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Sample records for heavy metals removal

  1. MICROBIAL REMOVAL OF HEAVY METALS FROM WASTEWATER

    Directory of Open Access Journals (Sweden)

    Justyna Koc-Jurczyk

    2014-10-01

    Full Text Available Industrialization and urbanization result in increase of heavy metals released into the environment (soil, lakes, rivers, seas, oceans, groundwater. Studies on biosorption of heavy metals are aimed to specify types of microorganisms which could efficiently bind metals. This approach has a very important significance for both slowing down metals exploitation by recovery, and also reduction of environmental pollution by decrease of their excessive concentration. Recent studies have reported about the capabilities of fungi, algae, yeasts, bacteria, waste and agricultural residues or materials containing chitosan derived from crustacean shells as a biosorbents. Biohydrometallurgy could be considered as a new “green” technology of heavy metals removal from wastewater.

  2. 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

  3. Heavy metals removal in dual media filters

    OpenAIRE

    Santos, Pedro Deyrieux Centeno Ogando

    2012-01-01

    The purpose of this study was to investigate physicochemical mechanisms for the removal of heavy metals from the effluent of Harnaschpolder’s WWTP Pilot Installation in the South of Netherlands. This effluent is partially submitted to tertiary treatment in a water reuse pilot which aims the production of water for two different end‑uses: crop irrigation in greenhouses and surface‑type water. Tertiary filters were mounted and started up at the reuse pilot and specific concentrations o...

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

    OpenAIRE

    Veeken, A.

    1998-01-01

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

  5. Phycoremediation of Wastewater: Heavy Metal and Nutrient Removal Processes

    Directory of Open Access Journals (Sweden)

    Kwarciak-Koz?owska Anna

    2014-12-01

    Full Text Available Phycoremediation is the use of algae for the removal or biotrans-formation of pollutants from wastewater. The study is a novel at-tempt to integrate nutrient (N and P removal and some heavy met-als (iron, manganese and zinc bioaccumulation from municipal wastewater using two microalgae species: Chlorella vulgaris and Scenedesmus armatus. The Chlorella vulgaris showed higher re-moval of total nitrogen (TN both in influent and effluent waste water than Scenedesmus armatus. Nevertheless, more than 51% of total phosphorus (TP in effluent and 36% in influent wastewaters were removed by Scenedesmus armatus. More efficient microalga in heavy metal removal in influent wastewater was Scenedesmus armatus. The results showed that Chlorella vulgaris was appropriate for TN removal and bioaccumulation of heavy metals from effluent wastewater. Nevertheless, Scenedesmus armatus was highly pref-erable for heavy metals removal from influent wastewater.

  6. REMOVAL OF HEAVY METALS BY ARTIFICIAL WETLANDS

    Science.gov (United States)

    Artificial wetlands have been operated successfully for treatment of municipal wastewater for a number of years at several locations in this country. However, the capability of these systems to treat heavy metal laden municipal wastewater had not previously been investigated. The...

  7. 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...

  8. 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

  9. Radiation-initiated removal of heavy metals from water

    International Nuclear Information System (INIS)

    This paper describes the technical viability of high-powered industrial radiation processes as high-volume and low-cost techniques suitable for the removal of the heavy metals and chelated heavy-metal compounds from water that has been contaminated by marine paints and other similar organometallic compounds

  10. ULTRASONIC ENHANCEMENT OF THE REMOVAL OF HEAVY METALS

    Science.gov (United States)

    EPA GRANT NUMBER: R828598C020Title: Ultrasonic Enhancement of the Removal of Heavy MetalsInvestigators: Dennis Truax, Krishnan BalasubramaniamInstitution: Mississippi State UniversityEPA Project Officer: S. Bala Krishnan...

  11. Heavy metals removal from dredged sediments using electro kinetics

    Directory of Open Access Journals (Sweden)

    Ammami M. T.

    2013-04-01

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

  12. Heavy metal removal potential of dried Salvinia biomass.

    Science.gov (United States)

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

    2010-02-01

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

  13. 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...

  14. Heavy metals removal from dredged sediments using electro kinetics

    OpenAIRE

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

    2013-01-01

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

  15. 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.

  16. 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

  17. Electrodialytic removal of heavy metals from fly ashes

    DEFF Research Database (Denmark)

    Pedersen, Anne Juul

    2002-01-01

    The aim of the Ph.D. work was to develop the electrodialytic remediation method for removal of heavy metals from fly ashes. The work was focused on two types of fly ashes: fly ashes from wood combustion and fly ashes from municipal solid waste incineration.......The aim of the Ph.D. work was to develop the electrodialytic remediation method for removal of heavy metals from fly ashes. The work was focused on two types of fly ashes: fly ashes from wood combustion and fly ashes from municipal solid waste incineration....

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

    DEFF Research Database (Denmark)

    Ottosen, Lisbeth M.; Christensen, Iben Vernegren; Pedersen, Anne Juul; Hansen, K.H.; Villumsen, Arne; Ribeiro, A.B.

    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...... 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...

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

    DEFF Research Database (Denmark)

    Ottosen, Lisbeth M.; Christensen, Iben Vernegren; Pedersen, Anne Juul; Hansen, K.H.; Villumsen, Arne; Ribeiro, A.B.

    2003-01-01

    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......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...... 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...

  20. 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.

  1. Simultaneous heavy metal removal mechanism by dead macrophytes.

    Science.gov (United States)

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

    2006-01-01

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

  2. Removal of heavy metals by hybrid electrocoagulation and microfiltration processes.

    Science.gov (United States)

    Keerthi; Vinduja, V; Balasubramanian, N

    2013-01-01

    This study is based on the investigation of the performance of electrocoagulation (EC), followed by the microfiltration process for heavy metal removal in synthetic model waste water containing Zn2+, Ni2+ and Cd2+ ions. Effects of initial concentration, current density and pH on metal removal were analysed to optimize the EC process. The optimized EC process was then integrated with dead-end microfiltration (MF) and was found that the hybrid process was capable of 99% removal of heavy metals. The cake layer formed over the membrane by the hybrid process was analysed through scanning electron microscope-energy-dispersive X-ray spectroscopy. The particle size analysis of the sludge formed during EC was done to investigate the fouling caused during the process. PMID:24527655

  3. Removal and recovery of heavy metals of residual water industrial

    International Nuclear Information System (INIS)

    On the next work the state of the art about the different methods and technologies for the present removal and recovery of heavy metals for the de-contamination and control of industrial wastewater is presented. Further more, it is introduce a removal alternative for chromium (III) and chromium (V I) using a solid waste material as an adsorbent, obtaining successful results which makes this proposal circumscribe into the clean technology program and residues bag

  4. Removal of Trichloroethylene and Heavy Metals by Zerovalent Iron Nanoparticles

    Science.gov (United States)

    Boparai, H. K.; O'Carroll, D. M.

    2009-05-01

    Heavy metals combined with chlorinated solvents are one class of mixed waste found at various hazardous waste sites in North America. Nano zerovalent iron (nZVI), an emerging technology, is being successfully used for treating chlorinated solvents and heavy metals independently, however comparatively little research has investigated the remediation of the wastes when they are present in the same mixture. The remediation of trichloroethylene (TCE)/heavy metal waste mixtures via nZVI has been investigated in the present study. Results suggest that some metals are reduced by nZVI to their zerovalent state and thus precipitate on nZVI particles. This improves the contaminant removal performance of nZVI by forming bimetallic iron nanoparticles. Other metals are directly precipitated or adsorbed on the nZVI particles in their original oxidation state and are rendered immobile. In some cases the presence of the heavy metals in the waste mixture enhanced the dechlorination of TCE while in other cases it did not. This study suggests that nano zerovalent iron particles can be effectively used for the remediation of mixed contamination of heavy metals and chlorinated solvents. Results have been supported by a variety of techniques including X-ray photoelectron spectroscopy (XPS) analysis.

  5. Heavy metal removal using reverse osmosis

    OpenAIRE

    Lucia Gajdošová; Milan Búgel; TomᚠBakalár

    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...

  6. Chitosan removes toxic heavy metal ions from cigarette mainstream smoke

    Science.gov (United States)

    Zhou, Wen; Xu, Ying; Wang, Dongfeng; Zhou, Shilu

    2013-09-01

    This study investigated the removal of heavy metal ions from cigarette mainstream smoke using chitosan. Chitosan of various deacetylation degrees and molecular weights were manually added to cigarette filters in different dosages. The mainstream smoke particulate matter was collected by a Cambridge filter pad, digested by a microwave digestor, and then analyzed for contents of heavy metal ions, including As(III/V), Pb(II), Cd(II), Cr(III/VI) and Ni(II), by graphite furnace atomic absorption spectrometry (GFAAS). The results showed that chitosan had a removal effect on Pb(II), Cd(II), Cr(III/VI) and Ni(II). Of these, the percent removal of Ni(II) was elevated with an increasing dosage of chitosan. Chitosan of a high deace tylation degree exhibited good binding performance toward Cd(II), Cr(III/VI) and Ni(II), though with poor efficiency for Pb(II). Except As(III/V), all the tested metal ions showed similar tendencies in the growing contents with an increasing chitosan molecular weight. Nonetheless, the percent removal of Cr(III/VI) peaked with a chitosan molecular weight of 200 kDa, followed by a dramatic decrease with an increasing chitosan molecular weight. Generally, chitosan had different removal effects on four out of five tested metal ions, and the percent removal of Cd(II), Pb(II), Cr(III/VI) and Ni(II) was approximately 55%, 45%, 50%, and 16%, respectively. In a word, chitosan used in cigarette filter can remove toxic heavy metal ions in the mainstream smoke, improve cigarette safety, and reduce the harm to smokers.

  7. Individual and competitive removal of heavy metals using capacitive deionization.

    Science.gov (United States)

    Huang, Zhe; Lu, Lu; Cai, Zhenxiao; Ren, Zhiyong Jason

    2016-01-25

    This study presents the viability and preference of capacitive deionization (CDI) for removing different heavy metal ions in various conditions. The removal performance and mechanisms of three ions, cadmium (Cd(2+)), lead (Pb(2+)) and chromium (Cr(3+)) were investigated individually and as a mixture under different applied voltages and ion concentrations. It was found that CDI could effectively remove these metals, and the performance was positively correlated with the applied voltage. When 1.2 V was applied into solution containing 0.5mM individual ions, the Cd(2+), Pb(2+), and Cr(3+) removal was 32%, 43%, and 52%, respectively, and the electrosorption played a bigger role in Cd(2+) removal than for the other two ions. Interestingly, while the removal of Pb(2+) and Cr(3+) remained at a similar level of 46% in the mixture of three ions, the Cd(2+) removal significantly decreased to 14%. Similar patterns were observed when 0.05 mM was used to simulate natural contaminated water condition, but the removal efficiencies were much higher, with the removal of Pb(2+), Cr(3+), and Cd(2+) increased to 81%, 78%, and 42%, respectively. The low valence charge and lack of physical sorption of Cd(2+) were believed to be the reason for the removal behavior, and advanced microscopic analysis showed clear deposits of metal ions on the cathode surface after operation. PMID:26476320

  8. Heavy metal removal from water solutions

    Directory of Open Access Journals (Sweden)

    Barbora Onderková

    2005-11-01

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

  9. Novel forward osmosis process to effectively remove heavy metal ions

    KAUST Repository

    Cui, Yue

    2014-10-01

    In this study, a novel forward osmosis (FO) process for the removal of heavy metal ions from wastewater was demonstrated for the first time. The proposed FO process consists of a thin-film composite (TFC) FO membrane made from interfacial polymerization on a macrovoid-free polyimide support and a novel bulky hydroacid complex Na4[Co(C6H4O7)2]·r2H2O (Na-Co-CA) as the draw solute to minimize the reverse solute flux. The removal of six heavy metal solutions, i.e., Na2Cr2O7, Na2HAsO4, Pb(NO3)2, CdCl2, CuSO4, Hg(NO3)2, were successfully demonstrated. Water fluxes around 11L/m2/h (LMH) were harvested with heavy metals rejections of more than 99.5% when employing 1M Na-Co-CA as the draw solution to process 2000ppm(1 ppm=1 mg/L) heavy metal solutions at room temperature. This FO performance outperforms most nanofiltration (NF) processes. In addition, the high rejections were maintained at 99.5% when a more concentrated draw solution (1.5M) or feed solution (5000ppm) was utilized. Furthermore, rejections greater than 99.7% were still achieved with an enhanced water flux of 16.5LMH by operating the FO process at 60°C. The impressive heavy metal rejections and satisfactory water flux under various conditions suggest great potential of the newly developed FO system for the treatment of heavy metal wastewater. © 2014 Elsevier B.V.

  10. 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.

  11. 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.

  12. 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

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

    International Nuclear Information System (INIS)

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

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

    Energy Technology Data Exchange (ETDEWEB)

    Elouear, Z. [Laboratoire Eau Energie et Environnement, Departement de genie geologique, Ecole Nationale d' Ingenieurs de Sfax, BP W 3038, Sfax (Tunisia)], E-mail: zouheir.elouaer@tunet.tn; Bouzid, J.; Boujelben, N. [Laboratoire Eau Energie et Environnement, Departement de genie geologique, Ecole Nationale d' Ingenieurs de Sfax, BP W 3038, Sfax (Tunisia); Feki, M. [Unite de chimie industriel I, Ecole Nationale d' Ingenieurs de Sfax, BP W 3038 Sfax (Tunisia); Jamoussi, F. [Laboratoire de Georessources CERTE BP 95, 2050 Hamam-Lif (Tunisia); Montiel, A. [Societe Anonyme de Gestion des Eaux de Paris, 9 rue Schoelcher, 75675 Paris cedex 14 (France)

    2008-08-15

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

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

    International Nuclear Information System (INIS)

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

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

    DEFF Research Database (Denmark)

    Pedersen, Anne Juul; Ottosen, Lisbeth M.; Villumsen, Arne

    2003-01-01

    Electrodialytic Remediation has recently been suggested as a potential method for removal of heavy metals from fly ashes. In this work electrodialytic remediation of three different fly ashes, i.e. two municipal solid waste incinerator (MSWI) fly ashes and one wood combustion fly ash was studied in lab scale, and the results were discussed in relation to the expected heavy metal speciation in the ashes. In initial leaching experiments the pH-dependent desorption characteristics of the heavy meta...

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

    International Nuclear Information System (INIS)

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

  18. Application of ionic liquids for the removal of heavy metals from wastewater and activated sludge.

    Science.gov (United States)

    Fuerhacker, Maria; Haile, Tadele Measho; Kogelnig, Daniel; Stojanovic, Anja; Keppler, Bernhard

    2012-01-01

    This paper presents the results of adsorption studies on the removal of heavy metals (Cr, Cu, Cd, Ni, Pb and Zn) from standard solutions, real wastewater samples and activated sewage sludge using a new technique of liquid-liquid extraction using quaternary ammonium and phosphonium ionic liquids (ILs). Batch sorption experiments were conducted using the ILs [PR4][TS], [PR4][MTBA], [A336][TS] and [A336][MTBA]. Removal of these heavy metals from standard solutions were not effective, however removal of heavy metals from the industrial effluents/wastewater treatment plants were satisfactory, indicating that the removal depends mainly on the composition of the wastewater and cannot be predicted with standard solutions. Removal of heavy metals from activated sludge proved to be more successful than conventional methods such as incineration, acid extraction, thermal treatment, etc. For the heavy metals Cu, Ni and Zn, ?90% removal was achieved. PMID:22546790

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

    DEFF Research Database (Denmark)

    Pedersen, Anne Juul; Ottosen, Lisbeth M.; Villumsen, Arne

    2003-01-01

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

  20. 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.; Villumsen, Arne

    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 d...

  1. Removal of heavy-metal ions from dilute waste streams using membrane-based hybrid systems

    International Nuclear Information System (INIS)

    At Bend research, the authors have developed hybrid systems that couple a process that removes solvent (water) and a process that removes solute (metal ions) such that toxic heavy-metal ions can be efficiently and selectively removed to very low levels while simultaneously concentrating the heavy-metal ions in relatively pure form. Although this technology is broadly applicable, the authors are focusing on the development of a system to treat groundwater that is contaminated with heavy-metal ions. The process utilizes coupled transport and reverse osmosis to reduce chromium and uranium concentration down to parts-per-billion levels

  2. Removal of dissolved heavy metals from acid rock drainage using iron metal

    International Nuclear Information System (INIS)

    The chemical and microbial activity of corroding iron metal is examined in the acid rock drainage (ARD) resulting from pyrite oxidation to determine the effectiveness in neutralizing the ARD and reducing the load of dissolved heavy metals. ARD from Berkeley Pit, MT, is treated with iron in batch reactors and columns containing iron granules. Iron, in acidic solution, hydrolyzes water producing hydride and hydroxide ion resulting in a concomitant increase in pH and decrease in redox potential. The dissolved metals in ARD are removed by several mechanisms. Copper and cadmium cement onto the surface of the iron as zerovalent metals. Hydroxide forming metals such as aluminum, zinc, and nickel form complexes with iron and other metals precipitating from solution as the pH rises. Metalloids such as arsenic and antimony coprecipitate with iron. As metals precipitate from solution, various other mechanisms including coprecipitation, sorption, and ion exchange also enhance removal of metals from solution. Corroding iron also creates a reducing environment supportive for sulfate reducing bacteria (SRB) growth. Increases in SRB populations of 5,000-fold are observed in iron metal treated ARD solutions. Although the biological process is slow, sulfidogenesis is an additional pathway to further stabilize heavy metal precipitates

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

    DEFF Research Database (Denmark)

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

    2005-01-01

    , which has been designed according to standard design criteria for several decades. The study will focus on heavy metals (Cd, Cr, Cu, Pb and Zn) and polyaromatic hydrocarbons (PAH). The long-term simulation of input of flow and pollution to the ponds will be a hind cast based on time series of historical...

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

    Science.gov (United States)

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

    2014-12-01

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

  5. 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.)

  6. 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

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

    DEFF Research Database (Denmark)

    Pedersen, Kristine B.; Jensen, Pernille Erland; Ottosen, Lisbeth M.; Lejon, Tore

    2015-01-01

    . 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......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...

  8. 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.

  9. 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

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

    OpenAIRE

    Ghaedi, M.; N. Mosallanejad

    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 ...

  11. 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...

  12. 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

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

    Science.gov (United States)

    Mishra, Virendra Kumar; Tripathi, B D

    2008-10-01

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

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

    International Nuclear Information System (INIS)

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

  15. Heavy metal removal from MSS fly ash by thermal and chlorination treatments.

    Science.gov (United States)

    Liu, Jingyong; Chen, Jiacong; Huang, Limao

    2015-01-01

    The thermal behavior of heavy metals in the co-incineration of municipal solid waste-sludge incinerator fly ash (MSS fly ash) was studied using a laboratory-scale tube furnace. The results indicate that without the addition of chlorinating agents, temperature was an important parameter and had significantly influenced on heavy metal removal, whereas the residence time had a weak effect. Between 900 and 1000?°C for 60 to 300?min, heavy metals reacted with chloride-inherent in the fly ash, and approximately 80 to 89% of Pb, 48% to 56% of Cd, 27% to 36% of Zn and 6% to 24% of Cu were removed. After the adding chlorinating agents, the evaporation rate of the heavy metals improved dramatically, where the evaporation rates of Cu and Zn were larger than that of Pb and Cd. As the amount of added chlorinating agents increased, the removal rate of heavy metals increased. However, the effect of the type of chlorinating agent on the chlorination of heavy metals differed considerably, where NaCl had the weakest effect on the removal rate of Cu, Cd and Zn. In terms of resource recovery and decontamination, MgCl2 and CaCl2 are the best choices due to their efficient removal of Zn. PMID:26602592

  16. Heavy metal removal from MSS fly ash by thermal and chlorination treatments

    Science.gov (United States)

    Liu, Jingyong; Chen, Jiacong; Huang, Limao

    2015-01-01

    The thermal behavior of heavy metals in the co-incineration of municipal solid waste-sludge incinerator fly ash (MSS fly ash) was studied using a laboratory-scale tube furnace. The results indicate that without the addition of chlorinating agents, temperature was an important parameter and had significantly influenced on heavy metal removal, whereas the residence time had a weak effect. Between 900 and 1000?°C for 60 to 300?min, heavy metals reacted with chloride-inherent in the fly ash, and approximately 80 to 89% of Pb, 48% to 56% of Cd, 27% to 36% of Zn and 6% to 24% of Cu were removed. After the adding chlorinating agents, the evaporation rate of the heavy metals improved dramatically, where the evaporation rates of Cu and Zn were larger than that of Pb and Cd. As the amount of added chlorinating agents increased, the removal rate of heavy metals increased. However, the effect of the type of chlorinating agent on the chlorination of heavy metals differed considerably, where NaCl had the weakest effect on the removal rate of Cu, Cd and Zn. In terms of resource recovery and decontamination, MgCl2 and CaCl2 are the best choices due to their efficient removal of Zn. PMID:26602592

  17. 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).

  18. 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 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)

  19. A highly efficient and selective polysilsesquioxane sorbent for heavy metal removal

    KAUST Repository

    Duan, Xiaonan

    2012-02-29

    Suited for heavy stuff: An efficient mesoporous sorbent based on a pure ethylendiamine-bridged polysilsesquioxane is presented. This material, with both a high amine loading and a high surface area, is applied for heavy metal ion removal. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

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

    OpenAIRE

    Z. Yousefi; M.A Zazouli

    2008-01-01

    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 conventiona...

  1. 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).

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

    OpenAIRE

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

    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...

  3. 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...

  4. Removal of heavy metals from waters by means of industrial brown coal products; Schwermetallentfernung aus Waessern mittels industrieller Braunkohlenprodukte

    Energy Technology Data Exchange (ETDEWEB)

    Scheibner, T.; Heschel, W.; Meyer, B. [Technische Univ. Bergakademie Freiberg, Freiberg (Germany). Inst. fuer Energieverfahrenstechnik und Chemieingenieurwesen

    2003-07-01

    The pollution of surface water with heavy metals differs locally. The mining and metal industries emit heavy metals in the form of aqueous solutions. The removal of heavy metals from water involves enormous investment and operating costs for multi-stage cleaning systems. An inexpensive method is the use of brown coal or brown coal products as sorbents for heavy metals. Since brown coals are cheap and available in sufficient quantities, they can be used as so called one-way sorbents. The results of the investigations show that brown coals of the Lusatia area in Germany are able to effectively remove heavy metals from aqueous solutions. (orig.)

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

    International Nuclear Information System (INIS)

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

  6. 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 a...

  7. 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.

  8. 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.

  9. 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

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

    Science.gov (United States)

    Ahluwalia, Sarabjeet Singh; Goyal, Dinesh

    2007-09-01

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

  11. Use of electrocoagulation for removal of heavy metals in industrial wastewaters

    Energy Technology Data Exchange (ETDEWEB)

    Dalrymple, C.W. [Hydrologics, Inc., Englewood, CO (United States)

    1995-07-01

    A wide variety of contaminants (heavy metals, suspended solids, colloids, oils, organics) have been successfully removed from wastewater using an electrocoagulation process. An innovative electrocoagulation system is described. This process involves a procedure which subjects dissolved and suspended wastewater contaminants to the simultaneous addition of metal ions in the presence of direct current. During the treatment process ionic and other charged particles in the wastewater are neutralized with oppositely charged ions generating the coagulation of contaminants: The process is called CURE, and presented here with application to wastewaters containing mainly heavy metals.

  12. Poultry litter-based activated carbon for removing heavy metal ions in water.

    Science.gov (United States)

    Guo, Mingxin; Qiu, Guannan; Song, Weiping

    2010-02-01

    Utilization of poultry litter as a precursor material to manufacture activated carbon for treating heavy metal-contaminated water is a value-added strategy for recycling the organic waste. Batch adsorption experiments were conducted to investigate kinetics, isotherms, and capacity of poultry litter-based activated carbon for removing heavy metal ions in water. It was revealed that poultry litter-based activated carbon possessed significantly higher adsorption affinity and capacity for heavy metals than commercial activated carbons derived from bituminous coal and coconut shell. Adsorption of metal ions onto poultry litter-based carbon was rapid and followed Sigmoidal Chapman patterns as a function of contact time. Adsorption isotherms could be described by different models such as Langmuir and Freundlich equations, depending on the metal species and the coexistence of other metal ions. Potentially 404 mmol of Cu2+, 945 mmol of Pb2+, 236 mmol of Zn2+, and 250-300 mmol of Cd2+ would be adsorbed per kg of poultry litter-derived activated carbon. Releases of nutrients and metal ions from litter-derived carbon did not pose secondary water contamination risks. The study suggests that poultry litter can be utilized as a precursor material for economically manufacturing granular activated carbon that is to be used in wastewater treatment for removing heavy metals. PMID:19783133

  13. Simultaneous heavy metals removal and municipal sewage sludge dewaterability improvement in bioleaching processes by various inoculums.

    Science.gov (United States)

    Shi, Chaohong; Zhu, Nengwu; Shang, Ru; Kang, Naixin; Wu, Pingxiao

    2015-11-01

    The heavy metals content and dewaterability of municipal sewage sludge (MSS) are important parameters affecting its subsequent disposal and land application. Six kinds of inoculums were prepared to examine the characteristics of heavy metals removal and MSS dewaterability improvement in bioleaching processes. The results showed that Cu, Zn and Cd bioleaching efficiencies (12 days) were 81-91, 87-93 and 81-89%, respectively, which were significantly higher than those of Fe-S control (P sludge structure from flocculent to obvious granular and the formation of secondary minerals mainly consisting of iron, oxygen and sulfur elements. The results above demonstrated that bacterial consortium enriched from acid mine drainage (AMD) was suitable to boost sludge bioleaching for heavy metals removal and dewaterability improvement. It also suggested that the synergy of sulfur/ferrous-oxidizing bacteria (SFOB) enriched from AMD and the cooperation of exogenous and indigenous SFOB significantly promoted bioleaching efficiencies. PMID:26271772

  14. 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)

  15. A review on progress of heavy metal removal using adsorbents of microbial and plant origin.

    Science.gov (United States)

    Srivastava, Shalini; Agrawal, S B; Mondal, M K

    2015-10-01

    Heavy metals released into the water bodies and on land surfaces by industries are highly toxic and carcinogenic in nature. These heavy metals create serious threats to all the flora and fauna due to their bioaccumulatory and biomagnifying nature at various levels of food chain. Existing conventional technologies for heavy metal removal are witnessing a downfall due to high operational cost and generation of huge quantity of chemical sludge. Adsorption by various adsorbents appears to be a potential alternative of conventional technologies. Its low cost, high efficiency, and possibility of adsorbent regeneration for reuse and recovery of metal ions for various purposes have allured the scientists to work on this technique. The present review compiles the exhaustive information available on the utilization of bacteria, algae, fungi, endophytes, aquatic plants, and agrowastes as source of adsorbent in adsorption process for removal of heavy metals from aquatic medium. During the last few years, a lot of work has been conducted on development of adsorbents after modification with various chemical and physical techniques. Adsorption of heavy metal ions is a complex process affected by operating conditions. As evident from the literature, Langmuir and Freundlich are the most widely used isotherm models, while pseudo first and second order are popularly studied kinetic models. Further, more researches are required in continuous column system and its practical application in wastewater treatment. PMID:26315592

  16. 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 Pb2+ and Hg2+ 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 Pb2+ or Hg2+, a cation exchange reaction takes place, and the heavy metal ions are successfully removed. The removal capacity for the Pb2+ ions exceeds 98% and the removal of Hg2+ 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

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

    Science.gov (United States)

    Chemical remediation of soil may involve the use of harsh chemicals that generate waste streams, which may adversely affect the soil's integrity and ability to support vegetation. This article reviews the potential use of benign reagents, such as biopolymers, to extract heavy me...

  18. 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

  19. 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

  20. 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 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

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

    International Nuclear Information System (INIS)

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

  2. 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+.

  3. EDTA Removal of Heavy Metals from Contaminated Soils Using Column Leaching Experiments (Continuous and Pulse Modes

    Directory of Open Access Journals (Sweden)

    S. Heydari

    2015-08-01

    Full Text Available Consequences of heavy metal accumulation in soils are of great concern. One way of decontaminating heavy metals from soils is using chelating agents, particularly EDTA. In this research, three contaminated soils (with total concentration of these metals of 10.5, 55.8 and 80.6 mmol kg-1 were collected from the surface layer of the lands surrounding a zinc-lead smelting plant in Zanjan province. The extent of Zn, Pb and Cd release by Na2H2EDTA (100 mmol kg-1 of dry soil from these soils in column leaching experiments (both continuous and pulse addition methods assembled into half of saturated hydraulic conductivity was assessed. In preliminary experiments, the leaching was stopped due to a drop in hydraulic conductivity. Therefore, the continuous addition method was performed with calcium nitrate as the background solution and the pulse addition method was conducted using this background solution coupled with pH adjustment to 8. Based on the results, the percentage removal of Cd as well as Pb was relatively the same for the two addition methods while the removal of Zn was 13% on average higher in the continuous addition method than in the pulse addition method. For both methods, the removal efficiencies followed the order of complex stability constants (as Pb>Zn>Cd in a limited concentration range of EDTA to complex heavy metals. Furthermore, in contrast to Cd and Pb, a direct linear relationship was found between the percentage removal of Pb and its total amount in the soils. Surprisingly, the Pb concentration was on average only about one-twentieth of the Zn concentration. The breakthrough curves of both methods showed the mobility order of Cd>Zn>Pb. In general, it seems that the removal pattern of soil heavy metals is dependent not only on the soil type but also on the removal method.

