WorldWideScience

Sample records for contaminant metal mobilization

  1. Remediation of heavy metal(loid)s contaminated soils--to mobilize or to immobilize?

    Science.gov (United States)

    Bolan, Nanthi; Kunhikrishnan, Anitha; Thangarajan, Ramya; Kumpiene, Jurate; Park, Jinhee; Makino, Tomoyuki; Kirkham, Mary Beth; Scheckel, Kirk

    2014-02-15

    Unlike organic contaminants, metal(loid)s do not undergo microbial or chemical degradation and persist for a long time after their introduction. Bioavailability of metal(loid)s plays a vital role in the remediation of contaminated soils. In this review, the remediation of heavy metal(loid) contaminated soils through manipulating their bioavailability using a range of soil amendments will be presented. Mobilizing amendments such as chelating and desorbing agents increase the bioavailability and mobility of metal(loid)s. Immobilizing amendments such of precipitating agents and sorbent materials decrease the bioavailabilty and mobility of metal(loid)s. Mobilizing agents can be used to enhance the removal of heavy metal(loid)s though plant uptake and soil washing. Immobilizing agents can be used to reduce the transfer to metal(loid)s to food chain via plant uptake and leaching to groundwater. One of the major limitations of mobilizing technique is susceptibility to leaching of the mobilized heavy metal(loid)s in the absence of active plant uptake. Similarly, in the case of the immobilization technique the long-term stability of the immobilized heavy metal(loid)s needs to be monitored. Copyright © 2013 Elsevier B.V. All rights reserved.

  2. Mobilization of heavy metals from contaminated paddy soil by EDDS, EDTA, and elemental sulfur

    NARCIS (Netherlands)

    Wang, G.; Koopmans, G.F.; Song, J.; Temminghoff, E.J.M.; Luo, Y.; Zhao, Q.; Japenga, J.

    2007-01-01

    For enhanced phytoextraction, mobilization of heavy metals (HMs) from the soil solid phase to soil pore water is an important process. A pot incubation experiment mimicking field conditions was conducted to investigate the performance of three soil additives in mobilizing HMs from contaminated paddy

  3. Metal release from contaminated coastal sediments under changing pH conditions: Implications for metal mobilization in acidified oceans.

    Science.gov (United States)

    Wang, Zaosheng; Wang, Yushao; Zhao, Peihong; Chen, Liuqin; Yan, Changzhou; Yan, Yijun; Chi, Qiaoqiao

    2015-12-30

    To investigate the impacts and processes of CO2-induced acidification on metal mobilization, laboratory-scale experiments were performed, simulating the scenarios where carbon dioxide was injected into sediment-seawater layers inside non-pressurized chambers. Coastal sediments were sampled from two sites with different contamination levels and subjected to pre-determined pH conditions. Sediment samples and overlying water were collected for metal analysis after 10-days. The results indicated that CO2-induced ocean acidification would provoke increased metal mobilization causing adverse side-effects on water quality. The mobility of metals from sediment to the overlying seawater was correlated with the reduction in pH. Results of sequential extractions of sediments illustrated that exchangeable metal forms were the dominant source of mobile metals. Collectively, our data revealed that high metal concentrations in overlying seawater released from contaminated sediments under acidic conditions may strengthen the existing contamination gradients in Maluan Bay and represent a potential risk to ecosystem health in coastal environments. Copyright © 2015 Elsevier Ltd. All rights reserved.

  4. Effects of incubation on solubility and mobility of trace metals in two contaminated soils

    International Nuclear Information System (INIS)

    Ma, Lena Q.; Dong Yan

    2004-01-01

    Much research has focused on changes in solubility and mobility of trace metals in soils under incubation. In this experiment, changes in solubility and mobility of trace metals (Pb, Cu and As) and Fe in two contaminated soils from Tampa, Florida and Montreal, Canada were examined. Soils of 30 g were packed in columns and were incubated for 3-80 days under water-flooding incubation. Following incubation, metal concentrations in pore water (water soluble) and in 0.01 M CaCl 2 leachates (exchangeable+water soluble) were determined. While both soils were contaminated with Pb (1600-2500 mg kg -1 ), Tampa soil was also contaminated with As (230 mg kg -1 ). Contrast to the low pH (3.8) of Tampa soil, Montreal soil had an alkaline pH of 7.7 and high Ca of 1.6%. Concentrations of Fe(II) increased with incubation time in the Tampa soil mainly due to reductive Fe dissolution, but decreased in the Montreal soil possibly due to formation of FeCO 3 . The inverse relationship between concentrations of Pb and Fe(II) in pore water coupled with the fact that Fe(II) concentrations were much greater than those of Pb in pore water may suggest the importance of Fe(II) in controlling Pb solubility in soils. However, changes in concentrations of Fe(II), Pb, Cu and As in pore water with incubation time were similar to those in leachate, i.e. water soluble metals were positively related to exchangeable metals in the two contaminated soils. This research suggests the importance of Fe in controlling metal solubility and mobility in soils under water-flooded incubation. - Iron is important in controlling metal solubility and mobility in flooded soils

  5. Distribution and mobility of metals in contaminated sites. chemometric investigation of pollutant profiles.

    Science.gov (United States)

    Abollino, Ornella; Aceto, Maurizio; Malandrino, Mery; Mentasti, Edoardo; Sarzanini, Corrado; Barberis, Renzo

    2002-01-01

    The distribution and mobility of heavy metals in the soils of two contaminated sites in Piedmont (Italy) was investigated, evaluating the horizontal and vertical profiles of 15 metals, namely Al, Cd, Cu, Cr, Fe. La, Mn, Ni, Pb, Sc, Ti, V, Y, Zn and Zr. The concentrations in the most polluted areas of the sites were higher than the acceptable limits reported in Italian and Dutch legislations for soil reclamation. Chemometric elaboration of the results by pattern recognition techniques allowed us to identify groups of samples with similar characteristics and to find correlations among the variables. The pollutant mobility was studied by extraction with water, dilute acetic acid and EDTA and by applying Tessier's procedure. The fraction of mobile species, which potentially is the most harmful for the environment, was found to be higher than the one normally present in unpolluted soils, where heavy metals are, to a higher extent, strongly bound to the matrix.

  6. Chelant extraction and REDOX manipulation for mobilization of heavy metals from contaminated soils

    International Nuclear Information System (INIS)

    Brewster, M.D.; Peters, R.W.; Miller, G.A.; Patton, T.L.; Martino, L.E.

    1994-01-01

    Was the result of open burning and open detonation of chemical agents and munitions in the Toxic Burning Pits area at J-Field, located in the Edgewood Area of Aberdeen Proving Ground in Harford County, Maryland, soils have been contaminated with heavy metals. Simultaneous extraction is complicated because of the multitude of contaminant forms that exist. This paper uses data from a treatability study performed at Argonne National Laboratory to discuss and compare several treatment methods that were evaluated for remediating metals-contaminated soils. J-Field soils were subjected to a series of treatability experiments designed to determine the feasibility of using soil washing/soil flushing, enhancements to soil washing/soil flushing, solidification/stabilization, and electrokinetics for remediating soils contaminated with metals. Chelating and mobilizing agents evaluated included ammonium acetate, ethylenediaminetetraacetic acid, citric acid, Citranox, gluconic acid, phosphoric acid, oxalic acid, and nitrilotriacetic acid, in addition to pH-adjusted water. REDOX manipulation can maximize solubilities, increase desorption, and promote removal of heavy metal contaminants. Reducing agents that were studied included sodium borohydride, sodium metabisulfite, and thiourea dioxide. The oxidants studied included hydrogen peroxide, sodium percarbonate, sodium hypochlorite, and potassium permanganate. This paper summaries the results from the physical/chemical characterization, soil washing/soil flushing, and enhancements to soil washing/soil flushing portions of the study

  7. An Investigation into Heavy Metal Contamination and Mobilization in the Lower Rouge River, Michigan

    Science.gov (United States)

    Shihadeh, M.; Forrester, J.; Napieralski, J. A.

    2010-12-01

    Similar to many densely populated watersheds in the Great Lakes Basin, the Rouge River in Michigan drains a heavily urbanized watershed, which, over time, has accumulated a substantial amount of contamination due to decades of manufacturing and refining industries. Statistically significant levels of heavy metals have been found in the bed sediment of the Rouge; however, little is known about the mobilization of these contaminated bed sediments. The goal of this study was to ascertain the extent to which these potentially contaminated sediments are mobilized and transported downstream. Suspended sediment samples were collected at four sites along the lower Rouge River using composite depth integrated sediment samples three times per week, resulting in a total of twenty samples from each site. Turbidity was measured simultaneously using a YSI datalogger at all sampling locations. Sediment was also extracted from floodplain soil pits and silted vegetation, as well as river bed sediment cores along stream channel cross-sections. Heavy metal concentrations (As, Cd, Cr, Cu, Fe, Pb, Hg, Ni, Se, Zn) were analyzed using ICP-MS and compared against both background characteristics for Michigan soils and EPA Hazardous Criteria Limits. As expected, a positive correlation exists between turbidity and heavy metal concentrations. Even in the sampling sites furthest upstream, heavy metal concentrations exceeded background soil characteristics, with a few also exceeding hazardous criteria limits. The heavy metal concentrations found in the Lower Rouge affirm the elevated pollution classification of the river, depict the overall influence of industrialization on stream health, and verify that contaminated sediments are being deposited in aquatic and floodplain environments during variable flow or high discharge events. Results from this study emphasize the need to remediate bed sediments in the Rouge and suggest that there may be significant bioaccumulation potential for organisms

  8. Solubility and Potential Mobility of Heavy Metals in Two Contaminated Urban Soils from Stockholm, Sweden

    International Nuclear Information System (INIS)

    Oborn, Ingrid; Linde, Mats

    2001-01-01

    The solubility and potential mobility of heavy metals (Cd, Cu,Hg, Pb and Zn) in two urban soils were studied by sequential and leaching extractions (rainwater). Compared to rural (arable) soils on similar parent material, the urban soils were highly contaminated with Hg and Pb and to a lesser extent also with Cd,Cu and Zn. Metal concentrations in rainwater leachates were related to sequential extractions and metal levels reported from Stockholm groundwater. Cadmium and Zn in the soils were mainly recovered in easily extractable fractions, whereas Cu and Pb were complex bound. Concentrations of Pb in the residual fraction were between two- and eightfold those in arable soils, indicating that the sequential extraction scheme did not reflect the solid phases affected by anthropogenic inputs. Cadmium and Zn conc. in the rainwater leachates were within the range detected in Stockholm groundwater, while Cu and Pb conc. were higher, which suggests that Cu and Pb released from the surface soil were immobilised in deeper soil layers. In a soil highly contaminated with Hg, the Hg conc. in the leachate was above the median concentration, but still 50 times lower than the max concentration found in groundwater, indicating the possibility of other sources. In conclusion, it proved difficult to quantitatively predict the mobility of metals in soils by sequential extractions

  9. Remediation of Heavy Metal(loid)s Contaminated Soils – To Mobilize or To Immobilize?

    Science.gov (United States)

    Unlike organic contaminants, metal(loid)s do not undergo microbial or chemical degradation and persist for a long time after their introduction. Bioavailability of metal(loid)s plays a vital role in the remediation of contaminated soils. In this review, the remediation of heavy ...

  10. Experimental determination of contaminant metal mobility as a function of temperature, time and solution chemistry. 1997 annual progress report

    International Nuclear Information System (INIS)

    Bruton, C.; Carroll, S.; O'Day, P.; Sahai, N.

    1997-01-01

    'Strontium is significantly more mobile than other hazardous radioactive metals. Its partitioning between aqueous and solid phases is controlled by reactions that occur at the interface between natural waters and minerals. At a groundwater site in Hanford (200-BP-5), the aerial extent of the 90 Sr plume is 100 times larger than the aerial extent of the 137 Cs and the 239 Pu plumes. Similarly, contaminated, perched watertables at INEL have much higher aqueous concentrations of 90 Sr than 137 Cs, presumably because Cs is preferentially sorbed to solids (Duncan 1995). Under high physical flow conditions, such as those in the highly fractured rock at Hanford and INEL, 90 Sr present in plumes may spread off-site and cause contamination of aquifers or other water sources. Geochemical factors that may contribute to the overall mobility of Sr in natural waters are the solubilities of phases such as strontianite (SrCO 3 ) and formation of strong complexes with sulfate and nitrate. Although 90 Sr is mobilized in natural waters in these examples, significant concentrations may also be present in solid phases. Sorption experiments using a wide variety of substrates at room temperature have shown that Sr is removed from solution under certain conditions. Additionally, strontianite (SrCO 3 ) may precipitate at low Sr concentrations in the pH range of waters in contact with basaltic rocks, which varies between pH 8 and 10. Waters contain variable amounts of carbonate owing to atmospheric interactions; the partial pressure of CO 2 is about 10 x 3.5 atm in air and commonly as high as 10 x 2.5 atm in soils. The objective of this work is to determine the fundamental data needed to predict the behavior of strontium at temperature and time scales appropriate to thermal remediation. The authors approach combines macroscopic sorption/precipitation and desorption/dissolution kinetic experiments, which track changes in solution composition, with direct molecular characterization of

  11. Assessing the influence of compost and biochar amendments on the mobility and toxicity of metals and arsenic in a naturally contaminated mine soil.

    Science.gov (United States)

    Beesley, Luke; Inneh, Onyeka S; Norton, Gareth J; Moreno-Jimenez, Eduardo; Pardo, Tania; Clemente, Rafael; Dawson, Julian J C

    2014-03-01

    Amending contaminated soils with organic wastes can influence trace element mobility and toxicity. Soluble concentrations of metals and arsenic were measured in pore water and aqueous soil extracts following the amendment of a heavily contaminated mine soil with compost and biochar (10% v:v) in a pot experiment. Speciation modelling and toxicity assays (Vibrio fischeri luminescence inhibition and Lolium perenne germination) were performed to discriminate mechanisms controlling metal mobility and assess toxicity risk thereafter. Biochar reduced free metal concentrations furthest but dissolved organic carbon primarily controlled metal mobility after compost amendment. Individually, both amendments induced considerable solubilisation of arsenic to pore water (>2500 μg l(-1)) related to pH and soluble phosphate but combining amendments most effectively reduced toxicity due to simultaneous reductions in extractable metals and increases in soluble nutrients (P). Thus the measure-monitor-model approach taken determined that combining the amendments was most effective at mitigating attendant toxicity risk. Copyright © 2013 Elsevier Ltd. All rights reserved.

  12. Effect of bamboo and rice straw biochars on the mobility and redistribution of heavy metals (Cd, Cu, Pb and Zn) in contaminated soil.

    Science.gov (United States)

    Lu, Kouping; Yang, Xing; Gielen, Gerty; Bolan, Nanthi; Ok, Yong Sik; Niazi, Nabeel Khan; Xu, Song; Yuan, Guodong; Chen, Xin; Zhang, Xiaokai; Liu, Dan; Song, Zhaoliang; Liu, Xingyuan; Wang, Hailong

    2017-01-15

    Biochar has emerged as an efficient tool to affect bioavailability of heavy metals in contaminated soils. Although partially understood, a carefully designed incubation experiment was performed to examine the effect of biochar on mobility and redistribution of Cd, Cu, Pb and Zn in a sandy loam soil collected from the surroundings of a copper smelter. Bamboo and rice straw biochars with different mesh sizes (Heavy metal concentrations in pore water were determined after extraction with 0.01 M CaCl 2 . Phytoavailable metals were extracted using DTPA/TEA (pH 7.3). The European Union Bureau of Reference (EUBCR) sequential extraction procedure was adopted to determine metal partitioning and redistribution of heavy metals. Results showed that CaCl 2 -and DTPA-extractable Cd, Cu, Pb and Zn concentrations were significantly (p soils, especially at 5% application rate, than those in the unamended soil. Soil pH values were significantly correlated with CaCl 2 -extractable metal concentrations (p metal fractions, and the effect was more pronounced with increasing biochar application rate. The effect of biochar particle size on extractable metal concentrations was not consistent. The 5% rice straw biochar treatment reduced the DTPA-extractable metal concentrations in the order of Cd metals were mainly bound in the soil organic matter fraction. The results demonstrated that the rice straw biochar can effectively immobilize heavy metals, thereby reducing their mobility and bioavailability in contaminated soils. Copyright © 2016 Elsevier Ltd. All rights reserved.

  13. Proposal of a simple screening method for a rapid preliminary evaluation of ''heavy metals'' mobility in soils of contaminated sites

    Energy Technology Data Exchange (ETDEWEB)

    Pinto, Valentina; Chiusolo, Francesca; Cremisini, Carlo [ENEA - Italian Agency for New Technologies, Energy and Environment, Rome (Italy). Section PROTCHIM

    2010-09-15

    Risks associated to ''heavy metals'' (HM) soil contamination depend not only on their total content but, mostly, on their mobility. Many extraction procedures have been developed to evaluate HM mobility in contaminated soils, but they are generally time consuming (especially the sequential extraction procedures (SEPs)) and consequently applicable on a limited number of samples. For this reason, a simple screening method, applicable even ''in field'', has been proposed in order to obtain a rapid evaluation of HM mobility in polluted soils, mainly focused on the fraction associated to Fe and Mn oxide/hydroxides. A buffer solution of trisodium citrate and hydroxylamine hydrochloride was used as extractant for a single-step leaching test. The choice of this buffered solution was strictly related to the possibility of directly determining, via titration with dithizone (DZ), the content of Zn, Cu, Pb and Cd, which are among the most representative contaminants in highly mineralised soils. Moreover, the extraction solution is similar, aside from for the pH value, which is the one used in the BCR SEP second step. The analysis of bivalents ions through DZ titration was exploited in order to further simplify and quicken the whole procedure. The proposed method generically measures, in few minutes, the concentration of total extractable ''heavy metals'' expressed as molL{sup -1} without distinguishing between elements. The proposed screening method has been developed and applied on soil samples collected from rural, urban and mining areas, representing different situation of soil contamination. Results were compared with data obtained from the BCR procedure. The screening method demonstrated to be a reliable tool for a rapid evaluation of metals mobility. Therefore, it could be very useful, even ''in field'', both to guide the sampling activity on site and to monitor the efficacy of the subsequent

  14. Changes in heavy metal mobility and availability from contaminated wetland soil remediated with combined biochar-compost.

    Science.gov (United States)

    Liang, Jie; Yang, Zhaoxue; Tang, Lin; Zeng, Guangming; Yu, Man; Li, Xiaodong; Wu, Haipeng; Qian, Yingying; Li, Xuemei; Luo, Yuan

    2017-08-01

    The combination of biochar and compost has been proven to be effective in heavy metals contaminated wetland soil restoration. However, the influence of different proportions between biochar and compost on immobilization of heavy metals in soil has been less studied up to date. Therefore, we investigated the effect of different ratios of biochar-compost mixtures on availability and speciation distribution of heavy metals (Cd, Zn and Cu) in wetland soil. The results showed that applying all amendment combinations into wetland soil increased gradually the total organic carbon (TOC) and water-extract organic carbon (WEOC) as the compost percentage rose in biochar-composts. The higher pH was obtained in a certain biochar addition (20% and 40%) in combinations due to efficient interaction of biochar with compost. All amendments could significantly decrease availability of Cd and Zn mainly from pH change, but increase available Cu concentration as the result of increased water-extract organic carbon and high total Cu content in compost. Moreover, amendments can decrease easily exchangeable fraction and increase reducible of Cd and Zn greatly with increase of compost content in combinations, while amendments containing compost promote transformation of Cu from Fe/Mn oxide and residual fractions to organic bindings. These results demonstrate that different ratios of biochar and compost have a significant effect on availability and speciation of heavy metals in multi-metal-contaminated wetland soil. Copyright © 2017 Elsevier Ltd. All rights reserved.

  15. Chemically enhanced phytoextraction of risk elements from a contaminated agricultural soil using Zea mays and Triticum aestivum: performance and metal mobilization over a three year period.

    Science.gov (United States)

    Neugschwandtner, Reinhard W; Tlustos, Pavel; Komárek, Michael; Száková, Jirina; Jakoubková, Lucie

    2012-09-01

    Enhanced phytoextraction using EDTA for the remediation of an agricultural soil contaminated with less mobile risk elements Cd and Pb originating from smelting activities in Príbram (Czech Republic) was assessed on the laboratory and the field scale. EDTA was applied to the first years crop Zea mays. Metal mobilization and metal uptake by the plants in the soil were monitored for two additional years when Triticum aestivum was planted. The application ofEDTA effectively increased water-soluble Cd and Pb concentrations in the soil. These concentrations decreased over time. Anyhow, increased concentrations could be still observed in the third experimental year indicating a low possibility of groundwater pollution after the addition of EDTA during and also after the enhanced phytoextraction process under prevailing climatic conditions. EDTA-applications caused phytotoxicity and thereby decreased biomass production and increased Cd and Pb uptake by the plants. Phytoextraction efficiency and phytoextraction potential were too low for Cd and Pb phytoextraction in the field in a reasonable time frame (as less than one-tenth of a percent of total Cd and Pb could be removed). This strongly indicates that EDTA-enhanced phytoextraction as implemented in this study is not a suitable remediation technique for risk metal contaminated soils.

  16. Mobility and toxicity of heavy metal(loid)s arising from contaminated wood ash application to a pasture grassland soil.

    Science.gov (United States)

    Mollon, L C; Norton, G J; Trakal, L; Moreno-Jimenez, E; Elouali, F Z; Hough, R L; Beesley, L

    2016-11-01

    Heavy metal(loid) rich ash (≤10,000 mg kg -1 total As, Cr, Cu and Zn) originating from the combustion of contaminated wood was subjected to several experimental procedures involving its incorporation into an upland pasture soil. Ash was added to soil that had been prior amended with local cattle manure, replicating practices employed at the farm scale. Metal(loid) concentrations were measured in soil pore water and ryegrass grown on soil/manure plus ash mixtures (0.1-3.0% vol. ash) in a pot experiment; toxicity evaluation was performed on the same pore water samples by means of a bacterial luminescence biosensor assay. Thereafter a sequential extraction procedure was carried out on selected soil, manure and ash mixtures to elucidate the geochemical association of ash derived metal(loid)s with soil constituents. Predictive modelling was applied to selected data from the pot experiment to determine the risk of transfer of As to meat and milk products in cattle grazing pasture amended with ash. The inclusion of manure to soils receiving ash reduced phyto-toxicity and increased ryegrass biomass yields, compared to soil with ash, but without manure. Elevated As and Cu concentrations in pore water and ryegrass tissue resulting from ash additions were reduced furthest by the inclusion of manure due to an increase in their geochemical association with organic matter. Zinc was the only measured metal(loid) to remain uniformly soluble and bioavailable regardless of the addition of ash and manure. Risk modelling on pot experimental data highlighted that an ash addition of >1% (vol.) to this pasture soil could result in As concentrations in milk and meat products exceeding acceptable limits. The results of this study therefore suggest that even singular low doses of ash applied to soil increase the risk of leaching of metal(loid)s and intensify the risk of As transfer in the food chain. Copyright © 2016 Elsevier Ltd. All rights reserved.

  17. Radioactive contamination of recycled metals

    International Nuclear Information System (INIS)

    Lubenau, J.O.; Cool, D.A.; Yusko, J.G.

    1996-01-01

    Radioactive sources commingled with metal scrap have become a major problem for the metals recycling industry worldwide. Worldwide there have been 38 confirmed reports of radioactive sources accidentally smelted with recycled metal. In some instances, contaminated metal products were subsequently distributed. The metal mills, their products and byproducts from the metal making process such as slags, crosses and dusts from furnaces can become contaminated. In the U.S., imported ferrous metal products such as reinforcement bars, pipe flanges, table legs and fencing components have been found contaminated with taco. U.S. steel mills have unintentionally smelted radioactive sources on 16 occasions. The resulting cost for decontamination waste disposal and temporary closure of the steel mill is typically USD 10,000,000 and has been as much as USD 23,000,000. Other metal recycling industries that have been affected by this problem include aluminum, copper, zinc, gold, lead and vanadium. (author)

  18. The remediation of heavy metals contaminated sediment.

    Science.gov (United States)

    Peng, Jian-Feng; Song, Yong-Hui; Yuan, Peng; Cui, Xiao-Yu; Qiu, Guang-Lei

    2009-01-30

    Heavy metal contamination has become a worldwide problem through disturbing the normal functions of rivers and lakes. Sediment, as the largest storage and resources of heavy metal, plays a rather important role in metal transformations. This paper provides a review on the geochemical forms, affecting factors and remediation technologies of heavy metal in sediment. The in situ remediation of sediment aims at increasing the stabilization of some metals such as the mobile and the exchangeable fractions; whereas, the ex situ remediation mainly aims at removing those potentially mobile metals, such as the Mn-oxides and the organic matter (OM) fraction. The pH and OM can directly change metals distribution in sediment; however oxidation-reduction potential (ORP), mainly through changing the pH values, indirectly alters metals distribution. Mainly ascribed to their simple operation mode, low costs and fast remediation effects, in situ remediation technologies, especially being fit for slight pollution sediment, are applied widely. However, for avoiding metal secondary pollution from sediment release, ex situ remediation should be the hot point in future research.

  19. Developments in Bioremediation of Soils and Sediments Polluted with Metals and Radionuclides - 3. Influence of Chemical Speciation and Bioavailability on Contaminants Immobilization/mobilization Bio-processes

    NARCIS (Netherlands)

    Hullebusch, van E.D.; Lens, P.N.L.; Tabak, H.H.

    2005-01-01

    The biotransformation of metals is an exciting, developing strategy to treat metal contamination, especially in environments that are not accessible to other remediation technologies. However, our ability to benefit from these strategies hinges on our ability to monitor these transformations in the

  20. Melting of contaminated metallic waste

    International Nuclear Information System (INIS)

    Lee, Y.-S.; Cheng, S.-Y.; Kung, H.-T.; Lin, L.-F.

    2004-01-01

    Approximately 100 tons of contaminated metallic wastes were produced each year due to maintenance for each TPC's nuclear power reactor and it was roughly estimated that there will be 10,000 tons of metallic scraps resulted from decommissioning of each reactor in the future. One means of handling the contaminated metal is to melt it. Melting process owns not only volume reduction which saves the high cost of final disposal but also resource conservation and recycling benefits. Melting contaminated copper and aluminum scraps in the laboratory scale have been conducted at INER. A total of 546 kg copper condenser tubes with a specific activity of about 2.7 Bq/g was melted in a vacuum induction melting facility. Three types of products, ingot, slag and dust were derived from the melting process, with average activities of 0.10 Bq/g, 2.33 Bq/g and 84.3 Bq/g respectively. After the laboratory melting stage, a pilot plant with a 500 kg induction furnace is being designed to melt the increasingly produced contaminated metallic scraps from nuclear facilities and to investigate the behavior of different radionuclides during melting. (author)

  1. Decontamination method of contaminated metals

    International Nuclear Information System (INIS)

    Kawamura, Fumio; Ueda, Yoshihiro; Sato, Chikara; Komori, Itaru.

    1980-01-01

    Purpose: To effectively separate radioactive materials from molten metals in dry-processing method by heating metals contaminated with radioactive materials at a temperature below melting point to oxidize the surface thereof, then heating them to melt and include the radioactive materials into the oxides. Method: Metals contaminated with radioactive materials are heated at a temperature below the melting point thereof in an oxidizing atmosphere to oxidize the surface. Thereafter they are heated to melt at temperature above the melting point of the metals, and the molten metals are separated with the radioactive materials included in the oxides. For instance, radiation-contaminated aluminum pipe placed on the bed of an electrical heating furnace, and heated at 500 0 C which is lower than the melting point 660 0 C of aluminum for 1 - 2 hours while supplying air from an air pipe into the furnace, and an oxide film is formed on the surface of the aluminum pipe. Then, the furnace temperature is increased to 750 0 C wherein molten aluminum is flown down to a container and the oxide film is separated by floating it as the slug on the molten aluminum. (Horiuchi, T.)

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

    International Nuclear Information System (INIS)

    Hansen, J.E.

    1991-01-01

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

  3. Recent developments for in situ treatment of metal contaminated soils

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1997-03-01

    Metals contamination is a common problem at hazardous waste sites. This report assists the remedy selection process by providing information on four in situ technologies for treating soil contaminated with metals. The four approaches are electrokinetic remediation, phytoremediation, soil flushing, and solidification/stabilization. Electrokinetic remediation separates contaminants from soil through selective migration upon application of an electric current. Phytoremediation is an emerging technology that uses plants to isolate or stabilize contaminants. Soil flushing techniques promote mobility and migration of metals by solubilizing contaminants so that they can be recovered. Two types of in situ solidification/stabilization (S/S) techniques are discussed, one based on addition of reagents and the other based on the use of energy. The report discusses different techniques currently in practice or under development, identifies vendors and summarizes performance data, and discusses technology attributes that should be considered during early screening of potential remedies. 8 refs., 9 figs., 9 tabs., 2 apps.

  4. The Microbial Contamination of Mobile Communication Devices

    Directory of Open Access Journals (Sweden)

    Joanna Verran

    2012-02-01

    Full Text Available This tip describes a simple laboratory exercise to assess the microbial contamination of mobile phones, and suggests extension work that enables additional exploration of the topic. At its most basic, it is suitable for the school classroom; more advanced development of the suggested activities are suitable for undergraduate project work.

  5. Potential use of lime combined with additives on (im)mobilization and phytoavailability of heavy metals from Pb/Zn smelter contaminated soils.

    Science.gov (United States)

    Hussain Lahori, Altaf; Zhang, Zengqiang; Guo, Zhanyu; Mahar, Amanullah; Li, Ronghua; Kumar Awasthi, Mukesh; Ali Sial, Tanveer; Kumbhar, Farhana; Wang, Ping; Shen, Feng; Zhao, Junchao; Huang, Hui

    2017-11-01

    This explorative study was aimed to assess the efficiency of lime alone and in combined with additives to immobilize Pb, Cd, Cu and Zn in soil and reduce their phytoavailability for plant. A greenhouse pot experiment was performed by using low and heavily contaminated top soils viz. Tongguan contaminated (TG-C); Fengxian heavily contaminated (FX-HC) and Fengxian low contaminated (FX-LC). The contaminated soils were treated with lime (L) alone and in combined with Ca-bentonite (CB), Tobacco biochar (TB) and Zeolite (Z) at 1% and cultivated by Chinese cabbage (Brassica campestris L). Results revealed that all amendments (plime alone and in combined with additives were drastically decreased the dry biomass yield of Brassica campestris L. as compared with control. Thus, these feasible amendments potentially maximum reduced the uptake by plant shoots upto Pb 53.47 and Zn 67.93% with L+Z and L+TB in FX-LC soil, while Cd 68.58 and Cu 60.29% with L+TB, L+CB in TG-C soil but Cu uptake in plant shoot was observed 27.26% and 30.17% amended with L+TB and L+Z in FX-HC and FX-LC soils. On the other hand, these amendments were effectively reduced the potentially toxic metals (PTMs) in roots upto Pb77.77% L alone in FX-HC, Cd 96.76% with L+TB in TG-C, while, Cu 66.70 and Zn 60.18% with L+Z in FX-LC. Meanwhile, all amendments were responsible for increasing soil pH and CEC but decreased soils EC level. Based on this result, these feasible soil amendments were recommended for long term-study under field condition to see the response of another hyper accumulator crop. Copyright © 2017. Published by Elsevier Inc.

  6. Considering bioavailability in the remediation of heavy metal contaminated sites

    Directory of Open Access Journals (Sweden)

    Leita L.

    2013-04-01

    Full Text Available Many years of research have demonstrated that instead of the total concentration of metals in soil, bioavailability is the key to understand the environmental risk derived by metals, since adverse effects are related only to the biologically available forms of these elements. The knowledge of bioavailability can decrease the uncertainties in evaluating exposure in human and ecological risk assessment. At the same time, the efficiency of remediation treatments could be greatly influenced by availability of the contaminants. Consideration of the bioavailability processes at contaminated sites could be useful in site-specific risk assessment: the fraction of mobile metals, instead of total content should be provided as estimates of metal exposure. Moreover, knowledge of the chemical forms of heavy metals in soils is a critical component in the evaluation of applicability of different remediation technologies such as phytoremdiation or soil washing.

  7. Remediating sites contaminated with heavy metals

    International Nuclear Information System (INIS)

    Swartzbaugh, J.; Sturgill, J.; Cormier, B.; Williams, H.D.

    1992-01-01

    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

  8. Contaminated metallic melt volume reduction testing

    International Nuclear Information System (INIS)

    Deichman, J.L.

    1981-01-01

    Laboratory scale metallic melts (stainless steel) were accomplished in support of Decontamination and Decommissioning's (D and D) contaminated equipment volume reduction and Low-Level Lead Site Waste programs. Six laboratory scale melts made with contaminated stainless steel provided data that radionuclide distribution can be predicted when proper temperature rates and ranges are employed, and that major decontamination occurs with the use of designed slagging materials. Stainless steel bars were contaminated with plutonium, cobalt, cesium and europium. This study was limited to stainless steel, however, further study is desirable to establish data for other metals and alloys. This study represents a positive beginning in defining the feasibility of economical volume reduction or conversion from TRU waste forms to LLW forms for a large portion of approximately 50 thousand tons of contaminated metal waste now being stored at Hanford underground or in deactivated facilities

  9. Decontamination method for radiation contaminated metal

    International Nuclear Information System (INIS)

    Enda, Masami; Hosaka, Katsumi; Sakai, Hitoshi.

    1997-01-01

    An organic acid solution is used as a decontamination liquid, and base materials of radiation contaminated metals are dissolved in the solution. The concentration of the organic acid is measured, and the organic acid is supplied by an amount corresponding to the lowering of the concentration. The decontamination liquid wastes generated during the decontamination step are decomposed, and metals leached in the organic acid solution are separated. With such procedures, contamination intruded into the inside of the mother materials of the metals can be removed, and radioactivity of the contaminated metals such as stainless steels and carbon steels can be eliminated, or the radiation level thereof can be reduced. In addition, the amount of secondary wastes generated along with the decontamination can be suppressed. (T.M.)

  10. Catalytic extraction processing of contaminated scrap metal

    International Nuclear Information System (INIS)

    Griffin, T.P.; Johnston, J.E.

    1994-01-01

    The contract was conceived to establish the commercial capability of Catalytic Extraction Processing (CEP) to treat contaminated scrap metal in the DOE inventory. In so doing, Molten Metal Technology, Inc. (MMT), pursued the following objectives: demonstration of the recycling of ferrous and non-ferrous metals--to establish that radioactively contaminated scrap metal can be converted to high-grade, ferrous and non-ferrous alloys which can be reused by DOE or reintroduced into commerce; immobilize radionuclides--that CEP will concentrate the radionuclides in a dense vitreous phase, minimize secondary waste generation and stabilize and reduce waste volume; destroy hazardous organics--that CEP will convert hazardous organics to valuable industrial gases, which can be used as feed gases for chemical synthesis or as an energy source; recovery volatile heavy metals--that CEP's off-gas treatment system will capture volatile heavy metals, such as mercury and lead; and establish that CEP is economical for processing contaminated scrap metal in the DOE inventory--that CEP is a more cost-effective and, complete treatment and recycling technology than competing technologies for processing contaminated scrap. The process and its performance are described

  11. Aromatic plant production on metal contaminated soils

    International Nuclear Information System (INIS)

    Zheljazkov, Valtcho D.; Craker, Lyle E.; Xing Baoshan; Nielsen, Niels E.; Wilcox, Andrew

    2008-01-01

    Field and container experiments were conducted to assess the feasibility of growing aromatic crops in metal contaminated areas and the effect of metals on herbage and oil productivity. The field experiments were conducted in the vicinities of the Non-Ferrous Metals Combine (Zn-Cu smelter) near Plovdiv, Bulgaria using coriander, sage, dill, basil, hyssop, lemon balm, and chamomile grown at various distances from the smelter. Herbage essential oil yields of basil, chamomile, dill, and sage were reduced when they were grown closer to the smelter. Metal removal from the site with the harvestable plant parts was as high as 180 g ha -1 for Cd, 660 g ha -1 for Pb, 180 g ha -1 for Cu, 350 g ha -1 for Mn, and 205 g ha -1 for Zn. Sequential extraction of soil demonstrated that metal fractionation was affected by the distance to the smelter. With decreasing distance to the smelter, the transfer factor (TF) for Cu and Zn decreased but increased for Cd, while the bioavailability factor (BF) for Cd, Pb, Cu, Mn, and Zn decreased. Scanning electron microscopy and X-ray microanalyses of contaminated soil verified that most of the Pb, Cd, Mn, Cu, and Zn were in the form of small (< 1 μm) particles, although there were larger particles (1-5 μm) with high concentrations of individual metals. This study demonstrated that high concentrations of heavy metals in soil or growth medium did not result in metal transfer into the essential oil. Of the tested metals, only Cu at high concentrations may reduce oil content. Our results demonstrated that aromatic crops may not have significant phytoremediation potential, but growth of these crops in metal contaminated agricultural soils is a feasible alternative. Aromatic crops can provide economic return and metal-free final product, the essential oil

  12. Aromatic plant production on metal contaminated soils

    Energy Technology Data Exchange (ETDEWEB)

    Zheljazkov, Valtcho D. [Mississippi State, Department of Plant and Soil Sciences and North Mississippi Research and Extension Center, 5421 Highway 145 South, Verona, MS 38879 (United States)], E-mail: vj40@pss.msstate.edu; Craker, Lyle E.; Xing Baoshan [Department of Plant and Soil Sciences, 12 Stockbridge Hall, University of Massachusetts, Amherst, MA 01003 (United States); Nielsen, Niels E. [Plant Nutrition and Soil Fertility Lab, Department of Agricultural Sciences, Royal Veterinary and Agricultural University, Thorvaldsensvej 40, DK1871, Copenhagen (Denmark); Wilcox, Andrew [Harper Adams University College, Newport, Shropshire, TF10 8NB (United Kingdom)

    2008-06-01

    Field and container experiments were conducted to assess the feasibility of growing aromatic crops in metal contaminated areas and the effect of metals on herbage and oil productivity. The field experiments were conducted in the vicinities of the Non-Ferrous Metals Combine (Zn-Cu smelter) near Plovdiv, Bulgaria using coriander, sage, dill, basil, hyssop, lemon balm, and chamomile grown at various distances from the smelter. Herbage essential oil yields of basil, chamomile, dill, and sage were reduced when they were grown closer to the smelter. Metal removal from the site with the harvestable plant parts was as high as 180 g ha{sup -1} for Cd, 660 g ha{sup -1} for Pb, 180 g ha{sup -1} for Cu, 350 g ha{sup -1} for Mn, and 205 g ha{sup -1} for Zn. Sequential extraction of soil demonstrated that metal fractionation was affected by the distance to the smelter. With decreasing distance to the smelter, the transfer factor (TF) for Cu and Zn decreased but increased for Cd, while the bioavailability factor (BF) for Cd, Pb, Cu, Mn, and Zn decreased. Scanning electron microscopy and X-ray microanalyses of contaminated soil verified that most of the Pb, Cd, Mn, Cu, and Zn were in the form of small (< 1 {mu}m) particles, although there were larger particles (1-5 {mu}m) with high concentrations of individual metals. This study demonstrated that high concentrations of heavy metals in soil or growth medium did not result in metal transfer into the essential oil. Of the tested metals, only Cu at high concentrations may reduce oil content. Our results demonstrated that aromatic crops may not have significant phytoremediation potential, but growth of these crops in metal contaminated agricultural soils is a feasible alternative. Aromatic crops can provide economic return and metal-free final product, the essential oil.

  13. Using biochar for remediation of soils contaminated with heavy metals and organic pollutants.

    Science.gov (United States)

    Zhang, Xiaokai; Wang, Hailong; He, Lizhi; Lu, Kouping; Sarmah, Ajit; Li, Jianwu; Bolan, Nanthi S; Pei, Jianchuan; Huang, Huagang

    2013-12-01

    Soil contamination with heavy metals and organic pollutants has increasingly become a serious global environmental issue in recent years. Considerable efforts have been made to remediate contaminated soils. Biochar has a large surface area, and high capacity to adsorb heavy metals and organic pollutants. Biochar can potentially be used to reduce the bioavailability and leachability of heavy metals and organic pollutants in soils through adsorption and other physicochemical reactions. Biochar is typically an alkaline material which can increase soil pH and contribute to stabilization of heavy metals. Application of biochar for remediation of contaminated soils may provide a new solution to the soil pollution problem. This paper provides an overview on the impact of biochar on the environmental fate and mobility of heavy metals and organic pollutants in contaminated soils and its implication for remediation of contaminated soils. Further research directions are identified to ensure a safe and sustainable use of biochar as a soil amendment for remediation of contaminated soils.

  14. Sequential extraction of uranium metal contamination

    International Nuclear Information System (INIS)

    Murry, M.M.; Spitz, H.B.; Connick, W.B.

    2016-01-01

    Samples of uranium contaminated dirt collected from the dirt floor of an abandoned metal rolling mill were analyzed for uranium using a sequential extraction protocol involving a series of five increasingly aggressive solvents. The quantity of uranium extracted from the contaminated dirt by each reagent can aid in predicting the fate and transport of the uranium contamination in the environment. Uranium was separated from each fraction using anion exchange, electrodeposition and analyzed by alpha spectroscopy analysis. Results demonstrate that approximately 77 % of the uranium was extracted using NH 4 Ac in 25 % acetic acid. (author)

  15. Bioleaching of multiple metals from contaminated sediment by moderate thermophiles.

    Science.gov (United States)

    Gan, Min; Jie, Shiqi; Li, Mingming; Zhu, Jianyu; Liu, Xinxing

    2015-08-15

    A moderately thermophilic consortium was applied in bioleaching multiple metals from contaminated sediment. The consortium got higher acidification and metals soubilization efficiency than that of the pure strains. The synergistic effect of the thermophilic consortium accelerated substrates utilization. The utilization of substrate started with sulfur in the early stage, and then the pH declined, giving rise to making use of the pyrite. Community dynamic showed that A. caldus was the predominant bacteria during the whole bioleaching process while the abundance of S. thermotolerans increased together with pyrite utilization. Solubilization efficiency of Zn, Cu, Mn and Cd reached 98%, 94%, 95%, and 89% respectively, while As, Hg, Pb was only 45%, 34%, 22%. Logistic model was used to simulate the bioleaching process, whose fitting degree was higher than 90%. Correlation analysis revealed that metal leaching was mainly an acid solubilization process. Fraction analysis revealed that metals decreased in mobility and bioavailability. Copyright © 2015 Elsevier Ltd. All rights reserved.

  16. Heavy metals contamination of Chrysichthys nigrodigitatus and ...

    African Journals Online (AJOL)

    This study investigates the presence of heavy metal contamination of Chrysichthys nigrodigitatus and Lates niloticus. Adult C. nigrodigitatus and L. niloticus were obtained from fishermen in Ikere Gorge, Oyo state, Nigeria. Water samples were also collected during the wet and dry seasons of the year in the same locality.

  17. Source Evaluation and Trace Metal Contamination in Benthic Sediments from Equatorial Ecosystems Using Multivariate Statistical Techniques.

    Directory of Open Access Journals (Sweden)

    Nsikak U Benson

    Full Text Available Trace metals (Cd, Cr, Cu, Ni and Pb concentrations in benthic sediments were analyzed through multi-step fractionation scheme to assess the levels and sources of contamination in estuarine, riverine and freshwater ecosystems in Niger Delta (Nigeria. The degree of contamination was assessed using the individual contamination factors (ICF and global contamination factor (GCF. Multivariate statistical approaches including principal component analysis (PCA, cluster analysis and correlation test were employed to evaluate the interrelationships and associated sources of contamination. The spatial distribution of metal concentrations followed the pattern Pb>Cu>Cr>Cd>Ni. Ecological risk index by ICF showed significant potential mobility and bioavailability for Cu, Cu and Ni. The ICF contamination trend in the benthic sediments at all studied sites was Cu>Cr>Ni>Cd>Pb. The principal component and agglomerative clustering analyses indicate that trace metals contamination in the ecosystems was influenced by multiple pollution sources.

  18. Evidence for groundwater contamination by heavy metals through soil passage under acidifying conditions

    NARCIS (Netherlands)

    Wilkens, B.J.

    1995-01-01

    The research reported here is aimed at improving the knowledge of the mobility of the heavy metals cadmium and zinc in vulnerable soil types. We use the term vulnerable with reference to vulnerability of groundwater for contamination by soil leaching. At diffuse soil immissions of heavy metals,

  19. Microbial links between sulfate reduction and metal retention in uranium- and heavy metal-contaminated soil.

    Science.gov (United States)

    Sitte, Jana; Akob, Denise M; Kaufmann, Christian; Finster, Kai; Banerjee, Dipanjan; Burkhardt, Eva-Maria; Kostka, Joel E; Scheinost, Andreas C; Büchel, Georg; Küsel, Kirsten

    2010-05-01

    Sulfate-reducing bacteria (SRB) can affect metal mobility either directly by reductive transformation of metal ions, e.g., uranium, into their insoluble forms or indirectly by formation of metal sulfides. This study evaluated in situ and biostimulated activity of SRB in groundwater-influenced soils from a creek bank contaminated with heavy metals and radionuclides within the former uranium mining district of Ronneburg, Germany. In situ activity of SRB, measured by the (35)SO(4)(2-) radiotracer method, was restricted to reduced soil horizons with rates of metals were enriched in the solid phase of the reduced horizons, whereas pore water concentrations were low. X-ray absorption near-edge structure (XANES) measurements demonstrated that approximately 80% of uranium was present as reduced uranium but appeared to occur as a sorbed complex. Soil-based dsrAB clone libraries were dominated by sequences affiliated with members of the Desulfobacterales but also the Desulfovibrionales, Syntrophobacteraceae, and Clostridiales. [(13)C]acetate- and [(13)C]lactate-biostimulated soil microcosms were dominated by sulfate and Fe(III) reduction. These processes were associated with enrichment of SRB and Geobacteraceae; enriched SRB were closely related to organisms detected in soils by using the dsrAB marker. Concentrations of soluble nickel, cobalt, and occasionally zinc declined uranium increased in carbon-amended treatments, reaching metal attenuation and (ii) the fate of uranium mobility is not predictable and may lead to downstream contamination of adjacent ecosystems.

  20. Metal contamination in environmental media in residential ...

    Science.gov (United States)

    Hard-rock mining for metals, such as gold, silver, copper, zinc, iron and others, is recognized to have a significant impact on the environmental media, soil and water, in particular. Toxic contaminants released from mine waste to surface water and groundwater is the primary concern, but human exposure to soil contaminants either directly, via inhalation of airborne dust particles, or indirectly, via food chain (ingestion of animal products and/or vegetables grown in contaminated areas), is also, significant. In this research, we analyzed data collected in 2007, as part of a larger environmental study performed in the Rosia Montana area in Transylvania, to provide the Romanian governmental authorities with data on the levels of metal contamination in environmental media from this historical mining area. The data were also considered in policy decision to address mining-related environmental concerns in the area. We examined soil and water data collected from residential areas near the mining sites to determine relationships among metals analyzed in these different environmental media, using the correlation procedure in SAS statistical software. Results for residential soil and water analysis indicate that the average values for arsenic (As) (85 mg/kg), cadmium (Cd) (3.2 mg/kg), mercury (Hg) (2.3 mg/kg) and lead (Pb) (92 mg/kg) exceeded the Romanian regulatory exposure levels [the intervention thresholds for residential soil in case of As (25 mg/kg) and Hg

  1. Evaluation of some heavy metal contaminants in biscuits, fruit drinks ...

    African Journals Online (AJOL)

    Evaluation of some heavy metal contaminants in biscuits, fruit drinks, concentrates, ... effect in human due to continual consumption of food contaminated with heavy metals gotten from raw materials, manufacturing and packaging processes.

  2. Microbial links between sulfate reduction and metal retention in uranium- and heavy metal-contaminated soil

    DEFF Research Database (Denmark)

    Sitte, Jana; Akob, Denise M.; Kaufmann, Christian

    2010-01-01

    Sulfate-reducing bacteria (SRB) can affect metal mobility either directly by reductive transformation of metal ions, e.g., uranium, into their insoluble forms or indirectly by formation of metal sulfides. This study evaluated in situ and biostimulated activity of SRB in groundwater-influenced soils...... from a creek bank contaminated with heavy metals and radionuclides within the former uranium mining district of Ronneburg, Germany. In situ activity of SRB, measured by the 35SO42– radiotracer method, was restricted to reduced soil horizons with rates of 142 ± 20 nmol cm–3 day–1. Concentrations...... of heavy metals were enriched in the solid phase of the reduced horizons, whereas pore water concentrations were low. X-ray absorption near-edge structure (XANES) measurements demonstrated that 80% of uranium was present as reduced uranium but appeared to occur as a sorbed complex. Soil-based dsrAB clone...

  3. Heavy metal movement in metal-contaminated soil profiles

    Energy Technology Data Exchange (ETDEWEB)

    Li, Zhenbin; Shuman, L.M. [Univ. of Georgia, Griffin, GA (United States)

    1996-10-01

    Heavy metal movement in soil profiles is a major environmental concern because even slow transport through the soil may eventually lead to deterioration of groundwater quality. In this study, three metal-contaminated soil (Fuquay, Dothan, and Clarendon) were selected from cropland were a high-metal flue dust had been applied annually for 6 years to raise soil pH, with application ending 4 years before sampling. One uncontaminated soil (Tifton) from the same physiographic area was also sampled as a control. Soil samples were collected in 15-cm increments from the surface to 105 cm in depth. Total contents of Zn, Cd, and Pb in the soils samples were determined. To better understand metal movement in relation to metal fractions in the soil profile, soil samples were also extracted sequentially for exchangeable (EXC), organic matter (OM), Mn oxide (MNO), amorphous Fe oxide (AFEO), crystalline Fe oxide (CFEO), and residual (RES) fractions. 35 refs., 6 figs., 2 tabs.

  4. Metal pollution in a contaminated bay: Relationship between metal geochemical fractionation in sediments and accumulation in a polychaete

    International Nuclear Information System (INIS)

    Fan, Wenhong; Xu, Zhizhen; Wang, Wen-Xiong

    2014-01-01

    Jinzhou Bay in Northern China has been seriously contaminated with metals due to the impacts of smelting activities. In this study, we investigated the relationship between metal accumulation in a deposit-feeding polychaete Neanthes japonica and metal concentration and geochemical fractionation (Cd, Cu, Pb, Zn and Ni) in sediments of Jinzhou Bay. Compared with the historical data, metals in the more mobile geochemical fraction (exchangeable and carbonate fractions) were gradually partitioned into the more stable fraction (Fe–Mn oxides) over time. Metal concentration and geochemical fractionation in sediment significantly affected metal bioavailability and accumulation in polychaetes, except for Ni. Metal accumulation in polychaetes was significantly influenced by Fe or Mn content, and to a lesser degree by organic matter. Prediction of metal bioaccumulation in polychaetes was greatly improved by normalizing metal concentrations to Mn content in sediment. The geochemical fractionation of metals in sediments including the exchangeable, organic matter and Fe–Mn oxides were important in controlling the sediment metal bioavailability to polychaetes. - Highlights: • Metals in contaminated sediments gradually partitioned into the more stable phase over time. • Metal accumulation in polychaetes was more significantly influenced by Fe/Mn content than by organic matter. • Prediction of metal bioaccumulation greatly improved by normalizing metals to Mn content in sediment. • Metals in exchangeable, organic matter and Fe–Mn oxides were important in controlling their bioavailability. - Prediction of metal bioaccumulation in polychaetes was significantly improved by normalizing metal concentrations to Mn content in sediment

  5. Remediation of soils contaminated with heavy metals

    Energy Technology Data Exchange (ETDEWEB)

    Boni, M.R.; D' Aprile, L. [Univ. of Rome ' ' La Sapienza' ' , Dept. of Hydraulic Transportation and Roads (Italy)

    2001-07-01

    In December 1999 Italy issued the national regulation (DM 471/99) for the clean-up of contaminated sites. This regulation applies both to derelict and to still operating industrial plants and waste management facilities. Target concentration values for clean-up interventions are issued and the requirements for design and planning of technical operation are defined. The selection of the appropriate clean-up technology are based on the following main criteria: - reduce the concentration in environmental media and the migration of pollutants without removing soil off-site; - in order to reduce contaminated material removal and transportation, remedial actions of soil, subsoil and groundwater should preferably be based on in-situ treatments. In-situ technologies commonly applied in Italy to the remediation of soils contaminated by heavy metals (As, Cd, Cr, Hg, Pb) are: - containment (caps, vertical barriers); - soil flushing; - cement based solidification/stabilization. (orig.)

  6. Mobile heavy metal fractions in soils

    International Nuclear Information System (INIS)

    Horak, O.; Kamel, A.A.; Ecker, S.; Benetka, E.; Rebler, R.; Lummerstorfer, E.; Kandeler, E.

    1994-01-01

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

  7. Mobile Monitoring System for Nuclear Contamination Analysis

    International Nuclear Information System (INIS)

    Broide, A.; Sheinfeld, M.; Marcus, E.; Wengrowicz, U.; Tirosh, D.

    2002-01-01

    In case of a nuclear accident, it is essential to have extensive knowledge concerning the nature of the radioactive plume expansion, for further analysis. For this purpose a mobile monitoring system may provide important data about the plume characteristics. An advanced Mobile Monitoring System is under development at the Nuclear Research Center-Negev. The system is composed of a network of mobile stations, typically installed onboard vehicles, which transmit radiation measurements along with position information to a central station. The mobile network's communications infrastructure is based on Motorola Mobile Logic Unit devices, which are state-of-the-art reliable modems with an integrated Global Positioning System module. The radiation measurements received by the central station are transferred to a risk assessment program, which evaluates the expected hazards to the populated areas located in the estimated plume's expansion direction

  8. Catalytic extraction processing of contaminated scrap metal

    Energy Technology Data Exchange (ETDEWEB)

    Griffin, T.P.; Johnston, J.E.; Payea, B.M. [Molten Metal Technology, Inc., Waltham, MA (United States)] [and others

    1995-10-01

    The U.S. Department of Energy issued a Planned Research and Development Announcement (PRDA) in 1993, with the objective of identifying unique technologies which could be applied to the most hazardous waste streams at DOE sites. The combination of radioactive contamination with additional contamination by hazardous constituents such as those identified by the Resource Conservation and Recovery Act (RCRA) pose an especially challenging problem. Traditional remediation technologies are increasingly becoming less acceptable to stakeholders and regulators because of the risks they pose to public health and safety. Desirable recycling technologies were described by the DOE as: (1) easily installed, operated, and maintained; (2) exhibiting superior environmental performance; (3) protective of worker and public health and safety; (4) readily acceptable to a wide spectrum of evaluators; and (5) economically feasible. Molten Metal Technology, Inc. (MMT) was awarded a contract as a result of the PRDA initiative to demonstrate the applicability of Catalytic Extraction Processing (CEP), MMT`s proprietary elemental recycling technology, to DOE`s inventory of low level mixed waste. This includes DOE`s inventory of radioactively- and RCRA-contaminated scrap metal and other waste forms expected to be generated by the decontamination and decommissioning (D&D) of DOE sites.

  9. Catalytic extraction processing of contaminated scrap metal

    International Nuclear Information System (INIS)

    Griffin, T.P.; Johnston, J.E.; Payea, B.M.

    1995-01-01

    The U.S. Department of Energy issued a Planned Research and Development Announcement (PRDA) in 1993, with the objective of identifying unique technologies which could be applied to the most hazardous waste streams at DOE sites. The combination of radioactive contamination with additional contamination by hazardous constituents such as those identified by the Resource Conservation and Recovery Act (RCRA) pose an especially challenging problem. Traditional remediation technologies are increasingly becoming less acceptable to stakeholders and regulators because of the risks they pose to public health and safety. Desirable recycling technologies were described by the DOE as: (1) easily installed, operated, and maintained; (2) exhibiting superior environmental performance; (3) protective of worker and public health and safety; (4) readily acceptable to a wide spectrum of evaluators; and (5) economically feasible. Molten Metal Technology, Inc. (MMT) was awarded a contract as a result of the PRDA initiative to demonstrate the applicability of Catalytic Extraction Processing (CEP), MMT's proprietary elemental recycling technology, to DOE's inventory of low level mixed waste. This includes DOE's inventory of radioactively- and RCRA-contaminated scrap metal and other waste forms expected to be generated by the decontamination and decommissioning (D ampersand D) of DOE sites

  10. Trace metal mobilization in an experimental carbon sequestration scenario

    Energy Technology Data Exchange (ETDEWEB)

    Marcon, Virginia [University of Wyoming, Geology and Geophysics, Laramie, WY. 82070 (United States); Kaszuba, John [University of Wyoming, Geology and Geophysics, Laramie, WY. 82070 (United States); Univeristy of Wyoming, School of Energy Resources, Larmaie, WY. 82070 (United States)

    2013-07-01

    Mobilizing trace metals with injection of supercritical CO{sub 2} into deep saline aquifers is a concern for geologic carbon sequestration. Hydrothermal experiments investigate the release of harmful metals from two zones of a sequestration injection reservoir: at the cap-rock-reservoir boundary and deeper within the reservoir, away from the cap-rock. In both systems, Cd, Cr, Cu, Pb, and Zn behave in a similar manner, increasing in concentration with injection, but subsequently decreasing in concentration over time. SEM images and geochemical models indicate initial dissolution of minerals and precipitation of Ca-Mg-Fe carbonates, metal sulfides (i.e. Fe, As, Ag, and Co sulfides), and anhydrite in both systems. The results suggest that Ba, Cu, and Zn will not be contaminants of concern, but Pb, Fe, and As may require careful attention. (authors)

  11. Heavy metal contamination in canned foods

    International Nuclear Information System (INIS)

    Sand, W.A.; Flex, H.; Allan, K.F.; Mahmoud, R.M.; Abdel-Haleem, A.E.

    2001-01-01

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

  12. Impact of the earthworm Lumbricus terrestris (L.) on As, Cu, Pb and Zn mobility and speciation in contaminated soils

    International Nuclear Information System (INIS)

    Sizmur, Tom; Palumbo-Roe, Barbara; Watts, Michael J.; Hodson, Mark E.

    2011-01-01

    To assess the risks that contaminated soils pose to the environment properly a greater understanding of how soil biota influence the mobility of metal(loid)s in soils is required. Lumbricus terrestris L. were incubated in three soils contaminated with As, Cu, Pb and Zn. The concentration and speciation of metal(loid)s in pore waters and the mobility and partitioning in casts were compared with earthworm-free soil. Generally the concentrations of water extractable metal(loid)s in earthworm casts were greater than in earthworm-free soil. The impact of the earthworms on concentration and speciation in pore waters was soil and metal specific and could be explained either by earthworm induced changes in soil pH or soluble organic carbon. The mobilisation of metal(loid)s in the environment by earthworm activity may allow for leaching or uptake into biota. - Research highlights: → Earthworms increase the mobility and availability of metals and metalloids in soils. → We incubated L. terrestris in three soils contaminated with As, Cu, Pb and Zn. → Earthworms increased the mobility of As, Cu, Pb and Zn in their casts. → The mechanisms for this could be explained by changes in pH or organic carbon. - Lumbricus terrestris change the partitioning of metal(loid)s between soil constituents and increase the mobility of metal(loid)s in casts and pore water.

  13. Impact of the earthworm Lumbricus terrestris (L.) on As, Cu, Pb and Zn mobility and speciation in contaminated soils

    Energy Technology Data Exchange (ETDEWEB)

    Sizmur, Tom, E-mail: t.p.sizmur@reading.ac.uk [Soil Research Centre, Department of Geography and Environmental Science, School of Human and Environmental Sciences, University of Reading, Whiteknights, Reading RG6 6DW (United Kingdom); Palumbo-Roe, Barbara; Watts, Michael J. [British Geological Survey, Kingsley Dunham Centre, Keyworth, Nottingham NG12 5GG (United Kingdom); Hodson, Mark E. [Soil Research Centre, Department of Geography and Environmental Science, School of Human and Environmental Sciences, University of Reading, Whiteknights, Reading RG6 6DW (United Kingdom)

    2011-03-15

    To assess the risks that contaminated soils pose to the environment properly a greater understanding of how soil biota influence the mobility of metal(loid)s in soils is required. Lumbricus terrestris L. were incubated in three soils contaminated with As, Cu, Pb and Zn. The concentration and speciation of metal(loid)s in pore waters and the mobility and partitioning in casts were compared with earthworm-free soil. Generally the concentrations of water extractable metal(loid)s in earthworm casts were greater than in earthworm-free soil. The impact of the earthworms on concentration and speciation in pore waters was soil and metal specific and could be explained either by earthworm induced changes in soil pH or soluble organic carbon. The mobilisation of metal(loid)s in the environment by earthworm activity may allow for leaching or uptake into biota. - Research highlights: > Earthworms increase the mobility and availability of metals and metalloids in soils. > We incubated L. terrestris in three soils contaminated with As, Cu, Pb and Zn. > Earthworms increased the mobility of As, Cu, Pb and Zn in their casts. > The mechanisms for this could be explained by changes in pH or organic carbon. - Lumbricus terrestris change the partitioning of metal(loid)s between soil constituents and increase the mobility of metal(loid)s in casts and pore water.

  14. Method for electrolytic decontamination of radioactive contaminated metals

    International Nuclear Information System (INIS)

    Tanaka, Akio; Horita, Masami; Onuma, Tsutomu; Kato, Koji

    1991-01-01

    The invention relates to an electrolytic decontamination method for radioactive contaminated metals. The contaminated sections are eluted by electrolysis after the surface of a piece of equipment used with radioactive substances has been immersed in an electrolyte. Metal contaminated by radioactive substances acts as the anode

  15. Bioavailability of Fe(III) in Natural Soils and the Impact on Mobility of Inorganic Contaminants (Final Report)

    Energy Technology Data Exchange (ETDEWEB)

    Kosson, David S. [Vanderbilt Univ., Nashville, TN (United States). Dept. of Civil and Environmental Engineering; Cowan, Robert M. [Rutgers Univ., New Brunswick, NJ (United States). Dept. of Environmental Science; Young, Lily Y. [Rutgers Univ., New Brunswick, NJ (United States). Center for Agriculture and the Environment; Hatcherl, Eric L. [Vanderbilt Univ., Nashville, TN (United States). Dept. of Civil and Environmental Engineering; Scala, David J. [Vanderbilt Univ., Nashville, TN (United States). Dept. of Civil and Environmental Engineering

    2005-08-02

    Inorganic contaminants, such as heavy metals and radionuclides, can adhere to insoluble Fe(III) minerals resulting in decreased mobility of these contaminants through subsurface environments. Dissimilatory Fe(III)-reducing bacteria (DIRB), by reducing insoluble Fe(III) to soluble Fe(II), may enhance contaminant mobility. The Savannah River Site, South Carolina (SRS), has been subjected to both heavy metal and radionuclide contamination. The overall objective of this project is to investigate the release of inorganic contaminants such as heavy metals and radionuclides that are bound to solid phase soil Fe complexes and to elucidate the mechanisms for mobilization of these contaminants that can be associated with microbial Fe(III) reduction. This is being accomplished by (i) using uncontaminated and contaminated soils from SRS as prototype systems, (ii) evaluating the diversity of DIRBs within the samples and isolating cultures for further study, (iii) using batch microcosms to evaluate the bioavailability of Fe(III) from pure minerals and SRS soils, (iv) developing kinetic and mass transfer models that reflect the system dynamics, and (v) carrying out soil column studies to elucidate the dynamics and interactions amongst Fe(III) reduction, remineralization and contaminant mobility.

  16. High level bacterial contamination of secondary school students' mobile phones.

    Science.gov (United States)

    Kõljalg, Siiri; Mändar, Rando; Sõber, Tiina; Rööp, Tiiu; Mändar, Reet

    2017-06-01

    While contamination of mobile phones in the hospital has been found to be common in several studies, little information about bacterial abundance on phones used in the community is available. Our aim was to quantitatively determine the bacterial contamination of secondary school students' mobile phones. Altogether 27 mobile phones were studied. The contact plate method and microbial identification using MALDI-TOF mass spectrometer were used for culture studies. Quantitative PCR reaction for detection of universal 16S rRNA, Enterococcus faecalis 16S rRNA and Escherichia coli allantoin permease were performed, and the presence of tetracycline ( tet A, tet B, tet M), erythromycin ( erm B) and sulphonamide ( sul 1) resistance genes was assessed. We found a high median bacterial count on secondary school students' mobile phones (10.5 CFU/cm 2 ) and a median of 17,032 bacterial 16S rRNA gene copies per phone. Potentially pathogenic microbes ( Staphylococcus aureus , Acinetobacter spp. , Pseudomonas spp., Bacillus cereus and Neisseria flavescens ) were found among dominant microbes more often on phones with higher percentage of E. faecalis in total bacterial 16S rRNA. No differences in contamination level or dominating bacterial species between phone owner's gender and between phone types (touch screen/keypad) were found. No antibiotic resistance genes were detected on mobile phone surfaces. Quantitative study methods revealed high level bacterial contamination of secondary school students' mobile phones.

  17. Phytoremediation of water bodies contaminated with radioactive heavy metal

    International Nuclear Information System (INIS)

    Yan Zhen; Yuan Shichao; Ling Hui; Xie Shuibo

    2012-01-01

    The sources of the radioactive heavy metal in the water bodies were analyzed. The factors that affect phyto remediation of water contaminated with radioactive heavy metal were discussed. The plant species, mechanism and major technology of phyto remediation of water contaminated with radioactive heavy metal were particularly introduced. The prospective study was remarked. (authors)

  18. Metal Contamination in the Republic of Armenia.

    Science.gov (United States)

    Kurkjian

    2000-05-01

    / Air, soil, and water samples were collected throughout the Republic of Armenia both before and after its independence from the Soviet Union in 1991. Reported analyses of those samples indicated that levels of several trace metal concentrations (Ag, Cd, Cr, Cu, Mo, Ni, Pb, Ti, and Zn) exceeded the maximum allowable concentrations established by the former Soviet Union (FSU) and subsequently adopted by Armenia. Although industrial production has declined by more than 80% since the 1980s, the economy is improving and there is potential for a significant increase in the generation of industrial metal emissions. These include automobile emissions, which are now considered to be the primary source of atmospheric lead. Historically, the Soviet Union did not strictly enforce environmental standards, and Armenia is now faced with the resulting environmental problems and the associated risks to public health. Since some trace metal concentrations may be at or near potentially toxic levels, there is a need to accurately assess the extent of metal contamination in order to devise cleanup plans and develop long-term environmental protection and public health strategies in Armenia.

  19. Heavy metal contamination of soil and sediment in Zambia

    African Journals Online (AJOL)

    USER

    Key words: Heavy metal, contamination, mining, soil, sediment. INTRODUCTION ... drinking water and inhaling air or soil contaminated by mining activities and the ..... indicates that copper waste discharged into the upper reaches of the Kafue ...

  20. Evidence for groundwater contamination by heavy metals through soil passage under acidifying conditions

    NARCIS (Netherlands)

    Wilkens, B.J,

    1995-01-01

    The research reported here is aimed at improving the knowledge of the mobility of the heavy metals cadmium and zinc in vulnerable soil types. We use the term vulnerable with reference to vulnerability of groundwater for contamination by soil leaching. At diffuse soil immissions of heavy

  1. Heavy metal contamination in bats in Britain

    International Nuclear Information System (INIS)

    Walker, L.A.; Simpson, V.R.; Rockett, L.; Wienburg, C.L.; Shore, R.F.

    2007-01-01

    Toxic metals are bioaccumulated by insectivorous mammals but few studies (none from Britain) have quantified residues in bats. We measured renal mercury (Hg), lead (Pb) and cadmium (Cd) concentrations in bats from south-west England to determine how they varied with species, sex, age, and over time, and if they were likely to cause adverse effects. Residues were generally highest in whiskered bats (Myotis mystacinus). Compared with other species, pipistrelle (Pipistrellus spp) and Natterer's bats (Myotis nattereri) had significantly lower kidney Hg and Pb concentrations, respectively. Renal Hg increased over time in pipistrelles but the contributory sources are unknown. Kidney Pb did not decrease over time despite concurrent declines in atmospheric Pb. Overall, median renal metal concentrations were similar to those in bats from mainland Europe and 6- to 10-fold below those associated with clinical effect, although 5% of pipistrelles had kidney Pb residues diagnostic of acute lead poisoning. - Heavy metal contamination has been quantified in bats from Britain for the first time and indicates increased accumulation of Hg and no reduction in Pb

  2. Heavy metal contamination in bats in Britain

    Energy Technology Data Exchange (ETDEWEB)

    Walker, L.A. [NERC Centre for Ecology and Hydrology, Monks Wood, Abbots Ripton, Huntingdon, Cambridgeshire PE28 2LS (United Kingdom); Simpson, V.R. [Wildlife Veterinary Investigation Centre, Jollys Bottom Farm, Chacewater, Truro, Cornwall TR4 8PB (United Kingdom); Rockett, L. [NERC Centre for Ecology and Hydrology, Monks Wood, Abbots Ripton, Huntingdon, Cambridgeshire PE28 2LS (United Kingdom); Wienburg, C.L. [NERC Centre for Ecology and Hydrology, Monks Wood, Abbots Ripton, Huntingdon, Cambridgeshire PE28 2LS (United Kingdom); Shore, R.F. [NERC Centre for Ecology and Hydrology, Monks Wood, Abbots Ripton, Huntingdon, Cambridgeshire PE28 2LS (United Kingdom)]. E-mail: rfs@ceh.ac.uk

    2007-07-15

    Toxic metals are bioaccumulated by insectivorous mammals but few studies (none from Britain) have quantified residues in bats. We measured renal mercury (Hg), lead (Pb) and cadmium (Cd) concentrations in bats from south-west England to determine how they varied with species, sex, age, and over time, and if they were likely to cause adverse effects. Residues were generally highest in whiskered bats (Myotis mystacinus). Compared with other species, pipistrelle (Pipistrellus spp) and Natterer's bats (Myotis nattereri) had significantly lower kidney Hg and Pb concentrations, respectively. Renal Hg increased over time in pipistrelles but the contributory sources are unknown. Kidney Pb did not decrease over time despite concurrent declines in atmospheric Pb. Overall, median renal metal concentrations were similar to those in bats from mainland Europe and 6- to 10-fold below those associated with clinical effect, although 5% of pipistrelles had kidney Pb residues diagnostic of acute lead poisoning. - Heavy metal contamination has been quantified in bats from Britain for the first time and indicates increased accumulation of Hg and no reduction in Pb.

  3. Metal availability in a highly contaminated, dredged-sediment disposal site: field measurements and geochemical modeling.

