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1

Heavy metal removal and recovery using microorganisms  

Energy Technology Data Exchange (ETDEWEB)

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.

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

1991-02-01

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

Peats and ferrites for heavy metal removal  

International Nuclear Information System (INIS)

Peat is a relatively inexpensive material which processes a native cation exchange capacity. Efforts to utilize peat have been hampered by its low permeability to water and its tendency to severely leach in water at pH>6. These disadvantages have been significantly minimized by treating the peat with concentrated sulfuric acid. The acid treatment also increases the cation exchange capacity of the peat. Results of both column batch studies of the modified peat for use as an actinide adsorbent will be presented. Ferrites are mixed valence iron compounds having metal sorptive and magnetic properties. A naturally occurring ferrite material is magnetite. We have studied activation techniques to give magnetite a high capacity for removing heavy metals and actinides from aqueous process waste solutions. The solution can then be magnetically filtered to removal magnetite sorbed metals from solution. results of the experiments will be described. 18 refs

4

Heavy metal removal using reverse osmosis  

Directory of Open Access Journals (Sweden)

Full Text Available The aim of this work was to study reverse osmosis characteristics for copper, nickel and zinc removal from technological aqueoussolutions. Reverse osmosis (RO is a separation process that uses pressure to force a solution through a membrane that retainsthe solute on one side and allows the pure solvent to pass to the other side. A polyamide thin-film composite membrane TW30-1812-50was used. The difference in flux decline is significant. There is a significant difference in flux decline depending on the anions of usedheavy metal salts. The heavy metal concentration also has a significant influence on the membrane separation. There is alsoa significant difference in flux decline depending on the transmembrane pressure.

Lucia Gajdošová

2009-12-01

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

Digital Repository Infrastructure Vision for European Research (DRIVER)

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...

Veeken, A.

1998-01-01

6

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

7

Removal of Heavy Metals from Waste Water Using Water Hyacinth  

Digital Repository Infrastructure Vision for European Research (DRIVER)

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

Mary Lissy, P. N.; G, Madhu

2011-01-01

8

Heavy metals removal from dredged sediments using electro kinetics  

Directory of Open Access Journals (Sweden)

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.

Ammami M. T.

2013-04-01

9

Heavy metal removal potential of dried Salvinia biomass.  

Science.gov (United States)

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

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

2010-02-01

10

Removal of Heavy Metals from Textile Wastewater using Zeolite  

Directory of Open Access Journals (Sweden)

Full Text Available 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 in textile effluent. The concentrations of these heavy metals in the textile wastewater samples were reduced to more than 50 percent after treating with zeolite. The sequence in increasing order of removal efficiency of these heavy metals using zeolite was Cd < Pb < Cr < Cu. When the textile wastewater sample was treated using zeolite and 10 mg/L of alum, 80% of the heavy metals (Cd and Cu were removed. The most effective treatment prior to removal of heavy metals from textile wastewater sample is by using zeolite with the addition of 10 mg/L of alum as flocculants.

Normala Halimoon

2010-01-01

11

Biosorption of heavy metals: Methodology example of uranium removal  

International Nuclear Information System (INIS)

Biosorption is receiving an increasing attention, particularly for its cost effectiveness, as an alternative treatment process for removing heavy metals from industrial effluents. Before its application in the continuous-flow sorption columns, development of the biosorption process rests on deriving the equilibrium sorption data and their interpretation. An example of uranium removal demonstrates some key aspects in application of new biosorbents. (orig.)

12

Removal of Heavy Metals from Textile Wastewater using Zeolite  

Digital Repository Infrastructure Vision for European Research (DRIVER)

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...

Normala Halimoon

2010-01-01

13

Removal of Heavy Metal Ions by Blended Periwinkle Shells  

Directory of Open Access Journals (Sweden)

Full Text Available In this study, coconut husk and palm kernel fiber were characterized, blended with periwinkle shells, thiolated and used to remove heavy metal ions-Co2+, Ni2+ and Cd2+ ions from aqueous solution. Periwinkle shells, palm kernel fiber and coco nut husk were obtained from New Benin market, Benin city, Nigeria. These were milled, sieved with a 300ìm mesh sieve, blended in seven different ratios: 1:1:1, 1:1:4, 1:4:1, 4:1:1, 1:3:2, 2:1:3, 3:2:1 and characterized. They were all thiolated and the best blend having the highest surface area was used to remove heavy metal ions-Co2+, Ni2+ and Cd2+ ions from solutions. The effect of time, temperature and concentration on the removal of heavy metal ions were studied. The optimum time for the removal of Co2+, Ni2+ and Cd2+ ions were 70, 90 and 80 min, respectively. The blended sample was more effective in the removal of heavy metal ions from their solutions compared with only periwinkle shells. The blended periwinkle shells were found to adsorb twenty six times as much as the periwinkle shells alone.

Okuo, James M.

2006-01-01

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Heavy metal removal from waste waters by ion flotation.  

Science.gov (United States)

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

Polat, H; Erdogan, D

2007-09-01

15

Removal of Trichloroethylene and Heavy Metals by Zerovalent Iron Nanoparticles  

Science.gov (United States)

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.

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

2009-05-01

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Chitosan removes toxic heavy metal ions from cigarette mainstream smoke  

Science.gov (United States)

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.

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

2013-09-01

17

Heavy metal removal from water solutions  

Directory of Open Access Journals (Sweden)

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.

Barbora Onderková

2005-11-01

18

Removal of heavy metals ions by synthetic carbonate apatite  

International Nuclear Information System (INIS)

The removal of cations such as Zn2+, Cd2+ and Pb2+ in aqueous solutions containing various counter-anions by synthetic carbonate apatite (CAP) has been in investigated using batch methods. The ranking of ions according to amount exchanged was as follows: Pb2+ > Cd2+ > Zn2+. The reaction with Pb2'+ ions was especially remarkable: after 2 hours, removal of Pb2+ ions from the 1000 ppm solution was 98,1%. XRD and IR analysis indicated the formation of a single phase of Pb'2+ ion-exchanged carbonate apatite. we can conclude that synthesized CAP is useful in removing heavy-metal ions from water. (author)

19

Removal of heavy metals from electroplating wastewater by membrane  

Directory of Open Access Journals (Sweden)

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.

Galaya Srisuwan

2002-11-01

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Heavy metal removal and recovery by contained liquid membrane permeator  

Energy Technology Data Exchange (ETDEWEB)

Heavy metals like Cu[sup 2+], Cr[sup 6+], and Hg[sup 2+] were removed successfully from wastewater and concentrated in a strip aqueous solution for recycle using the hollow-fiber-contained liquid membrane (HFCLM) technique. Using cotransport, Cr[sup 6+] and Hg[sup 2+] present as anions in the feed solution were transferred individually through a liquid membrane containing tri-n-octylamine in xylene and concentrated in an alkaline solution on the strip side. The removal efficiency of each heavy metal was studied as a function of the aqueous feed flow rate in an HFCLM permeator. Copper present as cation Cu[sup 2+] was removed and concentrated by countertransport using LIX84 in n-heptane as the liquid membrane. The efficiency of copper removal was studied as a function of feed copper concentration, feed flow rate, strip flow rate, and area ratio between the feed fiber set and strip fiber set. The strip side flow rate did not affect the Cu[sup 2+] transfer rate. A theoretical model presented predicts the copper transport rate from the feed solution to the strip solution in an HFCLM permeator with a variable feed to strip-side membrane area. Both feed aqueous boundary layer and interfacial complexation reaction on the feed side dominate the observed Cu[sup 2+] removal process through LIX84 in n-heptane for feed concentration levels used 90--500 mg/L. It was verified by providing two times larger liquid-liquid interfacial area in the feed aqueous side or in the strip aqueous side. The model can be used to design the membrane area required on the feed and strip fiber sides to remove essentially all of the copper from a given wastewater stream.

Guha, A.K.; Yun, C.H.; Basu, R.; Sirkar, K.K. (Stevens Inst. of Tech., Hoboken, NJ (United States))

1994-07-01

 
 
 
 
21

Hybrid process for heavy metal removal from wastewater sludge.  

Science.gov (United States)

Bioleaching processes have been demonstrated to be effective technologies in removing heavy metals from wastewater sludge, but long hydraulic retention times are typically required to operate these bioprocesses. A hybrid process (coupling biological and chemical processes) has been explored in laboratory pilot-scale experiments for heavy metals (cadmium [Cd], copper [Cu], chromium [Cr], and zinc [Zn]) removal from three types of sludge (primary sludge, secondary activated sludge, and a mixture of primary and secondary sludge). The hybrid process consisted of producing a concentrate ferric ion solution followed by chemical treatment of sludges. Ferric iron solution was produced biologically via oxidation of ferrous iron by A. ferrooxidans in a continuous-flow stirred tank (5.2 L) reactor (CSTR). Wastewater sludge filtrate (WSF) containing nutrients (phosphorus and nitrogen) has been used as culture media to support the growth and activity of indigenous iron-oxidizing bacteria. Results showed that total organic carbon (TOC) concentrations of the culture media in excess of 235 mg/L were found to be inhibitory to bacterial growth. The oxidation rate increased as ferrous iron concentrations ranged from 10 to 40 g Fe2+/L. The percentage of ferrous iron (Fe2+) oxidized to ferric iron (Fe3+) increased as the hydraulic retention time (HRT) increased from 12 to 48 h. Successful and complete Fe2+ oxidation was recorded at a HRT of 48 h using 10 g Fe2+/L. Subsequently, ferric ion solution produced by A. ferrooxidans in sludge filtrate was used to solubilize heavy metals contained in wastewater sludge. The best solubilization was obtained with a mixture of primary and secondary sludge, demonstrating a removal efficiency of 63, 71, 49, and 80% for Cd, Cu, Cr, and Zn, respectively. PMID:16121505

Drogui, Patrick; Blais, Jean-François; Mercier, Guy

2005-01-01

22

Removal of Heavy Metals and PAH in Highway Detention Ponds  

Digital Repository Infrastructure Vision for European Research (DRIVER)

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

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

2005-01-01

23

Removal of Heavy Metals and PAH in Highway Detention Ponds  

Digital Repository Infrastructure Vision for European Research (DRIVER)

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

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

2010-01-01

24

Industrial effluent treatments using heavy-metal removing bacterial bioflocculants  

Scientific Electronic Library Online (English)

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

J, Lin; C, Harichund.

2011-04-01

25

Heavy metal removal from aqueous solutions by activated phosphate rock  

Energy Technology Data Exchange (ETDEWEB)

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.

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

26

Heavy metal removal from aqueous solutions by activated phosphate rock  

International Nuclear Information System (INIS)

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

27

Membrane-assisted processes to remove heavy metals from soil and water  

Energy Technology Data Exchange (ETDEWEB)

Two membrane-based processes designed to remove heavy metals from soil and water, were evaluated through bench-scale testing. The first process incorporated slurry leaching with membrane filtration. Heavy metals were removed when the soil slurry was continuously filtered through a semipermeable membrane. The second process was designed to remove heavy metals from aqueous streams and involved the binding of metals with lignosulfonates followed by ultrafiltration. The ultrafiltration membranes rejected metal ions bound to the lignosulfonate molecules, thereby removing the heavy metals from the water. Tests were conducted for lead, chromium and mercury. 21 refs., 1 tab., 6 figs.

Volchek, K.; Veysov, B.; Ananieva, L.; Atamaniouk, V.; Mortazavi, S.; Ladanowski, C.; Whittaker, H. [Environment Canada, Ottawa, ON (Canada). Emergencies Engineering Div.

1996-09-01

28

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.

29

Removal Of Heavy Metals From Electroplating Wastewater By Anaerobic Bacteria  

Science.gov (United States)

Biosorption of heavy metals from simulated wastewater and the raw electroplating wastewater with "BM (Biosorption of Metals) bacteria" were investigated in this study. The influence of initial pH, biosorbents dose, concentration of ions, contact time and temperature on biosorption capacity of Cr(VI) and Ni(II) were studied. The optimum pH for biosorption of Cr(VI) was found to be low, and the removal efficiency of Cr(VI) was 98.60% with "BM bacteria" at pH 2. The removal efficiency of Ni(II) was increased with increasing the pH, and was enhanced up to 115% compared with the wastewater without BM bacteria. In this experiment, the "BM bacteria" efficiently removed Cu(II), Ni(II), Cr(VI), Zn(II) and COD from the raw electroplating wastewater, and the removal efficiencies were 98.92%, 99.92%, 99.86%, 99.93% and 45.20% respectively.

Ma, Wanggang; Sun, Peide; Song, Yingqi; Zhang, Yi; Yin, Jun

2010-11-01

30

Removal of Heavy Metals and PAH in Highway Detention Ponds  

DEFF Research Database (Denmark)

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

Bentzen, Thomas Ruby; Larsen, Torben

2005-01-01

31

The removal of heavy metal cations by natural zeolites.  

Science.gov (United States)

In this study, the adsorption behavior of natural (clinoptilolite) zeolites with respect to Co(2+), Cu(2+), Zn(2+), and Mn(2+) has been studied in order to consider its application to purity metal finishing wastewaters. The batch method has been employed, using metal concentrations in solution ranging from 100 to 400 mg/l. The percentage adsorption and distribution coefficients (K(d)) were determined for the adsorption system as a function of sorbate concentration. In the ion exchange evaluation part of the study, it is determined that in every concentration range, adsorption ratios of clinoptilolite metal cations match to Langmuir, Freundlich, and Dubinin-Kaganer-Radushkevich (DKR) adsorption isotherm data, adding to that every cation exchange capacity metals has been calculated. It was found that the adsorption phenomena depend on charge density and hydrated ion diameter. According to the equilibrium studies, the selectivity sequence can be given as Co(2+) > Cu(2+) > Zn(2+) > Mn(2+). These results show that natural zeolites hold great potential to remove cationic heavy metal species from industrial wastewater. PMID:15533402

Erdem, E; Karapinar, N; Donat, R

2004-12-15

32

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

Science.gov (United States)

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

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

2012-01-01

33

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

Energy Technology Data Exchange (ETDEWEB)

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.

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

2012-04-15

34

Heavy metals removal from industrial wastewaters by biosorption  

Digital Repository Infrastructure Vision for European Research (DRIVER)

The use of biological materials for removing metals and, possibly, recovering them from contaminated wastewaters has emerged as a potential alternative method to conventional treatment techniques. The ability of microorganisms to separate metal ions is a well-known phenomenon. Various experimental data are presented for different metals and biomass types, and are reviewed and critically commented in comparison with the literature. Dead biomass is usually obtained from fermentation wastes or b...

Zouboulis, A. I.; ???????????, ?. ?.; Lazaridis, N. K.; Karapantsios, Th D.; Matis, K. A.; ??????????, ?. ?.; ?????????????, ?. ?.; ??????, ?. ?.

2009-01-01

35

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

Science.gov (United States)

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

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

2013-11-01

36

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

Directory of Open Access Journals (Sweden)

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

M. Ghaedi

2013-06-01

37

Effect of operational parameters on heavy metal removal by electrocoagulation.  

Science.gov (United States)

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

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

2014-12-01

38

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

DEFF Research Database (Denmark)

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

Pedersen, Anne Juul; Ottosen, Lisbeth M.

2003-01-01

39

Removal of heavy metals from electroplating wastewater by membrane  

Digital Repository Infrastructure Vision for European Research (DRIVER)

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...