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

    Energy Technology Data Exchange (ETDEWEB)

    Huang, Hann-Sheng; Livengood, Charles David

    1997-12-01

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

  5. 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...

  6. Chelating capture and magnetic removal of non-magnetic heavy metal substances from soil.

    Science.gov (United States)

    Fan, Liren; Song, Jiqing; Bai, Wenbo; Wang, Shengping; Zeng, Ming; Li, Xiaoming; Zhou, Yang; Li, Haifeng; Lu, Haiwei

    2016-01-01

    A soil remediation method based on magnetic beneficiation is reported. A new magnetic solid chelator powder, FS@IDA (core-shell Fe3O4@SiO2 nanoparticles coated with iminodiacetic acid chelators), was used as a reactive magnetic carrier to selectively capture non-magnetic heavy metals in soil by chelation and removal by magnetic separation. FS@IDA was prepared via inorganic-organic and organic synthesis reactions that generated chelating groups on the surface of magnetic, multi-core, core-shell Fe3O4@SiO2 (FS) nanoparticles. These reactions used a silane coupling agent and sodium chloroacetate. The results show that FS@IDA could chelate the heavy metal component of Cd, Zn, Pb, Cu and Ni carbonates, lead sulfate and lead chloride in water-insoluble salt systems. The resulting FS@IDA-Cd and FS@IDA-Pb chelates could be magnetically separated, resulting in removal rates of approximately 84.9% and 72.2% for Cd and Pb, respectively. FS@IDA could not remove the residual heavy metals and those bound to organic matter in the soil. FS@IDA did not significantly alter the chemical composition of the soil, and it allowed for fast chelating capture, simple magnetic separation and facilitated heavy metal elution. FS@IDA could also be easily prepared and reprocessed. PMID:26878770

  7. 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

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

    International Nuclear Information System (INIS)

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

  9. Heavy metal removal from acid mine drainage by calcined eggshell and microalgae hybrid system.

    Science.gov (United States)

    Choi, Hee-Jeong; Lee, Seung-Mok

    2015-09-01

    This study investigates the use of calcined eggshells and microalgae for the removal of heavy metals from acid mine drainage (AMD) and the simultaneous enhancement of biomass productivity. The experiment was conducted over a period of 6 days in a hybrid system containing calcined eggshells and the microalgae Chlorella vulgaris. The results show that the biomass productivity increased to ~8.04 times its initial concentration of 0.367 g/L as measured by an optical panel photobioreactor (OPPBR) and had a light transmittance of 95 % at a depth of 305 mm. On the other hand, the simultaneous percent removal of Fe, Cu, Zn, Mn, As, and Cd from the AMD effluent was found to be 99.47 to 100 %. These results indicate that the hybrid system with calcined eggshells and microalgae was highly effective for heavy metal removal in the AMD. PMID:25940497

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

    Science.gov (United States)

    Singh, Anil Kumar; Cameotra, Swaranjit Singh

    2013-10-01

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

  11. 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.

  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 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 circulation through the airlift. Concerning the process of metal removal it could be shown, that processes of metal precipitation were responsible for an essential part of the total removal (biosorption only played a minor role, intracellular uptake could be excluded). Experiments in the lab sand filter showed, that these processes of precipitation were dependent on the bacterial metabolism ('bioprecipitation' of metals). Moreover, it could be demonstrated that an increased metal removal could be achieved under anoxic (denitrifying) conditions in the sand filter. The new process of metal immobilization was proved in a sand filter pilot system treating rinsing water of a chemical nickel plating plant. An increased metal removal of the system could be achieved by increasing the metabolic activity in the sand filter. In such a way, a metal removal capacity for practical application of the new technology could be demonstrated. Taking into consideration the technical properties of the moving bed sand filter (variable size, continuous operation, additional mechanical filtration, moderate installation and operation costs) and the metal removal capacity of the active filter, the new process represents a real alternative to existing technologies, especially in the case of high waste water flows with low heavy metal contents, for example as a final polishing step after conventional pre-treatment. (author)

  13. Removal of heavy metals from toxic wastes using composite polypyrrole films

    International Nuclear Information System (INIS)

    In this paper, we will present a new method of removal of heavy metals such as Pb2+, Ni+2, Ca+2, Cd+2 from contaminated waters or toxic wastes by using conductive polymer films. Procedures used in the preparation of composite polypyrrole films will be discussed. These films, when electrodeposited on the electrode, are capable of fast and efficient incorporation of any heavy metals which exist in aqueous solution in the form of cations by applying suitable potential step. To track the incorporation or release of heavy metals from the film, the Electrochemical Quartz Crystal Microbalance (EQCM) has been used. The EQCM technique, as a sensitive piezoelectric sensor offers a direct and open-quotes in-situclose quotes measurement of ion selectivity and ion dynamics in these conductive polymer films. The selectivity coefficients for a variety of heavy metals versus Na+ were evaluated. An electrochemical post-treatment step restores the incorporation capacity of the composite polymer for heavy metals to its initial state

  14. Removal Efficiency of Heavy Metals Using Various Resins and Natural Materials

    Directory of Open Access Journals (Sweden)

    M. Cochran

    2012-01-01

    Full Text Available Heavy metals found in local water are an environmental concern. These metals are potentially harmful since they can bio-accumulate in organisms and have been classified as toxic and/or carcinogenic. In this study, water was collected from a shipyard located on a bayou. Various materials (chitosan, mixed bed and amphoteric resins were tested to determine their efficiency for metal remediation. Inductively coupled plasma mass spectrometry (ICP/MS was used to quantify the efficiency of the materials examined. Overall, amphoteric resin was found to be the most efficient for a greater number of metals examined (Al, Co, Cu, Fe, Mn, followed by mixed bed which most efficiently removed As and Fe. Chitosan showed the poorest efficiency for metal removal.

  15. Rhizofiltration - the use of plants to remove heavy metals from aqueous streams

    Energy Technology Data Exchange (ETDEWEB)

    Raskin, I.; Dushenkov, V.; Kumar, P.B.A.N.; Motto, H. [Rutgers Univ., New Brunswick, NJ (United States)

    1995-12-31

    Heavy metal pollution of water is a major environmental problem facing the modern world. Rhizofiltration - the use of plant roots to remove heavy metals from water is an emerging environmental clean-up technology. Roots of many hydroponically grown terrestrial plants e.g. Indian mustard, sunflower (Hefianthus annuus L.) and various grasses effectively removed toxic metals such as CU{sup -2}, Cd{sup +2}Cr{sup +6}, Ni{sup +2}Pb{sup +2} and Zn{sup +2} from aqueous solutions. Roots of B. juncea concentrated these metals 131 to 563-fold (on a DW basis) above initial solution concentrations. Pb removal was based on tissue absorption and on root-mediated Pb precipitation in the form of insoluble inorganic compounds, mainly Pb phosphate. At high Pb concentrations precipitation played a progressively more important role in Pb removal than tissue absorption, which saturated at approximately 100 {mu}g Pb/g DW root. Dried roots were much less effective than live roots in accumulating Pb and in removing Pb from the solution.

  16. 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)

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

    Science.gov (United States)

    Yousefi, Z.; Zazouli, M. A.

    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.

  18. 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.

  19. Heavy metals removal from aqueous environments by electrocoagulation process- a systematic review.

    Science.gov (United States)

    Bazrafshan, Edris; Mohammadi, Leili; Ansari-Moghaddam, Alireza; Mahvi, Amir Hossein

    2015-01-01

    Heavy metals pollution has become a more serious environmental problem in the last several decades as a result releasing toxic materials into the environment. Various techniques such as physical, chemical, biological, advanced oxidation and electrochemical processes were used for the treatment of domestic, industrial and agricultural effluents. The commonly used conventional biological treatments processes are not only time consuming but also need large operational area. Accordingly, it seems that these methods are not cost-effective for effluent containing toxic elements. Advanced oxidation techniques result in high treatment cost and are generally used to obtain high purity grade water. The chemical coagulation technique is slow and generates large amount of sludge. Electrocoagulation is an electrochemical technique with many applications. This process has recently attracted attention as a potential technique for treating industrial wastewater due to its versatility and environmental compatibility. This process has been applied for the treatment of many kinds of wastewater such as landfill leachate, restaurant, carwash, slaughterhouse, textile, laundry, tannery, petroleum refinery wastewater and for removal of bacteria, arsenic, fluoride, pesticides and heavy metals from aqueous environments. The objective of the present manuscript is to review the potential of electrocoagulation process for the treatment of domestic, industrial and agricultural effluents, especially removal of heavy metals from aqueous environments. About 100 published studies (1977-2016) are reviewed in this paper. It is evident from the literature survey articles that electrocoagulation are the most frequently studied for the treatment of heavy metal wastewater. PMID:26512324

  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. 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)

  3. On the use of biosurfactants for the removal of heavy metals from oil-contaminated soil

    Energy Technology Data Exchange (ETDEWEB)

    Mulligan, C.N. [Concordia Univ., Montreal, Quebec (Canada). Dept. of Building, Civil and Environmental Engineering; Yong, R.N. [Univ. of Wales, Cardiff (United Kingdom); Gibbs, B.F. [Bivan Consultants Inc., Montreal, Quebec (Canada). Environmental Div.

    1999-05-01

    The feasibility of using biodegradable biosurfactants to remove heavy metals from an oil-contaminated soil was evaluated by batch washes with surfactin, a rhamnolipid and a sophorolipid. The soil contained 890 mg/kg of zinc and 420 mg/kg of copper with a 12.6% oil and grease content. Highest levels of zinc removal were obtained using 12% rhamnolipid and 4% sophorolipid/0.7% HCl. Highest copper removal rates were achieved with 12% rhamnolipid or with 2% rhamnolipid/1% NaOH or 0.25% surfactin/1% NaOH. A series of five batch washes removed 70% of the copper with 0.1% surfactin/1% NaOH while 4% sophorolipid/0.7% HCl was able to remove 100% of the zinc. Sequential extraction procedures showed that the carbonate and oxide fractions accounted for over 90% of the zinc present in the soil and the organic fraction in the soil constituted over 70% of the copper. Sequential extraction of the soil after washing with the surfactin or rhamnolipid indicated that these surfactants could remove the organically-bound copper and that the sophorolipid with acid could remove the carbonate and oxide-bound zinc. In conclusion, the results clearly indicated the feasibility of removing the metals with the anionic biosurfactants tested even though the exchangeable metal fractions were very low.

  4. 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.

  5. Removal of heavy metal ions from aqueous solution by zeolite synthesized from fly ash.

    Science.gov (United States)

    He, Kuang; Chen, Yuancai; Tang, Zhenghua; Hu, Yongyou

    2016-02-01

    Zeolite was synthesized from coal fly ash by a fusion method and was used for the removal of heavy metal ions (Pb(2+), Cd(2+), Cu(2+), Ni(2+), and Mn(2+)) in aqueous solutions. Batch method was employed to study the influential parameters such as adsorbent dosage, pH, and coexisting cations. Adsorption isotherms and kinetics studies were carried out in single-heavy and multiheavy metal systems, respectively. The Langmuir isotherm model fitted to the equilibrium data better than the Freundlich model did, and the kinetics of the adsorption were well described by the pseudo-second-order model, except for Cd(2+) and Ni(2+) ions which were fitted for the pseudo-first-order model in the multiheavy metal system. The maximum adsorption capacity and the distribution coefficients exhibited the same sequence for Pb(2+) > Cu(2+) > Cd(2+) > Ni(2+) > Mn(2+) in both single- and multiheavy metal systems. In the end, the adsorption capacity of zeolite was tested using industrial wastewaters and the results demonstrated that zeolite could be used as an alternative adsorbent for the removal of heavy metal ions from industrial wastewater. PMID:26446735

  6. 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

  7. Application of Novel Nanoporous Sorbents for the Removal of Heavy Metals, Metalloids, and Radionuclides

    International Nuclear Information System (INIS)

    A new class of hybrid nanoporous materials for removing toxic heavy metals, oxyanions, and radionuclides from aqueous waste streams has been developed at the Pacific Northwest National Laboratory. These novel materials consist of functional molecules such as thiols, ethylenediamine complexed copper, and carbamoylphosphonates that are self-assembled as monolayers within the nanopores of a synthetic silica-based material. Tests indicated that these sorbents (self-assembled monolayers on mesoporous silica ? SAMMS) can achieve very high sorbate loadings (?6 meq/g) very rapidly with relatively high specificity (Kd: 1?108 ml/g). Because of the specifically tunable nature of the functionalities, these nanoporous sorbents can be targeted to remove a selected category of contaminants such as heavy metals (Ag, Cd, Cu, Hg, and Pb), oxyanions (As and Cr), and radionuclides (137Cs, 129I, 237Np, and isotopes of Pu, Th, and U) from waste streams

  8. Removal of heavy metal ions from wastewater by chemically modified plant wastes as adsorbents: a review.

    Science.gov (United States)

    Wan Ngah, W S; Hanafiah, M A K M

    2008-07-01

    The application of low-cost adsorbents obtained from plant wastes as a replacement for costly conventional methods of removing heavy metal ions from wastewater has been reviewed. 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 general, chemically modified plant wastes exhibit higher adsorption capacities than unmodified forms. Numerous chemicals have been used for modifications which include mineral and organic acids, bases, oxidizing agent, organic compounds, etc. In this review, an extensive list of plant wastes as adsorbents including rice husks, spent grain, sawdust, sugarcane bagasse, fruit wastes, weeds and others has been compiled. Some of the treated adsorbents show good adsorption capacities for Cd, Cu, Pb, Zn and Ni. PMID:17681755

  9. Zeolitic adsorbent synthesized from powdered waste porcelain, and its capacity for heavy metal removal

    International Nuclear Information System (INIS)

    A zeolitic adsorbent was synthesized from powdered waste porcelain kept at 80oC for 24 h. The product contained the zeolite phases Na-P1 and hydroxysodalite. The product with the highest cation exchange capacity (CEC) was synthesized using 4 M NaOH and the sample weight / volume of alkali solution ratio was 1/4. The highest CEC obtained for the product was almost 1900 mmol/kg, which is the same as that of natural zeolite. The product with the highest CEC was tested for its ability to remove heavy metals (Fe, Cu, Ni, Zn, Pb, Cd, Mn, Cr, Al, B,Mo) from an acidic solution (pH 2). The product can neutralize the acidic solution to almost pH 7, and the capacity of the product for the removal of heavy metals is higher than that of the natural zeolite, except for Mo and B. (authors)

  10. Synthesis of LTA zeolite on corundum supports: Preliminary assessment for heavy metal removal from waste water

    International Nuclear Information System (INIS)

    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 SiO2/Al2O3 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 (? 4,7). (Author) 28 refs.

  11. Theoretical analysis of air classifiers used to remove heavy metals from soil

    International Nuclear Information System (INIS)

    Extensive nuclear testing that has been conducted at the Nevada Test Site, other Department of Energy (DOE) sites, and many Naval Facilities Command (NAFAC) sites has left heavy metal radioactive contaminants such as plutonium in the soil. Environmental restoration efforts have been initiated to purify the contaminated areas. The current effort by DOE involves many different approaches including physical, chemical and biological separation. This paper presents a theoretical analysis of the potential of air classifiers used to remove heavy metals from soil. Spreadsheet calculations indicate that air classifiers in conjunction with sieves can theoretically exceed the project goal which is to remove 80% or more of the plutonium with 20% or less (by volume) of the soil

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

    International Nuclear Information System (INIS)

    Magnetic polymer resins capable of efficient removal of actinides and heavy metals from contaminated water are disclosed together with methods for making, using, and regenerating them. The resins comprise polyamine-epichlorohydrin resin beads with ferrites attached to the surfaces of the beads. Markedly improved water decontamination is demonstrated using these magnetic polymer resins of the invention in the presence of a magnetic field, as compared with water decontamination methods employing ordinary ion exchange resins or ferrites taken separately. 9 figs

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

    DEFF Research Database (Denmark)

    Larsen, Torben; Neerup-Jensen, O.

    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...... which cover realistic sizes show that the long-term discharges of PAH are about half of the expected values without removal....

  14. The removal of heavy metals from aqueous solution by adsorption on weathered coal

    Energy Technology Data Exchange (ETDEWEB)

    Meena, A.K.; Gupta, M.D.; Mishra, G.K.; Rajagopal, C.; Nagar, P.N. [Central Research Institute (Ayurveda), Gwalior (India)

    2009-07-01

    The adsorption followed first-order kinetics. 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. On the basis of experimental results, it can be inferred that the adsorbent weathered coal may be useful in developing an adsorptive technology for the removal of heavy metals. 25 refs., 8 figs., 4 tabs.

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

    Science.gov (United States)

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

    1997-01-21

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

  16. 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

  17. 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...

  18. Removal of some heavy metals from wastewater using radiation-adsorption methods

    International Nuclear Information System (INIS)

    In the present study, a try was made to explain the degradation kinetics due to gamma irradiation and adsorption of some heavy metals, nickel, copper and cobalt. Factors affecting the process such as concentration, irradiation dose and pH of the solution were studied. Gamma radiation doses up to 20 kGy did not result in the degradation of the valency of these metal ions to other oxidation states that may have lower toxicity. Adsorption and ion-exchange purification of the heavy metals onto GAC, Merck Ion Exchangers I, IV and polymeric membranes. This may be due to its very high surface area and high porous nature. GAC was followed by the cation exchanger 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. (author)

  19. 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.

  20. 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.

  1. 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 system was applied to develop an analytical procedure for the retention of low concentrations of lead in wastewater and determination by ETAAS.

  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. Heavy metal removal from sewage sludge ash by thermochemical treatment with polyvinylchloride.

    Science.gov (United States)

    Vogel, Christian; Exner, Robert M; Adam, Christian

    2013-01-01

    Sewage sludge ash (SSA) is a prospective phosphorus source for the future production of recycling P-fertilizers. Due to its high heavy metals contents and the relatively low P plant-availability, SSA must be treated before agricultural utilisation. In this paper SSA was thermochemically treated with PVC in a bench-scale rotary furnace in order to remove heavy metals via the chloride pathway. PVC has a high Cl-content of 52-53% and a high heating value that can be beneficially used for the thermochemical process. Large amounts of waste PVC are already recovered in recycling processes, but there are still some fractions that would be available for the proposed thermochemical process, for example, the low quality near-infrared(NIR)-fraction from waste separation facilities. Heavy metals were effectively removed at temperatures in the range of 800-950 °C via the gas phase by utilisation of PVC as Cl-donor. The resulting P plant-availability was comparable to SSA thermochemically treated with MgCl(2) as Cl-donor if MgO was used as an additive (Mg-donor). A further increase of the plant availability of phosphorus was achieved by acid post-treatment of the thermochemically treated SSA. PMID:23189972

  5. 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; Ottosen, Lisbeth M.; Jensen, Pernille Erland; Lejon, Tore

    2015-01-01

    , 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....

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

    DEFF Research Database (Denmark)

    Sun, Tian Ran

    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......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...

  7. A novel route for the removal of bodily heavy metal lead (II)

    Science.gov (United States)

    Huang, Weirong; Zhang, Penghua; Xu, Hui; Chang, Shengli; He, Yongju; Wang, Fei; Liang, Gaowei

    2015-09-01

    The lead ion concentration in bile is considerably higher than in blood, and bile is released into the alimentary tract. Thiol-modified SBA-15 administered orally can combine with lead ions in the alimentary tract. In this paper, the in vitro lead absorption of bile was investigated. This thiol-modified SBA-15 material was used in pharmacodynamics studies on rabbits. The result that the lead content in faeces was notably higher indicates that thiol-modified SBA-15 can efficiently remove lead. The mechanism could include the following: thiol-modified SBA-15 material cuts off the heavy metal lead recirculation in the process of bile enterohepatic circulation by chelating the lead in the alimentary tract, causing a certain proportion of lead to be removed by the thiol mesoporous material, and the lead is subsequently egested out of the body in faeces. The results indicate that this material might be a potential non-injection material for the removal bodily heavy metal lead in the alimentary tract. This material may also be a useful means of lead removal, especially for non-acute sub-poisoning symptoms.

  8. 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.

  9. Adsorptive removal of heavy metals by magnetic nanoadsorbent: an equilibrium and thermodynamic study

    Science.gov (United States)

    Shirsath, D. S.; Shirivastava, V. S.

    2015-11-01

    An efficient and new magnetic nanoadsorbent photocatalyst was fabricated by co-precipitation technique. This research focuses on understanding metal removal process and developing a cost-effective technology for treatment of heavy metal-contaminated industrial wastewater. In this investigation, magnetic nanoadsorbent has been employed for the removal of Zn(II) ions from aqueous solutions by a batch adsorption technique. The adsorption equilibrium data fitted very well to Langmuir and Freundlich adsorption isotherm models. The thermodynamics of Zn(II) ions adsorption onto the magnetic nanoadsorbents indicated that the adsorption was spontaneous, endothermic and physical in nature. Surface morphology of magnetic nanoadsorbent by scanning electron microscopy (SEM) and elemental analysis by EDX technique. The structural and photocatalytic properties of magnetic nanoadsorbent were characterized using X-ray diffraction (XRD) and FTIR techniques. Also, the magnetic properties of synthesized magnetic nanoadsorbent were determined by vibrating spinning magnetometer (VSM).

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

    Science.gov (United States)

    El Zayat, Mohamed; Smith, Edward

    2013-01-01

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

  11. 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

  12. 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.

  13. 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)

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2010-12-15

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

  15. Heavy-metal removal from petroleum oily sludge using lemon- scented geraniums[General Conference

    Energy Technology Data Exchange (ETDEWEB)

    Badawieh, A.; Elektorowicz, M. [Concordia Univ., Montreal, PQ (Canada). Dept. of Building, Civil and Environmental Engineering

    2006-07-01

    Finding an acceptable method to manage oily sludge generated during petroleum processes is one of the challenges currently facing the petroleum industry. This study investigated the response of plants to heavy-metal removal from oily sludge to determine the feasibility of using phytoremediation technologies as a treatment method for oily sludge. In particular, scented geraniums (Pelargonium sp. Frensham) have shown a strong capability to survive harsh conditions such as poor soil, high/low temperatures, high heavy-metal concentrations and low water content. In response to this observation, this feasibility study placed scented geraniums in a series of pots containing oily sludge where heavy-metal concentrations were artificially increased up to 2000 ppm. Plants were grown in two systems over a period of 50 days. The first system included oily sludge and soil while the second system included oily sludge, soil and compost. The study revealed that the scented geraniums accumulated up to 1600 mg, 1000 mg, and 1200 mg, of cadmium, nickel and vanadium respectively per 1 kg of the plant's dry weight. The results suggest that phytoremediation technology may be a potential method for successfully treating or pretreating oily sludge in the field.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2010-10-01

    Functionalized nanoporous silica, often referred to as self-assembled monolayers on mesoporous supports (SAMMS) have previously demonstrated the ability to serve as very effective heavy metal sorbents in a range of aquatic and environmental systems suggesting they may be advantageously utilized for biomedical applications such as chelation therapy. Herein we evaluate surface chemistries for heavy metal capture from biological fluids, various facets of the materials biocompatibility and the suitability of these materials as potential therapeutics. Of the materials tested, thiol-functionalized SAMMS proved most capable of removing selected heavy metals from biological solutions (i.e. blood, urine, etc.) As a result, thiol SAMMS was further analyzed to assess the material’s performance under a number of different biologically relevant conditions (i.e. variable pH and ionic strength) as well to gauge any potentially negative cellular effects resulting from interaction with the sorbent, such as cellular toxicity or possible chelation of essential minerals. Additionally, cellular uptake studies demonstrated no cell membrane permeation by the silica-based materials generally highlighting their ability to remain cellularly inert and thus non-toxic. As a result, it has been determined that organic ligand-functionalized nanoporous silica materials could be a valuable material for detoxification therapeutics and potentially other biomedical applications as needed.

  17. 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.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2012-11-01

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

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

    OpenAIRE

    Kunierová 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 a...

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

    OpenAIRE

    Rafeah Wahi; Herman Senghie

    2011-01-01

    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 is...

  1. 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.

  2. 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.

  3. Removal of heavy metals from aqueous solution using Rhizopus delemar mycelia in free and polyurethane-bound form

    International Nuclear Information System (INIS)

    This study assesses the ability of mycelia of Rhizopus delemar (both free and immobilized on polyurethane foam) to remove heavy metals from single-ion solutions as well as from a mixture of them. All experiments were conducted using 0.5-5 mM solutions of CuSO4.5H2O, CoCl2.6H2O and FeSO4.7H2O. Mycelia immobilized on polyurethane foam cells showed some times increase in uptake compared with that of free cells. Metal ions accumulation from a mixed solution was decreased slightly for cobalt and iron and considerable for copper ions. Heavy metal uptake was examined in the immobilized column experiments and more than 92% heavy metal removal (mg heavy metals removed/mg heavy metals added) from a mixed solution was achieved during the 5 cycles. During these experiments, the dry weight of the immobilized cells was decreased by only 2%. These results showed that immobilized mycelia of Rhizopus delemar can be used repeatedly for removal of heavy metals from aqueous solutions. (orig.)

  4. 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)

  5. A study of the removal characteristics of heavy metals from wastewater by low-cost adsorbents

    Directory of Open Access Journals (Sweden)

    Omar E. Abdel Salam

    2011-10-01

    Full Text Available In this study, the adsorption behavior of some low-cost adsorbents such as peanut husk charcoal, fly ash, and natural zeolite, with respect to Cu2+, and Zn2+ ions, has been studied in order to consider its application to the purification of metal finishing wastewater. The batch method was employed: parameters such as pH, contact time, and initial metal concentration were studied. The influence of the pH of the metal ion solutions on the uptake levels of the metal ions by the different adsorbents used were carried out between pH 4 and pH 11. The optimum pH for copper and zinc removal was 6 in the case of peanut husk charcoal and natural zeolite, and it was 8 in case of fly ash. An equilibrium time of 2 h was required for the adsorption of Cu(II and Zn(II ions onto peanut husk charcoal and fly ash and an equilibrium time 3 h was required for the adsorption of Cu(II and Zn(II ions onto natural zeolite. Adsorption parameters were determined using both Langmuir and Freundlich isotherms, but the experimental data were better fitted to the Langmuir equation than to Freundlich equation. The results showed that peanut husk charcoal, fly ash and natural zeolite all hold potential to remove cationic heavy metal species from industrial wastewater in the order fly ash < peanut husk charcoal < natural zeolite.

  6. An immobilized cell bioprocess for the removal of heavy metals from aqueous flows

    International Nuclear Information System (INIS)

    Microorganisms can be used to remove toxic heavy metals from liquid industrial wastes. In addition to the chemical toxicity of many of the latter, the production of long-lived nuclides from nuclear power programmes has introduced additional radiotoxicological hazards. Associated problems of the presence of contaminating, non-metal co-pollutants and the presentation of dilute, high-volume wastes have received little attention. Traditional biotechnological waste treatments have relied either on the use of non-living biomass ('biosorption') or on the accumulation of metals by living cells with the associated problems of metal toxicity effects and the requirements for cell viability or growth. Identification of an enzymically-mediated metal accumulation step can permit decoupling of cell growth from metal accumulation. Using pre-grown biomass immobilized in a flow-through filter ('bioreactor') the metal-accumulative bioprocess can be described accurately applying traditional Michaelis-Menten kinetics. The effect of co-pollutants can be then quantified in order to run the bioreactor in the most efficient way. (author)

  7. 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% (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.

  8. The mechanisms of removal of heavy metals from water by ionizing radiation

    Science.gov (United States)

    Chaychian, Mahnaz; Al-Sheikhly, Mohamad; Silverman, Joseph; McLaughlin, William L.

    1998-08-01

    The removal of heavy metal ions from water using electron beam and gamma irradiation has been investigated for the cases of Pb 2+ and Hg 2+ ions. These metal ions are reduced by hydrated electrons and hydrogen atoms to lower or zero valence state and eventually precipitate out of solution. Ethanol is applied as a relatively non-toxic additive to scavenge ·OH radicals, to enhance reduction and inhibit oxidation. Mercury can be completely (>99.9%) removed from aqueous solution of 1×10 -3 mol L -1 mercury (II) chloride by using a 3 kGy dose. However, a 40 kGy dose is required to remove 96% of lead ions from a 1×10 -3 mol L -1 of PbCl 2 solution. The effect of dissolved oxygen and carbonate were also investigated. E-beam irradiation of 1×10 -3 mol L -1 lead ions complexed with ethylenediamine tetraacetic acid (EDTA) in deoxygenated as well as air-saturated solutions in the absence of ethanol resulted in removal of about 97% of the lead.