    Science.gov (United States)

    Lions, Julie; Guérin, Valérie; Bataillard, Philippe; van der Lee, Jan; Laboudigue, Agnès

    2010-09-01

    Two complementary approaches were used to characterize arsenic and metal mobilizations from a dredged-sediment disposal site: a detailed field study combined with hydrogeochemical modeling. Contaminants in sediments were found to be mainly present as sulfides subject to oxidation. Secondary phases (carbonates, sulfates, (hydr)oxides) were also observed. Oxidative processes occurred at different rates depending on physicochemical conditions and contaminant contents in the sediment. Two distinct areas were identified on the site, each corresponding to a specific contaminant mobility behavior. In a reducing area, Fe and As were highly soluble and illustrated anoxic behavior. In well-oxygenated material, groundwater was highly contaminated in Zn, Cd and Pb. A third zone in which sediments and groundwater were less contaminated was also characterized. This study enabled us to prioritize remediation work, which should aim to limit infiltration and long-term environmental impact. Copyright (c) 2010 Elsevier Ltd. All rights reserved.

  4. Metal Distribution and Mobility under alkaline conditions

    International Nuclear Information System (INIS)

    Dario, Maarten

    2004-01-01

    The adsorption of an element, expressed as its distribution between liquid (aquatic) and solid phases in the bio geosphere, largely determines its mobility and transport properties. This is of fundamental importance in the assessment of the performance of e.g. geologic repositories for hazardous elements like radionuclides. Geologic repositories for low and intermediate level nuclear waste will most likely be based on concrete constructions in a suitable bedrock, leading to a local chemical environment with pH well above 12. At this pH metal adsorption is very high, and thus the mobility is hindered. Organic complexing agents, such as natural humic matter from the ground and in the groundwater, as well as components in the waste (cleaning agents, degradation products from ion exchange resins and cellulose, cement additives etc.) would affect the sorption properties of the various elements in the waste. Trace element migration from a cementitious repository through the pH- and salinity gradient created around the repository would be affected by the presence and creation of particulate matter (colloids) that may serve as carriers that enhance the mobility. The objective of this thesis was to describe and quantify the sorption of some selected elements representative of spent nuclear fuel (Eu, Am) and other heavy metals (Zn, Cd, Hg) in a clay/cement environment (pH 10-13) and in the pH-gradient outside this environment. The potential of organic complexing agents and colloids to enhance metal migration was also investigated. It was shown that many organic ligands are able to reduce trace metal sorption under these conditions. It was not possible to calculate the effect of well-defined organic ligands on the metal sorption in a cement environment by using stability constants from the literature. A simple method for comparing the effect of different complexing agents on metal sorption is, however, suggested. The stability in terms of the particle size of suspended

  5. Method of electrolytic decontamination of contaminated metal materials for radioactivity

    International Nuclear Information System (INIS)

    Harada, Yoshio; Ishibashi, Masaru; Matsumoto, Hiroyo.

    1985-01-01

    Purpose: To electrolytically eliminate radioactive materials from metal materials contaminated with radioactive materials, as well as efficiently remove metal ions leached out in an electrolyte. Method: In the case of anodic dissolution of metal materials contaminated with radioactivity in an electrolyte to eliminate radioactive contaminating materials on the surface of the metal materials, a portion of an electrolytic cell is defined with partition membranes capable of permeating metal ions therethrough. A cathode connected to a different power source is disposed to the inside of the partition membranes and fine particle of metals are suspended and floated in the electrolyte. By supplying an electric current between an insoluble anode disposed outside of the partition membranes and the cathode, metal ions permeating from the outside of the partition membranes are deposited on the fine metal particles. Accordingly, since metal ions in the electrolyte are removed, the electrolyte can always be kept clean. (Yoshihara, H.)

  6. Chelant extraction of heavy metals from contaminated soils

    Energy Technology Data Exchange (ETDEWEB)

    Peters, R.W. [Energy Systems Division, Argonne National Laboratory, 9700 South Cass Avenue, Argonne, IL 60439 (United States)

    1999-04-23

    The current state of the art regarding the use of chelating agents to extract heavy metal contaminants has been addressed. Results are presented for treatability studies conducted as worst-case and representative soils from Aberdeen Proving Ground's J-Field for extraction of copper (Cu), lead (Pb), and zinc (Zn). The particle size distribution characteristics of the soils determined from hydrometer tests are approximately 60% sand, 30% silt, and 10% clay. Sequential extractions were performed on the 'as-received' soils (worst case and representative) to determine the speciation of the metal forms. The technique speciates the heavy metal distribution into an easily extractable (exchangeable) form, carbonates, reducible oxides, organically-bound, and residual forms. The results indicated that most of the metals are in forms that are amenable to soil washing (i.e. exchangeable+carbonate+reducible oxides). The metals Cu, Pb, Zn, and Cr have greater than 70% of their distribution in forms amenable to soil washing techniques, while Cd, Mn, and Fe are somewhat less amenable to soil washing using chelant extraction. However, the concentrations of Cd and Mn are low in the contaminated soil. From the batch chelant extraction studies, ethylenediaminetetraacetic acid (EDTA), citric acid, and nitrilotriacetic acid (NTA) were all effective in removing copper, lead, and zinc from the J-Field soils. Due to NTA being a Class II carcinogen, it is not recommended for use in remediating contaminated soils. EDTA and citric acid appear to offer the greatest potential as chelating agents to use in soil washing the Aberdeen Proving Ground soils. The other chelating agents studied (gluconate, oxalate, Citranox, ammonium acetate, and phosphoric acid, along with pH-adjusted water) were generally ineffective in mobilizing the heavy metals from the soils. The chelant solution removes the heavy metals (Cd, Cu, Pb, Zn, Fe, Cr, As, and Hg) simultaneously. Using a multiple

  7. Chelant extraction of heavy metals from contaminated soils

    International Nuclear Information System (INIS)

    Peters, R.W.

    1999-01-01

    The current state of the art regarding the use of chelating agents to extract heavy metal contaminants has been addressed. Results are presented for treatability studies conducted as worst-case and representative soils from Aberdeen Proving Ground's J-Field for extraction of copper (Cu), lead (Pb), and zinc (Zn). The particle size distribution characteristics of the soils determined from hydrometer tests are approximately 60% sand, 30% silt, and 10% clay. Sequential extractions were performed on the 'as-received' soils (worst case and representative) to determine the speciation of the metal forms. The technique speciates the heavy metal distribution into an easily extractable (exchangeable) form, carbonates, reducible oxides, organically-bound, and residual forms. The results indicated that most of the metals are in forms that are amenable to soil washing (i.e. exchangeable+carbonate+reducible oxides). The metals Cu, Pb, Zn, and Cr have greater than 70% of their distribution in forms amenable to soil washing techniques, while Cd, Mn, and Fe are somewhat less amenable to soil washing using chelant extraction. However, the concentrations of Cd and Mn are low in the contaminated soil. From the batch chelant extraction studies, ethylenediaminetetraacetic acid (EDTA), citric acid, and nitrilotriacetic acid (NTA) were all effective in removing copper, lead, and zinc from the J-Field soils. Due to NTA being a Class II carcinogen, it is not recommended for use in remediating contaminated soils. EDTA and citric acid appear to offer the greatest potential as chelating agents to use in soil washing the Aberdeen Proving Ground soils. The other chelating agents studied (gluconate, oxalate, Citranox, ammonium acetate, and phosphoric acid, along with pH-adjusted water) were generally ineffective in mobilizing the heavy metals from the soils. The chelant solution removes the heavy metals (Cd, Cu, Pb, Zn, Fe, Cr, As, and Hg) simultaneously. Using a multiple-stage batch extraction

  8. Method of melting decontamination of radioactive contaminated metals

    International Nuclear Information System (INIS)

    Uda, Tatsuhiko; Miura, Noboru; Tsuchiya, Hiroyuki.

    1984-01-01

    Purpose: To improve the transfer efficiency of radioactive materials into slags. Method: Contaminated metals are melt with adding slagging agent in order to transfer the radioactive materials into the slag, where the slagging agent holds less free energy than that of metal oxides contaminated with radioactive materials in order to promote the transfer of the contaminated materials into the slag layer. This effect can also be attained on metals or alloys other than iron contaminated with radioactive materials. In the case of alloy, the slagging agent is to containing such metal oxide that free energy is less than that of the oxide of metal being the main ingredient element of the alloy. The decontamination effect can further be improved by containing halogenide such as calcium fluoride together with the metal oxide into the slagging agent. (Ikeda, J.)

  9. Microbial controls on metal mobility under the low nutrient fluxes found throughout the subsurface

    International Nuclear Information System (INIS)

    Boult, Stephen; Hand, Victoria L.; Vaughan, David J.

    2006-01-01

    Laboratory simulations and field studies of the shallow subsurface have shown that microbes and their extracellular products can influence the mobility of toxic metals from waste disposal sites. Modelling the transport of contaminants in groundwater may, therefore, require the input of microbial ecology data in addition to geochemical data, thus increasing the costs and the uncertainty of predictions. However, whether microbial effects on contaminant mobility occur extensively in the natural subsurface is unknown because the conditions under which they have been observed hitherto are generally unrepresentative of the average subsurface environment. Here, we show that microbial activity affects the mobility of a toxic trace metal (Cu) under the relatively low nutrient fluxes that dominate subsurface systems. More particularly, we show that under these low nutrient conditions, microbes and microbial products can immobilize metal but may themselves be subject to subsequent mobilization, thus complicating the pattern of metal storage and release. Our results show that the capability of microbes in the subsurface to change both the capacity of porous media to store metal, and the behaviour of metal that is released, is not restricted to the well researched environments close to sites of waste disposal. We anticipate our simulations will be a starting point for generating input data for transport models, and specifying the mechanism of metal remobilisation in environments more representative of the subsurface generally

  10. Eco-monitoring of highly contaminated areas: historic heavy metal contamination in tree ring records

    Science.gov (United States)

    Baross, Norbert; Jordán, Győző; Albert, Julianna; Abdaal, Ahmed; Anton, Attila

    2014-05-01

    This study examines and compares tree rings of trees grown in a mining area highly contaminated with heavy metals. Tree rings offers an excellent opportunity for eco-monitoring polluted areas. Contamination dispersion from the source to the receptors can be studied in time and space. The sampled area is located in the eastern part of the Matra Mts. of the Inner-Carpathian calc-alkaline Volcanic Arc (Hungary) with abundant historical ore (Pb, Zn, Cu, etc.) mining in the area. Dense forests are composed of the most typical association of the Turkey oak (Quercus cerris). Scots pine (Pinus sylvestris), European black pine (Pinus nigra), oak (Quercus robur), beech (Fagus sylvatica), and hornbeam (Carpinus betulus) also occurs in the landscape. Sampled trees are located within a 1km radius of the abandoned historic ore mines. Sample sites were located above the old mines and waste rock heaps, under the waste rock heaps and on the floodplain of the Ilona Creek. The sampled trees were selected by the following criteria: the tree should be healthy, showing no signs of thunderbolt or diseases and having a minimum diameter of 50 cm. Samples were taken with a tree borer at the height of 150 cm. At the same time, soil samples were also taken near the trees in a 25 cm depth. Prior to laboratory analysis, the samples measured and air dried. Every fifth years tree ring was taken from the samples under microscope, working backwards from the most recent outer ring (2012, the year of the sampling). Samples were digested with a mixture of H2SO4 and H2O2m in Teflon vessels in a microwave unit. The samples were analyzed by ICP-OES instrument. The results were evaluated with statistical method. Results revealed a consistent picture showing distinct locations and years of the contamination history in the former mining area. Some elements are built into the trees more efficiently than other elements depending on mobility in the soil solution that is influenced by soil chemical properties

  11. Investigation of mangrove macroalgae as biomonitors of estuarine metal contamination

    Energy Technology Data Exchange (ETDEWEB)

    Melville, Felicity [Department of Environmental Sciences/Institute of Water and Environmental Resource Management, University of Technology, Sydney, PO Box 123, Broadway NSW 2007 (Australia)], E-mail: f.melville@cqu.edu.au; Pulkownik, Alex [Department of Environmental Sciences/Institute of Water and Environmental Resource Management, University of Technology, Sydney, PO Box 123, Broadway NSW 2007 (Australia)

    2007-11-15

    This study examined the potential use of macroalgae epiphytic on mangrove aerial roots as biomonitors of estuarine contamination. The metal concentrations of macroalgae were investigated in four estuaries in the vicinity of Sydney, Australia, and compared to water and sediment metal concentrations over three seasonal surveys. Macroalgal metal concentrations (copper, zinc, cadmium, chromium, lead, nickel, manganese and iron) appeared to be more associated with sediment metal concentrations than water concentrations, suggesting they may be useful biomonitors of estuarine sediment contamination. Algae in the more contaminated estuaries generally contained higher metal concentrations. However, concentrations of iron, nickel and manganese appeared to be similar in the algae despite the varying sediment concentrations, while accumulation of copper, zinc, lead and chromium appeared to be associated with ambient environmental concentrations. The uptake of metals also varied among the different species, suggesting that algal parameters, such as morphology, may also influence metal uptake and accumulation.

  12. Melting-decontamination method for radioactive contaminated metals

    International Nuclear Information System (INIS)

    Uda, Tatsuhiko; Tsuchiya, Hiroyuki; Miura, Noboru; Iba, Hajime.

    1985-01-01

    Purpose: To eliminate uranium components remaining in metals even after the uranium-contaminated metals are melted. Method: Metal wastes contaminated with actinide element or its compound as nuclear fuel substance are melted in a crucible. Molten metals are fallen through a filter disposed at the bottom of the crucible into another receiving crucible. Uranium compounds are still left in the molten metal fallen in the receiving crucible. The residual uranium compounds are concentrated by utilizing the principle of the zone-refining process. That is, a displaceable local-heating heater is disposed to the receiving crucible, by which metals once solidified in the receiving crucible is again heated locally to transfer from solid to molten phase in a quasi-equibilized manner. In this way, by eliminating the end of the metal rod at which the uranium is segregated, the contaminating coefficient can be improved. (Ikeda, J.)

  13. Heavy metals contamination and their risk assessment around the abandoned base metals and Au-Ag mines in Korea

    Science.gov (United States)

    Chon, Hyo-Taek

    2017-04-01

    Heavy metals contamination in the areas of abandoned Au-Ag and base metal mines in Korea was investigated in order to assess the level of metal pollution, and to draw general summaries about the fate of toxic heavy metals in different environments. Efforts have been made to compare the level of heavy metals, chemical forms, and plant uptake of heavy metals in each mine site. In the base-metals mine areas, significant levels of Cd, Cu, Pb and Zn were found in mine dump soils developed over mine waste materials and tailings. Leafy vegetables tend to accumulate heavy metals(in particular, Cd and Zn) higher than other crop plants, and high metal concentrations in rice crops may affect the local residents' health. In the Au-Ag mining areas, arsenic would be the most characteristic contaminant in the nearby environment. Arsenic and heavy metals were found to be mainly associated with sulfide gangue minerals, and the mobility of these metals would be enhanced by the effect of continuing weathering and oxidation. According to the sequential extraction of metals in soils, most heavy metals were identified as non-residual chemical forms, and those are very susceptible to the change of ambient conditions of a nearby environment. The concept of pollution index(PI) of soils gives important information on the extent and degree of multi-element contamination, and can be applied to the evaluation of mine soils before their agricultural use and remediation. The risk assessment process comprising exposure assessment, dose-response assessment, and risk characterization was discussed, and the results of non-cancer risk of As, Cd, and Zn, and those of cancer risk of As were suggested.

  14. Extractive decontamination of heavy metals from CCA contaminated ...

    African Journals Online (AJOL)

    In this paper, the mobilization and extraction of As, Cr and Cu from chromated copper arsenate (CCA) contaminated soil obtained from a wood treatment factory site by four organic acids are presented and discussed. The CCA contaminated soil (pH = 5.91, carbon = 0.32, CEC = 47.84 meq/100 g) was found to contain 39.55 ...

  15. Environmental Risk of Metal Mining Contaminated River Bank Sediment at Redox-Transitional Zones

    Directory of Open Access Journals (Sweden)

    Sarah F. L. Lynch

    2014-01-01

    Full Text Available Diffuse metal pollution from mining impacted sediment is widely recognised as a potential source of contamination to river systems and may significantly hinder the achievement of European Union Water Framework Directive objectives. Redox-transitional zones that form along metal contaminated river banks as a result of flood and drought cycles could cause biogeochemical changes that alter the behaviour of polyvalent metals iron and manganese and anions such as sulphur. Trace metals are often partitioned with iron, manganese and sulphur minerals in mining-contaminated sediment, therefore the dissolution and precipitation of these minerals may influence the mobility of potentially toxic trace metals. Research indicates that freshly precipitated metal oxides and sulphides may be more “reactive” (more adsorbent and prone to dissolution when conditions change than older crystalline forms. Fluctuations at the oxic-anoxic interface brought about through changes in the frequency and duration of flood and drought episodes may therefore influence the reactivity of secondary minerals that form in the sediment and the flux of dissolved trace metal release. UK climate change models predict longer dry periods for some regions, interspersed with higher magnitude flood events. If we are to fully comprehend the future environmental risk these climate change events pose to mining impacted river systems it is recommended that research efforts focus on identifying the primary controls on trace metal release at the oxic-anoxic interface for flood and drought cycles of different duration and frequency. This paper critically reviews the literature regarding biogeochemical processes that occur at different temporal scales during oxic, reducing and dry periods and focuses on how iron and sulphur based minerals may alter in form and reactivity and influence the mobility of trace metal contaminants. It is clear that changes in redox potential can alter the composition

  16. History of metal contamination in Lake Illawarra, NSW, Australia.

    Science.gov (United States)

    Schneider, Larissa; Maher, William; Potts, Jaimie; Batley, Graeme; Taylor, Anne; Krikowa, Frank; Chariton, Anthony; Zawadzki, Atun; Heijnis, Henk; Gruber, Bernd

    2015-01-01

    Lake Illawarra has a long history of sediment contamination, particularly by metals, as a result of past and current industrial operations and land uses within the catchment. In this study, we examined the history of metal contamination in sediments using metal analysis and (210)Pb and (137)Cs dating. The distributions of copper, zinc, arsenic, selenium, cadmium and lead concentrations within sediment cores were in agreement with historical events in the lake, and indicated that metal contamination had been occurring since the start of industrial activities in Port Kembla in the late 1800 s. Most metal contamination, however, has occurred since the 1960s. Sedimentation rates were found to be 0.2 cm year(-1) in Griffins Bay and 0.3 cm year(-1) in the centre of the lake. Inputs from creeks bringing metals from Port Kembla in the northeast of the lake and a copper slag emplacement from a former copper refinery on the Windang Peninsula were the main sources of metal inputs to Lake Illawarra. The metals of highest concern were zinc and copper, which exceeded the Australian and New Zealand sediment quality guideline values at some sites. Results showed that while historical contamination persists, current management practices have resulted in reduced metal concentrations in surface sediments in the depositional zones in the centre of the lake. Copyright © 2014 Elsevier Ltd. All rights reserved.

  17. The use of poplar during a two-year induced phytoextraction of metals from contaminated agricultural soils

    Energy Technology Data Exchange (ETDEWEB)

    Komarek, Michael [Department of Agrochemistry and Plant Nutrition, Czech University of Agriculture in Prague, Kamycka 129, 165 21, Prague 6 (Czech Republic)], E-mail: komarek@af.czu.cz; Tlustos, Pavel [Department of Agrochemistry and Plant Nutrition, Czech University of Agriculture in Prague, Kamycka 129, 165 21, Prague 6 (Czech Republic)], E-mail: tlustos@af.czu.cz; Szakova, Jirina [Department of Agrochemistry and Plant Nutrition, Czech University of Agriculture in Prague, Kamycka 129, 165 21, Prague 6 (Czech Republic)], E-mail: szakova@af.czu.cz; Chrastny, Vladislav [Department of Applied Chemistry and Chemistry Teaching, University of South Bohemia, Studentska 13, 370 05, Ceske Budejovice (Czech Republic)], E-mail: vladislavchrastny@seznam.cz

    2008-01-15

    The efficiency of poplar (Populus nigra L. x Populus maximowiczii Henry.) was assessed during a two-year chemically enhanced phytoextraction of metals from contaminated soils. The tested metal mobilizing agents were EDTA (ethylenediaminetetraacetic acid) and NH{sub 4}Cl. EDTA was more efficient than chlorides in solubilizing metals (especially Pb) from the soil matrix. The application of chlorides only increased the solubility of Cd and Zn. However, the increased uptake of metals after the application of higher concentrations of mobilizing agents was associated with low biomass yields of the poplar plants and the extraction efficiencies after the two vegetation periods were thus comparable to the untreated plants. Additionally, the application of mobilizing agents led to phytotoxicity effects and increased mobility of metals. Higher phytoextraction efficiencies were observed for Cd and Zn compared to Pb and Cu. Poplars are therefore not suitable for chemically enhanced phytoextraction of metals from severely contaminated agricultural soils. - Application of mobilizing agents is not optimal during a two-year phytoextraction of metals from severely contaminated soils using poplars.

  18. The use of poplar during a two-year induced phytoextraction of metals from contaminated agricultural soils

    International Nuclear Information System (INIS)

    Komarek, Michael; Tlustos, Pavel; Szakova, Jirina; Chrastny, Vladislav

    2008-01-01

    The efficiency of poplar (Populus nigra L. x Populus maximowiczii Henry.) was assessed during a two-year chemically enhanced phytoextraction of metals from contaminated soils. The tested metal mobilizing agents were EDTA (ethylenediaminetetraacetic acid) and NH 4 Cl. EDTA was more efficient than chlorides in solubilizing metals (especially Pb) from the soil matrix. The application of chlorides only increased the solubility of Cd and Zn. However, the increased uptake of metals after the application of higher concentrations of mobilizing agents was associated with low biomass yields of the poplar plants and the extraction efficiencies after the two vegetation periods were thus comparable to the untreated plants. Additionally, the application of mobilizing agents led to phytotoxicity effects and increased mobility of metals. Higher phytoextraction efficiencies were observed for Cd and Zn compared to Pb and Cu. Poplars are therefore not suitable for chemically enhanced phytoextraction of metals from severely contaminated agricultural soils. - Application of mobilizing agents is not optimal during a two-year phytoextraction of metals from severely contaminated soils using poplars

  19. The use of chelating agents in the remediation of metal-contaminated soils: A review

    Energy Technology Data Exchange (ETDEWEB)

    Lestan, Domen [Agronomy Department, Centre for Soil and Environmental Science, Biotechnical Faculty, University of Ljubljana, Jamnikarjeva 101, 1000 Ljubljana (Slovenia); Luo Chunling [Department of Civil and Structural Engineering, Hong Kong Polytechnic University, Hung Hom, Kowloon (Hong Kong); Li Xiangdong [Department of Civil and Structural Engineering, Hong Kong Polytechnic University, Hung Hom, Kowloon (Hong Kong)], E-mail: cexdli@polyu.edu.hk

    2008-05-15

    This paper reviews current remediation technologies that use chelating agents for the mobilization and removal of potentially toxic metals from contaminated soils. These processes can be done in situ as enhanced phytoextraction, chelant enhanced electrokinetic extraction and soil flushing, or ex situ as the extraction of soil slurry and soil heap/column leaching. Current proposals on how to treat and recycle waste washing solutions after soil is washed are discussed. The major controlling factors in phytoextraction and possible strategies for reducing the leaching of metals associated with the application of chelants are also reviewed. Finally, the possible impact of abiotic and biotic soil factors on the toxicity of metals left after the washing of soil and enhanced phytoextraction are briefly addressed. - The use of synthetic chelants for soil washing and enhanced phytoextraction by plants has been well studied for the remediation of metal-contaminated soils in the last two decades.

  20. The use of chelating agents in the remediation of metal-contaminated soils: A review

    International Nuclear Information System (INIS)

    Lestan, Domen; Luo Chunling; Li Xiangdong

    2008-01-01

    This paper reviews current remediation technologies that use chelating agents for the mobilization and removal of potentially toxic metals from contaminated soils. These processes can be done in situ as enhanced phytoextraction, chelant enhanced electrokinetic extraction and soil flushing, or ex situ as the extraction of soil slurry and soil heap/column leaching. Current proposals on how to treat and recycle waste washing solutions after soil is washed are discussed. The major controlling factors in phytoextraction and possible strategies for reducing the leaching of metals associated with the application of chelants are also reviewed. Finally, the possible impact of abiotic and biotic soil factors on the toxicity of metals left after the washing of soil and enhanced phytoextraction are briefly addressed. - The use of synthetic chelants for soil washing and enhanced phytoextraction by plants has been well studied for the remediation of metal-contaminated soils in the last two decades

  1. Assessing the bioavailability and risk from metal-contaminated ...

    Science.gov (United States)

    Exposure to contaminated soil and dust is an important pathway in human health risk assessment. Physical and chemical characteristics, as well as biological factors, determine the bioaccessibility/bioavailability of soil and dust contaminants. Within a single sample, contamination may arise from multiple sources of toxic elements that may exist as different forms (species) which impact bioavailability. In turn, the bioaccessibility/bioavailability of soil and dust contaminants has a direct impact on human health risk assessment and risk management practices. Novel research efforts focusing on development and application of in vitro and in vivo methods to measure the bioaccessibility/bioavailability of metal contaminated soils have advanced in the past few years. The objective of this workshop was to focus on recent developments in assessing the bioaccessibility/bioavailability of arsenic contaminated soils, metal contamination in urban residences in Canada and potential children’s exposures to toxic elements in house dust, a community-based study known as the West Oakland Residential Lead Assessment , studies of the bioavailability of soil cadmium, chromium, nickel and mercury and human exposures to contaminated Brownfield soils. These presentations covered issues related to human health and bioavailability along with the most recent studies on community participation in assessing metal contamination, studies of exposures to residential contamination, and

  2. Mobilization of Trace Metals in an Experimental Carbon Sequestration Scenario

    Science.gov (United States)

    Marcon, V.; Kaszuba, J. P.

    2012-12-01

    similar manner, increasing in concentration with injection but continually decreasing after about 830 hours until termination of the experiment. SEM images and geochemical models indicate initial dissolution of all rocks and minerals, re-precipitation of Ca-Mg-Fe carbonates and Fe-sulfides, and precipitation of anhydrite in both systems. Calcite dissolves more readily than dolomite in these experiments, but re-precipitates in veins on dolomite. If brines leak from a storage reservoir and mix with a potable aquifer, the experimental results suggest that Ba, Cu, and Zn will not be contaminants of concern. Pb, Fe and As (still under consideration) initially exceed the EPA threshold and may require careful attention in a sequestration scenario. However, experimentally observed trends of decreasing trace metal concentration suggest that these metals could become less of a concern during the life of a carbon repository. Finally, the caprock plays an active role in trace metal mobilization in the system. The caprock provides a source of metals, although subsequent precipitation may remove metals from solution.

  3. 49 Trace Metals' Contamination of Stream Water and Irrigated Crop ...

    African Journals Online (AJOL)

    ABUBAKAR AHMED

    human consumption as they pose serious health risks due to contamination with the metals. For environmental ... mining activities, industrial and domestic effluents, urban ... drinking and bathing water, irrigation, food, fuel and energy.

  4. Deciphering heavy metal contamination zones in soils of a granitic ...

    Indian Academy of Sciences (India)

    ., Ba, Cr, Cu,. Ni, Pb, Rb, Sr ... metal contamination in soils of different regions. The study ... in the Hyderabad city. ... A network of first and second order streams ... In this case, redun- ...... strategy for developing countries; In: Lead, mercury, cad-.

  5. Microbial and heavy metal contamination of pineapple products ...

    African Journals Online (AJOL)

    SAM

    Quantitative determination of heavy metals: zinc, iron, lead, copper, cadmium and aluminium ...... consumption of dairy products, fish/seafood and meat from Ismailia ... Contamination in Green Leafy Vegetables Grown in Bangalore Urban.

  6. assessment of trace metals contamination of soils around some ...

    African Journals Online (AJOL)

    ABSTRACT. This study was carried out to determine the level of soil contamination by metals around some automobile mechanic .... and this was done all through the sample preparation. ... shaking was done by a mechanical sieve shaker and.

  7. Heavy metals contamination of topsoil and dispersion in the ...

    African Journals Online (AJOL)

    Growing concern about reclamation of auto-repair workshop areas for residential and agricultural purposes makes risk assessment of heavy metal contamination of the study area imperative. In addition, the study is aimed at ascertaining the dispersion of contaminated Zn, Ni, Cr, Hg, and Pb within the soil profile. A total of 75 ...

  8. Geospatial analyses in support of heavy metal contamination ...

    African Journals Online (AJOL)

    This paper presents an exploratory assessment of heavy metal contamination along the main highways in Mafikeng, and illustrates how spatial analyses of the contamination for environmental management purposes can be supported by GIS and Remote Sensing. Roadside soil and grass (Stenotaphrum sp.) samples were ...

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

    Science.gov (United States)

    Chon, Hyo-Taek

    2015-04-01

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

  10. Assessment of trace metal contamination of soils around Oluyole ...

    African Journals Online (AJOL)

    This study was carried out to determine the level of metals contamination of the soils around Oluyole industrial estate in Ibadan. Oluyole industrial estate has heavy concentration of manufacturing industries that generate a lot of waste products capable of introducing metals into the environment. Consequently, twenty-one ...

  11. Metal Hydride assited contamination on Ru/Si surfaces

    NARCIS (Netherlands)

    Pachecka, Malgorzata; Lee, Christopher James; Sturm, Jacobus Marinus; Bijkerk, Frederik

    2013-01-01

    In extreme ultraviolet lithography (EUVL) residual tin, in the form of particles, ions, and atoms, can be deposited on nearby EUV optics. During the EUV pulse, a reactive hydrogen plasma is formed, which may be able to react with metal contaminants, creating volatile and unstable metal hydrides that

  12. Assessment of trace metals contamination of soils around some ...

    African Journals Online (AJOL)

    This study was carried out to determine the level of soil contamination by metals around some automobile mechanic workshops in Oyo town in order to assess their possible adverse health implications on man and his environment. Concentrations of metals above certain levels have been shown to impair man's health.

  13. Process for cleaning radioactively contaminated metal surfaces

    International Nuclear Information System (INIS)

    Mihram, R.G.; Snyder, G.A.

    1975-01-01

    A process is described for removing radioactive scale from a ferrous metal surface, including the steps of initially preconditioning the surface by contacting it with an oxidizing solution (such as an aqueous solution of an alkali metal permanganate or hydrogen peroxide), then, after removal or decomposition of the oxidizing solution, the metallic surface is contacted with a cleaning solution which is a mixture of a mineral acid and a complexing agent (such as sulfuric acid and oxalic acid), and which preferably contains a corrosion inhibitor. A final step in the process is the treatment of the spent cleaning solution containing radioactive waste materials in solution by adding a reagent selected from the group consisting of calcium hydroxide or potassium permanganate and an alkali metal hydroxide to thereby form easily recovered metallic compounds containing substantially all of the dissolved metals and radioactivity. (auth)

  14. Changing contaminant mobility in a dredged canal sediment during a three-year phytoremediation trial

    International Nuclear Information System (INIS)

    King, Rosalind F.; Royle, Anna; Putwain, Philip D.; Dickinson, Nicholas M.

    2006-01-01

    Metal mobility and degradation of organic pollutants were investigated in a contaminated canal sediment in NW England. Sediment was dredged and exposed above the water surface, planted with multiple taxa of Salix, Populus and Alnus and monitored over 32 months. Short-term metal fractionation and phytotoxicity during sediment oxidation were also evaluated in separate laboratory studies. Zinc and Pb redistributed into more mobile fractions, which increased toxicity of the sediment to plants in the laboratory. In contrast, at the canal site, mobility of most elements decreased and total concentrations of Zn, Pb, Cu and Cd fell. Petroleum hydrocarbon concentrations decreased, but the tree-planted treatments appeared less effective at reducing PAH concentrations than treatments colonised by invasive plants. Tree survivorship decreased over time, suggesting increasing phytotoxicity of the exposed sediment in the longer term. Trees provided little benefit in terms of sediment remediation. Options for future management of the sediment are evaluated. - Highly mobilised and toxic metals in a dredged canal sediment provided unexpected responses in a phytoremediation trial

  15. Worker exposures from recycling surface contaminated radioactive scrap metal

    International Nuclear Information System (INIS)

    Kluk, A.; Phillips, J.W.; Culp, J.

    1996-01-01

    Current DOE policy permits release from DOE control of real property with residual levels of surficial radioactive contamination if the contamination is below approved guidelines. If the material contains contamination that is evenly distributed throughout its volume (referred to as volumetric contamination), then Departmental approval for release must be obtained in advance. Several DOE sites presently recycle surface contaminated metal, although the quantities are small relative to the quantities of metal processed by typical mini-mills, hence the potential radiation exposures to mill workers from processing DOE metals and the public from the processed metal are at present also a very small fraction of their potential value. The exposures calculated in this analysis are based on 100% of the scrap metal being processed at the maximum contamination levels and are therefore assumed to be maximum values and not likely to occur in actual practice. This paper examines the relationship between the surface contamination limits established under DOE Order 5400.5, open-quotes Radiation Protection of the Public and the Environment,close quotes and radiation exposures to workers involved in the scrap metal recycling process. The analysis is limited to surficial contamination at or below the guideline levels established in DOE Order 5400.5 at the time of release. Workers involved in the melting and subsequent fabrication of products are not considered radiation workers (no requirements for monitoring) and must be considered members of the public. The majority of the exposures calculated in this analysis range from tenths of a millirem per year (mrem/yr) to less than 5 mrem/yr. The incremental risk of cancer associated with these exposures ranges from 10 -8 cancers per year to 10 -6 cancers per year

  16. Mobility of Hazardous Metals in Environment

    International Nuclear Information System (INIS)

    Fedor Macasek

    1999-01-01

    Mobility of metal ions, including radionuclides, is influenced by their interactions with natural components (inorganic and polyelectrolyte ligands, colloids, biota and biota debris) of water. The breakthrough of pollutant in aqueous flow, and hydrodynamic characterisation of near-and far-field of waste deposits is analysed on the base of Rosen's theory, by a particular accentuation of the role of the distribution coefficient KD of pollutant. Humic substances are those natural multifunctional ligands, which may enhance transportation of many pollutants by influencing their KD values. As an example, the distribution factors of plutonium were modelled through the ph-independent effective interaction constants with humic acids in solution and on the surface by a two-sites- two-species (''2s2s ) model of distribution. Though the interaction constant of plutonium with humic acid is rather high, the naturally occurring concentration of humic acids should not change seriously the patterns of its fixation in the far fields of the waste repositories, unless its distribution coefficient in the rock bed drops below 10 L/kg what depends at most on the nature of filtration media. The last conclusion is general for other pollutants as well

  17. Process for treating waste water having low concentrations of metallic contaminants

    Science.gov (United States)

    Looney, Brian B; Millings, Margaret R; Nichols, Ralph L; Payne, William L

    2014-12-16

    A process for treating waste water having a low level of metallic contaminants by reducing the toxicity level of metallic contaminants to an acceptable level and subsequently discharging the treated waste water into the environment without removing the treated contaminants.

  18. Bacterial metal resistance genes and metal bioavailability in contaminated sediments

    International Nuclear Information System (INIS)

    Roosa, Stéphanie; Wattiez, Ruddy; Prygiel, Emilie; Lesven, Ludovic; Billon, Gabriel; Gillan, David C.

    2014-01-01

    In bacteria a metal may be defined as bioavailable if it crosses the cytoplasmic membrane to reach the cytoplasm. Once inside the cell, specific metal resistance systems may be triggered. In this research, specific metal resistance genes were used to estimate metal bioavailability in sediment microbial communities. Gene levels were measured by quantitative PCR and correlated to metals in sediments using five different protocols to estimate dissolved, particle-adsorbed and occluded metals. The best correlations were obtained with czcA (a Cd/Zn/Co efflux pump) and Cd/Zn adsorbed or occluded in particles. Only adsorbed Co was correlated to czcA levels. We concluded that the measurement of czcA gene levels by quantitative PCR is a promising tool which may complement the classical approaches used to estimate Cd/Zn/Co bioavailability in sediment compartments. - Highlights: • Metal resistance genes were used to estimate metal bioavailability in sediments. • Gene levels were correlated to metals using 5 different metal extraction protocols. • CzcA gene levels determined by quantitative PCR is a promising tool for Cd/Zn/Co. - Capsule Bacterial czcA is a potential biomarker of Cd, Zn and Co bioavailability in aquatic sediments as shown by quantitative PCR and sequential metal extraction

  19. Mapping of contaminated sites using mobile gamma spectrometry: Marcassin system

    International Nuclear Information System (INIS)

    Panza, F.; Demongeot, S.; Crosland, E.; Foissard, B.

    2015-01-01

    Document available in abstract form only. Full text of publication follows: As part of the development of a tool for use in a nuclear emergency, post-accident situations and contaminated sites, the Institute for Radiation Protection and Nuclear Safety (IRSN) has designed an instrument for mapping natural and artificial radioactivity in soil using in situ gamma spectrometry. The development of this mobile system is based on various studies initiated by IRSN. The tool, named MARCASSIN (Moyen Autoporteur pour la Realisation de Cartographies de l'Activite Sur Sites contamINes, or automotive resource for mapping radioactivity at contaminated sites), has already been used to characterise various types of sites: contaminated soil (Fukushima), old open-pit mines (centre of France) and environmental sites (Paris region). Mounted on a quad-type vehicle, the instrument is composed of a spectrometer, a radiation meter and a global positioning system. Using coordinates and nuclear data, results are given in the form of mapping indicating type of radionuclides, radioactivity level, dose rate and contamination distribution in real-time. To improve detection level above sites where radioactivity levels are low, the system also is capable of processing data. Two of these methods are as follows: the first, 're-meshing', improves the estimate of soil radioactivity by increasing measurement statistics. The results agree with the reference values (soil samples measured in the laboratory), even for normal environmental levels of radioactivity. The second method, for which a patent is pending, is based on a deconvolution of mapping data. Re-processing deducts the impulse response of MARCASSIN from the radiation flux measurements in order to restore the value sought, which is the soil emission rate by radiological energy or activity. A theoretical example demonstrates the possibilities of this method. (authors)

  20. Quantifying heavy metals sequestration by sulfate-reducing bacteria in an acid mine drainage-contaminated wetland

    Directory of Open Access Journals (Sweden)

    John W Moreau

    2013-03-01

    Full Text Available Bioremediation strategies that depend on bacterial sulfate reduction for heavy metals remediation harness the reactivity of these metals with biogenic aqueous sulfide. Quantitative knowledge of the degree to which specific toxic metals are partitioned into various sulfide, oxide, or other phases is important for predicting the long-term mobility of these metals under environmental conditions. Here we report the quantitative partitioning into sedimentary biogenic sulfides of a suite of metals and metalloids associated with acid mine drainage contamination of a natural estuarine wetland for over a century.

  1. Accumulation of heavy metals from contaminated soil to plants and evaluation of soil remediation by vermiculite.

    Science.gov (United States)

    Malandrino, Mery; Abollino, Ornella; Buoso, Sandro; Giacomino, Agnese; La Gioia, Carmela; Mentasti, Edoardo

    2011-01-01

    We evaluated the distribution of 15 metal ions, namely Al, Cd, Cu, Cr, Fe, La, Mn, Ni, Pb, Sc, Ti, V, Y, Zn and Zr, in the soil of a contaminated site in Piedmont (Italy). This area was found to be heavily contaminated with Cu, Cr and Ni. The availability of these metal ions was studied using Tessier's sequential extraction procedure: the fraction of mobile species, which potentially is the most harmful for the environment, was much higher than that normally present in unpolluted soils. This soil was hence used to evaluate the effectiveness of treatment with vermiculite to reduce the availability of the pollutants to two plants, Lactuca sativa and Spinacia oleracea, by pot experiments. The results indicated that the addition of vermiculite significantly reduces the uptake of metal pollutants by plants, confirming the possibility of using this clay in amendment treatments of metal-contaminated soils. The effect of plant growth on metal fractionation in soils was investigated. Finally, the sum of the metal percentages extracted into the first two fractions of Tessier's protocol was found to be suitable in predicting the phytoavailability of most of the pollutants present in the investigated soil. Copyright © 2010 Elsevier Ltd. All rights reserved.

  2. Algal-bacterial interactions in metal contaminated floodplain sediments

    International Nuclear Information System (INIS)

    Boivin, M.E.Y.; Greve, G.D.; Garcia-Meza, J.V.; Massieux, B.; Sprenger, W.; Kraak, M.H.S.; Breure, A.M.; Rutgers, M.; Admiraal, W.

    2007-01-01

    The aim of the present study was to investigate algal-bacterial interactions in a gradient of metal contaminated natural sediments. By means of multivariate techniques, we related the genetic structure (denaturing gradient gel electrophoresis, DGGE) and the physiological structure (community-level physiological profiling, CLPP) of the bacterial communities to the species composition of the algal communities and to the abiotic environmental variables, including metal contamination. The results revealed that genetic and physiological structure of the bacterial communities correlated with the species composition of the algal community, but hardly to the level of metal pollution. This must be interpreted as an indication for a strong and species-specific linkage of algal and bacterial species in floodplain sediments. Metals were, however, not proven to affect either the algal or the bacterial communities of the Dutch river floodplains. - Algal and bacterial communities in floodplain sediments are interlinked, but are not affected by metal pollution

  3. Metal mobilization from metallurgical wastes by soil organic acids.

    Science.gov (United States)

    Potysz, Anna; Grybos, Malgorzata; Kierczak, Jakub; Guibaud, Gilles; Fondaneche, Patrice; Lens, Piet N L; van Hullebusch, Eric D

    2017-07-01

    Three types of Cu-slags differing in chemical and mineralogical composition (historical, shaft furnace, and granulated slags) and a matte from a lead recovery process were studied with respect to their susceptibility to release Cu, Zn and Pb upon exposure to organic acids commonly encountered in soil environments. Leaching experiments (24-960 h) were conducted with: i) humic acid (20 mg/L) at pH t 0  = 4.4, ii) fulvic acid (20 mg/L) at pH t 0  = 4.4, iii) an artificial root exudates (ARE) (17.4 g/L) solution at pH t 0  = 4.4, iv) ARE solution at pH t 0  = 2.9 and v) ultrapure water (pH t 0  = 5.6). The results demonstrated that the ARE contribute the most to the mobilization of metals from all the wastes analyzed, regardless of the initial pH of the solution. For example, up to 14%, 30%, 24% and 5% of Cu is released within 960 h from historical, shaft furnace, granulated slags and lead matte, respectively, when exposed to the artificial root exudates solution (pH 2.9). Humic and fulvic acids were found to have a higher impact on granulated and shaft furnace slags as compared to the ultrapure water control and increased the release of metals by a factor up to 37.5 (Pb) and 20.5 (Cu) for granulated and shaft furnace slags, respectively. Humic and fulvic acids amplified the mobilization of metals by a maximal factor of 13.6 (Pb) and 12.1 (Pb) for historical slag and lead matte, respectively. The studied organic compounds contributed to different release rates of metallic contaminants from individual metallurgical wastes under the conditions tested. Copyright © 2017 Elsevier Ltd. All rights reserved.

  4. [Recent advance in solidification/stabilization technology for the remediation of heavy metals-contaminated soil].

    Science.gov (United States)

    Hao, Han-zhou; Chen, Tong-bin; Jin, Meng-gui; Lei, Mei; Liu, Cheng-wu; Zu, Wen-pu; Huang, Li-mi

    2011-03-01

    Remediation of heavy metals-contaminated soil is still a difficulty and a hotspot of international research projects. At present, the technologies commonly adopted for the remediation of contaminated sites mainly include excavation, solidification/stabilization (S/S), soil washing, soil vapor extraction (SVE), thermal treatment, and bioremediation. Based on the S/S technical guidelines of Unite State Environmental Protection Agency (EPA) and United Kingdom Environment Agency (EA) and the domestic and foreign patents, this paper introduced the concepts of S/S and its development status at home and abroad, and discussed its future development directions. Solidification refers to a process that binds contaminated media with a reagent, changing the media's physical properties via increasing its compressive strength, decreasing its permeability, and encapsulating the contaminants to form a solid material. Stabilization refers to the process that involves a chemical reaction which reduces the leachability of a waste, chemically immobilizes the waste and reduces its solubility, making the waste become less harmful or less mobile. S/S technology includes cement solidification, lime pozzolanic solidification, plastic materials stabilization, vitrification, and regent-based stabilization. Stabilization (or immobilization) treatment processes convert contaminants to less mobile forms through chemical or thermal interactions. In stabilization technology, the aim of adding agents is to change the soil physical and chemical properties through pH control technology, redox potential technology, precipitation techniques, adsorption technology, and ion-exchange technology that change the existing forms of heavy metals in soil, and thus, reduce the heavy metals bioavailability and mobility. This review also discussed the S/S evaluation methods, highlighted the need to enhance S/S technology in the molecular bonding, soil polymers, and formulation of China's S/S technical guidelines.

  5. Catalytic extraction processing of contaminated scrap metal

    International Nuclear Information System (INIS)

    Griffin, T.P.; Johnston, J.E.; Payea, B.M.; Zeitoon, B.M.

    1995-01-01

    Molten Metal Technology was awarded a contract to demonstrate the applicability of the Catalytic Extraction Process, a proprietary process that could be applied to US DOE's inventory of low level mixed waste. This paper is a description of that technology, and included within this document are discussions of: (1) Program objectives, (2) Overall technology review, (3) Organic feed conversion to synthetic gas, (4) Metal, halogen, and transuranic recovery, (5) Demonstrations, (6) Design of the prototype facility, and (7) Results

  6. Oxidation and metal contamination of EUV optics

    NARCIS (Netherlands)

    Sturm, Jacobus Marinus; Liu, Feng; Pachecka, Malgorzata; Lee, Christopher James; Bijkerk, Frederik

    2013-01-01

    The next generation photolithography will use 13.5 nm Extreme Ultraviolet (EUV) for printing smaller features on chips. One of the hallenges is to optimally control the contamination of the multilayer mirrors used in the imaging system. The aim of this project is generating fundamental understanding

  7. Cd, Pb, and Zn mobility and (bio)availability in contaminated soils from a former smelting site amended with biochar.

    Science.gov (United States)

    Lomaglio, Tonia; Hattab-Hambli, Nour; Miard, Florie; Lebrun, Manhattan; Nandillon, Romain; Trupiano, Dalila; Scippa, Gabriella Stefania; Gauthier, Arnaud; Motelica-Heino, Mikael; Bourgerie, Sylvain; Morabito, Domenico

    2017-07-20

    Biochar is a potential candidate for the remediation of metal(loid)-contaminated soils. However, the mechanisms of contaminant-biochar retention and release depend on the amount of soil contaminants and physicochemical characteristics, as well as the durability of the biochar contaminant complex, which may be related to the pyrolysis process parameters. The objective of the present study was to evaluate, in a former contaminated smelting site, the impact of two doses of wood biochar (2 and 5% w/w) on metal immobilization and/or phytoavailability and their effectiveness in promoting plant growth in mesocosm experiments. Different soil mixtures were investigated. The main physicochemical parameters and the Cd, Pb, and Zn contents were determined in soil and in soil pore water. Additionally, the growth, dry weight, and metal concentrations were analyzed in the different dwarf bean plant (Phaseolus vulgaris L.) organs tested. Results showed that the addition of biochar at two doses (2 and 5%) improved soil conditions by increasing soil pH, electrical conductivity, and water holding capacity. Furthermore, the application of biochar (5%) to metal-contaminated soil reduced Cd, Pb, and Zn mobility and availability, and hence their accumulation in the different P. vulgaris L. organs. In conclusion, the data clearly demonstrated that biochar application can be effectively used for Cd, Pb, and Zn immobilization, thereby reducing their bioavailability and phytotoxicity.

  8. Assessment of biochar and iron filing amendments for the remediation of a metal, arsenic and phenanthrene co-contaminated spoil

    International Nuclear Information System (INIS)

    Sneath, Helen E.; Hutchings, Tony R.; Leij, Frans A.A.M. de

    2013-01-01

    Sites contaminated with mixtures of metals, metalloids and organics are difficult to remediate as each contaminant type may require a different treatment. Biochar, with high metal sorption capacity, used singly and in combination with iron filings, is investigated in microcosm trials to immobilise metal(loid)s within a contaminated spoil, thereby enabling revegetation and degradation of organic pollutants. A mine spoil, contaminated with heavy metals, arsenic and spiked with phenanthrene was treated with either 1%w/w biochar, 5%w/w iron or their combination, enhancing phenanthrene degradation by 44–65%. Biochar treatment reduced Cu leaching and enabled sunflower growth, but had no significant effect on As mobility. Iron treatment reduced Cu and As leaching but negatively impacted soil structure and released high levels of Fe causing sunflower plant mortality. The combined treatment reduced both Cu and As leaching and enabled sunflower growth suggesting this could be a useful approach for treating co-contaminated sites. -- Highlights: ► 56 day microcosm trials examine biochar for remediation of co-contaminated sites. ► Biochar reduces leachable Cu concentrations but phytotoxicity remains. ► Iron filings are investigated as a co-amendment with biochar to reduce As leaching. ► Removal of metal toxicity stimulates phenanthrene degradation. ► Biochar could enable revegetation of contaminated sites. -- Biochar and iron filings incorporated into contaminated spoils reduce Cu and As leaching and stimulate phenanthrene degradation, but do not prevent phytotoxicity to sunflowers

  9. Prospects for separating heavy metal from contaminated soil

    International Nuclear Information System (INIS)

    Langen, M.; Hoberg, H.; Hamacher, B.

    1994-01-01

    For decades, large quantities of organic and inorganic pollutants have been brought into the soil as a result of the industrial operations of smelting and coking plants. This paper reports on the prospects of separating heavy metals from soil contaminated by smelting and coking plants by means of a physical/chemical washing procedure. Besides the description of virgin soil characteristics, cleaning results and process parameters of calssification, density separation and flotation processes are presented. It is shown that heavy metal pollution of virgin soil can be reduced by the classical process stages of soil washing. The metal content of virgin soil are critically assessed whereby the limits of the physical-chimical washing process will also be entered into. Emphasis is placed on the significance of the determination of limiting values for inorganic contamination, especially for soil contaminated with both organic and inorganic pollution. (orig.) [de

  10. Comparison of keypads and touch-screen mobile phones/devices as potential risk for microbial contamination.

    Science.gov (United States)

    Koroglu, Mehmet; Gunal, Selami; Yildiz, Fatma; Savas, Mehtap; Ozer, Ali; Altindis, Mustafa

    2015-12-30

    Touch-screen mobile phones/devices (TMPs/Ds) are increasingly used in hospitals. They may act as a mobile reservoir for microbial pathogens. The rates of microbial contamination of TMPs/Ds and keypad mobile phones (KMPs) with respect to different variables including use by healthcare workers (HCWs)/non-HCWs and the demographic characteristics of users were investigated. A total of 205 mobile phones/devices were screened for microbial contamination: 76 devices belonged to HCWs and 129 devices belonged to the non-HCW group. By rubbing swabs to front screen, back, keypad, and metallic surfaces of devices, 444 samples were collected. Of 205 mobile phones/devices, 143 (97.9%) of the TMPs/Ds and 58 (98.3%) of the KMPs were positive for microbial contamination, and there were no significant differences in contamination rates between these groups, although TMPs/Ds had significantly higher microbial load than KMPs (p mobile phones ≥ 5". Microbial contamination rates increased significantly as phone size increased (p <0.05). Higher numbers of coagulase-negative Staphylococci (CNS) were isolated from KMPs than TMPs/Ds (p = 0.049). The incidence of Enterococcus spp. was higher on the KMPs of HCWs, and methicillin resistant CNS was higher from the TMPs/Ds of non-HCWs (p <0.05). Isolation of CNS, Streptococcus spp. and Escherichia coli was higher from the TMPs/Ds of HCWs (p <0.05). We found no significant difference between TMP/Ds and KMPs in terms of microbial contamination, but TMP/Ds harboured more colonies and total microbial counts increased with screen size.

  11. Heavy metal contamination in TIMS Branch sediments

    International Nuclear Information System (INIS)

    Pickett, J.B.

    1990-01-01

    The objective of this memorandum is to summarize results of previous sediment studies on Tims Branch and Steed's Pond conducted by Health Protection (HP) and by the Savannah River Laboratory (SRL) in conjunction with Reactor Materials Engineering ampersand Technology (RMET). The results for other heavy metals, such as lead, nickel, copper, mercury, chromium, cadmium, zinc, and thorium are also summarized

  12. Heavy metals contamination of Chrysichthys nigrodigitatus and ...

    African Journals Online (AJOL)

    GREGORY

    2010-09-27

    Sep 27, 2010 ... found to be highest in the bone of L. niloticus, copper recorded the least of all the metals. There is ... adequate enough to turn turbine engines to supply 6 megawatts of electricity .... demand of dissolved oxygen. Thus, a lot of ...

  13. HEAVY METALS CONTAMINATION OF TOPSOIL AND ...

    African Journals Online (AJOL)

    a

    emissions from automobile exhaust, waste incineration, land disposal of wastes, use of .... of total organic carbon increased from 2.0 ± 1.5 % in the top soil to 3.42 ± 0.83 ..... Thus, accumulation of heavy metals in the soil has potential to restrict.

  14. Influence of hydrological regime on pore water metal concentrations in a contaminated sediment-derived soil

    International Nuclear Information System (INIS)

    Du Laing, G.; Vanthuyne, D.R.J.; Vandecasteele, B.; Tack, F.M.G.; Verloo, M.G.

    2007-01-01

    Options for wetland creation or restoration might be limited because of the presence of contaminants in the soil. The influence of hydrological management on the pore water concentrations of Cd, Cr, Cu, Fe, Mn, Ni and Zn in the upper soil layer of a contaminated overbank sedimentation zone was investigated in a greenhouse experiment. Flooding conditions led to increased Fe, Mn, Ni and Cr concentrations and decreased Cd, Cu and Zn concentrations in the pore water of the upper soil layer. Keeping the soil at field capacity resulted in a low pore water concentration of Fe, Mn and Ni while the Cd, Cu, Cr and Zn concentrations increased. Alternating hydrological conditions caused metal concentrations in the pore water to fluctuate. Formation and re-oxidation of small amounts of sulphides appeared dominant in determining the mobility of Cd, Cu, and to a lesser extent Zn, while Ni behaviour was consistent with Fe/Mn oxidation and reduction. These effects were strongly dependent on the duration of the flooded periods. The shorter the flooded periods, the better the metal concentrations could be linked to the mobility of Ca in the pore water, which is attributed to a fluctuating CO 2 pressure. - The hydrological regime is a key factor in determining the metal concentration in the pore water of a contaminated sediment-derived soil

  15. SITE demonstration of the Dynaphore/Forager Sponge technology to remove dissolved metals from contaminated groundwater

    Energy Technology Data Exchange (ETDEWEB)

    Esposito, C.R. [Environmental Protection Agency, Edison, NJ (United States); Vaccaro, G. [Science Applications International Corp., Hackensack, NJ (United States)

    1995-10-01

    A Superfund Innovative Technology Evaluation (SITE) demonstration was conducted of the Dynaphore/Forager Sponge technology during the week of April 3, 1994 at the N.L. Industries Superfund Site in Pedricktown, New Jersey. The Forager Sponge is an open-celled cellulose sponge incorporating an amine-containing chelating polymer that selectively absorbs dissolved heavy metals in both cationic and anionic states. This technology is a volume reduction technology in which heavy metal contaminants from an aqueous medium are concentrated into a smaller volume for facilitated disposal. The developer states that the technology can be used to remove heavy metals from a wide variety of aqueous media, such as groundwater, surface waters and process waters. The sponge matrix can be directly disposed, or regenerated with chemical solutions. For this demonstration the sponge was set up as a mobile pump-and-treat system which treated groundwater contaminated with heavy metals. The demonstration focused on the system`s ability to remove lead, cadmium, chromium and copper from the contaminated groundwater over a continuous 72-hour test. The removal of heavy metals proceeded in the presence of significantly higher concentrations of innocuous cations such as calcium, magnesium, sodium, potassium and aluminum.

  16. Heavy metals contamination: implications for health and food safety

    Directory of Open Access Journals (Sweden)

    Yulieth C. Reyes

    2016-07-01

    Full Text Available Contamination by heavy metals in water resources, soil and air poses one of the most severe problems that compromise food safety and public health at global and local level. In this review, the specific problem of contamination by mercury (Hg, arsenic (As, cadmium (Cd and lead (Pb in the environment and food is presented. A description of the sources of contamination, exposure in living beings, accumulation and retention in food and consumer products is carried out. Study cases and results in some countries included Colombia are discussed.

  17. Characterizing toxicity of metal-contaminated sediments from mining areas

    International Nuclear Information System (INIS)

    Besser, John M.; Brumbaugh, William G.; Ingersoll, Christopher G.

    2015-01-01

    Highlights: • We review methods for testing toxicity of sediments affected by metals. • Toxicity testing provides site-specific assessment of impacts on resident biota. • Goals are to document extent of toxicity and associations with metal exposure. • Need to characterize bioavailability of metals in sediment and pore water. • Toxicity data is basis for guidelines used to predict hazards of metal toxicity. - Abstract: This paper reviews methods for testing the toxicity of metals associated with freshwater sediments, linking toxic effects with metal exposure and bioavailability, and developing sediment quality guidelines. The most broadly applicable approach for characterizing metal toxicity is whole-sediment toxicity testing, which attempts to simulate natural exposure conditions in the laboratory. Standard methods for whole-sediment testing can be adapted to test a wide variety of taxa. Chronic sediment tests that characterize effects on multiple endpoints (e.g., survival, growth, and reproduction) can be highly sensitive indicators of adverse effects on resident invertebrate taxa. Methods for testing of aqueous phases (pore water, overlying water, or elutriates) are used less frequently. Analysis of sediment toxicity data focuses on statistical comparisons between responses in sediments from the study area and responses in one or more uncontaminated reference sediments. For large or complex study areas, a greater number of reference sediments is recommended to reliably define the normal range of responses in uncontaminated sediments – the ‘reference envelope’. Data on metal concentrations and effects on test organisms across a gradient of contamination may allow development of concentration-response models, which estimate metal concentrations associated with specified levels of toxic effects (e.g. 20% effect concentration or EC20). Comparisons of toxic effects in laboratory tests with measures of impacts on resident benthic invertebrate

  18. Challenges in the Management of Potentially Contaminated Scrap Metal

    Energy Technology Data Exchange (ETDEWEB)

    Meehan, R.W., E-mail: meehanrw@em.doe.gov [US Department of Energy, National Nuclear Security Administration, Washington, DC (United States)

    2011-07-15

    This paper describes the background and current status of the management of potentially contaminated metals and materials at the US Department of Energy (DOE) sites across the USA. The current DOE policy prohibiting the release of metal scrap for recycling from radiation areas is explained. Finally, a potential path forward to competently assess, characterize and clear material from radiological control is proposed that uses a combination of administrative processes and empirical techniques that are valid irrespective of the standard used for clearance. (author)

  19. Removal of trace metal contaminants from potable water by electrocoagulation

    OpenAIRE

    Heffron, Joe; Marhefke, Matt; Mayer, Brooke K.

    2016-01-01

    This study investigated the effects of four operational and environmental variables on the removal of trace metal contaminants from drinking water by electrocoagulation (EC). Removal efficiencies for five metals (arsenic, cadmium, chromium, lead and nickel) were compared under varying combinations of electrode material, post-treatment, water composition and pH. Iron electrodes out-performed aluminum electrodes in removing chromium and arsenic. At pH 6.5, aluminum electrodes were slightly more...

  20. Assessment of Heavy Metal Contamination in Soils around Cassava ...

    African Journals Online (AJOL)

    The concentrations, contamination/pollution index, anthropogenic input and enrichment factors for metals in soil in the vicinity of cassava processing mills in sub-urban areas of Delta State of Nigeria were examined. The concentrations of metals in all sites and depths ranged from 0.1 to 383.2 mg kg-1 for Mn, 4.0 to 11.3 mg ...

  1. Oral bioaccessibility of toxic metals in contaminated oysters and relationships with metal internal sequestration.

    Science.gov (United States)

    Gao, Shi; Wang, Wen-Xiong

    2014-12-01

    The Hong Kong oysters Crassostrea hongkongensis are widely farmed in the estuarine waters of Southern China, but they accumulate Cu and Zn to alarmingly high concentrations in the soft tissues. Health risks of seafood consumption are related to contaminants such as toxic metals which are bioaccessible to humans. In the present study, we investigated the oral bioaccessibility of five toxic metals (Ag, Pb, Cd, Cu and Zn) in contaminated oysters collected from different locations of a large estuary in southern China. In all oysters, total Zn concentration was the highest whereas total Pb concentration was the lowest. Among the five metals, Ag had the lowest oral bioaccessibility (38.9-60.8%), whereas Cu and Zn had the highest bioaccessibility (72.3-93.1%). Significant negative correlation was observed between metal bioaccessibility and metal concentration in the oysters for Ag, Cd, and Cu. We found that the oral bioaccessibility of the five metals was positively correlated with their trophically available metal fraction (TAM) in the oyster tissues, and negatively correlated with metal distribution in the cellular debris. Thus, metal partitioning in the TAM and cellular debris controlled the oral bioaccessibility to humans. Given the dependence of oral bioaccessibility on tissue metal contamination, bioaccessibility needs to be incorporated in the risk assessments of contaminated shellfish. Copyright © 2014 Elsevier Inc. All rights reserved.

  2. Estimating children's exposure to toxic elements in contaminated toys and children's jewelry via saliva mobilization.

    Science.gov (United States)

    Guney, Mert; Nguyen, Alain; Zagury, Gerald J

    2014-09-19

    Children's potential for exposure to potentially toxic elements in contaminated jewelry and toys via mouth contact has not yet been fully evaluated. Various toys and jewelry (metallic toys and jewelry [MJ], plastic toys, toys with paint or coating, and brittle/pliable toys; n = 32) were tested using the saliva extraction (mouthing) compartment of the DIN and RIVM bioaccessibility protocols to assess As, Ba, Cd, Cr, Cu, Mn, Ni, Pb, Sb, and Se mobilization via saliva. Total concentrations of As, Cd, Cu, Ni, Pb, and Sb were found elevated in analyzed samples. Four metals were mobilized to saliva from 16 MJ in significant quantities (>1 μg for highly toxic Cd and Pb, >10 μg for Cu and Ni). Bioaccessible concentrations and hazard index values for Cd exceeded limit values, for young children between 6 mo- and 3 yr-old and according to both protocols. Total and bioaccessible metal concentrations were different and not always correlated, encouraging the use of bioaccessibility for more accurate hazard assessments. Bioaccessibility increased with increasing extraction time. Overall, the risk from exposure to toxic elements via mouthing was high only for Cd and for MJ. Further research on children's exposure to toxic elements following ingestion of toy or jewelry material is recommended.

  3. Removal of trace metal contaminants from potable water by electrocoagulation

    Science.gov (United States)

    Heffron, Joe; Marhefke, Matt; Mayer, Brooke K.

    2016-06-01

    This study investigated the effects of four operational and environmental variables on the removal of trace metal contaminants from drinking water by electrocoagulation (EC). Removal efficiencies for five metals (arsenic, cadmium, chromium, lead and nickel) were compared under varying combinations of electrode material, post-treatment, water composition and pH. Iron electrodes out-performed aluminum electrodes in removing chromium and arsenic. At pH 6.5, aluminum electrodes were slightly more effective at removing nickel and cadmium, while at pH 8.5, iron electrodes were more effective for these metals. Regardless of electrode, cadmium and nickel removal efficiencies were higher at pH 8.5 than at pH 6.5. Post-EC treatment using membrane filtration (0.45 μm) enhanced contaminant removal for all metals but nickel. With the exception of lead, all metals exhibited poorer removal efficiencies as the ionic strength of the background electrolyte increased, particularly in the very high-solids synthetic groundwaters. Residual aluminum concentrations were lowest at pH 6.5, while iron residuals were lowest in low ionic strength waters. Both aluminum and iron residuals required post-treatment filtration to meet drinking water standards. EC with post-treatment filtration appears to effectively remove trace metal contaminants to potable water standards, but both reactor and source water parameters critically impact removal efficiency.

  4. Economic comparison of management modes for contaminated metal scrap

    International Nuclear Information System (INIS)

    Janberg, K.

    1987-01-01

    This report presents an economic study of the three following management modes for contaminated metal scrap: - decontamination of scrap metal followed by release, - direct melting of scrap metal, followed by release or restricted reuse, - super-compaction followed by disposal as radioactive waste. The present study, which refers to conditions prevailing in Germany, includes reviews of the contaminated scrap arisings, of experience with scrap management and of the licensing conditions for metal recycling. The results obtained during the treatment of more than 140 t of contaminated scrap metal show that: - super-compaction is the best procedure for all mixed metallic wastes of small dimensions and complex geometries, as decontamination is very costly in such a case and the melting would lead to undefined metallurgical products; - decontamination is recommendable for simple geometries and activities higher than the regulatory upper limit for melting in an industrial foundry (74 Bq/g); - direct melting for lower activity levels is gaining in competitiveness and has a good chance to be the best solution, in particular when the free use levels will be reduced below the currently accepted levels in Germany

  5. Functioning of metal contaminated garden soil after remediation

    International Nuclear Information System (INIS)

    Jelusic, Masa; Grcman, Helena; Vodnik, Dominik; Suhadolc, Metka; Lestan, Domen

    2013-01-01

    The effect of remediation using three EDTA doses (10, 30, 60 mmol kg −1 ) on soil functioning was assessed using column experiment and Brassica rapa. Soil washing removed up to 77, 29 and 72% of metals from soil contaminated with 1378, 578 and 8.5 mg kg −1 of Pb, Zn and Cd, respectively. Sequential extraction indicated removal from the carbonate soil fraction. Metal oral-accessibility from the stomach phase was reduced by up to 75 and from the small intestine by up to 79% (Pb). Part of metals (up to 0.8% Cd) was lost due to leaching from columns. Remediation reduced toxic metal soil-root transfer by up to 61% but did not prevent metal accumulation in leaves. The fitness of plants grown on EDTA washed soils (gas exchange, fluorescence) was not compromised. Remediation initially reduced the soil DNA content (up to 29%, 30 mmol kg −1 EDTA) and changed the structure of microbial population. -- Highlights: ► Toxic metals contaminated garden soil was remediated in a pilot-scale. ► EDTA washing reduced soil Pb, Zn and Cd content and bioavailability. ► Remediated soil preserved the function of plant and microbial substrate. ► Remediation didn't prevent the accumulation of toxic metals in the test plant. -- EDTA soil washing effectively removed toxic metals and reduced their transfer from the soil to plant roots but did not prevent their accumulation in leaves

  6. Metal contamination and fractionation in sediments from the lower basin of the Vale do Ribeira (SE, Brazil).

    Science.gov (United States)

    Bonnail, Estefanía; Buruaem, Lucas M; Morais, Lucas G; Abessa, Denis M S; Sarmiento, Aguasanta M; DelValls, T Ángel

    2017-06-01

    The sediment quality of Ribeira de Iguape River is affected by former Pb extraction mining. Some studies affirm the restoration status of the basin, however, mobility of metals and its associated risk is still questioned. This study integrates the metal concentrations in the lower part of the basin with different contamination source to determine the existence of risks associated with the mobile fractions of the geochemical matrix. Despite concentrations of metals were low and the environmental risk factor values were negative, our results indicated that As, Mn, Pb, and V were present in the most labile forms. The multivariate analysis conducted using metal concentrations, environmental risk factor values and speciation suggested that any risk would be associated with the labile fractions of the analyzed elements, especially for Pb. The station from Registro was stressed by Co, Pb and Zn; with Pb under the reactive fraction that could be associated with high mobility and potential bioavailability.

  7. Biomonitoring of some heavy metal contaminations from a steel ...

    African Journals Online (AJOL)

    Soil and plants growing in the vicinity of industrial areas display increased concentrations of heavy metals and give an indication of the environmental quality. The contamination source for aluminum, iron, nickel and lead in the Botanical garden of Mobarakeh Steel Company was recognized by analyzing the leaves and ...

  8. Soil microbial effects of smelter induced heavy metal contamination

    Energy Technology Data Exchange (ETDEWEB)

    Nordgren, A

    1986-01-01

    The soil concentrations of Cu and Zn at the secondary smelter were 20 00 mu g/g dry soil. Close to the primary smelter the soil was contaminated with more than ten elements including Pb, Zn, Cu and As at levels ranging between 6000 and 1000 mu g/g dry soil. The correlations between the concentrations of the metals were high at both smelters. Soil respiration rate decreased by about 75% close to both smelters. Total and fluorescein diacetate stained mycelial lengths decrease with increasing heavy metal pollution at the secondary but not at the primary smelter. The fungal community structure was strongly affected by the contamination. General common in coniferous forest soils such as Penicillium and Oidiodendron virtually vanished, while less frequent species like Paecilomyces farinosus and Geomyces pannorum dominated the site close to the smelter. Colony forming units of a number of functional groups of bacteria were found to be very sensitive to metal contamination. The urease activity of the soil was inhibited. Multivariate statistical analyses showed that the metal contamination was the major environmental influence on the microbiotain the soils studied. A study of about 200 decomposition curves resulting from glutamic acid additions to the different soils produced four microbially related parameters: basal respiration rate, initial respiration rate after the addition of the glutamic acid, specific respiration rate during the exponential increase of the respiration rate and the lag time before the exponential phase. With 53 refs.

  9. Predicting the phytoextraction duration to remediate heavy metal contaminated soils

    NARCIS (Netherlands)

    Koopmans, G.F.; Römkens, P.F.A.M.; Song, J.; Temminghoff, E.J.M.; Japenga, J.

    2007-01-01

    The applicability of phytoextraction to remediate soils contaminated with heavy metals (HMs) depends on, amongst others, the duration before remediation is completed. The impact of changes in the HM content in soil occurring during remediation on plant uptake has to be considered in order to obtain

  10. Heavy metal contamination in stream water and sediments of gold ...

    African Journals Online (AJOL)

    This study assessed the seasonal variation in heavy metal contamination of stream water and sediments in the gold mining area of Atakunmosa West local Government, Osun State, Nigeria. Twelve villages of prominence in illegal gold mining were selected for the study covering dry and wet seasons of 2012. Stream water ...

  11. Simulation of heavy metal contamination of fresh water bodies: toxic ...

    African Journals Online (AJOL)

    Michael Horsfall

    www.bioline.org.br/ja. Simulation of heavy metal contamination of fresh water bodies: toxic effects in the ... 96 hours (though sampling was done at the 48th hour). Biochemical markers of ... silver, while enhancing the bioavailability of mercury in Ceriodaphnia ..... Biochemical and molecular disorders of bilirubin metabolism.

  12. Short communication Assessment of heavy metal contamination in ...

    African Journals Online (AJOL)

    2016-05-27

    May 27, 2016 ... Assessment of heavy metal contamination in raw milk for human consumption ... Long-term exposure to lower levels of Cd and Cr leads to stomach ... Toxicity by Pb can result in decreased performance, and damage to the ...

