaluate the removal alternative methods of heavy components in nuclear power plants. • The removal alternative methods of heavy components as a whole body are composed of three methods. • This paper presented the best alternative method of RPV removal. - Abstract: The purpose of this paper is to evaluate the removal alternative methods of heavy components in nuclear power plants. One of the important tasks in decommissioning a nuclear power plant is removal of heavy components. The removal alternative methods of heavy components as a whole body are composed of three methods. This paper presented the best alternative method of RPV removal

  11. [Tolerance of Arundo donax to heavy metals].

    Science.gov (United States)

    Han, Zhiping; Hu, Zhenghai

    2005-01-01

    This paper studied the tolerance of Arundo donax grown in a simulated heavy metals polluted wetland, and determined the biological characters and chlorophyll contents of the plant at its different growth stages as well as the changes of soil heavy metals contents. The results showed that Arundo donax could survive in the wetland when the concentrations of Cu2+, Pb2+, Cd2+, Zn2+, Ni2+ and Hg2+ were 100 mg x kg(-1) and Cr6+ concentration was 50 mg x kg(-1). During 40 days growth period, the chlorophyll content decreased by 20%-56% and the leaf became soft with its tip withered, but the plant still grew. Compared with control, Arundo donax in the polluted wetland was slight and yellow-green, but the impact on plant height was inconspicuous. Arundo donax treated with 100 mg x kg(-1) Cr6+ grew slowly with its root stock rotted, and its leaves withered in a short time, indicating that the plant could not tolerate the pollution of high concentration Cr6+. The concentrations of soil heavy metals declined with the growth of the plant, probably due to the translocation of heavy metals from peripheral soil to rhizosphere and the phytoextraction and phytovolatilization, because the heavy metals contents in rhizosphere were much higher than those in the bulk soil in the test jar. The characters of large biomass, exuberant root and good adaptability of Arundo donax suggested its great potential in remediation of polluted soils. The study on the application of Arundo donax to phytoremediation is of realistic significance. PMID:15852979

  12. Heavy metals in drinking water. January 1986-November 1991 (Citations from the NTIS Data-Base). Rept. for Jan 86-Nov 91

    International Nuclear Information System (INIS)

    The bibliography contains citations concerning the presence of heavy metals in drinking water. The effects of plumbing systems on water quality is discussed. Standards for safe drinking water are included. Treatment techniques to remove heavy metals are described. Methods for analyzing heavy metal contaminants in water are presented. The effects of heavy metals in drinking water on human health are briefly considered. (Contains 159 citations with title list and subject index.)

  13. Heavy Metal Contamination in Canned Tuna Fish

    Directory of Open Access Journals (Sweden)

    M Ghazi-Khansari

    2003-07-01

    Full Text Available Heavy metal contamination of food products, especially seafood is a major concern because of the bioaccumulation and biomagnification of metal contaminants. Their detection in fish is an indicator of marine pollution. In this study heavy metal concentrations were measured in a sample of commercially obtained canned tuna; after digestion and preparation of 21 such samples, levels of mercury and arsenic were determined by the hydride generation technique, while those of lead and cadmium were measured by the graphite furnace system. Tin levels were determined by flame atomic absorption spectrophotometery. The mean contents of heavy metals expressed in ug/g of wet weight were O.U3±0.027 (range 0.082-0.16 for mercury, 0.129±0.082 (0.037-0.262 for arsenic, 0.029±0.019 (0.006-0.088 for cadmium, and 0.33±0.12 (0.016-0.049 for lead. No tin was detected any of the samples. The concentrations of toxic metals in this study were below the WHO/FAO-recommended levels, but further studies are needed to assess the risk associated other types of food.

  14. Optical Algal Biosensor using Alkaline Phosphatase for Determination of Heavy Metals

    OpenAIRE

    Durrieu, Claude; Tran-Minh, Canh

    2002-01-01

    A biosensor is constructed to detect heavy metals from inhibition of alkaline phosphatase (AP) present on the external membrane of Chlorella vulgaris microalgae. The microalgal cells are immobilized on removable membranes placed in front of the tip of an optical fiber bundle inside a homemade microcell. C. vulgaris was cultivated in the laboratory and its alkaline phosphatase activity is strongly inhibited in the presence of heavy metals. This property has been used for the determination of t...

  15. Optical algal biosensor using alkaline phosphatase for determination of heavy metals.

    Science.gov (United States)

    Durrieu, Claude; Tran-Minh, Canh

    2002-03-01

    A biosensor is constructed to detect heavy metals from inhibition of alkaline phosphatase (AP) present on the external membrane of Chlorella vulgaris microalgae. The microalgal cells are immobilized on removable membranes placed in front of the tip of an optical fiber bundle inside a homemade microcell. C. vulgaris was cultivated in the laboratory and its alkaline phosphatase activity is strongly inhibited in the presence of heavy metals. This property has been used for the determination of those toxic compounds. PMID:11971642

  16. Aging of iron (hydr)oxides by heat treatment and effects on heavy metal binding

    OpenAIRE

    Sørensen, Mette Abildgaard; Starckpoole, M. M.; Frenkel, A. I.; Bordia, R. K.; Korshin, G.; Christensen, Thomas Højlund

    2006-01-01

    Amorphous iron (hydr)oxides are used to remove heavy metals from wastewater and in the treatment of air pollution control residues generated in waste incineration. In this study, iron oxides containing heavy metals (e.g., Pb, Hg, Cr, and Cd) were treated at 50, 600, and 900 °C to simulate their transformations caused by heat treatment prior to disposal or aging at a proper disposal site. The transformations were investigated by XRD, SEM, XANES, EXAFS, surface area mea...

  17. 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)

  18. 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…

  19. 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

  20. 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.

  1. Uptake of certain heavy metals from contaminated soil by mushroom--Galerina vittiformis.

    Science.gov (United States)

    Damodaran, Dilna; Vidya Shetty, K; Raj Mohan, B

    2014-06-01

    Remediation of soil contaminated with heavy metals has received considerable attention in recent years. In this study, the heavy metal uptake potential of the mushroom, Galerina vittiformis, was studied in soil artificially contaminated with Cu (II), Cd (II), Cr (VI), Pb (II) and Zn (II) at concentrations of 50 and 100mg/kg. G. vittiformis was found to be effective in removing the metals from soil within 30 days. The bioaccumulation factor (BAF) for both mycelia and fruiting bodies with respect to these heavy metals at 50mg/kg concentrations were found to be greater than one, indicating hyper accumulating nature by the mushroom. The metal removal rates by G. vittiformis was analyzed using different kinetic rate constants and found to follow the second order kinetic rate equation except for Cd (II), which followed the first order rate kinetics. PMID:24655915

  2. Removal of soluble toxic metals from water

    International Nuclear Information System (INIS)

    The removal of selected, soluble toxic metals from aqueous solutions has been accomplished using a combination of chemical treatment and ultrafiltration. The process has been evaluated at the bench-scale and is undergoing pilot-scale testing. Removal efficiencies in excess of 95-99% have been realized. The test program at the bench-scale investigated the limitations and established the optimum range of operating parameters for the process, while the tests conducted with the pilot-scale process equipment are providing information on longer-term process efficiencies, effective processing rates, and fouling potential of the membranes. With the typically found average concentrations of the toxic metals in groundwaters at Superfund sites used as the feed solution, the process has decreased levels up to 100-fold or more. Experiments were also conducted with concentrated solutions to determine their release from silica-based matrices. The solidified wastes were subjected to EP Toxicity test procedures and met the criteria successfully. The final phase of the program involving a field demonstration at a uranium tailings site will be outlined

  3. 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.

  4. 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)

  5. 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.

  6. Biotechnological potential of immobilized algae for wastewater N, P and metal removal: a review.

    Science.gov (United States)

    Mallick, Nirupama

    2002-12-01

    This presentation comprises a review on the use of immobilized algae for wastewater nitrogen, phosphorus and metal removal purposes. Details of the use of immobilized algae, the techniques of immobilization and the effects of immobilization on cell function are included. Particularly relevant in their use for heavy metal removal from wastewaters; upon enriching the biomass in metal, can be recoverd, thereby providing economic advantages. The use of immobilized microalgae in these processes is very adequate and offers significant advantages in bioreactors. The future of this area of algal cell biotechnology is considered. PMID:12405533

  7. Applicability of Moringa oleifera Lam. pie as an adsorbent for removal of heavy metals from waters Aplicabilidade da torta de Moringa oleifera Lam. como adsorvente para remoção de metais pesados de águas

    Directory of Open Access Journals (Sweden)

    Affonso C. Gonçalves Junior

    2013-01-01

    Full Text Available This study evaluated the efficacy of moringa seeds (Moringa oleifera Lam. as an adsorbent material for removing toxic heavy metals such as cadmium, lead, and chromium from contaminated solutions. The effect of the adsorbent mass was investigated at two pH conditions (5.0 and 7.0. The optimized conditions were 0.300 g of adsorbent at pH 5.0, used for the isotherms construction, and linearized according to Langmuir and Freundlich models. Results showed that cadmium adsorption was similar in both the models used. For lead, the Freundlich model had the best adjustment and chromium was better adjusted by the Langmuir model. It was concluded that the adsorbent was effective in the remediation of solutions containing cadmium, lead and chromium, thus, its use as sustainable alternative material is feasible, since it has low cost, does not need a previous treatment and it is a byproduct.Este estudo objetivou avaliar a eficácia do uso da torta de moringa (Moringa oleifera Lam. como material adsorvente dos metais pesados tóxicos cádmio (Cd, chumbo (Pb e cromo (Cr de soluções contaminadas. Nos testes cinéticos foram variadas as massas do adsorvente em duas condições de pH (5,0 e 7,0. As condições otimizadas foram pH 5,0 e massa de 0.300 g de adsorvente, utilizados para a construção das isotermas e linearizadas conforme os modelos de Langmuir e Freundlich. Realizou-se a determinação dos metais por espectrometria de absorção atômica. Os resultados mostraram que houve semelhança em ambos os modelos utilizados para a adsorção do Cd. Para o Pb, o modelo de Freundlich apresentou o melhor ajuste e, para o Cr, houve melhor ajuste pelo modelo de Langmuir. Conclui-se, com base nos resultados obtidos, que o adsorvente foi eficaz na remediação de soluções contendo Cd, Pb e Cr e, assim, é viável a utilização desse adsorvente como material alternativo sustentável, pois apresenta baixo custo, não necessita de tratamento prévio e se trata de um coproduto.

  8. Applicability of Moringa oleifera Lam. pie as an adsorbent for removal of heavy metals from waters / Aplicabilidade da torta de Moringa oleifera Lam. como adsorvente para remoção de metais pesados de águas

    Scientific Electronic Library Online (English)

    Affonso C., Gonçalves Junior; Ana P., Meneghel; Fernanda, Rubio; Leonardo, Strey; Douglas C., Dragunski; Gustavo F., Coelho.

    2013-01-01

    Full Text Available Este estudo objetivou avaliar a eficácia do uso da torta de moringa (Moringa oleifera Lam.) como material adsorvente dos metais pesados tóxicos cádmio (Cd), chumbo (Pb) e cromo (Cr) de soluções contaminadas. Nos testes cinéticos foram variadas as massas do adsorvente em duas condições de pH (5,0 e 7 [...] ,0). As condições otimizadas foram pH 5,0 e massa de 0.300 g de adsorvente, utilizados para a construção das isotermas e linearizadas conforme os modelos de Langmuir e Freundlich. Realizou-se a determinação dos metais por espectrometria de absorção atômica. Os resultados mostraram que houve semelhança em ambos os modelos utilizados para a adsorção do Cd. Para o Pb, o modelo de Freundlich apresentou o melhor ajuste e, para o Cr, houve melhor ajuste pelo modelo de Langmuir. Conclui-se, com base nos resultados obtidos, que o adsorvente foi eficaz na remediação de soluções contendo Cd, Pb e Cr e, assim, é viável a utilização desse adsorvente como material alternativo sustentável, pois apresenta baixo custo, não necessita de tratamento prévio e se trata de um coproduto. Abstract in english This study evaluated the efficacy of moringa seeds (Moringa oleifera Lam.) as an adsorbent material for removing toxic heavy metals such as cadmium, lead, and chromium from contaminated solutions. The effect of the adsorbent mass was investigated at two pH conditions (5.0 and 7.0). The optimized con [...] ditions were 0.300 g of adsorbent at pH 5.0, used for the isotherms construction, and linearized according to Langmuir and Freundlich models. Results showed that cadmium adsorption was similar in both the models used. For lead, the Freundlich model had the best adjustment and chromium was better adjusted by the Langmuir model. It was concluded that the adsorbent was effective in the remediation of solutions containing cadmium, lead and chromium, thus, its use as sustainable alternative material is feasible, since it has low cost, does not need a previous treatment and it is a byproduct.

