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1

Removal of heavy metals from waste streams  

Energy Technology Data Exchange (ETDEWEB)

A method for removing heavy metals from effluent water is described comprising performing sequentially the following steps: (a) adding from 7-333 ppm of an anionic surfactant to the effluent water to provide coagulatable heavy metal ion; (b) adjusting the effluent water pH to within the range of 8 to 10, (c) providing from 10-200 ppm of a cationic coagulant to coagulate the heavy metal ion, (d) providing from 0.3 to 5.0 ppm of a polymeric flocculant whereby a heavy metal containing floc is formed for removal from the effluent water, and, (e) then removing the floc from the effluent water, wherein the anionic surfactant is sodium lauryl ether sulfate. The cationic coagulant is selected from the group consisting of diallyl dimethylammonium chloride polymer, epichlorohydrin dimethylamine polymer, ethylene amine polymer, polyaluminum chloride, and alum; and the flocculant is an acrylamide/sodium acrylate copolymer having an RSV greater than 23.

Spence, M.D.; Kozaruk, J.M.; Melvin, M.; Gardocki, S.M.

1988-07-19

2

Heavy metal removal by fly ash  

Energy Technology Data Exchange (ETDEWEB)

The present work investigates the possible use of fly ash for the removal of heavy metal ions from aqueous solutions. Batch experiments were conducted and the influences of metal concentration, pH, and fly ash concentration were investigated. Heavy metals used in these studies were lead and zinc. Adsorption studies were done over a range of pH values(3 - 10) at 25 deg.C and heavy metal concentrations of 10-400mg/L using fly ash concentrations of 10 and 20 g/L. Experiments were also conducted without fly ash to determine the extent of heavy metal removal by precipitation. Kinetic and equilibrium experiments were performed and adsorption data were correlated with both Langmuir and Freundlich adsorption models. The results of these studies indicate that fly ash can be used as an adsorbent for heavy metals in the aqueous solutions, yet the degree of removal depends on the pH. (author). 3 refs., 5 tabs., 10 figs.

Cho, Hee-Chan; Oh, Dal-Young [Seoul National University, Seoul(Korea)

2001-08-31

3

Heavy metal removal and recovery using microorganisms  

International Nuclear Information System (INIS)

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

1991-01-01

4

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

5

Removal of dissolved heavy metals and radionuclides by microbial spores.  

Science.gov (United States)

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 a...

N. W. Revis C. T. Hadden H. Edenborn

1997-01-01

6

Material Removes Heavy Metal Ions From Water  

Science.gov (United States)

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

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

1995-01-01

7

Modeling heavy metal removal in wetlands  

Energy Technology Data Exchange (ETDEWEB)

Although the use of wetland ecosystems to purify water has gained increased attention only recently, it has been recognized as a wastewater treatment technique for centuries. While considerable research has occurred to quantify the nutrient (nitrogen and phosphorus) removal mechanisms of wetlands, relatively few investigators have focused on the mechanisms of heavy metal removal and uptake by wetland sediments and plants. The quantification of the assimilative capacity of heavy metals by wetland ecosystems is a critical component in the design and use of wetlands for this purpose. A computer model has been developed to simulate the fate and transport of heavy metals introduced to a wetland ecosystem. Modeled water quality variables include phytoplankton biomass and productivity; macrophyte (Nulumbo lutea) biomass; total phosphorus in the water column; dissolved copper in the water column and sediments; particulate copper in the water column and sediments; and suspended solids. These variables directly affect the calculated rate of copper uptake by macrophytes, and the rate of copper recycling as a function of the decomposition of copper-laden biomass litter. The model was calibrated using total phosphorus and chlorophyll a data from the Old Woman Creek Wetland in Ohio. Verification of the model was achieved using data on the copper content of the macrophyte Nelumbo lutea.

Lung, W.S. [Univ. of Virginia, Charlottesville, VA (United States); Light, R.N. [Army Environmental Center, Aberdeen Proving Ground, MD (United States)

1994-12-31

8

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

9

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

10

Traces of Heavy Metals in Water Removal Processes and Monitoring.  

Science.gov (United States)

The report includes twenty papers on removal and monitoring of trace qualities of heavy metals in water. Titles include: Overview of drinking water quality control at the federal level; Trace heavy metals in water: Removal processes by ion-exchange; Some ...

J. E. Sabadell

1973-01-01

11

Removal of dissolved heavy metals and radionuclides by microbial spores  

Energy Technology Data Exchange (ETDEWEB)

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 {sup 85}strontium and {sup 197}cesium. 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.

Revis, N.W.; Hadden, C.T.; Edenborn, H. [and others

1997-11-01

12

Radiation-initiated removal of heavy metals from water  

International Nuclear Information System (INIS)

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

1995-06-25

13

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

14

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

15

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

16

Heavy metals removal from dredged sediments using electro kinetics  

Digital Repository Infrastructure Vision for European Research (DRIVER)

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

2013-01-01

17

Heavy metals removal in industrial effluents by sequential adsorbent treatment  

Energy Technology Data Exchange (ETDEWEB)

A method for metal removal can be applied to industrial wastes without prior treatment using solid adsorbents such as sand, silica, coal and alumina. This study was conducted to evaluate the removal of heavy metals in an aquatic system without prior treatment. An important aspect of the proposed method was that the removal was performed on several metals at a pH range in which a given metal undergoes an adsorption process, making the method useful for wastewater treatment. Lead was the metal of most interest due to its occurrence in waste from storage-battery manufacture. After the adsorption process, the Pb concentration, as well as that of Cd, Ni, Cr and Cu, were below the detection limit. For other metals, removal was observed to be approximately 20-30% for Ca, Mg and Mn and above 80% for Cr, Pb, Ni, Cd and Cu, using alumina as an absorbent.

Yabe, M.J.S.; de Oliveira, E. [Universidade Estadual de Londrina, Londrina, PR (Brazil)

2003-01-01

18

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

19

BIOSORPTIVE REMOVAL OF HEAVY METALS FROM WASTEWATER USING DUCKWEED  

Directory of Open Access Journals (Sweden)

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

Ankita Suhag

2011-10-01

20

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

 
 
 
 
21

Heavy metal removal from water solutions  

Digital Repository Infrastructure Vision for European Research (DRIVER)

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 ...

2005-01-01

22

Removal of heavy metal impurities from dredged river sediment  

Energy Technology Data Exchange (ETDEWEB)

The goal of removing the sediment fraction containing heavy metals from river sediment was studied. Different parameters such as pH, flotation time, different collectors, distilled water, tap water, and different salts were investigated by the authors to achieve a high separation efficiency. Results of the flotation revealed that 63% by weight of the input dredged sediment can be safely and successfully separated, thereby, meeting the current environmental requirement of the Flemish regulation. (orig.)

Abd El-Rahman, M.K. [Central Metallurgical R and D Institute (CMRDI), Cairo (Egypt); Maes, A.; Cauwenberg, P. [Katholieke Univ., Leuven (Belgium). Faculty of Agriculture

1999-08-01

23

Electrolytic ferrite formation system for heavy metal removal  

Energy Technology Data Exchange (ETDEWEB)

An electrolytic coagulation process was developed for removal of heavy metals from industrial wastewaters. The process consists of an electro-bath in which hexavalent chromium is reduced to trivalent chromium, polymer coagulation and settling, and formation of ferrite in the settled sludge. Ferrite sludge is separated in a magnetic separator. The chromium in ferrite sludge is not soluble in water. Phosphate and silicon dioxide also are incorporated into the ferrite sludge. Supernatant water from the settling contains very little chromium.

Nojiri, N.; Tanaka, N.; Sato, K.; Sakai, Y.

1980-07-01

24

Bacteria immobilisation on hydroxyapatite surface for heavy metals removal.  

Science.gov (United States)

Selected bacterial strains were immobilised on the surface of hydroxyapatite (Ca10(PO4)6(OH)2 - HAp) of natural origin (fish bones). The capacity of the material, alone and in combination with the bacterial strains to act as heavy metal removers from aqueous streams was assessed. Pseudomonas fluorescens (S3X), Microbacterium oxydans (EC29) and Cupriavidus sp. (1C2) were chosen based on their resistance to heavy metals and capacity of adsorbing the metals. These systems were tested using solutions of Zn(II), Cd(II) and in solutions containing both metals. A synergistic effect between the strains and HAp, which is effective in removing the target heavy metals on its own, was observed, as the combination of HAp with the bacterial strains led to higher adsorption capacity for both elements. For the solutions containing only one metal the synergistic effect was greater for higher metal concentrations; 1C2 and EC29 were the most effective strains for Zn(II) and Cd(II) respectively, while S3X was less effective. Overall, an almost four-fold increase was observed for the maximum adsorption capacity for Zn(II) when 1C2 was employed - 0.433 mmol/g in comparison of 0.121 mmol/g for the unmodified HAp. For Cd(II), on the other hand, an almost three-fold increase was registered with EC29 bacterial strain - 0.090 vs 0.036 mmol/g for the unmodified HAp. When the solutions containing both metals were tested, the effect was more marked for lower concentrations. PMID:23524400

Piccirillo, C; Pereira, S I A; Marques, A P G C; Pullar, R C; Tobaldi, D M; Pintado, M E; Castro, P M L

2013-05-30

25

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.

26

Removal of Heavy Metal Ions by Blended Periwinkle Shells  

Digital Repository Infrastructure Vision for European Research (DRIVER)

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. T...

Okuo, James M.

2006-01-01

27

Removal of heavy metals and radionuclides by seeded magnetic filtration  

International Nuclear Information System (INIS)

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

1991-09-08

28

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

2008-08-15

29

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.

2012-04-15

30

Removal of heavy metals from the environment by biosorption  

Energy Technology Data Exchange (ETDEWEB)

The pollution of the environment with toxic metals is a result of many human activities, such as mining and metallurgy, and the effects of these metals on the ecosystems are of large economic and public-healthsignificance. This paper presents the features and advantages of the unconventional removal method of heavy metals - biosorption - as a part of bioremediation. Bioremediation consists of a group of applications, which involve the detoxification of hazardous substances instead of transferring them from one medium to another, by means of microbes and plants. This process is characterized as less disruptive and can be often carried out on site, eliminating the need to transport the toxic materials to treatment sites. The biosorption (sorption of metallic ions from solutions by live or dried biomass) offers an alternative to the remediation of industrial effluents as well as the recovery of metals contained in other media. Biosorbents are prepared from naturally abundant and/or waste biomass. Due to the high uptake capacity and very cost-effective source of the raw material, biosorption is a progression towards a perspective method. The mechanism by which microorganisms take up metals is relatively unclear, but it has been demonstrated that both living and non-living biomass may be utilized in biosorptive processes, as they often exhibit a marked tolerance towards metals and other adverse conditions. One of their major advantages is the treatment of large volumes of effluents with low concentrations of pollutants. Models developed were presented to determine both the number of adsorption sites required to bind each metal ion and the rate of adsorption, using a batch reactor mass balance and the Langmuir theory of adsorption to surfaces or continuous dynamic systems. Two main categories of bioreactors used in bioremediation - suspended growth and fixed film bioreactors - are discussed. Reactors with varying configurations to meet the different requirements for biosorption are analyzed considering two major groups of reactors - batch reactors and continuous reactors. Biosorption is treated as an emerging technology effective in removing even very low levels of heavy metal. (Abstract Copyright [2004], Wiley Periodicals, Inc.)

Gavrilescu, M. [Technical University of Iasi, Faculty of Industrial Chemistry, Department of Environmental Engineering, Mangeron Blvd. 71, 6600-Iasi (Romania)

2004-06-01

31

Utilization of pulp and paper industrial wastes to remove heavy metals from metal finishing wastewater.  

Science.gov (United States)

Two pulp and paper industrial wastes, lime mud (LM) and recovery boiler ash (RB), have low moisture contents, low heavy metal contaminations and contain various carbonate compounds which contribute to a high pH. Metal finishing wastewater (MF-WW) has a low pH, high levels of TDS and high contaminations from Cr, Cu, Pb and Zn. The heavy metals from MF-WW were removed by sorption and precipitation mechanisms. LM gave better results in removing heavy metals from MF-WW than RB. At a reaction time of 45min, the maximum removal efficiencies for Cr (93%) and Cu (99%) were obtained at 110gL(-1) of LM, but at 80gL(-1) for Pb (96%) and Zn (99%). Treatment with LM gives a higher sludge volume than with RB. However, the leachability of heavy metals from LM is lower. Leachability of heavy metals in the sediment for all selected treatment conditions is within government standards. PMID:19501952

Sthiannopkao, Suthipong; Sreesai, Siranee

2009-08-01

32

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

Digital Repository Infrastructure Vision for European Research (DRIVER)

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 ...

Binyuan Chen; Ruijuan Qu; Jiaqi Shi; Dinglong Li; Zhongbo Wei; Xi Yang; Zunyao Wang

2011-01-01

33

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

Digital Repository Infrastructure Vision for European Research (DRIVER)

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 ...

Binyuan Chen; Ruijuan Qu; Jiaqi Shi; Dinglong Li; Zhongbo Wei; Xi Yang; Zunyao Wang

2012-01-01

34

Residual heavy metal (Cu and Cd) removal by Iris pseudacorus  

Energy Technology Data Exchange (ETDEWEB)

The uptake of Cu and Cd by the roots of Iris pseudacorus and its transport to rhizome and leaves were examined using solutions containing 0.5 and 5.0 mg L/sup -1/ of Cu and Cd. Heavy metal accumulation was measured while replacing the metal absorbed by the plants with daily introduction to restore the initial concentrations. The heavy metal accumulation by Iris p. was 1.01 g Cu and 0.069 g Cd kg/sup -1/ of fresh plant at the end of the tests for the solutions of 5.0 mg L/sup -1/ metal concentration, respectively.

Barbolani, E.; Clauser, M.; Pantani, F.; Gellini, R.

1986-01-01

35

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

Digital Repository Infrastructure Vision for European Research (DRIVER)

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

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

2011-01-01

36

Utilization of Carbamoyethylated Cotton for Heavy Metal Ion Removal  

Digital Repository Infrastructure Vision for European Research (DRIVER)

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 stud...

Mostafa, Kh M.; Hassan Al-Bar

2005-01-01

37

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

International Nuclear Information System (INIS)

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

2008-03-21

38

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

Science.gov (United States)

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. PMID:22018872

Hua, Ming; Zhang, Shujuan; Pan, Bingcai; Zhang, Weiming; Lv, Lu; Zhang, Quanxing

2012-04-15

39

[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

40

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

International Nuclear Information System (INIS)

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

1999-01-15

 
 
 
 
41

Mechanisms of heavy metal removal using microorganisms as biosorbent.  

Science.gov (United States)

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

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

2014-01-01

42

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

2005-11-27

43

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

Science.gov (United States)

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

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

2011-11-15

44

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

International Nuclear Information System (INIS)

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

2002-01-01

45

Coal fly ash and alginate for the removal of heavy metals from aqueous solutions  

Energy Technology Data Exchange (ETDEWEB)

The use of a basic coal fly ash in the removal of heavy metal ions from aqueous solutions has been investigated. It has been shown that the yields depend on ash dosage and metal concentration; the results are generally good and can be improved in some cases by pH lowering. As a matter of fact, fly ash gives a basic pH to the metal solutions; heavy metals are removed principally by precipitation and adsorption on ash particles. The addition of sodium alginate sometimes makes it possible to reach higher yields at alow ash dosage, but its effect must be carefully evaluated in the case of mixed ions.

Ferrero, F.; Prati, M.P.G. [Politecnico di Torino, Torino (Italy). Dipt. di Scienzia Materiali e Ingegneria Chimica

1996-03-01

46

Imprinted polymers for the removal of heavy metal ions from water.  

Science.gov (United States)

In wastewater treatment, the removal of heavy metals is difficult due to the limited affinity of heavy metal ions to ion exchange resins. Here imprinting polymerization is used to develop resins with high capacity and selectivity for heavy metal ions for water treatment. A random copolymer of methacrylate and methacrylamide was found to be most effective for the removal of hydrophilic metal complexes, like CdCl2, ZnCI2, and the metalloid NaH2AsO4, particularly when the porosity of these resins is increased. For hydrophobic complexes imprinting emulsion polymerization was developed and data for the effective removal of mercury dithizonate will be described. Complete removal for up to 80 ppm of cadmium and mercury with only 200 mg of imprinted resin was obtained; competition and co-imprinting experiments are described as well. PMID:22214087

Ashraf, Syed; Cluley, Angela; Mercado, Ckarlos; Mueller, Anja

2011-01-01

47

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

48

Heavy-metal and toxic-metalloid removals from waste streams by biofilm populations  

Energy Technology Data Exchange (ETDEWEB)

A four stage continuous-flow bench-scale rotating biological contactor (RBC) was operated to maintain a constant-culture of biofilm for use in a separate batch-mode reactor. Removable discs allowed the biofilm to be transferred, at steady-state, from the continuous-flow RBC to the batch tank for studies pertaining to metals removals. Two heavy metals (cadmium and nickel) and two metalloids (arsenic and selenium) were tested in order to develop fundamental parameters of metals removals by the biofilm, including: (1) percent metals removals, (2) first-order batch metals removals kinetics, and (3) accumulation of metals within the biofilm. Variables included in the parameter development were stage origin of biofilm and presence of organic substrate. A general trend was observed for the biofilm's affinity for the four metals: Cd > Ni, Se > As.