  13. Characterizing toxicity of metal-contaminated sediments from mining areas

    Science.gov (United States)

    Besser, John M.; Brumbaugh, William G.; Ingersoll, Christopher G.

    2015-01-01

    This paper reviews methods for testing the toxicity of metals associated with freshwater sediments, linking toxic effects with metal exposure and bioavailability, and developing sediment quality guidelines. The most broadly applicable approach for characterizing metal toxicity is whole-sediment toxicity testing, which attempts to simulate natural exposure conditions in the laboratory. Standard methods for whole-sediment testing can be adapted to test a wide variety of taxa. Chronic sediment tests that characterize effects on multiple endpoints (e.g., survival, growth, and reproduction) can be highly sensitive indicators of adverse effects on resident invertebrate taxa. Methods for testing of aqueous phases (pore water, overlying water, or elutriates) are used less frequently. Analysis of sediment toxicity data focuses on statistical comparisons between responses in sediments from the study area and responses in one or more uncontaminated reference sediments. For large or complex study areas, a greater number of reference sediments is recommended to reliably define the normal range of responses in uncontaminated sediments – the ‘reference envelope’. Data on metal concentrations and effects on test organisms across a gradient of contamination may allow development of concentration-response models, which estimate metal concentrations associated with specified levels of toxic effects (e.g. 20% effect concentration or EC20). Comparisons of toxic effects in laboratory tests with measures of impacts on resident benthic invertebrate communities can help document causal relationships between metal contamination and biological effects. Total or total-recoverable metal concentrations in sediments are the most common measure of metal contamination in sediments, but metal concentrations in labile sediment fractions (e.g., determined as part of selective sediment extraction protocols) may better represent metal bioavailability. Metals released by the weak-acid extraction

  14. Electrokinetic treatment of an agricultural soil contaminated with heavy metals.

    Science.gov (United States)

    Figueroa, Arylein; Cameselle, Claudio; Gouveia, Susana; Hansen, Henrik K

    2016-07-28

    The high organic matter content in agricultural soils tends to complex and retain contaminants such as heavy metals. Electrokinetic remediation was tested in an agricultural soil contaminated with Co(+2), Zn(+2), Cd(+2), Cu(+2), Cr(VI), Pb(+2) and Hg(+2). The unenhanced electrokinetic treatment was not able to remove heavy metals from the soil due to the formation of precipitates in the alkaline environment in the soil section close to the cathode. Moreover, the interaction between metals and organic matter probably limited metal transportation under the effect of the electric field. Citric acid and ethylenediaminetetraacetic acid (EDTA) were used in the catholyte as complexing agents in order to enhance the extractability and removal of heavy metals from soil. These complexing agents formed negatively charged complexes that migrated towards the anode. The acid front electrogenerated at the anode favored the dissolution of heavy metals that were transported towards the cathode. The combined effect of the soil pH and the complexing agents resulted in the accumulation of heavy metals in the center of the soil specimen.

  15. Decontamination of transuranic contaminated metals by melt refining

    International Nuclear Information System (INIS)

    Heshmatpour, B.; Copeland, G.L.; Heestand, R.L.

    1983-01-01

    Melt refining of transuranic contaminated metals is a possible decontamination process with the potential advantages of producing metal for reuse and of simplifying chemical analyses. By routinely achieving the 10 nCi/g( about0.1ppm) level by melt refining, scrap metal can be removed from the transuranic waste category. (To demonstrate the effectiveness of this melt refining process, mild steel, stainless steel, nickel, and copper were contaminated with 500 ppm (μg/g) PuO 2 and melted with various fluxes. The solidified slags and metals were analyzed for their plutonium contents, and corresponding partition ratios for plutonium were calculated. Some metals were double refined in order to study the effect of secondary slag treatment. The initial weight of the slags was also varied to investigate the effect of slag weight on the degree of plutonium removal. In general, all four metals could be decontaminated below 1 ppm (μg/g) Pu ( about100 nCi/g) by a single slag treatment. Doubling the slag weight did not improve decontamination significantly; however, double slag treatment using 5 wt.% slag did decontaminate the metals to below 0.1 ppm (μg/g) Pu (10 nCi/g).)

  16. Healthcare workers mobile phone usage: A potential risk for viral contamination. Surveillance pilot study.

    Science.gov (United States)

    Cavari, Yuval; Kaplan, Or; Zander, Aviva; Hazan, Guy; Shemer-Avni, Yonat; Borer, Abraham

    2016-01-01

    Mobile phones are commonly used by healthcare workers (HCW) in the working environment, as they allow instant communication and endless resource utilisation. Studies suggest that mobile phones have been implicated as reservoirs of bacterial pathogens, with the potential to cause nosocomial infection. This study aimed to investigate the presence of Respiratory Syncytial Virus, Adenovirus and Influenza Virus on HCWs mobile phones and to identify risk factors implied by HCWs practice of mobile phones in a clinical paediatric environment. Fifty HCWs' mobile phones were swabbed over both sides of the mobile phone, for testing of viral contamination during 8 days in January 2015. During the same period, a questionnaire investigating usage of mobile phones was given to 101 HCWs. Ten per cent of sampled phones were contaminated with viral pathogens tested for. A total of 91% of sampled individuals by questionnaire used their mobile phone within the workplace, where 37% used their phone at least every hour. Eighty-nine (88%) responders were aware that mobile phones could be a source of contamination, yet only 13 (13%) disinfect their cell phone regularly. Mobile phones in clinical practice may be contaminated with viral pathogenic viruses. HCWs use their mobile phone regularly while working and, although the majority are aware of contamination, they do not disinfect their phones.

  17. Risk of post-fire metal mobilization into surface water resources: A review.

    Science.gov (United States)

    Abraham, Joji; Dowling, Kim; Florentine, Singarayer

    2017-12-01

    One of the significant economic benefits to communities around the world of having pristine forest catchments is the supply of substantial quantities of high quality potable water. This supports a saving of around US$ 4.1 trillion per year globally by limiting the cost of expensive drinking water treatments and provision of unnecessary infrastructure. Even low levels of contaminants specifically organics and metals in catchments when in a mobile state can reduce these economic benefits by seriously affecting the water quality. Contamination and contaminant mobility can occur through natural and anthropogenic activities including forest fires. Moderate to high intensity forest fires are able to alter soil properties and release sequestered metals from sediments, soil organic matter and fragments of vegetation. In addition, the increase in post-fire erosion rate by rainfall runoff and strong winds facilitates the rapid transport of these metals downslope and downstream. The subsequent metal deposition in distal soil and water bodies can influence surface water quality with potential impacts to the larger ecosystems inclusive of negative effects on humans. This is of substantial concern as 4 billion hectares of forest catchments provide high quality water to global communities. Redressing this problem requires quantification of the potential effects on water resources and instituting rigorous fire and environmental management plans to mitigate deleterious effects on catchment areas. This paper is a review of the current state of the art literature dealing with the risk of post-fire mobilization of the metals into surface water resources. It is intended to inform discussion on the preparation of suitable management plans and policies during and after fire events in order to maintain potable water quality in a cost-effective manner. In these times of climate fluctuation and increased incidence of fires, the need for development of new policies and management frameworks

  18. Recent history of sediment metal contamination in Lake Macquarie, Australia, and an assessment of ash handling procedure effectiveness in mitigating metal contamination from coal-fired power stations

    Energy Technology Data Exchange (ETDEWEB)

    Schneider, Larissa, E-mail: Larissa.Schneider@canberra.edu.au [Institute for Applied Ecology, University of Canberra, Canberra, ACT 2601 (Australia); Maher, William [Institute for Applied Ecology, University of Canberra, Canberra, ACT 2601 (Australia); Potts, Jaimie [New South Wales Office of Environmental and Heritage, Lidcombe, NSW, 2141 Australia (Australia); Gruber, Bernd [Institute for Applied Ecology, University of Canberra, Canberra, ACT 2601 (Australia); Batley, Graeme [CSIRO Land and Water, Lucas Heights, NSW 2234 (Australia); Taylor, Anne [Institute for Applied Ecology, University of Canberra, Canberra, ACT 2601 (Australia); Chariton, Anthony [CSIRO Land and Water, Lucas Heights, NSW 2234 (Australia); Krikowa, Frank [Institute for Applied Ecology, University of Canberra, Canberra, ACT 2601 (Australia); Zawadzki, Atun; Heijnis, Henk [Institute for Environmental Research, Australian Nuclear Science and Technology Organisation, Lucas Heights, NSW 2234 (Australia)

    2014-08-15

    This study assessed historical changes in metal concentrations in sediments of southern Lake Macquarie resulting from the activities of coal-fired power stations, using a multi-proxy approach which combines {sup 210}Pb, {sup 137}Cs and metal concentrations in sediment cores. Metal concentrations in the lake were on average, Zn: 67 mg/kg, Cu: 15 mg/kg, As: 8 mg/kg, Se: 2 mg/kg, Cd: 1.5 mg/kg, Pb: 8 mg/kg with a maximum of Zn: 280 mg/kg, Cu: 80 mg/kg, As: 21 mg/kg, Se: 5 mg/kg, Cd: 4 mg/kg, Pb: 48 mg/kg. The ratios of measured concentrations in sediment cores to their sediment guidelines were Cd 1.8, As 1.0, Cu 0.5, Pb 0.2 and Zn 0.2, with the highest concern being for cadmium. Of special interest was assessment of the effects of changes in ash handling procedures by the Vales Point power station on the metal concentrations in the sediments. Comparing sediment layers before and after ash handling procedures were implemented, zinc concentrations have decreased 10%, arsenic 37%, selenium 20%, cadmium 38% and lead 14%. An analysis of contaminant depth profiles showed that, after implementation of new ash handling procedures in 1995, selenium and cadmium, the main contaminants in Australian black coal had decreased significantly in this estuary. - Highlights: • The main sources of metals to Southern Lake Macquarie are coal-fired power stations. • The metal of highest concern in this estuary is cadmium. • Arsenic was mobile in sediments. • Selenium and cadmium decreased in sediments following new ash handling procedures.

  19. Recent history of sediment metal contamination in Lake Macquarie, Australia, and an assessment of ash handling procedure effectiveness in mitigating metal contamination from coal-fired power stations

    International Nuclear Information System (INIS)

    Schneider, Larissa; Maher, William; Potts, Jaimie; Gruber, Bernd; Batley, Graeme; Taylor, Anne; Chariton, Anthony; Krikowa, Frank; Zawadzki, Atun; Heijnis, Henk

    2014-01-01

    This study assessed historical changes in metal concentrations in sediments of southern Lake Macquarie resulting from the activities of coal-fired power stations, using a multi-proxy approach which combines 210 Pb, 137 Cs and metal concentrations in sediment cores. Metal concentrations in the lake were on average, Zn: 67 mg/kg, Cu: 15 mg/kg, As: 8 mg/kg, Se: 2 mg/kg, Cd: 1.5 mg/kg, Pb: 8 mg/kg with a maximum of Zn: 280 mg/kg, Cu: 80 mg/kg, As: 21 mg/kg, Se: 5 mg/kg, Cd: 4 mg/kg, Pb: 48 mg/kg. The ratios of measured concentrations in sediment cores to their sediment guidelines were Cd 1.8, As 1.0, Cu 0.5, Pb 0.2 and Zn 0.2, with the highest concern being for cadmium. Of special interest was assessment of the effects of changes in ash handling procedures by the Vales Point power station on the metal concentrations in the sediments. Comparing sediment layers before and after ash handling procedures were implemented, zinc concentrations have decreased 10%, arsenic 37%, selenium 20%, cadmium 38% and lead 14%. An analysis of contaminant depth profiles showed that, after implementation of new ash handling procedures in 1995, selenium and cadmium, the main contaminants in Australian black coal had decreased significantly in this estuary. - Highlights: • The main sources of metals to Southern Lake Macquarie are coal-fired power stations. • The metal of highest concern in this estuary is cadmium. • Arsenic was mobile in sediments. • Selenium and cadmium decreased in sediments following new ash handling procedures

  20. Disintegration and size reduction of slags and metals after melt refining of contaminated metallic wastes

    International Nuclear Information System (INIS)

    Heshmatpour, B.; Copeland, G.L.; Heestand, R.L.

    1981-04-01

    Melting under an oxidizing slag is an attractive method of decontaminating and reducing the volume of radioactively contaminated metal scrap. The contaminants are concentrated in a relatively small volume of slag, which leaves the metal essentially clean. A potential method of permanently disposing of the resulting slags (and metals if necessary) is emplacing them into deep shale by grout hydrofracture. Suspension in grout mixtures requires that the slag and metal be granular. The feasibility of size-reducing slags and disintegrating metals and subsequently incorporating both into grout mixtures was demonstrated. Various types of slags were crushed with a small jaw crusher into particles smaller than 3 mm. Several metals were also melted and water-blasted into coarse metal powder or shot ranging in size from 0.05 to 3 mm. A simple low-pressure water atomizer having a multiple nozzle with a converging-line jet stream was developed and used for this purpose. No significant slag dust and steam were generated during slag crushing and liquid-metal water-blasting tests, indicating that contamination can be well contained within the system. The crushed slags and the coarse metal powders were suspendable in group fluids, which indicates probable disposability by shale hydrofracture. The granulation of slags and metals facilitates their containment, transport, and storage

  1. Evaluation of the mobility and pollution index of selected essential/toxic metals in paddy soil by sequential extraction method.

    Science.gov (United States)

    Hasan, Maria; Kausar, Dilshad; Akhter, Gulraiz; Shah, Munir H

    2018-01-01

    Comparative distribution and mobility of selected essential and toxic metals in the paddy soil from district Sargodha, Pakistan was evaluated by the modified Community Bureau of Reference (mBCR) sequential extraction procedure. Most of the soil samples showed slightly alkaline nature while the soil texture was predominantly silty loam in nature. The metal contents were quantified in the exchangeable, reducible, oxidisable and residual fractions of the soil by flame atomic absorption spectrophotometry and the metal data were subjected to the statistical analyses in order to evaluate the mutual relationships among the metals in each fraction. Among the metals, Ca, Sr and Mn were found to be more mobile in the soil. A number of significant correlations between different metal pairs were noted in various fractions. Contamination factor, geoaccumulation index and enrichment factor revealed extremely severe enrichment/contamination for Cd; moderate to significant enrichment/contamination for Ni, Zn, Co and Pb while Cr, Sr, Cu and Mn revealed minimal to moderate contamination and accumulation in the soil. Multivariate cluster analysis showed significant anthropogenic intrusions of the metals in various fractions. Copyright © 2017 Elsevier Inc. All rights reserved.

  2. Environmental remediation through sequestration of airfall-derived metals contamination by selective revegetation strategies

    Science.gov (United States)

    Sahagian, D.; Peters, S.; Yasko, G.

    2006-12-01

    Industrial activities in the 20th century left a legacy of contaminated air, water, and soils. The relative environmental enlightenment of the 21st century has already led to reductions in pollution sources, and has improved air and surface water quality in many areas. However, the residence time of contaminants in soils can be lengthy, presenting a challenge to 21st century restoration of impacted ecosystems and communities. The present study is centered on the Borough of Palmerton, PA, and a broad region of adjacent communities that were affected by two zinc smelters that operated continuously for more than 80 years, emitting thousands of tons of heavy metals including zinc, cadmium, lead and arsenic. While the air quality has vastly improved since the closure of the zinc smelters, the community remains adversely affected by the ecological damage caused by the pollution. The north face of the Kittatiny ridge was completely denuded of vegetation from the high metals concentrations. The region suffers further due to the ongoing perception of contaminated soils and water, leaving the town and surrounding areas economically depressed. In this study, we are examining the impact of revegetation strategies, particularly those using warm season grasses to determine which species survive and indeed thrive in the metals-contaminated soils. Because of the large areal extent and locally steep slopes in the broad area of concern, removal of metals from the entire region is impractical. It is considered more effective to sequester the metals in the soil so that they do not leach into the rivers, or enter the food web. Vegetation that absorbs and transports the metals throughout its tissues would mobilize these pollutants into the food web as well as make the metals available to reach the river via leaves and other vegetative structures. In this study, we are monitoring the uptake of metals by test grasses and other plants that are colonizing the contaminated area, as well as

  3. Transboundary Movement of Radioactively Contaminated Scrap Metal - Lessons Learned

    Energy Technology Data Exchange (ETDEWEB)

    Nizamska, M., E-mail: m.nimzamska@bnra.bg [Emergency Planning and Preparedness Division, Bulgarian Nuclear Regulatory Agency, Sofia (Bulgaria)

    2011-07-15

    Starting in 1989, Bulgaria has undergone a comprehensive transformation of its economy and social conditions. Part of this process is related to the intensive privatization that started in 2001. This privatization included facilities, as well as sites that use radioactive material for different applications - industry, medicine, agriculture, science, etc. The rapid change of property ownership and, in some cases, the resulting bankruptcy, has caused difficulties in tracing and identifying radioactive sources and materials and a deterioration of the system of safety, physical protection, etc. of radioactive material. In some cases, radioactive sources were stolen because of the value of their protective containers and sold for scrap metal. This led to the occurrence of different types of radiation incidents, mainly related to the discovery of radioactive sources in scrap metal. The consequences of these incidents include the risk of radiation exposure of the workers at scrap metal yards or reprocessing facilities and of members of the public and, in addition, radioactive contamination of the environment. The Bulgarian Nuclear Regulatory Agency (BNRA) has been responding to these incidents and has carried out a series of measures to improve the control over materials (e.g. activated or surface contaminated materials) and radioactive sources and to strengthen the preventive, monitoring, emergency preparedness and mitigating measures at facility, national and transboundary levels. This paper presents an analysis of the lessons learned by the BNRA and of the control of the transboundary movement of radioactively contaminated scrap metal through the territory of Bulgaria. (author)

  4. Investigation on reusing water treatment residuals to remedy soil contaminated with multiple metals in Baiyin, China

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Changhui; Zhao, Yuanyuan [The Key Laboratory of Water and Sediment Sciences, Ministry of Education, School of Environment, Beijing Normal University, Beijing 100875 (China); Pei, Yuansheng, E-mail: yspei@bnu.edu.cn [The Key Laboratory of Water and Sediment Sciences, Ministry of Education, School of Environment, Beijing Normal University, Beijing 100875 (China)

    2012-10-30

    Highlights: Black-Right-Pointing-Pointer Fe/Al water treatment residuals (FARs) can stabilize As, Pb, Ni, Zn, Cr and Cu. Black-Right-Pointing-Pointer FARs cannot stabilize Ba and Cd. Black-Right-Pointing-Pointer The properties of FARs and soil affect the FARs' ability of stabilizing metals. - Abstract: In this work, the remediation of soils contaminated with multiple metals using ferric and alum water treatment residuals (FARs) in Baiyin, China, was investigated. The results of metals fractionation indicated that after the soil was treated with FARs, arsenic (As), lead (Pb), nickel (Ni), zinc (Zn) and copper (Cu) could be transformed into more stable forms, i.e., As bound in crystalline Fe/Al oxides and other metals in the oxidable and residual forms. However, the forms of chromium (Cr) and cadmium (Cd) were unaffected. Interestingly, due to the effect of FARs, barium (Ba) was predominantly transformed into more mobile forms. The bioaccessibility extraction test demonstrated that the FARs reduced the bioaccessibility of As by 25%, followed by Cu, Cr, Zn, Ni and Pb. The bioaccessibility of Cd and Ba were increased; in particular, there was an increase of 41% for Ba at the end of the test. In conclusion, the FARs can be used to remedy soil contaminated with multiple metals, but comprehensive studies are needed before practical applications of this work.

  5. Investigation on reusing water treatment residuals to remedy soil contaminated with multiple metals in Baiyin, China

    International Nuclear Information System (INIS)

    Wang, Changhui; Zhao, Yuanyuan; Pei, Yuansheng

    2012-01-01

    Highlights: ► Fe/Al water treatment residuals (FARs) can stabilize As, Pb, Ni, Zn, Cr and Cu. ► FARs cannot stabilize Ba and Cd. ► The properties of FARs and soil affect the FARs’ ability of stabilizing metals. - Abstract: In this work, the remediation of soils contaminated with multiple metals using ferric and alum water treatment residuals (FARs) in Baiyin, China, was investigated. The results of metals fractionation indicated that after the soil was treated with FARs, arsenic (As), lead (Pb), nickel (Ni), zinc (Zn) and copper (Cu) could be transformed into more stable forms, i.e., As bound in crystalline Fe/Al oxides and other metals in the oxidable and residual forms. However, the forms of chromium (Cr) and cadmium (Cd) were unaffected. Interestingly, due to the effect of FARs, barium (Ba) was predominantly transformed into more mobile forms. The bioaccessibility extraction test demonstrated that the FARs reduced the bioaccessibility of As by 25%, followed by Cu, Cr, Zn, Ni and Pb. The bioaccessibility of Cd and Ba were increased; in particular, there was an increase of 41% for Ba at the end of the test. In conclusion, the FARs can be used to remedy soil contaminated with multiple metals, but comprehensive studies are needed before practical applications of this work.

  6. Considerations in recycling contaminated scrap metal and rubble

    International Nuclear Information System (INIS)

    Kluk, A.F.; Hocking, E.K.

    1992-01-01

    Management options for the Department of Energy's increasing amounts of contaminated scrap metal and rubble include reuse as is, disposal, and recycling. Recycling, with its promise of resource recovery, virgin materials conservation, and land disposal minimization, emerges as a preferred management technique. Implementing a cost effective recycling program requires resolution of several issues including: establishing release limits for contaminants, controlling use of recycled materials creating effective public communication programs; developing economical, reliable assay technologies; managing secondary waste streams, expanding availability of unrestricted markets; and solving conflicting legal considerations

  7. Feasibility of re-melting NORM-contaminated scrap metal

    Energy Technology Data Exchange (ETDEWEB)

    Winters, S. J.; Smith, K. P.

    1999-10-26

    Naturally occurring radioactive materials (NORM) sometimes accumulate inside pieces of equipment associated with oil and gas production and processing activities. Typically, the NORM accumulates when radium that is present in solution in produced water precipitates out in scale and sludge deposits. Scrap equipment containing residual quantities of these NORM-bearing scales and sludges can present a waste management problem if the radium concentrations exceed regulatory limits or activate the alarms on radiation screening devices installed at most scrap metal recycling facilities. Although NORM-contaminated scrap metal currently is not disposed of by re-melting, this form of recycling could present a viable disposition option for this waste stream. Studies indicate that re-melting NORM-contaminated scrap metal is a viable recycling option from a risk-based perspective. However, a myriad of economic, regulatory, and policy issues have caused the recyclers to turn away virtually all radioactive scrap metal. Until these issues can be resolved, re-melting of the petroleum industry's NORM-impacted scrap metal is unlikely to be a widespread practice. This paper summarizes the issues associated with re-melting radioactive scrap so that the petroleum industry and its regulators will understand the obstacles. This paper was prepared as part of a report being prepared by the Interstate Oil and Gas Compact Commission's NORM Subcommittee.

  8. Decontamination method for radiation-contaminated metal waste

    International Nuclear Information System (INIS)

    Suwa, Takeshi; Kuribayashi, Nobuhide; Yasumune, Taketoshi.

    1991-01-01

    In immersing radiation-contaminated metal wastes into a sulfuric acid solution thereby peeling and removing radioactive deposition cruds and dissolving the surface of the matrix metals to eliminate radioactive contaminants, when the potential of the sulfuric acid solution is shifted to a higher direction by more than a certain level due to the increase of the amount of metal ions leached from the cruds and the matrix material, the leached metal ions are electrolytically reduced to control the potential of the sulfuric acid solution to less than a predetermined potential level. Although the dissolving rate is increased as the concentration of the sulfuric acid solution is higher, it is preferably from 0.5 to 2 mol/l, since higher concentration increases the load on the waste liquid processing. Further, the temperature for solution is set to higher than a room temperature and, preferably from 50 to 90degC. Further, the potential level of the solution, although varies somewhat depending on the concentration of the leached metal ions and the temperature, is preferably controlled to less than 0.1 to 0.2 V. This can attain high decontaminating effect in a short period of time by using a sulfuric acid solution alone. (T.M.)

  9. The potential of genetic engineering of plants for the remediation of soils contaminated with heavy metals.

    Science.gov (United States)

    Fasani, Elisa; Manara, Anna; Martini, Flavio; Furini, Antonella; DalCorso, Giovanni

    2018-05-01

    The genetic engineering of plants to facilitate the reclamation of soils and waters contaminated with inorganic pollutants is a relatively new and evolving field, benefiting from the heterologous expression of genes that increase the capacity of plants to mobilize, stabilize and/or accumulate metals. The efficiency of phytoremediation relies on the mechanisms underlying metal accumulation and tolerance, such as metal uptake, translocation and detoxification. The transfer of genes involved in any of these processes into fast-growing, high-biomass crops may improve their reclamation potential. The successful phytoextraction of metals/metalloids and their accumulation in aerial organs have been achieved by expressing metal ligands or transporters, enzymes involved in sulfur metabolism, enzymes that alter the chemical form or redox state of metals/metalloids and even the components of primary metabolism. This review article considers the potential of genetic engineering as a strategy to improve the phytoremediation capacity of plants in the context of heavy metals and metalloids, using recent case studies to demonstrate the practical application of this approach in the field. © 2017 John Wiley & Sons Ltd.

  10. Studies on the mobility of some heavy metals and transuranic radionuclides in major Indian soil types

    International Nuclear Information System (INIS)

    D'Souza, T.J.; Vyas, B.N.; Athalye, V.V.; Ramachandran, V.; Mistry, K.B.

    1983-01-01

    Studies on the mobility of the heavy metals, chromium, lead, zinc and transuranic radionuclides plutonium and americium in three major Indian soils, namely a vertisol-pellustert (black soil), an oxisol (laterite soil) and an entisol-haplaquent (alluvial soil), indicated that more than 98% of the surface-deposited pollutants were retained in the top 0 to 2.5 cm layer when leached with rain-water. In general, the mobility of these elements was either unaffected or marginally reduced at high doses of added organic matter as compared with controls. However, leaching with dilute solutions of (10 -4 M-bar) EDTA, EDDHA and DTPA resulted in enhancement of the mobility of all these pollutants with a high degree of chelate specificity for individual ions, depending upon the soil type. Rapid formation of stable soluble Cr-EDDHA, Pu-DTPA and Am-DTPA complexes facilitated the leaching of these pollutants from the contaminated soils. (author)

  11. Evaluation of Mobility, Bioavailability and Toxicity of Pb and Cd in Contaminated Soil Using TCLP, BCR and Earthworms

    Science.gov (United States)

    Kede, Maria Luiza F. M.; Correia, Fabio V.; Conceição, Paulo F.; Salles Junior, Sidney F.; Marques, Marcia; Moreira, Josino C.; Pérez, Daniel V.

    2014-01-01

    The objective of the present study was to investigate the reduction of mobility, availability and toxicity found in soil contaminated with lead (Pb) and cadmium (Cd) from Santo Amaro Municipality, Bahia, Brazil using two combined methods, commonly tested separately according to the literature: metal mobilization with phosphates and phytoextraction. The strategy applied was the treatment with two sources of phosphates (separately and mixed) followed by phytoremediation with vetiver grass (Vetiveria zizanioides (L.)). The treatments applied (in triplicates) were: T1—potassium dihydrogen phosphate (KH2PO4); T2—reactive natural phosphate fertilizer (NRP) and; T3—a mixture 1:1 of KH2PO4 and NRP. After this step, untreated and treated soils were planted with vetiver grass. The extraction procedures and assays applied to contaminated soil before and after the treatments included metal mobility test (TCLP); sequential extraction with BCR method; toxicity assays with Eisenia andrei. The soil-to-plant transfer factors (TF) for Pb and Cd were estimated in all cases. All treatments with phosphates followed by phytoremediation reduced the mobility and availability of Pb and Cd, being KH2PO4 (T1) plus phytoremediation the most effective one. Soil toxicity however, remained high after all treatments. PMID:25386955

  12. Evaluation of Mobility, Bioavailability and Toxicity of Pb and Cd in Contaminated Soil Using TCLP, BCR and Earthworms

    Directory of Open Access Journals (Sweden)

    Maria Luiza F. M. Kede

    2014-11-01

    Full Text Available The objective of the present study was to investigate the reduction of mobility, availability and toxicity found in soil contaminated with lead (Pb and cadmium (Cd from Santo Amaro Municipality, Bahia, Brazil using two combined methods, commonly tested separately according to the literature: metal mobilization with phosphates and phytoextraction. The strategy applied was the treatment with two sources of phosphates (separately and mixed followed by phytoremediation with vetiver grass (Vetiveria zizanioides (L.. The treatments applied (in triplicates were: T1—potassium dihydrogen phosphate (KH2PO4; T2—reactive natural phosphate fertilizer (NRP and; T3—a mixture 1:1 of KH2PO4 and NRP. After this step, untreated and treated soils were planted with vetiver grass. The extraction procedures and assays applied to contaminated soil before and after the treatments included metal mobility test (TCLP; sequential extraction with BCR method; toxicity assays with Eisenia andrei. The soil-to-plant transfer factors (TF for Pb and Cd were estimated in all cases. All treatments with phosphates followed by phytoremediation reduced the mobility and availability of Pb and Cd, being KH2PO4 (T1 plus phytoremediation the most effective one. Soil toxicity however, remained high after all treatments.

  13. Mathematical modeling of heavy metals contamination from MSW landfill site in Khon Kaen, Thailand.

    Science.gov (United States)

    Tantemsapya, N; Naksakul, Y; Wirojanagud, W

    2011-01-01

    Kham Bon landfill site is one of many municipality waste disposal sites in Thailand which are in an unsanitary condition. The site has been receiving municipality wastes without separating hazardous waste since 1968. Heavy metals including, Pb, Cr and Cd are found in soil and groundwater around the site, posing a health risk to people living nearby. In this research, contamination transport modelling of Pb, Cr and Cd was simulated using MODFLOW for two periods, at the present (2010) and 20 years prediction (2030). Model results showed that heavy metals, especially Pb and Cr migrated toward the north-eastern and south-eastern direction. The 20 years prediction showed that, heavy metals tend to move from the top soil to the deeper aquifer. The migration would not exceed 500 m radius from the landfill centre in the next 20 years, which is considered to be a slow process. From the simulation model, it is recommended that a mitigation measure should be performed to reduce the risk from landfill contamination. Hazardous waste should be separated for proper management. Groundwater contamination in the aquifer should be closely monitored. Consumption of groundwater in a 500 m radius must be avoided. In addition, rehabilitation of the landfill site should be undertaken to prevent further mobilization of pollutants.

  14. Air separation of heavy metal contaminants from soil

    International Nuclear Information System (INIS)

    Nelson, M.E.; Harper, M.J.; Buckon, A.D.

    1995-01-01

    Several heavy metal separation techniques are currently being developed for soil remediation at various Department of Defense and Department of Energy (DOE) Facilities. The majority of these techniques involve a wet process using water, pH modifiers or other compounds. The US Naval Academy (USNA) has developed a dry process for heavy metal separation. The process uses air classification technology to concentrate the metal contaminant into a fraction of the soil. The advantages of this dry process are that it creates no contaminated byproduct and uses commercially available technology. The USNA process is based on using a Gayco-Reliance air classifier. Tests have been conducted with the system at the Naval Academy and the University of Nevada-Reno (UNR). The USNA tests used soil from the Nevada Test Site mixed with bismuth at a concentration of 500--1,000 ppm. The UNR tests used soil from four DOE sites mixed with uranium oxides and plutonium at an activity level of 100--700 pCi per gram. Concentration of activities and volume reduction percentages are presented for the various soils and contaminants tested

  15. Radiation protection aspects of the trafficking radionuclides contaminated metal scrap

    International Nuclear Information System (INIS)

    Prouza, Z.

    1999-01-01

    This paper covers the legal base of the release in the environment of radionuclides containing materials and the radiation protection aspects of trafficking in radionuclides contaminated materials. Materials, substance and objects containing radionuclides or contaminated by them may be released into the environment, if they do not exceed values authorized by SONS (State Office of Nuclear Safety). Legislative measures should be taken against illicit trafficking of the nuclear material in all the areas. The creation of a sophisticated system for the control and regulation of all important radionuclides released into the environment should be based on the radiation protection limits, constraints, reference and exemption levels which are introduced in the legislative documents; the strong supervision of producers and users of the sealed sources by SONS side, in addition to the requirements of the licensing process of their sources; a complete data-base and information exchange system related to illicit trafficking in contaminated material; in this system all the authorities with jurisdiction should be involved. The responsibilities of the persons involved in metal scrap trafficking should include arrangement of appropriate monitoring, rules for transport of the metal scrap, an adequate measuring system to monitor metal scrap including monitoring to prevent processing or smelting of the radioactive material, control measures, etc. All of the above items of legislation are an important challenge for the Czech Republic. (author)

  16. Metal contamination in water sediments; Contaminacion por metales en sedimentos acuaticos

    Energy Technology Data Exchange (ETDEWEB)

    Usero Garcia, J.; Morillo Aguado, J.; Gracia Manarillo, I. [Universidad de Sevilla. Sevilla (Spain)

    1997-09-01

    The origin, distribution, and behaviour of metals in aquatic systems, and factors affecting the solubilization and entry into the water column of metals associated with sediments are examined. Also, the interaction of these metals with and toxic effects on living organisms are studied. Finally, the existing methods for assessing the degree of pollution of sediments and the mobility of the metals associated with the sediments are explained. In the second section of this paper, the methods used for sampling, preparing, and analysing the sediments are described. (Author) 48 refs.

  17. Bioaccumulation of radionuclides and metals by microorganisms: Potential role in the separation of inorganic contaminants and for the in situ treatment of the subsurface

    International Nuclear Information System (INIS)

    Bolton, H. Jr.; Wildung, R.E.

    1993-01-01

    Radionuclide, metal and organic contaminants are present in relatively inaccessible subsurface environments at many U.S Department of Energy (DOE) sites. Subsurface contamination is of concern to DOE because the migration of these contaminants into relatively deep subsurface zones indicates that they exist in a mobile chemical form and thus could potentially enter domestic groundwater supplies. Currently, economic approaches to stabilize or remediate these deep contaminated zones are limited, because these systems are not well characterized and there is a lack of understanding of how geochemical, microbial, and hydrological processes interact to influence contaminant behavior. Microorganisms offer a potential means for radionuclide and metal immobilization or mobilization for subsequent surface treatment. Bioaccumulation is a specific microbial sequestering mechanism wherein mobile radionuclides and metals become associated with the microbial biomass by both intra- and extracellular sequestering ligands. Since most of the microorganism in the subsurface are associated with the stationary strata, bioaccumulation of mobile radionuclides and metals would initially result in a decrease in the transport of inorganic contaminants. How long the inorganic contaminants would remain immobilized, the selectivity of the bioaccumulation process for specific inorganic contaminants, the mechanism involved, and how the geochemistry and growth conditions of the subsurface environment influence bioaccumulation are not currently known. This presentation focuses on the microbial process of immobilizing radionuclides and metals and using this process to reduce inorganic contaminant migration at DOE sites. Background research with near-surface microorganisms will be presented to demonstrate this process and show its potential to reduce inorganic contaminant migration. Future research needs and approaches in this relatively new research area will also be discussed

  18. Metal and nutrient dynamics in decomposing tree litter on a metal contaminated site

    International Nuclear Information System (INIS)

    Van Nevel, Lotte; Mertens, Jan; Demey, Andreas; De Schrijver, An; De Neve, Stefaan; Tack, Filip M.G.; Verheyen, Kris

    2014-01-01

    In a forest on sandy, metal polluted soil, we examined effects of six tree species on litter decomposition rates and accompanied changes in metal (Cd, Zn) and nutrient (base cations, N, C) amounts. Decomposition dynamics were studied by means of a litterbag experiment lasting for 30 months. The decomposition peak occurred within the first year for all tree species, except for aspen. During litter decomposition, high metal litter types released part of their accumulated metals, whereas low metal litter types were characterized by a metal enrichment. Base cations, N and C were released from all litter types. Metal release from contaminated litter might involve risks for metal dispersion towards the soil. On the other hand, metal enrichment of uncontaminated litter may be ecologically relevant as it can be easily transported or serve as food source. - Highlights: • Litter decomposition peak occurred within the first year for all tree species, except for aspen. • Base cations, N and C were released from all litter types during decomposition. • Cd and Zn were released from the high metal litter types. • Low metal litter types were characterized by a net Cd and Zn enrichment. • Metal and nutrient releases were reflected in topsoil characteristics. - Litter decomposition rates, as well as enrichment and release dynamics of metals and nutrients in decomposing litter were divergent under the different tree species

  19. Chemical Speciation and Mobility of Some Heavy Metals in Soils ...

    African Journals Online (AJOL)

    The mobility of some heavy metals (Fe, Co, Ni and Mn) in soils around automobile waste dumpsites in Northern part of Niger Delta was assessed using Tessier et al. five syteps sequential chemical extraction procedure. The results showed that majority of iron and manganese were associated with the residual fraction with ...

  20. Remediation of heavy metal contaminated sites in the Venice lagoon and conterminous areas (Northern Italy)

    Science.gov (United States)

    Bini, Claudio; Wahsha, Mohammad; Fontana, Silvia; Maleci, Laura

    2013-04-01

    The lagoon of Venice and the conterminous land are affected by heavy contamination of anthropogenic origin, and for this reason the whole area has been classified as site of national interest, and must be restored. Heavy metals (As, Cd, Cr, Cu, Hg, Mn, Pb, Sb, Se, Zn) and organic compounds (IPA, PCB, Dioxine) have been identified as the main contaminants at various sites, owing to agriculture and industrial wastes discharged on soils and convoyed to the lagoon. Five case studies of soil remediation are here reported. S. Giuliano is a former palustrine area reclaimed since the 60's with various human transported materials (HTM). In this area, hot spots overpassing the reference limits for residential and green areas have been recorded for Cd, Cu, Pb, Zn and IPA. Campalto is a site bordering the Venice lagoon and subjected to oscillating water level, that enhances metal mobility; diffuse contamination by heavy metals, particularly Pb, has been recorded at this site, utilized since 30 years for military and sport (skate) activities. Marghera is dramatically famous for its numerous factories and for oil refineries that affected the lagoon sediments since the 50's. Sediments proved heavily contaminated by As (up to 137 mgkg-1), Cd (57 mgkg-1), Hg (30mgkg-1), Ni, Pb (700 mgkg-1), Zn (5818 mgkg-1). Murano is a small island where many glass factories (the most famous all over the world) are running since XIII century. Glass is stained with several metals and, moreover, some substances are used to regulate fusion temperature, purity, etc., and therefore the surrounding environment is heavily contaminated by these substances. Mean concentrations of As (429 mgkg-1), Cd (1452 mgkg-1), Pb (749 mgkg-1), Zn (1624 mgkg-1), Se (341 mgkg-1), Sb (74 mgkg-1) widely overpass the reference values for both residential and industrial areas in national guidelines. Molo Serbatoi is a former oil container currently under restoration in the port of Venice. Soil contamination by As, Hg, Zn and

  1. Mitigation effects of silicon rich amendments on heavy metal accumulation in rice (Oryza sativa L.) planted on multi-metal contaminated acidic soil.

    Science.gov (United States)

    Gu, Hai-Hong; Qiu, Hao; Tian, Tian; Zhan, Shu-Shun; Deng, Teng-Hao-Bo; Chaney, Rufus L; Wang, Shi-Zhong; Tang, Ye-Tao; Morel, Jean-Louis; Qiu, Rong-Liang

    2011-05-01

    The mechanisms of stabilization by silicon-rich amendments of cadmium, zinc, copper and lead in a multi-metal contaminated acidic soil and the mitigation of metal accumulation in rice were investigated in this study. The results from a pot experiment indicated that the application of fly ash (20 and 40gkg(-1)) and steel slag (3 and 6gkg(-1)) increased soil pH from 4.0 to 5.0-6.4, decreased the phytoavailability of heavy metals by at least 60%, and further suppressed metal uptake by rice. Diffusion gradient in thin-film measurement showed the heavy metal diffusion fluxes from soil to solution decreased by greater than 84% after remediation. X-ray diffraction analysis indicated the mobile metals were mainly deposited as their silicates, phosphates and hydroxides in amended treatments. Moreover, it was found metal translocation from stem to leaf was dramatically restrained by adding amendments, which might be due to the increase of silicon concentration and co-precipitation with heavy metals in stem. Finally, a field experiment showed the trace element concentrations in polished rice treated with amendments complied with the food safety standards of China. These results demonstrated fly ash and steel slag could be effective in mitigating heavy metal accumulation in rice grown on multi-metal contaminated acidic soils. Copyright © 2011 Elsevier Ltd. All rights reserved.

  2. Solubility of Heavy Metals/Metalloid on Multi-Metal Contaminated Soil Samples from a Gold Ore Processing Area: Effects of Humic Substances

    Directory of Open Access Journals (Sweden)

    Cácio Luiz Boechat

    2016-01-01

    Full Text Available ABSTRACT Bioavailability of heavy metals at contaminated sites is largely controlled by the physicochemical properties of the environmental media such as dissolved organic matter, hydroxides and clay colloids, pH, soil cation exchange capacity and oxidation-reduction potential. The aim of this study was to investigate soil pH and heavy metal solubility effect by levels of humic and fulvic acids applied in soil samples with different levels of contamination by heavy metals. The soil samples used in this study were collected in a known metal-contaminated site. Humic acid (HA and fulvic acid (FA were purchased as a commercially available liquid material extracted from Leonardite. The experiment was carried out in a factorial scheme of 4 × (4 + 1, with four contaminated soil samples and four treatments, comprised of two levels of HA, two levels of FA and a control. The HA treatments increased the solubility of Cu, Zn, Ni, Cr, Cd, Pb, As and Ba from soils, while FA treatments decreased, thus raising or not their availability and mobility in soil. Humic acid concentration did not influence soil pH and FA decreased soil pH until 0.7 units. The initial heavy metal concentration in soil affects the magnitude of the processes involving humic substances. The lower releases of heavy metals by FA verified the importance of the complexation properties of organic compounds. These results appear to encourage the use of HA for increased plant-availability of heavy metals in remediation projects and the use of FA for decreased plant-availability of heavy metals at contaminated sites with a risk of introducing metals into the food chain.

  3. Remedial Investigation of Contaminant Mobility at Naval Weapons Station, Concord, California.

    Science.gov (United States)

    1986-01-01

    Houghton. 1983. Heavy Metal Uptake by Agronomic Crops Grown on Contaminated Soils and Cyperus esculentus Grown on Oxidized and Reduced Contaminated Soils...Respiratory Metabolism and Haemoglobin Concentration in an Earthworm Eisenia foetida (SAVIGNY 1826) Under Exposure of Lead Intoxication . Acta...Comparison of the Heavy-Metal Uptake of Cyperus esculentus and of Agronomic Plants Grown on Contaminated Sediments. Miscellaneous Paper D-83-1. US

  4. Fractionation of heavy metals and assessment of contamination of the sediments of Lake Titicaca.

    Science.gov (United States)

    Cáceres Choque, Luis Fernando; Ramos Ramos, Oswaldo E; Valdez Castro, Sulema N; Choque Aspiazu, Rigoberto R; Choque Mamani, Rocío G; Fernández Alcazar, Samuel G; Sracek, Ondra; Bhattacharya, Prosun

    2013-12-01

    Chemical weathering is one of the major geochemical processes that control the mobilization of heavy metals. The present study provides the first report on heavy metal fractionation in sediments (8-156 m) of Lake Titicaca (3,820 m a.s.l.), which is shared by the Republic of Peru and the Plurinational State of Bolivia. Both contents of total Cu, Fe, Ni, Co, Mn, Cd, Pb, and Zn and also the fractionation of these heavy metals associated with four different fractions have been determined following the BCR scheme. The principal component analysis suggests that Co, Ni, and Cd can be attributed to natural sources related to the mineralized geological formations. Moreover, the sources of Cu, Fe, and Mn are effluents and wastes generated from mining activities, while Pb and Zn also suggest that their common source is associated to mining activities. According to the Risk Assessment Code, there is a moderate to high risk related to Zn, Pb, Cd, Mn, Co, and Ni mobilization and/or remobilization from the bottom sediment to the water column. Furthermore, the Geoaccumulation Index and the Enrichment Factor reveal that Zn, Pb, and Cd are enriched in the sediments. The results suggest that the effluents from various traditional mining waste sites in both countries are the main source of heavy metal contamination in the sediments of Lake Titicaca.

  5. Hazard potential of widespread but hidden historic offshore heavy metal (Pb, Zn) contamination (Gulf of Cadiz, Spain).

    Science.gov (United States)

    Hanebuth, Till J J; King, Mary Lee; Mendes, Isabel; Lebreiro, Susana; Lobo, Francisco J; Oberle, Ferdinand K; Antón, Laura; Ferreira, Paulo Alves; Reguera, Maria Isabel

    2018-05-10

    Natural and human-induced seabed sediment disturbances affect wide areas of the global coastal ocean. These recurrent to chronic disturbances mobilize significant amounts of material, including substances that have the potential to significantly harm the environment once re-released. This very challenging issue is difficult to deal with if sub-surface contaminant concentrations are unknown. Based on the analysis of 11 new, up to 5-m long sediment cores taken offshore in the Gulf of Cadiz, the contamination history (using the trace elements lead and zinc) is well documented over major parts of the gulf. Ore mining and metal processing industries on the southwestern Iberian Peninsula started five thousand years ago and experienced a first peak during the Roman Period, which can be detected over the entire gulf. The Industrial Era added a massive, shelf-wide heavy metal excursion of unprecedented dimension. This metal contamination to the coastal ocean decreased in the 1990s and appears to be today limited to larger areas off the Tinto/Odiel and Guadiana River mouths. The unforeseen, significant finding of this study is that the gulf-wide, peak heavy metal concentration, stemming from the Industrial Era, is widely overlain by a modern sediment veneer just thick enough to cover the contaminant horizon, but thin enough to have this layer within the reach of natural or human-induced sediment mobilization events. Published by Elsevier B.V.

  6. Characterisation of contaminated metals using an advanced statistical toolbox - Geostatistical characterisation of contaminated metals: methodology and illustrations

    International Nuclear Information System (INIS)

    Larsson, Arne; Lidar, Per; Desnoyers, Yvon

    2014-01-01

    Radiological characterisation plays an important role in the process to recycle contaminated or potentially contaminated metals. It is a platform for planning, identification of the extent and nature of contamination, assessing potential risk impacts, cost estimation, radiation protection, management of material arising from decommissioning as well as for the release of the materials as well as the disposal of the generated secondary waste as radioactive waste. Key issues in radiological characterisation are identification of objectives, development of a measurement and sampling strategy (probabilistic, judgmental or a combination thereof), knowledge management, traceability, recording and processing of obtained information. By applying advanced combination of statistical and geostatistical in the concept better performance can be achieved at a lower cost. This paper will describe the benefits with the usage of the available methods in the different stages of the characterisation, treatment and clearance processes aiming for reliable results in line with the data quality objectives. (authors)

  7. Assessment of mobility and bioavailability of contaminants in MSW incineration ash with aquatic and terrestrial bioassays.

    Science.gov (United States)

    Ribé, V; Nehrenheim, E; Odlare, M

    2014-10-01

    Incineration of municipal solid waste (MSW) is a waste treatment method which can be sustainable in terms of waste volume reduction as well as a source of renewable energy. In the process fly and bottom ash is generated as a waste material. The ash residue may vary greatly in composition depending on the type of waste incinerated and it can contain elevated levels of harmful contaminants such as heavy metals. In this study, the ecotoxicity of a weathered, untreated incineration bottom ash was characterized as defined by the H14 criterion of the EU Waste Framework Directive by means of an elemental analysis, leaching tests followed by a chemical analysis and a combination of aquatic and solid-phase bioassays. The experiments were conducted to assess the mobility and bioavailability of ash contaminants. A combination of aquatic and terrestrial bioassays was used to determine potentially adverse acute effects of exposure to the solid ash and aqueous ash leachates. The results from the study showed that the bottom ash from a municipal waste incineration plant in mid-Sweden contained levels of metals such as Cu, Pb and Zn, which exceeded the Swedish EPA limit values for inert wastes. The chemical analysis of the ash leachates showed high concentrations of particularly Cr. The leachate concentration of Cr exceeded the limit value for L/S 10 leaching for inert wastes. Filtration of leachates prior to analysis may have underestimated the leachability of complex-forming metals such as Cu and Pb. The germination test of solid ash and ash leachates using T. repens showed a higher inhibition of seedling emergence of seeds exposed to the solid ash than the seeds exposed to ash leachates. This indicated a relatively low mobility of toxicants from the solid ash into the leachates, although some metals exceeded the L/S 10 leaching limit values for inert wastes. The Microtox® toxicity test showed only a very low toxic response to the ash leachate exposure, while the D. magna

  8. DECHEM: A remedial planning tool for metallic contaminants in soil at UMTRA Project sites

    International Nuclear Information System (INIS)

    1989-03-01

    The DECHEM (DEcontamination of CHEMicals) method was developed for the Uranium Mill Tailings Remedial Action (UMTRA) Project to guide characterization and remedial planning for metals contamination in soils. This is necessary because non-radiological hazardous constituents may be more mobile than radium-226 (Ra-226), and hence may migrate more deeply into subpile soils (beneath tailings that are to be relocated) or into adjacent contaminated soils at UMTRA Project sites. The result is that remedial action to the Ra-226 excavation limit, as specified in the US Environmental Protection Agency (EPA) standards, may not adequately remove hazardous non-radiological contamination. Unmitigated, these contaminants in soil may cause health risks because of their presence in resuspended particles, their uptake by crops or fodder their seepage into aquifers used for drinking water or other possible exposure pathways. The DECHEM method was developed in response to the need for advanced planning for the remediation of chemical contaminants at UMTRA Project sites, and includes the following elements: Establishment of acceptable exposure rates for humans to chemicals, based on EPA guidelines or other toxicological literature. Modeling of chemical migration through environmental pathways from a remediated UMTRA Project site to humans. Determination of allowable residual concentrations (i.e., cleanup guidelines) for chemicals in soils that results in doses to humans that are below established acceptable exposure rates. The initial development and application of the DECHEM method has focused upon hazardous metallic contaminants such as arsenic, lead, molybdenum, and selenium, which are known to occur in elevated concentrations at some UMTRA Project sites

  9. Evaluation of geochemical mobility of heavy metals in the dump mine rocks Western Donbass

    Directory of Open Access Journals (Sweden)

    Yatsechko N.Y.

    2014-12-01

    Full Text Available Typification of turn mine rocks of Western Donbas is conducted after a size acid-lye the index of water-soluble complex. It is set that exactly rocks with the low value of it an index characterized the most sizes of middle content of water-soluble forms of heavy metals. It is well-proven that exactly mine dumps are the generating source of contamination of objects of environment of this region by heavy metals. The significant impact on the environment inflicted not only directly in the process of coal mining, but for many years after its completion. The source of contamination of environmental objects are dumps that occupy large areas of fertile land. Every year in the dumps is stored about 40 million. m3 moldboard mine rock. Most of the waste coal industry have potential toxic and mutagenic properties as containing a significant amount of heavy metals, which are practically not biodegradable in the environment and is therefore especially dangerous for living organisms paramount importance score geochemical mobility of heavy metals, ie their property to move from solid to liquid phase, migrate to the natural landscape and absorbed by vegetation. This applies particularly to water-soluble forms of metals, as in warehousing surface mine dump piles of rocks, the priority factor that regulates the processes of migration of heavy metals are leaching precipitation of solid phase wastes. It is the existence and content of heavy metals in water-soluble complex characterized by their solubility and migration activity and can be used to assess the real extent of possible contamination of the hydrosphere.

  10. Remediation of metal-contaminated urban soil using flotation technique

    Energy Technology Data Exchange (ETDEWEB)

    Dermont, G., E-mail: dermonge@gmail.com [Institut National de la Recherche Scientifique Eau Terre et Environnement (INRS-ETE), 490, rue de la Couronne, Quebec, QC, Canada G1K 9A9 (Canada); Bergeron, M.; Richer-Lafleche, M.; Mercier, G. [Institut National de la Recherche Scientifique Eau Terre et Environnement (INRS-ETE), 490, rue de la Couronne, Quebec, QC, Canada G1K 9A9 (Canada)

    2010-02-01

    A soil washing process using froth flotation technique was evaluated for the removal of arsenic, cadmium, copper, lead, and zinc from a highly contaminated urban soil (brownfield) after crushing of the particle-size fractions > 250 {mu}m. The metal contaminants were in particulate forms and distributed in all the particle-size fractions. The particle-by-particle study with SEM-EDS showed that Zn was mainly present as sphalerite (ZnS), whereas Cu and Pb were mainly speciated as various oxide/carbonate compounds. The influence of surfactant collector type (non-ionic and anionic), collector dosage, pulp pH, a chemical activation step (sulfidization), particle size, and process time on metal removal efficiency and flotation selectivity was studied. Satisfactory results in metal recovery (42-52%), flotation selectivity (concentration factor > 2.5), and volume reduction (> 80%) were obtained with anionic collector (potassium amyl xanthate). The transportation mechanisms involved in the separation process (i.e., the true flotation and the mechanical entrainment) were evaluated by the pulp chemistry, the metal speciation, the metal distribution in the particle-size fractions, and the separation selectivity indices of Zn/Ca and Zn/Fe. The investigations showed that a great proportion of metal-containing particles were recovered in the froth layer by entrainment mechanism rather than by true flotation process. The non-selective entrainment mechanism of the fine particles (< 20 {mu}m) caused a flotation selectivity drop, especially with a long flotation time (> 5 min) and when a high collector dose is used. The intermediate particle-size fraction (20-125 {mu}m) showed the best flotation selectivity.

  11. Remediation of metal-contaminated urban soil using flotation technique.

    Science.gov (United States)

    Dermont, G; Bergeron, M; Richer-Laflèche, M; Mercier, G

    2010-02-01

    A soil washing process using froth flotation technique was evaluated for the removal of arsenic, cadmium, copper, lead, and zinc from a highly contaminated urban soil (brownfield) after crushing of the particle-size fractions >250microm. The metal contaminants were in particulate forms and distributed in all the particle-size fractions. The particle-by-particle study with SEM-EDS showed that Zn was mainly present as sphalerite (ZnS), whereas Cu and Pb were mainly speciated as various oxide/carbonate compounds. The influence of surfactant collector type (non-ionic and anionic), collector dosage, pulp pH, a chemical activation step (sulfidization), particle size, and process time on metal removal efficiency and flotation selectivity was studied. Satisfactory results in metal recovery (42-52%), flotation selectivity (concentration factor>2.5), and volume reduction (>80%) were obtained with anionic collector (potassium amyl xanthate). The transportation mechanisms involved in the separation process (i.e., the true flotation and the mechanical entrainment) were evaluated by the pulp chemistry, the metal speciation, the metal distribution in the particle-size fractions, and the separation selectivity indices of Zn/Ca and Zn/Fe. The investigations showed that a great proportion of metal-containing particles were recovered in the froth layer by entrainment mechanism rather than by true flotation process. The non-selective entrainment mechanism of the fine particles (flotation selectivity drop, especially with a long flotation time (>5 min) and when a high collector dose is used. The intermediate particle-size fraction (20-125 microm) showed the best flotation selectivity. Copyright 2009 Elsevier B.V. All rights reserved.

  12. Remediation of metal-contaminated urban soil using flotation technique

    International Nuclear Information System (INIS)

    Dermont, G.; Bergeron, M.; Richer-Lafleche, M.; Mercier, G.

    2010-01-01

    A soil washing process using froth flotation technique was evaluated for the removal of arsenic, cadmium, copper, lead, and zinc from a highly contaminated urban soil (brownfield) after crushing of the particle-size fractions > 250 μm. The metal contaminants were in particulate forms and distributed in all the particle-size fractions. The particle-by-particle study with SEM-EDS showed that Zn was mainly present as sphalerite (ZnS), whereas Cu and Pb were mainly speciated as various oxide/carbonate compounds. The influence of surfactant collector type (non-ionic and anionic), collector dosage, pulp pH, a chemical activation step (sulfidization), particle size, and process time on metal removal efficiency and flotation selectivity was studied. Satisfactory results in metal recovery (42-52%), flotation selectivity (concentration factor > 2.5), and volume reduction (> 80%) were obtained with anionic collector (potassium amyl xanthate). The transportation mechanisms involved in the separation process (i.e., the true flotation and the mechanical entrainment) were evaluated by the pulp chemistry, the metal speciation, the metal distribution in the particle-size fractions, and the separation selectivity indices of Zn/Ca and Zn/Fe. The investigations showed that a great proportion of metal-containing particles were recovered in the froth layer by entrainment mechanism rather than by true flotation process. The non-selective entrainment mechanism of the fine particles ( 5 min) and when a high collector dose is used. The intermediate particle-size fraction (20-125 μm) showed the best flotation selectivity.

  13. Radioactive contamination in metal recycling industry - an environmental issue

    International Nuclear Information System (INIS)

    Agarwal, S.P.

    2012-01-01

    Metal recycling has become an important industrial activity worldwide; it is seen as being socially and environmentally beneficial because it conserves natural ore resources and saves energy. However, there have been several accidents over the past decades involving orphan radioactive sources or other radioactive material that were inadvertently collected as metal scrap that was destined for recycling. The consequences of these accidents have been serious with regard to the protection of people and the environment from the harmful effects of ionizing radiation as well as from an economic point of view. India produces and exports steel products to various countries. In the recent years there were rejection and return of steel products as they were found to be contaminated with trace quantities of radioactive materials. During investigation of incidents of radioactive contamination in steel products exported from India, it was observed that steel products are contaminated with low level radioactivity. Though radioactivity level in steel products is found to be too low to pose any significant hazards to the handling personnel or to the users or the public at large, its presence is undesirable and need to be probed as to how it has entered in the steel products. Atomic Energy Regulatory Board (AERB) has investigated the incidents of such nature in the recent past and it is gathered that the steel products are made out of steel produced in a foundry where metal scrap containing radioactive material has been used. In this talk, incidents of radioactive contamination, its roots cause, and its radiological impact on person, property and environment, lessons learnt, remedial measures and international concerns will be discussed

  14. Electrokinetic In Situ Treatment of Metal-Contaminated Soil

    Science.gov (United States)

    Quinn, Jacqueline; Clausen, Christian A., III; Geiger, Cherie; Reinhart, Debra

    2004-01-01

    An electrokinetic technique has been developed as a means of in situ remediation of soils, sludges, and sediments that are contaminated with heavy metals. Examples of common metal contaminants that can be removed by this technique include cadmium, chromium, zinc, lead, mercury, and radionuclides. Some organic contaminants can also be removed by this technique. In the electrokinetic technique, a low-intensity direct current is applied between electrodes that have been implanted in the ground on each side of a contaminated soil mass. The electric current causes electro-osmosis and migration of ions, thereby moving aqueous-phase subsurface contaminants from one electrode to the other. The half reaction at the anode yields H+, thereby generating an acid front that travels from the anode toward the cathode. As this acid front passes through a given location, the local increase in acidity increases the solubility of cations that were previously adsorbed on soil particles. Ions are transported towards one electrode or the other which one depending on their respective electric charges. Upon arrival at the electrodes, the ionic contaminants can be allowed to become deposited on the electrodes or can be extracted to a recovery system. Surfactants and other reagents can be introduced at the electrodes to enhance rates of removal of contaminants. Placements of electrodes and concentrations and rates of pumping of reagents can be adjusted to maximize efficiency. The basic concept of electrokinetic treatment of soil is not new. What is new here are some of the details of application and the utilization of this technique as an alternative to other techniques (e.g., flushing or bioremediation) that are not suitable for treating soils of low hydraulic conductivity. Another novel aspect is the use of this technique as a less expensive alternative to excavation: The cost advantage over excavation is especially large in settings in which contaminated soil lies near and/or under

  15. Prevalence of antibacterial resistant bacterial contaminants from mobile phones of hospital inpatients.

    Science.gov (United States)

    Vinod Kumar, B; Hobani, Yahya Hasan; Abdulhaq, Ahmed; Jerah, Ahmed Ali; Hakami, Othman M; Eltigani, Magdeldin; Bidwai, Anil K

    2014-01-01

    Mobile phones contaminated with bacteria may act as fomites. Antibiotic resistant bacterial contamination of mobile phones of inpatients was studied. One hundred and six samples were collected from mobile phones of patients admitted in various hospitals in Jazan province of Saudi Arabia. Eighty-nine (83.9%) out of 106 mobile phones were found to be contaminated with bacteria. Fifty-two (49.0%) coagulase-negative Staphylococcus, 12 (11.3%) Staphylococcus aureus, 7 (6.6%) Enterobacter cloacae, 3 (2.83%) Pseudomonas stutzeri, 3 (2.83%) Sphingomonas paucimobilis, 2 (1.8%) Enterococcus faecalis and 10 (9.4%) aerobic spore bearers were isolated. All the isolated bacteria were found to be resistant to various antibiotics. Hence, regular disinfection of mobile phones of hospital inpatients is advised.

  16. Heavy metal contamination in an urban stream fed by contaminated air-conditioning and stormwater discharges.

    Science.gov (United States)

    O'Sullivan, Aisling; Wicke, Daniel; Cochrane, Tom

    2012-03-01

    Urban waterways are impacted by diffuse stormwater runoff, yet other discharges can unintentionally contaminate them. The Okeover stream in Christchurch, New Zealand, receives air-conditioning discharge, while its ephemeral reach relies on untreated stormwater flow. Despite rehabilitation efforts, the ecosystem is still highly disturbed. It was assumed that stormwater was the sole contamination source to the stream although water quality data were sparse. We therefore investigated its water and sediment quality and compared the data with appropriate ecotoxicological thresholds from all water sources. Concentrations of metals (Zn, Cu and Pb) in stream baseflow, stormwater runoff, air-conditioning discharge and stream-bed sediments were quantified along with flow regimes to ascertain annual contaminant loads. Metals were analysed by ICP-MS following accredited techniques. Zn, Cu and Pb concentrations from stormflow exceeded relevant guidelines for the protection of 90% of aquatic species by 18-, 9- and 5-fold, respectively, suggesting substantial ecotoxicity potential. Sporadic copper (Cu) inputs from roof runoff exceeded these levels up to 3,200-fold at >4,000 μg L⁻¹ while Cu in baseflow from air-conditioning inputs exceeded them 5.4-fold. There was an 11-fold greater annual Cu load to the stream from air-conditioning discharge compared to stormwater runoff. Most Zn and Cu were dissolved species possibly enhancing metal bioavailability. Elevated metal concentrations were also found throughout the stream sediments. Environmental investigations revealed unsuspected contamination from air-conditioning discharge that contributed greater Cu annual loads to an urban stream compared to stormwater inputs. This discovery helped reassess treatment strategies for regaining ecological integrity in the ecosystem.

  17. Effect of multiple metal resistant bacteria from contaminated lake sediments on metal accumulation and plant growth

    International Nuclear Information System (INIS)

    Li, Kefeng; Ramakrishna, Wusirika

    2011-01-01

    Naturally occurring bacteria play an important role in bioremediation of heavy metal pollutants in soil and wastewater. This study identified high levels of resistance to zinc, cesium, lead, arsenate and mercury in eight copper resistant Pseudomonas strains previously isolated from Torch Lake sediment. These strains showed variable susceptibility to different antibiotics. Furthermore, these metal resistant strains were capable of bioaccumulation of multiple metals and solubilization of copper. Bacterial strains TLC 3-3.5-1 and TLC 6-6.5-1 showed high bioaccumulation ability of Zn (up to 15.9 mg/g dry cell) and Pb (80.7 mg/g dry cell), respectively. All the strains produced plant growth promoting indole-3-acetic acid (IAA), iron chelating siderophore and solubilized mineral phosphate and metals. The effect of bacterial inoculation on plant growth and copper uptake by maize (Zea mays) and sunflower (Helianthus annuus) was investigated using one of the isolates (Pseudomonas sp. TLC 6-6.5-4) with higher IAA production and phosphate and metal soubilization, which resulted in a significant increase in copper accumulation in maize and sunflower, and an increase in the total biomass of maize. The multiple metal-resistant bacterial isolates characterized in our study have potential applications for remediation of metal contaminated soils in combination with plants and metal contaminated water.

  18. Effect of multiple metal resistant bacteria from contaminated lake sediments on metal accumulation and plant growth

    Energy Technology Data Exchange (ETDEWEB)

    Li, Kefeng [Department of Biological Sciences, Michigan Technological University, 1400 Townsend Drive, Houghton, MI 49931 (United States); Ramakrishna, Wusirika, E-mail: wusirika@mtu.edu [Department of Biological Sciences, Michigan Technological University, 1400 Townsend Drive, Houghton, MI 49931 (United States)

    2011-05-15

    Naturally occurring bacteria play an important role in bioremediation of heavy metal pollutants in soil and wastewater. This study identified high levels of resistance to zinc, cesium, lead, arsenate and mercury in eight copper resistant Pseudomonas strains previously isolated from Torch Lake sediment. These strains showed variable susceptibility to different antibiotics. Furthermore, these metal resistant strains were capable of bioaccumulation of multiple metals and solubilization of copper. Bacterial strains TLC 3-3.5-1 and TLC 6-6.5-1 showed high bioaccumulation ability of Zn (up to 15.9 mg/g dry cell) and Pb (80.7 mg/g dry cell), respectively. All the strains produced plant growth promoting indole-3-acetic acid (IAA), iron chelating siderophore and solubilized mineral phosphate and metals. The effect of bacterial inoculation on plant growth and copper uptake by maize (Zea mays) and sunflower (Helianthus annuus) was investigated using one of the isolates (Pseudomonas sp. TLC 6-6.5-4) with higher IAA production and phosphate and metal soubilization, which resulted in a significant increase in copper accumulation in maize and sunflower, and an increase in the total biomass of maize. The multiple metal-resistant bacterial isolates characterized in our study have potential applications for remediation of metal contaminated soils in combination with plants and metal contaminated water.

  19. Impact of Saw Dust Application on the Distribution of Potentially Toxic Metals in Contaminated Soil.

    Science.gov (United States)

    Awokunmi, Emmmanuel E

    2017-12-01

    The need to develop an approach for the reclamation of contaminated site using locally available agricultural waste has been considered. The present study investigated the application of sawdust as an effective amendment in the immobilization of potentially toxic metals (PTMs) by conducting a greenhouse experiment on soil collected from an automobile dumpsite. The amended and non-amended soil samples were analyzed for their physicochemical parameters and sequential extraction of PTMs. The results revealed that application of amendment had positive impact on the physicochemical parameters as organic matter content and cation exchange capacity increased from 12.1% to 12.8% and 16.4 to 16.8 meq/100 g respectively. However, the mobility and bioavalability of these metals was reduced as they were found to be distributed mostly in the non-exchangeable phase of soil. Therefore, application of sawdust successfully immobilized PTMs and could be applied for future studies in agricultural soil reclamation.

  20. Remediation of Cd-contaminated soil around metal sulfide mines

    Science.gov (United States)

    Lu, Xinzhe; Hu, Xuefeng; Kang, Zhanjun; Luo, Fan

    2017-04-01

    The mines of metal sulfides are widely distributed in the southwestern part of Zhejiang Province, Southeast China. The activities of mining, however, often lead to the severe pollution of heavy metals in soils, especially Cd contamination. According to our field investigations, the spatial distribution of Cd-contaminated soils is highly consistent with the presence of metal sulfide mines in the areas, further proving that the mining activities are responsible for Cd accumulation in the soils. To study the remediation of Cd-contaminated soils, a paddy field nearby large sulfide mines, with soil pH 6 and Cd more than 1.56 mg kg-1, five times higher than the national recommended threshold, was selected. Plastic boards were deeply inserted into soil to separate the field and make experimental plots, with each plot being 4 m×4 m. Six treatments, TK01˜TK06, were designed to study the effects of different experimental materials on remediating Cd-contaminated soils. The treatment of TK01 was the addition of 100 kg zeolites to the plot; TK02, 100 kg apatites; TK03, 100 kg humid manure; TK04, 50 kg zeolites + 50 kg apatites; TK05, 50 kg zeolites + 50 kg humid manure; TK06 was blank control (CK). One month after the treatments, soil samples at the plots were collected to study the possible change of chemical forms of Cd in the soils. The results indicated that these treatments reduced the content of available Cd in the soils effectively, by a decreasing sequence of TK04 (33%) > TK02 (25%) > TK01 (23%) > TK05 (22%) > TK03 (15%), on the basis of CK. Correspondingly, the treatments also reduced the content of Cd in rice grains significantly, by a similar decreasing sequence of TK04 (83%) > TK02 (77%) > TK05 (63%) > TK01 (47%) > TK03 (27%). The content of Cd in the rice grains was 0.071 mg kg-1, 0.094 mg kg-1, 0.159 mg kg-1, 0.22 mg kg-1 and 0.306 mg kg-1, respectively, compared with CK, 0.418 mg kg-1. This experiment suggested that the reduction of available Cd in the soils is

  1. Potential and real ecological threat of heavy metals in contaminated soils

    Science.gov (United States)

    Motuzova, Galina; Barsova, Natalia; Makarichev, Ivan; Karpova, Elena

    2013-04-01

    organisms. Within the last 20-40 years a bulk of information has been accumulating to study the impact of technogenic sources on the HM content in soils and the ratio between their compounds. They serve as evidence that in the contaminated soils the total content of HM is several orders (2-3) higher than that in soils of natural landscapes. Based upon a comprehensive analysis of data obtained in field and laboratory it is possible to speak about following differences in soils of natural and technogenic landscapes. (1) The total content of HM in contaminated soils reveals weak connection with their content in soil-forming rocks being depended on technological and landscape-geochemical conditions. (2) A share of mobile forms of HM from their total content increases in comparison to that in natural soils, what is associated with soil contamination and even toxicity, because they can be easily taken up by plants and other living organisms. (3) The surplus of HM in soils leads to degradation of the most important properties so vital for soil fertility (acid base saturation, ion exchange capacity, the humus status, absorbing capacity and others). The enhanced knowledge of soil chemical properties which are subject to contamination by HM, regularities in sorption of heavy metals bond to soil components, the composition of compounds formed by soil with heavy metals allows forecasting the real ecological threat of landscape contamination with HM. The indices of the foregoing soil chemical properties serve as a basis for application of current technologies for soil remediation from HM. Acknowledgments. This work was supported by the Russian Found of Basic Researches (projects no. 06-05-48894, 09-05-00575, 11-05-90351)

  2. The filter feeder Dreissena polymorpha affects nutrient, silicon, and metal(loid) mobilization from freshwater sediments.