Galaya Srisuwan; Poonpetch Thongchai

2002-01-01

40

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

 
 
 
 
41

Effects of different cleaning treatments on heavy metal removal of Panax notoginseng (Burk) F. H. Chen.  

Science.gov (United States)

The quality and safety of Panax notoginseng products has become a focus of concern in recent years. Contamination with heavy metals is one of the important factors as to P. notoginseng safety. Cleaning treatments can remove dust, soil, impurities or even heavy metals and pesticide residues on agricultural products. But effects of cleaning treatments on the heavy metal content of P. notoginseng roots have still not been studied. In order to elucidate this issue, the effects of five different cleaning treatments (CK, no treatment; T1, warm water (50°C) washing; T2, tap water (10°C) washing; T3, drying followed by polishing; and T4, drying followed by tap water (10°C) washing) on P. notoginseng roots' heavy metal (Cu, Pb, Cd, As and Hg) contents were studied. The results showed that heavy metal (all five) content in the three parts all followed the order of hair root > rhizome > root tuber under the same treatment. Heavy metal removals were in the order of Hg > As > Pb > Cu > Cd. Removal efficiencies of the four treatments were in the order of T2 > T1 > T3 > T4. Treatments (T1-T4) could decrease the contents of heavy metal in P. notoginseng root significantly. Compared with the requirements of WM/T2-2004, P. notoginseng roots' heavy metal contents of Cu, Pb, As and Hg were safe under treatments T1 and T2. In conclusion, the cleaning process after production was necessary and could reduce the content of heavy metals significantly. Fresh P. notoginseng root washed with warm water (T2) was the most efficient treatment to remove heavy metal and should be applied in production. PMID:25315359

Dahui, Liu; Na, Xu; Li, Wang; Xiuming, Cui; Lanping, Guo; Zhihui, Zhang; Jiajin, Wang; Ye, Yang

2014-12-01

42

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

International Nuclear Information System (INIS)

avy 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)

43

Utilization of Carbamoyethylated Cotton for Heavy Metal Ion Removal  

Directory of Open Access Journals (Sweden)

Full Text Available Cotton cellulose in fabric form was rendered ion exchanger via Carbamoyethylation Reaction (CER. The latter was carried out using acrylamide (Aam and sodium hydroxide. The resulted carbamoyethylated cotton having amide functional groups (CONH2 was monitored for its ability to adsorb heavy metals from their aqueous solutions. Different factors affecting adsorption of metal ions onto the latter substrate such as metal ion concentration, pH, treatment time and temperature were studied systematically. Results obtained reflect the following findings: (a the adsorption value increases by increasing the metal ion concentration up to 60 m mol L-1 then levels off, (b the carbamoylethylated cotton was found to be selective adsorbent for Hg2+ at pH 0.5, (c the adsorption values is higher at 40 °C then levels off by raising the temperature to 60 and 80 °C, respectively, (d. The adsorption values increase by increasing the treatment time up to 5 h at 40 and 60 °C and 3 h at 80 °C then levels off and (e The adsorption values of the aforementioned substrate in question at different metal ions follow the order: Hg2+ > Cu2+ > Zn2+ > Co2+ > Pb2+.

Kh.M. Mostafa

2005-01-01

44

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

International Nuclear Information System (INIS)

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

45

A new material for removing heavy metals from water  

Science.gov (United States)

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).

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

1994-01-01

46

Heavy metal-binding proteins from metal-stimulated bacteria as a novel adsorbent for metal removal technology.  

Science.gov (United States)

Water pollution with toxic heavy metals is of growing concern because heavy metals could bring about serious problems for not only ecosystems in the water environment but also human health. Some metal removal technologies have been in practical use, but much energy and troublesome treatments for chemical wastes are required to operate these conventional technologies. In this study, heavy metal-binding proteins (HMBPs) were obtained from metal-stimulated activated sludge culture with affinity chromatography using copper ion as a ligand. Two-dimensional electrophoresis revealed that a number of proteins in activated sludge culture were recovered as HMBPs for copper ion. N-termini of five HMBPs were determined, and two of them were found to be newly discovered proteins for which no amino acid sequences in protein databases were retrieved at more than 80% identities. Metal-coordinating amino acids occupied 38% of residues in one of the N-terminal sequences of the newly discovered HMBPs. Since these HMBPs were expected to be stable under conditions of water and wastewater treatments, it would be possible to utilize HMBPs as novel adsorbents for heavy metal removal if mass volume of HMBPs can be obtained with protein cloning techniques. PMID:16749461

Sano, D; Myojo, K; Omura, T

2006-01-01

47

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

Digital Repository Infrastructure Vision for European Research (DRIVER)

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

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

2010-01-01

48

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

Directory of Open Access Journals (Sweden)

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

Nastiti Siswi Indrasti

2010-04-01

49

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...

50

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

Science.gov (United States)

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

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

2014-12-01

51

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

Energy Technology Data Exchange (ETDEWEB)

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.

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

1991-02-01

52

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

Energy Technology Data Exchange (ETDEWEB)

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.

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

1991-02-01

53

Removal of heavy metals in rinsing wastewater from plating factory by adsorption with economical viable materials.  

Science.gov (United States)

The removal of heavy metals from plating factory wastewater with economical materials was investigated by the column method. Montmorillonite, kaolin, tobermorite, magnetite, silica gel and alumina were used as the economical adsorbents to wastewater containing Cd(II), Cr(VI), Cu(II) and Pb(II). This removal method of heavy metals proved highly effective as removal efficiency tended to increase with increasing pH and decrease with increasing metal concentration. The removal percentages by adsorption onto montmorillonite, tobermorite, magnetite, and silica gel showed high values for all metals. From the results for the heat of adsorption, the adsorption process in the present study might be chemisorption. The proposed method was successfully applied to the removal of Cd(II), Cr(VI) and Cu(II) in rinsing wastewater from plating factory in Nagoya City, Aichi Prefecture, Japan. Since the economical adsorbents used can be obtained commercially because they are easily synthesized, the wastewater treatment system developed is rapid, simple and cheap for the removal of heavy metals. PMID:14550661

Katsumata, Hideyuki; Kaneco, Satoshi; Inomata, Kentaro; Itoh, Kumiko; Funasaka, Kunihiro; Masuyama, Kazuaki; Suzuki, Tohru; Ohta, Kiyohisa

2003-10-01

54

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

Science.gov (United States)

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

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

2012-04-01

55

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

Science.gov (United States)

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

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

2008-11-01

56

Heavy metals removal from aqueous solutions and wastewaters by using various byproducts.  

Science.gov (United States)

Water contamination with heavy metals (HM) represents a potential threat to humans, animals and plants, and thus removal of these metals from contaminated waters has received increasing attention. The present study aimed to assess the efficiency of some low cost sorbents i.e., chitosan (CH), egg shell (ES), humate potassium (HK), and sugar beet factory lime (SBFL) for removal of cadmium (Cd), copper (Cu), lead (Pb) and zinc (Zn) from wastewaters. For this purpose batch equilibrium experiments were conducted with aqueous solutions containing various concentrations of the metals and sorbents in a mono-metal and competitive sorption system. Sorption isotherms were developed, and sorption parameters were determined. The potential applicability of the tested sorbents in the removal of Cd, Cu, and Zn from contaminated wastewaters was also investigated by equilibrating different sorbents and water ratios. Chitosan expressed the highest affinity for the metals followed by SBFL, ES, and HK. Nearly 100% of the metals were removed from aqueous solutions with the lowest initial metal concentrations by the sorbents especially CH and SBFL. However, the sorption efficiency decreased as the initial metal concentrations increased. Competition among the four metals changed significantly their distribution coefficient (Kd) values with the sorbents. The selectivity sequence of the metals was: Pb > Cu > Zn > Cd. The metal removal from the wastewaters varied from 72, 69, and 60 to nearly 100% for Cd, Cu and Zn, respectively. The efficiency of the studied byproducts in removing metals from the wastewaters differed based on the source of contamination and metal concentrations. Cadmium removal percentages by HK and CH were higher than SBFL and ES. The HK and CH exhibited the highest removal percentage of Cu from water with high concentrations. The SBFL and ES revealed the highest removal percentage of Zn from water with high concentrations. The results, demonstrate a high potential of CH, SBFL, HK, and ES for the remediation of HM contaminated wastewaters. PMID:23831673

Shaheen, Sabry M; Eissa, Fawzy I; Ghanem, Khaled M; Gamal El-Din, Hala M; Al Anany, Fathia S

2013-10-15

57

Heavy Metal and Phosphorus Removal from Waters by Optimizing Use of Calcium Hydroxide and Risk Assessment  

Directory of Open Access Journals (Sweden)

Full Text Available The optimizing using calcium hydroxide to remove dissolved heavy metal, phosphorus pollutants and algae was investigated. It was found that the concentration of calcium ion was minimal at pH 10.5 when a large amount of generated calcium carbonate increased the particle size of the precipitates and improved sedimentation of sludge and the removal efficiency of heavy metal and phosphorus significantly. Regardless of the initial heavy metals concentrations contained in the wastewater, the final treated concentrations were all extremely low. Risk assessment in alkaline environment of pH 10.5 was tested by fancy carp, daphnia, seed, luminescent bacterium Q67. The results showed that pH 10.5 had a little influence on the four tested organisms. Thus it is suggested that calcium hydroxide at pH 10.5 may be a potential method for treating wastewater and eutrophication water.

Binyuan Chen

2012-01-01

58

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)

59

Enhanced removal of heavy metals in primary treatment using coagulation and flocculation.  

Science.gov (United States)

The goal of this study was to determine the removal efficiencies of chromium, copper, lead, nickel, and zinc from raw wastewater by chemically enhanced primary treatment (CEPT) and to attain a total suspended solids removal goal of 80%. Operating parameters and chemical doses were optimized by bench-scale tests. Locally obtained raw wastewater samples were spiked with heavy metal solutions to obtain representative concentrations of metals in wastewater. Jar tests were conducted to compare the metals removal efficiencies of the chemical treatment options using ferric chloride, alum, and anionic polymer. The results obtained were compared with those from other studies. It was concluded that CEPT using ferric chloride and anionic polymer is more effective than CEPT using alum for metals removal. The CEPT dosing of 40 mg/L ferric chloride and 0.5 mg/L polymer enhanced heavy metals removal efficiencies by over 200% for chromium, copper, zinc, and nickel and 475% for lead, compared with traditional primary treatment. Efficient metals capture during CEPT can result in increased allowable headworks loadings or lower metal levels in the outfall. PMID:18605386

Johnson, Pauline D; Girinathannair, Padmanabhan; Ohlinger, Kurt N; Ritchie, Stephen; Teuber, Leah; Kirby, Jason

2008-05-01

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

DEFF Research Database (Denmark)

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

Sun, Tian R.; Ottosen, Lisbeth M.

2012-01-01

 
 
 
 
61

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

62

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

Energy Technology Data Exchange (ETDEWEB)

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.

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

2014-01-15

63

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

International Nuclear Information System (INIS)

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

64

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

65

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

Science.gov (United States)

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

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

2009-10-01

66

USING BIOPOLYMERS TO REMOVE HEAVY METALS FROM SOIL AND WATER  

Science.gov (United States)

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

67

Removal of Heavy Metal from Contaminated Soil with Chelating Agents  

Digital Repository Infrastructure Vision for European Research (DRIVER)

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...

Wei Jiang; Tao Tao; Zhi-Ming Liao

2011-01-01

68

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

Science.gov (United States)

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

Singh, Anil Kumar; Cameotra, Swaranjit Singh

2013-10-01

69

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

Directory of Open Access Journals (Sweden)

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(?-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(?-glutamic acid, heavy metals, chelation therapy, gastrointestinal pH, kinetics

Inbaraj BS

2012-08-01

70

Removal of Heavy Metal from Contaminated Soil with Chelating Agents  

Directory of Open Access Journals (Sweden)

Full Text Available 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 control the extraction, especially to chitosan solution. It was evident that the chitosan solution was the most efficient when the pH value was 3 - 3.5, the rate of extraction of copper being 43.36% and of nickel being 37.07%. And the best match of concentration and liquid/solid was 0.3 g/L and 10 mL/g.

Wei Jiang

2011-09-01

71

Removal Efficiency of Heavy Metals Using Various Resins and Natural Materials  

Directory of Open Access Journals (Sweden)

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.

M. Cochran

2012-01-01

72

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

Energy Technology Data Exchange (ETDEWEB)

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.

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

1995-12-31

73

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

74

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

Science.gov (United States)

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.

Yousefi, Z.; Zazouli, M. A.

75

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)

76

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

Energy Technology Data Exchange (ETDEWEB)

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.

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

77

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

DEFF Research Database (Denmark)

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.

NystrØm, Gunvor Marie; Ottosen, Lisbeth M.

2005-01-01

78

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

Science.gov (United States)

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

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

2014-09-01

79

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

80

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

Directory of Open Access Journals (Sweden)

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

Bianchi F.

2013-04-01

 
 
 
 
81

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

82

The role of algae in heavy metals removal from mining wastewater  

Digital Repository Infrastructure Vision for European Research (DRIVER)

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

Benchraka, Chouaib

2010-01-01

83

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

Digital Repository Infrastructure Vision for European Research (DRIVER)

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...

Ku?nierová Mária; Luptáková Alena

2000-01-01

84

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

Digital Repository Infrastructure Vision for European Research (DRIVER)

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. B...

Rafeah Wahi; Herman Senghie

2011-01-01

85

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

International Nuclear Information System (INIS)

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

86

Nitrogen removal and heavy metals in leachate treatment using SBR technology  

International Nuclear Information System (INIS)

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

87

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

Science.gov (United States)

Biological nitrogen removal by the use of Sequencing Batch Reactors (SBRs) is today an accepted and well proven model. The results of SBR performance on nitrogen removal have encouraged consultants, engineering companies and landfill operators to develop and build full scale SBR plants at a number of sites in Sweden. Two of these plants, Isätra and Norsa, have been studied closely. The Norsa plant treats leachate at a controlled water temperature, while the Isätra plant is exposed to temperature variation throughout the year. Both plants have very well proven nitrogen removal capacities, although winter conditions have an adverse impact on their performance. Typical nitrification efficiency is close to 100%, while the total nitrogen removal is about 90-95% under stable operation conditions. A good relationship between the nitrogen load and the nitrification rate has been observed at the Norsa SBR plant. The heavy metal content in the leachate is very low thanks to anaerobic precipitation inside the landfill into metal sulphides. The heavy metal content in the biological sludge is consequently also very low. PMID:19836884

Morling, S

2010-02-15

88

Polyaza macroligands as potential agents for heavy metal removal from wastewater  

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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.

Elizondo Martínez Perla

2013-01-01

89

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

Science.gov (United States)

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.

Visa, Maria; Chelaru, Andreea-Maria

2014-06-01

90

Removal of heavy metal using poly (N-vinyl imidazole)-grafted-carboxymethylated starch.  