Engelder, C.L.

1988-01-01

49

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

Digital Repository Infrastructure Vision for European Research (DRIVER)

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

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

2009-01-01

50

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

Digital Repository Infrastructure Vision for European Research (DRIVER)

The main objectives of present research were to determine heavy metals (Ni, Cd, Cr, Zn and Cu) and COD concentration in raw leachate in Esfahan (Iran) composting plant and to examine the application of coagulation-flocculation process for the treatment of raw leachates. Jar-test experiments were employed in order to determine the optimum conditions (effective dosage and optimum pH) for the removal of COD and heavy metals. Alum (aluminum sulphate) and Ferric chloride were tested as conventiona...

Yousefi, Z.; Zazouli, M. A.

2008-01-01

51

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

CERN Multimedia

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

Dash, Monika

2013-01-01

52

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

53

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

Science.gov (United States)

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

Gupta, Rani; Mohapatra, Harapriya

2003-09-01

54

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

International Nuclear Information System (INIS)

This report details the pyrometallurgical process for recycling spent metal fuels from the Integral Fast Reactor (IFR) which involves electrorefining spent fuel in a molten salt electrolyte (LiCl-KCI-U/PuCl_3) at 500 degree C. The total heavy metal chloride concentration in the salt will be about 2 mol %. At some point, the concentrations of alkali, alkaline earth, and rare earth fission products in the salt must be reduced to lower the amount of heat generated in the electrorefiner. The heavy metal concentration in the salt must be reduced before removing the fission products from the salt. The operation uses a lithium-cadmium alloy anode that is solid at 500 degree C, a solid mandrel cathode with a ceramic catch crucible below to collect heavy metal that falls off it, and a liquid cadmium cathode. The design criteria that had to be met by this equipment included the following: (1) control of the reduction rate by lithium, (2) good separation between heavy metal and rare earths, and (3) the capability to collect heavy metal and rare earths over a wide range of salt compositions. In tests conducted in an engineering-scale electrorefiner (10 kg uranium per cathode), good separation was achieved while removing uranium and rare earths from the salt. Only 13% of the rare earths was removed, while 99.9% of the uranium in the salt was removed; subsequently, the rare earths were also reduced to low concentrations. The uranium concentration in the salt was reduced to 0.05 ppm after uranium and rare earths were transferred from the salt to a solid mandrel cathode with a catch crucible. Rare earth concentrations in the salt were reduced to less than 0.01 wt % in these operations. Similar tests are planned to remove plutonium from the salt in a laboratory-scale (100--300 g heavy metal) electrorefiner

1994-04-24

55

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

Digital Repository Infrastructure Vision for European Research (DRIVER)

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....

2004-01-01

56

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

International Nuclear Information System (INIS)

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

1991-01-01

57

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

58

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

59

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

60

Heavy metal removal by novel CBD-EC20 sorbents immobilized on cellulose.  

Science.gov (United States)

Heavy metals are major contributors to pollution of the biosphere, and their efficient removal from contaminated water is required. Biosorption is an emerging technology that has been shown to be effective in removing very low levels of heavy metal from wastewater. Although peptides such as metallothioneins or phytotchelatins are known to immobilize heavy metals, peptide-based biosorbents have not been extensively investigated. In this paper, we describe the construction and expression of bifunctional fusion proteins consisting of synthetic phytochelatin (EC20) linked to a Clostridium-derived cellulose-binding domain (CBD(clos)), enabling purification and immobilization of the fusions onto different cellulose materials in essentially a single step. The immobilized sorbents were shown to be highly effective in removing cadmium at parts per million levels. Repeated removal of cadmium was demonstrated in an immobilized column. The ability to genetically engineer biosorbents with precisely defined properties could provide an attractive strategy for developing high-affinity bioadsorbents suitable for heavy metal removal. PMID:12005515

Xu, Zhaohui; Bae, Weon; Mulchandani, Ashok; Mehra, Rajesh K; Chen, Wilfred

2002-01-01

 
 
 
 
61

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

62

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)

2010-01-01

63

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

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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

64

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

Science.gov (United States)

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 tec...

R. W. Peters L. Shem

1993-01-01

65

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

2014-01-15

66

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

67

Metabolic Engineering for Heavy Metal and Actinide Removal.  

Science.gov (United States)

Engineering hydrogen sulfide production and cadmium removal by expression of the thiosulfate reductase gene (phsABC) from Salmonella enterica serovar Typhimurium in Escherichia coli. The thiosulfate reductase operon (phsABC) from Salmonella typhimurium wa...

J. D. Keasling

2005-01-01

68

Removal of heavy metals from wastewaters by cellulose xanthate chelating exchangers  

International Nuclear Information System (INIS)

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

1989-01-01

69

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

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

Zhaoxiang YU

2009-05-01

70

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

International Nuclear Information System (INIS)

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

2007-08-17

71

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

Energy Technology Data Exchange (ETDEWEB)

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

Kocaoba, Sevgi [Yildiz Technical University, Faculty of Art and Science, Department of Chemistry, Davutpasa Cad. No: 127, 34210 Davutpasa, Istanbul (Turkey)]. E-mail: kocaoba@yildiz.edu.tr

2007-08-17

72

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

2000-02-06

73

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

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

M.S. Rana

2009-01-01

74

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

75

Removal of heavy metals in a horizontal sub-surface flow constructed wetland.  

Science.gov (United States)

Constructed wetlands with horizontal sub-surface flow designed for the treatment of municipal sewage have been monitored extensively with respect to removal of organics (BOD5, COD), suspended solids, nutrients (N, P) and microbial pollution. However, the information on the removal and distribution of heavy and other metals in these systems are very limited because heavy metals do not constitute a major problem in wastewater from small villages with no industry. The measurements were carried out in a constructed wetland with sub-surface flow at Morina near Prague. Removal of metals in constructed wetland at Morina near Prague varied widely among studied metals. The highest removal was recorded for aluminium (> 98.9%), zinc (94.1%) and chromium (92.8%). Iron and manganese increased their concentration in the outflow suggesting that these metals are actually washed out of the system. This phenomenon is attributed to the fact that in the absence of dissolved oxygen and nitrate manganic Mn and then ferric Fe are used by microorganisms as the terminal electron acceptors during respiration. It has been shown that substantial amounts of metals were retained in pretreatment units. PMID:15921288

Vymazal, Jan

2005-01-01

76

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

77

Selective heavy metals removal from waters by amorphous zirconium phosphate: behavior and mechanism.  

Science.gov (United States)

Selective removal of heavy metals from water has been of considerable concern for several decades. In the present study, the amorphous zirconium phosphate (ZrP) was synthesized and characterized by X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD), scanning electron micrography (SEM), thermogravimetric analysis (TGA) as well as pH-titration experiments. Uptake of heavy metals including lead, cadmium, and zinc onto ZrP was studied by using a polystyrene sulfonic-acid exchanger D-001 as a reference sorbent and Ca(2+) as a competing cation due to its ubiquity in natural or industrial waters. The results indicated that the uptake of heavy metals onto ZrP is essentially an ion-exchange process and dependent upon solution pH. In comparison with D-001, ZrP exhibited more favorable sorption of heavy metals particularly in terms of high selectivity, as indicated by the distribution coefficients of ZrP even several orders higher than D-001 towards heavy metals when calcium ion coexisted at a high level in solution. The Fourier transform-infrared (FT-IR) spectroscopic investigation indicated that the uptake of calcium, cadmium, and zinc ions onto ZrP is only driven by the electrostatic interaction, while that of lead ion is possibly dependent upon the inner-sphere complex formation with ZrP. XPS results further elucidated that ZrP displays different sorption affinity towards heavy metals in the same order as selectivity sequence of Pb(2+)>Zn(2+) approximately Cd(2+)>Ca(2+), which can be explained by hard and soft acids and bases (HASB) theory. Moreover, uptake of heavy metals onto ZrP approached to equilibrium quickly and the used ZrP could be readily regenerated for reuse by the dilute HCl solution. Thus, all the results suggest that amorphous ZrP has excellent potential as a sorption material for water treatment. PMID:17433402

Pan, Bingcai; Zhang, Qingrui; Du, Wei; Zhang, Weiming; Pan, Bingjun; Zhang, Qingjian; Xu, Zhengwen; Zhang, Quanxing

2007-07-01

78

Removal of Heavy Metal from Contaminated Soil with Chelating Agents  

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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

79

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

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

Z. Yousefi

2008-01-01

80

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

2008-12-01

 
 
 
 
81

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)

2012-01-01

82

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

83

Removal of heavy metals from oil sludge using ion exchange textiles.  

Science.gov (United States)

Development of a new simple and economic method for heavy-metal removal from oil sludge using ion exchange textiles was the main objective of this research. Three experimental stages were developed for this purpose using the bottom tank oil sludge from the Shell Canada refinery in Montreal, Canada. The first stage consisted of the direct application of ion exchange to oil sludge. The second stage included the pretreatment of oil sludge with organic solvents prior to the application of ion exchange process. The third stage included the pretreatment of oil sludge with an aqueous solution in order to extract heavy metals to the aqueous phase and then apply ion exchange textiles to the aqueous phase. Best results were obtained when acetone was used as an organic solvent leading to a total removal of vanadium while cadmium, zinc, nickel, iron, copper by 99%; 96%; 94%; 92% and 89%, respectively. PMID:18619144

Elektorowicz, M; Muslat, Z

2008-04-01

84

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

85

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

International Nuclear Information System (INIS)

The effectiveness of materials based on LTA Zeolite as active phase, for their incorporation into systems aimed at the removal of heavy metals on waste water is evaluated in a preliminary way. This type of Zeolite with the main channel of a minimum free diameter of 0,41 nm and a low SiO2/Al2O3 ratio is an interesting molecular sieve, which in turn display a high ion exchange capacity. From this point of view, LTA Zeolite crystals were obtained in situ by hydrothermal synthesis and characterized by x ray diffraction (XRD) and scanning electron microscopy (SEM). We have studied the effect of hydrothermal synthesis time at 378 K. Likewise, the removal capacity of heavy metal from the active phase was evaluated in as a first step on diluted solutions of cooper salts at slightly acidic pH (? 4,7). (Author) 28 refs.

2012-01-01

86

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

2005-01-01

87

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

Digital Repository Infrastructure Vision for European Research (DRIVER)

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

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

2010-01-01

88

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

Digital Repository Infrastructure Vision for European Research (DRIVER)

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 ...

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

2013-01-01

89

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

90

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

Digital Repository Infrastructure Vision for European Research (DRIVER)

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...

2010-01-01

91

Removal of Heavy Metals from Water: An Environmentally Significant Atomic Absorption Spectrometry Experiment  

Science.gov (United States)

A laboratory experiment that combines the environmentally significant topic of wastewater treatment with atomic absorption spectrometry (AAS) is described. In the first portion of the laboratory project, students perform treatment studies on simulated wastewater samples that contain heavy metal contaminants common to the effluent of the metal finishing industry. Following pretreatment reduction of Cr(VI) to Cr(III), sparingly soluble metal hydroxides are produced by pH adjustment and removed by filtration with the aid of a polyacrylamide flocculant. In the second portion of the experiment, AAS is used to determine metal concentrations in treated and untreated water samples, thus enabling the students to determine the effectiveness of the treatment process. Details of how this experiment integrates topics such as the pH-dependent solubility of metal hydroxides, complex equilibria, matrix interference, and polymers in the context of an environmentally important analysis are presented.

Buffin, Brian P.

1999-12-01

92

Removal of heavy metals from wastewater using steelmaking slag and sludge  

Energy Technology Data Exchange (ETDEWEB)

This study was carried out to investigate the efficiency of steelmaking slag and sludge in removing metals existing in wastewater or leachate. Laboratory experiments were performed as a function of initial concentration of metals, pH and temperature of the background solution and the presence of chelating agent, EDTA. The test conditions were temperatures ranging from 25 deg.C to 50 deg.C; initial concentrations varying from 5 mg/L to 50 mg/L; pH between 3 and 11; and Cu, Cd, and Pb is adsorbates. The results of tests showed that overall rates of metals removal were 20-30% at pH 3 and greater than 90% at pH 7 and 11. Metals were removed from the solution predominantly via adsorption in acidic conditions, and the combined effects of adsorption and precipitation in neutral and alkaline conditions. In view of the test results and other engineering characteristics of steelmaking slag and sludge, these industrial by-products from steel industry have a high potential to be used in wastewater treatment and are particularly beneficial when used as landfill liner additives due to their ability to remove heavy metals from leachate. (author). 17 refs., 7 tabs., 5 figs.

Hyun, Jae-Hyuk; Kim, Min-Gil; Nam, In-Young; Baek, Jung-Sun [Chungnam National University, Taejon (Korea)

1999-03-31

93

Polyaza macroligands as potential agents for heavy metal removal from wastewater  

Directory of Open Access Journals (Sweden)

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

94

Innovative use of activated carbon for the removal of heavy metals from ground water sources  

Energy Technology Data Exchange (ETDEWEB)

This report discusses the evaluation of the ENVIRO-CLEAN PROCESS, a technology developed by Lewis Environmental Services, Inc. for the recovery of metals such as chromium, mercury, copper, cadmium, lead, and zinc from surface and groundwater streams. This new heavy metal removal process (patent-pending) utilizes granular activated carbon with a proprietary conditioning pretreatment to enhance heavy metal adsorption combined with electrolytic metal recovery to produce a saleable metallic product. The process generates no sludge or hazardous waste and the effluent meets EPA limits. A 50 gpm system was installed for recovering hexavalent chromium from a ground water stream at a site located in Fresno, California. The effluent from the activated carbon system was reinjected into the ground water table with the hexavalent chromium concentration < 10 ppb. The system simultaneously removed trichloroethylene (TCE) to concentrations levels < 05 ppb. The activated carbon is regenerated off-site and the chromium electrolytically recovered. The full scale system has treated over 5 million gallons of ground water since installation. 5 refs., 1 fig., 3 tabs.

Lewis, T. III [Lewis Environmental Services, Inc., Pittsburgh, PA (United States)

1996-12-31

95

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

96

Functionalized nanoporous silica for the removal of heavy metals from biological systems: adsorption and application.  

Science.gov (United States)

Surface-functionalized nanoporous silica, often referred to as self-assembled monolayers on mesoporous supports (SAMMS), has previously demonstrated the ability to serve as very effective heavy metal sorbents in a range of aquatic and environmental systems, suggesting that they may be advantageously utilized for biomedical applications such as chelation therapy. Herein we evaluate surface chemistries for heavy metal capture from biological fluids, various facets of the materials' 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.) Consequentially, thiol-functionalized 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) to gauge any potentially negative effects resulting from interaction with the sorbent, such as cellular toxicity or the removal 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 nontoxic. The results show that organic ligand functionalized nanoporous silica could be a valuable material for a range of detoxification therapies and potentially other biomedical applications. PMID:20939537

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

2010-10-01

97

Impact of humic/fulvic acid on the removal of heavy metals from aqueous solutions using nanomaterials: a review.  

Science.gov (United States)

Nowadays nanomaterials have been widely used to remove heavy metals from water/wastewater due to their large surface area and high reactivity. Humic acid (HA) and fulvic acid (FA) exist ubiquitously in aquatic environments and have a variety of functional groups which allow them to complex with metal ions and interact with nanomaterials. These interactions can not only alter the environmental behavior of nanomaterials, but also influence the removal and transportation of heavy metals by nanomaterials. Thus, the interactions and the underlying mechanisms involved warrant specific investigations. This review outlined the effects of HA/FA on the removal of heavy metals from aqueous solutions by various nanomaterials, mainly including carbon-based nanomaterials, iron-based nanomaterials and photocatalytic nanomaterials. Moreover, mechanisms involved in the interactions were discussed and potential environmental implications of HA/FA to nanomaterials and heavy metals were evaluated. PMID:24095965

Tang, Wang-Wang; Zeng, Guang-Ming; Gong, Ji-Lai; Liang, Jie; Xu, Piao; Zhang, Chang; Huang, Bin-Bin

2014-01-15

98

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

Digital Repository Infrastructure Vision for European Research (DRIVER)

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 ...

Dahlan, I.; Ismail, S.