    Science.gov (United States)

    Schaller, Jörg; Planer-Friedrich, Britta

    2017-05-01

    Organic sediments in aquatic ecosystems are well known sinks for nutrients, silicon, and metal(loid)s. Organic matter-consuming organisms like invertebrate shredders, grazers, and bioturbators significantly affect element fixation or remobilization by changing redox conditions or binding properties of organic sediments. Little is known about the effect of filter feeders, like the zebra mussel Dreissena polymorpha, an invasive organism in North American and European freshwater ecosystems. A laboratory batch experiment exposing D. polymorpha (∼1200 organisms per m 2 ) to organic sediment from a site contaminated with arsenic, copper, lead, and uranium revealed a significant uptake and accumulation of arsenic, copper, iron, and especially uranium both into the soft body tissues and the seashell. This is in line with previous observations of metal(loid) accumulation from biomonitoring studies. Regarding its environmental impact, D. polymorpha significantly contributed to mobilization of silicon, iron, phosphorus, arsenic, and copper and to immobilization of uranium (p < 0.001), probably driven by redox conditions, microbial activity within the gut system, or active control of element homeostasis. No net mobilization or immobilization was observed for zinc and lead, because of their low mobility at the prevailing pH of 7.5-8.5. The present results suggest that D. polymorpha can both ameliorate (nutrient mobilization, immobilization of toxicants mobile under oxic conditions) or aggravate negative effects (mobilization of toxicants mobile under reducing conditions) in ecosystems. Relating the results of the present study to observed population densities in natural freshwater ecosystems suggests a significant influence of D. polymorpha on element cycling and needs to be considered in future studies. Copyright © 2017 Elsevier Ltd. All rights reserved.

  3. Feasibility of biochar manufactured from organic wastes on the stabilization of heavy metals in a metal smelter contaminated soil.

    Science.gov (United States)

    Abdelhafez, Ahmed A; Li, Jianhua; Abbas, Mohamed H H

    2014-12-01

    The main objectives of the current study were to evaluate the potential effects of biochar derived from sugar cane bagasse (SC-BC) and orange peel (OP-BC) on improving the physicochemical properties of a metal smelter contaminated soil, and determining its potentiality for stabilizing Pb and As in soil. To achieve these goals, biochar was produced in a small-scale biochar producing plant, and an incubation experiment was conducted using a silt loam metal-contaminated soil treated with different application rates of biochar (0-10% w/w). The obtained results showed that, the addition of SC-BC and OP-BC increased significantly the soil aggregate stability, water-holding capacity, cation exchange capacity, organic matter and N-status in soil. SC-BC considerably decreased the solubility of Pb to values lower than the toxic regulatory level of the toxicity characteristics leaching procedure extraction (5 mg L(-1)). The rise in soil pH caused by biochar application, and the increase of soil organic matter transformed the labile Pb into less available fractions i.e. "Fe-Mn oxides" and "organic" bound fractions. On the other hand, As was desorbed from Fe-Mn oxides, which resulted in greater mobility of As in the treated soil. We concluded that SC-BC and OP-BC could be used successfully for remediating soils highly contaminated with Pb. However, considerable attention should be paid when using it in soil contaminated with As. Copyright © 2014 Elsevier Ltd. All rights reserved.

  4. Use of composts in the remediation of heavy metal contaminated soil.

    Science.gov (United States)

    Farrell, Mark; Jones, Davey L

    2010-03-15

    High levels of heavy metals in soil can ultimately lead to pollution of drinking water and contamination of food. Consequently, sustainable remediation strategies for treating soil are required. The potential ameliorative effect of several composts derived from source-separated and mixed municipal wastes were evaluated in a highly acidic heavily contaminated soil (As, Cu, Pb, Zn) in the presence and absence of lime. Overall, PTE (potentially toxic element) amelioration was enhanced by compost whilst lime had little effect and even exacerbated PTE mobilization (e.g. As). All composts reduced soil solution PTE levels and raised soil pH and nutrient levels and are well suited to revegetation of contaminated sites. However, care must be taken to ensure correct pH management (pH 5-6) to optimize plant growth whilst minimizing PTE solubilization, particularly at high pH. In addition, 'metal excluder' species should be sown to minimize PTE entry into the food chain. (c) 2009 Elsevier B.V. All rights reserved.

  5. Studies on heavy metal contamination in Godavari river basin

    Science.gov (United States)

    Hussain, Jakir; Husain, Ikbal; Arif, Mohammed; Gupta, Nidhi

    2017-12-01

    Surface water samples from Godavari river basin was analyzed quantitatively for the concentration of eight heavy metals such as arsenic, cadmium, chromium, copper, iron, lead, nickel and zinc using atomic absorption spectrophotometer. The analyzed data revealed that iron and zinc metals were found to be the most abundant metals in the river Godavari and its tributaries. Iron (Fe) recorded the highest, while cadmium (Cd) had the least concentration. Arsenic, cadmium, chromium, iron and zinc metals are within the acceptable limit of BIS (Bureau of Indian Standards (BIS) 1050 (2012) Specification for drinking water, pp 1-5). The analysis of Godavari river and its tributary's water samples reveals that the water is contaminated at selected points which are not suitable for drinking. Nickel and Copper concentration is above acceptable limit and other metal concentration is within the acceptable limit. Comprehensive study of the results reveals that out of 18 water quality stations monitored, water samples collected at 7 water quality stations are found to be within the permissible limit for all purposes. While Rajegaon, Tekra, Nandgaon, P. G. Bridge, Bhatpalli, Kumhari, Pauni, Hivra, Ashti, Bamini, and Jagda stations were beyond the desirable limit due to presence of copper and nickel metals. The contents of copper metal ions were higher at some water quality stations on Wunna river (Nandgaon); Wardha river (Hivra) and Wainganga river (Kumhari, Pauni, Ashti) during Feb. 2012, while nickel concentration during Feb. 2012, June 2012, March 2013 and Aug. 2013 at some water quality stations on rivers Bagh, Indravati, Pranhita, Wunna, Penganga, Peddavagu, Wainganga and Wardha. It can be concluded that rapid population growth and industrialization have brought about resource degradation and a decline in environmental quality.

  6. Differential Effects of Low-Molecular-Weight Organic Acids on the Mobilization of Soil-Borne Arsenic and Trace Metals.

    Science.gov (United States)

    Nworie, Obinna Elijah; Qin, Junhao; Lin, Chuxia

    2017-08-21

    A batch experiment was conducted to examine the effects of six low-molecular-weight organic acids on the mobilization of arsenic and trace metals from a range of contaminated soils. The results showed that the organic acids behaved differently when reacting with soil-borne As and trace metals. Oxalic acid and acetic acid had the strongest and weakest capacity to mobilize the investigated elements, respectively. The solubilisation of iron oxides by the organic acids appears to play a critical role in mobilizing other trace metals and As. Apart from acidification and complexation, reductive dissolution played a dominant role in the dissolution of iron oxides in the presence of oxalic acid, while acidification tended to be more important for dissolving iron oxides in the presence of other organic acids. The unique capacity of oxalic acid to solubilize iron oxides tended to affect the mobilization of other elements in different ways. For Cu, Mn, and Zn, acidification-driven mobilization was likely to be dominant while complexation might play a major role in Pb mobilization. The formation of soluble Fe and Pb oxalate complexes could effectively prevent arsenate or arsenite from combining with these metals to form solid phases of Fe or Pb arsenate or arsenite.

  7. Pathways of heavy metals contamination and associated human health risk in Ajay River basin, India.

    Science.gov (United States)

    Singh, Umesh Kumar; Kumar, Balwant

    2017-05-01

    The sources of heavy metals and their loads in the Ajay River were investigated based on the seasonal and spatial variations. To identify variation and pathways of heavy metals, seventy-six water samples were estimated for 2 years at nineteen sampling sites. The multifaceted data were applied to evaluate statistical relation between variables and arithmetic calculation of the indices. Fickling plot suggested that the acidic pollutants do not affect the water quality because all samples lie within the neutral pH range. Further, OC showed significant relation with Fe, Mn, Ni and Co. Compositional analysis identified weathering of rocks, mobility of soil and sediment, atmospheric deposition and numerous anthropogenic inputs as major sources of heavy metals. The mean values of heavy metal pollution index (HPI) and pollution index (PI) were found above the critical index and strong loadings respectively due to higher values of Cd, Pb and Fe. Similarly, assessment of human risk revealed that the high load of Cd, Pb and Fe in water body could harm the population. Majority of the samples showed high concentration of heavy metals as compared to regulatory standard and background values, which suggests that the water is highly contaminated through numerous geogenic and anthropogenic sources. Copyright © 2017 Elsevier Ltd. All rights reserved.

  8. Metal resistant plants and phytoremediation of environmental contamination

    Science.gov (United States)

    Meagher, Richard B.; Li, Yujing; Dhankher, Om P.

    2010-04-20

    The present disclosure provides a method of producing transgenic plants which are resistant to at least one metal ion by transforming the plant with a recombinant DNA comprising a nucleic acid encoding a bacterial arsenic reductase under the control of a plant expressible promoter, and a nucleic acid encoding a nucleotide sequence encoding a phytochelatin biosynthetic enzyme under the control of a plant expressible promoter. The invention also relates a method of phytoremediation of a contaminated site by growing in the site a transgenic plant expressing a nucleic acid encoding a bacterial arsenate reductase and a nucleic acid encoding a phytochelatin biosynthetic enzyme.

  9. Heavy Metals Contamination in Coastal Sediments of Karachi, Pakistan

    Science.gov (United States)

    Siddique, A.; Mumtaz, M.; Zaigham, N. A.; Mallick, K. A.; Saied, S.; Khwaja, H. A.

    2008-12-01

    Toxic compounds such as heavy metals exert chronic and lethal effects in animals, plants, and human health. With the rapid industrialization, urbanization, and economic development in Karachi, heavy metals are continuing to be introduced to estuarine and coastal environment through rivers, runoff and land-based point sources. Pollution in the Karachi coastal region (167 km long) is mainly attributed to Lyari and Malir Rivers flowing through the city of Karachi. Both rivers are served by various channels of domestic and industrial wastes carrying more than 300 million gallons per day untreated effluent of 6000 industries and ultimately drain into the beaches of Arabian Sea. Concentrations of selected heavy metals (Cd, Co, Cr, Cu, Fe, Mn, Ni, Pb, and Zn) in surface sediments from eighty-eight sites in Karachi coastal region were studied in order to understand metal contamination due to industrialization, urbanization, and economic development in Karachi. Sediment samples were collected in 2005 and 2006. We have found that heavy metal concentrations in surface sediments varied from 0.006 to 24.3 ug/g for Cd, 5.1 to 95 ug/g for Co, 2.9 to 571 ug/g for Cr, 6.9 to 272 ug/g for Cu, 0.55 to 6.5% for Fe, 1.2 to 318 ug/g for Mn, 7.5 to 75 ug/g for Ni, 6.3 to 121 ug/g for Pb, and 3.3 to 389 ug/g for Zn. Enrichment factors (EFs) were calculated to assess whether the concentrations observed represent background or contaminated levels. The highest levels of metals were found to be at the confluence of the Lyari and Malir River streams at the Arabian Sea, indicating the impact of the effluents of the highly urbanized and industrialized city of Karachi. Furthermore, this study assessed heavy metal toxicity risk with the application of Sediment Quality Guideline (SQG) indices (effect range low/effect range median values, ERL/ERM). Results indicated that the potential toxicity of marine environment can cause adverse biological effects to the biota directly and the human health

  10. Shear bond strength of metallic brackets: influence of saliva contamination

    Directory of Open Access Journals (Sweden)

    Luciana Borges Retamoso

    2009-06-01

    Full Text Available OBJECTIVE: To evaluate the influence of saliva contamination on shear bond strength and the bond failure pattern of 3 adhesive systems (Transbond XT, AdheSE and Xeno III on orthodontic metallic brackets bonded to human enamel. MATERIAL AND METHODS: Seventy-two permanent human molars were cut longitudinally in a mesiodistal direction, producing seventy-two specimens randomly divided into six groups. Each system was tested under 2 different enamel conditions: no contamination and contaminated with saliva. In T, A and X groups, the adhesive systems were applied to the enamel surface in accordance with manufacturer's instructions. In TS, AS and XS groups, saliva was applied to enamel surface followed by adhesive system application. The samples were stored in distilled water at 37ºC for 24 h, and then tested for shear bond strength in a universal testing machine (Emic, DL 2000 running at a crosshead speed of 1 mm/min. After bond failure, the enamel surfaces were observed under an optical microscope at 40x magnification. RESULTS: The control and contaminated groups showed no significant difference in shear bond strength for the same adhesive system. However, shear bond strength of T group (17.03±4.91 was significantly higher than that of AS (8.58±1.73 and XS (10.39±4.06 groups (p<0.05. Regarding the bond failure pattern, TS group had significantly higher scores of no adhesive remaining on the tooth in the bonding area than other groups considering the adhesive remnant index (ARI used to evaluate the amount of adhesive left on the enamel. CONCLUSIONS: Saliva contamination showed little influence on the 24-h shear bond strength of orthodontic brackets.

  11. Safety of Potato Consumption in Slovak Region Contaminated by Heavy Metals due to Previous Mining Activity

    Directory of Open Access Journals (Sweden)

    Janette Musilova

    2017-01-01

    Full Text Available Heavy metals are among the most serious environmental contaminants in mining districts. Soil, as one of the main components of the environment, is the place of heavy metal entry into plants and consequently into the food chain, too. Potatoes grown in the region of Middle Spis (Slovakia may be a source of increased content of heavy metals and pose a health risk to the consumer. The contents of heavy metals (Cd, Pb, and Ni in potato and soil samples were determined using the AAS method and compared with limit values set by the Slovak Republic and the European Union. The content of heavy metals was determined in 12 potato cultivars with different length of vegetation period (mid-early, very early, and early, resp., which were grown in three localities with a highly disturbed environment. Total contents and mobile forms of heavy metals as well as physical and chemical properties were determined in soil samples which were collected from the same sampling sites. Only Pb content in potato tubers was higher than the hygienic limit value (0.1 mg kg−1 FM in 15 sampling sites (interval was n.d. –0.2298 mg kg−1 FM. The contents of exchangeable forms (total content of heavy metals in soil were ranged between the intervals: Cd 0.004–0.055 (0.94–1 56, Pb 0.023–0.295 (17.00–26.80, and Ni 0.019–0.475 (30.80–71.00 mg kg−1. At current average consumption levels of potatoes, tolerable weekly intake (TWI or tolerable daily intake (TDI for observed heavy metals was not exceeded.

  12. Mobilization and attenuation of metals downstream from a base-metal mining site in the Matra Mountains, northeastern Hungary

    Science.gov (United States)

    Odor, L.; Wanty, R.B.; Horvath, I.; Fugedi, U.; ,

    1999-01-01

    Regional geochemical baseline values have been established for Hungary by the use of low-density stream-sediment surveys of flood-plain deposits of large drainage basins and of the fine fraction of stream sediments. The baseline values and anomaly thresholds thus produced helped to evaluate the importance of high toxic element concentrations found in soils in a valley downstream of a polymetallic vein-type base-metal mine. Erosion of the mine dumps and flotation dump, losses of metals during filtering, storage and transportation, human neglects, and operational breakdowns, have all contributed to the contamination of a small catchment basin in a procession of releases of solid waste. The sulfide-rich waste material weathers to a yellow color; this layer of 'yellow sand' blankets a narrow strip of the floodplain of Toka Creek in the valley near the town of Gyongyosoroszi. Contamination was spread out in the valley by floods. Metals present in the yellow sand include Pb, As, Cd, Cu, Zn, and Sb. Exposure of the local population to these metals may occur through inhalation of airborne particulates or by ingestion of these metals that are taken up by crops grown in the valley. To evaluate the areal extent and depth of the contamination, active stream sediment, flood-plain deposits, lake or reservoir sediments, soils, and surface water were sampled along the erosion pathways downstream of the mine and dumps. The flood-plain profile was sampled in detail to see the vertical distribution of elements and to relate the metal concentrations to the sedimentation and contamination histories of the flood plain. Downward migration of mobile Zn and Cd from the contaminated upper layers under supergene conditions is observed, while vertical migration of Pb, As, Hg and Sb appears to be insignificant. Soil profiles of 137Cs which originated from above-ground atomic bomb tests and the Chernobyl accident, provide good evidence that the upper 30-40 cm of the flood-plain sections, which

  13. Bioavailability and mobility of organic contaminants in soil: new three-step ecotoxicological evaluation.

    Science.gov (United States)

    Prokop, Zbyněk; Nečasová, Anežka; Klánová, Jana; Čupr, Pavel

    2016-03-01

    A novel approach was developed for rapid assessment of bioavailability and potential mobility of contaminants in soil. The response of the same test organism to the organic extract, water extract and solid phase of soil was recorded and compared. This approach was designed to give an initial estimate of the total organic toxicity (response to organic extractable fraction), as well as the mobile (response to water extract) and bioavailable fraction (response to solid phase) of soil samples. Eighteen soil samples with different levels of pollution and content of organic carbon were selected to validate the novel three-step ecotoxicological evaluation approach. All samples were chemically analysed for priority contaminants, including aromatic hydrocarbons (PAHs), polychlorinated biphenyls (PCBs), hexachlorocyclohexane (HCH) and dichlordiphenyltrichloroethane (DDT). The ecotoxicological evaluation involved determination of toxicity of the organic, mobile and bioavailable fractions of soil to the test organism, bacterium Bacillus cereus. We found a good correlation between the chemical analysis and the toxicity of organic extract. The low toxicity of water extracts indicated low water solubility, and thus, low potential mobility of toxic contaminants present in the soil samples. The toxicity of the bioavailable fraction was significantly greater than the toxicity of water-soluble (mobile) fraction of the contaminants as deduced from comparing untreated samples and water extracts. The bioavailability of the contaminants decreased with increasing concentrations of organic carbon in evaluated soil samples. In conclusion, the three-step ecotoxicological evaluation utilised in this study can give a quick insight into soil contamination in context with bioavailability and mobility of the contaminants present. This information can be useful for hazard identification and risk assessment of soil-associated contaminants. Graphical Abstract New three-step ecotoxicological

  14. Arsenic mobility and speciation in a contaminated urban soil are affected by different methods of green waste compost application

    Energy Technology Data Exchange (ETDEWEB)

    Hartley, William, E-mail: w.hartley@ljmu.ac.u [Liverpool John Moores University, Faculty of Science, Byrom Street, Liverpool L3 3AF (United Kingdom); Dickinson, Nicholas M.; Riby, Philip [Liverpool John Moores University, Faculty of Science, Byrom Street, Liverpool L3 3AF (United Kingdom); Leese, Elizabeth; Morton, Jackie [Health and Safety Laboratory, Harpur Hill, Buxton, Derbyshire SK17 9JN (United Kingdom); Lepp, Nicholas W., E-mail: nickandeileenlepp@hotmail.co [35 Victoria Road, Formby L37 7DH (United Kingdom)

    2010-12-15

    Application of green waste compost (GWC) to brownfield land is now common practice in soil restoration. However, previous studies have demonstrated both beneficial and detrimental effects on arsenic and metal mobility. In this paper, trace element behaviour was investigated following GWC application, either as surface mulch to, or mixed into soil from a previously described brownfield site in the U.K. Significant differences in arsenic mobility were observed between treatments. Mulching caused most disturbance, significantly increasing soil pore water As, together with Fe, P, Cr, Ni and dissolved organic carbon, the latter was a critical factor enhancing As mobilization. Arsenate was the main inorganic As species in soil pore water, increasing in concentration over time. An initial flush of potentially more toxic arsenite decreased 4 weeks after compost application. Biological processes appeared to play an important role in influencing As mobility. The results point to the necessity for careful management of As-contaminated soils. - A comparison of mulching and mixing of green waste compost to an urban soil results in differences in arsenic and metal leaching.

  15. Arsenic mobility and speciation in a contaminated urban soil are affected by different methods of green waste compost application

    International Nuclear Information System (INIS)

    Hartley, William; Dickinson, Nicholas M.; Riby, Philip; Leese, Elizabeth; Morton, Jackie; Lepp, Nicholas W.

    2010-01-01

    Application of green waste compost (GWC) to brownfield land is now common practice in soil restoration. However, previous studies have demonstrated both beneficial and detrimental effects on arsenic and metal mobility. In this paper, trace element behaviour was investigated following GWC application, either as surface mulch to, or mixed into soil from a previously described brownfield site in the U.K. Significant differences in arsenic mobility were observed between treatments. Mulching caused most disturbance, significantly increasing soil pore water As, together with Fe, P, Cr, Ni and dissolved organic carbon, the latter was a critical factor enhancing As mobilization. Arsenate was the main inorganic As species in soil pore water, increasing in concentration over time. An initial flush of potentially more toxic arsenite decreased 4 weeks after compost application. Biological processes appeared to play an important role in influencing As mobility. The results point to the necessity for careful management of As-contaminated soils. - A comparison of mulching and mixing of green waste compost to an urban soil results in differences in arsenic and metal leaching.

  16. Strippable gel for decontamination of contaminated metallic surfaces

    International Nuclear Information System (INIS)

    Banerjee, D.; Sandhya, U.; Khot, S.A.; Srinivas, C.; Wattal, P.K.

    2013-01-01

    Periodic decontamination of radioactive laboratories including fume hoods, glove boxes and all surfaces used for handling, processing and transporting radioactive materials is mandatory in all nuclear installations as this reduces spread of contamination and decreases total man rem exposure. Conventionally, chemical decontaminating agents or surfactant solutions are used for this purpose. However, this approach leads to generation of large volume of secondary radioactive waste. The use of strippable gel is an attractive alternative with low secondary waste generation particularly where removal of loose or weakly fixed contamination is necessary and also when the decontaminated material are to be reused, for e.g. decontamination of fume hoods, glove boxes, transport casks, spent fuel storage racks, control rod drive transport containers etc. Literature on gel formulations is scarce and mostly in the patent form. The sustained effort on gel formulation development has resulted in a basic gel formulation. The gel is a highly viscous water-based organic polymer, particularly suitable for application on vertical surfaces including difficult to reach metallic surfaces of complex geometry and not just limited to horizontal surfaces. The gel can be easily applied on contaminated surfaces by brushing or spraying. Curing of the gel is complete within 16-24 hours under ambient conditions and can then be removed by peeling as a dry sheet. While curing, the contaminants are trapped in gel either physically or chemically depending upon the nature of the contaminant. Salient features of cured gel include that it is water soluble and can be disposed off after immobilization in cement. Decontamination performance of the gel was initially evaluated by applying it on SS planchettes contaminated with known amount of radionuclides such as Cs(I), Co(II) and Ce(III). The measured decontamination factor was found to be in the range of 50-500, lowest for Ce(III) and highest for Co

  17. Mobility of potentially harmful metals in latosols impacted by the municipal solid waste deposit of Londrina, Brazil

    International Nuclear Information System (INIS)

    Souza Teixeira, Raquel; Cambier, Philippe; Davison Dias, Regina; Peccinini Pinese, Jose Paulo; Jaulin-Soubelet, Anne

    2010-01-01

    The contamination of soils by metals issuing from municipal solid waste (MSW) disposal in tropical environments has hardly been studied with regard to the particular problems associated with them, i.e., generally a high permeability of soils despite the abundance of clay, and the role of reactive Fe compounds. From a previous geotechnical and chemical survey, three latosol profiles differently affected by MSW leachates in the region of Londrina (Parana, Brazil) were selected. The aims were to evaluate the extent of their contamination, to better understand the fate of potentially harmful metals in tropical soils and rank the determining factors. Samples between 0.5 and 7 m depth were analyzed for their physical, mineralogical and chemical properties, and their micro-morphology was described by optical and transmission electron microscopy. Two steps of a sequential extraction procedure helped to assess the mobility of elements and to better discriminate between metals originating from pedogenesis and issued from MSW. These combined approaches showed that exposed soil profiles have been impacted at various depths, down to 7 m, through increased metal content, especially enhanced mobility of Zn, Co, Mn, Cu and Fe, and through increased salinity and organic matter. The mobility of potentially harmful metals should decrease with pH, which significantly increased in some impacted horizons, but other factors can reverse this trend.

  18. Study of Wastewaters Contaminated with Heavy Metals in Bioethanol Production

    Science.gov (United States)

    Bartošová, Alica; Blinová, Lenka

    2017-06-01

    Bioethanol as a substitute for traditional sources of energy, especially oil transport, is currently one of the most researched alternative motor fuels. Normally, bioethanol is produced from agricultural crops such as sugar cane or corn. However, this is counter-productive, because agriculture is primarily serving to ensure enough food for the people. It is therefore necessary to look for new production of appropriate non-food crops or find an added value to this process. Utilisation of contaminated water from metal industry could be one of them. Based on the hypothesis of reduction of some toxic metals with higher oxidation number is opening the possibility of using this wastewater in alcohol fermentation of any kind of biomass. In this study, hexavalent chromium Cr(VI) was used as a model contaminant in the process of aerobic fermentation of corn to bioethanol. To determine the reduction potential of glucose to Cr(VI), and to quantitatively determinate the glucose content after saccharification, UV/VIS spectrophotometry was used. As a method of qualitative determination of fermentation product, gas chromatography with mass detection was used. Infrared spectrometry was used for qualitative analyses of produced ethanol. Based on the established results shown in this paper, we can conclude that the presence of hexavalent chromium in the fermentation process does not have a significant negative impact, while offering the opportunity of using the industrial wastewaters for the production of bioethanol fuel.

  19. Leaching of metals from soil contaminated by mining activities.

    Science.gov (United States)

    Yukselen, M A; Alpaslan, B

    2001-10-12

    Stabilization/solidification (s/s) is one of the most effective methods of dealing with heavy metal contaminated sites. The ability of lime and cement stabilization to immobilize Pb, Cu and Fe contained in a contaminated soil originating from an old mining and smelting area located along the Mediterranean Sea shore in northern Cyprus was investigated. The stabilization was evaluated by applying leaching tests. A series of tests were conducted to optimize the additive soil ratio for the best immobilization process. Additive/soil=1/15 (m/m) ratio was found to be the optimum for both lime and cement. Application of the US EPA toxicity characteristic leaching procedure (TCLP) on the soil samples treated with lime at additive/soil=1/15 (m/m) mixing ratios showed that Cu and Fe solubility was reduced at 94 and 90%, respectively. The results of cement treatment using the same ratio, reduced the solubility 48 and 71% for Cu and Fe, respectively. The Pb solubility was found to be below the regulatory limit of 5mg/l so no additive treatment was needed. The optimum additive/soil amount (1/15) was selected for more detailed column studies, that were carried out in the acidic pH range. According to the results of column leaching tests, it was found that, the degree of heavy metal leaching is highly dependent on pH.

  20. Study of Wastewaters Contaminated with Heavy Metals in Bioethanol Production

    Directory of Open Access Journals (Sweden)

    Bartošová Alica

    2017-06-01

    Full Text Available Bioethanol as a substitute for traditional sources of energy, especially oil transport, is currently one of the most researched alternative motor fuels. Normally, bioethanol is produced from agricultural crops such as sugar cane or corn. However, this is counter-productive, because agriculture is primarily serving to ensure enough food for the people. It is therefore necessary to look for new production of appropriate non-food crops or find an added value to this process. Utilisation of contaminated water from metal industry could be one of them. Based on the hypothesis of reduction of some toxic metals with higher oxidation number is opening the possibility of using this wastewater in alcohol fermentation of any kind of biomass. In this study, hexavalent chromium Cr(VI was used as a model contaminant in the process of aerobic fermentation of corn to bioethanol. To determine the reduction potential of glucose to Cr(VI, and to quantitatively determinate the glucose content after saccharification, UV/VIS spectrophotometry was used. As a method of qualitative determination of fermentation product, gas chromatography with mass detection was used. Infrared spectrometry was used for qualitative analyses of produced ethanol. Based on the established results shown in this paper, we can conclude that the presence of hexavalent chromium in the fermentation process does not have a significant negative impact, while offering the opportunity of using the industrial wastewaters for the production of bioethanol fuel.

  1. Remediation of soil contaminated with the heavy metal (Cd2+)

    International Nuclear Information System (INIS)

    Lin, C.-C.; Lin, H.-L.

    2005-01-01

    Soil contamination by heavy metals is increasing. The biosorption process for removal of the heavy metal Cd 2+ from contaminated soil is chosen for this study due to its economy, commercial applications, and because it acts without destroying soil structure. The study is divided into four parts (1) soil leaching: the relationships between the soil leaching effect and agitation rates, solvent concentrations, ratios of soil to solvent, leaching time and pH were studied to identify their optimum conditions; (2) adsorption Cd 2+ tests of immobilized Saccharomycetes pombe beads: different weight percentages of chitosan and polyvinyl alcohol (PVAL) were added to alginate (10 wt.%) and then blended or cross-linked by epichlorohydrin (ECH) to increase their mechanical strength. Next, before blending or cross-linking, different weight percentages of S. pombe 806 or S. pombe ATCC 2476 were added to increase Cd 2+ adsorption. Thus, the optimum beads (blending or cross-linking, the percentages of chitosan, PVAL and S. pombe 806 or S. pombe ATCC 2476) and the optimum adsorption conditions (agitation rate, equilibrium adsorption time, and pH in the aqueous solution) were ascertained; (3) regeneration tests of the optimum beads: the optimum beads adsorbing Cd 2+ were regenerated by various concentrations of aqueous HCl solutions. The results indicate that the reuse of immobilized pombe beads was feasible; and (4) adsorption model/kinetic model/thermodynamic property: the equilibrium adsorption, kinetics, change in Gibbs free energy of adsorption of Cd 2+ on optimum beads were also investigated

  2. Assessment of radionuclide and metal contamination in a thorium rich area in Norway.

    Science.gov (United States)

    Popic, Jelena Mrdakovic; Salbu, Brit; Strand, Terje; Skipperud, Lindis

    2011-06-01

    The Fen Central Complex in southern Norway, a geologically well investigated area of magmatic carbonatite rocks, is assumed to be among the world largest natural reservoirs of thorium ((232)Th). These rocks, also rich in iron (Fe), niobium (Nb), uranium ((238)U) and rare earth elements (REE), were mined in several past centuries. Waste locations, giving rise to enhanced levels of both radionuclides and metals, are now situated in the area. Estimation of radionuclide and metal contamination of the environment and radiological risk assessment were done in this study. The average outdoor gamma dose rate measured in Fen, 2.71 μGy h(-1), was significantly higher than the world average dose rate of 0.059 μGy h(-1). The annual exposure dose from terrestrial gamma radiation, related to outdoor occupancy, was in the range 0.18-9.82 mSv. The total activity concentrations of (232)Th and (238)U in soil ranged from 69 to 6581 and from 49 to 130 Bq kg(-1), respectively. Enhanced concentrations were also identified for metals, arsenic (As), lead (Pb), chromium (Cr) and zinc (Zn), in the vicinity of former mining sites. Both radionuclide and heavy metal concentrations suggested leaching, mobilization and distribution from rocks into the soil. Correlation analysis indicated different origins for (232)Th and (238)U, but same or similar for (232)Th and metals As, Cr, Zn, nickel (Ni) and cadmium (Cd). The results from in situ size fractionation of water demonstrated radionuclides predominately present as colloids and low molecular mass (LMM) species, being potentially mobile and available for uptake in aquatic organisms of Norsjø Lake. Transfer factors, calculated for different plant species, showed the highest radionuclide accumulation in mosses and lichens. Uptake in trees was, as expected, lower. Relationship analysis of (232)Th and (238)U concentrations in moss and soil samples showed a significant positive linear correlation.

  3. Combined SEM/AVS and attenuation of concentration models for the assessment of bioavailability and mobility of metals in sediments of Sepetiba Bay (SE Brazil).

    Science.gov (United States)

    Ribeiro, Andreza Portella; Figueiredo, Ana Maria Graciano; dos Santos, José Osman; Dantas, Elizabeth; Cotrim, Marycel Elena Barboza; Figueira, Rubens Cesar Lopes; Silva Filho, Emmanoel V; Wasserman, Julio Cesar

    2013-03-15

    This study proposes a new methodology to study contamination, bioavailability and mobility of metals (Cd, Cu, Ni, Pb, and Zn) using chemical and geostatistics approaches in marine sediments of Sepetiba Bay (SE Brazil). The chemical model of SEM (simultaneously extracted metals)/AVS (acid volatile sulfides) ratio uses a technique of cold acid extraction of metals to evaluate their bioavailability, and the geostatistical model of attenuation of concentrations estimates the mobility of metals. By coupling the two it was observed that Sepetiba Port, the urban area of Sepetiba and the riverine discharges may constitute potential sources of metals to Sepetiba Bay. The metals are concentrated in the NE area of the bay, where they tend to have their lowest mobility, as shown by the attenuation model, and are not bioavailable, as they tend to associate with sulfide and organic matter originated in the mangrove forests of nearby Guaratiba area. Copyright © 2013 Elsevier Ltd. All rights reserved.

  4. Phytoremediation Opportunities with Alimurgic Species in Metal-Contaminated Environments

    Directory of Open Access Journals (Sweden)

    Marianna Bandiera

    2016-04-01

    Full Text Available Alimurgic species are edible wild plants growing spontaneously as invasive weeds in natural grassland and farmed fields. Growing interest in biodiversity conservation projects suggests deeper study of the multifunctional roles they can play in metal uptake for phytoremediation and their food safety when cultivated in polluted land. In this study, the responses of the tap-rooted perennial species Cichorium intybus L., Sonchus oleracerus L., Taraxacum officinale Web., Tragopogon porrifolius L. and Rumex acetosa L. were studied in artificially-highly Cd-Co-Cu-Pb-Zn-contaminated soil in a pot-scale trial, and those of T. officinale and R. acetosa in critical open environments (i.e., landfill, ditch sediments, and sides of highly-trafficked roads. Germination was not inhibited, and all species showed appreciable growth, despite considerable increases in tissue metal rates. Substantial growth impairments were observed in C. intybus, T. officinale and T. porrifolius; R. acetosa and S. oleracerus were only marginally affected. Zn was generally well translocated and reached a high leaf concentration, especially in T. officinale (~600 mg·kg−1·dry weight, DW, a result which can be exploited for phytoremediation purposes. The elevated Cd translocation also suggested applications to phytoextraction, particularly with C. intybus, in which leaf Cd reached ~16 mg·kg−1·DW. The generally high root retention of Pb and Cu may allow their phytostabilisation in the medium-term in no-tillage systems, together with significant reductions in metal leaching compared with bare soil. In open systems, critical soil Pb and Zn were associated with heavily trafficked roadsides, although this was only seldom reflected in shoot metal accumulation. It is concluded that a community of alimurgic species can serve to establish an efficient, long-lasting vegetation cover applied for phytoremediation and reduction of soil metal movements in degraded environments. However

  5. Microbial contamination of mobile phones in a health care setting in Alexandria, Egypt.

    Science.gov (United States)

    Selim, Heba Sayed; Abaza, Amani Farouk

    2015-01-01

    This study aimed at investigating the microbial contamination of mobile phones in a hospital setting. Swab samples were collected from 40 mobile phones of patients and health care workers at the Alexandria University Students' Hospital. They were tested for their bacterial contamination at the microbiology laboratory of the High Institute of Public Health. Quantification of bacteria was performed using both surface spread and pour plate methods. Isolated bacterial agents were identified using standard microbiological methods. Methicillin-resistant Staphylococcus aureus was identified by disk diffusion method described by Bauer and Kirby. Isolated Gram-negative bacilli were tested for being extended spectrum beta lactamase producers using the double disk diffusion method according to the Clinical and Laboratory Standards Institute recommendations. All of the tested mobile phones (100%) were contaminated with either single or mixed bacterial agents. The most prevalent bacterial contaminants were methicillin-resistant S. aureus and coagulase-negative staphylococci representing 53% and 50%, respectively. The mean bacterial count was 357 CFU/ml, while the median was 13 CFU/ml using the pour plate method. The corresponding figures were 2,192 and 1,720 organisms/phone using the surface spread method. Mobile phones usage in hospital settings poses a risk of transmission of a variety of bacterial agents including multidrug-resistant pathogens as methicillin-resistant S. aureus. The surface spread method is an easy and useful tool for detection and estimation of bacterial contamination of mobile phones.

  6. Human impact on fluvial sediments: distinguishing regional and local sources of heavy metals contamination

    Science.gov (United States)

    Novakova, T.; Matys Grygar, T.; Bábek, O.; Faměra, M.; Mihaljevič, M.; Strnad, L.

    2012-04-01

    , or whether more or less qualitative information on local point sources is searched for. The profiles from regulated river reaches are highly prone to local sources and due to the stratigraphic chaos and post-depositional mobilization of heavy metals, which we revealed using 206Pb/207Pb ratio; such profiles were further excluded from an evaluation of regional contamination. Overbank fines in the study area (middle and lower reach of the Morava) are only weakly but whole-regionally contaminated (maximal EFs are 1.3-2 for Pb and Zn, 1.2-1.7 for Cu, 1.1-1.2 for Cr and 2-4 for magnetic susceptibility). Regulated river channel sediments, which reflect the actual contamination from local sources, produced apparent EFs ranging from 0.3 to 15 for heavy metals and 0.4-21 for MS, with the highest values obtained downstream from the most relevant point source in the study area, shoe-making and related chemical industry in Zlín and Otrokovice.

  7. Mobility of Source Zone Heavy Metals and Radionuclides: The Mixed Roles of Fermentative Activity on Fate and Transport of U and Cr. Final Report

    Energy Technology Data Exchange (ETDEWEB)

    Gerlach, Robin [Montana State Univ., Bozeman, MT (United States); Peyton, Brent M. [Montana State Univ., Bozeman, MT (United States); Apel, William A. [Idaho National Lab., Idaho Falls, ID (United States)

    2014-01-29

    Various U. S. Department of Energy (DOE) low and medium-level radioactive waste sites contain mixtures of heavy metals, radionuclides and assorted organic materials. In addition, there are numerous sites around the world that are contaminated with a mixture of organic and inorganic contaminants. In most sites, over time, water infiltrates the wastes, and releases metals, radionuclides and other contaminants causing transport into the surrounding environment. We investigated the role of fermentative microorganisms in such sites that may control metal, radionuclide and organics migration from source zones. The project was initiated based on the following overarching hypothesis: Metals, radionuclides and other contaminants can be mobilized by infiltration of water into waste storage sites. Microbial communities of lignocellulose degrading and fermenting microorganisms present in the subsurface of contaminated DOE sites can significantly impact migration by directly reducing and immobilizing metals and radionuclides while degrading complex organic matter to low molecular weight organic compounds. These low molecular weight organic acids and alcohols can increase metal and radionuclide mobility by chelation (i.e., certain organic acids) or decrease mobility by stimulating respiratory metal reducing microorganisms. We demonstrated that fermentative organisms capable of affecting the fate of Cr6+, U6+ and trinitrotoluene can be isolated from organic-rich low level waste sites as well as from less organic rich subsurface environments. The mechanisms, pathways and extent of contaminant transformation depend on a variety of factors related to the type of organisms present, the aqueous chemistry as well as the geochemistry and mineralogy. This work provides observations and quantitative data across multiple scales that identify and predict the coupled effects of fermentative carbon and electron flow on the transport of radionuclides, heavy metals and organic contaminants in

  8. Mobility of Source Zone Heavy Metals and Radionuclides: The Mixed Roles of Fermentative Activity on Fate and Transport of U and Cr. Final Report

    International Nuclear Information System (INIS)

    Gerlach, Robin; Peyton, Brent M.; Apel, William A.

    2014-01-01

    Various U. S. Department of Energy (DOE) low and medium-level radioactive waste sites contain mixtures of heavy metals, radionuclides and assorted organic materials. In addition, there are numerous sites around the world that are contaminated with a mixture of organic and inorganic contaminants. In most sites, over time, water infiltrates the wastes, and releases metals, radionuclides and other contaminants causing transport into the surrounding environment. We investigated the role of fermentative microorganisms in such sites that may control metal, radionuclide and organics migration from source zones. The project was initiated based on the following overarching hypothesis: Metals, radionuclides and other contaminants can be mobilized by infiltration of water into waste storage sites. Microbial communities of lignocellulose degrading and fermenting microorganisms present in the subsurface of contaminated DOE sites can significantly impact migration by directly reducing and immobilizing metals and radionuclides while degrading complex organic matter to low molecular weight organic compounds. These low molecular weight organic acids and alcohols can increase metal and radionuclide mobility by chelation (i.e., certain organic acids) or decrease mobility by stimulating respiratory metal reducing microorganisms. We demonstrated that fermentative organisms capable of affecting the fate of Cr6+, U6+ and trinitrotoluene can be isolated from organic-rich low level waste sites as well as from less organic rich subsurface environments. The mechanisms, pathways and extent of contaminant transformation depend on a variety of factors related to the type of organisms present, the aqueous chemistry as well as the geochemistry and mineralogy. This work provides observations and quantitative data across multiple scales that identify and predict the coupled effects of fermentative carbon and electron flow on the transport of radionuclides, heavy metals and organic contaminants in

  9. Basis of the detection, assessment and cleaning up of sites contaminated with heavy metals

    International Nuclear Information System (INIS)

    Calmano, W.; Foerstner, U.

    1993-01-01

    The cleaning up of sites contaminated with heavy metals is still in its infancy. Depending on the type and extent of the contamination, new methods of treatment must be developed and matched to each situation. A survey is given of the groundwater contamination of soil heavy metals; the binding, availability and mobilisation of heavy metals; geo-chemical concepts for sites contaminated by heavy metals; judging the potential danger; safety measures; cleaning up processes and the reinstatement and renaturing of the soil. (orig.) [de

  10. SIMON: A mobile robot for floor contamination surveys

    International Nuclear Information System (INIS)

    Dudar, E.; Teese, G.; Wagner, D.

    1991-01-01

    The Robotics Development group at the Savannah River Site is developing an autonomous robot to perform radiological surveys of potentially contaminated floors. The robot scans floors at a speed of one-inch/second and stops, sounds an alarm, and flashes lights when contamination in a certain area is detected. The contamination of interest here is primarily alpha and beta-gamma. The contamination levels are low to moderate. The robot, a Cybermotion K2A, is radio controlled, uses dead reckoning to determine vehicle position, and docks with a charging station to replenish its batteries and calibrate its position. It has an ultrasonic collision avoidance system as well as two safety bumpers that will stop the robot's motion when they are depressed. Paths for the robot are preprogrammed and the robot's motion can be monitored on a remote screen which shows a graphical map of the environment. The radiation instrument being used is an Eberline RM22A monitor. This monitor is microcomputer based with a serial I/O interface for remote operation. Up to 30 detectors may be configured with the RM22A. For our purposes, two downward-facing gas proportional detectors are used to scan floors, and one upward-facing detector is used for radiation background compensation. SIMON is interfaced with the RM22A in such a way that it scans the floor surface at one-inch/second, and if contamination is detected, the vehicle stops, alarms, and activates a voice synthesizer. Future development includes using the contamination data collected to provide a graphical contour map of a contaminated area. 3 refs

  11. Metal contamination in wildlife living near two zinc smelters

    Science.gov (United States)

    Beyer, W.N.; Pattee, O.H.; Sileo, L.; Hoffman, D.J.; Mulhern, B.M.

    1985-01-01

    Wildlife in an oak forest on Blue Mountain was studied 10 km upwind (Bake Oven Knob site) and 2 km downwind (Palmerton site) of two zinc smelters in eastern Pennsylvania, USA. Previous studies at sites near these smelters had shown changes in populations of soil microflora, lichens, green plants and litter-inhabiting arthropods. The 02 soil litter horizon at Palmerton was heavily contaminated with Pb (2700 mg kg-1), Zn (24000 mg kg-1), and Cd (710 mg kg-1), and to a lesser extent with Cu (440 mg kg-1). Various kinds of invertebrates (earthworms, slugs and millipedes) that feed on soil litter or soil organic matter were rare at, or absent from, the Palmerton site. Those collected at Bake Oven Knob tended to have much higher concentrations of metals than did other invertebrates. Frogs, toads and salamanders were very rare at, or absent from, the Palmerton site, but were present at Bake Oven Knob and at other sites on Blue Mountain farther from the smelters. Metal concentrations (dry wt) in different organisms from Palmerton were compared. Concentrations of Pb were highest in shrews (110 mg kg-1), followed by songbirds (56 mg kg-1), leaves (21 mg kg-1), mice (17 mg kg-1), carrion insects (14 mg kg-1), berries (4.0 mg kg-1), moths (4,3 mg kg-1) and fungi (3.7 mg kg-1). Concentrations of Cd, in contrast, were highest in carrion insects (25 mg kg-1 ),followed by fungi (9.8 mg kg-1), leaves (8.1 mg kg-1), shrews (7.3 mg kg-I), moths (4.9 mg kg-1), mice (2.6 mg kg -1), songbirds (2.5 mg kg -1) and berries (1.2 mg kg-1). Concentrations of Zn and Cu tended to be highest in the same organisms that had the highest concentrations of Cd. Only a small proportion of the metals in the soil became incorporated into plant foliage, and much of the metal contamination detected in the biota probably came from aerial deposition. The mice from both sites seemed to be healthy. Shrews had higher concentrations of metals than did mice, and one shrew showed evidence of Pb poisoning; its red

  12. Mobility of Pb, Cu, and Zn in the phosphorus-amended contaminated soils under simulated landfill and rainfall conditions.

    Science.gov (United States)

    Cao, Xinde; Liang, Yuan; Zhao, Ling; Le, Huangying

    2013-09-01

    Phosphorus-bearing materials have been widely applied in immobilization of heavy metals in contaminated soils. However, the study on the stability of the initially P-induced immobilized metals in the contaminated soils is far limited. This work was conducted to evaluate the mobility of Pb, Cu, and Zn in two contrasting contaminated soils amended with phosphate rock tailing (PR) and triple superphosphate fertilizer (TSP), and their combination (P + T) under simulated landfill and rainfall conditions. The main objective was to determine the stability of heavy metals in the P-treated contaminated soils in response to the changing environment conditions. The soils were amended with the P-bearing materials at a 2:1 molar ratio of P to metals. After equilibrated for 2 weeks, the soils were evaluated with the leaching procedures. The batch-based toxicity characteristic leaching procedure (TCLP) was conducted to determine the leachability of heavy metals from both untreated and P-treated soils under simulated landfill condition. The column-based synthetic precipitation leaching procedure (SPLP) were undertaken to measure the downward migration of metals from untreated and P-treated soils under simulated rainfall condition. Leachability of Pb, Cu, and Zn in the TCLP extract followed the order of Zn > Cu > Pb in both soils, with the organic-C- and clay-poor soil showing higher metal leachability than the organic-C- and clay-rich soil. All three P treatments reduced leachability of Pb, Cu, and Zn by up to 89.2, 24.4, and 34.3 %, respectively, compared to the untreated soil, and TSP revealed more effectiveness followed by P + T and then PR. The column experiments showed that Zn had the highest downward migration upon 10 pore volumes of SPLP leaching, followed by Pb and then Cu in both soils. However, migration of Pb and Zn to subsoil and leachate were inhibited in the P-treated soil, while Cu in the leachate was enhanced by P treatment in the organic

  13. Changes in metal availability, desorption kinetics and speciation in contaminated soils during repeated phytoextraction with the Zn/Cd hyperaccumulator Sedum plumbizincicola.

    Science.gov (United States)

    Li, Zhu; Jia, Mingyun; Wu, Longhua; Christie, Peter; Luo, Yongming

    2016-02-01

    Phytoextraction is one of the most promising technologies for the remediation of metal contaminated soils. Changes in soil metal availability during phytoremediation have direct effects on removal efficiency and can also illustrate the interactive mechanisms between hyperaccumulators and metal contaminated soils. In the present study the changes in metal availability, desorption kinetics and speciation in four metal-contaminated soils during repeated phytoextraction by the zinc/cadmium hyperaccumulator Sedum plumbizincicola (S. plumbizincicola) over three years were investigated by chemical extraction and the DGT-induced fluxes in soils (DIFS) model. The available metal fractions (i.e. metal in the soil solution extracted by CaCl2 and by EDTA) decreased greatly by >84% after phytoextraction in acid soils and the deceases were dramatic at the initial stages of phytoextraction. However, the decreases in metal extractable by CaCl2 and EDTA in calcareous soils were not significant or quite low. Large decreases in metal desorption rate constants evaluated by DIFS were found in calcareous soils. Sequential extraction indicated that the acid-soluble metal fraction was easily removed by S. plumbizincicola from acid soils but not from calcareous soils. Reducible and oxidisable metal fractions showed discernible decreases in acid and calcareous soils, indicating that S. plumbizincicola can mobilize non-labile metal for uptake but the residual metal cannot be removed. The results indicate that phytoextraction significantly decreases metal availability by reducing metal pool sizes and/or desorption rates and that S. plumbizincicola plays an important role in the mobilization of less active metal fractions during repeated phytoextraction. Copyright © 2015 Elsevier Ltd. All rights reserved.

  14. Remediation techniques for heavy-metals contamination in lakes: A Mini-Review

    Digital Repository Service at National Institute of Oceanography (India)

    Giripunje, M.D.; Fulke, A.B.; Meshram, P.U.

    Heavy-metals contamination in lakes has a negative impact on lake ecosystems This review provides an insight into possible heavy-metals remediation techniques for lake environments using different techniques, for example, physical, chemical...

  15. Metal resistance in populations of red maple (Acer rubrum L.) and white birch (Betula papyrifera Marsh.) from a metal-contaminated region and neighbouring non-contaminated regions

    International Nuclear Information System (INIS)

    Kirkey, Fallon M.; Matthews, Jennifer; Ryser, Peter

    2012-01-01

    Metal resistance in populations of Acer rubrum and Betula papyrifera in the industrially contaminated region of Sudbury, Ontario, was compared with resistance in populations from neighbouring uncontaminated regions. In two one-season experiments, seedlings were grown outdoors on contaminated (mainly Cu, Ni) and uncontaminated substrates. Sudbury populations of both species responded less to contamination than populations from uncontaminated regions. In A. rubrum this difference was small. For both species, Sudbury plants were smaller when grown on uncontaminated substrate. B. papyrifera from Sudbury grew better on contaminated substrate than the other populations. There is indication of variation in metal resistance within the populations from the non-contaminated regions. The data shows that trees may develop adaptive resistance to heavy metals, but the low degree of resistance indicates that the development of such resistances are slower than observed for herbaceous species with shorter generation times. - Highlights: ► Metal resistance in trees from an industrially contaminated region was investigated. ► Both red maple and white birch have developed some degree of resistance. ► There is indication of a cost for resistance. ► Populations from non-contaminated regions show variation in response to contamination. - Adaptive metal resistance can also develop in trees with long generation times, but the degree of resistance is lower than for herbaceous species from the same region.

  16. Arsenic and other heavy metal accumulation in plants and algae growing naturally in contaminated area of West Bengal, India.

    Science.gov (United States)

    Singh, N K; Raghubanshi, A S; Upadhyay, A K; Rai, U N

    2016-08-01

    The present study was conducted to quantify the arsenic (As) and other heavy metal concentrations in the plants and algae growing naturally in As contaminated blocks of North-24-Pargana and Nandia district, West Bengal, India to assess their bioaccumulation potential. The plant species included five macrophytes and five algae were collected from the nine selected sites for estimation of As and other heavy metals accumulated therein by using Inductively Coupled Plasma Mass Spectrophotometer (ICP-MS). Results revealed that maximum As concentration (117mgkg(-1)) was recorded in the agricultural soil at the Barasat followed by Beliaghat (111mgkg(-1)) sites of North-24-Pargana. Similarly, concentration of selenium (Si, 249mgkg(-1)), lead (Pb, 79.4mgkg(-1)), chromium (Cr, 138mgkg(-1)) was also found maximum in the soil at Barasat and cadmium (Cd, 163mgkg(-1)) nickel (Ni, 36.5mgkg(-1)) at Vijaynagar site. Among the macrophytes, Eichhornia crassipes found more dominating species in As contaminated area and accumulate As (597mgkg(-1)) in the shoot at kanchrapara site. The Lemna minor found to accumulate maximum As (735mgkg(-1)) in the leaves at Sonadanga and Pistia stratiotes accumulated minimum As (24.5mgkg(-1)) in the fronds from Ranaghat site. In case of diatoms, maximum As (760mgkg(-1)) was accumulated at Kanchrapara site followed by Hydrodictiyon reticulatum (403mgkg(-1)) at the Ranaghat site. High concentration of As and other heavy metal in soil indicates long term effects of irrigation with contaminated ground water, however, high concentration of heavy metals in naturally growing plants and algae revealed their mobilization through leaching and possible food chain contamination. Therefore, efficient heavy metal accumulator macrophytes Eichhornia crassipes, Lemna minor, Spirodela polyrhiza may be exploited in removing metals from contaminated water by developing a plant based treatment system. However, As accumulator algal species may be used as a bioresource for

  17. Chemical resilience of clay rich barrier materials to redox-oscillating conditions and implications for contaminant mobility

    International Nuclear Information System (INIS)

    Parsons, Chris; Rossetto, Lionel; Charlet, Laurent; Made, Benoit

    2012-01-01

    nitrate and sulphate in addition to the reductive dissolution of manganese and iron oxide minerals and an increase in CO 2 partial pressure. Whilst some authors demonstrate that such cyclic redox conditions may alter the properties of clay barrier materials due to illitisation of smectite clays (6, 7), the dynamic chemical conditions occurring during redox cycling may also result in the dissolution and re-precipitation of metal oxides, sulphides and carbonates. The balance of these minerals, even if present at sub-per cent levels as impurities has the potential to dramatically alter contaminant mobility. Many inorganic contaminants often associated with LL-LLW including Sb, Cr, As, Hg and U are also highly sensitive to changes in redox conditions which may result in changes to their speciation, toxicity and mobility (8, 9). We demonstrate through the combination of redox-stat batch-reactor experiments and thermodynamic modelling that periodic and cumulative changes to matrix mineralogy, contaminant speciation and mineral surface properties occur following periodic cycles of reduction and oxidation. These changes result in both short term (intra-cycle) and long-term (inter-cycle) changes to K d values for a range of redox sensitive contaminants associated with LL-LLW including arsenic, chromium, selenium, mercury and uranium (Table 1 and Figures 1 and 2). During a series of laboratory experiments argillaceous substrates were subjected to successive cycles of oxidising and reducing conditions with Eh oscillating between -215 and +340 mV induced via both abiotic and microbial methods. Chemically induced cycles of oxidation and reduction were achieved via a combination of gas sparging (nitrogen vs compressed air) and the addition of a synthetic reduced humic substance analogue (AH 2 DS 2- ). Microbially induced cycles of oxidation and reduction were achieved using gas sparging (nitrogen vs compressed air) to stimulate different metabolic pathways of a natively present

  18. The Use of Plants for Remediation of Metal-Contaminated Soils

    Directory of Open Access Journals (Sweden)

    Andon Vassilev

    2004-01-01

    Full Text Available The use of green plants to remove, contain, inactivate, or degrade harmful environmental contaminants (generally termed phytoremediation is an emerging technology. In this paper, an overview is given of existing information concerning the use of plants for the remediation of metal-contaminated soils. Both site decontamination (phytoextraction and stabilization techniques (phytostabilization are described. In addition to the plant itself, the use of soil amendments for mobilization (in case of phytoextraction and immobilization (in case of phytostabilization is discussed. Also, the economical impacts of changed land-use, eventual valorization of biomass, and cost-benefit aspects of phytoremediation are treated. In spite of the growing public and commercial interest and success, more fundamental research is needed still to better exploit the metabolic diversity of the plants themselves, but also to better understand the complex interactions between metals, soil, plant roots, and micro-organisms (bacteria and mycorrhiza in the rhizosphere. Further, more demonstration experiments are needed to measure the underlying economics, for publicacceptance and last but not least, to convince policy makers.

  19. Trace element mobility in a contaminated soil two years after field-amendment with a greenwaste compost mulch

    Energy Technology Data Exchange (ETDEWEB)

    Clemente, Rafael, E-mail: rclemente@cebas.csic.e [Faculty of Sciences, Liverpool John Moores University, Liverpool L3 3AF (United Kingdom); Hartley, William [Faculty of Sciences, Liverpool John Moores University, Liverpool L3 3AF (United Kingdom); Riby, Philip [School of Pharmacy and Chemistry, Liverpool John Moores University, Liverpool L3 3AF (United Kingdom); Dickinson, Nicholas M.; Lepp, Nicholas W. [Faculty of Sciences, Liverpool John Moores University, Liverpool L3 3AF (United Kingdom)

    2010-05-15

    Application of greenwaste compost to brownfield land is increasingly common in soil and landscape restoration. Previous studies have demonstrated both beneficial and detrimental effects of this material on trace element mobility. A pot experiment with homogenised soil/compost investigated distribution and mobility of trace elements, two years after application of greenwaste compost mulch to shallow soils overlying a former alkali-works contaminated with Pb, Cu and As (approx900, 200 and 500 mg kg{sup -1}, respectively). Compost mulch increased organic carbon and Fe in soil pore water, which in turn increased As and Sb mobilization; this enhanced uptake by lettuce and sunflower. A very small proportion of the total soil trace element pool was in readily-exchangeable form (<0.01% As, <0.001% other trace elements), but the effect of compost on behaviour of metals was variable and ambiguous. It is concluded that greenwaste compost should be applied with caution to multi-element contaminated soils. - Arsenic solubility and bioavailability increases in soil two years after application of greenwaste compost mulch.

  20. Trace element mobility in a contaminated soil two years after field-amendment with a greenwaste compost mulch

    International Nuclear Information System (INIS)

    Clemente, Rafael; Hartley, William; Riby, Philip; Dickinson, Nicholas M.; Lepp, Nicholas W.

    2010-01-01

    Application of greenwaste compost to brownfield land is increasingly common in soil and landscape restoration. Previous studies have demonstrated both beneficial and detrimental effects of this material on trace element mobility. A pot experiment with homogenised soil/compost investigated distribution and mobility of trace elements, two years after application of greenwaste compost mulch to shallow soils overlying a former alkali-works contaminated with Pb, Cu and As (∼900, 200 and 500 mg kg -1 , respectively). Compost mulch increased organic carbon and Fe in soil pore water, which in turn increased As and Sb mobilization; this enhanced uptake by lettuce and sunflower. A very small proportion of the total soil trace element pool was in readily-exchangeable form (<0.01% As, <0.001% other trace elements), but the effect of compost on behaviour of metals was variable and ambiguous. It is concluded that greenwaste compost should be applied with caution to multi-element contaminated soils. - Arsenic solubility and bioavailability increases in soil two years after application of greenwaste compost mulch.

  1. Simulating Mobility of Chemical Contaminants from Unconventional Gas Development for Protection of Water Resources

    Science.gov (United States)

    Kanno, C.; Edlin, D.; Borrillo-Hutter, T.; McCray, J. E.

    2014-12-01

    Potential contamination of ground water and surface water supplies from chemical contaminants in hydraulic fracturing fluids or in natural gas is of high public concern. However, quantitative assessments have rarely been conducted at specific energy-producing locations so that the true risk of contamination can be evaluated. The most likely pathways for contamination are surface spills and faulty well bores that leak production fluids directly into an aquifer. This study conducts fate and transport simulations of the most mobile chemical contaminants, based on reactivity to subsurface soils, degradation potential, and source concentration, to better understand which chemicals are most likely to contaminate water resources, and to provide information to planners who wish to be prepared for accidental releases. The simulations are intended to be most relevant to the Niobrara shale formation.

  2. Is metal contamination responsible for increasing aneuploidy levels in the Manila clam Ruditapes philippinarum?

    KAUST Repository

    Piló, D.

    2016-11-03

    The present study assessed the metal genotoxicity potential at chromosome-level in the bivalve Ruditapes philippinarum collected along different areas of the Tagus estuary. Higher levels of aneuploidy on gill cells were detected at the most sediment contaminated area both in May (31.7%) and October (36.0%) when compared to a less contaminated area over the same periods (20.3% and 29.0% respectively). Interestingly, metal bioaccumulation in gills was higher in the specimens collected at the least contaminated area with the exception of Pb. Indeed, the multivariate analysis revealed a stronger relation between aneuploidy and sediment contamination than between aneuploidy and the bioaccumulation of the metals. The temporal and spatial inconsistency found for the bioaccumulation of metals in R. philippinarum and the positive correlation between sediment contamination and aneuploidy at the most contaminated area suggest that these chromosome-level effects might be due to chronic metal contamination occurring in the Tagus estuary, rather than a direct result of the temporal variation of bioavailable contaminants. The vertical transmission phenomenon of bivalve aneuploidy levels may then be perpetuating those levels on clams from the most contaminated area. The present results shed light about the effect of metal toxicity at the chromosome-level in species inhabiting chronic contaminated areas and highlight the use of aneuploidy as an effective tool to identify persistent contamination in worldwide transitional waters.

  3. Biomonitoring for metal contamination near two Superfund sites in Woburn, Massachusetts, using phytochelatins

    International Nuclear Information System (INIS)

    Gawel, James E.; Hemond, Harold F.

    2004-01-01

    Characterizing the spatial extent of groundwater metal contamination traditionally requires installing sampling wells, an expensive and time-consuming process in urban areas. Moreover, extrapolating biotic effects from metal concentrations alone is problematic, making ecological risk assessment difficult. Our study is the first to examine the use of phytochelatin measurements in tree leaves for delimiting biological metal stress in shallow, metal-contaminated groundwater systems. Three tree species (Rhamnus frangula, Acer platanoides, and Betula populifolia) growing above the shallow groundwater aquifer of the Aberjona River watershed in Woburn, Massachusetts, display a pattern of phytochelatin production consistent with known sources of metal contamination and groundwater flow direction near the Industri-Plex Superfund site. Results also suggest the existence of a second area of contaminated groundwater and elevated metal stress near the Wells G and H Superfund site downstream, in agreement with a recent EPA ecological risk assessment. Possible contamination pathways at this site are discussed

  4. A mine of information: Benthic algal communities as biomonitors of metal contamination from abandoned tailings

    International Nuclear Information System (INIS)

    Lavoie, Isabelle; Lavoie, Michel; Fortin, Claude

    2012-01-01

    Various biomonitoring approaches were tested in the field to assess the response of natural periphythic algal communities to chronic metal contamination downstream from an abandoned mine tailings site. The accumulation of cadmium (Cd), copper (Cu), lead (Pb) and zinc (Zn) as well as the production of phytochelatins, the presence of diatom taxa known to tolerate high metal concentrations, diatom diversity and the presence of teratologies were determined. We observed highly significant relationships between intracellular metal and calculated free metal ion concentrations. Such relationships are often observed in laboratory studies but have been rarely validated in field studies. These results suggest that the concentration of metal inside the field-collected periphyton, regardless of its species composition, is a good indicator of exposure and is an interesting proxy for bioavailable metal concentrations in natural waters. The presence of teratologies and metal-tolerant taxa at our contaminated sites provided a clear indication that diatom communities were responding to this metal stress. A multi-metric approach integrating various bioassessment methods could be used for the field monitoring of metal contamination and the quantification of its effects. Highlights: ► Various approaches for metal contamination biomonitoring were used in the field. ► Metal accumulation in periphyton is correlated to free ion concentration. ► Teratologies and metal-tolerant taxa provided a clear indication of metal stress. ► Stream periphyton shows great potential as a biomonitor of metal contamination.

  5. Metal resistance in populations of red maple (Acer rubrum L.) and white birch (Betula papyrifera Marsh.) from a metal-contaminated region and neighbouring non-contaminated regions.

    Science.gov (United States)

    Kirkey, Fallon M; Matthews, Jennifer; Ryser, Peter

    2012-05-01

    Metal resistance in populations of Acer rubrum and Betula papyrifera in the industrially contaminated region of Sudbury, Ontario, was compared with resistance in populations from neighbouring uncontaminated regions. In two one-season experiments, seedlings were grown outdoors on contaminated (mainly Cu, Ni) and uncontaminated substrates. Sudbury populations of both species responded less to contamination than populations from uncontaminated regions. In A. rubrum this difference was small. For both species, Sudbury plants were smaller when grown on uncontaminated substrate. B. papyrifera from Sudbury grew better on contaminated substrate than the other populations. There is indication of variation in metal resistance within the populations from the non-contaminated regions. The data shows that trees may develop adaptive resistance to heavy metals, but the low degree of resistance indicates that the development of such resistances are slower than observed for herbaceous species with shorter generation times. Copyright © 2012 Elsevier Ltd. All rights reserved.

  6. ASSESSING THE MOBILITY OF ARSENIC IN CONTAMINATED SEDIMENTS

    Science.gov (United States)

    The mobility of arsenic is controlled, in part, by partitioning to mineral surfaces in soils and sediments. Determination of the risk posed to human or ecosystem health by arsenic and identification of remediation technologies that could be employed to eliminate or reduce risk i...

  7. Metal contamination of vineyard soils in wet subtropics (southern Brazil)

    International Nuclear Information System (INIS)

    Mirlean, Nicolai; Roisenberg, Ari; Chies, Jaqueline O.

    2007-01-01

    The vine-growing areas in Brazil are the dampest in the world. Copper maximum value registered in this study was as much as 3200 mg kg -1 , which is several times higher than reported for vineyard soils in temperate climates. Other pesticide-derived metals accumulate in the topsoil layer, surpassing in the old vineyards the background value several times for Zn, Pb, Cr and Cd. Copper is transported to deeper soils' horizons and can potentially contaminate groundwater. The soils from basaltic volcanic rocks reveal the highest values of Cu extracted with CaCl 2 , demonstrating a high capacity of copper transference into plants. When evaluating the risks of copper's toxic effects in subtropics, the soils from rhyolitic volcanic rocks are more worrisome, as the Cu extracted with ammonium acetate 1 M surpasses the toxic threshold as much as 4-6 times. - Copper-based pesticide use in wet subtropics is environmentally more risky

  8. Redox oscillation impact on natural and engineered biogeochemical systems: chemical resilience and implications for contaminant mobility

    Energy Technology Data Exchange (ETDEWEB)

    Charlet, Laurent [ISTerre, University of Grenoble, B.P. 53X, 38041 Grenoble (France); Institut Universitaire de France, Paris (France); Markelova, Ekaterina [ISTerre, University of Grenoble, B.P. 53X, 38041 Grenoble (France); Department of Earth and Environmental Sciences, University of Waterloo, Waterloo, ON N2L3G1 4 (Canada); Parsons, Chris; Couture, Raoul-Marie [Department of Earth and Environmental Sciences, University of Waterloo, Waterloo, ON N2L3G1 4 (Canada); Made, Benoit [Andra / DRD-TR, Direction Recherche et Developpement, 1-7 rue Jean Monnet, 92298 Chatenay-Malabry cedex (France)

    2013-07-01

    Many geochemical systems fluctuate regularly from oxic to anoxic conditions (flooded soils and nuclear waste surface repositories, for instance). In these conditions many inorganic contaminants including Sb, Se, Cr, As, and U are highly sensitive to changes in redox conditions. These oscillations may result in changes to their speciation, toxicity, and mobility. We demonstrate through the combination of redox-stat batch-reactor experiments that periodic and cumulative changes to matrix mineralogy, contaminant speciation, and mineral surface properties occur following periodic cycles of reduction and oxidation. These changes result in both short-term (intra-cycle) and long-term (inter-cycle) changes to K{sub d} values for a range of redox sensitive contaminants. These results demonstrate that naturally occurring redox oscillations may result in long-term immobilization of contaminants in the solid phase in addition to short-term variations in mobility. (authors)

  9. Heavy metal stabilization in contaminated road-derived sediments.

    Science.gov (United States)

    Rijkenberg, Micha J A; Depree, Craig V

    2010-02-01

    There is increasing interest in the stabilization of heavy metals in road-derived sediments (RDS), to enable environmentally responsible reuse applications and circumvent the need for costly landfill disposal. To reduce the mobility of heavy metals (i.e. Cu, Pb and Zn) the effectiveness of amendments using phosphate, compost and fly ash addition were investigated using batch leaching experiments. In general, phosphate amendments of RDS were found to be ineffective at stabilizing heavy metals, despite being used successfully in soils. Phosphate amendment resulted in enhanced concentrations of dissolved organic carbon (DOC), which increased the solubilisation of heavy metals via complexation. Amendment with humified organic matter (compost) successfully stabilized Cu and Pb in high DOC leaching RDS with an optimum loading of 15-20% (w/w). Compost, however, was ineffective at stabilizing Zn. Increasing the pH by amending RDS/compost blends with 2.5-15% (w/w) coal fly ash resulted in the stabilization of Zn, Cu and Pb. However, above a pH of approximately 7.5 and 8 enhanced leaching of organic matter resulted in an increase in leached Cu and Pb, respectively. Accordingly, the optimum level of fly ash amendment for the RDS/compost blends was estimated to be ca. 10%. Boosted regression trees analysis (BRT) of the data revealed that DOC accounted for 56% and 65% of the Cu and Pb leaching, respectively, whereas pH only accounted for ca. 18% of Cu and Pb leaching. RDS sample characteristics (i.e. metal concentrations, size fractionation and organic matter content) were more important at reconciling the leaching concentrations of copper Cu (27%) than Pb (16%). The most important parameter explaining Zn leaching was pH. Overall, the choice of a suitable stabilization agent/s depends on the composition of RDS with respect to the amount of organic matter present, and the sorption chemistry of the heavy metal of interest. Copyright 2009 Elsevier B.V. All rights reserved.

  10. Study of the mobilization of pollutants in soils of the Bogota Savanna - phase 1, Heavy Metals

    International Nuclear Information System (INIS)

    Gonzalez, Luz Myrian; Vargas Zarate, Orlando

    1997-01-01

    In this study the soils contamination of the Bogota Savanna was evaluated by heavy metals, that they have importance to be this the area of population's of the country bigger density, where the use of the soils has suffered changes in the last years that have affected its properties, as consequence of the not controlled growth of the urban area, of the industrialization and of the agricultural use not planned. As a first stage toward the risk evaluation for the presence of metals weighed in the soils of the Bogota Savanna, the concentrations of cadmium, cobalt, chromium, copper, manganese, nickel, lead, zinc, molybdenum, arsenic and mercury were measured. It was also measured the movilizable fraction and the mobile fraction, that is to say, the quantity of metals that can be taken by the roots of the plants or that it can be leached toward the water bodies. Equally, the soils of the Savanna were characterized in an area of the plane part that covers 800 km 2 , as for the physical and chemical properties that can affect the retention and mobilization of heavy metals. The results obtained shows elements, that will allow in a future to develop mobilization and transport models, adapted for our specific conditions and to make an risks evaluation for the population's health, foods consumption on these soils or for the possibility of contamination of the underground waters. The obtained data of levels of heavy metals and other properties of the soils will serve as base for future studies of the conditions of the Savanna soils and for the establishment of standard of quality in our country. During 1997 it plans to enlarge the study area to 1200 km 2 and to begin the sampling and analysis of the soils. In the first phase of the study were found levels of heavy metals that overcome the world averages especially cadmium, cobalt, nickel, lead and zinc and in some cases chromium and mercury, levels that put in evidence the existence an ecological risk and for the population

  11. Synergistic effect of metal deactivator and antioxidant on oxidation stability of metal contaminated Jatropha biodiesel

    Energy Technology Data Exchange (ETDEWEB)

    Sarin, Amit [Department of Applied Sciences, Amritsar College of Engineering and Technology, Amritsar 143001 (India); Arora, Rajneesh; Singh, N.P. [Punjab Technical University, Jalandhar (India); Sarin, Rakesh; Malhotra, R.K. [Indian Oil Corporation Ltd., R and D Centre, Sector-13, Faridabad 121007 (India); Sharma, Meeta [Indian Oil Corporation Ltd., R and D Centre, Sector-13, Faridabad 121007 (India); University School of Basic and Applied Sciences, Guru Gobind Singh Indraprastha University, Kashmere Gate, Delhi 110403 (India); Khan, Arif Ali [University School of Basic and Applied Sciences, Guru Gobind Singh Indraprastha University, Kashmere Gate, Delhi 110403 (India)

    2010-05-15

    Biodiesel is relatively unstable on storage and European biodiesel standard EN-14214 calls for determining oxidation stability at 110 C with a minimum induction time of 6 h by the Rancimat method (EN-14112). According to proposed National Mission on biodiesel in India, we have undertaken studies on stability of biodiesel from tree borne non-edible oil seeds Jatropha. Neat Jatropha biodiesel exhibited oxidation stability of 3.95 h. It is found possible to meet the desired EN specification for neat Jatropha biodiesel and metal contaminated Jatropha biodiesel by using antioxidants; it will have a cost implication, as antioxidants are costly chemicals. Research was conducted to increase the oxidation stability of metal contaminated Jatropha biodiesel by doping metal deactivator with antioxidant, with varying concentrations in order to meet the aforementioned standard required for oxidation stability. It was found that usage of antioxidant can be reduced by 30-50%, therefore the cost, even if very small amount of metal deactivator is doped in Jatropha biodiesel to meet EN-14112 specification. (author)

  12. Redox oscillation affecting mercury mobility from highly contaminated coastal sediments: a mesocosm incubation experiment

    Directory of Open Access Journals (Sweden)

    Emili A.