Science.gov (United States)

Carboxymethyl starch (CMS) grafted with N-vinyl imidazole was investigated for heavy metal removal from aqueous solutions. Poly (N-vinyl imidazole)-grafted carboxymethyl starch (PVI-g-CMS) was prepared in aqueous solution using potassium persulfate (KPS) as initiator. The produced grafted copolymer was characterized by FTIR, TGA, surface area and elemental analysis. The grafted material was used for the sorption of Mn(II), Zn(II) and Cd(II). Uptake parameters such as affinity of metal ions, effect of metal ion concentration, adsorbent amount and agitation time were investigated. The polymers were more sensitive to Cd(II) and Zn(II) and the order of metal ion binding was Cd(II)>Zn(II)>Mn(II). The adsorption data was fitted very well in a Freundlich isotherm equation and the kinetics of adsorption was found to follow the pseudo-first order kinetic model. PMID:24589473

El-Hamshary, Hany; Fouda, Moustafa M G; Moydeen, Meera; Al-Deyab, Salem S

2014-05-01

91

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

International Nuclear Information System (INIS)

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

92

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

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

Germán C. Quintana

2008-11-01

93

Foamy complex formation for removing and recovering of heavy metal ions in dilute solutions with N-monodecanoyl diethylenetriamine  

International Nuclear Information System (INIS)

In order to highly selectively remove and recover heavy metals, usually harmful, from wastewater, a modified foam-separating method using a fatty compound, i.e. N-monodecanoyl diethylenetriamine, was investigated on real and model wastewater, containing several kinds of metals. This agent forms soluble and foamy complexes with the metals. (auth.)

94

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

Digital Repository Infrastructure Vision for European Research (DRIVER)

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

Kyong-Soo Hong; Hak Myoung Lee; Jong Seong Bae; Myoung Gyu Ha; Jong Sung Jin; Tae Eun Hong; Jong Pil Kim; Euh Duck Jeong

2011-01-01

95

Teawaste as An Adsorbent for Heavy Metal Removal from Industrial Wastewaters  

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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.

Amir H.A. Mahvi

2005-01-01

96

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)

97

Removal of some heavy metal cations by synthetic resin purolite C100.  

Science.gov (United States)

The discharge of heavy metals into aquatic ecosystems has become a matter of concern over the last few decades. These pollutants are introduced into the aquatic systems significantly as a result of various industrial operations. This paper describes the adsorption behaviour of cation exchange resin purolite C100 with respect to Ce(4+), Fe(3+) and Pb(2+) in order to consider its application to purify metal finishing wastewaters. The batch method has been employed, using metal concentrations in solution ranging from 2.65 to 265mg/L. The adsorption percentages (%) and distribution coefficient (K(d)) were determined for the adsorption system in the aqueous media as a function of sorbate concentration. The experimental isotherm data were analyzed using the Langmuir, Freundlich, and Dubinin-Kaganer-Radushkevich (DKR) equations. It was found that the adsorption phenomena depend on charge density and hydrated ion diameter. According to the equilibrium studies, the metal ions sequence can be given as Ce(4+)>Fe(3+)>Pb(2+). These results show that cation exchange resin purolite C100 holds great potential to remove cationic heavy metal species from polluted wastewater. PMID:19403237

Abo-Farha, S A; Abdel-Aal, A Y; Ashour, I A; Garamon, S E

2009-09-30

98

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.)

99

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

Directory of Open Access Journals (Sweden)

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

Abdunnaser Mohamed Etorki

2014-03-01

100

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

International Nuclear Information System (INIS)

Highlights: ? Simultaneous IPN hydrogels were prepared by hybrid photopolymerization of AM and DVE-3. ? The synergistic complexation was found in the adsorption studies. ? 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 materialnsive and renewable sorbent materials in heavy metal removing processes.

 
 
 
 
101

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

Energy Technology Data Exchange (ETDEWEB)

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.

Peters, R.W.; Shem, L.

1993-01-01

102

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

Energy Technology Data Exchange (ETDEWEB)

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.

Peters, R.W.; Shem, L.

1993-03-01

103

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

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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.

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

2013-09-01

104

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

Energy Technology Data Exchange (ETDEWEB)

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.

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

105

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

Energy Technology Data Exchange (ETDEWEB)

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)

Mustafiz, S. [Dalhousie University, halifax, Nova Scotia (Canada). Faculty of Engineering

2003-09-01

106

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

International Nuclear Information System (INIS)

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

107

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

International Nuclear Information System (INIS)

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

108

Utilization of Nitrogen Containing Pregelled Starch Derivatives as Biodegradable Polymers for Heavy Metal Ions Removal  

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Full Text Available Two type of nitrogen containing pregelled starch derivatives having amide groups (CONH2 were used in heavy metal ions removal from its solutions. These pregelled starch derivatives were carbamated pregelled starch (CPS and poly (methacrylamide-pregelled starch graft copolymer (PMamPSGC. Different factors affecting adsorption of metal ions onto these substrates such as metal ion concentration, pH, treatment time and temperature as well as type of starch derivatives were studied. Results obtained reflect the following findings: (a the adsorption values of both nitrogen containing starch derivatives in question increase by increasing the metal ion concentration up to 50 mmol L-1 then levels off, (b poly (methacrylamide-pregelled starch graft copolymer was selective adsorbent for Hg2+ at pH 0.5-1, (c The adsorption values on these pregelled starch derivatives at different metal ions follow the order: Hg2+ > Cu2+ > Zn2+ > Pb2+, (d The adsorption efficiency % of metal ions in case of poly (methacrylamide-pregelled starch graft copolymer is higher than that in case of carbamated pregelled starch irrespective of the metal ion used, (e The adsorption values is higher at 30?C then decreases by raising the temperature to 50 and 70?C and (f The adsorption values increase by increasing the treatment time up to 5 h then levels off.

Kh. M. Mostafa

2004-01-01

109

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

Energy Technology Data Exchange (ETDEWEB)

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

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

2004-01-30

110

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.

111

Heavy Metal Removal from Aqueous Solution by Adsorption on Modified Banana Shell  

Directory of Open Access Journals (Sweden)

Full Text Available Background and Objectives: Heavy Metals in Water resources is one of the most important environmental problems of countries. Up to now various methods of removing of these metals is considered, which is including using of low prices materials. In this study the potential of banana shells was assessed for adsorption of heavy metal ions such as Pb and Cd from aqueous solution. "nMaterials and Methods: Banana shells were pretreated separately with 0.4 mol/L NaOH, 0.4 mol/L HNO and distilled water and their adsorption ability were compared. Batch adsorption experiments were carried out as a function of the initial ion concentration, pH and adsorbent dosage. Adsorption isotherms of metal ions on adsorbents were determined and correlated with common isotherm equations such as Lungmuir, Freundlich and BET models."nResults: The maximum adsorption capacities were achieved by alkali modified banana shells (36 mg/g for Pb and by acidic modified banana shells (16 mg/g for Cd. Experimental results showed that the best pH for adsorption was 6 and the adsorption values decreased with lowering pH. Isotherm models indicated best fit for Freundlich model for modified banana shells."nConclusion: In comparing the parameters of models, it was observed that the capacity of banana shells for adsorption of lead is higher  than for adsorption of cadmium, but the adsorption of  cadmium is stronger than the adsorption of lead.

MR Mehrasbi

2008-09-01

112

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

International Nuclear Information System (INIS)

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

113

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

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

Kyong-Soo Hong

2011-10-01

114

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

Science.gov (United States)

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 micromol/cm(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 (30-400mg/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. PMID:12573833

Genç, O; Soysal, L; Bayramo?lu, G; Arica, M Y; Bekta?, S

2003-02-28

115

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

116

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

Directory of Open Access Journals (Sweden)

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

Ashish Gadhave

2014-07-01

117

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

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

ISLEM CHAARI

2011-06-01

118

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

Energy Technology Data Exchange (ETDEWEB)

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

Gay, E.C.

1993-12-23

119

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

Science.gov (United States)

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

Gay, Eddie C. (Park Forest, IL)

1995-01-01

120

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

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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.

MADHAVI G MULGUND,

2011-02-01

 
 
 
 
121

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

122

Soil heavy metals  

Energy Technology Data Exchange (ETDEWEB)

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

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

2010-07-01

123

Biological processes for environmental control of effluent streams in the nuclear fuel cycle. [Denitrification; removal of heavy metals  

Energy Technology Data Exchange (ETDEWEB)

Nitrates and radioactive heavy metals need to be removed from aqueous effluent streams in the fuel cycle. Biological methods are being developed for reducing nitrate or nitrite to N/sub 2/ gas and for decreasing dissolved metal concentration to less than 1 g/m/sup 3/. Fluidized-bed denitrification bioreactors are being tested. Removal of uranium from solution by Saccharomyces cerevisiae and Pseudomonas aeruginosa was studied. (DLC)

Shumate, II, S E; Hancher, C W; Strandberg, G W; Scott, C D

1978-01-01

124

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

125

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

Energy Technology Data Exchange (ETDEWEB)

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.

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

2001-01-01

126

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

127

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

Energy Technology Data Exchange (ETDEWEB)

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

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

2013-09-15

128

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

DEFF Research Database (Denmark)

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

Larsen, Torben; Neerup-Jensen, O.

2004-01-01

129

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

Directory of Open Access Journals (Sweden)

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.

R.W. Krause

2010-01-01

130

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

Science.gov (United States)

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.

Kang, Kyoung Ho; Sui, Zhenghong

2010-11-01

131

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

132

Heavy metal removal and recovery using microorganisms. Volume 1, State-of-the-art and potential applications at the SRS  

Energy Technology Data Exchange (ETDEWEB)

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.

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

1991-02-01

133

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)

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.

Maike Rossmann

2010-08-01

134

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

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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.

Mokhlesur M. Rahman

2014-05-01

135

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

Science.gov (United States)

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

Rincón, Guillermo J; La Motta, Enrique J

2014-11-01

136

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

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

Ku?nierová Mária

2000-09-01

137

Rapid magnetic removal of aqueous heavy metals and their relevant mechanisms using nanoscale zero valent iron (nZVI) particles.  

Science.gov (United States)

Much work is devoted to heavy metal sorption, reduction and relevant mechanisms by nanoscale zero valent iron (nZVI) particle, but fewer studies utilize its magnetic properties in aqueous metal removals. Here, we have investigated the use of nZVI particles both electrosprayed (E-nZVI) and non-electrosprayed (NE-nZVI) with different concentration levels (0.186-1.86 mg/mL) in removing aqueous Cd(II), Cr(IV), and Pb(II) through the magnetic separation means. The effects of the reaction time (5-20 min) and magnetic treatment time (1-30 min) on relevant magnetic removal efficiencies were studied. Metal ion concentration was analyzed using inductively coupled plasma (ICP), and the magnetically obtained metal-nZVI mixtures were further analyzed using X-ray photoelectron spectroscopy (XPS). Results showed that the magnetic removal efficiencies of heavy metals varied with the metal species, nZVI loading, reaction and magnetic separation time. In most cases, use of 1.5 mg/mL E-nZVI or NE-nZVI resulted in removal efficiencies of more than 80% for Pb(II), Cd(II), and Cr(IV). Increasing the magnetic treatment time from 1 to 20 min was shown to lead to ? 20% increase in Pb(II) removal efficiency, but no improvements for Cd(II) and Cr(IV). In contrast, increasing the reaction time decreased the Pb(II) removal efficiency, yet no effects observed for Cd(II) and Cr(IV). In general, 1 min reaction and 5 min magnetic treatment were found sufficient to achieve considerable heavy metal removals. For comparable efficiencies, use of magnetic method could significantly reduce nZVI loading. XPS analysis results indicated that atomic percentages of O 1s, Fe 2p, Cd 3d, Pb 4f and Cr 2p varied with metal exposures. Different from Cd(II) and Cr(IV), aqueous iron ions might be possibly present when treating Pb(II). This study demonstrated a rapid heavy metal removal method using the magnetic property of nZVI particles, while contributing to understanding of the relevant removal mechanisms. PMID:23566331

Huang, Pengpeng; Ye, Zhengfang; Xie, Wuming; Chen, Qi; Li, Jing; Xu, Zhencheng; Yao, Maosheng

2013-08-01

138

Activated parthenium carbon as an adsorbent for the removal of dyes and heavy metal ions from aqueous solution.  

Science.gov (United States)

Parthenium hysterophorous (L) is a perennial weed distributed all over the country. Carbonized parthenium activated with conc. H2SO4 and ammonium persulphate was effective in the removal of dyes, heavy metals and phenols. Variation in the percentage removal of adsorbates was observed with increase in the contact time. Among the adsorbates tested, the affinity of the activated parthenium carbon was highest for Hg2+, Methylene Blue and Malachite Green. PMID:12227547

Rajeshwarisivaraj; Subburam, V

2002-11-01

139

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

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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.

Ali Jalilzadeh

2007-01-01

140

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

Science.gov (United States)

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

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

2002-05-27

 
 
 
 
141

Heavy metal removal in groundwater originating from acid mine drainage using dead Bacillus drentensis sp. immobilized in polysulfone polymer.  

Science.gov (United States)

Batch, column, and pilot scale feasibility experiments for a bio-sorption process using a bio-carrier (beads) with dead Bacillus drentensis sp. in polysulfone polymer were performed to remove heavy metals in groundwater originating from an acid mine drainage (AMD). For batch experiments, various amounts of bio-carrier each containing a different amount of dead biomass were added in artificial solution, of which the initial heavy metal concentration and pH were about 10 mg/L and 3, respectively. The heavy metal removal efficiencies of the bio-carrier under various conditions were calculated and more than 92% of initial Pb and Cu were found to have been removed from the solution when using 2 g of bio-carriers containing 5% biomass. For a continuous experiment with a column packed with bio-carriers (1 m in length and 0.02 m in diameter), more than 98% of Pb removal efficiency was maintained for 36 pore volumes and 1.553 g of Pb per g of bio-carrier was removed. For the pilot scale feasibility test, a total of 80 tons of groundwater (lower than pH of 4) were successfully treated for 40 working days and the removal efficiencies of Cu, Cd, Zn, and Fe were maintained above 93%, demonstrating that one kg of bio-carrier can clean up at least 1098 L of groundwater in the field. PMID:25199604

Kim, Insu; Lee, Minhee; Wang, Sookyun

2014-12-15

142

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

Digital Repository Infrastructure Vision for European Research (DRIVER)

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-...

Ali Jalilzadeh; Abdorrahim Parvaresh

2007-01-01

143

Removal of heavy metals from industrial wastewaters using amine-functionalized nanoporous carbon as a novel sorbent  

International Nuclear Information System (INIS)

Nano-porous carbon (NPC) was synthesized by hydrothermal condensation of fructose and characterized by X-ray powder diffraction and also nitrogen adsorption analysis. It was then modified with amino groups and used as a sorbent for the removal of heavy metal ions. The formation of amino-modified NPC was confirmed by X-ray powder diffraction, infrared spectroscopy, thermogravimetric and elemental analysis. NPC was applied for removal of Pb(II), Cd(II), Ni(II) and Cu(II) ions. The effects of sample pH and the adsorption kinetics were studied, and the adsorption capacity was determined. The sorbent was applied to the removal of heavy metal ions in industrial waste water samples. (author)

144

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

International Nuclear Information System (INIS)

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

145

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

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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.

Rafeah Wahi

2011-09-01

146

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

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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.

Sdiri A.

2014-07-01

147

Heavy metals (Cd, Pb, Zn, Ni, Cu and Cr(III)) removal from water in Malaysia: post treatment by high quality limestone.  