2012-01-01

99

Comparison of the heavy metal removal efficiency of biosorbents and granular activated carbons  

Energy Technology Data Exchange (ETDEWEB)

The adsorption efficiencies of granular carbon (GAC) and biosorbents: Saccaromyces cerevisiae yeast (caustic treated and active) immobilized in GAC; yeast (caustic treated) immobilized in alginate acid, and alginate itself were compared for the removal of Cu{sup 2+}, Cd{sup 2+}, Zn{sup 2+} from simulated waste waters. Yeast biomass has a high capacity for uptake of heavy metal ions, and can be adsorbed on activated carbon. The alginate used in this study was used as an entrapment material to immobilize yeast. It was observed that the pH of the solution was a critical parameter for the adsorption process; the value chosen in the experiments was 4.5. Two different experimental modes were used, a batch mode and a flow mode were used. In batch mode operation, using biosorbents yeast immobilized on GAC and on alginate, the percentage removal of heavy metal can exceed 90%. When only GAC was used as an adsorbent, acceptable results were obtained. Comparing the two different experimental modes, no difference was observed in the percentage removal of metal ions, although a longer time was needed for the flow system to reach adsorption equilibrium compared to batch mode. 32 refs., 5 figs., 4 tabs.

Wilkins, E.; Yang, Q. [Univ. of New Mexico, Albuquerque, NM (United States)

1996-10-01

100

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

Directory of Open Access Journals (Sweden)

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

A.O. Ogunfowokan

2007-01-01

 
 
 
 
101

Metal biosorption capability of Cupriavidus taiwanensis and its effects on heavy metal removal by nodulated Mimosa pudica.  

Science.gov (United States)

A novel metal biosorption system consisting of the symbiotic combination of an indigenous metal-resistant rhizobial strain, Cupriavidus taiwanensis TJ208, and its host plant Mimosa pudica has been developed for the removal of heavy-metal pollutants. Free-living C. taiwanensis TJ208 cells were able to adsorb 50.1, 19.0, and 19.6 mg/g of Pb, Cu, and Cd, respectively. After nodulation via inoculation with strain TJ208, the metal uptake ability of M. pudica markedly increased, as the nodulated M. pudica displayed a high metal uptake capacity (qmax) of 485, 25, and 43 mg/g, respectively, which is 86, 12, and 70% higher than that of nodule-free plants. Moreover, with TJ208 nodules, the M. pudica plant also displayed a 71, 81, and 33% enhancement in metal adsorption efficiency (eta) for Pb, Cu, and Cd, respectively. The nodulation appeared to give the greatest enhancing effect on the uptake of Pb, which is consistent with the preference of metal adsorption ability of TJ208. This seems to indicate the crucial role that the rhizobial strain may play in stimulating metal uptake of the nodulated plant. Furthermore, the results show that metal accumulation in the nodulated plant mainly occurred in the roots, accounting for 65-95% of total metal uptake. In contrast, the nodules and the shoots only contributed to 3-12 and 2-23% of total metal uptake, respectively. Nevertheless, the specific adsorption capacity of nodules is comparable to that of the roots. Hence, this work demonstrates the feasibility and effectiveness of using the nodulated plants to promote phyto-removal of heavy metals from the polluted environment as well as to restrict the metal contaminants in the unharmful region of the plant. PMID:17624667

Chen, Wen-Ming; Wu, Chih-Hui; James, Euan K; Chang, Jo-Shu

2008-03-01

102

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

Directory of Open Access Journals (Sweden)

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

103

Simultaneous removal of heavy metal ions from wastewater by foam separation techniques  

Energy Technology Data Exchange (ETDEWEB)

The objective of the present work is to extend the application of adsorbing colloid flotation techniques to remove mixtures of metal ions. The systems studied are: 1) Co(II) and Cr(VI); 2) Co(II), Ni(II), and Cr(VI); 3) Cr(VI), Cu(II), and Zn(II); 4) Cr(VI), Cu(II), Zn(II), and Ni(II); 5) Cd(II), Pd(II), and Cu(II). Ferric hydroxide and aluminum hydroxide were used as the coprecipitant, and sodium lauryl sulfate was used as the collector and frother. The ionic strength of the solution was adjusted with NaNO/sub 3/ or Na/sub 2/SO/sub 4/. It was found that all the heavy metals can be removed effectively by a single step foam flotation treatment.

Huang, S.D.; Huang, M.K.; Gua, J.Y.; Wu, T.P.; Huang, J.Y.

1988-04-01

104

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.)

1976-01-01

105

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

International Nuclear Information System (INIS)

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

2001-01-01

106

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

DEFF Research Database (Denmark)

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

Sun, Tian Ran

2013-01-01

107

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

Energy Technology Data Exchange (ETDEWEB)

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

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

2010-12-15

108

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

109

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

International Nuclear Information System (INIS)

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

1986-01-01

110

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

Energy Technology Data Exchange (ETDEWEB)

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

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

2012-11-01

111

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 materials in heavy metal removing processes.

2012-11-01

112

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

Directory of Open Access Journals (Sweden)

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

113

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

114

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

115

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

116

Heavy metal removal from soils using magnetic separation: 1. Laboratory experiments  

Energy Technology Data Exchange (ETDEWEB)

The removal of Cu, Zn, and Cd from a sandy soil was investigated using iron filings as an adsorbent, and subsequently recovering the iron filings by magnetic separation. The best treatment was obtained by using 5% iron filings and 3 h contact time between iron filings and the soil. The metal removal efficiency from soil extracts was evaluated, using MetPLATE trademark, a toxicity test that is specific for heavy metals, and the 48 h Ceriodaphnia dubia acute toxicity test. The toxicity removal was generally higher than 95% for Cu after a single treatment. With regard to Zn-spiked soil, the toxicity removal was 96.1%, 70.0%, and 49.6% after single treatment at the input concentration of 200 mg/kg, 400 mg/kg, and 800 mg Zn{sup 2+}/kg soil, respectively. After two or three successive treatments, more than 90% of the toxicity was removed for 400 mg/kg and 800 mg/kg Zn-spiked soils. In the case of Cd-spiked soil, a single treatment removed 51.1% of the toxicity from 200 mg/kg Cd-spiked soil extracts while more than 90% of the toxicity was removed after two or three treatments. Chemical analysis and a mass balance study were also carried out to investigate the Cu distribution in the soil fractions. The results indicate that, before treatment, a large portion of Cu was immobilized in the soil matrix. Following magnetic separation, Cu was removed from both the soil matrix and extracts and was indeed adsorbed and concentrated on the iron filings. The retrieval of Cu by iron filings was further examined by energy dispersive X-ray spectroscopy (EDS). (Abstract Copyright [2007], Wiley Periodicals, Inc.)

Feng, Nan; Bitton, Gabriel; Yeager, Philip; Bonzongo, Jean-Claude [Laboratory of Environmental Microbiology and Toxicology, Department of Environmental Engineering Sciences, University of Florida, Gainesville (United States); Boularbah, Ali [Faculte des Sciences et Techniques Gueliz, Departement de Biologie, Universite Cadi Ayyad, Marrakech (Morocco)

2007-09-15

117

Heavy metal removal from aqueous solution using carbonaceous K{sub 2}S-impregnated adsorbent  

Energy Technology Data Exchange (ETDEWEB)

A novel carbonaceous adsorbent for heavy metal removal was prepared from raw coal by one-step simple sulfur impregnation using K{sub 2}S. Raw coal was mixed with K{sub 2}S powder and then heated at 800{sup o} C for 30 min in nitrogen to produce K{sub 2}S char. The sulfur content and form in K{sub 2}S char were determined, and the ability of K{sub 2}S Char to adsorb Zn{sup 2+}, Cd{sup 2+} and Pb{sub 2+} was examined. The K2S impregnation was effective at impregnating sulfur into coal, especially in the form of elemental, thiophenic and sulfatic sulfur. The sulfur content of K{sub 2}S char was higher than those of raw coal and pyrolysis char. The Zn{sup 2+} removal in 2.4 mmol/L of Zn{sup 2+} solution by K{sub 2}S char was higher than raw coal with the removal rate of 100%. K{sub 2}S char adsorbed Pb{sup 2+} and Cd{sup 2+} in 24 mmol/L of Pb{sup 2+} and Cd{sup 2+} solution with the removal rate of 97% and 35%, respectively. The elution extents of adsorbed Pb{sup 2+} and Cd{sup 2+} were zero in distilled water and 27% in 0.1 mol/L HCl solution. These results indicated that an effective adsorbent for heavy metal ions was prepared from coal using K{sub 2}S sulfur impregnation, and that the adsorbed metals were strongly retained in K{sub 2}S char.

Wajima, T.; Murakami, K.; Kato, T.; Sugawara, K. [Akita University, Akita (Japan). Faculty of Engineering & Resource Science

2009-07-01

118

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

International Nuclear Information System (INIS)

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

1989-05-18

119

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

Directory of Open Access Journals (Sweden)

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

120

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

Energy Technology Data Exchange (ETDEWEB)

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.

Bayat, Belgin, E-mail: bbayat@cu.edu.tr [Department of Environmental Engineering, Faculty of Engineering and Architecture, Cukurova University, Balcali, Adana 01330 (Turkey); Sari, Bulent [Department of Environmental Engineering, Faculty of Engineering and Architecture, Cukurova University, Balcali, Adana 01330 (Turkey)

2010-02-15

 
 
 
 
121

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.

2010-02-15

122

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

Energy Technology Data Exchange (ETDEWEB)

The removal of heavy metal ions from water using electron beam and gamma irradiation has been investigated for the cases of Pb{sup 2+} and Hg{sup 2+} ions. These metal ions are reduced by hydrated electrons and hydrogen atoms to lower or zero valence state and eventually precipitate out of solution. Ethanol is applied as a relatively non-toxic additive to scavenge {sup {center_dot}}OH radicals, to enhance reduction and inhibit oxidation. Mercury can be completely (>99.9%) removed from aqueous solution of 1x10{sup -3} mol L{sup -1} mercury (II) chloride by using a 3 kGy dose. However, a 40 kGy dose is required to remove 96% of lead ions from a 1x10{sup -3} mol L{sup -1} of PbCl{sub 2} solution. The effect of dissolved oxygen and carbonate were also investigated. E-beam irradiation of 1x10{sup -3} mol L{sup -1} lead ions complexed with ethylenediamine tetraacetic acid (EDTA) in deoxygenated as well as air-saturated solutions in the absence of ethanol resulted in removal of about 97% of the lead.

Chaychian, Mahnaz; Al-Sheikhly, Mohamad; Silverman, Joseph [Department of Materials and Nuclear Engineering, University of Maryland, College Park, MD (United States); McLaughlin, William L. [Ionizing Radiation Division, National Institute of Standards and Technology, Gaithersburg, MD (United States)

1998-08-01

123

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

International Nuclear Information System (INIS)

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

1998-08-01

124

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

Science.gov (United States)

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

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

1998-08-01

125

Coal ash conversion into effective adsorbents for removal of heavy metals and dyes from wastewater.  

Science.gov (United States)

Fly ash was modified by hydrothermal treatment using NaOH solutions under various conditions for zeolite synthesis. The XRD patterns are presented. The results indicated that the samples obtained after treatment are much different. The XRD profiles revealed a number of new reflexes, suggesting a phase transformation probably occurred. Both heat treatment and chemical treatment increased the surface area and pore volume. It was found that zeolite P would be formed at the conditions of higher NaOH concentration and temperature. The treated fly ash was tested for adsorption of heavy metal ions and dyes in aqueous solution. It was shown that fly ash and the modified forms could effectively absorb heavy metals and methylene blue but not effectively adsorb rhodamine B. Modifying fly ash with NaOH solution would significantly enhance the adsorption capacity depending on the treatment temperature, time, and base concentration. The adsorption capacity of methylene blue would increases with pH of the dye solution and the sorption capacity of FA-NaOH could reach 5 x 10(-5) mol/g. The adsorption isotherm could be described by the Langmuir and Freundlich isotherm equations. Removal of copper and nickel ions could also be achieved on those treated fly ash. The removal efficiency for copper and nickel ions could be from 30% to 90% depending on the initial concentrations. The increase in adsorption temperature will enhance the adsorption efficiency for both heavy metals. The pseudo second-order kinetics would be better for fitting the dynamic adsorption of Cu and Ni ions. PMID:16310947

Wang, Shaobin; Soudi, Mehdi; Li, Li; Zhu, Z H

2006-05-20

126

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

International Nuclear Information System (INIS)

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

2010-11-24

127

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

Science.gov (United States)

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

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

2010-11-01

128

Heavy metals removal in fixed-bed column by the macro fungus Pycnoporus sanguineus.  

Science.gov (United States)

The ability of Pycnoporus sanguineus to adsorb heavy metals from aqueous solution was investigated in fixed-bed column studies. The experiments were conducted to study the effect of important design parameters such as column bed height, flow rate and initial concentration of solution. The breakthrough profiles were obtained in these studies. A mathematical model based on external mass transfer and pore diffusion was used for the prediction of mass transfer coefficient and effective diffusivity of metals in macro-fungi bed. Experimental breakthrough profiles were compared with the simulated breakthrough profiles obtained from the mathematical model. Bed Depth Service Time (BDST) model was used to analyse the experimental data and evaluated the performance of biosorption column. The BDST model parameters needed for the design of biosorption columns were evaluated for lead, copper and cadmium removal in the column. The columns were regenerated by eluting the metal ions using 0.1 M hydrochloric acid solution after the adsorption studies. The columns were subjected to repeated cycles of adsorption of same metal ions and desorption to evaluate the removal efficiency after adsorption-desorption. PMID:11291452

Zulfadhly, Z; Mashitah, M D; Bhatia, S

2001-01-01

129

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

2001-01-01

130

Enzymically accelerated biomineralization of heavy metals: application to the removal of americium and plutonium from aqueous flows.  

Science.gov (United States)

A biological process for the removal of heavy metals from the aqueous flows is described. Metals are precipitated on the surface of immobilized cells of a Citrobacter sp. as cell-bound metal phosphates. This uses phosphate liberated by the activity of a cell-bound phosphatase. Some radionuclides (e.g. 241americium) form metal phosphates readily; efficient removal of 241Am on a continuous basis is demonstrated. At low phosphatase activities, the efficiency of uranium removal correlates with enzyme activity. High phosphatase activities are not realised as an increase in metal removal, suggesting that chemical events become rate-limiting. Studies have suggested that maximal metal uptake occurs only after nucleation and the formation of precipitation foci. A model is presented to illustrate how nucleation and crystallization processes could enhance the removal of plutonium and neptunium from dilute solutions. PMID:7917422

Macaskie, L E; Jeong, B C; Tolley, M R

1994-08-01

131

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

International Nuclear Information System (INIS)

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

2010-07-26

132

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, Eddie C. (Park Forest, IL)

1995-01-01

133

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

134

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

Directory of Open Access Journals (Sweden)

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

Mohammed Nsaif

2013-12-01

135

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

136

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

Directory of Open Access Journals (Sweden)

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

H. Zolgharnein

2010-01-01

137

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

138

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

Science.gov (United States)

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

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

2009-05-15

139

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

International Nuclear Information System (INIS)

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

2009-05-15

140

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

Energy Technology Data Exchange (ETDEWEB)

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

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

2009-05-15

 
 
 
 
141

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

International Nuclear Information System (INIS)

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

2005-10-03

142

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

143

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

Science.gov (United States)

This work describes the preparation of the cellulose phosphate with high ion exchange capacity from rice straw and bagasse for removal of heavy metals. In this study, rice straw and bagasse were modified by the reaction with phosphoric acid in the presence of urea. The introduced phosphoric group is an ion exchangeable site for heavy metal ions. The reaction by microwave heating yielded modified rice straw and modified bagasse with greater ion exchange capacities (?3.62?meq/g) and shorter reaction time (1.5–5.0?min) than the phosphorylation by oil bath heating. Adsorption experiments towards Pb2+, Cd2+, and Cr3+ ions of the modified rice straw and the modified bagasse were performed at room temperature (heavy metal concentration 40?ppm, adsorbent 2.0?g/L). The kinetics of adsorption agreed with the pseudo-second-order model. It was shown that the modified rice straw and the modified bagasse could adsorb heavy metal ions faster than the commercial ion exchange resin (Dowax). As a result of Pb2+ sorption test, the modified rice straw (RH-NaOH 450W) removed Pb2+ much faster in the initial step and reached 92% removal after 20?min, while Dowax (commercial ion exchange resin) took 90?min for the same removal efficiency.

2014-01-01

144

Concurrent Removal of Toxic Heavy Metals and Organic Substances by Activated Carbon Process from Contaminated Groundwater.  

Science.gov (United States)

The treatability of groundwater containing both toxic heavy metals and organic substances was performed in the laboratory using synthetic solutions and activated carbon adsorption process. Two typical activated carbons, i.e., Nuchar SA (an L-type) and Fil...

C. P. Huang

1984-01-01

145

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

146

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

147

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

Directory of Open Access Journals (Sweden)

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

148

Removal of heavy metals in a wet detention pond in Reykjavik  

Digital Repository Infrastructure Vision for European Research (DRIVER)

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

Vollertsen, Guðbjo?rg Esther G.