    2013-04-01

    Full Text Available Mercury (Hg mobility at the sediment-water interface was investigated during a laboratory incubation experiment on highly contaminated sediments (up to 23 μg g−1 of the Gulf of Trieste. Undisturbed sediment was collected in front of the Isonzo River mouth, which inflows Hg-rich suspended material originating from the Idrija (NW Slovenia mining district. Since hypoxic and anoxic conditions at the bottom are frequently observed, a redox oscillation was simulated in the laboratory at in situ temperature, using a dark flux chamber. Temporal variations of several parameters were monitored simultaneously: dissolved Hg and methylmercury (MeHg, O2, NH4+, NO3−+NO2−, PO43−, H2S, dissolved Fe and Mn, dissolved inorganic and organic carbon (DIC and DOC. Benthic fluxes of Hg and MeHg were higher under anoxic conditions while re-oxygenation caused concentrations of MeHg and Hg to rapidly drop, probably due to re-adsorption onto Fe/Mn oxyhydroxides and enhanced demethylation. Hence, during anoxic events, sediments of the Gulf of Trieste may be considered as an important source of dissolved Hg species for the water column. However, re-oxygenation of the bottom compartment mitigates Hg and MeHg release from the sediment, thus acting as a natural “defence” from possible interaction between the metal and the aquatic organisms.

  13. Heavy metal contamination in vegetables grown in Rawalpindi, Pakistan

    International Nuclear Information System (INIS)

    Ahmed, W.; Ahmed, A.; Ahmad, A.; Randhawa, M.A.; Ahmad, R.; Khalid, N.

    2012-01-01

    Copper (Cu), cadmium (Cd), chromium (Cr) nickel (Ni), lead (Pb), Iron (Fe), Manganese (Mn) and zinc (Zn) contents of various vegetables (bitter melon, tomato, eggplant, lettuce, cucumber and bell pepper) produced in Rawalpindi, Pakistan was determined using Atomic absorption spectrophotometer (AAS). These plants are the basis of human nutrition in the study area. All vegetables grown at sewage water by farmers showed the highest contamination of heavy metals, followed by local market, Progressive farmers and hydroponic plant. The concentration ranges in mg/kg were (1.45 -2.55) for Cd, (3.10 to 4.92) Cr, (12.15- 20.50) Cu, (25.00-51.00) for Fe, (7.80 to 15.60) for Mn, (10.16 to 15.42) for Ni, (2.12 to 5.41) Pb and (16.58 to 24.08) for zinc. The contamination was above the Maximum Residue Limits (MRLs), set out by WHO. Irregular trends in concentration were also observed in vegetables obtained from local market, progressive farmers and hydroponic plant. (author)

  14. Chemodynamics of heavy metals in long-term contaminated soils: metal speciation in soil solution.

    Science.gov (United States)

    Kim, Kwon-Rae; Owens, Gary

    2009-01-01

    The concentration and speciation of heavy metals in soil solution isolated from long-term contaminated soils were investigated. The soil solution was extracted at 70% maximum water holding capacity (MWHC) after equilibration for 24 h. The free metal concentrations (Cd2+, CU2+, Pb2+, and Zn2+) in soil solution were determined using the Donnan membrane technique (DMT). Initially the DMT was validated using artificial solutions where the percentage of free metal ions were significantly correlated with the percentages predicted using MINTEQA2. However, there was a significant difference between the absolute free ion concentrations predicted by MINTEQA2 and the values determined by the DMT. This was due to the significant metal adsorption onto the cation exchange membrane used in the DMT with 20%, 28%, 44%, and 8% mass loss of the initial total concentration of Cd, Cu, Pb, and Zn in solution, respectively. This could result in a significant error in the determination of free metal ions when using DMT if no allowance for membrane cation adsorption was made. Relative to the total soluble metal concentrations the amounts of free Cd2+ (3%-52%) and Zn2+ (11%-72%) in soil solutions were generally higher than those of Cu2+ (0.2%-30%) and Pb2+ (0.6%-10%). Among the key soil solution properties, dissolved heavy metal concentrations were the most significant factor governing free metal ion concentrations. Soil solution pH showed only a weak relationship with free metal ion partitioning coefficients (K(p)) and dissolved organic carbon did not show any significant influence on K(p).

  15. Environmental hazard of cadmium, copper, lead and zinc in metal-contaminated soils remediated by sulfosuccinamate formulation.

    Science.gov (United States)

    del Carmen Hernández-Soriano, Maria; Peña, Aránzazu; Mingorance, M Dolores

    2011-10-01

    Accumulation of metals in soil at elevated concentrations causes risks to the environmental quality and human health for more than one hundred million people globally. The rate of metal release and the alteration of metal distribution in soil phases after soil washing with a sulfosuccinamate surfactant solution (Aerosol 22) were evaluated for four contaminated soils. Furthermore, a sequential extraction scheme was carried out using selective extractants (HAcO, NH(2)OH·HCl, H(2)O(2) + NH(4)AcO) to evaluate which metal species are extracted by A22 and the alteration in metal distribution upon surfactant-washing. Efficiency of A22 to remove metals varied among soils. The washing treatment released up to 50% of Cd, 40% of Cu, 20% of Pb and 12% of Zn, mainly from the soluble and reducible soil fractions, therefore, greatly reducing the fraction of metals readily available in soil. Metal speciation analysis for the solutions collected upon soil washing with Aerosol 22 further confirmed these results. Copper and lead in solution were mostly present as soluble complexes, while Cd and Zn were present as free ions. Besides, redistribution of metals in soil was observed upon washing. The ratios of Zn strongly retained in the soil matrix and Cd complexed with organic ligands increased. Lead was mobilized to more weakly retained forms, which indicates a high bioavailability of the remaining Pb in soil after washing. Comprehensive knowledge on chemical forms of metals present in soil allows a feasible assessment of the environmental impact of metals for a given scenario, as well as possible alteration of environmental conditions, and a valuable prediction for potential leaching and groundwater contamination.

  16. METAL TOLERANCE ANALYSIS OF MICROFUNGI ISOLATED FROM METAL CONTAMINATED SOIL AND WASTE WATER

    Directory of Open Access Journals (Sweden)

    Mathan Jayaraman

    2014-08-01

    Full Text Available The influence of Cr6+, Pb2+, Cu2+, Ni2+, Zn2+ and Cd2+ on the development of 24 fungi was investigated for Metal Tolerance Index (MTI at 1mg ml-1 Cr6+, Pb2+, Cu2+, Ni2+, Zn2+ and Cd2+ concentrations and also for Minimum Inhibitory Concentration (MIC. The MIC ranged from 0.5 to 1.5 mg ml-1 depending on the isolate Aspergillus, Fusarium and Penicillium sp. were tested for their metal tolerance index. Out of these Aspergillus flavus (ED4 shows a better tolerance index of 0.80 Cr6+, 0.72 for Pb2+ , 0.63 for Cu2+, 0.58 for Ni2+, 0.46 for Zn2+ and 0.60 Cd2+ for MIC value for the removal of heavy metals from contaminated soil and wastewaters.

  17. Electrorecycling of Critical and Value Metals from Mobile Electronics

    Energy Technology Data Exchange (ETDEWEB)

    Lister, Tedd E.; Wang, Peming; Anderko, Andre

    2014-09-01

    Mobile electronic devices such as smart phones and tablets are a significant source of valuable metals that should be recycled. Each year over a billion devices are sold world-wide and the average life is only a couple years. Value metals in phones are gold, palladium, silver, copper, cobalt and nickel. Devices now contain increasing amounts of rare earth elements (REE). In recent years the supply chain for REE has moved almost exclusively to China. They are contained in displays, speakers and vibrators within the devices. By US Department of Energy (DOE) classification, specific REEs (Nd, Dy, Eu, Tb and Y) are considered critical while others (Ce, La and Pr) are deemed near critical. Effective recycling schemes should include the recovery of these critical materials. By including more value materials in a recovery scheme, more value can be obtained by product diversification and less waste metals remains to be disposed of. REEs are mined as a group such that when specific elements become critical significantly more ore must be processed to capture the dilute but valuable critical elements. Targeted recycling of items containing the more of the less available critical materials could address their future criticality. This presentation will describe work in developing aqueous electrochemistry-based schemes for recycling metals from scrap mobile electronics. The electrorecycling process generates oxidizing agents at an anode while reducing dissolved metals at the cathode. E vs pH diagrams and metals dissolution experiments are used to assess effectiveness of various solution chemistries. Although several schemes were envisioned, a two stages process has been the focus of work: 1) initial dissolution of Cu, Sn, Ag and magnet materials using Fe+3 generated in acidic sulfate and 2) final dissolution of Pd and Au using Cl2 generated in an HCl solution. Experiments were performed using simulated metal mixtures. Both Cu and Ag were recovered at ~ 97% using Fe+3 while

  18. Mobilization of arsenic and heavy metals from polluted soils by humic acid

    Science.gov (United States)

    Reyes, Arturo; Fuentes, Bárbara; Letelier, María Victoria; Cuevas, Jacqueline

    2017-04-01

    The existence of soils contaminated with harmful elements by mining activities is a global environmental concern. The northern part of Chile has several heavy metal contaminated sites due to former copper and gold artisanal mining activities. Therefore, a complete characterization of abandoned sites and the implementation of remediation technologies are of interest for regulators, the industry, and the population. The objective of the study was to test the use of humic acid as a washing treatment to reduce the heavy metal concentration of soil samples impacted by mine waste material. A stratified random sampling was conducted on the target site to determine the physical and chemical composition of mine waste and soil material. The sampling consisted of taking 37 samples at 0-20 cm depths in a 10,000 square-meter area. The samples were dried and sieved at 2 mm. The batch washing experiments were conducted in triplicate at pH 7.0. A 1:10 solid to liquid ratio and three humic acid dose (0, 50, and 100 mg/l) were used. After shaking (24 h, room temperature) and subsequently filtration (0.22 μm), the supernatants were analyzed for heavy metals, redox potential and pH. The heavy metals mobility was assessed using extraction methods before and after treatments. The soils had alkaline pH values, conductivity ranged between 8 and 35 mS/cm, with low organic matter. Total concentrations of Vanadium (V) (10.80 to 175.00 mg/kg), Lead (Pb) (7.31 to 90.10 mg/kg), Antimonium (Sb) (0.83 to 101.00 mg/kg), and Arsenic (As) (9.53 to 2691.00 mg/kg) exceeded several times the EPA`s recommended values for soils. At 100 mg/L HA the removal efficiencies for V, Pb, Sb, and As were 32, 68, 77, and 82% respectively. According to the extraction procedure V, Pb, Sb, and As species are mainly as oxidizable and residual fractions. According to the results, the target mine site is contaminated with harmful elements. It can be concluded that the use of humic acid is a good alternative as a

  19. Perspectives of humic substances application in remediation of highly heavy metals contaminated soils in Kola Subarctic

    Science.gov (United States)

    Tregubova, Polina; Turbaevskaya, Valeria; Zakharenko, Andrey; Kadulin, Maksim; Smirnova, Irina; Stepanov, Andrey; Koptsik, Galina

    2016-04-01

    Northwestern part of Russia, the Kola Peninsula, is one of the most heavy metals (HM) contaminated areas in the northern hemisphere. The main polluters, mining-and-metallurgical integrated works "Pechenganikel" and "Severonikel", are surrounded by heavily damaged barren lands that require remediation. The main contaminating metals are Ni and Cu. Using of exogenous humic substances could be possible effective and cost-efficient solution of HM contamination problem. Rational application of humates (Na-K salts of humic acids) can result in improvement of soil properties, localization of contamination and decreasing bioavailability through binding HM in relatively immobile organic complexes. Our research aim was to evaluate the influence of increasing doses of different origin humates on i) basic properties of contaminated soils; ii) mobility and bioavailability of HMs; iii) vegetation state and chemistry. In summer 2013 a model field experiment was provided in natural conditions of the Kola Peninsula. We investigated the Al-Fe-humus abrazem, soil type that dominates in technogenic barren lands around the "Severonikel" work. These soils are strongly acid: pHH2O was 3.7-4.1; pHKCl was 3.4-4.0. The exchangeable acidity is low (0.8-1.6 cmol(+)/kg) due to the depletion of fine particles and organic matter, being the carriers of exchange positions. The abrazems of barrens had lost organic horizon. 12 sites were created in 1 km from the work. In those sites, except 2 controls, various amendments were added: i) two different by it's origin types of humates: peat-humates and coal-humates, the last were in concentrations 0.5% and 1%; ii) lime; iii) NPK-fertilizer; iv) biomates (organic degradable cover for saving warm and erosion protection). As a test-culture a grass mixture with predominance of Festuca rubra and Festuca ovina was sowed. As a result we concluded that humates of different origin have unequal influence on soil properties and cause decreasing as well as

  20. Beyond the bed: Effects of metal contamination on recruitment to bedded sediments and overlying substrata

    International Nuclear Information System (INIS)

    Hill, Nicole A.; Simpson, Stuart L.; Johnston, Emma L.

    2013-01-01

    Metal-contaminated sediments pose a recognised threat to sediment-dwelling fauna. Re-mobilisation of contaminated sediments however, may impact more broadly on benthic ecosystems, including on diverse assemblages living on hard substrata patches immediately above sediments. We used manipulative field experiments to simultaneously test for the effects of metal contamination on recruitment to marine sediments and overlying hard substrata. Recruitment to sediments was strongly and negatively affected by metal contamination. However, while assemblage-level effects on hard-substratum fauna and flora were observed, most functional groups were unaffected or slightly enhanced by exposure to contaminated sediments. Diversity of hard-substratum fauna was also enhanced by metal contamination at one site. Metal-contaminated sediments appear to pose less of a hazard to hard-substratum than sediment-dwelling assemblages, perhaps due to a lower direct contaminant exposure or to indirect effects mediated by contaminant impacts on sediment fauna. Our results indicate that current sediment quality guidelines are protective of hard-substrata organisms. - Highlights: ► Potential for contaminated sediments to exert impacts beyond the sediment communities. ► We examine effects on recruitment to sediments and overlying hard substrata simultaneously. ► Metal-contaminated sediments had a strong negative impact on sediment fauna. ► Metal-contaminated sediments pose less of a hazard to hard-substratum fauna. ► Sediment quality guidelines are likely protective of hard-substrata organisms. - Under natural disturbance regimes, metal-contaminated sediments pose less of a direct risk to hard-substratum fauna than to sediment-dwelling fauna and SQG appear appropriate.

  1. Eurochemic reprocessing plant decommissioning. Decontamination of contaminated metal

    International Nuclear Information System (INIS)

    Walthery, R.; Teunckens, L.; Lewandowski, P.

    1998-01-01

    When decommissioning nuclear installations, large quantifies of metal components are produced as well as significant amounts of other radioactive materials, which mostly show low surface contamination. Having been used or having been brought for a while in a controlled area, marks them as 'suspected material'. In view of the very high costs for radioactive waste processing and disposal, alternatives have been considered, and much effort has been spent in recycling through decontamination, melting and unconditional release of metals. In a broader context, recycling of materials can be considered as a first order ecological priority to limit the quantities of radioactive wastes to be disposed of, to reduce the technical and economic problems involved with the management of radioactive wastes, and to make economic use of primary material and conserve natural resources of basic material for future generations. Other evaluations as the environmental impact of recycling compared to non recycling (mining or production of new material) and waste treatment, with the associated risks involved, can also be considered, as well as social and political impacts of recycling. This document gives an overview of the current practices in recycling of materials at the decommissioning of the Eurochemic reprocessing plant in Dessel, Belgium. It deals with the decontamination and measurement techniques in use, and considers related technical and economic aspects and constraints. (author)

  2. Heavy metal-immobilizing organoclay facilitates polycyclic aromatic hydrocarbon biodegradation in mixed-contaminated soil

    International Nuclear Information System (INIS)

    Biswas, Bhabananda; Sarkar, Binoy; Mandal, Asit; Naidu, Ravi

    2015-01-01

    Highlights: • A novel metal-immobilizing organoclay (MIOC) synthesized and characterized. • MIOC immobilizes toxic metals and reduces metal bioavailability. • It enhances PAH-bioavailability to soil bacteria. • It improves microbial growth and activities in mixed-contaminated soils. • MIOC facilitates PAH-biodegradation in metal co-contaminated soils. - Abstract: Soils contaminated with a mixture of heavy metals and polycyclic aromatic hydrocarbons (PAHs) pose toxic metal stress to native PAH-degrading microorganisms. Adsorbents such as clay and modified clay minerals can bind the metal and reduce its toxicity to microorganisms. However, in a mixed-contaminated soil, an adsorption process more specific to the metals without affecting the bioavailability of PAHs is desired for effective degradation. Furthermore, the adsorbent should enhance the viability of PAH-degrading microorganisms. A metal-immobilizing organoclay (Arquad ® 2HT-75-bentonite treated with palmitic acid) (MIOC) able to reduce metal (cadmium (Cd)) toxicity and enhance PAH (phenanthrene) biodegradation was developed and characterized in this study. The MIOC differed considerably from the parent clay in terms of its ability to reduce metal toxicity (MIOC > unmodified bentonite > Arquad–bentonite). The MIOC variably increased the microbial count (10–43%) as well as activities (respiration 3–44%; enzymatic activities up to 68%), and simultaneously maintained phenanthrene in bioavailable form in a Cd-phenanthrene mixed-contaminated soil over a 21-day incubation period. This study may lead to a new MIOC-assisted bioremediation technique for PAHs in mixed-contaminated soils

  3. Assessment of a mussel as a metal bioindicator of coastal contamination: Relationships between metal bioaccumulation and multiple biomarker responses

    International Nuclear Information System (INIS)

    Chandurvelan, Rathishri; Marsden, Islay D.; Glover, Chris N.; Gaw, Sally

    2015-01-01

    This is the first study to use a multiple biomarker approach on the green-lipped mussel, Perna canaliculus to test its feasibility as a bioindicator of coastal metal contamination in New Zealand (NZ). Mussels were collected from six low intertidal sites varying in terms of anthropogenic impacts, within two regions (West Coast and Nelson) of the South Island of NZ. Trace elements, including arsenic (As), cadmium (Cd), copper (Cu), lead (Pb), nickel (Ni), and zinc (Zn), were measured in the gills, digestive gland, foot and mantle, and in the surface sediments from where mussels were collected. Metal levels in the sediment were relatively low and there was only one site (Mapua, Nelson) where a metal (Ni) exceeded the Australian and New Zealand Interim Sediment Quality Guideline values. Metal levels in the digestive gland were generally higher than those from the other tissues. A variety of biomarkers were assessed to ascertain mussel health. Clearance rate, a physiological endpoint, correlated with metal level in the tissues, and along with scope for growth, was reduced in the most contaminated site. Metallothionein-like protein content and catalase activity in the digestive gland, and catalase activity and lipid peroxidation in the gill, were also correlated to metal accumulation. Although there were few regional differences, the sampling sites were clearly distinguishable based on the metal contamination profiles and biomarker responses. P. canaliculus appears to be a useful bioindicator species for coastal habitats subject to metal contamination. In this study tissue and whole organism responses provided insight into the biological stress responses of mussels to metal contaminants, indicating that such measurements could be a useful addition to biomonitoring programmes in NZ. - Highlights: • Multiple biomarker responses were measured in mussels from 6 sites. • Metal content of mussel tissues correlated with specific biomarker responses. • Clearance rate

  4. Assessment of a mussel as a metal bioindicator of coastal contamination: Relationships between metal bioaccumulation and multiple biomarker responses

    Energy Technology Data Exchange (ETDEWEB)

    Chandurvelan, Rathishri, E-mail: rch118@uclive.ac.nz [School of Biological Sciences, University of Canterbury, Private Bag 4800, Christchurch 8140 (New Zealand); Marsden, Islay D., E-mail: islay.marsden@canterbury.ac.nz [School of Biological Sciences, University of Canterbury, Private Bag 4800, Christchurch 8140 (New Zealand); Glover, Chris N., E-mail: chris.glover@canterbury.ac.nz [School of Biological Sciences, University of Canterbury, Private Bag 4800, Christchurch 8140 (New Zealand); Gaw, Sally, E-mail: sally.gaw@canterbury.ac.nz [Department of Chemistry, University of Canterbury, Private Bag 4800, Christchurch 8140 (New Zealand)

    2015-04-01

    This is the first study to use a multiple biomarker approach on the green-lipped mussel, Perna canaliculus to test its feasibility as a bioindicator of coastal metal contamination in New Zealand (NZ). Mussels were collected from six low intertidal sites varying in terms of anthropogenic impacts, within two regions (West Coast and Nelson) of the South Island of NZ. Trace elements, including arsenic (As), cadmium (Cd), copper (Cu), lead (Pb), nickel (Ni), and zinc (Zn), were measured in the gills, digestive gland, foot and mantle, and in the surface sediments from where mussels were collected. Metal levels in the sediment were relatively low and there was only one site (Mapua, Nelson) where a metal (Ni) exceeded the Australian and New Zealand Interim Sediment Quality Guideline values. Metal levels in the digestive gland were generally higher than those from the other tissues. A variety of biomarkers were assessed to ascertain mussel health. Clearance rate, a physiological endpoint, correlated with metal level in the tissues, and along with scope for growth, was reduced in the most contaminated site. Metallothionein-like protein content and catalase activity in the digestive gland, and catalase activity and lipid peroxidation in the gill, were also correlated to metal accumulation. Although there were few regional differences, the sampling sites were clearly distinguishable based on the metal contamination profiles and biomarker responses. P. canaliculus appears to be a useful bioindicator species for coastal habitats subject to metal contamination. In this study tissue and whole organism responses provided insight into the biological stress responses of mussels to metal contaminants, indicating that such measurements could be a useful addition to biomonitoring programmes in NZ. - Highlights: • Multiple biomarker responses were measured in mussels from 6 sites. • Metal content of mussel tissues correlated with specific biomarker responses. • Clearance rate

  5. Flexible Aperture Tuning Solution for Cellular Main Antenna in Metallic Back Cover Mobile Phone

    Directory of Open Access Journals (Sweden)

    Yew Choon Mark Tan

    2017-10-01

    Full Text Available Metal housing has been used extensively on portable communication devices such as on mobile phones and tablets. The choice of metal housing ranges from metallic rim to metallic back cover. This metal housing tends to improve the outlook appearance of the mobile devices, and add mechanical strength towards the mobile devices. However, from the aspect of the communication antenna, the metal housing often posts great challenges towards the flexibility in antenna design and reduction in antenna performance. This paper presents an approach to overcome the challenges by integrating the metal housing of the mobile phone as part of the antenna, along with the introduction of tunable antenna concept to provide different forms of Aperture Tuning to the Cellular Main Antenna, to satisfy its wide frequency band coverages for the 2nd, 3rd and 4th Generation (2G, 3G and 4G mobile network.

  6. Potential value of phosphate compounds in enhancing immobilization and reducing bioavailability of mixed heavy metal contaminants in shooting range soil.

    Science.gov (United States)

    Seshadri, B; Bolan, N S; Choppala, G; Kunhikrishnan, A; Sanderson, P; Wang, H; Currie, L D; Tsang, Daniel C W; Ok, Y S; Kim, G

    2017-10-01

    Shooting range soils contain mixed heavy metal contaminants including lead (Pb), cadmium (Cd), and zinc (Zn). Phosphate (P) compounds have been used to immobilize these metals, particularly Pb, thereby reducing their bioavailability. However, research on immobilization of Pb's co-contaminants showed the relative importance of soluble and insoluble P compounds, which is critical in evaluating the overall success of in situ stabilization practice in the sustainable remediation of mixed heavy metal contaminated soils. Soluble synthetic P fertilizer (diammonium phosphate; DAP) and reactive (Sechura; SPR) and unreactive (Christmas Island; CPR) natural phosphate rocks (PR) were tested for Cd, Pb and Zn immobilization and later their mobility and bioavailability in a shooting range soil. The addition of P compounds resulted in the immobilization of Cd, Pb and Zn by 1.56-76.2%, 3.21-83.56%, and 2.31-74.6%, respectively. The reactive SPR significantly reduced Cd, Pb and Zn leaching while soluble DAP increased their leachate concentrations. The SPR reduced the bioaccumulation of Cd, Pb and Zn in earthworms by 7.13-23.4% and 14.3-54.6% in comparison with earthworms in the DAP and control treatment, respectively. Bioaccessible Cd, Pb and Zn concentrations as determined using a simplified bioaccessibility extraction test showed higher long-term stability of P-immobilized Pb and Zn than Cd. The differential effect of P-induced immobilization between P compounds and metals is due to the variation in the solubility characteristics of P compounds and nature of metal phosphate compounds formed. Therefore, Pb and Zn immobilization by P compounds is an effective long-term remediation strategy for mixed heavy metal contaminated soils. Copyright © 2017 Elsevier Ltd. All rights reserved.

  7. Interaction of mobile phones with superficial passive metallic implants

    International Nuclear Information System (INIS)

    Virtanen, H; Huttunen, J; Toropainen, A; Lappalainen, R

    2005-01-01

    The dosimetry of exposure to radiofrequency (RF) electromagnetic (EM) fields of mobile phones is generally based on the specific absorption rate (SAR, W kg -1 ), which is the electromagnetic energy absorbed in the tissues per unit mass and time. In this study, numerical methods and modelling were used to estimate the effect of a passive, metallic (conducting) superficial implant on a mobile phone EM field and especially its absorption in tissues in the near field. Two basic implant models were studied: metallic pins and rings in the surface layers of the human body near the mobile phone. The aim was to find out 'the worst case scenario' with respect to energy absorption by varying different parameters such as implant location, orientation, size and adjacent tissues. Modelling and electromagnetic field calculations were carried out using commercial SEMCAD software based on the FDTD (finite difference time domain) method. The mobile phone was a 900 MHz or 1800 MHz generic phone with a quarter wave monopole antenna. A cylindrical tissue phantom models different curved sections of the human body such as limbs or a head. All the parameters studied (implant size, orientation, location, adjacent tissues and signal frequency) had a major effect on the SAR distribution and in certain cases high local EM fields arose near the implant. The SAR values increased most when the implant was on the skin and had a resonance length or diameter, i.e. about a third of the wavelength in tissues. The local peak SAR values increased even by a factor of 400-700 due to a pin or a ring. These highest values were reached in a limited volume close to the implant surface in almost all the studied cases. In contrast, without the implant the highest SAR values were generally reached on the skin surface. Mass averaged SAR 1g and SAR 10g values increased due to the implant even by a factor of 3 and 2, respectively. However, at typical power levels of mobile phones the enhancement is unlikely to be

  8. Techniques for assessing the performance of in situ bioreduction and immobilization of metals and radionuclides in contaminated subsurface environments

    Energy Technology Data Exchange (ETDEWEB)

    Jardine, P.M.; Watson, D.B.; Blake, D.A.; Beard, L.P.; Brooks, S.C.; Carley, J.M.; Criddle, C.S.; Doll, W.E.; Fields, M.W.; Fendorf, S.E.; Geesey, G.G.; Ginder-Vogel, M.; Hubbard, S.S.; Istok, J.D.; Kelly, S.; Kemner, K.M.; Peacock, A.D.; Spalding, B.P.; White, D.C.; Wolf, A.; Wu, W.; Zhou, J.

    2004-11-14

    Department of Energy (DOE) facilities within the weapons complex face a daunting challenge of remediating huge below inventories of legacy radioactive and toxic metal waste. More often than not, the scope of the problem is massive, particularly in the high recharge, humid regions east of the Mississippi river, where the off-site migration of contaminants continues to plague soil water, groundwater, and surface water sources. As of 2002, contaminated sites are closing rapidly and many remediation strategies have chosen to leave contaminants in-place. In situ barriers, surface caps, and bioremediation are often the remedial strategies of chose. By choosing to leave contaminants in-place, we must accept the fact that the contaminants will continue to interact with subsurface and surface media. Contaminant interactions with the geosphere are complex and investigating long term changes and interactive processes is imperative to verifying risks. We must be able to understand the consequences of our action or inaction. The focus of this manuscript is to describe recent technical developments for assessing the performance of in situ bioremediation and immobilization of subsurface metals and radionuclides. Research within DOE's NABIR and EMSP programs has been investigating the possibility of using subsurface microorganisms to convert redox sensitive toxic metals and radionuclides (e.g. Cr, U, Tc, Co) into a less soluble, less mobile forms. Much of the research is motivated by the likelihood that subsurface metal-reducing bacteria can be stimulated to effectively alter the redox state of metals and radionuclides so that they are immobilized in situ for long time periods. The approach is difficult, however, since subsurface media and waste constituents are complex with competing electron acceptors and hydrogeological conditions making biostimulation a challenge. Performance assessment of in situ biostimulation strategies is also difficult and typically requires detailed

  9. Phytoremediation of Heavy Metals in Contaminated Water and Soil Using Miscanthus sp. Goedae-Uksae 1.

    Science.gov (United States)

    Bang, Jihye; Kamala-Kannan, Seralathan; Lee, Kui-Jae; Cho, Min; Kim, Chang-Hwan; Kim, Young-Jin; Bae, Jong-Hyang; Kim, Kyong-Ho; Myung, Hyun; Oh, Byung-Taek

    2015-01-01

    The aim of this study is to characterize the heavy metal phytoremediation potential of Miscanthus sp. Goedae-Uksae 1, a hybrid, perennial, bio-energy crop developed in South Korea. Six different metals (As, Cu, Pb, Ni, Cd, and Zn) were used for the study. The hybrid grass effectively absorbed all the metals from contaminated soil. The maximum removal was observed for As (97.7%), and minimum removal was observed for Zn (42.9%). Similarly, Goedae-Uksae 1 absorbed all the metals from contaminated water except As. Cd, Pb, and Zn were completely (100%) removed from contaminated water samples. Generally, the concentration of metals in roots was several folds higher than in shoots. Initial concentration of metals highly influenced the phytoremediation rate. The results of the bioconcentration factor, translocation factor, and enrichment coefficient tests indicate that Goedae-Uksae 1 could be used for phytoremediation in a marginally contaminated ecosystem.

  10. Pollution Status of Pakistan: A Retrospective Review on Heavy Metal Contamination of Water, Soil, and Vegetables

    Directory of Open Access Journals (Sweden)

    Amir Waseem

    2014-01-01

    Full Text Available Trace heavy metals, such as arsenic, cadmium, lead, chromium, nickel, and mercury, are important environmental pollutants, particularly in areas with high anthropogenic pressure. In addition to these metals, copper, manganese, iron, and zinc are also important trace micronutrients. The presence of trace heavy metals in the atmosphere, soil, and water can cause serious problems to all organisms, and the ubiquitous bioavailability of these heavy metal can result in bioaccumulation in the food chain which especially can be highly dangerous to human health. This study reviews the heavy metal contamination in several areas of Pakistan over the past few years, particularly to assess the heavy metal contamination in water (ground water, surface water, and waste water, soil, sediments, particulate matter, and vegetables. The listed contaminations affect the drinking water quality, ecological environment, and food chain. Moreover, the toxicity induced by contaminated water, soil, and vegetables poses serious threat to human health.

  11. Design and Development of a Continuous-Flow Countercurrent Metal Extraction System to Remove Heavy Metals from Contaminated Soils

    National Research Council Canada - National Science Library

    Neale, Christopher M. U

    1997-01-01

    .... The research focused on eight contaminated soils from Army installations and the metal extraction capabilities of eight extracting agents including HNO3, HCI, fluorosilicic acid, citric acid, EDTA, DTPA, NTA, and NaOH...

  12. Metal bioaccumulation and oxidative stress profiles in Ruditapes philippinarum – insights towards its suitability as bioindicator of estuarine metal contamination

    KAUST Repository

    Marques, Ana; Piló , David; Carvalho, Susana; Araú jo, Olinda; Guilherme, Sofia; Santos, Maria Ana; Vale, Carlos; Pereira, Fá bio; Pacheco, Má rio; Pereira, Patrí cia

    2017-01-01

    is not consensual. This study provided clarification on this issue by evaluating the ability of R. philippinarum to signalise trace element contamination in an estuary chronically impacted by metals and metalloids (Tagus estuary, Portugal). A multidimensional

  13. Characterization of heavy-metal-contaminated sediment by using unsupervised multivariate techniques and health risk assessment.

    Science.gov (United States)

    Wang, Yeuh-Bin; Liu, Chen-Wuing; Wang, Sheng-Wei

    2015-03-01

    This study characterized the sediment quality of the severely contaminated Erjen River in Taiwan by using multivariate analysis methods-including factor analysis (FA), self-organizing maps (SOMs), and positive matrix factorization (PMF)-and health risk assessment. The SOMs classified the dataset with similar heavy-metal-contaminated sediment into five groups. FA extracted three major factors-traditional electroplating and metal-surface processing factor, nontraditional heavy-metal-industry factor, and natural geological factor-which accounted for 80.8% of the variance. The SOMs and FA revealed the heavy-metal-contaminated-sediment hotspots in the middle and upper reaches of the major tributary in the dry season. The hazardous index value for health risk via ingestion was 0.302. PMF further qualified the source apportionment, indicating that traditional electroplating and metal-surface-processing industries comprised 47% of the health risk posed by heavy-metal-contaminated sediment. Contaminants discharged from traditional electroplating and metal-surface-processing industries in the middle and upper reaches of the major tributary must be eliminated first to improve the sediment quality in Erjen River. The proposed assessment framework for heavy-metal-contaminated sediment can be applied to contaminated-sediment river sites in other regions. Copyright © 2014 Elsevier Inc. All rights reserved.

  14. Subcellular partitioning of metals in Aporrectodea caliginosa along a gradient of metal exposure in 31 field-contaminated soils

    Energy Technology Data Exchange (ETDEWEB)

    Beaumelle, Léa [INRA, UR 251 PESSAC, 78026 Versailles Cedex (France); Gimbert, Frédéric [Laboratoire Chrono-Environnement, UMR 6249 University of Franche-Comté/CNRS Usc INRA, 16 route de Gray, 25030 Besançon Cedex (France); Hedde, Mickaël [INRA, UR 251 PESSAC, 78026 Versailles Cedex (France); Guérin, Annie [INRA, US 0010 LAS Laboratoire d' analyses des sols, 273 rue de Cambrai, 62000 Arras (France); Lamy, Isabelle, E-mail: lamy@versailles.inra.fr [INRA, UR 251 PESSAC, 78026 Versailles Cedex (France)

    2015-07-01

    Subcellular fractionation of metals in organisms was proposed as a better way to characterize metal bioaccumulation. Here we report the impact of a laboratory exposure to a wide range of field-metal contaminated soils on the subcellular partitioning of metals in the earthworm Aporrectodea caliginosa. Soils moderately contaminated were chosen to create a gradient of soil metal availability; covering ranges of both soil metal contents and of several soil parameters. Following exposure, Cd, Pb and Zn concentrations were determined both in total earthworm body and in three subcellular compartments: cytosolic, granular and debris fractions. Three distinct proxies of soil metal availability were investigated: CaCl{sub 2}-extractable content dissolved content predicted by a semi-mechanistic model and free ion concentration predicted by a geochemical speciation model. Subcellular partitionings of Cd and Pb were modified along the gradient of metal exposure, while stable Zn partitioning reflected regulation processes. Cd subcellular distribution responded more strongly to increasing soil Cd concentration than the total internal content, when Pb subcellular distribution and total internal content were similarly affected. Free ion concentrations were better descriptors of Cd and Pb subcellular distribution than CaCl{sub 2} extractable and dissolved metal concentrations. However, free ion concentrations and soil total metal contents were equivalent descriptors of the subcellular partitioning of Cd and Pb because they were highly correlated. Considering lowly contaminated soils, our results raise the question of the added value of three proxies of metal availability compared to soil total metal content in the assessment of metal bioavailability to earthworm. - Highlights: • Earthworms were exposed to a wide panel of historically contaminated soils • Subcellular partitioning of Cd, Pb and Zn was investigated in earthworms • Three proxies of soil metal availability were

  15. Assisted phytoremediation of a multi-contaminated soil: Investigation on arsenic and lead combined mobilization and removal.

    Science.gov (United States)

    Barbafieri, Meri; Pedron, Francesca; Petruzzelli, Gianniantonio; Rosellini, Irene; Franchi, Elisabetta; Bagatin, Roberto; Vocciante, Marco

    2017-12-01

    The removal of contaminants from an earthy matrix by phytoremediation requires the selection of appropriate plant species and a suitable strategy to be effective. In order to set up an assisted phytoremediation intervention related to a disused industrial site affected by an arsenic and lead complex contamination, an extensive experimental investigation on micro and mesocosm scale has been conducted. Particular attention was given to the choice of plant species: using crop plants (Lupinus albus, Helianthus annuus and Brassica juncea) a series of parallel test campaigns have been realized to investigate different scenarios for the reclamation. With regard to the arsenic contamination, which is certainly the most worrying, the possibility of employing a hyper-accumulator species (Pteris vittata) has also been investigated, highlighting advantages and difficulties associated with such an approach. The application of various mobilizing agents in different concentrations was tested, in order to maximize the extraction efficiency of plants in respect of both contaminants, showing the necessity of a chemically assisted approach to promote their uptake and translocation in the shoots. Phosphate addition appears to produce the desired results, positively affecting As phyto-extraction for both hyper-accumulator and crop plants, while minimizing its toxic effects at the investigated concentrations. With regard to Pb, although tests with EDDS have been encouraging, EDTA should be preferred at present due to lower uncertainties about its effectiveness. The performed tests also improved the addition of mobilizing agents, allowing the simultaneous removal of the two metals despite their great diversity (which in general discourages such approach), with significant saving of time and an obvious improvement of the overall process. Copyright © 2017 Elsevier Ltd. All rights reserved.

  16. Towards metals analysis using corona discharge ionization ion mobility spectrometry.

    Science.gov (United States)

    Jafari, Mohammad T; Saraji, Mohammad; Sherafatmand, Hossein

    2016-02-25

    For the first time, the capability of corona discharge ionization ion mobility spectrometry (CD-IMS) in the determination of metal complex was evaluated. The extreme simplicity of dispersive liquid-liquid microextraction (DLLME) coupled to the high sensitivity of CD-IMS measurement could make this combination really useful for simple, rapid, and sensitive determination of metals in different samples. In this regard, mercury, as a model metal, was complexed with diethyldithiocarbamate (DEDTC), and then extracted into the carbon tetrachloride using DLLME. Some parameters affecting the extraction efficiency, including the type and volume of the extraction solvent, the type and volume of the disperser solvent, the concentration of the chelating agent, salt addition and, pH were exhaustively investigated. Under the optimized condition, the enrichment factor was obtained to be 142. The linear range of 0.035-10.0 μg mL(-1) with r(2) = 0.997 and the detection limit of 0.010 μg mL(-1) were obtained. The relative standard deviation values were calculated to be lower than 4% and 8% for intra-day and inter-day, respectively. Finally, the developed method was successfully applied for the extraction and determination of mercury in various real samples. The satisfactory results revealed the capability of the proposed method in trace analysis without tedious derivatization or hydride generation. Copyright © 2016 Elsevier B.V. All rights reserved.

  17. Comparison of natural organic acids and synthetic chelates at enhancing phytoextraction of metals from a multi-metal contaminated soil

    International Nuclear Information System (INIS)

    Clistenes do Nascimento, Williams A.; Amarasiriwardena, Dula; Xing, Baoshan

    2006-01-01

    Chemically assisted phytoremediation has been developing to induce accumulation of metals by high biomass plants. Synthetic chelates have shown high effectiveness to reach such a goal, but they pose serious drawbacks in field application due to the excessive amount of metals solubilized. We compared the performance of synthetic chelates with naturally occurring low molecular weight organic acids (LMWOA) in enhancing phytoextraction of metals by Indian mustard (Brassica juncea) from multi-metal contaminated soils. Gallic and citric acids were able to induce removal of Cd, Zn, Cu, and Ni from soil without increasing the leaching risk. Net removal of these metals caused by LMWOA can be as much as synthetic chelates. A major reason for this is the lower phytotoxicity of LMWOA. Furthermore, supplying appropriate mineral nutrients increased biomass and metal removal. - Organic acids can be as efficient as synthetic chelates for use in phytoextraction of multi-metal contaminated soils

  18. Seasonal and annual variations of metal uptake, bioaccumulation, and toxicity in Trifolium repens and Lolium perenne growing in a heavy metal-contaminated field.

    Science.gov (United States)

    Bidar, Géraldine; Pruvot, Christelle; Garçon, Guillaume; Verdin, Anthony; Shirali, Pirouz; Douay, Francis

    2009-01-01

    organs showed the effective contamination by industrial dust emissions. Metals absorbed by plants were mainly stored in the roots. With regard to this storage, the plants seemed to limit the metal transfer to their aerial parts over the time, thereby indicating their availability for metal phytostabilization. Aerial deposition was another source of plant exposure to nonferrous metals. Despite the occurrence of metal-induced oxidative alterations in plant organs, both plant species seemed to tolerate a high metal concentration in soils. Taken together, these results indicated that T. repens and L. perenne were able to form a plant cover on highly Cd-, Pb-, and Zn-polluted soils, to limit the metal transfer to their aerial parts and were relatively metal-tolerant. All these characteristics made them suitable for phytostabilization on metal-contaminated soils. These findings also highlighted the necessity to take into account seasonal and annual variations for a future phytomanagement. In this work, the behavior of plant species grown in metal-polluted soil has been studied during 2 years. Obviously, this time is too short to ensure that metals remain accumulated in the root system and few are transferred in aerial parts over the time. It is why regular monitoring should be achieved during more than a decade after the settlement of the plant cover. This work will be completed by the study of the T. repens and L. perenne effects on mobility of metals in order to evaluate the quantities of pollutants which could be absorbed by the biota and transferred to groundwater. Bioaccessibility tests could be also realized on polluted soils in order to evaluate the phytostabilization impacts on the exposition risks for humans.

  19. Characterisation by PIXE RBS of metallic contamination of tissues surrounding a metallic prosthesis on a knee

    Science.gov (United States)

    Guibert, G.; Irigaray, J. L.; Moretto, Ph.; Sauvage, T.; Kemeny, J. L.; Cazenave, A.; Jallot, E.

    2006-09-01

    Implants used as biomaterials have to fulfill conditions of functionality, compatibility and sometimes bioactivity. There are four main families of biomaterials: metals and metal alloys, polymers, bioceramics and natural materials. Because of corrosion and friction in the human body, implants generate debris. This debris may develop toxicity, inflammation and prosthetic unsealing by osseous dissolution. Nature, size, morphology and amount of debris are the parameters influencing the tissue responses. In this paper, we characterised metallic contamination produced by knee prosthesis, composed with TiAl 6V 4 or Co-Cr-Mo alloys, into surrounding capsular tissue by depth migration, in vivo behaviour, content, size and nature of debris by PIXE (Particle Induced X-ray Emission) method associated with RBS (Rutherford Backscattering Spectroscopy). Debris distribution in the whole articulation is very heterogeneous. Debris migrates several thousand micrometers in tissues, with a characteristic decrease. Solid metallic particles of about micrometer size are found in the most polluted samples, in both alloys TiAl 6V 4 and Cr-Co-Mo. In the mean volume analysed by PIXE, the concentration mass ratios [Ti]/[V] and [Co]/[Cr] confirm the chemical stability of TiAl 6V 4 debris and show the chemical evolution of Cr-Co-Mo debris. Development of a protocol to prepare thin targets permits us to correlate PIXE and histological analysis in the same zone. The fibrous tissue (collagen fibres, fibroblasts) and macrophage cells are observed with optical microscope in polluted areas. This protocol could locate other pathologies in ppm contamination range, thanks to the great sensitivity of the PIXE method.

  20. Changes in metal mobility assessed by EDTA kinetic extraction in three polluted soils after repeated phytoremediation using a cadmium/zinc hyperaccumulator.

    Science.gov (United States)

    Li, Zhu; Wu, Longhua; Luo, Yongming; Christie, Peter

    2018-03-01

    Phytoextraction is one of the most promising technologies for the decontamination of metal-polluted agricultural soils. Effects of repeated phytoextraction by the cadmium (Cd)/zinc (Zn) hyperaccumulator Sedum plumbizincicola on metal (Cd, Zn, copper (Cu) and lead (Pb)) mobility were investigated in three contaminated soils with contrasting properties. EDTA kinetic extraction and the two first-order reactions model showed advantages in the assessment of soil metal mobility and clearly discriminated changes in metal fractions induced by phytoextraction. Repeated phytoextraction led to large decreases in readily labile (Q 1 0 ) and less labile (Q 2 0 ) fractions of Cd and Zn in all three soils with the sole exception of an increase in the Q 2 0 of Zn in the highly polluted soil. However, Q 1 0 fractions of soil Cu and Pb showed apparent increases with the sole exception of Pb in the acid polluted soil but showed a higher desorption rate constant (k 1 ). Furthermore, S. plumbizincicola decreased the non-labile fraction (Q 3 0 ) of all metals tested, indicating that the hyperaccumulator can redistribute soil metals from non-labile to labile fractions. This suggests that phytoextraction decreased the mobility of the metals hyperaccumulated by the plant (Cd and Zn) but increased the mobility of the metals not hyperaccumulated (Cu and Pb). Thus, phytoextraction of soils contaminated with mixtures of metals must be performed carefully because of potential increases in the mobility of non-hyperaccumulated metals in the soil and the consequent environmental risks. Copyright © 2017 Elsevier Ltd. All rights reserved.

  1. A review on heavy metal contamination in the soil worldwide: Situation, impact and remediation techniques

    Directory of Open Access Journals (Sweden)

    Chao Su

    2014-06-01

    Full Text Available Heavy metals in the soil refers to some significant heavy metals of biological toxicity, including mercury (Hg, cadmium (Cd, lead (Pb, chromium (Cr, and arsenic (As, etc. With the development of the global economy, both type and content of heavy metals in the soil caused by human activities have gradually increased in recent years, which have resulted in serious environment deterioration. In present study we compared and analyzed soil contamination of heavy metals in various cities/countries, and reviewed background, impact and remediation methods of soil heavy metal contamination worldwide.

  2. Mobility and eco-risk of trace metals in soils at the Hailuogou Glacier foreland in eastern Tibetan Plateau.

    Science.gov (United States)

    Bing, Haijian; Wu, Yanhong; Zhou, Jun; Liang, Jianhong; Wang, Jipeng; Yang, Zijiang

    2016-03-01

    The concentrations and fractions of cadmium (Cd), copper (Cu), lead (Pb), and zinc (Zn) in soils collected from Hailuogou Glacier foreland in eastern Tibetan Plateau were analyzed to decipher their mobility, and their eco-risk was assessed combined with multiple environmental indices. The concentrations of Cd were more than ten times higher than its local background in the O horizon and nearly three times higher in the A horizon. The concentrations of Pb and Zn were relatively high in the O horizon, whereas that of Cu increased with soil depth. The main fractions of metals in the surface horizons were reducible and acid-soluble for Cd, oxidizable and residual for Cu, reducible and oxidizable for Pb, and reducible and residual for Zn. The metal mobility generally followed the order of Cd > Pb > Zn > Cu in the O horizon and Cd > Pb > Cu > Zn in the A horizon. Sorption and complexation by soil organic matters imparted an important effect on the mobilization and transformation of Cd, Pb, and Zn in the soils. The oxidizable Cu fraction in the soils showed significant correlation with organic matters, and soil pH mainly modulated the acid-soluble and reducible Cu fractions. The concentrations and other environmental indices including contamination factor, enrichment factor, geoaccumulation index, and risk assessment index revealed that Cd reached high contamination and very high eco-risk, Pb had medium contamination but low eco-risk, Zn showed low contamination and low eco-risk, and Cu was not contaminated in the soils. The data indicated that Cd was the priority to concern in the soils of Hailuogou Glacier catchment.

  3. Changes in metal availability, desorption kinetics and speciation in contaminated soils during repeated phytoextraction with the Zn/Cd hyperaccumulator Sedum plumbizincicola

    International Nuclear Information System (INIS)

    Li, Zhu; Jia, Mingyun; Wu, Longhua; Christie, Peter; Luo, Yongming

    2016-01-01

    Phytoextraction is one of the most promising technologies for the remediation of metal contaminated soils. Changes in soil metal availability during phytoremediation have direct effects on removal efficiency and can also illustrate the interactive mechanisms between hyperaccumulators and metal contaminated soils. In the present study the changes in metal availability, desorption kinetics and speciation in four metal-contaminated soils during repeated phytoextraction by the zinc/cadmium hyperaccumulator Sedum plumbizincicola (S. plumbizincicola) over three years were investigated by chemical extraction and the DGT-induced fluxes in soils (DIFS) model. The available metal fractions (i.e. metal in the soil solution extracted by CaCl_2 and by EDTA) decreased greatly by >84% after phytoextraction in acid soils and the deceases were dramatic at the initial stages of phytoextraction. However, the decreases in metal extractable by CaCl_2 and EDTA in calcareous soils were not significant or quite low. Large decreases in metal desorption rate constants evaluated by DIFS were found in calcareous soils. Sequential extraction indicated that the acid-soluble metal fraction was easily removed by S. plumbizincicola from acid soils but not from calcareous soils. Reducible and oxidisable metal fractions showed discernible decreases in acid and calcareous soils, indicating that S. plumbizincicola can mobilize non-labile metal for uptake but the residual metal cannot be removed. The results indicate that phytoextraction significantly decreases metal availability by reducing metal pool sizes and/or desorption rates and that S. plumbizincicola plays an important role in the mobilization of less active metal fractions during repeated phytoextraction. - Highlights: • Metal availability, desorption, and speciation were tested during phytoextraction. • Metal availability showed an initial sharp decline then a slight change in acid soils. • Metal availability changed little during

  4. Contaminated Metal Components in Dismantling by Hot Cutting Processes

    International Nuclear Information System (INIS)

    Cesari, Franco G.; Conforti, Gianmario; Rogante, Massimo; Giostri, Angelo

    2006-01-01

    During the preparatory dismantling activities of Caorso's Nuclear Power Plant (NPP), an experimental campaign using plasma and oxyacetylene metal cutting processes has been performed and applied to plates and tubes exposed to the coolant steam of the reactor. The plant (Boiling Water Reactor, 870 MWe) was designed and built in the 70's, and it was fully operating by 1981 to 1986 being shut down after 1987 Italy's poll that abrogated nuclear power based on U235 fission. The campaign concerns no activated materials, even if the analyses have been performed of by use contaminated components under the free release level, not yet taking into account radioactivity. In this paper, the parameters related to inhalable aerosol, solid and volatile residuals production have been, studied during hot processes which applies the same characteristics of the cutting in field for the dismantling programs of Caorso NPP. The technical parameters such as cutting time and cutting rate vs. pipe diameter/thickness/schedule or plate thickness for ferritic alloys and the emissions composition coming from the sectioning are also reported. The results underline the sort of trouble that can emerge in the cutting processes, in particular focusing on the effects comparison between the two cutting processes and the chemical composition of powders captured by filtering the gaseous emission. Some preliminary considerations on methodology to be used during the dismantling have been presented. (authors)

  5. Health hazards and heavy metals accumulation by summer squash (Cucurbita pepo L.) cultivated in contaminated soils.

    Science.gov (United States)

    Galal, Tarek M

    2016-07-01

    The present study was carried out to investigate the heavy metal concentration accumulated by summer squash cultivated in contaminated soil and their health hazards for public consumers at south Cairo Province, Egypt. Soil and plants were sampled from contaminated and reference farms, using 1 m(2) quadrats, for biomass estimation and nutrient analysis. The daily intake of metals (DIM) and health risk index (HRI) were estimated. Significant differences in soil variables (except As) between contaminated and reference sites were recognized. Summer squash showed remarkable reduction in fresh and dry biomass, fruit production, and photosynthetic pigments under pollution stress. The inorganic and organic nutrients in the aboveground and belowground parts showed significant reduction in contaminated site. In addition, higher concentrations of heavy metals were accumulated in the edible parts and roots more than shoots. The bioaccumulation factor of summer squash for investigated metals was greater than 1, while the translocation factor did not exceed unity in both contaminated and reference sites. The DIM for all investigated metals in the reference site and in the contaminated site (except Fe and Mn) did not exceed 1 in both adults and children. However, HRI of Ni and Mn in the reference site and Pb, Cd, Cu, Ni, Fe, Mn, and Zn in the contaminated one exceeded unity indicating great potential to pose health risk to the consumers. The author recommends that people living in the contaminated area should not eat large quantities of summer squash, so as to avoid excess accumulation of heavy metals in their bodies.

  6. Nitrogen effects on mobility and plant uptake of heavy metals in sewage sludge applied to soil columns

    Energy Technology Data Exchange (ETDEWEB)

    Giordano, P.M.; Mortvedt, J.J.

    1976-01-01

    Cation movement in soil under leaching conditions has been associated with N fertilization. Therefore, this study was conducted to determine whether the mobility of some heavy metals applied in the inorganic form or in sewage sludge is enhanced in the presence of various sources of N. Columns of heavy metal-amended soil in plastic well casings were cropped with tall fescue (Festuca arundinacea Schreb.) and leached three times with deionized H/sub 2/O. Heavy metal concentrations above check values were not detected in leachates from any column. Mobility of the heavy metals from the inorganic sources was slightly greater than that from the sewage sludge. Nitrogen fertilization did not affect the downward movement of Zn, Cd, Cr, Pb, or Ni in soil but enhanced uptake of these metals by fescue because of increased growth. These results suggest that heavy metal contamination of ground water is not likely in heavy textured soils when sewage sludge applications are accompanied by N fertilization, at least for short periods of time. 11 references, 1 figure, 4 tables.

  7. Remediation of soils contaminated with heavy metals with an emphasis on immobilization technology.

    Science.gov (United States)

    Derakhshan Nejad, Zahra; Jung, Myung Chae; Kim, Ki-Hyun

    2018-06-01

    The major frequent contaminants in soil are heavy metals which may be responsible for detrimental health effects. The remediation of heavy metals in contaminated soils is considered as one of the most complicated tasks. Among different technologies, in situ immobilization of metals has received a great deal of attention and turned out to be a promising solution for soil remediation. In this review, remediation methods for removal of heavy metals in soil are explored with an emphasis on the in situ immobilization technique of metal(loid)s. Besides, the immobilization technique in contaminated soils is evaluated through the manipulation of the bioavailability of heavy metals using a range of soil amendment conditions. This technique is expected to efficiently alleviate the risk of groundwater contamination, plant uptake, and exposure to other living organisms. The efficacy of several amendments (e.g., red mud, biochar, phosphate rock) has been examined to emphasize the need for the simultaneous measurement of leaching and the phytoavailability of heavy metals. In addition, some amendments that are used in this technique are inexpensive and readily available in large quantities because they have been derived from bio-products or industrial by-products (e.g., biochar, red mud, and steel slag). Among different amendments, iron-rich compounds and biochars show high efficiency to remediate multi-metal contaminated soils. Thereupon, immobilization technique can be considered a preferable option as it is inexpensive and easily applicable to large quantities of contaminants derived from various sources.

  8. Mobility and accumulation of heavy metals in podsolic soil via fertilizers usage

    International Nuclear Information System (INIS)

    Pukhovskaya, T.Yu.; Pukhovskij, A.V.

    2008-01-01

    Forecasting of heavy metal mobility and accumulation in soil has a great value for ecosystem status assessment. Results of long-term field and greenhouse experiments with the using X-ray fluorescence method are presented in this paper. New approaches have been proposed for using X-ray spectrometry in agrochemical investigations and heavy metal mobility measurements. (author)

  9. The Pseudomonas community in metal-contaminated sediments as revealed by quantitative PCR: a link with metal bioavailability.

    Science.gov (United States)

    Roosa, Stéphanie; Wauven, Corinne Vander; Billon, Gabriel; Matthijs, Sandra; Wattiez, Ruddy; Gillan, David C

    2014-10-01

    Pseudomonas bacteria are ubiquitous Gram-negative and aerobic microorganisms that are known to harbor metal resistance mechanisms such as efflux pumps and intracellular redox enzymes. Specific Pseudomonas bacteria have been quantified in some metal-contaminated environments, but the entire Pseudomonas population has been poorly investigated under these conditions, and the link with metal bioavailability was not previously examined. In the present study, quantitative PCR and cell cultivation were used to monitor and characterize the Pseudomonas population at 4 different sediment sites contaminated with various levels of metals. At the same time, total metals and metal bioavailability (as estimated using an HCl 1 m extraction) were measured. It was found that the total level of Pseudomonas, as determined by qPCR using two different genes (oprI and the 16S rRNA gene), was positively and significantly correlated with total and HCl-extractable Cu, Co, Ni, Pb and Zn, with high correlation coefficients (>0.8). Metal-contaminated sediments featured isolates of the Pseudomonas putida, Pseudomonas fluorescens, Pseudomonas lutea and Pseudomonas aeruginosa groups, with other bacterial genera such as Mycobacterium, Klebsiella and Methylobacterium. It is concluded that Pseudomonas bacteria do proliferate in metal-contaminated sediments, but are still part of a complex community. Copyright © 2014 Institut Pasteur. Published by Elsevier Masson SAS. All rights reserved.

  10. Removal of heavy metals from contaminated soil by electrodialytic remediation enhanced with organic acids.

    Science.gov (United States)

    Merdoud, Ouarda; Cameselle, Claudio; Boulakradeche, Mohamed Oualid; Akretche, Djamal Eddine

    2016-11-09

    The soil from an industrial area in Algeria was contaminated with Cr (8370 mg kg -1 ), Ni (1135 mg kg -1 ) and zinc (1200 mg kg -1 ). The electrodialytic remediation of this soil was studied using citric acid and EDTA as facilitating agents. 0.1 M citric acid or EDTA was added directly to the soil before it was introduced in an electrodialytic cell in an attempt to enhance the heavy metal solubility in the interstitial fluid. The more acidic pH in the soil when citric acid was used as the facilitating agent was not enough to mobilize and remove the metals from the soil. Only 7.2% of Ni and 6.7% of Zn were removed from the soil in the test with citric acid. The best results were found with EDTA, which was able to solubilize and complex Zn and Ni forming negatively charged complexes that were transported and accumulated in the anolyte. Complete removal was observed for Ni and Zn in the electrodialytic treatment with EDTA. Minor amounts of Cr were removed with both EDTA and citric acid.

  11. Diuron mobility through vineyard soils contaminated with copper

    Energy Technology Data Exchange (ETDEWEB)

    Jacobson, Astrid R. [UMR INRA 1229 Microbiologie-Geochimie des Sols, Centre des Sciences de la Terre, Universite de Bourgogne, 6 Bd Gabriel, 21000 Dijon (France) and Department of Crop and Soil Sciences, Cornell University, 1002 Bradfield Hall, Ithaca, NY 14853 (United States)]. E-mail: arj5@cornell.edu; Dousset, Sylvie [UMR INRA 1229 Microbiologie-Geochimie des Sols, Centre des Sciences de la Terre, Universite de Bourgogne, 6 Bd Gabriel, 21000 Dijon (France); Guichard, Nathalie [UMR CNRS 5561 Biogeosciences, Centre des Sciences de la Terre, Universite de Bourgogne, 6 Bd Gabriel, 21000 Dijon (France); Baveye, Philippe [Department of Crop and Soil Sciences, Cornell University, 1002 Bradfield Hall, Ithaca, NY 14853 (United States); Andreux, Francis [UMR INRA 1229 Microbiologie-Geochimie des Sols, Centre des Sciences de la Terre, Universite de Bourgogne, 6 Bd Gabriel, 21000 Dijon (France)

    2005-11-15

    The herbicide diuron is frequently applied to vineyard soils in Burgundy, along with repeated treatments with Bordeaux mixture (a blend of copper sulfate and calcium hydroxide) that result in elevated copper concentrations. Cu could in principle affect the fate and transport of diuron or its metabolites in the soil either directly by complexation or indirectly by altering the populations or activity of microbes involved in their degradation. To assess the effect of high Cu concentrations on diuron transport, an experiment was designed with ten undisturbed columns of calcareous and acidic soils contaminated with 17-509 mg kg{sup -1} total Cu (field-applied). Grass was planted on three columns. Diuron was applied to the soils in early May and in-ground lysimeters were exposed to outdoor conditions until November. Less than 1.2% of the diuron applied was found in the leachates as diuron or its metabolites. Higher concentrations were found in the effluents from the grass-covered columns (0.1-0.45%) than from the bare-soil columns (0.02-0.14%), and they were correlated with increases in dissolved organic carbon. The highest amounts of herbicide were measured in acidic-soil column leachates (0.98-1.14%) due to the low clay and organic matter contents of these soils. Cu also leached more readily through the acidic soils (32.8-1042 {mu}g) than in the calcareous soils (9.5-63.4 {mu}g). Unlike in the leachates, the amount of diuron remaining in the soils at the end of the experiment was weakly related to the Cu concentrations in the soils. - Cu accumulation, from Bordeaux mixture, in vineyard soils may be affecting microbial activity and thus slightly increasing the persistence of diuron in the soils.

  12. Diuron mobility through vineyard soils contaminated with copper.

    Science.gov (United States)

    Jacobson, Astrid R; Dousset, Sylvie; Guichard, Nathalie; Baveye, Philippe; Andreux, Francis

    2005-11-01

    The herbicide diuron is frequently applied to vineyard soils in Burgundy, along with repeated treatments with Bordeaux mixture (a blend of copper sulfate and calcium hydroxide) that result in elevated copper concentrations. Cu could in principle affect the fate and transport of diuron or its metabolites in the soil either directly by complexation or indirectly by altering the populations or activity of microbes involved in their degradation. To assess the effect of high Cu concentrations on diuron transport, an experiment was designed with ten undisturbed columns of calcareous and acidic soils contaminated with 17--509 mg kg(-1) total Cu (field-applied). Grass was planted on three columns. Diuron was applied to the soils in early May and in-ground lysimeters were exposed to outdoor conditions until November. Less than 1.2% of the diuron applied was found in the leachates as diuron or its metabolites. Higher concentrations were found in the effluents from the grass-covered columns (0.1--0.45%) than from the bare-soil columns (0.02--0.14%), and they were correlated with increases in dissolved organic carbon. The highest amounts of herbicide were measured in acidic-soil column leachates (0.98--1.14%) due to the low clay and organic matter contents of these soils. Cu also leached more readily through the acidic soils (32.8--1042 microg) than in the calcareous soils (9.5--63.4 microg). Unlike in the leachates, the amount of diuron remaining in the soils at the end of the experiment was weakly related to the Cu concentrations in the soils.

  13. Diuron mobility through vineyard soils contaminated with copper

    International Nuclear Information System (INIS)

    Jacobson, Astrid R.; Dousset, Sylvie; Guichard, Nathalie; Baveye, Philippe; Andreux, Francis

    2005-01-01

    The herbicide diuron is frequently applied to vineyard soils in Burgundy, along with repeated treatments with Bordeaux mixture (a blend of copper sulfate and calcium hydroxide) that result in elevated copper concentrations. Cu could in principle affect the fate and transport of diuron or its metabolites in the soil either directly by complexation or indirectly by altering the populations or activity of microbes involved in their degradation. To assess the effect of high Cu concentrations on diuron transport, an experiment was designed with ten undisturbed columns of calcareous and acidic soils contaminated with 17-509 mg kg -1 total Cu (field-applied). Grass was planted on three columns. Diuron was applied to the soils in early May and in-ground lysimeters were exposed to outdoor conditions until November. Less than 1.2% of the diuron applied was found in the leachates as diuron or its metabolites. Higher concentrations were found in the effluents from the grass-covered columns (0.1-0.45%) than from the bare-soil columns (0.02-0.14%), and they were correlated with increases in dissolved organic carbon. The highest amounts of herbicide were measured in acidic-soil column leachates (0.98-1.14%) due to the low clay and organic matter contents of these soils. Cu also leached more readily through the acidic soils (32.8-1042 μg) than in the calcareous soils (9.5-63.4 μg). Unlike in the leachates, the amount of diuron remaining in the soils at the end of the experiment was weakly related to the Cu concentrations in the soils. - Cu accumulation, from Bordeaux mixture, in vineyard soils may be affecting microbial activity and thus slightly increasing the persistence of diuron in the soils

  14. Phytotoxicity of trace metals in spiked and field-contaminated soils: Linking soil-extractable metals with toxicity.

    Science.gov (United States)

    Hamels, Fanny; Malevé, Jasmina; Sonnet, Philippe; Kleja, Dan Berggren; Smolders, Erik

    2014-11-01

    Soil tests have been widely developed to predict trace metal uptake by plants. The prediction of metal toxicity, however, has rarely been tested. The present study was set up to compare 8 established soil tests for diagnosing phytotoxicity in contaminated soils. Nine soils contaminated with Zn or Cu by metal mining, smelting, or processing were collected. Uncontaminated reference soils with similar soil properties were sampled, and series of increasing contamination were created by mixing each with the corresponding soil. In addition, each reference soil was spiked with either ZnCl2 or CuCl2 at several concentrations. Total metal toxicity to barley seedling growth in the field-contaminated soils was up to 30 times lower than that in corresponding spiked soils. Total metal (aqua regia-soluble) toxicity thresholds of 50% effective concentrations (EC50) varied by factors up to 260 (Zn) or 6 (Cu) among soils. For Zn, variations in EC50 thresholds decreased as aqua regia > 0.43 M HNO3  > 0.05 M ethylenediamine tetraacetic acid (EDTA) > 1 M NH4 NO3  > cobaltihexamine > diffusive gradients in thin films (DGT) > 0.001 M CaCl2 , suggesting that the last extraction is the most robust phytotoxicity index for Zn. The EDTA extraction was the most robust for Cu-contaminated soils. The isotopically exchangeable fraction of the total soil metal in the field-contaminated soils markedly explained the lower toxicity compared with spiked soils. The isotope exchange method can be used to translate soil metal limits derived from soils spiked with metal salts to site-specific soil metal limits. © 2014 SETAC.

  15. Influence of dissimilatory metal reduction on fate of organic and metal contaminants in the subsurface

    Science.gov (United States)

    Lovley, Derek R.; Anderson, Robert T.

    Dissimilatory Fe(III)-reducing microorganisms have the ability to destroy organic contaminants under anaerobic conditions by oxidizing them to carbon dioxide. Some Fe(III)-reducing microorganisms can also reductively dechlorinate chlorinated contaminants. Fe(III)-reducing microorganisms can reduce a variety of contaminant metals and convert them from soluble forms to forms that are likely to be immobilized in the subsurface. Studies in petroleum-contaminated aquifers have demonstrated that Fe(III)-reducing microorganisms can be effective agents in removing aromatic hydrocarbons from groundwater under anaerobic conditions. Laboratory studies have demonstrated the potential for Fe(III)-reducing microorganisms to remove uranium from contaminated groundwaters. The activity of Fe(III)-reducing microorganisms can be stimulated in several ways to enhance organic contaminant oxidation and metal reduction. Molecular analyses in both field and laboratory studies have demonstrated that microorganisms of the genus Geobacter become dominant members of the microbial community when Fe(III)-reducing conditions develop as the result of organic contamination, or when Fe(III) reduction is artificially stimulated. These results suggest that further understanding of the ecophysiology of Geobacter species would aid in better prediction of the natural attenuation of organic contaminants under anaerobic conditions and in the design of strategies for the bioremediation of subsurface metal contamination. Des micro-organismes simulant la réduction du fer ont la capacité de détruire des polluants organiques dans des conditions anérobies en les oxydant en dioxyde de carbone. Certains micro-organismes réducteurs de fer peuvent aussi dé-chlorer par réduction des polluants chlorés. Des micro-organismes réducteurs de fer peuvent réduire tout un ensemble de métaux polluants et les faire passer de formes solubles à des formes qui sont susceptibles d'être immobilisées dans le milieu

  16. Trace metal contamination of Beaufort's Dyke, North Channel, Irish Sea: A legacy of ordnance disposal

    International Nuclear Information System (INIS)

    Callaway, Alexander; Quinn, Rory; Brown, Craig J.; Service, Matthew; Benetti, Sara

    2011-01-01

    Highlights: → Our samples are the first trace metal concentrations taken from the valley of Beaufort's Dyke. → There is no clear trend between concentrations of trace metals in Dyke and NMMP sediments. → Particle transport simulations show dispersal of trace metals from Beaufort's Dyke is possible. → Disposed ordnance may also contribute to contamination of surrounding areas. → These methods could help predict areas at risk of future trace metal contamination as a result of ordnance disposal. - Abstract: Beaufort's Dyke is a disused ordnance disposal ground within the North Channel of the Irish Sea. Over 1 million tonnes of ordnance were disposed of in the dyke over a 40 year period representing a substantial volume of trace metal pollutants introduced to the seabed. Utilising particle transport modelling software we simulated the potential transport of metal particles from Beaufort's Dyke over a 3 month period. This demonstrated that Beaufort's Dyke has the potential to act as a source for trace metal contamination to areas beyond the submarine valley. Trace metal analysis of sediments from the Dyke and surrounding National Marine Monitoring Programme areas demonstrate that the Dyke is not the most contaminated site in the region. Particle transport modelling enables the transport pathways of trace metal contaminants to be predicted. Implementation of the technique in other munitions disposal grounds will provide valuable information for the selection of monitoring stations.