Science.gov (United States)

This paper presents the results of research on heavy metals removal from water by filtration using low cost coarse media which could be used as an alternative approach to remove heavy metals from water or selected wastewater. A series of batch studies were conducted using different particle media (particle size 2.36-4.75 mm) shaken with different heavy metal solutions at various pH values to see the removal behaviour for each metal. Each solution of cadmium (Cd), lead (Pb), zinc (Zn), nickel (Ni), copper (Cu) and chromium (Cr(III)) with a concentration of 2 mg/L was shaken with the media. At a final pH of 8.5, limestone has significantly removed more than 90% of most metals followed by 80% and 65% removals using crushed bricks and gravel, respectively. The removal by aeration and settlement methods without solid media was less than 30%. Results indicated that the removal of heavy metals was influenced by the media and not directly by the pH. Investigations on the removal behaviour of these metals indicated that rough solid media with the presence of carbonate were beneficial for the removal process. Adsorption and precipitation as metals oxide and probably as metals carbonate were among the two mechanisms that contributed to the removal of metals from solution. PMID:17540556

Aziz, Hamidi A; Adlan, Mohd N; Ariffin, Kamar S

2008-04-01

148

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

Science.gov (United States)

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

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

2012-01-01

149

[Impact of compounded chelants on removal of heavy metals and characteristics of morphologic change in soil from heavy metals contaminated sites].  

Science.gov (United States)

Na2 EDTA (EDTA) has been extensively applied in remediation of soil contaminated by heavy metals (HMs). However, it poses a threat to the environment due to its difficulty of degradation. In addition, it is of great importance to clarify the morphological distribution of these metals in soil, as it is related to the environmental risk of contaminated sites. Thus, in order to cut back the use of EDTA, a series of batch washing experiments were conducted to evaluate the removal of arsenic, cadmium, copper, and lead from the contaminated soil collected in a chemical plant. Furthermore, adopting the optimal ratio of EDTA/EDDS, the change of morphological distribution of HMs before and after washing was studied. The results indicated that the removal of arsenic, cadmium and lead reached the maximum when the ratio of EDTA/EDDS was 7:3 and the optimal value was 12.67%, 38.71% and 31.09%, respectively. The removal of copper reached 16.91% at an EDTA/EDDS ratio of 9:1. After washing, the absolute Fe-Mn oxide fraction concentration of arsenic was higher, which would increase the environmental risk; the morphological fraction distribution of cadmium was similar to the original soil; the removal of copper and lead was mainly derived from the Fe-Mn oxide fraction; as to lead, the absolute concentration of Fe-Mn oxide fraction decreased dramatically, was and the same was observed for the percentage in the organic fraction. Employing the compounded system, the removal of HMs could be improved, and meanwhile the amounts of bioavailable HMs declined. Hence, it is beneficial for providing theoretical support for HMs remediation. PMID:24812971

Yin, Xue; Chen, Jia-Jun; Lü, Ce

2014-02-01

150

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

Digital Repository Infrastructure Vision for European Research (DRIVER)

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...

Lasheras-zubiate, M.; Fernandez, J. M.; Navarro-blasco, I.

2008-01-01

151

Removal of heavy metals from aqueous solution using platinum nanopartcles/Zeolite-4A  

Science.gov (United States)

The effects of varying operating conditions on metals removal from aqueous solution using a novel platinum nanopartcles/Zeolite-4A adsorbent are reported in this paper. Characterization of the adsorbent showed successful production of platinum nanopartcles on Zeolite-4A using 3 Wt% platinum. The effects of operation conditions on metals removal using this adsorbent were investigated. The optimal metals adsorption was observed at pH 7, 0.1 g/10 mL dosage and 30 min contact time. Sorption data have been interpreted in terms of Langmuir and Freundlich isotherms. PMID:24397886

2014-01-01

152

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

Directory of Open Access Journals (Sweden)

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.

K. Adouby

2007-01-01

153

Metal oxide/hydroxide-coated dual-media filter for simultaneous removal of bacteria and heavy metals from natural waters.  

Science.gov (United States)

The present study was conducted to compare the performance of a dual-media filter consisting of manganese oxide-coated (MOCS) and iron hydroxide-coated sand (IOCS) with that of IOCS filter and uncoated sand filter in treating water contaminated by microorganisms, heavy metals and turbidity with a view to its use in simple household water purification devices in developing countries. Long-duration column tests were conducted using two natural waters namely, roof-harvested rainwater and canal water. Performance of the filters showed that dual-media filter was more efficient in removing bacteria and heavy metals compared to IOCS filter, while uncoated sand filter showed very poor performance. The average effluent levels for dual-media filter when tested with rainwater were: turbidity 1.0+/-0.1 NTU; total coliforms 3+/-2 MPN/100 mL; heterotrophic plate count 170+/-20 CFU/mL; zinc 0.06+/-0.01 mg/L, while that for IOCS filter were: turbidity 1.0+/-0.1 NTU; total coliforms 4+/-2 MPN/100 mL; heterotrophic plate count 181+/-37 CFU/mL; zinc 0.20+/-0.07 mg/L. Similar results were obtained for canal water also. Up to 900 bed volumes (BV) could be treated without affecting the efficiency in the case of rainwater, while the filter operation had to be terminated after 500 BV due to excessive headloss in the case of canal water. The study thus showed the potential of the dual-media for use in low-cost household water filters for purification of natural waters. PMID:20566239

Ahammed, M Mansoor; Meera, V

2010-09-15

154

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

Science.gov (United States)

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

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

2013-11-01

155

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

DEFF Research Database (Denmark)

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

Pedersen, Anne Juul; Ottosen, Lisbeth M.

2005-01-01

156

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

International Nuclear Information System (INIS)

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

157

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)

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.

S. Gueu

2006-01-01

158

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

Digital Repository Infrastructure Vision for European Research (DRIVER)

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,...

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

2006-01-01

159

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

Digital Repository Infrastructure Vision for European Research (DRIVER)

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 condit...

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

2006-01-01

160

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

Energy Technology Data Exchange (ETDEWEB)

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.

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

1993-12-31

 
 
 
 
161

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

162

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

Science.gov (United States)

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

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

2008-08-15

163

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.

164

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

Energy Technology Data Exchange (ETDEWEB)

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

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

2008-06-30

165

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

166

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

Directory of Open Access Journals (Sweden)

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.

S. Ismail

2012-01-01

167

EVALUATION OF ION-EXCHANGE PROPERTIES OF FERRIC-HYDROXIDE FLOCS FOR THE REMOVAL OF HEAVY METAL WASTES USING A HIGH GRADIENT MAGNETIC SEPARATOR  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Preliminary adsorption studies showed no effect on the effluent heavy metals with a magnetite dose of 500 or 1000 mg/l but removal was lower when 200 mg/l of magnetite was used. Adsorption of metals onto ferric flocs was found to be independent of initial heavy metals concentration provided the surface available for adsorption of ions was not saturated. As surface area coverage approached saturation percent removal of heavy metals decreased. The pH of the medium was found to have a major infu...

Anand, Praveen

1984-01-01

168

Removal of heavy metal ions by iron oxide coated sewage sludge.  

Science.gov (United States)

The municipal sewage sludge was modified with iron oxide employed in metal ions removal. The surface modification method was proposed and the effect of parameters in the preparation was studied. The iron oxide coated sludge had higher surface area, pore volume and iron content, compared to uncoated sludge. The suitable conditions for removal of Cu(II), Cd(II), Ni(II) and Pb(II) ions from solutions were investigated using batch method. The suitable pH value in the extraction was 7 for adsorption of Cd(II) and Ni(II), 6 for Cu(II) and 5 for Pb(II) ions. The presence of NaNO(3), Ca(NO(3))(2) and Na(2)SO(4) in metal solution in the concentration of 0.01 M and 0.50 M could reduce the removal efficiency. The adsorption isotherms for the adsorption of the metal ions were defined by Langmuir relation. The maximum adsorption capacity of the iron oxide coated sludge for Cu(II), Cd(II), Ni(II) and Pb(II) was 17.3, 14.7, 7.8 and 42.4 mg g(-1), respectively. The adsorption kinetics for every metal ions followed pseudo-second order model. The metal removal from wastewater by iron oxide coated sludge was also demonstrated. PMID:21167637

Phuengprasop, Thapanapong; Sittiwong, Jarinya; Unob, Fuangfa

2011-02-15

169

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

Digital Repository Infrastructure Vision for European Research (DRIVER)

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...

Veeken, A. H. M.; Hamelers, H. V. M.

1999-01-01

170

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

Energy Technology Data Exchange (ETDEWEB)

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.

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

1995-12-31

171

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

Science.gov (United States)

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

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

2003-11-01

172

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.

173

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

Directory of Open Access Journals (Sweden)

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.

P. Lakshmanaperumalsamy

2011-01-01

174

Heavy metal removal from synthetic wastewaters in an anaerobic bioreactor using stillage from ethanol distilleries as a carbon source.  

Science.gov (United States)

This work was conducted to investigate the possibility of using stillage from ethanol distilleries as substrate for sulfate reducing bacteria (SRB) growth and to evaluate the removal efficiency of heavy metals present in wastewaters containing sulfates. The experiments were carried out in a continuous bench-scale Upflow Anaerobic Sludge Blanket reactor (13 l) operated with a hydraulic retention time of 18 h. The bioreactor was inoculated with 7 l of anaerobic sludge. Afterwards, an enrichment procedure to increase SRB numbers was started. After this, cadmium and zinc were added to the synthetic wastewater, and their removal as metal sulfide was evaluated. The synthetic wastewater used represented the drainage from a dam of a metallurgical industry to which a carbon source (stillage) was added. The results showed that high percentages of removal (>99%) of Cd and Zn were attained in the bioreactor, and that the removal as sulfide precipitates was not the only form of metal removal occurring in the bioreactor environment. PMID:17644156

Gonçalves, M M M; da Costa, A C A; Leite, S G F; Sant'Anna, G L

2007-11-01

175

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

Directory of Open Access Journals (Sweden)

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.

Xiaodong Zheng

2010-06-01

176

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

Science.gov (United States)

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.

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

177

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

Directory of Open Access Journals (Sweden)

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.

Abdouss Majid

2012-01-01

178

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

Directory of Open Access Journals (Sweden)

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

H. Tahir

2012-09-01

179

Effects of humic substances on the heavy metal removal and the phytotoxicity of pesticide  

Energy Technology Data Exchange (ETDEWEB)

Efficiency of humic (HA) or fulvic acid (FA) on the removal of Cu or Pb from aqueous solution and phytotoxicity of Paraquat were assessed using the principle of contaminant-ligand complexation. Increasing HA concentrations enhanced the efficiency of Cu or Pb removal, up to a critical ligand concentration capable of forming a maximum HA-metal complex. Removal efficiency ranged from 70 to 95% for Pb, but only 13 to 65% for Cu. HA of 100mg was estimated to complex with 7.5 mg of Cu and 34.1 mg of Pb. Fulvic acid removed nearly 100% of Pb, but only 13 to 29% of Cu. The reactions followed the first- or multiple first-order kinetics depending on the concentrations of metal and ligand, pH and temperature. Paraquat alone exerted a high degree of phytotoxicity at low concentration to the hydroponically grown rye (Secale cereale L.), but the presence of HA or FA decreased the Paraquat toxicity up to 40% and enhanced the yield and growth of rye up to 20% indicating that humic substances reduced the bioavailability of paraquat to rye due to the complexation.

Yang, J.E.; Shin, Y.K.; Rhee, H.I.; Kim, J.J. [Kangwon National Univ., Chuncheon (Korea, Republic of). Dept. of Agricultural Chemistry and Applied Biology and Technology

1995-12-31

180

Recovery and removal of heavy metals from aqueous solutions by pertraction  

Directory of Open Access Journals (Sweden)

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.

Baron Miroslav

1998-12-01

 
 
 
 
181

Removal of heavy metals from Water Rinsing of Plating Baths by Electrodialysis  

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Full Text Available During the chromic plating of parts, the baths become more and more poor in chromic acid and rich in metallic impurities such as Cu2+, Zn2+, Fe3+ and Cr3+ which makes the bath useless. Also, the water used to rinse parts contains chromic acid and metallic impurities. As it is known that chromic acid is relatively expensive and very toxic, so its recovery has double interest: economic and environmental. Its reuse is possible after removal of metallic impurities. In this work, we studied the possibility of metallic impurities elimination from the chromic acid. The influence of the current density and the circulating solution flow rate on the process efficiency has been studied. The elimination rates obtained in the presence of ion exchange textile are superior to those obtained in the absence of textile. The analysis of the results showed that for the three metallic impurities studied (Cu2+, Fe3+ and Zn2+, the purification rate increases versus the applied current density and solution flow rate. The importance of the elimination of the three metal cations is as the following order: Cu2+ >Zn2+ >Fe3+.

Delimi R.

2013-04-01

182

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

Scientific Electronic Library Online (English)

Full Text Available SciELO Chile | Language: English Abstract in english 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.

Nomanbhay, Saifuddin M; Palanisamy, Kumaran.

2005-04-15

183

Removal of heteroatoms and metals from heavy oils by bioconversion processes  

Energy Technology Data Exchange (ETDEWEB)

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.

Kaufman, E.N.

1996-06-01

184

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

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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.

Onyeji, L. I.

2011-12-01

185

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

Directory of Open Access Journals (Sweden)

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.

Nur Azreen Fuadi

2014-01-01

186

Removing heavy metals in water: the interaction of cactus mucilage and arsenate (As (V)).  

Science.gov (United States)

High concentrations of arsenic in groundwater continue to present health threats to millions of consumers worldwide. Particularly, affected communities in the developing world need accessible technologies for arsenic removal from drinking water. We explore the application of cactus mucilage, pectic polysaccharide extracts from Opuntia ficus-indica for arsenic removal. Synthetic arsenate (As (V)) solutions were treated with two extracts, a gelling extract (GE) and a nongelling extract (NE) in batch trials. The arsenic concentration at the air-water interface was measured after equilibration. The GE and NE treated solutions showed on average 14% and 9% increases in arsenic concentration at the air-water interface respectively indicating that the mucilage bonded and transported the arsenic to the air-water interface. FTIR studies showed that the -CO groups (carboxyl and carbonyl groups) and -OH (hydroxyl) functional groups of the mucilage were involved in the interaction with the arsenate. Mucilage activity was greater in weakly basic (pH 9) and weakly acidic (pH 5.5) pH. This interaction can be optimized and harnessed for the removal of arsenic from drinking water. This work breaks the ground for the application of natural pectic materials to the removal of anionic metallic species from water. PMID:22401577

Fox, Dawn I; Pichler, Thomas; Yeh, Daniel H; Alcantar, Norma A

2012-04-17

187

Organic matter and heavy metal removals from complexed metal plating effluent by the combined electrocoagulation/Fenton process.  

Science.gov (United States)

In the present study, the treatment of metal plating wastewater containing complexed metals originating from the nickel and zinc plating process by electrocoagulation (EC) using stainless steel electrodes was explored. In order to improve the organic matter removal efficiency, the effect of H(2)O(2) addition to the electrocoagulation (the combined EC/Fenton process) application was investigated. For this purpose, a wide range of H(2)O(2) concentrations varying between 15 and 230 mM was tested. All EC and EC/Fenton processes were performed at an initial pH of 2.6 and at an optimized current density of 22 mA/cm(2). Although up to 30 mM H(2)O(2) addition improved the EC process performance in terms of organic matter abatement, the highest COD and TOC removal efficiencies were obtained for the combined EC/Fenton process in the presence of 20 mM H(2)O(2). Nickel and zinc were completely removed for all runs tested in the present study after pH adjustments. At the optimized operation conditions, the combined EC/Fenton process proved to be an alternative treatment method for the improvement of organic matter reduction as well as complexed metal removal from metal plating industry wastewater. PMID:20453336

Kabda?li, I; Arslan, T; Arslan-Alaton, I; Olmez-Hanci, T; Tünay, O

2010-01-01

188

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

Science.gov (United States)

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

Singha, A S; Guleria, Ashish

2014-06-01

189

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

190

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

191

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

Energy Technology Data Exchange (ETDEWEB)

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.