2010-01-01

149

Removal of heavy metals in a wet detention pond in Reykjavik  

Digital Repository Infrastructure Vision for European Research (DRIVER)

A wet detention pond draining a residential area in the outskirts of Reykjavik was monitored during a 12 month period starting June 1st, 2008. The goal of the project was to increase the local information on stormwater pollution and detention pond treatment efficiency. Water samples taken during five runoff events were analyzed for a range of heavy metals and particle size. The results of this study was that on average, the heavy metal content of residential surface runoff entering the Icelan...

Vollertsen, Guðbjo?rg Esther G.; Hrund Ólöf Andradóttir 1972; --, Hildur Ingvarsdo?ttir

2009-01-01

150

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

Digital Repository Infrastructure Vision for European Research (DRIVER)

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

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

2010-01-01

151

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

Science.gov (United States)

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

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

2013-11-01

152

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

Directory of Open Access Journals (Sweden)

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

153

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

154

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

Digital Repository Infrastructure Vision for European Research (DRIVER)

The present study aimed at effective management and purification of industrial wastewaters using cheaper and locally available local alum for removal of heavy metals as a substitute to convectional coagulants. The effect of local alum, aluminum sulphate and ferric chloride on the metal contents of industrial wastewaters was investigated in the pH range of 5.9-7.5. Wastewater samples from battery, paint and textile industries were treated with different doses of locally available alum, aluminu...

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

2007-01-01

155

Soil treatment to remove uranium and related mixed radioactive heavy metal contaminants. Quarterly report, January--March 1995  

Energy Technology Data Exchange (ETDEWEB)

The objective of this project is to design and develop a physico- chemical treatment process for the removal of uranium and heavy metals from contaminated soil to achieve target contamination levels below 35 pCi/g of soil and a target for non-radioactive heavy metals below concentration levels permissible for release of the soil. Ex- situ pilot-scale soil decontamination and leachate treatment test using Chalk River Chemical Pit soil are nearing completion. Soil decontamination tests using Fernald Incinerator Area soil originally scheduled for February 1995 was postponed to May 1995 as result of unexpected delays in the preparation of two drums of soils.

NONE

1995-05-01

156

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.

2010-12-02

157

Removal of heavy metals from aqueous waste streams using surface-modified nanosized TiO{sub 2} photocatalysts.  

Energy Technology Data Exchange (ETDEWEB)

Titanium dioxide (TiO{sub 2}) colloidal particles ({approximately}45{angstrom}) whose surfaces were modified with chelating agents for photocatalytic removal of heavy-metal ions and their subsequent reduction to metallic form were investigated. Experiments were performed on nanoparticle TiO{sub 2} colloids derivatized with bidentate and tridentate ligands (thiolactic acid [TLA], cysteine, and alanine [ALA]) in batch mode in a photoreactor with 254nm light. We used catalysts designed and synthesized for selective and efficient removal of Pb and Cu with and without added hole scavenger (methanol). Parallel experiments also have been carried out in the dark to study metal ion adsorption properties. Solutions have been filtered to remove TiO{sub 2}, and metal particulates. Both the native solution and the metal deposited on the nanocrystalline TiO{sub 2} particles were analyzed. Results demonstrate that for the case of lead, the most effective TiO{sub 2} surface modifier was TLA (>99% Pb(II) removed from solution). Experiments performed to study Cn removal using TiO{sub 2} colloids modified with alanine showed that copper ions were effectively removed and reduced to metallic form in the presence of methanol.

Meshkov, N. K.

1998-08-27

158

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

Directory of Open Access Journals (Sweden)

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

159

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

Energy Technology Data Exchange (ETDEWEB)

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

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

2011-04-15

160

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

International Nuclear Information System (INIS)

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

2011-01-01

 
 
 
 
161

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.

2014-01-01

162

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

163

Plasmid Mediated Tolerance and Removal of Heavy Metals by Enterobacter sp  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Problem statement: The role of plasmid in the heavy metal resistance and accumulation by endophytic bacteria was investigated. Approach: The experimental results showed that high level plasmid mediated Cd2+ and Zn2+ resistance in this strain is due to decreased Cd2+ and/or Zn2+ uptake/accumulation by resistance strain. Results: Based on the fact that subsequent plasmid curing...

Bahig El-Deeb

2009-01-01

164

MECHANISMS OF HEAVY METAL REMOVAL FROM ACID MINE DRAINAGE USING CHITIN  

Science.gov (United States)

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

165

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

166

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

Energy Technology Data Exchange (ETDEWEB)

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

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

2010-06-15

167

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

168

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

Energy Technology Data Exchange (ETDEWEB)

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

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

2011-08-15

169

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.

2011-08-15

170

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

171

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

Science.gov (United States)

Poly(vinyl pyridine-poly ethylene glycol methacrylate-ethylene glycol dimethacrylate) [poly(VP-PEGMA-EGDMA)] beads with an average size of 30-100 microm 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. PMID:18164127

Duran, Ali; Soylak, Mustafa; Tuncel, S Ali

2008-06-30

172

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

2008-06-30

173

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

174

Heavy metal removal from industrial effluents by sorption on cross-linked starch: chemical study and impact on water toxicity.  

Science.gov (United States)

Batch sorption experiments using a starch-based sorbent were carried out for the removal of heavy metals present in industrial water discharges. The influence of contact time, mass of sorbent and pollutant load was investigated. Pollutant removal was dependent on the mass of sorbent and contact time, but independent of the contaminant load. The process was uniform, rapid and efficient. Sorption reached equilibrium in 60 min irrespective of the metal considered (e.g. Zn, Pb, Cu, Ni, Fe and Cd), reducing concentrations below those permitted by law. The material also removed residual turbidity and led to a significant decrease in the residual chemical oxygen demand (COD) present in the industrial water discharge. The germination success of lettuce (Lactuca sativa) was used as a laboratory indicator of phytotoxicity. The results show that the sorption using a starch-based sorbent as non-conventional material, is a viable alternative for treating industrial wastewaters. PMID:21067859

Sancey, Bertrand; Trunfio, Giuseppe; Charles, Jérémie; Minary, Jean-François; Gavoille, Sophie; Badot, Pierre-Marie; Crini, Grégorio

2011-03-01

175

Innovative developments in the selective removal and reuse of heavy metals from wastewaters  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Sulphide precipitation of heavy metal containing wastewaters results in low effluent concentrations. However, sulphide precipitation is not widely applied in practice because the dosing of sulphide cannot adequately be controlled. A new process was developed where the combination of a sulphide-selective electrode (pS-electrode) and pH electrode controls the sulphide addition. Precipitation experiments were performed on a laboratory-scale in batch and continuous reactor systems with synthetic ...

Veeken, A. H. M.; Rulkens, W. H.

2003-01-01

176

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

Energy Technology Data Exchange (ETDEWEB)

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

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

2003-07-01

177

Removal of heavy metals and dyes by supported nano zero-valent iron on barium ferrite microfibers.  

Science.gov (United States)

The binary nano zero-valent iron/barium ferrite (NZVI/BFO) microfibers with uniform diameters and high porosity were prepared by the organic gel-thermal selective reduction process. The composite microfibers are fabricated from nano zero-valent iron and nano BaFe12O19 grains. The effects of pH, adsorbent dosage, and contact time on the adsorption of heavy metals and dyes have been investigated. The adsorption isotherms of heavy metals and dyes on the microfibers are well described by the Langmuir model, in which the estimated adsorption capacities are 14.5, 29.9, 68.3 and 110.4 mg/g for Pb(II), As(V), Congo red and methylene blue, respectively. After five cycles, these microfibers still exhibit a high removal efficiency for As(V), Pb(II), Congo red and methylene blue. The enhanced adsorption characteristics can be attributed to the porous structure, strong surface activity and electronic hopping. Therefore, the magnetic NZVI/BFO microfibers can be used as an efficient, fast and high capacity adsorbent for heavy metals and dyes removal. PMID:24758012

Yang, Xinchun; Shen, Xiangqian; Jing, Maoxiang; Liu, Ruijiang; Lu, Yi; Xiang, Jun

2014-07-01

178

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

Scientific Electronic Library Online (English)

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

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

179

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

Science.gov (United States)

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

Vanthuyne, Mathias; Maes, André

2002-05-01

180

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

 
 
 
 
181

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

Energy Technology Data Exchange (ETDEWEB)

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

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

2008-08-15

182

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

Science.gov (United States)

Studies were carried out to assess changes in nitrogen, phosphorus and potassium contents in soil during bioleaching of heavy metals from soil contaminated by tannery effluents. Indigenous sulfur oxidizing bacteria Acidithiobacillus thiooxidans isolated from the contaminated soil were used for bioremediation. Solubilization efficiency of chromium, cadmium, copper and zinc from soil was 88, 93, 92 and 97%, respectively. However, loss of nitrogen, phosphorus and potassium from the soil was 30, 70 and 68%, respectively. These findings indicate that despite its high potential for removal of heavy metals from contaminated soils, bioleaching results in undesirable dissolution/loss of essential plant nutrients. This aspect warrants urgent attention and detailed studies to evaluate the appropriateness of the technique for field application. PMID:18206305

NareshKumar, R; Nagendran, R

2008-08-15

183

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

International Nuclear Information System (INIS)

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

2008-08-15

184

Removal of heavy metals by waste tea leaves from aqueous solution  

Energy Technology Data Exchange (ETDEWEB)

In this paper, tea leaves were shown to be an effective, low-cost biosorbent. Removal of lead, iron, zinc and nickel from 20 mg/L metal solution by dried biomass of waste tea leaves amounted to 96, 91, 72 and 58 %, respectively, at equilibrium, which followed Langmuir and Freundlich adsorption isotherms. Adsorption of metal was in the order of Pb > Fe > Zn > Ni from 5-100 mg/L of metal solution. From a multi-metallic mixture, 92.5, 84 and 73.2 % of lead, iron and zinc, respectively, were removed. Fourier transform infrared (FTIR) studies indicated that the carboxyl group was involved in the binding of lead and iron, whereas the amine group was involved in the binding of nickel and zinc. A flow through sorption column packed with dried biomass demonstrated a sorption capacity of 73 mg Pb/g of biomass, indicating its potential in cleaning metal containing wastewater. The metal laden biomass obtained could be disposed off by incineration. (Abstract Copyright [2005], Wiley Periodicals, Inc.)

Ahluwalia, S.S.; Goyal, D. [Thapar Institute of Engineering and Technology, Department of Biotechnology and Environmental Sciences, Patiala 147 004, Punjab (India)

2005-04-01

185

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

Science.gov (United States)

A concept of electrochemically switched ion exchange (ESIX) hybrid film system with piston-like proton pumping effect for the removal of heavy metal ions was proposed. Based on this concept, a novel ESIX hybrid film composed of layered alpha zirconium phosphate (?-Zr(HPO4)2; ?-ZrP) nanosheets intercalated with a potential-responsive conducting polyaniline (PANI) was developed for the removal of Ni(2+) ions from wastewater. It is expected that the space between ?-ZrP nanosheets acts as the reservoir for the functional ions while the intercalated PANI works as the potential-sensitive function element for piston-like proton pumping in such ESIX hybrid films. The prepared ESIX hybrid film showed an excellent property of rapid removal of Ni(2+) ions from wastewater with a high selectivity. The used film was simply regenerated by only altering the applied potential. The ion pumping effect for the ESIX of Ni(2+) ions using this kind of film was proved via XPS analysis. The proposed ESIX hybrid film should have high potential for the removal of Ni(2+) ions and/or other heavy metal ions from wastewater in various industrial processes. PMID:24813663

Wang, Zhongde; Feng, Yanting; Hao, Xiaogang; Huang, Wei; Guan, Guoqing; Abudula, Abuliti

2014-06-15

186

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

187

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

188

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

189

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

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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

190

Heavy metals removal from wastewaters using organic solid waste-rice husk.  

Science.gov (United States)

In this study, the removal of Cr(III) and Cu(II) from contaminated wastewaters by rice husk, as an organic solid waste, was investigated. Experiments were performed to investigate the influence of wastewater initial concentration, pH of solution, and contact time on the efficiency of Cr(III) and Cu(II) removal. The results indicated that the maximum removal of Cr(III) and Cu(II) occurred at pH 5-6 by rice husk and removal rate increased by increased pH from 1 to 6. It could be concluded that the removal efficiency was enhanced by increasing wastewater initial concentration in the first percentage of adsorption and then decreased due to saturation of rice husk particles. Also according to achieved results, calculated saturation capacity in per gram rice husk for Cr(III) and Cu(II) were 30 and 22.5 mg?g(-1), respectively. The amounts of Cr(III) and Cu(II) adsorbed increased with increase in their contact time. The rate of reaction was fast. So that 15-20 min after the start of the reaction, between 50 and 60 % of metal ions were removed. Finally, contact time of 60 min as the optimum contact time was proposed. PMID:23381799

Sobhanardakani, S; Parvizimosaed, H; Olyaie, E

2013-08-01

191

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

Digital Repository Infrastructure Vision for European Research (DRIVER)

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 mechan...

Abdouss Majid; Shoushtari Mousavi Ahmad; Haji Aminoddin; Moshref Behnam

2012-01-01

192

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

193

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

Science.gov (United States)

The demand for clean water is on the increase as the population increases. One of the ways to address the water shortage is to treat the polluted water through removal of the contaminants. The use of adsorbents for pollutant removal is one of the promising methods. Seaweed is an aquatic plant and its sorption ability for selected metals in water was investigated in this study. We report the performance of the seaweed (Caulerpa serrulata) before and after modification with ethylenediamine (EDA), on adsorption of copper, lead and cadmium in aqueous solution. The adsorption capacities for Cu, Cd and Pb were 5.27 mg g-1, 2.12 mg g-1 and 2.16 mg g-1, respectively, with the EDA-modified seaweed, and 3.29 mg g-1, 4.57 mg g-1 and 1.06 mg g-1, with the unmodified weed, respectively. The pH for maximum adsorption was found to be within the range of pH 4-pH 6. In a separate investigation, it was found that 0.1 g of dried seaweed leached 20 mg of dissolved organic carbon (DOC) using 100 ml of distilled-deionised water. The resulting solution was green. The leaching phenomenon contributes to secondary pollution. Modification of the seaweed with EDA reduced the DOC content by half (50%) and also removed the green colouration. Kinetic studies showed that the adsorbent was able to take up to 95% of the metals (in synthetic standard solutions) in less than 10 min. The adsorbed metals were then stripped using a solution of 0.5 M HNO3 indicating that the adsorbent can be regenerated. In addition, the study revealed that modification improved the thermal stability of the adsorbent such that even when the temperature was raised to 1000 °C, more than 80% (compared to seaweed. The modified seaweed has been shown to have great potential for the removal of metals and DOC in polluted water. The modified adsorbent can therefore be applied for the removal of metals in polluted waters hence suitable for treatment of water for domestic consumption at a point of use.

Mwangi, Isaac W.; Ngila, J. Catherine

194

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

195

Efficient removal of the organochlorine pesticide and heavy-metal residues in Epimedium brevicornum Maxim by supercritical fluid extraction.  

Science.gov (United States)

A method involving depuration of 12 organochlorine pesticides (OCPs) and 7 heavy metals from Epimedium brevicomum Maxim was developed using supercritical fluid extraction (SPE). The pesticides in the study consisted of alpha, beta-, gamma-, and delta-Benzene hexachloride, Pentachloronitrobenzene (PCNB), Pentachloroaniline (PCA), Heptachlor (HEPT), Methyl -pentachlorophenyl sulfide (MPCPS), pp'-DDE[1,1-dichloro-2, 2-bis (p-chlorophenyl) ethylene], op'-DDT [1,1,1-trichloro-2-(o-chlorophenyl)-2-(p-chlorophenyl)ethane], pp'-DDD [1,1-dichloro-2-2-bis(p-chlorophenyl)]ethane, pp'-DDT [1,1,1-trichloro-2,2-bis(p-chlorophenyl) ethane]. A series of experiments was conducted to optimize the final extraction conditions as following: pure CO2, extraction pressure of 15 Mpa, extration temperature of 60 degrees C, extraction time of 10 min, flow rate at 55 kg/h. A GC method with electron capture detection was employed to determination of the OCPs, and an atomic absorption spectrometry (AAS) was designed for the determination of 7 heavy metals including of Pb, Cd, Cu, Fe, Zn, As, Hg in Epimedium brevicomum Maxim. A HPLC method was developed for the quantitative determination of active constituents. The SFE was used to remove the organochlorine pesticide and heavy metals from Epimedium brevicornum Maxim, receiving high decontamination rate of pesticide residue and low loss of active constituents. PMID:18254243

Zhao, Chunjie; Bai, Lu; Li, Huanxin; Li, Fei; Xin, Chunhong

2007-12-01

196

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

197

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

198

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

199

Heavy metal sorption by microalgae  

International Nuclear Information System (INIS)

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

1996-01-01

200

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

 
 
 
 
201

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

International Nuclear Information System (INIS)

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

2009-12-30

202

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

203

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

1993-05-01

204

In situ XANES study of removal of heavy metals from laboratory wasteliquid by the ferrite process  

International Nuclear Information System (INIS)

Heavy metals in the laboratory wasteliquid can be recovered as stable and economic ferrite by the ferrite process. The spectrum of X-ray absorption near edge structure (XANES) specifically shows that 92% of Cr(OH)3 and 8% of CrCl2 in the original laboratory wasteliquid are converted to 70% of Cr2O3 and 30% of CrCl2 in the precipitates by the ferrite process. The concentrations of total chromium, lead and zinc in the laboratory wasteliquid also dropped from 383,000, 20.9 and 277 ppb, respectively, to lower than the effluent standards of the Environmental Protection Administration (EPA) in Taiwan. The XRD (X-ray diffraction) analysis shows that the chromium ferrite is achieved at pH > 9. On the other hand, the XANES spectra of the in situ experiment show there were 52% of Fe3O4 in the precipitates

2007-05-01

205

Modeling heavy-metal removal in wetlands (final report). Master's thesis  

Energy Technology Data Exchange (ETDEWEB)

A computer model has been developed to simulate the fate transport of heavy metals introduced to a wetland ecosystem. Modeled water quality variables include plankton biomass and productivity; macrophyte (Nuiumbo lutea) biomass; total phosphorus in the water column; dissolved copper in the water column and sediments; particulate copper in the water column and sediments; and suspended solids. These variables directly affect the modeled rate of copper uptake by macrophytes, and the rate of copper recycling as a function of the decomposition of copper-laden biomass litter. The model was calibrated using total phosphorus and chlorophyll-a data from the Old Woman Creek Wetland in Ohio. Verification of the model was achieved using data on the copper content of the macrophyte Nelumbo lutea. The effects of harvesting copper-laden biomass on the longevity of the wetland ecosystem were also evaluated.