  17. Microbial functional genes enriched in the Xiangjiang River sediments with heavy metal contamination.

    Science.gov (United States)

    Jie, Shiqi; Li, Mingming; Gan, Min; Zhu, Jianyu; Yin, Huaqun; Liu, Xueduan

    2016-08-08

    Xiangjiang River (Hunan, China) has been contaminated with heavy metal for several decades by surrounding factories. However, little is known about the influence of a gradient of heavy metal contamination on the diversity, structure of microbial functional gene in sediment. To deeply understand the impact of heavy metal contamination on microbial community, a comprehensive functional gene array (GeoChip 5.0) has been used to study the functional genes structure, composition, diversity and metabolic potential of microbial community from three heavy metal polluted sites of Xiangjiang River. A total of 25595 functional genes involved in different biogeochemical processes have been detected in three sites, and different diversities and structures of microbial functional genes were observed. The analysis of gene overlapping, unique genes, and various diversity indices indicated a significant correlation between the level of heavy metal contamination and the functional diversity. Plentiful resistant genes related to various metal were detected, such as copper, arsenic, chromium and mercury. The results indicated a significantly higher abundance of genes involved in metal resistance including sulfate reduction genes (dsr) in studied site with most serious heavy metal contamination, such as cueo, mer, metc, merb, tehb and terc gene. With regard to the relationship between the environmental variables and microbial functional structure, S, Cu, Cd, Hg and Cr were the dominating factor shaping the microbial distribution pattern in three sites. This study suggests that high level of heavy metal contamination resulted in higher functional diversity and the abundance of metal resistant genes. These variation therefore significantly contribute to the resistance, resilience and stability of the microbial community subjected to the gradient of heavy metals contaminant in Xiangjiang River.

  18. Distribution and Potential Mobility of Selected Heavy Metals in a Fluvial Environment Under the Influence of Tanneries

    Directory of Open Access Journals (Sweden)

    Rodrigues M. L. K.

    2013-04-01

    Full Text Available In this study we evaluated the occurrence of heavy metals in a fluvial environment under the influence of tanneries – the Cadeia and Feitoria rivers basin (RS, south Brazil, highlighting the distribution and potential mobility of the selected elements. Every three months, over one year-period, selected heavy metals and ancillary parameters were analyzed in water and sediment samples taken at ten sites along the rivers. Water analyses followed APHA recommendations, and sediment analyses were based on methods from USEPA (SW846 and European Community (BCR sequential extraction. The determinations were performed by ICP/OES, except for Hg (CV/ETA. Statistical factor analysis was applied to water and sediment data sets, in order to obtain a synthesis of the environmental diagnosis. The results revealed that water quality decreased along the rivers, and mainly on the dry period (January, showing the influence of tannery plants vicinity and flow variations. Except for Fe, Al, and eventually Mn, heavy metal contents in water were in agreement with Brazilian standards. Concerning sediments, Al, Cu, Fe, Ni, Mn, Ti, and Zn concentrations appeared to reflect the base levels, while Cr and Hg were enriched in the deposits from the lower part of the basin. The partition of heavy metals among the sediment geochemical phases showed higher mobility of Mn along the sampling sites, followed by Cr in the lower reach of the basin, most affected by tanneries. Since Cr was predominantly associated to the oxidizable fraction, its potential mobilization from contaminated sediments would be associated to redox conditions. The detection of Hg in the tissue of a bottom-fish species indicated that the environmental conditions are apparently favoring the remobilization of this metal from contaminated sediments.

  19. Evaluation of Microbial Contamination of Mobile Phone among Dentists in College of Dentistry in Baghdad University

    Directory of Open Access Journals (Sweden)

    Batool H. Al-Ghurabi

    2017-11-01

    Full Text Available Background: Mobiles have become one of the most indispensable accessories of profession and social life. The mobiles make life easier, but they pose a number of new hazards also. Objectives: The principle aim of this study was to evaluate the microbial contamination of mobile phones belonging to dentists in College of Dentistry in Baghdad University. Materials and Methods: 35 dentists (20 female and 15 male were enrolled in this study. Sampling was taken from each participant’s mobile by using moist sterile swab impregnated by normal saline for microbial analyses. Results: The findings of this study revealed that the growth of microorganisms has found in all samples taken from the mobile phones of dentists. The most common microorganisms detected were Staphylococcus epidermidis, Micrococcus spp., Candida albicans and Aspergillus niger. On the other hand, there was no significant difference (P>0.05 in the microorganisms isolated and their percentage frequency of occurrence between mobile phones for male and female. Concussions: The current results indicated that mobile phones can serve as a vector for crosstransmission of community-acquired pathogenic organisms for human.

  20. Spatial assessment of soil contamination by heavy metals from informal electronic waste recycling in Agbogbloshie, Ghana.

    Science.gov (United States)

    Kyere, Vincent Nartey; Greve, Klaus; Atiemo, Sampson M

    2016-01-01

    This study examined the spatial distribution and the extent of soil contamination by heavy metals resulting from primitive, unconventional informal electronic waste recycling in the Agbogbloshie e-waste processing site (AEPS) in Ghana. A total of 132 samples were collected at 100 m intervals, with a handheld global position system used in taking the location data of the soil sample points. Observing all procedural and quality assurance measures, the samples were analyzed for barium (Ba), cadmium (Cd), cobalt (Co), chromium (Cr), copper (Cu), mercury (Hg), nickel (Ni), lead (Pb), and zinc (Zn), using X-ray fluorescence. Using environmental risk indices of contamination factor and degree of contamination (C deg ), we analyzed the individual contribution of each heavy metal contamination and the overall C deg . We further used geostatistical techniques of spatial autocorrelation and variability to examine spatial distribution and extent of heavy metal contamination. Results from soil analysis showed that heavy metal concentrations were significantly higher than the Canadian Environmental Protection Agency and Dutch environmental standards. In an increasing order, Pb>Cd>Hg>Cu>Zn>Cr>Co>Ba>Ni contributed significantly to the overall C deg . Contamination was highest in the main working areas of burning and dismantling sites, indicating the influence of recycling activities. Geostatistical analysis also revealed that heavy metal contamination spreads beyond the main working areas to residential, recreational, farming, and commercial areas. Our results show that the studied heavy metals are ubiquitous within AEPS and the significantly high concentration of these metals reflect the contamination factor and C deg , indicating soil contamination in AEPS with the nine heavy metals studied.

  1. Final Report for Project ''Role of Metal Bioavailability in In Situ Bioremediation of Metal and Organic Co-Contaminated Sites''; FINAL

    International Nuclear Information System (INIS)

    Raina M. Maier

    2002-01-01

    A large proportion of hazardous waste sites are co-contaminated with organics and various metals. Such co-contaminated sites are difficult to bioremediate due to the nature of the mixed contaminants. Specifically, the presence of a co-contaminating metal imposes increased stress on indigenous populations already impacted by organic contaminant stress. The overall objective of this research is to investigate the effect of varying metal bioavailability on microbial populations and biodegradation of organics to allow a better understanding of how optimize remediation of co-contaminated sites. The hypothesis for this project is that metal bioavailability is not directly correlated with metal stress imposed on microbial populations that are degrading organics in soil and that further understanding of the relationship between metal bioavailability and metal stress is required for successful treatment of sites contaminated with mixtures of organics and metals. The specific objectives to be addressed to accomplish this goal are: (1) To determine the influence of metal bioavailability in soil microcosms co-contaminated with organics and metals on degradation of the organic contaminants and on mechanisms of metal resistance and (2) To determine the efficacy of different bioremediation strategies for co-contaminated soils based on metal bioavailability

  2. Biodegradation of metal citrate complexes and implications for toxic-metal mobility

    International Nuclear Information System (INIS)

    Francis, A.J.; Dodge, C.J.; Gillow, J.B.

    1992-01-01

    The presence of synthetic and naturally occurring chelating agents in nuclear and toxic-metal wastes is a major concern because of their potential to enhance mobilization of metal ions away from the disposal sites. Of particular interest is citric acid, which is present in low-level and transuranic radioactive wastes and in domestic and industrial wastes (as washing fluids, for instance), as well as being found naturally. Citrate ions form multidentate, stable complexes with a variety of toxic metals and radionuclides; but biodegradation of these complexes, precipitating the metal ions as insoluble hydroxides, oxides or other salts, may retard migration. Here we report a study of the biodegradation of citrate complexes of Ca, Fe(II), Fe(III), Cd, Cu, Ni, Pb and U. Several of these complexes were not readily degraded by bacteria, and the biodegradability depended on the chemical nature of the complex, not on the toxicity of the metal to the bacteria. This resistance to biodegradation implies that citrate complexation may play an important part in migration of these hazardous wastes. (author)

  3. A review on heavy metal contamination in the soil worldwide: Situation, impact and remediation techniques

    OpenAIRE

    Chao Su; LiQin Jiang; WenJun Zhang

    2014-01-01

    Heavy metals in the soil refers to some significant heavy metals of biological toxicity, including mercury (Hg), cadmium (Cd), lead (Pb), chromium (Cr), and arsenic (As), etc. With the development of the global economy, both type and content of heavy metals in the soil caused by human activities have gradually increased in recent years, which have resulted in serious environment deterioration. In present study we compared and analyzed soil contamination of heavy metals in various cities/count...

  4. A comparison of technologies for remediation of heavy metal contaminated soils

    OpenAIRE

    Khalid , Sana; Shahid , Muhammad; Niazi , Nabeel Khan; Murtaza , Behzad; Bibi , Irshad; Dumat , Camille

    2016-01-01

    International audience; Soil contamination with persistent and potentially (eco)toxic heavy metal(loid)s is ubiquitous around the globe. Concentration of these heavy metal(loid)s in soil has increased drastically over the last three decades, thus posing risk to the environment and human health. Some technologies have long been in use to remediate the hazardous heavy metal(loid)s. Conventional remediation methods for heavy metal(loid)s are generally based on physical, chemical and biological a...

  5. Microbial characterization of a radionuclide- and metal-contaminated waste site

    International Nuclear Information System (INIS)

    Bolton, H. Jr.; Lumppio, H.L.; Ainsworth, C.C.; Plymale, A.E.

    1993-04-01

    The operation of nuclear processing facilities and defense-related nuclear activities has resulted in contamination of near-surface and deep-subsurface sediments with both radionuclides and metals. The presence of mixed inorganic contaminants may result in undetectable microbial populations or microbial populations that are different from those present in uncontaminated sediments. To determine the impact of mixed radionuclide and metal contaminants on sediment microbial communities, we sampled a processing pond that was used from 1948 to 1975 for the disposal of radioactive and metal-contaminated wastewaters from laboratories and nuclear fuel fabrication facilities on the Hanford Site in Washington State. Because the Hanford Site is located in a semiarid environment with average rainfall of 159 mm/year, the pond dried and a settling basin remained after wastewater input into the pond ceased in 1975. This processing pond basin offered a unique opportunity to obtain near-surface sediments that had been contaminated with both radionuclides and metals for several decades. Our objectives were to determine the viable populations of microorganisms in the sediments and to test several hypotheses about how the addition of both radionuclides and metals influenced the microbial ecology of the sediments. Our first hypothesis was that viable populations of microorganisms would be lower in the more contaminated sediments. Second, we expected that long-term metal exposure would result in enhanced metal resistance. Finally, we hypothesized that microorganisms from the most radioactive sediments should have had enhanced radiation resistance

  6. Do earthworms impact metal mobility and availability in soil? - A review

    International Nuclear Information System (INIS)

    Sizmur, Tom; Hodson, Mark E.

    2009-01-01

    The importance of earthworms to ecosystem functioning has led to many studies on the impacts of metals on earthworms. Far less attention has been paid to the impact that earthworms have on soil metals both in terms of metal mobility and availability. In this review we consider which earthworms have been used in such studies, which soil components have been investigated, which types of soil have been used and what measures of mobility and availability applied. We proceed to review proposed reasons for effects: changes in microbial populations, pH, dissolved organic carbon and metal speciation. The balance of evidence suggests that earthworms increase metal mobility and availability but more studies are required to determine the precise mechanism for this. - We review the impact of earthworms on metal mobility and availability and suggest areas for further investigation.

  7. Low-cost bioremediation of heavy metals and radionuclides of contaminated soils

    International Nuclear Information System (INIS)

    Sathiyamoorthy, P.; Golan-Goldhrish, A.

    2005-01-01

    The environmental pollution by toxic metals, especially lead (Pb), mercury (Hg), cadmium (Cd), nickel (Ni), copper (Cu), selenium (Se), chromium (Cr) and radionuclides ( 137 Cs, 90 Sr, 238 Pu, 226 Ra) is a potential hazard to health and welfare of mankind. Rapid industrial revolution has left an international legacy of soil and water contaminated with a combination of toxic and potentially carcinogenic compounds and heavy metals. Many of the contaminated sites were abandoned due to high cost of traditional clean-up approaches. Various approaches are being practiced to decontaminate heavy metals and radionuclides from polluted-soil. Remediation of heavy metal and radionuclides contaminated soils poses a significant expense to many industries and government organizations. Remediation cost in the United States and European Union alone is expected to exceed US$20 billion annually. Bioremediation strategy depends on the limitations of technology, cost and nature of the contaminant in the soil. Certain higher plants are capable of accumulation of heavy metals (2-5 %) in roots and shoots to the level far exceeding those present in the soils, these are called hyper-accumulators. Using heavy metal hyper-accumulating higher plants for environmental clean-up of contaminated soil is a recently emerged technology known as 'phytoremediation'. Genetically engineered (Transgenic) plants have a remarkable potential to absorb heavy metals and show a new avenue for biotechnology technique in Phytoremediation. The cost-effective approach of using heavy metal and radionuclide hyper-accumulators in phytoremediation is discussed. (author)

  8. Heavy metal-immobilizing organoclay facilitates polycyclic aromatic hydrocarbon biodegradation in mixed-contaminated soil

    Energy Technology Data Exchange (ETDEWEB)

    Biswas, Bhabananda; Sarkar, Binoy [Centre for Environmental Risk Assessment and Remediation, University of South Australia, Mawson Lakes Campus, SA 5095 (Australia); Cooperative Research Centre for Contamination Assessment and Remediation of the Environment, P.O. Box 486, Salisbury, SA 5106 (Australia); Mandal, Asit [Centre for Environmental Risk Assessment and Remediation, University of South Australia, Mawson Lakes Campus, SA 5095 (Australia); Division of Soil Biology, Indian Institute of Soil Science, Bhopal, Madhya Pradesh (India); Naidu, Ravi [Centre for Environmental Risk Assessment and Remediation, University of South Australia, Mawson Lakes Campus, SA 5095 (Australia); Cooperative Research Centre for Contamination Assessment and Remediation of the Environment, P.O. Box 486, Salisbury, SA 5106 (Australia)

    2015-11-15

    Highlights: • A novel metal-immobilizing organoclay (MIOC) synthesized and characterized. • MIOC immobilizes toxic metals and reduces metal bioavailability. • It enhances PAH-bioavailability to soil bacteria. • It improves microbial growth and activities in mixed-contaminated soils. • MIOC facilitates PAH-biodegradation in metal co-contaminated soils. - Abstract: Soils contaminated with a mixture of heavy metals and polycyclic aromatic hydrocarbons (PAHs) pose toxic metal stress to native PAH-degrading microorganisms. Adsorbents such as clay and modified clay minerals can bind the metal and reduce its toxicity to microorganisms. However, in a mixed-contaminated soil, an adsorption process more specific to the metals without affecting the bioavailability of PAHs is desired for effective degradation. Furthermore, the adsorbent should enhance the viability of PAH-degrading microorganisms. A metal-immobilizing organoclay (Arquad{sup ®} 2HT-75-bentonite treated with palmitic acid) (MIOC) able to reduce metal (cadmium (Cd)) toxicity and enhance PAH (phenanthrene) biodegradation was developed and characterized in this study. The MIOC differed considerably from the parent clay in terms of its ability to reduce metal toxicity (MIOC > unmodified bentonite > Arquad–bentonite). The MIOC variably increased the microbial count (10–43%) as well as activities (respiration 3–44%; enzymatic activities up to 68%), and simultaneously maintained phenanthrene in bioavailable form in a Cd-phenanthrene mixed-contaminated soil over a 21-day incubation period. This study may lead to a new MIOC-assisted bioremediation technique for PAHs in mixed-contaminated soils.

  9. Assessment of potentially toxic metal contamination in the soils of a legacy mine site in Central Victoria, Australia.

    Science.gov (United States)

    Abraham, Joji; Dowling, Kim; Florentine, Singarayer

    2018-02-01

    The environmental impact of toxic metal contamination from legacy mining activities, many of which had operated and were closed prior to the enforcement of robust environmental legislation, is of growing concern to modern society. We have carried out analysis of As and potentially toxic metals (Cd, Co, Cr, Cu, Hg, Mn, Ni, Pb, and Zn) in the surface soil of a legacy gold mining site in Maldon, Victoria, Australia, to reveal the status of the current metal concentration. The results revealed the median concentrations of metals from highest to lowest, in the order: Mn > Zn > As > Cr > Cu > Pb > Ni > Co > Hg > Cd. The status of site was assessed directly by comparing the metal concentrations in the study area with known Australian and Victorian average top soil levels and the health investigation levels set by the National Environmental Protection Measures (NEPM) and the Department of Environment and Conservation (DEC) of the State of Western Australia. Although, median concentrations of As, Hg, Pb, Cu and Zn exceeded the average Australian and Victorian top soil concentrations, only As and Hg exceeded the ecological investigation levels (EIL) set by DEC and thus these metals are considered as risk to the human and aquatic ecosystems health due to their increase in concentration and toxicity. In an environment of climate fluctuation with increased storm events and forest fires may mobilize these toxic metals contaminants, pose a real threat to the environment and the community. Copyright © 2017 Elsevier Ltd. All rights reserved.

  10. Remediation of Steel Slag on Acidic Soil Contaminated by Heavy Metal

    OpenAIRE

    Gu, Haihong; Li, Fuping; Guan, Xiang; Li, Zhongwei; Yu, Qiang

    2013-01-01

    The technology of in situ immobilization with amendments is an important measure that remediates the soil contaminated by heavy metal, and selecting economical and effective modifier is the key. The effects and mechanism of steel slag, the silicon-rich alkaline by-product which can remediate acidic soil contaminated by heavy metal, are mainly introduced in this paper to provide theory inferences for future research. Firstly, the paper analyzes current research situation of in situ immobilizat...

  11. Modeling phytoextraction of heavy metals at multiply contaminated soils with hyperaccumulator plants

    OpenAIRE

    Khodaverdiloo, Habib

    2009-01-01

    Soils and waters contaminated with heavy metals pose a major environmental and human health problem that needs an effective and affordable technological solution. Phytoextraction offers a reasonable technology which uses plants to extract the heavy metals from soils. However, the effectiveness of this new method needs to be demonstrated by means of mathematical modeling. The phytoextraction models also are needed to manage the contaminated soils. A thorough literature review indic...

  12. Utilization of plants for stabilization and cleaning up of metal contaminated soil and water

    Directory of Open Access Journals (Sweden)

    Miroslav Štofko

    2006-06-01

    Full Text Available Phytoremediation has been defined as the use of green plants and their associated rhizospheric microorganisms to remove, degrade, or contain contaminants located in soisl, sediments, groundwater, surface water, and even the atmosphere. Categories of phytoremediation include - phytoextraction or phytoaccumulation, phytotransformation, phytostimulation or plant-assisted bioremediation, phytovolatilization, rhizofiltration, pump and tree, phytostabilization, and hydraulic control. Phytoremediation of heavy metal contaminated soils basically includes phytostabilization, phytoextraction, rhizofiltration and phytovolatilization. Selection of plants for phytoremediation of metals depends on a particular application.

  13. Potential of Sunflower (Helianthus annuus L.) for Phytoremediation of Soils Contaminated with Heavy Metals

    OpenAIRE

    Violina R. Angelova; Mariana N. Perifanova-Nemska; Galina P. Uzunova; Krasimir I. Ivanov; Huu Q. Lee

    2016-01-01

    A field study was conducted to evaluate the efficacy of the sunflower (Helianthus annuus L.) for phytoremediation of contaminated soils. The experiment was performed on an agricultural field contaminated by the Non-Ferrous-Metal Works near Plovdiv, Bulgaria. Field experiments with a randomized, complete block design with five treatments (control, compost amendments added at 20 and 40 t/daa, and vemicompost amendments added at 20 and 40 t/daa) were carried out. The accumulation of heavy metals...

  14. CHANGING THE LANDSCAPE--LOW-TECH SOLUTIONS TO THE PADUCAH SCRAP METAL REMOVAL PROJECT ARE PROVIDING SAFE, COST-EFFECTIVE REMEDIATION OF CONTAMINATED SCRAP YARDS

    International Nuclear Information System (INIS)

    Watson, Dan; Eyman, Jeff

    2003-01-01

    Between 1974 and 1983, contaminated equipment was removed from the Paducah Gaseous Diffusion Plant (PGDP) process buildings as part of an enrichment process upgrade program. The upgrades consisted of the dismantlement, removal, and on-site storage of contaminated equipment, cell components, and scrap material (e.g., metal) from the cascade facilities. Scrap metal including other materials (e.g., drums, obsolete equipment) not related to this upgrade program have thus far accumulated in nine contiguous radiologically-contaminated and non-contaminated scrap yards covering 1.05E5 m2 (26 acres) located in the northwestern portion of the PGDP. This paper presents the sequencing of field operations and methods used to achieve the safe removal and disposition of over 47,000 tonnes (53,000 tons) of metal and miscellaneous items contained in these yards. The methods of accomplishment consist of mobilization, performing nuclear criticality safety evaluations, moving scrap metal to ground level, inspection and segregation, sampling and characterization, scrap metal sizing, packaging and disposal, and finally demobilization. Preventing the intermingling of characteristically hazardous and non-hazardous wastes promotes waste minimization, allowing for the metal and materials to be segregated into 13 separate waste streams. Low-tech solutions such as using heavy equipment to retrieve, size, and package scrap materials in conjunction with thorough planning that integrates safe work practices, commitment to teamwork, and incorporating lessons learned ensures that field operations will be conducted efficiently and safely

  15. Contamination and health risks of soil heavy metals around a lead/zinc smelter in southwestern China.

    Science.gov (United States)

    Li, Peizhong; Lin, Chunye; Cheng, Hongguang; Duan, Xiaoli; Lei, Kai

    2015-03-01

    Anthropogenic emissions of toxic metals from smelters are a global problem. The objective of this study was to investigate the distribution of toxic metals in soils around a 60 year-old Pb/Zn smelter in a town in Yunnan Province of China. Topsoil and soil core samples were collected and analyzed to determine the concentrations of various forms of toxic metals. The results indicated that approximately 60 years of Pb/Zn smelting has led to significant contamination of the local soil by Zn, Pb, Cd, As, Sb, and Hg, which exhibited maximum concentrations of 8078, 2485, 75.4, 71.7, 25.3, and 2.58mgkg(-1), dry wet, respectively. Other metals, including Co, Cr, Cu, Mn, Ni, Sc, and V, were found to originate from geogenic sources. The concentrations of smelter driven metals in topsoil decreased with increasing distance from the smelter. The main contamination by Pb, Zn, and Cd was found in the upper 40cm of soil around the Pb/Zn smelter, but traces of Pb, Zn, and Cd contamination were found below 100cm. Geogenic Ni in the topsoil was mostly bound in the residual fraction (RES), whereas anthropogenic Cd, Pb, and Zn were mostly associated with non-RES fractions. Therefore, the smelting emissions increased not only the concentrations of Cd, Pb, and Zn in the topsoil but also their mobility and bioavailability. The hazard quotient and hazard index showed that the topsoil may pose a health risk to children, primarily due to the high Pb and As contents of the soil. Copyright © 2014 Elsevier Inc. All rights reserved.

  16. Challenges and opportunities in the phytoremediation of heavy metals contaminated soils: A review.

    Science.gov (United States)

    Mahar, Amanullah; Wang, Ping; Ali, Amjad; Awasthi, Mukesh Kumar; Lahori, Altaf Hussain; Wang, Quan; Li, Ronghua; Zhang, Zengqiang

    2016-04-01

    Mining operations, industrial production and domestic and agricultural use of metal and metal containing compound have resulted in the release of toxic metals into the environment. Metal pollution has serious implications for the human health and the environment. Few heavy metals are toxic and lethal in trace concentrations and can be teratogenic, mutagenic, endocrine disruptors while others can cause behavioral and neurological disorders among infants and children. Therefore, remediation of heavy metals contaminated soil could be the only effective option to reduce the negative effects on ecosystem health. Thus, keeping in view the above facts, an attempt has been made in this article to review the current status, challenges and opportunities in the phytoremediation for remediating heavy metals from contaminated soils. The prime focus is given to phytoextraction and phytostabilization as the most promising and alternative methods for soil reclamation. Copyright © 2015 Elsevier Inc. All rights reserved.

  17. Influence of multi-step washing using Na2EDTA, oxalic acid and phosphoric acid on metal fractionation and spectroscopy characteristics from contaminated soil.

    Science.gov (United States)

    Wei, Meng; Chen, Jiajun

    2016-11-01

    A multi-step soil washing test using a typical chelating agent (Na 2 EDTA), organic acid (oxalic acid), and inorganic weak acid (phosphoric acid) was conducted to remediate soil contaminated with heavy metals near an arsenic mining area. The aim of the test was to improve the heavy metal removal efficiency and investigate its influence on metal fractionation and the spectroscopy characteristics of contaminated soil. The results indicated that the orders of the multi-step washing were critical for the removal efficiencies of the metal fractions, bioavailability, and potential mobility due to the different dissolution levels of mineral fractions and the inter-transformation of metal fractions by XRD and FT-IR spectral analyses. The optimal soil washing options were identified as the Na 2 EDTA-phosphoric-oxalic acid (EPO) and phosphoric-oxalic acid-Na 2 EDTA (POE) sequences because of their high removal efficiencies (approximately 45 % for arsenic and 88 % for cadmium) and the minimal harmful effects that were determined by the mobility and bioavailability of the remaining heavy metals based on the metal stability (I R ) and modified redistribution index ([Formula: see text]).

  18. Characterization of soil and plant-associated bacteria on a metal contaminated site

    International Nuclear Information System (INIS)

    Boulet, J.; Weyens, N.; Barac, T.; Dupae, J.; Lelie, D. van der; Taghavi, S.; Vaqngronsveld, J.

    2009-01-01

    Conventional methods for the remediation of heavy metal contaminated soils and ground water are very expensive and often damaging to the environment. Complementary to these traditional methods, especially for sites with a diffuse contamination in relatively low concentrations, phyto extraction is proposed as a promising technology for effective and inexpensive radiation. (Author)

  19. Remediation of heavy metal contaminated soils by using Solanum nigrum: A review.

    Science.gov (United States)

    Rehman, Muhammad Zia Ur; Rizwan, Muhammad; Ali, Shafaqat; Ok, Yong Sik; Ishaque, Wajid; Saifullah; Nawaz, Muhammad Farrakh; Akmal, Fatima; Waqar, Maqsooda

    2017-09-01

    Heavy metals are among the major environmental pollutants and the accumulation of these metals in soils is of great concern in agricultural production due to the toxic effects on crop growth and food quality. Phytoremediation is a promising technique which is being considered as an alternative and low-cost technology for the remediation of metal-contaminated soils. Solanum nigrum is widely studied for the remediation of heavy metal-contaminated soils owing to its ability for metal uptake and tolerance. S. nigrum can tolerate excess amount of certain metals through different mechanism including enhancing the activities of antioxidant enzymes and metal deposition in non-active parts of the plant. An overview of heavy metal uptake and tolerance in S. nigrum is given. Both endophytic and soil microorganisms can play a role in enhancing metal tolerance in S. nigrum. Additionally, optimization of soil management practices and exogenous application of amendments can also be used to enhance metal uptake and tolerance in this plant. The main objective of the present review is to highlight and discuss the recent progresses in using S. nigrum for remediation of metal contaminated soils. Copyright © 2017 Elsevier Inc. All rights reserved.

  20. Repeated phytoextraction of four metal-contaminated soils using the cadmium/zinc hyperaccumulator Sedum plumbizincicola

    International Nuclear Information System (INIS)

    Li, Zhu; Wu, Longhua; Hu, Pengjie; Luo, Yongming; Zhang, Hao; Christie, Peter

    2014-01-01

    A cadmium/zinc hyperaccumulator extracted metals from four contaminated soils over three years in a glasshouse experiment. Changes in plant metal uptake and soil total (aqua regia-extractable) and available metals were investigated. Plant Cd concentrations in a high-Cd acid soil and plant Zn concentrations in two acid soils decreased during repeated phytoextraction and were predicted by soil available metal concentrations. However, on repeated phytoextraction, plant Cd concentrations remained constant in lightly Cd-polluted acid soils, as did plant Cd and Zn in alkaline soils, although soil available metal concentrations decreased markedly. After phytoextraction acid soils showed much higher total metal removal efficiencies, indicating possible suitability of phytoextraction for acid soils. However, DGT-testing, which takes soil metal re-supply into consideration, showed substantial removal of available metal and distinct decreases in metal supply capacity in alkaline soils after phytoextraction, suggesting that a strategy based on lowering the bioavailable contaminant might be feasible. - Highlights: • Plant shoot Cd decreased in high-Cd acid soil and also plant Zn did in two acid soils. • Plant shoot Cd remained constant in low-Cd acid soil and also plant Zn did in alkaline soils. • Acidic soils showed much higher total metal removal efficiency than the alkaline soils. - Acid soil has high total metal phytoremediation efficiency while a strategy based on stripping of the bioavailable contaminant might be feasible for alkaline soil phytoremediation

  1. Determination of heavy metal pollution in soils from selected potentially contaminated sites in Tema

    International Nuclear Information System (INIS)

    Nyaaba, A.K.L.

    2011-01-01

    The objective of the study was to assess the concentration and determine the level of pollution by harmful heavy metals in soils from selected potentially contaminated sites in Tema. The metals of interest include; mercury, lead, cadmium, cobalt zinc, arsenic, nickel, copper and chromium. A total of forty seven (47) samples comprising thirty eight sub-samples (38) and nine (9) composite samples were collected from nine (9) different locations. These included playgrounds, steel processing factories, used Lead Acid Battery (ULAB) recycling plant, mechanic workshops and the municipal waste disposal site. The samples were prepared after which the elemental concentrations were determined using energy dispersive X-ray fluorescence (EDXRF) with a secondary target excitation arrangement (5.9 keV). The analysis of the samples yielded the following mean heavy metal concentrations in mg/kg: 424.38 (Cr); 408.68 (Ni); 14427 (Cu); 4129.87 (Zn); 1580.68 (As); 647.48 (Hg); 73361.51 (Pb) and 1176.16 (Co). The mean concentrations of heavy metals in the soils were in the following order Pb>Zn>As>Co>Cu>Hg>Cr>Ni. Mercury was detected at only two of the sites. The average heavy metals in the soils from the sites were generally high since most of them exceeded the optimum and action values of the New Dutch List. The Enrichment Factor (EF) ratios show that the enrichment of the elements in the soils ranged from deficiently to extremely highly enriched. The contamination factor show that the contamination by the heavy metals were low at some of the sites and very high at others. The geoaccumulation indices indicated that the playground (PG) has not been contaminated by any of the metals, C8 is contaminated strongly by mercury only and the contamination at the remaining sites varied from moderately contaminated to extremely contaminated by the metals. The Igeo also indicated that the elements accounting for extreme contamination are lead, arsenic, copper, zinc mercury and chromium. Lead

  2. A test to illustrate the effects of BioSolve on the mobility of contaminated soils

    International Nuclear Information System (INIS)

    Jackson, Lorri M.

    1999-01-01

    Mountain States BioSolve manufactures products for in-situ bioremediation projects. One of their products, BioSolve, desorbs and emulsifies hydrocarbons in a contaminated substrate. BioSolve is a blend of water-based, biodegradable surfactants which were engineered as a clean-up and mitigation agent for hydrocarbon products. Its basic mechanism is to emulsify the hydrocarbon into small encapsulated particles in a water/oxygen-bearing solution, desorbing hydrocarbon molecules from soil particles. This allows bacteria to more effectively metabolize the contaminate. During desorption, Total Petroleum Hydrocarbons (TPH) levels may increase shortly after application due to the removal of contaminate from soil particles which increases the total recoverable hydrocarbon. This allows the hydrocarbon, in the pump and treat process, to become mobile, and thus carried with the water to the recovery wells where it can be removed. This testing does not address pump and treat technology but only the increased surface area for bioremediation enhancement

  3. Mercury (II) reduction and co-precipitation of metallic mercury on hydrous ferric oxide in contaminated groundwater.

    Science.gov (United States)

    Richard, Jan-Helge; Bischoff, Cornelia; Ahrens, Christian G M; Biester, Harald

    2016-01-01

    Mercury (Hg) speciation and sorption analyses in contaminated aquifers are useful for understanding transformation, retention, and mobility of Hg in groundwater. In most aquifers hydrous ferric oxides (HFOs) are among the most important sorbents for trace metals; however, their role in sorption or mobilization of Hg in aquifers has been rarely analyzed. In this study, we investigated Hg chemistry and Hg sorption to HFO under changing redox conditions in a highly HgCl2-contaminated aquifer (up to 870μgL(-1) Hg). Results from aqueous and solid phase Hg measurements were compared to modeled (PHREEQC) data. Speciation analyses of dissolved mercury indicated that Hg(II) forms were reduced to Hg(0) under anoxic conditions, and adsorbed to or co-precipitated with HFO. Solid phase Hg thermo-desorption measurements revealed that between 55 and 93% of Hg bound to HFO was elemental Hg (Hg(0)). Hg concentrations in precipitates reached more than 4 weight %, up to 7000 times higher than predicted by geochemical models that do not consider unspecific sorption to and co-precipitation of elemental Hg with HFO. The observed process of Hg(II) reduction and Hg(0) formation, and its retention and co-precipitation by HFO is thought to be crucial in HgCl2-contaminated aquifers with variable redox-conditions regarding the related decrease in Hg solubility (factor of ~10(6)), and retention of Hg in the aquifer. Copyright © 2015 Elsevier B.V. All rights reserved.

  4. Heavy metal contamination of selected spices obtained from Nigeria ...

    African Journals Online (AJOL)

    ADOWIE PERE

    ABSTRACT: In this study, the levels of trace metals (Cd, Cr, Cu, Co, Fe, Mn, Ni, Mo, Pb,. Zn) in twenty ... can accumulate exceeding levels of toxic metals whose potential risk to human health should ..... toxicity of the metal (WHO, 1999b). In fact ...

  5. Heavy metal contamination in stream water and sediments of gold ...

    African Journals Online (AJOL)

    I.O.OLABANJI

    3D) with 0.457 ± 0.061 and 0.364 ± 0.056 mg/L in dry and wet seasons. The mean .... safe limit clearly indicating that Cd contamination of the stream water might be ... of lead contaminant in the study area is the formation of acid mine drainage.

  6. Heavy Metal Contamination Assessment and Partition for Industrial and Mining Gathering Areas

    Directory of Open Access Journals (Sweden)

    Yang Guan

    2014-07-01

    Full Text Available Industrial and mining activities have been recognized as the major sources of soil heavy metal contamination. This study introduced an improved Nemerow index method based on the Nemerow and geo-accumulation index. Taking a typical industrial and mining gathering area in Tianjin (China as example, this study then analyzed the contamination sources as well as the ecological and integrated risks. The spatial distribution of the contamination level and ecological risk were determined using Geographic Information Systems. The results are as follows: (1 Zinc showed the highest contaminant level in the study area; the contamination levels of the other seven heavy metals assessed were relatively lower. (2 The combustion of fossil fuels and emissions from industrial and mining activities were the main sources of contamination in the study area. (3 The overall contamination level of heavy metals in the study area ranged from heavily contaminated to extremely contaminated and showed an uneven distribution. (4 The potential ecological risk showed an uneven distribution, and the overall ecological risk level ranged from low to moderate. This study also emphasized the importance of partition in industrial and mining areas, the extensive application of spatial analysis methods, and the consideration of human health risks in future studies.

  7. Heavy Metal Contamination Assessment and Partition for Industrial and Mining Gathering Areas

    Science.gov (United States)

    Guan, Yang; Shao, Chaofeng; Ju, Meiting

    2014-01-01

    Industrial and mining activities have been recognized as the major sources of soil heavy metal contamination. This study introduced an improved Nemerow index method based on the Nemerow and geo-accumulation index. Taking a typical industrial and mining gathering area in Tianjin (China) as example, this study then analyzed the contamination sources as well as the ecological and integrated risks. The spatial distribution of the contamination level and ecological risk were determined using Geographic Information Systems. The results are as follows: (1) Zinc showed the highest contaminant level in the study area; the contamination levels of the other seven heavy metals assessed were relatively lower. (2) The combustion of fossil fuels and emissions from industrial and mining activities were the main sources of contamination in the study area. (3) The overall contamination level of heavy metals in the study area ranged from heavily contaminated to extremely contaminated and showed an uneven distribution. (4) The potential ecological risk showed an uneven distribution, and the overall ecological risk level ranged from low to moderate. This study also emphasized the importance of partition in industrial and mining areas, the extensive application of spatial analysis methods, and the consideration of human health risks in future studies. PMID:25032743

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

    Directory of Open Access Journals (Sweden)

    Leela Kaur

    2015-02-01

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

  9. Application of carbon nanotubes to immobilize heavy metals in contaminated soils

    International Nuclear Information System (INIS)

    Matos, Martim P. S. R.; Correia, António Alberto S.; Rasteiro, Maria G.

    2017-01-01

    The contamination of soils with heavy metals is a growing concern in modern societies. To avoid the spread of contamination, soil stabilization techniques can be applied mixing materials with the soil in order to partially immobilize heavy metals. Carbon nanotubes (CNTs) are nanomaterials known for its exceptional properties, like high surface area and adsorption capacity. Due to these unique properties, the potential use of CNTs in heavy metal contaminated water has been studied, with very satisfactory results; however, their application in contaminated soils is practically unexplored. This experimental work is focused on studying the potential of using CNTs in soil remediation, especially to immobilize the heavy metals ions: lead (Pb"2"+), copper (Cu"2"+), nickel (Ni"2"+), and zinc (Zn"2"+), commonly present in contaminated soils. In order to avoid CNT agglomeration, which originates the loss of their beneficial properties, an aqueous suspension of CNTs was prepared using a non-ionic surfactant combined with ultrasonic energy to promote CNTs dispersion. Then, the soil, with and without the addition of CNTs, was subjected to adsorption tests to evaluate the CNT capacity to improve heavy metal immobilization. To validate the adsorption test results, permeability tests were executed, simulating the conditions of a real-case scenario. The results obtained led to the conclusion that the addition of a small amount of dispersed CNTs can successfully increase the adsorption capacity of the soil and consequently improve the immobilization of heavy metals in the soil matrix. The immobilization percentage varies with the different heavy metals under study.

  10. Application of carbon nanotubes to immobilize heavy metals in contaminated soils

    Science.gov (United States)

    Matos, Martim P. S. R.; Correia, António Alberto S.; Rasteiro, Maria G.

    2017-04-01

    The contamination of soils with heavy metals is a growing concern in modern societies. To avoid the spread of contamination, soil stabilization techniques can be applied mixing materials with the soil in order to partially immobilize heavy metals. Carbon nanotubes (CNTs) are nanomaterials known for its exceptional properties, like high surface area and adsorption capacity. Due to these unique properties, the potential use of CNTs in heavy metal contaminated water has been studied, with very satisfactory results; however, their application in contaminated soils is practically unexplored. This experimental work is focused on studying the potential of using CNTs in soil remediation, especially to immobilize the heavy metals ions: lead (Pb2+), copper (Cu2+), nickel (Ni2+), and zinc (Zn2+), commonly present in contaminated soils. In order to avoid CNT agglomeration, which originates the loss of their beneficial properties, an aqueous suspension of CNTs was prepared using a non-ionic surfactant combined with ultrasonic energy to promote CNTs dispersion. Then, the soil, with and without the addition of CNTs, was subjected to adsorption tests to evaluate the CNT capacity to improve heavy metal immobilization. To validate the adsorption test results, permeability tests were executed, simulating the conditions of a real-case scenario. The results obtained led to the conclusion that the addition of a small amount of dispersed CNTs can successfully increase the adsorption capacity of the soil and consequently improve the immobilization of heavy metals in the soil matrix. The immobilization percentage varies with the different heavy metals under study.

  11. Risk Assessment of Heavy Metals in Abandoned Mine Lands as Signifcant Contamination Problem in Romania

    Science.gov (United States)

    Horvath, E.; Jordan, G.; Fugedi, U.; Bartha, A.; Kuti, L.; Heltai, G.; Kalmar, J.; Waldmann, I.; Napradean, I.; Damian, G.

    2009-04-01

    lower topographic elevations. Several mine adits, waste rock dumps are located along the main stream and a large tailings dump is found next to village Baiut just above the receiving floodplain. Predominant land cover is coniferous and mixed forests with agricultural lands on the downstream floodplain. METHODS Six samples at vaious depths were collected from the two major waste rock dumps in the headwater area, and the large tailings dump was also sampled for heavy metal source characterisation. 11 stream sediment samples were collected along the main surface water contamination transport pathway, and a further 11 soil samples were collected in 2 boreholes in the receptor floodplain in October 2008. Besides background stream sediment samples, samples from the exposed rock formations were also collected in order to capture natural background geochemistry in the studied mineralised area. The collected waste rock, stream sediment, soil and rock samples are analysed for total chemical composition (major elements and heavy metals) by ICP-MS spectroscopy, and XRD is used for the determination of mineralogical composition. Rock sample mineralogy is further investigated in thin-sections by petrological microscopy. According to EU legislation expectations, a special emphasis is taken on the determination of metal mobility from the waste rock dumps and various leaching tests are performed and compared including US EPA, USGS and ISO methods. A simple cathcment-based distributed sediment transport model (Jordan et al, 2005; Jordan et al. 2005, 2008) is used to decribe the pathways and quantities of particle-bound contamination. RESULTS AND CONCLUSIONS Results show that (1) sediments are an efficient means for the preliminary inventory of mine contamination as a preparation for the more detailed hydrological sampling and assessment, and (2) the risk-based contamination assessment of mining sites often located in diverse geological, hydrological and landcover environment requires

  12. Effects of remediation train sequence on decontamination of heavy metal-contaminated soil containing mercury.

    Science.gov (United States)

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

    2014-09-01

    When a contaminated site contains pollutants including both nonvolatile metals and Hg, one single remediation technology may not satisfactorily remove all contaminants. Therefore, in this study, chemical extraction and thermal treatment were combined as a remediation train to remove heavy metals, including Hg, from contaminated soil. A 0.2 M solution of ethylenediamine tetraacetic acid (EDTA) was shown to be the most effective reagent for extraction of considerable amounts of Cu, Pb, and Zn (> 50%). Hg removal was ineffective using 0.2 M EDTA, but thermogravimetric analysis suggested that heating to 550 degrees C with a heating rate of 5 degrees C/min for a duration of 1 hr appeared to be an effective approach for Hg removal. With the employment of thermal treatment, up to 99% of Hg could be removed. However executing thermal treatment prior to chemical extraction reduced the effectiveness of the subsequent EDTA extraction because nonvolatile heavy metals were immobilized in soil aggregates after the 550 degrees C treatment. The remediation train of chemical extraction followed by thermal treatment appears to remediate soils that have been contaminated by many nonvolatile heavy metals and Hg. Implications: A remediation train conjoining two or more techniques has been initialized to remove multiple metals. Better understandings of the impacts of treatment sequences, namely, which technique should be employed first on the soil properties and the decontamination efficiency, are in high demand. This study provides a strategy to remove multiple heavy metals including Hg from a contaminated soil. The interactions between thermal treatment and chemical extraction on repartitioning of heavy metals was revealed. The obtained results could offer an integrating strategy to remediate the soil contaminated with both heavy metals and volatile contaminants.

  13. Characteristics of Heavy Metals Contamination in Lotus Root in the Dongting Lake Area, China

    Directory of Open Access Journals (Sweden)

    LUO Man

    2016-11-01

    Full Text Available Heavy metal contamination in soils in the Dongting Lake areas has evoked widespread concerns about the excessive heavy metals in aquatic product. Based on the national standards of food contaminant limits and the method of comprehensive pollution index, heavy metals of Cd, Pb, Cu, Zn, Mn in lotus root were clarified through field investigation in the Dongting Lake area. Results showed that lotus root in the Dongting Lake area was contaminated seriously by heavy metals. Cd and Pb were two main pollutants and the single pollution indices were 5.70 and 8.35 respectively. According to the comprehensive pollution index of heavy metals, lotus root in Yueyanglou District and Yuanjiang City were classified into medium pollution and Junshan District, Huarong County, Nan County, and Datong District were classified into heavy pollution. Principal component analysis showed that planting areas of lotus root were clumped and medium and heavy pollution areas were separated significantly. Habitat contamination by heavy metals and decreasing area of lotus ponds were two main factors for excessive heavy metals in lotus root. Thus, some measurements, such as habit restoration, were proposed for local government to decrease heavy metals in planting areas and to promote the healthy development of lotus root industry in the Dongting Lake area.

  14. Distribution of six heavy metals in contaminated clay soils before and after extractive cleaning

    NARCIS (Netherlands)

    Tuin, B.J.W.; Tels, M.

    1990-01-01

    A sequential extraction procedure according to Tessier et al. is carried out to compare the distribution of six metals (Cd, Cr, Cu, Ni, Pb and Zn) in contaminated clay soils before and after extractive cleaning. Extraction of metals from the ‘soil fractions’ with 0.1 N HC1 or 0.1 M EDTA becomes more

  15. Laser assisted removal of fixed contamination from metallic substrate

    International Nuclear Information System (INIS)

    Kumar, Aniruddha; Prasad, Manisha; Prakash, Tej; Shail, Shailini; Bhatt, R.B.; Behere, P.G.; Mohd Afzal; Kumar, Arun; Biswas, D.J.

    2015-01-01

    A single mode pulsed fiber laser was used to remove fixed contamination from stainless steel substrate by ablation. Samples were simulated by electro-deposition technique with 232 U as the test contaminant. Laser power, repetition rate, laser beam scanning speed and number of passes were optimised to obtain the desired ablation depth in the substrate. Ablation depth varying between few microns to few hundreds of microns could be achieved through careful control of these processing parameters. The absence of any activity in laser treated samples provided experimental signature of the efficacy of the laser assisted removal of fixed contamination. (author)

  16. Heavy Metal Contaminated Soil Imitation Biological Treatment Overview

    Science.gov (United States)

    Pan, Chang; Chen, Jun; Wu, Ke; Zhou, Zhongkai; Cheng, Tingting

    2018-01-01

    In this paper, the treatment methods of heavy metal pollution in soils were analyzed, the existence and transformation of heavy metals in soil were explored, and the mechanism of heavy metal absorption by plants was studied. It was concluded that the main form of plants absorb heavy metals in the soil is exchangeable. The main mechanism was that the plant cell wall can form complex with heavy metals, so that heavy metals fixed on the cell wall, and through the selective absorption of plasma membrane into the plant body. In addition, the adsorption mechanism of the adsorbed material was analyzed. According to the results of some researchers, it was found that the mechanism of adsorption of heavy metals was similar to that of plants. According to this, using adsorbent material as the main material, Imitate the principle of plant absorption of heavy metals in the soil to removing heavy metals in the soil at one-time and can be separated from the soil after adsorption to achieve permanent removal of heavy metals in the soil was feasibility.

  17. Metal immobilization and phosphorus leaching after stabilization of pyrite ash contaminated soil by phosphate amendments.

    Science.gov (United States)

    Zupančič, Marija; Lavrič, Simona; Bukovec, Peter

    2012-02-01

    In this study we would like to show the importance of a holistic approach to evaluation of chemical stabilization using phosphate amendments. An extensive evaluation of metal stabilization in contaminated soil and an evaluation of the leaching of phosphorus induced after treatment were performed. The soil was highly contaminated with Cu (2894 mg kg(-1)), Zn (3884 mg kg(-1)), As (247 mg kg(-1)), Cd (12.6 mg kg(-1)) and Pb (3154 mg kg(-1)). To immobilize the metals, mixtures of soil with phosphate (from H(3)PO(4) and hydroxyapatite (HA) with varying ratios) were prepared with a constant Pb : P molar ratio of 1: 10. The acetic acid extractable concentration of Pb in the mixture with the highest amount of added phosphoric acid (n(H(3)PO(4)) : n(HA) = 3 : 1) was reduced to 1.9% (0.62 mg L(-1)) of the extractable Pb concentration in the untreated soil, but the content of water extractable phosphorus in the samples increased from 0.04 mg L(-1) in the untreated soil sample up to 14.3 mg L(-1) in the same n(H(3)PO(4)) : n(HA) = 3 : 1 mixture. The high increase in arsenic mobility was also observed after phosphate addition. The PBET test showed phosphate induced reduction in Pb bioavailability. In attempting to stabilize Pb in the soil with the minimum treatment-induced leaching of phosphorus, it was found that a mixture of soil with phosphate addition in the molar ratio of H(3)PO(4) : HA of 0.75 : 1 showed the most promising results, with an acetic acid extractable Pb concentration of 1.35 mg L(-1) and a water extractable phosphorus concentration of 1.76 mg L(-1). The time-dependent leaching characteristics of metals and phosphorus for this mixture were evaluated by a column experiment, where irrigation of the soil mixture with the average annual amount of precipitation in Slovenia (1000 mm) was simulated. The phosphorus concentration in the leachates decreased from 2.60 mg L(-1) at the beginning of irrigation to 1.00 mg L(-1) at the end.

  18. Spatial Distribution and Mobility Assessment of Carcinogenic Heavy Metals in Soil Profiles Using Geostatistics and Random Forest, Boruta Algorithm

    Directory of Open Access Journals (Sweden)

    Asma Shaheen

    2018-03-01

    Full Text Available In third world countries, industries mainly cause environmental contamination due to lack of environmental policies or oversight during their implementation. The Sheikhupura industrial zone, which includes industries such as tanneries, leather, chemical, textiles, and colour and dyes, contributes massive amounts of untreated effluents that are released directly into drains and used for the irrigation of crops and vegetables. This practice causes not only soil contamination with an excessive amount of heavy metals, but is also considered a source of toxicity in the food chain, i.e., bioaccumulation in plants and ultimately in human body organs. The objective of this research study was to assess the spatial distribution of the heavy metals chromium (Cr, cadmium (Cd, and lead (Pb, at three depths of soil using geostatistics and the selection of significant contributing variables to soil contamination using the Random Forest (RF function of the Boruta Algorithm. A total of 60 sampling locations were selected in the study area to collect soil samples (180 samples at three depths (0–15 cm, 15–30 cm, and 60–90 cm. The soil samples were analysed for their physico-chemical properties, i.e., soil saturation, electrical conductivity (EC, organic matter (OM, pH, phosphorus (P, potassium (K, and Cr, Cd, and Pb using standard laboratory procedures. The data were analysed with comprehensive statistics and geostatistical techniques. The correlation coefficient matrix between the heavy metals and the physico-chemical properties revealed that electrical conductivity (EC had a significant (p ≤ 0.05 negative correlation with Cr, Cd, and Pb. The RF function of the Boruta Algorithm employed soil depth as a classifier and ranked the significant soil contamination parameters (Cr, Cd, Pb, EC, and P in relation to depth. The mobility factor indicated the leachate percentage of heavy metals at different vertical depths of soil. The spatial distribution pattern of

  19. Dietary toxicity of field-contaminated invertebrates to marine fish: effects of metal doses and subcellular metal distribution.

    Science.gov (United States)

    Dang, Fei; Rainbow, Philip S; Wang, Wen-Xiong

    2012-09-15

    There is growing awareness of the toxicological effects of metal-contaminated invertebrate diets on the health of fish populations in metal-contaminated habitats, yet the mechanisms underlying metal bioaccumulation and toxicity are complex. In the present study, marine fish Terapon jurbua terepon were fed a commercial diet supplemented with specimens of the polychaete Nereis diversicolor or the clam Scrobicularia plana, collected from four metal-impacted estuaries (Tavy, Restronguet Creek, West Looe, Gannel) in southwest England, as environmentally realistic metal sources. A comparative toxicological evaluation of both invertebrates showed that fish fed S. plana for 21 d exhibited evident mortality compared to those fed N. diversicolor. Furthermore, a spatial effect on mortality was observed. Differences in metal doses rather than subcellular metal distributions between N. diversicolor and S. plana appeared to be the cause of such different mortalities. Partial least squares regression was used to evaluate the statistical relationship between multiple-metal doses and fish mortality, revealing that Pb, Fe, Cd and Zn in field-collected invertebrates co-varied most strongly with the observed mortality. This study provides a step toward exploring the underlying mechanism of dietary toxicity and identifying the potential causality in complex metal mixture exposures in the field. Copyright © 2012 Elsevier B.V. All rights reserved.

  20. Assessment of the mobility and bioavailability of 60 Co and 137 Cs in contaminated soils

    International Nuclear Information System (INIS)

    Wasserman, Maria Angelica; Bartoly, Flavia; Poquet, Isabel; Perez, Daniel V.

    2001-01-01

    Results of a classical sequential chemical extraction procedure for 137 Cs in an acid Oxisol showed that after 3 years of contamination radiocesium remains potentially available for transfer processes: 40% bio-available, 20% mobile under oxidizing conditions and 40% bound to Fe and Mn oxides (available under reducing conditions). At this time, the transfer factor obtained in this soil was higher than values obtained in basic Oxisol and was higher than values obtained in soils from temperate climate areas. Seven years after the contamination, the 137 Cs distribution in this acid Oxisol have been changed as consequence of changes in soil properties: 8% bioavailable, 16% mobile under oxidizing conditions, 43% bound to Fe and Mn oxides and 33% strongly bound to soil compounds. Changes in the 137 Cs distribution in this soil were followed by reductions in soil to plant transfer factor. Between 1996 and 2000, the 137 Cs distribution, 137 Cs soil to plant transfer factor and soil properties in the basic Oxisol remained almost the same. The 60 Co distribution showed that Mn oxides is the main sink for this element and four years after contamination no 60 Co was detected as bioavailable or detectable in plants. In this study the use of an alternative sequential chemical extraction protocol to evaluate 60 Co and 137 Cs mobility under a large range of physico-chemical soil properties has shown to be very consistent with soil to plant transfer factors data for maize. The knowledge of bio-geochemical behavior of radionuclides in soil system can be used for the risk assessment in the case of nuclear accident or contamination scenarios. (author)

  1. Extraction procedure compared to attenuation model to assess heavy metals mobility in sediments from Sepetiba Bay, Rio de Janeiro

    International Nuclear Information System (INIS)

    Ribeiro, Andreza Portella

    2006-01-01

    Sepetiba bay, located about 60 km west of the metropolitan region of Rio de Janeiro city, has undergone notable development in the last decades, with the establishment of about 400 industrial plants in its basin, basically metallurgical, which release its industrial waste either straight into the bay or through local rivers. The Sepetiba harbor also brought up a lot of industrial investment in that area. This urban and industrial expansion caused several environmental impacts, mainly due to the presence of heavy metals and other potentially toxic substances present in the effluents discharged into the bay. This work aimed to assess heavy metal (Cd, Cu, Ni, Pb e Zn) contamination and mobility in sediments from Sepetiba bay. The acid-volatile sulfides (AVS) and the concentration of simultaneously extracted metals (SIGMA[SEM) were determined in 65 sediment samples from Sepetiba bay, representing the whole area. The results obtained showed that Cd, Cu, Pb and Zn presented higher concentrations in the northeastern area (mainly in the mouth of Guandu and Canal de Sao Francisco rivers), while the highest concentration of Ni were observed in the western region of the bay. The comparison between SEM concentrations with the Canadian Sediment Quality Guidelines (TEL and PEL) indicated that Cd and Zn presented values which may hazard to aquatic organisms (concentration levels above PEL); the elements Cu, Pb and Ni presented concentration levels below PEL, suggesting low probability of toxicological effects to the aquatic organisms. On the other hand, the ratio Σ[SEM]/[AVS] was below 1 in the northeastern region, indicating that, in spite of the high concentration of the analyzed metals in this area, they are trapped in the sediment, as sulfides. The total metal concentrations in the sediments were also determined and the same distribution pattern obtained for the SEM were observed, with high concentrations in the northeastern region of the bay, classifying the area as level 2

  2. Perilous Effects of Heavy Metals Contamination on Human Health

    Directory of Open Access Journals (Sweden)

    Naseem Zahra

    2017-06-01

    Full Text Available Heavy metals form a versatile group of high density elements that vary considerably in their biological roles and chemical properties. Although many heavy metals are essential trace elements yet they have long been recognized as environmental pollutants due their toxic effects. Increased industrialization, urbanization anthropogenic activities like mining, smelting and other agricultural activities have resulted in accumulation of heavy metals in the environment. Heavy metals such as nickel, cadmium, zinc, copper, mercury, arsenic and chromium are not easily degradable and tend to build up in soil. These heavy metals through various routes such as fish and plants make their way into the human body and are known to have serious detrimental effects on human health at elevated levels. The harmful effects of some important heavy metals on human health have been discussed.

  3. Extractive decontamination of heavy metals from CCA contaminated ...

    African Journals Online (AJOL)

    user

    investigated operating conditions, oxalic acid extracted the lowest amount of As, Cr and Cu from the contaminated soil ... available fraction of the soil treated with the four different organic acid chelants. ...... polluted soils using oxalate. Water ...

  4. Application of Microbial Products to Promote Electrodialytic Remediation of Heavy Metal Contaminated Soil

    DEFF Research Database (Denmark)

    Jensen, Pernille Erland

    2006-01-01

    remediation (EDR) method for efficient treatment of Pb-contaminated soil by application of microbial products. Mobilization of Pb in soil by complexation with exopolymers and whole or disintegrated cells was investigated in column studies. Although exopolymers were previously shown to mobilize Pb in soil...... as potential methods for promotion of EDR of Pb contaminated soil. By these methods mobilization of Pb would occur due to complexation with much smaller substances than the previously examined and rejected exopolymers, why they were considered more efficient for mobilization of Pb in an electric current field...... also rejected, primarily due to the insufficient concentrations produced by microorganisms in general and the unrealistic high costs of industrially produced siderophores in relation to the low value of the product to be treated. Furthermore no detection of siderophore production was possible during...

  5. Research Progress of Artificial Forest in the Remediation of Heavy Metal Contaminated Soils

    Science.gov (United States)

    Jiafang, MA; Guangtao, MENG; Liping, HE; Guixiang, LI

    2017-01-01

    (1) Remediation of soil contaminated by heavy metals has become a hot topic in the world, and phytoremediation technology is the most widely used. (2) In addition to traditional economic benefits, ecological benefits of artificial forest have been more and more important, which are very helpful to soil polluted with heavy metals in the environment. (3) The characteristics of heavy metal pollution of soil and plantations of repair mechanism have been reviewed, and the current mining areas, wetlands, urban plantations on heavy metal elements have enriched the research results. The purpose is to find a new path for governance of heavy metal soil pollution.

  6. Food safety of milk and dairy product of dairy cattle from heavy metal contamination

    Science.gov (United States)

    Harlia, E.; Rahmah, KN; Suryanto, D.

    2018-01-01

    Food safety of milk and dairy products is a prerequisite for consumption, which must be free from physical, biological and chemical contamination. Chemical contamination of heavy metals Pb (Plumbum/Lead) and Cd (Cadmium) is generally derived from the environment such as from water, grass, feed additives, medicines and farm equipment. The contamination of milk and dairy products can affect quality and food safety for human consumption. The aim of this research is to investigate contamination of heavy metals Pb and Cd on fresh milk, pasteurized milk, and dodol milk compared with the Maximum Residue Limits (MRL). The methods of this researched was through case study and data obtained analyzed descriptively. Milk samples were obtained from Bandung and surrounding areas. The number of samples used was 30 samples for each product: 30 samples of fresh milk directly obtained from dairy farm, 30 samples of pasteurized milk obtained from street vendors and 30 samples of dodol milk obtained from home industry. Parameters observed were heavy metal residues of Pb and Cd. The results showed that: 1) approximately 83% of fresh milk samples were contaminated by Pb which 57% samples were above MRL and 90% samples were contaminated by Cd above MRL; 2) 67% of pasteurized milk samples were contaminated by Pb below MRL; 3) 60% of dodol milk samples were contaminated by Pb and Cd above MRL.

  7. Proteomic analysis of Sydney Rock oysters (Saccostrea glomerata) exposed to metal contamination in the field

    International Nuclear Information System (INIS)

    Thompson, Emma L.; Taylor, Daisy A.; Nair, Sham V.; Birch, Gavin; Hose, Grant C.; Raftos, David A.

    2012-01-01

    This study used proteomics to assess the impacts of metal contamination in the field on Sydney Rock oysters. Oysters were transplanted into Lake Macquarie, NSW, for two weeks in both 2009 and 2010. Two-dimensional electrophoresis identified changes in protein expression profiles of oyster haemolymph between control and metal contaminated sites. There were unique protein expression profiles for each field trial. Principal components analysis attributed these differences in oyster proteomes to the different combinations and concentrations of metals and other environmental variables present during the three field trials. Identification of differentially expressed proteins showed that proteins associated with cytoskeletal activity and stress responses were the most commonly affected biological functions in the Sydney Rock oyster. Overall, the data show that proteomics combined with multivariate analysis has the potential to link the effects of contaminants with biological consequences. - Highlights: ► Sydney Rock oyster haemolymph was analysed by proteomics after metal exposure in 3 field trials. ► 2-DE analysis was used to compare protein profiles between control and contaminated sites. ► Different protein expression profiles were revealed per field trial. ► Principal components analysis attributed profiles to different suites of metals and environmental variables per trial. ► The study highlights the need to do multiple field trials and to combine proteomic and enviro. data. - This study used proteomics to analyse impacts of metal contamination on Sydney Rock oyster (Saccostrea glomerata) haemolymph in multiple field trials.

  8. Status of metal levels and their potential sources of contamination in Southeast Asian rivers.

    Science.gov (United States)

    Chanpiwat, Penradee; Sthiannopkao, Suthipong

    2014-01-01

    To assess the concentration and status of metal contaminants in four major Southeast Asian river systems, water were collected from the Tonle Sap-Bassac Rivers (Cambodia), Citarum River (Indonesia), lower Chao Phraya River (Thailand), and Saigon River (Vietnam) in both dry and wet seasons. The target elements were Be, Al, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, As, Se, Mo, Ag, Cd, Ba, Tl, and Pb and the concentrations exceeded the background metal concentrations by 1- to 88-fold. This distinctly indicates enrichment by human urban area activities. The results of a normalization technique used to distinguish natural from enriched metal concentrations confirmed contamination by Al, Cd, Co, Mn, Ni, Pb, and Zn. Cluster analysis revealed the probable source of metals contamination in most sampling sites on all rivers studied to be anthropogenic, including industrial, commercial, and residential activities. Stable lead isotopes analyses applied to track the sources and pathways of anthropogenic lead furthermore confirmed that anthropogenic sources of metal contaminated these rivers. Discharges of wastewater from both industrial and household activities were major contributors of Pb into the rivers. Non-point sources, especially road runoff and street dust, also contributed contamination from Pb and other metals.

  9. Octanol-solubility of dissolved and particulate trace metals in contaminated rivers: implications for metal reactivity and availability

    Energy Technology Data Exchange (ETDEWEB)

    Turner, Andrew [School of Earth, Ocean and Environmental Sciences, University of Plymouth, Drake Circus, Plymouth PL4 8AA (United Kingdom)]. E-mail: aturner@plymouth.ac.uk; Mawji, Edward [School of Earth, Ocean and Environmental Sciences, University of Plymouth, Drake Circus, Plymouth PL4 8AA (United Kingdom)

    2005-05-01

    The lipid-like, amphiphilic solvent, n-octanol, has been used to determine a hydrophobic fraction of dissolved and particulate trace metals (Al, Cd, Co, Cu, Mn, Ni, Pb, Zn) in contaminated rivers. In a sample from the River Clyde, southwest Scotland, octanol-solubility was detected for all dissolved metals except Co, with conditional octanol-water partition coefficients, D{sub ow}, ranging from about 0.2 (Al and Cu) to 1.25 (Pb). In a sample taken from the River Mersey, northwest England, octanol-solubility was detected for dissolved Al and Pb, but only after sample aliquots had been spiked with individual ionic metal standards and equilibrated. Spiking of the River Clyde sample revealed competition among different metals for hydrophobic ligands. Metal displacement from hydrophobic complexes was generally most significant following the addition of ionic Al or Pb, although the addition of either of these metals had little effect on the octanol-solubility of the other. In both river water samples hydrophobic metals were detected on the suspended particles retained by filtration following their extraction in n-octanol. In general, particulate Cu and Zn (up to 40%) were most available, and Al, Co and Pb most resistant (<1%) to octanol extraction. Distribution coefficients defining the concentration ratio of octanol-soluble particle-bound metal to octanol-soluble dissolved metal were in the range 10{sup 3.3}-10{sup 5.3} ml g{sup -1}. The presence of hydrophobic dissolved and particulate metal species has implications for our understanding of the biogeochemical behaviour of metals in aquatic environments. Specifically, such species are predicted to exhibit characteristics of non-polar organic contaminants, including the potential to penetrate the lipid bilayer. Current strategies for assessing the bioavailability and toxicity of dissolved and particulate trace metals in natural waters may, therefore, require revision. - New approaches are presented for fractionating

  10. Assessment of Heavy Metal Contamination in the Surrounding Soils and Surface Sediments in Xiawangang River, Qingshuitang District

    Science.gov (United States)

    Jiang, Min; Zeng, Guangming; Zhang, Chang; Ma, Xiaoying; Chen, Ming; Zhang, Jiachao; Lu, Lunhui; Yu, Qian; Hu, Langping; Liu, Lifeng

    2013-01-01

    Xiawanggang River region is considered to be one of the most polluted areas in China due to its huge amount discharge of pollutants and accumulation for years. As it is one branch of Xiang River and the area downstream is Changsha city, the capital of Hunan Province, the ecological niche of Xiawangang River is very important. The pollution treatment in this area was emphasized in the Twelfth Five-Year Plan of Chinese government for Xiang River Water Environmental Pollution Control. In order to assess the heavy metal pollution and provide the base information in this region for The Twelfth Five-Year Plan, contents and fractions of four heavy metals (Cd, Cu, Pb and Zn) covering both sediments and soils were analyzed to study their contamination state. Three different indexes were applied to assess the pollution extent. The results showed this area was severely polluted by the four heavy metals, and the total concentrations exceeded the Chinese environmental quality standard for soil, grade III, especially for Cd. Moreover, Cd, rated as being in high risk, had a high mobility as its great contents of exchangeable and carbonates fractions in spite of its relative low content. Regression analysis revealed clay could well explain the regression equation for Cd, Cu and Zn while pH and sand could significantly interpret the regression equation for Pb. Moreover, there was a significant correlation between Non-residual fraction and Igeo for all the four metals. Correlation analysis showed four metals maybe had similar pollution sources. PMID:23951103

  11. Indices of soil contamination by heavy metals - methodology of calculation for pollution assessment (minireview).

    Science.gov (United States)

    Weissmannová, Helena Doležalová; Pavlovský, Jiří

    2017-11-07

    This article provides the assessment of heavy metal soil pollution with using the calculation of various pollution indices and contains also summarization of the sources of heavy metal soil pollution. Twenty described indices of the assessment of soil pollution consist of two groups: single indices and total complex indices of pollution or contamination with relevant classes of pollution. This minireview provides also the classification of pollution indices in terms of the complex assessment of soil quality. In addition, based on the comparison of metal concentrations in soil-selected sites of the world and used indices of pollution or contamination in soils, the concentration of heavy metal in contaminated soils varied widely, and pollution indices confirmed the significant contribution of soil pollution from anthropogenic activities mainly in urban and industrial areas.

  12. Sediment Metal Contamination in the Kafue River of Zambia and Ecological Risk Assessment.

    Science.gov (United States)

    M'kandawire, Ethel; Choongo, Kennedy; Yabe, John; Mwase, Maxwell; Saasa, Ngonda; Nakayama, Shouta M M; Bortey-Sam, Nesta; Blindauer, Claudia A

    2017-07-01

    Zambia's Kafue River receives wastes from various sources, resulting in metal pollution. This study determined the degree of contamination of 13 metals (Al, Cr, Mn, Fe, Co, Ni, Cu, Zn, As, Se, Cd, Hg and Pb) in Kafue River sediment and the associated ecological risks at six sites in three different seasons. The level of contamination for most metals showed significant site and seasonal differences. The contamination factor and pollution load index indicated that concentrations of most metals particularly copper (Cu), cobalt (Co), manganese (Mn) and arsenic (As) were very high at sites within the Copperbelt mining area. The geoaccumulation index showed an absence of anthropogenic enrichment with Cd and Hg at all the study sites and extreme anthropogenic enrichment with Cu at sites in the Copperbelt mining area. Potential ecological risk showed that Cu and As were likely to cause adverse biological effects to aquatic organisms in the Copperbelt mining region of the Kafue River.

  13. Heavy metals in soils along unpaved roads in south west Cameroon: Contamination levels and health risks.

    Science.gov (United States)

    Ngole-Jeme, Veronica M

    2016-04-01

    Soils enriched with heavy metals from vehicular emission present a significant exposure route of heavy metals to individuals using unpaved roads. This study assessed the extent of Cd, Cr, Co, Cu, Ni, Pb and Zn contamination of soils along unpaved roads in Cameroon, and the health risks presented by incidental ingestion and dermal contact with the soils using metal contamination factor (CF) pollution load index, hazard quotients (HQ) and chronic hazard index (CHI). CF values obtained (0.9-12.2) indicate moderate to high contamination levels. HQ values for Cr, Cd and Pb exceeded the reference doses. Moderate health hazard exists for road users in the areas with intense anthropogenic activities and high average daily traffic (ADT) volume according to CHI values (1-4) obtained. The economy and quality of life in cities with unpaved roads could be threatened by health challenges resulting from long-term exposure to heavy metal derived from high ADT volumes.

  14. Applying acoustic telemetry to understand contaminant exposure and bioaccumulation patterns in mobile fishes.

    Science.gov (United States)

    Taylor, Matthew D; van der Meulen, Dylan E; Brodie, Stephanie; Cadiou, Gwenaël; Knott, Nathan A

    2018-06-01

    Contamination in urbanised estuaries presents a risk to human health, and to the viability of populations of exploited species. Assessing animal movements in relation to contaminated areas may help to explain patterns in bioaccumulation, and assist in the effective management of health risks associated with consumption of exploited species. Using polychlorinated dibenzodioxin and polychlorinated dibenzofuran (PCDD/Fs) contamination in Sydney Harbour estuary as a case study, we present a study that links movement patterns resolved using acoustic telemetry to the accumulation of contaminants in mobile fish on a multi-species basis. Fifty-four individuals across six exploited species (Sea Mullet Mugil cephalus; Luderick Girella tricuspidata; Yellowfin Bream Acanthopagrus australis; Silver Trevally Pseudocaranx georgianus; Mulloway Argyrosomus japonicus; Yellowtail Kingfish Seriola lalandi) were tagged with acoustic transmitters, and their movements tracked for up to 3years. There was substantial inter-specific variation in fish distribution along the estuary. The proportion of distribution that overlapped with contaminated areas explained 84-98% of the inter-specific variation in lipid-standardised biota PCDD/F concentration. There was some seasonal variation in distribution along the estuary, but movement patterns indicated that Sea Mullet, Yellowfin Bream, Silver Trevally, and Mulloway were likely to be exposed to contaminated areas during the period of gonadal maturation. Acoustic telemetry allows examination of spatial and temporal patterns in exposure to contamination. When used alongside biota sampling and testing, this offers a powerful approach to assess exposure, bioaccumulation, and potential risks faced by different species, as well as human health risks associated with their consumption. Crown Copyright © 2017. Published by Elsevier B.V. All rights reserved.