Rodriguez, N.M.

2000-08-01

192

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)

193

High-density three-dimension graphene macroscopic objects for high-capacity removal of heavy metal ions.  

Science.gov (United States)

The chemical vapor deposition (CVD) fabrication of high-density three-dimension graphene macroscopic objects (3D-GMOs) with a relatively low porosity has not yet been realized, although they are desirable for applications in which high mechanical and electrical properties are required. Here, we explore a method to rapidly prepare the high-density 3D-GMOs using nickel chloride hexahydrate (NiCl?·6H?O) as a catalyst precursor by CVD process at atmospheric pressure. Further, the free-standing 3D-GMOs are employed as electrolytic electrodes to remove various heavy metal ions. The robust 3D structure, high conductivity (~12?S/cm) and large specific surface area (~560?m²/g) enable ultra-high electrical adsorption capacities (Cd²? ~ 434?mg/g, Pb²?~ 882?mg/g, Ni²? ~ 1,683?mg/g, Cu²? ~ 3,820?mg/g) from aqueous solutions and fast desorption. The current work has significance in the studies of both the fabrication of high-density 3D-GMOs and the removal of heavy metal ions. PMID:23821107

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

2013-01-01

194

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

Science.gov (United States)

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

Xu, Xiaoyun; Cao, Xinde; Zhao, Ling

2013-08-01

195

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

Science.gov (United States)

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 1M NaOH solution. Two different FA/NaOH solution/ratios (50, 100g/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. PMID:19765901

Koukouzas, Nikolaos; Vasilatos, Charalampos; Itskos, Grigorios; Mitsis, Ioannis; Moutsatsou, Angeliki

2010-01-15

196

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.

197

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

198

Removal of heavy metals from aqueous systems with thiol functionalized superparamagnetic nanoparticles.  

Science.gov (United States)

We have shown that superparamagnetic iron oxide (Fe3O4) nanoparticles with a surface functionalization of dimercaptosuccinic acid (DMSA) are an effective sorbent material for toxic soft metals such as Hg, Ag, Pb, Cd, and Tl, which effectively bind to the DMSA ligands and for As, which binds to the iron oxide lattices. The nanoparticles are highly dispersible and stable in solutions, have a large surface area (114 m2/g), and have a high functional group content (1.8 mmol thiols/g). They are attracted to a magnetic field and can be separated from solution within a minute with a 1.2 T magnet. The chemical affinity, capacity, kinetics, and stability of the magnetic nanoparticles were compared to those of conventional resin based sorbents (GT-73), activated carbon, and nanoporous silica (SAMMS) of similar surface chemistries in river water, groundwater, seawater, and human blood and plasma. DMSA-Fe3O4 had a capacity of 227 mg of Hg/g, a 30-fold larger value than GT-73. The nanoparticles removed 99 wt% of 1 mg/L Pb within a minute, while it took over 10 and 120 min for Chelex-100 and GT-73 to remove 96% of Pb. PMID:17711232

Yantasee, Wassana; Warner, Cynthia L; Sangvanich, Thanapon; Addleman, R Shane; Carter, Timothy G; Wiacek, Robert J; Fryxell, Glen E; Timchalk, Charles; Warner, Marvin G

2007-07-15

199

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

Energy Technology Data Exchange (ETDEWEB)

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.

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

200

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

Energy Technology Data Exchange (ETDEWEB)

The influence of initial cation concentration, temperature and pH was investigated to optimize Pb{sup 2+}, Cu{sup 2+} and Zn{sup 2+} removal from aqueous solutions using acid formaldehyde pre-treated chestnut shell as adsorbent. Experiments were planned according to an incomplete 3{sup 3} 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 Pb{sup 2+} ions, 8.5 mg g{sup -1}, and the order of cation affinity was Pb{sup 2+} > Cu{sup 2+} > Zn{sup 2+}. A model that considered the effect of axial dispersion was successfully used to describe the fixed-bed adsorption behaviour of Pb{sup 2+}, Cu{sup 2+} and Zn{sup 2+} 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.

Vazquez, Gonzalo, E-mail: gonzalo.vazquez@usc.es [School of Engineering, University of Santiago de Compostela, Rua Lope Gomez de Marzoa s/n, 15782 Santiago de Compostela (Spain); Calvo, Marcos, E-mail: norrisnoia@hotmail.com [School of Engineering, University of Santiago de Compostela, Rua Lope Gomez de Marzoa s/n, 15782 Santiago de Compostela (Spain); Sonia Freire, M., E-mail: mariasonia.freire@usc.es [School of Engineering, University of Santiago de Compostela, Rua Lope Gomez de Marzoa s/n, 15782 Santiago de Compostela (Spain); Gonzalez-Alvarez, Julia, E-mail: julia.gonzalez@usc.es [School of Engineering, University of Santiago de Compostela, Rua Lope Gomez de Marzoa s/n, 15782 Santiago de Compostela (Spain); Antorrena, Gervasio, E-mail: gervasio.antorrena@usc.es [School of Engineering, University of Santiago de Compostela, Rua Lope Gomez de Marzoa s/n, 15782 Santiago de Compostela (Spain)

2009-12-30

 
 
 
 
201

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

Science.gov (United States)

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.

Wang, Jianqiang; Luo, Chao; Qi, Genggeng; Pan, Kai; Cao, Bing

2014-10-01

202

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

Energy Technology Data Exchange (ETDEWEB)

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.

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

2013-09-15

203

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

Science.gov (United States)

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.

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

2011-12-01

204

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

Science.gov (United States)

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

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

2013-09-15

205

Factors affecting the removal of selected heavy metals using a polymer immobilised Sphagnum moss as a biosorbent.  

Science.gov (United States)

A hydrophilic polyurethane foam was used to immobilise dried sphagnum moss as a polymer/biomass matrix. This was then tested for its ability to remove Cu(II), Zn(II) and Pb(II) from aqueous solution. Further selected experiments using copper looked at factors which it was thought might affect the performance of the biosorbent. The optimum pH for Cu(II) and Zn(II) sorption was found to be in the range 6 - 7, whilst Pb(II) showed a more uniform sorption profile over the pH range 3 - 8. At pH values above 8 there was significant leaching of organic components from the immobilisation matrix. The immobilised biomass maintained around 90% of its sorption capacity over 10 repetitive cycles of sorption/desorption using HCl as a desorbent with typically > 95% metal ion recovery from each cycle. There were no marked differences in the maximum sorption capacities for Cu(II) using different biomass particle sizes in the immobilisation matrix, but the affinity of the immobilised biomass for Cu(II) decreased with increasing particle size. Alkali and alkaline-earth metal ions did not affect the heavy metal biosorption, but aluminium ion had a significant influence and itself could be adsorbed to a large extent. Acetic acid, urea, and carrageenan did not affect the maximum biosorption capacity of Cu(II), but carrageenan significantly reduced the affinity of biomass to metal ions probably as a result of its own biosorptive properties. PMID:16080329

Zhang, Y; Banks, C

2005-07-01

206

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

Science.gov (United States)

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" (CaCO(3)) 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. PMID:19733966

Ouhadi, V R; Yong, R N; Shariatmadari, N; Saeidijam, S; Goodarzi, A R; Safari-Zanjani, M

2010-01-15

207

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

Science.gov (United States)

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

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

2014-06-01

208

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

Directory of Open Access Journals (Sweden)

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

S. A. Mirbagheri, M. Salehi M

2006-10-01

209

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

Science.gov (United States)

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

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

210

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

Scientific Electronic Library Online (English)

Full Text Available SciELO Chile | Language: English Abstract in english 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).

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

2011-07-15

211

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

Science.gov (United States)

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

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

2014-06-14

212

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

DEFF Research Database (Denmark)

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

Kirkelund, Gunvor Marie; Ottosen, Lisbeth M.

2009-01-01

213

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

Science.gov (United States)

Electrodialytic remediation was used to remove heavy metals from a suspension of dredged harbour sediment. The studied metals Cu, Pb, Zn and Cd are normally strongly bound in anoxic sediment. Six electrodialytic laboratory remediation experiments were made, lasting 14 days and under oxic conditions. The influence on the metal removal was investigated by changing current densities and stirring velocity of the sediment suspension. Using a current density of 1.0 mA/cm(2) gave the highest metal removal. The sediment suspension was partly oxidised when mixed into a suspension for the electrodialytic remediation experiments and was further oxidised during the experiments. Even at low stirring velocities, oxic conditions were obtained. The metal removal was dependent on the achieved pH in the sediment and the highest metal removal and corresponding low pH was obtained by using a current density of 1.0 mA/cm(2) and a stirring velocity of the sediment suspension of 1000rpm. The highest removal obtained was 98% Cd, 78% Zn, 65% Pb and 44% Cu after 14 days of remediation. The metal removal was more dependent on the stirring velocity than on the current density. When manually stirring the sediment suspension or using a stirring velocity of 60 rpm the sediment deposited, which led to a slightly higher pH in the sediment and keeping all the sediment in suspension is essential for a successful remediation. PMID:19409702

Kirkelund, Gunvor M; Ottosen, Lisbeth M; Villumsen, Arne

2009-09-30

214

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

Directory of Open Access Journals (Sweden)

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

María C. Ponce-Caballero

2012-08-01

215

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

Science.gov (United States)

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.

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

216

Heavy metals precipitation in sewage sludge  

Digital Repository Infrastructure Vision for European Research (DRIVER)

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

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

2005-01-01

217

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

Science.gov (United States)

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

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

2008-07-01

218

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

DEFF Research Database (Denmark)

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.

Ferreira, Célia Maria Dias; Jensen, Pernille Erland

2005-01-01

219

Heavy metals and lysosomes.  

Science.gov (United States)

Much can be gained by reassessing the processes which determine the ability of lysosomes to take up or exclude, sequester and mobilize heavy metals. To achieve a better understanding of these events, the chemical forms, intracellular pathways and modes of delivery of metals to lysosomes, as well as the specific physiologic ligands and molecular targets susceptible to metal toxicity have to be identified. None of these can be derived from measurements of metal contents of whole lysosomal fractions because the metal's "effective concentration" at a specific target site may be affected by the binding properties of the lysosomal ligand as well as by those of cation carrier proteins present in the cytosol (e.g., metallothionein), and by interactions with and competitions by other cellular organelles. Therefore, the possibility of such events diminishing or enhancing a metal's direct effect observable in in vitro systems has to be considered before extrapolating to the in vivo situation. Another pitfall to be wary of is the equation of an organelle's relative affinity for a metal in vitro with its susceptibility to the metal's toxic effects. This is evident, albeit at a tissue level rather than at that of organelles, from the discordance between the low affinity of nervous tissue for lead and this metal's pronounced encephalopathic effect. The answers to some of the questions raised in this review may possibly lead to pharmacologic applications, particularly to the development of effective agents for the removal from or the inactivation of toxic metals deposited in lysosomes. At present, considerable uncertainty exists regarding the possible interaction of therapeutic chelating agents with lysosomes in vivo. We do not know, for example, whether the contrasts between the remarkable effectiveness of penicillamine in mobilizing copper from tissues and the limited effectiveness of desferioxamine in removing excess iron stores can be accounted for by differences in accessibility of these two chelators to lysosomes. Or, alternatively, can these differences in effectiveness be related to different ligands or macromolecules interacting with each metal? At least part of the lysosomal iron is bound to ferritin molecules which may not be susceptible to the action of chelating agents after incorporation. Such speculation is not without foundation since ferritin molecules are heterogeneous. However, whether this heterogeneity, which is reflected in different organ-specific patterns of distribution (Powell et al. 1973), is the result of differing affinities of the isoferritins for specific subcellular organelles has not been established. It is conceivable that ferritin molecules present in the cytoplasm may be subtly different from those taken up by lysosomes, implying that the latter are endowed with capabilities for selection of specific macromolecules... PMID:789127

Sternlieb, I; Goldfischer, S

1976-01-01

220

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

Digital Repository Infrastructure Vision for European Research (DRIVER)

The environment is under increasing pressure from solid and liquid wastes emanating from the leather industry. These areinevitable by-products of the leather manufacturing process and causes significant pollution unless treated in some way prior todischarge. The tanneries wastes samples were collected from Lahore Pakistan. The samples were digested by wet oxidationmethod and the concentrations of metals: Cr, Co, Cu, Cd, Mn, Zn, Ni and Pb were estimated in sediments and liquid wastesamples by ...

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

2012-01-01

 
 
 
 
221

Application of zeolite prepared from Egyptian kaolin for the removal of heavy metals: II. Isotherm models.  

Science.gov (United States)

In this study, the adsorption behavior of zeolites A and X, which are prepared from very cheap local Egyptian clay (kaolin), with respect to Cu(2+), Cd(+2), Cr(+2), Ni(+2) and Zn(2+) has been studied. The batch method has been employed, using metal solutions ranging from 100 to 400 mg/L. The distribution coefficients (K(d)) and adsorption percent were determined for the adsorption system as a function of sorbate concentration. In the uptake evaluation part of the study, adsorption ratios of metal cations on zeolites A and X match to Langmuir, Freundlich, and Dubinin-Kaganer-Radushkevich (DKR) adsorption isotherm data. Also, every cation exchange capacity for metals has been calculated. According to the equilibrium studies, the selectivity sequence can be given as Pb(2+)>Cd(2+)>Cu(2+)>Zn(2+)>Ni(2+). It was found that the uptake depend on hydrated ion diameter. This study may attract more interest due to the presence of large reservoirs of very cheap kaolin in Egypt from which both zeolite types were prepared. PMID:20655657

Ibrahim, Hanan S; Jamil, Tarek S; Hegazy, Eman Z

2010-10-15

222

Heavy Metals Removal in Aqueous Solution by two Delta-diketones  

Directory of Open Access Journals (Sweden)

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

D. Fanou

2007-01-01

223

Preparation of organic-inorganic composite adsorbent beads for removal of radionuclides and heavy metal ions  

International Nuclear Information System (INIS)

Composite ion exchanger beads were prepared to remove the strontium and silver ions in acidic solution. Potassium titanate and nickelferrocyanate powder, which are acid resistant inorganic ion exchangers were synthesized and then mixed with polyacrylonitrile (PAN) binder to form a PAN-potassium titanate and a PAN-nickelferrocyanate composite ion exchanger beads. Spherical composite beads could be obtained by adjusting the viscosities of the composite dope in the range of 700-1000 cP. The composite beads porosities such as macropore volume and pore size were increased in proportion to the contents of PVP (polyvinylpyrrolidone) which was used as the porosity modifying chemical. The synthesized composite ion exchangers were evaluated on their adsorption characteristics for the Ag+ and Sr2+ ion solutions of pH 2. (author)

224

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

Energy Technology Data Exchange (ETDEWEB)

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

Kaufman, E N; Borole, A P

1999-03-01

225

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

Scientific Electronic Library Online (English)

Full Text Available SciELO Chile | Language: English Abstract in english 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.