  9. The mechanisms of removal of heavy metals from water by ionizing radiation

    International Nuclear Information System (INIS)

    The removal of heavy metal ions from water using electron beam and gamma irradiation has been investigated for the cases of Pb2+ and Hg2+ ions. These metal ions are reduced by hydrated electrons and hydrogen atoms to lower or zero valence state and eventually precipitate out of solution. Ethanol is applied as a relatively non-toxic additive to scavenge ·OH radicals, to enhance reduction and inhibit oxidation. Mercury can be completely (>99.9%) removed from aqueous solution of 1x10-3 mol L-1 mercury (II) chloride by using a 3 kGy dose. However, a 40 kGy dose is required to remove 96% of lead ions from a 1x10-3 mol L-1 of PbCl2 solution. The effect of dissolved oxygen and carbonate were also investigated. E-beam irradiation of 1x10-3 mol L-1 lead ions complexed with ethylenediamine tetraacetic acid (EDTA) in deoxygenated as well as air-saturated solutions in the absence of ethanol resulted in removal of about 97% of the lead

  10. 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

  11. 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 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

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

    Energy Technology Data Exchange (ETDEWEB)

    Genc, Oe.; Soysal, L.; Bayramoglu, G.; Arica, M.Y.; Bektas, S

    2003-02-28

    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 {mu}mol/cm{sup 2} 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 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.

  13. 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.

  14. synthesis and utilization of some new chelating resins in heavy metal ions removal from waste water

    International Nuclear Information System (INIS)

    four types of chelating resins were synthesized and used in the removal of heavy metal ions from solutions using batch and column methods. these chelating resins are based on poly (glycidyl methacrylate - co - N, N - methylene -bis -acrylamide) and containing ethylenediamine, iminodiacetic acid, and dithiocarbamate ligands for the chelating resins xxxviii, xxxix,and xxxx, respectively. also, the chelating resin xxxxii based on poly ( acrylonitrile - co- divinylbenzene) and functionalized with amidoxime group was prepared . the chemical structure of these chelating resins were confirmed from their infrared spectra and elemental analysis. the different factors affecting the metal ions adsorption of these chelating resins such as Ph, treatment time, cross - linking density and type of chelating resins were studied

  15. 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.; Villumsen, Arne

    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 e...

  16. Rapid Preparation of Biosorbents with High Ion Exchange Capacity from Rice Straw and Bagasse for Removal of Heavy Metals

    OpenAIRE

    Supitcha Rungrodnimitchai

    2014-01-01

    This work describes the preparation of the cellulose phosphate with high ion exchange capacity from rice straw and bagasse for removal of heavy metals. In this study, rice straw and bagasse were modified by the reaction with phosphoric acid in the presence of urea. The introduced phosphoric group is an ion exchangeable site for heavy metal ions. The reaction by microwave heating yielded modified rice straw and modified bagasse with greater ion exchange capacities (?3.62?meq/g) and shorter rea...

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

    International Nuclear Information System (INIS)

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

  18. BIOSORPTIVE REMOVAL OF HEAVY METALS (Cd+2, Pb+2 AND Cu+2 FROM AQUEOUS SOLUTIONS BY CASSIA ANGUSTIFOLIA BARK

    Directory of Open Access Journals (Sweden)

    MADHAVI G MULGUND,

    2011-02-01

    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. The aim of this present study was to investigate the removal of heavy metals (Cd+2, Pb+2 and Cu+2 using Cassia angustifolia bark. The objective was to evaluate the biosorbent for its metal uptake and study its batch equilibrium. The batch mode was carried out at varying initial pH (5 to 9, emperature (300C to 450C, metal ion concentration (20mg to 140mg/L and contact time (5 min to 240 min and desorption studies from pH 1 to 11. The equilibrium data obtained fit well in Langmuir and Freundlich isotherms. The results of the investigations show the efficacy of Cassia angustifolia bark as a low cost promising biosorbent for removal of heavy metals from industrial wastewaters.

  19. 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.

  20. 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

  1. Pectin-rich fruit wastes as biosorbents for heavy metal removal: equilibrium and kinetics.

    Science.gov (United States)

    Schiewer, Silke; Patil, Santosh B

    2008-04-01

    Biosorption can be used as a cost effective and efficient technique for the removal of toxic heavy metals from wastewater. Waste materials from industries such as food processing and agriculture may act as biosorbents. This study investigates the removal of cadmium by fruit wastes (derived from several citrus fruits, apples and grapes). Citrus peels were identified as the most promising biosorbent due to high metal uptake in conjunction with physical stability. Uptake was rapid with equilibrium reached after 30-80 min depending on the particle size (0.18-0.9 mm). Sorption kinetics followed a second-order model. Sorption equilibrium isotherms could be described by the Langmuir model in some cases, whereas in others an S-shaped isotherm was observed, that did not follow the Langmuir isotherm model. The metal uptake increased with pH, with uptake capacities ranging between 0.5 and 0.9 meq/g of dry peel. Due to their low cost, good uptake capacity, and rapid kinetics, citrus peels are a promising biosorbent material warranting further study. PMID:17540559

  2. Toxicity and removal of heavy metals (cadmium, copper, and zinc) by Lemna gibba.

    Science.gov (United States)

    Megateli, Smain; Semsari, Saida; Couderchet, Michel

    2009-09-01

    Effects of cadmium, copper, and zinc on the aquatic plant Lemna gibba were determined under controlled conditions; in parallel their removal from the growth medium was followed. The results showed that the three heavy metals affected growth, a physiological stress index defined as the ratio of Chlorophyll to phaeophytin (D665/D665a), and the contents of proline. After 4 days, 10(-3)-10(-1)mg/L Cd inhibited growth by 25-100%, reduced D665/D665a by 35-89%, and increased proline content by 44-567%. Under the same conditions, 10(-4)-10(-1) microg/L Cu inhibited growth by 36-75%, reduced D665/D665a by 19-81%, and increased proline content by 67-288%. Comparable concentrations of Zn had little effect. However, higher concentrations (4, 30, and 50mg/L) inhibited growth by 50-79%. Also, 0.1 and 30 mg/L induced a small reduction of D665/D665a (-3.8% and -22%) and an increase in proline contents (+144% and +177%). When it was observed, proline accumulation was always transient and the maximum was reached after 4 days. Monitoring metal concentration in the medium showed that L. gibba was able to remove metals from the medium. Zn and Cu removal was biphasic, it was rapid during the first 2 days (> 60% reduction) and slow (10-20%) during the following 8 days. For Cd, removal was linear and depended on the initial concentration. It reached approximately 90% after 6 or 8 days for initial concentrations of 10(-1) and 10(-3)mg/L, respectively. PMID:19505721

  3. Organic substrates as electron donors in permeable reactive barriers for removal of heavy metals from acid mine drainage.

    Science.gov (United States)

    Kijjanapanich, P; Pakdeerattanamint, K; Lens, P N L; Annachhatre, A P

    2012-12-01

    This research was conducted to select suitable natural organic substrates as potential carbon sources for use as electron donors for biological sulphate reduction in a permeable reactive barrier (PRB). A number of organic substrates were assessed through batch and continuous column experiments under anaerobic conditions with acid mine drainage (AMD) obtained from an abandoned lignite coal mine. To keep the heavy metal concentration at a constant level, the AMD was supplemented with heavy metals whenever necessary. Under anaerobic conditions, sulphate-reducing bacteria (SRB) converted sulphate into sulphide using the organic substrates as electron donors. The sulphide that was generated precipitated heavy metals as metal sulphides. Organic substrates, which yielded the highest sulphate reduction in batch tests, were selected for continuous column experiments which lasted over 200 days. A mixture of pig-farm wastewater treatment sludge, rice husk and coconut husk chips yielded the best heavy metal (Fe, Cu, Zn and Mn) removal efficiencies of over 90%. PMID:23437664

  4. 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.

  5. 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 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

  6. 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

  7. 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

  8. 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.

  9. Removing adsorbed heavy metal ions from sand surfaces via applying interfacial properties of rhamnolipid.

    Science.gov (United States)

    Haryanto, Bode; Chang, Chien-Hsiang

    2015-01-01

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

  10. Microfungal spores (Ustilago maydis and U. digitariae) immobilised chitosan microcapsules for heavy metal removal.

    Science.gov (United States)

    Sarg?n, ?dris; Arslan, Gulsin; Kaya, Murat

    2016-03-15

    Designing effective chitosan-based biosorbents from unexploited biomass for heavy metal removal has received much attention over the past decade. Ustilago, loose smut, is a ubiquitous fungal plant pathogen infecting over 4000 species including maize and weed. This study aimed to establish whether the spores of the phytopathogenic microfungi Ustilago spores can be immobilised in cross-linked chitosan matrix, and it reports findings on heavy metal sorption performance of chitosan/Ustilago composite microcapsules. Immobilisation of Ustilago maydis and U. digitariae spores (from maize and weed) in chitosan microcapsules was achieved via glutaraldehyde cross-linking. The cross-linked microcapsules were characterised using scanning electron microscopy, FT-IR spectroscopy and thermogravimetric analysis. Sorption capacities of chitosan-U. maydis and chitosan-U. digitariae microcapsules were investigated and compared to cross-linked chitosan beads: Cu(II): 66.72, 69.26, 42.57; Cd(II): 49.46, 53.96, 7.87; Cr(III): 35.88, 49.40, 43.68; Ni(II): 41.67, 33.46, 16.43 and Zn(II): 30.73, 60.81, 15.04mg/g, respectively. Sorption experiments were conducted as a function of initial metal ion concentration (2-10mg/L), contact time (60-480min), temperature (25, 35 and 45°C), amount of the sorbent (0.05-0.25g) and pH of the metal solution. The microcapsules with spores exhibited better performance over the plain chitosan beads, demonstrating their potential use in water treatment. PMID:26794753

  11. Chemical studies for the removal of some heavy metals from toxic waste solutions using organic and inorganic sorbents

    International Nuclear Information System (INIS)

    the use of organic and inorganic sorbents in the treatment of toxic wastes to remove the heavy metals from these wastes is based on their resistance to chemical attack, specially thermal resistance and selectivity of inorganic sorbents and specially high measured capacities of organic resins. organic and inorganic sorbents have faced many applications not only in hydrometallurgy of rare elements, preparation of high purity materials, water purification but also in the removal of some toxic heavy metals from toxic wastes and industrial waste water

  12. 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.

  13. 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.

  14. 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. 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)

  15. Application of Multiwalled Carbon Nanotube-Cyclodextrin Polymers in the Removal of Heavy Metals from Water

    Directory of Open Access Journals (Sweden)

    R.W. Krause

    2010-01-01

    Full Text Available The aim of this study was to synthesize oxidized multiwalled carbon nanotube-cyclodextrin polymer and explore the possibility of using this polymer for the remediation of heavy metal contamination in the aquatic environment. Herein we report the results obtained from testing the polymer for the removal of lead and cobalt from synthetic water solutions. The performance of the polymer was matched against pristine and oxidized multiwalled carbon nanotubes. The polymer was found to perform better at lower concentrations (10 mg L-1 with adsorption capacities of 4.08 and 3.89 mg g-1 for lead and cobalt, respectively. These correspond to 68.0 and 64.8% removal of lead and cobalt, respectively. The maximum adsorption capacity of the polymer from the Langmuir isotherms was calculated to be 28.86 and 21.44 mg g-1 for lead and cobalt, respectively, at an initial concentration range of 10-50 mg L-1. Competitive adsorption studies revealed that lead is adsorbed better than cobalt. Furthermore, the adsorption capacity of the polymer is lower in the competitive adsorption than in the single metal ion adsorption, suggesting competition between the lead and cobalt ions.

  16. Removal of eutrophication factors and heavy metal from a closed cultivation system using the macroalgae, Gracilaria sp. (Rhodophyta)

    Science.gov (United States)

    Kang, Kyoung Ho; Sui, Zhenghong

    2010-11-01

    In this study, the ability of macroalgae Gracilaria sp. of removing eutrophication factors and toxic heavy metals Al, Cr, and Zn in a closed cultivation system is reported. The results show that the concentration of the three heavy metals decreased significantly during the experimental period in an algal biomass dependent manner. The biofiltration capacity of the alga for Al, Cr, and Zn is 10.1%-72.6%, 52.5%-83.4% and 36.5%-91.7%, respectively. Using more materials resulted in stronger heavy metal removal. Additionally, the concentration of chl- a, TN, TP and DIN of water samples from aquariums involving large, medium, and small algal biomass cultivation increased first and then decreased during the experiment. COD value of all three groups decreased with time and displayed algal biomass dependency: more algae resulting in a greater COD value than those of less biomass. Furthermore, changes in COD reflect an obvious organic particles deprivation process of algae. This is the first report on heavy metal removal effect by Gracilaria species. The results suggest that macroalgae can be used as a biofilter for the treatment of nutrient-enriched or heavy-metal polluted water, to which an appropriate time range should be carefully determined.

  17. Contemplating the feasibility of vermiculate blended chitosan for heavy metal removal from simulated industrial wastewater

    Science.gov (United States)

    Prakash, N.; Soundarrajan, M.; Arungalai Vendan, S.; Sudha, P. N.; Renganathan, N. G.

    2015-12-01

    Wastewater contaminated by heavy metals pose great challenges as they are non biodegradable, toxic and carcinogenic to the soil and aquifers. Vermiculite blended with chitosan have been used to remove Cr(VI) and Cd(II) from the industrial wastewater. The results indicate that the vermiculite blended with chitosan adsorb Cr(VI) and Cd(II) from industrial waste water. Batch adsorption experiments were performed as a function of pH 5.0 and 5.5 respectively for chromium and cadmium. The adsorption rate was observed to be 72 and 71 % of chromium and cadmium respectively. The initial optimum contact time for Cr(VI) was 300 min with 59.2 % adsorption and 300 min for Cd(II) with 71.5 % adsorption. Whereas, at 4-6 there is saturation, increasing the solid to liquid ratio for chitosan biopolymers increases the number of active sites available for adsorption. The optimum pH required for maximum adsorption was found to be 5.0 and 5.5 for chromium and cadmium respectively. The experimental equilibrium adsorption data were fitted using Langmuir and Freundlich equations. It was observed that adsorption kinetics of both the metal ions on vermiculite blended chitosan is well be analyzed with pseudo-second-order model. The negative free energy change of adsorption indicates that the process was spontaneous and vermiculite blended chitosan was a favourable adsorbent for both the metals.

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

    Science.gov (United States)

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

    2003-09-01

    A promising process for the removal of heavy metal ions from aqueous solutions involves bonding the metals firstly to a special bonding agent and then separating the loaded bonding agents from the wastewater stream by separation processes. For the separation stage, a new hybrid process of flotation and membrane separation has been developed in this work by integrating specially designed submerged microfiltration modules directly into a flotation reactor. This made it possible to combine the advantages of both flotation and membrane separation while overcoming the limitations. The feasibility of this hybrid process was proven using powdered synthetic zeolites as bonding agents. Stable fluxes of up to 80l m(-2)h(-1) were achieved with the ceramic flat-sheet multi-channel membranes applied at low transmembrane pressure (<100 mbar). The process was applied in lab-scale to treat wastewater from the electronics industry. All toxic metals in question, namely copper, nickel and zinc, were reduced from initial concentrations of 474, 3.3 and 167mg x l(-1), respectively, to below 0.05 mg x l(-1), consistently meeting the discharge limits. PMID:12909122

  19. 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%.

  20. 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 (κ) 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 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%

  1. 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

  2. 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%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, filtrat

  3. Chitosan/sporopollenin microcapsules: preparation, characterisation and application in heavy metal removal.

    Science.gov (United States)

    Sarg?n, ?dris; Arslan, Gulsin

    2015-04-01

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

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

    International Nuclear Information System (INIS)

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

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

    OpenAIRE

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

    2010-01-01

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

  6. 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.

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

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    Kušnierová 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, Šobov 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 železiarne (works – VSŽ 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.

  8. 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.

  9. Micellar-enhanced ultrafiltration for the removal of heavy metals from phosphorous-rich wastewaters : from end-of-pipe to clean technology

    OpenAIRE

    Landaburu-Aguirre, Junkal

    2012-01-01

    Abstract Fertilizer industry often generates phosphorous rich wastewaters containing heavy metals. While phosphorous is a valuable compound for the industry, heavy metals hinder the recovery of phosphorous due to their detrimental effects on human health and the environment. Consequently, heavy metals must be removed from the wastewaters. In this study the use of micellar-enhanced ultrafiltration (MEUF) was evaluated for the removal of cadmium, copper, zinc and nickel from phosphorous ric...

  10. Enhanced chitosan beads-supported Fe(0)-nanoparticles for removal of heavy metals from electroplating wastewater in permeable reactive barriers.

    Science.gov (United States)

    Liu, Tingyi; Yang, Xi; Wang, Zhong-Liang; Yan, Xiaoxing

    2013-11-01

    The removal of heavy metals from electroplating wastewater is a matter of paramount importance due to their high toxicity causing major environmental pollution problems. Nanoscale zero-valent iron (NZVI) became more effective to remove heavy metals from electroplating wastewater when enhanced chitosan (CS) beads were introduced as a support material in permeable reactive barriers (PRBs). The removal rate of Cr (VI) decreased with an increase of pH and initial Cr (VI) concentration. However, the removal rates of Cu (II), Cd (II) and Pb (II) increased with an increase of pH while decreased with an increase of their initial concentrations. The initial concentrations of heavy metals showed an effect on their removal sequence. Scanning electron microscope images showed that CS-NZVI beads enhanced by ethylene glycol diglycidyl ether (EGDE) had a loose and porous surface with a nucleus-shell structure. The pore size of the nucleus ranged from 19.2 to 138.6 ?m with an average aperture size of around 58.6 ?m. The shell showed a tube structure and electroplating wastewaters may reach NZVI through these tubes. X-ray photoelectron spectroscope (XPS) demonstrated that the reduction of Cr (VI) to Cr (III) was complete in less than 2 h. Cu (II) and Pb (II) were removed via predominant reduction and auxiliary adsorption. However, main adsorption and auxiliary reduction worked for the removal of Cd (II). The removal rate of total Cr, Cu (II), Cd (II) and Pb (II) from actual electroplating wastewater was 89.4%, 98.9%, 94.9% and 99.4%, respectively. The findings revealed that EGDE-CS-NZVI-beads PRBs had the capacity to remediate actual electroplating wastewater and may become an effective and promising technology for in situ remediation of heavy metals. PMID:24075723

  11. 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.

  12. Pumice Characteristics and Their Utilization on the Synthesis of Mesoporous Minerals and on the Removal of Heavy Metals

    OpenAIRE

    Ismail, A. I. M.; El-Shafey, O. I.; Amr, M. H. A.; El-Maghraby, M. S.

    2014-01-01

    Wastewater treatment of some heavy metals was carried out by synthetic zeolite P1, which was prepared by alkaline hydrothermal treatment of the pumice. Both of the pumice raw materials and synthetic zeolite were investigated for their chemical phase composition, physical properties, and microstructure. The adsorption behavior of Na-zeolite P1 with respect to Co+2, Cu+2, Fe+2, and Cd+2 has been studied to be applied in the industrial wastewater treatment. Metal removal was investigated using s...

  13. Removal of heavy metals by using adsorption on alumina or chitosan

    Energy Technology Data Exchange (ETDEWEB)

    Luisa Cervera, M.; Carmen Arnal, M.; Guardia, Miguel de la [Department of Analytical Chemistry, Research Building, University of Valencia, 50 Dr Moliner St. 46100 Burjassot, Valencia (Spain)

    2003-03-01

    The removal of heavy metals from wastewater by using activated alumina or chitosan as adsorbers was evaluated. Cd(II) and Cr(III) were employed as models of the behaviour of divalent and trivalent metal ions. The adsorption of Cd(II) and Cr(III) onto the adsorbers evaluated was studied as a function of pH, time, amount of adsorber, concentration of metal ions and sample volume. A 0.4-g portion of activated alumina can retain 0.6 mg Cr(III) and 0.2 mg Cd(II) from 20 mL sample adjusted at pH 4 and stirred for 30 min. It is therefore possible to totally decontaminate 500 mL of a waste containing 5 mg L{sup -1} Cd(II) and Cr(III) with 10 g alumina. On the other hand, 0.4 g chitosan can totally decontaminate 20 mL of a pH 5 solution containing up to 50 mg L{sup -1} Cd(II) and Cr(III). A 99.2{+-}0.1% retention of Cd(II) and 83{+-}1% retention of Cr(III) was obtained from 500 mL of a laboratory waste. The aforementioned strategies were applied for the minimization of analytical chemistry teaching laboratories and atomic spectrometry laboratory wastes. On comparing both adsorbers it can be concluded that chitosan is more preferable than alumina due to the reduced price of chitosan and the absence of side-pollution effects. (orig.)

  14. Heavy metal removal from multicomponent system by the cyanobacterium Nostoc muscorum: kinetics and interaction study.

    Science.gov (United States)

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

    2015-04-01

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

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

    Science.gov (United States)

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

    2015-04-28

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

  16. Mechanism study of selective heavy metal ion removal with polypyrrole-functionalized polyacrylonitrile nanofiber mats

    International Nuclear Information System (INIS)

    Graphical abstract: - Highlights: • PAN/PPy core/shell nanofiber used for Cr(VI) removal. • Adsorption mechanisms were investigated. • Selective adsorption performances were investigated. - Abstract: Polyacrylonitrile/polypyrrole (PAN/PPy) core/shell nanofiber mat was prepared through electrospinning followed by a simple chemical oxidation method. The polypyrrole-functionalized nanofiber mats showed selective adsorption performance for anions. The interaction between heavy metal anions and polypyrrole (especially the interaction between Cr2O72? and polypyrrole) during the adsorption process was studied. The results showed that the adsorption process included two steps: one was the anion exchange process between the Cl? and Cr(VI), and the other was the redox process for the Cr(VI) ions. The adsorption amount was related to the protonation time of the PAN/PPy nanofiber mat and increased as protonation time increased. Meanwhile, the Cr(VI) ions were reduced to Cr(III) through the reaction with amino groups of polypyrrole (from secondary amines to tertiary amines). PAN/PPy nanofiber mat showed high selectivity for Cr(VI), and the adsorption performance was nearly unaffected by other co-existing anions (Cl?, NO3?, and SO42?) except for PO43? for the pH change

  17. Mechanism study of selective heavy metal ion removal with polypyrrole-functionalized polyacrylonitrile nanofiber mats

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Jianqiang; Luo, Chao [Key Laboratory of Carbon Fiber and Functional Polymers, Ministry of Education, Beijing University of Chemical Technology, Beijing 100029 (China); Qi, Genggeng [Department of Materials Science and Engineering, Cornell University, Ithaca, NY (United States); Pan, Kai, E-mail: pankai@mail.buct.edu.cn [Key Laboratory of Carbon Fiber and Functional Polymers, Ministry of Education, Beijing University of Chemical Technology, Beijing 100029 (China); Department of Materials Science and Engineering, Cornell University, Ithaca, NY (United States); Cao, Bing, E-mail: bcao@mail.buct.edu.cn [Key Laboratory of Carbon Fiber and Functional Polymers, Ministry of Education, Beijing University of Chemical Technology, Beijing 100029 (China)

    2014-10-15

    Graphical abstract: - Highlights: • PAN/PPy core/shell nanofiber used for Cr(VI) removal. • Adsorption mechanisms were investigated. • Selective adsorption performances were investigated. - Abstract: Polyacrylonitrile/polypyrrole (PAN/PPy) core/shell nanofiber mat was prepared through electrospinning followed by a simple chemical oxidation method. The polypyrrole-functionalized nanofiber mats showed selective adsorption performance for anions. The interaction between heavy metal anions and polypyrrole (especially the interaction between Cr{sub 2}O{sub 7}{sup 2?} and polypyrrole) during the adsorption process was studied. The results showed that the adsorption process included two steps: one was the anion exchange process between the Cl{sup ?} and Cr(VI), and the other was the redox process for the Cr(VI) ions. The adsorption amount was related to the protonation time of the PAN/PPy nanofiber mat and increased as protonation time increased. Meanwhile, the Cr(VI) ions were reduced to Cr(III) through the reaction with amino groups of polypyrrole (from secondary amines to tertiary amines). PAN/PPy nanofiber mat showed high selectivity for Cr(VI), and the adsorption performance was nearly unaffected by other co-existing anions (Cl{sup ?}, NO{sub 3}{sup ?}, and SO{sub 4}{sup 2?}) except for PO{sub 4}{sup 3?} for the pH change.

  18. 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.

  19. In vitro removal of toxic heavy metals by poly(γ-glutamic acid-coated superparamagnetic nanoparticles

    Directory of Open Access Journals (Sweden)

    Inbaraj BS

    2012-08-01

    Full Text Available Baskaran Stephen Inbaraj,1 Bing-Huei Chen1,21Department of Food Science, 2Graduate Institute of Medicine, Fu Jen University, Taipei, TaiwanBackground: Chelation therapy involving organic chelators for treatment of heavy metal intoxication can cause cardiac arrest, kidney overload, mineral deficiency, and anemia.Methods: In this study, superparamagnetic iron oxide nanoparticles (SPIONs modified with an edible biopolymer poly(γ-glutamic acid (PGA were synthesized by coprecipitation method, characterized and evaluated for their removal efficiency of heavy metals from a metal solution, and simulated gastrointestinal fluid (SGIF.Results: Instrumental characterization of bare- and PGA-SPIONs revealed 7% coating of PGA on SPIONs with a spherical shape and an iron oxide spinel structure belonging to magnetite. The particle sizes as determined from transmission electron microscopy images were 8.5 and 11.7 nm for bare- and PGA-SPIONs, respectively, while the magnetization values were 70.3 and 61.5 emu/g. Upon coating with PGA, the zeta potentials were shifted from positive to negative at most of the environmental pH (3–8 and biological pH (1–8, implying good dispersion in aqueous suspension and favorable conditions for heavy metal removal. Batch studies showed rapid removal of lead and cadmium with the kinetic rates estimated by pseudo-second-order model being 0.212 and 0.424 g/mg•min, respectively. A maximum removal occurred in the pH range 4–8 in deionized water and 5–8 in SGIF corresponding to most gastrointestinal pH except for the stomach. Addition of different ionic strengths (0.001–1 M sodium acetate and essential metals (Cu, Fe, Zn, Mg, Ca, and K did not show any marked influence on lead removal by PGA-SPIONs, but significantly reduced the binding of cadmium. Compared to deionized water, the lead removal from SGIF was high at all pH with the Langmuir monolayer removal capacity being 98.70 mg/g for the former and 147.71 mg/g for the latter. However, a lower cadmium removal capacity was shown for SGIF (23.15 mg/g than for deionized water (31.13 mg/g.Conclusion: These results suggest that PGA-SPIONs could be used as a metal chelator for clinical treatment of metal poisoning.Keywords: superparamagnetic iron oxide nanoparticles, poly(γ-glutamic acid, heavy metals, chelation therapy, gastrointestinal pH, kinetics

  20. Simultaneous removal of heavy metals from aqueous solution by natural limestones

    Science.gov (United States)

    Sdiri, Ali; Higashi, Teruo

    2013-03-01

    Two natural limestone samples, collected from the Campanian-Maastrichtian limestones, Tunisia, were used as adsorbents for the removal of toxic metals in aqueous systems. The results indicated that high removal efficiency could be achieved by the present natural limestones. Among the metal ions studied, Pb2+ was the most preferably removed cation because of its high affinity to calcite surface. In binary system, the presence of Cu2+ effectively depressed the sorption of Cd2+ and Zn2+. Similarly Cu2+ strongly competed with Pb2+ to limestone surface. In ternary system, the removal further decreased, but considerable amount of Pb2+ and Cu2+ still occurred regardless of the limestone sample. The same behavior was observed in quadruple system, where the selectivity sequence was Pb2+ > Cu2+ > Cd2+ > Zn2+. From these results, it was concluded that the studied limestones have the required technical specifications to be used for the removal of toxic metals from wastewaters.

  1. Simultaneous removal of several heavy metals from aqueous solution by natural limestones

    Directory of Open Access Journals (Sweden)

    Sdiri A.

    2014-07-01

    Full Text Available Four natural limestone samples, collected from the Campanian-Maastrichtian limestones, Tunisia, were used as adsorbents for the removal of toxic metals in aqueous systems. The results indicated that high removal efficiency could be achieved by the present natural limestones. Among the metal ions studied, Pb2+ was the most preferably removed cation because of its high affinity to calcite surface. In binary system, the presence of Cu2+ effectively depressed the sorption of Cd2+ and Zn2+. Similarly Cu2+ strongly competed with Pb2+ to limestone surface. In ternary system, the removal further decreased, but considerable amount of Pb2+ and Cu2+ still occurred regardless of the limestone sample. The same behavior was observed in quadruple system, where the selectivity sequence was Pb2+ > Cu2+ > Cd2+ > Zn2+. From these results, it was concluded that the studied limestones have the required technical specifications to be used for the removal of toxic metals from wastewaters.