Light, R.N.

1992-05-01

206

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

207

Estimation of efficiency of removing of heavy metal ions from waste waters in the form of hydroxides  

International Nuclear Information System (INIS)

Values of minimal solubility of heavy metal hydroxides (Fe, Cr, Cd, Mn, Co, Pb) are calculated. Comparison of obtained data with permissible concentrations of metal ions in reservoirs of different purpose is done. Efficiency of reagent method of waste water purification based on heavy metal hydroxide precipitation is estimated

2003-02-01

208

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

209

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

210

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.

2010-01-15

211

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

International Nuclear Information System (INIS)

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

2010-03-04

212

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

International Nuclear Information System (INIS)

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

2012-08-01

213

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

214

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

International Nuclear Information System (INIS)

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

2013-09-15

215

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

216

Chemistry of heavy metals in groundwater and river water and heavy metal removal. Final report. Chemie der Schwermetalle in Grundwasser und Flusswasser und ihre Abtrennung. Abschlussbericht  

Energy Technology Data Exchange (ETDEWEB)

The investigation was intended to develop methods for analyzing the chemical composition and chemical reactions of heavy metals in groundwater and river water and, on this basis, to obtain as much information as possible on the chemistry of trace elements in water. The second part of the investigation was dedicated to a critical analysis of the efficiency, advantages and drawbacks and error rate of different techniques for trace element detection in natural surface water, especially rivers.

Lieser, K.H.; Dyck, W.; Glueck, C.; Paetzold, R.; Peschke, S.; Pilz, N.; Scharf, K.; Sendelbach, G.; Sondermeyer-Knoop, S.; Weidenauer, M.

1985-01-01

217

Biosorption of heavy metals  

Energy Technology Data Exchange (ETDEWEB)

Only within the past decade has the potential of metal biosorption by biomass materials been well established. For economic reasons, of particular interest are abundant biomass types generated as a waste byproduct of large-scale industrial fermentations or certain metal-binding algae found in large quantities in the sea. These biomass types serve as a basis for newly developed metal biosorption processes foreseen particularly as a very competitive means for the detoxification of metal-bearing industrial effluents. The assessment of the metal-building capacity of some new biosorbents is discussed. Lead and cadmium, for instance, have been effectively removed from very dilute solutions by the dried biomass of some ubiquitous species of brown marine algae such as Ascophyllum and Sargassum, which accumulate more than 30% of biomass dry weight in the metal. Mycelia of the industrial steroid-transforming fungi Rhizopus and Absidia are excellent biosorbents for lead, cadmium, copper, zinc, and uranium and also bind other heavy metals up to 25% of the biomass dry weight. Biosorption isotherm curves, derived from equilibrium batch sorption experiments, are used in the evaluation of metal uptake by different biosorbents. Further studies are focusing on the assessment of biosorbent performance in dynamic continuous-flow sorption systems. In the course of this work, new methodologies are being developed that are aimed at mathematical modeling of biosorption systems and their effective optimization. 115 refs., 7 figs., 3 tabs.

Volesky, B. [McGill Univ., Montreal (Canada)]|[B.V. Sorbex, Inc., Montreal (Canada); Holan, Z.R. [McGill Univ., Montreal (Canada)

1995-05-01

218

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

Science.gov (United States)

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

219

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

220

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

 
 
 
 
221

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

DEFF Research Database (Denmark)

Sorption to iron-oxide coated sand (IOCS) is a promosing technology for removal of the dissolved heavy metal fraction in stormwater runoff. The development of a new technology is necessary since studies of stormwater runoff from traffic areas indicate that an oil separator and detention pond may not guarantee that emission limit values set by the Danish EPA are satisfied. Runoff water was sampled from an urban highway, allowed to settle for 24 hours to simulate the effect of a detention pond, and finally spiked with metals to ensure concentration levels similar to high levels reported in the leterature (Pb=20, Cu=40, Zn=110, and Cr=15 ppb). Column experiments were conducted to test the influence of the infiltration rate (1 or 3 m/h) and the type of iron(hydr)oxide mineral (amorphous ferrihydrite and goethite coated sand). The results show that at least 90% of lead, copper and zinc can be removed by IOCS after 480 pore volumes. Control columns with uncoated filter sand show that lead, copper and zinc were removed with >95%, 35% and 5%, respectively. The removal of the negative metaloxy-ion, CrO4-3 was insignificant in both IOCS and sand columns at pH=7.7. Destruction of the columns after the experiments showed, that Pb, Cu and Zn penetrated to different depths in the columns. No saturation of lead was found in the first cm of the column after 1696 pore volumes of teated water. Copper showed a curved adsorption front, indicating that an infiltration speed of 3 m/h is sligtly too fast for the equilibrium between water phase and IOCS to be reached. The column with ferrihydrite was fully saturated with regard to zinc after 1696 pore volumes. In general the coating of goethite is found to be at least twice as effective as ferrihydrite with respect to the adsorption capacity of copper and zinc. Furthermore, desorption of metals from the IOCS by soaking in weak acid (pH=2.25) showed that 20%, 58% and 75% of the adsorbed Pb, Cu and Zn was recovered. Reuse of the IOCS after soaking in weak acis is possible, but it is likely to lower the adsorption capacities found in this study.

Møller, J.; Ledin, Anna

2002-01-01

222

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).

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

223

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

224

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.

225

Biosorption of heavy metals.  

Science.gov (United States)

Only within the past decade has the potential of metal biosorption by biomass materials been well established. For economic reasons, of particular interest are abundant biomass types generated as a waste byproduct of large-scale industrial fermentations or certain metal-binding algae found in large quantities in the sea. These biomass types serve as a basis for newly developed metal biosorption processes foreseen particularly as a very competitive means for the detoxification of metal-bearing industrial effluents. The assessment of the metal-binding capacity of some new biosorbents is discussed. Lead and cadmium, for instance, have been effectively removed from very dilute solutions by the dried biomass of some ubiquitous species of brown marine algae such as Ascophyllum and Sargassum, which accumulate more than 30% of biomass dry weight in the metal. Mycelia of the industrial steroid-transforming fungi Rhizopus and Absidia are excellent biosorbents for lead, cadmium, copper, zinc, and uranium and also bind other heavy metals up to 25% of the biomass dry weight. Biosorption isotherm curves, derived from equilibrium batch sorption experiments, are used in the evaluation of metal uptake by different biosorbents. Further studies are focusing on the assessment of biosorbent performance in dynamic continuous-flow sorption systems. In the course of this work, new methodologies are being developed that are aimed at mathematical modeling of biosorption systems and their effective optimization. Elucidation of mechanisms active in metal biosorption is essential for successful exploitation of the phenomenon and for regeneration of biosorbent materials in multiple reuse cycles. The complex nature of biosorbent materials makes this task particularly challenging. Discussion focuses on the composition of marine algae polysaccharide structures, which seem instrumental in metal uptake and binding. The state of the art in the field of biosorption is reviewed in this article, with many references to recent reviews and key individual contributions. PMID:7619394

Volesky, B; Holan, Z R

1995-01-01

226

Application of electrochemical process for landfill leachate treatment with emphasis on heavy metal and organic removal.  

Science.gov (United States)

This study was conducted to investigate the mechanisms of electrochemical treatment of a landfill leachate with emphasis on lead and organic removal. Laboratory electrochemical experiments were conducted using both synthetic wastewater and landfill leachate samples. From the synthetic wastewater experiments, the lead removal efficiencies were found to be more than 99%. The lead removal was observed to be dependent on: the electrical current, ratio between reacting surface area and volume of reactor and operation time, and following a first-order reaction. Similar results on lead removal were obtained when the landfill leachate samples were treated in the electrochemical reactor; the percent removal of soluble biological oxygen demand and soluble chemical oxygen demand concentrations from the landfill leachate during the electrochemical treatment were 30-60%, while the color removal was 70%. The sludge generated from the electrochemical reactions using the synthetic lead wastewater, analyzed by X-ray diffractometry, was found to be composed mainly of maghemite, magnetite, and laurionite. Based on the X-ray fluorescence spectrometry analysis, the percent contents of iron and lead were 68.6% as maghemite and 10.1% as lead oxide, respectively. The sludge generated from the landfill leachate treatment containing lead, analyzed by X-ray diffractometry, was found to be composed mainly of maghemite. Based on the X-ray fluorescence spectrometry analysis, the percent contents of iron and lead in the sludge were 69.49% as maghemite and 0.63% as lead oxide, respectively. The sludge volume index, capillary suction time and leachability values of the sludge were in suitable range for settling, dewatering and disposal. PMID:14599147

Thaveemaitree, Y; Polprasert, C; Seung-Hwan, L

2003-09-01

227

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

228

Removal of Heavy Metals from Aqueous Systems with Thiol Functionalized Superparamagnetic Nanoparticles  

Energy Technology Data Exchange (ETDEWEB)

We have shown that superparamagnetic iron oxide (Fe3O4) nanoparticles with a surface functionalization of dimercaptosuccinic acid is an effective, magnetic, sorbent material for toxic metals such as Hg, Ag, Pb, Cd and other soft cations. The chemical affinity, stability, capacity and kinetics of the functionalized nanoparticles has been explored and compared to conventional resin based sorbents and nanoporous silica materials with similar surface chemistries.

Yantasee, Wassana; Warner, Cynthia L.; Sangvanich, Thanapon; Addleman, Raymond S.; Carter, Timothy G.; Wiacek, Robert J.; Fryxell, Glen E.; Timchalk, Chuck; Warner, Marvin G.

2007-06-09

229

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

International Nuclear Information System (INIS)

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

1997-01-01

230

Heavy metal removal from contaminated sludges with dissolved sulfur dioxide in combination with bacterial leaching  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Treatment of dredged sludge from the Hamburg harbour area with sulfurous acid (6%) shows nearly complete removal of Cd, Zn, and Mn within the first 10 minutes. Within 1 hour more than 50% of Cr, Ni, Pb and Hg are mobilized; dissolution of Cu and Fe reaches about 40%. The capability of certain bacteria (Thiobacillus thiooxidans and Thiobacillus ferrooxidans) to oxidize sulfur and ferrous iron respectively, while decreasing the pH value from 4-5 to about 2 was utilized for enhancing dissolution...

Calmano, Wolfgang; Ahlf, Wolfgang; Fo?rstner, Ulrich

1983-01-01

231

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.

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

232

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

233

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

234

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

International Nuclear Information System (INIS)

We prepared novel Fe3O4 magnetic nanoparticles (MNPs) modified with 3-aminopropyltriethoxysilane (APS) and copolymers of acrylic acid (AA) and crotonic acid (CA). The MNPs were characterized by transmission electron microscopy, X-ray diffraction, infra-red spectra and thermogravimetric analysis. We explored the ability of the MNPs for removing heavy metal ions (Cd2+, Zn2+, Pb2+ and Cu2+) from aqueous solution. We investigated the adsorption capacity of Fe3O4-APS-AA-co-CA at different pH in solution and metal ion uptake capacity as a function of contact time and metal ion concentration. Moreover, adsorption isotherms, kinetics and thermodynamics were studied to understand the mechanism of the synthesized MNPs adsorbing metal ions. In addition, we evaluated the effect of background electrolytes on the adsorption. Furthermore, we explored desorption and reuse of MNPs. Fe3O4-APS-AA-co-CA MNPs are excellent for removal of heavy metal ions such as Cd2+, Zn2+, Pb2+ and Cu2+ from aqueous solution. Furthermore, the MNPs could efficiently remove the metal ions with high maximum adsorption capacity at pH 5.5 and could be used as a reusable adsorbent with convenient conditions.

2012-04-15

235

Removal of heavy metal cations by biogenic magnetite nanoparticles produced in Fe(III)-reducing microbial enrichment cultures.  

Science.gov (United States)

The biogenic magnetite nanoparticles presented here had a high capacity of adsorbing metal cations, which was approximately 30- to 40-fold greater than commercially available magnetite. These results suggest the potential application of microbial magnetite formation in the removal of toxic metal cations from water. PMID:24060652

Iwahori, Keisuke; Watanabe, Jun-ichi; Tani, Yukinori; Seyama, Haruhiko; Miyata, Naoyuki

2014-03-01

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

Influence of solution acidity and CaCl2 concentration on the removal of heavy metals from metal-contaminated rice soils  

International Nuclear Information System (INIS)

Soil washing is considered a useful technique for remediating metal-contaminated soils. This study examined the release edges of Cd, Zn, Ni, Cr, Cu or Pb in two contaminated rice soils from central Taiwan. The concentrations exceeding the trigger levels established by the regulatory agency of Taiwan were Cu, Zn, Ni and Cr for the Ho-Mei soil and Pb for the Nan-Tou soil. Successive extractions with HCl ranging from 0 to 0.2 M showed increased release of the heavy metals with declining pH, and the threshold pH value below which a sharp increase in the releases of the heavy metals was highest for Cd, Zn, and Ni (pH 4.6 to 4.9), intermediate for Pb and Cu (3.1 to 3.8) and lowest for Fe (2.1), Al (2.2) and Cr (1.7) for the soils. The low response slope of Ni and Cr particularly for the rice soils make soil washing with the acid up to the highest concentration used ineffective to reduce their concentrations to below trigger levels. Although soil washing with 0.1 M HCl was moderately effective in reducing Cu, Pb, Zn and Cd, which brought pH of the soils to 1.1 ± 0.1 (S.D.), the concurrent release of large quantities of Fe and Al make this remediation technique undesirable for the rice soils containing high clay. Successive washings with 0.01 M HCl could be considered an alternative as the dissolution of Fe and Al was minimal, and between 46 to 64% of Cd, Zn, and Cu for the Ho-Mei soil and 45% of Pb in the Na-Tou soil were extracted after four successive extractions with this dilute acid solution. The efficacy of Cd extraction improved if CaCl2 was added to the acid solution. The correlation analysis revealed that Cr extracted was highly correlated (P < 0.001) with Fe extracted, whereas the Cu, Ni, Zn, Cd or Pb extracted was better correlated (P < 0.001) with Al than with Fe extracted. It is possible that the past seasonal soil flooding and drainage in the soils for rice production was conducive to incorporating Cr within the structure of Fe oxide, thereby making them extremely insoluble even in 0.2 M HCl solution. The formation of solid solution of Ni with Al oxide was also possible, making it far less extractable than Cd, Zn, Cu, or Pb with the acid concentrations used. - Release edges and threshold pH values for heavy metals determine how effective dilute HCl in removing the metals from metal-contaminated rice soils

2006-12-01

238

Silica-polyamine composite materials for heavy metal ion removal, recovery, and recycling. 2. Metal ion separations from mine wastewater and soft metal ion extraction efficiency  

Energy Technology Data Exchange (ETDEWEB)

Silica-polyamine composites have been synthesized which have metal ion capacities as high as 0.84 mmol/g for copper ions removed from aqueous solutions. In previous reports it has been demonstrated that these materials survive more than 3,000 cycles of metal ion extraction, elution, and regeneration with almost no loss of capacity (less than 10%). This paper describes two modified silica-polyamine composite materials and reveals the results of tests designed to determine the effectiveness of these materials for extracting and separating metal ions from actual mining wastewater samples. Using these materials, the concentration of copper, aluminum, and zinc in Berkeley Pit mine wastewater is reduced to below allowable discharge limits. The recovered copper and zinc solutions were greater than 90% pure, and metal ion concentration factors of over 20 for copper were realized. Further, the ability of one of these materials to decrease low levels of the soft metals cadmium, mercury, and lead from National Sanitation Foundation recommended challenge levels to below Environmental Protection Agency allowable limits is also reported.