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

2010-07-15

226

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

Directory of Open Access Journals (Sweden)

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

Babak Samiey

2014-01-01

227

Removal of Heavy Metal Ions and Diethylenetriamine Species from Solutions by Magnetic Activated Carbon  

Science.gov (United States)

Even though activated carbon is widely used in the removal of contaminants from effluents, it is difficult to be completely recovered by screening or classification. In this project, we prepared a magnetic form of activated carbon (M-AC) by co-precipitation of iron oxides onto activated carbon surface. M-AC can be separated from solutions by applying an external magnetic field and regenerated for reuse. The synthesized M-AC was characterized by X-ray diffraction, specific surface area measurement, and scanning electron microscope. Characterization results show that the major phase of coated iron oxides is magnetite (Fe 3O4). Batch adsorption experiments were carried out for single-component and multi-component solutions. M-AC shows a better adsorption capacity for singlecomponent of Cu (II), Ni (II), or diethylenetriamine (DETA) and for multiple-components of Cu-DETA and Ni-DETA complexes in deionized water than activated carbon. M-AC also shows the potential application in carbon-in-pulp process for gold recovery.

Liu, Kaiwen

228

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)

229

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)

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+.

Jaber SALEHZADEH

2013-11-01

230

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

Digital Repository Infrastructure Vision for European Research (DRIVER)

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...

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

2011-01-01

231

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

Science.gov (United States)

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

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

2009-06-01

232

COPRECIPITATION AND ADSORPTION FOR REMOVAL OF CADMIUM, LEAD, AND ZINC BY THE LIME - SODA ASH WATER SOFTENING PROCESS (CRYSTALLIZATION, HEAVY METAL, CALCIUM-CARBONATE)  

Digital Repository Infrastructure Vision for European Research (DRIVER)

The crystallization kinetics for the precipitation of calcium carbonate and magnesium hydroxide in the presence of cadmium, lead, and zinc were studied. The kinetics for the precipitation have been studied in a continuous reactor operated under MSMPR (mixed suspension mixed product removal) conditions. Reactor residence times, effluent alkalinity conditions, and initial heavy metal concentrations (acting as impurity) were varied to determine these kinetics. The crystal size distribution was m...

Chang, Tsun-kuo

1985-01-01

233

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

Digital Repository Infrastructure Vision for European Research (DRIVER)

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...

S A Mirbagheri, M. Salehi M.

2006-01-01

234

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.

235

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

236

Removal of toxic heavy metal ions from waste water by functionalized magnetic core-zeolitic shell nanocomposites as adsorbents.  

Science.gov (United States)

Functionalized magnetic core-zeolitic shell nanocomposites were prepared via hydrothermal and precipitation methods. The products were characterized by vibrating sample magnetometer, X-ray powder diffraction, Fourier transform infrared spectroscopy, nitrogen adsorption-desorption isotherms, and transmission electron microscopy analysis. The growth of mordenite nanocrystals on the outer surface of silica-coated magnetic nanoparticles at the presence of organic templates was well approved. The removal performance and the selectivity of mixed metal ions (Pb(2+) and Cd(2+)) in aqueous solution were investigated via the sorption process. The batch method was employed to study the sorption kinetic, sorption isotherms, and pH effect. The removal mechanism of metal ions was done by chem-phys sorption and ion exchange processes through the zeolitic channels and pores. The experimental data were well fitted by the appropriate kinetic models. The sorption rate and sorption capacity of metal ions could be significantly improved by optimizing the parameter values. PMID:23184130

Padervand, Mohsen; Gholami, Mohammad Reza

2013-06-01

237

Heavy transition metals  

International Nuclear Information System (INIS)

Consideration is given to results of studies on magnetochemistry of coordination compounds of various compositions of heavy transition metals, including Mo(3), Ru(3), Re(4). It is noted that 4d- and 5d-metals are characterized by high value of spin-orbital interaction, which complicates magnetic properties of ions. 4 refs.; 1 tab

238

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

Energy Technology Data Exchange (ETDEWEB)

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

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

2009-06-15

239

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.

240

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

 
 
 
 
241

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)

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

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

242

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)

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

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

2013-06-01

243

Influence of pH on removal of heavy metallic cations by fly ash in aqueous solution  

Energy Technology Data Exchange (ETDEWEB)

Coal fly ash was used to study adsorption of several cations (Cu{sup 2+}, Ni{sup 2+}, Zn{sup 2+}, Cd{sup 2+}, Pb{sup 2+}, Cr (III)) within various experimental conditions: dry or wet fly ash, constant or not constant pH, metallic ion/fly ash mass ratio varying from 0.005 to 0.05. It was shown that alkalinity of fly ash, increasing pH to 11 for a fly ash concentration equal to 20 g l{sup -1} leads to higher removal capacity, due partly to bulk solution precipitation. Wet fly ash gives smaller adsorption capacity resulting from lost alkalinity and dissolution of alumina sites at pH 11. Removal order established in non-constant pH condition is: Pb {gt} Cu {gt} Ni {gt} Zn. Experiments carried out at several constant pH levels indicate that sorption capacities for metallic ions increase from 10%, or 40% to 100% when pH varies from 1 to 10. The removal order is: pH {gt} Cr {gt} Cu {gt} Ni {gt} Zn {gt} Cd. It was concluded that two groups of metallic cations should be distinguished: hydrolysing (CU{sup 2+}, Pb{sup 2+}) and non-hydrolysing (Ni{sup 2+}, Zn{sup 2+}). Lead, nickel, zinc and cadmium are certainly adsorbed in their free ionic form, even when both hydroxide species and free ionic forms are responsible for the removal of copper and chromium. However, removal affinity order separates easily hydrolyzable ions from less hydrolyzable ions.

Ricou, P.; Lecuyer, I.; Lecloirec, P. [Ecole des Mines de Nantes, Nantes (France)

1998-10-01

244

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

International Nuclear Information System (INIS)

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

245

Results of a SITE demonstration of the COGNIS Terramet{reg_sign} lead extraction process to remove heavy metals from soil  

Energy Technology Data Exchange (ETDEWEB)

The COGNIS, Inc. Terramet{reg_sign} process is a chemical process that extracts and recovers lead and other metals from contaminated soil, dust, sludge, or sediment. The process begins by removing and washing oversize material and then separating the remaining soil into sands and fines fractions. The sands fraction is further treated by density separation methods to isolate particulate metals as a concentrate. The sands and fines fractions are then separately leached in the Terramet{reg_sign} portion of the process by a proprietary leachant to bring fine metallic particles and ionic metals into solution. Leached metals are recovered through proprietary reductive electrochemical cells, producing a metal concentrate and regenerating the leachant for recycling. Clean soil exiting the system can be returned to the site. The recovered metals are recyclable. No wastewater streams are generated during process operations. The COGNIS, Inc. Terramet{reg_sign} process was selected to remediate approximately 10,000 tons of heavy-metal (predominantly lead) contaminated soil at the Twin Cities Army Ammunition Plant (TCAAP), New Brighton, Minnesota. EPA`s Superfund Innovative Technology Evaluation (SITE) program is currently evaluating the COGNIS, Inc. Terramet{reg_sign} process. The evaluation included a 4-day sampling effort (August 2-5, 1994) during the TCAAP remediation. The SITE sampling effort focussed primarily on determining the effectiveness of the leaching processes for removing lead from both the sands and the fines fractions of the soil. Other results that will be reported as part of the evaluation include overall effectiveness of lead removal, efficiency of lead recovery cells, and costs.

Banerjee, P. [PRC Environmental Management, Inc., Rolling Meadows, IL (United States); Royer, M.D. [Environmental Protection Agency, Edison, NJ (United States)

1995-10-01

246

Preparation of hybrid CaCO 3-pepsin hemisphere with ordered hierarchical structure and the application for removal of heavy metal ions  

Science.gov (United States)

In this paper, a simple way for preparation of hybrid CaCO 3-pepsin material with ordered hierarchical structure was reported. It could be observed that the nanoparticles self-assembled into a lot of tetrahedral calcite crystals, which assembled into highly ordered surfaces of hemisphere-shaped CaCO 3 with hierarchical structures. These products were characterized by X-ray powder diffraction (XRD), Scanning electron microscope (SEM), High resolution transmission electron microscopy (HRTEM), Fourier transform infrared (FT-IR) spectroscopy, thermogravimetry-differential thermal analyses (TG-DTA) and photoluminescence (PL). A rational mechanism was proposed for the formation of hybrid CaCO 3-pepsin material ordered hierarchical structure. Functional study using the hybrid CaCO 3-pepsin material as an adsorbent for removal of heavy metal ions demonstrates that its distinguishing features in water treatment involve not only high removal capacities, but also decontamination of trace ions. The acquired experimental data show that both the functional and hierarchical structural features of hybrid CaCO 3-pepsin material provide a promising adsorbent for removal of heavy metal ions.

Ma, Xiaoming; Li, Liping; Yang, Lin; Su, Caiyun; Wang, Kui; Jiang, Kai

2012-01-01

247

Mushrooms store heavy metals  

International Nuclear Information System (INIS)

Heavy metals like lead and cadmium, but also radioactive cesium are accumulated in varying degrees by different types of mushrooms. So those mushrooms are suitable biological indicators of the load of these pollutants in the soil, and complement physical and chemical measurements. The article is about measurements and effects in biological objects. (orig./PW)

248

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

Energy Technology Data Exchange (ETDEWEB)

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

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

1999-11-01

249

Kinetic study of liquid-phase adsorptive removal of heavy metal ions by almond tree (Terminalia catappa L. leaves waste  

Directory of Open Access Journals (Sweden)

Full Text Available The kinetic sorption of five metal ions – Al3+, Cr6+, Zn2+, Ag+ and Mn2+- from aqueous solution onto almond tree leaves (ATL waste in single component system has been studied. The experimental data was analyzed in terms of intraparticle diffusion and rate of adsorption, thus comparing transport mechanism and chemical sorption processes. The sorption rates based on the pseudo-second order rate constants for the five metal ions are 0.018 (Al3+, 0.016 (Cr6+, 0.023 (Zn2+, 0.021 (Ag+ and 0.022 (Mn2+ g/mg.min. The adsorption rates are rapid and within 180 min of agitation more than 85 percent of these metal ions has been removed from solution by the ATL waste biomass. The kinetic data suggest that the overall adsorption process is endothermic, and that the rate-limiting step is a surface diffusion controlled process. The results from this study have revealed that the ATL waste, which is hitherto an environmental nuisance, has the ability to adsorb metal ions from solution and the data are relevant for optimal design of wastewater treatment plants. The low cost and easy availability of ATL waste make potential industrial application a strong possibility.

Michael Horsfall Jnr

2007-04-01

250

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)

251

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

Directory of Open Access Journals (Sweden)

Full Text Available 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 of As (III to As (V so the adsorption process was investigated at pH range 2-8. The batch experiments were revealed that adsorption of As ion on Nigella sativa L. was maximal at low pH (at a 3.0 value. The adsorption studies revealed that the ongoing adsorption validates Langmuir adsorption isotherms at temperatures 25, 35 and 45°C. The adsorption isotherm data was also employed to calculate the thermodynamic parameter of Gibb’s free energy which gives a negative value for the adsorption of As ion on Nigella sativa L. The negative values of free energy indicate the feasibility and spontaneous nature of the adsorption process. From these results, it can be concluded that the Nigella sativa L. could be a good adsorbent for the removal of cationic metals coming from waste water.

S.M. El-Said

2009-01-01

252

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.

253

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

Science.gov (United States)

Complexing agents are extensively applied in many fields of industry. They are used to provide effective controlling trace metal ions in cleaning industries, textile, pulp and paper production, water treatment, agriculture, food industries, etc. Recently, the low biodegradability of these ligands and their accumulation in the environment has become a cause for concern. Therefore, replacement of ethylenediaminetetraacetic acid and diethylenetriaminepentaacetic acid by more environmentally friendly chelating agents is highly desirable. So far, these acids and their salts have been applied as components of household chemistry, cosmetics, modern microelement fertilizers and agrochemicals. This paper reviews the sorption of heavy metal ions such as Cu(II), Zn(II), Cd(II) and Pb(II) in the presence of the above-mentioned complexing agents on commercially available anion exchangers of different matrix. The obtained sorption results were fitted using the Langmuir and Freundlich sorption isotherm models. The kinetic data were also analysed using the Lagergren, Ho and McKay sorption kinetic equations. The studies were carried out considering the effects of such important parameters as phase contact time, initial concentration, pH and temperature. PMID:23463276

Ko?ody?ska, Dorota

2013-09-01

254

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

Digital Repository Infrastructure Vision for European Research (DRIVER)

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 reacti...

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

2009-01-01

255

Heavy metal: musiikkia vai elämäntapa?  

Digital Repository Infrastructure Vision for European Research (DRIVER)

My thesis is an ontological description about Heavy Metal music and culture. The thesis is contemplating about what Heavy Metal is and what it means to its listeners. The thesis also handles different historical eras. The thesis is accomplished independently without any subscribers. I have used document movies, literature and social media as sources. Is Heavy Metal just music or is it a larger-than-life institution for its listeners? The research will show that some people like Heavy Met...

Rimbacher, Niko

2010-01-01

256

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

International Nuclear Information System (INIS)

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

257

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

Science.gov (United States)

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

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

2013-10-21

258

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

Science.gov (United States)

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

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

2007-01-01

259

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.

260

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

Energy Technology Data Exchange (ETDEWEB)

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

Sakai, Takaaki; Ohshima, Hiroyuki; Yamaguchi, Akira [Japan Nuclear Cycle Development Inst., Oarai, Ibaraki (Japan). Oarai Engineering Center; Iwasaki, Takashi [Nuclear Energy System Inc., Tokyo (Japan)

2000-04-01

 
 
 
 
261

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

International Nuclear Information System (INIS)

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

262

Process for separating heavy metals from waste water. Verfahren zum Entziehen von Schwermetallen aus Abwaessern  

Energy Technology Data Exchange (ETDEWEB)

A method for the elimination of heavy metals from waste water removes the heavy metals concerned, by treating the waste water containing heavy metals with a water-soluble trithiocarbonate, especially with an alkaline metal trithiocarbonate such as sodium trithiocarbonate (Na{sub 2}CS{sub 3}) in order to precipitate the heavy metals from it. (orig.).

Elfline, G.S.

1987-01-02

263

Ion exchange extraction of heavy metals from wastewater sludges.  

Science.gov (United States)

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

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

2004-01-01

264

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

Energy Technology Data Exchange (ETDEWEB)

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

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

2012-08-15

265

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

Science.gov (United States)

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

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

2013-01-01

266

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)

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.

Jesús Mora Molina

2012-11-01

267

Phytoremediation of heavy-metal-polluted soils: screening for new accumulator plants in Angouran mine (Iran) and evaluation of removal ability.  

Science.gov (United States)

Heavy metal pollution is a worldwide problem. Phytoremediation is an effective and low-cost interesting technology. This study was conducted in a dried waste pool of a lead and zinc mine in Angouran (Iran) to find accumulator plant(s). Concentrations of heavy metals were determined both in the soil and the plants that were grown in the mine and out of mine. The concentration of total Cu, Fe, Zn, Pb and Ni in the mine area were higher than the control soil. The results showed that five dominant vegetations namely Amaranthus retroflexus, Polygonum aviculare, Gundelia tournefortii, Noea mucronata and Scariola orientalis accumulated heavy metals. Based on the results, it was concluded that N. mucronata is the best accumulator for Pb, Zn, Cu, Cd and Ni, but the best Fe accumulator is A. retroflexus. Phytoremediation ability of N. mucronata was evaluated in experimental pots. The study showed that the amounts of heavy metals were decreased in polluted soils during experiments. The accumulation of metals in the root, leave and shoot portions of N. mucronata varied significantly but all the concentrations were more than natural soils. The results indicated that N. mucronata is an effective accumulator plant for phytoremediation of heavy-metals-polluted soils. PMID:19386362

Chehregani, Abdolkarim; Noori, Mitra; Yazdi, Hossein Lari

2009-07-01

268

Heavy Metal Pumps in Plants  

Energy Technology Data Exchange (ETDEWEB)

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

Harper, J.F.