  2. Linen Fire as Biosorbent to Remove Heavy Metal Ions From Wastewater Modeling

    Directory of Open Access Journals (Sweden)

    Ildar G. Shaikhiev

    2014-03-01

    Full Text Available The possibility of using linen fires – lnopererabotk i waste as a sorption material for the extraction of heavy metal ions from wastewater modeling. It is shown that treatment with acid solutions linen fires a low concentration increases the surface area of linen fires and thus sorption capacity for heavy metal ions. The values of the maximum sorption capacity ions Fe (III, Co (II, Ni (II and Zn (II under static and dynamic conditions. IR spectroscopy shows that along with the physical sorption process proceeds chemisorption.

  3. 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)

  4. Plant-driven removal of heavy metals from soil: uptake, translocation, tolerance mechanism, challenges, and future perspectives.

    Science.gov (United States)

    Thakur, Sveta; Singh, Lakhveer; Wahid, Zularisam Ab; Siddiqui, Muhammad Faisal; Atnaw, Samson Mekbib; Din, Mohd Fadhil Md

    2016-04-01

    Increasing heavy metal (HM) concentrations in the soil have become a significant problem in the modern industrialized world due to several anthropogenic activities. Heavy metals (HMs) are non-biodegradable and have long biological half lives; thus, once entered in food chain, their concentrations keep on increasing through biomagnification. The increased concentrations of heavy metals ultimately pose threat on human life also. The one captivating solution for this problem is to use green plants for HM removal from soil and render it harmless and reusable. Although this green technology called phytoremediation has many advantages over conventional methods of HM removal from soils, there are also many challenges that need to be addressed before making this technique practically feasible and useful on a large scale. In this review, we discuss the mechanisms of HM uptake, transport, and plant tolerance mechanisms to cope with increased HM concentrations. This review article also comprehensively discusses the advantages, major challenges, and future perspectives of phytoremediation of heavy metals from the soil. PMID:26940329

  5. 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

  6. Voltammetric evaluation of chitosan as an effective complexing ligand for the removal of toxic heavy metals

    OpenAIRE

    Lasheras-Zubiate, M. (María); Fernandez, J.M.; Navarro-Blasco, I. (Íñigo)

    2008-01-01

    Program of the 59th Annual Meeting of the International Society of Electrochemistry, 2008:138: The aim of this study is to evaluate de complexation of toxic heavy metals such as Pb, Zn, Cd and Cu by three commercial chitosans with different molecular weights. For this purpose, the complexation capacity of chitosan was evaluated through competitive deposit of the metals onto the HMDE from ligand-containing solutions and subsequent voltammetric measurement of the anodic stripping...

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

    Directory of Open Access Journals (Sweden)

    K. Adouby

    2007-01-01

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

  8. 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.

  9. Soil amendments for heavy metals removal from stormwater runoff discharging to environmentally sensitive areas

    Science.gov (United States)

    Trenouth, William R.; Gharabaghi, Bahram

    2015-10-01

    Concentrations of dissolved metals in stormwater runoff from urbanized watersheds are much higher than established guidelines for the protection of aquatic life. Five potential soil amendment materials derived from affordable, abundant sources have been tested as filter media using shaker tests and were found to remove dissolved metals in stormwater runoff. Blast furnace (BF) slag and basic oxygenated furnace (BOF) slag from a steel mill, a drinking water treatment residual (DWTR) from a surface water treatment plant, goethite-rich overburden (IRON) from a coal mine, and woodchips (WC) were tested. The IRON and BOF amendments were shown to remove 46-98% of dissolved metals (Cr, Co, Cu, Pb, Ni, Zn) in repacked soil columns. Freundlich adsorption isotherm constants for six metals across five materials were calculated. Breakthrough curves of dissolved metals and total metal accumulation within the filter media were measured in column tests using synthetic runoff. A reduction in system performance over time occurred due to progressive saturation of the treatment media. Despite this, the top 7 cm of each filter media removed up to 72% of the dissolved metals. A calibrated HYDRUS-1D model was used to simulate long-term metal accumulation in the filter media, and model results suggest that for these metals a BOF filter media thickness as low as 15 cm can be used to improve stormwater quality to meet standards for up to twenty years. The treatment media evaluated in this research can be used to improve urban stormwater runoff discharging to environmentally sensitive areas (ESAs).

  10. 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...

  11. Removal of heavy metal contamination from peanut skin extracts by waste biomass adsorption

    Science.gov (United States)

    Polyphenols are a rapidly increasing portion of the nutraceutical and functional food marketplace. Peanut skins are a waste product which have potential as a low-cost source of polyphenols. Extraction and concentration of peanut skin extracts can cause normally innocuous levels of the heavy metal co...

  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. Removal of Heavy Metals from Water by Lignite-Based Sorbents.

    Czech Academy of Sciences Publication Activity Database

    Jochová, M.; Pun?ochá?, Miroslav; Horá?ek, Jan; Štamberg, K.; Vopálka, D.

    2004-01-01

    Ro?. 83, ?. 9 (2004), s. 1197-1203. ISSN 0016-2361 Institutional research plan: CEZ:AV0Z4072921 Keywords : waste water * heavy metals * lignite Subject RIV: CI - Industrial Chemistry, Chemical Engineering Impact factor: 1.368, year: 2004

  14. Characterization of potassium hydroxide (KOH) modified hydrochars from different feedstocks for enhanced removal of heavy metals from water.

    Science.gov (United States)

    Sun, Kejing; Tang, Jingchun; Gong, Yanyan; Zhang, Hairong

    2015-11-01

    Hydrochars produced from different feedstocks (sawdust, wheat straw, and corn stalk) via hydrothermal carbonization (HTC) and KOH modification were used as alternative adsorbents for aqueous heavy metals remediation. The chemical and physical properties of the hydrochars and KOH-treated hydrochars were characterized, and the ability of hydrochars for removal of heavy metals from aqueous solutions as a function of reaction time, pH, and initial contaminant concentration was tested. The results showed that KOH modification of hydrochars might have increased the aromatic and oxygen-containing functional groups, such as carboxyl groups, resulting in about 2-3 times increase of cadmium sorption capacity (30.40-40.78 mg/g) compared to that of unmodified hydrochars (13.92-14.52 mg/g). The sorption ability among different feedstocks after modification was as the following: sawdust?>?wheat straw?>?corn stack. Cadmium sorption kinetics on modified hydrochars could be interpreted with a pseudo-second order, and sorption isotherm was simulated with Langmuir adsorption model. High cadmium uptake on modified hydrochars was observed over the pH range of 4.0-8.0, while for other heavy metals (Pb(2+), Cu(2+), and Zn(2+)) the range was 4.0-6.0. In a multi-metal system, the sorption capacity of heavy metals by modified hydrochars was also higher than that by unmodified ones and followed the order of Pb(II)?>?Cu(II)?>?Cd(II)?>?Zn(II). The results suggest that KOH-modified hydrochars can be used as a low cost, environmental-friendly, and effective adsorbent for heavy metal removal from aqueous solutions. PMID:26081779

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2010-06-15

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

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

    Directory of Open Access Journals (Sweden)

    S. Gueu

    2006-01-01

    Full Text Available The purpose of this study is to convert locally vegetal materials such as coconut shell and seed shell of palm tree, which are low-cost, renewable and widely available into inexpensive adsorbent materials for heavy metal copper, lead and zinc removal from wastewater. Both raw materials were chemically activated by phosphoric acid (H3PO4. Various parameters such as adsorbent dose, pH and activation temperature of carbon were studied to establish optimum adsorption conditions. The results showed that the rates of adsorption of metals increase with adsorbent dose. The pH variation showed that maximum adsorption capacities were observed at pH 4. The carbons activated at 400°C display the better adsorption capacities. The amount of metal adsorbed on the activated carbons increases in the order Zn, Cu and Pb. Moreover, the presence of other metallic ions in the solution decreases the rate of removal of each of them.

  17. 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.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2011-08-15

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

  19. 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

  20. 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.

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

    OpenAIRE

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

    2006-01-01

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

  2. UV/O3 Preirradiated Cotton Fabric-Containing Chitosan for Effective Removal of Heavy Metals

    OpenAIRE

    Hebeish, A.; Kh. Elnagar; M. H. Helal; M. S. Ragab; M. F. Shaaban

    2014-01-01

    The present work aims at studying the effect of Ultra-Violet/Ozone (UV/O3) irradiation of cotton fabrics on their interaction with chitosan/citric acid based formulation and, the onset of this on the ability of treated fabrics to remove heavy metal ions from their aqueous solutions. To achieve the goal, the cotton fabrics were preirradiated for 90 minutes using UV/O3 as radiation source. The irradiated and the unirrdadiated cotton fabrics were submitted to finishing ...

  3. 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

  4. Evaluation of biosurfactants grown in corn oil by Rhodococcus rhodochrous on removing of heavy metal ion from aqueous solution

    Science.gov (United States)

    Suryanti, Venty; Hastuti, Sri; Pujiastuti, Dwi

    2016-02-01

    The potential application of biosurfactants to remove heavy metal ion from aqueous solution by batch technique was examined. The glycolipids type biosurfactants were grown in a media containing of 20% v/v corn oil with 7 days of fermentation by Rhodococcus rhodochrous. The biosurfactants reduced the surface tension of water of about 51% from 62 mN/m to 30 mN/m. The biosurfactant increased the E24 of water-palm oil emulsion of about 55% from 43% to 97% and could maintain this E24 value of above 50% for up to 9 days. Heavy metal ion removal, in this case cadmium ion, by crude and patially purified biosurfactants has been investigated from aqueous solution at pH 6. Adsorption capacity of Cd(II) ion by crude biosurfactant with 5 and 10 minutes of contact times were 1.74 and 1.82 mg/g, respectively. Additionally, the adsorption capacity of Cd(II) ion by partially purified biosurfactant with 5 and 10 minutes of contact times were 0.79 and 1.34 mg/g, respectively. The results demonstrated that the adsorption capacity of Cd(II) ion by crude biosurfactant was higher than that of by partially purified biosurfactant. The results suggested that the biosurfactant could be used in the removal of heavy metal ions from aqueous solution.

  5. 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.

  6. Efficiency of Aluminum and Iron Electrodes for the Removal of Heavy Metals [(Ni (II), Pb (II), Cd (II)] by Electrocoagulation Method

    Energy Technology Data Exchange (ETDEWEB)

    Khosa, Muhammad Kaleem; Jamal, Muhammad Asghar; Hussain, Amira; Muneer, Majid; Zia, Khalid Mahmood [Government College Univ., Faisalabad (Pakistan); Hafeez, Samia [Bahaud-din-Zakariya Univ., Multan (Pakistan)

    2013-06-15

    Electrocoagulation (EC) technique is applied for the treatment of wastewater containing heavy metals ions such as nickel (Ni), lead (Pb) and cadmium (Cd) by using sacrificial anodes corrode to release active coagulant flocs usually aluminium or iron cations into the solution. During electrolytic reactions hydrogen gas evolve at the cathode. All the experiments were carried out in Batch mode. The tank was filled with synthetic wastewater containing heavy metals and efficiency of electrocoagulation in combination with aluminum and iron electrodes were investigated for removal of such metals. Several parameters, such as contact time, pH, electro-coagulant concentration, and current density were optimized to achieve maximum removal efficiency (%). The concentrations of heavy metals were determined by using Atomic Absorption Spectroscopy (AAS). It is found that the electro-coagulation process has potential to be utilized for the cost-effective removal of heavy metals from wastewater specially using iron electrodes in terms of high removal efficiencies and operating cost.

  7. Efficiency of Aluminum and Iron Electrodes for the Removal of Heavy Metals [(Ni (II), Pb (II), Cd (II)] by Electrocoagulation Method

    International Nuclear Information System (INIS)

    Electrocoagulation (EC) technique is applied for the treatment of wastewater containing heavy metals ions such as nickel (Ni), lead (Pb) and cadmium (Cd) by using sacrificial anodes corrode to release active coagulant flocs usually aluminium or iron cations into the solution. During electrolytic reactions hydrogen gas evolve at the cathode. All the experiments were carried out in Batch mode. The tank was filled with synthetic wastewater containing heavy metals and efficiency of electrocoagulation in combination with aluminum and iron electrodes were investigated for removal of such metals. Several parameters, such as contact time, pH, electro-coagulant concentration, and current density were optimized to achieve maximum removal efficiency (%). The concentrations of heavy metals were determined by using Atomic Absorption Spectroscopy (AAS). It is found that the electro-coagulation process has potential to be utilized for the cost-effective removal of heavy metals from wastewater specially using iron electrodes in terms of high removal efficiencies and operating cost

  8. 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...

  9. 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

  10. Characterisation and removal of heavy metals in tannery effluents through the use of local materials

    OpenAIRE

    Robertsson, Jonas; Andersson, Camilla

    2014-01-01

    Chromium and other heavy metals are known to cause issues related to human and environmental health when they occur in high concentrations in ecosystems. Chromium poses a particularly large threat if it occurs in its hexavalent form, Cr(VI), as it is highly reactive and carcinogenic. The aim of this project was to investigate the wastewater emitted from a tannery in Liwonde, Malawi, with respect to the metals Cr, Al, Cd, Cu, Fe, Mn, Pb and Zn, and to reduce the concentrations using locally av...

  11. Heavy metals removal from aqueous environments by electrocoagulation process– a systematic review

    OpenAIRE

    Bazrafshan, Edris; Mohammadi, Leili; Ansari-Moghaddam, Alireza; MAHVI, Amir Hossein

    2015-01-01

    Heavy metals pollution has become a more serious environmental problem in the last several decades as a result releasing toxic materials into the environment. Various techniques such as physical, chemical, biological, advanced oxidation and electrochemical processes were used for the treatment of domestic, industrial and agricultural effluents. The commonly used conventional biological treatments processes are not only time consuming but also need large operational area. Accordingly, it seems...

  12. Economically Viable Fungal Production by Using Alternative Plant Material for the Removal of Heavy Metal

    OpenAIRE

    Shipra Jha; S. N. Dikshit

    2015-01-01

    Environmental pollution affects the quality of atmosphere, lithosphere and biosphere. Efforts have been made in the last two decades to reduce the pollution sources and remedy the polluted water sources. Water quality monitoring in developing countries is inadequate especially in stream water affected by urban effluent and runoff. The purpose of this study was to investigate heavy metal contaminants in sank stream water in Gwalior. The water sample from stream and industrial effluents that dr...

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

    OpenAIRE

    Veeken, A.; Hamelers, B.

    1999-01-01

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

  14. Phytoextraction - thte use of plants to remove heavy metals from soils

    Energy Technology Data Exchange (ETDEWEB)

    Raskin, I.; Kumar, P.B.A.N.; Dushenkov, V.; Motto, H. [Rutgers Univ., New Brunswick, NJ (United States)

    1995-12-31

    A small number of wild plants which grow on metal contaminated soil accumulate large amounts of heavy metals in their roots and shoots. This property may be exploited for soil reclamation if an easily cultivated, high biomass crop plant able to accumulate heavy metals is identified. Therefore, the ability of various crop plants to accumulate Pb in shoots and roots was compared. While all crop Brassicas tested accumulated Pb, some cultivars of Brassica juncea (L). Czern. showed a strong ability to accumulate Pb in roots and to transport Pb to the shoots (108.3 mg Pb/g DW in the roots and 34.5 mg Pb/g DW in the shoots). B. juncea was also able to concentrate Cr{sup -6}, Cd, Ni, Zn, and Cu in the shoots 58, 52, 31, 17, and 7 fold, respectively, from a substrate containing sulfates and phosphates as fertilizers. The high metal accumulation by some cultivars of B. juncea suggests that these plants may be used to clean up toxic metal-contaminated sites in a process termed phytoextraction.

  15. Removal of heavy metals of used oils lubricants by biosorption; Remocao de metais pesados de oleo lubrificantes usados por biossorcao

    Energy Technology Data Exchange (ETDEWEB)

    Moreira, Albina da Silva [Rio Grande do Norte Univ., Natal, RN (Brazil). Dept. de Engenharia Quimica. Programa de Pos-graduacao em Engenharia Quimica]. E-mail: albina@eq.ufrn.br; Macedo, Gorete Ribeiro de; Duarte, Marcia Maria Lima [Universidade Federal do Rio Grande do Norte, Natal, RN (Brazil)]. E-mail: marcia@eq.ufrn.br; gomacedo@eq.ufrn.br

    2003-07-01

    The used lube oils when thrown directly in the environment (water bodies, sewerage nets, soils) or when burned in a non-controlled way, causes serious problems to the environment. Used lube oils contain high levels of hydrocarbons and heavy metals, of which Iron (Fe), Copper (Cu), Lead (Pb), Nickel (Ni) and Chrome (Cr) are the most representative. Due to these problems and to the high consumption of energy in the re-refining process, came the interest of studying a new methodology for removing those heavy metals from discarded automotive lube oil through the process of biosorption. A type of heavy lube oil used in a bus fleet was chosen and it was characterized in order to find out which metals it contained and its concentration. Then the bio-solvent material was prepared, in this case, the pheophyta seaweed Sargassum Sp. For the biosorption study, some preliminary tests using Sargassum Sp protonated with HCl 0,06 M and without protonation were run. The purpose of using protonated and non-protonated biosorbent was to verify the process efficiency. It was observed that for metal with high level of concentration the protonated biosorbent was more efficient, while for metals with lower concentrations the non-protonated biosorbent was more efficient. (author)

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

    Science.gov (United States)

    Olguín, Eugenia J; Sánchez-Galván, Gloria

    2012-11-15

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

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

    International Nuclear Information System (INIS)

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

  18. Removal of heavy metals from a metaliferous water solution by Typha latifolia plants and sewage sludge compost.

    Science.gov (United States)

    Manios, T; Stentiford, E I; Millner, P

    2003-11-01

    Typha latifolia plants, commonly known as cattails, were grown in a mixture of mature sewage sludge compost, commercial compost and perlite (2:1:1 by volume). Four Groups (A, B, C and D) were irrigated (once every two weeks) with a solution containing different concentrations of Cu, Ni, and Zn, where in the fifth (group M) tap water was used. At the end of the 10 weeks experimental period substrate and plants were dried, weighed and analysed for heavy metals. The amounts of all three metals removed from the irrigation solution, were substantial. In the roots and leaves/stems of T. latifolia the mean concentration of Zn reached values of 391.7 and 60.8 mg/kg of dry weight (d.w.), respectively. In the substrate of Group D all three metals recorded their highest mean concentrations of 1156.7 mg/kg d.w. for Cu, 296.7 mg/kg d.w. for Ni and 1231.7 mg/kg d.w. for Zn. Linear correlation analyses suggested that there was a linear relationship between the concentration of metals in the solutions and the concentration of metals in the substrates at the end of the experiment. The percentage removal of the metals in the substrate was large, reaching 100% for Cu and Zn in some groups and almost 96% for Ni in group D. The total amount of metals removed by the plants was considerably smaller than that of the substrate, due mainly to the small biomass development. A single factor ANOVA test (5% level) indicated that the build up in the concentration of metals in the roots and the leaves/stems was due to the use of metaliferous water solution and not from the metals pre-existing in the substrate. The contribution of the plants (both roots and leaves/stems) in the removing ability of the system was less than 1%. PMID:12948532

  19. Hydrogen peroxide modification enhances the ability of biochar (hydrochar) produced from hydrothermal carbonization of peanut hull to remove aqueous heavy metals: Batch and column tests

    Science.gov (United States)

    Experimental and modeling investigations were conducted to examine the effect of hydrogen peroxide treatment on hydrothermally produced biochar (hydrochar) from peanut hull to remove aqueous heavy metals. Characterization measurements showed that hydrogen peroxide modification increased the oxygen-c...

  20. 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.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2008-08-15

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

  2. 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.

    2015-01-01

    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.

  3. 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

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

    Directory of Open Access Journals (Sweden)

    A. Shenbaga Devi

    2013-01-01

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

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

    Directory of Open Access Journals (Sweden)

    Xiaodong Zheng

    2010-06-01

    Full Text Available Crayfish carapace, a plentiful waste in China, was applied to remove divalent heavy metal ions—copper (Cu, cadmium (Cd, zinc (Zn, and lead (Pb—from wastewater. The adsorption capacities of crayfish carapace micro-powder (CCM for heavy metal ions were studied with adsorbent dosages ranging from 0.5–2.5 g/L and with initial metal concentrations ranging from 50–250 mg/L. CCM particle size, initial solution pH (from 2.5–6.5, temperature (from 25–65 °C and calcium level (from 3.5–21.5% were also varied in batch mode. The results indicated that the adsorption capacity increases with both decreasing particle size and increasing calcium level of the crayfish carapace. The kinetic studies indicated that the adsorption could be complete within 2 h, and that the data correlated with the pseudo-second-order model. CCM recorded maximum uptakes of 200, 217.39, 80, and 322.58 mg/g for Cu, Cd, Zn, and Pb, respectively. The adsorption capacities and removal efficiencies of CCM for metal ions were three-times higher than those of chitin and chitosan extracted from the CCM.

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

    Science.gov (United States)

    Chowdhury, M. N. K.; Khan, M. W.; Mina, M. F.; Beg, M. D. H.; Khan, Maksudur R.; Alam, A. K. M. M.

    2012-10-01

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

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

    Directory of Open Access Journals (Sweden)

    Abdouss Majid

    2012-01-01

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

  8. Recovery and removal of heavy metals from aqueous solutions by pertraction

    Directory of Open Access Journals (Sweden)

    Baron Miroslav

    1998-12-01

    Full Text Available Overview on membrane based solvent extraction and pertraction through liquid membranes and their application in recovery of heavy metals from aqueous waste solutions. Recent data shows potential for these processes. Results of experimental study of influence of sulfuric acid concentration in the stripping solution on pertraction rate are presented. Liquid membrane with carrier Aorga P50 was studied. Rate of stripping is much slower than rate of extraction even when using 4M H2SO4. This fact should be reflected in model of mass-transfer presented in the paper. Further study should be directed to search for modifier enhancing stripping rate.

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

    Directory of Open Access Journals (Sweden)

    Rypi?ska Iwona

    2014-12-01

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

  10. 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.

  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. 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.)

  13. 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.

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

    Directory of Open Access Journals (Sweden)

    Eman A.H. Mohamed

    2009-01-01

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

  15. An effective and recyclable adsorbent for the removal of heavy metal ions from aqueous system: Magnetic chitosan/cellulose microspheres.

    Science.gov (United States)

    Luo, Xiaogang; Zeng, Jian; Liu, Shilin; Zhang, Lina

    2015-10-01

    Development of highly cost-effective, highly operation-convenient and highly efficient natural polymer-based adsorbents for their biodegradability and biocompatibility, and supply of safe drinking water are the most threatening problems in water treatment field. To tackle the challenges, a new kind of efficient recyclable magnetic chitosan/cellulose hybrid microspheres was prepared by sol-gel method. By embedding magnetic ?-Fe2O3 nanoparticles in chitosan/cellulose matrix drops in NaOH/urea aqueous solution, it combined renewability and biocompatibility of chitosan and cellulose as well as magnetic properties of ?-Fe2O3 to create a hybrid system in heavy metal ions removal. PMID:26216781

  16. Subcritical water treatment of explosive and heavy metals co-contaminated soil: Removal of the explosive, and immobilization and risk assessment of heavy metals.

    Science.gov (United States)

    Islam, Mohammad Nazrul; Jung, Ho-Young; Park, Jeong-Hun

    2015-11-01

    Co-contamination of explosives and heavy metals (HMs) in soil, particularly army shooting range soil, has received increasing environmental concern due to toxicity and risks to ecological systems. In this study, a subcritical water (SCW) extraction process was used to remediate the explosives-plus-HMs-co-contaminated soil. A quantitative evaluation of explosives in the treated soil, compared with untreated soil, was applied to assess explosive removal. The immobilization of HMs was assessed by toxicity characteristic leaching procedure tests, and by investigating the migration of HMs fractions. The environmental risk of HMs in the soil residue was assessed according to the risk assessment code (RAC) and ecological risk indices (Er and RI). The results indicated that SCW treatment could eliminate the explosives, >99%, during the remediation, while the HM was effectively immobilized. The effect of water temperature on reducing the explosives and the risk of HMs in soil was observed. A marked increase in the non-bioavailable concentration of each HM was observed, and the leaching rate of HMs was decreased by 70-97% after SCW treatment at 250 °C, showing the effective immobilization of HMs. According to the RAC or RI, each tested HM showed no or low risk to the environment after treatment. PMID:26340419

  17. 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.

  18. 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.

  19. A breakthrough biosorbent in removing heavy metals: Equilibrium, kinetic, thermodynamic and mechanism analyses in a lab-scale study.

    Science.gov (United States)

    Abdolali, Atefeh; Ngo, Huu Hao; Guo, Wenshan; Lu, Shaoyong; Chen, Shiao-Shing; Nguyen, Nguyen Cong; Zhang, Xinbo; Wang, Jie; Wu, Yun

    2016-01-15

    A breakthrough biosorbent namely multi-metal binding biosorbent (MMBB) made from a combination of tea wastes, maple leaves and mandarin peels, was prepared to evaluate their biosorptive potential for removal of Cd(II), Cu(II), Pb(II) and Zn(II) from multi-metal aqueous solutions. FTIR and SEM were conducted, before and after biosorption, to explore the intensity and position of the available functional groups and changes in adsorbent surface morphology. Carboxylic, hydroxyl and amine groups were found to be the principal functional groups for the sorption of metals. MMBB exhibited best performance at pH5.5 with maximum sorption capacities of 31.73, 41.06, 76.25 and 26.63mg/g for Cd(II), Cu(II), Pb(II) and Zn(II), respectively. Pseudo-first and pseudo-second-order models represented the kinetic experimental data in different initial metal concentrations very well. Among two-parameter adsorption isotherm models, the Langmuir equation gave a better fit of the equilibrium data. For Cu(II) and Zn(II), the Khan isotherm describes better biosorption conditions while for Cd(II) and Pb(II), the Sips model was found to provide the best correlation of the biosorption equilibrium data. The calculated thermodynamic parameters indicated feasible, spontaneous and exothermic biosorption process. Overall, this novel MMBB can effectively be utilized as an adsorbent to remove heavy metal ions from aqueous solutions. PMID:26544889

  20. Thermodynamics Study of Removal of Heavy Metal by TiN-Nanotubes

    Science.gov (United States)

    Mahdavian, Leila

    2015-12-01

    The ability of TiN-nanotube to remove lead (Pb(II)) and arsenic (As(III)) ions from aqueous solutions is investigated. The thermodynamics properties of Pb(II) and As(III) ions passing through TiN-nanotubes (TiN-NTs) is calculated in basis set (B3LYP/6-31G**) DFT-IR method by Gaussian program package. The results showed, Pb(II) and As(III) passing through had low potential in middle nanotubes, and are trapped in this place. The thermodynamic properties showed; the passing through are spontaneous and favorable because ?Gele (MJ/mol) is negative for them. The goal of this study is the detection of surface species of TiN-NTs for metal ions removal by using computer calculations. The structural and thermodynamic properties studied ions absorption on TiN-NTs at room temperature.

  1. 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.

  2. 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

  3. Removal of heavy-metal pollutants from ground water using a reverse-osmosis/coupled-transport hybrid system

    International Nuclear Information System (INIS)

    Two membrane processes - reverse osmosis (RO) and coupled transport (CT) - are useful in removing heavy metals from aqueous solutions and producing purified water. Each process has advantages. RO produces clean water reliably and relatively inexpensively. However, the pollutants are removed nonselectively and cannot be appreciably concentrated. CT removes pollutants selectively and can concentrate them by several orders of magnitude, but CT suffers from limited reliability and performs poorly at low pollutant concentrations. By combining these two unit processes in a hybrid process, it is possible to capitalize on the advantages of each process and to minimize their disadvantages. The RO/CT hybrid process the authors are developing removes more than 98% of the uranium and chromium in a contaminated groundwater stream - reducing concentrations of each pollutant to less than 100 ppb. These pollutants are simultaneously recovered as a concentrate at metal-ion concentrations greater than 1 wt% in relatively pure form. The hybrid process promises to be reliable and to reduce treatment costs below that for costs if either CT or RO were used alone. Even more importantly, the high selectivity of the hybrid process minimizes the volume of waste requiring disposal

  4. 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

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

    International Nuclear Information System (INIS)

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

  6. 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.