  15. Influence of fly ash aided phytostabilisation of Pb, Cd and Zn highly contaminated soils on Lolium perenne and Trifolium repens metal transfer and physiological stress

    International Nuclear Information System (INIS)

    Lopareva-Pohu, Alena; Verdin, Anthony; Garcon, Guillaume; Lounes-Hadj Sahraoui, Anissa; Pourrut, Bertrand; Debiane, Djouher; Waterlot, Christophe; Laruelle, Frederic

    2011-01-01

    Due to anthropogenic activities, large extends of soils are highly contaminated by Metal Trace Element (MTE). Aided phytostabilisation aims to establish a vegetation cover in order to promote in situ immobilisation of trace elements by combining the use of metal-tolerant plants and inexpensive mineral or organic soil amendments. Eight years after Coal Fly Ash (CFA) soil amendment, MTE bioavailability and uptake by two plants, Lolium perenne and Trifolium repens, were evaluated, as some biological markers reflecting physiological stress. Results showed that the two plant species under study were suitable to reduce the mobility and the availability of these elements. Moreover, the plant growth was better on CFA amended MTE-contaminated soils, and the plant sensitivity to MTE-induced physiological stress, as studied through photosynthetic pigment contents and oxidative damage was lower or similar. In conclusion, these results supported the usefulness of aided phytostabilisation of MTE-highly contaminated soils. - Highlights: → Aided phytostabilisation aims to establish a vegetation cover in order to promote immobilisation of MTE. → 8 years after the soil amendments, a pot culture study was carried out in greenhouse conditions. → MTE bioavailability and uptake by the two plants was drastically decreased with amendments. → Our results support the usefulness of aided phytostabilisation of MTE-highly contaminated soils. → CFA addition contributed to the reduction of the MTE mobility and availability for the plants. - Efficiency of Coal Fly Ash amendment for phytostabilisation of Pb, Cd and Zn in MTE-highly contaminated soils.

  16. Remediation of heavy metal contaminated ecosystem: an overview on technology advancement

    International Nuclear Information System (INIS)

    Singh, A.; Prasad, S. M.

    2015-01-01

    The issue of heavy metal pollution is very much concerned because of their toxicity for plant, animal and human beings and their lack of biodegradability. Excess concentrations of heavy metals have adverse effect on plant metabolic activities hence affect the food production, quantitatively and qualitatively. Heavy metal when reaches human tissues through various absorption pathways such as direct ingestion, dermal contact, diet through the soil-food chain, inhalation, and oral intake may seriously affect their health. Therefore, several management practices are being applied to minimize metal toxicity by attenuating the availability of metal to the plants. Some of the traditional methods are either extremely costly or they are simply applied to isolate contaminated site. The biology based technology like use of hyper metal accumulator plants occurring naturally or created by transgenic technology, in recent years draws great attention to remediate heavy metal contamination. Recently, applications of nanoparticle for metal remediation are also attracting great research interest due to their exceptional adsorption and mechanical properties and unique electrical property, highly chemical stability, and large specific surface area. Thus the present review deals with different management approaches to reduce level of metal contamination in soil and finally to the food chain

  17. Investigation into metal contamination of the Berg River, Western ...

    African Journals Online (AJOL)

    The nitric acid digestion technique was used to extract metals from water, sediment and biofilm samples collected at various points (Site A . agricultural area, Site B . informal settlement and Site C . Newton pumping station) along the Berg River. Metal concentrations were determined using inductively coupled plasma atomic ...

  18. Heavy metal contamination of some vegetables from pesticides and ...

    African Journals Online (AJOL)

    Vegetable farming in developing countries is characterized by the indiscriminate application of pesticides and the resultant pollution of agricultural soil with heavy metals that form constituents of these pesticides. These heavy metals have long term toxicity to human and other biota in the ecosystem. This problem is ...

  19. Effects of organic carbon supply rates on uranium mobility in a previously bioreduced contaminated sediment.

    Science.gov (United States)

    Wan, Jiamin; Tokunaga, Tetsu K; Kim, Yongman; Brodie, Eoin; Daly, Rebecca; Hazen, Terry C; Firestone, Mary K

    2008-10-15

    Bioreduction-based strategies for remediating uranium (U)-contaminated sediments face the challenge of maintaining the reduced status of U for long times. Because groundwater influxes continuously bring in oxidizing terminal electron acceptors (O2, NO3(-)), it is necessary to continue supplying organic carbon (OC) to maintain the reducing environment after U bioreduction is achieved. We tested the influence of OC supply rates on mobility of previously microbial reduced uranium U(IV) in contaminated sediments. We found that high degrees of U mobilization occurred when OC supply rates were high, and when the sediment still contained abundant Fe(III). Although 900 days with low levels of OC supply minimized U mobilization, the sediment redox potential increased with time as did extractable U(VI) fractions. Molecular analyses of total microbial activity demonstrated a positive correlation with OC supply and analyses of Geobacteraceae activity (RT-qPCR of 16S rRNA) indicated continued activity even when the effluent Fe(II) became undetectable. These data support our hypothesis on the mechanisms responsible for remobilization of U under reducing conditions; that microbial respiration caused increased (bi)carbonate concentration and formation of stable uranyl carbonate complexes, thereby shifted U(IV)/U(VI) equilibrium to more reducing potentials. The data also suggested that low OC concentrations could not sustain the reducing condition of the sediment for much longer time. Bioreduced U(IV) is not sustainable in an oxidizing environment for a very long time.

  20. Partitioning of heavy metals in a soil contaminated by slag: A redistribution study

    International Nuclear Information System (INIS)

    Bunzl, K.; Trautmannsheimer, M.; Schramel, P.

    1999-01-01

    In order to interpret reasonably the partitioning of heavy metals in a contaminated soil as observed from applying a sequential extraction procedure, information on possible redistribution processes of the metals during the various extraction steps is essential. For this purpose, sequential extraction was used to study the chemical partitioning of Ag, Cu, Ni, Pb, and Zn in a soil contaminated wither by a slag from coal firing or by a slag from pyrite roasting. Through additional application of sequential extraction to the pure slags as well as to the uncontaminated soil, it was shown that during the various extraction steps applied to the soil/slag mixtures, substantial redistribution processes of the metals between the slag- and soil particles can occur. In many cases, metals ions released during the extraction with acid hydroxylamine or acid hydrogen peroxide are partially readsorbed by solid constituents of the mixture and will therefore be found in the subsequent fractions extracted. As a result, one has to realize that (1) it will be difficult to predict the chemical partitioning of these metals in contaminated soils by investigating pure slags only, and (2) information on the partitioning of a metal in a slag contaminated soil will not necessarily give any relevant information on the form of this metal in the slag or in the slag/soil mixture, because the redistribution processes during sequential extraction will not be the same as those occurring in the soil solution under natural conditions

  1. Effect of biosludge and biofertilizer amendment on growth of Jatropha curcas in heavy metal contaminated soils.

    Science.gov (United States)

    Juwarkar, Asha Ashok; Yadav, Santosh Kumar; Kumar, Phani; Singh, Sanjeev Kumar

    2008-10-01

    The pot experiments were conducted to evaluate the effect of different concentrations of arsenic, chromium and zinc contaminated soils, amended with biosludge and biofertilizer on the growth of Jatropha curcas which is a biodiesel crop. The results further showed that biosludge alone and in combination with biofertilizer significantly improved the survival rates and enhanced the growth of the plant. With the amendments, the plant was able to grow and survive upto 500, 250 and 4,000 mg kg(-1) of As, Cr and Zn contaminated soils, respectively. The results also showed that zinc enhanced the growth of J. curcas more as compared to other metals contaminated soils. The heavy metal accumulation in plant increased with increasing concentrations of heavy metals in soil, where as a significant reduction in the metal uptake in plant was observed, when amended with biosludge and biofertilizer and biosludge alone. It seems that the organic matter present in the biosludge acted as metal chelator thereby reducing the toxicity of metals to the plant. Findings suggest that plantation of J. curcas may be promoted in metal contaminated soils, degraded soils or wasteland suitably after amending with organic waste.

  2. Physiological and metagenomic analyses of microbial mats involved in self-purification of mine waters contaminated with heavy metals

    Directory of Open Access Journals (Sweden)

    Lukasz Drewniak

    2016-08-01

    Full Text Available Two microbial mats found inside two old (gold and uranium mines in Zloty Stok and Kowary located in SW Poland seem to form a natural barrier that traps heavy metals leaking from dewatering systems. We performed complex physiological and metagenomic analyses to determine which microorganisms are the main driving agents responsible for self-purification of the mine waters and identify metabolic processes responsible for the observed features. SEM and energy dispersive X-ray microanalysis showed accumulation of heavy metals on the mat surface, whereas, sorption experiments showed that neither microbial mats were completely saturated with heavy metals present in the mine waters, indicating that they have a large potential to absorb significant quantities of metal. The metagenomic analysis revealed that Methylococcaceae and Methylophilaceae families were the most abundant in both communities, moreover, it strongly suggest that backbones of both mats were formed by filamentous bacteria, such as Leptothrix, Thiothrix, and Beggiatoa. The Kowary bacterial community was enriched with the Helicobacteraceae family, whereas the Zloty Stok community consist mainly of Sphingomonadaceae, Rhodobacteraceae, and Caulobacteraceae families. Functional (culture-based and metagenome (sequence-based analyses showed that bacteria involved in immobilization of heavy metals, rather than those engaged in mobilization, were the main driving force within the analyzed communities. In turn, a comparison of functional genes revealed that the biofilm formation and heavy metal resistance functions are more desirable in microorganisms engaged in water purification than the ability to utilize heavy metals in the respiratory process (oxidation-reduction. These findings provide insight on the activity of bacteria leading, from biofilm formation to self-purification, of mine waters contaminated with heavy metals

  3. Octanol-solubility of dissolved and particulate trace metals in contaminated rivers: implications for metal reactivity and availability.

    Science.gov (United States)

    Turner, Andrew; Mawji, Edward

    2005-05-01

    The lipid-like, amphiphilic solvent, n-octanol, has been used to determine a hydrophobic fraction of dissolved and particulate trace metals (Al, Cd, Co, Cu, Mn, Ni, Pb, Zn) in contaminated rivers. In a sample from the River Clyde, southwest Scotland, octanol-solubility was detected for all dissolved metals except Co, with conditional octanol-water partition coefficients, D(ow), ranging from about 0.2 (Al and Cu) to 1.25 (Pb). In a sample taken from the River Mersey, northwest England, octanol-solubility was detected for dissolved Al and Pb, but only after sample aliquots had been spiked with individual ionic metal standards and equilibrated. Spiking of the River Clyde sample revealed competition among different metals for hydrophobic ligands. Metal displacement from hydrophobic complexes was generally most significant following the addition of ionic Al or Pb, although the addition of either of these metals had little effect on the octanol-solubility of the other. In both river water samples hydrophobic metals were detected on the suspended particles retained by filtration following their extraction in n-octanol. In general, particulate Cu and Zn (up to 40%) were most available, and Al, Co and Pb most resistant (octanol extraction. Distribution coefficients defining the concentration ratio of octanol-soluble particle-bound metal to octanol-soluble dissolved metal were in the range 10(3.3)-10(5.3)mlg(-1). The presence of hydrophobic dissolved and particulate metal species has implications for our understanding of the biogeochemical behaviour of metals in aquatic environments. Specifically, such species are predicted to exhibit characteristics of non-polar organic contaminants, including the potential to penetrate the lipid bilayer. Current strategies for assessing the bioavailability and toxicity of dissolved and particulate trace metals in natural waters may, therefore, require revision.

  4. Enhancing phytoextraction: the effect of chemical soil manipulation on mobility, plant accumulation, and leaching of heavy metals.

    Science.gov (United States)

    Schmidt, Ulrich

    2003-01-01

    For heavy metal-contaminated agricultural land, low-cost, plant-based phytoextraction measures can be a key element for a new land management strategy. When agents are applied into the soil, the solubility of heavy metals and their subsequent accumulation by plants can be increased, and, therefore, phytoextraction enhanced. An overview is given of the state of the art of enhancing heavy metal solubility in soils, increasing the heavy metal accumulation of several high-biomass-yielding and metal-tolerant plants, and the effect of these measures on the risk of heavy metal leaching. Several organic as well as inorganic agents can effectively and specifically increase solubility and, therefore, accumulation of heavy metals by several plant species. Crops like willow (Salix viminalis L.), Indian mustard [Brassica juncea (L.) Czern.], corn (Zea mays L.), and sunflower (Helianthus annuus L.) show high tolerance to heavy metals and are, therefore, to a certain extent able to use the surpluses that originate from soil manipulation. More than 100-fold increases of lead concentrations in the biomass of crops were reported, when ethylenediaminetetraacetic acid (EDTA) was applied to contaminated soils. Uranium concentrations could be strongly increased when citric acid was applied. Cadmium and zinc concentrations could be enhanced by inorganic agents like elemental sulfur or ammonium sulfate. However, leaching of heavy metals due to increased mobility in soils cannot be excluded. Thus, implementation on the field scale must consider measures to minimize leaching. So, the application of more than 1 g EDTA kg(-1) becomes inefficient as lead concentration in crops is not enhanced and leaching rate increases. Moreover, for large-scale applications, agricultural measures as placement of agents, dosage splitting, the kind and amount of agents applied, and the soil properties are important factors governing plant growth, heavy metal concentrations, and leaching rates. Effective

  5. Pollution in the urban soils of Lianyungang, China, evaluated using a pollution index, mobility of heavy metals, and enzymatic activities.

    Science.gov (United States)

    Li, Yu; Li, Hong-Guan; Liu, Fu-Cheng

    2017-01-01

    Soil samples from 16 urban sites in Lianyungang, China were collected and analyzed. A pollution index was used to assess the potential ecological risk of heavy metals and a sequential extraction procedure was used to evaluate the relative distribution of Cu, Zn, Pb, Cd, Cr, and As in exchangeable, carbonate, Fe/Mn oxide, organic/sulfide, and residual fractions. The mobility of heavy metals and urease (URE) activity, alkaline phosphatase (ALP) activity, and invertase (INV) activity of soils was determined. The results showed that the average concentrations of Cu, Zn, Pb, Cd, Cr, and As in Lianyungang soils were much higher than those in the coastal city soil background values of Jiangsu and China. Among the five studied regions (utilities, commercial, industrial, tourism, and roadside), the industrial region had the highest metal concentrations demonstrating that land use had a significant impact on the accumulation of heavy metals in Lianyungang soils. Compared to the other metals, Cd showed the highest ecological risk. According to chemical partitioning, Cu was associated with the organic/sulfides and Pb and Zn were mainly in the carbonate and the Fe/Mn oxide phase. The greatest amounts of Cd were found in exchangeable and carbonate fractions, while Cr and As were mainly in the residual fraction. Cd had the highest mobility of all metals, and the order of mobility (highest to lowest) of heavy metals in Lianyungang soils was Cd > Zn > Pb > Cu > As > Cr. Soil urease activity, alkaline phosphatase activity, and invertase activity varied considerably in different pollution degree sites. Soil enzyme activities had the lowest levels in roadside and industrial regions. Across all the soil data in the five regions, the total Cu, Zn, Pb, Cd, Cr, and As level was negatively correlated with urease activity, alkaline phosphatase activity, and invertase activity, but the relationship was not significant. In the industrial region, alkaline phosphatase activity had

  6. Soil contamination of toxic metals from zinc carbon batteries inadequate disposal

    International Nuclear Information System (INIS)

    Gazano, Vanessa Santos Oliveira

    2006-01-01

    The aim of the present study was to determine the concentration of Zn, Mn, Pb, Cd, Cu, Cr, and Ni in an oxisol column contaminated with zinc-carbon batteries. Two control and two contaminated columns, and batteries alone were leached for a periods of six months and one year with aqueous solution of HNO3 and H2SO4 (1:1, pH 4,0) to simulate rainwater. The metal concentrations in effluent and soil were measured by means of ICP-OES technique. Results from the contaminated column showed enhanced concentrations in both effluent and soil (mainly zinc, manganese and lead). In addition, the total amount of metals in effluent and soil showed similar sequence order as observed for batteries alone (Zn > Mn > Pb > Cr > Cu > Ni > Cd) indicating that batteries can be considered the main source of contamination. We also observed migration of Zn and Mn from the top to the lower layers of the soil columns. The study gives further evidence that batteries can significantly contaminate the soil with metals like Zn, Mn and Pb, and maybe Cd too. This soil contamination combined with the enhanced concentrations found in the effluent can point out a probable groundwater contamination. (author)

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

    Science.gov (United States)

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

    2014-06-01

    Remediation of soil contaminated with heavy metals has received considerable attention in recent years. In this study, the heavy metal uptake potential of the mushroom, Galerina vittiformis, was studied in soil artificially contaminated with Cu (II), Cd (II), Cr (VI), Pb (II) and Zn (II) at concentrations of 50 and 100mg/kg. G. vittiformis was found to be effective in removing the metals from soil within 30 days. The bioaccumulation factor (BAF) for both mycelia and fruiting bodies with respect to these heavy metals at 50mg/kg concentrations were found to be greater than one, indicating hyper accumulating nature by the mushroom. The metal removal rates by G. vittiformis was analyzed using different kinetic rate constants and found to follow the second order kinetic rate equation except for Cd (II), which followed the first order rate kinetics. Copyright © 2013 Elsevier Inc. All rights reserved.

  8. Geostatistical exploration of dataset assessing the heavy metal contamination in Ewekoro limestone, Southwestern Nigeria

    Directory of Open Access Journals (Sweden)

    Kehinde D. Oyeyemi

    2017-10-01

    Full Text Available The dataset for this article contains geostatistical analysis of heavy metals contamination from limestone samples collected from Ewekoro Formation in the eastern Dahomey basin, Ogun State Nigeria. The samples were manually collected and analysed using Microwave Plasma Atomic Absorption Spectrometer (MPAS. Analysis of the twenty different samples showed different levels of heavy metals concentration. The analysed nine elements are Arsenic, Mercury, Cadmium, Cobalt, Chromium, Nickel, Lead, Vanadium and Zinc. Descriptive statistics was used to explore the heavy metal concentrations individually. Pearson, Kendall tau and Spearman rho correlation coefficients was used to establish the relationships among the elements and the analysis of variance showed that there is a significant difference in the mean distribution of the heavy metals concentration within and between the groups of the 20 samples analysed. The dataset can provide insights into the health implications of the contaminants especially when the mean concentration levels of the heavy metals are compared with recommended regulatory limit concentration.

  9. Testing Single and Combinations of Amendments for Stabilization of Metals in Contrasting Extremely Contaminated Soils

    Directory of Open Access Journals (Sweden)

    Siebielec G.

    2013-04-01

    Full Text Available Metals can be stabilized by soil amendments that increase metals adsorption or alter their chemical forms. Such treatments may limit the risk related to the contamination through reduction of metal transfer to the food chain (reduction of metal uptake by plants and its availability to soil organisms and metals migration within the environment. There is a need for experiments comparing various soil amendments available at reasonable amounts under similar environmental conditions. The other question is whether all components of soil environment or soil functions are similarly protected after remediation treatment. We conducted a series of pot studies to test some traditional and novel amendments and their combinations. The treatments were tested for several highly Zn/Cd/Pb contaminated soils. Among traditional amendments composts were the most effective – they ensured plant growth, increased soil microbial activity, reduced Cd in earthworms, reduced Pb bioaccessibility and increased share of unavailable forms of Cd and Pb.

  10. Heavy metal contamination in the muscle of Aegean chub (Squalius fellowesii) and potential risk assessment.

    Science.gov (United States)

    Şaşi, Hüseyin; Yozukmaz, Aykut; Yabanli, Murat

    2018-03-01

    Especially after the industrial revolution, the amount of contaminants released in aquatic ecosystems has considerably increased. For this reason, the necessity to carry on research on the existence of contaminants, specifically heavy metals, has emerged. In this study, heavy metal concentrations in muscle tissues of Aegean chub, which was an endemic species of south western part of Turkey, gathered from Tersakan River were examined. Heavy metal concentrations of the samples were analyzed with ICP-MS. Estimated daily intakes (EDI), target hazard quotient (THQ), and carcinogenic risk (CR) of elements were calculated. The heavy metals detected in muscle tissues were Zn > Cu > Cr > Mn > Pb > Cd, consecutively. According to the results of the applied health risk assessment (EDI, THQ and CR) for heavy metal exposure from fish consumption in children and adults, it was determined that there was no any significant threat to human health.

  11. Heavy metal accumulation and phytostabilisation potential of tree fine roots in a contaminated soil

    International Nuclear Information System (INIS)

    Brunner, Ivano; Luster, Joerg; Guenthardt-Goerg, Madeleine S.; Frey, Beat

    2008-01-01

    Root systems of Norway spruce (Picea abies) and poplar (Populus tremula) were long-term exposed to metal-contaminated soils in open-top chambers to investigate the accumulation of the heavy metals in the fine roots and to assess the plants suitability for phytostabilisation. The heavy metals from the contaminated soil accumulated in the fine roots about 10-20 times more than in the controls. The capacity to bind heavy metals already reached its maximum after the first vegetation period. Fine roots of spruce tend to accumulate more heavy metals than poplar. Copper and Zinc were mainly detected in the cell walls with larger values in the epidermis than in the cortex. The heavy metals accumulated in the fine roots made up 0.03-0.2% of the total amount in the soils. We conclude that tree fine roots adapt well to conditions with heavy metal contamination, but their phytostabilisation capabilities seem to be very low. - Long-term exposed fine roots of trees are well adapted to soils with high heavy metal contents, but their phytostabilisation capabilities are rather low

  12. Effects of heavy-metal-contaminated soil on growth, phenology and biomass turnover of Hieracium piloselloides

    International Nuclear Information System (INIS)

    Ryser, Peter; Sauder, Wendy R.

    2006-01-01

    The effects of low levels of heavy metals on plant growth, biomass turnover and reproduction were investigated for Hieracium pilosella. Plants were grown for 12 weeks on substrates with different concentrations of heavy metals obtained by diluting contaminated soils with silica sand. To minimize effects of other soil factors, the substrates were limed, fertilized, and well watered. The more metal-contaminated soil the substrate contained, the lower the leaf production rate and the plant mass were, and the more the phenological development was delayed. Flowering phenology was very sensitive to metals. Leaf life span was reduced at the highest and the lowest metal levels, the latter being a result of advanced seed ripening. Even if the effect of low metal levels on plant growth may be small, the delayed and reduced reproduction may have large effects at population, community and ecosystem level, and contribute to rapid evolution of metal tolerance. - Flowering phenology shows a very sensitive response to heavy metal contamination of soils

  13. Contaminated scrap metal management on the Oak Ridge Reservation

    International Nuclear Information System (INIS)

    Hayden, H.W.; Stephenson, M.J.; Bailey, J.K.; Weir, J.R.; Gilbert, W.C.

    1993-01-01

    Large quantities of scrap metal are accumulating at the various Department of Energy (DOE) installations across the country as a result of ongoing DOE programs and missions in concert with present day waste management practices. DOE Oak Ridge alone is presently storing around 500,000 tons of scrap metal. The local generation rate, currently estimated at 1,400 tons/yr, is expected to increase sharply over the next couple of years as numerous environmental restoration and decommissioning programs gain momentum. Projections show that 775,000 tons of scrap metal could be generated at the K-25 Site over the next ten years. The Y-12 Plant and Oak Ridge National Laboratory (ORNL) have similar potentials. The history of scrap metal management at Oak Ridge and future challenges and opportunities are discussed

  14. Plasma treatment of INEL soil contaminated with heavy metals

    International Nuclear Information System (INIS)

    Detering, B.A.; Batdorf, J.A.

    1992-01-01

    INEL soil spiked with inorganic salts of chromium, lead, mercury, silver, and zinc was melted in a 150 kW plasma furnace to produce a glassy slag product. This glassy slag is an environmentally safe waste form. In order to reduce the melting temperature of the soil, sodium carbonate was added to half of the test batches. Random sample from each batch of glassy slag product were analyzed by an independent laboratory for total metals concentration and leachability of metals via the Environmental Protection Agency (EPA) toxicity characterization leaching procedure (RCLP) tests. These tests showed the residual metals were very tightly bound to the slag matrix and were within EPA TCLP limits under these test conditions. Additionally, scanning electron microscopy (SEM) and emissions dispersive spectroscopy (EDS) analysis of the vitrified soil also confirmed that the added metals present in the vitrified soil were totally contained in the crystalline phase as distinct oxide crystallites

  15. Mobile means for the monitoring of atmospheric contamination in a reactor building

    International Nuclear Information System (INIS)

    Marques, S.; Lestang, M.

    2009-01-01

    After having evoked the context and challenges of contamination monitoring when exploiting nuclear reactors, the authors discuss the representativeness of the atmospheric contamination measurement as it depends on the different physicochemical forms of radionuclides present in the circuits. They indicate the different gaseous or aerosol radioactive elements which are monitored within EDF installations. They discuss the incorporation of monitoring means at the installation design level, briefly present the use of beacons inside and outside the reactor building. They describe how monitoring is organized on the basis of alert threshold adjustments: an investigation threshold and an evacuation threshold. They discuss the beacon (or sensor) selection and indicate recommendations for their implementation for optimization purposes. They indicate where these beacons are installed and evoke the experimentation of networked mobile beacons with data remote transmission

  16. The Mobile Surface Contamination Monitor II environmental radiological characterization utilizing GPS/GIS technologies

    International Nuclear Information System (INIS)

    Wendling, M.A.

    1993-05-01

    Time, cost, and most importantly quality of data are the three factors to measure the success of field radiological characterizations. The application of coupling radiation detection instrumentation to a GPS receiver has dramatically increased the data quality achievable compared to traditional environmental radiological survey methods. Improvements in verifying adequate spatial coverage of an area while collecting data and at,the same time reducing field time requirements can be realized. Data acquired during the recent implementation of the Mobile Surface Contamination Monitor 11 (MSCM-11) will be presented to demonstrate the advantages of this system over traditional radiological survey methods. The comparison will include time and manpower requirements. Linking the complimentary GPS, GIS and radiation detection technologies on a mobile tractor based platform has provided a tool to provide radiological characterization data faster, cheaper, and better to assist in the Environmental Restoration Mission of the Hanford Site

  17. Octanol-solubility of dissolved and particulate trace metals in contaminated rivers: implications for metal reactivity and availability

    International Nuclear Information System (INIS)

    Turner, Andrew; Mawji, Edward

    2005-01-01

    The lipid-like, amphiphilic solvent, n-octanol, has been used to determine a hydrophobic fraction of dissolved and particulate trace metals (Al, Cd, Co, Cu, Mn, Ni, Pb, Zn) in contaminated rivers. In a sample from the River Clyde, southwest Scotland, octanol-solubility was detected for all dissolved metals except Co, with conditional octanol-water partition coefficients, D ow , ranging from about 0.2 (Al and Cu) to 1.25 (Pb). In a sample taken from the River Mersey, northwest England, octanol-solubility was detected for dissolved Al and Pb, but only after sample aliquots had been spiked with individual ionic metal standards and equilibrated. Spiking of the River Clyde sample revealed competition among different metals for hydrophobic ligands. Metal displacement from hydrophobic complexes was generally most significant following the addition of ionic Al or Pb, although the addition of either of these metals had little effect on the octanol-solubility of the other. In both river water samples hydrophobic metals were detected on the suspended particles retained by filtration following their extraction in n-octanol. In general, particulate Cu and Zn (up to 40%) were most available, and Al, Co and Pb most resistant ( 3.3 -10 5.3 ml g -1 . The presence of hydrophobic dissolved and particulate metal species has implications for our understanding of the biogeochemical behaviour of metals in aquatic environments. Specifically, such species are predicted to exhibit characteristics of non-polar organic contaminants, including the potential to penetrate the lipid bilayer. Current strategies for assessing the bioavailability and toxicity of dissolved and particulate trace metals in natural waters may, therefore, require revision. - New approaches are presented for fractionating trace metals in natural waters

  18. 3D unmanned aerial vehicle radiation mapping for assessing contaminant distribution and mobility

    Science.gov (United States)

    Martin, P. G.; Kwong, S.; Smith, N. T.; Yamashiki, Y.; Payton, O. D.; Russell-Pavier, F. S.; Fardoulis, J. S.; Richards, D. A.; Scott, T. B.

    2016-10-01

    Following the events of March 2011 at the Fukushima Daiichi Nuclear Power Plant, significant quantities of radioactive material were released into the local and wider global environment. At five years since the incident, much expense is being currently devoted to the remediation of a large portion of eastern Japan contaminated primarily by radiocesium, yet further significant expenditure will be required over the succeeding decades to complete this clean-up. People displaced from their homes by the incident are now increasingly keen to return, making it more important than ever to provide accurate quantification and representation of any residual radiological contamination. Presented here is the use of an unmanned aerial vehicle equipped with a laser rangefinder unit to generate a three dimensional point-cloud of an area onto which a radiation contamination map, also obtained concurrently via the unmanned aerial platform, can be rendered. An exemplar site of an un-remediated farm consisting of multiple stepped rice paddy fields with a dedicated irrigation system was used for this work. The results obtained show that heightened radiological contamination exists around the site within the drainage network where material is observed to have collected, having been transported by transient water runoff events. These results obtained in May 2014 suggest that a proportion of the fallout material is highly mobile within the natural environment and is likely to be transported further through the system over the succeeding years.

  19. Feasibility study of X-ray K-edge analysis of RCRA heavy metal contamination of sludge packaged in drums

    International Nuclear Information System (INIS)

    Jensen, T.

    1999-01-01

    A study has been completed to assess the capabilities of X-ray K-edge analysis in the measurement of RCRA metal contamination of sludge packaged in drums. Results were obtained for mercury and lead contamination. It was not possible to measure cadmium contamination using this technique. No false positive signals were observed. In cases where uniformity of the sludge can be assumed, this analysis can provide a quick, accurate measurement of heavy-metal contamination

  20. Study of different environmental matrices to access the extension of metal contamination along highways.

    Science.gov (United States)

    Zanello, Sônia; Melo, Vander Freitas; Nagata, Noemi

    2018-02-01

    Metals are indicators of contamination by anthropic activities, such as road traffic. To assess the extent of the metal contamination, more comprehensive studies analyzing different environmental matrices, such as soils, dust, and plants, collected in different sites that are potential sources of these pollutants along the highways, must be prioritized. Samples of soils, dust, and plants were collected alongside the highways of Brazil at 20 sites selected in strategic locations of metal accumulation (Cr, Pb, Zn, As, and Sb) or different situations of the high ways during two rain conditions (wet and dry weeks of sampling): nearby gutters and water supplies, tolls, petrol stations, a federal road police station, and areas associated with agriculture (yearly culture planting upstream of the highway). The geoaccumulation index (metal concentration in the sample of interest/background) varied from 0 to 6, and the decreasing order of contamination by metals during the wet and dry periods were, respectively: Zn > As > Pb = Sb > Cr and Zn > As > Pb > Cr > Sb. In the soils near the highways, the highest concentrations of metals were as follows (mg kg -1 ): As = 15.6, Cr = 81.9, Pb = 39.7, Sb = 5.0, and Zn = 379.3. The highest amounts of these elements in the most superficial layer in soils indicated their addition through atmospheric emissions. The most prominent metal was Sb, whose concentration was greater than the quality limits for soils. The concentration of Sb in soils was higher in the wet week than in the dry week. The emissions from road traffic promoted the increase in metals in the dust on the track, especially Zn and Pb. The highest metal concentrations in grasses (Brachiaria) were found in the roots, except for Sb and Zn, which suggests leaf absorption of atmospheric deposition. Metal contamination was widespread in all studied matrices along the highways.

  1. Proximal spectral sensing to monitor phytoremediation of metal - contaminated soils

    NARCIS (Netherlands)

    Rathod, P.H.; Rossiter, D.; Noomen, M.; van der Meer, F.D.

    2013-01-01

    Assessment of soil contamination and its long-term monitoring are necessary to evaluate the effectiveness of phytoremediation systems. Spectral sensing-based monitoring methods promise obvious benefits compared to field-based methods: lower cost, faster data acquisition and better spatio-temporal

  2. Microbial and heavy metal contamination of pineapple products ...

    African Journals Online (AJOL)

    SAM

    3Department of Social Sciences, University of Rwanda, P.O. Box 117 Butare, ... pineapple processing Enterprises (SMEs) over a storage duration of 12 months. .... The results were measured against ... analyzed for microbial contamination using International Organization ... All culture media used were manufactured by.

  3. CLOPYRALID DISSIPATION IN THE SOIL CONTAMINATED WITH HEAVY METALS

    Directory of Open Access Journals (Sweden)

    Mariusz Kucharski

    2014-12-01

    Full Text Available The aim of the studies was to determine the influence of copper and zinc contamination on clopyralid dissipation in soil. The experiment was carried out in laboratory conditions (plant growth chamber. Clopyralid was applied to three different soils [similar textures, pH, organic carbon content and contrasting copper and zinc content: soil natural contaminated with Cu and Zn (S1, soil with natural low Cu and Zn concentration (S2 and soil S21 prepared in the laboratory (S2 soil additionally contaminated with Cu and Zn salts in the amounts equivalent to contamination level of S1 soil]. Soil samples were taken for analyses for 1 hour (initial concentration and 2, 4, 8, 16, 32, 64 and 96 days after treatment. Clopyralid residue was analysed using GC/ECD (gas chromatography with electron capture detector. Good linearity was found between logarithmic concentration of clopyralid residues and time. The differences in Cu and Zn content influenced the clopyralid decay in soil. The values of DT50 obtained in the experiment ranged from 21 to 27 days. A high concentration of Cu and Zn in soil slowed down clopyralid degradation (the DT50 value was higher – 25–27 days.

  4. Mobile phones in clinical practice: reducing the risk of bacterial contamination.

    Science.gov (United States)

    Mark, D; Leonard, C; Breen, H; Graydon, R; O'Gorman, C; Kirk, S

    2014-09-01

    Mobile smart phones have become increasingly integrated into the practice of doctors and allied medical professionals. Recent studies suggest them to represent reservoirs for pathogens with potential to cause nosocomial infections. This study aimed to investigate the level of contamination on phones used on surgical wards and identify strategies for their safe use within clinical areas. Fifty mobile phones were taken from members of the multidisciplinary team working in a surgical unit. Phones were swabbed by two trained investigators using a standardised technique and samples streaked out using an automated specimen inoculator onto two types of culture media (Columbia blood agar and MacConkey agar). Colonies were identified and counted by a single trained investigator in a blinded fashion. Simultaneously a questionnaire investigating usage levels of phones was given to 150 healthcare workers. Sixty per cent of phones sampled had some form of contaminant isolated from their phone. Thirty-one (62%) of phones had only three colonies or less isolated on medium. No pathogenic or drug resistant strains of bacteria were identified. A total of 88% of individuals sampled by questionnaire used their phone within the workplace of which 55% used it for clinical purposes. Sixty-three per cent expected there to be some form of contaminant on their phone with only 37% admitting to cleaning it regularly. Seventy-five per cent of people did not view a ban on phones as a practical solution was they found to be an infection risk. Touch screen smart phones may be used safely in a clinical environment, with a low risk of cross-contamination of nosocomial bacteria to patients, in the setting of effective adherence to hand hygiene policies. © 2014 John Wiley & Sons Ltd.

  5. Heavy metal contamination and risk assessment in water, paddy soil, and rice around an electroplating plant.

    Science.gov (United States)

    Liu, Jie; Zhang, Xue-Hong; Tran, Henry; Wang, Dun-Qiu; Zhu, Yi-Nian

    2011-11-01

    The objective of this paper is to assess the impact of long-term electroplating industrial activities on heavy metal contamination in agricultural soils and potential health risks for local residents. Water, soil, and rice samples were collected from sites upstream (control) and downstream of the electroplating wastewater outlet. The concentrations of heavy metals were determined by an atomic absorption spectrophotometer. Fractionation and risk assessment code (RAC) were used to evaluate the environmental risks of heavy metals in soils. The health risk index (HRI) and hazard index (HI) were calculated to assess potential health risks to local populations through rice consumption. Hazardous levels of Cu, Cr, and Ni were observed in water and paddy soils at sites near the plant. According to the RAC analysis, the soils showed a high risk for Ni and a medium risk for Cu and Cr at certain sites. The rice samples were primarily contaminated with Ni, followed by Cr and Cu. HRI values >1 were not found for any heavy metal. However, HI values for adults and children were 2.075 and 1.808, respectively. Water, paddy soil, and rice from the studied area have been contaminated by Cu, Cr, and Ni. The contamination of these elements is related to the electroplating wastewater. Although no single metal poses health risks for local residents through rice consumption, the combination of several metals may threaten the health of local residents. Cu and Ni are the key components contributing to the potential health risks.

  6. Environmental impact of ongoing sources of metal contamination on remediated sediments

    Energy Technology Data Exchange (ETDEWEB)

    Knox, Anna Sophia, E-mail: anna.knox@srn.doe.gov [Savannah River National Laboratory, Aiken, SC 29808 (United States); Paller, Michael H., E-mail: michael.paller@srnl.doe.gov [Savannah River National Laboratory, Aiken, SC 29808 (United States); Milliken, Charles E., E-mail: charles.milliken@srnl.doe.gov [Savannah River National Laboratory, Aiken, SC 29808 (United States); Redder, Todd M., E-mail: tredder@limno.com [LimnoTech, Ann Arbor, Minnesota 48108 (United States); Wolfe, John R., E-mail: jwolfe@limno.com [LimnoTech, Ann Arbor, Minnesota 48108 (United States); Seaman, John, E-mail: seaman@srel.uga.edu [Savannah River Ecology Laboratory, University of Georgia, Aiken, SC 29802 (United States)

    2016-09-01

    A challenge to all remedial approaches for contaminated sediments is the continued influx of contaminants from uncontrolled sources following remediation. We investigated the effects of ongoing contamination in mesocosms employing sediments remediated by different types of active and passive caps and in-situ treatment. Our hypothesis was that the sequestering agents used in active caps and in situ treatment will bind elements (arsenic, chromium, cadmium, cobalt, copper, nickel, lead, selenium, and zinc) from ongoing sources thereby reducing their bioavailability and protecting underlying remediated sediments from recontamination. Most element concentrations in surface water remained significantly lower in mesocosms with apatite and mixed amendment caps than in mesocosms with passive caps (sand), uncapped sediment, and spike solution throughout the 2520 h experiment. Element concentrations were significantly higher in Lumbriculus variegatus from untreated sediment than in Lumbriculus from most active caps. Pearson correlations between element concentrations in Lumbriculus and metal concentrations in the top 2.5 cm of sediment or cap measured by diffusive gradient in thin films (DGT) sediment probes were generally strong (as high as 0.98) and significant (p < 0.05) for almost all tested elements. Metal concentrations in both Lumbriculus and sediment/cap were lowest in apatite, mixed amendment, and activated carbon treatments. These findings show that some active caps can protect remediated sediments by reducing the bioavailable pool of metals/metalloids in ongoing sources of contamination. - Graphical abstract: Conventional methods of remediating contaminated sediments may be inadequate for the protection of benthic organisms when ongoing sources of contamination are present. However, sediment caps with chemically active sequestering agents have the ability to reduce the bioavailable pool of metals in ongoing sources of contamination (red dots), reduce toxicity to

  7. Environmental impact of ongoing sources of metal contamination on remediated sediments

    International Nuclear Information System (INIS)

    Knox, Anna Sophia; Paller, Michael H.; Milliken, Charles E.; Redder, Todd M.; Wolfe, John R.; Seaman, John

    2016-01-01

    A challenge to all remedial approaches for contaminated sediments is the continued influx of contaminants from uncontrolled sources following remediation. We investigated the effects of ongoing contamination in mesocosms employing sediments remediated by different types of active and passive caps and in-situ treatment. Our hypothesis was that the sequestering agents used in active caps and in situ treatment will bind elements (arsenic, chromium, cadmium, cobalt, copper, nickel, lead, selenium, and zinc) from ongoing sources thereby reducing their bioavailability and protecting underlying remediated sediments from recontamination. Most element concentrations in surface water remained significantly lower in mesocosms with apatite and mixed amendment caps than in mesocosms with passive caps (sand), uncapped sediment, and spike solution throughout the 2520 h experiment. Element concentrations were significantly higher in Lumbriculus variegatus from untreated sediment than in Lumbriculus from most active caps. Pearson correlations between element concentrations in Lumbriculus and metal concentrations in the top 2.5 cm of sediment or cap measured by diffusive gradient in thin films (DGT) sediment probes were generally strong (as high as 0.98) and significant (p < 0.05) for almost all tested elements. Metal concentrations in both Lumbriculus and sediment/cap were lowest in apatite, mixed amendment, and activated carbon treatments. These findings show that some active caps can protect remediated sediments by reducing the bioavailable pool of metals/metalloids in ongoing sources of contamination. - Graphical abstract: Conventional methods of remediating contaminated sediments may be inadequate for the protection of benthic organisms when ongoing sources of contamination are present. However, sediment caps with chemically active sequestering agents have the ability to reduce the bioavailable pool of metals in ongoing sources of contamination (red dots), reduce toxicity to

  8. Assessing the fate of antibiotic contaminants in metal contaminated soils four years after cessation of long-term waste water irrigation

    International Nuclear Information System (INIS)

    Tamtam, Fatima; Oort, Folkert van; Le Bot, Barbara; Dinh, Tuc; Mompelat, Sophie; Chevreuil, Marc; Lamy, Isabelle; Thiry, Medard

    2011-01-01

    Spreading of urban wastewater on agricultural land may lead to concomitant input of organic and inorganic pollutants. Such multiple pollution sites offer unique opportunities to study the fate of both heavy metals and pharmaceuticals. We examined the occurrence and fate of selected antibiotics in sandy-textured soils, sampled four years after cessation of 100 years irrigation with urban wastewater from the Paris agglomeration. Previous studies on heavy metal contamination of these soils guided our sampling strategy. Six antibiotics were studied, including quinolones, with a strong affinity for organic and mineral soil components, and sulfonamides, a group of more mobile molecules. Bulk samples were collected from surface horizons in different irrigation fields, but also in subsurface horizons in two selected profiles. In surface horizons, three quinolones (oxolinic acid, nalidixic acid, and flumequine) were present in eight samples out of nine. Their contents varied spatially, but were well-correlated one to another. Their distributions showed great similarities regarding spatial distribution of total organic carbon and heavy metal contents, consistent with a common origin by wastewater irrigation. Highest concentrations were observed for sampling sites close to irrigation water outlets, reaching 22 μg kg -1 for nalidixic acid. Within soil profiles, the two antibiotic groups demonstrated an opposite behavior: quinolones, found only in surface horizons; sulfamethoxazole, detected in clay-rich subsurface horizons, concomitant with Zn accumulation. Such distribution patterns are consistent with chemical adsorption properties of the two antibiotic groups: immobilization of quinolones in the surface horizons ascribed to strong affinity for organic matter (OM), migration of sulfamethoxazole due to a lower affinity for OM and its interception and retention in electronegative charged clay-rich horizons. Our work suggests that antibiotics may represent a durable

  9. Metales pesados en hongos de areas contaminadas Heavy metals in wild mushrooms from contaminated areas

    Directory of Open Access Journals (Sweden)

    A. Moyano

    2010-01-01

    organic matter. Mycorrhizal improve their hosts mineral nutrition. The mycorrhizal as­sociations give resistance in contaminated areas to the plants. Sometimes inoculated plants hold up better the contamination that non-inoculated plants. The mycelia absorbs (extracts the soil available fraction and de­crease the heavy metal concentration in the plants. The fruit-bodies can be eaten by many animal specie as well as by humans. Some specie wild fungi have a high nutri­tional value and represent an important eco­nomical resource. Soil, mushrooms and litter were sampled in a lead (Pb-zinc (Zn mine (Soria prov­ince, Spain. The distribution of metals in soil, litter and fungi shows a high concentra­tion of metals in relation to the control ar­eas. The Zn soil contents ranges are 797­3540 mg/kg, Cd: 2.1-10 mg/kg and Pb: 1485-8166 mg/kg, Litter content ranges: (Zn: 92-1475 mg/kg; Cd 0.9-4.2 mg/kg; Pb: 54-2756 mg/kg and fruit-bodies ranges: (Zn 118-915 mg/kg; Cd: 1.2-45.2 mg/kg and Pb 12-1475 mg/kg. The bioacumula­tion factors show high environmental and toxicological risks.

  10. Response of soil microbial communities and microbial interactions to long-term heavy metal contamination.

    Science.gov (United States)

    Li, Xiaoqi; Meng, Delong; Li, Juan; Yin, Huaqun; Liu, Hongwei; Liu, Xueduan; Cheng, Cheng; Xiao, Yunhua; Liu, Zhenghua; Yan, Mingli

    2017-12-01

    Due to the persistence of metals in the ecosystem and their threat to all living organisms, effects of heavy metal on soil microbial communities were widely studied. However, little was known about the interactions among microorganisms in heavy metal-contaminated soils. In the present study, microbial communities in Non (CON), moderately (CL) and severely (CH) contaminated soils were investigated through high-throughput Illumina sequencing of 16s rRNA gene amplicons, and networks were constructed to show the interactions among microbes. Results showed that the microbial community composition was significantly, while the microbial diversity was not significantly affected by heavy metal contamination. Bacteria showed various response to heavy metals. Bacteria that positively correlated with Cd, e.g. Acidobacteria_Gp and Proteobacteria_thiobacillus, had more links between nodes and more positive interactions among microbes in CL- and CH-networks, while bacteria that negatively correlated with Cd, e.g. Longilinea, Gp2 and Gp4 had fewer network links and more negative interactions in CL and CH-networks. Unlike bacteria, members of the archaeal domain, i.e. phyla Crenarchaeota and Euryarchaeota, class Thermoprotei and order Thermoplasmatales showed only positive correlation with Cd and had more network interactions in CH-networks. The present study indicated that (i) the microbial community composition, as well as network interactions was shift to strengthen adaptability of microorganisms to heavy metal contamination, (ii) archaea were resistant to heavy metal contamination and may contribute to the adaption to heavy metals. It was proposed that the contribution might be achieved either by improving environment conditions or by cooperative interactions. Copyright © 2017 Elsevier Ltd. All rights reserved.

  11. Microbiological contamination of mobile phones of clinicians in intensive care units and neonatal care units in public hospitals in Kuwait.

    Science.gov (United States)

    Heyba, Mohammed; Ismaiel, Mohammad; Alotaibi, Abdulrahman; Mahmoud, Mohamed; Baqer, Hussain; Safar, Ali; Al-Sweih, Noura; Al-Taiar, Abdullah

    2015-10-15

    The objective of this study was to explore the prevalence of microbiological contamination of mobile phones that belong to clinicians in intensive care units (ICUs), pediatric intensive care units (PICUs), and neonatal care units (NCUs) in all public secondary care hospitals in Kuwait. The study also aimed to describe mobile phones disinfection practices as well as factors associated with mobile phone contamination. This is a cross-sectional study that included all clinicians with mobile phones in ICUs, PICUs, and NCUs in all secondary care hospitals in Kuwait. Samples for culture were collected from mobile phones and transported for microbiological identification using standard laboratory methods. Self-administered questionnaire was used to gather data on mobile phones disinfection practices. Out of 213 mobile phones, 157 (73.7 %, 95 % CI [67.2-79.5 %]) were colonized. Coagulase-negative staphylococci followed by Micrococcus were predominantly isolated from the mobile phones; 62.9 % and 28.6 % of all mobile phones, respectively. Methicillin-resistant Staphylococcus aureus (MRSA) and Gram-negative bacteria were identified in 1.4 % and 7.0 % of the mobile phones, respectively. Sixty-eight clinicians (33.5 %) reported that they disinfected their mobile phones, with the majority disinfecting their mobile phones only when they get dirty. The only factor that was significantly associated with mobile phone contamination was whether a clinician has ever disinfected his/her mobile phone; adjusted odds ratio 2.42 (95 % CI [1.08-5.41], p-value = 0.031). The prevalence of mobile phone contamination is high in ICUs, PICUs, and NCUs in public secondary care hospitals in Kuwait. Although some of the isolated organisms can be considered non-pathogenic, various reports described their potential harm particularly among patients in ICU and NCU settings. Isolation of MRSA and Gram-negative bacteria from mobile phones of clinicians treating patients in high-risk healthcare

  12. Plants as biomarkers for monitoring heavy metal contaminants on landfill sites using sequential extraction and inductively coupled plasma atomic emission spectrophotometry (ICP-AES).

    Science.gov (United States)

    Murphy, A P; Coudert, M; Barker, J

    2000-12-01

    There have been a number of studies investigating metal uptake in plants on contaminated landfill sites, but little on their role as biomarkers to identify metal mobility for continuous monitoring purposes. Vegetation can be used as a biomonitor of site pollution, by identifying the mobilisation of heavy metals and by providing an understanding of their bioavailability. Plants selected were the common nettle (Uritica Dioica), bramble (Rubus Fruticosa) and sycamore (Acer Pseudoplatanus). A study of the soil fractionation was made to investigate the soil properties that are likely to influence metal mobility and a correlation exercise was undertaken to investigate if variations in concentration of metals in vegetation can reflect variations in concentration of the metals in soil. The soil was digested using aqua regia in a microwave closed vessel. The vegetation was digested using both microwave and a hydrogen peroxide-nitric acid mixture, refluxed on a heating block and a comparison made. The certified reference materials (CRMs) used were Standard Reference Material (SRM) 1547, peach leaves for vegetation (NIST) and for soil CRM 143R, sewage sludge-amended soil (BCR). The relative standard deviations (RSDs) were 2-6% for the analyses. Our findings show evidence of phytoextraction by some plants, (especially bramble and nettle), with certain plants, (sycamore) exhibiting signs of phytostabilisation. The evidence suggests that there is a degree of selectivity in metal uptake and partitioning within the plant compartments. It was also possible to correlate mobility phases of certain metals (Pb, Cu and Zn) using the soil and plant record. Zn and Cu exhibited the greatest potential to migrate from the roots to the leaves, with Pb found principally in the roots of ground vegetation. Our results suggest that analysis of bramble leaves, nettle leaves and roots can be used to monitor the mobility of Pb in the soil with nettle, bramble and sycamore leaves to monitor Cu and Zn.

  13. Cleanup operations at the Oak Ridge Gaseous Diffusion Plant contaminated metal scrapyard

    International Nuclear Information System (INIS)

    Williams, L.C.

    1987-01-01

    Cleanup operations at the contaminated metal storage yard located at the Oak Ridge, Tennessee, Gaseous Diffusion Plant have been completed. The storage yard, in existence since the early 1970s, contained an estimated 35,000 tons of mixed-type metals spread over an area of roughly 30 acres. The overall cleanup program required removing the metal from the storage yard, sorting by specific metal types, and size reduction of specific types for future processing. This paper explains the methods and procedures used to accomplish this task

  14. Soil Contamination with Heavy Metals around Jinja Steel Rolling Mills in Jinja Municipality, Uganda

    Directory of Open Access Journals (Sweden)

    Noel Namuhani

    2015-01-01

    Conclusions. The concentration levels of heavy metals around the steel rolling mills did not appear to be of serious concern, except for copper and cadmium, which showed moderate pollution and moderate to strong pollution, respectively. All heavy metals were within the limits of the United States Environmental Protection Agency (USEPA residential soil standards and the Dutch intervention soil standards. Overall, soils around the Jinja steel rolling mills were slightly polluted with heavy metals, and measures therefore need to be taken to prevent further soil contamination with heavy metals.

  15. DOE`s radioactively - contaminated metal recycling: The policy and its implementation

    Energy Technology Data Exchange (ETDEWEB)

    Warren, S.; Rizkalla, E.

    1997-02-01

    In 1994, the Department of Energy`s Office of Environmental Restoration initiated development of a recycling policy to minimize the amount of radioactively-contaminated metal being disposed of as waste. During the following two years, stakeholders (including DOE and contractor personnel, regulators, members of the public, and representatives of labor and industry) were invited to identify key issues of concern, and to provide input on the final policy. As a result of this process, a demonstration policy for recycling radioactively-contaminated carbon steel resulting from decommissioning activities within the Environmental Management program was signed on September 20, 1996. It specifically recognizes that the Office of Environmental Management has a tremendous opportunity to minimize the disposal of metals as waste by the use of disposal containers fabricated from contaminated steel. The policy further recognizes the program`s demand for disposal containers, and it`s role as the major generator of radioactively-contaminated steel.

  16. Heavy metal contamination characteristic of soil in WEEE (waste electrical and electronic equipment) dismantling community: a case study of Bangkok, Thailand.

    Science.gov (United States)

    Damrongsiri, Seelawut; Vassanadumrongdee, Sujitra; Tanwattana, Puntita

    2016-09-01

    Sue Yai Utit is an old community located in Bangkok, Thailand which dismantles waste electrical and electronic equipment (WEEE). The surface soil samples at the dismantling site were contaminated with copper (Cu), lead (Pb), zinc (Zn), and nickel (Ni) higher than Dutch Standards, especially around the WEEE dumps. Residual fractions of Cu, Pb, Zn, and Ni in coarse soil particles were greater than in finer soil. However, those metals bonded to Fe-Mn oxides were considerably greater in fine soil particles. The distribution of Zn in the mobile fraction and a higher concentration in finer soil particles indicated its readily leachable character. The concentration of Cu, Pb, and Ni in both fine and coarse soil particles was mostly not significantly different. The fractionation of heavy metals at this dismantling site was comparable to the background. The contamination characteristics differed from pollution by other sources, which generally demonstrated the magnification of the non-residual fraction. A distribution pathway was proposed whereby contamination began by the deposition of WEEE scrap directly onto the soil surface as a source of heavy metal. This then accumulated, corroded, and was released via natural processes, becoming redistributed among the soil material. Therefore, the concentrations of both the residual and non-residual fractions of heavy metals in WEEE-contaminated soil increased.

  17. Lead (Pb) and other metals in New York City community garden soils: factors influencing contaminant distributions.

    Science.gov (United States)

    Mitchell, Rebecca G; Spliethoff, Henry M; Ribaudo, Lisa N; Lopp, Donna M; Shayler, Hannah A; Marquez-Bravo, Lydia G; Lambert, Veronique T; Ferenz, Gretchen S; Russell-Anelli, Jonathan M; Stone, Edie B; McBride, Murray B

    2014-04-01

    Urban gardens provide affordable fresh produce to communities with limited access to healthy food but may also increase exposure to lead (Pb) and other soil contaminants. Metals analysis of 564 soil samples from 54 New York City (NYC) community gardens found at least one sample exceeding health-based guidance values in 70% of gardens. However, most samples (78%) did not exceed guidance values, and medians were generally below those reported in NYC soil and other urban gardening studies. Barium (Ba) and Pb most frequently exceeded guidance values and along with cadmium (Cd) were strongly correlated with zinc (Zn), a commonly measured nutrient. Principal component analysis suggested that contaminants varied independently from organic matter and geogenic metals. Contaminants were associated with visible debris and a lack of raised beds; management practices (e.g., importing uncontaminated soil) have likely reduced metals concentrations. Continued exposure reduction efforts would benefit communities already burdened by environmental exposures. Copyright © 2014 Elsevier Ltd. All rights reserved.

  18. Lead (Pb) and other metals in New York City community garden soils: factors influencing contaminant distributions

    Science.gov (United States)

    Mitchell, Rebecca G.; Spliethoff, Henry M.; Ribaudo, Lisa N.; Lopp, Donna M.; Shayler, Hannah A.; Marquez-Bravo, Lydia G.; Lambert, Veronique T.; Ferenz, Gretchen S.; Russell-Anelli, Jonathan M.; Stone, Edie B.; McBride, Murray B.

    2014-01-01

    Urban gardens provide affordable fresh produce to communities with limited access to healthy food but may also increase exposure to lead (Pb) and other soil contaminants. Metals analysis of 564 soil samples from 54 New York City (NYC) community gardens found at least one sample exceeding health-based guidance values in 70% of gardens. However, most samples (78%) did not exceed guidance values, and medians were generally below those reported in NYC soil and other urban gardening studies. Barium (Ba) and Pb most frequently exceeded guidance values and along with cadmium (Cd) were strongly correlated with zinc (Zn), a commonly measured nutrient. Principal component analysis suggested that contaminants varied independently from organic matter and geogenic metals. Contaminants were associated with visible debris and a lack of raised beds; management practices (e.g., importing uncontaminated soil) have likely reduced metals concentrations. Continued exposure reduction efforts would benefit communities already burdened by environmental exposures. PMID:24502997

  19. Effect of leaf and soil contaminations on heavy metals content in spring wheat crops

    International Nuclear Information System (INIS)

    Weber, R.; Hrynczuk, B.

    2000-01-01

    Glass house experiments were carried out in Wagner pots containing 6 kg of soil. The amounts were compared of Zn, Pb and Cd taken up by the crop of spring wheat from contamination introduced into the soil or upon leaves. The heavy metals were labelled with the radioactive isotopes 65 Zn, 210 Pb and 115 Cd. The experiment was performed as a series of independent analyses in four replications. The dynamics of the labelled heavy metals translocation from contaminations sprayed on the upper or bottom side of the flag leaf was also tested. The highest concentration of 65 Zn was found in the straw and gain of wheat. much higher amounts of the metals appeared to have been taken up by the plants from leaf contamination than from soil. The highest dynamics of translocation from leaves to other vegetative and generative organs of plants was that of zinc. (author)

  20. Heavy Metal Contamination of Popular Nail Polishes in Iran

    Directory of Open Access Journals (Sweden)

    Golnaz Karimi

    2015-06-01

    Full Text Available Background: Toxic and hazardous heavy metals like arsenic, lead, mercury, zinc, chromium and iron are found in a variety of personal care products, e.g. lipstick, whitening toothpaste, eyeliner and nail color. The nails absorb the pigments of nail polishes and vaporized or soluble metals can easily pass it. The goal of this survey was to assess whether the different colors of nail polishes comply with maximum concentrations of heavy metals in the EPA’s guidelines. Methods: 150 samples of different popular brands of nail polishes in 13 colors (yellow, beige, silver, pink, white, violet, brown, golden, green, black, colorless, red and blue were randomly purchased from beauty shops in Tehran City, Iran, in 2014. Microwave digestion EPA method 3051 was used by a microwave oven to determine the amount of 5 heavy metals; Nickel, Chromium, Lead, Arsenic and Cadmium. One-way ANOVA, Two-way ANOVA, hierarchical cluster, and principal component analyses were applied by Statistica 7.0 software. Results: The concentrations of chrome, lead, nickel and arsenic showed significant differences between the colors (p<0.05. In all studied samples, the level of cadmium was beyond the safe maximum permissible limit (MPS, but no significance difference in the cadmium content was identified. Conclusion: Due to the high concentrations of toxic metals in many brands of nail polishes, meticulous quality control is recommended for these beauty products.

  1. Eco-toxicity and metal contamination of paddy soil in an e-wastes recycling area

    International Nuclear Information System (INIS)

    Zhang Junhui; Hang Min

    2009-01-01

    Paddy soil samples taken from different sites in an old primitive electronic-waste (e-waste) processing region were examined for eco-toxicity and metal contamination. Using the environmental quality standard for soils (China, Grade II) as reference, soil samples of two sites were weakly contaminated with trace metal, but site G was heavily contaminated with Cd (6.37 mg kg -1 ), and weakly contaminated with Cu (256.36 mg kg -1 ) and Zn (209.85 mg kg -1 ). Zn appeared to be strongly bound in the residual fraction (72.24-77.86%), no matter the soil was metal contaminated or not. However, more than 9% Cd and 16% Cu was present in the non-residual fraction in the metal contaminated soils than in the uncontaminated soil, especially for site G and site F. Compared with that of the control soil, the micronucleus rates of site G and site F soil treatments increased by 2.7-fold and 1.7-fold, respectively. Low germination rates were observed in site C (50%) and site G (50%) soil extraction treated rice seeds. The shortest root length (0.2377 cm) was observed in site G soil treated groups, which is only 37.57% of that of the control soil treated groups. All of the micronucleus ratio of Vicia faba root cells, rice germination rate and root length after treatment of soil extraction indicate the eco-toxicity in site F and G soils although the three indexes are different in sensitivity to soil metal contamination.

  2. Stabilization and solidification of a heavy metal contaminated site soil using a hydroxyapatite based binder

    OpenAIRE

    Xia, Wei-Yi; Feng, Ya-Song; Jin, Fei; Zhang, Li-Ming; Du, Yan-Jun

    2017-01-01

    Synthetic hydroxyapatite (HA) is an efficient and environment-friendly material for the remediation of heavy metal contaminated soils. However, the application of conventional HA powder in stabilizing contaminated soils is limited, due to high cost of final products, difficulties in synthesizing purified HA crystals. A new binder named SPC, which composes of single superphosphate (SSP) and calcium oxide (CaO), is presented as an alternative in this study. HA can form in the soil matrix by an ...

  3. Removal of contaminated asphalt layers by using heat generating powder metallic systems

    International Nuclear Information System (INIS)

    Barinov, A.S.; Karlina, O.K.; Ojovan, M.I.

    1996-01-01

    Heat generating systems on the base of powder metallic fuel were used for the removal of contaminated asphalt layers. Decontamination of spots which had complex geometric form was performed. Asphalt layers with deep contamination were removed essentially all radionuclides being retained in asphalt residue. Only a small part (1 - 2 %) of radionuclides could pass to combustion slag. No radionuclides were detected in aerosol-gas phase during decontamination process

  4. Role of organic amendments on enhanced bioremediation of heavy metal(loid) contaminated soils.

    Science.gov (United States)

    Park, Jin Hee; Lamb, Dane; Paneerselvam, Periyasamy; Choppala, Girish; Bolan, Nanthi; Chung, Jae-Woo

    2011-01-30

    As land application becomes one of the important waste utilization and disposal practices, soil is increasingly being seen as a major source of metal(loid)s reaching food chain, mainly through plant uptake and animal transfer. With greater public awareness of the implications of contaminated soils on human and animal health there has been increasing interest in developing technologies to remediate contaminated sites. Bioremediation is a natural process which relies on soil microorganisms and higher plants to alter metal(loid) bioavailability and can be enhanced by addition of organic amendments to soils. Large quantities of organic amendments, such as manure compost, biosolid and municipal solid wastes are used as a source of nutrients and also as a conditioner to improve the physical properties and fertility of soils. These organic amendments that are low in metal(loid)s can be used as a sink for reducing the bioavailability of metal(loid)s in contaminated soils and sediments through their effect on the adsorption, complexation, reduction and volatilization of metal(loid)s. This review examines the mechanisms for the enhanced bioremediation of metal(loid)s by organic amendments and discusses the practical implications in relation to sequestration and bioavailability of metal(loid)s in soils. Copyright © 2010 Elsevier B.V. All rights reserved.

  5. Metal contamination in benthic macroinvertebrates in a sub-basin in the southeast of Brazil

    Directory of Open Access Journals (Sweden)

    WAC Chiba

    Full Text Available Benthic macroinvertebrates have many useful properties that make possible the use of these organisms as sentinel in biomonitoring programmes in freshwater. Combined with the characteristics of the water and sediment, benthic macroinvertebrates are potential indicators of environmental quality. Thus, the spatial occurrence of potentially toxic metals (Al, Zn, Cr, Co, Cu, Fe, Mn and Ni in the water, sediment and benthic macroinvertebrates samples were investigated in a sub-basin in the southeast of Brazil in the city of São Carlos, São Paulo state, with the aim of verifying the metals and environment interaction with benthic communities regarding bioaccumulation. Hypothetically, there can be contamination by metals in the aquatic environment in the city due to lack of industrial effluent treatment. All samples were analysed by the USEPA adapted method and processed in an atomic absorption spectrophotometer. The sub-basin studied is contaminated by toxic metals in superficial water, sediment and benthic macroinvertebrates. The Bioaccumulation Factor showed a tendency for metal bioaccumulation by the benthic organisms for almost all the metal species. The results show a potential human and ecosystem health risk, contributing to metal contamination studies in aquatic environments in urban areas.

  6. Metal contamination of agricultural soils in the copper mining areas of Singhbhum shear zone in India

    Science.gov (United States)

    Giri, Soma; Singh, Abhay Kumar; Mahato, Mukesh Kumar

    2017-06-01

    The study was intended to investigate the heavy metal contamination in the agricultural soils of the copper mining areas in Singhbhum shear zone, India. The total concentrations of the metals were determined by inductively coupled plasma-mass spectrometer (ICPMS). Pollution levels were assessed by calculating enrichment factor (EF), geo-accumulation index (I_geo), contamination factors (CF), pollution load index ( PLI), Nemerow index and ecological risk index (RI). The metal concentrations in the soil samples exceeded the average shale values for almost all the metals. Principal component analysis resulted in extraction of three factors explaining 82.6% of the data variability and indicated anthropogenic contribution of Cu, Ni, Co, Cr, Mn and Pb. The EF and I_geo values indicated very high contamination with respect to Cu followed by As and Zn in the agricultural soils. The values of PLI, RI and Nemerow index, which considered the overall effect of all the studied metals on the soils, revealed that 50% of the locations were highly polluted with respect to metals. The pollution levels varied with the proximity to the copper mining and processing units. Consequently, the results advocate the necessity of periodic monitoring of the agricultural soils of the area and development of proper management strategies to reduce the metal pollution.

  7. Metal contamination in zebra mussels (Dreissena polymorpha) along the St. Lawrence River.

    Science.gov (United States)

    Kwan, K H Michael; Chan, Hing Man; de Lafontaine, Yves

    2003-01-01

    In order to evaluate the use of zebra mussels as biomonitors for metal bioavailability in the St. Lawrence River, we tested the hypothesis that the concentrations of 11 metals in zebra mussels vary significantly between sites along the river and that the season of collection and body size affect metal bioaccumulation. Mussels were collected at 14 sites during June 1996 and at monthly intervals at one site. Specimens were grouped in three size classes and their soft tissue was analyzed for As, Ca, Cd, Cr, Hg, Mn, Ni, Pb, Se, and Zn. Significant size effects were found for Ca, Cd, Cr, Cu, Ni and Zn. Spatial and seasonal variations in bioconcentration were significant for all metals. Spatial patterns in contamination that corresponded to known point sources of pollution or hydrology of the river were identified by principal component analysis. Seasonal variations can be attributed to the reproductive cycle of mussels and hydrological variability of the river. In comparison with values reported for zebra mussels in other contaminated sites in North America and Europe, levels of metal in the St. Lawrence River are low or intermediate. Our results show that when controlled for size and seasonal effects, zebra mussels represent a useful biomonitor for metal availability in the river and may offer an interesting alternative to native mussels and fish for such a role. Local contamination by some toxic metals is still a cause for concern in the St. Lawrence River.

  8. Metal Contamination In Plants Due To Tannery Effluent

    Directory of Open Access Journals (Sweden)

    Md. Farhad Ali

    2015-08-01

    Full Text Available Abstract This paper analyzes the determination of heavy metals named Chromium Lead and Cadmium deposited in soil as well as in the plants and vegetables due to the tanning industries of the area of Hazaribagh Dhaka. The tanneries discharge untreated tannery effluents which get mixed with the soil water of rivers and canals in this area. The determination of metals was performed for the soil that was collected from the land adjacent to the canals which bear untreated tannery effluents. The soil is affected with the untreated effluents through the deposition of heavy metals. The metals were furthers deposited into the plants and vegetables grown on that soil. The roots stems and leaves of the plants of Jute Corchorus capsularis and Spinach Basella alba grown on that soil were analyzed for determining these metals. Extreme amount of chromium was found for plants and again Lead Cadmium were found in higher amount in these parts of the two plants. These two plants are taken as a popular vegetables extensively. In case of soil the amount of Chromium Lead and Cadmium were analyzed as 87 mgL 0.131 mgL and 0.190 mgL respectively. For the roots stems and leaves of Jute Corchorus capsularis the average values are 115.62 mgL for Chromium 11.25 mgL for Lead and 2.27 mgL for Cadmium respectively. Again in case of Spinach Basella alba 124.42 mgL was found for Chromium 7.38 mgL for lead and 2.97 mgL for Cadmium as average values for these parts of the two trees. All the observed values of metals of Chromium Lead and Cadmium are higher than the permissible and specially for Chromium the amount is extremely higher.

  9. 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...

  10. A new cleaning process for the metallic contaminants on a post-CMP wafer's surface

    International Nuclear Information System (INIS)

    Gao Baohong; Liu Yuling; Wang Chenwei; Wang Shengli; Zhou Qiang; Tan Baimei; Zhu Yadong

    2010-01-01

    This paper presents a new cleaning process using boron-doped diamond (BDD) film anode electrochemical oxidation for metallic contaminants on polished silicon wafer surfaces. The BDD film anode electrochemical oxidation can efficiently prepare pyrophosphate peroxide, pyrophosphate peroxide can oxidize organic contaminants, and pyrophosphate peroxide is deoxidized into pyrophosphate. Pyrophosphate, a good complexing agent, can form a metal complex, which is a structure consisting of a copper ion, bonded to a surrounding array of two pyrophosphate anions. Three polished wafers were immersed in the 0.01 mol/L CuSO 4 solution for 2 h in order to make comparative experiments. The first one was cleaned by pyrophosphate peroxide, the second by RCA (Radio Corporation of America) cleaning, and the third by deionized (DI) water. The XPS measurement result shows that the metallic contaminants on wafers cleaned by the RCA method and by pyrophosphate peroxide is less than the XPS detection limits of 1 ppm. And the wafer's surface cleaned by pyrophosphate peroxide is more efficient in removing organic carbon residues than RCA cleaning. Therefore, BDD film anode electrochemical oxidation can be used for microelectronics cleaning, and it can effectively remove organic contaminants and metallic contaminants in one step. It also achieves energy saving and environmental protection. (semiconductor technology)

  11. Remediation of a heavy metal-contaminated soil by means of agglomeration.

    Science.gov (United States)

    Polettini, Alessandra; Pomi, Raffaella; Valente, Mattia

    2004-01-01

    The feasibility of treating a heavy metal-contaminated soil by means of a solidification/stabilization treatment consisting of a granulation process is discussed in the present article. The aim of the study was to attain contaminant immobilization within the agglomerated solid matrix. The soil under concern was characterized by varying levels of heavy metal contamination, ranging from 50 to 500 mg kg(-1) dry soil for chromium. from 300 to 2000 mg kg(-1) dry soil for lead and from 270 to 5000 mg kg(-1) dry soil for copper. An artificially contaminated soil with contaminant concentrations corresponding to the upper level of the mentioned ranges was prepared from a sample of uncontaminated soil by means of spiking experiments. Pure soluble species of chromium, copper and lead. namely CrCl3.6H2O, CuCl2.2H2O and Pb(NO3)2, were selected for the spiking experiments, which were arranged according to a 2(3) full factorial design. The solidification/stabilization treatment was based on an agglomeration process making use of hydraulic binders including Portland cement, hydrated lime and sodium methasilicate, which were selected on the basis of preliminary test runs. It was found that after 7 days of curing the applied treatment was able to efficiently immobilize the investigated heavy metals within the hydrated matrix. Good acid neutralization behavior was also observed, indicating improved matrix resistance to acid attack and decreased potential for metal leaching.