2000-10-01

269

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

Science.gov (United States)

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 (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. PMID:18687522

Aziz, Abdellah; Ouali, Mohand Said; Elandaloussi, El Hadj; De Menorval, Louis Charles; Lindheimer, Marc

2009-04-15

270

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

Energy Technology Data Exchange (ETDEWEB)

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.

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

271

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

272

Effect of two heavy metals, cadmium and nickel, on the organic load removal efficiency in a laboratory UASB reactor  

International Nuclear Information System (INIS)

Experiments were carried out in three up flow anaerobic sludge blanket, UASB, reactors each with 3 L capacity, four hours of hydraulic retention time, (HRT) and volumetric organic load of 4,8 g/L/d. After the initial start phase, which was of 4.000 hours for the three reactors, they were affected in the following way: the first reactor was continuously feed with 5 mg/L of cadmium chloride, the second one was continuously feed with 10 mg/L of nickel chloride and the last one was not affected and served as reference. Efficiency in organic load removal was measured as oxygen chemical demand (OCD), the first reactor changed from 60% in the start phase (phase one) to 18% in the cadmium-affected phase (phase two), efficiency in removal (OCI) in reactor two varied from 60 to 24% and the last one did not change in a noticeable manner. Reactor one accumulated cadmium in the mud, whereas reactor two did not do that with nickel

273

Metals removal from spent salts  

Science.gov (United States)

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

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

274

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)

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.

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

275

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

International Nuclear Information System (INIS)

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

276

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

Science.gov (United States)

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

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

2013-08-15

277

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

DEFF Research Database (Denmark)

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

Ottosen, Lisbeth M.; Pedersen, Anne Juul

2007-01-01

278

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

International Nuclear Information System (INIS)

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

279

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

Energy Technology Data Exchange (ETDEWEB)

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

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

2013-02-25

280

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

International Nuclear Information System (INIS)

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

 
 
 
 
281

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

Scientific Electronic Library Online (English)

Full Text Available SciELO Portugal | Language: English Abstract in english 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+

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

282

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

Directory of Open Access Journals (Sweden)

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+

S.A. Shama

2010-01-01

283

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

284

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

Science.gov (United States)

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

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

2008-04-01

285

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)

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

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

286

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)

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+.

S.A. Shama

2010-01-01

287

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, ...

288

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

289

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

290

Metals Removal from Recovered base Oil using Chitosan Biopolymers  

Directory of Open Access Journals (Sweden)

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.

A. Ahmad

2010-01-01

291

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

Digital Repository Infrastructure Vision for European Research (DRIVER)

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 stu...

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

2007-01-01

292

Heavy metals in air depositions  

International Nuclear Information System (INIS)

A new way to calculate critical pollutant loads is presented. This paper describes a methodological approach, including modelling procedure, for assessing the critical loads of heavy metals and the findings produced by a monitoring programme designed to establish the amount of several heavy metals (Cd, Cr, Cu, Ni, Pb, Zn) resulting from wet and dry deposition. An innovative system is used to collect cry deposits at a sampling located in Northern Italy (Bologna urban area, Italy). Rating total deposition flows against critical loads makes it possible to identify exceedence areas

293

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

Directory of Open Access Journals (Sweden)

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

Eduardo Soto

2006-01-01

294

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)

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.

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

295

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.

296

Heavy metals hyper accumulation in plants; Le piante come decontaminanti ambientali dai metalli pesanti  

Energy Technology Data Exchange (ETDEWEB)

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.

Sanita` di Toppi, L.; Gabbrielli, L. [Florence, Univ. (Italy). Dipt. di Biologia Vegetale. Lab. di Fisiologia

1998-03-01

297

FINAL REPORT. NEW STRATEGIES FOR DESIGNING BIOADSORBANTS FOR METAL REMOVAL: SELECTION OF ANTIBODIES AND PEPTIDES WITH HIGH SPECIFICITY FOR HEAVY METALS AND THEIR CELL SURFACE EXPRESSION  

Science.gov (United States)

The broad, long term objective of the research plan is to develop exquisitely selective polypeptide metal chelators for the remediation of aqueous systems. A variety of polypeptide chelators will be developed and optimized ranging from antibodies to small peptides. Then, through ...

298

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

Energy Technology Data Exchange (ETDEWEB)

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

Fan, Huan Jung; Anderson, P.R.

1995-12-31

299

Heavy Metal Concentrations in Predator Fish  

Digital Repository Infrastructure Vision for European Research (DRIVER)

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,...

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

2011-01-01

300

Phytoremediation of Heavy Metals in Aqueous Solutions  

Directory of Open Access Journals (Sweden)

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.

Felix Aibuedefe AISIEN

2010-12-01

 
 
 
 
301

Short-term uptake of heavy metals by periphyton algae  

Energy Technology Data Exchange (ETDEWEB)

The utilization of periphyton for the removal of heavy metals from enriched small streams has been examined. By means of short-term batch laboratory experiments the courses of metal uptake have been studied. For uptake study naturally growing periphyton community and periphytic filamentous algae Cladophora glomerata and Oedogonium rivulare have been used. Uptakes of nine heavy metals (Pb, Cd, Cu, Co, Cr, Ni, Zn, Fe and Mn) have been determined during four hours exposure. In addition the influence of humic substances on heavy metals uptake has been determined. Uptake of all metals increased during four hours exposure but not in the same way. Some metals were removed continuously (Ni, Cr, Fe and Mn), other metals were removed more rapidly during the first hour or first two hours of exposure and then only slight removal continued (Cu, Pb, Cd, Co). Uptake of Zn was rather unambiguous. Results of these experiments suggest that the course of uptake for individual metals could be similar for most periphyton algae. It was established that humic substances significantly reduce heavy metals uptake. The highest decrease of uptake was observed in Cu, Cr, Co and Cd. The results of model experiments are being tested in a pilot scale with respect to the demands of engineering practice. (J.R.)

Vymazal, J.

1984-12-31

302

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

303

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.

304

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)

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.

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

305

Study on Biosorption of Heavy Metals by Modified Lignocellulosic Waste  

Digital Repository Infrastructure Vision for European Research (DRIVER)

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...

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

2011-01-01

306

Mosses accumulate heavy metals from the substrata of coal ash  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Plants that are able to accumulate and tolerate extraordinarily high concentrations of heavy metals (hyperaccumulators) can be used for phytoremediation (removal of contaminants from soils) or phytomining (growing a crop of plants to harvest the metals). Two moss species, Bryum capillare Hedw. and Ceratodon purpureus Hedw., were tested as potential phytoremedies under in vivo conditions on a coal ash disposal site in the surroundings of Obrenovac (NW Serbia). The content of various heavy meta...

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

2005-01-01

307

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

Science.gov (United States)

Wastewater particularly from electroplating, paint, leather, metal and tanning industries contain enormous amount of heavy metals. Microorganisms including fungi have been reported to exclude heavy metals from wastewater through bioaccumulation and biosorption at low cost and in eco-friendly way. An attempt was, therefore, made to isolate fungi from sites contaminated with heavy metals for higher tolerance and removal of heavy metals from wastewater. Seventy-six fungal isolates tolerant to heavy metals like Pb, Cd, Cr and Ni were isolated from sewage, sludge and industrial effluents containing heavy metals. Four fungi (Phanerochaete chrysosporium, Aspegillus awamori, Aspergillus flavus, Trichoderma viride) also were included in this study. The majority of the fungal isolates were able to tolerate up to 400 ppm concentration of Pb, Cd, Cr and Ni. The most heavy metal tolerant fungi were studied for removal of heavy metals from liquid media at 50 ppm concentration. Results indicated removal of substantial amount of heavy metals by some of the fungi. With respect to Pb, Cd, Cr and Ni, maximum uptake of 59.67, 16.25, 0.55, and 0.55 mg/g was observed by fungi Pb3 (Aspergillus terreus), Trichoderma viride, Cr8 (Trichoderma longibrachiatum), and isolate Ni27 (A. niger) respectively. This indicated the potential of these fungi as biosorbent for removal of heavy metals from wastewater and industrial effluents containing higher concentration of heavy metals. PMID:23024411

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

2011-10-01

308

Heavy metals adsorption on rolling mill scale  

International Nuclear Information System (INIS)

A great quantity of industries are responsible for contaminating the environment with the heavy metals which are containing in their wastewaters. The recovery of these metals is both from an environmental and economical points of view of the upmost interest. A study is made of the use of mill scale-originating in the hot rolling of steel-as an adsorbent for the removal of heavy metals from liquid effluents. The adsorption of Zn''2+, Cd''2+ y Pb''2+ on the rolling mill scale was investigated by determination of adsorption isotherms. The effect of time, equilibrium temperature and concentration of metal solution on mill scale adsorption efficiency was evaluated. The adsorption process was analysed using the theories of Langmuir and Freundlich. Desorption process of metals from loaded mill scales was also studied using several doser bent at different experimental conditions. It has been proved that the mill scale is an effective adsorbent for the cations studies in aqueous solutions within the range of the working concentrations. (Author) 32 refs

309

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

Digital Repository Infrastructure Vision for European Research (DRIVER)

This study evaluated the efficacy of moringa seeds (Moringa oleifera Lam.) as an adsorbent material for removing toxic heavy metals such as cadmium, lead, and chromium from contaminated solutions. The effect of the adsorbent mass was investigated at two pH conditions (5.0 and 7.0). The optimized conditions were 0.300 g of adsorbent at pH 5.0, used for the isotherms construction, and linearized according to Langmuir and Freundlich models. Results showed that cadmium adsorption was similar in b...

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

2013-01-01

310

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)

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

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

2014-01-01

311

Biosolids and heavy metals in soils  

Directory of Open Access Journals (Sweden)

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.

Silveira Maria Lucia Azevedo

2003-01-01

312

Adsorption of Heavy Metal from Recovered base Oil using Zeolite  

Digital Repository Infrastructure Vision for European Research (DRIVER)

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...

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

2010-01-01

313

The influence of heavy metals on the production of extracellular polymer substances in the processes of heavy metal ions elimination.  

Science.gov (United States)

Wastewaters from a chemical industry polluted by heavy metal ions represent a hazard for all living organisms. It can mean danger for ecosystems and human health. New methods are sought alternative to traditional chemical and physical processes. Active elimination process of heavy metals ions provided by living cells, their components and extracellular products represents a potential way of separating toxic heavy metals from industrial wastewaters. While the abilities of bacteria to remove metal ions in solution are extensively used, fungi have been recognized as a promising kind of low-cost adsorbents for removal of heavy-metal ions from aqueous waste sources. Yeasts and fungi differ from each other in their constitution and in their abilities to produce variety of extracellular polymeric substances (EPS) with different mechanisms of metal interactions. The accumulation of Cd(2+), Cr(6+), Pb(2+), Ni(2+) and Zn(2+) by yeasts and their EPS was screened at twelve different yeast species in microcultivation system Bioscreen C and in the shaking Erlenmayer's flasks. This results were compared with the production of yeast EPS and the composition of yeast cell walls. The EPS production was measured during the yeast growth and cell wall composition was studied during the cultivations in the shaking flasks. At the end of the process extracellular polymers and their chemical composition were isolated and amount of bound heavy metals was characterized. The variable composition and the amount of the EPS were found at various yeast strains. It was influenced by various compositions of growth medium and also by various concentrations of heavy metals. It is evident, that the amount of bound heavy metals was different. The work reviews the possibilities of usage of various yeast EPS and components of cell walls in the elimination processes of heavy metal ions. Further the structure and properties of yeasts cell wall and EPS were discussed. The finding of mechanisms mentioned above is necessary to identify the functional groups entered in the metals elimination processes. PMID:16459787

Mikes, J; Siglova, M; Cejkova, A; Masak, J; Jirku, V

2005-01-01

314

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

Scientific Electronic Library Online (English)

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

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

2007-07-15

315

Effect of ultrasonic treatment on heavy metal decontamination in milk.  

Science.gov (United States)

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

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

2014-11-01

316

Poisoning of domestic animals with heavy metals  

Directory of Open Access Journals (Sweden)

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. .

Velev Romel

2009-01-01

317

Heavy metal displacement in chelate-irrigated soil during phytoremediation  

Science.gov (United States)

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.

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

2003-03-01

318

Heavy metal frost on Venus  

Science.gov (United States)

Chemical equilibrium calculations of volatile metal geochemistry on Venus show that high dielectric constant compounds of lead and bismuth such as PbS (galena), Bi 2S 3 (bismuthite) or Pb-Bi sulfosalts condense in the venusian highlands and may be responsible for the low radar emissivities observed by Magellan and Pioneer Venus. Our calculations also show that elemental tellurium is unstable on Venus' surface and will not condense below 46.6 km. This is over 30 km higher than Maxwell Montes, the highest point on Venus' surface. Elemental analyses of Venus' highlands surface by laser induced breakdown spectroscopy (LIBS) and/or X-ray fluorescence (XRF) can verify the identity of the heavy metal frost on Venus. The Pb-Pb age of Venus could be determined by mass spectrometric measurements of the Pb 207/Pb 204 and Pb 206/Pb 204 isotopic ratios in Pb-bearing frosts. All of these measurements are technologically feasible now.

Schaefer, Laura; Fegley, Bruce

2004-03-01

319

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

320

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)

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)

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

 
 
 
 
321

Heavy metals in Antarctic organisms  

Energy Technology Data Exchange (ETDEWEB)

To evaluate levels of essential (zinc and copper) and non-essential (mercury and cadmium) heavy metals, 34 species of organisms from different areas close to the Antarctic Peninsula were analysed. These included algae, filter-feeders, omnivorous invertebrates and vertebrates. Mercury was not detected, while cadmium was found in the majority of organisms analysed (detection limit was 0.05 ppm for both metals). The highest cadmium concentration was observed in the starfish Odontaster validus. Anthozoans, sipunculids and nudibranchs showed maximum levels of zinc, while the highest copper level was found in the gastropod Trophon brevispira. Mercury and cadmium levels in fishes were below the detection limit. Concentrations of essential and non-essential metals in birds were highest in liver followed by muscle and eggs. Cadmium and mercury levels in muscle of southern elephant seals were above the detection limit, whereas in Antarctic fur seals they were below it. The objective of the study was to gather baseline information for metals in Antarctic Ocean biota that may be needed to detect, measure and monitor future environmental changes. 46 refs., 7 figs., 8 tabs.

Moreno, J.E.A. de; Moreno, V.J. [Universidad Nacional de Mar del Plata (Argentina); Gerpe, M.S.; Vodopivez, C. [Instituto Antartico Argentino, Buenos Aires (Argentina)

1997-02-01

322

Mosses accumulate heavy metals from the substrata of coal ash  

Directory of Open Access Journals (Sweden)

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.

Vukojevi? Vanja

2005-01-01

323

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

Energy Technology Data Exchange (ETDEWEB)

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

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

1994-08-01

324

Heavy metals and living systems: An overview  

Digital Repository Infrastructure Vision for European Research (DRIVER)

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...

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

2011-01-01

325

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

Science.gov (United States)

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). PMID:19560268

Mbareck, Chamekh; Nguyen, Quang Trong; Alaoui, Ouafa Tahiri; Barillier, Daniel

2009-11-15

326

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).