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

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Zhongde, E-mail: zdwangtyut@hotmail.com [Department of Chemical Engineering, Taiyuan University of Technology, Taiyuan 030024 (China); Feng, Yanting [Department of Chemical Engineering, Taiyuan University of Technology, Taiyuan 030024 (China); Hao, Xiaogang, E-mail: xghao@tyut.edu.cn [Department of Chemical Engineering, Taiyuan University of Technology, Taiyuan 030024 (China); Huang, Wei [Department of Chemical Engineering, Taiyuan University of Technology, Taiyuan 030024 (China); Guan, Guoqing, E-mail: guan@cc.hirosaki-u.ac.jp [North Japan Research Institute for Sustainable Energy (NJRISE), Hirosaki University, 2-1-3, Matsubara, Aomori 030-0813 (Japan); Abudula, Abuliti [North Japan Research Institute for Sustainable Energy (NJRISE), Hirosaki University, 2-1-3, Matsubara, Aomori 030-0813 (Japan)

    2014-06-01

    Highlights: • A new concept for design of an intelligent displacement pumping film was proposed. • As-prepared ESIX hybrid film system showed excellent Ni{sup 2+} 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(HPO{sub 4}){sub 2}; ?-ZrP) nanosheets intercalated with a potential-responsive conducting polyaniline (PANI) was developed for the removal of Ni{sup 2+} 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 Ni{sup 2+} 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 Ni{sup 2+} ions using this kind of film was proved via XPS analysis. The proposed ESIX hybrid film should have high potential for the removal of Ni{sup 2+} ions and/or other heavy metal ions from wastewater in various industrial processes.

  8. Effects of Humic Acid and Suspended Solids on the Removal of Heavy Metals from Water by Adsorption onto Granular Activated Carbon

    Directory of Open Access Journals (Sweden)

    Danious P. Sounthararajah

    2015-08-01

    Full Text Available Heavy metals constitute some of the most dangerous pollutants of water, as they are toxic to humans, animals, and aquatic organisms. These metals are considered to be of major public health concern and, therefore, need to be removed. Adsorption is a common physico-chemical process used to remove heavy metals. Dissolved organic carbon (DOC and suspended solids (SS are associated pollutants in water systems that can interact with heavy metals during the treatment process. The interactions of DOC and SS during the removal of heavy metals by granular activated carbon were investigated in batch and fixed-bed column experiments. Batch adsorption studies indicated that Langmuir adsorption maxima for Pb, Cu, Zn, Cd, and Ni at pH 6.5 were 11.9, 11.8, 3.3, 2.0, and 1.8 mg/g, respectively. With the addition of humic acid (HA (DOC representative, they were 7.5, 3.7, 3.2, 1.6, and 2.5 mg/g, respectively. In the column experiment, no breakthrough (complete removal was obtained for Pb and Cu, but adding HA provided a breakthrough in removing these metals. For Zn, Cd and Ni, this breakthrough occurred even without HA being added. Adding kaolinite (representative of SS had no effect on Pb and Cu, but it did on the other metals.

  9. Effects of Humic Acid and Suspended Solids on the Removal of Heavy Metals from Water by Adsorption onto Granular Activated Carbon.

    Science.gov (United States)

    Sounthararajah, Danious P; Loganathan, Paripurnanda; Kandasamy, Jaya; Vigneswaran, Saravanamuthu

    2015-09-01

    Heavy metals constitute some of the most dangerous pollutants of water, as they are toxic to humans, animals, and aquatic organisms. These metals are considered to be of major public health concern and, therefore, need to be removed. Adsorption is a common physico-chemical process used to remove heavy metals. Dissolved organic carbon (DOC) and suspended solids (SS) are associated pollutants in water systems that can interact with heavy metals during the treatment process. The interactions of DOC and SS during the removal of heavy metals by granular activated carbon were investigated in batch and fixed-bed column experiments. Batch adsorption studies indicated that Langmuir adsorption maxima for Pb, Cu, Zn, Cd, and Ni at pH 6.5 were 11.9, 11.8, 3.3, 2.0, and 1.8 mg/g, respectively. With the addition of humic acid (HA) (DOC representative), they were 7.5, 3.7, 3.2, 1.6, and 2.5 mg/g, respectively. In the column experiment, no breakthrough (complete removal) was obtained for Pb and Cu, but adding HA provided a breakthrough in removing these metals. For Zn, Cd and Ni, this breakthrough occurred even without HA being added. Adding kaolinite (representative of SS) had no effect on Pb and Cu, but it did on the other metals. PMID:26343692

  10. 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)

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

    International Nuclear Information System (INIS)

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

  12. 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

  13. 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.

  14. 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)

  15. Economically Viable Fungal Production by Using Alternative Plant Material for the Removal of Heavy Metal

    Directory of Open Access Journals (Sweden)

    Shipra Jha

    2015-01-01

    Full Text Available Environmental pollution affects the quality of atmosphere, lithosphere and biosphere. Efforts have been made in the last two decades to reduce the pollution sources and remedy the polluted water sources. Water quality monitoring in developing countries is inadequate especially in stream water affected by urban effluent and runoff. The purpose of this study was to investigate heavy metal contaminants in sank stream water in Gwalior. The water sample from stream and industrial effluents that drain into the stream were collected and analyzed for the total elemental concentration using atomic absorption spectrophotometer. The result showed that:-the wastewater was highly encircled with copper above the maximum permissible limit. 2 the level of dissolved oxygen was below the maximum permissible limit, while biological oxygen demand was above the maximum permissible limit. All industrial effluents/wastewater were classified as strong. Factors analysis results reveal two sources of pollutants; multiple origin of copper and mixed origin or chemical phenomena of industrial and vehicular emission.

  16. 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

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

    Science.gov (United States)

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

    2011-12-01

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

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

    International Nuclear Information System (INIS)

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

  19. Removal of heavy metals in wastewater by using zeolite nano-particles impregnated polysulfone membranes.

    Science.gov (United States)

    Yurekli, Yilmaz

    2016-05-15

    In this study, the adsorption and the filtration processes were coupled by a zeolite nanoparticle impregnated polysulfone (PSf) membrane which was used to remove the lead and the nickel cations from synthetically prepared solutions. The results obtained from X-ray diffraction (XRD), scanning electron microscopy (SEM) and energy dispersive X-ray (EDX) analysis indicated that the synthesized zeolite nanoparticles, using conventional hydrothermal method, produced a pure NaX with ultrafine and uniform particles. The performance of the hybrid membrane was determined under dynamic conditions. The results also revealed that the sorption capacity as well as the water hydraulic permeability of the membranes could both be improved by simply tuning the membrane fabricating conditions such as evaporation period of the casting film and NaX loading. The maximum sorption capacity of the hybrid membrane for the lead and nickel ions was measured as 682 and 122mg/g respectively at the end of 60min of filtration, under 1bar of transmembrane pressure. The coupling process suggested that the membrane architecture could be efficiently used for treating metal solutions with low concentrations and transmembrane pressures. PMID:26874311

  20. A highly efficient polyampholyte hydrogel sorbent based fixed-bed process for heavy metal removal in actual industrial effluent.

    Science.gov (United States)

    Zhou, Guiyin; Luo, Jinming; Liu, Chengbin; Chu, Lin; Ma, Jianhong; Tang, Yanhong; Zeng, Zebing; Luo, Shenglian

    2016-02-01

    High sorption capacity, high sorption rate, and fast separation and regeneration for qualified sorbents used in removing heavy metals from wastewater are urgently needed. In this study, a polyampholyte hydrogel was well designed and prepared via a simple radical polymerization procedure. Due to the remarkable mechanical strength, the three-dimensional polyampholyte hydrogel could be fast separated, easily regenerated and highly reused. The sorption capacities were as high as 216.1 mg/g for Pb(II) and 153.8 mg/g for Cd(II) owing to the existence of the large number of active groups. The adsorption could be conducted in a wide pH range of 3-6 and the equilibrium fast reached in 30 min due to its excellent water penetration for highly accessible to metal ions. The fixed-bed column sorption results indicated that the polyampholyte hydrogel was particularly effective in removing Pb(II) and Cd(II) from actual industrial effluent to meet the regulatory requirements. The treatment volumes of actual smelting effluent using one fixed bed column were as high as 684 bed volumes (BV) (7736 mL) for Pb(II) and 200 BV (2262 mL) for Cd(II). Furthermore, the treatment volumes of actual smelting effluent using tandem three columns reached 924 BV (31,351 mL) for Pb(II) and 250 BV (8483 mL) for Cd(II), producing only 4 BV (136 mL) eluent. Compared with the traditional high density slurry (HDS) process with large amount of sludge, the proposed process would be expected to produce only a small amount of sludge. When the treatment volume was controlled below 209.3 BV (7103 mL), all metal ions in the actual industrial effluent could be effectively removed (wastewater. PMID:26650450

  1. 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

  2. Functionalized paper-A readily accessible adsorbent for removal of dissolved heavy metal salts and nanoparticles from water.

    Science.gov (United States)

    Setyono, Daisy; Valiyaveettil, Suresh

    2016-01-25

    Paper, a readily available renewable resource, comprises of interwoven cellulosic fibers, which can be functionalized to develop interesting low-cost adsorbent material for water purification. In this study, polyethyleneimine (PEI)-functionalized paper was used for the removal of hazardous pollutants such as Au and Ag nanoparticles, Cr(VI) anions, Ni(2+), Cd(2+), and Cu(2+) cations from spiked water samples. Compared to untreated paper, the PEI-coated paper showed significant improvement in adsorption capacities toward the pollutants investigated in this study. Kinetics, isotherm models, pH, and desorption studies were carried out to study the adsorption mechanism of pollutants on the adsorbent surface. Adsorption of pollutants was better described by pseudo-second order kinetics and Langmuir isotherm model. Maximum adsorption of anionic pollutants was achieved at pH 5 while that of cations was at pH>6. Overall, the PEI-functionalized paper showed interesting Langmuir adsorption capacities for heavy metal ions such as Cr(VI) (68mg/g), Ni(2+) (208mg/g), Cd(2+) (370mg/g), and Cu(2+) (435mg/g) ions at neutral pH. In addition, the modified paper was also used to remove Ag-citrate (79mg/g), Ag-PVP (46mg/g), Au-citrate (30mg/g), Au-PVP (17mg/g) nanoparticles from water. Desorption of NPs from the adsorbent was done by washing with 2M HCl or thiourea solution, while heavy metal ions were desorbed using 1M NaOH or HNO3 solution. The modified paper retained its extraction efficiencies upon desorption of pollutants. PMID:26452090

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

    International Nuclear Information System (INIS)

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

  4. Investigating the Effectiveness of Mineral Precipitate as a Tool in the Removal of Heavy Metals from Mine Waters

    Science.gov (United States)

    Abongwa, P. T.; Geyer, C.; Puckette, J.

    2014-12-01

    Mine water from a precious metal mine in Colorado drains into an underground tunnel and flows for about 8 km before being discharged into a series of sequentially connected settling ponds (5) aimed at removing suspended particulate. Our results suggest these ponds also remove heavy metals from solution through adsorption and mineral precipitation. Analyses of the precipitates and water in the settling ponds showed relatively higher metal concentration on the precipitates than in the corresponding aqueous solutions. Speciation modeling showed that the precipitates were mainly travertine, ferrihydrite, fe-oxyhdroxide and gypsum and these are expected to provide surfaces for metal adsorption. Overall, the average concentrations of trace metals were such that, Al concentration was 0.0 mg/L for the aqueous sample and 9.4 mg/L for the precipitate; Fe concentration was 0.04 mg/L for the aqueous sample and 20.1 mg/L for the precipitate; Mn concentration was 0.2 mg/L for the aqueous sample and 10.2 mg/L for the precipitate; Sr concentration was 3 mg/L for the aqueous sample and 8 mg/L for the precipitate; Zn concentration was 0.1 mg/L for the aqueous sample and 1.4 mg/L for the precipitate. Sulfate concentrations in solutions (1346 mg/L) were about seventeen times higher than on the precipitate (80 mg/L). As the water exits the tunnel, its carbon is expected to consistently decrease over space as it moves along the settling ponds while precipitating carbonates. The dissolved inorganic carbon (DIC) concentrations showed consistent drop from 109 mg/L at the tunnel exit to 96 mg/L at middle pond and 92 mg/L at the exit pond, which corresponds to decreasing pCO2 and removal of carbon from solution through travertine precipitation and CO2 outgassing. This data indicate a strong influence of mineral precipitate as an effective component in the attenuation of metals in mine

  5. REMOVAL OF HEAVY METALS AND SUSPENDED SOLIDS FROM BATTERY WASTEWATERS: APPLICATION OF HYDROPERM CROSS-FLOW MICROFILTRATION

    Science.gov (United States)

    This project was undertaken to evaluate the capability of crossflow microfiltration to remove suspended toxic metal and metal hydroxides from battery manufacturing wastewaters. The demonstration was conducted at the General Battery Corporation plant at Hamburg, Pennsylvania. A fu...

  6. Synergic adsorption in the simultaneous removal of acid blue 25 and heavy metals from water using a Ca(PO3)2-modified carbon.

    Science.gov (United States)

    Tovar-Gómez, R; Rivera-Ramírez, D A; Hernández-Montoya, V; Bonilla-Petriciolet, A; Durán-Valle, C J; Montes-Morán, M A

    2012-01-15

    We report the simultaneous adsorption of acid blue 25 dye (AB25) and heavy metals (Zn(2+), Ni(2+) and Cd(2+)) on a low-cost activated carbon, whose adsorption properties have been improved via a surface chemistry modification using a calcium solution extracted from egg shell wastes. Specifically, we have studied the removal performance of this adsorbent using the binary aqueous systems: AB25-Cd(2+), AB25-Ni(2+) and AB25-Zn(2+). Multi-component kinetic and equilibrium experiments have been performed and used to identify and characterize the synergic adsorption in the simultaneous removal of these pollutants. Our results show that the presence of AB25 significantly favors the removal of heavy metals and may increase the adsorption capacities up to six times with respect to the results obtained using the mono-cationic metallic systems, while the adsorption capacities of AB25 are not affected by the presence of metallic ions. It appears that this anionic dye favors the electrostatic interactions with heavy metals or may create new specific sites for adsorption process. In particular, heavy metals may interact with the -SO(3)(-) group of AB25 and to the hydroxyl and phosphoric groups of this adsorbent. A response surface methodology model has been successfully used for fitting multi-component adsorption data. PMID:22118844

  7. 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.

  8. 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

  9. 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).

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

    OpenAIRE

    María C. Ponce-Caballero; Roger Méndez-Novelo; Icela D. Barceló-Quintal; Germán Giácoman-Vallejos; Jorge A. Cortes-Esquivel

    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 ...

  11. 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.

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

    Science.gov (United States)

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

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

  13. Perspectives of phytoremediation using water hyacinth for removal of heavy metals, organic and inorganic pollutants in wastewater.

    Science.gov (United States)

    Rezania, Shahabaldin; Ponraj, Mohanadoss; Talaiekhozani, Amirreza; Mohamad, Shaza Eva; Md Din, Mohd Fadhil; Taib, Shazwin Mat; Sabbagh, Farzaneh; Sairan, Fadzlin Md

    2015-11-01

    The development of eco-friendly and efficient technologies for treating wastewater is one of the attractive research area. Phytoremediation is considered to be a possible method for the removal of pollutants present in wastewater and recognized as a better green remediation technology. Nowadays the focus is to look for a sustainable approach in developing wastewater treatment capability. Water hyacinth is one of the ancient technology that has been still used in the modern era. Although, many papers in relation to wastewater treatment using water hyacinth have been published, recently removal of organic, inorganic and heavy metal have not been reviewed extensively. The main objective of this paper is to review the possibility of using water hyacinth for the removal of pollutants present in different types of wastewater. Water hyacinth is although reported to be as one of the most problematic plants worldwide due to its uncontrollable growth in water bodies but its quest for nutrient absorption has provided way for its usage in phytoremediation, along with the combination of herbicidal control, integratated biological control and watershed management controlling nutrient supply to control its growth. Moreover as a part of solving wastewater treatment problems in urban or industrial areas using this plant, a large number of useful byproducts can be developed like animal and fish feed, power plant energy (briquette), ethanol, biogas, composting and fiber board making. In focus to the future aspects of phytoremediation, the utilization of invasive plants in pollution abatement phytotechnologies can certainly assist for their sustainable management in treating waste water. PMID:26311085

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

    DEFF Research Database (Denmark)

    Ferreira, Célia Maria Dias; Jensen, Pernille Erland; Ottosen, Lisbeth M.; Ribeiro, Alexandra

    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....

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

    DEFF Research Database (Denmark)

    Ferreira, Célia Maria Dias; Jensen, Pernille Erland; Ottosen, Lisbeth M.; Ribeiro, Alexandra

    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 dissol...

  16. 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.

  17. 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...

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

    OpenAIRE

    B. Gajda; M.B. Bogacki

    2012-01-01

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

  19. 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)

  20. 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

  1. 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.

  2. Arsenic removal via electrocoagulation from heavy metal contaminated groundwater in La Comarca Lagunera México.

    Science.gov (United States)

    Parga, Jose R; Cocke, David L; Valenzuela, Jesus L; Gomes, Jewel A; Kesmez, Mehmet; Irwin, George; Moreno, Hector; Weir, Michael

    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 México, use well water with arsenic in excess of the water standard regulated by the Secretary of Environment and Natural Resources of México (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 Mössbauer 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. PMID:15990229

  3. Fast microwave-assisted preparation of a low-cost and recyclable carboxyl modified lignocellulose-biomass jute fiber for enhanced heavy metal removal from water.

    Science.gov (United States)

    Du, Zhaolin; Zheng, Tong; Wang, Peng; Hao, Linlin; Wang, Yanxia

    2016-02-01

    A low-cost and recyclable biosorbent derived from jute fiber was developed for high efficient adsorption of Pb(II), Cd(II) and Cu(II) from water. The jute fiber was rapidly pretreated and grafted with metal binding groups (COOH) under microwave heating (MH). The adsorption behavior of carboxyl-modified jute fiber under MH treatment (CMJFMH) toward heavy metal ions followed Langmuir isotherm model (R(2)>0.99) with remarkably high adsorption capacity (157.21, 88.98 and 43.98mg/g for Pb(II), Cd(II) and Cu(II), respectively). Also, CMJFMH showed fast removal ability for heavy metals in a highly significant correlation with pseudo second-order kinetics model. Besides, CMJFMH can be easily regenerated with EDTA-2Na solution and reused up to at least four times with equivalent high adsorption capacity. Overall, cheap and abundant production, rapid and facile preparation, fast and efficient adsorption of heavy metals and high regeneration ability can make the CMJFMH a preferred biosorbent for heavy metal removal from water. PMID:26630582

  4. 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.

  5. 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)

  6. Feasibility of using humic substances from compost to remove heavy metals (Cd, Cu, Ni, Pb, Zn) from contaminated soil aged for different periods of time.

    Science.gov (United States)

    Kulikowska, Dorota; Gusiatin, Zygmunt Mariusz; Bu?kowska, Katarzyna; Klik, Barbara

    2015-12-30

    There is a need for inexpensive, readily-available and environmentally-friendly soil washing agents to remediate polluted soils. Thus, batch washing experiments were performed to evaluate the feasibility of using a solution of humic substances (HS) extracted from compost as a washing agent for simultaneous removal of Cu, Cd, Zn, Pb and Ni from artificially contaminated soils aged for 1 month, 12 months and 24 months. The efficiency of metal removal in single and multiple washings and kinetic constants (equilibrium metal concentration qe and rate constant k from the second-order kinetic equation) were determined. On average, triple washing removed twice as much metal as that removed with a single washing. At pH 7 and a HS concentration of 2.2 g C L(-1), metal removal from all soils decreased in this order: Cd (79.1-82.6%) > Cu (51.5-71.8%) > Pb (44.8-47.6%) > Ni (35.4-46.1%) > Zn (27.9-35.8%). However, based on qe (mg kg(-1)), metal removal was in this order: Pb > Zn ? Cu > Ni > Cd. This difference was due to different concentrations of metals, which is typical for multi-metal contaminated soils. Regardless of washing mode, removal of Cd and Pb was not affected by soil age, whereas removal of Cu, Ni and Zn was higher in soils that had been aged for a shorter time. These results indicate that HS are suitable for remediating soil contaminated with multiple heavy metals in extremely high concentrations. PMID:26462121

  7. 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.

  8. 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+.

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

    OpenAIRE

    P. Lakshmanaperumalsamy; J. Rathinamala; 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...

  10. Effect of soil washing with only chelators or combining with ferric chloride on soil heavy metal removal and phytoavailability: Field experiments.

    Science.gov (United States)

    Guo, Xiaofang; Wei, Zebin; Wu, Qitang; Li, Chunping; Qian, Tianwei; Zheng, Wei

    2016-03-01

    In a field experiment on multi-metal contaminated soil, we investigated the efficiency of Cd, Pb, Zn, and Cu removal by only mixture of chelators (MC) or combining with FeCl3. After washing treatment, a co-cropping system was performed for heavy metals to be extracted by Sedum alfredii and to produce safe food from Zea mays. We analyzed the concentration of heavy metals in groundwater to evaluate the leashing risk of soil washing with FeCl3 and MC. Results showed that addition of FeCl3 was favorable to the removal of heavy metals in the topsoil. Metal leaching occurred mainly in rain season during the first co-cropping. The removal rates of Cd, Zn, Pb, and Cu in topsoil were 28%, 53%, 41%, and 21% with washing by FeCl3+MC after first harvest. The application of FeCl3 reduced the yield of S. alfredii and increased the metals concentration of Z. mays in first harvest. However, after amending soil, the metals concentration of Z. mays in FeCl3+MC treatment were similar to that only washing by MC. The grains and shoots of Z. mays were safe for use in feed production. Soil washing did not worsen groundwater contamination during the study period. But the concentration of Cd in groundwater was higher than the limit value of Standard concentrations for Groundwater IV. This study suggests that soil washing using FeCl3 and MC for the remediation of multi-metal contaminated soil is potential feasibility. However, the subsequent measure to improve the washed soil environment for planting crop is considered. PMID:26774307

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

    OpenAIRE

    S. A. Mirbagheri, M. Salehi M

    2006-01-01

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

  12. 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)

  13. Heavy metals hyper accumulation in plants

    International Nuclear Information System (INIS)

    The possibility of growing heavy-metal-hyper accumulating plants in highly polluted environments is a novel strategy, currently named phyto remediation. This process could be very reliable both to remove (and often to utilize again) with low costs heavy metals from water and soil and to enhance the landscape beauty in environments otherwise unlikely enjoyable

  14. Effects of particulates, heavy metals and acid gas on the removals of NO and PAHs by V2O5-WO3 catalysts in waste incineration system

    International Nuclear Information System (INIS)

    This study investigated the activities of prepared and commercial V2O5-WO3 catalysts for simultaneous removals of NO and polycyclic aromatic hydrocarbons (PAHs) and the influences of particulates, heavy metals, SO2, and HCl on the performances of catalysts. The experiments were carried out in a laboratory-scale waste incineration system equipped with a catalyst reactor. The DREs of PAHs by prepared and commercial V2O5-WO3 catalysts were 64% and 72%, respectively. Increasing the particulate concentrations in flue gas suppressed the DRE of PAHs, but increasing the carbon content on surface of catalysts promotes the NO conversions. The DRE of PAHs by the catalysts was significantly decreased by the increased concentrations of heavy metal Cd, but was promoted by high concentration of Pb. The influence level of SO2 was higher than HCl on the performances of V2O5-WO3 catalysts for PAHs removal, but was lower than HCl for NO removal. Prepared and commercial V2O5-WO3 catalysts have similar trends on the effects of particulates, heavy metals, SO2, and HCl. The results of ESCA analysis reveal that the presences of these pollutants on the surface of catalysts did not change the chemical state of V and W.

  15. 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

    2015-01-01

    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

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

    Science.gov (United States)

    Wu, Peng; Zhou, Yu-shan

    2009-09-15

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

  17. Biosorption of Heavy Metals by Biomass

    OpenAIRE

    AKÇ?N, Göksel

    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...

  18. In vitro removal of toxic heavy metals by poly(γ-glutamic acid)-coated superparamagnetic nanoparticles

    OpenAIRE

    Inbaraj BS; Chen BH

    2012-01-01

    Baskaran Stephen Inbaraj,1 Bing-Huei Chen1,21Department of Food Science, 2Graduate Institute of Medicine, Fu Jen University, Taipei, TaiwanBackground: Chelation therapy involving organic chelators for treatment of heavy metal intoxication can cause cardiac arrest, kidney overload, mineral deficiency, and anemia.Methods: In this study, superparamagnetic iron oxide nanoparticles (SPIONs) modified with an edible biopolymer poly(γ-glutamic acid) (PGA) were synthesized by coprecipitation...

  19. 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.; Jensen, Pernille Erland

    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 slud...

  20. Influence of solution acidity and CaCl{sub 2} concentration on the removal of heavy metals from metal-contaminated rice soils

    Energy Technology Data Exchange (ETDEWEB)

    Kuo, S. [Environmental Engineering Department, Da-Yeh University, Da-Tsuen, ChangHua, Taiwan (China)]. E-mail: skuo@wsu.edu; Lai, M.S. [Environmental Engineering Department, Da-Yeh University, Da-Tsuen, ChangHua, Taiwan (China); Lin, C.W. [Environmental Engineering Department, Da-Yeh University, Da-Tsuen, ChangHua, Taiwan (China)

    2006-12-15

    Soil washing is considered a useful technique for remediating metal-contaminated soils. This study examined the release edges of Cd, Zn, Ni, Cr, Cu or Pb in two contaminated rice soils from central Taiwan. The concentrations exceeding the trigger levels established by the regulatory agency of Taiwan were Cu, Zn, Ni and Cr for the Ho-Mei soil and Pb for the Nan-Tou soil. Successive extractions with HCl ranging from 0 to 0.2 M showed increased release of the heavy metals with declining pH, and the threshold pH value below which a sharp increase in the releases of the heavy metals was highest for Cd, Zn, and Ni (pH 4.6 to 4.9), intermediate for Pb and Cu (3.1 to 3.8) and lowest for Fe (2.1), Al (2.2) and Cr (1.7) for the soils. The low response slope of Ni and Cr particularly for the rice soils make soil washing with the acid up to the highest concentration used ineffective to reduce their concentrations to below trigger levels. Although soil washing with 0.1 M HCl was moderately effective in reducing Cu, Pb, Zn and Cd, which brought pH of the soils to 1.1 {+-} 0.1 (S.D.), the concurrent release of large quantities of Fe and Al make this remediation technique undesirable for the rice soils containing high clay. Successive washings with 0.01 M HCl could be considered an alternative as the dissolution of Fe and Al was minimal, and between 46 to 64% of Cd, Zn, and Cu for the Ho-Mei soil and 45% of Pb in the Na-Tou soil were extracted after four successive extractions with this dilute acid solution. The efficacy of Cd extraction improved if CaCl{sub 2} was added to the acid solution. The correlation analysis revealed that Cr extracted was highly correlated (P < 0.001) with Fe extracted, whereas the Cu, Ni, Zn, Cd or Pb extracted was better correlated (P < 0.001) with Al than with Fe extracted. It is possible that the past seasonal soil flooding and drainage in the soils for rice production was conducive to incorporating Cr within the structure of Fe oxide, thereby making them extremely insoluble even in 0.2 M HCl solution. The formation of solid solution of Ni with Al oxide was also possible, making it far less extractable than Cd, Zn, Cu, or Pb with the acid concentrations used. - Release edges and threshold pH values for heavy metals determine how effective dilute HCl in removing the metals from metal-contaminated rice soils.

  1. 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.

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

    Energy Technology Data Exchange (ETDEWEB)

    Jimenez-Rodriguez, A.M. [Departamento de Sistemas Fisicos, Quimicos y Naturales, Facultad de Ciencias Ambientales, Universidad Pablo de Olavide. Carretera de Utrera, km 1. 41013 Sevilla (Spain); Duran-Barrantes, M.M. [Departamento de Ingenieria Quimica, Facultad de Quimica, Universidad de Sevilla, C/Profesor Garcia Gonzalez, s/n, 41071 Sevilla (Spain); Borja, R., E-mail: rborja@cica.es [Consejo Superior de Investigaciones Cientificas (CSIC), Instituto de la Grasa, Avda. Padre Garcia Tejero 4, 41012 Sevilla (Spain); Sanchez, E.; Colmenarejo, M.F. [Consejo Superior de Investigaciones Cientificas (CSIC), Centro de Ciencias Medioambientales, C/Serrano, 115-duplicado, 28006 Madrid (Spain); Raposo, F. [Consejo Superior de Investigaciones Cientificas (CSIC), Instituto de la Grasa, Avda. Padre Garcia Tejero 4, 41012 Sevilla (Spain)

    2009-06-15

    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.

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

    International Nuclear Information System (INIS)

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

  4. 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.

  5. Removal and recovery of heavy metals from aqueous solution using Ulmus carpinifolia and Fraxinus excelsior tree leaves.