  12. Repeated phytoextraction of four metal-contaminated soils using the cadmium/zinc hyperaccumulator Sedum plumbizincicola.

    Science.gov (United States)

    Li, Zhu; Wu, Longhua; Hu, Pengjie; Luo, Yongming; Zhang, Hao; Christie, Peter

    2014-06-01

    A cadmium/zinc hyperaccumulator extracted metals from four contaminated soils over three years in a glasshouse experiment. Changes in plant metal uptake and soil total (aqua regia-extractable) and available metals were investigated. Plant Cd concentrations in a high-Cd acid soil and plant Zn concentrations in two acid soils decreased during repeated phytoextraction and were predicted by soil available metal concentrations. However, on repeated phytoextraction, plant Cd concentrations remained constant in lightly Cd-polluted acid soils, as did plant Cd and Zn in alkaline soils, although soil available metal concentrations decreased markedly. After phytoextraction acid soils showed much higher total metal removal efficiencies, indicating possible suitability of phytoextraction for acid soils. However, DGT-testing, which takes soil metal re-supply into consideration, showed substantial removal of available metal and distinct decreases in metal supply capacity in alkaline soils after phytoextraction, suggesting that a strategy based on lowering the bioavailable contaminant might be feasible. Copyright © 2014 Elsevier Ltd. All rights reserved.

  13. Surfactant-induced mobilisation of trace metals from estuarine sediment: Implications for contaminant bioaccessibility and remediation

    Energy Technology Data Exchange (ETDEWEB)

    Singh, Anu [School of Earth, Ocean and Environmental Sciences, University of Plymouth, Drake Circus, Plymouth PL4 8AA (United Kingdom); Turner, Andrew [School of Earth, Ocean and Environmental Sciences, University of Plymouth, Drake Circus, Plymouth PL4 8AA (United Kingdom)], E-mail: aturner@plymouth.ac.uk

    2009-02-15

    The mobilisation of metals (Al, Fe, Cd, Cu, Mn, Ni, Pb, Sn, Zn) from contaminated estuarine sediment has been examined using commercially available surfactants. Metal release by the anionic surfactant, sodium dodecyl sulphate (SDS), increased with increasing amphiphile concentration up to and above its critical micelle concentration (CMC). Metal mobilisation by the bile acid salt, sodium taurocholate, and the nonionic surfactant, Triton X-100, however, did not vary with amphiphile concentration. SDS was the most efficient surfactant in mobilising metals from the sample, and Cd, Cu and Ni were released to the greatest extents (12-18% of total metal at [SDS] > CMC). Metal mobilisation appeared to proceed via complexation with anionic amphiphiles and denudation of hydrophobic host phases. Surfactants may play an important role in the solubilisation of metals in the digestive environment of deposit-feeding animals and, potentially, in the remediation of metal-contaminated soil and sediment. - Significant quantities of metals are mobilised from estuarine sediment by commercially available surfactants.

  14. Sublethal effects of contamination on the Mediterranean sponge Crambe crambe: metal accumulation and biological responses

    International Nuclear Information System (INIS)

    Cebrian, E.; Marti, R.; Uriz, J.M.; Turon, X.

    2003-01-01

    The effect of low levels of pollution on the growth, reproduction output, morphology and survival of adult sponges and settlers of the sponge Crambe crambe were examined. We transplanted sponges from a control area to a contaminated site and measured the main environmental variables (chemical and physical) of both sites during the study period. Except some punctual differences in particulate organic matter, silicates, nitrates, and water motion, most environmental variables in the water were similar at both sites during the study months. Mainly copper, lead and OM concentrations in the sediment, and water motion were significantly higher at the polluted site and may be implicated in the biological effects observed: decrease in the percentage of specimens with embryos, increase in shape irregularity and decrease in growth rate. Individuals naturally occurring at the polluted site and those transplanted there for four months accumulated ten times more copper than either untouched or transplant controls. Although lead concentration in sediment did not differ between sites, native specimens from the contaminated site accumulated this metal more than untouched controls. Vanadium concentration also tended to increase in the sponges living at or transplanted to the contaminated site but this difference was not significant. C. crambe is a reliable indicator of metal contamination since it accumulates copper, lead and vanadium in high amounts. At the contaminated site, sponge growth, fecundity and survival were inhibited, whereas sponge irregularity ending in sponge fission was promoted. All these effects may compromise the structure and dynamics of the sponge populations in sheltered, metal-contaminated habitats

  15. Utilization of grasses for potential biofuel production and phytoremediation of heavy metal contaminated soils.

    Science.gov (United States)

    Balsamo, Ronald A; Kelly, William J; Satrio, Justinus A; Ruiz-Felix, M Nydia; Fetterman, Marisa; Wynn, Rodd; Hagel, Kristen

    2015-01-01

    This research focuses on investigating the use of common biofuel grasses to assess their potential as agents of long-term remediation of contaminated soils using lead as a model heavy metal ion. We present evidence demonstrating that switch grass and Timothy grass may be potentially useful for long-term phytoremediation of heavy metal contaminated soils and describe novel techniques to track and remove contaminants from inception to useful product. Enzymatic digestion and thermochemical approaches are being used to convert this lignocellulosic feedstock into useful product (sugars, ethanol, biocrude oil+biochar). Preliminary studies on enzymatic hydrolysis and fast pyrolysis of the Switchgrass materials that were grown in heavy metal contaminated soil and non-contaminated soils show that the presence of lead in the Switchgrass material feedstock does not adversely affect the outcomes of the conversion processes. These results indicate that the modest levels of contaminant uptake allow these grass species to serve as phytoremediation agents as well as feedstocks for biofuel production in areas degraded by industrial pollution.

  16. Review in Strengthening Technology for Phytoremediation of Soil Contaminated by Heavy Metals

    Science.gov (United States)

    Wu, Chishan; Zhang, Xingfeng; Deng, Yang

    2017-07-01

    In view of current problems of phytoremediation technology, this paper summarizes research progress for phytoremediation technology of heavy metal contaminated soil. When the efficiency of phytoremediation may not meet the demand in practice of contaminated soil or water. Effective measures should be taken to improve the plant uptake and translocation. This paper focuses on strengthening technology mechanism, which can not only increase the biomass of plant and hyperaccumulators, but also enhance the tolerance and resistance to heavy metals, and application effect of phytoremediation, including agronomic methods, earthworm bioremediation and chemical induction technology. In the end of paper, deficiencies of each methods also be discussed, methods of strengthening technology for phytoremediation need further research.

  17. Decontamination of alpha contaminated metallic waste by cerium IV redox process

    International Nuclear Information System (INIS)

    Shah, J.G.; Dhami, P.S.; Gandhi, P.M.; Wattal, P.K.

    2012-01-01

    Decontamination of alpha contaminated metallic waste is an important aspect in the management of waste generated during dismantling and decommissioning of nuclear facilities. Present work on cerium redox process targets decontamination of alpha contaminated metallic waste till it qualifies for the non alpha waste category for disposal in near surface disposal facility. Recovery of the alpha radio nuclides and cerium from aqueous secondary waste streams was also studied deploying solvent extraction process and established. The alpha-lean secondary waste stream has been immobilised in cement based matrix for final disposal. (author)

  18. Estimation of Heavy Metals Contamination in the Soil of Zaafaraniya City Using the Neural Network

    Science.gov (United States)

    Ghazi, Farah F.

    2018-05-01

    The aim of this paper is to estimate the heavy metals Contamination in soils which can be used to determine the rate of environmental contamination by using new technique depend on design feedback neural network as an alternative accurate technique. The network simulates to estimate the concentration of Cadmium (Cd), Nickel (Ni), Lead (Pb), Zinc (Zn) and Copper (Cu). Then to show the accuracy and efficiency of suggested design we applied the technique in Al- Zafaraniyah in Baghdad city. The results of this paper show that the suggested networks can be successfully applied to the rapid and accuracy estimation of concentration of heavy metals.

  19. Application of carbon nanotubes to immobilize heavy metals in contaminated soils

    Energy Technology Data Exchange (ETDEWEB)

    Matos, Martim P. S. R.; Correia, António Alberto S., E-mail: aalberto@dec.uc.pt [University of Coimbra, Department of Civil Engineering, CIEPQPF—Chemical Process Engineering and Forest Products Research Centre (Portugal); Rasteiro, Maria G. [University of Coimbra, Department of Chemical Engineering, CIEPQPF (Portugal)

    2017-04-15

    The contamination of soils with heavy metals is a growing concern in modern societies. To avoid the spread of contamination, soil stabilization techniques can be applied mixing materials with the soil in order to partially immobilize heavy metals. Carbon nanotubes (CNTs) are nanomaterials known for its exceptional properties, like high surface area and adsorption capacity. Due to these unique properties, the potential use of CNTs in heavy metal contaminated water has been studied, with very satisfactory results; however, their application in contaminated soils is practically unexplored. This experimental work is focused on studying the potential of using CNTs in soil remediation, especially to immobilize the heavy metals ions: lead (Pb{sup 2+}), copper (Cu{sup 2+}), nickel (Ni{sup 2+}), and zinc (Zn{sup 2+}), commonly present in contaminated soils. In order to avoid CNT agglomeration, which originates the loss of their beneficial properties, an aqueous suspension of CNTs was prepared using a non-ionic surfactant combined with ultrasonic energy to promote CNTs dispersion. Then, the soil, with and without the addition of CNTs, was subjected to adsorption tests to evaluate the CNT capacity to improve heavy metal immobilization. To validate the adsorption test results, permeability tests were executed, simulating the conditions of a real-case scenario. The results obtained led to the conclusion that the addition of a small amount of dispersed CNTs can successfully increase the adsorption capacity of the soil and consequently improve the immobilization of heavy metals in the soil matrix. The immobilization percentage varies with the different heavy metals under study.

  20. In situ and laboratory bioassays with Chironomus riparius larvae to assess toxicity of metal contamination in rivers: the relative toxic effect of sediment versus water contamination.

    Science.gov (United States)

    Faria, Mafalda S; Lopes, Ricardo J; Nogueira, António J A; Soares, Amadeu M V M

    2007-09-01

    We used bioassays employing head capsule width and body length increase of Chironomus riparius larvae as end points to evaluate metal contamination in streams. Bioassays were performed in situ near an abandoned Portuguese goldmine in the spring of 2003 and 2004. Bioassays also were performed under laboratory conditions with water and sediment collected from each stream to verify if laboratory bioassays could detect in situ toxicity and to evaluate the relative contribution of sediment and water to overall toxicity. We used field sediments with control water and control sediments with field water to discriminate between metal contamination in water and sediment. Field water with dry and sieved, organic matter-free, and nontreated sediments was used to determine the toxicity of heavy metals that enter the organism through ingested material. In both in situ and laboratory bioassays, body length increase was significantly inhibited by metal contamination, whereas head capsule width was not affected. Body length increase was more affected by contaminated sediment compared to contaminated water. The lowest-effect level of heavy metals was observed in the dry and sieved sediment that prevented ingestion of sediment particles by larvae. These results suggest that body length increase of C. riparius larvae can be used to indicate the impact of metal contamination in rivers. Chironomus riparius larvae are more affected by heavy metals that enter the organism through ingested sediment than by heavy metals dissolved in the water column. Nevertheless, several factors, such as the particle size and organic matter of sediment, must be taken into account.

  1. Phytoremediation of Metal Contaminated Soil Using Willow: Exploiting Plant-Associated Bacteria to Improve Biomass Production and Metal Uptake.

    Science.gov (United States)

    Janssen, Jolien; Weyens, Nele; Croes, Sarah; Beckers, Bram; Meiresonne, Linda; Van Peteghem, Pierre; Carleer, Robert; Vangronsveld, Jaco

    2015-01-01

    Short rotation coppice (SRC) of willow and poplar is proposed for economic valorization and concurrently as remediation strategy for metal contaminated land in northeast-Belgium. However, metal phytoextraction appears insufficient to effectuate rapid reduction of soil metal contents. To increase both biomass production and metal accumulation of SRC, two strategies are proposed: (i) in situ selection of the best performing clones and (ii) bioaugmentation of these clones with beneficial plant-associated bacteria. Based on field data, two experimental willow clones, a Salix viminalis and a Salix alba x alba clone, were selected. Compared to the best performing commercial clones, considerable increases in stem metal extraction were achieved (up to 74% for Cd and 91% for Zn). From the selected clones, plant-associated bacteria were isolated and identified. All strains were subsequently screened for their plant growth-promoting and metal uptake enhancing traits. Five strains were selected for a greenhouse inoculation experiment with the selected clones planted in Cd-Zn-Pb contaminated soil. Extraction potential tended to increase after inoculation of S. viminalis plants with a Rahnella sp. strain due to a significantly increased twig biomass. However, although bacterial strains showing beneficial traits in vitro were used for inoculation, increments in extraction potential were not always observed.

  2. Source identification of heavy metal contamination using metal association and Pb isotopes in Ulsan Bay sediments, East Sea, Korea

    International Nuclear Information System (INIS)

    Chae, Jung Sun; Choi, Man Sik; Song, Yun Ho; Um, In Kwon; Kim, Jae Gon

    2014-01-01

    Highlights: • The levels of Cu, Zn, and Pb in sediments were higher than the Korean TEL at one-third of all sites. • The primary source of metal contamination came from activities related to nonferrous metal refineries near Onsan Harbor. • Three different anthropogenic sources and background sediments could be identified as endmembers using Pb isotopes. • The major anthropogenic Pb sources were identified as imported ores from Australia and Peru. • Isotope ratios in anthropogenic Pb discharged from Ulsan Bay to offshore could be identified. - Abstract: To determine the characteristics of metal pollution sources in Ulsan Bay, East Sea, 39 surface and nine core sediments were collected within the bay and offshore area, and analyzed for metals and stable lead (Pb) isotopes. Most surface sediments (>95% from 48 sites) had high copper (Cu), zinc (Zn), cadmium (Cd), and Pb concentrations that were as much as 1.3 times higher than background values. The primary source of metal contamination came from activities related to nonferrous metal refineries near Onsan Harbor, and the next largest source was from shipbuilding companies located at the mouth of the Taehwa River. Three different anthropogenic sources and background sediments could be identified as end-members using Pb isotopes. Isotopic ratios for the anthropogenic Pb revealed that the sources were imported ores from Australia, Peru, and the United States. In addition, Pb isotopes of anthropogenic Pb discharged from Ulsan Bay toward offshore could be determined

  3. The use of dialdehyde starch derivatives in the phytoremediation of soils contaminated with heavy metals.

    Science.gov (United States)

    Antonkiewicz, Jacek; Para, Andrzej

    2016-01-01

    Products of the reaction between dialdehyde starch and Y-NH2 compounds (e.g. semicarbazide or hydrazine) are effective ligands for metal ions. The usefulness of these derivatives was tested in the experiment, both in terms of the immobilization of heavy metal ions in soil and the potential application in phytoextraction processes. The experimental model comprised maize and the ions of such metals as: Zn(II), Pb(II), Cu(II), Cd(II), and Ni(II). The amount of maize yield, as well as heavy metal content and uptake by the aboveground parts and roots of maize, were studied during a three-year pot experiment. The results of the study indicate the significant impact of heavy metals on reduced yield and increased heavy metal content in maize. Soil-applied dialdehyde starch derivatives resulted in lower yields, particularly disemicarbazone (DASS), but in heavy metal-contaminated soils they largely limited the negative impact of these metals both on yielding and heavy metal content in plants, particularly dihydrazone (DASH). It was demonstrated that the application of dihydrazone (DASH) to a soil polluted with heavy metals boosted the uptake of Zn, Pb, Cu, and Cd from the soil, hence there is a possibility to use this compound in the phytoextraction of these metals from the soil. Decreased Ni uptake was also determined, hence the possibility of using this compound in the immobilization of this metal. The study showed that dialdehyde starch disemicarbazone was ineffective in the discussed processes.

  4. Metal contamination and human health risk associated with the ...

    African Journals Online (AJOL)

    Metals are accumulating in the muscle tissue of L. rosae even although the fish populations appear to be healthy. At Loskop Dam all L. rosae analysed exceeded the recommended hazard quotient (HQ) of 1 for antimony, and less than 50% exceeded that for lead. At Flag Boshielo Dam, the recommended HQ was exceeded ...

  5. Optimal selection of biochars for remediating metals contaminated mine soils

    Science.gov (United States)

    Approximately 500,000 abandoned mines across the U.S. pose a considerable, pervasive risk to human health and the environment due to possible exposure to the residuals of heavy metal extraction. Historically, a variety of chemical and biological methods have been used to reduce ...

  6. Heavy metal contamination of Clarias gariepinus from a lake and ...

    African Journals Online (AJOL)

    Adult Clarias gariepinus (African Catfish) were purchased from Eleiyele Lake and Zartech fish farm in Ibadan. Water samples were also collected in February (dry season) and June (rainy season), 2002. Gill, bone, intestine, muscle and water samples were analyzed for five metals: manganese, copper, zinc, iron, and ...

  7. Trace Metal Contamination in Water from Abandoned Mining and ...

    African Journals Online (AJOL)

    Fiifi Baidoo

    copper and lead sulpho-salts (Dzigbordi-Adjimah, 1988). ... The resulting solution was analysed for trace metals at the Institute of Mining and Mineral ..... found in the samples (Tables 3 and 4) may be due to the mineral-water interactions and.

  8. Directed Selection of Biochars for Amending Metal Contaminated Mine Soils

    Science.gov (United States)

    Approximately 500,000 abandoned mines across the U.S. pose a considerable, pervasive risk to human health and the environment. World-wide the problem is even larger. Lime, organic matter, biosolids and other amendments have been used to decrease metal bioavailability in contami...

  9. Innovative technologies for recycling contaminated concrete and scrap metal

    International Nuclear Information System (INIS)

    Bossart, S.J.; Moore, J.

    1993-01-01

    Decontamination and decommissioning of US DOE's surplus facilities will generate enormous quantities of concrete and scrap metal. A solicitation was issued, seeking innovative technologies for recycling and reusing these materials. Eight proposals were selected for award. If successfully developed, these technologies will enable DOE to clean its facilities by 2019

  10. In-Situ Electrokinetic Remediation for Metal Contaminated Soils

    Science.gov (United States)

    2001-03-01

    phytoremediation , and electrokinetic extraction. The US Army Environmental Center (USAEC) and Engineer Research and Development Center (ERDC...California (CA) List Metals: Antimony, arsenic, barium, beryllium, cadmium, chromium, cobalt, copper, lead, mercury , molybdenum, nickel, selenium...Comparison Technologies with which electrokinetic remediation must compete are "Dig and Haul", Soil Washing, and Phytoremediation . "Dig and haul

  11. Metal contamination of agricultural soils in the copper mining areas ...

    Indian Academy of Sciences (India)

    Soma Giri

    2017-06-07

    Jun 7, 2017 ... Agricultural soil; heavy metals; copper mining areas; multivariate analysis; ... multivariate statistical analysis. 2. ... sieved through standard sieve of 200 mesh size (Giri ... Pearson's correlation is a bivariate correlation ... is a variation reduction technique in which a num- ... Varimax rotation is applied to all the.

  12. Assessment of Heavy Metal Contamination in Soils around Cassava ...

    African Journals Online (AJOL)

    Manihot esculentum is a major farm produce in southern .... Heavy metals enrichment factor was derived based ... VII. 0-15. 6.1. 2.3. 58.41. 15-30. 6.3. 1.8. 54.28. VIII. 0-15. 6.5. 2.5. 62.21 ... levels of iron in soils around foam manufacturing, ...

  13. Recent advances in conventional and contemporary methods for remediation of heavy metal-contaminated soils.

    Science.gov (United States)

    Sharma, Swati; Tiwari, Sakshi; Hasan, Abshar; Saxena, Varun; Pandey, Lalit M

    2018-04-01

    Remediation of heavy metal-contaminated soils has been drawing our attention toward it for quite some time now and a need for developing new methods toward reclamation has come up as the need of the hour. Conventional methods of heavy metal-contaminated soil remediation have been in use for decades and have shown great results, but they have their own setbacks. The chemical and physical techniques when used singularly generally generate by-products (toxic sludge or pollutants) and are not cost-effective, while the biological process is very slow and time-consuming. Hence to overcome them, an amalgamation of two or more techniques is being used. In view of the facts, new methods of biosorption, nanoremediation as well as microbial fuel cell techniques have been developed, which utilize the metabolic activities of microorganisms for bioremediation purpose. These are cost-effective and efficient methods of remediation, which are now becoming an integral part of all environmental and bioresource technology. In this contribution, we have highlighted various augmentations in physical, chemical, and biological methods for the remediation of heavy metal-contaminated soils, weighing up their pros and cons. Further, we have discussed the amalgamation of the above techniques such as physiochemical and physiobiological methods with recent literature for the removal of heavy metals from the contaminated soils. These combinations have showed synergetic effects with a many fold increase in removal efficiency of heavy metals along with economic feasibility.

  14. Risks to humans and wildlife from metal contamination in soils/sediments at CERCLA sites

    International Nuclear Information System (INIS)

    Hitch, J.P.; Hovatter, P.S.; Opresko, D.M.; Sample, B.; Young, R.A.

    1994-01-01

    A common problem that occurs at DOD and DOE CERCLA sites is metal contamination in soils and aquatic sediments and the protection of humans and wildlife from potential exposure to this contamination. Consequently, the authors have developed a site-specific reference dose for mercury in sediments at the Oak Ridge Reservation and site-specific cleanup levels for certain metals, including arsenic and nickel, in soils at an Army ammunition plant. Another concern during remediation of these sites is that limited data are available to determine the direct risks to indigenous wildlife. Therefore, the authors have developed toxicological benchmarks for certain metals and metal compounds to be used as screening tools to determine the potential hazard of a contaminant to representative mammalian and avian wildlife species. These values should enable the Army and DOE to more accurately determine the risks to humans and wildlife associated with exposure to these contaminated media at their sites in order to achieve a more effective remediation. This effort is ongoing at ORNL with toxicological benchmarks also being developed for metal compounds and other chemicals of concern to DOD and DOE in order to address the potential hazard to

  15. Adverse events associated with metal contamination of traditional chinese medicines in Korea: a clinical review.

    Science.gov (United States)

    Kim, Hyunah; Hughes, Peter J; Hawes, Emily M

    2014-09-01

    This study was performed to review studies carried out in Korea reporting toxic reactions to traditional Chinese medicines (TCMs) as a result of heavy metal contamination. PubMed (1966-August 2013) and International Pharmaceutical Abstracts (1965-August 2013) were searched using the medical subject heading terms of "Medicine, Chinese Traditional," "Medicine, Korean Traditional," "Medicine, Traditional," "Metals, Heavy," and "Drug Contamination". For Korean literature, Korea Med (http://www.koreamed.org), the Korean Medical Database (http://kmbase.medric.or.kr), National Discovery for Science Leaders (www.ndsl.kr), Research Information Sharing Service (http://www.riss.kr), and Google Scholar were searched using the terms "Chinese medicine," "Korean medicine," "herbal medicine," and "metallic contamination" in Korean. Bibliographies of case reports and case series, identified using secondary resources, were also utilized. Only literature describing cases or studies performed in Korea were included. Case reports identified clear issues with heavy metal, particularly lead, contamination of TCMs utilized in Korea. No international standardization guidelines for processing, manufacturing and marketing of herbal products exist. Unacceptably high levels of toxic metals can be present in TCM preparations. Health care providers and patients should be educated on the potential risks associated with TCMs. International advocacy for stricter standardization procedures for production of TCMs is warranted.

  16. Bacterial contamination of fabric and metal-bead identity card lanyards: A cross-sectional study

    Directory of Open Access Journals (Sweden)

    Thomas Pepper

    2014-11-01

    Full Text Available Summary: In healthcare, fabric or metal-bead lanyards are universally used for carrying identity cards. However there is little information on microbial contamination with potential pathogens that may readily re-contaminate disinfected hands. We examined 108 lanyards from hospital staff. Most grew skin flora but 7/108 (6% had potentially pathogenic bacteria: four grew methicillin-susceptible Staphylococcus aureus, and four grew probable fecal flora: 3 Clostridium perfringens and 1 Clostridium bifermentans (one lanyard grew both S. aureus and C. bifermentans. Unused (control lanyards had little or no such contamination. The median duration of lanyard wear was 12 months (interquartile range 3–36 months. 17/108 (16% of the lanyards had reportedly undergone decontamination including wiping with alcohol, chlorhexidine or chlorine dioxide; and washing with soap and water or by washing machine. Metal-bead lanyards had significantly lower median bacterial counts than those from fabric lanyards (1 vs. 4 CFU/cm2; Mann–Whitney U = 300.5; P < 0.001. 12/32 (38% of the metal-bead lanyards grew no bacteria, compared with 2/76 (3% of fabric lanyards. We recommend that an effective decontamination regimen be instituted by those who use fabric lanyards, or that fabric lanyards be discarded altogether in preference for metal-bead lanyards or clip-on identity cards. Keywords: Lanyard, Contamination, Identity card, Metal, Fabric

  17. The Research of Nanoparticle and Microparticle Hydroxyapatite Amendment in Multiple Heavy Metals Contaminated Soil Remediation

    Directory of Open Access Journals (Sweden)

    Zhangwei Li

    2014-01-01

    Full Text Available It was believed that when hydroxyapatite (HAP was used to remediate heavy metal-contaminated soils, its effectiveness seemed likely to be affected by its particle size. In this study, a pot trial was conducted to evaluate the efficiency of two particle sizes of HAP: nanometer particle size of HAP (nHAP and micrometer particle size of HAP (mHAP induced metal immobilization in soils. Both mHAP and nHAP were assessed for their ability to reduce lead (Pb, zinc (Zn, copper (Cu, and chromium (Cr bioavailability in an artificially metal-contaminated soil. The pakchoi (Brassica chinensis L. uptake and soil sequential extraction method were used to determine the immobilization and bioavailability of Pb, Zn, Cu, and Cr. The results indicated that both mHAP and nHAP had significant effect on reducing the uptake of Pb, Zn, Cu, and Cr by pakchoi. Furthermore, both mHAP and nHAP were efficient in covering Pb, Zn, Cu, and Cr from nonresidual into residual forms. However, mHAP was superior to nHAP in immobilization of Pb, Zn, Cu, and Cr in metal-contaminated soil and reducing the Pb, Zn, Cu, and Cr utilized by pakchoi. The results suggested that mHAP had the better effect on remediation multiple metal-contaminated soils than nHAP and was more suitable for applying in in situ remediation technology.

  18. Spatial distribution of heavy metal contamination in soils near a primitive e-waste recycling site.

    Science.gov (United States)

    Quan, Sheng-Xiang; Yan, Bo; Yang, Fan; Li, Ning; Xiao, Xian-Ming; Fu, Jia-Mo

    2015-01-01

    The total concentrations of 12 heavy metals in surface soils (SS, 0-20 cm), middle soils (MS, 30-50 cm) and deep soils (DS, 60-80 cm) from an acid-leaching area, a deserted paddy field and a deserted area of Guiyu were measured. The results showed that the acid-leaching area was heavily contaminated with heavy metals, especially in SS. The mean concentrations of Ni, Cu, Zn, Cd, Sn, Sb and Pb in SS from the acid-leaching area were 278.4, 684.1, 572.8, 1.36, 3,472, 1,706 and 222.8 mg/kg, respectively. Heavy metal pollution in the deserted paddy field was mainly concentrated in SS and MS. The average values of Sb in SS and MS from the deserted paddy field were 16.3 and 20.2 mg/kg, respectively. However, heavy metal contamination of the deserted area was principally found in the DS. Extremely high concentrations of heavy metals were also observed at some special research sites, further confirming that the level of heavy metal pollution was very serious. The geoaccumulation index (Igeo) values revealed that the acid-leaching area was severely polluted with heavy metals in the order of Sb > Sn > Cu > Cd > Ni > Zn > Pb, while deserted paddy field was contaminated predominately by metals in the order of Sb > Sn > Cu. It was obvious that the concentrations of some uncommon contaminants, such as Sb and Sn, were higher than principal contaminants, such as Ni, Cu, Zn and Pb, suggesting that particular attention should be directed to Sn and Sb contamination in the future research of heavy metals in soils from e-waste-processing areas. Correlation analysis suggested that Li and Be in soils from the acid-leaching area and its surrounding environment might have originated from other industrial activities and from batteries, whereas Ni, Cu, Zn, Cd, Pb, Sn and Sb contamination was most likely caused by uncontrolled electronic waste (e-waste) processing. These results indicate the significant need for optimisation of e-waste-dismantling technologies and remediation of polluted soil

  19. Contamination by heavy metals and petroleum hydrocarbons: a threat to mangroves

    Directory of Open Access Journals (Sweden)

    Thaís dos Santos Alencar

    2016-12-01

    Full Text Available The mangrove ecosystem is one of the most productive ecosystems on the planet with relevant ecological importance. It offers several services such as protection of the coastal region, immobilization of contaminants, as it is a food source and refuge for various organisms. However, mangroves are threatened by human activities. Oil spills in areas close to mangroves, for example, are potential sources for the entry of contaminants such as heavy metals and hydrocarbons. Among other sources of threat, we list industrial waste and sewage, mining and fertilizer use. When they reach the mangroves, these contaminants may cause several negative effects and affect its balance.

  20. Microbe and Mineral Mediated Transformation of Heavy Metals, Radionuclides, and Organic Contaminants

    Science.gov (United States)

    Gerlach, R.

    2011-12-01

    Microorganisms influence their surroundings in many ways and humans have utilized microbially catalyzed reactions for benefit for centuries. Over the past few decades, microorganisms have been used for the control of contaminant transport in subsurface environments where many microbe mineral interactions occur. This presentation will discuss microbially influenced mineral formation and transformation as well as their influence on the fate of organic contaminants such as chlorinated aliphatics & 2,4,6-trinitrotoluene (TNT), heavy metals such as chromium, and radionuclides such as uranium & strontium. Both, batch and flow experiments have been performed, which monitor the net effect of microbe mineral interactions on the fate of these contaminants. This invited presentation will place an emphasis on the relative importance of direct microbial (i.e. biotic) transformations, mineral-mediated transformations as well as other abiotic reactions influencing the fate of environmental contaminants. Experiments will be summarized and placed in context of past and future engineered applications for the control of subsurface contaminants.

  1. Heavy metal contamination and its indexing approach for groundwater of Goa mining region, India

    Science.gov (United States)

    Singh, Gurdeep; Kamal, Rakesh Kant

    2017-06-01

    The objective of the study is to reveal the seasonal variations in the groundwater quality with respect to heavy metal contamination. To get the extent of the heavy metals contamination, groundwater samples were collected from 45 different locations in and around Goa mining area during the monsoon and post-monsoon seasons. The concentration of heavy metals, such as lead, copper, manganese, zinc, cadmium, iron, and chromium, were determined using atomic absorption spectrophotometer. Most of the samples were found within limit except for Fe content during the monsoon season at two sampling locations which is above desirable limit, i.e., 300 µg/L as per Indian drinking water standard. The data generated were used to calculate the heavy metal pollution index (HPI) for groundwater. The mean values of HPI were 1.5 in the monsoon season and 2.1 in the post-monsoon season, and these values are well below the critical index limit of 100.

  2. Remediation of Deep Vadose Zone Radionuclide and Metal Contamination: Status and Issues

    Energy Technology Data Exchange (ETDEWEB)

    Dresel, P. Evan; Truex, Michael J.; Cantrell, Keri

    2008-12-30

    This report documents the results of a PNNL literature review to report on the state of maturity of deep vadose zone remediation technologies for metal contaminants including some radionuclides. Its recommendations feed into decisionmakers need for scientific information and cost-effective in situ remediation technlogies needed under DOE's Environmental Management initiative Enhanced Remediation Methods: Scientific & Technical Basis for In Stu Treatment Systems for Metals and Radionuclides.

  3. Beneficial of Coriander Leaves (Coriandrum sativum L.) to Reduce Heavy Metals Contamination in Rod Shellfish

    Science.gov (United States)

    Winarti, S.; Pertiwi, C. N.; Hanani, A. Z.; Mujamil, S. I.; Putra, K. A.; Herlambang, K. C.

    2018-01-01

    Contamination of heavy metals in certain levels of food can disrupt human health. Heavy metals have toxic properties, cannot be overhauled or destroyed by living organisms, can accumulate in the body of organisms including humans, either directly or indirectly. Heavy metal Hg, Cd, Cr is a very toxic metals (can result in death or health problems that are not recovered in a short time), while heavy metal Co, Pb, Cu toxicity is moderate (can lead to both recoverable and non-recoverable health problems in a relatively long time). Hence the heavy metal contaminating the food must be eliminated or reduced to a safe level. One effort was use coriander leaves to reduce the contamination of heavy metals in fish/shellfish. The objective of the research was to prove the extract of coriander leaves can reduce heavy metal contamination of Pb, Hg and Cu in rod shellfish (lorjuk). The treatment of this research was long soaking in coriander leaves extract that were 0, 30, 60 and 90 minutes. The results showed that the longer time of soaking can decrease Pb level from 4.4 ± 0.424 ppb to 1.7 ± 0.5 ppb, Hg level from 4.11± 0.07 to 1.12± 0.6 ppb, and Cu level from 433.7 ± 0.1 ppb to 117 ± 0.78 ppb. Protein content not significant decrease in rod shellfish (lorjuk) after 90 minutes soaking time, that was from 28.56 ± 0.403% to 26,625 ± 0.19%.

  4. Mapping human health risks from exposure to trace metal contamination of drinking water sources in Pakistan

    International Nuclear Information System (INIS)

    Bhowmik, Avit Kumar; Alamdar, Ambreen; Katsoyiannis, Ioannis; Shen, Heqing; Ali, Nadeem; Ali, Syeda Maria; Bokhari, Habib; Schäfer, Ralf B.; Eqani, Syed Ali Musstjab Akber Shah

    2015-01-01

    The consumption of contaminated drinking water is one of the major causes of mortality and many severe diseases in developing countries. The principal drinking water sources in Pakistan, i.e. ground and surface water, are subject to geogenic and anthropogenic trace metal contamination. However, water quality monitoring activities have been limited to a few administrative areas and a nationwide human health risk assessment from trace metal exposure is lacking. Using geographically weighted regression (GWR) and eight relevant spatial predictors, we calculated nationwide human health risk maps by predicting the concentration of 10 trace metals in the drinking water sources of Pakistan and comparing them to guideline values. GWR incorporated local variations of trace metal concentrations into prediction models and hence mitigated effects of large distances between sampled districts due to data scarcity. Predicted concentrations mostly exhibited high accuracy and low uncertainty, and were in good agreement with observed concentrations. Concentrations for Central Pakistan were predicted with higher accuracy than for the North and South. A maximum 150–200 fold exceedance of guideline values was observed for predicted cadmium concentrations in ground water and arsenic concentrations in surface water. In more than 53% (4 and 100% for the lower and upper boundaries of 95% confidence interval (CI)) of the total area of Pakistan, the drinking water was predicted to be at risk of contamination from arsenic, chromium, iron, nickel and lead. The area with elevated risks is inhabited by more than 74 million (8 and 172 million for the lower and upper boundaries of 95% CI) people. Although these predictions require further validation by field monitoring, the results can inform disease mitigation and water resources management regarding potential hot spots. - Highlights: • Predictions of trace metal concentration use geographically weighted regression • Human health risk

  5. Trace metal contamination in mangrove sediments, Guanabara Bay, Rio de Janeiro, Brazil

    OpenAIRE

    Farias,Cassia O.; Hamacher,Claudia; Wagener,Angela de Luca R.; Campos,Reinaldo C. de; Godoy,José M.

    2007-01-01

    The Guanabara Bay in Rio de Janeiro has undergone profound alterations of its natural environmental conditions. Metal concentration increase in sediments has been reported to be among these alterations. Trace-metal contamination and availability were studied in sediments of 3 mangrove areas of the bay. Cd, Zn, Pb, Ni, Cu and Al concentrations were determined in segments of sediment cores, after treatment with 1 mol L-1 HCl and with concentrated HNO3. Fe and Mn were determined in the leach wit...

  6. Mapping human health risks from exposure to trace metal contamination of drinking water sources in Pakistan

    Energy Technology Data Exchange (ETDEWEB)

    Bhowmik, Avit Kumar [Institute for Environmental Sciences, University of Koblenz-Landau, Fortstrasse 7, D-76829 Landau in der Pfalz (Germany); Alamdar, Ambreen [Key Lab of Urban Environment and Health, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021 (China); Katsoyiannis, Ioannis [Aristotle University of Thessaloniki, Department of Chemistry, Division of Chemical Technology, Box 116, Thessaloniki 54124 (Greece); Shen, Heqing [Key Lab of Urban Environment and Health, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021 (China); Ali, Nadeem [Department of Environmental Sciences, FBAS, International Islamic University, Islamabad (Pakistan); Ali, Syeda Maria [Center of Excellence in Environmental Studies, King Abdulaziz University, Jeddah (Saudi Arabia); Bokhari, Habib [Public Health and Environment Division, Department of Biosciences, COMSATS Institute of Information Technology, Islamabad (Pakistan); Schäfer, Ralf B. [Institute for Environmental Sciences, University of Koblenz-Landau, Fortstrasse 7, D-76829 Landau in der Pfalz (Germany); Eqani, Syed Ali Musstjab Akber Shah, E-mail: ali_ebl2@yahoo.com [Key Lab of Urban Environment and Health, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021 (China); Public Health and Environment Division, Department of Biosciences, COMSATS Institute of Information Technology, Islamabad (Pakistan)

    2015-12-15

    The consumption of contaminated drinking water is one of the major causes of mortality and many severe diseases in developing countries. The principal drinking water sources in Pakistan, i.e. ground and surface water, are subject to geogenic and anthropogenic trace metal contamination. However, water quality monitoring activities have been limited to a few administrative areas and a nationwide human health risk assessment from trace metal exposure is lacking. Using geographically weighted regression (GWR) and eight relevant spatial predictors, we calculated nationwide human health risk maps by predicting the concentration of 10 trace metals in the drinking water sources of Pakistan and comparing them to guideline values. GWR incorporated local variations of trace metal concentrations into prediction models and hence mitigated effects of large distances between sampled districts due to data scarcity. Predicted concentrations mostly exhibited high accuracy and low uncertainty, and were in good agreement with observed concentrations. Concentrations for Central Pakistan were predicted with higher accuracy than for the North and South. A maximum 150–200 fold exceedance of guideline values was observed for predicted cadmium concentrations in ground water and arsenic concentrations in surface water. In more than 53% (4 and 100% for the lower and upper boundaries of 95% confidence interval (CI)) of the total area of Pakistan, the drinking water was predicted to be at risk of contamination from arsenic, chromium, iron, nickel and lead. The area with elevated risks is inhabited by more than 74 million (8 and 172 million for the lower and upper boundaries of 95% CI) people. Although these predictions require further validation by field monitoring, the results can inform disease mitigation and water resources management regarding potential hot spots. - Highlights: • Predictions of trace metal concentration use geographically weighted regression • Human health risk

  7. Bioaugmentation-assisted phytoextraction of Co, Pb and Zn: an assessment with a phosphate-solubilizing bacterium isolated from metal-contaminated mines of Boryeong Area in South Korea

    Directory of Open Access Journals (Sweden)

    Arunakumara, KKIU.

    2015-01-01

    Full Text Available Description of the subject. Make use of microbes having remarkable metal tolerance and plant growth-promoting abilities to remediate metal-contaminated soils. Objectives. The objectives were to isolate phosphate solubilizing bacterial strain, assess metal (Co, Pb and Zn mobilization potential of the strain and to evaluate the effects of the strain on growth and uptake of metals by Helianthus annuus. Method. A phosphate solubilizing bacterium was isolated from metal-contaminated soils. Heavy metal (Co, Pb and Zn tolerance of the strain was assessed using the agar dilution method. Bacterial-assisted growth promotion and metal uptake by H. annuus was evaluated in a pot experiment. The impact of bacterial inoculation on the mobility of metals in soil was investigated in a batch experiment. Results. The strain showed close proximity with Klebsiella oxytoca JCM1665, according to 16S rRNA sequence analysis. The strain was efficient in solubilizing phosphate, both in the presence and absence of metals. Inoculation of the strain enhanced the growth of H. annuus (49, 22 and 39% respectively in Co, Pb and Zn contaminated soils compared to non-inoculated plants. Accumulation and translocation of Co, Pb and Zn from roots to shoots were also enhanced by the strain. Water soluble fraction of Co, Pb and Zn in soil was increased by 51, 24 and 76% respectively in inoculated soils with regard to those of non-inoculated soils. Conclusions. Taking the plant growth promotion and metal mobilizing potential of the strain into account, practical application of the strain in enhancing phytoextraction of Co, Pb and Zn from contaminated soils could be recommended.

  8. Fresh organic matter of municipal solid waste enhances phytoextraction of heavy metals from contaminated soil

    Energy Technology Data Exchange (ETDEWEB)

    Salati, S.; Quadri, G.; Tambone, F. [Dipartimento di Produzione Vegetale, Universita degli Studi di Milano, Via Celoria 2, 20133 Milano (Italy); Adani, F., E-mail: fabrizio.adani@unimi.i [Dipartimento di Produzione Vegetale, Universita degli Studi di Milano, Via Celoria 2, 20133 Milano (Italy)

    2010-05-15

    In this study, the ability of the organic fraction of municipal solid wastes (OFMSW) to enhance heavy metal uptake of maize shoots compared with ethylenediamine disuccinic acid (EDDS) was tested on soil contaminated with heavy metals. Soils treated with OFMSW and EDDS significantly increased the concentration of heavy metals in maize shoots (increments of 302%, 66%, 184%, 169%, and 23% for Cr, Cu, Ni, Zn, and Pb with respect to the control and increments of 933%, 482%, 928%, 428%, and 5551% for soils treated with OFMSW and EDDS, respectively). In soil treated with OFMSW, metal uptake was favored because of the high presence of dissolved organic matter (DOM) (41.6x than soil control) that exhibited ligand properties because of the high presence of carboxylic acids. Because of the toxic effect of EDDS on maize plants, soil treated with OFMSW achieved the highest extraction of total heavy metals. - Organic fraction of MSW affects the bioavailability of heavy metals in soil.

  9. Fresh organic matter of municipal solid waste enhances phytoextraction of heavy metals from contaminated soil

    International Nuclear Information System (INIS)

    Salati, S.; Quadri, G.; Tambone, F.; Adani, F.

    2010-01-01

    In this study, the ability of the organic fraction of municipal solid wastes (OFMSW) to enhance heavy metal uptake of maize shoots compared with ethylenediamine disuccinic acid (EDDS) was tested on soil contaminated with heavy metals. Soils treated with OFMSW and EDDS significantly increased the concentration of heavy metals in maize shoots (increments of 302%, 66%, 184%, 169%, and 23% for Cr, Cu, Ni, Zn, and Pb with respect to the control and increments of 933%, 482%, 928%, 428%, and 5551% for soils treated with OFMSW and EDDS, respectively). In soil treated with OFMSW, metal uptake was favored because of the high presence of dissolved organic matter (DOM) (41.6x than soil control) that exhibited ligand properties because of the high presence of carboxylic acids. Because of the toxic effect of EDDS on maize plants, soil treated with OFMSW achieved the highest extraction of total heavy metals. - Organic fraction of MSW affects the bioavailability of heavy metals in soil.

  10. Experience with melting beta and gamma contaminated metals

    International Nuclear Information System (INIS)

    Feaugas, J.; Laplante, D.; Puechlong, Y.; Barbusse, R.

    1994-01-01

    Following a description of the melting facility operated for purposes of decommissioning the G2 and G3 gas-cooled reactors at Marcoule, the physical and radiological characteristics of 4070 tonnes of metal processed to date in the furnace are discussed. Considerable data have been recorded regarding operating and measurement procedures; the results show that secondary wastes account for less than 5 wt% of the processed scrap metal, and that all the 137 Cs is transferred to the dust and slag. During the last two months of 1993, the ingot mold line was replaced by rails on which dollies carrying integral work-form molds can be moved into position beneath the casting ladle. (authors). 21 figs

  11. Biological leaching of heavy metals from a contaminated soil by Aspergillus niger

    International Nuclear Information System (INIS)

    Ren Wanxia; Li Peijun; Geng Yong; Li Xiaojun

    2009-01-01

    Bioleaching of heavy metals from a contaminated soil in an industrial area using metabolites, mainly weak organic acids, produced by a fungus Aspergillus niger was investigated. Batch experiments were performed to compare the leaching efficiencies of one-step and two-step processes and to determine the transformation of heavy metal chemical forms during the bioleaching process. After the one or two-step processes, the metal removals were compared using analysis of variance (ANOVA) and least-significance difference (LSD). A. niger exhibits a good potential in generating a variety of organic acids effective for metal solubilisation. Results showed that after the one-step process, maximum removals of 56%, 100%, 30% and 19% were achieved for copper, cadmium, lead and zinc, respectively. After the two-step process, highest removals of 97.5% Cu, 88.2% Cd, 26% Pb, and 14.5% Zn were obtained. Results of sequential extraction showed that organic acids produced by A. niger were effective in removing the exchangeable, carbonate, and Fe/Mn oxide fractions of Cu, Cd, Pb and Zn; and after both processes the metals remaining in the soil were mainly bound in stable fractions. Such a treatment procedure indicated that leaching of heavy metals from contaminated soil using A. niger has the potential for use in remediation of contaminated soils.

  12. Influence of dams on sediment continuity: A study case of a natural metallic contamination.

    Science.gov (United States)

    Frémion, Franck; Bordas, François; Mourier, Brice; Lenain, Jean-François; Kestens, Tim; Courtin-Nomade, Alexandra

    2016-03-15

    Sediments play an important role on the quality of aquatic ecosystems, notably in the reservoir areas where they can either be a sink or a source of contaminants, depending on the management and hydrological conditions. The physicochemical properties of 25 surface sediments samples of a reservoir catchment (Vaussaire, Cantal, France) were studied. Results show a strong influence of dam presence, notably on the grain size and organic matter (OM) contents. The concentrations of trace metals and metalloids (As, Cd, Cr, Cu, Ni, Pb and Zn) were also measured and compared with worldwide reservoir concentrations and international sediment quality guideline levels in order to assess the intensity of the metallic contamination. Cr and Ni are the trace elements presenting the significantly highest values at the catchment scale. Enrichment Factors (EF), calculated using both local and national backgrounds, show that metals have mainly a natural origin, explaining especially the Cr and Ni values, linked with the composition of parental rocks. Unexpectedly, all the observed metal concentrations are lower in the reservoir than upstream and downstream, which might be related to the high fresh OM inputs in the reservoir, diluting the global metallic contamination. Multivariate statistical analyses, carried out in order to identify the relationship between the studied metals and sediment characteristics, tend to support this hypothesis, confirming the unusually low influence of such poorly-degraded OM on trace element accumulation in the reservoir. Copyright © 2016 Elsevier B.V. All rights reserved.

  13. Biological leaching of heavy metals from a contaminated soil by Aspergillus niger

    Energy Technology Data Exchange (ETDEWEB)

    Ren Wanxia, E-mail: ren_laura@163.com [Institute of Applied Ecology, Chinese Academy of Sciences, 72 Wenhua Road, Shenyang 110016 (China); Li Peijun, E-mail: lipeijun@iae.ac.cn [Institute of Applied Ecology, Chinese Academy of Sciences, 72 Wenhua Road, Shenyang 110016 (China); Geng Yong; Li Xiaojun [Institute of Applied Ecology, Chinese Academy of Sciences, 72 Wenhua Road, Shenyang 110016 (China)

    2009-08-15

    Bioleaching of heavy metals from a contaminated soil in an industrial area using metabolites, mainly weak organic acids, produced by a fungus Aspergillus niger was investigated. Batch experiments were performed to compare the leaching efficiencies of one-step and two-step processes and to determine the transformation of heavy metal chemical forms during the bioleaching process. After the one or two-step processes, the metal removals were compared using analysis of variance (ANOVA) and least-significance difference (LSD). A. niger exhibits a good potential in generating a variety of organic acids effective for metal solubilisation. Results showed that after the one-step process, maximum removals of 56%, 100%, 30% and 19% were achieved for copper, cadmium, lead and zinc, respectively. After the two-step process, highest removals of 97.5% Cu, 88.2% Cd, 26% Pb, and 14.5% Zn were obtained. Results of sequential extraction showed that organic acids produced by A. niger were effective in removing the exchangeable, carbonate, and Fe/Mn oxide fractions of Cu, Cd, Pb and Zn; and after both processes the metals remaining in the soil were mainly bound in stable fractions. Such a treatment procedure indicated that leaching of heavy metals from contaminated soil using A. niger has the potential for use in remediation of contaminated soils.

  14. Interactions of ceramic, metallic and polymeric filters with gaseous contaminants

    International Nuclear Information System (INIS)

    Haider, A.M.; Ma, Ce; Shadman, Farhang

    1993-01-01

    Outgassing characteristics of ceramic, metallic, and polymeric fitters for H 2 O, O 2 , CO 2 , and CH 4 were explored using APIMS in this study. The outgassing data has been normalized with respect to the parameters that varied from one filter to the other. Hydrocarbon outgassing is also explored both at room temperature from freshly installed filters as well as at elevated temperatures. Polymeric filters appeared to be more transparent but did show hydrocarbon outgassing when heated to 50 C

  15. The fate of heavy metals during combustion and gasification of contaminated biomass—A brief review

    Energy Technology Data Exchange (ETDEWEB)

    Nzihou, Ange, E-mail: ange.nzihou@mines-albi.fr [Université de Toulouse, Mines Albi, CNRS, Centre RAPSODEE, Campus Jarlard, F-81013 Albi cedex 09 (France); Stanmore, Brian [Formerly of the University of Queensland, Brisbane, QLD 4072 (Australia)

    2013-07-15

    Highlights: ► A review on metal behaviour during the thermal treatment of contamined biomass. ► Wide range of biomass waste reported. ► Distribution of metals in the ash, and in the sub-micron particles discussed. -- Abstract: The literature on the presence of heavy metals in contaminated wastes is reviewed. Various categories of materials produced from domestic and industrial activities are included, but municipal solid waste, which is a more complex material, is excluded. This review considers among the most abundant the following materials – wood waste including demolition wood, phytoremediation scavengers and chromated copper arsenate (CCA) timber, sludges including de-inking sludge and sewage sludge, chicken litter and spent pot liner. The partitioning of the metals in the ashes after combustion or gasification follows conventional behaviour, with most metals retained, and higher concentrations in the finer sizes due to vaporisation and recondensation. The alkali metals have been shown to catalyse the biomass conversion, particularly lithium and potassium, although other metals are active to a lesser extent. The most prevalent in biomass is potassium, which is not only inherently active, but volatilises to become finely distributed throughout the char mass. Because the metals are predominantly found in the ash, the effectiveness of their removal depends on the efficiency of the collection of particulates. The potential for disposal into soil depends on the initial concentration in the feed material.

  16. The fate of heavy metals during combustion and gasification of contaminated biomass—A brief review

    International Nuclear Information System (INIS)

    Nzihou, Ange; Stanmore, Brian

    2013-01-01

    Highlights: ► A review on metal behaviour during the thermal treatment of contamined biomass. ► Wide range of biomass waste reported. ► Distribution of metals in the ash, and in the sub-micron particles discussed. -- Abstract: The literature on the presence of heavy metals in contaminated wastes is reviewed. Various categories of materials produced from domestic and industrial activities are included, but municipal solid waste, which is a more complex material, is excluded. This review considers among the most abundant the following materials – wood waste including demolition wood, phytoremediation scavengers and chromated copper arsenate (CCA) timber, sludges including de-inking sludge and sewage sludge, chicken litter and spent pot liner. The partitioning of the metals in the ashes after combustion or gasification follows conventional behaviour, with most metals retained, and higher concentrations in the finer sizes due to vaporisation and recondensation. The alkali metals have been shown to catalyse the biomass conversion, particularly lithium and potassium, although other metals are active to a lesser extent. The most prevalent in biomass is potassium, which is not only inherently active, but volatilises to become finely distributed throughout the char mass. Because the metals are predominantly found in the ash, the effectiveness of their removal depends on the efficiency of the collection of particulates. The potential for disposal into soil depends on the initial concentration in the feed material

  17. Phytoremediation of heavy metals and hydrocarbon contaminated soils; Phytoremediation des sols contamines aux metaux lourds et aux hydrocarbures recalcitrants

    Energy Technology Data Exchange (ETDEWEB)

    Leblanc, R.; Chateauneuf, G.; Sura, C. [Inspec-Sol Inc., Montreal, PQ (Canada); Labrecque, M.; Galipeau, C. [Jardin botanique de Montreal, Montreal, PQ (Canada). Institut de Recherche en Biologie Vegetale; Greer, C.; Delisle, S.; Roy, S.; Labelle, S. [National Research Council of Canada, Montreal, PQ (Canada). Inst. for Research in Biotechnology

    2003-07-01

    Phytoremediation is a technology that uses plants to decontaminate soils and underground water. Inspec-Sol, a company located in Montreal, Quebec, conducted a two-year study to evaluate the decontamination capabilities of this technology. Trials in greenhouses and field studies at the Pitt Park along the Lachine Canal were conducted. The soils chosen for the studies were soils with concentrations of polycyclic aromatic hydrocarbons (PAH) and heavy metals (lead, copper, zinc) higher than those prescribed for the safe utilization of soils. The trials identified the three plant species (Salix viminalis, Brassica juncea, and Festuca arundinacea) which had the best characteristics for phytoremediation. Controlled experiments were performed to optimize the technology to achieve the maximum extraction of contaminant. It was concluded that phytoremediation has potential for the remediation of urban soils contaminated with organic and inorganic pollutants.

  18. Field-scale assessment of phytotreatment of soil contaminated with weathered hydrocarbons and heavy metals

    Energy Technology Data Exchange (ETDEWEB)

    Palmroth, M.R.T.; Koskinen, P.E.P.; Tuhkanen, T.A.; Puhakka, J.A. [Inst. of Environmental Engineering and Biotechnology, Tampere Univ. of Tech., Tampere (Finland); Pichtel, J. [Natural Resources and Environmental Management, Ball State Univ., Muncie, IN (United States); Vaajasaari, K. [Pirkanmaa Regional Environment Centre, Tampere (Finland); Joutti, A. [Finnish Environment Inst., Helsinki (Finland)

    2006-08-15

    Background, Aims, and Scope. Phytoremediation is remediation method which uses plants to remove, contain or detoxify environmental contaminants. Phytoremediation has successfully been applied for the removal of fresh hydrocarbon contamination, but removal of aged hydrocarbons has proven more difficult. Biodegradation of hydrocarbons in the subsurface can be enhanced by the presence of plant roots, i.e. the rhizosphere effect. Phytostabilization reduces heavy metal availability via immobilization in the rhizosphere. Soils contaminated by both hydrocarbons and heavy metals are abundant and may be difficult to treat. Heavy metal toxicity can inhibit the activity of hydrocarbon-degrading micro-organisms and decrease the metabolic diversity of soil bacteria. In this experiment, weathered hydrocarbon- and heavy metal-contaminated soil was treated using phytoremediation in a 39-month field study in attempts to achieve both hydrocarbon removal and heavy metal stabilization. Methods. A combination of hydrocarbon degradation and heavy metal stabilization was evaluated in a field-scale phytoremediation study of weathered contaminants. Soil had been contaminated over several years with hydrocarbons (11,400{+-}4,300 mg kg dry soil){sup -1} and heavy metals from bus maintenance activities and was geologically characterized as till. Concentrations of soil copper, lead and zinc were 170{+-}50 mgkg{sup -1}, 1,100{+-}1,500 mg kg{sup -1} and 390{+-} 340 mg kg{sup -1}, respectively. The effect of contaminants, plant species and soil amendment (NPK fertilizer or biowaste compost) on metabolic activity of soil microbiota was determined. Phytostabilization performance was investigated by analyses of metal concentrations in plants, soil and site leachate as well as acute toxicity to Vibrio fischeri and Enchtraeus albidus. Results. Over 39 months hydrocarbon concentrations did not decrease significantly (P=0.05) in non-amended soil, although 30% of initial hydrocarbon concentrations were

  19. Effect of salinity on metal mobility in Sečovlje salina sediment (northern Adriatic, Slovenia)

    Science.gov (United States)

    Kovač, N.; Ramšak, T.; Glavaš, N.; Dolenec, M.; Rogan Šmuc, N.

    2016-12-01

    Saline sediment (saline healing mud or "fango") from the Sečovlje Salina (northern Adriatic, Slovenia) is traditionally used in the coastal health resorts as a virgin material for medical treatment, wellness and relax purposes. Therapeutic qualities of the healing mud depend on its mineralogical composition and physical, mineralogical, geochemical and biological properties. Their microbial and potentially toxic elements contamination are the most important features affecting user safety. However, the degree of metal toxicity (and its regulation) for natural healing mud is still under discussion. Therefore, the influence of the overlying water salinity on the mobility of heavy metals (and some other geochemical characteristic) was studied for saline sediments of the Sečovlje Salina. Experiments takes place in tanks under defined conditions i.e. at day (21 °C): night (16 °C) cycle for three months. Sediment was covered with water of different salinities (36, 155, 323 g NaCl L-1 and distillate water) and mixed/stirred every week during the experimental period. At the same time, the evaporated water was replaced with distilled water. The mud samples were analyzed, at the beginning and at the end of experiment, for mineral (XRD), elemental composition (ICP-MS) and organic content (% TOC, % TN). Geochemical analysis of the aqueous phase (content of cations and anions) have also been carried out in an accredited Canadian laboratory Actlabs (Activation Laboratories, Canada). Salinity and maturation of sediment does not significantly affect its mineral composition. The samples taken at the end of the experiment have higher percent of water but lower organic carbon concentration. Concentrations of investigated elements are comparable to that in surface sediments from Central Adriatic Sea. In the water phase, concentrations of most elements (As, Ba, Cu, Mo, Mn, Ni, Sr, Sb) rise from the beginning to the end of the experiment, whereas the metal (potentially toxic elements

  20. [Bacterial contamination of mobile phones shared in hospital wards and the consciousness and behavior of nurses about biological cleanliness].

    Science.gov (United States)

    Morioka, Ikuharu; Tabuchi, Yuna; Takahashi, Yuko; Oda, Yuriko; Nakai, Masami; Yanase, Aki; Watazu, Chiyoko

    2011-01-01

    The purpose of this study was to clarify the contamination of mobile phones shared in hospital wards and its relationship with the consciousness and behavior of nurses about biological cleanliness. Samples from mobile phones were cultured to detect viable bacteria (n=110) and Staphylococcus aureus (n=54). A questionnaire survey was conducted on 110 nurses carrying mobile phones on the day of sampling. Viable bacteria were detected on 79.1% of the mobile phones, whereas S. aureus was detected on 68.6%. All the nurses were aware of hand washing with water or alcohol after regular work, but 33.6% of the nurses were not conscious of hand washing with water or alcohol after using a mobile phone. There was a significant positive relationship between the frequency of using mobile phones and the number of hand washings with water or alcohol. A significant negative relationship was found between the detection of viable bacteria and the number of hand washings with alcohol. The results of logistic regression analysis showed that the detection of viable bacteria was related significantly with the number of hand washings with alcohol (Odds ratio, 0.350; 95%CI, 0.143-0.857) and that the detection of S. aureus was related significantly with the frequency of using mobile phones (Odds ratio, 0.183; 95%CI, 0.036-0.933). It is important to be conscious of the fact that mobile phones shared in hospital wards are easily contaminated. Because hand washing with water or alcohol prevents the contamination of the mobile phones, nurses should take standard precautions after using mobile phones.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2011-08-15

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

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

    International Nuclear Information System (INIS)

    Fang Di; Zhang Ruichang; Zhou Lixiang; Li Jie

    2011-01-01

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

  3. Strong links between metal contamination, habitat modification and estuarine larval fish distributions

    Energy Technology Data Exchange (ETDEWEB)

    McKinley, Andrew C., E-mail: andrew.mckinley@hotmail.com [Evolution and Ecology Research Centre, School of Biological, Earth and Environmental Sciences, University of New South Wales, Sydney, New South Wales 2052 (Australia); Miskiewicz, Anthony [Environment and Recreation, Wollongong City Council, 41 Burelli Street, Wollongong, New South Wales 2500 (Australia); Taylor, Matthew D.; Johnston, Emma L. [Evolution and Ecology Research Centre, School of Biological, Earth and Environmental Sciences, University of New South Wales, Sydney, New South Wales 2052 (Australia)

    2011-06-15

    Changes to larval fish assemblages may have far reaching ecological impacts. Correlations between habitat modification, contamination and marine larval fish communities have rarely been assessed in situ. We investigated links between the large-scale distribution of stressors and larval fish assemblages in estuarine environments. Larval fish communities were sampled using a benthic sled within the inner and outer zones of three heavily modified and three relatively unmodified estuaries. Larval abundances were significantly greater in modified estuaries, and there were trends towards greater diversity in these systems. Differences in larval community composition were strongly related to sediment metal levels and reduced seagrass cover. The differences observed were driven by two abundant species, Paedogobius kimurai and Ambassis jacksoniensis, which occurred in large numbers almost exclusively in highly contaminated and pristine locations respectively. These findings suggest that contamination and habitat alteration manifest in substantial differences in the composition of estuarine larval fish assemblages. - Highlights: > We examine contamination/habitat modification impacts on larval fish. > Larvae communities differ between modified/unmodified estuaries. > Larvae are more abundant/diverse in modified areas. > Trends are strongly related to sediment metals/seagrass cover. > Larval impacts have wider ecological importance. - We describe strong links between sediment metals contamination, habitat modification and substantial differences in the composition of the estuarine larval fish assemblage.

  4. Strong links between metal contamination, habitat modification and estuarine larval fish distributions

    International Nuclear Information System (INIS)

    McKinley, Andrew C.; Miskiewicz, Anthony; Taylor, Matthew D.; Johnston, Emma L.

    2011-01-01

    Changes to larval fish assemblages may have far reaching ecological impacts. Correlations between habitat modification, contamination and marine larval fish communities have rarely been assessed in situ. We investigated links between the large-scale distribution of stressors and larval fish assemblages in estuarine environments. Larval fish communities were sampled using a benthic sled within the inner and outer zones of three heavily modified and three relatively unmodified estuaries. Larval abundances were significantly greater in modified estuaries, and there were trends towards greater diversity in these systems. Differences in larval community composition were strongly related to sediment metal levels and reduced seagrass cover. The differences observed were driven by two abundant species, Paedogobius kimurai and Ambassis jacksoniensis, which occurred in large numbers almost exclusively in highly contaminated and pristine locations respectively. These findings suggest that contamination and habitat alteration manifest in substantial differences in the composition of estuarine larval fish assemblages. - Highlights: → We examine contamination/habitat modification impacts on larval fish. → Larvae communities differ between modified/unmodified estuaries. → Larvae are more abundant/diverse in modified areas. → Trends are strongly related to sediment metals/seagrass cover. → Larval impacts have wider ecological importance. - We describe strong links between sediment metals contamination, habitat modification and substantial differences in the composition of the estuarine larval fish assemblage.

  5. Preliminary evaluation of heavy metal contamination in the Zarrin-Gol River sediments, Iran.

    Science.gov (United States)

    Malvandi, Hassan

    2017-04-15

    The major objectives of the study were to test the hypothesis of the Zarrin-Gol River as a reference site for ecotoxicological studies and to assess the contamination degree of heavy metals and metalloids in the river using four contamination indices. For these purposes, eleven heavy metal and metalloid concentrations were analyzed. The average concentrations (mgkg -1 ) in the sediments were: 37.67 (chromium) 286.28 (manganese), 13,751.04 (iron), 8.79 (cobalt), 12.39 (nickel), 32.68 (zinc), 21.91 (arsenic), 40.59 (selenium), 2923.86 (aluminum), ND (silver) and 785.96 (magnesium). Contamination factor, enrichment factor, pollution load index, and geoaccumulation index were calculated to evaluate the contamination degree and influence of human activities on heavy metal levels. The contamination indices of the sediment samples showed that arsenic and selenium were the highest pollutants. The results indicated that the Zarrin-Gol River could not be used as a reference site at least for arsenic and selenium. Copyright © 2017 Elsevier Ltd. All rights reserved.

  6. Health Risk-Based Assessment and Management of Heavy Metals-Contaminated Soil Sites in Taiwan

    Directory of Open Access Journals (Sweden)

    Zueng-Sang Chen

    2010-10-01

    Full Text Available Risk-based assessment is a way to evaluate the potential hazards of contaminated sites and is based on considering linkages between pollution sources, pathways, and receptors. These linkages can be broken by source reduction, pathway management, and modifying exposure of the receptors. In Taiwan, the Soil and Groundwater Pollution Remediation Act (SGWPR Act uses one target regulation to evaluate the contamination status of soil and groundwater pollution. More than 600 sites contaminated with heavy metals (HMs have been remediated and the costs of this process are always high. Besides using soil remediation techniques to remove contaminants from these sites, the selection of possible remediation methods to obtain rapid risk reduction is permissible and of increasing interest. This paper discusses previous soil remediation techniques applied to different sites in Taiwan and also clarified the differences of risk assessment before and after soil remediation obtained by applying different risk assessment models. This paper also includes many case studies on: (1 food safety risk assessment for brown rice growing in a HMs-contaminated site; (2 a tiered approach to health risk assessment for a contaminated site; (3 risk assessment for phytoremediation techniques applied in HMs-contaminated sites; and (4 soil remediation cost analysis for contaminated sites in Taiwan.

  7. Health Risk-Based Assessment and Management of Heavy Metals-Contaminated Soil Sites in Taiwan

    Science.gov (United States)

    Lai, Hung-Yu; Hseu, Zeng-Yei; Chen, Ting-Chien; Chen, Bo-Ching; Guo, Horng-Yuh; Chen, Zueng-Sang

    2010-01-01

    Risk-based assessment is a way to evaluate the potential hazards of contaminated sites and is based on considering linkages between pollution sources, pathways, and receptors. These linkages can be broken by source reduction, pathway management, and modifying exposure of the receptors. In Taiwan, the Soil and Groundwater Pollution Remediation Act (SGWPR Act) uses one target regulation to evaluate the contamination status of soil and groundwater pollution. More than 600 sites contaminated with heavy metals (HMs) have been remediated and the costs of this process are always high. Besides using soil remediation techniques to remove contaminants from these sites, the selection of possible remediation methods to obtain rapid risk reduction is permissible and of increasing interest. This paper discusses previous soil remediation techniques applied to different sites in Taiwan and also clarified the differences of risk assessment before and after soil remediation obtained by applying different risk assessment models. This paper also includes many case studies on: (1) food safety risk assessment for brown rice growing in a HMs-contaminated site; (2) a tiered approach to health risk assessment for a contaminated site; (3) risk assessment for phytoremediation techniques applied in HMs-contaminated sites; and (4) soil remediation cost analysis for contaminated sites in Taiwan. PMID:21139851

  8. heavy metal fixation in contaminated soil using non-toxic agents

    African Journals Online (AJOL)

    USER

    2013-05-08

    May 8, 2013 ... agricultural ecosystems (Chukwuka and Omotayo,. 2008), as well as remediation of former industrial sites which have been exposed to diffuse pollution by toxic heavy metals (Finžgar et al., 2006; Belviso et al., 2010). Among the remediation technologies available for contaminated sites, in situ (in place) ...

  9. Impact of metal-ion contaminated silica particles on gate oxide integrity

    NARCIS (Netherlands)

    Rink, Ingrid; Wali, F.; Knotter, D.M.

    2009-01-01

    The impact of metal-ion contamination (present on wafer surface before oxidation) on gate oxide integrity (GOI) is well known in literature, which is not the case for clean silica particles [1, 2]. However, it is known that particles present in ultra-pure water (UPW) decrease the random yield in

  10. Phytoextraction with Brassica napus L.: A tool for sustainable management of heavy metal contaminated soils.

    NARCIS (Netherlands)

    Grispen, V.M.J.; Nelissen, H.J.M.; Verkleij, J.A.C.

    2006-01-01

    Phytoextraction is a promising tool to extract metals from contaminated soils and Brassica napus L. seems to be a possible candidate species for this purpose. To select accessions with the ability to accumulate cadmium, hydroponically grown 21 day old seedlings of 77 B. napus L. accessions were

  11. Preliminary Results: Release Of Metals From Acid-Mine Drainage Contaminated Streambed Sediments Under Anaerobic Conditions

    Science.gov (United States)

    Many miles of streams in the western U.S. are contaminated with acid-mine drainage (AMD) from abandoned metal mines. Treatment of these streams may include removal of the existing sediments, with subsequent burial (e.g., in a repository). Burial of previously aerobic sediments ma...

  12. Leaching of heavy metals from contaminated soils: An experimental and modeling study

    NARCIS (Netherlands)

    Dijkstra, J.J.; Meeussen, J.C.L.; Comans, R.N.J.

    2004-01-01

    In this paper, we characterize the leaching of heavy metals (Ni, Cu, Zn, Cd, and Pb) from eight contaminated soils over a wide range of pH (pH 0.4-12) using an original approach based on batch pH-static leaching experiments in combination with selective chemical extractions and geochemical modeling.

  13. Assessment of toxicity of heavy metal contaminated soils for Collembola in the field and laboratory

    DEFF Research Database (Denmark)

    Xu, Jie; Krogh, Paul Henning; Luo, Yongming

    2008-01-01

    We present a field and laboratory investigation of effects of increasing levels of heavy metal contamination on the biodiversity and performance of collembolans. A 40 year old pollution with Cu, Zn, Pb and Cd pollution due to Cu smelting over 40 years was investigated in a paddy field area of Zhe...

  14. Metal contamination in environmental media in residential areas around Romanian mining sites

    Science.gov (United States)

    Hard-rock mining for metals, such as gold, silver, copper, zinc, iron and others, is recognized to have a significant impact on the environmental media, soil and water, in particular. Toxic contaminants released from mine waste to surface water and groundwater is the primary co...

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