Fischer, R.J.; Pang, D.; Beatty, S.T.; Rosenberg, E.

1999-12-01

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.

2009-06-15

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

2006-07-31

 
 
 
 
241

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

Directory of Open Access Journals (Sweden)

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

Mauro Célio da Silveira Pio

2013-06-01

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.

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

243

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

International Nuclear Information System (INIS)

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

2005-11-01

244

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

Energy Technology Data Exchange (ETDEWEB)

'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.'

Rodriguez, N.M.

1998-06-01

245

Photoactivated metal removal  

Energy Technology Data Exchange (ETDEWEB)

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

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

1999-07-01

246

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

Science.gov (United States)

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

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

2014-07-01

247

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

International Nuclear Information System (INIS)

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

2012-05-01

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

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

Science.gov (United States)

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

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

2014-07-15

250

Removal of Heavy Metals from Aqueous Solution Using Novel Nanoengineered Sorbents: Self-Assembled Carbamoylphosphonic Acids on Mesoporous Silica  

Energy Technology Data Exchange (ETDEWEB)

Self-assembled monolayers of carbamoylphosphonic acids (acetamide phosphonic acid and propionamide phosphonic acid) on mesoporous silica supports were studied as potential absorbents for heavy and transition metal ions in aqueous wastes. The adsorption capacity, selectivity, and kinetics of the materials in sequestering metal ions, including Cd2+, Co2+, Cu2+, Cr3+, Pb2+, Ni2+, Zn2+, and Mn2+, were measured in batch experiments with excess sodium ion. The solution pH ranged from 2.2 to 5.5. The kinetics study shows that the adsorption reached equilibrium in seconds, indicating that there is little resistance to mass transfer, intraparticle diffusion, and surface chemical reaction. The competitive adsorption study found the phosphonic acid-SAMMS to have an affinity for divalent metal ions in decreasing order of Pb2+ > Cu2+ > Mn2+ > Cd2+ > Zn2+ > Co2+ > Ni2+. The measured Cd2+ adsorption isotherm was of the Langmuirian type and had a saturation binding capacity of 0.32 mmol/g.

Yantasee, Wassana; Lin, Yuehe; Fryxell, Glen E.; Busche, Brad J.; Birnbaum, Jerome C.

2003-08-01

251

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)

2013-06-01

252

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

253

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.

2006-09-28

254

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

Energy Technology Data Exchange (ETDEWEB)

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

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

2012-11-01

255

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

256

Removal of metals from solution  

International Nuclear Information System (INIS)

Metals are removed from aqueous or organic solution by contacting the solution with a product, derived from an inorganic oxide containing surface hydroxyl groups, e.g., silica, containing groups of general formulae. Suitable metals for removal include copper, silver, rhodium, lead, uranium, palladium, cobalt and mercury. The process may be used to recover wanted metals or to remove contaminants

1978-11-15

257

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

International Nuclear Information System (INIS)

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

1994-01-01

258

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

International Nuclear Information System (INIS)

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

1995-07-31

259

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

Energy Technology Data Exchange (ETDEWEB)

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

NONE

1995-05-01

260

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

International Nuclear Information System (INIS)

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

2011-11-15

 
 
 
 
261

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

Science.gov (United States)

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

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

2014-02-01

262

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+)reported here. PMID:23708454

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

2013-08-15

263

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.

2010-01-01

264

Microbial heavy metal accumulation  

Energy Technology Data Exchange (ETDEWEB)

Silver uptake by a strain of Citrobacter intermedius was examined in batch culture, continuous culture and in non-growing populations of the bacterium. Evidence is presented to suggest that silver interacts solely with the cell envelope of the organism. Saturation kinetics are exhibited as the external metal ion concentration is raised, both in growing and non-growing populations, a maximum cellular silver ion concentration of 9.1% (w/w) being achieved. The effect of pH on silver accumulation and inhibition of the phenomenon by cadmium, an ion of similar mass and radius, also support the hypothesis that silver uptake is a cell wall phenomenon. Bioaccumulation is shown to be independent of temperature, thus precluding active transport and facilitative diffusion as accumulation mechanisms. Examination of cadmium uptake kinetics revealed differences and similarities to the silver accumulation mechanics. Attempts were made to produce a strain of Citrobacter intermedius which did not harbor a 150kb plasmid in order to demonstrate its involvement with silver resistance and/or bioaccumulation unequivocally. Primary enrichment cultures in the presence of elevated levels of silver, cadmium, copper, cobalt and nickel, were performed in chemostats, batch cultures and on solid media. Inocula included electroplating effluent, activated sludge and landfill material exposed to heavy metals. Metal resistance was shown to be a common phenomenon in such environments but incidences of metal bioaccumulation were limited.

Highton, G.

1987-01-01

265

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

Digital Repository Infrastructure Vision for European Research (DRIVER)

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

Turan, Nurdan Gamze; Gu?mu?s?el, Emine Beril; Ozgonenel, Okan

2013-01-01

266

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%).

Turan, Nurdan Gamze; Gumusel, Emine Beril; Ozgonenel, Okan

2013-01-01

267

Disorders of heavy metals.  

Science.gov (United States)

Heavy metals and trace elements play an important role in relation to the physiology and pathology of the nervous system. Neurologic diseases related to disorders of metabolism of copper and iron are reviewed. Copper disorders are divided into two classes: ATP7A- or ATP7B-related inherited copper transport disorders (Menkes disease, occipital horn syndrome, ATP7A-related distal motor neuropathy, and Wilson disease) and acquired diseases associated with copper deficiency or copper excess. Iron brain disorders are divided into genetic neurodegeneration with brain iron accumulation (NBIA, neuroferritinopathy, and aceruloplasminemia), genetic systemic iron accumulation with neurologic features (hemochromatosis), and acquired diseases associated with iron excess (superficial siderosis) or iron deficiency (restless leg syndrome). The main features of cadmium, lead, aluminum, mercury, and manganese toxicity are summarized. PMID:24365357

Woimant, France; Trocello, Jean-Marc

2014-01-01

268

Heavy metals in water organisms  

Energy Technology Data Exchange (ETDEWEB)

Chemical substances of anthropogenic origin polluting surface waters are dangerous to aquatic organisms and have varying effects on microbes, plants and animals. Living organisms frequently accumulate pollutants, signaling in this way their presence in the environment. Accumulation is particularly characteristic of heavy metals entering surface waters as industrial, agricultural and communal wastes. Heavy metals have come into the focus of environmental biological research all over the world. Beyond the monitoring of pollution, attention is being paid to the various organisms which make early detection possible. The papers presented in this book provide information on the latest results in this field. The main topics discussed were accumulation of heavy metals, ecological monitoring of heavy metal pollution, organisms as indicators and the effect of heavy metal pollution on vital functions.

Salanki, J.

1985-01-01

269

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

International Nuclear Information System (INIS)

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

2013-05-01

270

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

International Nuclear Information System (INIS)

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

2005-05-01

271

Plant rhamnogalacturonan II complexation of heavy metal cations  

Energy Technology Data Exchange (ETDEWEB)

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

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

1999-03-02

272

Plant rhamnogalacturonan II complexation of heavy metal cations  

Energy Technology Data Exchange (ETDEWEB)

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

O' Neill, Malcolm A. (Winterville, GA); Pellerin, Patrice J. M. (Montpellier, FR); Warrenfeltz, Dennis (Athens, GA); Vidal, Stephane (Combaillaux, FR); Darvill, Alan G. (Athens, GA); Albersheim, Peter (Athens, GA)

1999-01-01

273

Assessing fly ash treatment: Remediation and stabilization of heavy metals  

Digital Repository Infrastructure Vision for European Research (DRIVER)

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

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

2012-01-01

274

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

275

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

International Nuclear Information System (INIS)

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

2006-01-23

276

Consequential species of heavy metals. Final report  

Energy Technology Data Exchange (ETDEWEB)

Highway stormwater runoff contains significantly higher concentrations of trace metals, particularly Pb, Zn, Cd, Cu, Cr, Fe, and Ni than the water samples from adjacent receiving water bodies. The metals associated with highway runoff tend to be detoxified by the organic content and chemical conditions of natural waters and sediments. Most of the metals are retained by the bottom sediments on a permanent basis if aerobic conditions and high redax-potential (Eh) values are maintained. Retention/detention ponds similar to the Maitland Pond site are very effective in nutrient and heavy metal removal from highway runoff.

Yousef, Y.A.; Harper, H.H.; Wiseman, L.; Bateman, M.

1985-02-01

277

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

278

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+

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

279

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

280

Catalytic removal of NO in waste incineration processes over Rh/Al{sub 2}O{sub 3} and Rh-Na/Al{sub 2}O{sub 3}: Effects of particulates, heavy metals, SO{sub 2} and HCl  

Energy Technology Data Exchange (ETDEWEB)

Two novel catalysts Rh/Al{sub 2}O{sub 3} and Rh-Na/Al{sub 2}O{sub 3} were prepared for NO removal and tested their practical performances in a laboratory-scale waste incineration system. The effects of particulates, heavy metals, and acid gases on the catalysts were evaluated and investigated through several characterization techniques, such as SEM, EA, XRPD, ESCA, and FTIR. The results indicated that the NO conversions were increased with the accumulation of particulates on the surface of catalysts, which was attributed to the increase in carbon content. However, the increase in heavy metals Cd and Pb contents on the surface of catalysts decreased the activity of catalyst for NO removal but did not change the chemical state of Rh and Na. The Rh/Al{sub 2}O{sub 3} catalysts were poisoned when the acid gases SO{sub 2} and HCl were present in the flue gas, because Rh and Al reacted with S and Cl to form inactive products. Adding Na to Rh/Al{sub 2}O{sub 3} catalysts produced a promoting effect for SO{sub 2} removal due to the formation of Na{sub 2}SO{sub 4}. The influence levels of different pollutants on the performances of Rh/Al{sub 2}O{sub 3} and Rh-Na/Al{sub 2}O{sub 3} catalysts for NO removal followed the sequence of HCl > heavy metals > SO{sub 2} > particles. (author)

Chang, Feng-Yim; Wey, Ming-Yen [Department of Environmental Engineering, National Chung Hsing University, Taichung 402 (China); Chen, Jyh-Cherng [Department of Safety, Health and Environmental Engineering, HungKuang University, Taichung 43302 (China)

2009-04-15

 
 
 
 
281

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

Energy Technology Data Exchange (ETDEWEB)

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

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

2012-12-15

282

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

2008-04-01

283

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

International Nuclear Information System (INIS)

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

2007-11-01

284

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

Science.gov (United States)

Silica-supported dithiocarbamate adsorbent (Si-DTC) was synthesized by anchoring the chelating agent of macromolecular dithiocarbamate (MDTC) to the chloro-functionalized silica matrix (SiCl), as a new adsorbent for adsorption of Pb(II), Cd(II), Cu(II) and Hg(II) from aqueous solution. The surface characterization was performed by FT-IR, XPS, SEM and elemental analysis indicating that the modification of the silica surface was successfully performed. The effects of media pH, adsorption time, initial metal ion concentration and adsorption temperature on adsorption capacity of the adsorbent had been investigated. Experimental data were exploited for kinetic and thermodynamic evaluations related to the adsorption processes. The characteristics of the adsorption process were evaluated by using the Langmuir, Freundlich and Dubinin-Radushkevich (D-R) adsorption isotherms and adsorption capacities were found to be 0.34 mmol g(-1), 0.36 mmol g(-1), 0.32 mmol g(-1) and 0.40 mmol g(-1) for Pb(II), Cd(II), Cu(II) and Hg(II), respectively. The adsorption mechanism of Hg(II) onto Si-DTC is quite different from that of Pb(II), Cd(II) or Cu(II) onto Si-DTC, which is demonstrated by the XPS and FT-IR results. PMID:21889843

Bai, Lan; Hu, Huiping; Fu, Weng; Wan, Jia; Cheng, Xiliang; Zhuge, Lei; Xiong, Lei; Chen, Qiyuan

2011-11-15

285

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

International Nuclear Information System (INIS)

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

2009-04-15

286

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, ...

287

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+

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

288

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

289

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

1995-02-12

290

Biosorption of heavy metals and uranium from dilute solutions  

Energy Technology Data Exchange (ETDEWEB)

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.

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

1995-08-01

291

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

2005-10-01

292

Uso de biomassa seca de aguapé (Eichornia crassipes visando à remoção de metais pesados de soluções contaminadas = Use of water hyacinth (Eichornia crassipes dry biomass for removing heavy metals from contaminated solutions  

Directory of Open Access Journals (Sweden)

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

Affonso Celso Gonçalves Junior

2009-01-01

293

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

294

Development of superparmagnetic composite particles for removal of heavy metal ions from industrial effluents; Zur Entwicklung von superparamagnetischen Kompositpartikeln zur Entfernung von Schwermetallionen aus Industrieabwaessern  

Energy Technology Data Exchange (ETDEWEB)

New composite particles for separation of heavy metal ions from liquid effluents are presented which consist of superparamagnetic iron oxide nanoparticles in a borosilicate glass matrix. The surface of the composite particles has been modified with organic silanes. A siloxane function enables chemical bonding to the particles while a complexing agent functionality enables reversible bonding of metal ions. [German] Es wurden neue Kompositpartikel zur Abtrennung von Schwermetallionen aus waessrigen Abwasserstroemen entwickelt. Die Kompositpartikel bestehen aus superparamagnetischen Eisenoxid-Nanopartikeln in einer Borosilikatglasmatrix. Die Oberflaeche der Kompositpartikel ist mit Organosilanen modifiziert. Eine Siloxanfunktion erlaubt die chemische Anbindung an die Partikel, eine Komplexbildnerfunktionalitaet erlaubt die reversible Bindung von Metallionen. (orig.)

Mueller, T.S.; Rogin, P.; Mennig, M.; Schmidt, H. [INM - Leibnitz-Inst. fuer Neue Materialien gem. GmbH, Saarbruecken (Germany)

2003-07-01

295

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

Digital Repository Infrastructure Vision for European Research (DRIVER)

Wastewater particularly from electroplating, paint, leather, metal and tanning industries contain enormous amount of heavy metals. Microorganisms including fungi have been reported to exclude heavy metals from wastewater through bioaccumulation and biosorption at low cost and in eco-friendly way. An attempt was, therefore, made to isolate fungi from sites contaminated with heavy metals for higher tolerance and removal of heavy metals from wastewater. Seventy-six fungal isolates tolerant to he...

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

2011-01-01

296

Heavy metal depositions in Germany  

International Nuclear Information System (INIS)

Methods and importance of the measurement of dust precipitation and its metallic components are discussed. Test programs and results of heavy metal measurements in precipitations in Germany are summarized. The focus is on measurements of lead and cadmium. There is a clearly decreasing trend also seen in long-term test programs. The limiting values set in the Clean Air Act were hardly ever exceeded in recent years. (orig.)

1990-05-15

297

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

Energy Technology Data Exchange (ETDEWEB)

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

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

2006-07-31

298

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

Digital Repository Infrastructure Vision for European Research (DRIVER)

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 soluti...

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

2010-01-01

299

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

Digital Repository Infrastructure Vision for European Research (DRIVER)

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...

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

2010-01-01

300

Remediation processes for heavy metals contaminated soils  

Energy Technology Data Exchange (ETDEWEB)

This paper provides information on selected technologies available for remediation of metal contaminated soils and industrial effluent solutions. Because some of the industrial sites are contaminated with organics (solvents, gasolines and oils), an effort has been made to introduce the most frequently used cost-effective cleanup methods, such as {open_quotes}bioventing{close_quotes} and {open_quotes}composting.{close_quotes} The microorganisms involved in these processes are capable of degrading organic soil contaminants to environmentally harmless compounds: water and carbon dioxide. Heavy metals and radionuclides contaminated mining and industrial sites can be remediated by using adapted heap and dump leaching technologies, which can be chemical in nature or bio-assisted. The importance of volume reduction by physical separation is discussed. A special attention is devoted to the remediation of soils by leaching (soil washing) to remove heavy metal contaminants, such as chromium, lead, nickel and cadmium. Furthermore, the applicability of biosorption technology in the remediation of heavy metals and radionuclides contaminated industrial waste waters and acidic mining effluent solutions was indicated. 60 refs., 9 figs.

Torma, G.A.; Torma, A.E. [AMROT International, Rio Rancho, NM (United States); Hsu, Pei-Cheng [Mining and Waste Management, Arvado, CO (United States)

1996-12-31

 
 
 
 
301

Heavy Metal Stars  

Science.gov (United States)

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

2001-08-01

302

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...

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

2011-01-01

303

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

304

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

2003-01-01

305

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

306

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.

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

307

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

308

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...