    Science.gov (United States)

    Sangi, Mohammad Reza; Shahmoradi, Ali; Zolgharnein, Javad; Azimi, Gholam Hassan; Ghorbandoost, Morteza

    2008-07-15

    Ulmus carpinifolia and Fraxinus excelsior tree leaves, which are in great supply in Iran, were evaluated for removal of Pb(II), Cd(II) and Cu(II) from aqueous solution. Maximum biosorption capacities for U. carpinifolia and F. excelsior were measured as 201.1, 172.0 mg/g for Pb(II), 80.0, 67.2 mg/g for Cd(II) and 69.5, 33.1 mg/g for Cu(II), respectively. For both sorbents the most effective pH range was found to be 2-5 for Pb(II), 3-5 for Cd(II) and 4-5 for Cu(II). Metal ion biosorption increased as the ratio of metal solution to the biomass quantity decreased. Conversely, biosorption/g biosorbent decreased as the quantity of biomass increased. The biosorption of metal ions increased as the initial metal concentration increased. Biosorption capacities of metal ions were in the following order: Pb(II)>Cd(II)>Cu(II). The equilibrium data for Pb(II) and Cu(II) best fit the Langmuir adsorption isotherm model. Kinetic studies showed that the biosorption rates could be described by a second-order expression. Both the sorbents could be regenerated using 0.2 M HCl during repeated biosorption-desorption cycles with no loss in the efficiency of the Cu(II) removal observed. Biosorption of Pb(II), Cd(II) and Cu(II) was investigated in the presence of Na, K, Mg and Ca ions. The results from these studies show a novel way of using U. carpinifolia and F. excelsior tree leaves to remove Pb(II), Cd(II) and Cu(II) from metal-polluted waters. PMID:18191021

  6. 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 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)

  7. Aluminosilicate-based adsorbent in equimolar and non-equimolar binary-component heavy metal removal systems.

    Science.gov (United States)

    Xu, Meng; Hadi, Pejman; Ning, Chao; Barford, John; An, Kyoung Jin; McKay, Gordon

    2015-01-01

    Cadmium (Cd) and lead (Pb) are toxic heavy metals commonly used in various industries. The simultaneous presence of these metals in wastewater amplifies the toxicity of wastewater and the complexity of the treatment process. This study has investigated the selective behavior of an aluminosilicate-based mesoporous adsorbent. It has been demonstrated that when equimolar quantities of the metals are present in wastewater, the adsorbent uptakes the Pb(2+) ions selectively. This has been attributed to the higher electronegativity value of Pb(2+) compared to Cd(2+) which can be more readily adsorbed on the adsorbent surface, displacing the Cd(2+) ions. The selectivity can be advantageous when the objective is the separation and reuse of the metals besides wastewater treatment. In non-equimolar solutions, a complete selectivity can be observed up to a threshold Pb(2+) molar ratio of 30%. Below this threshold value, the Cd(2+) and Pb(2+) ions are uptaken simultaneously due to the abundance of Cd(2+) ions and the availability of adsorption sites at very low Pb(2+) molar ratios. Moreover, the total adsorption capacities of the adsorbent for the multi-component system have been shown to be in the same range as the single-component system for each metal ion which can be of high value for industrial applications. PMID:26676004

  8. Polyacrylamido-2-methyl-1-propane sulfonic acid-grafted-natural rubber as bio-adsorbent for heavy metal removal from aqueous standard solution and industrial wastewater.

    Science.gov (United States)

    Phetphaisit, Chor Wayakron; Yuanyang, Siriwan; Chaiyasith, Wipharat Chuachuad

    2016-01-15

    Bio-adsorbent modified natural rubber (modified NR) was prepared, by placing the sulfonic acid functional group on the isoprene chain. This modification was carried out with the aim to prepare material capable to remove heavy metals from aqueous solution. The structures of modified NR materials were characterized by FT-IR and NMR spectroscopies. Thermal gravimetric analysis of modified NR showed that the initial degradation temperature of rubber decreases with increasing amount of polyacrylamido-2-methyl-1-propane sulfonic acid (PAMPS) in the structure. In addition, water uptake of the rubber based materials was studied as a function of time and content of PAMPS. The influence of the amount of PAMPS grafted onto NR, time, pH, concentration of metal ions, temperature, and regeneration were studied in terms of their influence on the adsorption of heavy metals (Pb(2+), Cd(2+) and Cu(2+)). The adsorption isotherms of Pb(2+) and Cd(2+) were fitted to the Freundlich isotherm model, while Cu(2+) was fitted to the Langmuir isotherm. However, the results from these two isotherms resulted in a similar behavior. The adsorption capacity of the modified NR for the various heavy metals was in the following order: Pb(2+)?Cd(2+)>Cu(2+). The maximum adsorption capacities of Pb(2+), Cd(2+), and Cu(2+) were 272.7, 267.2, and 89.7mg/g of modified rubber, respectively. Moreover, the modified natural rubber was used for the removal of metal ions in real samples of industrial effluents where the efficiency and regeneration were also investigated. PMID:26348149

  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. Evaluation of the potential of indigenous calcareous shale for neutralization and removal of arsenic and heavy metals from acid mine drainage in the Taxco mining area, Mexico.

    Science.gov (United States)

    Romero, F M; Núñez, L; Gutiérrez, M E; Armienta, M A; Ceniceros-Gómez, A E

    2011-02-01

    In the Taxco mining area, sulfide mineral oxidation from inactive tailings impoundments and abandoned underground mines has produced acid mine drainage (AMD; pH 2.2-2.9) enriched in dissolved concentrations (mg l?¹) sulfate, heavy metals, and arsenic (As): SO?²? (pH 1470-5454), zinc (Zn; 3.0-859), iron (Fe; pH 5.5-504), copper (Cu; pH 0.7-16.3), cadmium (Cd; pH 0.3-6.7), lead (Pb; pH limestone have been widely used to remediate AMD in many parts of the world. In limestone-treatment systems, calcite simultaneously plays the role of neutralizing and precipitating agent. However, the acid-neutralizing potential of limestone decreases when surfaces of the calcite particles become less reactive as they are progressively coated by metal precipitates. This study constitutes first-stage development of passive-treatment systems for treating AMD in the Taxco mine area using indigenous calcareous shale. This geologic material consists of a mixture of calcite, quartz, muscovite, albite, and montmorillonite. Results of batch leaching test indicate that calcareous shale significantly increased the pH (to values of 6.6-7.4) and decreased heavy metal and As concentrations in treated mine leachates. Calcareous shale had maximum removal efficiency (100%) for As, Pb, Cu, and Fe. The most mobile metals ions were Cd and Zn, and their average percentage removal was 87% and 89%, respectively. In this natural system (calcareous shale), calcite provides a source of alkalinity, whereas the surfaces of quartz and aluminosilicate minerals possibly serve as a preferred locus of deposition for metals, resulting in the neutralizing agent (calcite) beings less rapidly coated with the precipitating metals and therefore able to continue its neutralizing function for a longer time. PMID:20523977

  11. Cost effective and shape controlled approach to synthesize hierarchically assembled NiO nanoflakes for the removal of toxic heavy metal ions in aqueous solution

    Indian Academy of Sciences (India)

    K Yogesh Kumar; H B Muralidhara; Y Arthoba Nayaka; H Hanumanthappa; M S Veena; S R Kiran Kumar

    2015-02-01

    Hierarchical mesoporous NiO nanoflakes (NiOs) have been synthesized in high yield via a simple, economical and environmentally friendly hydrothermal route. The as-prepared NiOs were characterized by powder X-ray diffraction (PXRD), scanning electronicmicroscopy (SEM), transmission electronmicroscopy (TEM), selected area electron diffraction patterns (SAED), X-ray energy dispersive spectroscopy (EDS) and nitrogen adsorption–desorption techniques (Brunauer–Emmett–Teller, BET). Adsorption of heavy metal ions onto the as-prepared sample from aqueous solutions was investigated using differential pulse anodic stripping voltametry (DPASV) technique and discussed. The product possesses a BET surface area of 69.27 m2 g-1. It is found that NiOs exhibited the excellent performance for the removal of Hg(II), Pb(II) and Cd(II) from aqueous solution. The equilibrium adsorption data of Hg(II), Pb(II) and Cd(II) on the as-prepared NiOs were analyzed by Langmuir and Freundlich models, suggesting that the Langmuir model provides the better correlation of the experimental data. The adsorption capacities for removal of Hg(II), Pb(II) and Cd(II) were determined using the Langmuir equation and found to be 1324.5, 1428.9 and 1428.5 mg g-1, respectively. Adsorption kinetics of all the metal ions followed pseudo second-order model. Moreover, NiOs can be recycled by simple acid treatment, which could retain the high removal efficiency in three successive cycles. This study suggests that nanoflakes could be explored as a new adsorbent with high efficiency and recyclability for removing heavy metal ions from aqueous solution.

  12. Immobilization of 5-aminopyridine-2-tetrazole on cross-linked polystyrene for the preparation of a new adsorbent to remove heavy metal ions from aqueous solution.

    Science.gov (United States)

    Zhang, Yu; Chen, Youning; Wang, Chaozhan; Wei, Yinmao

    2014-07-15

    Novel 5-aminopyridine-2-tetrazole-functionalized polystyrene resin (APTZ-PS) was prepared by anchoring 5-aminopyridine-2-carbonitrile onto chloromethylated polystyrene beads (CMPS) and subsequently using the cyano-tetrazole conversion reaction. The APTZ-PS resin was characterized by Fourier transform infrared spectroscopy (FT-IR), X-ray photoelectron spectroscopy (XPS) and specific surface area and pore size analyses. The adsorption experiments of the prepared resin for heavy metal ions were conducted by batch methods. The effects of the experimental conditions, such as pH, contact time and initial metal ion concentration on the adsorption properties of Cu(II), Pb(II) and Hg(II) were investigated. The results showed that the resin possessed perfect adsorption capacities for Cu(II), Pb(II) and Hg(II), and the selectivity was different from the commonly used iminodiacetic acid-chelating resin. The sorption kinetics of the three metal ions followed the pseudo-second-order equation. The adsorption isotherms for Cu(II) and Pb(II) could be better fitted by the Langmuir model than the Freundlich model, whereas the Freundlich model was the best for the Hg(II) ion. Even after five consecutive adsorption-desorption cycles, no obvious change in the adsorption capacity of the resin was found, which implied that the APTZ-PS resin was suitable for the efficient removal of heavy metal ions from aqueous solution. PMID:24875375

  13. 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.; Jensen, Pernille Erland

    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...

  14. Fluoride free new nano-particles-Mn-Biotite synthesis for removal of some toxic heavy metals, Th(IV) and U(VI) from aqueous solutions

    International Nuclear Information System (INIS)

    The present paper aims to synthesize new family of fluoride free Mn- Biotite type having the optimized formula NaMn/sub 2.5/(Al,Si)/sub 4/O/sub 10/(OH)/sub 2/. The free fluoride Mn- Biotite was prepared carefully by using solid- state reaction technique using nominal compositions of individual oxides in the main formula for the potential removal of some heavy metals and some radioactive elements from aqueous solution. The crystal structure of Mn-Biotite was well characterized via powder X-ray diffraction (XRD). The particle size was estimated and found to be 54 nm. Analysis of XRD profile indicated that Mn- Biotite is belonging mainly to the monoclinic crystal structure. Infrared spectroscopy (IR) showed the most intensive absorption peaks for monoclinic phase observed at 3420, 2360, 1620, 1440cm/sup -1/. Furthermore the morphological microstructure was investigated by SE-microscopy (SEM), the estimated grain size was found to be in between (0.8-7.7) micro m. Electron spin resonance (ESR) proved that Mn-biotite has paramagnetic behavior. Also DC- electrical conductivity and TGA were investigated. In conclusion results suggest that the synthesized Mn- biotite can be used as good ion exchanger with high performance to remove heavy metals and some radioactive species from wastewater. (author)

  15. Design of a new integrated chitosan-PAMAM dendrimer biosorbent for heavy metals removing and study of its adsorption kinetics and thermodynamics.

    Science.gov (United States)

    Zarghami, Zabihullah; Akbari, Ahmad; Latifi, Ali Mohammad; Amani, Mohammad Ali

    2016-04-01

    In this research, different generations of PAMAM-grafted chitosan as integrated biosorbents were successfully synthesized via step by step divergent growth approach of dendrimer. The synthesized products were utilized as adsorbents for heavy metals (Pb(2+) in this study) removing from aqueous solution and their reactive Pb(2+) removal potential was evaluated. The results showed that as-synthesized products with higher generations of dendrimer, have more adsorption capacity compared to products with lower generations of dendrimer and sole chitosan. Adsorption capacity of as-prepared product with generation 3 of dendrimer is 18times more than sole chitosan. Thermodynamic and kinetic studies were performed for understanding equilibrium data of the uptake capacity and kinetic rate uptake, respectively. Thermodynamic and kinetic studies showed that Langmuir isotherm model and pseudo second order kinetic model are more compatible for describing equilibrium data of the uptake capacity and kinetic rate of the Pb(2+) uptake, respectively. PMID:26836608

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

    International Nuclear Information System (INIS)

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

  17. Post-synthetic metalation in an anionic MOF for efficient catalytic activity and removal of heavy metal ions from aqueous solution.

    Science.gov (United States)

    Chakraborty, Anindita; Bhattacharyya, Sohini; Hazra, Arpan; Ghosh, Ashta Chandra; Maji, Tapas Kumar

    2016-02-01

    A new 3D porous anionic MOF (AMOF-1) based on Zn(II) and a flexible tetracarboxylate linker has been synthesized. AMOF-1 showed potential for capture and removal of toxic metal ions from aqueous solution with a detection limit in the ppm level. The Cu(II)@AMOF-1' hybrid obtained by post-synthetic metalation is studied as a heterogeneous catalyst for the synthesis of benzimidazole derivatives. PMID:26776086

  18. 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)

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

    OpenAIRE

    Jaber SALEHZADEH

    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...

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

    OpenAIRE

    Eman A.H. Mohamed; Nermeen A. ElSersy

    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...

  1. 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.

  2. 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.

  3. Inorganic particulates in removal of toxic heavy metal ions: rapid and efficient removal of Hg(II) and Cr(III) ions from aqueous solutions by sodium titanate

    International Nuclear Information System (INIS)

    Radiotracer technique has been used to study the removal of Hg(II) and Cr(III) ions from aqueous solutions by synthesized and well characterized sodium titanate powder. Adsorptive concentration (10-2-10-8 mol dm-3), pH (ca. 3.0-10.0) and temperature (303-333 K) were examined for assessing optimal conditions for removal of these ions. The uptake of Hg(II) and Cr(III) ions, which fitted well for Freundlich isotherm, increased with increase in the temperature and no significant desorption took place in the studied temperature range. The presence of some anions/cations affected the uptake of metal ions markedly. Increasing the H+ ion concentration (HCl/H2SO4) decreased the removal of these ions. Irradiation of sodium titanate by using a 11.1 GBq (Ra-Be) neutron source having a neutron flux density of 3.9 x 106 cm-2 s-1 and associated with a ?-dose rate of 1.7 Gy/h and also by using a Gamma cell (4.7 kGy/h) did not influence the extent of adsorption of Hg(II) and Cr(III) ions. (orig.)

  4. Heavy metal removal from sludge with organic chelators: Comparative study of N, N-bis(carboxymethyl) glutamic acid and citric acid.

    Science.gov (United States)

    Suanon, Fidèle; Sun, Qian; Dimon, Biaou; Mama, Daouda; Yu, Chang-Ping

    2016-01-15

    The applicability and performance of a new generation of biodegradable chelator, N, N-Bis(carboxymethyl) glutamic acid (GLDA), for extracting heavy metals from sewage sludge was carried out and compared with citric acid (CA). Targeted metals included Cd, Co, Cu, Zn, Ni and Cr, and their contents in the raw sludge were 63.1, 73.4, 1103.2, 2060.3, 483.9 and 604.1 mg kg(-1) (dry sludge basis), respectively. Metals were divided into six fractions including water soluble, exchangeable, carbonates bound, Fe-Mn bound, organic matters bound and residual fraction via chemical fractionation. Washing results showed that in general GLDA exhibited better performance compared with CA, with removal efficiency of 83.9, 87.3, 81.2, 85.6, 89.3 and 90.2% for Cd, Co, Cu, Zn, Ni and Cr, respectively at equilibrium pH = 3.3. Residual metals were better stabilized in the GLAD-washed sludge than in the CA-washed sludge, and were mostly tightly bonded to the residual fraction. Furthermore, CA promoted phosphorus (P) release while GLDA had an opposite effect and tended to retain P within sludge, which could be beneficial for further application in agricultural use. Findings from this study suggested that GLDA could be a potential replacement for refractory and less environmentally-friendly chelators in the extraction of metals from sludge. PMID:26520041

  5. 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

  6. Soil treatment to remove uranium and related mixed radioactive heavy metal contaminants. Seventh quarterly technical progress report, July 1, 1994--September 30, 1994

    International Nuclear Information System (INIS)

    The objective of this project is to design and develop a physico-chemical treatment process for the removal of uranium and heavy metals from contaminated soil to achieve target contamination levels below 35 pCi/g of soil and a target for non-radioactive heavy metals below concentration levels permissible for release of the soil. The work will involve bench-scale and pilot-scale tests, using chelation-flotation, chemical leaching and ultrasonic leaching techniques, in conjunction with cross-flow microfiltration and filter-press operations. The effectiveness of an integrated process to treat leachates generated from soil processing will be demonstrated. Process flow-sheets suitable for in-situ and ex-situ applications will be developed and preliminary costs will be provided for the soil and leachate treatment technologies. The Task 2 Topical Report (milestone No. 4) summarizing contaminant removal results obtained from bench-scale studies using Fernald uranium soils and Chalk River Laboratories Chemical Pit soils was completed and issued on August 8, 1994. The results have shown that the soils containing uranium (about 400 pCi/g of soil) and strontium-90 (about 1200 pCi/g of soil) can be decontaminated to the target level of 35 pCi/g of treated soil in the presence of an ultrasonic field. Preliminary results obtained from the in-situ soil leaching tests are the average strontium-90 concentration in the cell was about 250 pCi/g; and the use of a dilute mineral acid (0. 1 mol/L HCl) removed in excess of 85% of strontium-90 originally present in the soil

  7. Application of novel consortium TSR for treatment of industrial dye manufacturing effluent with concurrent removal of ADMI, COD, heavy metals and toxicity.

    Science.gov (United States)

    Patel, Tallika L; Patel, Bhargav C; Kadam, Avinash A; Tipre, Devayani R; Dave, Shailesh R

    2015-01-01

    The present study was aimed towards the effective bio-treatment of actual industrial effluent containing as high as 42,000 mg/L COD (chemical oxygen demand), >28,000 ADMI (American Dye Manufacturers Institute) color value and four heavy metals using indigenous developed bacterial consortium TSR. Mineral salt medium supplemented with as low as 0.02% (w/v) yeast extract and glucose was found to remove 70% ADMI, 69% COD and >99% sorption of heavy metals in 24 h from the effluent by consortium TSR. The biodegradation of effluent was monitored by UV-vis light, HPLC (high performance liquid chromatography), HPTLC (high performance thin layer chromotography) and FTIR (Fourier transform infrared spectroscopy) and showed significant differences in spectra of untreated and treated effluent, confirming degradation of the effluent. Induction of intracellular azoreductase (107%) and NADH-DCIP reductase (128%) in addition to extracellular laccase (489%) indicates the vital role of the consortium TSR in the degradation process. Toxicity study of the effluent using Allium cepa by single cell gel electrophoresis showed detoxification of the effluent. Ninety per cent germination of plant seeds, Triticum aestivum and Phaseolus mungo, was achieved after treatment by consortium TSR in contrast to only 20% and 30% germination of the respective plants in case of untreated effluent. PMID:25945844

  8. Soil treatment to remove uranium and related mixed radioactive heavy metal contaminants. Ninth quarterly technical and financial progress report, January 1, 1995--March 31, 1995

    International Nuclear Information System (INIS)

    The objective of this project is to design and develop a physico-chemical treatment process for the removal of uranium and heavy metals from contaminated soil to achieve target contamination levels below 35 pCi/g of soil and a target for non-radioactive heavy metals below concentration levels permissible for release of the soil. The work will involve bench-scale and pilot-scale tests, using chelation-flotation, chemical leaching and ultrasonic leaching techniques, in conjunction with cross-flow microfiltration and filter-press operations. The effectiveness of an integrated process to treat leachates generated from soil processing will be demonstrated. Process flow-sheets suitable for in-situ and ex-situ applications will be developed and preliminary costs will be provided for the soil and leachate treatment technologies. In accordance with 10CFR 600.31 (d)(i), an extension of the project period including final report submission to 31 July 1995 was made in anticipation of potential delays in receiving Fernald soil samples at Chalk River Laboratories for the planned pilot-scale verification tests. Ex-situ pilot-scale soil decontamination and leachate treatment tests using Chalk River Chemical Pit soil are nearing completion. Soil decontamination tests using Fernald Incinerator Area soil originally scheduled for February 1995 was postponed to May 1995 as result of unexpected delays in the preparation of two drums of soils (?416 kg) by FERMCO and paperwork required to arrange for export/import licenses

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2011-11-15

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

  10. Immobilization of 5-aminopyridine-2-tetrazole on cross-linked polystyrene for the preparation of a new adsorbent to remove heavy metal ions from aqueous solution

    International Nuclear Information System (INIS)

    Highlights: • Novel chelating resin was prepared using pyridine-2-tetrazole as ligand. • The resin has quite high adsorption capacity for Cu(II), Pb(II) and Hg(II). • The resin shows the different selectivity from the common used IDA resin. • The preparation procedure is a two-step reaction and is easy to carry out. - Abstract: Novel 5-aminopyridine-2-tetrazole-functionalized polystyrene resin (APTZ-PS) was prepared by anchoring 5-aminopyridine-2-carbonitrile onto chloromethylated polystyrene beads (CMPS) and subsequently using the cyano-tetrazole conversion reaction. The APTZ-PS resin was characterized by Fourier transform infrared spectroscopy (FT-IR), X-ray photoelectron spectroscopy (XPS) and specific surface area and pore size analyses. The adsorption experiments of the prepared resin for heavy metal ions were conducted by batch methods. The effects of the experimental conditions, such as pH, contact time and initial metal ion concentration on the adsorption properties of Cu(II), Pb(II) and Hg(II) were investigated. The results showed that the resin possessed perfect adsorption capacities for Cu(II), Pb(II) and Hg(II), and the selectivity was different from the commonly used iminodiacetic acid-chelating resin. The sorption kinetics of the three metal ions followed the pseudo-second-order equation. The adsorption isotherms for Cu(II) and Pb(II) could be better fitted by the Langmuir model than the Freundlich model, whereas the Freundlich model was the best for the Hg(II) ion. Even after five consecutive adsorption–desorption cycles, no obvious change in the adsorption capacity of the resin was found, which implied that the APTZ-PS resin was suitable for the efficient removal of heavy metal ions from aqueous solution

  11. Removal of chemical oxygen demand, nitrogen, and heavy metals using a sequenced anaerobic-aerobic treatment of landfill leachates at 10-30 degrees C.

    Science.gov (United States)

    Kalyuzhnyi, Sergey; Gladchenko, Marina; Epov, Andrey; Appanna, Vasu

    2003-01-01

    As a first step of treatment of landfill leachates (total chemical oxygen demand [COD]: 1.43-3.81 g/L; total nitrogen: 90-162 mg/L), performance of laboratory upflow anaerobic sludge bed reactors was investigated under mesophilic (30 degrees C), submesophilic (20 degrees C), and psychrophilic (10 degrees C) conditions. Under hydraulic retention times (HRTs) of about 0.3 d, when the average organic loading rates (OLRs) were about 5 g of COD/(L.d), the total COD removal accounted for 81% (on average) with the effluent concentrations close to the anaerobic biodegradability limit (0.25 g of COD/L) for mesophilic and submesophilic regimes. The psychrophilic treatment conducted under an average HRT of 0.34 d and an average OLR of 4.22 g of COD/(L.d) showed a total COD removal of 47%, giving effluents (0.75 g of COD/L) more suitable for subsequent biologic nitrogen removal. All three anaerobic regimes used for leachate treatment were quite efficient for elimination of heavy metals (Fe, Zn, Cu, Pb, Cd) by concomitant precipitation in the form of insoluble sulfides inside the sludge bed. The application of aerobic/ anoxic biofilter as a sole polishing step for psychrophilic anaerobic effluents was acceptable for elimination of biodegradable COD and nitrogen approaching the current standards for direct discharge of treated wastewater. PMID:12794293

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

    International Nuclear Information System (INIS)

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

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

    Science.gov (United States)

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

    2004-01-01

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

  14. Prediction of Heavy Metal Removal by Different Liner Materials from Landfill Leachate: Modeling of Experimental Results Using Artificial Intelligence Technique

    OpenAIRE

    Nurdan Gamze Turan; Emine Beril Gümü?el; Okan Ozgonenel

    2013-01-01

    An intensive study has been made to see the performance of the different liner materials with bentonite on the removal efficiency of Cu(II) and Zn(II) from industrial leachate. An artificial neural network (ANN) was used to display the significant levels of the analyzed liner materials on the removal efficiency. The statistical analysis proves that the effect of natural zeolite was significant by a cubic spline model with a 99.93% removal efficiency. Optimization of liner materials was achiev...

  15. Prediction of heavy metal removal by different liner materials from landfill leachate: modeling of experimental results using artificial intelligence technique.

    Science.gov (United States)

    Turan, Nurdan Gamze; Gümü?el, Emine Beril; Ozgonenel, Okan

    2013-01-01

    An intensive study has been made to see the performance of the different liner materials with bentonite on the removal efficiency of Cu(II) and Zn(II) from industrial leachate. An artificial neural network (ANN) was used to display the significant levels of the analyzed liner materials on the removal efficiency. The statistical analysis proves that the effect of natural zeolite was significant by a cubic spline model with a 99.93% removal efficiency. Optimization of liner materials was achieved by minimizing bentonite mixtures, which were costly, and maximizing Cu(II) and Zn(II) removal efficiency. The removal efficiencies were calculated as 45.07% and 48.19% for Cu(II) and Zn(II), respectively, when only bentonite was used as liner material. However, 60% of natural zeolite with 40% of bentonite combination was found to be the best for Cu(II) removal (95%), and 80% of vermiculite and pumice with 20% of bentonite combination was found to be the best for Zn(II) removal (61.24% and 65.09%). Similarly, 60% of natural zeolite with 40% of bentonite combination was found to be the best for Zn(II) removal (89.19%), and 80% of vermiculite and pumice with 20% of bentonite combination was found to be the best for Zn(II) removal (82.76% and 74.89%). PMID:23844384

  16. Hydroponics reducing effluent's heavy metals discharge.

    Science.gov (United States)

    Rababah, Abdellah; Al-Shuha, Ahmad

    2009-01-01

    This paper investigates the capacity of Nutrient Film Technique (NFT) to control effluent's heavy metals discharge. A commercial hydroponic system was adapted to irrigate lettuces with primary treated wastewater for studying the potential heavy metals removal. A second commercial hydroponic system was used to irrigate the same type of lettuces with nutrient solution and this system was used as a control. Results showed that lettuces grew well when irrigated with primary treated effluent in the commercial hydroponic system. The NFT-plant system heavy metals removal efficiency varied amongst the different elements, The system's removal efficiency for Cr was more than 92%, Ni more than 85%, in addition to more than 60% reduction of B, Pb, and Zn. Nonetheless, the NFT-plants system removal efficiencies for As, Cd and Cu were lower than 30%. Results show that lettuces accumulated heavy metals in leaves at concentrations higher than the maximum acceptable European and Australian levels. Therefore, non-edible plants such as flowers or pyrethrum are recommended as value added crops for the proposed NFT. PMID:19151500

  17. A critical review on the bio-removal of hazardous heavy metals from contaminated soils: issues, progress, eco-environmental concerns and opportunities.

    Science.gov (United States)

    Wu, Gang; Kang, Hubiao; Zhang, Xiaoyang; Shao, Hongbo; Chu, Liye; Ruan, Chengjiang

    2010-02-15

    Mechanism of four methods for removing hazardous heavy metal are detailed and compared-chemical/physical remediation, animal remediation, phytoremediation and microremediation with emphasis on bio-removal aspects. The latter two, namely the use of plants and microbes, are preferred because of their cost-effectiveness, environmental friendliness and fewer side effects. Also the obvious disadvantages of other alternatives are listed. In the future the application of genetic engineering or cell engineering to create an expected and ideal species would become popular and necessary. However, a concomitant and latent danger of genetic pollution is realized by a few persons. To cope with this potential harm, several suggestions are put forward including choosing self-pollinated plants, creating infertile polyploid species and carefully selecting easy-controlled microbe species. Bravely, the authors point out that current investigation of noncrop hyperaccumulators is of little significance in application. Pragmatic development in the future should be crop hyperaccumulators (newly termed as "cropaccumulators") by transgenic or symbiotic approach. Considering no effective plan has been put forward by others about concrete steps of applying a hyperaccumulator to practice, the authors bring forward a set of universal procedures, which is novel, tentative and adaptive to evaluate hyperaccumulators' feasibility before large-scale commercialization. PMID:19864055

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

    International Nuclear Information System (INIS)

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

  19. Synthesis and adsorption behavior of chitosan-coated MnFe2O4 nanoparticles for trace heavy metal ions removal

    Science.gov (United States)

    Xiao, Yanzhen; Liang, Hanfeng; Chen, Wei; Wang, Zhoucheng

    2013-11-01

    Chitosan-coated MnFe2O4 nanoparticles (CCMNPs) of uniform size were synthesized by an eco-friendly method. The obtained product was characterized by XRD, TEM, FTIR and SQUID. The results show that NaOH played a key role in the formation of CCMNPs. The as-prepared CCMNPs with a saturation magnetization of 16.5 emu/g were used as magnetic nanoadsorbents to remove toxic Cu(II) and Cr(VI) ions from aqueous solution. Factors influencing the adsorption of heavy metal ions, such as pH value, agitation time and initial metal concentration were investigated. The maximum adsorption capacities of Cu(II) and Cr(VI) on CCMNPs were 22.6 and 15.4 mg/g, respectively. The competitive adsorption of Cu(II) and Cr(VI) from binary solution by CCMNPs was also studied, and the result shows that the affinity between Cu(II) and CCMNPs was much higher than that between Cr(VI) and CCMNPs.