  9. 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 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.

  10. Bioremoval of heavy metals by the use of microalgae.

    Science.gov (United States)

    Wilde, E W; Benemann, J R

    1993-01-01

    Bioremoval, the use of biological systems for the removal of metal ions from polluted waters, has the potential to achieve greater performance at lower cost than conventional wastewater treatment technologies for metal removal. Bioremoval capabilities of microalgae have been extensively studied, and some commercial applications have been initiated. Although microalgae are not unique in their bioremoval capabilities, they offer advantages over other biological materials in some conceptual bioremoval process schemes. Selected microalgae strains, purposefully cultivated and processed for specific bioremoval applications, have the potential to provide significant improvements in dealing with the world-wide problems of metal pollution. In addition to strain selection, significant advances in the technology appear possible by improving biomass containment or immobilization techniques and by developing bioremoval process steps utilizing metabolically active microalgae cultures. The latter approach is especially attractive in applications where extremely low levels of residual metal ions are desired. This review summarizes the current literature, highlighting the potential benefits and problems associated with the development of novel algal-based bioremoval processes for the abatement of heavy metal pollution. PMID:14538057

  11. Heavy metal interactions with phosphatic clay: sorption and desorption behavior.

    Science.gov (United States)

    Singh, S P; Ma, L Q; Harris, W G

    2001-01-01

    Heavy metals produced and released during agricultural and industrial activities may pose a serious threat to the environment. This study investigated the effectiveness of phosphatic clay, a by-product of the phosphate mining industry, for immobilizing heavy metals (Pb(+2), Cd(+2), and Zn(+2)) from aqueous solutions. A batch equilibrium technique was adopted to evaluate metal sorption in the presence of 0.05 M KNO3 background electrolyte solution. The amounts of metals sorbed onto phosphatic clay decreased in the order Pb(+2) > Cd(+2) > Zn(+2). Desorption data suggest that a large fraction of metals sorbed onto phosphatic clay stayed intact under a wide variation in extracting solution pH (ranging from 3 to 10). Desorption rates were slowest for Pb followed by Cd and Zn. Only 8.1 to 23.1% of Pb, 8.4 to 45% of Cd, and 21.9 to 73.9% of Zn sorbed on phosphatic clay was mobilized by USEPA toxicity characteristic leaching procedure (TCLP) solutions at pH 2.93+/-0.05 and 4.93+/-0.05, respectively. Formation of fluoropyromorphite [Pb10(PO4)6(F2)], confirmed by scanning electron microscopy (SEM) and X-ray diffraction (XRD), after reaction of aqueous Pb with phosphatic clay suggested that precipitation remained the dominant mechanism for Pb removal from aqueous solution. In the case of aqueous Cd and Zn interaction with phosphatic clay, we are not able to confirm the formation of a new amorphous and/or crystalline phase on the basis of available information. Other possible sorption mechanisms for Cd and Zn may include sorption and coprecipitation. Thus, phosphatic clay may be an effective amendment for in situ immobilization of heavy metals in contaminated soils and sediments. PMID:11790002

  12. 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

  13. 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.

  14. Heavy metals occurrence in Italian food supplements

    OpenAIRE

    Brizio P.; Benedetto A.; Squadrone S.; Tarasco R.; Gavinelli S.; Pellegrino M.; Abete M. C.

    2013-01-01

    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 It...

  15. Geneticaly modified flax for heavy metal phytoremediation.

    Czech Academy of Sciences Publication Activity Database

    Najmanová, J.; Kotrba, P.; Macek, Tomáš; Macková, Martina

    Praha : VŠCHT, 2007 - (Macková, M.; Macek, T.; Demnerová, K.; Pazlar, V.; Nováková, M.), s. 167-168 ISBN 978-80-7080-026-3. [Symposium on Biosorption and Bioremediation /4./. Praha (CZ), 26.08.2007-30.08.2007] R&D Projects: GA MŠk 1M06030 Grant ostatní: GA MŠk(CZ) OC 117 Institutional research plan: CEZ:AV0Z40550506 Keywords : phytoremediation * heavy metals * glutathione * flax * transformation Subject RIV: EI - Biotechnology ; Bionics

  16. Natural radionuclides and heavy metals in soils

    International Nuclear Information System (INIS)

    The vertical distribution of radium-226, lead-210 uranium and thorium and some heavy metals in three types of soil (brown formed from loess, podsolic formed from loess and podsolic formed from loamy sands) in the rural regions of Poland down to the depth of 160 cm and in the virgin soils of Alaska down to the depth of 100 cm has been studied and results are presented. The results are discussed. (M.G.B.)

  17. Heavy Metals Stimulate Human LINE-1 Retrotransposition

    OpenAIRE

    Roy-engel, Astrid M.; Deininger, Prescott L.; Lakisha Moore; Kale, Shubha P.

    2005-01-01

    L1 and Alu elements are among the most active retroposons (mobile elements) in the human genome. Several human diseases, including certain forms of breast cancer and leukemia, are associated with L1 and Alu insertions in functionally important areas of the genome. We present data demonstrating that environmental pollutants, such as heavy metals, can stimulate L1 retrotransposition in a tissue culture system using two different types of assays. The response to these agents was equivalent when ...

  18. Polution of the environment by heavy metals

    International Nuclear Information System (INIS)

    An overview is given of the problems caused by pollution of the environment by heavy metals and the important role played by nuclear examination methods such as activation analysis and particle induced X-ray emission. A number of examples taken from work initiated by the interuniversitair Reactor Instituut, demonstrate that this research should be continued and extended, particularly in relation to the expected increase in the use of coal for energy generation in electricity centres. (C.F.)

  19. 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.

  20. 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.

  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. Growth and heavy metals accumulation potential of microalgae grown in sewage wastewater and petrochemical effluents.

    Science.gov (United States)

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

    2011-08-15

    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. PMID:22545355

  3. 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.

  4. [The concentration of heavy metals from a micromycete biomass using zeolites].

    Science.gov (United States)

    Oliferchuk, V P; Lebedinets, L O; Sukhomlin, M N

    1996-01-01

    A method is suggested to be used for removing ions of heavy metals from the micromycete biomass immobilized on a porous carrier after exposition of this biomass in sewage water of a settler of a precise machine-building enterprise. A complex of micromyctes has embraced species belonging to Ulocladium, Arthrinium and Humicola genera. Optimal concentration of soda ash for efficient removal of ions of metals adsorbed on the micromycete biomass is elaborated. Later the H(+)- form of zeolites is used to concentration of metals from the soda solution. This permits putting the metals back to the industry and micromycete mass to decontamination tanks. PMID:8777467

  5. Metal Cutting for Large Component Removal

    International Nuclear Information System (INIS)

    Decommissioning of commercial nuclear power plants presents technological challenges. One major challenge is the removal of large components mainly consisting of the reactor vessel, steam generators and pressurizer. In order to remove and package these large components nozzles must be cut from the reactor vessel to precise tolerances. In some cases steam generators must be segmented for size and weight reduction. One innovative technology that has been used successfully at several commercial nuclear plant decommissioning is diamond wire sawing. Diamond wire sawing is performed by rotating a cable with diamond segments attached using a flywheel approximately 24 inches in diameter driven remotely by a hydraulic pump. Tension is provided using a gear rack drive which also takes up the slack in the wire. The wire is guided through the use of pulleys keeps the wire in a precise location. The diamond wire consists of 1/4 inch aircraft cable with diamond beads strung over the cable separated by springs and brass crimps. Standard wire contains 40 diamond beads per meter and can be made to any length. Cooling the wire and controlling the spread of contamination presents significant challenges. Under normal circumstances the wire is cooled and the cutting kerf cleaned by using water. In some cases of reactor nozzle cuts the use of water is prohibited because it cannot be controlled. This challenge was solved by using liquid Carbon Dioxide as the cooling agent. The liquid CO2 is passed through a special nozzle which atomizes the liquid into snowflakes which is introduced under pressure to the wire. The snowflakes attach to the wire keeping it cool and to the metal shavings. As the CO2 and metal shavings are released from the wire due to its fast rotation, the snowflakes evaporate leaving only the fine metal shavings as waste. Secondary waste produced is simply the small volume of fine metal shavings removed from the cut surface. Diamond wire sawing using CO2 cooling has been employed for cutting the reactor nozzles at San Onofre Unit 1 and at Connecticut Yankee. These carbon steel nozzles ranged up to 54 inch diameter with a 15 inch thick wall and an interior stainless cladding. Diamond wire sawing using traditional water cooling has been used to segment the reactor head at Rancho Seco and for cutting reactor nozzles and control rod drive tubes at Dairyland Power's Lacrosse BWR project. Advantages: - ALARA: All cutting is preformed remotely significantly reducing dose. Stringing of wires is accomplished using long handle tools. - Secondary waste is reduced to just the volume of material cut with the diamond wire. - The potential for airborne contamination is eliminated. Due to the flexibility of the wire, any access restrictions and interferences can be accommodated using pulleys and long handle tools. - The operation is quiet. Disadvantages: - With Liquid Carbon Dioxide cooling and cleaning, delivery of the material must be carefully planned. The longer the distance from the source to the cut area, the greater the chance for pressure drop and subsequent problems with line freezing. - Proper shrouding and ventilation are required for environmental reasons. In each case, the metal structures were cut at a precise location. Radiation dose was reduced significantly by operating the equipment from a remote location. The cuts were very smooth and completed on schedule. Each project must be analyzed individually and take into account many factors including access, radiological conditions, environmental conditions, schedule requirements, packaging requirements and size of cuts

  6. 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 metals...

  7. 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.)

  8. 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)

  9. Investigation of possibilities for high heavy metal content sludges utilization by incorporating them in concrete products

    OpenAIRE

    Simeonova A.; Petkov A.; Delchev N.; Balgaranova J.

    2006-01-01

    The safe removal of sludge, obtained during the surface treatment of different metal products, is a serious environmental problem. These sludges are usually characterized by a high content of heavy metals (Pb, Cu, Ni, Zn, Cr, Cd, Mn), low quality and are obtained in many small industrial units in the whole country, which makes their centralized treatment difficult. In world practice, different methods are used for component fixation of such sludge, in the aim to prevent leaching of the metals...

  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. 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)

  12. 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.

  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. On the structure of heavy metals

    International Nuclear Information System (INIS)

    The properties of the last series of Mendeleef's table are compared with those of the elements of the preceding series. This comparison suggests an electronic structure of the 'transition metal' type, with narrow bands, at the beginning of this series (up to certain phases at least of plutonium); then of the rare earth metal type, with independent non-saturated internal layers, further on in the series. The 5 f orbits seem to play an important part in these two types of structure, from uranium on. A more detailed study of the very heavy elements (americium and beyond) and alloys would allow these conclusions to be confirmed. Certain general points, concerning the nature of homopolar connections and paramagnetism in the transition metals, are developed in an additional section. (author)

  15. Heavy metals binding properties of esterified lemon.

    Science.gov (United States)

    Arslanoglu, Hasan; Altundogan, Hamdi Soner; Tumen, Fikret

    2009-05-30

    Sorption of Cd(2+), Cr(3+), Cu(2+), Ni(2+), Pb(2+) and Zn(2+) onto a carboxyl groups-rich material prepared from lemon was investigated in batch systems. The results revealed that the sorption is highly pH dependent. Sorption kinetic data indicated that the equilibrium was achieved in the range of 30-240 min for different metal ions and sorption kinetics followed the pseudo-second-order model for all metals studied. Relative sorption rate of various metal cations was found to be in the general order of Ni(2+)>Cd(2+)>Cu(2+)>Pb(2+)>Zn(2+)>Cr(3+). The binding characteristics of the sorbent for heavy metal ions were analyzed under various conditions and isotherm data was accurately fitted to the Langmuir equation. The metal binding capacity order calculated from Langmuir isotherm was Pb(2+)>Cu(2+)>Ni(2+)>Cd(2+)>Zn(2+)>Cr(3+). The mean free energy of metal sorption process calculated from Dubinin-Radushkevich parameter and the Polanyi potential was found to be in the range of 8-11 kJ mol(-1) for the metals studied showing that the main mechanism governing the sorption process seems to be ion exchange. The basic thermodynamic parameters of metals ion sorption process were calculated by using the Langmuir constants obtained from equilibration study. The DeltaG degrees and DeltaH degrees values for metals ion sorption on the lemon sorbent showed the process to be spontaneous and exothermic in nature. Relatively low DeltaH degrees values revealed that physical adsorption significantly contributed to the mechanism. PMID:18980807

  16. Heavy metals binding properties of esterified lemon

    International Nuclear Information System (INIS)

    Sorption of Cd2+, Cr3+, Cu2+, Ni2+, Pb2+ and Zn2+ onto a carboxyl groups-rich material prepared from lemon was investigated in batch systems. The results revealed that the sorption is highly pH dependent. Sorption kinetic data indicated that the equilibrium was achieved in the range of 30-240 min for different metal ions and sorption kinetics followed the pseudo-second-order model for all metals studied. Relative sorption rate of various metal cations was found to be in the general order of Ni2+ > Cd2+ > Cu2+ > Pb2+ > Zn2+ > Cr3+. The binding characteristics of the sorbent for heavy metal ions were analyzed under various conditions and isotherm data was accurately fitted to the Langmuir equation. The metal binding capacity order calculated from Langmuir isotherm was Pb2+ > Cu2+ > Ni2+ > Cd2+ > Zn2+ > Cr3+. The mean free energy of metal sorption process calculated from Dubinin-Radushkevich parameter and the Polanyi potential was found to be in the range of 8-11 kJ mol-1 for the metals studied showing that the main mechanism governing the sorption process seems to be ion exchange. The basic thermodynamic parameters of metals ion sorption process were calculated by using the Langmuir constants obtained from equilibration study. The ?Go and ?Hoo and ?Ho values for metals ion sorption on the lemon sorbent showed the process to be spontaneous and exothermic in nature. Relatively low ?Ho values revealed that physical adsorption significantly contributed to the mechanism.