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

2010-01-01

309

Method for Removing Gadolinium from Used Heavy Water Reactor Moderator  

International Nuclear Information System (INIS)

A novel process is described that treats used heavy water moderator (D2O) contaminated with high concentrations of the neutron poison gadolinium nitrate, Gd(NO3)3. Gadolinium is removed by precipitation. The resultant precipitate, GdPO4.6H2O, represents an extremely rare compound of considerable potential value. The resultant supernatant consisting of residual nitrate, NaNO3 or KNO3, is less toxic and easier to process than the original waste. Thus, the alkali metal waste handling can be done with considerably less environmental concern. This waste can potentially be treated by a combination of electrochemical and biological methods

2003-10-01

310

Removal of Dissolved Metals from Water Using Micellar-Enhanced Ultrafiltration.  

Science.gov (United States)

Micellar-enhanced ultrafiltration (MEUF) is a novel technique to remove dissolved heavy metals from water by addition of ionic surfactant. Positively charged metal cations bind onto negatively charged surfactant aggregates (micelles) when anionic surfacta...

J. F. Scamehorn S. D. Christian

1988-01-01

311

Mechanisms of bacterial metals removal from solids.  

Science.gov (United States)

The Great Lakes area sediments are contaminated with varying amounts of heavy metals and polychlorinated organic matter. With respect to the bioremediation of metallic contents of these sediments, it was shown that a number of microorganisms exist which c...

A. E. Torma P. A. Pryfogle

1990-01-01

312

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

313

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

2007-01-01

314

Heavy metal uptake by fast growing willow species  

Energy Technology Data Exchange (ETDEWEB)

Bioremediation is a general term used to describe the use of biological systems for renovating contaminated soil. The technique can be divided into two categories: the use of microbiological processes, and the use of vegetation, to immobilize, transform or remove contaminants from the soil. It has been suggested that the rapid biomass accumulation of Salix species grown intensively as in short-rotation forestry systems, may be used to remove heavy metal contamination from soil. Many potentially toxic heavy metals are also essential plant nutrients, hence the mechanisms exist for the absorption by plants of these and similar ions and their translocation through the plant structure. A limited number of deciduous species have been found to translocate metals to the leaves immediately before senescence, however, the principal site of metal accumulation in higher plants is the roots. A small number of species endemic to metalliferous soils are capable of accumulating unusually high concentrations of potentially toxic metals in their above ground biomass. These have been termed hyperaccumulators. This paper reports on the level and location of heavy metal accumulation by four varieties of Salix growing in soils with elevated levels of heavy metals. A trial was established in 1991 on land with a long history of sewage sludge application. Further applications have been made each year and the first harvest taken in January 1994. Significant differences have been found between the take-up of individual metals, between willow varieties and across differing sludge applications. 7 refs, 1 fig, 6 tabs

Riddell-Black, D. [Water Research centre, Waste Disposal Division, Bucks (United Kingdom)

1994-12-31

315

Mechanisms of bacterial metals removal from solids  

International Nuclear Information System (INIS)

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

1990-07-17

316

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

Science.gov (United States)

Phanerochaete chrysosporium are known to be vital hyperaccumulation species for heavy metal removal with admirable intracellular bioaccumulation capacity. This study analyzes the heavy metal-induced glutathione (GSH) accumulation and the regulation at the intracellular heavy metal level in P. chrysosporium. P. chrysosporium accumulated high levels of GSH, accompanied with high intracellular concentrations of Pb and Cd. Pb bioaccumulation lead to a narrow range of fluctuation in GSH accumulation (0.72-0.84 ?mol), while GSH plummeted under Cd exposure at the maximum value of 0.37 ?mol. Good correlations between time-course GSH depletion and Cd bioaccumulation were determined (R (2)?>?0.87), while no significant correlations have been found between GSH variation and Pb bioaccumulation (R (2)?1.53-3.32, confirming the dominant role of GSH in Cd chelation. The study also demonstrated that P. chrysosporium showed considerable hypertolerance to Pb ions, accompanied with demand-driven stimulation in GSH synthesis and unconspicuous generation of reactive oxygen stress. GSH plummeted dramatically response to Cd exposure, due to the strong affinity of GSH to Cd and the involvement of GSH in Cd detoxification mechanism mainly as Cd chelators. Investigations into GSH metabolism and its role in ameliorating metal toxicity can offer important information on the application of the microorganism for wastewater treatment. PMID:24723291

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

2014-07-01

317

Using algae for adsorptive removal of heavy metals from industrial effluents; Einsatz von Algen zur adsorptiven Entfernung von Schwermetallen aus gewerblichen Abwaessern  

Energy Technology Data Exchange (ETDEWEB)

In view of the many different species of micro-algae (about 50,000), screening for heavy metal capacity and selectivity appears highly promising. Many different reactor configurations are feasible, e.g. stirred reactors, fluidized bed reactors and fixed bed reactor adsorption systems. For column operation, immobilization of the micro-algae or algae extraction residues will be required. The matrix system must be modified and optimized in consideration of the effluent composition, desorption agent and micro-algae. Reaction times of fixed bed reactors must be assessed on the basis of cyclic adsorption and desorption experiments using model effluents and real effluents. [German] Die vielversprechenden Untersuchungen an Mikroalgen bezueglich der Metallaufnahme beziehen sich zumeist nur auf eine geringe Anzahl verschiedener, leicht kultivierbarer Gattungen. Vor dem Hintergrund der Vielzahl an Mikroalgenspezies (ca. 50000) erscheint ein Screening auf Schwermetallkapazitaet und Selektivitaet eine vielversprechende Moeglichkeit zu sein, neue Biosorbentien zu finden. Fuer eine verfahrenstechnische Umsetzung koennen unterschiedliche Reaktorkonfigurationen verwendet werden. Denkbar waere eine Adsorption im Ruehr- oder Wirbelschichtreaktor und Adsorptionssysteme in Festbettreaktoren. Um einen Kolonnenbetrieb zu realisieren, muessen die Mikroalgen oder Algenextraktionsrueckstaende zuvor immobilisiert werden. Um diesen anspruchsvollen Forderungen gerecht zu werden, muessen verschiedene Immobilisierungstechniken sowie Immobilisierungsmaterialien auf ihre Eignung getestet werden. Entsprechend der Zusammensetzung des Realabwassers, des verwendeten Desorptionsmittels und natuerlich der eingesetzten Mikroalgen ist das Matrixsystem zu modifizieren und zu optimieren. Um Aussagen ueber Standzeiten eines Festbettreaktors treffen zu koennen, sind zyklische Adsorptions- und Desorptionsversuche mit Modell- und Realabwaessern durchzufuehren. (orig.)

Buchholz, R.; Bunke, G.; Goetz, P.; Wilke, A.

1999-06-01

318

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

Energy Technology Data Exchange (ETDEWEB)

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).

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

2009-11-15

319

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).

2009-11-15

320

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

 
 
 
 
321

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

322

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

323

A glutathione S-transferase from Proteus mirabilis involved in heavy metal resistance and its potential application in removal of Hg²?.  

Science.gov (United States)

Glutathione S-transferases (GSTs) are a family of multifunctional proteins playing important roles in detoxification of harmful physiological and xenobiotic compounds in organisms. In our study, a gene encoding a GST from Proteus mirabilis strain V7, gstPm-4, was cloned and conditionally expressed in Escherichia coli strain BL21(DE3). The purified GstPm-4 protein, with an estimated molecular mass of approximately 23kDa, was able to conjugate 1-chloro-2,4-dinitrobenzene and bind to the GSH-affinity matrix. Real-time reverse transcriptase PCR suggested that mRNA level of gstPm-4 was increased in the presence of CdCl2, CuCl2, HgCl2 and PbCl2, respectively. Correspondingly, overexpression of gstPm-4 in the genetically engineered bacterium Top10/pLacpGst exhibited higher heavy metal resistance compared to the control Top10/pLacP3. Another genetically engineered bacterium Top10/pBATGst, in which the DNA encoding GstPm-4 protein was fused with the DNA encoding Pfa1-based auto surface display system, was built. Top10/pBATGst could constitutively express the chimeric GstPm-4 and anchor it onto the cell surface subsequently. Almost 100% of the Hg(2+) within the range of 0.1-100 nM was adsorbed by Top10/pBATGst, and 80% of the bounded Hg(2+) could be desorbed from bacterial cells when pH was adjusted to 6.0. Thus, Top10/pBATGst can be potentially used for efficient treatment of Hg(2+)-contaminated aquatic environment. PMID:23995561

Zhang, Weiwei; Yin, Kun; Li, Bowei; Chen, Lingxin

2013-10-15

324

Poisoning of domestic animals with heavy metals  

Digital Repository Infrastructure Vision for European Research (DRIVER)

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. ...

Velev Romel; Krleska-Veleva Nataša; ?upi? Vitomir

2009-01-01

325

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

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

326

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)

2001-01-01

327

The composite sorbents selective for heavy non-ferrous metals  

Digital Repository Infrastructure Vision for European Research (DRIVER)

The nickel, zinc and cadmium removal from aqueous solutions by polymer-inorganic com-posite Dowex Marathon C – iron hydroxide sorbent was studied at dynamic conditions. The total dynamic capacity of composite sorbent to metals under investigation is 1.5 – 2.3 times greater than the same value of basic Dowex Marathon C cation exchanger (analog ??-2×8). The use of compo-site sorbent for aftertreatment of wastewater with compound salt background allows reducing heavy metal concentration b...

2013-01-01

328

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...

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

2003-01-01

329

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

Digital Repository Infrastructure Vision for European Research (DRIVER)

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

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

2011-01-01

330

Biosorption of heavy metals from wastewater by biosolids  

Energy Technology Data Exchange (ETDEWEB)

In a study where the removal of heavy metals from wastewater is the primary aim, the biosorption of heavy metals onto biosolids prepared as Pseudomonas aeruginosa immobilized onto granular activated carbon was investigated in batch and column systems. In the batch system, adsorption equilibriums of heavy metals were reached between 20 and 50 min, and the optimal dosage of biosolids was 0.3 g/L. The biosorption efficiencies were 84, 80, 79, 59 and 42 % for Cr(VI), Ni(II), Cu(II), Zn(II) and Cd(II) ions, respectively. The rate constants of biosorption and pore diffusion of heavy metals were 0.013-0.089 min{sup -1} and 0.026-0.690 min{sup -0.5}. In the column systems, the biosorption efficiencies for all heavy metals increased up to 81-100 %. The affinity of biosorption for various metal ions towards biosolids was decreased in the order: Cr = Ni > Cu > Zn > Cd. (Abstract Copyright [2006], Wiley Periodicals, Inc.)

Orhan, Y.; Bueyuekguengoer, H. [Ondokuz Mayis University, Engineering Faculty, Environmental Engineering Department, 55139 Samsun (Turkey); Hrenovic, J. [University of Zagreb, Faculty of Science, Department of Biology, Rooseveltov trg 6, 10000 Zagreb (Croatia)

2006-08-15

331

Heavy metal content of cereals and potatoes  

Energy Technology Data Exchange (ETDEWEB)

By means of atomic absorption spectrometry, the cadmium, zinc, copper and manganese contents was determined in potatoes and cereals from three territories differently burdened by heavy-metal emissions. Of these elements, cadmium was most enriched, followed by zinc and copper, whereas the manganese level was slightly high in the burdened region. On the basis of the results obtained and of data from the literature, an estimate is calculated for the expected values in territories differently burdened by heavy-metal emissions. Finally, targeted suggestions are given for preventing or impeding the entrance of heavy metals into the biocycle.

Auermann, E.; D' assler, H.G.; Jacobi, J.; Cumbrowski, J.; Meckel, U.

1980-01-01

332

Extraction of heavy metals by amines adsorbed onto silica gel.  

Science.gov (United States)

Previous work has established the possibility of using known coordinating agents supported on silica gel in the removal of heavy metals such as lead, copper, cadmium, and nickel from aqueous media. Functionalized silica gel has been used in the removal of heavy metals with notable success. Silica gel is currently being used as a support for various monofunctional aliphatic amines as coordinating ligands. The current study reports the results of an investigation involving the use of saturated, straight chain primary amines as coordinating ligands in the removal of copper(II), cadmium(II), lead(II), nickel(II), and silver(I) ions from aqueous solutions of known concentration. Primary amines used in this investigation were n-butylamine, n-hexylamine, n-octylamine, n-decylamine, and n-hexadecylamine. PMID:14533930

Bowe, Craig A; Pooré, Duke D; Benson, Robert F; Martin, Dean F

2003-01-01

333

Heavy metals in same Latvian clays constitution  

International Nuclear Information System (INIS)

Latvian clays contain low content of 'heavy metals' therefore pint - size amount of this metals slide in ground water. Although Cu and Zn is mobile in acetous ground, but these metals may be insufficient in Latvian soil for plants. Latvian clays contain low content of zircon. (authors)

2005-05-05

334

Gamma radiation-polymerized methacrylates used as heavy metals adsorbents  

International Nuclear Information System (INIS)

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

2009-01-01

335

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

1992-01-01

336

Experimental research on heavy metal wastewater treatment with dipropyl dithiophosphate  

International Nuclear Information System (INIS)

In view of the existing technical problems about treatment of heavy metal pollution, a new organic heavy metal chelator-dipropyl dithiophosphate has been developed. This paper focuses on the mechanism about the laboratory synthesis of dipropyl dithiophosphate and chelate heavy metal, discusses the effects of pH value, added quantity of chelator, reactive time and coexistence of several heavy metal ions on the treatment effectiveness, and compares the stability of chelate complex with conventional neutral precipitation method. The results of the experiment show that, within the scope of pH 3-6, for the wastewater with the concentration of lead, cadmium, copper and mercury being 200 mg/L, dipropyl dithiophosphate enjoys a removal rate about these elements up to over 99.9%, and the concentrations of the lead, cadmium, copper and mercury in the wastewater after treatment are less than 1, 0.1, 0.5 and 0.05 mg/L, respectively, which meet the limit value of concentration stipulated in the Integrated Wastewater Discharge Standard (GB8978-1996). And the treatment effectiveness are not affected by pH value and coexistent heavy metal ions, which makes up the deficiency that neutral precipitation must be used under the condition of high alkalinity. The optimum quantity of dipropyl dithiophosphate chelator added is 1.2 times as much as stoichiometric amount and the optimum reactive time is 20 min for lead, cadmium and copper, and 30 min for mercury. Within the scope of pH 3-9, each heavy metal ion release of chelate complex will decrease along with increased pH value. But under any pH conditions, the release of heavy metal ions in hydroxide is far higher than that in chelate complex, therefore reducing the risk of polluting the environment again

2006-10-11

337

Heavy Metals and the Petroleum Industry.  

Science.gov (United States)

The purpose of this report is to investigate the amounts of heavy metals introduced into the environment by the petroleum industry during exploration and production operations, to examine their environmental impacts, and to compare those impacts to the he...

K. D. Ware

1993-01-01

338

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.)

1981-01-01

339

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

340

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...

2012-01-01

 
 
 
 
341

Adsorption of heavy metals on kaolinite and montmorillonite: a review.  

Science.gov (United States)

The process of adsorption is considered to be one of the best water treatment technologies around the world. Different heavy metals, due to their toxic and hazardous nature, are possibly the most widespread groundwater contaminants imposing a serious threat to human health. In this review, an attempt has been made to discuss the use of two common clay materials, namely kaolinite and montmorillonite, along with their modified forms for heavy metal removal on the basis of published reports (2008 onwards). The modifications of clays have been attempted by the process of pillaring, intercalation, acid/base activation, functionalization, etc. The adsorption of toxic metals, viz., As, Cd, Cr, Co, Cu, Fe, Pb, Mn, Ni, Zn, etc., has been studied predominantly. Montmorillonite and its modified forms have much higher metal adsorption capacity compared to that of kaolinite as well as modified-kaolinite. The modification often boosted the adsorption capacities of the clays, however, reverse trends are also reported in some cases. PMID:22499238

Sen Gupta, Susmita; Bhattacharyya, Krishna G

2012-04-12

342

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

Digital Repository Infrastructure Vision for European Research (DRIVER)

The scope of the paper was to demonstrate the technical feasibility of the remediation processes by electrowinning and selective sequential precipitation, for toxic metals removal from acid mine drainage. By electrochemical experiments, high metals removal has been achieved: in particular, by Zn and Mn electrodeposition, it was possible to achieve about 93-99% Zn and Mn removal (as MnO2), with a relatively low energetic consumption. The principle of the heavy metals selective sequential preci...

Ubaldini S.; Luptakova A.; Fornari P.; Yoplac E.