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

    DEFF Research Database (Denmark)

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

    2012-01-01

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

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

    International Nuclear Information System (INIS)

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

  2. Heavy metal removal from MSWI fly ash by electrokinetic remediation coupled with a permeable activated charcoal reactive barrier

    Science.gov (United States)

    Huang, Tao; Li, Dongwei; Kexiang, Liu; Zhang, Yuewei

    2015-10-01

    This paper presents the investigations into the feasibility of the application of a remediation system that couples electrokinetic remediation (EKR) with the permeable reactive barrier (PRB) concept for municipal solid waste incineration (MSWI) fly ash with activated charcoal as the PRB material. The experimental results of this study showed that the proposed combined method can effectively improve the remediation efficiency and that the addition of the oxalic acid to the PRB media before the coupled system can further enhance the remediation process. In the optimization tests, the maximum removals of Zn, Pb, Cu and Cd were achieved under different experimental conditions. The voltage gradient and processing time were shown to have significant effects on the removal of Cu and Cd, whereas the addition of the oxalic acid had a more significant influence on the removal of Pb. Generally, the processing time is the most significant factor in changing the removal rates of HMs in the enhanced coupled system. In terms of the leaching toxicity, the specimen remediated by ENEKR?+?PRB showed the lowest leaching value for each HM in the S2 and S3 regions.

  3. Heavy metal removal from MSWI fly ash by electrokinetic remediation coupled with a permeable activated charcoal reactive barrier

    Science.gov (United States)

    Huang, Tao; Li, Dongwei; Kexiang, Liu; Zhang, Yuewei

    2015-01-01

    This paper presents the investigations into the feasibility of the application of a remediation system that couples electrokinetic remediation (EKR) with the permeable reactive barrier (PRB) concept for municipal solid waste incineration (MSWI) fly ash with activated charcoal as the PRB material. The experimental results of this study showed that the proposed combined method can effectively improve the remediation efficiency and that the addition of the oxalic acid to the PRB media before the coupled system can further enhance the remediation process. In the optimization tests, the maximum removals of Zn, Pb, Cu and Cd were achieved under different experimental conditions. The voltage gradient and processing time were shown to have significant effects on the removal of Cu and Cd, whereas the addition of the oxalic acid had a more significant influence on the removal of Pb. Generally, the processing time is the most significant factor in changing the removal rates of HMs in the enhanced coupled system. In terms of the leaching toxicity, the specimen remediated by ENEKR?+?PRB showed the lowest leaching value for each HM in the S2 and S3 regions. PMID:26486449

  4. Inorganic particulates in removal of toxic heavy metal ions: Part-X. removal behaviour of aluminum hydroxide for Hg(II) - a radiotracer study

    International Nuclear Information System (INIS)

    The present paper deals with a study on the removal behaviour of amorphous-type aluminum hydroxide for Hg(II) at micro to tracer level concentrations from aqueous solutions by employing the radiotracer technique. The solid/solution interface study was carried out for various physico-chemical parameters, e.g., effect of concentration, temperature and pH. The effect of the presence of several added cations/anions towards its removal behaviour was also assessed

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

    DEFF Research Database (Denmark)

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

    2002-01-01

    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...... 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...

  6. Heavy metals and soil microbes

    OpenAIRE

    Giller, K.E.; Witter, E.; McGrath, S.

    2009-01-01

    The discovery in the early 1980s that soil microorganisms, and in particular the symbiotic bacteria Rhizobium, were highly sensitive to heavy metals initiated a new line of research. This has given us important insights into a range of topics: ecotoxicology, bioavailability of heavy metals, the role of soil biodiversity, and the existence of ‘keystone’ organisms. Concurrently, and particularly in Europe, the research led to new approaches to the protection of soils from pollution that take in...

  7. 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.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2009-04-15

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

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

    International Nuclear Information System (INIS)

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

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

    International Nuclear Information System (INIS)

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

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

    Energy Technology Data Exchange (ETDEWEB)

    Ottosen, Lisbeth M. [Department of Civil Engineering, Techncial University of Denmark, Building 204, 2800 Lyngby (Denmark)]. E-mail: lo@byg.dtu.dk; Pedersen, Anne J. [Department of Civil Engineering, Techncial University of Denmark, Building 204, 2800 Lyngby (Denmark); Hansen, Henrik K. [Departamento de Procesos Quimicos, Biotecnologicos y Ambientales, Universidad Tecnica Federico Santa Maria, Casilla 110-V, Valparaiso (Chile); Ribeiro, Alexandra B. [Departamento de Ciencias e Engenharia do Ambiente, Faculdade de Cadencies e Technologia, Universidade Nova de Lisboa, 2829-516 Caparica (Portugal)

    2007-02-25

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

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

    International Nuclear Information System (INIS)

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

  13. Removal Efficiency of the Heavy Metals Zn(II), Pb(II) and Cd(II) by Saprolegnia delica and Trichoderma viride at Different pH Values and Temperature Degrees

    OpenAIRE

    Esam H. Ali; Hashem, Mohamed

    2007-01-01

    The removal efficiency of the heavy metals Zn, Pb and Cd by the zoosporic fungal species Saprolegnia delica and the terrestrial fungus Trichoderma viride, isolated from polluted water drainages in the Delta of Nile in Egypt, as affected by various ranges of pH values and different temperature degrees,was extensively investigated. The maximum removal efficiency of S. delica for Zn(II) and Cd(II) was obtained at pH 8 and for Pb(II) was at pH 6 whilst the removal efficiency of T. viride was foun...

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

    Energy Technology Data Exchange (ETDEWEB)

    Akieh, Marceline N. [Laboratory of Applied Environmental Chemistry, Department of Environmental Sciences, University of Kuopio, Patteristonkatu 1, FIN-50100 Mikkeli (Finland); Lahtinen, Manu; Vaeisaenen, Ari [Department of Chemistry, University of Jyvaeskylae, P.O. Box 35, FIN-40014 JY (Finland); Sillanpaeae, Mika [Laboratory of Applied Environmental Chemistry, Department of Environmental Sciences, University of Kuopio, Patteristonkatu 1, FIN-50100 Mikkeli (Finland)], E-mail: mika.sillanpaa@uku.fi

    2008-04-01

    The ion exchange properties of sodium iron titanates, namely, NaFeTiO{sub 4}, Na{sub 2}Fe{sub 2}Ti{sub 6}O{sub 16} 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. Preparation and characterization of sodium iron titanate ion exchanger and its application in heavy metal removal from waste waters

    International Nuclear Information System (INIS)

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

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

    Science.gov (United States)

    Akieh, Marceline N; Lahtinen, Manu; Väisänen, Ari; Sillanpää, Mika

    2008-04-01

    The ion exchange properties of sodium iron titanates, namely, NaFeTiO(4), Na(2)Fe(2)Ti(6)O(16) 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. PMID:17766041

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

    Directory of Open Access Journals (Sweden)

    S.A. Shama

    2010-01-01

    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+< Cr3+

  18. 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+

  19. Post-crosslinking towards stimuli-responsive sodium alginate beads for the removal of dye and heavy metals.

    Science.gov (United States)

    Lu, Ting; Xiang, Tao; Huang, Xue-Lian; Li, Cheng; Zhao, Wei-Feng; Zhang, Qian; Zhao, Chang-Sheng

    2015-11-20

    Post-crosslinking as a new strategy to prepare sodium alginate (SA) beads with controllable swelling behavior, pH sensitivity and adsorption capacity was developed by using the solution of glutaraldehyde (GA), acetic acid and hydrochloric acid as the coagulating agent, for which could be used to fabricate polysaccharide beads in a large scale. Fourier transform infrared spectroscopy and thermogravimetric analysis convinced the successful cross-linking of SA by GA. The macro-porous structures of the beads were observed by scanning electron microscopy. Both acetic acid and hydrochloric acid had great effects on the swelling behavior and pH sensitivity of the SA beads. The SA beads could adsorb cationic dye (methylene blue) as high as 572mg/g and other metal ions (Cu(2+), Ag(+) and Fe(3+)). The adsorption processes fitted well with the pseudo-second-order kinetic model and the Freundlich isotherm. The large-scale production of SA beads with tunable properties opens a new route to industrially utilize polysaccharide beads in wastewater treatments, intelligent separation and so on. PMID:26344317

  20. Inorganic particulates in removal of toxic heavy metal ions. 4. Efficient removal of zinc ions from aqueous solution by hydrous zirconium oxide

    International Nuclear Information System (INIS)

    Adsorption behavior of zinc ions on hydrous zirconium oxide (HZO) in aqueous solution has been studied as a function of concentration (10-2-10-8M), temperature (303-333 K) and pH 3-8 of adsorptive solution applying radiotracer technique. The kinetics of adsorption follows first order rate law and agrees well with the classical Freundlich isotherm in the entire range of adsorptive concentration. The removal was found to be increasing with pH of the adsorptive solution while it was suppressed in the presence of acid concentrations. The overall process is found to be endothermic and irreversible in nature. (author). 27 refs., 5 figs., 2 tabs

  1. Rapid removal of heavy metal cations and anions from aqueous solutions by an amino-functionalized magnetic nano-adsorbent

    International Nuclear Information System (INIS)

    A novel magnetic nano-adsorbent has been developed by the covalent binding of polyacrylic acid (PAA) on the surface of Fe3O4 nanoparticles and the followed amino-functionalization using diethylenetriamine (DETA) via carbodiimide activation. Transmission electron microscopy image showed that the amino-functionalized Fe3O4 nanoparticles were quite fine with a mean diameter of 11.2 ± 2.8 nm. X-ray diffraction analysis indicated that the binding process did not result in the phase change of Fe3O4. Magnetic measurement revealed they were nearly superparamagnetic with a saturation magnetization of 63.2 emu/g Fe3O4. The binding of DETA on the PAA-coated Fe3O4 nanoparticles was demonstrated by the analyses of Fourier transform infrared (FTIR) spectroscopy and zeta potential. After amino-functionalization, the isoelectric point of PAA-coated Fe3O4 nanoparticles shifted from 2.64 to 4.59. The amino-functionalized magnetic nano-adsorbent shows a quite good capability for the rapid and efficient adsorption of metal cations and anions from aqueous solutions via the chelation or ion exchange mechanisms. The studies on the adsorption of Cu(II) and Cr(VI) ions revealed that both obeyed the Langmuir isotherm equation. The maximum adsorption capacities and Langmuir adsorption constants were 12.43 mg/g and 0.06 L/mg for Cu(II) ions and 11.24 mg/g and 0.0165 L/mg for Cr(VI) ions, respectively

  2. 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)

  3. Metals removal from spent salts

    Science.gov (United States)

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

    2002-01-01

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

  4. Lipid lather removes metals.

    OpenAIRE

    Frazer, L

    2000-01-01

    Metal contamination has been linked to birth defects, cancer, skin lesions, retardation, learning disabilities, liver and kidney damage, and a host of other maladies, and the United States alone will spend some $7 trillion over the next five years or so to clean up sites contaminated with metals. Until recently, there have only been a few time-consuming, costly methods for dealing with metal contamination in soils, but research developed at the University of Arizona uses biosurfactants, lipid...

  5. 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)

  6. 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, ...

  7. 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+.

  8. 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+

  9. Biosorption of heavy metals and uranium from dilute solutions

    Energy Technology Data Exchange (ETDEWEB)

    Schneider, I.A.H. [Federal Univ. of Rio Grande do Sul (Brazil); Misra, M.; Smith, R.W. [Univ. of Nevada, Reno, NV (United States). Mackay School of Mines

    1995-08-01

    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.

  10. 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

  11. 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...

  12. Metal Removal in Wastewater

    OpenAIRE

    Sanchez Roldan, Laura

    2014-01-01

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

  13. Inorganic particulates in removal of toxic heavy metal ions: rapid and efficient removal of Zn(II) from aqueous solutions by sodium titanate

    International Nuclear Information System (INIS)

    Removal behavior for Zn(II) ions from aqueous solutions at micro and tracer concentration levels has been carried out utilizing a 'radiotracer technique' through an adsorption process using synthesized and well characterized sodium titanate as an adsorbent. The study comprises of various physico-chemical parameters viz. concentration, temperature, pH and the effect of some added cations/anions and acid concentrations (HCl/H2SO4) on the adsorption process. The results show that the high uptake of Zn(II) on a sodium titanate surface follows first order rate law and that equilibrium data fit well for a Freundlich adsorption isotherm. A change in temperature (303 - 333 K) does not markedly affect the uptake of Zn(II) ions. Radiation stability of sodium titanate was also observed by exposing it to neutron and gamma rays from a 11.1 GBq (Ra-Be) neutron source having an integral neutron flux of 3.85 x 106 n/cm2/sec associated with gamma-dose of 1.72 Gy/h also using a gamma-cell (4.66 KGy/h) Co-60 source. (orig.)

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

    International Nuclear Information System (INIS)

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

  15. Heavy metal-induced glutathione accumulation and its role in heavy metal detoxification in Phanerochaete chrysosporium.

    Science.gov (United States)

    Xu, Piao; Liu, Liang; Zeng, Guangming; Huang, Danlian; Lai, Cui; Zhao, Meihua; Huang, Chao; Li, Ningjie; Wei, Zhen; Wu, Haipeng; Zhang, Chen; Lai, Mingyong; He, Yibin

    2014-01-01

    Phanerochaete chrysosporium are known to be vital hyperaccumulation species for heavy metal removal with admirable intracellular bioaccumulation capacity. This study analyzes the heavy metal-induced glutathione (GSH) accumulation and the regulation at the intracellular heavy metal level in P. chrysosporium. P. chrysosporium accumulated high levels of GSH, accompanied with high intracellular concentrations of Pb and Cd. Pb bioaccumulation lead to a narrow range of fluctuation in GSH accumulation (0.72-0.84 ?mol), while GSH plummeted under Cd exposure at the maximum value of 0.37 ?mol. Good correlations between time-course GSH depletion and Cd bioaccumulation were determined (R (2) > 0.87), while no significant correlations have been found between GSH variation and Pb bioaccumulation (R (2) metal toxicity can offer important information on the application of the microorganism for wastewater treatment. PMID:24723291

  16. Customizable Biopolymers for Heavy Metal Remediation

    International Nuclear Information System (INIS)

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

  17. 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

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

    Science.gov (United States)

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

    2015-01-20

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

  19. 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.

  20. Evaluation of remediation process with soapberry derived saponin for removal of heavy metals from contaminated soils in Hai-Pu, Taiwan.

    Science.gov (United States)

    Maity, Jyoti Prakash; Huang, Yuh Ming; Fan, Cheng-Wei; Chen, Chien-Cheng; Li, Chun-Yi; Hsu, Chun-Mei; Chang, Young-Fo; Wu, Ching-I; Chen, Chen-Yen; Jean, Jiin-Shuh

    2013-06-01

    The use of a biodegradable natural plant-based surfactant extracted from soapberry is proposed for the remediation of Ni, Cr and Mn from industrial soil site in Hai-Pu, Taiwan. Batch experiments were performed under variation of fundamental factors (saponin concentration, pH, and incubation time) for metal remediation. Removal of Ni and Mn were increased with increasing saponin concentration (0.015-0.150 g/L), whereas the removal of Cr was increased upto 0.075 g/L saponin. The Ni, Cr and Mn were removed significantly (p soil washing process in presence of plant derived saponin. PMID:24191608

  1. Studies on the optimum conditions using acid-washed zero-valent iron/aluminum mixtures in permeable reactive barriers for the removal of different heavy metal ions from wastewater.

    Science.gov (United States)

    Han, Weijiang; Fu, Fenglian; Cheng, Zihang; Tang, Bing; Wu, Shijiao

    2016-01-25

    The method of permeable reactive barriers (PRBs) is considered as one of the most practicable approaches in treating heavy metals contaminated surface and groundwater. The mixture of acid-washed zero-valent iron (ZVI) and zero-valent aluminum (ZVAl) as reactive medium in PRBs to treat heavy metal wastewater containing Cr(VI), Cd(2+), Ni(2+), Cu(2+), and Zn(2+) was investigated. The performance of column filled with the mixture of acid-washed ZVI and ZVAl was much better than the column filled with ZVI or ZVAl alone. At initial pH 5.4 and flow rates of 1.0mL/min, the time that the removal efficiencies of Cr(VI), Cd(2+), Ni(2+), Cu(2+), and Zn(2+) were all above 99.5% can keep about 300h using 80g/40g acid-washed ZVI/ZVAl when treating wastewater containing each heavy metal ions (Cr(VI), Cd(2+), Ni(2+), Cu(2+), and Zn(2+)) concentration of 20.0mg/L. Scanning electron microscopy (SEM), X-ray diffraction (XRD), and X-ray photoelectron spectroscopy (XPS) were used to characterize ZVI/ZVAl before and after reaction and the reaction mechanism of the heavy metal ions with ZVI/ZVAl was discussed. PMID:26521089

  2. 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

  3. Metals Removal from Recovered base Oil using Chitosan Biopolymers

    OpenAIRE

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

    2010-01-01

    It was common to use solvent extraction to recover base oil from used lubricants. Although, significant amount of contaminants removal was achieved by using solvent extraction, some problems arised which need to be resolved. The recovered base oil from solvent extraction was still in the darkish color with stink odor and only minimum heavy metals were removed. As an alternative, an adsorption method which used chitosan to remove metals and contaminants was being investigated. This paper prese...

  4. Heavy Metal Stars

    Science.gov (United States)

    2001-08-01

    La Silla Telescope Detects Lots of Lead in Three Distant Binaries Summary Very high abundances of the heavy element Lead have been discovered in three distant stars in the Milky Way Galaxy . This finding strongly supports the long-held view that roughly half of the stable elements heavier than Iron are produced in common stars during a phase towards the end of their life when they burn their Helium - the other half results from supernova explosions. All the Lead contained in each of the three stars weighs about as much as our Moon. The observations show that these "Lead stars" - all members of binary stellar systems - have been more enriched with Lead than with any other chemical element heavier than Iron. This new result is in excellent agreement with predictions by current stellar models about the build-up of heavy elements in stellar interiors. The new observations are reported by a team of Belgian and French astronomers [1] who used the Coude Echelle Spectrometer on the ESO 3.6-m telescope at the La Silla Observatory (Chile). PR Photo 26a/01 : A photo of HD 196944 , one of the "Lead stars". PR Photo 26b/01 : A CES spectrum of HD 196944 . The build-up of heavy elements Astronomers and physicists denote the build-up of heavier elements from lighter ones as " nucleosynthesis ". Only the very lightest elements (Hydrogen, Helium and Lithium [2]) were created at the time of the Big Bang and therefore present in the early universe. All the other heavier elements we now see around us were produced at a later time by nucleosynthesis inside stars. In those "element factories", nuclei of the lighter elements are smashed together whereby they become the nuclei of heavier ones - this process is known as nuclear fusion . In our Sun and similar stars, Hydrogen is being fused into Helium. At some stage, Helium is fused into Carbon, then Oxygen, etc. The fusion process requires positively charged nuclei to move very close to each other before they can unite. But with increasing atomic mass and hence, increasing positive charge of the nuclei, the electric repulsion between the nuclei becomes stronger and stronger. In fact, the fusion process only works up to a certain mass limit, corresponding to the element Iron [2]. All elements that are heavier than Iron cannot be produced via this path. But then, how were those heavy elements we now find on the Earth produced in the first place? From where comes the Zirconium in artificial diamonds, the Barium that colours fireworks, the Tungsten in the filaments in electric bulbs? Which process made the Lead in your car battery? Beyond iron The production of elements heavier than Iron takes place by adding neutrons to the atomic nuclei . These neutral particles do not feel any electrical repulsion from the charged nuclei. They can therefore easily approach them and thereby create heavier nuclei. This is indeed the way the heaviest chemical elements are built up. There are actually two different stellar environments where this process of "neutron capture" can happen. One place where this process occurs is inside very massive stars when they explode as supernovae . In such a dramatic event, the build-up proceeds very rapidly, via the so-called "r-process" ( "r" for rapid ). The AGB stars But not all heavy elements are created in such an explosive way. A second possibility follows a more "peaceful" road. It takes place in rather normal stars, when they burn their Helium towards the end of their lives. In the so-called "s-process" ( "s" for slow ), heavier elements are then produced by a rather gentle addition of neutral neutrons to atomic nuclei. In fact, roughly half of all the elements heavier than Iron are believed to be synthesized by this process during the late evolutionary phases of stars. This process takes place during a specific stage of stellar evolution, known as the "AGB" phase [3]. It occurs just before an old star expels its gaseous envelope into the surrounding interstellar space and sometime thereafter dies as a burnt-out, dim "white dwarf" . Stars with masses between 0.8 and 8 time

  5. Electrodialytic remediation of heavy metal polluted soil

    DEFF Research Database (Denmark)

    Ottosen, Lisbeth M.; Jensen, Pernille Erland; Kirkelund, Gunvor Marie; Dias-Ferreira, Celia; Hansen, Henrik K.

    Electrodialytic soil remediation is a method for removal of heavy metals. Good results have previously been obtained with both treatment of a stationary, water saturated soil matrix and with remediation of a stirred suspension of soil in water. The two different setups have different uses. The...... stirred setup it is possible to shorten the transport route to few mm and to have a faster and continuous process. The present paper for the first time reports a direct comparison of the two options. The remediation of the stirred suspension showed faster than remediation of the water saturated soil even...... without a short distance between the membranes. The acidification of the suspended soil was fastest and following the mobilization of heavy metals. This may indicate that water splitting at the anion exchange membrane is used more efficiently in the stirred setup....

  6. 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...

  7. Heavy Metal Concentrations in Predator Fish

    OpenAIRE

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

    2011-01-01

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

  8. 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.

  9. 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.

  10. Metals Removal from Recovered base Oil using Chitosan Biopolymers

    Directory of Open Access Journals (Sweden)

    A. Ahmad

    2010-01-01

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

  11. 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.

  12. 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

  13. Heavy metals and the origin of life

    Science.gov (United States)

    Nriagu, J.

    2003-05-01

    The functional value of heavy metals in proto-cells was immense and involved critical roles in catalysis of molecular synthesis, translation, electrical neutrality and conduction, energy capture, cross-linking and precipitation (stabilizers of protective cell walls), and to a limited extent, osmotic pressure control. Metals must have modulated the evolutionary choices of the types of building blocks, such as ribose sugars as a constituent of RNA, or the the chirality and enantiopurity of many biomolecules. The formation of an enclosing membrane led to intracellular prokaryotic life (believed to have originated in an anaerobic environment) and much enhanced control over primary metabolism, the uptake and incorporation of heavy metals and the management of biomolecules (especially RNA, DNA and proteins) that were formed. Cells of the most primitive organisms (archaebacteria) reveal complex mechanisms designed specifically to deal with selective pressures from metal-containing environments including intra- and extra-cellular sequestration, exclusion by cell wall barrier, removal through active efflux pumps, enzymatic detoxification, and reduction in sensitivity of cellular targets to metal ions. Adaptation to metals using a variety of chromosomal, and transposon and plasmid-mediated systems began early in the evolution of life on Earth. Recent studies, however, show that the roles played by many heavy metals have changed over time. Divalent lead, for instance, has relinquished its unique catalytic role in the conversion of carbohydrates into ribose in the prebiotic world. The putative elements that dominated the primordial biochemistry were V, Mo, W, Co, Fe(II) and Ni; with the development of oxygenated atmosphere, these elements gave way to Zn, Cu and Fe(Ill) in their metabolic functions.

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

    OpenAIRE

    Usama Eldemerdash; Maitra, S.; A. Mesfin Yeneneh

    2011-01-01

    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 r...

  15. 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.

  16. 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

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

    OpenAIRE

    Hajar Norouznia; Amir Hossein Hamidian

    2014-01-01

    Plant-based remediation (i.e. phytoremediation) is one of the most significant eco-sustainable techniques to cope with devastating consequences of pollutants. In the present study, the potential of a wetland macrophyt (i.e. Potamogeton crispus) for the phytoremediation of heavy metals (i.e. Cu, Cr, Pb, As and Cd) in the Anzali wetland was evaluated. The results showed that P. crispus tends to accumulate notable amounts of Cu, Cr, Pb, As and Cd according to their assayed concentrations as foll...

  18. 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.

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

    Energy Technology Data Exchange (ETDEWEB)

    Salam, Mohamed Abdel, E-mail: masalam16@hotmail.com [Chemistry Department, Faculty of Science, King Abdulaziz University, P.O. Box 80200, Jeddah 21589 (Saudi Arabia); Makki, Mohamad S.I.; Abdelaal, Magdy Y.A. [Chemistry Department, Faculty of Science, King Abdulaziz University, P.O. Box 80200, Jeddah 21589 (Saudi Arabia)

    2011-02-03

    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.

  20. 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

  1. 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.

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

    OpenAIRE

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

    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...

  3. The role of compost properties in sorption of heavy metals

    OpenAIRE

    Martinho, João; Campos, Bruno; Brás, Isabel; Silva, Elisabete

    2015-01-01

    The feasibility of various composts to operate as sorbents for heavy metals (Cu and Zn) removal from wastewater has been evaluated. Three commercial composts obtained from municipal solid wastes (MWS), sludge sewage (SS) and poultry manure (PM) were selected as potential sorbents. Kinetic and equilibrium tests were conducted in order to assess the equilibrium conditions to remove metals from aqueous samples. For all composts, the maximum time necessary to reach the equilibrium was 240 min....

  4. Removal of heavy metals and suspended solids from battery wastewaters: application of hydroperm cross-flow microfiltration. Report for August 78-June 80

    Energy Technology Data Exchange (ETDEWEB)

    Shapira, N.I.; Liu, H.; Baranski, J.; Kurzweg, D.

    1981-08-01

    This project was undertaken to evaluate the capability of crossflow microfiltration to remove suspended toxic metal and metal hydroxides from battery manufacturing wastewaters. The demonstration was conducted at the General Battery Corporation plant at Hamburg, Pennsylvania. A full scale system capable of processing 150,000 liters per day (40,000 gal/day) was constructed and installed at the General Battery facility. The following conclusions were determined from the demonstration at General Battery: (1) cross-flow filtration will effectively remove suspended solids and suspended metal hydroxides including arsenic hydroxide and antimony hydroxide from battery manufacturing wastewaters, (2) reasonable flux rates can be achieved with the use of the microfiltration membrane filters, (3) sludges of up to 35 percent solids can be easily generated significantly reducing the sludge generation rate. Suspended solid in feed ranging as high as 180,000 ppm were typically reduced to less than 5 ppm in the permeate. Lead was reduced from several hundred ppm in the feed to less than .10 ppm in the permeate. The pH of the wastewater was maintained between 8 and 9.

  5. 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.

  6. 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.…

  7. Dissymmetrical tunnelling in heavy fermion metals

    OpenAIRE

    Shaginyan, V. R.

    2005-01-01

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

  8. 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. .

  9. 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

  10. 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

  11. Heavy Metal Risk Management: Case Analysis

    OpenAIRE

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

    2012-01-01

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

  12. Heavy metal displacement in chelate-irrigated soil during phytoremediation

    Science.gov (United States)

    Madrid, F.; Liphadzi, M. S.; Kirkham, M. B.

    2003-03-01

    Heavy metals in wastewater sewage sludge (biosolids), applied to land, contaminate soils. Phytoremediation, the use of plants to clean up toxic heavy metals, might remove them. Chelating agents are added to soil to solubilize the metals for enhanced phytoextraction. Yet no studies follow the displacement and leaching of heavy metals in soil with and without roots following solubilization with chelates. The objective of this work was to determine the mobility of heavy metals in biosolids applied to the surface of soil columns (76 cm long; 17 cm diam.) with or without plants (barley; Hordeum vulgare L.). Three weeks after barley was planted, all columns were irrigated with the disodium salt of the chelating agent, EDTA (ethylenediamine tetraacetic acid) (0.5 g/kg soil). Drainage water, soil, and plants were analyzed for heavy metals (Cd, Cu, Fe, Mn, Ni, Pb, Zn). Total concentrations of the heavy metals in all columns at the end of the experiment generally were lower in the top 30 cm of soil with EDTA than without EDTA. The chelate increased concentrations of heavy metals in shoots. With or without plants, the EDTA mobilized Cd, Fe, Mn, Ni, Pb, and Zn, which leached to drainage water. Drainage water from columns without EDTA had concentrations of these heavy metals below detection limits. Only Cu did not leach in the presence of EDTA. Even though roots retarded the movement of Cd, Fe, Mn, Ni, Pb, and Zn through the EDTA-treated soil from 1 d (Cd) to 5 d (Fe), the drainage water from columns with EDTA had concentrations of Cd, Fe, Mn, and Pb that exceeded drinking water standards by 1.3, 500, 620, and 8.6 times, respectively. Because the chelate rendered Cd, Fe, Mn, Ni, Pb, and Zn mobile, it is suggested that the theory for leaching of soluble salts, put forward by Nielsen and associates in 1965, could be applied to control movement of the heavy metals for maximum uptake during chelate-assisted phytoremediation.