  17. Magnetoresistance in paramagnetic heavy fermion metals

    Science.gov (United States)

    Parihari, D.; Vidhyadhiraja, N. S.

    2009-10-01

    A theoretical study of magnetic field (h) effects on single-particle spectra and the transport quantities of heavy fermion metals in the paramagnetic phase is carried out. We have employed a non-perturbative local moment approach (LMA) to the asymmetric periodic Anderson model within the dynamical mean field framework. The lattice coherence scale ?L, which is proportional within the LMA to the spin-flip energy scale, and has been shown in earlier studies to be the energy scale at which crossover to single-impurity physics occurs, increases monotonically with increasing magnetic field. The many body Kondo resonance in the density of states at the Fermi level splits into two, with the splitting being proportional to the field itself. For h>=0, we demonstrate adiabatic continuity from the strongly interacting case to a corresponding non-interacting limit, thus establishing Fermi liquid behaviour for heavy fermion metals in the presence of a magnetic field. In the Kondo lattice regime, the theoretically computed magnetoresistance is found to be negative in the entire temperature range. We argue that such a result could be understood at T\\gtrsim \\omega _L by field-induced suppression of spin-flip scattering and at T\\lesssim \\omega _L through lattice coherence. The coherence peak in the heavy fermion resistivity diminishes and moves to higher temperatures with increasing field. Direct comparison of the theoretical results to the field dependent resistivity measurements in CeB6 yields good agreement.

  18. 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.

  19. 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.

  20. 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

  1. Application of Innovative Remediation Processes to Mining Effluents contaminated by Heavy Metals

    Directory of Open Access Journals (Sweden)

    Ubaldini S.

    2013-04-01

    Full Text Available The scope of the paper was to demonstrate the technical feasibility of the remediation processes by electrowinning and selective sequential precipitation, for toxic metals removal from acid mine drainage. By electrochemical experiments, high metals removal has been achieved: in particular, by Zn and Mn electrodeposition, it was possible to achieve about 93-99% Zn and Mn removal (as MnO2, with a relatively low energetic consumption. The principle of the heavy metals selective sequential precipitation is the combined application of sodium hydroxide solution and hydrogen sulfide produced by sulfate-reducing bacteria. For the hydrogen sulfide production the sulphate-reducing bacteria of genus Desulfovibrio was used. The selective sequential precipitation process reaches the selective precipitation of chosen metals with 99% efficiency – Fe, As, Al and Mn in the form of metal hydroxides, Cu and Zn as metal sulfides.

  2. Facultative hyperaccumulation of heavy metals and metalloids.

    Science.gov (United States)

    Pollard, A Joseph; Reeves, Roger D; Baker, Alan J M

    2014-03-01

    Approximately 500 species of plants are known to hyperaccumulate heavy metals and metalloids. The majority are obligate metallophytes, species that are restricted to metalliferous soils. However, a smaller but increasing list of plants are "facultative hyperaccumulators" that hyperaccumulate heavy metals when occurring on metalliferous soils, yet also occur commonly on normal, non-metalliferous soils. This paper reviews the biology of facultative hyperaccumulators and the opportunities they provide for ecological and evolutionary research. The existence of facultative hyperaccumulator populations across a wide edaphic range allows intraspecific comparisons of tolerance and uptake physiology. This approach has been used to study zinc and cadmium hyperaccumulation by Noccaea (Thlaspi) caerulescens and Arabidopsis halleri, and it will be instructive to make similar comparisons on species that are distributed even more abundantly on normal soil. Over 90% of known hyperaccumulators occur on serpentine (ultramafic) soil and accumulate nickel, yet there have paradoxically been few experimental studies of facultative nickel hyperaccumulation. Several hypotheses suggested to explain the evolution of hyperaccumulation seem unlikely when most populations of a species occur on normal soil, where plants cannot hyperaccumulate due to low metal availability. In such species, it may be that hyperaccumulation is an ancestral phylogenetic trait or an anomalous manifestation of physiological mechanisms evolved on normal soils, and may or may not have direct adaptive benefits. PMID:24467891

  3. 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.

  4. Heavy metal distribution in the Godavari River basin

    Energy Technology Data Exchange (ETDEWEB)

    Biksham, G. (Mineral Exploration Corp., Nagpur (India)); Subramanian, V.; Ramanathan, A.L. (Jawaharial Nehru Univ., New Delhi (India)); Van Grieken, R. (Univ. of Antwerp, Wilrijk (Belgium))

    Suspended and bed sediments collected from the entire region of the Godavari River basin were analyzed for Fe, Man, Cr, Cu, Ni, and Zn. There are pronounced temporal and spatial variations in the heavy metal distributions. The concentrations of heavy metals in the suspended sediments are significantly higher than the bed sediments. Throughout the basin heavy metals are enriched in the finer fractions (<2 {mu}m) of the bed sediments. The average heavy-metal composition of the sediments is higher when compared to the average Indian river sediments. Heavy-metal concentration in the two shallow cores collected shows, to some extent, the influence of urbanization. When compared to the other tropical Indian rivers such as the Krishna, the Godavari appears to be a significant contributor of heavy metals to the Bay of Bengal. Considering the enormous sediment load of the Godavari River - 170 million tons/yr, the heavy metal fluxes to the Bay of Bengal is very significant. Except for the Pranhita, other tributaries of the Godavari do not contribute significant loads of heavy metals. All the metals show high correlation among themselves and the correlation is more pronounced in suspended sediments than in the bed sediments. The heavy-metal distribution, fractionation, and its relationship with total suspended sediments and depth in various parts of the basin are discussed in detail.

  5. 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

  6. 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)

  7. 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...

  8. Brassinosteroids and Plant Responses to Heavy Metal Stress. An Overview

    OpenAIRE

    Miriam Núñez Vázquez; Yanelis Reyes Guerrero; Lisbel Martínez González; Walfredo Torres de la Noval

    2013-01-01

    Soil contamination with heavy metals has become a world-wide problem, leading to the loss in agricultural productivity. Plants have a remarkable ability to take up and accumulate heavy metals from their external environment and it is well known that high levels of heavy metals affect different physiological and metabolic processes. Brassinosteroids are considered as the sixth class of plant hormones and they are essential for plant growth and development. These compounds are able of inducing...

  9. Physical measurements of heavy metal filter performance

    International Nuclear Information System (INIS)

    Contrast, relative tube loading, and relative entrance exposure have been measured for a number of heavy metal filters (Gd, Ho, Yb, and W) at several filter thicknesses, tube voltages (70-100 kV), and phantom thicknesses (1.5-2.5 cm of aluminum). The rare-earth filters consistently gave higher contrast (relative to water) for air, CaCl2, iodine, and oil than the standard 2 mm of added aluminum, at a given tube voltage. It was found that the best filter choices gave a constant product of relative exposure and relative tube loading

  10. Biosorption of heavy metal by thermotolerant polymerproducing bacterial cells and the bioflocculant

    Directory of Open Access Journals (Sweden)

    Saithong Kaewchai

    2002-07-01

    Full Text Available Three strains of thermotolerant polymer-producing bacteria; Bacillus subtilis WD 90, Bacillus subtilis SM 29, and Enterobacter agglomerans SM 38 as well as their biofloculants were used to investigate on the adsorption of heavy metal, nickel and cadmium. The effects of pH and concentrations of heavy metal were investigated. The optimum pH for nickel and cadmium adsorption by the dried cells of E. agglomerans SM 38 were found to be 7.0 (25.5% removal and 8.0 (32% removal, respectively. For B. subtilis WD 90 and B. subtilis SM 29, the optimum pH at 8.0 exhibited the nickel removal of 27% and 25%, respectively, and cadmium removal of 28% and 28.5%, respectively. The heavy metal adsorption by the dried cells and wet cells of E. agglomerans SM 38 were slightly increased with increasing initial concentrations of nickel and cadmium up to 60 and 30 ppm, respectively. The bioflocculant of B. subtilis WD 90 and B. subtilis SM 29 showed the highest nickel removal of 90.7% and 87.0% respectively, while the cadmium removal was 90.9 and 91.4%, respectively. The optimum pH for adsorption of both nickel and cadmium by the bioflocculant of E. agglomerans SM 38 was 7.0 with the removal of 92.8 and 84.2%, respectively. The optimum nickel concentration for adsorption by the bioflocculant of E. agglomerans SM 38 was 10 ppm, with the removal of 92.5%, and rather stable up to 60 ppm. The optimum cadmium concentration for adsorption by the bioflocculant of B. subtilis SM 29 was 60 ppm at pH 8.0 with the removal of 85.7%. Therefore, the bioflocculant of the three isolates gave higher heavy metal adsorption than the cells.

  11. Nano sized carbonized waste biomass for heavy metal ion remediation

    Directory of Open Access Journals (Sweden)

    Mahajan Garima

    2014-12-01

    Full Text Available Utilization of agricultural waste material with approach to enhance the heavy metal remediation properties by carbonizing the biomass at nano size particles has been explored in present investigation from aqueous solutions. In this study the lignocellulosic, nitrogenous agricultural waste biomass Delbergia sissoo pods (DSP has been tried for sequestering of Cd (II, Pb (II and Ni (II metal ions from aqueous solutions. Batch experiments were performed for removal of targeted metal ions keeping in consideration the preliminary affecting parameters such as effect of adsorption dose, pH, initial metal ion concentration, stirring speed and contact time. The sorption studies were analyzed by using, Freundlic isotherm and Langmuir isotherm models. The kinetics of the process was evaluated by pseudo pseudo-first order and pseudo second order kinetic models. Studies reveal that the equilibrium was achieved with in 30 min of the contact time at optimized parameters. Analytical studies of biosorbent were done by means of FT-IR, SEM and XRD. Desorption experiments were carried out using HCl solution with a view to regenerate the spent adsorbent and to recover the adsorbed metal ions.

  12. Effect of pH on the heavy metal-clay mineral interaction

    Energy Technology Data Exchange (ETDEWEB)

    Altyn, O.; Oezbelge, H.O.; Dogu, T.; Oezbelge, T.A. [Middle East Technical Univ., Ankara (Turkey)

    1997-12-31

    Adsorption and ion exchange of Pb and Cd on the surface of kaolinite and montmorillonite were studied with a strong emphasis on the pH values of solutions containing heavy metal ions. The pH range studied was 2.5 - 9. For kaolinite at a clay/solution ratio of 1/10 (w/w), Pb removal changes from 20 to 30% for an initial Pb concentration of 1640 ppm, and Cd removal changes from 10 to 20% for an initial Cd concentration of 1809 ppm. Due to its high exchange capacity, montmorillonite can remove more heavy metal than kaolinite. Removal rates for montmorillonite can reach up to 90% for both Pb and Cd. In the pH range of 3-6, there is a plateau for the removal rates. At pH values higher than 6, removal seems to increase artificially due to the precipitation of heavy metals. Under similar conditions for both clays, the rate of removal of Pb is always higher than that of Cd. As the pH value decreases for montmorillonite, there is a strong tendency for decreased surface area and swelling, as indicated by BET surface area measurements, adsorbed layer thickness and pore size distribution data. In the range of pH values studied, X-ray diffraction analysis showed the appearance of a characteristic (001) peak for montmorillonite, indicating that the crystalline structure of the clay was intact during the experiments.