2013-01-01

343

Plant transporters involved in heavy metal homeostasis  

Directory of Open Access Journals (Sweden)

Full Text Available Transition metal ions (predominately manganese, iron, cobalt, nickel, copper and zinc havean array of catalytic and regulatory roles in the growth and development of all living organisms.However, an excess of these metal ions can also be toxic to any life form and therefore every cell andwhole organism needs to maintain the concentration of these essential nutrient metals within a narrowrange: a process known as metal homeostasis. Heavy metal ions are taken up into cells by selectivetransporters and as they cannot be degraded, the “desired” levels of metal ions are achieved by anumber of strategies that involve: chelation, sequestration and export out of the cell. Cation DiffusionFacilitators (CDF is a large family of transporters involved in maintaining the cytosolic metalconcentration. They transport different heavy metal divalent ions, but exhibit main affinity for zinc, ironand manganese. Metal Tolerance Proteins (MTPs are a subfamily of the Cation Diffusion Facilitator (CDFfamily found in plants. There has been much interest in these heavy metal transporters in order toprovide an insight into plant metal homeostasis, which has significant implications in human health andphytoremediation. Although data regarding the CDFs/MTPs mechanism is gathering there is still littleinformation with respect to metal selectivity determinants.

Dorina Podar

2010-12-01

344

Adsorption of Heavy Metal from Recovered base Oil using Zeolite  

Directory of Open Access Journals (Sweden)

Full Text Available 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 magnesium and zinc removal obtained were 50 and 62%, respectively. The most influential parameter affecting the magnesium and zinc removal was the time of adsorption. Further investigations on the optimum conditions will be performed.

A. Ahmad

2010-01-01

345

The Effect of Generated Chlorine Gas on Electroremediation of Heavy Metals from Offshore Muds  

Digital Repository Infrastructure Vision for European Research (DRIVER)

The removal efficiency of heavy metals from offshore muds is enhanced in the presence of generated chlorine gas (Cl2). The tests showed a high removal efficiency of heavy metals at the anode end of cores after 24 hours of EK application. In the initial tests, high electrokinetic flow potential was achieved; however, high levels of chlorine gas were produced in the high-salinity environments. The process was improved by controlling and maintaining a certain fraction of t...

Sanghee Shin; Chilingar, George V.; Muhammad Haroun; Bisweswar Ghosh; Najmedin Meshkati; Sibel Pamukcu; Kenneth Wittle, J.; Manal Al Badawi

2012-01-01

346

Surfactant biocatalyst for remediation of recalcitrant organics and heavy metals  

Energy Technology Data Exchange (ETDEWEB)

Novel strains of isolated and purified bacteria have been identified which have the ability to degrade petroleum hydrocarbons including a variety of PAHs. Several isolates also exhibit the ability to produce a biosurfactant. The combination of the biosurfactant-producing ability along with the ability to degrade PAHs enhances the efficiency with which PAHs may be degraded. Additionally, the biosurfactant also provides an additional ability to bind heavy metal ions for removal from a soil or aquatic environment.

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

2011-03-15

347

Surfactant biocatalyst for remediation of recalcitrant organics and heavy metals  

Energy Technology Data Exchange (ETDEWEB)

Novel strains of isolated and purified bacteria have been identified which have the ability to degrade petroleum hydrocarbons including a variety of PAHs. Several isolates also exhibit the ability to produce a biosurfactant. The combination of the biosurfactant-producing ability along with the ability to degrade PAHs enhances the efficiency with which PAHs may be degraded. Additionally, the biosurfactant also provides an additional ability to bind heavy metal ions for removal from a soil or aquatic environment.

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

2009-01-06

348

Surfactant biocatalyst for remediation of recalcitrant organics and heavy metals  

Energy Technology Data Exchange (ETDEWEB)

Novel strains of isolated and purified bacteria have been identified which have the ability to degrade petroleum hydrocarbons including a variety of PAHs. Several isolates also exhibit the ability to produce a biosurfactant. The combination of the biosurfactant-producing ability along with the ability to degrade PAHs enhances the efficiency with which PAHs may be degraded. Additionally, the biosurfactant also provides an additional ability to bind heavy metal ions for removal from a soil or aquatic environment.

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

2011-05-03

349

Surfactant biocatalyst for remediation of recalcitrant organics and heavy metals  

Energy Technology Data Exchange (ETDEWEB)

Novel strains of isolated and purified bacteria have been identified which have the ability to degrade petroleum hydrocarbons including a variety of PAHs. Several isolates also exhibit the ability to produce a biosurfactant. The combination of the biosurfactant-producing ability along with the ability to degrade PAHs enhances the efficiency with which PAHs may be degraded. Additionally, the biosurfactant also provides an additional ability to bind heavy metal ions for removal from a soil or aquatic environment.

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

2011-03-29

350

Heavy metals and woody plants - biotechnologies for phytoremediation  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Soil contamination by heavy metals is among the most serious danger for the environment, and new methods for its containment and removal are claimed, in particular for agricultural soils. Phytoremediation is an emerging, potentially effective technology applicable to restoration of contaminated soils and waters. Besides hyperaccumulator herbaceous plants, several woody species are now considered of interest to this aim. Many woody plants are fast growing, have deep roots, produce abundant bio...

Capuana M

2011-01-01

351

Studies of channel sediments contaminated with organics and heavy metals.  

Science.gov (United States)

The paper discusses the geo-environmental studies carried out to revitalise a silted up channel in Guanabara Bay. A dredging operation has been planned to remove about 1.5 million cubic meters of contaminated sediment. Investigations were performed to characterise the sediment in terms of its physical and chemical properties and to evaluate the presence of heavy metals and organic compounds, particularly polycyclic aromatic hydrocarbons PAH. Finally, dredging and disposal schemes are briefly outlined based on measured contamination levels. PMID:15177724

Barbosa, Maria Claudia; de Almeida, Márcio de Souza Soares; Mariz, Digna Faria; de Almeida, José Luis Duarte Silva Serzedelo

2004-07-01

352

Full scale biological treatment of heavy metal contaminated groundwater  

Energy Technology Data Exchange (ETDEWEB)

Soil and groundwater beneath a zinc production plant in The Netherlands are contaminated with metals and sulfate. To avoid contamination of nearby drinking water aquifers, a hydro-geological containment system and a biological treatment plant for the extracted ground water have been installed. Currently about 5,000 M{sup 3}/day of groundwater is extracted from a combination of 12 shallow and deep wells. Heavy metals and sulfate have to be removed from the extracted water before it can be discharged into a river. Several water treatment methods have been studied and pilot tested at the site. The preferred and selected process is based on the activity of sulfate reducing bacteria (SRB) and combines sulfate removal and heavy metal removal in one single installation. Anaerobic bacteria reduce sulfate to sulfide resulting in the precipitation of metal sulfides. Excess sulfide is biologically converted to elemental sulfur. A full scale biological treatment system was started up in May 1992. Design, start-up, commissioning and operational experiences are reported in this paper. Concentrations of metals and sulfate in the SRB water treatment plant effluent are well within the limits set by the Dutch Authorities for discharge to surface water.

Vegt, A.L. De [Paques, Inc., Exton, PA (United States); Buisman, C.J.N. [Paques B.V., Balk (Netherlands)

1995-07-01

353

A comparative study of the removal of heavy metal ions from water using a silica-polyamine composite and a polystyrene chelator resin  

Energy Technology Data Exchange (ETDEWEB)

The maximum Cu(II), Ni(II), and Co(II) ion capacities of a silica-poly(ethyleneimine) composite (WP-1) are compared with those of the commercially available iminodiacetic acid chelator resin Amberlite IRC-718. Under batch (static) conditions, IRC-718 exhibits better capacities for these metals than WP-1. Dynamic studies, however, revealed that WP-1 possessed a much higher capacity for all three divalent metals than IRC-718, with relative metal capacities in the order CU(II) {gt} CO(II) {approximately} Ni(II). In the presence of the competing chelator ethylenediaminetetraacetic acid, the Cu(II) capacities of WP-1 and IRC-718 lost 48% and 45%, respectively, of their original adsorption values. Even with this decrease, however, WP-1 maintained a higher CU(II) capacity than IRC-718. Repeated cycle testing, using CU(II) solutions at both room temperature and 97 C, was conducted to compare the long-term stability of each material. WP-1 maintained 94% of its original Cu(II) capacity and maintained structural integrity after 3,000 cycles using room temperature copper solutions, while IRC-718 compressed and dropped to 64% of its original capacity. When boiling copper solutions were used, the capacity of WP-1 increased slightly over 1500 cycles, while IRC-718 lost 13% of its original copper capacity and again became compressed, indicating degradation of the polystyrene beads.

Beatty, S.T.; Fischer, R.J.; Hagers, D.L.; Rosenberg, E.

1999-11-01

354

Removal of gadolinium nitrate from heavy water  

International Nuclear Information System (INIS)

Work was conducted to develop a cost-effective process to purify 181 55-gallon drums containing spent heavy water moderator (D2O) contaminated with high concentrations of gadolinium nitrate, a chemical used as a neutron poison during former nuclear reactor operations at the Savannah River Site (SRS). These drums also contain low level radioactive contamination, including tritium, which complicates treatment options. Presently, the drums of degraded moderator are being stored on site. It was suggested that a process utilizing biological mechanisms could potentially lower the total cost of heavy water purification by allowing the use of smaller equipment with less product loss and a reduction in the quantity of secondary waste materials produced by the current baseline process (ion exchange)

2000-01-01

355

Removal of gadolinium nitrate from heavy water  

Energy Technology Data Exchange (ETDEWEB)

Work was conducted to develop a cost-effective process to purify 181 55-gallon drums containing spent heavy water moderator (D2O) contaminated with high concentrations of gadolinium nitrate, a chemical used as a neutron poison during former nuclear reactor operations at the Savannah River Site (SRS). These drums also contain low level radioactive contamination, including tritium, which complicates treatment options. Presently, the drums of degraded moderator are being stored on site. It was suggested that a process utilizing biological mechanisms could potentially lower the total cost of heavy water purification by allowing the use of smaller equipment with less product loss and a reduction in the quantity of secondary waste materials produced by the current baseline process (ion exchange).

Wilde, E.W.

2000-03-22

356

EXTRACTION, RECOVERY, AND BIOSTABILITY OF EDTA FOR REMEDIATION OF HEAVY METAL-CONTAMINATED SOIL. (R825549C052)  

Science.gov (United States)

Chelation removal of heavy metals from contaminated soil is seen as a viable remediation technique. A useful chelating agent should be strong, reusable, and biostable during metal extraction and recovery operations. This work tested the extraction, recovery, and biostability o...

357

Selective accumulation of heavy metals by microorganisms  

International Nuclear Information System (INIS)

An investigation of the removal and recovery of uranium from aqueous systems using microbial biomass has been described previously (Nakajima et al. 1982). To establish which microorganisms accumulate the most uranium, we extended our investigation of uranium uptake to 83 species of microorganisms, 32 bacteria, 15 yeasts, 16 fungi and 20 actinomycetes. Of these 83 species of microorganisms tested, extremely high uranium-absorbing ability was found in Pseudomonas stutzeri, Neurospora sitophila, Streptomyces albus and Streptomyces viridochromogenes. The selective accumulation of heavy metal ions by various microorganisms has also been examined. Uranyl, mercury and lead ions were readily accumulated by almost all the species of microorganisms tested. Actinomycetes and fungi differ from many bacteria and most yeasts in their selective accumulation of uranium and mercury. In addition to this fundamental research, uranium recovery was investigated in immobilized Streptomyces albus, a microorganism with high uranium-uptake ability. These immobilized cells adsorbed uranium readily and selectively. The immobilized cells recovered uranium almost quantitatively and almost all uranium absorbed was desorbed with 0.1 M Na_2CO_3. The dry weight of the free cells decreased by 50% during 5 adsorption-desorption cycles. However, the dry weight of the immobilized cells decreased by only 2% during 5 cycles. These results showed that microbial cells are more stable after immobilization and can be used repeatedly for the process of uranium adsorption-desorption. (orig.)

1986-01-01

358

Regenerative process for removal of mercury and other heavy metals from gases containing H.sub.2 and/or CO  

Science.gov (United States)

A method for removal of mercury from a gaseous stream containing the mercury, hydrogen and/or CO, and hydrogen sulfide and/or carbonyl sulfide in which a dispersed Cu-containing sorbent is contacted with the gaseous stream at a temperature in the range of about 25.degree. C. to about 300.degree. C. until the sorbent is spent. The spent sorbent is contacted with a desorbing gaseous stream at a temperature equal to or higher than the temperature at which the mercury adsorption is carried out, producing a regenerated sorbent and an exhaust gas comprising released mercury. The released mercury in the exhaust gas is captured using a high-capacity sorbent, such as sulfur-impregnated activated carbon, at a temperature less than about 100.degree. C. The regenerated sorbent may then be used to capture additional mercury from the mercury-containing gaseous stream.

Jadhav, Raja A. (Naperville, IL)

2009-07-07

359

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

International Nuclear Information System (INIS)

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

2007-03-07

360

Biosorption of Heavy Metal Ions from Aqueous Solutions Using a Biomaterial  

Digital Repository Infrastructure Vision for European Research (DRIVER)

An increase in population initiating rapid industrialization was found to consequently increase the effluents and domestic wastewater into the aquatic ecosystem. Heavy metals are major toxicants found in industrial wastewaters; they may adversely affect the biological treatment of wastewater. Conventional methods for the removal of heavy metals from waste waters are often cost prohibitive hence, there is a need for cheap methods for effluent treatment. The residual metallic ion concentrations...

2009-01-01

 
 
 
 
361

Colloquium: treatment of wastewaters containing heavy metal compounds; Kolloquium: Behandlung von Abwaessern mit schwermetallhaltigen Verbindungen  

Energy Technology Data Exchange (ETDEWEB)

The contamination of wastewater with toxic heavy metal compounds is a complex problem. The removal of these contaminants has received much attention in recent years. Heavy metal contamination should be removed at source in order to avoid pollution of natural waters and subsequent metal accumulation in the environment. Process wastewaters contaminated with heavy metals result from various industrial activities, mainly the metallurgical industry, breweries, production of viscose fibres and coal-fired power stations. Practically all metallurgical activities, but also many other industrial processes are point sources of emission. The maximum permissible concentrations of pollutants in wastewaters for discharges into surface waters or sewage systems are laid down in national, European, and international guidelines. It is reasonable to expect that these discharge limits will be lowered in future. For this reason, the further development of existing processes and the investigation of new processes for the reduction of heavy metals in wastewaters are of special importance. At present, chemical precipitation is the main process for the removal of heavy metal contaminations from wastewater, followed by other conventional methods such as chemical oxidation or reduction, ion exchange, filtration or electrochemical treatment. A recent approach is the use of biomasses as adsorbents for the removal of heavy metals from the aqueous phase. For more than ten years, international efforts have been made to investigate the basic principles of the biosorption of heavy metals and to apply such biosorbents in technical processes of wastewater treatment. This volume of colloquium proceedings 'Treatment of wastewaters containing heavy metal compounds' contains presentations concerning the legal guidelines for concentration limits of heavy metals in wastewaters, concerning basic research, and process development up to the industrial scale. (orig.)

Kornmueller, A. (comp.)

2000-07-01

362

Biosorption of heavy metals and uranium by starfish and Pseudomonas putida  

International Nuclear Information System (INIS)

Biosorption of heavy metals and uranium from contaminated wastewaters may represent an innovative purification process. This study investigates the removal ability of unit mass of Pseudomonas putida and starfish for lead, cadmium, and uranium by quantifying the adsorption capacity. The adsorption of heavy metals and uranium by the samples was influenced by pH, and increased with increasing Pb, Cd, and U concentrations. Dead cells adsorbed the largest quantity of all heavy metals than live cells and starfish. The adsorption capacity followed the order: U(VI) > Pb > Cd. The results also suggest that bacterial membrane cells can be used successfully in the treatment of high strength metal-contaminated wastewaters

2009-01-15

363

Determination of heavy metals in sediments  

International Nuclear Information System (INIS)

This work is an approach to study the determination of heavy metals in sediments. It analyzer the different ways by means of which heavy metals are introduced into the river sediments, as well as their toxicity in the total concentration and in each of the species of the system. This study presents the main operation methods in sediments. One of the most relevant and suitable method to identify the way in which metals are joined in the different stages (phases) of sediments is the sequential extraction proposed by the MS and T from the Buorean of Certified Reference (European Community). Its also discussed the possible ways to determine if the presence of metals is caused by the anthropogenic action or by lithogenic cause

2004-07-01

364

Removal of dissolved metals from water using micellar-enhanced ultrafiltration  

Energy Technology Data Exchange (ETDEWEB)

Micellar-enhanced ultrafiltration (MEUF) is a novel technique to remove dissolved heavy metals from water by addition of ionic surfactant. Positively charged metal cations bind onto negatively charged surfactant aggregates (micelles) when anionic surfactants are used; negatively charged metal complexes can be bound onto positively charged micelles using cationic surfactants. In addition to the metal binding, dissolved organics solubilize or dissolve in the micelles. The solution is then passed through an ultrafiltration membrane which blocks the micelles, resulting in pure permeate water. The ability of this technique to remove divalent metal cations and divalent anionic metallic complexes from water is demonstrated in this work, either as individual metals or as mixtures of metals. A 500-fold reduction in metal concentration can be attained in one pass. Simultaneous removal of metals and organics is demonstrated. The effect of important operating variables on performance is also discussed. 10 refs., 3 figs., 3 tabs.