  13. Biosorption of heavy metals under anaerobic conditions. Final report

    International Nuclear Information System (INIS)

    The precipitation of heavy metals as hydroxides is the standard technique for the decontamination of waste water streams polluted by these elements. On the other side, progress in research has been made concerning the biosorption onto dead biomass and bioprecipitation supported by physiologically active bacteria. As the aim of this study, a flexible strategy has been envisaged cleaning a waste water with definite heavy metal load underlying the process mentioned above. Suitable bacteria were enriched and the process was tested in a technical plant. As result, a very high efficiency of heavy metal elimination has been found. The field of application covered by the acquired process is identical with the whole range of the waste water streams polluted by heavy metals. In addition, a second stage may be necessary if there are any further contaminants to be removed. (orig.)

  14. Modeling Heavy Metal Sorption Kinetics Using Fractional Calculus

    OpenAIRE

    Friesen, V. C.; D. P. Leitoles; Gonçalves, G.; E. K. Lenzi; Lenzi, M. K.

    2015-01-01

    Heavy metals are commonly regarded as environmentally aggressive and hazardous to human health. Among the different metals, lead plays an important economic role due to its large use in the automotive industry, being an essential component of batteries. Different approaches have been reported in the literature aimed at lead removal, and among them a very successful one considers the use of water hyacinths for sorption-based operation. The modeling of the metal sorption kinetics is a fundament...

  15. Hazards of heavy metal contamination.

    Science.gov (United States)

    Järup, Lars

    2003-01-01

    The main threats to human health from heavy metals are associated with exposure to lead, cadmium, mercury and arsenic. These metals have been extensively studied and their effects on human health regularly reviewed by international bodies such as the WHO. Heavy metals have been used by humans for thousands of years. Although several adverse health effects of heavy metals have been known for a long time, exposure to heavy metals continues, and is even increasing in some parts of the world, in particular in less developed countries, though emissions have declined in most developed countries over the last 100 years. Cadmium compounds are currently mainly used in re-chargeable nickel-cadmium batteries. Cadmium emissions have increased dramatically during the 20th century, one reason being that cadmium-containing products are rarely re-cycled, but often dumped together with household waste. Cigarette smoking is a major source of cadmium exposure. In non-smokers, food is the most important source of cadmium exposure. Recent data indicate that adverse health effects of cadmium exposure may occur at lower exposure levels than previously anticipated, primarily in the form of kidney damage but possibly also bone effects and fractures. Many individuals in Europe already exceed these exposure levels and the margin is very narrow for large groups. Therefore, measures should be taken to reduce cadmium exposure in the general population in order to minimize the risk of adverse health effects. The general population is primarily exposed to mercury via food, fish being a major source of methyl mercury exposure, and dental amalgam. The general population does not face a significant health risk from methyl mercury, although certain groups with high fish consumption may attain blood levels associated with a low risk of neurological damage to adults. Since there is a risk to the fetus in particular, pregnant women should avoid a high intake of certain fish, such as shark, swordfish and tuna; fish (such as pike, walleye and bass) taken from polluted fresh waters should especially be avoided. There has been a debate on the safety of dental amalgams and claims have been made that mercury from amalgam may cause a variety of diseases. However, there are no studies so far that have been able to show any associations between amalgam fillings and ill health. The general population is exposed to lead from air and food in roughly equal proportions. During the last century, lead emissions to ambient air have caused considerable pollution, mainly due to lead emissions from petrol. Children are particularly susceptible to lead exposure due to high gastrointestinal uptake and the permeable blood-brain barrier. Blood levels in children should be reduced below the levels so far considered acceptable, recent data indicating that there may be neurotoxic effects of lead at lower levels of exposure than previously anticipated. Although lead in petrol has dramatically decreased over the last decades, thereby reducing environmental exposure, phasing out any remaining uses of lead additives in motor fuels should be encouraged. The use of lead-based paints should be abandoned, and lead should not be used in food containers. In particular, the public should be aware of glazed food containers, which may leach lead into food. Exposure to arsenic is mainly via intake of food and drinking water, food being the most important source in most populations. Long-term exposure to arsenic in drinking-water is mainly related to increased risks of skin cancer, but also some other cancers, as well as other skin lesions such as hyperkeratosis and pigmentation changes. Occupational exposure to arsenic, primarily by inhalation, is causally associated with lung cancer. Clear exposure-response relationships and high risks have been observed. PMID:14757716

  16. Heavy metal uptake of Geosiphon pyriforme

    International Nuclear Information System (INIS)

    Geosiphon pyriforme represents the only known endosymbiosis between a fungus, belonging to the arbuscular mycorrhizal (AM) fungi, and cyanobacteria (blue-green algae). Therefore we use Geosiphon as a model system for the widespread AM symbiosis and try to answer some basic questions regarding heavy metal uptake or resistance of AM fungi. We present quantitative micro-PIXE measurements of a set of heavy metals (Cu, Cd, Tl, Pb) taken up by Geosiphon-cells. The uptake is studied as a function of the metal concentration in the nutrient solution and of the time Geosiphon spent in the heavy metal enriched medium. The measured heavy metal concentrations range from several ppm to some hundred ppm. Also the influence of the heavy metal uptake on the nutrition transfer of other elements will be discussed

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

    Directory of Open Access Journals (Sweden)

    Vukojević 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.

  18. Arbuscular mycorrhiza and heavy metal tolerance.

    Science.gov (United States)

    Hildebrandt, Ulrich; Regvar, Marjana; Bothe, Hermann

    2007-01-01

    Arbuscular mycorrhizal fungi (AMF) have repeatedly been demonstrated to alleviate heavy metal stress of plants. The current manuscript summarizes results obtained to date on the colonization of plants by AMF in heavy metal soils, the depositions of heavy metals in plant and fungal structures and the potential to use AMF-plant combinations in phytoremediation, with emphasis on pennycresses (Thlaspi ssp.). The focus of this manuscript is to describe and discuss studies on the expression of genes in plants and fungi under heavy metal stress. The summary is followed by data on differential gene expression in extraradical mycelia (ERM) of in vitro cultured Glomus intraradices Sy167 supplemented with different heavy metals (Cd, Cu or Zn). The expression of several genes encoding proteins potentially involved in heavy metal tolerance varied in their response to different heavy metals. Such proteins included a Zn transporter, a metallothionein, a 90 kD heat shock protein and a glutathione S-transferase (all assignments of protein function are putative). Studies on the expression of the selected genes were also performed with roots of Medicago truncatula grown in either a natural, Zn-rich heavy metal "Breinigerberg" soil or in a non-polluted soil supplemented with 100 microM ZnSO(4). The transcript levels of the genes analyzed were enhanced up to eight fold in roots grown in the heavy metal-containing soils. The data obtained demonstrate the heavy metal-dependent expression of different AMF genes in the intra- and extraradical mycelium. The distinct induction of genes coding for proteins possibly involved in the alleviation of damage caused by reactive oxygen species (a 90 kD heat shock protein and a glutathione S-transferase) might indicate that heavy metal-derived oxidative stress is the primary concern of the fungal partner in the symbiosis. PMID:17078985

  19. Heavy metals and living systems: An overview

    OpenAIRE

    Singh, Reena; Gautam, Neetu; Mishra, Anurag; Gupta, Rajiv

    2011-01-01

    Heavy metals are natural constituents of the earth's crust, but indiscriminate human activities have drastically altered their geochemical cycles and biochemical balance. This results in accumulation of metals in plant parts having secondary metabolites, which is responsible for a particular pharmacological activity. Prolonged exposure to heavy metals such as cadmium, copper, lead, nickel, and zinc can cause deleterious health effects in humans. Molecular understanding of plant metal accumula...

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

    International Nuclear Information System (INIS)

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

  1. 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)

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

    Science.gov (United States)

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

    2006-12-01

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

  3. Treatment of heavy metal contaminated soils by in situ vitrification

    International Nuclear Information System (INIS)

    Contaminated soil site remediation objectives call for the destruction, removal, and/or immobilization of contaminant species. Destruction is applicable to hazardous compounds (e.g., hazardous organics such as PCBs; hazardous inorganics such as cyanide); however, it is not applicable to hazardous elements such as the heavy metals. Removal and/or immobilization are typical objectives for heavy metal contaminants present in soil. Many technologies have been developed specifically to meet these needs. One such technology is In Situ Vitrification (ISV), an innovative mobile, onsite, in situ solids remediation technology that has been available on a commercial basis for about two years. ISV holds potential for the safe and permanent treatment/remediation of previously disposed or current process solids waste (e.g., soil, sludge, sediment, tailings) contaminated with hazardous chemical and/or radioactive materials. This paper focuses on the application of ISV to heavy metal-contaminated soils

  4. Environmental pollution by heavy metals

    International Nuclear Information System (INIS)

    Environmental pollution by radioactive and non-radioactive heavy metals is considered. The concern surrounding the radioecologically important nuclides 90Sr, 137Cs, 131I, 140Ba, 140La, 106Ru, 144Ce, 65Zn, 55Fe and plutonium is discussed. It is felt that the dangers to health from radioactive materials are so well understood and the machinery for their monitoring and control is so well established that in practice radioactive materials may be regarded as among the safest of the environmental contaminants. The health hazards involved in the pollution of the environment by cadmium, lead and mercury are described and the means of reducing pollution by the treatment and recycling of industrial wastes and effluents is studied. (U.K.)

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

    Directory of Open Access Journals (Sweden)

    Hajar Norouznia

    2014-08-01

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

  6. Heavy Metal, Religiosity, and Suicide Acceptability.

    Science.gov (United States)

    Stack, Steven

    1998-01-01

    Reports on data taken from the General Social Survey that found a link between "heavy metal" rock fanship and suicide acceptability. Finds that relationship becomes nonsignificant once level of religiosity is controlled. Heavy metal fans are low in religiosity, which contributes to greater suicide acceptability. (Author/JDM)

  7. 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.

  8. Heavy Metal Music and Adolescent Suicidal Risk.

    Science.gov (United States)

    Lacourse, Eric; Claes, Michel; Villeneuve, Martine

    2001-01-01

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

  9. Removal of heavy metals by means of selective cation exchangers in drinking water treatment. Final report; Entfernung von Schwermetallen mit Selektiv-Kationenaustauschern bei der Trinkwasseraufbereitung

    Energy Technology Data Exchange (ETDEWEB)

    Doerdelmann, O.; Stetter, D.; Overath, H. [IWW Rheinisch-Westfaelisches Inst. fuer Wasserforschung, Muelheim an der Ruhr (Germany)

    2002-07-01

    The research project on the ''Development of process techniques for eliminating heavy metals from crude water by means of chelating cation exchangers for drinking water production'' ran from 1998 to 2001. Its chief goals were to identify possible application areas for chelating cation exchangers in drinking water treatment, elaborate a mathematical model from the results obtained with a view to dimensioning technical plants, optimise the process steps regeneration and conditioning, elaborate a concept for the treatment and disposal of waste water and wastes and examine selective exchangers with regard to their certification for use in the food industry (drinking water). [German] Das Forschungsvorhaben 'Entwicklung der Verfahrenstechnik zur Eliminierung von Schwermetallen aus Rohwaessern zur Trinkwassergewinnung mit chelatbildenden Kationenaustauschern' wurde in den Jahren 1998 bis 2001 durchgefuehrt. Die wesentlichen Ziele waren: Ermittlung der Einsatzmoeglichkeiten von Chelat-Kationenaustauschern bei der Trinkwasseraufbereitung, Erarbeitung eines mathematischen Modells auf der Grundlage der erzielten Ergebnisse zur Auslegung von technischen Anlagen, Optimierung der Prozessschritte Regeneration und Konditionierung, Erarbeitung eines Konzepts zur Behandlung und Entsorgung der anfallenden Abwaesser und Abfaelle. Untersuchungen der Selektiv-Austauscher hinsichtlich einer Zulassung fuer den Lebensmittelbereich (Trinkwasser). (orig.)

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2009-11-15

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

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

    International Nuclear Information System (INIS)

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

  12. Effect of heavy metals on soil fungi

    Science.gov (United States)

    Sosak-?widerska, Bo?ena

    2010-05-01

    Fungi constitute a high proportion of the microbial biomass in soil.Being widespread in soil their large surface-to-volume ratio and high metabolic activity, fungi can contribute significantly to heavy metal dynamics in soil. At neutral pH heavy metals in soils tend to be immobilized to precipitation and/or absorption to cation exchange sites of clay minerals. In the acidic soils, metals are more mobile and enter food webs easier. Microbial production of acids and chelating agents can mobilize to toxic metals. Mobilization is often by uptake and intracellular accumulation of the heavy metlas, and in this way, the bioavailability of metals towards other organisms can be more reduced. Fungi were isolated from soils from Upper Silesia in Poland and belonged to widespread genera: Aspergillus, Cladosporium, Penicillium and Trichoderma. Fungi from different taxonomic groups differ greatly in their tolerance to heavy metals. This could be related to their wall structure and chemistry as well as biochemical and physiological characteristics of fungi. Localization of metals in fungal cells was studied using electron microscopy analysis. Metal biosorption in the cell wall can be complex as melanin granules. Fungal vacuoles have an important role in the regulation of the cytosolic concentration of metal ions, and may contribute to heavy metal tolerance.In polluted soils with heavy metals, fungal species composition can be changed and their physiological activity can be changed, too.

  13. 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.

  14. Changes of heavy metal chemical bonds in thermally treated soils

    International Nuclear Information System (INIS)

    The cleaning performance of thermal decontamination methods for heavy metals is reviewed by means of a 8-step sequential extraction process. With the help of this extraction process different soils of varying contents (acidity, proportion of clay, carbonates, C/org, heavy metals and KAK) are treated thermally at temperature levels of 300 C, 600 C, 800 C and 1000 C. Thereafter, the changes of the typical forms of heavy metal bonds in soil are determined. It was proven that a decontamination in the strict sense of the word does not occur because the heavy metals zinc, lead, chrome, nickel and copper, with the exception of cadmium, cannot be removed at a temperature of 1000 C. A further conclusion is that a successful decontamination in form of a mineral incorporation of heavy metals is not feasible unless temperatures exceed 600 C. Still, a considerable proportion of heavy metals remains mobile also over longer time in soils with a low level of clay (e.g. Podzol) or a high proportion of carbonate even if temperatures exceed 600 C. (orig.)

  15. Heavy metal deposition mapping: concentrations and deposition of heavy metals in rural areas of the UK

    OpenAIRE

    Malcolm, Heath; Fowler, David; Crossley, Alan; Kentisbeer, John; Hallsworth, Steve; Lawlor, Alan; Rowland, Phil; Guyatt, Hayley; Beith, Sarah; Thacker, Sarah; Halford, Alan; Rogers, Stuart; Cape, J Neil; Leeson, Sarah; Harmens, Harry

    2012-01-01

    CEH has been monitoring the concentrations of a range of heavy metals in rural locations across the UK since 2004. This report presents the annual average concentrations and deposition of heavy metals in air and rainfall samples collected from rural locations during 2011 and it reviews the temporal and spatial trends in heavy metal concentrations and deposition between 2004 and 2011. The monitoring network was established to measure the background concentration of a range of heavy meta...

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

    Science.gov (United States)

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

    2014-01-01

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

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

    Science.gov (United States)

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

    2014-12-01

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

  18. 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).

  19. Concentration and partitioning of heavy metals in the Scheldt estuary

    OpenAIRE

    Van Alsenoy, V.

    2001-01-01

    The continuous growth of technology has lead to an (uncontrolled) introduction of contaminants into the biosphere. The efforts of removing man-made pollutants from the natural environment have been unable to cope with the increasing amounts of waste materials and growing population. This work studies one group of substances which have a particular lasting effect on the natural balance in aquatic systems; the heavy metals. Trace metals are present in all the abiotic reservoirs of the aquatic s...

  20. Stabilization of heavy metals in sludge ceramsite.

    Science.gov (United States)

    Xu, G R; Zou, J L; Li, G B

    2010-05-01

    This paper attempts to investigate the stabilization behaviours of heavy metals in ceramsite made from wastewater treatment sludge (WWTS) and drinking-water treatment sludge (DWTS). Leaching tests were conducted to find out the effects of sintering temperature, (Fe(2)O(3) + CaO + MgO)/(SiO(2) + Al(2)O(3)) (defined as F/SA ratios), pH, and oxidative condition. Results show that sintering exhibits good binding capacity for Cd, Cr, Cu, and Pb in ceramsite and leaching contents of heavy metals will not change above 1000 degrees C. The main crystalline phases in ceramsite sintered at 1000 degrees C are kyanite, quartz, Na-Ca feldspars, sillimanite, and enstatite. The main compounds of heavy metals are crocoite, chrome oxide, cadmium silicate, and copper oxide. Leaching contents of Cd, Cu, and Pb increase as the F/SA ratios increase. Heavy metals in ceramsite with variation of F/SA ratios are also in same steady forms, which prove that stronger chemical bonds are formed between these heavy metals and the components. Leaching contents of heavy metals decrease as pH increases and increase as H(2)O(2) concentration increases. The results indicate that when subjected to rigorous leaching conditions, the crystalline structures still exhibit good chemical binding capacity for heavy metals. In conclusion, it is environmentally safe to use ceramsite in civil and construction fields. PMID:20219229

  1. Interaction of heavy metals and pyrene on their fates in soil and tall fescue (Festuca arundinacea).

    Science.gov (United States)

    Lu, Mang; Zhang, Zhong-Zhi; Wang, Jing-Xiu; Zhang, Min; Xu, Yu-Xin; Wu, Xue-Jiao

    2014-01-21

    90-Day growth chamber experiments were performed to investigate the interactive effect of pyrene and heavy metals (Cu, Cd, and Pb) on the growth of tall fescue and its uptake, accumulation, and dissipation of heavy metals and pyrene. Results show that plant growth and phytomass production were impacted by the interaction of heavy metals and pyrene. They were significantly decreased with heavy metal additions (100-2000 mg/kg), but they were only slightly declined with pyrene spiked up to 100 mg/kg. The addition of a moderate dosage of pyrene (100 mg/kg) lessened heavy metal toxicity to plants, resulting in enhanced plant growth and increased metal accumulation in plant tissues, thus improving heavy metal removal by plants. In contrast, heavy metals always reduced both plant growth and pyrene dissipation in soils. The chemical forms of Cu, Cd, and Pb in plant organs varied with metal species and pyrene addition. The dissipation and mineralization of pyrene tended to decline in both planted soil and unplanted soils with the presence of heavy metals, whereas they were enhanced with planting. The results demonstrate the complex interactive effects of organic pollutants and heavy metals on phytoremediation in soils. It can be concluded that, to a certain extent, tall fescue may be useful for phytoremediation of pyrene-heavy metal-contaminated sites. Further work is needed to enhance methods for phytoremediation of heavy metal-organics co-contaminated soil. PMID:24383577

  2. 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

  3. Transport of heavy metals in process wastewaters

    Energy Technology Data Exchange (ETDEWEB)

    Wilson, R.F.

    1990-01-01

    Coal-conversion process wastewaters, obtained in the gasification and liquefaction of coal, generally contain appreciable quantities of toxic heavy metals and phenolic-type compounds in the aqueous phase which give rise to a substantial need for the study and elucidation of the complex ions formed in their interaction. Thus, these studies were undertaken to determine the extent of transport of these ions and/or their interaction products across the organic-aqueous phase and the characteristics of the interaction products. During the past year, the participants have been engaged in the systematic study of the transport and removal of the interaction products of several heavy metal ions, viz., Cu, Cd, Co, Fe, and Ni with selected coal tar phenols from aqueous media. These extraction studies were carried out using different liquid pairs such as dissopropyl ether-water and methyl iso-butyl ketone-water at various concentrations, ionic strengths, and pH's. More recently, the authors has standardized methods for carrying out these studies. Detailed transport of the transport of Cu, Fe, Zn, Pb, Cd and Ni resorcinol and/or catacohol complexes have been studied using polargraphy and HPLC Techniques. The polargraph was employed to ascertain the metal ion concentration and the HPLC was employed using electrochemical detection to determine the resorcinol or catecohol concentrations. The aqueous-organic extraction studies were generally carried out using iso-butyl ketone-water liquid-liquid pairs. These data indicate that after three successive extractions essential 100% of the phenolic complex agent is transported from the aqueous phase into the organic phase. 10 figs., 10 tabs.

  4. Plant transporters involved in heavy metal homeostasis

    OpenAIRE

    Dorina Podar

    2010-01-01

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

  5. Ecotoxic heavy metals transformation by bacteria and fungi in aquatic ecosystem.

    Science.gov (United States)

    Chaturvedi, Amiy Dutt; Pal, Dharm; Penta, Santhosh; Kumar, Awanish

    2015-10-01

    Water is the most important and vital molecule of our planet and covers 75% of earth surface. But it is getting polluted due to high industrial growth. The heavy metals produced by industrial activities are recurrently added to it and considered as dangerous pollutants. Increasing concentration of toxic heavy metals (Pb(2+), Cd(2+), Hg(2+), Ni(2+)) in water is a severe threat for human. Heavy metal contaminated water is highly carcinogenic and poisonous at even relatively low concentrations. When they discharged in water bodies, they dissolve in the water and are distributed in the food chain. Bacteria and fungi are efficient microbes that frequently transform heavy metals and remove toxicity. The application of bacteria and fungi may offer cost benefit in water treatment plants for heavy metal transformation and directly related to public health and environmental safety issues. The heavy metals transformation rate in water is also dependent on the enzymatic capability of microorganisms. By transforming toxic heavy metals microbes sustain aquatic and terrestrial life. Therefore the application of microbiological biomass for heavy metal transformation and removal from aquatic ecosystem is highly significant and striking. This paper reviews the microbial transformation of heavy metal, microbe metal interaction and different approaches for microbial heavy metal remediation from water bodies. PMID:26250544

  6. 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...

  7. 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 ...

  8. Using untraditional sorbents for sorption of certain heavy metals from waste water

    OpenAIRE

    Kyncl, Miroslav; Pavolová, Henrieta; Kyse?ová, Katarína

    2008-01-01

    The environment incl. water is exposed to heavy metals in the long term. Typically, industrial activities are the source of heavy metals penetrating the environment. The heavy metals are contained in many products and are a part of many waste substances. This paper deals with removal of copper, zinc and lead from waste waters by means of adsorption. Adsorbents are typically cheap substances, such as synthetic zeolite, bentonite or slovakite. Attention is paid to the adsorption rate and effici...

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

    DEFF Research Database (Denmark)

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

    2012-01-01

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

  10. 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.

  11. Heavy Metal Bviosorbent Based on Silicate Matrix.

    Czech Academy of Sciences Publication Activity Database

    Dostálek, P.; Debourg, A.; Kuncová, Gabriela; Patzák, M.; Palmi, P.; Marceau, S.

    2000, s. 1. [ Mikroelementy . Liblice (CZ), 05.09.2000-07.09.2000] Institutional research plan: CEZ:AV0Z4072921 Keywords : heavy metal biosorbent * yeast cells * sol-gel technique Subject RIV: CI - Industrial Chemistry, Chemical Engineering

  12. 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, 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

  13. Heavy metals in MSW incineration fly ashes

    DEFF Research Database (Denmark)

    Ferreira, Celia; Ribeiro, Alexandra B.; Ottosen, Lisbeth M.

    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 ...

  14. Heavy Metal Compositions in Gaborone Industrial Effluent

    OpenAIRE

    E. Nkegbe; I. Koorapetse

    2005-01-01

    This study assessed the compositions of five heavy metals in Gaborone Industrial effluent from five industrial premises; a brewery, pharmaceutical company, paints and chemical industry (commercial photography studios and a soap manufacturing company).The heavy metals monitored were Lead (Pb), Cadmium (Cd), Iron (Fe), Nickel (Ni) and Zinc (Zn). All the industries discharged during the study period a certain amount of Nickel although in very minute concentrations in relation to the Gaborone Cit...

  15. 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 ...

  16. Development of a Microbe-Zeolite Carrier for the Effective Elimination of Heavy Metals from Seawater.

    Science.gov (United States)

    Kim, In Hwa; Choi, Jin-Ha; Joo, Jeong Ock; Kim, Young-Kee; Choi, Jeong-Woo; Oh, Byung-Keun

    2015-09-01

    The purpose of this study was to investigate the potential of zeolite-supported sulfatereducing bacteria (SRB) in enhancing the removal of Cu(2+), Ni(2+), and Cr(6+) in contaminated seawater. Our results show that SRB-immobilized zeolite carriers can enhance the removal of heavy metals. In addition, heavy metals were generally better removed at conditions of 37°C. Cu(2+), Ni(2+), and Cr(6+) were effectively removed by 98.2%, 90.1%, and 99.8% at 100 parts per million concentration of the heavy metals, respectively. These results indicate that SRB-zeolite carriers hold great potential for use in the removal of cationic heavy metal species from marine environment. PMID:26032363

  17. Phytoremediation potential of Lemna minor L. for heavy metals.

    Science.gov (United States)

    Bokhari, Syeda Huma; Ahmad, Iftikhar; Mahmood-Ul-Hassan, Muhammad; Mohammad, Ashiq

    2016-01-01

    Phytoremediation potential of L. minor for cadmium (Cd), copper (Cu), lead (Pb), and nickel (Ni) from two different types of effluent in raw form was evaluated in a glass house experiment using hydroponic studies for a period of 31 days. Heavy metals concentration in water and plant sample was analyzed at 3, 10, 17, 24, and 31 day. Removal efficiency, metal uptake and bio-concentration factor were also calculated. Effluents were initially analyzed for physical, chemical and microbiological parameters and results indicated that municipal effluent (ME) was highly contaminated in terms of nutrient and organic load than sewage mixed industrial effluent (SMIE). Results confirmed the accumulation of heavy metals within plant and subsequent decrease in the effluents. Removal efficiency was greater than 80% for all metals and maximum removal was observed for nickel (99%) from SMIE. Accumulation and uptake of lead in dry biomass was significantly higher than other metals. Bio-concentration factors were less than 1000 and maximum BCFs were found for copper (558) and lead (523.1) indicated that plant is a moderate accumulator of both metals. Overall, L. minor showed better performance from SMIE and was more effective in extracting lead than other metals. PMID:26114480

  18. Heavy metals in equine biological components

    Directory of Open Access Journals (Sweden)

    Maria Verônica de Souza

    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.

  19. 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.

  20. Optimization and/or acclimatization of activated sludge process under heavy metals stress.

    Science.gov (United States)

    El Bestawy, Ebtesam; Helmy, Shacker; Hussein, Hany; Fahmy, Mohamed

    2013-04-01

    The present study aimed to overcome the toxicity of the heavy metals load, discharged with the industrial effluents into Alexandria sewerage network, on the activated sludge treatment system through effective acclimation for organic matter and heavy metals removal. Optimization and/or acclimatization of the activated sludge process in the presence of Cu, Cd, Co and Cr contaminating mixed domestic-industrial wastewater was investigated. Acclimatization process was performed through abrupt and stepwise addition of tested metals using sequencing batch reactors treatment approach and evaluated as microbial oxygen uptake rate (OUR), dehydrogenase activity (DHA), organic matter (COD) and heavy metals removal. Abrupt addition of metals adversely affected sludge bioactivity leading to decline in the removal efficiency of the targeted contaminants and loss of floc structure. Metals IC50 confirmed that copper possessed the highest toxicity towards the OUR, DHA activity and COD removal with orders Cu > Cd > Cr > Co; Cu > Cd > Co = Cr and Cu > Cd > Cr > Co, respectively. The highest metal removal was recorded for Cd followed by Co, Cu and finally Cr, most of which was retained in the dissolved influent. However, controlled stepwise application of the tested metals exhibited high sensitivity of DHA and OUR activities only at the highest metal concentrations although enhanced at the lowest concentrations while COD removal was not significantly affected. In conclusion, this approach resulted in adaptation of the system where sludge microbes acquired and developed natural resistance to such metals leading to remarkable enhancement of both organic matter and heavy metals removal. PMID:23212207

  1. 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; Guedes, Paula; Jensen, Pernille Erland; Ribeiro, Alexandra B.; Ottosen, Lisbeth M.

    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 th...

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

    OpenAIRE

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

    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. Quantification of uncertainty in modelled partitioning and removal of heavy metals (Cu, Zn) in a stormwater retention pond and a biofilter

    OpenAIRE

    Vezzaro, Luca; Eriksson, Eva; Ledin, Anna; Mikkelsen, Peter Steen

    2011-01-01

    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 mod...

  4. 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 determi