  13. Turning the volume down on heavy metals using tuned diatomite. A review of diatomite and modified diatomite for the extraction of heavy metals from water.

    Science.gov (United States)

    Danil de Namor, Angela F; El Gamouz, Abdelaziz; Frangie, Sofia; Martinez, Vanina; Valiente, Liliana; Webb, Oliver A

    2012-11-30

    Contamination of water by heavy metals is a global problem, to which an inexpensive and simple solution is required. Within this context the unique properties of diatomite and its abundance in many regions of the world have led to the current widespread interest in this material for water purification purposes. Defined sections on articles published on the use of raw and modified diatomite for the removal of heavy metal pollutants from water are critically reviewed. The capability of the materials as extracting agents for individual species and mixtures of heavy metals are considered in terms of the kinetics, the thermodynamics and the recyclability for both, the pollutant and the extracting material. The concept of 'selectivity' for the enrichment of naturally occurring materials such as diatomite through the introduction of suitable functionalities in their structure to target a given pollutant is emphasised. Suggestions for further research in this area are given. PMID:23062514

  14. 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 steps by ICP-MS, with the exception of mercury, detected by the direct analyser TDA-AAS. Only one sample exceed the European maximum limits for lead (3,00 mg/kg but warning levels of chromium (over 3,00 mg/Kg has been detected in three of them.

  15. Thermal and hydrometallurgical recovery methods of heavy metals from municipal solid waste fly ash

    Energy Technology Data Exchange (ETDEWEB)

    Kubo?ová, L., E-mail: lenka.kubonova@vsb.cz [VSB – Technical University of Ostrava, 17. listopadu 15/2172, 708 33 Ostrava (Czech Republic); Langová, Š. [VSB – Technical University of Ostrava, 17. listopadu 15/2172, 708 33 Ostrava (Czech Republic); Nowak, B.; Winter, F. [Institute of Chemical Engineering, Vienna University of Technology, Getreidemarkt 9/166, A-1060 Vienna (Austria)

    2013-11-15

    Highlights: • MSW fly ash was thermally and hydrometallurgically treated to remove heavy metals. • More than 90% of easy volatile heavy metals (Cd and Pb) were removed thermally. • More than 90% of Cd, Cr, Cu an Zn were removed by alkaline – acid leaching. • The best results were obtained for the solution of 3 M NaOH and 2 M H{sub 2}SO{sub 4}. - Abstract: Heavy metals in fly ash from municipal solid waste incinerators are present in high concentrations. Therefore fly ash must be treated as a hazardous material. On the other hand, it may be a potential source of heavy metals. Zinc, lead, cadmium, and copper can be relatively easily removed during the thermal treatment of fly ash, e.g. in the form of chlorides. In return, wet extraction methods could provide promising results for these elements including chromium and nickel. The aim of this study was to investigate and compare thermal and hydrometallurgical treatment of municipal solid waste fly ash. Thermal treatment of fly ash was performed in a rotary reactor at temperatures between 950 and 1050 °C and in a muffle oven at temperatures from 500 to 1200 °C. The removal more than 90% was reached by easy volatile heavy metals such as cadmium and lead and also by copper, however at higher temperature in the muffle oven. The alkaline (sodium hydroxide) and acid (sulphuric acid) leaching of the fly ash was carried out while the influence of temperature, time, concentration, and liquid/solid ratio were investigated. The combination of alkaline-acidic leaching enhanced the removal of, namely, zinc, chromium and nickel.

  16. Limitations for heavy metal release during thermo-chemical treatment of sewage sludge ash

    International Nuclear Information System (INIS)

    Phosphate recycling from sewage sludge can be achieved by heavy metal removal from sewage sludge ash (SSA) producing a fertilizer product: mixing SSA with chloride and treating this mixture (eventually after granulation) in a rotary kiln at 1000 ± 100 deg. C leads to the formation of volatile heavy metal compounds that evaporate and to P-phases with high bio-availability. Due to economical and ecological reasons, it is necessary to reduce the energy consumption of this technology. Generally, fluidized bed reactors are characterized by high heat and mass transfer and thus promise the saving of energy. Therefore, a rotary reactor and a fluidized bed reactor (both laboratory-scale and operated in batch mode) are used for the treatment of granulates containing SSA and CaCl2. Treatment temperature, residence time and - in case of the fluidized bed reactor - superficial velocity are varied between 800 and 900 deg. C, 10 and 30 min and 3.4 and 4.6 m s-1. Cd and Pb can be removed well (>95 %) in all experiments. Cu removal ranges from 25% to 84%, for Zn 75-90% are realized. The amount of heavy metals removed increases with increasing temperature and residence time which is most pronounced for Cu. In the pellet, three major reactions occur: formation of HCl and Cl2 from CaCl2; diffusion and reaction of these gases with heavy metal compounds; side reactions from heavy metal compounds with matrix material. Although, heat and mass tranix material. Although, heat and mass transfer are higher in the fluidized bed reactor, Pb and Zn removal is slightly better in the rotary reactor. This is due the accelerated migration of formed HCl and Cl2 out of the pellets into the reactor atmosphere. Cu is apparently limited by the diffusion of its chloride thus the removal is higher in the fluidized bed unit.

  17. Thermal and hydrometallurgical recovery methods of heavy metals from municipal solid waste fly ash

    International Nuclear Information System (INIS)

    Highlights: • MSW fly ash was thermally and hydrometallurgically treated to remove heavy metals. • More than 90% of easy volatile heavy metals (Cd and Pb) were removed thermally. • More than 90% of Cd, Cr, Cu an Zn were removed by alkaline – acid leaching. • The best results were obtained for the solution of 3 M NaOH and 2 M H2SO4. - Abstract: Heavy metals in fly ash from municipal solid waste incinerators are present in high concentrations. Therefore fly ash must be treated as a hazardous material. On the other hand, it may be a potential source of heavy metals. Zinc, lead, cadmium, and copper can be relatively easily removed during the thermal treatment of fly ash, e.g. in the form of chlorides. In return, wet extraction methods could provide promising results for these elements including chromium and nickel. The aim of this study was to investigate and compare thermal and hydrometallurgical treatment of municipal solid waste fly ash. Thermal treatment of fly ash was performed in a rotary reactor at temperatures between 950 and 1050 °C and in a muffle oven at temperatures from 500 to 1200 °C. The removal more than 90% was reached by easy volatile heavy metals such as cadmium and lead and also by copper, however at higher temperature in the muffle oven. The alkaline (sodium hydroxide) and acid (sulphuric acid) leaching of the fly ash was carried out while the influence of temperature, time, concentration, and liquid/solid ratio were investigated. The combination of alkaline-acidic leaching enhanced the removal of, namely, zinc, chromium and nickel

  18. Leaching of heavy metals from steelmaking slags

    Directory of Open Access Journals (Sweden)

    Gomes, J. F. P

    2006-12-01

    Full Text Available Leaching tests with EAF and Ladle slags were performed, using a flow through test 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, an 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, slag samples submitted to these trials presented very low total leaching levels. The most extracted elements are calcium and magnesium. Nevertheless, in flow-through 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.

    Este articulo contiene los resultados obtenidos en ensayos de lixiviación de escorias de acero (horno electrico y cuchara ejecutados siguiendo la metodologia de flujo dinámico así como el ensayo normalizado DIN 38414-S4. El primer ensayo intenta simular el comportamiento de lixiviación de las escorias en vertedero. Para las escorias ensayadas se han complementado los ensayos con el análisis químico de los lixiviados y se ha verificado un aumento de la liberación de metales pesados. El ensayo DIN 38414-S4 se ha utilizado para evaluar la lixiviación por agua de metales pesados, en muestras de escorias originales. Despues de un año de ensayos, se han observado niveles muy bajos de lixiviación. Los elementos mas lixiviados han sido calcio y magnesio. No obstante, en los ensayos de flujo dinámico, el calcio y el magnesio lixiviados de las escorias sólidas era menor de 0,5% y el resto de los otros metales era inferior a 0,1%. Los lixiviados obtenidos con el ensayo DIN 38414-S4 presentan, como era de esperar, valores mas elevados de los lixiviados: casi, 5 % para el calcio y casi, 1 % para todos los demás metales.

  19. Acid leaching of heavy metals from bentonite clay, used in the cleaning of acid mine drainage

    Scientific Electronic Library Online (English)

    F., Enslin; L., van der Mey; F., Waanders.

    2010-04-01

    Full Text Available Heavy metals and sulphates in acid mine drainage (AMD) can be adsorbed onto bentonite clay, leaving clean water and a heavy metal loaded clay precipitate as products. Due to the toxicity of heavy metals, the clay could not be disposed of safely in the past. A method was thus required to remove the h [...] eavy metal content from the clay. Acid leaching was proposed to liberate the heavy metals from the loaded clay. Sulphuric, nitric and hydrochloric acid were considered as lixiviants. Loaded clay samples were leached over a range of pH values from 1 to 3.5 to identify an optimum leaching condition. From the results it was found that metals can be recovered from loaded bentonite clay by means of acid leaching and the optimum pH for heavy metal liberation was found to be 2.5, with uranium as an exception, being optimally leached at a pH of 3. This allows for the possibility of selective leaching. Furthermore, X-ray diffraction analyses indicated that the clay structure did not deteriorate significantly during acid leaching, suggesting that the bentonite could be reused. The treatment of AMD with bentonite clay, and subsequent acid leaching of the clay, is a sustainable solution, and current outcomes could possibly lead to industrial implementation of the process during water purifying and metal recovery from waste streams.

  20. Turning the volume down on heavy metals using tuned diatomite. A review of diatomite and modified diatomite for the extraction of heavy metals from water

    International Nuclear Information System (INIS)

    Highlights: ? Critical assessment of published work on raw and modified diatomites. ? Counter-ion effect on the extraction of heavy metal speciation by diatomite. ? Selection of the counter-ion by the use of existing thermodynamic data. ? Enrichment of diatomites by attaching heavy metal selective functionalities. ? Supramolecular chemistry for conferring selectivity to diatomites. - Abstract: Contamination of water by heavy metals is a global problem, to which an inexpensive and simple solution is required. Within this context the unique properties of diatomite and its abundance in many regions of the world have led to the current widespread interest in this material for water purification purposes. Defined sections on articles published on the use of raw and modified diatomite for the removal of heavy metal pollutants from water are critically reviewed. The capability of the materials as extracting agents for individual species and mixtures of heavy metals are considered in terms of the kinetics, the thermodynamics and the recyclability for both, the pollutant and the extracting material. The concept of ‘selectivity’ for the enrichment of naturally occurring materials such as diatomite through the introduction of suitable functionalities in their structure to target a given pollutant is emphasised. Suggestions for further research in this area are given.

  1. Turning the volume down on heavy metals using tuned diatomite. A review of diatomite and modified diatomite for the extraction of heavy metals from water

    Energy Technology Data Exchange (ETDEWEB)

    Danil de Namor, Angela F., E-mail: A.Danil-De-Namor@surrey.ac.uk [Instituto Nacional de Tecnologia Industrial, Parque Tecnologico Industrial Miguelete, Buenos Aires (Argentina); Department of Chemistry, University of Surrey, Guildford, Surrey GU2 7XH (United Kingdom); El Gamouz, Abdelaziz [Department of Chemistry, University of Surrey, Guildford, Surrey GU2 7XH (United Kingdom); Frangie, Sofia; Martinez, Vanina; Valiente, Liliana [Instituto Nacional de Tecnologia Industrial, Parque Tecnologico Industrial Miguelete, Buenos Aires (Argentina); Webb, Oliver A. [Department of Chemistry, University of Surrey, Guildford, Surrey GU2 7XH (United Kingdom)

    2012-11-30

    Highlights: Black-Right-Pointing-Pointer Critical assessment of published work on raw and modified diatomites. Black-Right-Pointing-Pointer Counter-ion effect on the extraction of heavy metal speciation by diatomite. Black-Right-Pointing-Pointer Selection of the counter-ion by the use of existing thermodynamic data. Black-Right-Pointing-Pointer Enrichment of diatomites by attaching heavy metal selective functionalities. Black-Right-Pointing-Pointer Supramolecular chemistry for conferring selectivity to diatomites. - Abstract: Contamination of water by heavy metals is a global problem, to which an inexpensive and simple solution is required. Within this context the unique properties of diatomite and its abundance in many regions of the world have led to the current widespread interest in this material for water purification purposes. Defined sections on articles published on the use of raw and modified diatomite for the removal of heavy metal pollutants from water are critically reviewed. The capability of the materials as extracting agents for individual species and mixtures of heavy metals are considered in terms of the kinetics, the thermodynamics and the recyclability for both, the pollutant and the extracting material. The concept of 'selectivity' for the enrichment of naturally occurring materials such as diatomite through the introduction of suitable functionalities in their structure to target a given pollutant is emphasised. Suggestions for further research in this area are given.