327

Heavy Metal Music and Adolescent Suicidal Risk.  

Science.gov (United States)

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…

Lacourse, Eric; Claes, Michel; Villeneuve, Martine

2001-01-01

328

Heavy Metal, Religiosity, and Suicide Acceptability.  

Science.gov (United States)

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)

Stack, Steven

1998-01-01

329

LIMING EFFECT ON SOIL HEAVY METALS AVAILABILITY  

Directory of Open Access Journals (Sweden)

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

Krunoslav Karali?

2013-06-01

330

Heavy Metal Concentrations in Predator Fish  

Directory of Open Access Journals (Sweden)

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.

Srebrenka Nejedli

2011-01-01

331

EFFICIENCY OF NANOFILTRATION PROCESS BY METAL ION REMOVAL FROM MODEL WATER  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Heavy metal ions in water can harm health and load the environment and living organisms, already when they are present in low concentrations. Among many conventional treatment methods, membrane separation processes, i.e. nanofiltration (NF) enables efficient heavy metal ion removal from wastewaters. Nanofiltration membranes should be able to reject multivalent cations, (including heavy metal ions), while the monovalent ions pass through the membrane. The experimental part of the diploma ...

S?panbauer, Aleksandra

2010-01-01

332

Oil palm biomass as an adsorbent for heavy metals.  

Science.gov (United States)

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

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

2014-01-01

333

Phytoremediation of heavy metal contaminated soil by Jatropha curcas.  

Science.gov (United States)

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

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

2014-12-01

334

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)

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).

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

335

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

Science.gov (United States)

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

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

2014-06-01

336

Heavy metal uptake by agro based waste materials  

Scientific Electronic Library Online (English)

Full Text Available SciELO Chile | Language: English Abstract in english 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

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

2007-07-15

337

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

Energy Technology Data Exchange (ETDEWEB)

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

Sakai, Takaaki; Enuma, Yasuhiro [Japan Nuclear Cycle Development Inst., Oarai, Ibaraki (Japan). Oarai Engineering Center; Iwasaki, Takashi [Nuclear Energy System Inc., Tokyo (Japan); Ohyama, Kazuhiro [Advanced Reactor Technology Co., Ltd., Tokyo (Japan)

2001-05-01

338

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

International Nuclear Information System (INIS)

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

339

Robust removal of heavy metals from water by intercalation chalcogenide [CH3NH3]2xMnxSn3-xS6·0.5H2O  

Science.gov (United States)

The intercalation chalcogenide, [CH3NH3]2xMnxSn3-xS6·0.5H2O (x = 0.5-1.1) (CMS), was synthesized by simply hydrothermal method, which exhibited excellent adsorption properties for the removal of Cd2+/Pb2+. CNS analysis, SEM-EDX, ICP-OES, TG-DTG, XPS, N2 physical-adsorption and XRD were used to characterize the crystal structure, chemical composition and micro-morphologies of CMS material. The results indicated that the CH3NH3+ ions intercalated between the layers can exchange with heavy metal ions in the solution. The pH effect on Cd2+/Pb2+ adsorption was slight and the suitable pH value for Cd2+/Pb2+ removal by CMS materials was between 2 to 7. The equilibrium times were 7 h for 200 mg/L Cd2+ and 2 h for 400 mg/L Pb2+, respectively, and the adsorption kinetics was in agreement with pseudo-second-order kinetic model. The adsorption capacities of the CMS for Cd2+ and Pb2+ were 515 mg/g for Cd2+ and 1053 mg/g at 20 °C, respectively. The Freundlich isotherm was applied to describe the adsorption process, which fit the experimental dates well. Competitive adsorption results showed that the presence of 1 M Na+, Ca2+ or Mg2+ exerted slightly inhibiting effect on Cd2+/Pb2+ adsorption. The reaction temperature also affected the adsorption capacity of CMS. The adsorbed CMS can be considered as an excellent permanent waste form without the risk of lease of heavy metals.

Li, Jian-Rong; Wang, Xu; Yuan, Baoling; Fu, Ming-Lai; Cui, Hao-Jie

2014-11-01

340

Heavy Metal Contamination in Canned Tuna Fish  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Heavy metal contamination of food products, especially seafood is a major concern because of the bioaccumulation and biomagnification of metal contaminants. Their detection in fish is an indicator of marine pollution. In this study heavy metal concentrations were measured in a sample of commercially obtained canned tuna; after digestion and preparation of 21 such samples, levels of mercury and arsenic were determined by the hydride generation technique, while those of lead and cadmium were me...

Ghazi-khansari, M.; Abdollahi, M.; Emami-khansari, F.

2003-01-01

 
 
 
 
341

Attrition resistant catalysts and sorbents based on heavy metal poisoned FCC catalysts  

Science.gov (United States)

A heavy metal poisoned, spent FCC catalyst is treated by chemically impregnating the poisoned catalyst with a new catalytic metal or metal salt to provide an attrition resistant catalyst or sorbent for a different catalytic or absorption processes, such as catalysts for Fischer-Tropsh Synthesis, and sorbents for removal of sulfur gasses from fuel gases and flue-gases. The heavy metal contaminated FCC catalyst is directly used as a support for preparing catalysts having new catalytic properties and sorbents having new sorbent properties, without removing or "passivating" the heavy metals on the spent FCC catalyst as an intermediate step.

Gangwal, Santosh (Cary, NC); Jothimurugesan, Kandaswamy (Hampton, VA)

1999-01-01

342

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...

343

Heavy metals in municipal solid waste deposits  

Energy Technology Data Exchange (ETDEWEB)

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

Flyhammar, P.

1997-12-01

344

Organic reagents for removing heavy metals from a 10-34-0 (N-P{sub 2}O{sub 5}--K{sub 2}O) grade fertilizer solution and wet-process phosphoric acid  

Energy Technology Data Exchange (ETDEWEB)

Fertilizer solutions and wet-process phosphoric acid (WPA) contain heavy metal impurities such as arsenic, cadmium, zinc, mercury, lead, copper, manganese, and chromium. Trisodium trithiocyanuric acid, sodium trithiocarbonate, and sodium polythiocarbonate were evaluated as precipitating agents for heavy metals in a 10-34-0 (N-P{sub 2}O{sub 5}-K{sub 2}O) grade fertilizer solution and WPA. A water-insoluble starch xanthate was also evaluated as an adsorbent for the heavy metals in 10-34-0 and WPA.

Norwood, V.M. III

1991-12-31

345

Organic reagents for removing heavy metals from a 10-34-0 (N-P[sub 2]O[sub 5]--K[sub 2]O) grade fertilizer solution and wet-process phosphoric acid  

Energy Technology Data Exchange (ETDEWEB)

Fertilizer solutions and wet-process phosphoric acid (WPA) contain heavy metal impurities such as arsenic, cadmium, zinc, mercury, lead, copper, manganese, and chromium. Trisodium trithiocyanuric acid, sodium trithiocarbonate, and sodium polythiocarbonate were evaluated as precipitating agents for heavy metals in a 10-34-0 (N-P[sub 2]O[sub 5]-K[sub 2]O) grade fertilizer solution and WPA. A water-insoluble starch xanthate was also evaluated as an adsorbent for the heavy metals in 10-34-0 and WPA.

Norwood, V.M. III.

1991-01-01

346

Study on Biosorption of Heavy Metals by Modified Lignocellulosic Waste  

Directory of Open Access Journals (Sweden)

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.

Usama Eldemerdash

2011-01-01

347

Catalyst regeneration process including metal contaminants removal  

Science.gov (United States)

Spent catalysts removed from a catalytic hydrogenation process for hydrocarbon feedstocks, and containing undesired metals contaminants deposits, are regenerated. Following solvent washing to remove process oils, the catalyst is treated either with chemicals which form sulfate or oxysulfate compounds with the metals contaminants, or with acids which remove the metal contaminants, such as 5-50 W % sulfuric acid in aqueous solution and 0-10 W % ammonium ion solutions to substantially remove the metals deposits. The acid treating occurs within the temperature range of 60.degree.-250.degree. F. for 5-120 minutes at substantially atmospheric pressure. Carbon deposits are removed from the treated catalyst by carbon burnoff at 800.degree.-900.degree. F. temperature, using 1-6 V % oxygen in an inert gas mixture, after which the regenerated catalyst can be effectively reused in the catalytic process.

Ganguli, Partha S. (Lawrenceville, NJ)

1984-01-01

348

Remediating sites contaminated with heavy metals  

International Nuclear Information System (INIS)

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

349

Experimental perspectives on heavy electron metals  

Energy Technology Data Exchange (ETDEWEB)

We motivate the description of heavy electron metals in terms of concepts from the Kondo problem. These concepts are used to discuss magnetism and superconductivity in heavy electron systems. Particular attention is given to what we view as the principal outstanding questions in this field and direction in which the field is developing. This will include consideration of the differences between Ce and U heavy electron compounds, as well as the occurrence of very small ordered magnetic moments. 26 refs., 5 figs.

Fisk, Z.; Ott, H.R.; Aeppli, G.

1987-01-01

350

El heavy metal y la música académica  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Se señalan razones antropológicas, sociológicas y tecnológicas (institucionales) de por qué el heavy metal no puede ser considerado más de lo que es respecto a la música académica, de la que dice en parte beber.

Armesilla Conde, Santiago Javier

2012-01-01

351

A biosystem for removal of metal ions from water  

Energy Technology Data Exchange (ETDEWEB)

The presence of heavy metal ions in ground and surface waters constitutes a potential health risk and is an environmental concern. Moreover, processes for the recovery of valuable metal ions are of interest. Bioaccumulation or biosorption is not only a factor in assessing the environmental risk posed by metal ions; it can also be used as a means of decontamination. A biological system for the removal and recovery of metal ions from contaminated water is reported here. Exopolysaccharide-producing microorganisms, including a methanotrophic culture, are demonstrated to have superior metal binding ability, compared with other microbial cultures. This paper describes a biosorption process in which dried biomass obtained from exopolysaccharide-producing microorganisms is encapsulated in porous plastic beads and is used for metal ion binding and recovery. 22 refs., 13 figs.

Kilbane, J.J. II.

1990-01-01

352

Method of heavy metal trapping and separating  

International Nuclear Information System (INIS)

The use is described of pearl cellulose and the derivatives thereof for heavy metal sorption and separation. At pH 3 to 8, an aqueous solution containing heavy metals of the transition and post-transition metals of the 4th to 7th periods, this to advantage U, Cu, Pb, Cd, Hg, is passed through a layer of pearl cellulose with sorption-active hydroxyl, phosphate, carboxy methyl, amine, acetamide, imidazole, guanidine or thiol groups. Metal separation proceeds at pH 1 to 9; at pH 0.1 to 1 cellulose regenerates. (B.S.)

353

Automatic subgenre classification of heavy metal music  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Automatic genre classification of music has been of interest for researchers over a decade. Many success-ful methods and machine learning algorithms have been developed achieving reasonably good results. This thesis explores automatic sub-genre classification problem of one of the most popular meta-genres, heavy metal. To the best of my knowledge this is the first attempt to study the issue. Besides attempting automatic classification, the thesis investigates sub-genre taxonomy of heavy metal...

Tsatsishvili, Valeri

2011-01-01

354

Heavy Metal Compositions in Gaborone Industrial Effluent  

Digital Repository Infrastructure Vision for European Research (DRIVER)

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...

Nkegbe, E.; Koorapetse, I.

2005-01-01

355

Heavy Metal Poisoning and Cardiovascular Disease  

Digital Repository Infrastructure Vision for European Research (DRIVER)

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 ...

Ferns, Gordon A.; Alissa, Eman M.

2011-01-01

356

Heavy metals in packaging : a literature survey  

Digital Repository Infrastructure Vision for European Research (DRIVER)

The use of the heavy metals cadmium, mercury, chromium and lead in packaging is forbidden internationally for some years because these substances are harmful to the environment. In 2002 the Dutch national Inspectorate for the Environment determined the presence of heavy metals in packaging for consumer products.
A literature survey was commissioned by the Dutch national Inspectorate for the Environment. Objective was to gather information about actions and checks in other countries o...

Em, Putten

2012-01-01

357

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

Scientific Electronic Library Online (English)

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

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

2011-01-01

358

Biorreagentes: aplicações na remoção de metais pesados contidos em efluentes líquidos por biossorção/bioflotação / Bioreagents: their use in the removal of heavy metals from liquid streams by biosorption/ bioflotation  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: Portuguese Abstract in portuguese Esse trabalho tem o objetivo de apresentar uma análise dos principais aspectos sobre o uso de biomassas como biorreagentes na remoção de metais pesados contidos em efluentes líquidos. As vantagens de se utilizarem biossorventes ao invés de sorventes convencionais estão notadamente na relação custo-b [...] enefício inerente a essa tecnologia contemporânea. Algas, bactérias, fungos e materiais biológicos em geral (casca de coco, madeira, turfa, etc.) têm revelado avidez na captura de íons metálicos em ambientes aquosos, sendo que sua ubiqüidade diminui o custo total de sistemas de tratamento. Exemplos de pesquisas e patentes são discutidos, demonstrando o sucesso dessa tecnologia emergente. Abstract in english The objective of this work is to present a review concerning the use of biomass as bioreagents in the removal of heavy metals while treating liquid effluents. The advantages of using these biosorbents instead of conventional sorbents lie on the cost benefit relations inherent in this recent technolo [...] gy. Algae, bacteria, fungi and biological materials (coconut shells, wood, peat etc.) have shown avidity for metal ion uptaking in aqueous environments and their ubiquity decreases the overall treatment system cost. Research and patent examples are discussed, showing the success of this emergent technology.

Bruno Abreu, Calfa; Maurício Leonardo, Torem.

359

Mobile heavy metal fractions in soils  

International Nuclear Information System (INIS)

A long term outdoor experiment was conducted in plastic containers (50 litres) with three soils, contaminated by increasing concentrations of zinc, copper, nickel, cadmium and vanadium. The aim of the study was to investigate the influence of heavy metal contamination on soil microbial processes as well as the accumulation of heavy metals in plants. Spring barley, followed by winter endive were grown as experimental crops in a first vegetation period, while spring wheat was grown during the second year. The soil microbial activities, indicated by arylsulfatase, dehydrogenase, and substrate-induced respiration, decreased with increasing heavy metal contamination. Significant correlations were observed between the inhibition of soil microorganisms and the easily mobilizable heavy metal fractions of soils, extracted by a solution of 1 M ammoniumacetate at pH = 7. The heavy metal accumulation in vegetative and generative parts of the crop plants also showed a good agreement with mobilizable soil fractions. The results of the experiment indicate, that the extraction with ammoniumacetate can be used as a reference method for determination of tolerable heavy metal concentrations in soils. (authors)

360

Bioaccumulation of heavy metals in fauna from wet detention ponds for stormwater runoff  

DEFF Research Database (Denmark)

Stormwater detention ponds remove pollutants e.g. heavy metals and nutrients from stormwater runoff. These pollutants accumulate in the pond sediment and thereby become available for bioaccumulation in fauna living in the ponds. In this study the bioaccumulation was investigated by fauna samples from 5 wet detention ponds for analyses of heavy metal contents. Five rural shallow lakes were included in the study to survey the natural occurrence of heavy metals in water-dwelling fauna. Heavy metal concentrations in water-dwelling fauna were generally found higher in wet detention ponds compared to rural shallow lakes.

Stephansen, Diana; Nielsen, AsbjØrn Haaning

2012-01-01