  2. Removal of heavy metals from water by zeolite mineral chemically modified. Mercury as a particular case; Remocion de metales pesados del agua por mineral zeolitico quimicamente modificado. Mercurio como un caso particular

    Energy Technology Data Exchange (ETDEWEB)

    Gebremedhin H, T

    2002-07-01

    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. Selective removal of dissolved toxic metals from groundwater by ultrafiltration in combination with chemical treatment

    International Nuclear Information System (INIS)

    An alternative in-place process for the removal of toxic heavy metals based on aqueous solution chemistry and treatment is being evaluated under the auspices of the Emerging Technologies Program funded through the USEPA's Superfund Innovative Technology Evaluation Program. The technique involves the contacting of aqueous solutions containing the heavy metal contaminants with low concentrations of polyelectrolytes, and then removing the polyelectrolytes from solution with ultrafiltration membranes. The first phase of the program is considered complete. Success has been achieved for the separation of soluble, heavy metal ions: cadmium, lead, and mercury even in the presence of an organic compound, toluene. Removal was successful at alkaline conditions, using any combination of membrane material or polyelectrolyte. Arsenic was removed, but not effectively, using the current polyelectrolytes, simply because arsenic is present as an anionic species rather than as a cationic species. Optimization of the process variables is nearing completion and pilot and field testing will take place in the second year of the program to verify the process under realistic conditions and to establish process economics

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

    OpenAIRE

    Austin Kanayo ASIAGWU; Patrice-Anthony-Chudi OKOYE; Orji IFEOMA; Patrick Ejo OMUKU

    2009-01-01

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

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

    Directory of Open Access Journals (Sweden)

    Austin Kanayo ASIAGWU

    2009-07-01

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

  6. Heavy metal distribution in the Godavari River basin

    Science.gov (United States)

    Biksham, G.; Subramanian, V.; Ramanathan, A. L.; van Grieken, R.

    1991-03-01

    Suspended and bed sediments collected from the entire region of the Godavari River basin were analyzed for Fe, Mn, Cr, Cu, Ni, and Zn. There are pronounced temporal and spatial variations in the heavy metal distributions. The concentrations of heavy metals in the suspended sediments are significantly higher than the bed sediments. Throughout the basin heavy metals are enriched in the finer fractions (river sediments. Heavy-metal concentration in the two shallow cores collected shows, to some extent, the influence of urbanization. When compared to the other tropical Indian rivers such as the Krishna, the Godavari appears to be a significant contributor of heavy metals to the Bay of Bengal. Considering the enormous sediment load of the Godavari River—170 million tons/yr, the heavy metal fluxes to the Bay of Bengal is very significant. Except for the Pranhita, other tributaries of the Godavari do not contribute significant loads of heavy metals. All the metals show high correlation among themselves and the correlation is more pronounced in suspended sediments than in the bed sediments. The heavy-metal distribution, fractionation, and its relationship with total suspended sediments and depth in various parts of the basin are discussed in detail.

  7. Bioremediation of heavy metal-contaminated effluent using optimized activated sludge bacteria

    Science.gov (United States)

    Bestawy, Ebtesam El.; Helmy, Shacker; Hussien, Hany; Fahmy, Mohamed; Amer, Ranya

    2013-03-01

    Removal of heavy metals from contaminated domestic-industrial effluent using eight resistant indigenous bacteria isolated from acclimatized activated sludge was investigated. Molecular identification using 16S rDNA amplification revealed that all strains were Gram-negative among which two were resistant to each of copper, cadmium and cobalt while one was resistant to each of chromium and the heavy metal mixture. They were identified as Enterobacter sp. (Cu1), Enterobacter sp. (Cu2), Stenotrophomonas sp. (Cd1), Providencia sp. (Cd2), Chryseobacterium sp. (Co1), Comamonas sp. (Co2), Ochrobactrum sp. (Cr) and Delftia sp. (M1) according to their resistance pattern. Strains Cu1, Cd1, Co2 and Cr were able to resist 275 mg Cu/l, 320 mg Cd/l, 140 mg Co/l and 29 mg Cr/l respectively. The four resistant strains were used as a mixture to remove heavy metals (elevated concentrations) and reduce the organic load of wastewater effluent. Results revealed that using the proposed activated sludge with the resistant bacterial mixture was more efficient for heavy metal removal compared to the activated sludge alone. It is therefore recommended that the proposed activated sludge system augmented with the acclimatized strains is the best choice to ensure high treatment efficiency and performance under metal stresses especially when industrial effluents are involved.

  8. HEAVY METALS IN MIDDLE NITRA RIVERSIDE

    Directory of Open Access Journals (Sweden)

    Silvia ?éryová

    2012-02-01

    Full Text Available Present state of environment is widely affected by various impacts of man which significantly eliminate negative affecting of its influence on the environment. In the past this fact was not so implemented and thus there was uncontrolled escape of contaminants of organic, but also inorganic origin into various components of environment. The most sensitive component is water ecosystem and its close plates (base sediments, banks sediments and biosphere near the flows. River Nitra ranks among the most affected water ecosystems in SR that was in 1965 the recipient of sludge, that was by accident in Zemianske Kosto?any uncontrolled spilled into the river with aftermath of long-term contamination of all sub-components in ecosystem, mainly by heavy metals (Hg, As, Pb, etc.. Soil contamination by Cd and Hg was analytically confirmed. The contents of these risk elements in soil extract of aqua regia 1.85 - 3.7 fold (Cd and 4.57- 36.3 fold (Hg exceeded the limit values (0.4 mg.kg-1 and 0.15 mg.kg-1 respectively given by the legislative. Other metals exceeding limit values were lead (1.064 - 1.072 fold, zinc (1.096 - 1.192 fold and chromium (1.172 – 1.644 fold. From assessed soil content of heavy metals only bioavailable forms of Pb determined in soil extract by NH4NO3 2.0 - 3.3 fold exceeded the limit value 0.1 mg.kg-1.

  9. A combination of bioleaching and bioprecipitation for deep removal of contaminating metals from dredged sediment

    Energy Technology Data Exchange (ETDEWEB)

    Fang Di, E-mail: dfang@ouc.edu.cn [Department of Environmental Engineering, Ocean University of China, Qingdao 266100 (China); State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, Nanjing 210008 (China); Zhang Ruichang [Department of Environmental Engineering, Ocean University of China, Qingdao 266100 (China); Zhou Lixiang [Department of Environmental Engineering, Nanjing Agricultural University, Nanjing 210095 (China); Li Jie [Department of Environmental Engineering, Ocean University of China, Qingdao 266100 (China)

    2011-08-15

    Highlights: {yields} Bioleaching-bioprecipitation can deeply cleanup sediment-borne metal contaminants. {yields} Bioleaching results in a sufficient solubilisation of sediment-borne metals. {yields} Bioprecipitation removes most of solubilised metals from sediment leachate at pH 3.7. {yields} Bioremoval of soluble Zn, Cu and Cr is due to the formation of ZnS, Cu{sub 2}S and CrOOH. {yields} Alkalization of bioleached sediment by Ca(OH){sub 2} excludes the risk of re-acidification. - Abstract: A linked microbial process comprising bioleaching with sulfate-oxidizing bacteria and bioprecipitation with sulfate-reducing bacteria operating sequentially was investigated to deeply remove contaminating metals from dredged sediment. The results showed that sediment bioleaching resulted in a sharp decrease in sediment pH from an initial pH {approx}7.6 to pH {approx}2.5 within 10-20 days, approximately 65% of the main heavy metals present (Zn + Cu + Cr) were solubilized, and most of the unsolubilized metals existed in residual form of sediment. The acidic leachate that resulted from sediment bioleaching was efficiently stripped of metal sulfates using a bioprecipitation reactor when challenged with influent as low as pH {approx}3.7. More than 99% of Zn{sup 2+}, 99% of Cu{sup 2+} and 90% of Cr{sup 3+} were removed from the leachate, respectively, due to the formation of ZnS, Cu{sub 2}S and CrOOH precipitates, as confirmed by SEM-EDS and XRD detection. It was also found that alkalization of bioleached sediment using Ca(OH){sub 2} excluded the risk of sediment re-acidification. The ability of the combined process developed in this study to deeply remove heavy metals in insoluble sulfides or hydroxides forms makes it particularly attractive for the treatment of different types of metal contaminants.

  10. A combination of bioleaching and bioprecipitation for deep removal of contaminating metals from dredged sediment

    International Nuclear Information System (INIS)

    Highlights: ? Bioleaching-bioprecipitation can deeply cleanup sediment-borne metal contaminants. ? Bioleaching results in a sufficient solubilisation of sediment-borne metals. ? Bioprecipitation removes most of solubilised metals from sediment leachate at pH 3.7. ? Bioremoval of soluble Zn, Cu and Cr is due to the formation of ZnS, Cu2S and CrOOH. ? Alkalization of bioleached sediment by Ca(OH)2 excludes the risk of re-acidification. - Abstract: A linked microbial process comprising bioleaching with sulfate-oxidizing bacteria and bioprecipitation with sulfate-reducing bacteria operating sequentially was investigated to deeply remove contaminating metals from dredged sediment. The results showed that sediment bioleaching resulted in a sharp decrease in sediment pH from an initial pH ?7.6 to pH ?2.5 within 10-20 days, approximately 65% of the main heavy metals present (Zn + Cu + Cr) were solubilized, and most of the unsolubilized metals existed in residual form of sediment. The acidic leachate that resulted from sediment bioleaching was efficiently stripped of metal sulfates using a bioprecipitation reactor when challenged with influent as low as pH ?3.7. More than 99% of Zn2+, 99% of Cu2+ and 90% of Cr3+ were removed from the leachate, respectively, due to the formation of ZnS, Cu2S and CrOOH precipitates, as confirmed by SEM-EDS and XRD detection. It was also found that alkalization of bund that alkalization of bioleached sediment using Ca(OH)2 excluded the risk of sediment re-acidification. The ability of the combined process developed in this study to deeply remove heavy metals in insoluble sulfides or hydroxides forms makes it particularly attractive for the treatment of different types of metal contaminants.

  11. Highly ordered three-dimensional macroporous carbon spheres for determination of heavy metal ions

    International Nuclear Information System (INIS)

    Highlights: ? Highly ordered three dimensional macroporous carbon spheres (MPCSs) were prepared. ? MPCS was covalently modified by cysteine (MPCS–CO–Cys). ? MPCS–CO–Cys was first time used in electrochemical detection of heavy metal ions. ? Heavy metal ions such as Pb2+ and Cd2+ can be simultaneously determined. -- Abstract: An effective voltammetric method for detection of trace heavy metal ions using chemically modified highly ordered three dimensional macroporous carbon spheres electrode surfaces is described. The highly ordered three dimensional macroporous carbon spheres were prepared by carbonization of glucose in silica crystal bead template, followed by removal of the template. The highly ordered three dimensional macroporous carbon spheres were covalently modified by cysteine, an amino acid with high affinities towards some heavy metals. The materials were characterized by physical adsorption of nitrogen, scanning electron microscopy, and transmission electron microscopy techniques. While the Fourier-transform infrared spectroscopy was used to characterize the functional groups on the surface of carbon spheres. High sensitivity was exhibited when this material was used in electrochemical detection (square wave anodic stripping voltammetry) of heavy metal ions due to the porous structure. And the potential application for simultaneous detection of heavy metal ions was also investigated.

  12. Heavy metal pollution in aquatic ecosystems and its phytoremediation using wetland plants: An ecosustainable approach

    Energy Technology Data Exchange (ETDEWEB)

    Rai, P.K. [Mizoram Central University, Tanhril (India). School for Earth Science & Natural Resource Management

    2008-07-01

    This review addresses the global problem of heavy metal pollution originating from increased industrialization and urbanization and its amelioration by using wetland plants both in a microcosm as well as natural/field condition. This review mentions salient features of wetland ecosystems, their vegetation component, and the pros and cons involved in heavy metal removal. Wetland plants are preferred over other bio-agents due to their low cost, frequent abundance in aquatic ecosystems, and easy handling. Constructed wetlands proved to be effective for the abatement of heavy metal pollution from acid mine drainage; landfill leachate; thermal power; and municipal, agricultural, refinery, and chlor-alkali effluent. the physicochemical properties of wetlands provide many positive attributes for remediating heavy metals. Typha, Phragmites, Eichhornia, Azolla, Lemna, and other aquatic macrophytes are some of the potent wetland plants for heavy metal removal. Biomass disposal problem and seasonal growth of aquatic macrophytes are some limitations in the transfer of phytoremediation technology from the laboratory to the field. However, the disposed biomass of macrophytes may be used for various fruitful applications. An ecosustainable model has been developed through the author's various works, which may ameliorate some of the limitations. The creation of more areas for phytoremediation may also aid in wetlands conservation. Genetic engineering and biodiversity prospecting of endangered wetland plants are important future prospects in this regard.

  13. Solvent extraction aplied to the recovery of heavy metals from galvanic sludges

    OpenAIRE

    Silva, João Eudes da; Paiva, A. P.; Delfim SOARES; Labrincha, J. A.; De Castro, F.

    2005-01-01

    In this study, a hydrometallurgical treatment involving the solvent extraction and recovery of some heavy metals from a sulphuric acid leach solution of galvanic sludge, using di-(2-ethylhexyl)-phosphoric acid (D2EHPA) and bis-(2,4,4- trimethylpentyl)-phosphinic acid (Cyanex 272), both diluted in kerosene, has been investigated. The preliminary tests revealed the necessity to remove other metal species than zinc and nickel, contained in the leach solution, and therefore, processes to...

  14. The efficiency of vermiculite as natural sorbent for heavy metals. Application to a contaminated soil

    OpenAIRE

    Abollino, Ornella; Giacomino, Agnese; Malandrino, Mery; Mentasti, Edoardo

    2007-01-01

    Vermiculite is a natural clay that has many applications as acoustic and thermal insulator, additive in concrete and plaster, fertilizer carrier and adsorbent. Moreover, clay minerals have been studied as adsorbent materials to remove heavy metals from industrial and/or municipal waste waters. In this work we have investigated the possibility to apply vermiculite for the clean-up of extracts resulting from the application of soil washing to a metal-contaminated soil collected from a polluted ...

  15. Heavy Metal Music and Reckless Behavior among Adolescents.

    Science.gov (United States)

    Arnett, Jeffrey

    1991-01-01

    Fifty-four male and 30 female adolescents who like heavy metal music were compared on various outcome variables to 56 male and 105 female peers who do not like it. Those who like heavy metal report a wider range of reckless behavior than those who do not like it. (SLD)

  16. ENZYME-MEDIATED TRANSFORMATIONS OF HEAVY METALS/METALLOIDS

    Science.gov (United States)

    A major emphasis has been placed on the bioremediation of organic compounds and their fate and transport throughout the environment. However, another important class of chemicals polluting our environment are inorganic, particularly heavy metals and metalloids. Heavy metals are elements of the Per...

  17. BIOACCUMULATION OF HEAVY METALS BY LITTORAL AND PELAGIC MARINE ORGANISMS

    Science.gov (United States)

    Marine organisms appear to be useful indicators of heavy metal pollution in the marine environment. In order to test this concept, research was performed to determine the levels of heavy metals in selected indicator organisms. Several approaches were used. The first was to select...

  18. A magnetic record of heavy metal pollution in the Yangtze River subaqueous delta

    Energy Technology Data Exchange (ETDEWEB)

    Dong, Chenyin [State Key Laboratory of Estuarine and Coastal Research, East China Normal University, Shanghai 200062 (China); Zhang, Weiguo, E-mail: wgzhang@sklec.ecnu.edu.cn [State Key Laboratory of Estuarine and Coastal Research, East China Normal University, Shanghai 200062 (China); Ma, Honglei [State Key Laboratory of Estuarine and Coastal Research, East China Normal University, Shanghai 200062 (China); Feng, Huan [Department of Earth and Environmental Studies, Montclair State University, NJ 07043 (United States); Lu, Honghua [Department of Geography, College of Resources and Environmental Science, East China Normal University, Shanghai 200241 (China); Dong, Yan [State Key Laboratory of Estuarine and Coastal Research, East China Normal University, Shanghai 200062 (China); Institute of Geographic Engineering Technology, School of Geographical Science, Nantong University, Nantong 226007 (China); Yu, Lizhong [State Key Laboratory of Estuarine and Coastal Research, East China Normal University, Shanghai 200062 (China)

    2014-04-01

    The rapid industrial development in the Yangtze River watershed over the last several decades has drawn great attention with respect to heavy metal pollution to the Yangtze River estuary and nearby coastal areas. In this study, a 236 cm long sediment core was retrieved from the Yangtze River subaqueous delta (122°36? E, 31°00? N) in 2008 and analyzed for magnetic properties and geochemical compositions to investigate heavy metal pollution history. The activity of {sup 137}Cs peaked at depth 140 cm, with a broad plateau between 120 cm and 140 cm, suggesting an average sedimentation rate of 3.11 cm yr{sup ?1} for the upper 140 cm layer. Magnetic susceptibility (?), saturation isothermal remanent magnetization (SIRM), anhysteretic remanent magnetization (?{sub ARM}) and heavy metal enrichment factors (EF) all showed an upward increase trend above depth 140 cm, suggesting that increased ferrimagnetic mineral concentration was accompanied by heavy metal enrichment in the sediment. Geochemical and granolumetric analyses showed that sediment sources and particle sizes played minor roles in the variations of magnetic properties. The effect of diagenesis, which can lead to the selective removal of magnetic minerals, was noticeable in the lower part of the core (140–236 cm). Co-variation between magnetic properties (?, SIRM and ?{sub ARM}) and EF of Cu and Pb suggests that the elevated ferrimagnetic mineral concentration can be used as an indicator of heavy metal pollution in the reconstruction of environmental changes in estuarine and coastal settings. - Highlights: • Magnetic parameters can be used as heavy metal pollution proxy. • Heavy metal contents in the Yangtze River estuary increase since the 1960s. • Heavy metal pollution is largely driven by population growth in the catchment.

  19. A magnetic record of heavy metal pollution in the Yangtze River subaqueous delta

    International Nuclear Information System (INIS)

    The rapid industrial development in the Yangtze River watershed over the last several decades has drawn great attention with respect to heavy metal pollution to the Yangtze River estuary and nearby coastal areas. In this study, a 236 cm long sediment core was retrieved from the Yangtze River subaqueous delta (122°36? E, 31°00? N) in 2008 and analyzed for magnetic properties and geochemical compositions to investigate heavy metal pollution history. The activity of 137Cs peaked at depth 140 cm, with a broad plateau between 120 cm and 140 cm, suggesting an average sedimentation rate of 3.11 cm yr?1 for the upper 140 cm layer. Magnetic susceptibility (?), saturation isothermal remanent magnetization (SIRM), anhysteretic remanent magnetization (?ARM) and heavy metal enrichment factors (EF) all showed an upward increase trend above depth 140 cm, suggesting that increased ferrimagnetic mineral concentration was accompanied by heavy metal enrichment in the sediment. Geochemical and granolumetric analyses showed that sediment sources and particle sizes played minor roles in the variations of magnetic properties. The effect of diagenesis, which can lead to the selective removal of magnetic minerals, was noticeable in the lower part of the core (140–236 cm). Co-variation between magnetic properties (?, SIRM and ?ARM) and EF of Cu and Pb suggests that the elevated ferrimagnetic mineral concentration can be used as an indicator of heavy metal pollution in the reconstruction of environmental changes in estuarine and coastal settings. - Highlights: • Magnetic parameters can be used as heavy metal pollution proxy. • Heavy metal contents in the Yangtze River estuary increase since the 1960s. • Heavy metal pollution is largely driven by population growth in the catchment

  20. Development of HUMASORB{trademark}, a lignite derived humic acid for removal of metals and organic contaminants from groundwater

    Energy Technology Data Exchange (ETDEWEB)

    Sanjay, H.G.; Srivastave, K.C.; Walia, D.S. [ARCTECH, Inc., Chantilly, VA (United States)

    1995-10-01

    Heavy metal and organic contamination of surface and groundwater systems is a major environmental concern. The contamination is primarily due to improperly disposed industrial wastes. The presence of toxic heavy metal ions, volatile organic compounds (VOCs) and pesticides in water is of great concern and could affect the safety of drinking water. Decontamination of surface and groundwater can be achieved using a broad spectrum of treatment options such as precipitation, ion-exchange, microbial digestion, membrane separation, activated carbon adsorption, etc. The state of the art technologies for treatment of contaminated water however, can in one pass remediate only one class of contaminants, i.e., either VOCs (activated carbon) or heavy metals (ion exchange). This would require the use of at a minimum, two different stepwise processes to remediate a site. The groundwater contamination at different Department of Energy (DOE) sites (e.g., Hanford) is due to the presence of both VOCs and heavy metals. The two-step approach increases the cost of remediation. To overcome the sequential treatment of contaminated streams to remove both organics and metals, a novel material having properties to remove both classes of contaminants in one step is being developed as part of this project.The objective of this project is to develop a lignite-derived adsorbent, Humasorb{sup TM} to remove heavy metals and organics from ground water and surface water streams.

  1. A review of the global emissions, transport and effects of heavy metals in the environment

    International Nuclear Information System (INIS)

    The purpose of this report is to describe the current state of knowledge regarding the sources and quantities of heavy metal emissions, their transport and fate, their potential health and environmental effects, and strategies to control them. The approach is to review the literature on this topic and to consult with experts in the field. Ongoing research activities and research needs are discussed. Estimates of global anthropogenic and natural emissions indicate that anthropogenic emissions are responsible for most of the heavy metals released into the atmosphere and that industrial activities have had a significant impact on the global cycling of trace metals. The largest anthropogenic sources of trace metals are coal combustion and the nonferrous metal industry. Atmospheric deposition is an important pathway by which trace metals enter the environment. Atmospheric deposition varies according to the solubility of the element and the length of time it resides in the atmosphere. Evidence suggests that deposition is influenced by other chemicals in the atmosphere, such as ozone and sulfur dioxide. Trace metals also enter the environment through leaching. Existing emissions-control technologies such as electrostatic precipitators, baghouses, and scrubbers are designed to remove other particulates from the flue gas of coal-fired power plants and are only partially effective at removing heavy metals. Emerging technologies such as flue gas desulfurization, lignite coke, and fluidized bed combustion could further reduce emissions. 108 refs

  2. Development of Bacterium-Based Heavy Metal Biosorbents: Enhanced Uptake of Cadmium and Mercury by Escherichia coli Expressing a Metal Binding Motif

    OpenAIRE

    Pazirandeh, Mehran; Wells, Bridget M.; Ryan, Rebecca L.

    1998-01-01

    A gene coding for a de novo peptide sequence containing a metal binding motif was chemically synthesized and expressed in Escherichia coli as a fusion with the maltose binding protein. Bacterial cells expressing the metal binding peptide fusion demonstrated enhanced binding of Cd2+ and Hg2+ compared to bacterial cells lacking the metal binding peptide. The potential use of genetically engineered bacteria as biosorbents for the removal of heavy metals from wastewaters is discussed.

  3. Heavy metal determination in fish tissues by atomic absorption spectrometry

    International Nuclear Information System (INIS)

    Avoidance of polluted waters is one of the most significant sublethal reactions of aquatic organisms. The monitoring of fish communities, populations and accumulation of toxic materials is important in estimation of the state and stability of hydro systems. The effectivity of toxical - fermentative influence on the heavy metals influence on water organisms is determined by the heavy metal concentration in organs and tissues. The aim of investigation is the establishment of regularities and peculiarities of heavy metals bioaccumulation and bioconcentration in different organs and tissues in fish of Latvia reservoirs. It was investigated the concentrations of Hg, Cd, Pb (mandatory monitoring in fish tissues stated by Latvian Government) and Zn, Cu (potentially harmful substances) in muscles and liver of perch (Perca fluviatilis L.). The level of heavy metal content in different part of fish organs depend on heavy metal accumulation dynamic in different fish organs. (full text)

  4. Flow analysis of heavy metals in a pilot-scale incinerator for residues from waste electrical and electronic equipment dismantling

    International Nuclear Information System (INIS)

    Highlights: • Cu, Zn, Pb, and Ni are enriched in bottom ash from WEEE dismantling residues. • The heavy metal residual fraction restricts transfer in the incinerator. • Pre-treatment to remove heavy metals from WEEE residues would reduce emissions. -- Abstract: The large amount of residues generated from dismantling waste electrical and electronic equipment (WEEE) results in a considerable environmental burden. We used material flow analysis to investigate heavy metal behavior in an incineration plant in China used exclusively to incinerate residues from WEEE dismantling. The heavy metals tested were enriched in the bottom and fly ashes after incineration. However, the contents of heavy metals in the bottom ash, fly ash and exhaust gas do not have a significant correlation with that of the input waste. The evaporation and recondensation behavior of heavy metals caused their contents to differ with air pollution control equipment because of the temperature difference during gas venting. Among the heavy metals tested, Cd had the strongest tendency to transfer during incineration (TCd = 69.5%) because it had the lowest melting point, followed by Cu, Ni, Pb and Zn. The exchangeable and residual fractions of heavy metals increased substantially in the incineration products compared with that of the input residues. Although the mass of residues from WEEE dismantling can be reduced by 70% by incineration, the safe disposal of the metal-enriched bottom and fly ashes is still required

  5. Flow analysis of heavy metals in a pilot-scale incinerator for residues from waste electrical and electronic equipment dismantling

    Energy Technology Data Exchange (ETDEWEB)

    Long, Yu-Yang; Feng, Yi-Jian; Cai, Si-Shi; Ding, Wei-Xu; Shen, Dong-Sheng, E-mail: shends@zju.edu.cn

    2013-10-15

    Highlights: • Cu, Zn, Pb, and Ni are enriched in bottom ash from WEEE dismantling residues. • The heavy metal residual fraction restricts transfer in the incinerator. • Pre-treatment to remove heavy metals from WEEE residues would reduce emissions. -- Abstract: The large amount of residues generated from dismantling waste electrical and electronic equipment (WEEE) results in a considerable environmental burden. We used material flow analysis to investigate heavy metal behavior in an incineration plant in China used exclusively to incinerate residues from WEEE dismantling. The heavy metals tested were enriched in the bottom and fly ashes after incineration. However, the contents of heavy metals in the bottom ash, fly ash and exhaust gas do not have a significant correlation with that of the input waste. The evaporation and recondensation behavior of heavy metals caused their contents to differ with air pollution control equipment because of the temperature difference during gas venting. Among the heavy metals tested, Cd had the strongest tendency to transfer during incineration (T{sub Cd} = 69.5%) because it had the lowest melting point, followed by Cu, Ni, Pb and Zn. The exchangeable and residual fractions of heavy metals increased substantially in the incineration products compared with that of the input residues. Although the mass of residues from WEEE dismantling can be reduced by 70% by incineration, the safe disposal of the metal-enriched bottom and fly ashes is still required.

  6. Heavy metal contamination in canned foods

    International Nuclear Information System (INIS)

    The work carried out in this paper aims to the study of contamination of different foodstuffs, that are consumed frequently in our daily life, such as tomatoes concentrate, jam, tuna, and bean, as a result of canning in glass or tin cans. The effect of the storage time on the contamination of the aforementioned foods with heavy metals was also investigated. The technique used for the simultaneous determination of these elements was the instrumental neutron activation analysis (INAA). This technique was selected due to its high accuracy, sensitivity and selectivity. In the light of the obtained results it was suggested that tin cans is the best choice for canning jam and it is suitable also for preserving tuna. On the other hand, glass utensils were found to be the most suitable for preserving tomatoes concentrate. detailed studies are needed to throw more light on the effect of canning material on the concentration level of both essential and toxic trace elements in bean

  7. Hydroponic phytoremediation of heavy metals and radionuclides

    International Nuclear Information System (INIS)

    It is estimated that the Departments of Defense, Energy, and Agriculture will spend up to 300 billion federal dollars on environmental remediation during the next century. Current remediation processes can be expensive, non-aesthetic, and non-versatile. Therefore, the need exists for more innovative and cost effective solutions. Phytoremediation, the use of vegetation for the remediation of contaminated sediments, soils, and ground water, is an emerging technology for treating several categories of persistent, toxic contaminants. Although effective, phytoremediation is still in a developmental stage, and therefore is not a widely accepted technology by regulatory agencies and public groups. Research is currently being conducted to validate the processes effectiveness as well as increase regulatory and community acceptance. This research will focus on the ability of plants to treat an aquifer contaminated with heavy metals and radionuclides. Specifically, the effectiveness of hydroponically grown dwarf sunflowers and mustard seed will be investigated

  8. Heavy metals biogeochemistry in abandoned mining areas

    Directory of Open Access Journals (Sweden)

    Favas P. J. C.

    2013-04-01

    Full Text Available Plants growing on the abandoned Portuguese mines, highly contaminated with W, Sn, As, Cd, Cu, Zn and Pb, have been studied for their biogeochemical indication/prospecting and mine restoration potential. The results of analysis show that the species best suited for biogeochemical indicating are: aerial tissues of Halimium umbellatum (L. Spach, for As and W; leaves of Erica arborea L. for Bi, Sn, W and mostly Pb; stems of Erica arborea L. for Pb; needles of Pinus pinaster Aiton and aerial tissues of Pteridium aquilinum (L. Kuhn for W; and leaves of Quercus faginea Lam. for Sn. The aquatic plant studied (Ranunculus peltatus Schrank can be used to decrease the heavy metals, and arsenic amounts into the aquatic environment affected by acid mine drainages.

  9. Effects of sulfur dioxide and heavy metals

    International Nuclear Information System (INIS)

    Produced from burning coal, sulfur dioxide persists not so much from home heating as in the furnaces of coal-fired, electric power-generating plants. Particulate emissions may be over 99% controlled, and sulfur dioxide may be 70-90% controlled in some countries, but older plants or newer facilities in developing countries often lack such technology. Even where controls exist, the tremendous amounts of coal burned still result in the emission of significant quantities of sulfur dioxide. And despite pollution control equipment in modern smelters, the sulfur dioxide and heavy metal particulate emissions can still damage neighboring vegetation. The problem is especially critical in developing countries where control technology is lacking, or in developed countries where control has a low priority

  10. Behavior and Distribution of Heavy Metals Including Rare Earth Elements, Thorium, and Uranium in Sludge from Industry Water Treatment Plant and Recovery Method of Metals by Biosurfactants Application

    OpenAIRE

    Lidi Gao; Naoki Kano; Yuichi Sato; Chong Li; Shuang Zhang; Hiroshi Imaizumi

    2012-01-01

    In order to investigate the behavior, distribution, and characteristics of heavy metals including rare earth elements (REEs), thorium (Th), and uranium (U) in sludge, the total and fractional concentrations of these elements in sludge collected from an industry water treatment plant were determined and compared with those in natural soil. In addition, the removal/recovery process of heavy metals (Pb, Cr, and Ni) from the polluted sludge was studied with biosurfactant (saponin and sophorolipid...

  11. Development of a regenerable metal oxide CO removal system

    Science.gov (United States)

    Cusick, Robert J.

    1990-01-01

    A regenerable metal oxide carbon dioxide (CO2) removal system was developed to replace the current means of a nonreusable chemical, lithium hydroxide, for removing the metabolic CO2 of an astronaut in a space suit. Testing indicates that a viable low-volume metal oxide concept can be used in the portable life support system for CO2 removal during Space Station extravehicular activity (EVA). A canister of nearly the same volume as that used for the Space Shuttle, containing 0.10 cu ft of silver-oxide-based pellets, was tested; test data analysis indicates that 0.18 cu ft of the metal oxide will result in an 8-hour EVA capability. The testing suggests that the metal oxide technology offers a low-volume approach for a reusable CO2 removal concept applicable for at least 40 EVA missions. The development and testing of the breadboard regeneration package is also described.

  12. Research and development for molten heavy metal targets

    International Nuclear Information System (INIS)

    Spallation facilities of the future will, to a large extent, have to rely on molten heavy metal targets to be able to remove the heat from the reaction zone and to avoid excessive radiation damage in the target material. This, however, results in rather stringent requirements on the safety and durability of the proton beam window and of the walls of the liquid metal system. Effects to be considered in detail in this context are high gas production rates in both the solid window and the liquid target itself, transmutation and fission products and their effects on the solid material as well as on the corrosive and physical properties of the liquid metal. In this context it is not only important to understand the direct effects on the wall material, which are so far largely unexplored, but also the chemistry going on in the liquid metal between the various species present after prolonged operation. Destruction and formation of surface-coating layers, liquid metal-solid metal reactions and the effects of stress and irradiation on these processes must be investigated in detail in addition to such fundamental questions like flow configurations, the effect of buoyancy, heat transfer coefficients and the influence of gases in the liquid. A joint effort has been launched between various laboratories interested in the development of next generation neutron sources in which existing and available installations world wide shall be utilized to the largest possible extent in order d to the largest possible extent in order to optimize the return for the resources used in a coordinated research and development effort. 30 refs., 6 figs., 3 tabs

  13. Remoção de metais pesados tóxicos cádmio, chumbo e cromo em biofertilizante suíno utilizando macrófita aquática (Eichornia crassipes como bioindicador - DOI: 10.4025/actascitechnol.v30i1.3179 Removal of toxic heavy metals cadmium, lead and chromium from swine biofertilizer, using an aquatic macrophyte (eichornia crassipes as a bioindicator - DOI: 10.4025/actascitechnol.v30i1.3179

    Directory of Open Access Journals (Sweden)

    Reinaldo Bariccatti

    2008-05-01

    Full Text Available Este trabalho objetivou avaliar a eficiência da macrófita aquática (Eichornia crassipes como bioindicador e alternativa na remoção dos metais pesados tóxicos Cd, Pb e Cr em biofertilizante de origem suína. Foi utilizado o esquema fatorial 2x4, sendo os fatores representados pelas partes da planta (aérea e raiz, e pelos quatro tratamentos. Na instalação do experimento coletou-se uma alíquota da solução de cada tratamento para determinar as concentrações iniciais dos metais e, após 30 dias de cultivo, as plantas foram retiradas, coletando-se novamente uma alíquota da solução de cada tratamento. As plantas foram separadas em parte aérea e raiz, secas e trituradas. A macrófita apresentou-se eficiente na remoção dos metais pesados, observou-se que o sistema radicular da macrófita apresentou maiores concentrações de Cd, Pb e Cr. Com este trabalho, conclui-se que a macrófita aquática (Eichornia crassipes pode ser uma alternativa para o tratamento de biofertilizante e dejetos provenientes da suinoculturaThe objective of this work was to evaluate the efficiency of an aquatic macrophyte (Eichornia crassipes as a bioindicator and as an alternative sorbent for the removal of toxic heavy metals Cd, Pb and Cr from swine biofertilizer. A 2x4 factorial design was used, with the factors represented by plant parts (leaves and roots and the four treatments. The metal concentrations were determined at the beginning of the experiment and after 30 days. The macrophyte showed good efficiency in the removal of toxic heavy metals from swine biofertilizer. It was observed that its radicular system presented larger amounts of Cd, Pb and Cr than did the leaves. Our results show that Eichornia crassipes could be an alternative treatment for biofertilizer and waste from swine culture

  14. Heavy metals in trees and energy crops - a literature review; Tungmetaller i traed och energigroedor - en litteraturstudie

    Energy Technology Data Exchange (ETDEWEB)

    Johnsson, Lars [Swedish Univ. of Agricultural Sciences, Uppsala (Sweden). Dept. of Soil Sciences

    1995-12-01

    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

  15. Indicators of Lake Temsah Potential by some heavy metals Heavy Metals in Sediment

    International Nuclear Information System (INIS)

    The Environmental impact of industrial, agricultural and domestic waster on heavy metals sediment content in lake Temsah has been investigated. Seven sites were chosen, differ in nature of activity and quantity of wastes, namely from south to north-west; Arab contractors shipyard workshop(A), The junction between the western logon and the lake(B), El-Temsah workshop (C), El-Temsah shipyard (private workshop) (D), El-Karakat workshop for SCA (E), El-Forsan drain out fall to the lake (F) and SCA Press outlet (G). Eight of heavy metal concentrations of concern (Fe, Mn, Zn, Cu, Co, Ni, Cd and Pb) were estimated in sediment samples collected from different chosen sites during the seasons; summer , autumn 1995 and winter , spring 1996. Results of this study reveal that pollution is directly related to the type of the activity in each site. Sediment samples results showed that the most suffering sites were found to be in the order of B> D> C> G> F, and the least polluted ones were E> A. And the highest polluted season was summer, whereas the least one was winter. It is obvious that the general mean values of Cu, Ni and Cd are exceeding the allowed concentrations documented for diverse trace components in coastal sediments. Strict regulations that must be followed in order to minimize this pollution specially, by heavy metals from marine workshop

  16. Adaptation of plants to an environment polluted with heavy metals

    OpenAIRE

    Antosiewicz, Danuta M.

    1992-01-01

    This paper presents the problem of tolerance of plants to heavy metals. Induction, development and stability of tolerance are described. Multiple and co-tolerance are presented in the context of specificity of acquired tolerance to heavy metals. Phenomena involved in the uptake and distribution of metals in plant tissues along with the mechanisms of exclusion and accumulation are discussed. The problem of tolerance development in plants is presented also in the light of the nutritional condit...

  17. Remediation technologies for heavy metal contaminated groundwater.

    Science.gov (United States)

    Hashim, M A; Mukhopadhyay, Soumyadeep; Sahu, Jaya Narayan; Sengupta, Bhaskar

    2011-10-01

    The contamination of groundwater by heavy metal, originating either from natural soil sources or from anthropogenic sources is a matter of utmost concern to the public health. Remediation of contaminated groundwater is of highest priority since billions of people all over the world use it for drinking purpose. In this paper, thirty five approaches for groundwater treatment have been reviewed and classified under three large categories viz chemical, biochemical/biological/biosorption and physico-chemical treatment processes. Comparison tables have been provided at the end of each process for a better understanding of each category. Selection of a suitable technology for contamination remediation at a particular site is one of the most challenging job due to extremely complex soil chemistry and aquifer characteristics and no thumb-rule can be suggested regarding this issue. In the past decade, iron based technologies, microbial remediation, biological sulphate reduction and various adsorbents played versatile and efficient remediation roles. Keeping the sustainability issues and environmental ethics in mind, the technologies encompassing natural chemistry, bioremediation and biosorption are recommended to be adopted in appropriate cases. In many places, two or more techniques can work synergistically for better results. Processes such as chelate extraction and chemical soil washings are advisable only for recovery of valuable metals in highly contaminated industrial sites depending on economical feasibility. PMID:21708421

  18. Predicting radioactive heavy metal movement through soil

    International Nuclear Information System (INIS)

    The rate of movement through soils of constituents in wastes depends on the nature of the disposal environment with respect to three major components: the porous medium through which the fluid moves (soil), the vehicle that transports the constituent (fluid), and the potential pollutant constituent itsel (heavy metal). A laboratory soil-column method was developed to provide data for predicting movement of potential pollutants through soils. The research describes the rate of movement of radionuclides32 P, 89 Sr, 90 Sr-(90Y), 45Ca, 59Fe in biological residues and metals As, Be, Cd, Cr, Cu, Fe, Hg, Ni, Pb, Se, V, and Zn in leachates. Attenuation of pollutants in soils was statistically compared to the measurable parameters of the components of the disposal environment. The application of the soil attentuation data to the Lapidus-Amundson and Error Function models for development of a simple universal equation, useful as a field oriented tool for predicting pollutant movement through soils is provided

  19. Enhancing toxic metal removal from acidified sludge with nitrite addition.

    Science.gov (United States)

    Du, Fangzhou; Freguia, Stefano; Yuan, Zhiguo; Keller, Jürg; Pikaar, Ilje

    2015-05-19

    The production of sludge (biosolids) during wastewater treatment is a major issue for water utilities. A main issue limiting its beneficial reuse on agricultural lands is the presence of toxic metals. The currently used metal reduction technologies achieve insufficient removal of metals that are bound to the organic fraction of the sludge. In this study, we propose and demonstrate a novel method that involves the addition of nitrite during sludge acidification to enhance metal removal. Using waste activated sludge collected from three full-scale wastewater treatment plants, we found that acidification to pH 2.0 achieved good Zn solubilization of around 70%, but only 3-7% of Cu was being dissolved. Nitrite addition to the acidified sludge at a concentration of 20 mg NO2(-)-N/L (equals to 19.2 mg HNO2-N/L), substantially enhanced Cu removal to 45-64%, while Zn removal was also increased to over 81%. Metal distribution analysis using sequential chemical extraction revealed that the improvement of Cu and Zn removal was mainly due to the release of the organically bound metal fraction. We hypothesize that free nitrous acid (HNO2, FNA) may assist in the (partial) disruption of extracellular polymeric substances (EPS) and the subsequent release and solubilization of fixed metals. PMID:25872418

  20. Application of aragonite shells for the removal of aqueous metals in polluted soils and wastewaters.

    Science.gov (United States)

    Bucca, M.; Köhler, S. J.; Dietzel, M.

    2009-04-01

    In the present study the use of coupled precipitation/dissolution processes for metal (Me) removal from polluted soils and waters by biogenic carbonate (CaCO3) shell surfaces is proposed, according to the following overall reaction: CaCO3 + Me2+ = MeCO3 + Ca2+ This reaction has been investigated at fixed experimental conditions using synthetic model systems consisting in columns, batch, and reactors (e.g. lead, zinc, and cadmium artificial solutions mixed with aragonite shells) that allowed quantifying the kinetics of the process of metal carbonate formation. The above mentioned process has the potential of being used in three different areas of water treatment: a) use of shells as a cheap and effective geologic barrier for contaminated ground or surface waters, b) use as a material in filter beds or fluidized bed for selective cleaning of waste water with the potential of partial metal recovery and c) use as seed crystals during the elimination of metals through precipitation with soda (Na2CO3). Acidic wastewaters containing several pollutants, including heavy and trace metals, are created during production of pesticides, paper, lubricating oil, batteries, acid/alkali, or in ship repair manufacturing, mines drainage systems, metalworking and metal plating industries. Biogenic shells are a waste product in many coastal countries and may thus be more favorable than other solid phases such as clays or zeolithes from an economic viewpoint. Our metal elimination study aims at setting up a low-cost effective elimination system for various types of metal rich waste waters. A number of experimental techniques such as batch, column and flow through reactors were used to optimize the metal removal efficiency in both synthetic and waste waters from the metal finishing industry. Solid liquid ratio, initial and final pH, metal concentration and combination of metals have been varied. Measurements of pH, metal concentration, conductivity and alkalinity were recorded over the time. Metal content of Fe, Zn and other heavy metals of the precipitate from the different reactors systems were characterized using FT-IR spectroscopy, X-ray diffraction, scanning electron microscopy (SEM) and Raman Spectroscopy. The most important factors that influence metal removal efficiency, experimental setup, the total iron content, reaction pH, metal to shell ratio will be discussed.

  1. Removal of toxic metals from aqueous solutions by fungal biomass of Agaricus macrosporus

    International Nuclear Information System (INIS)

    Fungi such as Agaricus macrosporus show potential for the removal of heavy metals from aqueous solutions contaminated by zinc, copper, mercury, cadmium or lead. This study investigated biosorption of these metals by living or non-living biomass of A. macrosporus from an acid solution, an acid solution supplemented with potassium and phosphorus, and an alkaline solution. Uptake showed a pH-dependent profile. Maximum percentage uptake of all metals was found to occur at alkaline pH (Cu 96%, Pb 89%). With living biomass, metal biosorption was greater and faster in K/P-supplemented acid medium than in non-supplemented acid medium, with equilibrium reached within 15 min for all metals, and the highest percentage uptake being of cadmium (96%). In general, the greatest differences in biosorption capacity were seen for living biomass, between supplemented and non-supplemented acid medium; the smallest differences were between living and dead biomass in alkaline medium. These results support the potential utility of A. macrosporus for heavy metal removal

  2. Development and testing of inorganic sorbents for radionuclide and heavy metal separations

    Energy Technology Data Exchange (ETDEWEB)

    Collins, J. [Oak Ridge National Lab., TN (United States)

    1996-10-01

    The objectives of this task are to develop, prepare, and test microspheres and granular forms of inorganic ion exchangers to remove radionuclides and heavy metals from waste streams occurring at various sites. Several inorganic materials, such as hexacyanoferrates, titanates, phosphates, and oxides have high selectivities and efficiencies for separating and removing radionuclides such as uranium, technetium, cesium and strontium, and metals such as cobalt, silver, zinc, and zirconium from aqueous waste streams. However, these sorvents frequently exist only as powders and consequently are not readily adaptable to continuous processing such as column chromatography.

  3. Interaction of Heavy Metal Ions with Carbon and Iron Based Particles

    Directory of Open Access Journals (Sweden)

    Dana Fialova

    2014-03-01

    Full Text Available Due to the rapid development of industry and associated production of toxic waste, especially heavy metals, there is a great interest in creating and upgrading new sorption materials to remove these pollutants from the environment. This study aims to determine the effectiveness of different carbon forms (graphene, expanded carbon, multi-wall nanotubes and paramagnetic particles (Fe2O3 for adsorption of cadmium(II, lead(II, and copper(II on its surface, with different interaction time from 1 min to 24 h. The main attention is paid to the detection of these metals using differential pulse voltammetry. Based on the obtained results, graphene and Fe2O3 are found to be good candidates for removal of heavy metals from the environment.

  4. Role of mycorrhiza to reduce heavy metal stress

    Directory of Open Access Journals (Sweden)

    Syeda Asma Bano

    2013-12-01

    Full Text Available 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- (Kono and Fridovich, 1982. These ROS are O2-, H2O2, and -OH which can react with many other biomolecules. Several metallic ions are produced by radical displacement reactions. These metallic ions inhibit the activity of antioxidant enzymes. Hence, enzymic antioxidant defense system of plants is affected and adversely inhibits plant growth and productivity. Mycorrhizal fungi are important in phytostabilization of toxic heavy metals. Plants having mycorrhizal association accumulate metallic pollutants by storing these heavy metals in Vesicles as well as in fungal hyphae in their roots, hence these metallic pollutants are immobilized and do not inhibit the growth and uptake of phosphorus and some other micronutrients. Mycorrhizal fungi also release various organic acids which increase the solubilisation of insoluble phosphate compounds present in soil. The unavailable forms of phosphorus are converted into available forms as a result of organic acids produced by fungi. AM fungi release glomalins that are certain metal sorble glycoproteins which increase the immobilization of toxic metals. Another protein is metallothionine released by certain AM fungi, which also reduces the heavy metal toxicity in soil. Mycorrhizal fungi also induce resistance in plants against pathogens, drought and salinity stress. Investigation on heavy metal stress resistant genes in mycorrhizal plants can be very helpful for phytoremediation. This review focuses on the use of AM fungi for phytoremediation.

  5. Heavy metal composition in stormwater and retention in ponds dependent on pond age, design and catchment type

    DEFF Research Database (Denmark)

    Egemose, Sara; SØnderup, Melanie J.

    2015-01-01

    Heavy metals have toxic effects on flora and fauna in the aquatic environments and are of great concern in stormwater. Heavy metal runoff was studied in 37 stormwater ponds in Denmark with varying heavy metal load, catchment type and pond design. The studied metals were Cu, Cr, Cd, Pb, Ni and Zn. The concentrations varied considerably depending on the catchment type, with the highest concentrations coming from industrial areas and the lowest from uncultivated and rural areas. Ponds can effectively remove heavy metals in particulate forms through sedimentation processes, but the dissolved forms are more difficult to retain. The removal efficiency in the ponds varied considerably, with the highest retention of Pb, Ni and Zn due to higher particulate fraction. The retention increased with increased pond volume-to-reduced catchment area ratio. In addition, the pond age affected the efficiency; whereas ponds less than 1-2 years efficiently removed all metals, 30-40-year-old ponds only removed Pb, Ni and Zn, but steeply decreasing over the years. Physical parameters such as pond size, age and sedimentation patterns were found to play a more significant role in the removal compared with chemical parameters such as pH, oxygen and organic matter. Input of metals to the ponds was reflected in the sediment content, but not significantly for all heavy metals probably due to low or varying retention caused by mineralization and re-suspension. The heavy metal concentration in the outlets was reduced to non-toxic levels, except for Cu and Cr at a few study sites.

  6. Interaction of heavy metals with dehydrated carbon

    Directory of Open Access Journals (Sweden)

    El-Shafey E. I.

    2013-04-01

    Full Text Available Dehydrated carbon material was prepared from date palm leaflets via sulphuric acid treatment. The acid causes dehydration via the removal of water. In addition it causes oxidation to the dehydrated carbon surface. The carbon was tested for the removal of Pb2+, Zn2+, Cu2+, Co2+, Ag+, Pd2+ and Hg2+ from aqueous solution in terms of different pH, time and concentrations and temperature. Optimum pH was found to be in the range of 3-5 for the metals under investigation. Sorption of Pb2+, Zn2+, Cu2+, Co2+ was found fast, reaching equilibrium within ? 2 hr while the sorption of Ag+, Pd2+ and Hg2+ (nitrate and chlo